Operating instruction
Contents
1. computer capacity Elements which are not in use can be hidden 4 5 The channels are assigned as followed MFC 1 MFC 2 MFC 3 differential pressure gauge not in use not in use not in use ae el ON IE es ee OS oe not in use 7 Titration Figure 10 Titration set up The consumption of SiCl in the reaction is calculated by the produced amount of HCl eq 1 SiC 2H O gt 4HCI SiO eq 1 The generated HCl is titrated automatically with sodium hydroxide solution 0 1 M However if unused SiCl enter the system there will be an artificial titration Therefore it is necessary to cool the SiCl4 gas in order to prevent its entrance to the system Figure 11 illustrates the assembly of the titration vessel A 3 3 6 2 1 Figure 11 Titration vessel with connectors The vessel water consists of a 4 neck bottle with GL connectors It is cooled with an ice bath 2 and stirred with a magnetic stirrer 1 The valves are connected as followed GL 16 pH electrode 4 connected with the titrator GL 14 titration syringe 5 connected with the titrator GL 14 Teflon tube heated HCl gas connected to the titrator and the reactor GL 14 exhaustion hose Figure 12 Assembly of the online titrator TitroLine alpha The used digital titrator 1 TitroLine alpha has a 50 ml container for titration solutuion and a keypad 2 The pH electrode is connected to the DIN port Elect by the electrode2. in the instruction manuals Fluidized bed reactor 7 Temperature controller Reactor _ aami with expansion zone l heating bands with Swayevalves co m pam m E eii 1 Controll unit E MFC pressure ee D jh etc Printer Temperature res controller n aA gH furnace furnace i i _ Quenching bath cryo traps Titration Titrator Figure 2 Front view of the coating equipment 1 Reactor The main part of the equipment is the heated reactor in which the coating experiment takes place A detailed assembly of the components are illustrated as follows 1 1 Solid bed reactor For Duran reactors a maximum temperature of 250 C 373K is allowed The oxide is filled up in the reactor to a packing height of not more than 10 cm ca 2 3 g It is important that the temperature does not exceed 250 C 373 K because of the material stability By exceeding the temperature a leak can occur However a silica reactor can be used at higher temperatures up to 700 C 973 K BARA T CEHI EEEE Feo e eh ee mm ar 8 8 8 8 8 8 6 G be i J L k UES E EKNER BEW Le aa Al TiQ max 10 cm 1 259 Quartzwolle Figure 3 View and sketch of the reactor 1 2 Stainless steel fittings The reactor entrance see is 1 1 connects to a argon containing Teflon tube by an stainless steel swagelock connector SS 6MO 6 To avoid damage it is import
3. Fluidized bed reactor 4 Furnace sesiessiisisssissesssesetss hi 33333333 lt 6 0o odd TH3 m sd X HX THY Y m NaOH Synthetic air k Exhaust gas MFC mass flow controller i At O UNE TEN a Saturator Titration vessel Stainless steel Quenching bath Silica Teflon Figure 1 Experimental apparatus of CVD set up for production of coated oxides 2 1 Gas supply Argon or synthetic air gas cylinders up to 200 bars are used The pressure gauge is between 2 and 6 bars Absence of water for modification of the TiO surface with silica is strongly recommended Therefore an additional purification of argon is required An Oxysorb is used for trapping oxygen and water before argon flows though the system The reactant gases are controlled by mass flow controller MFC 1 3 The flow can be applied to a solid bed reactor MFC 2 MFC 1 H6 or a fluidized bed reactor MFC 3 MFC 1 H6 The argon flow MFC 1 is controlled through a saturator water by the valves H4 and H5 An injection plunger controls the flow of silicon tetrachloride liquid During the coating experiments a SiCl flow rate between 0 20 and 2 00 ml h and a total volume between 0 5 and 5 ml is applied 2 2 Reactor CVD The reactant gas is heated up to 450 C 723 K in the reactor and flows through the TiO packing The system is heated by a furnace The thermocouple inside the packing measures and controls the furnace temperatur
4. Operating instruction Description of the equipment for the production of oxides by chemical vapour deposition CVD in fixed bed as well as in fluidized bed in room 488 NBCEF 05 south E a eo Do kaia Ba O ee Operators Dipl Ing Ralf BergstraBer room 689 NBCF 04 south Tel 22341 Adelkampstr 5 45147 Essen 0201 7204846 1 General Description The described set up is used to produce coated oxides such as titanium oxide T102 through chemical vapour deposition CVD of silicon tetrachloride SiCl4 An oxide is treated either in solid or in fluidized bed by silicon tetrachloride SiCl After the compound is adsorbed it must be treated with water and finally calcinated with argon or air The maximum temperature that the reaction can reach is 450 C 723 K The system is heated by a furnace in which Duran or silica reactors are inserted Currently the whole system is operating at atmospheric pressure Attention corrosive gases and corrosive liquids can be produced SiCl4 HCl If these corrosive materials leak from the system corrosion can occur The equipment is set under the hood and must be examined by experienced staff 2 Assembly The whole equipment is set on aluminium foil MKS Tubes and hoses in this system are made of stainless steel and Teflon The schematic of the set up is shown in Figure 1 syringe plunger Fr me Expansion zone y H8 L Me Exhaust gas Reactor
