Home

2 Setup - Ruhr-Universität Bochum

1. can not exceed 2 C min while the speed in a temperature decreasing sequence marked as can be a random value larger than 1 21 TL SETSUFT 2000 Acquisition Collection Zone Display Window Y S EE E x Salal Standard zone a Mew atas 040902 List of sequences Standard zone N Type Initial T 30 Final T Delay Speed Valves Far Durati id 2 Standard zone 1 30 G0 0000 0000 0 1 0 ld 3 Standard zone 30 145 6900 1 0000 0000 1 56 0 Ld 4 Standard zone 145 145 229200 ogo 0000 F356 0 be 5 Standard zone ON bel E Standard zone bl 7 Standard zone z fee ies Initial F7 E Time s hominis l 10 Standard zone 3t bl 1 Standard zone Bl 12 Standard zone be 13 Standard zone fel 14 Standard zone fel 15 Standard zone E 16 Standard zone be 17 Standard zone es a B ee I HEIL ngs to p E 19 Standard zone a JP Fert ntl ees ere ee mete et Vee et rn o rr Fig 3 8 Programming temperature for heating during evacuation It should be noticed that the fan inside the calorimetric block is utilized only in the temperature decreasing sequence So if such a zone runs the fan blower switch in the front penal of the calorimeter should be adjusted to Automatic 3 1 4 Data export It is convenient to process the data collected by SETSOFT 2000 with MicroCal Origin or Microsoft Excel So the data need to export Click the Data proces
2. Fig 3 11 Interface of the valve control program VENT PULS To protect the turbo pump do not open the turbo pump valve here the V1 directly when the pressure inside the dosing section displayed in PR4000 is higher than 100Pa Besides if this pressure is between l1kPa 10kPa just pulse it with a gradually increasing pulsing delay in this manual method Do not pulse the turbo pump valve V1 when the dosing section pressure is over 10kPa use the rough vacuum pump to lower down the pressure 3 Programmed operation The above mentioned program VENT PULS can also run a series operation on the valves automatically Before that a file should be prepared to define the operation for VENT PULS This file can be created with the help of the program VENT PULS EDIT in computer Quincy whose interface is shown as Fig 3 12 3l E VENT PULS EDIT Y v Wo V4 Wo vb Vi vg 0 10 sec 0 10 sec 010 sec 4 10 sec 010 sec 0 10 sec O10 sec 0 10 sec ZEIT 7sec 3 u2 5 alznr 31 ENNENNNNEN LID BEEBE Eee FEREEEEE Fig 3 12 Interface of program VENT PULS EDIT To create such a file for each step press the corresponding key in the interface of VENT PULS EDIT for a pulse the pulse time should also be defined then click the REPLACE key Click the gt button for next step Click WRITE and give a file name to save it In this file the
3. NEW FILE button to create a new file in the dialog box then click STORE to begin logging Noting that only data from one of the two Baratron sensors can be logged See section 2 2 7 The data are saved as text files Ib MABBDA mV C3 File Edit Operate Windows Help Tz 100 7 fs us CAME4ATempda sd 34 nV 12000 0 11000 0 10000 0 9000 0 2000 0 000 0 6000 0 5000 0 4000 0 3000 0 2000 0 1000 0 0 0 Fig 3 13 Interface of program M4660A mV C3 3 3 Microcalorimeter calibration Before the first measurement of heats of adsorption with the microcalorimeter it should be calibrated The mechanism of microcalorimeter calibration is based on Joule s effect using a small resistance about 22 KQO give different voltage measure the current then compare the electric power with the heat flow of the calorimeter to get the calibration coefficient Fig 3 14 33 Fig 3 14 Determination of the calibration coefficient by integration The procedure is all the number referred the number in Fig 2 10 1 Disconnect the measuring cell from the calorimeter set the resistance with wire into the measuring cell put the measuring cell in to the calorimetric block tight the connection 34 combine the two leads of the resistance with a power adapter and an amperemeter Wrap the heating tape 29 and the isolating materials Be sure to close the turbo pump valve 18 and the calorimeter
4. close the helium shutoff open the valve for CO begin the second automatic adsorption after twice measurement if no further measurements are needed disconnect the measuring cell take out the sample pick up glass chippings and weigh the sample 49 4 Data processing 4 1 Getting the adsorption isotherm 4 1 1 Principles From the steps of a dosing cycle described in section 3 7 a series of pressure change will be logged in the computer Quincy plotted as the dashed line in Fig 4 1 Pob Pia Pra P3a Pinert 0 x Pi P LE ed 171 ha s l Leakage p c I Pip as 2 red he p s 7a measu d Pic i Pr I e ee wu l l l l l i p l li 11 Padl star 1 Pag start I j l l Pad eq I l i Pad 1 eq l l li l l i l l i l I wu t t t t Ostart loend fistan lend 2start 2end t Logged dosing vessel pressure Inert gas partial pressure in measuring cell amp CO partial pressure in measuring cell Fig 4 1 Pressure change during dosing cycles The actions that bring about the change of logged dosing section pressure includes Poa Start pressure at tostart With the calorimeter valve open and the turbo pump valve closed Pov pressure at toena Increase from po due to leakage Pia a overflow pressure gt 110Pa after closing the calorimeter valve opening the turbo pump valve and then a pulse of gas supply valve Piv a suitable pressure 85 100Pa after several
5. 85Pa and 100Pa 3 Create a data file and start to log pressure data See section 3 2 4 Wait until the baseline is good that means the noise and the baseline shift will be small enough compared with heat flow peaks For the first dose pressure change in the setup during this waiting period can be applied to calculate leakage rate 45 5 Close the calorimetric valve and open the turbo pump valve so as to evacuate the dosing section for about 1 minutes the readout of the lower readout of PR4000 should drop to 0 6 Fill the dosing section with CO by the following step 1 shut off valve for CO 2 Close the turbo pump valve close the shut off valve for rough vacuum pump open the Pulse the gas supply valve to have a pressure of over 85Pa shown the PR4000 then close the shut off valve for CO open the shut off valve for the rough pump 3 pressure in PR4000 between 100Pa and 1kPa 4 have a value between 85Pa and 100Pa If the pressure displayed in PR4000 exceeds 1kPa pulse the gas supply valve to have a If the pressure displayed in PR4000 exceeds 100Pa use the pulse the turbo pump valve to 7 open the calorimeter valve CO goes to the measuring cell so the adsorption begins a heat flow peak happens in the display of SETSOFT 2000 Then repeat from step 4 The necessary amount of cycles varies with different samples from 10 cycles to 50 cycles samples are often measured twice After the las
6. Dumesic 1996 Microcalorimetric measurement of differential heats of adsorption on reactive catalyst surface Thermochimica Acta Vol 290 pp 43 53 4 Swagelok Company http www swagelok com downloads webcatalogs MS 01 140 pdf Sept 22 2004 5 Swagelok Company http www swagelok com downloads webcatalogs MS 01 24 pdf Sept 22 2004 6 Caburn Vacuum Science Ltd http www caburn co uk resources downloads pdfs sec1 1 1 pdf sept 22 2004 7 Caburn Vacuum Science Ltd http www caburn co uk resources downloads pdfs sec1 2 1 1 pdf Sept 22 2004 8 Laboratory of Technical Chemistry Ruhr University Bochum http www techem ruhr uni bochum de local belehrung verhalten htm Sept 22 2004 58
7. Eee 28 32 Operating the pneumatic valves and logging the pressure data sse 30 3 3 Microcalorumeter Can bration ct 33 34 Dosing section volume canDratio s eee s reg recede a ee a 35 35 Measuring cell volume calibrati0N occccccccnnnnnnnooonananononononcnnnnnnnnnnnnnnnnnnnonnnnnannnnnnnnnnnnnss 39 3 6 Preparing samples for tieasurement Aa 40 SJ Sample patticle ESTADO da 40 02 Operation before and after Pretreatment soi rae eec v b edit ntu bt ied ec rbd 41 Su OperatiomoP COSI cl unidad dt 44 3 8 Me as remertorheats Of AdSOFPIION dia 47 4 Data DEOCOSSIIIG Gioco t ar ei Eee ba E PENSIERI IT ERES 50 4 Getme the adsorption TSOLDG TENE did 50 Aiek PENEDES Ree ene ene ia 50 4 1 2 Using the Microsoft Excel template file for calculation sese nennen 51 4 2 Cetina the CLC Rem AMIN taria 53 5 In case of Malfunctions and Accidents cere e eee eee e eee e eee eee eee eee 55 5 1 WAC THOM SOE SC UD dba dtes dieta ei ost cuenta item ese as teae Diete dd t Rete dus 55 5 2 PUOI MT PEE 57 6 References Principles 1 1 Differential heat of adsorption The measurement of the heat of adsorption by a suitable microcalorimeter is the most reliable method to study the strength of interaction between adsorbed species and adsorbents There are different definitions of heats of adsorption which are measured under different circumstance a Tian Calvet
8. PR1 outread in the PR4000 to about 1kPa then close the shut off valve for the rough vacuum pump open the gas supply valve by pulsing the turbo pump valve to make the PR2 outread in the PR4000 lower than 100Pa and record it this is a pop Close the gas supply valve open the turbo pump valve to evacuate the dosing section then close the turbo pump valve and open the gas supply valve the gas will come from Vout to Vaose record the PR1 outread in the PR4000 at ecquilibrium this is a piv If the pressure measured in step 4 is still higher than 5Pa record it as a new pov then repeat 4 to get a new pis When the pressure measured in step 4 1s lower than 5Pa repeat from 2 to 5 for several times After setting the metal block inside the Vout repeat the above procedure to get a group of pop and pip Of course these two way can be done with filling of the metal block only once The volume of the dosing section is calculated to be 39 38cm in this setup 38 After calibration close the valve between the chamber and other parts of the setup 3 5 Measuring cell volume calibration Since the volume of the dosing section Vadose are known it is easier to measure the volume of the measuring cell volume The principle is evacuate both of the dosing section and the measuring cell then close the valve between them 1 e the calorimeter valve 19 fill the dosing section with an certain pressure of helium Pdose then conn
