GB570434A - Improved dust separator and collector combined with an air heater - Google Patents

Abstract

570,434. Combined dust separator and air heater for steam boilers. DAVIDSON & Co., Ltd., and WHITMORE, J.. July 21, 1943, No. 11861. [Classes 64 (iii) and 123 (ii)] [Also in Group II] The air supply to a boiler &c. is heated by contact with the outer surfaces of outer and inner tubular members 1, 2 of the dust-separating elements of a dust collector through which combustion gases from the boiler are adapted to flow. In the form shown in Fig 1 the outer tubes 1 are located between a dust-laden gas inlet header 10a and a dust header 7, and the tubes 2 extend from a clean gas outlet header 9a to near the outlet ends of the tubes 1. The annular passages 3, formed between each pair of tubes 1, 2, are provided with vanes 4 to effect whirling of the gases and ejection of the dust therefrom into the header 7, and the tubes 1, 2 are enclosed in a casing 35 which forms, with the header 10a, two compartments 35a; 35b for the passage of the air to be heated which may pass through these compartments in two parallel streams from an inlet 36 to an outlet 37. A bypass flue 33 having control dampers 34, 47 is provided between the headers 10a, 9a so that the dust collector may be cut out, e.g. when starting up the boiler, and a regulator 48 is preferably fitted at the inlet or outlet of the compartment 35b, which has a resistance to flow less than that of the compartment 35a, to restrict the flow of air therethrough. The apparatus also includes a secondary dust collector 16, located at the bottom of the header 7, terminating in a hopper 18 and provided with exhausting means, such as a fan 17 and associated piping 19, 19a and 20 respectively leading from the collector 16 and to the outlet header 9a. In a modification. Fig 4, the gas headers 9a, 10a may be at opposite ends of the tubes 1, 2, with the dust header 7 separating the compartments 35a, 35b and the air to be heated flowing in parallel or in series through these compartments. As shown, the annular passages 3 are constituted by the tubes 1 and additional inner cylindrical members 13. Specification 555,908, [Group II], is referred to.