Oct. 2, 1920.] 



Agricultural Gazette of N.S.W. 



711 



average factory engineer to construct. For a small factory a useful plant 

 would consist of a 200-gallon square tank, with a vertical jacket round the 

 exhaust pipe of the engine about 10 or 12 feet long. The jacket, should be 

 4 to 5 inches greater in diameter than the exhaust pipe. The tank is elevated 

 on a platform alongside the jacketed exhaust, and connected to the jacket by 

 means of suitable lengths of piping at top and bottom. The tank jacket and 

 piping are kept filled with water, and by means of the thermo-syphon 

 principle the water is induced to circulate from the tank through the lower 

 pipe to the jacket, thence upwards in the jacket and back again through the top 

 pipe to the tank. This action is 



continuous, the water gathering 

 more heat as it is allowed to con- 

 tinue circulating. It is a principle 

 well known to motorists, as many 

 motor cars use it in the reverse way 

 to cool the engine, circulating water 

 by subjecting it to a cold draught. 

 For a small factory quite a useful 

 heating of water can be secured 

 in this way. It is advisable to 

 insulate the tank, jacket and piping 

 with some suitable material, to re- 

 duce the escape of heat into the 

 atmosphere as much as possible. 



A method employed in larger 

 factories where .several steam pumps 

 are in use, is to connect the exhaust 

 of each to one common exhaust, 

 and then to connect with a coil 

 of piping immersed in a tank of 

 water. The exhaust from three 

 steam pumps with an aggregate of 

 5 horse-power in one of the North 

 Coast factories produces boiling 



water in a 600-gallon tank in 



^ 



Water Heated by Exhaust from Suction Gas Engine. 



A. Water Tank on Stand. b. Engine Silencers, 

 c. Engine Exhaust Pipe. d. Half-inch hole for 

 drainage of any water in Exhaust Pipe. e. Cold 

 Water Supply Pipe and Ball Cock. f. Hot Water 

 Supply Pipe. 



Tank and Hot Water Pipe should be insulated. 



hours and supplies a large factory 

 with all the hot water required. A 

 300-feet copper coil, 3 feet 6 inches 

 in diameter, 4-inch pipe and a heavy cast-iron tank (portion of an old sugar 

 mill plant) is used. The tank is well elevated to deliver hot water to any 

 part of the factory. The exhaust from the pumps first of all passes through 

 a commercial feed water heater, afterwards passing through the coil men- 

 tioned. This plant has given the most satisfactory results, supplying 

 hundreds of gallons of hot water daily. 



Suction gas engines are frequently made use of at butter factories where 

 fuel is expensive and difficult to obtain. The heat of the exhaust gas of these 



