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Blends of CFC 113 and alcohol contribute to CFC 113 conservation
Nouvelfes and 120kW h-i (4.25, 8.5, 17 and 34 TR), respectively. In equivalent weight of cereals, these models will treat 30-45,60-90,12&l 80 and 240360 tQnnes weight during a 24 h period. Refrigeration treatment preserves the cereals for long periods, without loss of quality, so that the product is always at optimum marketable condition. Losses caused by cereals ‘breathing’ are avoided. The development of insects, parasites and moulds is prevented, thus eliminating the need for chemical disinfestation. As air from the Frig-O-Dry system passes upwards through the silo, it cools and, therefore, dries the cereals. Initially, grain at the bottom of the stack is brought to the temperature and humidity set by the incoming air, and conversely the air expelled from the top of the silo is at a higher temperature and humidity having absorbed heat and moisture from the cereals. The amount of moisture absorbed by the air depends upon the difference between its relative humidity and the humidity of the cereals. As the cooling continues, the ‘cold front’ gradually moves upwards through the cereals until the whole of the stored product has been conditioned for preservation. Once the entire mass of cereals has been chilled, it will usually remain at the same temperature for an indefinite period of time. If there is a high proportion of impurities in the grain, or if exceptionally high humidity results in incomplete drying, the temperature may rise again but this can be easily cured by temporarily repeating the cooling/drying process. A constant read-out of the cereal inside the silo is temperature the Frig-O-Dry provided by monitor. The user can thus follow the position of the moving cold front and decide when to stop the cooling cycle or, if subsequently the product starts to overheat again, when to repeat the process. Aiax (UK) Limited, Veneto House, Park Drive, Rayners Lane, North Harrow, Middlesex HA2 7LT, UK.
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de l7ndustrie
CFC 113conservation and recovery A report just published by ICI lists a number of practical ways to reduce consumption of chlorofluorocarbon (CFC) 113 in industry by optimizing conservation and recovery practices. The report, ‘CFC 113 Conservation and Recovery Practice in Europe’ is based on a paper presented at a Washington conference earlier this year by J. J. Clementson, ICI’s senior technical product manager. Reduction of consumption by users in industry, that is, more clean parts per gallon of solvent, is seen by ICI as the most effective way of achieving satisfactory and cost effective cleaning with minimal emissions. A large proportion of the emissions from the solvent occur when it is being delivered and stored. The use of totally enclosed high-pressure storage tanks and barrel pumps for transfer will make a significant contribution to emission reduction. The report puts a figure of approximately 4600 tonnes on the savings to be made in this way. All valves and taps should be checked regularly for leaks and storage should always be in a dry, cool, place to minimize any evaporation that might occur on opening of drums. Degreaser design and operation is the second major area identified by ICI as having potential to reduce emissions. A higher freeboard, that is the part of the tank wall which is above the surface of the solvent, which can be retrofitted to existing tanks, has been proven in tests to reduce escape of solvent vapour. The EUR 9510 EN code of practice for the design of batch degreasers is cited in the report as a useful guide. The code recommends that the maximum temperature of the cooling water be 64”F, that the vapour level be at the mid-point of the condenser, that the freeboard be 50 to 75% of the degreaser width, and that a low solvent detector and heater cut-out be provided. All the ICI cleaning
ht. J. Refrig. 1999 Vol 12 January
plant on the market adheres to this code. As to operation, personnel should be properly trained to follow procedures, understand the safety rules and report any leaks. Lids should always be used, and spray nozzles should always be situated below the vapour level. ‘Choosing a CFC 113 based solvent with a lower boiling point generally reduces the emissions from the plant during use. The relationship is in fact a complicated one and ICI can offer specialist help for particular applications to help users minimize emissions in this way’, said Clementson. ‘Recovery of contaminated solvent is essential if a real effort to reduce amounts used is to be made. The ease with which different types and grades of solvents can be recovered varies and this may well become a crucial factor in the initial choice of solvent.’ Chlor-Chemicals, ICI Chemicals and Polymers Limited, PO Box 14, The Heath, Runcorn, Cheshire WA7 4QG, UK.