9. Pfeiffer DUO 2 5 pump its series number is PKD 41 702A It connects to the system with a valve 12 The final pressure can reach 2 4 x 10 mbar The pressure can be read from a Pirani gauge 13 This pump also serves for the preparation of the sample capsule See section 3 6 2 so there 1s a switch to open another gas line Fig 2 11 Since the system use CO which is a kind of toxic gas so it should be sure that the outlet of the rough vacuum pump is connected to the ventilating arrangement of the laboratory Besides since the shutoff valve of this vacuum is neighbor to the shutoff valves of CO and helium bottle so whenever before open the shut off valve for rough vacuum 12 both the shutoff valves of the eas bottles 7 and 8 should be closed Otherwise gas in the bottles will be evacuate away The turbo pump is a TMP 071P turbomolecular pump It is compacted with a Pfeiffer TSU 071E PMO051 668 S pump The turbo pump can only work under a pressure of lower than 1kPa so whenever before opening or pulsing the turbo pump valve 18 the pressure in the dosing section should be lower than that The turbo pump has a display control unit DCU 15 which can display the status of the pump A full range pressure gauge 14 measures the pressure of the gas line near the turbo pump A heater 17 is set to heat the gas line to the turbo pump to prevent condensation of water steam Its temperature 1s set as 75 C which is the maximum for the
10. The highest temperature for the SWAGELOK CAJON VCR stainless fittings and gaskets is 537 C 1000 F The maximum leak rate for helium tested by the cooperation is 4x10 std cm s for a connection with silver plated gaskets and 4 x 10 std cm s with unplated gaskets A VCR connection is easy to install and disassemble but if it is too frequently its tightness will get Worse 2 1 3 CF Flange CF flanges are used for the frequent install and disassembling position 1 e the connection between the sample cell and the T piece between the reference cell and the T piece in the measuring cell see section 2 2 5 and the connection to connect the measuring cell with other parts of the setup It is also used in the cap of a chamber for calibration the volume of which should be kept constant see section 3 4 To install a CF flange place an OFE oxygen free electronic grade copper gasket against the knife edge seal of one of two standard CF flanges preferably the flange most likely to hold and support the gasket from falling With the gasket in place arrange mating flange with the desired bolt hole orientation After hand tightening all bolts support bolt and turn nut The tightening process must be done gradually in 1 4 to 1 2 turn increments in a alternating crisscross pattern Continue until the desired torque ratings have been achieved Tightening bolts in this fashion will insure a reliable seal with even gasket compression and d
11. action of the valves are recorded as valve operation with varies time delay Each operation occupies one line in 10 columns The definition 1s 0 000 0 100 0 100 0 100 0 100 0 100 0 100 0 100 0 100 10 000 Pulse time for the corresponding valve Delay time The operation code has a binary meaning The lowest 8 bits of the binary form of an operation code represent the status of open or close of some of eight valves 0 is close 1 is open The next 8 bits represents the status of pulse or not of eight valves 1 1s pulse 0 is not pulse As a result the useful code in decimal for the operation of this set up is All valves Open Open Open both Open Pulse Pulse Pulse closed valve 1 valve2 valve 1 and2 valve 3 valve 1 valve 2 valve 3 Here valve 1 refers to the turbo pump valve valve 2 refers to the calorimeter valve valve 3 refers to the gas supply valve 32 After the programmed file is ready press the AUTO button in the VENT PULS program select the file in the dialog box then the VENT PULS will run the programmed file immediately Since a fault operation of valves may damage the turbo pump or evacuate the sample vessel unsuitably so one should be always cautious when programming the valve actions The dosing section pressure data measured by two Baratron sensors 25 and 26 can be logged by the computer Quincy with the program M4660A mV C3 Fig 3 13 Click the
12. adsorbate during a dose can be calculated out from the difference between the start pressure and the end pressure of adsorptive Mad n Dad n start Pad eq n x Veet Vise Roas T y Msample 4 5 The isotherm of adsorption can be directly plotted with the equilibrium adsorptive partial pressure and the increasing amount of adsorbate 4 1 2 Using the Microsoft Excel template file for calculation All the above calculation will be processed by a Microsoft Excel file which acts as a template Key in the parameters and the pressure data needed all the in between and final results explained above will be obtained The needed data include 51 l Key in the leakage rate sample mass CONDITION area RUN CONDITIONS Sample mass Sample area Dosing Section Temp Ads Calorimeter Temp Dosing Section Volume Cell Section Volume Leak Rate Leak Rate and dosing section volume values in the RUN 0 107 g 0 0 m 2 g 40 0 C 30 0 C 39 13 cm 3 84 49 cm 3 6 19E 05 Pa s 3 7 E 03 Pa min 2 Key in the data for the measuring cell volume calibration in the CELL VOLUME CALCULATION area in order to get the dosing section volume These data can be also input in the same time of measuring cell volume calibration 0 JO 0 ON CELL VOLUME CALCULATION Dose Pdose Peq Vcell Pa Pa cmA3 Average Std Dev 84 49 0 03 0 03 3 Open the pressure data file with Microcal Origin program
13. computer C ASCI in clipbo Example C In Report Cancel 1235 Filename File ASCH Output ASCH delimited C ASCI fixed lenght 10000 12000 14000 Time s Fig 3 10 Export a data zone to ASCII file 3 2 Operating the pneumatic valves and logging the pressure data There are three ways to operate the pneumatic valves 18 19 and 20 in Fig 2 10 all the operation of each pneumatic valve should a solenoid valves as explained in section 2 2 3 1 Open or close directly by turn the switches in the valve controller 47 in Fig 2 10 2 Click the buttons in the controlling program in computer Quincy The interface of the controlling program VENT PULS is shown as Fig 3 11 Click an ON OFF button to change the status of a valve or click a PULS button to make the valve open for a short pulse The minimum pulse time is 0 05 second but a pulse time shorter than 0 20 second will not open the pneumatic valve in fact it can be increased with a step of 0 05 second by clicking the arrow button or keying in the text box When the pressure change shown in PR4000 is not ideal e g it increases too slow after a gas incoming pulse of V3 the pulse time should be adjusted 30 I VENT PULS auto oo J uo j o o ON OFF button i S005 sec 20 05 sec 20 05 sec 20 05 sec 20 05 sec 0 05 sec 0 05 sec 4 Q5 sec m ruts mj B im Bim Bim Wim Bim Wi m us
14. draw a p t plot collect the pw and Pna values of each dose input them in the CHEMISORPTION ISOTHRM DATA area The dosing time can also be calculated out from the p t plot 22 CHEMISORPTION ISOTHERM DATA Dose Pdose Peq Dose Time Pa Pa min 88 96 1 83 82 86 5 112 6 2 86 73 86 45 3 3 3 87 88 86 68 37 1 4 88 67 87 11 37 1 5 89 05 87 54 37 1 6 88 69 87 76 37 1 7 88 22 87 2 37 1 8 88 88 87 95 37 1 9 89 55 88 25 37 1 10 89 90 88 65 37 1 11 89 42 88 71 37 1 12 91 74 89 48 37 1 13 91 60 89 97 37 1 14 91 99 90 43 37 1 15 93 82 91 27 37 1 After that adjust the data series source and the axis scales in the ADS ISOTHERM worksheet of the Excel file then the adsorption isotherm of a measurement will be obtained 4 2 Getting the differential heats ES is the heat generated during this dose divided by the The differential heat of each dose g increasing adsorbate amount during this time and by the mass of adsorbents the heat generated during each dose 1s the integral of heat flow measured by calorimeter with time AQ nam dt naa n m 4 6 The integral of a heat flow peak can be processed with Microcal Origin software 1 Run Origin program import a zone file a zone file 1s exported by Setsoft 2000 see section 3 1 draw a heatflow time plot The heat flow peaks will appear If a peak meets the end of a zone the next zone file should be combined to process 2 Draw baseline with the Base
15. explained in the User s Manual of SETSOFT 2000 here only the operation for the experiment will be showed The SETSOFT 2000 program is installed in the computer Calvet It is the controlling program for the microcalorimeter Run it from the Microsoft Windows NT interface by click Start Programme SETSOFT2000 Setsoft2000 Then a popup window will occur as Fig 3 1 login by selecting a users name and typing the correct password Then click OK after one or two minutes of initialization the program interface will appear Connect to SETSOFT 2000 Name administrator ha Password XXXIX tee Setting password Francais English Fig 3 1 Popup window for SETSOFT registration Whenever the mouse cursor moves near the left edge of an active window of SETSOFT 2000 a toolbar with five buttons will appear Fig 3 2 The two modules expressed by the upper two buttons Acquisition and Data processing are needed for the operation during measurement These modules can interchange from each to another at any time by clicking a button in the toolbar 22 Acquisition Data processing Tools Preferences NC Apparatus Fig 3 2 Toolbar of SETSOFT 2000 3 1 2 Start collection Data collection 1s the function that the SETSOFT 2000 collect the data from calorimeter through the CS32 controller To start collection click the Acquisition button of the toolbar then click the New Collection m
16. first part of the pressure data will be used to calculate the leakage of the system switch off the fans for the pneumatic valves wrap the isolating materials in the upper part of the measuring cell 48 6 7 8 9 prepare the file for automatic dosing see section 3 2 and 3 7 start acquisition of the prepared experiment in SETSOFT 2000 program close the shutoff valve for the rough vacuum pump 12 open the shutoff valve for CO 7 the absolute pressure should be bar When the baseline is fine start the first dosing either manually or automatically See section 3 7 5 After first measurement 1 2 3 4 5 6 after all the doses finishes stop the pressure data logging open both of the turbo pump valve and the calorimeter valve to degas the sample with adsorbates overnight close the valve for turbo pump 18 close the shutoff valve for CO open the shutoff valve for the rough vacuum pump 12 then wash this part several times with helium with the alternative open and close of the two shutoff valves for helium and rough vacuum pump 8 and 12 close the valve for mechanic pump open that for helium calibrate the measuring cell volume with helium see section 3 5 at the last step of measuring cell calibration close the calorimeter valve to preserve helium with a pressure of 85 100Pa in the measuring cell open the valve for turbo pump evacuate the dosing section alone when the baseline is fine
