Document xd5RG4NOZznZ34e8RbL6J3y4Q

T able 7. D etailed R equirements for F uel OiLsa HEATING VENTILATING AIR CONDITIONING CUIDE 1944 S&ybolt Furol a t 122 F a m2 e 8 CD s E a I sis S 5 2 ! a 2 0 <0 10 ID ?! d a*, s CL, I2 1O eo.2 <u gg <2<5 a 2 a 2 0 gel IK <2<5 UiS < c0boojfaai pa 2I 1 1 iO (0O) <=>C* O a 00 2 2 H 5O 2 0 0 CD O 65'g 23 1 10 S 0 10 0 0 0H O O CD iO CO * US 4cL-a5> ' C/5 m 0 0 O & 04 0 O O O m fcEs* j23 50 9 o a CD s tH 3 O CO 04 d0 2 2 O 4? ,-J ^ 0 Jf O j* 0 `O , s? 2 0 Sf ~ato 2s 0 0 CO 8s I- l9Va9Ccf jOOati V *-> u 9 *j oS*-oSS8 Sj 83 *> a 18-8 iCsaSn 8 4>.S ll egg* ho 8 M=3> o8 Kj *: i a L1 |a-S5 5=5 "S 'o ^2 S 3fO =>" a, a rt 5 tb I *3 2 cSs ill Ip KC t) =--- T3 '*0 9-a5c cn S -vko,va" .-->oBSScoc" *cg* 2"B w9 *~j "'*a Igi^PesP 8i| `SaSj8SSgoug^--g"|SShggcS=o=:--;S"S"p'r6-g?"i>\ags IoEo^..-a8.Su!g5-E|"5iS=-ggS-S aSC d "g>oSi S a *8o"oS8o-gS,,3a*a^]?|Ij*g}8%|s^WJ.a39i'.20 B2S"|| as Mb *-h a3 - "5S' oS 8* "=3>'<a<"- _HKI3 0 0 04 3 .a o a So1n !j Ba_a- 8 li! 13 s Bo dS d3 -davd S7?'lO;ioOcN>OzfOc c &S " --_ 5 fla. O to IgS s= a sjb a ,s5 Isa. I 111iS|J%a c'SJ52 0 0w r0-- 3 *3 u O0 --> *5 & 0 bo S.5 --u CT 0 ? (0 1 a3 ns c 0 n3 h4> -a U. *5 0 bo m -n <u 33 w cr-- *5 gji> $ CO '-Dr- ns c P %* 3> 0^ ^O `O <8 bO * C s!5 3 o *-o a f 1 <u a 0 3 >. U 0) s>. .5 S o>.3 S'S i_ 0 ,, rt O bo G.S f-s-a -! cr 3 S^ sj& 4)9(0 0.8 _2 s-s> ra*-S 5 Q. rt f a be 'I 3.5 "S S'.? -s 3h S*a S -0 do-<3"d SEB 1 |sl I |8S 8 aa 5 -gg~ >, |a 3 |l| 1 2SI I -1" u$r*S--3 (2.S2 6 *3xx* 3 (2.5 8 04 CO 66 *33 Wu .wtl ,b3 4s) 0u to d 1E1 3 4) 4) tea CD 0 Ks-c t* nniotfi > ".i5i=3if! Ouq.ZoZ0Z0Z0Z0 o52 sej*- Sc *a" ' 'Z 3a 180 CHAPTER 8. COMBUSTION AND FUELS produce all the heat possible. The use of unreasonable quantities of air in excess of theoretical combustion requirements results in lowered efficiencies due to increased stack losses. Such losses, if not accompanied by unburned products of combustion may be offset somewhat by in creasing the secondary heating surfaces of the heat absorbing medium boiler or furnace. Oil is a highly concentrated fuel composed mainly of hydrogen and carbon. In its liquid form oil cannot burn. It must be converted into a gas or vapor by some means. If the excess air is to be kept within efficient limits, air must be supplied in carefully regulated quantities. The air and oil vapor must be thoroughly mixed to get a rapid and complete chemical reaction. The better the mixing, the less excess air will be . needed. The combustion must take place in a space that maintains the temperatures high so the reaction will be completed. Table 8. Approximate Gravity and Calorific Value of Standard Grades of Fuel Oil COUMEBCIAL Standabd No. 1 2 3 5 6 Afpkozhuts Grattit, Ranob Battue 38-40 34-36 28-32 18-22 14-16 Calorctic Value Btu Feb Gallon 136,000 138,500 141,000 148,500 152,000 CLASSIFICATION OF GAS Gas is broadly classified as being either natural or manufactured. Natural gas is a mechanical mixture of several combustible and inert gases rather than a chemical compound. Manufactured gas as dis tributed is usually a combination of certain proportions of gases produced by two or more processes. Representative properties of gaseous fuels commonly used in domestic heating are presented in Table 9. Natural gas is the richest of the gases and contains from 80 to 95 per cent methane, with small percentages of the other combustible hydrocarbons. In addition, it contains from 0.5 to 5.0 per cent of COt, and from 1 to 12 or 14 per cent of nitrogen. The heat value varies from 1000 to 1200 Btu per cubic foot, the majority of natural gases averaging about 1000 Btu per cubic foot. Table 9 shows typical values for the four main oil fields, although values from any one field vary materially. Table 9 also gives the calorific values of the more common types of manufactured gas. Most states have legislation which controls the distri bution of gas and fixes a minimum limit to its heat content. The gross or higher calorific value usually ranges between 520 and 545 Btu per cubic foot, with an average of 535. A given heat value may be maintained and yet leave considerable latitude in the composition of the gas so that as distributed the composition is not necessarily the same in different dis tricts, nor at successive times in the same district. However, in any community the variations in gas composition are held within suitable limits so that the performance of approved gas appliances will not be adversely affected. 181