Blends of CFC 113 and alcohol contribute to CFC 113 conservation The use of non-azeotropic blends of chlorofluorocarbon (CFC) 113 and low boiling point alcohols in flux and grease removal cleaning plant can contribute significantly to CFC 113 conservation in the electronics and engineering industries. According to ICI Chlor-Chemicals, conservation of solvent can contribute significantly to cleaning cost effectiveness and to preservation of the environment. Lower recovery yields than those obtained from the use of pure CFC 113 are more than offset by the 25 to 35% substitution in the original mixture. The mixing of CFC 113 with low
Ill
news Nouvelles
boiling point alcohols such as isopropanol and ethanol creates a highly effective solvent for flux removal. This non-azeotropic blend of chemicals typically contains 25 % of the alcohol by weight and as such is still non-flammable. During the cleaning process, however, the CFC 113 diffuses into the atmosphere more quickly than the alcohol, causing the remaining solvent to become richer in alcohol, and so pushing up the temperature of the vapour. In Europe, where these non-azeotropic blends are most commonly used, it is the usual practice to use an automatic cut out switch on the heating system of the plant to prevent the temperature of the mixture posing a potential fire risk threat. For example, CFC 113/isopropan01mixtures are considered flammable at 70°C. Shut down is normally triggered at 56°C to ensure safe working conditions. Similar shut down procedures are used in the distillation of used solvent for recovery. Typically, the residual solvent will contain about 45 % CFC 113, which is slightly more than with azeotropic blends of the same chemicals. Chlor-Chemicals, ICI Chemicals and Polymers Limited, PO Box 14, The Heath, Runcorn, Cheshire WA7 4QG, UK.
Environmentally safe refrigeration systems As concern increases about the effect of CFC refrigerants on the Earth’s ozone layer, Stanley Cooling and Freezing is offering environmentally safe refrigeration plant as a standard option on all future installations. Stanley will be redesigning many of its refrigeration systems to use refrigerant R22 which has been proved to be safe. The company is the first major refrigeration contractor
de l’l’ndustrie
to offer its customers this option. Mike Stanley, Chairman and Managing Director, said: ‘As the UK’s fastest growing refrigeration contractors, we believe it is essential to promote these “safe” systems to our customers. Whilst it is not possible to offer refrigerant 22 systems without some cost implications, in many cases, the actual increase is very small’. ‘We are also working very closely with our trade association, the Refrigeration Unit Air Conditioning Group of the Heating and Ventilating Contractors’ Association, to promote good practise in the handling of refrigeration, ensuring that loss and wastage are kept to a minimum’. Stanley Refrigeration Limited, Unit 3, Elmdon Trading Estate, Birmingham Bickenhill Lane, B37 7EZ, UK.
Sea trial results show benefits of freezers Torry research vessel the Lancella returned home after its 20 day charter, approving the 15 station plate freezer developed by Marine & . I. Ia& ; ~ Refrigeration (MIR) Limited. Torry tests resulted in a report on the benefits of this radically new design of freezer. The freezers were on loan to Torry who have been investigating various methods of at-sea fish freezing. The
Modular fBh freezing package from MIR
trip was the culmination of several years research and development including continuous freeze trials on different products. The MIR lo/15 series plate freezer proved its benefits in operation, engineering and shipbuilding during sea trials. Because the freezers are fitted with roller double skin curtains each side, the freezer trays or frames can be loaded in a straight-through manner. The incoming trays push out the frozen trays, allowing continuous freezing. Wash down is another benefit due to the sea water resistant aluminium and stainless steel construction. Additionally, benefits include controls of the entirely automatic refrigeration plant which can hold a load in the plates overnight to suit work patterns. The only operational control is a single lever to start the hydraulic pump to open or close the plates. Despite all the functionalities, the unit is extremely quiet in operation, being totally clad in acoustic lined stainless steel. Ship spares become much less expensive and more comprehensive because the system operates with a direct expansion refrigerant with a patent pending liquid injection maximizing device, the heat exchange rate. The compressor is rotary vane and very robust considering it is one third the size of the. equivalent piston compressor. The high quality marine shell and tube condensers make removal for cleaning easy. Each MIR unit is fully wired with its own control panel and requires only 20 kVA 3 phase 415 V, 50 Hz supply (other voltages available). An equivalent capacity plant on secondary pumped refrigerant would use as much as three times the electrical load. Shipbuilder and vessel installation is designed for flexibility. The freezer installation, removal or resitement can also be accomplished in around four days. Marine & Industrial Refrigeration (Yorkshire) Limited, Unit BT514, Bergen Way, Sutton Fields Industrial Estate, Hull HU8 OXN, UK.
