Operators Manual - Wolf Laboratories
Contents
1. T400 Mobile Fume Cabinet Operators Manual CONTROL PANEL THE FUME CUPBOARD IS FITTED WITH THE FOLLOWING INSTRUMENTATION AND CONTROLS 1 Mains on off rocker switch Green Illuminated 2 Light switch 3 Operating hours display counter 4 Low airflow alarm The unit is started by switching on the mains rocker switch and the light switch The low airflow alarm warning light will indicate an alarm for a few seconds until the fan has reached it s normal operating speed If the warning light is flickering or remains on constantly this can indicate the filters require attention possibly the alarm needs re LABCAIRE 400 Schools Model calibrating see section 6 on maintenance The saturation of the filter and the airflow must be checked at routine intervals see monitoring ae che ee rere EN E 7400 Mobile Fume Cabinet Operators Manual Z E OPERATION AND SAFE USE SITING OF FUME CUPBOARD The siting of the fume cupboard is important and since this model is mobile it should be checked in all potential locations of use A safe siting is A Away from any cross draughts from doors open windows ventilation outlets etc B gt Not adjacent to side walls and not within a wall 2m from the front of the cabinet C Not impeding any fire safety exit points2. Pure Science Pure Life T400 Mobile Fume Cabinet For use in Schools and Colleges Operators Manual Issue 04 August 2010 Puricore International Ltd 175 Kenn Road Clevedon North Somerset BS21 6LH Tel 44 1275 793000 Fax 44 1275 341313 labcaire puricore com www puricore com Registered in England No 2695450 Q ALITY MANAGEMENT 001 Certificate No 0954499 CE Marking certifies that this equipment conforms to the following EEC directives Low Voltage Equipment 72 23 8 93 68 EEC Electromagnetic Compatibility 89 336 CONTENTS INTRODUCTION EE 4 PRINCIPLES OF OFERATION EE 5 SPECIFICATION WEEN 6 at ei EEN D EE eege D 8 EH PANEG T 8 OPERATION AND SAFE USE NENNEN 9 sinn eor Fume Tt seo Us oos oer qnas dn Nd ec a tite P dA RN MM Eee rM 9 le E ele upper er 9 PRECAUTIONS DURING 10 ciu Ee EE 10 BU E 11 Particulate Pre EE 11 MAIN ACTIVATED CARBON FILTER geet 11 FILTER REMOVAL AND FITTING esessesssssesessessesseesessessesoesossoesossossossoesossossessossessesoesseseees 13 FITEING THE EE 13 DATE UPINSTAELA TION erore I PIN 14 FILTER PART NO sesinin EEEE 14 MARTOR LEE 15 Instructions for face veloc
3. sa MATERIAL FINISH ILABCAIRE eT A PRIVATE amp CONFIDENTIAL TITLE T400 DRAWN G B DATE 09 10 99 CHECKED DIMENSIONS IN mm SCALE N A PRODUCTION ISSUE BRA ING 1 5 Rd Clevedon Somerset 8527 GLA UR Zeil 01279 793000 Fav 012372 3541313 T400 Mobile Fume Cabinet Operators Manual OPTIONAL SERVICES The work surface will be fitted with a moulded drip cup and a services module will be fitted on the right hand side of the unit The service will comprise of 1 A gas supply through a remote valve on the front of the module which connects to a Gas Board approved quick release connector Service connector required is a 1 8 NPTF Male outlet 2 A water supply through a remote valve on the front of the service module The water hose is fitted with a quick release sealed connector Service connector required is a 1 4 BSP male thread water outlet 3 The waste service is through a 1 5 Vulcathene flexible hose which requires a 1 5 BSP female thread drain point A sealing cap is required when the drain is not in use A waste trap should be installed downstream of the connection point The services outlet from the module is from the rear right hand side and the hoses can be stored inside the module when not in use Extra fittings are available for use in several locations 32 Labcaire T400 LS Mobile Fume Cabinet ILABCAIRE JS DRAWING
4. CHECK ELECTRICAL CIRCUIT AND COMPONENTS 1 Unit will not switch on fan or lighting circuit CHECK a Main fuse in plug and that electricity is turned on at the mains switch b Circuit breaker in Head unit C Condition of mains inlet cable 2 Lighting Fault on one or both lights CHECK a Circuit breaker by mains inlet cable b Starter switches inside Head unit access is via top cover C Replace fluorescent tube starter inside the Head unit 3 Fan off but Lights on CHECK a Circuit breakers on Head unit by mains inlet cable b SWITCH OFF Allow unit to cool if warm and restart If fan now starts then the thermal overload in the fan has been tripped C Failure of fan or fan capacitor contact LABCAIRE for replacement items 4 Low Airflow Alarm a Warning light does not illuminate briefly at start up CHECK a Calibration b Indicator Lamp 27 7400 Mobile Fume Cabinet Operators Manual d t b Warning light does not go off after start up CHECK a Filter seals b Fan Failure C Calibration c Warning light comes on goes off and then comes on and flickers after start up CHECK a Condition of particulate pre filter replace if required b Calibration of pressure switches 5 Filter Saturation Alarm if fitted See Optional Services Warning light on a Reduce stop chemical challenge b Replace main filter Check filter seal after fitting new filter d Recali