17. for metric tubing and have no step on forging Fig 2 2 Ho shoulder Swagelok Swagelok metric tube end fractional v tube stub al il va PO i stepped shoulder Swagelok metnc tube ends stepped shoulder Fig 2 2 Distinguishing a SWAGELOK metric fitting To install a new SWAGELOK tube fitting in this system larger than 1 in 25 mm insert tubing into the SWAGELOK tube fitting make sure that the tubing rests firmly on the shoulder of the tube fitting body and that the nut 1s finger tight Then scribing the nut at the 6 o clock position While holding fitting body steady tighten the nut 1 1 4 turns to the 9 o clock position Fig 2 3 Fig 2 3 Installation of a SWAGELOK tube fittin SWAGELOK tube fitting If a SWAGELOK tube fitting was used before just tighten it for 1 2 turn 2 1 2 SWAGELOK CAJON VCR connection A whole set of SWAGELOK CAJON VCR connection includes two glands and two nuts or includes a female nut a body part and a gland Fig 2 4 They can also be connected to SWAGELOK or PFEIFFER valves and the sensors of MKS Baratron pressure transducers In this setup all connections of this type are made of stainless steel The surface of the glands is polished very finely if the it is damaged thread galling may occur which will damage the fitting components cause a poor seal So they cannot be cleaned with chemicals and cannot be touched by hand side load Female nut Gland retainer gasket Gland Male nut
18. help the whole measuring cell to have similar temperature In this setup the auxiliary thermostat temperature is adjusted 10 C above the temperature of the calorimetric block so during a measurement of heats of adsorption the temperature inside the calorimetric block is 30 C while the temperature of the auxiliary thermostat 1s 40 C The CS 32 controller is mainly made up of a CPU card a keyboard and various acquisition and amplification cards It controls the power module 40 the oven and the fan of the calorimeter It receives the electronic signal from the calorimeter transformed it to the computer Calvet 51 The calorimetric chamber is mounted on a linear adjust device 42 which can be raised up and lowered down so as to allow the calorimeter to be fixed and the measuring sample to pass through See the SETARAM C380II User Manual to know the installation of the calorimeter 2 2 7 Pressure measurement and control units Pressure measurement unit The function of pressure measurement units is to measure the pressure in the dosing section If the calorimeter valve 19 1s open then pressure in the measuring cell is measured because it equals to that 1n the dosing section The pressure measurement unit includes an MKS BARATRON absolute pressure transducer with a range of 1 atm including 25 and 43 an MKS BARATRON absolute pressure transducer with a range of 100 Pa including 26 and 44 and an MKS PR4000 digital power
19. period for a data zone 25 If a new zone is needed just click the last zone in the Experiment explorer area with the right button of mouse then select Add zone Standard zone After all the zones are set select the Start experiment menu item in the Collection menu then SETSOFT 2000 begin to collect data Click the Real time drawing menu item in the Display menu a chart area will appear showing the temperature and heat flow change with time Meanwhile the program can also show other two areas if the corresponding menu items are selected in the C80 menu they are PID and Manual programming All the areas are shown as Fig 3 7 n SETSOFT 2000 Acquisition Collection lt one Display Realtime drawing Window Y C80 Il Ic hcl Ec nett Ex Manual programming C80_ll RO al Initial T 7 E pm Final T C e ON ISDTH Current T C e ON ISUTH Scanning rate mE re Delay s 3057 7 WE gt Fan mE v n BEEN n Furnace Fan Ma ma Min es P T e 3 jm wd e vs y sones D z T E Sample temperature C Tf E 30 17 Tss y 45 6 30 56 on I5OTH System DK mi Fig 3 7 Interface with three areas during data collection chart area PID area left and Manual programming area The PID area shows the heating actions of the calorimeter They are Proportional action P Integral action D Derivative act
20. pressure of lower than 100 Pa In this way helium in the Vgose and Vout are in lower pressure initially pop then close the gas supply valve 20 open the turbo pump valve 18 to evacuate the dosing section then close the turbo pump valve open the gas supply valve to get a pressure pir In this time pob Vout Pib Vaose Vout 3 6 SO Vou Vadose P1 Po piv 3 7 If Vout 1s filled with the metal block with volume Vp Pov Vout Vg 7 Piv Vaose Vout VB 3 8 then Vou VB Vaose P1b pov piv 3 9 37 From equation 3 7 and 3 9 Vaose Vg pw pob pio piv pov piv 3 10 So with the known value of Vg by measuring Po piv pov and pio the volume of dosing section can also be known The procedure is 1 2 3 4 5 6 Close the turbo pump valve and the calorimeter valve open the neighboring valve of the chamber connect the voltmeter 46 with the 2GND and 2S pins from PR4000 See section 2 2 7 Be sure the shut off valve for helium and CO is close open the shut off valve for the rough vacuum pump and the gas supply valve evacuate Vaose and Vout then close the gas supply valve open the turbo pump valve to go on evacuating Close turbo pump valve give a very short open of the shut off valve for helium then close it close the gas supply valve 20 open the shut off valve for the rough vacuum pump by pulsing the gas supply valve lower down the
21. pressure presented by the full range pressure gauge 16 if the readout can not drop down to 10 mbar in ten minutes then the system is not leakage tight it need re installation Otherwise evacuate the system for 72 hours 3 Preparation for measurement 1 2 3 4 adjust the three temperature controller to 40 C it will cost a night for the system to cool down prepare a new experiment in the SETSOFT 2000 program make sure that the zone time are enough see section 3 1 switch off the fans for the calorimeter one hour before the measurement close the valve for turbo pump 18 with the calorimetric valve 19 opening test the leakage rate of the system for about 10 minutes a leakage rate lower than 0 003Pa min is ideal then open the valve for turbo pump 18 4 Start measurement 1 2 3 4 5 as the temperature is ideal about 30 C or 5 C above room temperature whichever is warmer close the valve for turbo pump 18 with the calorimetric valve 19 being open unwrap the isolating materials in the upper part of the measuring cell turn the linear motion feedthrough 35 to crush the sample capsule and then turn 1t back to the uppermost position be careful the electric currents in the heating tapes 1f there is an overflow pulse the valve for turbo pump for several times to get a pressure of 80 100Pa in the cell create a file for pressure logging start data logging see section 3 2 and 3 7 the
22. the 4 way valve shortly so that the relative pressure inside the Pyrex NMR tube drop to between negative 0 5 0 8 atm 6 Usea blowtorch Fig 3 18 to melt and seal the Pyrex NMR tube to get a capsule the length of the capsule should be controlled as about 95mm Place the capsule to a safe place nearby then quench the blowtorch with two hands It is impossible to quench the blowtorch with only one hand 7 Preserve the capsule disconnect the rest part of the Pyrex NMR tube and hand it with a glass tube to the glass workshop to have a new Pyrex NMR tube Fig 3 19 The blowtorch to seal the capsule 3 7 Operation of dosing cycles A dosing cycle is to make the adsorbtive pooled in the dosing section to mix with the gas in the measuring cell so that the partial pressure of adsorbtive will increase in the measuring cell and the adsorption will go on Before each mixing there should be no serious pressure difference between the dosing section and the measuring cell otherwise a work of gas expansion will bring about an error in the measurement of heat flow So the preparation of suitable pressure in the dosing section and measuring cell is very important 44 In the start of a dosing cycle the dosing section and the measuring cell are connected and the adsorbtive partial pressure is at equilibrium with the coverage of adsorbate on adsorbent Then isolate the dosing section and the measuring cell evacuate the former then fill it with adso
23. valve 19 switch off all the three temperature controllers 31 32 and 33 before disconnect the measuring cell 2 Close the two shut off valves for CO and helium 7 and 8 open the shut off valve for the rough vacuum pump 12 then open the gas supply valve 20 and the calorimeter valve 19 to evacuate the system with the rough vacuum pump be sure this pump is switched on When the pressure displayed in PR 4000 45 is lower than 110Pa close the gas supply valve open the turbo pump valve so as to get a UHV with turbo pump 3 Check the calorimeter status be sure that the fan switch is adjusted to Automatic Switch on the three temperature controllers 31 32 and 33 set their setpoint to 145 C the setpoint of the heating tape should increase gradually see section 2 2 4 4 Start SETSOFT 2000 prepare enough zones program a zone for evacuating at 145 C See section 3 1 3 5 When the temperature has lowed down to 30 C and the heat flux baseline in SETSOFT 2000 is stable give the resistance a voltage of 5V for 20min record the current value waiting for the baseline to be stable again for about 30 60min from experience 34 6 Such a measurement can be repeated in different pressure of helium close the turbo pump valve close the shut off valve for the rough vacuum pump open the shut off valve for helium pulse the gas supply valve the calorimeter valve should be open observe the pressure value of PR 4
24. 000 if the pressure is to high e g over 10kPa close the shut off valve for helium open the shut off valve for the rough vacuum pump pulse the gas supply valve until the pressure in shown in PR4000 is down to nearly 100kPa Pulse the turbo pump valve to get suitable helium pressure 1 e 25Pa 50Pa 75Pa and 100Pa measure the Joule effect 7 The measurement can also be repeated under different voltage 1 e 2 5V 10V 20V and 30V 3 4 Dosing section volume calibration The value of dosing section volume is one of the basic parameters to calculate the sample cell volume in each experiment If any changes happens that might affect the volume of dosing section then it needs be calibrated It is obtained on the relationship of the pressures and the volumes of two sections in the gas line the two sections are the dosing section and the section between gas supply valve 20 and the shut off valves 7 8 and 12 The latter can be connected to a chamber where a cylindrical metal block with known volume can be put in to change the volume of this section Fig 3 15 _ SS ae Pd 12 pe l l 18 l l l l Chamber where the metal block can be put in l 8 IN Pi N yv N r ix wt i br 7 gt Volume of this Volume of this section section Vdose including chamber Vout Fig 3 15 The sections for dosing vessel volume calibration Labels for the valv