5. ant to use Teflon fittings T 6M3 1 T 6M4 1 on the glass site 1 3 GL Teflon fitting The exit of the reactor is connected to the heated 100 C 373 K 6 mm Teflon tube by an GL Teflon screwing Semadeni Laboratory fitting HAT PTFE PPS GL14 4686 connector GL14 PTFE 4897 1 4 Furnace The required heat for the reactor is generated by a furnace The furnace temperature is automatically controlled by a temperature regulator Fig 4 Detailed information can be obtained from the controller manual which is attached to the equipment Actual value h min s C lt 4 Dimension display Set value Parameter Display Channel selection Up key l Set value key Display Timer controll A Figure 4 Eurotherm controller Down key Parameter key Attention Before starting the controller one must fix the thermocouple in the furnace Otherwise uncontrolled overheating and massive damage could occur The thermocouple must be tested before starting an experiment and it must be replaced 1f necessary 1 5 Inlet system The used inlet system for SiCl is illustrated in Figure 4 no 5 The hoses a b c Perfusor hoses Braun 150 cm Luer lock 872296 0 are made of PVC Hose a is connected to an SiCl4 storage vessel hose b is attached to a syringe which is controlled by an injection plunger Both hoses have direct contact with SiCl and have to be replaced at the end of each experiment Hose c contains argo
6. e The gas leaving the reactor is heated to 100 C 373 K With the valves TH1 TH3 the flow can either be passed through two cryo traps or bypassed To condensate the silicon tetrachloride in the reaction mixture the two cryo traps route is used The two cryo traps are cooled with dry ice and isopropyl alcohol to 77 C 196K The consumption of silicon tetrachloride is calculated by the amount of generated HCl see eq 1 After the reaction the gas is analysed by an digital titrator with sodium hydroxide solution 0 1 M However to assure trapping all the trace gases the exhaust gas flow is controlled through a containment filled with water SiCl 2H O gt 4HCI SiO eq 1 Fluidization The reactant gas can be used for cold flow experiment in the fluidized bed The gases are fed bottom up flowing through the packing and fluidizing the particles These experiments are done at room temperature and in the absence of SiCl4 The states of the fluidization are recorded by a digital camera To proof a stable fluidization a differential pressure gauge is applied and the data is collected by a PC Above the fluidized bed is an expansion zone which should avoid the discharge of the particles In order to filter traces of particles the exhaustion gas is discharged in a beaker filled with water 3 Components The components and their position in the equipment are shown in Figure 2 Additional informations can be found
7. e different heating zones Figure 7 Controller panel for different heating zones left not in use middle before the reactor right after the reactor All non SiCl containing tubes are heated to 100 C 373 K to avoid adsorption of SiCl and or HC at the inner tube walls At this time the left controller is not in use but an additional heating zone for the fluidized bed reactor or an indicator for the cooling bath could be attached The actual usage of the heating zones is written under each of the Biirkert controllers Detailed information can be obtained from the Biirkert controller manual which is attached to the equipment 5 Cooling bath Figure 8 Cooling bath with two cryo traps The SiCl gas flows into the cooling bath which is frozen out in one ore two cryo traps d right after its arrival These traps are connected to the Teflon tubes by GL connector novodirect Teflon GL 14 4897 Tube a is connected to the reactor and tube b connects to the digital titrator Both cryo traps are in line and connected with a short Teflon tube and GL connectors The cryo traps are put in an isopropyl alcohol dry ice mixture 77 C 196 K Dewar It is important to note that at this time no connected tubes can be placed in the water due to the low pressure which exist in the system 6 Massflow controller The massflow controllers are from Mattig type Bronkhorst and from Brooks The adjustment rang