5. No 25900 5 75mm diameter x 20mm or Cat No R25902 9 93mm diameter x 25mm Use either a Gastec Precision Pump with a trichloroethylene tube 132L low range 1 50 ppm or a Draeger Gas Detection Pump with a trichloroethylene tube 2 a 2 200 ppm This assumes that the efficiency of the filter has dropped to 9690 for organo halogens at this level the fume cupboard will still not emit a dangerous level of any organic vapour a school is likely to use in a normal sized laboratory 25 7400 Mobile Fume Cabinet Operators Manual 7 d SERVICING Whilst schools can carry out their own monitoring an annual service by a Labcaire engineer is recommended and will cover the following points Airflow check with new pre filter fitted Filter condition check by chemical testing Re calibration of the low airflow alarm Inspection of electrical components lighting cables etc Earth bonding of electrical components Cleaning and checking the condition of the glazing hinges castors etc Issuing of a test report complete with an airflow certificate Examination of services if fitted The gas supply line must be checked carefully for leaks and damage LABCAIRE have a national team of service engineers who can offer a comprehensive service at very competitive rates on all types of equipment from air purifiers to clean rooms 26 7400 Mobile Fume Cabinet Operators Manual d E FAULT FINDING WARNING 240V ONLY QUALIFIED PERSONNEL TO
6. No MFE 080 ISSUE D 3m LONG FLEXIBLE GAS HOSE 22000 FITTED WITH SELF SEALING QUICK RELEASE COUPLINGS SUPPLIED WITH CABINET 3m LONG FLEXIBLE COLD WATER HOSE 21102 FITTED WITH SELF SEALING QUICK RELEASE COUPLINGS SUPPLIED WITH CABINET STAINLESS STEEL WIRE TETHER OPTIONAL WITH CABINET TETHER WALL PLATE OPTIONAL WITH CABINET POSITION ADJACENT TO GAS OUTLET GAS AND WATER SUPPLY TO TERMINATE ON WALL WITH 1 4 BSP MALE THREAD TO ACCEPT SELF SEALING QUICK RELEASE COUPLING CONNECTOR SUPPLIED WITH CABINET WALL PLATE ELBOWS TO ENSURE THAT PIPE IS HELD SECURELY CUSTOMER SUPPLY a set e IT SUITABLE ISOLATION VALVES GAS AND WATER SUPPLY Z it CUSTOMER SUPPLY 300mm RECOMENDED DRAIN HEIGHT TYPICAL VULCATHENE DRAIN ARRANGMENT CUSTOMER TO SUPPLY COMPRISING 38mm VULCATHENE PIPE MAXIMUM DISTANCE 38mm RUNNING TRAP is WALL 2 METRES e 38mm W18 SERIES 925 BEND 38mm W24 SERIES BLANKING OFF PLUG 38mm PIPE CLAMPS AS REQUIRED 0 WASTE HOSE BLANKING PLUG COMPRISING 2m LONG FLEXIBLE WASTE HOSE ASSEMBLY 211001 W161 COUPLER 21008 amp W241 PLUG 21009 SUPPLIED WITH CABINET TERMINATED WITH TO BE INSERTED WHEN CABINET IS NOT CONECTED W141 SERIES 38mm 14 BSP ADAPTOR 21007 TO ALLOW TO PREVENT SPILLAGE OF LIQUID IN HOSE CONECTION TO 11 BSP FEMALE SOCKET OR ANY LABCAIRE SUPPLIED WITH CABINET For Tomorrow s Environment 175 Kenn Road Clevedon Nort
7. SASH ARRANGEMENT To meet the recommendations of Design Note 29 and to ensure safety hazardous gases or vapors should not be released in this cupboard unless the flaps are down Flaps should only be lifted to install apparatus or for cleaning 7400 Mobile Fume Cabinet Operators Manual bl d PRECAUTIONS DURING OPERATION A Remove unwanted apparatus etc from the fume cupboard B Switch cabinet on and verify ventilation system is functioning C Prior to release of hazardous gases or vapours far as possible install apparatus and check service connections for leaks etc D Wear eye protection whilst using the cabinet E Ensure flaps are fully down before releasing hazardous vapours or gases F A Bunsen Burner should not be placed within 150mm of the sides or back of the cabinet and the flame kept below 100mm high G The operator should move their arms carefully so as not to draw fumes out of the cabinet The fume cupboard is designed for normal experimental release rates and should not be used for boiling off large quantities of acids or solvents Please consult Labcaire before using cabinet outside normal schools curriculum J The cabinet should not be switched off at the end of an experiment until the cabinet has purged itself of fumes SPILLAGES opillages should be mopped up immediately with absorbent granules NOTE Absorbent cloths should not be used as they can increase the evaporation rate of Solve
