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CHECKING COSTLY 



CHIMNEY LOSSES 



Since the greenhouse owner must pay more money for the things he 

 needs most, he can only keep down his costs hy using less. To do this he 

 must become acquainted with the possible ways of reducing waste, one of 

 the most important of which is pointed out in this article. 



HE subject of fuel economy 

 is today of greater interest 

 to florists than ever be- 

 fore. There are two rea- 

 sons: First, fuel costs 

 two or three times as 

 much as it did a few 

 years ago, and second, in 

 many instances during the 

 last few years it has been 

 difficult to get at any price. The first 

 reason is one that will remain. Prices 

 of fuel, no matter what kind, will un- 

 doubtedly stay high, compared with 

 prices before the war. The second 

 reason should, however, vanish entirely 

 when once labor and transportation 

 facilities are properly controlled. 



The high cost of fuel, therefore, pro- 

 vides the principal incentive to save it, 

 and the greater the cost the greater will 

 be that incentive. The two principal 

 factors which enter into the cost of fuel 

 are labor and transportation. Its price 

 to the consumer will be governed by 

 these two charges, plus whatever addi- 

 tional charge competition will permit 

 the mining interests to add. 



Up the Stack. 



No matter how fuel is consumed and 

 no matter what kind of fuel is burned, 

 whether solid, powdered, liquid or gase- 

 ous, the biggest loss is always due to 

 the heat energy 

 wasted up the chim- 

 ney. In this connec- 

 tion it might be well 

 to quote the follow- 

 ing conservative 

 statement from bulle- 

 tin No. 205, issued 

 by the bureau of 

 mines: 



"In the average 

 boiler plant, thirty- 

 five per cent of the 

 heat in the coal 

 burned under the 

 boilers is lost with 

 the stack gases. That 

 is, out of every 100 

 tons of coal burned 

 under the boilers, the 

 heat of thirty-five 

 tons literally goes up 

 the stack. It is this 

 loss that can be 

 greatly reduced, and 

 every effort should 

 be made to do so. ' ' 



The loss up the 

 chimney, which is al- 

 ways the largest in- 

 dividual loss in any 

 heating plant, de- 

 pends for its magni- 



By F. F. UEHLING, 

 Combustion Engineer. 



tude on three factors. These are, in or- 

 der of importance: First, excess air in 

 the products of combustion; second, tem- 

 perature of the products of combustion; 

 third, amount of unconsumed fuel in 

 the i^roducts of combustion. 



Air Consumed. 



The excess air in the products of 

 combustion results in loss greater than 

 that from any other source. Every kind 

 of fuel requires a definite amount of air 

 to burn it, the exact quantity depending 

 principally upon the ratio of its carbon 

 and hydrogen. When considering coal, 

 for example, the principal constituent is 

 carbon, every pound of which requires 

 twelve pounds of air to completely con- 

 sume or oxidize it. All air that is used 

 above this amount is known as excess 

 air, and when supplied in greater quan- 

 tities than is necessary to meet the 

 particular conditions of the furnace in 

 which the fuel is burned an unnecessary 

 burden is immediately placed on the 

 temperature possibilities of the furnace 

 and the amount of fuel consumed to ac- 

 complish a desired result increased in 

 proportion. 



Even in fairly good practice about 



Waste Costs High When Boilers Burn Fifty Tons of Coal a Day 



twenty-five tons of air is used to burn 

 one ton of coal, and in the more poorly 

 operated plants this amount is often 

 doubled. Twenty-five tons represent a 

 lot of air. Under normal conditions, it 

 occupies a space nearly 16,000 times 

 as large as the coal which it consumes. 

 If this amount of air were contained in 

 a pipe with one square foot cross sec- 

 tional area, it would have to be long 

 enough to extend nearly from New York 

 to Baltimore. Stated in another way, if 

 the floor of a room were covered with 

 coal to a depth of one foot, the ceiling 

 would have to be three miles high in 

 order for the room to contain as much 

 air as is generally used to burn that 

 amount of fuel. The fact that so much 

 air is consumed in burning one ton of 

 coal is not realized by the fireman and 

 the important relation which this huge 

 mass bears to fuel economy is generally 

 not given sufficient thought by his su- 

 ])eriors. Although air costs nothing and 

 is available in unlimited quantities, 

 when used to burn fuel in excess of what 

 is re(|uir('d, as is the case in the average 

 lieating jjlant, it becomes one of the 

 most expensive raw materials. 



Determining Waste. 



All the air that is used in burning coal, 

 whether under steam boilers or for any 

 other process, ai)i)ears in the products 

 of combustion. If 

 three times as much 

 iiir is used as is neces- 

 sary there will b»' just 

 about three times as 

 m u c h products of 

 combustion as neces- 

 sary. This gas as it 

 passes up the chim- 

 ney contains the 

 major portion of the 

 heat that is unneces- 

 sarily wasted. Every 

 degree of temjiera- 

 ture to which each 

 ])()und of this gas is 

 licated above the 

 temperature of the 

 atmosphere means 

 iibout 0.2.J heat units 

 that go to waste. The 

 exact amount of heat 

 wjisfed in this wav 

 can be determined by 

 tlie weight of the 

 jiroducts of combus- 

 tion i)er jtound of fuel 

 burned, and the tem- 

 ])erature at which 

 tlicy leave the furnace 

 or enter tlio stack. 

 Tluis, in the averag<' 

 lil.'iut. for every ton of 