25. 102 Their severe phone can be obtained from secretary Ms Kalender in NBCF 04 690 5 3 Accidents This setup uses CO gas which is severely toxic If a leakage of CO happens and detected by the alarm system the gas alarm will beep But when 1t beeps it 1s not definitely that the CO leakage comes from this setup So when the gas alarm beeps go to room NBCF 04 664 to see the channel 655 2 CO 1n this setup in the gas alarm system and discuss with colleagues to decide whether the CO bottle for this setup should be closed If the House alarm bells the operator must stop every work at once switched off the gas water and air flow If possible switch off plants and equipment Close the windows and doors but do not lock them use the designated escape routes do not use the lifts go to the meeting point parking lot ND eastern N NordstraBe The building may only be entered again with the permission of the officers in charge For all the procedures in case of danger and fires read the following website thoroughly http www techem ruhr uni bochum de local belehrung verhalten htm 57 6 References 1 Cardona Martinez N and J A Dumesic 1992 Application of adsorption microcalorimetry to the study of heterogeneous catalysis Advances in Catalysis Vol 38 pp 149 244 2 H hne G W H W F Hemminger and H J Flammersheim 2003 Differential Scanning Calorimetry Berlin Springer 3 Spiewak B E and J A
26. 7 fan in heated box 28 oven heating the heated box 29 heating tape 30 oven heating the auxiliary thermostat 3 temperature controller for oven 28 32 temperature controller for heating tape 29 33 temperature controller for the auxiliary thermostat 30 34 CF flange to connect measuring cell 35 Linear motion feedthrough with thread adapter 36 sample cell 37 reference cell 38 auxiliary thermostat 39 Calorimeter block 40 CS 32 controller for the calorimeter 41 Power module for the calorimeter 42 Linear adjust device for the calorimeter 43 Signal conditioner for Baratron latm 44 Signal conditioner for Baratron 100Pa 45 PR4000 power supply and readout 46 Voltmeter 47 Controller for the solenoid valves 18 19 20 48 Power supply for the solenoid valves 18 19 20 49 pressure and gas supplying controlling computer Quincy 50 Power failure protector 5 calorimeter controlling computer Calvet 11 Fig 2 11 Photos showing the position of the parts of the setup 12 Fig 2 11 continued Fig 2 11 continued 14 2 2 2 Pumps The system uses a rough vacuum pump 10 to get a rough vacuum 1 bar Imbar and a turbo pump 11 to get a ultra high vacuum 10 mbar The turbo pump should work with a mechanic pump 12 in series connection The rough vacuum pump is a
27. Before pretreatment the reactor should be prepared in the following procedure 41 glass CF CF glass lined steel tube Fig 3 17 Device for pretreatment of catalysts a U tube b Upper CF flange c Lower CF flange d VCR fitting e Pyrex NMR tube f pressure gauge g 4 way valve h clamp 1 thermocouple j oven k linear adjust device weigh the sample with suitable particle size for 0 1000 0 1100 g in a special glass boat Fig 3 18 2 Disconnect the U shaped tube at the lower CF flange c and the VCR d if the Pyrex NMR tube is still connected to the reactor disconnect it at the upper CF flange b use compressed air in the laboratory to blow the small quartz wool bar out if there 1s use distilled water wash the U tube three time then wash it acetone 3 Connect the CF flange c and the VCR fitting d of the U tube to the device twist a small amount of quartz wool to a 2 cm plug with glove insert it into the flange branch of the U tube use a metal stick in the quartz wool bar side of the U tube and a soft Teflon stick in the opposite side to adjust the position of the quartz wool bar about 1cm above the bottom of the U tube branch 42 This quartz wool bar is applied to prevent the catalyst particle from falling down to the bottom of the U tube or even blown to the filter between the U tube and the 4 way valve so it should be neither too tight nor too loose Put the sample
28. In depth Practical Course 2004 SS Semester Measurements of Heats of Adsorption with a Tian Calvet Microcalorimeter Xinyu Xia NBCF 04 692 Tel 26475 LaerholzstraDe 21 44801 Bochum Tel 0234 970 52 88 Dr Raoul Naumann Tel 0234 546 88 23 Dr Elke L ffler Leiterin des Teilprojekts A2 SFB 558 NBCF 04 686 Tel 24102 GrabelohstraDe 14 44982 Bochum Tel 0234 297 04 40 Ruhr University Bochum Laboratory of Industrial Chemistry December 2005 Contents E o ERR REN 1 1 DitferenttabBeatot adsobpLIOIs ista l 12 TACA MECO A nales l ME npe 2 1 COMING CE OTA A stet pese Oeo Dese ead eaten restes Uc TU Metu d T 4 2b SWAGELOK tube fittings and adapter NE S oi 4 2 1 2 SWAGELOK CAJON VER COMECON artritis 6 Eo CTE A Eaa A 8 DN KEFRIDI cenia a a a a ler edad a a rem 9 2 2 wisis de Im 10 22W GAS SW OU UO NER Soc esses se passes seh sei eee dane A IERE 10 225 PETS da 15 2 2 5 Pheumaticvalves dosime section and heated DOX ins 15 2 201 Temperature COMO odia 17 223 SWIC AS UENO COM arrar O OA 18 220 Merocalorime t c 19 22 Pressure measurement and control bltscusc uoo do 19 3 AU ON essence IEEE 3 1 Using the SETSOFT 2000 prOgraM ccccccccccnnnnnnnnnnnnonnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnns 22 dell sRUI SBISORT OD aaa 27 e o mer 23 3 1 3 Direct programming for heating during CVaCuatiON cccccccessssesseeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeees Zi Sel AIDA LAO Qe
29. M WP OR Female nut Gland Gasket Fig 2 4 SWAGELOK CAJON VCR connection There are two kinds of gaskets used for the VCR connection Fig 2 5 1 non retained style The size is 5 6mm for inner diameter E 11 9mm for outer diameter Tx and 0 7mm for thickness H There are two types for this style one is silver plated the ordering number of which is SS 4 VCR 2 the other is unplated its number is SS 4 VCR 2 VS The former one is softer and the latter one is harder For a VCR connection which is disconnected and connected frequently the former type should be used to avoid the damage on the surface of VCR bodies and glands 2 Gasket retainer assembly The Retainer and gasket must be used as an assembly the size 1s 6 1mm for inner diameter E 12 7mm for outer diameter Tx and 0 7mm for thickness H There are also two types Number SS 4 VCR 2 GR is plated and Number SS 4 VCR 2 GR VS is unplated H H um I A rs 4 E Tx E TX 7 Fig 2 5 Gasket for SWAGELOK CAJON VCR connection non retained style left and Gasket retainer assembly right The installation instruction of a SWAGELOK CAJON VCR connection is shown in Fig 2 6 First tighten the different fittings and a suitable gasket with finger the surface of a gasket can not be touched by hand otherwise it will be contaminated and cause a poor tightness then use two wrenches turn 45 to make tight Fig 2 6 VCR Fitting Installation Instructions
30. ans 24 if the heated box is to be heated up 2 Open the gas supply valves including the valve for helium from central gas supplying system ZGV the valve for helium bottle and the valve for CO Noting if the pressure measured by the gauges do not increase after the valve 1s open that means the magnet valve for the ZGV is still closed due to the power switch off ask Ms Astrid Gomann to open it Be sure not to turn the reducing valves 3 Switch on the power failure protector 50 switch on computer Quincy start the two LabVIEW programs VENT PULS and M4660A mV C3 in Computer Quincy 4 Connect the solenoid valve controller 47 and the cable to computer Quincy 5 Switch on rough vacuum pump 10 6 Make sure the turbo pump valve 18 is closed switch on the turbo pump 13 56 5 2 Malfunctions of setup If any malfunction occurs with the setup contact with the person in charge according to the malfunction type Type Person in charge Office Telephone Computer hard ware software and network Pfeiffer Heinrich Josef NBCF04 662 32 28517 Mechanics pumps NBCF04 684 32 24534 Electrics heating tape heating elements NBCF04 684 32 24534 Gas supply safety issues Buse Susanna NBCF04 688 32 26834 If the setup does not work ordinarily call the persons in the order of the following list Order Office Telephone l NBCF 04 692 32 26475 2 NBCF 04 692 32 26475 3 NBCF04 686 32 24
31. are used to combine gas tubes two types of metal tubes are applied as gas line one is 1 4 inch and the other is 1 8 inch They includes different shapes unions and connectors in straight or elbow configurations A typical SWAGELOK fitting has one nut and two ferrules Fig 2 1 shows its working mechanism The elements of the fitting are depicted in cross section prior to make up the fitting nut top the advanced geometry back ferrule left the front ferrule center and the fitting body right The tube wall section is shown below the ferrules and body During make up the front ferrule center is driven into the body of the fitting right and the tube bottom to create primary seals tube and body while the back ferrule left hinges inward to create a strong grip on the tube m 1 BEBSBRSRRRRA Fig 2 1 SWAGELOK tube fitting Left 316 SS Advanced SWAGELOK Tube Fitting prior to make up right after Make up A SWAGELOK tube fitting can be reusable until the edge of the front ferrule nearly reaches the edge of the back ferrule If that happens cut a small segment of the tube with the ferrules and use a pair of new ferrules It should be noticed that there are two specifications of SWAGELOK tube fittings one is metric and the other is in length based on inches they cannot interchange All metric tube fittings have a stepped shoulder on the body hex Shaped fittings such as elbows crosses and tees are stamped MM