8. burner two gauze squares both with ceramic circular centres a tripod a heat proof mat and a ruler Wear eye protection Sulphur dioxide is a toxic gas so not breathe 1 Powder roll sulphur in a mortar with a pestle 2 Fill a porcelain flat bottom evaporating basin with the sulphur so that it is with the rim Weigh the porcelain basin the sulphur and of the gauzes 20 7400 Mobile Fume Cabinet Operators Manual wm 4 Set the Bunsen burner tripod the other gauze the evaporating basin heat proof mat so that the centre of the basin is 5 cm inside the upper rim of the aperture This places the sulphur in the maximum incoming draught and encourages complete combustion 5 Switch on the fume cupboard 6 Light the Bunsen burner with the gas tap half open and the collar open enough so that the flame is non luminous The incoming draught may require you to place the burner a little more forward than under the centre of the basin Figure 5 2 7 The sulphur melts slowly to a pale amber liquid Extreme care is now required not to knock the tripod base with your hands or the Bunsen burner molten sulphur can Cause severe burns Remove the Bunsen burner from under the gauze and adjust the collar so that it is half open Place it back under the gauze very carefully The liquid will quickly darken Changes in the appearance of the liquid surface indicate that burning is about to
9. start Sulphur catches light with a blue flame 8 Start the stop clock when half of the surface of sulphur has caught alight Immediately turn off the Bunsen burner at the gas tap The flame above the sulphur has two coloured areas the inner brown flame of incomplete combustion and the outer flame of complete combustion Extinguishing the Bunsen burner causes the area of brown flame to diminish leaving the blue flame 9 After 60 seconds take a reading of the concentration of the sulphur dioxide being emitted through the exhaust with a gas detection kit A slight smell of sulphur dioxide should be ignored but if the exhaust gas causes breathing difficulties stop the test 10 Place the other gauze which was used in the weighing on top of the basin and stop the clock noting the time seconds The gauze puts out the flame but some sulphur condenses onto it which is why it should be included in the weighing 11 When the sulphur has cooled down for about 20 minutes and solidified reweigh the basin the remaining sulphur and the gauze M 2 g The sulphur and dish may be kept and used the next time the test is carried out A Little more powered roll sulphur may need to be added to make up for any lost in the previous burning Calculation M4 M2 x 750 Rate of release of sulphur dioxide cm s Now check your results with Table 21 1400 Mobile Fume Cabinet Operators Manual wm E TEST FOR SATURATION
10. 2 locking front castors The work surface is manufactured from fibreglass with integral moulded sink if water services are specified Face Velocity gt 0 4 m sec min Lighting gt 700 Lux at work surface Noise lt 55 Volume Air Flow gt 350 m HR Aperture Size Average width 700mm Average height 400mm to work surface 7400 Mobile Fume Cabinet Operators Manual 7 d INSTALLATION The machine will be supplied ready assembled and with a correctly fused mains 3 pin plug fitted The filter and pre filter will be fitted into the unit at Labcaire Systems Plug Fuse is 5A The cabinet will be tested at Labcaire and a test certificate supplied Since damage could occur in transportation the cabinet filters should be checked before use i e the pre filter and main filter is in the correct position The cabinet should be checked before use for airflow and efficiency of filter seal SERVICES OPTIONAL If the cabinet is ordered with gas and water services the hoses will be stored inside the services module accessed through the panel on the right hand side The services are connected using the quick release fittings
11. BY ORGANIC GASES Method using trichloroethylene in normal school use a filter is most likely to saturate with acid gases long before It saturates with organic vapours this test has only a limited use It is an alternative test for seeing whether a filter is properly seated and the seals round it are effective The rate of release of trichloroethylene vapour is calculated by weighing a vessel containing trichloroethylene liquid before and after it has been boiled for a measured time Items required are a gas detection kit trichloroethylene anti bumping granules a balance weighing to 0 1 g or less a stop clock a 100ml conical flask with a bung about 25ml of cold water in a 250ml beaker a Bunsen burner tripod and gauze square A hot plate is a suitable alternative NOTE Trichloroethylene is classified as HARMFUL and possibly has carcinogenic effects but there is inadequate evidence for a satisfactory assessment 1 Pour about 25ml of trichloroethylene into the conical flask add a few anti bumping granules attach the bung and find the overall mass 2 oet up the Bunsen burner tripod and gauze in the fume cupboard and light the gas Switch on the fume cupboard remove the bung from the flask and place the flask on the gauze 3 As the trichloroethylene begins to boil the vapour condenses on the cooler parts of the flask forming a boundary line When the boundary reaches the top of the flask start the stop cl
