The Need for Refrigeration Standards
Page 49
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Britain is Lagging Behind, says Leading Consultant
" FHE compliance of British road transport equipment with certain Continental minimum standards which are already in force in various Common Market countries will beciime a necessity and not much time seems to be left to start thinking about this development." This was claimed by Dr. F. L: Levy, consultant on refrigeration, when speaking at the International Refrigeration Convention in London this week.
He was .referring to the possibility of the Channel Tunnel laeing built and the absence of a British standard in relation to the construction and .testing of refrigerated transport equipment. In contrast, he added, there was already legislation to this effect on the Continent, for example in France, since 1952. Work had already been done by the Economic Commission for Europe in Geneva in collaboration with the International Institute of Refrigeration in Paris, and details were available in the United Nations publication entitled "Transport of Perishable Foodstuffs."
Progress. Abroad Rapid development and great improvement had already been achieved in other countries, said Dr. Levy, by close collaboration between body builders, manufacturers Of equipment, research and trade organizations, Government authorities and transporters. It appeared that similar collaboration in this country would be welcomed. .
This would involve the setting up of testing stations and preparation of adequate legislation concerning the conveyance of perishable foods. Some standardization had already been achieved in international railway transport through the International Railway Union, lnterfrigo and the Container Bureau.
Disappointment Referring to disappointment which some users of refrigerated transport equipment sometimes experienced, Dr. Levy summarized the service which such users can reasonably expect from their equipment. It was unreasonable to expect from insulated or refrigerated equipment more than a purely protective service against the known adverse effect of undue temperature rise. When such equipment was applied to any method of transport it should not be expected to remove heat at a rate faster than the nature and arrangement of the goods was able to release.
Among the wide range of insulating materials available there were variations in their suitability according to weight, resistance to vibration, water absorption and vapour transmission, compression strength, dimensional stability, inflammability, and absence of odour and cost.
Whilst constructors were aware of the problem of condensation or ice formation inside vans or containers, and were endeavouring to minimize the adverse defects, rit had to be admitted that the maintenance of a complete vapour seal had not yet been achieved in practice. A realistic approach to this problem. Dr. Levy suggested, was to allow for the so-called breathing of the insulation. while taking all possible precautions to reduce this to a minimum.
Due to the combined influence of movement, handling, thermal expansion and contraction, the penetration of some water vapour had to be faced and it was important that the insulating material itself should offer the highest possible resistance to the passage of water vapour without absorption.
If ice was formed within the insulation, the result became particularly drastic, not only due to the higher conductivity of ice as compared with liquid water, but also on account of the It/ per cent, increase in volume. Great pressures were then exerted on the material, leading possibly to its, rupture. Of the selection of insulating naateriak. Dr. Levy referred to the deterioration in insulating materials during use. After about one year of operational service the original ideal conditions no longer applied and designers and constructoi is should make due allowance for such ageing" of equipment.
At the Exhibition
AS was to be expected, the Exhibition was mainly concerned with retail and domestic applications of the fields covered. Only one refrigerated vehicle was shown, a Thames Trader on the stand of G. M. Power Plant Co., Ltd.. which was shown in conjunction with Blox Services, Ltd. The vehicle and its equipment are fully described on this page.
Vehicle applications of refrigeration equipment are shown on three stands. J. Stone and Co. (Deptford), Ltd., show their Stone-Carrier equipment fitted to a test chamber which represents a 30-ft, refrigerated body.
The condensing unit uses a Perkins 4-99 oil engine direct coupled to a compressor. Both units are mounted on a sub-frame which also carries a radiator. the refrigeration condenser and pipe work and other refrigeration units. A temperature range of from —20° C. tJ +20° C. is claimed for the equipment. but a temperature as low as —32° C. k said to be attainable.
Self-eoniained Five units from the range of ThermoKing Refrigeration Equipment are shown on the stand of Petters, Ltd. Compressors are petrol-engine driven and electric motors can be incorporated also if required. Each of the units is self-contained and they are fitted to the front of the body so that the refrigeration unit is on the outside and the cooling unit inside the body.
Also on Petters' stand is the only application at the Exhibition of air conditioning equipment applied to commercial vehicles. This is the Thermo-King AM2 unit which is intended for application to passenger vehicles.
Equipment which uses the " hold over" principle for cold storage is shown by Winget Refrigeration. Ltd. On one application—the Winget-Dole Truck-Cel—the unit is frozen at the vehicle's base and the load is kept at a low temperature during delivery. This is primarily intended for the retail delivers of ice cream and frozen foods.
Insulation materials for use on commercial vehicle bodies are shown by Cape Insulation and Asbestos Products. Ltd.. and Microcell, Ltd. The former show Rocksill which is available in slabs of various thicknesses or in roll form. for fitting between the inner and outer skins of a body. Microcell show their product Plasticell. This is an expanded p.v.c. and examples of its use as an interlayer in sandwich forms of constructio are shown.