32. cludes the three pneumatic valves explained in section 2 2 3 18 19 and 20 a valve controller 47 and its power adaptor 48 the computer Quincy 49 and a power failure protector 50 Through a program designed in this laboratory based on NATIONAL INSTRUMENTS LabVIEW the computer can give signals to the valve controller to open close or pulse of the three pneumatic valves These valves can also be open or close through the switches in the front panel of the controller 47 directly The power adaptor 48 and the power failure protector 50 are designed to protect the turbo pump That 1s when the computer Quincy 1s reset or switched on it will generate random signals during booting in the parallel port which is linked to the valve controller and might cause an unexpected open of the turbo pump valve 18 and damage the turbo pump if the pressure inside the dosing section is not lower enough if the gas supply valve 20 1s open it will get even worse With the power failure protector 50 the computer cannot restart automatically after a power failure it can only be switched on again after pressing the green button on the protector If the computer needs to be switched on the power adaptor 48 should be always switched off until the LabVIEW programs in the computer have finished starting 21 3 Operation 3 1 Using the SETSOFT 2000 program 3 1 1 Run SETSOFT 2000 The installation and basic operation of this software is
33. d heating parts 1 Close the SETSOFT 2000 program switch off computer Calvet 2 Switch off the temperature controller 31 32 33 switch off the oven for the heated box 28 3 Switch off the power of CS 32 controller 40 and the power module for the calorimeter 41 the latter has two keys and both should be switched off 55 4 Switch off the two NOT AUS keys on the panel of the Siemens Sicherungskasten fuse box HT25 on the wall i e the WS220V II 16A S key and T key They are the keys for this setup 5 1 2 After the power switch on After the power is on restart the setup in the following steps 1 Switch on the WS220V II 16A S key and T key on the panel of the Siemens Sicherungskasten fuse box HT25 2 Start the calorimeter and heating parts 1 Switch on the power module for the calorimeter 41 then the power of CS 32 controller 40 2 Switch off the temperature controller 31 32 33 switch off the oven for the heated box 28 Be sure that the setpoint of the temperature controller for the heating band 32 does not exceed its measured temperature too much see section 2 2 4 3 Switch on computer Calvet start the SETSOFT 2000 program 3 Start the gas supply and pressure control units 1 Switch on the PR 4000 45 voltmeter 46 full range pressure gauge 16 heater 17 and the power supply for the solenoid valves 48 Set the temperature of heater 17 as 75 C Switch on the power for the f
34. d to input to the computer during experiment Normally the PR4000 displays the pressure value measured by both the two pressure transducers the upper readout is from the 1 atm pressure transducer and the lower one from the 100Pa pressure transducer The upper readout is in the unit of kPa and the lower one in Pa If the pressure exceeds 110kPa both the readouts is OVERFLOW If the pressure exceeds 110Pa only the lower one displays OVERFLOW The maximum pressure for both the transducers 1s 35psia 240kPa the pressure inside the dosing section cannot exceed that The digitals can occasionally shift away from zero when it is indeed vacuum in the dosing section then the PR4000 need to be rezero by this way 1 Press the ENTER key in the PR4000 front panel several times until it displays the following AZ1 VLV1 R1 AZZ VLV2 R2 20 2 Press the right arrow key in the PR4000 front panel so that the a cursor will occur under the AZI in the upper display or press the left arrow key until the cursor occurs under the AZ1 in the upper display 3 Press ENTER key then the corresponding digital will be rezeroed 4 Press ESC key in the PR4000 front panel then it will display the pressure again The pressure data input to the computer Quincy can be both displayed and logged by programs The operation will be explained in section 3 2 2 Pressure control unit The pressure control unit in
35. d zone ld 16 Standard zone bel 17 Standard zone fel 18 Standard zone bel 19 Standard zone 0 Standard zone List of sequences N Type Initial T RS 20 Final T Delay Speed Valves Fan Durati EN 14400 0000 0000 240 0 Description of sequence Initial T E Final T Cz Time s h mincs 30 EX E Valves ER i n 2 EH s Ms ma rr nm rn re n ec ju Pr Pr ll ll rn m nn jn change to 14400 automatically Fig 3 5 An example showing how to define a data zone For data collection in this setup there 1s only one sequence in each zone its type is isotherm shown as in the interface Its initial and the final temperature 1s 30 C Its length 1s 4 hours without fan running To enter these configuration just click one zone in the Experiment explorer area then click the sequence in the List of sequences area in Fig 3 5 An important thing is that in such a zone defined above the data will be collected every 2 9 seconds and there are only 4966 data points in one zone which is not convenient for data processing So it is needed to click the Standard Zone menu item in the Zone menu to change the Acquisition period to 1 in the popup window shown as Fig 3 6 press OK then the number of points will 20 Standard zone Acquisition period im s 3 Humber of points 4966 Cancel Fig 3 6 Popup window for setting the acquisition
36. e environment takes place via a well defined heat conduction path with given thermal resistance The primary measurement signal is a temperature difference which determines the intensity of exchange and the flow rate can be calculated out from it In more detail a Tian Calvet microcalorimeter belongs to the type of heat flux DSCs with cylindrical measuring system A block type cylindrical furnace is provided with two cylindrical cavities each containing a cylindrical fixed cell which is connected with the furnace or directly with the other cell by means of thermopiles Fig 1 1 The outer surface of each cell is in contact with a great number of thermocouples connected in series between the container and the furnace Both cells are thermally decoupled heat exchange takes place only with part of the massive furnace heatflux transducers SA reference sample Ups thermostated calorimetric block Fig 1 1 Heat flux DSC with cylinder type system The measurement signal proper of a heat flux DSC is the temperature difference AT of both cells averaged over surface it is generated by differential connection of both thermopiles AT ATFs ATFR ATsr 1 3 The heat flow rate amp t can be obtained from the change of AT t with Tian s equation SON LC A 14 di ty a R R dt Where R is the global heat resistance between the furnace and the cells the cells should be thermal symmetry Cs and Cp ar
37. e the heat capacity of sample and reference P is the heating rate 7 1s a time constant and equals to Cs R For a measurement of heat of adsorption the heating rate 1s often zero 1 e isothermal so ane s 14 Since the rand R are calorimeter constants the A7 t can be measured out by the thermopile thus Gt can be calculated out every time The interval heat of adsorption can be obtained by calculating the peak areas of measured curve Q d dt 1 5 with the increasing amount of adsorbates the differential heats of adsorption can be calculated out Fig 1 2 Getting O from measured t curve 2 Setup The system for measuring heat of adsorptions has a Tian Calvet microcalorimeter and the auxiliary parts including gas supplying unit temperature and pressure control units It is modified after the setup by Spiewak and Dumesic All the gas lines including tubes valves and connections are metal wares so that a ultra high vacuum can be obtained 2 1 Connection fittings Connection fittings are very important in a vacuum system because they are necessary to combine different parts and have the most significant influence on the tightness of the system There are three kinds of connection fittings applied in the system SWAGELOK fittings SWAGELOK CAJON VCR fittings and CF flanges A KF flange is used in the connection of a rough vacuum pump 2 1 1 SWAGELOK tube fittings and adapter fittings SWAGELOK tube fittings
38. ect these two parts to get a new pressure Peq From state equation of ideal gas Pdose Vaose Peal Vaoset Veet 3 11 then Veet Vaose D ose7 Peq Peg 3 12 The measuring procedure is 1 The gas supply valve 20 and the shut off valve for CO should be always closed open the shutoff valve for the rough vacuum pump 2 Atlower pressure 100Pa in the dosing section and the measuring cell open both of the turbo pump valve and the calorimeter valve to evacuate the dosing section and the measuring cell 3 Close the calorimeter valve keep the cell in vacuum close the turbo pump valve close the shutoff valve of the rough vacuum pump then open the shutoff valve for helium pulse the gas supply valve 4 Ifthe pressure shown in PR 4000 is higher than 100Pa pulse the turbo pump several times until the pressure is between 85 100Pa record the pressure this 1s paosc 5 Open the calorimetric valve 19 the pressure will drop Record the equilibrium pressure this 18 Peq With these two pressure values Veen can be calculated out 6 Repeat 2 5 for 10 to 25 times in order to get a statistic result of Veen 39 The pressure data are generally recorded by keying in a Microsoft Excel file for data processing See section 4 1 2 The measuring cell is about 85cm varying due to the difference of the position of the screw 35 and the volume of the glass capsule 3 6 Preparing samples for measurement The mai
39. eformation Hex head bolts CF flanges Hexagon head bolts di gt CF flange Leak check MB pr grooves Fig 2 7 Structure of a CF flange Fig 2 8 CF flange Installation The vacuum range for a CF flange can be as low as 1x10 Pa The temperature range for CF flange is 200 C to 450 C Besides it can be opened and closed for over 5000 times with a good feature for vacuum 2 1 4 KF Flange A KF flange is applied to connect the rough vacuum pump to the system Its most important advantage is that it can be connected and disconnected quickly It uses a Viton O ring which can keep a vacuum of 1x10 Pa This value is enough for the rough vacuum pump because the latter can reach a vacuum of not lower than 10 Pa KA retainer O ring Fig 2 9 a KF flange 2 3 Setup The whole construction of the setup is shown as Fig 2 10 and Fig 2 11 2 23 1 Gas Supplying CO is applied as the adsorbtive gas and helium as the gas to calibrate volumes and to control the pressure in the system The 50 L CO bottle 1 stands in the cabinet Schrank 8 in the room Fig 2 11 the SOL helium bottle 2 stands near the back of the computers The purity of CO is 99 997 and the purity of helium is 99 99990 Each kind of gas from the bottle goes through a pressure reducing valve with a pressure gauge 3 4 and 5 6 the pressure reducing gauges should be adjusted so that the relative pressure shown in the gauge is about 0 bar 1 e
