GB1465952A - Incineration control - Google Patents

Abstract

1465952 Incineration control SALEM CORP 21 June 1974 [13 Sept 1973] 14118/74 Heading F4B The operating temperature of an incinerator for incinerating combustible material (such as solid liquid or gaseous effluents) is controlled. The incinerator has an inlet, to which is fed an input flow comprising the combustible material entrained in gaseous diluent, and also has an outlet, from which emanates an output flow of gaseous products by incineration of the input flow. The method of operating comprises feeding a fuel to the incinerator at a substantially constant rate, maintaining substantially constant the temperature of the input flow, and controlling the flow rate of the input flow in such a manner as to maintain the temperature of the output flow substantially constant. As shown, an incinerator 13 incinerates solvent which has evaporated from freshly painted products in an oven. The freshly painted products enter an oven zone 1 through an inlet 10. Reference 11 indicates entry to the oven of the paint solvent on the painted product and reference 12 indicates entry of air through the oven inlet. The air together with evaporated solvent from the painted products is blown by a fan 15 to the incinerator 13 which is fed with fuel at a constant rate through a line 16. To keep constant the temperature of the gaseous input flow to the incinerator, some of the incinerator output flow from a duct 18 is returned to the incinerator via a duct 25, oven zone 1 and duct 14. The return is controlled by a valve 26 and thermoresponsive device 27. So as to maintain safe operation, it is required to keep constant the concentration of solvent in the input stream to the incinerator (even though the rate at which solvent is evaporated in the oven may vary, e.g. with oven load). Under the above conditions of constant fuel feed rate and constant temperature of the input flow, any variations in solvent concentration cause changes in the temperature of the output flow in duct 18. However, temperature in duct 18 is monitored by a device 56 which in turn actuates a valve 55 so as to keep the output flow temperature constant. Actuation of valve 55 causes alteration of the rate of input flow with consequential adjustment of the solvent concentration in the input flow. A portion of the output flow from duet 18 is supplied via duct 19 to a radiant baffle 20 which physically surrounds and heats the oven zone 1. The flow of output gases to the baffle is controlled by valves 35, 36 and thermally responsive device 37 to keep the temperature of the baffle constant. The painted products pass through oven zones 1, 2 and 3 (diagramatically shown separate but usually abutting one another) and further solvent is evaporated therefrom. A portion of the incinerator output flow passes to the zones 2 and 3 through ducts 21, 40 and 41 and is returned to the incinerator via ducts 52, 54 and 22 and oven zone 1. The amount of incinerator output flow which is supplied to oven zones 2 and 3 is controlled by valves 46 and 50 and thermally responsive devices 47 and 51. In a modification (Fig. 2, not shown), duct 25, instead of leading to oven zone 1, passes directly to duet 14.