8. e for the described equipment is listed in the following e MFC 1 for Argon V 0 400 ml min e MFC 1 for 1000 ppm oxygen in helium V 0 400 ml min e MFC 2 for Argon V 0 50 ml min e MFC 3 for Argon V 0 3500 ml min Par faz Ges fae w 100 109 9 f 8p a A WE E W 40 x 2 0 oo 00 u o 0 ji oo fours ours fours oo Gore o fours 10 100 10 8 10 8 10 8 100 a t a w a u 6 6 2 B ap a a 40D a 29 2 37 207 D 0 9 00 9 09 zoo Eue Rame Re RANE t oo i 100 7 ORS GE Asua OK GO Fan pane S rP_oan_name 45 me Figure 9 User interface of the PC Program for MFC s and differential pressure gauge The PC Program for mass flow controllers differential pressure gauge and data acquisition is shown in Figure 9 The program is divided in three main parts A set values output B calibrated value input C graphic visualisation and data acquisition The calibrated value is entered as percentage of the maximal flow in section B either manually 4 or by setting a slide 3 As an alternative a slope can be entered 7 In this case EN is the final value and min 1s the slope velocity The set value is shown in section A The graph on the screen could show the set and calibrated values The name of the file is at free choice 2 and can be chosen under the name the acquisition frequency in respect to the
9. en 0201 7204846 28
10. flow have to be controlled all the time The pressure of the gas bottles have to be controlled continuous At a sudden pressure drop the connection must be checked and if needed the gas bottles have to be closed and the experiment must be stopped The controlling PC and the titrator are not in the aspirator separated from the equipment Electric wires thermo couples and the furnace have to be controlled continuous and repaired or replaced if necessary 7 Measures in case of an emergency If a fault occurs despite safety precautions the standard shut down procedure must be initialised Furthermore all heating bands must be switched off At the first sign of disintegration or chemical permeability the protection gloves must be taken of and renewed Small amounts of slopped liquids can be dilute with plenty water and be flushed away Emergency and eye washes are installed in the neighbouring room NC 05 487 8 Used chemicals and their material properties Silica tetrachloride from Aldrich SiCl R 14 35 37 e Reacts violently with water e Causes severe burns e Irritating to respiratory system S 7 9 26 36 37 39 45 e Keep container tightly closed and in a well ventilated place e In case of contact with eyes rinse immediately with plenty of water and seek medical advice e Wear suitable protective clothing gloves and eye face protection e In case of accident or if you feel unwell seek medical advice immediately sh
11. ion pH 10 boric acid sodium chloride sodium hydroxide from Riedel de Haen R 36 37 38 e Irritating to eyes respiratory system and skin S 26 37 39 e Incase of contact with eyes rinse immediately with plenty of water and seek medical advice e Wear suitable gloves and eye face protection At the work buffer solution pH 10 with nitril protection gloves can be used The use of goggles is a must Silica wool Roth A dusk mask and protection gloves should be worn when working with silica wool Sodium hydroxide solid from J T Baker Sodium dye 0 1 mol l R 35 e Causes severe burns S 26 37 39 45 e Incase of contact with eyes rinse immediately with plenty of water and seek medical advice e Wear suitable gloves and eye face protection e In case of accident or if you feel unwell seek medical advice immediately show the label where possible Titandioxid P25 from Degussa R sD e Avoid contact with eyes A dusk mask and protection gloves should be worn as prevention when working with titan dioxide 9 Material specified operation instructions All the safety instructions are for the chemical in room 488 NBCF 05 south The university wide emergency number is 3333 In the cause of questions please contact one of the operators Dr Simone Geisler Raum 689 NBCF 04 Sud Tel 22341 Tanneneck 1a 45525 Hattingen 02324 28257 Dipl Ing Ralf BergstraBer NBCF 04 Sud Tel 22341 Adelkampsir 5 45147 Ess
12. itate the eyes respiratory organ and the skin and they can generate severe corrosion All bases react with acids fierce and exothermic also they generate heat by diluting them with water All bases and acids react corrosive Bases amplify vasculars and penetrate deep inside the tissue Never neutralize corrosion of bases with acids and vice versa 6 Procedure to minimize risks The receiver must be cooled with ice water when working with SiCl and or NaOH SiC is only allowed to be stored under the aspirator Concentrated Acids are only allowed to handle under the aspirator Gas smoke steam aerosol of acids and bases must never be inhalated Because of the risks mentioned above the equipment is installed in the aspirator When working with SiCly Neopren or Nitril protection gloves can provide a short time splash guard If needed a protection apron must be worn The following materials for protection gloved are not adequate Naturkautschuk Naturlatex NR Polychloropren Ck Butylkautschuk Butyl Polyvinylchlorid PVC Adequate protection gloves for the directed exposion with NaOH is Neopren Latex as a short time splash guard Nitril can be used Goggles must be worn at the work with SiCl4 HCl NaOH When working with fines T102 a dust musk must be worn The general safety rules in the laboratory have to be attended A leak test must be run before starting the experimental work All volume flows specially the SiCl