40. enu item in the Collection menu A pop up window will appear Fig 3 3 Select C80 II in the SETARAM apparatus then press OK to confirm The interface as Fig 3 4 will appear after a certain time for the computer to execute Selected apparatus SETARAM apparatus Ceol Measurement module Mo option Fig 3 3 Popup window for selecting apparatus 23 TL SETSOFT 2000 Acquisition Collection sone Display Window S Olejel4 Sala Description Parameters Temp Car Furnace Sensitivity Other signals T E soma Experiment name Bd 1 Standard zone e bl 2 Standard zone Latas 101403012 ll 3 Standard zone Comment ld 4 Standard zone Cata CO adsorption E 5 Standard zone zin Mass mg Molar mass g mol E 8 Standard zone 1 E 3 Standard zone Cell E 10 Standard zone Crushcel gt bl 11 Standard zone Atmosphere Bl 12 Standard zone ld 13 Standard zone ImbarHe CO o E 14 Standard zone Procedure name E 15 Standard zone Calibration bel 16 Standard zone bl 17 Standard zone Experiment group User lel 18 Standard zone CO Adsorption os administrator m Fi NN NN NN NN NN NR O NR NR NN NN NR NR UNA NR Fig 3 4 An example of the interface to set experiment explorer In the interface shown in Fig 3 4 the different parameters can be input in the right area Most important is the name of experiment it acts also as the file name Other items will give remar
41. es and pressure gauges are the same as in Fig 2 10 35 There are two ways to measure the dosing section volume 1 Evacuating the outer part with a pressure of over 1kPa in the dosing section Supposing the dosing section volume is Vadose the volume between gas supply valve 20 and the shut off valves 7 8 and 12 is Vouw including the chamber First a certain amount of gas using helium here is filled in Vagose while Vout 18 vacuum Then open the valve between them the gas supply valve the pressure measured by the Baratron sensors in the dosing section 25 and 26 will drop assuming from poa to Pia shown in PR4000 From state equation of ideal gas we have Poa Vaose Pia Vadose Vout 3 1 SO Vow V dose powDla 3 2 If we fill the chamber in Vout with a metal block the volume of which is known as Vp then we will have the following relationship repeating the above operation Poa Vdose Pia Vdose Vou VB 3 3 then Vout VB Vaose Poa pia 1 3 4 From equation 3 2 and 3 4 we have Vaose Vp Dos D1a Doa Pia 3 5 That means with the known value of Vg by measuring poa pia Poa and pia we can know the volume of dosing section So the procedure is 1 Close the turbo pump valve and the calorimeter valve they should be always closed in this way open the valve neighbored to the chamber in the heated box Connect the voltmeter 46 with the IGND and 1S pins from PR4000 because thi
42. happens just close this zone and open it again after it has finished collection After the above plot appeared the data in the corresponding zone can be exported Select Export menu item in the Zone menu in the popup window define the file name select the ASCII output type this determines how the Origin and Excel can open it it is better to select ASCII fixed length click the Format button to define the decimal separator use for German operating systems then select Time and HeatFlow in the Signal s selection box in the first popup window press OK to export Fig 3 10 29 T SETSOFT 2000 Processing FORMAT Experiment one Processing Window 7 El signals initials characteristics Mame Cu n COpt O040830 Signal s Selection Preferences on selected signals ll Field Type Maximum number af points 14401 Preference Period 2 1 Duration xj 14400 Decimal number Export Export from point 1 to 14401 C time 3 a fa 14500 Signalis selection Preferences an all signals Decimal separator gt Thousands separ 5 Mone s Data delimiter Mane e Field separator None e Time Murnber of points p HeatF low Export select ASCH in file Caution The separators used must be coherent with those configured for your
43. he cycle begins with all valve closed for 10 seconds then open the turbo pump valve delay 30 seconds to evacuate the dosing section close the turbo pump valve delay 30 seconds pulse the gas supply valve for 0 35 second delay 5 seconds pulse the turbo pump valve seven times in each time it pulses 0 25 second and delay 5 seconds except that the delay time after the last pulse is 20 seconds finally open the calorimetric valve to start adsorption delay 2700 seconds 45 minutes so that the baseline can be good 3 8 Measurement of heats of adsorption A typical measurement of heats of adsorption with encapsulated sample includes the following steps 1 Installation of the measuring cell with new sample 1 2 3 4 5 6 7 close the turbo pump valve 18 close the shut off valves for CO and helium 7 and 8 close all of the three temperature controller 31 32 and 33 unwrap the isolating materials and the heating tape 29 around the upper part of the measuring cell with glove disconnect the CF flange 34 lower down the calorimeter through the linear adjust device 42 plug the measuring cell a bit out if it is two tight turn the calorimetric block slightly lean the calorimeter a bit to the left side in order to move out the measuring cell open the lower connection of the sample cell see section 2 2 5 1f there samples inside collect it make sure the length of the sealed glass capsule contai
44. in the glass boat into the U tube with a special glass funnel See Fig 3 18 at the mouth above the upper CF flange Connect the Pyrex NMR tube e to the device at the CF flange b Be careful not to damage the Pyrex NMR tube especially in the wide part near the connection of glass and metal because it 1s quite difficult to fabricate such a connection Connect the inlet and outlet of the device to the corresponding gas line through 2 VCR connections set the thermocouple to the right position the end of the thermocouple should be 1 em above the bottom of the U tube lift the oven up j so that the U tube is in the oven chamber Fig 3 18 The glass boat and funnel to contain and transfer sample After the pretreatment do the following steps to get a sample capsule l Switch off the oven move it down wait until the U tube 1s cooled down Switch the 4 way valve g so that the U tube is closed Now the U tube should be filled with helium which flows through the reactor in the last step of pretreatment Disconnect two VCR connections at the inlet and outlet of the reactor loose the screw of the clamp h turn around the U tube with the Pyrex NMR tube so that the catalyst particle can fall from the U tube down to the Pyrex NMR tube Connect the inlet and outlet of the device to the rough vacuum pump Fig 2 12 turn the switch of the pump to this gas line 43 5 Observing the pressure gauge f of the device open
45. ine between the heated box and the calorimeter and the oven in the auxiliary thermostat of the calorimeter 30 Each of them is controlled by an EUROTHERM 2416 programmable temperature and process controller 31 32 and 33 When the power of a controller 1s switched on it runs a self test sequence for about three seconds and then shows the measured temperature in the upper readout and the setpoint in the lower readout of the display On this display the setpoint can be adjusted by pressing up and down arrow buttons Two seconds after releasing either button the display blinks to show that the controller has accepted the new value During measurement of heats of adsorption the setpoints of all the three controller are always set to 40 C During evacuation after the measuring cell is connected the setpoints of them are set to 145 C to evacuate the water inside the system It should be noticed that the setpoint of the controller for the heating tape 32 cannot be set to 145 C directly otherwise the temperature increasing rate is so fast that it can raise up to a much higher degree before equilibrium So just adjust the setpoint 10 C above the measured temperature when the measured temperature reaches the setpoint adjust the setpoint 10 C higher again Observe the blink of the display when the setpoint reaches 100 C it can only be set to 5 C higher in one step and this value should be decreased to 2 C then 1 C before the setpoint is
46. ion D and Scanning rate U The SETARAM company has regulated that P 8 I 60 D 800 and U 0 so as to have good temperature scanning and control If it is not so click the Modify button in the bottom of the PID area to correct them 26 Data collection can be ended by two way if all zones are finished the collection will stop automatically or click the red square button near the right edge of the Manual programming area to stop it manually It should be noticed that when a new collection begins the heat flow and temperature of the calorimeter will change which will cost about 1 hour for the calorimeter to get a good baseline 3 1 3 Direct programming for heating during evacuation As mentioned in 2 2 4 the temperature of this setup 1s 145 C during evacuation after it 1s open to atmosphere The temperature change of the calorimetric block is programmed by SETSOFT 2000 Select the New collection menu item in the Collection menu click the first zone in a new experiment In the Standard Zone area click a sequence with right button to add new sequence either Add isotherm or Add ramp Add ramp if a temperature increasing or decreasing sequence is needed Define the initial temperature final temperature fan action and delay time of each zone so a temperature program will be created Fig 3 8 For an real programming for heating during evacuation the speed in a temperature increasing sequence marked as
47. ks of an experiment but they will not affect the experiment result In the left area Experiment explorer area shown in Fig 3 4 the numbers and features of record zones can be modified which describes the collection procedure SETSOFT 2000 program logs the experiment result in data zones the zones follow one another with time going on In this setup each zone for heat flow data collection is generally set as 4 hours long So for example if we have 15 zones SETSOFT 2000 can collect heatflow data for 15 zone x 4 hr zone 60 hours Each zone can include a series of sequences There are two type of sequences according to the programmed temperature change the isotherm one without temperature change and the ramp one with temperature change The feature to describe a sequences includes its time length temperature profile type fan condition and initial temperature For a ramp sequence the final temperature should also be defined Click a zone in the experiment explorers area shown in Fig 3 4 to define a zone an interface as Fig 3 5 will appear 24 n SETSOFT 2000 Acquisition Collection zone Display window S aliil allel Standard zone bel 2 Standard zone bel 3 Standard zone bel 4 Standard zone ll 5 Standard zone ll E Standard zone ll 7 Standard zone bel 9 Standard zone ll 3 Standard zone Bd 10 Standard zone bel 11 Standard zone fel 12 Standard zone bel 13 Standard zone Bd 14 Standard zone bel 15 Standar
