Document VJrDvZe8zn7dV9EBJodMVVXgq

344 CHAPTER 13 1958 Guide formlv Spaced Flat Opaque Slats, by G. V. Parmelee and W. W. Aubele (A.S.H.V.E. Transactions, Vol. 58, 1952, p. 337). ** The Mechanism of Heat Transfer, Panel Cooling, Heat Storage, by C. S. Leopold (Refrigerating Engi neering, July 1947, p. 33). Hydraulic Analogue for the Solution of Problems of Thermal Storage, Radiation, Convection and Conduction, by C. S. Leopold (A.S.H.V.E. Journal Transactions, Vol. 54, 1948, p. 389). *i Heat Gains Are Not Cooling Loads, by C. O. Mackey and N. R. Gay (A.S.H.V JE. Transactions, Vol. 55, 1949, p. 413). Cooling Load From Sunlit Glass, by C. O. Mackey and N. R. Gay (A.S.H.V.E. Transactions, Vol. 58, 1952, p. 321). See Reference 1, p. 8. so psychrometric Factors in the Air Conditioning Estimate, by C. M. Ashley (A.SlH.V.E. Transactions, Vol. 55, 1949, p. 91). st Cooler Footcandles for Air Conditioning, by W. G. Darley (A.S.H.VJE. Transactions, Vol. 48, 1940, p. 367). T.ightmg and Air Conditioning Design Factors, Report of I.E.S.--A.S.H.VJS. Joint Committee on Lighting and Air Conditioning (A.S.H.V.E. Journal Section, Healing, Piping and Air Conditioning, Sep tember 1941, p. 605). lighting and Air Conditioning, by Howard M. Sharp (Heating and Ventilating, No vember 1942, p. 35). n Compiled by J. P. Stewart from various sources. CHAPTER 14 FUELS AND COMBUSTION Solid Fuels: Analysis, Classification of Coals, Dustless Treatment, Classification of Cokes, Combustion of Solid Fuels, Firing Methods for Solid Fuels, Secondary Air, Draft Requirements and Regulation, Furnace Volume; Fuel Oils: Classification, Analysis, Combustion, Air Required; Fuel Gases: Classification, Heat Value, Combustion; General Combustion Principles; Air Required; Efficiency from Flue Gas Analysis; Heat Balance; Condensation and Corrosion; Soot; Air Supply to Furnace Rooms FUELS may be classified according to their physical state as solid, liquid, or gaseous. The principal fuels used for domestic heating are coal, oil, and gas. However, coke, wood, kerosene, sawdust, briquettes, and other substances are used for heating in special applications or in localities where an adequate supply is available. Experiments are in progress in the use of a colloidal suspension of coal particles in fuel oil, but this fuel has not attained wide-spread usage as yet. The choice of fuel is usually based on dependability, cleanliness, availability, economy, operating requirements, and control. Analysis of Fuels SOLID FUELS Coal has a complex composition that makes classification into clear-cut types difficult. Chemically it consists of carbon, hydrogen, oxygen, nitro gen, sulfur, and a mineral residue called ash. A chemical analysis provides some indication of the quality of a coal, but does not define its burning characteristics sufficiently. The coal user is interested principally in the available heat per pound of coal, the handling and storing properties, the amount of ash and dust produced, and the burning characteristics. A description of the relationship between the qualities of coals and these characteristics requires considerable space; a treatment applicable to heating boilers is given in a Bureau of Mines Bulletin.*1 There are two forms of coal analyses, namely, the proximate analysis and the ultimate analysis. In the proximate analysis the proportions of moisture, volatile matter, fixed carbon, sulfur, and ash are determined, f tb anf1ysis ls more easily made and is satisfactory for indicating most oi the characteristics which are of interest to the user. For the proximate nalysis the moisture is determined by observing the loss of weight of a "ample of coal when dried at about 220 F. To determine the volatile and tb' 1 <^r'e<^ s^haple ls heated to about 1750 F in a closed crucible, an the oss .* weight is noted. The remaining sample is then burned in carh^6n TMble> an<i tim accompanying loss of weight represents the fixed th,,DOn,'f The unburned residue is ash. Although determined separately, causpfh1 con*eni' ls frequently reported with the proximate analysis becontent 6 useb^ness f a eoal for certain purposes depends on its sulfur gaju w^lwlafe analysis, which is difficult to make, the percentages of are d*V roSen> oxygen, nitrogen, sulfur, and ash in the coal sample etermined. It is used for detailed studies of fuels, and in computing 345