Rev. ht. Froid 1989 Vol 12 Janvier
53
52
de l7ndustrie
CFC 113conservation and recovery A report just published by ICI lists a number of practical ways to reduce consumption of chlorofluorocarbon (CFC) 113 in industry by optimizing conservation and recovery practices. The report, ‘CFC 113 Conservation and Recovery Practice in Europe’ is based on a paper presented at a Washington conference earlier this year by J. J. Clementson, ICI’s senior technical product manager. Reduction of consumption by users in industry, that is, more clean parts per gallon of solvent, is seen by ICI as the most effective way of achieving satisfactory and cost effective cleaning with minimal emissions. A large proportion of the emissions from the solvent occur when it is being delivered and stored. The use of totally enclosed high-pressure storage tanks and barrel pumps for transfer will make a significant contribution to emission reduction. The report puts a figure of approximately 4600 tonnes on the savings to be made in this way. All valves and taps should be checked regularly for leaks and storage should always be in a dry, cool, place to minimize any evaporation that might occur on opening of drums. Degreaser design and operation is the second major area identified by ICI as having potential to reduce emissions. A higher freeboard, that is the part of the tank wall which is above the surface of the solvent, which can be retrofitted to existing tanks, has been proven in tests to reduce escape of solvent vapour. The EUR 9510 EN code of practice for the design of batch degreasers is cited in the report as a useful guide. The code recommends that the maximum temperature of the cooling water be 64”F, that the vapour level be at the mid-point of the condenser, that the freeboard be 50 to 75% of the degreaser width, and that a low solvent detector and heater cut-out be provided. All the ICI cleaning
ht. J. Refrig. 1999 Vol 12 January
plant on the market adheres to this code. As to operation, personnel should be properly trained to follow procedures, understand the safety rules and report any leaks. Lids should always be used, and spray nozzles should always be situated below the vapour level. ‘Choosing a CFC 113 based solvent with a lower boiling point generally reduces the emissions from the plant during use. The relationship is in fact a complicated one and ICI can offer specialist help for particular applications to help users minimize emissions in this way’, said Clementson. ‘Recovery of contaminated solvent is essential if a real effort to reduce amounts used is to be made. The ease with which different types and grades of solvents can be recovered varies and this may well become a crucial factor in the initial choice of solvent.’ Chlor-Chemicals, ICI Chemicals and Polymers Limited, PO Box 14, The Heath, Runcorn, Cheshire WA7 4QG, UK.