48. line tool of Origin A baseline segment should meet the start and end point of a peak The start point 1s always easy to determine if the scale of baseline shift 1s rather small compared with the measured peak the end point is also easy to determine or the accuracy of the position of end point will not bring 53 obvious error to the integral of the following step However if a peak signal is not large enough compared with the baseline shift and noises its end point is not very clear but the it should be determined as such a point after which the baseline shift is linear There are different ways to draw a baseline from the start and the end point of a peak H hne et al 2003 one way is to take the straight line between them 3 Make the integral of each peak input the area to the CALORIMETRY DATA area of the CALORIMETRY DATA Excel file Dose Heat Evid mJ 1 11 55 2 10 50 3 6 70 4 6 03 5 3 5 6 3 92 7 1 93 8 2 42 9 3 40 10 1 35 11 0 78 12 1 23 13 1 63 14 0 64 15 0 88 After the area of every peak is input adjust the data series source and the axis scales in the DIFFERENTIAL HEAT worksheet of the Excel file then the differential heat plot will be obtained 54 5 Incase of Malfunctions and Accidents 5 1 Power switch off 5 1 1 Before a planned power switch off Before a planned power switch off the whole setup should be switched off in the following steps 1 Fill the se
49. lium from ZGV now its relative pressure is adjusted as about 5 0 bar Gas flow from solenoid valve goes through here Fig 2 12 A pneumatic valve To avoid the damage of pneumatic valves by dusts besides the filter 9 one piece of SWAGELOK SS 4 VCR 2 2M gaskets which can act as filters 1s applied at each of the outside fittings of the turbopump valve and the calorimeter valve 1 e the fittings between 18 and 16 and between 19 and 34 in Fig 2 10 The dosing section is set in a heated box where the temperature can reach as high as 145 C in order to remove water during evacuating Since solenoid can endure a temperature only up to 48 C the solenoid valves are set outside the heated box Three fans 21 22 23 are used to cool down the 16 solenoid they have one switch 24 So whenever the heated box is heating the fans should be switched on The sensors of two MKS BARATRON type 121A absolute pressure transducers are in the heated box linked to the dosing section one is type 121A01000B with the range of 1 atm 24 the other is type 121A0001B with the range of 100 Pa 25 Their working temperature is 0 150 C their maximum overpressure is 35psia 240kPa The usage of them will be explained in section 2 2 7 2 2 4 Temperature control unit The temperature control unit of this setup includes three heater with controller The three heaters are the oven in the heated box 28 the heating tape 29 wrapping the gas l
50. microcalorimeter measures the differential heat of adsorption is a change in internal energy it is related to the integral i 1 1 n T m V where the superscript o refers to the Gibbs surface 1 e a surface up to which both the gas phase and The differential heat of adsorption q heat of adsorption Q5 according to the solid are assumed to be homogeneous The integral heat of adsorption Q is defined as the amount of heat evolved by system when a certain amount of adsorbtive n are adsorbed at constant temperature and volume O n u u 1 2 The differential heat of adsorption can be measured fairly accurately 1n an adsorption experiment if the step width Ar is small enough 1 2 Tian Calvet Microcalorimeter A Tian Calvet microcalorimeter is a kind of differential scanning calorimeter DSC As all other DSCs its measuring system has a twin type design of same kind so that the disturbance such as temperature variation in the environment of the measuring system expansion of adsorbtive gas and so on will affect the two measuring systems in the same way and are compensated when the difference between the individual signals is formed Besides the difference signal can be strongly amplified because the high basic signal 1s almost compensated by the reference system The Tian Calvet microcalorimeter belongs to heat flux DSCs In heat flux DSCs a defined exchange of the heat to be measured with th
51. n type of sample measured with this setup is the catalyst for methanol synthesis including ZnO alumina Cu ZnO alumina Cu ZnO samples etc The suitable size of sample for the measurement is 250 3554 m Some samples need reduction and or other pretreatment 3 6 1 Sample particle resizing If the size of sample 1s not suitable it need to be resized The procedure 1s l Ifthe original size is smaller than suitable size make the sample powder as tablets with a press Fig 3 16 2 Grind the tablets or the powder if its the original size is large than suitable size with an agate mortar 3 Collect the ground powder to a series of screen a 355um screen a 250um screen and a container in the order of coarser to finer from upper to lower sift it collect the powder with suitable size 4 Make the powder inside the finer screen to tablets grind it with the powder inside the coarser screen and repeat the above steps until enough sample is obtained All the tools mentioned above including the tools for the press the mortar with the pestle the screens and the brush to clean them are special in the lab for the methanol synthesis catalysts 40 Fig 3 16 A Perkin Elmer hydraulic hand press 3 6 2 Operation before and after pretreatment Fig 3 17 shows the reactor for sample pretreatment It includes a steel U shaped tube as a reactor and a Pyrex NMR tube for sample sealing The complete cell consists of UHV components
52. near 145 C The temperature control unit should work with the temperature control function of the microcalorimeter During measurement of heats of adsorption the working temperature of the 17 microcalorimeter should be set to 30 C During evacuation after the measuring cell 1s connected the working temperature of the microcalorimeter should be set to 145 C The temperature control function of the microcalorimeter will be explained in section 3 1 3 2 2 5 Measuring cell The measuring cell is made up of stainless steel tubes It has a sample cell 36 a reference cell 37 and a T piece The connection between either cell and the T piece is a CF flange The sample cell has a linear feedthrough 35 to crush the sample glass capsule Fig 2 13 The connection between the measuring cell and the gas line from the dosing section is a CF flange 34 The measuring cell is inserted into the microcalorimeter to have a measurement of heats of adsorption It can be plugged out to input new sample for a new measurement When input new sample always open the lower flange of the sample cell in order to avoid that sample particle might go into the reference cell 18 Fig 2 13 Measuring cell 2 2 06 Microcalorimeter The kernel of this setup is a SETARAM Tian Calvet C80 II microcalorimeter It has an auxiliary thermostat 38 a calorimetric chamber 39 a CS 32 controller 40 and a power module 41 The auxiliary thermostat can
53. ning sample is 95mm put the sample glass in carefully with some tools then close the sample cell lean the calorimeter slightly to insert the measuring cell into the calorimeter lift the calorimeter through the linear adjust device till the distance between the two parts of the flange 34 1s about 1 2mm place the copper gasket lift the calorimeter through the linear adjust device for the last distance connect the flange wrap the isolating materials with gloves be careful that the different wires should not touch one another 2 Evacuating with heating 1 create a new collection in SETSOFT 2000 see section 3 1 2 program the heating 2 process in the first zone see section 3 1 3 start acquisition switch on the fans for the pneumatic valves 24 47 3 4 5 6 open the three temperature controllers 31 32 and 33 adjust the setpoint of those for the heated box and auxiliary thermostat 31 and 33 as 145 C directly adjust that for the heating tape gradually to 145 C see section 2 2 4 make sure the turbo pump valve 16 is closed open the calorimeter valve 19 be sure the shutoff valve for CO and helium 7 and 8 are closed open shut off valve for the rough vacuum pump 12 open the gas supply valve 20 use the rough vacuum pump to evacuate the system to a pressure lower than 100Pa close the gas supply valve 20 open the turbo pump valve 18 to evacuate the system with the turbopump check the
54. pulses of turbo pump valve Pic open the calorimetric valve Pia pressure at tiena change from fistar due to adsorption and leakage Based on the meaning of pressure change in dosing section the amount of adsorbate can be calculated out in the following way 1 Calculating the leakage rate of the system Lrate slope of the pressure change from fostart tO foend 4 1 It can be calculated out with a Microcal Origin 6 0 program 50 2 Calculating the inert gas pressure in the measuring cell The inert gas includes helium and the air leaked from outside The inert gas partial pressure in the measuring cell at the end of each dosing cycle depends on two parameters this partial pressure at the end of last dose e g at tiend tzend tn ena etc and leakage amount during this cycle So it can be expressed as Pinert n Pinert n 1 Vea Veet Vaose Lrate X th end 7 n 1 end 4 2 The change of inert gas partial pressure in the measuring cell is shown in Fig 4 1 3 Calculating the amount of adsorbate At the end of each dose when the adsorption 1s at equilibrium the partial pressure of the adsorbtive gas 1s the difference between the total pressure and the inert gas partial pressure Dad n eq P nd Pinert n 4 3 At the start of each dose the partial pressure of the adsorptive can be calculated out from the mixing Pad n start Ddose n X Vaose Pad eqn 1 X Vee11 Voe Vdose 4 4 The increasing amount of
