GB810436A - Improved assembly for sealing access openings - Google Patents

Abstract

810,436. Cleaning dross. FOSTER WHEELER Ltd. Sept. 13, 1957 [Oct. 5, 1956], 28982/57. Class 25 [Also in Group XII] An assembly for sealing the access opening of a boiler furnace comprises a frame fitting within the opening, a refractory wall towards the inner side of the opening and in contact with the frame and the furnace wall, an .anchor frame within the opening on the outer side of the refractory wall, means for preventing inward movement of the anchor frame and means for securing the refractory wall to the anchor frame and a cover plate secured to the outer side of the furnace wall to retain the anchor frame. The opening is surrounded by a L- section metal frame 17, the flanges of the framing members lying in recesses in the outer surface of the wall and in the surfaces surrounding the opening, which is divided into four sections by transverse closure lintels 31 supported' from the frame 17 and held against inward movement. A wall of refractory bricks 39 fills the inner part of the sections of the opening, abutting the wall surrounding the opening at the inner side of the frame 17, and receiving the transverse lintels 31 in recesses in the bricks 39. Projections 42 on the upper sides of the lintels 31 engage the bricks 39 immediately above, and notches in the bricks 39 receive the supports of the lintels 31. An anchor frame 43, comprising upper and lower angle irons 44, 46 connected by three angle irons 45, is placed in each section with one flange 47 of each angle iron 45 in contact with the bricks 39. The horizontal flange of the upper angle iron 44 lies against the lower surface of a lintel 31 and the vertical flange of the lower angle iron 46 rests on a lintel 31. Lugs 52 on the supports for the lintels 31 and lugs 53 on the upper side of the lintels 31 hold the anchor frames against inward displacement. The refractory bricks 39 are secured to the anchor frames 43 by hook-like bolts 55 having a diamond shaped head 58 which engages recesses in adjacent bricks. The bolts 55 pass through slots in the flanges 47 of the vertical members of the frames and are locked by sleeves 62. The space within each anchor frame 43 is filled by refractory blocks 64 and each section has a metal cover plate 66 reinforced by parallel ribs 69 and having flanges 67, 68 at the top and bottom. The flanges of adjacent cover plates are bolted together. The cover plates for the top section has a flange at its lower edge only, and the cover plate for the lowest section is made of two plates spaced apart by insulation, the thickness of the refractory wall 39 and the arrangement of the anchor frame 43 being such that the outer cover plate is flush with the upper cover plates. The edges of the cover plates 66 over-lap the wall surrounding the opening and are held in place by U-catches 82 screwed to the furnace wall. To gain access to the interior of the furnace the appropriate cover plate, anchor bolts and anchor frame are removed and the bricks removed.