Blends of CFC 113 and alcohol contribute to CFC 113 conservation The use of non-azeotropic blends of chlorofluorocarbon (CFC) 113 and low boiling point alcohols in flux and grease removal cleaning plant can contribute significantly to CFC 113 conservation in the electronics and engineering industries. According to ICI Chlor-Chemicals, conservation of solvent can contribute significantly to cleaning cost effectiveness and to preservation of the environment. Lower recovery yields than those obtained from the use of pure CFC 113 are more than offset by the 25 to 35% substitution in the original mixture. The mixing of CFC 113 with low
Ill
news Nouvelles
boiling point alcohols such as isopropanol and ethanol creates a highly effective solvent for flux removal. This non-azeotropic blend of chemicals typically contains 25 % of the alcohol by weight and as such is still non-flammable. During the cleaning process, however, the CFC 113 diffuses into the atmosphere more quickly than the alcohol, causing the remaining solvent to become richer in alcohol, and so pushing up the temperature of the vapour. In Europe, where these non-azeotropic blends are most commonly used, it is the usual practice to use an automatic cut out switch on the heating system of the plant to prevent the temperature of the mixture posing a potential fire risk threat. For example, CFC 113/isopropan01mixtures are considered flammable at 70°C. Shut down is normally triggered at 56°C to ensure safe working conditions. Similar shut down procedures are used in the distillation of used solvent for recovery. Typically, the residual solvent will contain about 45 % CFC 113, which is slightly more than with azeotropic blends of the same chemicals. Chlor-Chemicals, ICI Chemicals and Polymers Limited, PO Box 14, The Heath, Runcorn, Cheshire WA7 4QG, UK.
Environmentally safe refrigeration systems As concern increases about the effect of CFC refrigerants on the Earth’s ozone layer, Stanley Cooling and Freezing is offering environmentally safe refrigeration plant as a standard option on all future installations. Stanley will be redesigning many of its refrigeration systems to use refrigerant R22 which has been proved to be safe. The company is the first major refrigeration contractor
de l’l’ndustrie
to offer its customers this option. Mike Stanley, Chairman and Managing Director, said: ‘As the UK’s fastest growing refrigeration contractors, we believe it is essential to promote these “safe” systems to our customers. Whilst it is not possible to offer refrigerant 22 systems without some cost implications, in many cases, the actual increase is very small’. ‘We are also working very closely with our trade association, the Refrigeration Unit Air Conditioning Group of the Heating and Ventilating Contractors’ Association, to promote good practise in the handling of refrigeration, ensuring that loss and wastage are kept to a minimum’. Stanley Refrigeration Limited, Unit 3, Elmdon Trading Estate, Birmingham Bickenhill Lane, B37 7EZ, UK.
Sea trial results show benefits of freezers Torry research vessel the Lancella returned home after its 20 day charter, approving the 15 station plate freezer developed by Marine & . I. Ia& ; ~ Refrigeration (MIR) Limited. Torry tests resulted in a report on the benefits of this radically new design of freezer. The freezers were on loan to Torry who have been investigating various methods of at-sea fish freezing. The
Modular fBh freezing package from MIR
trip was the culmination of several years research and development including continuous freeze trials on different products. The MIR lo/15 series plate freezer proved its benefits in operation, engineering and shipbuilding during sea trials. Because the freezers are fitted with roller double skin curtains each side, the freezer trays or frames can be loaded in a straight-through manner. The incoming trays push out the frozen trays, allowing continuous freezing. Wash down is another benefit due to the sea water resistant aluminium and stainless steel construction. Additionally, benefits include controls of the entirely automatic refrigeration plant which can hold a load in the plates overnight to suit work patterns. The only operational control is a single lever to start the hydraulic pump to open or close the plates. Despite all the functionalities, the unit is extremely quiet in operation, being totally clad in acoustic lined stainless steel. Ship spares become much less expensive and more comprehensive because the system operates with a direct expansion refrigerant with a patent pending liquid injection maximizing device, the heat exchange rate. The compressor is rotary vane and very robust considering it is one third the size of the. equivalent piston compressor. The high quality marine shell and tube condensers make removal for cleaning easy. Each MIR unit is fully wired with its own control panel and requires only 20 kVA 3 phase 415 V, 50 Hz supply (other voltages available). An equivalent capacity plant on secondary pumped refrigerant would use as much as three times the electrical load. Shipbuilder and vessel installation is designed for flexibility. The freezer installation, removal or resitement can also be accomplished in around four days. Marine & Industrial Refrigeration (Yorkshire) Limited, Unit BT514, Bergen Way, Sutton Fields Industrial Estate, Hull HU8 OXN, UK.
Rev. ht. Froid 1989 Vol 12 Janvier
53