GB558059A - Improvements in or relating to pulverised fuel burners - Google Patents

Abstract

558,059. Pneumatic conveyers. BABCOCK & WILCOX, Ltd. June 15, 1942, No. 8165. Convention date, Sept. 30, 1941. [Class 78 (i)] [Also in Group XI] Pulverized fuel and carrier air are supplied through conduits having a terminal section 25 of rectangular cross-section to flow-division boxes or riffles 26 mounted on furnace wind box 15, the slots 28 of the riffle being connected to grouped tubular discharge members 29 of oval cross-section. Each group of four members 29 has its discharge tips arranged in line above tapering heat-resistant protectors 33 carried by alternate inclined fluid heating tubes 14 extending across a rectangular burner port 12 in the inclined roof of the furnace chamber 10. The intervening tubes 14 have arcuate protectors 34 on their upper sides. The members 29 are held in position by notched plates 35 on the protectors 33 and are spaced by bars 31. The windbox 15 may be divided by partitions 18 into chambers each having its own damper-controlled air inlet 19, observation door 22 and fuel igniter 23. To prevent segregation of the pulverized fuel and air mixture it is supplied through a vertical supply pipe 37 of circular cross-section connected by a bend 39 of rectangular cross-section to a straight section 41 of circular cross-section leading to the terminal section 25. The dimensions of the various sections where D is the diameter of the section 41 are indicated in Figs. 1 and 3. The terminal section 25 should have a minimum developed length of 1.88 (3N-1.56D) where N is the number of members 29. Holes for lancing tips are provided in boxes 36 on the section 35 in alignment with the members 29. In another construction in which the terminal section of the supply conduit is elongated in a direction parallel to the tubes 14 the slots 53, Fig. 10, between the riffle bars are connected to groups of tubular discharge members 55a ... 55d each group being spaced above a fluid heating tube 14. In a third construction shown in Fig. 11 groups of tubular discharge members 70 of circular cross-section leading from the riffle 26 have flattened ends 71 spaced along the tubes 14.