12. Clevedon North Somerset BS21 6LH England UK 01275 793000 UK Fax 01275 341313 INT Tel 44 1275 793000 INT Fax 44 1275 341313 E mail labcaire puricore com Pure Science Pure Life Website http www puricore com LABCAIRE ji For fame T400 Mobile Fume Cabinet Operators Manual August 2010 Issue 04
13. ase contact Labcaire for details of the contracts available The notes below are for the benefit of customers who wish to do their own A rotating vane airflow meter with vane diameter between 60 and 100mm and with a facility for averaging readings over periods of 10 seconds is suitable unidirectional hot wire airflow meter with the same facility is also suitable but is more expensive A gas detection kit consists of a disposable tube used with a special hand pump which pump which draws a measured volume of air through the tube The length of the colour change within the tube indicates the concentration of the gas tested This equipment is available from Labcaire 15 7400 Mobile Fume Cabinet Operators Manual d t INSTRUCTIONS FOR FACE VELOCITY MEASUREMENTS Procedure 1 Imagine the face of the fume cupboard divided into nine cells otand as far as practicable from the fume cupboard with the sensing head in the plane of the sash and take airflow readings at approximately the centres of the nine cells 2 Record for each cell the approximate average reading over a period of at least ten seconds applying any correction from the calibration chart See form on Page 22 3 Look at the table and repeat any reading which seems to be very different from the general pattern Record the average of this and the previous reading Calculation Minimum face velocity Record which of a b c d e f g h i is the smallest i e record the minimum face
14. brate alarm contact Labcaire for assistance 28 T400 Mobile Fume Cabinet Operators Manual d WARNING Removal of the right hand side panel will expose electrical contacts Disconnect electrical supply before opening 1 FILTERS Particulate pre filter This filter will need changing if the airflow drops below 0 3 m sec The low airflow alarm will indicate when changing is required 2 CARBON FILTER The carbon filter will need testing every 14 months and after a major spillage has occurred which may have saturated the filter please see section on monitoring and section on Filters 3 LIGHTING The starters and tubes are accessible through the access panel on top of the unit The unit MUST be disconnected from the mains before opening the panel The lights are protected by a circuit breaker 4 LOW AIRFLOW ALARM Two pressure switches are fitted between the fan and filter to detect too low or too high a vacuum The low vacuum switch indicates that there is a lower than normal pressure and can be due to fan failure or the filters not sealing During use the pre filter will gradually block and this will increase the vacuum in the plenum chamber When the vacuum reaches a pre determined level the red indicator will be illuminated CALIBRATION OF AIRFLOW ALARM a Insert new particulate pre filter into the cabinet b Switch on and leave for a few moments to allow airflow to stabilise Remove the righ
15. f the sulphur dioxide canister M2 9 Calculation x 750 Rate of release of sulphur dioxide cms s Now check your results with Table Filter efficiency Compare your value of the rate with the concentration of sulphur dioxide in the exhaust gas If the concentration of sulphur dioxide is greater than the value in the table then a new filter is required 19 7400 Mobile Fume Cabinet Operators Manual d t SAFE FILTER EFFICIENCIES FOR SULPHUR DIOXIDE Rate of Sulphur Dioxide Released Maximum Permitted concentration of sulphur dioxide in the exhaust Method using burning sulphur The centre of the porcelain dish is situated 5 cm from upper rim of the opening 5 cm Fume cupboard opening This method can be used if sulphur dioxide in a small cartridge or cylinder which can be weighed cannot be obtained at a reasonable price The rate of release of sulphur dioxide is calculated by weighing the vessel containing the sulphur before and after it has burned for a measured time It is satisfactory provided a the Bunsen burner is turned off once the burning of sulphur starts and b the apparatus is sited as far forward in the fume cupboard as possible as shown in Figure 5 2 to obtain complete combustion The items required are powdered roll sulphur 1150 200grm a balance weighing to 0 1 g or less a flat bottom porcelain evaporating basin a gas detection kit for Sulphur Dioxide a stop clock a Bunsen
