REFRIGERATING MACHINES.

Patea Mail, 28 April 1881, Page 4

REFRIGERATING MACHINES.

The Engineer gives the following details relative to the refrigerating machine constructed by Messrs Hall, of Hartford, for use in the Australian meat trade : The machine consists of a pair of horizontal trunk engines, mounted on the top of a condenser. To one side is bolted a compressing cylinder, 27 inches diameter, and 18 inches stroke ; both these cylinders are open-topped. The valves are placed in the bottoms ot the cylinders, and are worked by cams on the crank shaft and levers. Air is drawn into the compressing cylinder on the up stroke, and delivered on the down stroke into the surface condensei, at a pressure of about 501b to 55 lb on the square inch. The air hero parts with its heat te the condenser, and it is then delivered into the expansion cylinder the valve of which cuts off about onefourth stroke. The expanded air is then delivered through a pipe into the room to be cooled. About fifty per cent, of the work expended in the compressing cylinder is returned in the expansion cylinder, the difference being made up by the engine. The machine is but one of several Messrs Hall have in hand of different patterns. The height is kept down to render it specially suitable for use between decks, but the machine can be made to take any form almost, and can be made of any dimensions to suit particular requirements. The condenser or refrigerator consists of nests of brass tubes, through which the water circulates. The tubes are of brass, half an inch in diameter outside. The ends of the tubes are accessible through the main lids.