Indust
l news
No u velles de I "indus trie Pump for small spaces Small size and compact design of the E2M1.5 rotary vacuum pump from Edwards High Vacuum makes it suitable for bench-top use, or in instruments, portable and mobile equipment, or in any other installations where mechanical dimensions and weight could be a problem. This two-stage pump is 300ram ( 1 2 i n ) long and l O k g (22 Ib) in weight. A special design feature contributing to compactness is an alternate vacuum inlet at the side of the pump (in addition to the usual one at the top). This can be used when the installed height of the pump must be kept to a minimum or when a horizontal connection is more convenient. Displacement is 1.8 m 3 h 1 and ultimate vacuum 5x 10 -4 mbar. It is constructed in corrosion resistant materials, and has a lubrication system using an integral oil pump to ensure reliable running by giving a more than adequate oil flow through the stator/rotor assembly at all times. Automatic additional oil feed gives improved performance when running on gas batlast. Where normal hydrocarbon oils cannot be used the pump can be supplied with Fomblin lubrication. The E2M1.5 runs with minimum vibration and a tow noise level of less than 5 0 d B at 1 m. Maintenance is simplified by a demountable drive coupling between motor and pump and also by a
The compact model E2M1.5 vacuum pump from Edwards
rotary
Volume 7 Numero 2 Mars 1984
separate outer shaft seal which avoids the need to strip the pump completely if the outer shaft seal fails. Edwards High Vacuum, Manor Royal, Crawley, West Sussex, RH 10 2LW, UK
Heat pumps for drying For those interested in using electric heat pumps for industrial drying processes information is available in a four page booklet recently published by the Electricity Council (UK). The leaflet describes how a heat pump dryer works and gives advice on selecting equipment. It lists the advantages which heat pump dryers have over batch fuel fired convection plants as lower energy costs, less product spoilage, faster drying, more uniform product quality and increased productivity. The booklets are available free of charge. The Electricity Council, Marketing Dept., 30 Millbank, London S W l P 4RD, UK.
Packaging lobsters Frozen lobsters can be kept fresh for two years with a packaging system based on Du Pont's 'Surlyn' ionomer resin. In addition production speeds are six times greater w i t h o u t an increase in packaging costs. This is significant news for a branch of the fishing industry limited to catches during two months of the year, May and June. It follows tests aimed at preserving the quality of lobster over several months between catching off Canada's maritime provinces and passage through distribution channels to Europe and the United States. Freezing thus allows the lobster season to be extended over the full year. While the freezing process can slow down deterioration of the lobster, it does not inhibit it com-
pletely, as some oxygen is still left. If this remaining oxygen is extracted by vacuum packaging, deterioration is virtually halted. The use of a film combining the properties of polyamide and ionomer provides an excellent barrier to oxygen that might otherwise reenter the pack. Early trials were made using pouches of polyamide and polyethylene films carrying a brine solution. While the contents emulated sea water and kept out oxygen to some extent, the frozen package could not provide the necessary shelf life. These problems were solved with the new material combination. Here, the toughness and puncture resistance of 'Surlyn' ionomer resin offered better protection against the sharp spines and claws on the lobster. The presence of ionomer also ensured a good seal through brine solution. With the new vacuum packaging system the film is first drawn into a mould. A lobster is then placed into the depression, and the cavity filled with brine solution. A second layer of film is passed over the top, vacuum is applied, and the package is heat-sealed. Standard film rolls can be used for all moulds, unlike the ten different-sized pouches required for the former system. Machine speeds range from 39 to 52 lobsters per minute depending on lobster size. When the lobsters were packed in pouches, an average of nine per minute could be processed. Vacuum packaging has also improved the sales appeal of the finished product because the lack of oxygen prevents yellowing of the lobster and clouding of the brine solution. G. E. Stuevermann, E408 (PAFID-070), Du Pont de Nemours International SA, CH-1 211 Geneva 24, Switzerland
Refrigerator de-icer De-icing commercial and industrial refrigerators can be time
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