Document zQpG6q233o3YDDg5mEJ6KVmzm

332 CHAPTER 17 1946 Guide oil burners usually have available detailed plans for adapting their burners to various types of boilers, and such information should be utilized. Controls Controls for oil burner operation, including devices for the safety and protection of a boiler or furnace, are fully described in Chapter 34. GAS-FIRED HEATING EQUIPMENT A gas burner is defined by the American Gas Association as "a device for the final conveyance of the gas, or a mixture of gas and air, to the combustion zone." Burners used for domestic heating are of the atmos pheric injection, yellow flame, or power burner types. The use of gas has resulted in the production of a number of types of domestic gas heating appliances, and systems. These may be classified Automatic Fuel Burning Equipment 233 are of circular or rectangular shape in order to fit in space available. The control equipment is generally the same as for gas boilers and furnaces. Various baffles made of clay'radiants or metal are used for the purpose of guiding the products of combustion along the heating surface in the firebox or flues. Automatic air dampers are supplied on many models, to prevent flow of air into the firebox^ when the burner is- not operating.A typical gas conversion burner is shown in Fig. 20, Burners of this type are available in sizes ranging from 80,000 to 500,000 Btu per hour capacity. Burners of even larger capacity, for use with natural gas in large steel boilers are usually engineered by the local utility or contractor. . They are available in an infinite number of sizes because the burner may be an assembly of multiple burner heads filling the entire firebox. . Domestic sizes of conversion burners should be installed with due attention to the method of venting. Draft hoods, conforming to Ameri in. types designed for central heating plants^ and those for unit applica-' tion. Gas-designed units and- conversion burners are available for the several kinds of central systems. Unit heaters, space heaters and circu lators may be had for installation in the space being heated. Central Heating Systems Boilers and furnaces specially designed for gas-firing incorporate design features for obtaining maximum efficiency and performance. Small flue passes to secure good heat transfer, the use of materials resistant to the corrosive effects of products of combustion, and draft hoods are notable features. Control equipment includes gas pressure regulators, thermostatic pilots and limit controls designed to protect the appliance and to insure safety of operation. A boiler designed for gas-burning is illustrated in Fig. 19. , Conversion burners are usually complete burner and control units designed for installation in existing boilers and furnaces. Burner.heads can Standard .Requirements, should be installed in place of the dampers- used with a solid fuel. , .: . . . One form of central heating system is the warm air floor furnace5. The use of these furnaces is adaptable to mild climates. They are used for' heating first floors, or where heat is required in only, one or two rooms. A number may be used to provide heat for the entire building where all rooms are on the ground floor, thus giving the heating system flexibility.- With the usual type the register is installed in the floor, the heating element and gas piping being suspended below. Unit Type Heaters Space heaters may be used for auxiliary heating, but in many cases are installed for furnishing heat to entire buildings. With the exception of wall heaters, they are semi-portable. Parlor Heaters or circulators are usually of the cabinet type. They heat" the room entirely by convection, i.e., die cold air of the room is drawn in near the base, passes up inside the jacket around a heating section, and, out of the heater at, or near, the top. These heaters cause a continuous circulation of- the air in the room during the time they are in operation.