16. filters are easily accessed from the front of the base section by turning the catches through 180 degrees The filter can be slid out ready for disposal and can be changed in the school laboratory CAUTION a Used filters should only be handled when wearing rubber gloves b Used filters should be sealed inside a polythene bag for disposal by incineration or with your normal laboratory non hazardous waste c The carbon filter is high capacity and heavy 22kg it is recommended that two people fit the filter FITTING THE FILTER The main filter should be removed from the polythene wrapping and after checking the filter identity Labcaire part No LA 3416 slide back into the locating frame Care should be taken that the filter seal is in a good condition prior to assembly and that no damage occurs to this seal during the assembly process The filter seal MUST be on the bottom face of the filter for assembly purposes It is important that the filter is shaken from side to side in the horizontal plane filter seal underneath before fitting This will equalise the carbon granules in the filter Silicone grease on the seal face will help assembly and sealing The pre filter Labcaire part No LA 3413 is placed into the locating frame and placed on top of the carbon filter The pre filter will require replacement more frequently than the main carbon filter 13 7400 Mobile Fume Cabinet Operators Manual m t DATE OF INSTALLATION Rec
17. h Somerset BS21 6LH Tel 01275 793000 Fax 01275 341313 e mail info labcaire co uk MOD C 29 09 98 1 4 BSP WAS 3 8 BSP W161 COUPLER ADDED LABCAIRE PART NOS ADDED MOD D 1 6 99 TETHER AND TETHER WALL PLATE ADDED 500mm MAXIMUM DELETED FROM DRAIN HEIGHT 38mm VULCATHENE FITTING NOTE WHEN IN USE POSITION FUME CUPBOARD SO THAT THE DRAIN HOSE HAS A CONSTANT FALL TO DRAIN T400 080 DRG 7400 Mobile Fume Cabinet Operators Manual Ml J OPTIONAL FILTER SATURATION ALARM DESCRIPTION The sensor is situated to allow exhaust air from the fume cabinet to pass over the sensor The sensor will detect Hydrocarbons fumes passing through the filter and the signal after processing is displayed on the green LED if in normal condition The gas sensor is very responsive to hydrocarbon fumes and will indicate when the main carbon filter requires replacement The sensor is electrically heated and will take a short time to reach operating temperature During this period the alarm will be activated the audio may be muted at this time The signal will reduce to normal levels after approximately 60 seconds when the normal green LED s will illuminate The normal reasons for the alarm sounding are Excessive Challenge to the filters caused by evaporation of large quantities Hydrocarbons The filter is approaching end of its iii Leakage of fumes past the filter seals if the filter has not been fi
18. hose listed in Section 7 Filters have a high efficiency but because the nose is very sensitive the residual gases passing through the filter may sometimes be noticed even though their level is not hazardous However should they cause distress the operation should be finished and the filter saturation monitored During use the filters will absorb chemicals and particulates and the cabinet must be inspected at least every 14 months to ensure it is operating satisfactorily and to comply with C O S H H regulations Control of Substances Hazardous to Health A low airflow alarm is fitted to indicate when the pre filter requires changing Please keep this manual in an accessible but secure place Further copies are available from Labcaire if required T400 Mobile Fume Cabinet Operators Manual ME ce amp W PRINCIPLES OF OPERATION The fan draws air through the front of the cabinet and the slots at the lower middle and top of the cabinet ensure fumes lighter or heavier than air are drawn down through the filters The design of the baffle panel ensures that pockets of gas cannot build up inside the cabinet The ED Filter must be fitted Labcaire part No LA 3416 7400 Mobile Fume Cabinet Operators Manual d E SPECIFICATION The cabinet is constructed of Zintec coated steel epoxy powder coated for maximum corrosion protection All glazing is in 6mm clear acrylic with polished edges The unit is mobile with
19. ity measurements NEE 16 Tests Tor saturation DV acid 48 EE 18 Setting the rate of flow of sulphur dioxide 19 TestTor saturation by organic gases 22 tm e S 26 WEE 27 Oe at fois le EE 28 al 29 CARBON FILTER 29 ee cer SS 29 LOW AIRFLOW ALARM e rU TEN 29 CALIBRATION OF AIRFLOW AL ARM 29 X REI UT P TTE EUN 30 T400 ELECTRICAL WIRING 31 OPTIONAL SERVICES ence canneries se cet FE GUI 32 OPTIONAL FILTER SATURATION 34 DESCRIFTIDN KEE 34 Cor 35 foe BEE 35 0 EE 35 T400 Mobile Fume Cabinet Operators Manual INTRODUCTION The Labcaire T300D T400D is a recirculatory fume cabinet which has been designed for use in Educational Establishments and requires no connection to ducting The cabinet has clear glazing all round and when fitted with the particulate pre filter Activated Carbon fume filter and used with the door in the CLOSED position conforms to the requirements of DFE Design Note 29 and BB88 The cabinet will satisfactorily absorb the substances released in normal education activities up to A Level namely t
