712 Agricultural Gazette of N.S.W. [Oct. 2, 1920. 



engines is very great, and can be made use of quite simply in heating water. 

 A factory near Lismore has for some years successfully made use of the 

 exhaust from a gas engine to heat water for washing cans, scalding churns, 

 butter-workers, &c. The circulating water from the gas engine cylinder 

 jacket is conveyed to an old 6 horse-power galloway tube vertical boiler. 

 The end of the engine exhaust pipe enters the boiler fire-box, and the exhaust 

 heat and gases impinge on the tubes and heating surfaces of the boiler, and heat 

 the water in the same way as a fire in the boiler would do. The water being 

 already somewhat warmed by passing through the engine cylinder jacket, 

 about one hour's running of the engine will give a good supply of hot water 

 at about 160 degrees Fah. 



In some factories using suction gas engines, only small boilers for supplying 

 steam for heating water, steaming cans, and driving testing machines have 

 been provided. Mostly these boilers were part of the factory equipment 

 before the days of pasteurisation, and although amply sufficient then, it has 

 been found that they are now too small to permit of all the steam require- 

 ments of the factory being met at the one time. This has necessarily meant 

 the shutting oiF of steam from the testing room, wash-up, or some other 

 portion of the factory to ensure a satisfactory head of steam to the pasteuriser, 

 or else resorting to excessive firing of the boiler. 



The engineer of one of the factories in this position, with a view to relieving 

 the boiler from the heavy demand on it for steam and utilising the waste 

 heat of a suction gas engine, decided to experiment with an exhaust heatei-, 

 which has been an unqualified success, and has more than twice paid for itself 

 during nine months' service. A 400-gallon square iron tank to provide a 

 delivery of hot water to any part of the factory, was placed on a high stand 

 near the engine-room. This tank was insulated with boards, and 4 inches of 

 charcoal well packed round the sides and bottom. The silencer portion of 

 the exhaust pipe of the 80 horse-power suction gas engine was placed inside 

 this tank and covered with water, the top of the outlet pipe being above the 

 top of the water. In practice the circulating water from the engine cylinder 

 is run into the tank. This water being already warmed is further heated in 

 the tank, and during the day a supply of water at an average temperature of 

 170 degrees is available. In the early morning, and before the engine starts, 

 there is water hot enough for the buttermaker to rinse the churns, (fee., owing 

 to the tank being insulated. From 1,200 to 1,400 gallons a day are used 

 through this heater, and the boiler is now only used for pasteurising, steaming 

 cans, and testing. The heater provides all the hot water for washing down, 

 washing cans, factory utensils, ifec, and since its installation has resulted in 

 about four hours less firing of the boiler per day being necessary. 



The cost of the plant was about £25, exclusive of cost of erection, which 

 was done by the engineer and his staff". This cost includes £18 for 200 feet 

 of water piping to deliver the water at the far end of the building. This 

 long length of piping is placed inside some old 2-inch piping, which provides 

 a dead air space all rouiid the smaller pipe and affords a very fair insulation. 

 One of the features of this plant is the insulation provided to maintain the 



