GB1500231A - Heat exchangers - Google Patents

Abstract

1500231 Thermal regenerators STONEPLATT FLUIDFIRE Ltd 25 July 1975 [30 April 1974] 18854/74 Heading F4K Heat is exchanged between two gas streams (e.g. hot and cold air streams, or air and combustion gases) via fluidized beds positioned in each gas stream, the beds being substantially at the same level and the bed particles being caused to migrate from each of the beds to the other. The bed particles may be of alumina or zircon. Fig. 1 shows one arrangement wherein fluidized beds 24, 23 disposed respectively in the hot gas duct 14 and air duct 15, are interconnected via an opening 25 in the wall 12 separating the two gas streams. The beds 23, 24 rest on a perforated support 16 in which are slits 27 shaped as, e.g. in Fig. 4 to produce a horizontal flow component in the air or hot gas passing upwardly through the support. The disposition of the slits 27 (e.g. in zones as indicated at 29- 33 in Fig. 2) is such as to cause a circulatory flow of particles between the beds 23, 24 (as indicated by arrows in Fig. 2). 26 is a central guide partition separating particle streams flowing in opposite directions. The perforated support (e.g. 16) may slope in the direction of particle flow thereover. The flow rate of particles between the two beds may be regulated at the opening 25 by means such as a rotary valve. The hot gas fluidizing and heating the bed 24 may emanate from a burner 33, or it may comprise boiler flue gases entering at 17. A blower 18 supplies the air which fluidizes and is heated by the bed 23, the heated air being discharged at 22 to the point of use. The hot gases cooled in the bed 24 are discharged via a blower 20 to a flue 21. To prevent gas leakage into the air stream a higher air pressure is maintained. In another scavenging arrangement described (Fig. 5) the parts of the partition wall respectively above and below the bed-connecting opening are laterally offset. A modification described (Figs. 3 and 5) comprises a two-stage apparatus in which the heat exchanging gases are both directed in series through a plurality of the fluidized beds.