20. mounts eg emitted from a test tube then there is sufficient dilution by the incoming air to render the exhaust gas relatively harmless 11 7400 Mobile Fume Cabinet Operators Manual should be noted that certain chemicals such as ammonia and Hydrogen Sulphide have a disagreeable odour at concentrations well below the O E S Occupational Exposure Standard The cabinet will be fitted with a Label detailing the chemicals in the Schools Curriculum INORGANIC aluminium chloride and bromide ammonia ammonium chloride fumes bromine chlorine chromium dichloride dioxide chromyl chloride hydrochloric acid vapour hydrogen chloride hydrogen sulphide iodine iodine chlorides lead fumes lead bromide fumes mercury and its compounds nitric acid vapour acidic nitrogen oxides phosphine phosphorus white phosphorus chlorides and bromides phosphorus oxides silicon tetrachloride sulphur chlorides sulphur dioxide thionyl chloride tin IV chloride titanium tetrachloride zinc chloride fumes ORGANIC acid amides acid anhydrides acid chlorides alcohols aldehydes aliphatic amines and their salts aliphatic hydrocarbons aromatic amines and aromatic hydrocarbons aromatic nitro compounds carboxylic acids esters ethers ketones nitriles organo halogens phenols pyridine Dusts etc dyes enzymes smoke 7400 Mobile Fume Cabinet Operators Manual d t FILTER REMOVAL AND FITTING The
21. nts The fiberglass tray is resistant to most chemicals but spillages should be quickly dealt with to avoid staining 10 T400 Mobile Fume Cabinet Operators Manual 7 d FILTERS The filtration system is mounted inside the cabinet underneath the work surface PARTICULATE PRE FILTER The particulate pre filter white fibrous cloth is mounted on top of the carbon filter and secured with a frame This filter removes dusts mists and smoke although the smallest particles below 0 5 micron will pass through The filter prevents these contaminants being recirculated back into the laboratory as well as preventing the main carbon filter from becoming blocked MAIN ACTIVATED CARBON FILTER The filter is of large capacity 22kg of carbon and will retain and absorb chemicals The formulation of the schools filter has been specially selected to give good absorption of the main chemicals in use in the schools curriculum and to give an extended filter life Typical Efficiency percentages for chemicals used in schools Ammonia 9990 Bromine 99 Carbon Tetrachloride 99 Chlorine 99 Ethanol 99 Ethoxyethane 99 Hydrochloric Acid 99 Hydrogen Sulphide 99 Methanal 99 Sulphur Dioxide 99 Sulphuric Acid 99 Trichloroethane 99 Trichloroethylene 99 Hydrogen methane carbon monoxide and nitrogen monoxide will not be absorbed by the Activated Carbon filter on account of their low molar mass However in schools and if produced in small a
22. ock 4 After 60 seconds take a reading of the concentration of trichloroethylene in the exhaust gas using a gas detection kit with a suitable tube 9 Turn off the Bunsen burner Place the conical flask Care necessary as the glass is hot into the beaker of cold water in the fume cupboard and replace the bung Stop the clock noting the time of the run t seconds 6 After 3 minutes remove the flask from the water dry the outside of the conical flask and find the mass of the flask contents and bung M2 9 22 7400 Mobile Fume Cabinet Operators Manual ul t Calculation Rate of release of trichloroethylene vapour lt 2 183 Now check your results with the table Filter efficiency Compare your value of the rate with the concentration of trichloroethylene vapour in the exhaust gas If the concentration of trichloroethylene vapour is greater than the value in the Table the filter is not properly seated or a new filter is required Safe filter efficiencies for trichloroethylene Rate of Sulphur Dioxide Maximum Permitted concentration Vapour Released of trichloroethylene in the exhaust 23 7400 Mobile Fume Cabinet Operators Manual E E Record form 14 monthly face velocity filter saturation and visual examination School College Location Of Fume Cupboard Airflow Meter Used Date Readings in the 9 cells at max aperture Avge Drop Do the Does a Any Initials m s m s gt 10 filters tes
