Operation of Multiple-Hearth Furnace
The operator must be able to maintain stable furnace operation, be able to operate the furnace in its most efficient manner, and be able to operate the furnace within design parameters. The bottom line is quite simple: for the operator to be able to perform any of these functions, he/she must know how to operate the furnace and its equipment. It is important for the operator of the multiple-hearth furnace to remember that an excess amount of air must be available at all times. This excess air assures that all volatiles can contact sufficient oxygen to ensure complete combustion. If there is inadequate oxygen present, there will be incomplete combustion, which means smoke. Smoke indicates unburned hydrocarbons. To aid the furnace operator an oxygen analyzer is installed in the furnace system to measure excess air in the furnace. The oxygen analyzer draws a sample from the exhaust after the I.D. fan and indicates the amount of oxygen remaining after combustion.