13. ment is conducted at room temperature A differential pressure gauge is connected to the fluidized bed reactor in order to measure pressure drop in the bed however in order to avoid corrosion no SiCl is used In the case of heating The maximum allowable temperature is 250 C 523 K The states of the fluidization are registered by a digital camera To proof a stable fluidization a differential pressure gauge MKS Baratron type 223BD 00100AAB SP is applied and the data is collected by a PC further information at the description of the computer program for the Massflow controllers 3 Injection plunger The injection plunger measures and controls the amount of SiCl which enters the reactor Figure 6 After filling the syringe with SiCl see also chapter 1 5 the syringe is fixed a The ON OFF switch is at the rear right corner b Figure 6 Injection plunger The menu can be selected by pressing the keys gt and SELECT d Numeric parameters are entered with the numeric pad c and confirmed with ENTER c You have to pay attention to enter the numbers with 3 decimal places e g 0 500 To start or stop the program use RUN STOP bottom To draw or inject the SiCl quickly push RUN STOP and or gt simultaneously All informations are shown in the display f Detailed information can be obtained from the controller manual which is attached to the equipment 4 Heating band The temperature controller has thre
14. n MFC 2 The three hoses are connected by two c e T valves novodirect Polycarbonat N13317 N13324 The first step is filling the syringe Argon is given in the reactor e open to d g closed to c and the syringe is filled via the storage vessel c open in all directions The syringe is filled and emptied until no longer bubbles are visible in the valves and hoses as a general rule 3 4 times The storage valve is cut of a and the syringe is fixed in the injection plunger see also chapter 3 3 and the experiment starts The argon flow is switched off and the valves b and g get connected After the experiment the whole system is purged through with argon The SiCl containing materials which are in directly contact the reactor g runs high reaction temperature The materials made of PVC are not stable at temperatures above 200 C 373 K and stainless steel tubes would corrode However Teflon can be used up to a reaction temperature of 350 C 573 K but you have to pay attention that the end of the Teflon hose is outside of the reactor because it 1s limited to 200 C 473 K At higher temperatures a very thin silica capillary can be used The capillary must be handled with care because of breakage The transition from soft Luer lock valves to hard Teflon tube or silica capillary is complicated First a Tefzel adapter novodirect N24630 or N24814 and second an Omnifi
15. ow the label where possible The equipment is installed in an aspirator because auf the risks mentioned above When working with SiCly Neopren or Nitril protection gloves can provide a short time splash guard If needed a protection apron must be worn The following materials for protection gloved are not adequate Naturkautschuk Naturlatex NR Polychloropren CR Butylkautschuk Butyl Polyvinylchlorid PVC At the first sign of disintegration or chemical permeability the protection gloves must be taken of and renewed Small amounts of slopped liquids can be dilute with plenty water and be flushed away An exposure can cause skin irritation especially when the skin is wet Severe irritation of the respiratory organ or intestinal tract are generally possible Medical aid must be accomplished after inhalation The person must be brought to fresh air and be supported with oxygen if needed Exposed skin must be flushed with water for at least 15 min Contaminated cloth and shoes must be put of and in the last step the irritated skin can be swabbed with Polyethylenglykol 400 In the cause of swallowing never induce vomiting Directly contact a doctor and give the person a lot of water or milk to drink In cause of an exposure to the eyes hold up the eyelid and flush with water for at least 15 min A doctor must be consulted directly Buffer Solution pH 7 di sodium hydrogenphosphate kalium hydrogenphosphat from J T Baker Buffer Solut
