Thermometer-cum-calibrator

and the associated building in a complete, compact unit. The building is a prefabricated structure based on insulated panels. Models available have, 5, 10 or 15 tons per day production capacities. Storage capacities are 25, 50 and 75 tons. StaI-Levin Ltd, River Pinn Works, Yiewsley High Street, West Drayton, Middx UG7 7TA, UK

Sulphur dioxide is liquefied Sulphur dioxide is a highly irritating and non-flammable gas. If the amount of SO 2 in the raw gas is as low as 2-5% by volume, it has to be concentrated in water or another solvent in an absorption tower, followed by evaporation in a stripping tower, before being liquefied by a low temperature refrigeration plant. Where raw gas has a concentration of 7-1 4% SO 2 it can be fed directly into a refrigerated plant for liquefaction. When Inco Europe built a new plant for roasting nickel sulphide ore, it was decided that gaseous byproducts would be used for producing sulphuric acid and liquid sulphur dioxide. The sulphur dioxide liquefaction was sub-contracted to StaI-Levin. Gas is liquefied from a side stream taken from the process gas feeding a sulphuric acid plant. Uncondensed gases are returned to the acid plant to prevent pollution. The gas is dried in a 96% sulphuric acid drying tower operating at 45°C. It is then passed through a candle filter to remove traces of sulphuric acid mist before being fed to the primary heat exchanger. The refrigeration system is a two stage compound type using R13B1 refrigerant with a low stage evaporating temperature of - 7 0 ° C . The high stage unit was assembled from a Stal-type UD4 reciprocating compressor, a horizontal shell and tube refrigerant condenser, and intercooler and a liquid sulphur dioxide liquid refrigerant heat exchanger. The low stage unit consists of a Stal-type $51 screw

Volume 3 Number 6 November 1980

compressor and an oil separator. The third unit is the sulphur dioxide liquefier assembly. The total unit is enclosed within an insulated box provided with access doors. StaI-Levin also provided gas heat-exchangers to cool the incoming sulphur dioxide (from 110°C to - 4 0 ° C ) using the uncondensed gases as cooling medium, Hermetic liquid sulphur dioxide pumps are used to feed the liquid to the storage tanks via heat exchangers which subcool the refrigerant to the intercooler and to the gas liquefier.

inject the desired auto-linearized temperature signal, the result of which can be assessed by comparing the display of the instrument under test with that of the calitherm. It can measure and calibrate up to 1 750°C. Standard features include automatic cold junction compensation, resolution of 1.0°C and an accuracy of 0.1% of reading ~-1°C. Jenway Ltd, Gransmore Green, Felsted, Dunmow, Essex CM6 3LB, UK

StaI-Levin Ltd, River Pinn Works, Yiewsley High Street. West Drayton, Middx UB7 7TA, UK

Thermometer-cu mcalibrator A novel digital thermometer and calibrator is available. Doubling as a thermometer calibration instrument, the Model 8553 Calitherm from Jenway Ltd offers a means of calibrating thermocouple-based instrumentation of all types. The instrument under test is coupled to the calitherm and then zeroed by means of a high-resolution potentiometer, which provides a swing of 60°C to enable the suppression of 50°C elevated cold junctions. A second, multi-turn potentiometer is then used to

Chilled eggs for baking EEC regulations require multiple bakers to use pasteurized eggs. Such pasteurizing involves heating followed by rapid cooling. F & R Cooling Ltd are providing the cooling system for Freshfayre Products. The EAC heat pump cools process water and all auxiliary equipment. An added bonus has been the use of 'exchanged' heat to warm the plant in winter and to improve summer time ventilation. F & R Cooling Ltd, Wellington Trading Estate, Wellington, Somerset TA21 8ST, UK

F & R Cooling's chiller for eggs

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