Document RjxJ8v0wQBz7ka4E4Qwae33vn

342 CHAPTER 13 . 1951 Guide Report 2062, Utilization of Anthracite for Domestic Heating. Report 2204, The Crater Method of Firing. Report 2403, Anthracite Industries Manual. Oil and Gas Publications: Oil Fuels and Burners, by James A. Moyer (McGraw-Hill Co., 1937). Handbook of Oil Burning, by Harry F. Tapp (American Oil Burner Association). Industrial Gas Series, Combustion (American Gas Association). . Comfort Heating (American Gas Association). Gaseous Fuels (American Gas Association,1948). CHAPTER 14 automatic fuel burning equipment Classification of Stokers, Combustion Process and Adjustments, Furnace Design, Rating; Classification of Oil Burners, Combustion Process, Combustion Chamber Design; Classification of Gas-Fired Heating Equipment, Combustion Process, Ratings; Sizing of Gas Piping, Fuel Burning Rates AUTOMATIC mechanical equipment for the combustion of solid, liquid, and gaseous fuels is considered in this chapter. MECHANICAL STOKERS A mechanical stoker is a device that feeds a solid fuel into a combustion chamber, provides a supply of air for burning the fuel under automatic control and, in some cases, incorporates a means of removing the ash and refuse of combustion automatically. Coal can be burned more efficiently by a mechanical stoker than by hand firing because the stoker provides a uniform rate of fuel feed,, better distribution in the fuel bed and positive control of the air supplied for combustion. Classification of Stokers According to Capacity Stokers may be classified according to their coal feeding rates. The following classification has been made by the XJ. S. Department of Com merce, in cooperation with the Stoker Manufacturers Association. Class 1. Capacity under 61 lb of coal per hour. Class 2. Capacity 61. to 100 lb of coal per hour. Class 3. Capacity 101 to 300 lb of coal per hour. Class 4. Capacity 300 to 1200 lb of coal per hour. Class 5. Capacity 1200 lb of coal per hour and over. Class 1 Stokers These stokers are used primarily for home heating and are designed for quiet, automatic operation. Simple, trouble-free construction and at tractive appearance are desirable characteristics of these small,units. A common stoker in this class (Fig. 1) consists essentially of a coal hopper, 'a screw for conveying the coal from the hopper to the retort, a fan which supplies the air for combustion, a transmission for driving the coal feed worm, and an electric motor for supplying power for coal feed and air supply. Air for combustion is admitted to the fuel through tuyeres at the top of the retort which may be either round or rectangular. Stokers in this class are made for burning anthracite, bituminous, semi-bituminous, and lignite coals, and coke. The U. S. Department of Commerce has issued commercial standards for household anthracite stokers.1 Units are available in either the hopper type, as shown in Fig. 1, or in the bin-feed type as shown in Figs. 2 and 3. Some stokers, particularly those designed for use with anthracite, automatically remove ash from the ash pit and deposit it in an ash receptacle as shown in Fig. 3. Most 343