23. ord the date of installation on the filter label for future reference The access panel can now be refitted using the 180 degree turn fasteners The filter should be checked with a chemical challenge before use Trichloroethane is suitable for this purpose with appropriate gas detection tube NOTE THE PANEL CANNOT BE REFITTED IF THE FILTER HAS NOT BEEN FULLY INSERTED FILTER PART Nos MAIN PRE FILTER T300 LA1816 LA1813 1400 LA3416 LA3413 14 1400 Mobile Fume Cabinet Operators Manual wm E MONITORING This fume cupboard is a portable appliance powered by mains electricity and must meet the requirements of the Electricity at Work Regulations 1989 As for other such appliances the correct fuse should be fitted to the mains plug and this and other exposed parts of the electrical system should be examined frequently for obvious damage There should be regular formal inspections including earth bonding and insulation testing It is a requirement of the COSHH Regulations that this fume cupboard should be monitored every 14 months In particular the face velocity and filter efficiency need checking The calibration of the airflow detectors should be checked If the fan motor is vibrating it requires attention from LABCAIRE If there are gas and water supplies these should be checked particularly the hoses and connectors so also should the drainage system Labcaire has a Service Department and can carry out the monitoring Ple
24. t deterioration or of from Last pass show damage Fail tester Year saturation flow if face velocity test inwards 0 3 m s LLLLLLLLECLLELELLLLELELLELE e IF ADROP OF MORE THAN 10 IS FOUND THE SYSTEM SHOULD BE INVESTIGATED UNTIL THE CAUSE IS CLEAR IF IT RESULTS IN THE MINIMUM FACE VELOCITY FALLING BELOW 0 3M S THEN THE FUME CUPBOARD SHOULD FAILED 2 I 7400 Mobile Fume Cabinet Operators Manual wm NOTES 1 Guidance is given the HSE s Guidance Note GS23 Electricity in Schools revised 1990 from HSE books Equipment can be obtained from either Detectawl Ltd 2 Cochran Close Crownhill Milton Keynes MK8 OAJ Gastec or from Draeger Ltd Ullswater Close Kitty Brewster Industrial Estate Blyth NE24 4RG Use either a Gastec Precision Pump with a sulphur dioxide tube 5Lb Low range 0 05 10 ppm or a Draeger Gas Detection Pump with a sulphur dioxide Draeger tube 0 5 0 05 25 ppm See reference 7 This assumes that the efficiency of the filter has fallen to 98 for sulphur dioxide at this level the fume cupboard will still not emit a dangerous level of gas well ventilated laboratory SSERC earlier developed a similar method See Monitoring of recirculatory filters Science and Technology Bulletin 177 June 1993 from SSERC Available from Griffin and George Cat BHW 300 010 V 63mm diameter x 13mm or Cat No BHW 300 030 P 80 mm diameter x 20mm or Philip Harris Cat
25. t hand end panel adjacent to the mains cable to expose the pressure gauge WARNING This will expose contacts at MAINS VOLTAGE and only qualified personnel must perform this calibration 29 7400 Mobile Fume Cabinet Operators Manual d Switch unit off and open the filter access panel lower front Partially cover the filter with paper approx 75 of the area and replace the panel to check the airflow The area of paper requires adjusting until the airflow through the aperture reduces to 0 3m sec Remove the transparent cover off the pressure gauge and slowly rotate until warning light flickers and then adjust further until light is almost continuously on f Switch off and remove paper from the filter in the filter box 9 Replace the access panel h Check the face velocity has returned to give an average above 0 3m s and then return the unit to service 5 FAN The fan requires no normal maintenance A thermal cutout is fitted into the wiring of the fan to prevent overheating This will reset on cooling but the cause of overheating should be investigated 6 ENCLOSURE a The Glazing Panels etc should be examined for mechanical damage and the condition of the friction hinges checked ADJUST AS REQUIRED b The spillage tray and glazing should be cleaned with a dilute detergent solution 30 T400 ELECTRICAL WIRING SCHEMATIC Light h ain Fuse 5A Socket Fuse Main Earth Stud
26. ter regularly Further it is prudent to conduct an initial test to ensure that the filter is seated properly and that its contents have not been displaced in transit It is sensible to test for this every time the filter is replaced What test to carry out In normal school use the layer of the filter treated to absorb acid gases will almost certainly saturate first Therefore it is recommended that the only test needed is one using an acid gas The trichloroethylene test is an alternative test useful for testing filter seating The general procedure This involves releasing a gas eg sulphur dioxide inside the fume cupboard at a known rate and comparing that rate with the concentration of gas in the air coming out of the exhaust A gas detection kit is used to measure the concentration of the gas emitted in the fume cupboard exhaust 17 7400 Mobile Fume Cabinet Operators Manual 7 d TESTS FOR SATURATION BY ACID GASES Method using a canister This method has ceased to be practicable because canisters of sulphur dioxide are no longer readily available It is included because contractors may prefer to use a similar method using small cylinders Schools may prefer to use the burning sulphur method see below The canister providing the sulphur dioxide is weighed before and after some gas has been released inside the fume cupboard for a measured time enabling the rate of release to be calculated The rate of flow is set first by obser
