Document mp9J2xEjOM2knzKjb0xLyvbpb

T able 7. D etailed R equirements for F uel Oils8 OO Heating Ventilating Air Conditioning Guide 1939 Saybolt Furol I at 122 F Viscosm Seconds d s 1 2 1 Universal | at 100 F Saybolt s i i s Point End c 90 Per Cent Point Hg Ke3 1 a Ash Paa Cent 10. ;Per Cent Point || Max. || Max. J Carbon Residue PEn Cent Max. Water and Sediment Per Cent Pour Point Deo F tb iO CD Trace 0.05 on 10% Residuum 1' 410 560* 190 .15* 0.25 on 10% Residuum/ 440 000 o ro 900 0.15 Straight 675 55 09 .009 o ro 40 45 ,C C ..25*0o OOCO 2.5a sa o 0cII^o iS* 'gc 0 u I.5 1"H *0 8., S ,; g c 6 S' 8 'l"o 8. E.SS gSsantsa |sS . V)Ov h-- eg joa'ort V O OaSySgC 11*1 sUl 111 in icc sJ.2ej!fs Scfc Sag 2g||g'|!!| =g 2* ..'g 8 Scf E g c >|c>n>cCu;OvgoQgaSr.=a^~c,,.-aS, o an*j2*-- hg.--e tc -so ooaoScga ioSoSa-caia-sa?^ oo 5.. S*'v.eS3' als--sg|^BSs|d a4*h *ObS_`VE. Jh3>*8^Si h"OUh--Q3hJ3h..&$B22co 'i So" sH89r-54 '-2S"-a<* EKscg v' 0 00 <N *= Si J.f s ooZZIQlCN O O |C Bs3i SB & 150 1 Legal No. 6 Fuel oil-- an oil for use in bur ners equipped w ith preheaters perm itting a high viscosity fuel. No. 5 Fuel oil-- an oil for use in bur 130 ! ners requiring a medium vis or Legal in burners requiring a low vis- or . 230 20* No. 3 Fuel oil-- a distillate oil for uSe n o 1 j Min. | Max. | Max. j Max. j Flash Point Deq F Legal in burners requiring a moder or No. 2 Fuel oil-- a distillate oil for use -110 100 or Legal No. 1 Fuel oil--a distillate oil for use in burners requiring a volatile fuel. 21* g"'2 --a a ehs Szi 8 $ cosity fuel. cosity fuel. ately volatile fuel. ugj '0ll 2 0 las & CO -* .C.S>. 3OtStlCs44v>) o i s|f 3 sis i i"| u -S css 1a coo;- , o. fi C4C0U3O S^^5li*v0 . u g<11 aM w dw ow ow dwowg5.S aZZZZZ Ofcye id o sI Chapter 9. Combustion and Fuels Table 8. Approximate Gravity and Calorific Value of Standard Grades of Fuel Oil Commercial Standard No. 1 2 3 5 6 Approximate Gravttt, Range Baumb 38-40 34-36 28-32 18-22 14-16 Calo&ipic Value Btu Per Gallon 136,000 138,500 141,000 148,500 152,000 eas or vapor by some means. If the excess air is to be kept within efficient limits it means that air must be supplied in carefully regulated quantities. The air and oil vapor must be vigorously mixed to get a rapid and com plete chemical reaction. The better the mixing, the less excess air that will be needed. The combustion must take place in a space that maintains the temperatures high so the reaction will not be stopped before com pletion. When equipped with a means of igniting the oil and safety devices to guard against mishaps, the oil burner possesses all of the elements to be efficient and automatic. 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, and is often designated as city gas. Repre sentative 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 CO2, and from 1 to 12 or 14 per cent of nitrogen. The heat values varies from 700 to 1500 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. COMBUSTION OF GAS The majority of gas burners utilized in central domestic heating plants are of the Bunsen type and operate with a non-luminous flame. In this type of burner part of the air required for combustion is mixed with the gas as primary air, the air and gas mixture being fed to the burner ports. 181