GB1452290A - Rotor for rotary regenerative heat exchanger - Google Patents

Abstract

1452290 Thermal regenerators ADVANCED MATERIALS ENG Ltd 16 Sept 1974 [24 Oct 1973 16 April 1974] 26826/74 and 16607/74 Divided out of 1452289 Heading F4K In a rotary-matrix type thermal regenerator, the rotor comprises a plurality of modules each containing at least one mass of heat transfer material, each module having at least one outer face which is flat or which is, curvilinear, and the rotor having at least one external surface which is either a plain endsurface transverse to the central axis of rotation of the rotor, or which is a curvilinear surface coaxial with said axis and which is formed by like outer nodule faces adjoining one another. The modules are preferably made up of separable parts to allow replacement of the heat transfer material. The heat transfer material may comprise plates (e.g. Figs. 2 and 9) of metal or of a ceramic material such as silicon nitride, a cellular ceramic foam, a mass of ceramic fibres, or a mixture of fibres and porous or particulate material. In one form, Figs. 1 and 4, sector shaped modules 10 are assembled to form a disc-shaped rotor 50 in which the modules are retained in position by an encircling steel band 52. In use, the rotor is in sliding engagement with two fixed seals 54, 56 each shown as having two sets of openings therein for the passage of the heat exchanging fluids (e.g. turbine exhaust gases and air) each flowing in two separate streams to and from the rotor. The module components, Fig. 1, may be made of metal or of a ceramic material such as silicon nitride; or the front cover 14 at the "hot" face of the rotor may be of ceramic material whilst the remaining components are of metal. In the disc-shaped rotor of Fig. 12, sixteen modules 322 (only one being shown) of ceramic material such as silicon nitride are fitted into a rotor housing 312 of ceramic or metal and are held therein by retainer rings 342, 344. Each module 322 comprises open ended sector-shaped box containing the heat transfer material 372 and packings (330, Fig. 11) which permit independent distortion of the heat transfer material. Fig. 10 shows a drum-shaped rotor 200. The stationary seals 316 and 364 (see also Fig. 11) are of a soft ceramic fibre comprising an assembly of sector-shaped modules (Fig. 8) which may be retained in position by an encircling steel band (not shown). In use, the rotor is engaged by seal assemblies 202, 204, the steel band being positioned out of the area swept by the seal assemblies. The rotor drive may be at the rim, or through a hub (not shown); and the ratio of the inside to outside diameters is between 0.4 and 0.6. Fig. 13 shows another embodiment in which the modules are mounted between cylindrical metal or ceramic walls 400, 402 of the rotor shell. Each module comprises an end wall 416 connected to opposed side walls 414, and an end wall 418 sealed by a gasket 420 to the rotor shell. The heat transfer material comprises blocks 430 arranged as shown, the gas flow through the blocks being denoted by the arrows.