GB329787A - Improvements in muffle furnaces - Google Patents

Abstract

329,787. Gibbons Bros., Ltd., and Bridgford, T. E. April 19, 1929. Muffle furnaces.-The roof and side walls of a muffle are formed by transversely arranged parallel tubes, 2, 4, 5, which communicate with a flue passage beneath the floor, and are spaced from the enclosing walls 28, 29 of the furnace. In the construction shown combustion products from a fireplace and hot secondary air are supplied to the space beneath the roof 29 and enter the flue system of the muffle through the apertures 9 in the arched roof flue 2, from which they pass down the side flues 5, across the floor, and up the flues 4 to the downcast flue 10, horizontal floor flues 11, and the waste flue 12. The secondary air is heated in fires alternating with the flues 11 and in wall flues 14. The roof and wall flues of the muffle are spaced apart, and are built up of short lengths of the tapered section shown in Fig. 6, and having interengaging ends and panelled walls. The roof flues are spaced apart by grooved bricks 20 adapted to engage the edges of the two adjacent sections, and the spaces between these bricks are filled in by blocks 37 supported on the recessed edges 39 of the roof sections. The floor of the muffle is constructed in the manner described in Specification 296,936.