Patent GB-745556-A (GB)
Title: Improvements in apparatus for cleaning the surfaces of heat exchange means
Inventor: KIRKBY ALBERT HARRY
IPC: F23J3/02
Filed: 1953-06-18
Abstract: 745,556. Cleaning heat-exchangers. BABCOCK & WILCOX, Ltd. June 18, 1954 [June 18, 1953], No. 16830/53. Class 99(2). In apparatus for cleaning the surfaces of heat-exchange tubes 1 in an upright gas pass 2 and comprising distributing means 12 which direct a stream of solid cleaning particles on to deposits on the tubes with which the particles, in falling impact, means to collect the particles at a location below the pass, and means to convey the particles to a location above the pass, provision is made for withdrawing particles below a predetermined size from the particle circulating system. The particles may comprise irregularly shaped shot of wrought iron, pig iron or mild steel. As shown in Fig. 1, the pass 2 has a gas inlet 7 and a gas outlet 9, and at the lower end thereof a hopper 3 to which is attached a shot-collecting duct 13 connected by a shoot 30 to a collecting bin 31 provided with a cut-off valve 32 and an overflow 33 having suitable closing means, the valve being connected by a pipe 34 to a nozzle 35 disposed in a pipe-line 38 leading to the upwardly directed inlet 40 of a separator 39. Collecting duct. Internally of the duct 13, Fig. 3, are inclined screens 14, 15, the screen 14 being of larger mesh and more robust construction than the screen 15 and serving to arrest and prevent large pieces of slag and brick entering and damaging the shot circulating system, those pieces being removed through a closeable aperture 26. The screen 15 arrests the shot which pass down the sboot 30 to the bin 31, shot which have been worn down by repeated use to a size rendering them unsuitable for cleaning purposes passing through the screen and over a damper 16, Fig. 1, to a suitable receptacle ; the screen is pivoted at 21 and held in position by a strut 22 pivoted to the screen at 23, the screen on becoming clogged with shot being swung downwardly under the control of the strut and after the bolts 20 have been removed. Separator. A circular impact plate 43, Fig. 4, in alignment with the inlet 40, which has a diameter larger than that of the pipe 38, is supported on a vertically adjustable rod 44 and is formed with a lower surface which in diametral cross-section slopes upwardly from a central peak 51 and then curves downwardly to form an inverted, peripheral channel 52. Shot carried by air pressure from the bin 31 and through the pipe 38 strike the plate 43 and fall towards the outlets 42, the air leaving by the separator outlet 41 and a duct 46. The shot pass down pipes 53, Fig. 1, to the distributing means 12. Distributing means. As shown in Fig. 5, a deflector 56 of parabolic form in diametral cross-section is located by a spigot 58 on a disc 57 mounted on a cross-piece 59 supported by arms 60 secured to a spout 55, Fig. 1, in communication with the pipes 53, each arm, in transverse cross-section, tapering inwardly. In modifications, (a), Fig. 7 (not shown), the deflector is of conical shape and formed with curved flutes and a rounded peak, the flutes increasing in width and depth as they extend towards the base of the deflector, and (b), Fig. 9 (not shown), the deflector has a cylindrical base and an upper part formed with a surface which slopes with increasing steepness towards a central, rounded peak, a downwardly sloping hood being mounted above the deflector to redirect shot which rebounds from the deflector. Specification 745,620, [Group XXX], is referred to.