16. rmation can be extracted from the attached user manual of the titrator 4 The start up procedure for CVD The chosen reactor is filled with oxide and than heated up to Tmax 450 C 723 K in a stream of inert gases to remove adsorbents The reaction temperature is set and the CVD with SiC is accomplished see also chapter 3 1 Different parameters such as time and or volume can be chosen A variety of samples get hydrolysed with water Ar H2O at the reaction temperature All samples are calcined at the end of an experiment by air or argon Table 2 2 Flow sheet of a CVD experiment 1 Weigh the P25 2 Fill the reactor a ca cm quartz wool b Fill the reactor with the weighted amount of P25 c Close the reactor with the septum including the thermo couple capillary and the inlet tubes for SiCl and inert gas 3 Installation of the reactor a Connect inert gas swagelok b Connect syringe luer lok c Close connection at the bottom 4 Adjust inert gas flow 5 Control leakage 6 Heat up the tubes by setting the heating zones to 100 C 373 K All the tubes which get in contact with water in the previous experiment must be heated with a hot air unit or heating bands 7 Start the temperature program for the furnace 8 During the heat up a Calibrate the electrode pH 7 and pH 10 b Fill the syringe and install it in the syringe plunger check for bubbles and fill SiCl up to the T valve which is directly connected to the reac
17. t low pressure fitting made of Teflon novodirect N24600 is used In order to avoid breakage and leakage of the system all SiCly hoses and the thermo couple containing silica capillary are fixed with tape To minimize condensation and adsorption at the inner wall all non SiCl containing tubes and hoses such as gas supply and the tubes to the analytic are heated to 100 C 373 K 2 Fluidized bed reactor Figure 5 Fluidized bed reactor A second core part of the system is the fluidized bed reactor Figure 5 The reactor 3 1s made of Duran glass The inflow gas could either pass through the CVD part or bypassed Currently the fluidized bed reactor is not heated However by inserting the fluidized bed reactor inside the CVD set up the reactor could be heated The reactant gases flowing from the bottom 6 of the reactor in order to fluidize the bed The gas tubes at the bottom of the reactor are connected to MFC 1 and or MFC 3 by Teflon tubes 5 Swaglok SS 6MO 6 4 grind 6 mm tube To examine the precise dimension of the reactor for fluidization there is an extended reactor 2 that could be connected to the original fluidized bed reactor to test higher beds An expansion zone above the fluidized bed decreases the gas velocity to separate the particles from the gas A Teflon tube from the expansion zone is connected to a beaker filled with water to wash out fines The argon is exhausted in to the hood Currently the experi
18. tor c Prepare the dry ice isopropyl alcohol quenching bath 9 At the end of the heating install the cryo traps Be aware that no attached tube is in contact with water exhaustion gas and analytic 10 Set the reaction temperature 11 Analytic a Fill the vessel 35 ml H20 b Close the connections c Check leakage d Start the analytic method at least 6 h 12 Stop the upside inert gas stream and add the SiCl gas flow 13 After finishing the addition flush all SiCly containig tubes and hoses with a low flow inert gas stream 14 Flow the inert gas stream through the saturator and be aware that the cryo traps are bypassed Restart the analytic method 15 Dry out and calcine 1 1 5h 3 3 5h 0 5 h 2 4h gt 1h Over night 1 2h The SiCl which did not react is frozen out in the cryo traps and the generated HCl is neutralized with a sodium hydroxide solution 0 1M The pH value is kept constant and the needed volume of NaOH used in the neutralization is registered The data can be obtained via PC Stop the experiment The heater must be shut off and the reactor must be reached to room temperature by a stream of inert gas Silicon tetrachloride is hydrolysed by NaOH at the end of an experiment An ice bath is used to cool the system All parts which are in direct contact of SiCl must be cleaned accurately and if it is necessary they must be replaced 5 Potential risks SiCl4 and HCI react fierce with water They irr
19. wire The titration syringe is connected to the front side valve 6 and the NaOH storage 4 is connected to the backside valve 6 If all connections are linked and controlled the titrator can be switched ON The electrode is calibrated by buffer solution with pH 4 and pH 7 press cal on the keypad 2 The titrator has different programs To start a program press start at the key pad and enter a name Press enter to confirm the name and to start the titration To obtain the data one could save the data on a PC 5 or print it directly Further information can be obtained from the controller manual which is attached to the equipment To transfer the data to a PC the program ARDTest exe must be started It is important to note that the program must be started before choosing the method and calibrate Test Serial Port Access Ea Select a com port 1001 _ Befehl senden Figure 13 User interface of the PC program ARDTest exe To ensure transfer of data between titrator and PC Port 2 1 and channel 12 Adresse 12 must be chosen To test the connection you can select Report Hardware 4 In the lower panel 2 a short string of data is displayed and the name TitroLine alpha must be visible To start the data collection the command RH must be entered 5 The collection of data is stopped by pressing the OK button The file can be imported in any editing programs Further info
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