GB746276A - Improvements in or relating to tubulous fluid heat exchangers - Google Patents

Abstract

746,276. Tubular heat exchangers. BABCOCK & WILCOX, Ltd. Dec. 19, 1952 [Dec. 22, 1951], No. 30078/51. Class 64(1). The external surfaces of a bank of horizontal or inclined heat exchanger tubes are cleaned by causing the gases, which normally have an upward or downward flow, to flow transversely of the tubes laterally within the tube bank. In the drawings the reference 2a indicates one only of four vertically spaced tube banks of an air heater associated with a tubulous vapour generating and superheating unit. Above the unit are three dampers 12a, 12b, 12c, Fig. 2a, and below are three dampers 13a, 13b, 13c. These dampers each consists of a plurality of spaced tubes which normally are clear of the tube bank, as in the case of the damper 13a, Fig. 3, so as to permit the downflow of the gases, but which can be moved to close the spaces between the adjacent row of the tube bank as in the case of the dampers 13b, 13c. Actuation of the dampers is effected by fingers 22 which extend radially from rotatably mounted shafts 24a, 24b, 24c and 24a<SP>1</SP>, 24b<SP>1</SP>, 24c<SP>1</SP>, arranged as shown, the fingers projecting into the ends of the damper tubes. Rotation of the shafts is effected by handles 46a, 46b, 46c, and 46a<SP>1</SP>, 46b<SP>1</SP>, 46c<SP>1</SP>, associated with holding devices, Fig. 6 (not shown). In use, the normal downflow of gases can be temporarily interrupted as shown in Fig. 2a by moving the dampers 12b, 12c, 13a, 13b to the closed position, thus causing the gases to flow laterally over the tube bank as illustrated and freeing them from dust. The gases may then be made to pass in the reverse direction by closing the dampers 12a, 13c and opening dampers 12c, 13a. Specification 746,335 is referred to.