710 



Agricultural Gazette of N.S.W. 



[Oct. 2, 1920. 



pressure on the boiler can be more easily maintained, and there will be an 

 additional saving of fuel, attributable to more even firing. It is further 

 estimated that the heating of feed water for boiler purposes from a tem- 

 perature of 50 degrees Fah. to 200 degrees Fah. by means of exhaust steam 

 will reduce the fuel consumption 13 per cent. — in other words, will reduce a 

 £100 fuel bill to £87. Not only this, but the life of the boiler will be longer 

 owing to the avoidance of expansion and contraction strains get up on 

 the shell of the boiler by feeding with cold water. 



It is estimated that in a factory where 800 gallons of hot water are used 

 daily, and where it is heated by live steam from the boiler, approximately 

 127 lb. of coal are I'equired daily to raise the temperature of that quantity 



from 50 degrees to 170 degrees Fah. 

 If this amount of water was heated 

 by means of exhaust heat, there 

 would be a direct saving of 127 lb. 

 of coal per day, or taking coal at 

 35s. 3d. per ton (the price delivered 

 to factories at Lismore to-day), 

 there would be a saving of about 

 £31 15s. per annum. To emphasise 

 the increase in the cost of coal 

 to butter factories, and also the 

 desirability of .putting it to the 

 fullest possible use, it may be 

 recalled that coal was at one time 

 landed at Lismore at 16s. per ton. 

 It is also stated, that to heat 

 300 gallons of milk from 60 degrees 

 Fah. to 145 degrees Fah. requires 

 30 lb. of coal, so that with that 

 amount of milk an exhaust heater 

 would effect an annual saving of 

 more than 4 tons of coal. In 

 factories where the holding pas- 

 teuriser is in use, this hot water 

 can be used for pasteurising. If 

 the water is not just as hot as 

 required, live ste^m can be added to bring it to tlio desired temperature. 

 One or two factories using the holding method have found it more effective 

 to provide a large reservoir of hot water for pasteurising cream, sufficient for 

 two or three pasteurisers to use at the one time, than the small vats usually 

 provided for this purpose. 



If the cost of an exhaust heating plant was considerable, the question 

 would have to be determined whether the saving in fuel balanced the interest 

 on the money expended in materials, labour, depreciation, &c. Fortunately 

 the plant required is quite a modest one, and not beyond the resources of the 



Exhaust Steam Water Heater. 



A. Jacket Cylinder. b. Engine Exhaust Pipe. 

 C. Water Pipini;. n. Water Cocks. E. Water Tank 

 on Stand. r. Cold Water Supplj- Pipe. o. Hot 

 Water Supply Pipe. n. Ball Cock (wire and ball). 

 J. Cylinder Urain Pipe and Cock. 



Tank and pipes should be insulated. 



