Document QgbrwKaDX9N2E64E5rgpN70mk

Heating Ventilating Air Conditioning Guide 1939 Chapter 13. Heating Boilers per hour for'mechanically fired- boilers when operating at design load When operating at maximum load2 these values will run between. 5000 and 1 6000 Btu per sq ft per hour. : Boilers operating under favorable conditions 1 at the above heat transfer rates will give exit gas temperatures that are considered consistent with good practice. TESTING AND RATING CODES The. Society has.adopted three solid .fuel testing codes, a solid fUe[ rating code and; an oil .fuel testing code. A.S.H.V.E. Standard: and Short Form Heat Balance Codes for Testing Low-Pressure Steam Heating Solid Fuel Boilers--Codes 1 and 2--(Reyisionof June 1929)3, are intended to provide a method for conducting and reporting tests to determine heat i % ?r efficiency and performance characteristics. A.S.H.V.E. Performance Test Code for Steam Heating Solid Fuel Boilers--Code No. 3--(Edition of 1929)8 is intended for use With A.S.H.V.E. Code for Rating Steam Heating Solid Fuel Hand-Fired Boilers4. The object of this test code is to specify the tests'to be conducted and to provide a method for conducting and reporting tests to determine the efficiencies and performance of the boiler/ The A.S.H.V.E. Standard Code for Testing Steam Heating Boilers Burning Oil Fuel3 is intended to provide a standard method for con ducting and reporting, tests to determine the heating efficiency and performance characteristics when oil fuel is used with steam heating boilers. Steel Heating Boilers Ratings ' The Steel Heating Boiler Institule has adopted a method for the rating of low pressure boilers based on their physical characteristics and expressed in square feet of steam or water radiation or in Btu per hour as given in Table 2. The following requirements are included in this Code: 1. One square foot of steam radiation is to be considered equal to the emission of 240 Btu per hour and one sqiiare foot of water radiation is to -be considered equal to emission of 150 Btu.per hour;: -.; : : :. 2. The rating pf a boiler expressed in square;feet.of steam radiation in which solid fuel hand fired is used is based, on the amount .equal to 14,times the heating surface of the boiler in square feet. ... .. : - . .. r.. 7 / 3.'The`rating of a boiler expressed m square feet of steam radiation in which solid fu^ mechanically; fired, or in which: oil or gas; is burned, ;is based on the amount equal to 17 times the-heating surface of the boilerin square feet. ; 4. Heating surface is to be expressed in square feet and include those surfaces in the boiler which are exposed to the products of combustion on brie side and water on the other. . In. measuring surfaces, the outer tube areas are to be considered. Wh?n a boiler has the water leg height increased, the heating surface noted in -the published ratings are not to be increased. 5. A grate area is to be considered as an area of the grate surface expressed in square feet and measured in the plane of the top surface of the grate.. For double grate boilers the grate surface is to be considered as the area of the upper grate plus one-quarter of the area of the lower grate. ' .. 6. The grate area of a boiler for rating, as determined in No. 2 is to be not less than that determined by the [following formulae: , , For boilers with ratings 1800,sq ft to 4000 sq ft of steam radiation: \ ii I VGrate Area = Catalogue Rating (in square feet steam radiation) -- 200 .. . 25.5 " _" (\) aFor definitions of design load and-maximum load see pages.237 and 238. *See A.S.H.V.E. Transactions, Vol. 35, 1929. p. 12. Also Chapter 45. 3See A.S.H.V.E. Transactions, Vol. 36, 1930, p. 35. Also Chapter 45. *See A.S.H.V.E. Transactions, Vol:-37,1931vp'. 23. Also. Chapter.45. Table 2. Standard Steel Heating Boiler Ratings3 1,800 2,200 2,600 3.000 3.500 4.000 4.500 <5,000 6.000 7,000 8;500 10,000 12.500 15.000 17.500 20.000 25.000 .30,000 35.000 Hisu Fired CiPACirr Ratino Btu per Hr Surface Sq Ft 2,880 3,520 4,160 4,800 5.600 6,400 .7,200 8,000 9.600 11,200 13.600 16,000 20,000 24.000 28.000 32,000 40.000 48.000 56.000 432,000528,000 624,000 720,000 840,000 960,000 1,080,000 1,200,000 1,440,000 1,680,000 2,040,000 2,400,000 3,000,000 3,600,000 4,200,000 4,-800,000 6,000,000 7,200,000 8,400,000 129 158 186 215 250 286 322 358 429 500 608 715 893 1,072 1,250 1,429 1,786 2,143 2,500 Mechanically Fired Capacity Rating Grate Steam Water Area Radiation Radiation Sq Ft Sq Ft Sq Ft Bto per Hr Furnace Volume Bituminous Coal CuFt 7.9 8.9 9.7 10.5 11.4 12.2 13.4 14.5 16.4 18.1 . 20.5 22.5 25.6 28.4 30.9 33.2 37.4 41.2 44.7 2,190 .2,680 3,160 3,650 4,250 4,860 5,470 6,080 7,290 8,500 10,330 12,150 15,180 18,220 21,250 24,290 30,360 36,430 42,500 3,500 4,280 5,050 5,840 6,800 7,770 8,750 9,720 11,660 13,600 16,520 19,440 24,280 29,150 34,000 38,860 .48,570 58,280 68,000 525,600 643,200 : 758,400 876,000 1,020,000 1,166,400 .1,312,800 1,459,200 1,749,600 2,040,000 2,479,200 2,916,000 3,643,200 4,372,800 5,100,000 5,829,600 7,286,400 8,743,200 10,200,000 15.7 19.2. 22.6 26.1 30.4 34.8 39.1 43.5 52.1 60.8 73.8 86.8 108.5 130.2 151.8 173.5 216.9 260.3 303.6 .AHftntpd bv the Sled Healing Boiler Institute in cooperation with the Bureau of Standards, United States Deportment of Commerce Simplified Practice Recommendation R 167-S5. For boilers with ratings 4000 sq ft of steam radiation arid larger: VGrate Area = Catalogue Rating (in square feet steam radiation) 16.8 1500 (2) 7. The volume for furnaces in which solid fuel is burned is to be considered as the cubical content of the space between the bottom of the fuel bed and the first plane of entry into or between the tubes. Volume of furnaces in which pulverized liquid fuel or gaseous fuel is burned are to be considered as the cubical content of the space between the hearth and the first plane of entry into.or between the tubes. No minimum furnace volume is to be specified for mechanical-fired boilers burning anthracite. 8. The furnace volume for a^boiler, with a rating as determined in No.- 3 in which oil, gas or bituminous coal stoker fired is burned is not to be less than one cubic foot for every 140 sq ft of steam rating. 9. .The: average.height of furnace for the rating determined in No. 3 in which bitu minous coal, stoker fired is burned is riot to be less than that determined graphically in Fig. 1 or mathematically by the following forhuila: . r:. :V;2&+V" H - '(3) where H = average furnace'height; inches as determined by the following formula: 12F ._ 12F H = A ~ WI. R- -- stoker fired boiler rating, square,foot steam radiation. A -- planarea of firebox, square: feet measured at the bottom of-the fuel bed.'F = furnace volume, cubic feet. 255 /'