GB1244048A - The supply and/or discharge of solid particles in contact heat exchangers - Google Patents

Abstract

1,244,048. Thermal regenerators. SIEMENS A.G. 23 Dec., 1968 [22 Dec., 1967], No. 61163/68. Heading F4K. Particles at the inlet or outlet zones of a moving particle bed 3 in which heat is exchanged by direct contact between the particles and a gas, are fluidized by the gas at least at one of these zones so that the particles are enabled by such fluidizing to flow along collecting and/or distributing paths which are horizontal or only slightly inclined, e.g. with a slope of 1 in 10, thus enabling the overall height of the heat exchanger to be reduced. The apparatus shown is a thermal regenerator in which the particles are contacted in an upper bed by a hot gas stream G1, gravitate through a duct 22 to a lower bed in which they are contacted and cooled by a cold gas stream G2 and are thereafter recycled to the upper bed by conveyer means 7. The particles may, e.g. comprise spherical or cylindrical ceramic bodies having a mean diameter of about 5-10 mm. Each bed of particles is supported on a layer 8 of hollow members and comprising baffle members 19A, 19B, 19C (see Fig. 4) and providing chambers 16 in which particles passing downwardly from the beds are fluidized before falling into funnelling arrangements 14 which deliver the particles to localized feeding points 11 distributed over an array of horizontal or slightly incl.ned channels 10, which may be generally parallel to one another as shown n Fig. 2, or radial (Fig. 3) and from which the particles either gravitate (arrows F<SP>1</SP>) via duct 22 to the lower bed, or pass from the lower bed, via duct 6, to the conveyer 7. The respective gas streams G1, G2 enter the channels 10 via perforated plates 9, or arrangements of guide blades (15, Figs. 5 and 6) forming the lower boundary of the channels 10. The lower particle bed shown is provided with means to regulate passage of the particles through the layer 8 to the discharge region. Said means comprise a division G21 of the gas stream G2. The stream G21 is directed through a duct 4a in which it may be controllable by valve means (not shown), and ports 4b (see Fig. 4) to chambers 21 below the layer 8. From chambers 21 the stream G21 flows via apertured walls 20 through wedge-shaped regions 13a where bed particles tend to accumulate and from which more or less particles are blown by the stream G22 over the edges 23 and into passages 12 where they are fluidized by the other division G22 of the stream G2. Some of the gas stream may be recirculated (as a stream G<SP>1</SP>22) by a fan 25 in order to maintain particle fluidization in the outlet channels 10 of the lower bed. In the particle supply region at the top of each bed the particles are fluidized by the upflowing gas stream G1 or G2 as they move from the respective inlet G<SP>1</SP> or 22 along passages 26 which are open at the bottom to allow the particles to enter the bed. The arrangement of the passages 26 is shown in Fig. 7 and below these passages are baffle walls 27 (see also Fig. 9), said to provide uniform distribution and hence fluidization conditions over the area of the supply region. The particle supply passages may be radially extending from a central supply point (Fig. 3).