GB758449A - Improvements relating to tunnel furnaces or kilns - Google Patents

Abstract

758,449. Tunnel furnaces. GIBBONS BROS., Ltd. July 19, 1954 [April 17, 1953], No. 10522/53. Class 51(2). In a tunnel furnace of the multiple-track tmiflow or counter-flow type, passageways for the articles to be treated are arranged in vertical rows 11a-11d heated in the firing zone by heating flues 17a-17e extending between a combustion chamber 14 and a waste gases header 20, each flue being associated with its own row of burners 16. The header 20 extends longitudinally on either side of the firing zone to further sets of vertical flues 18 and 19 respectively corresponding to the flues 17a-17e and leading to further headers 21 extending across the furnace and formed at each end with vertical outlet ducts for the waste gases, Fig. 3 (not shown). The flues 18, 19 may be given a zig-zag configuration and the header 20 may be so partitioned as to lead gases from the inner members of the flues 17 to the outer members of the flues 18, 19. A third set of waste gases flues may be provided in which case they will be dis. posed near the ends of a counterflow tunnel or near the exit end of a uniflow tunnel in which latter case the firing zone will be arranged near the furnace entrance. The outer heating flues 17a and 17e may have a greater cross-sectional area than the inner flues 17b-17d. Valves, dampers or the like may be provided in operative association with the burners or heating flues and made thermostatically responsive to the temperature in the particular passageways heated by the flues concerned. The outer passageways may have a more extensive heat exchange with the heating flues than those in the centre e.g. by the provision of a tertiary or additional traverse of the heating flues in the outer regions.