The Weekly Florists' Review. 



591 



Omaha Florists' Club on an Outing, July 23, 1903. 



something of the heating power of 

 rious grades of coal, and t In- hum 

 determiniDg this efficiency. 



In all our calculations we use Mi 

 r. (British Thermal Dnlt) as our I 

 measuring the heal givi u oil bj il 

 bustton of any fuel. This unit 

 amount of heat required to raise on. 



Fahrenheit. i:.i>i n- is also made 



Carbon and hydrogen represe 

 tible portion of a fuel, ar 

 value depends upon the propt 

 these elements are present. 



contain some mnisttuv and more or less in- 

 combustible matter, either sulphur or ash. 

 The anthracite coals contain a moderate 

 Percentage of moisture, are low in hydrogen, 

 high in carbon, and moderately high in ash : 

 these produce very little flame. Ordinary 

 wood, on the other hand, is high in moist 

 comparatively high in hydrogen, and 



)W in carbon and ash 



The following table J 

 ive heating value of th 

 oals : 



hov, 



k-i.Jntr™l Carbon Volatile B.T U. Water evap. 



Kind of Coal. comen ma „ er per Ib Der lh 



\nthrarite sit. On :-;.S0 13.220 13.66 lbs. 



Seml-P.iliiinin's 73. St IS. 56 1-l.T.li > 14. us ll.s. 



Bituminous r>r,. no ::.:,. no 13,000 13.50 ll.s. 



Lignites 3S.7S 40.19 9,670 10.00 lbs. 



It will be observed that as we pass from 

 anthracite to the softer grades of coal, as 

 the carbon decreases the volatile matter in- 

 creases, and the heating value decreases. 

 except in certain of the semi-bituminous 

 coals found in Pennsylvania. Maryland and 

 West Virginia, which contain a higher num 

 ber of heat units and are capable of evapo- 

 rating more water per pound than are the 

 anthracite coals. The highest of these is 

 known as Broad Top. Pa., containing 14,- 

 S20 heat units per pound of coal. 



By reference to the above table of heat- 

 ing values of the various classes of coals, 

 we can ascertain the comparative cost per 

 thousand heat units at the prices of coal 

 delivered. Assuming the price per ton for 

 the various coals to be that given in the 

 following table, we have : 



on of Price Cost pe' 



These figures, however, would not h. 

 comparable with actual results accomplished 

 by burning coal under the ordinary boiler. 

 for they are based upon the theoretical 

 heating efficiency of the coal according to 

 ehemical analysis. The results obtained in 

 burning coal as reported by the United 

 States Naval Fuel Board were as an aver- 

 age for seventeen tests about eight pounds 

 of water evaporated per pound of coal 

 burned. Upon this basis the foregoing table 

 should be corrected to read as follows : 



i-;—i „( /-„.! Pnce Price Cost of evap 



kind of Coal. per ton „ er ]b j lh TOter 



Anthracite $6.50 .290 ct. .036 ct.- 



Semi-Bituminous . 4.50 .200 ct. .025 ct. 



Bituminous 3.50 .156 ct. .0195 ct. 



It should be stated, however, that the 

 above Included the raising the water from 

 abont 130 degrees F. and evaporating if 

 under a pressure of about 280 pounds. This 

 VOOld require a greater expenditure of en- 

 1Ur and would in a measure compensate 



ordinary conditions. 

 Substitutes for Coal. 



fuels that might be 



ead are wood, peat, 



lust, spent tanbark. 



bagasse or crushed 



available, it is 

 ■ end the cheap- 

 icipally because 



gel 



efficiency is concerned. The heating effi- 

 ciency of wood varies with the kind, as 

 well as with the amount of moisture it 

 contains. Where an excessive amount of 

 moisture is present in the wood, a large 

 amount of heat is consumed in vaporizing 

 tills moisture. This heat would otherwise 

 be expended in doing the work for which 

 the fuel is being burned. 



In some parts of the country there are 

 large beds of peat that might be used as 

 fuel, especially if put up in the form of 

 briquettes. The manufacture and sale of 

 briquettes has become an important indus- 

 try in some of the foreign countries, where 

 many kinds of fuel are wanting. Various 

 materials are used in the manufacture of 

 these briquettes, among which are lignite, 

 coal dust and screenings, peat, coal tar 

 and products, coke, charcoal and crude pe 

 troleum. Although almost any of the 

 fuels, except the gaseous, may be made 

 into briquettes, the principal use for this 

 method is the transforming of such sub- 

 stances as peat, coal dust and fine slack 

 into a form in which it may be readily 

 burned. Peat usually contains a high per 

 centage of moisture, 10 per cent when thor- 

 oughly dried, and 23 per cent when n-'r 

 dried. About 30 per cent of its available 

 heat is consumed in evaporating this moist- 

 ure. Peat also contains a large amount of 

 ash. 15 per cent on an average, which very 

 greatly diminishes its fuel value. It is. 

 however, about equivalent to good wood as 

 a heat producer, evaporating about six and 

 one half pounds of water to the pound of 

 peat fed into the furnace. 



If charcoal be burned in ovens, the by- 

 products of its manufacture make the 

 process profitable, but owing to the limited 

 quantity of charcoal produced it can sonroe- 



li I nsidered as a regular fuel. There 



in 1.1 no advantage connected with the 

 usi oi charcoal for heal production, as it 

 contains as a rule only about 00 per cert 



,,l 1 I riginal heating value of the w 1. 



and it is more economical to burn the wood 

 itself. Charcoal has about the same heat- 

 ing efficiency as coke and anthracite coal. 



Coke is prepared by the distillation of 

 bituminous coal in ovens or retorts. Un- 

 fortunately the same conditions that gov- 

 ern the output of coal also control the pro- 

 duction and shipment of coke, and it can 

 not be depended upon for use as a substi 

 tute for coal. Coke has about the same 

 heating value per pound as anthracite mil. 

 and burns more freely, but does not last 

 so long in the furnace. 



Sawdust can be utilized for fuel, but to 



nace. The quantity 

 however, is not suf 

 giving it any parti 

 about 50 per cent o: 

 under good draught, 

 evaporation of four 



Spent tanbark is sin 

 the same results as 

 of both of these fut 

 hie to dry them as 

 and then burn then 

 of semi-bituminous 

 i airy the fire. 



Cither wheat or 

 plication as a fue; 

 plentiful, three and 



pounds 1 

 be requi 



of fuel, 

 es about 

 the use 





ton of 2.240 

 and one-half 

 work of one 

 if straw will 

 of coal. It 

 to purchase 

 •d weight, or 

 that the cost 



ny particular 

 cobs, where 



a be used to 

 available as 



is often Used a- fuel, but to be properly 



burned ii re, mires either to be first dried 

 or else in a furnace that is adapted to its 



This practically covers the range of solid 

 fuels, except perhaps a few of minor im- 

 poi tance. found in isolated locations only. 



Through certain sections of the United 

 states there is to be found tin abiindaiiee 

 of natural :;e Where it occurs ill great 



Hie building and to supply coal and the 

 necessary firemen in case the gas should 

 fail at anv time during the year. Where 

 natural gas is used as the regular fuel it is 

 always wise to have a small supply of coal 

 on hand, as the supply of gas is occasion- 

 ally cut off bv breaks in the main pipe line. 

 Coal or illuminating gas is produced by 

 beai nig hituraiiioi:- .in in ail 1 igh 