55. rbtive adjust to a suitable pressure link the dosing section and the measuring cell again wait until equilibrium this 1s the end of a dosing cycle and the start of the next dosing cycle A dosing cycle can be fulfilled by the following steps l Make sure that the calorimeter valve is open the turbo pump valve and the gas supply valve are closed 2 Be sure the pressure shown in PR 4000 is 80 100Pa It is very important that before the first cycle the helium pressure is 85 100Pa in the dosing section and measuring cell with calorimeter valve being open The helium comes either from the crushed sample capsule or from the helium supply If the helium from the capsule is not enough or no helium in the dosing section e g for a non encapsulated sample or for a sample under repeating measurement do the following steps 1 Make sure that the calorimeter valve is open the turbo pump valve the gas supply valve and the shut off valve for CO are closed close the shut off valve for the rough pump open the shut off valve for helium 2 Pulse the gas supply valve to have a pressure of over 85Pa shown the PR4000 then close the shut off valve for helium open the shut off valve for the rough pump 3 If the pressure displayed in PR4000 exceeds 1kPa pulse the gas supply valve to have a pressure in PR4000 between 100Pa and 1kPa 4 Ifthe pressure displayed in PRA000 exceeds 100Pa use the pulse the turbo pump valve to have a value between
56. s time the pressure inside the dosing section 1s in rough vacuum See section 2 2 7 2 Besure the shut off valve for helium and CO is close open the gas supply valve 20 open the shut off valve for the rough vacuum pump evacuate V4ose and Vout 36 3 Close the shut off valve for the rough vacuum pump give a very short open of the shut off valve for helium then close it close the gas supply valve 20 record the PR1 outread in the PR4000 for Baratron 1 atm this is a poa 4 Opening the shut off valve for the rough vacuum pump for a while so that the pressure Vout is about 0 01 mbar close the shut off valve for the rough vacuum pump open the gas supply valve record the PR1 outread in the PR4000 this is a pia 5 Ifthe pressure measured in step 4 is still higher than 5kPa close the gas supply valve 20 record the PR1 outread in the PR4000 as a new poa then repeat 4 to get a new pja 6 When the pressure measured in step 4 1s lower than 5kPa repeat from 2 to 5 for several times Then open the heated box close the valve between the camber and the other part of Vout disconnect the camber at the VCR position take it out from the heated box Open its mouth a CF flange set the metal block inside and close it connect it again with the other part of Vou open its neighboring valve repeat the above procedure to get a group of po and pi Fig 3 15 2 Evacuating the dosing section and filling it with a
57. sensor of the full range pressure gauge 14 The turbo pump should always be on only when a power failure will happen or some error occurred with the pump then can it be switched off 2 2 3 Pneumatic valves dosing section and heated box 15 There are three pneumatic valves in the setup which control the adsorption procedure directly the turbopump valve 18 the calorimeter valve 19 and the gas supply valve 20 The gas line between them acts as the dosing segment that means the adsorbate gas 1s pooled here before it goes to the sample cell where adsorption happens A pneumatic valve works with a solenoid valve and 1s controlled by the latter Fig 2 12 When the solenoid valve receive a signal from the pressure control computer Quincy 49 it can make the pneumatic valve open close or give a pulse open a short time then close The solenoid valve use helium to make the pulse of the pneumatic valve that means when the solenoid valve receives a signal for pulse it give a pulse of helium itself the helium gas open the pneumatic valve for a short time The minimum pulse time can be 0 20 second and it can be increased by a step of 0 05 second in the controlling program in the computer Quincy The helium through the solenoid valve comes from the central gas supplying system ZGV its pressure affects the pressure change of the dosing section during a pulse sensitively It can be adjusted at the supplying valve of he
58. sing button in the tool bar See Fig 3 2 Then the current collected experiment will appear in the left area of an interface shown in Fig 3 9 Or open an existing experiment by select the open menu item in the Experiment menu an opened experiment will also appeared there Click any a to spread an item In any spread zone press the block beside the HeatFlow drag it to any of the Y1 Y6 box then loose the mouse a plot showing the heat flow change with time in this zone will appear Temperature can also be plotted by this way 28 Tn SETSOFT 2000 Processing Expenment Zone Processing Window a Alabel Ble eme ill pele i Cu Zn COpt 0040830 12 Standard zone 5 xl amp v Cu 2n COpt O04082 2 0 25646 p Y3 Y5 YB Yd Y2 8 2 Cu 2n COpt 004082 B X 1 Standard zone amp 2 Standard zone H 3 Standard zone 4 Standard zone 5 Standard zone g amp 7 6 Standard zone 7 Standard zone amp 8 Standard zone 3 Standard zone 10 Standard zone HL 11 Standard zone E 12 Standard zone EESTE STEM 52 Time af 13 Standard zone A HeatFlow 7 Sample temperati m Time 4 14 Standard zone E HeatFlow SE Sample temperati di Time 4000 8000 10000 12000 14000 Time s oH 15 Standard zone of ERR a AR Fig 3 9 Plot the heat flow data of a zone If a zone is still under experiment such an operation will bring about an X axis of only 3 seconds If such matter
59. supply and readout 45 through a voltmeter 46 the pressure data can be input to a computer 49 Each of the pressure transducer has a sensor 24 and 25 Each sensor is connected 19 to a signal conditioner the sensor of 121A01000B should be connected to the signal conditioner 121A01000B 43 and the sensor of 121A00001B should be connected to the signal conditioner 121A00001B 44 The two signal conditioners are then connected to an MKS PR4000 digital power supply and readout 45 The outlet of PR4000 is connected to a voltmeter 46 and then to a computer 49 which is named Quincy in the local area network It should be noted that the computer receives only one series of signals from PR4000 through the voltmeter The tuner of the voltmeter should point to DC 20V If the pressure data of the atm pressure transducer are needed to input to the computer then the pin labeled 1S with red wire from PR4000 should be inserted to the V Q jack and the pin labeled 1GND with green wire from PR4000 should be inserted to the ground jack S If pressure data of the 100Pa pressure transducer are needed to input to the computer then the pin labeled 2S with green wire from PR4000 should be inserted to the V Q jack and the pin labeled 2GND with yellow wire from PR4000 should be inserted to the ground jack During the measurement of heats of adsorption the pressure data of the 100Pa pressure transducer are neede
60. t dose of the first measurement open the turbo pump valve to evacuate overnight and then close the turbo pump valve start from step 1 of this section It is convenient to apply the automatic running function of VENT PULS see section 3 2 but before that it is necessary to know the times of pulses of the gas supply valve and the turbo pump valve and the delay time of each pulse to get a suitable CO pressure in the dosing section in step 4 of the above So that should be try it several time during trying the calorimeter valve should be always closed Then create an automatic running file with the help of VENT PULS EDIT section 3 2 The following is the content of an automatic running file sample for a dosing cycle 0 099 00100 5050190 L 000 0 050 07 0 50 07000 07050 0050 1024 000 0 950 2563008 05 250 2 56 4 990 0 250 256 000 0 250 256000 05 250 256 000 0 250 256 009 O22 20 0 100 0 050 0 050 0050 0 050 0050 0 0 90 0 050 02 050 04050 04 100 0 050 Uy 090 0 350 00590 0050 04050 0 050 0 050 O 050 0 100 0 050 OO SG 0 050 0050 0 050 0 050 0 050 0 050 0 050 46 0 100 0 050 0 050 05 050 07050 00 50 0050 07050 07050 05056 10 000 30 000 30 000 0 050 0050 00 50 07050 070 50 0 050 0 050 5 000 250 000 0 200 07050 07050 07050 07050 10 050 0 050 05 050 207 000 2 000 9 050 07050 07050 0050 07050 05050 0 050 90 050 27007000 The upper operations mean that t
61. the absolute pressure is 1 bar The gases that reach the dosing section the gas line between valve 18 19 and 20 can be switched by shut off valve 7 and 8 Before the gases comes to the pneumatic valve 20 they should pass through a filter 9 to avoid the damage of the pneumatic valve by dusts The gas pressure inside either bottle should be over 10 bar if the pressure is lower than that the gas bottle should be substituted 10 Gas line PR 4000 45 Cables Fig 2 10 Setup CO bottle 2 helium bottle 3 CO supplying pressure gauge 4 CO pressure reducing valve 5 helium supplying pressure gauge 6 helium pressure reducing valve 7 shut off valve for CO 8 shut off valve for helium 9 filter 10 rough vacuum pump 11 Pirani gauge 12 shut off valve for rough vacuum 13 turbopump 14 mechanic pump 15 Digital control unit of turbo pump 13 16 full range pressure gauge 17 heater for the gas line to the turbo pump 18 turbopump valve 19 calorimeter valve 20 gas supply valve 2 fan for the solenoid valve controlling the turbopump valve 18 22 fan for the solenoid valve controlling the calorimeter valve 19 23 fan for the solenoid valve controlling the gas supply valve 20 24 Power supply for fans 21 22 23 25 Sensor for Baratron latm 26 Sensor for Baratron 100Pa 2
62. tup with helium 1 Close the shut off valve for CO 7 close the shut off valve for rough vacuum pump 12 2 Close the turbo pump valve 18 open the calorimeter valve 19 open the shut off valve for helium 8 3 Pulse the gas supplying valve 20 several times then open it fill the setup with helium the final pressure depends on the helium pressure controlled by the pressure reducing valve 6 4 Close the shut off valve for helium 8 2 Stop the gas supply and pressure control units 1 Disconnect the solenoid valve controller 47 and the cable to computer Quincy 2 Stop the LabVIEW programs in Computer Quincy by clicking the round red button in the upper right of each interface then close these programs switch off computer Quincy 3 Close the gas supply valves including the valve for helium from central gas supplying system ZGV the valve for helium bottle and the valve for CO Noting that the valve for CO to be closed is not in Schrank 5 it is near the valve for helium from ZGV in the panel see the second photo of Fig 2 11 Be sure not to turn the reducing valves 4 Switch off rough vacuum pump 10 5 Switch off the turbo pump 13 and the membrane pump 14 They share one switch 6 Switch off the PR 4000 45 voltmeter 46 full range pressure gauge 16 heater 17 and the power supply for the solenoid valves 48 7 Switch off the power for the fans 24 3 Stop the calorimeter an

2 Setup - Ruhr-Universität Bochum

Contents

Download Pdf Manuals

Related Search

Related Contents

2 Setup - Ruhr-Universit&auml;t Bochum

Contents

Download Pdf Manuals

Related Search

Related Contents

2 Setup - Ruhr-Universität Bochum