A breath of fresh air

warehouse at Atherstone in Warwickshire, UK, to British Home Stores" outlets throughout the country. They are fitted with specially designed and adapted versions of the BOC Polarstream liquid nitrogen vehicle refrigeration systems. Increased flexibility of their food distribution fleet was necessary so that all categories of product, fresh, chilled or frozen, could be carried economically to all their stores. The volume of a particular category at some stores did not justify the use of a complete delivery in a single temperature vehicle. The system is powered pneumatically, as are most Polarstreams on articulated trailers, by taking gas from the head space of the liquid nitrogen storage tank. Liquid nitrogen storage is in either a 430 I tank slung crosswise under the chassis, or three coupled 210 I tanks mounted vertically at the front of the trailer. The latter has now been accepted as a standard for BHS. giving more than enough refrigeration capacity for even the longest runs, currently to Aberdeen and Plymouth. Benefits of the new system to BHS and Christian Salvesen are flexibility, cleanliness, fuel saving by optimizing payloads, and accurate temperature controls to 4-1°C at their standards of +2°C for chilled food and - 1 8 ° C for frozen food. BOC Gases Division, BOC Ltd, Great West House, PO Box 39, Great West Road, Brentford, Middlesex, TW8 9DQ, UK

Trolley mounted flushing pump A trolley-mounted version of Robinair's portable motorised flushing/washing pump has recently been developed. Primarily intended for workshop use, the trolley version model 30066, also features a delivery pressure gauge with isolating valve. Both versions are based on a plasticised double diaphragm

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Trolley mounted flushing pump from Robinair pump running at 650 rpm. powered by a 0.75 hp (559 W) 50 Hz electric motor. The combination of pump design and slow running speed produces a significant pressure ripple, which is particularly effective in removing internal contaminants. Delivery is 4.5 gal min -1 (1 227.4 dm 3 h -1) with maximum pressure, controlled by an adjustable unloading valve, at 300 Ib in -2 (21 092 g cm -2) of fluids can be accommodated, including refrigerants F 11 and F 113 for internal flushing of refrigeration systems and water, detergent, etc for external power cleaning. Both models are supplied complete with tools and hoses, including a spraying lance with on-off valve and interchangeable nozzles. Kent-Moore UK Ltd, 19-21 Stockfield Road, Acocks Green, Birmingham, B27 6A J, UK

A breath of fresh air Air drawn into a compressed air system is laden with dirt, oil and water and unless this is removed the contaminents are likely to cause product spoilage, machine breakdown, air line leakage and increased production costs. CompAir Industrial Ltd has set up a complete industrial air treatment service individually tailored to meet customer's compressed air quality needs. This packaged deal includes CompAir BroomWade after coolers, filters, air dryers, receivers and non-return valves.

Used on their own, aftercoolers reduce the temperature of the compressed air and remove some water. Filters remove the other contaminents such as oil, dirt and odour, and dryers remove condensate. Aftercoolers are the first stage of water removal from compressed air, there are two types, water-cooled or air blast. A new range of free standing aluminium air blast after-coolers are available, consisting of six units which cover free air deliveries up to 300 ft 3 min (509.7 m 3 s 1) at pressures up to 10 bar (106 N m 2). These air blast coolers are complete with separators and condensate automatic discharge. The allwelded aluminium cone is contained in a vinyl covered shell housing. Inlets and outlets are reversible by connecting the separators to the desired exit position. Eight sizes of watercooled aftercoolers complete the range and under normal conditions provide more efficient means of water extraction. Although aftercoolers remove about 60% of the water vapour in compressed air systems, a combination of after-cooler and refrigerant dryer will remove around 95% of the total contained moisture. This is adequate for most installations needing upgraded air. BroomWade D range of refrigerant dryers in the air treatment package now include fifteen self contained models grouped in four basic sizes with performances to suit most industrial needs. Air capacities range up to 950 I s 1 at a dewpoint of 2°C and up to 1140 I s -1 at a dewpoint of 10°C. Dewpoints are variable between these limits. The range of CompAir BroomWade oil removal filters are suitable for a variety of air flow duties eliminating solid particles down to 1 /~m with removal of liquid water and maximum remaining oil content of 0.01 ppm. CompAir Industrial Ltd, PO Box 7, BroomWade Works, High Wycombe, Bucks, U K

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