27. tted correctly ACTIONS l Remove the challenge to the filters The sensor will return to its normal state after the filter stabilises The alarm mute can be used and the cabinet should be left running during this time ll As the filter reaches the end of its the condition will be reached with very low challenge rates The filter will now need to be replaced If a new filter has been fitted and the alarm activated by low challenge rates to the filter the filter seals should be checked 34 7400 Mobile Fume Cabinet Operators Manual d J COMMISSIONING g The unit should be switched for approximately 20 minutes to reach a stable operating condition Follow calibration procedure is not possible to commission with previously used filters these should be removed and new filters fitted to commission The previously used filters should be refitted afterwards NB The unit may require recalibration after the first 3 4 weeks of use once the sensor has fully established TESTING The sensor can be tested by raising the filter off of its seal releasing a small quantity of alcohol on a cloth or a spray The alarm will sound at low levels of release CALIBRATION Please contact Puricore International Ltd for more information regarding the calibration of the unit 35 ABCAIRE Pure Science Pure Life For Tomorrow s Environment Puricore International Ltd 175 Kenn Road
28. velocity Is it above or below 0 3 m s If below the fume cupboard fails Variation Useful for checking if sites are suitable Add a b c d e f g h i and divide by 9 to get the average Find the highest and lowest out of a b c d e f g h i Work out highest minus average Divide the answer by the average and multiply by 100 to obtain the upper percentage variation Work out average minus smallest Divide the answer by the average and multiply by 100 to obtain the lower percentage variation Is each of these less than 3096 If not the site of the fume cupboard is not suitable Is the failure due to cross draughts the nearness of walls etc 16 T400 Mobile Fume Cabinet Operators Manual INSTRUCTIONS FOR FILTER SATURATION TESTING OF FILTER FUME CUPBOARDS Electronic detectors for monitoring filter saturation have not yet been shown to be sufficiently reliable for the range of gases used in school science therefore chemical tests are needed Pre filter The purpose of this filter is to absorb dust smoke and mists It is a layer of white Filtrete through which air passes before reaching the main filter As it becomes clogged the face velocity reading of the fume cupboard will fall Main filter The purpose of this filter is to absorb hazardous gases Frequency of saturation testing As there are strict limits to the concentrations of hazardous gases in which air could be breathed it is necessary to test the efficiency of the fil
29. ving the gas displacing water into a measuring cylinder The concentration of sulphur dioxide in the exhaust is measured with a gas detection tube as described above Items required are a gas detection kit a sulphur dioxide canister TOXIC a balance weighing to 0 1 g or less a stop clock plus the glassware shown on the next page Wear eye protection Sulphur dioxide is a toxic gas so do not breathe it in 18 7400 Mobile Fume Cabinet Operators Manual ES 6 SETTING THE OF FLOW OF SULPHUR DIOXIDE 500 ml bottle Sulphur dioxide cylinder 1 Find the mass of the sulphur dioxide canister M19 2 Set apparatus fume cupboard as shown above Switch fume Cupboard on 3 Open the valve on the gas canister very slowly When bubbles appear in the measuring cylinder start the stop clock Adjust the valve so that 100ml of gas bubbles into the measuring cylinder during a period of between 10 and 20 seconds 4 Without touching the valve break the connection between the canister the apparatus 5 After 60 seconds take reading of the concentration of sulphur dioxide the exhaust gas with the gas detection kit with a suitable tube A slight smell of sulphur dioxide should be ignored but if the exhaust gas causes breathing difficulties stop the test 6 Close the valve on the gas canister and stop the clock noting the time of the run t seconds 7 Find mass o
Download Pdf Manuals
Related Search