WO2001053767B1

WO2001053767B1 - Rotary regenerative heat exchanger and rotor therefor

Info

Publication number: WO2001053767B1
Application number: PCT/GB2001/000206
Authority: WO
Inventors: John A Hamilton
Original assignee: Howden Power Ltd; John A Hamilton
Priority date: 2000-01-19
Filing date: 2001-01-19
Publication date: 2002-01-10
Also published as: TW464756B; WO2001053767A1; EP1248936A1; GB2358698A; AU2001231979A1; GB0001226D0

Abstract

A rotary regenerative heat exchanger includes a rotor having primary vanes (14) extending between the hub and the periphery of the rotor, and additional secondary vanes (15) between said primary vanes and extending over an outer annulus of the rotor. Such an arrangement facilitates having several of the primary and secondary vanes sealed with respect to a sector plate over the outer annulus as compared with the number of primary vanes sealing with the same sector plate over the inner annulus.

Claims

AMENDED CLAIMS[received by the International Bureau on 3 August 2001 (03.08.01); original claims 1-13 replaced by amended claims 1-13 (3 pages)]

1. A rotor (2) for a rotary regenerative heat exchanger, comprising :- a hub; a plurality of radially extending vanes (14) defining between them sector-shaped spaces to receive heat exchange media and defining first and second opposed faces of the rotor and an axially extending face between them; and first and second sets of radially extending seals on said rotor (2) to seal with the adjacent face of the respective one of first and second opposed stator plates, respectively, some of said seals extending along each said vane on both the first face and the second face; characterised in that each said set of radially extending seals includes seals extending along secondary vanes (15) between the first mentioned vanes over a radially outer annulus of the rotor but not over a radially inner annulus thereof.

2. A rotor according to claim 1 and including axially extending seals ( 14a, 15a) on the radially outer surface of each primary (14) and secondary (15) vane.

3. A rotor according to either of claims 1 and 2, wherein there are at least two secondary vanes (15) disposed between the adjacent successive primary (14) vanes of the rotor.

4. A rotor according to any one of claims 1 to 3 , and including a circumferentially extending wall separating the inner annulus from the outer and extending between said opposed first and second faces of the rotor, and continuous seals (1 ) on said cjjcumferentially extending wall at said first face and at said second face of the rotor.

5. A rotary regenerative heat exchanger comprising: - a rotor (2) having a plurality of radial vanes (14) defining between them spaces in which fluid treatment medium is located; a stator (14) forming a housing for the rotor and defining first and further fluid flow paths to and through the rotor in different sectors thereof; sectorplates (20) of the stator, extending in the radial direction relative to the rotor axis and serving to separate the heat exchange sectors corresponding to said first and further fluid flow paths; and

AMENDED SHEET (ARTICLE ! 9) seal means on said radially extending vanes to seal against the adjacent surface of a respective one of said sector plates as the respective rotor vane sweeps in close relationship to said sector plate surface during rotation of the rotor, characterized in that additional vanes (15) are provided between the first mentioned vanes, over a radially outer annulus of the rotor, said additional vanes including further seals to seal against said sector plate surfaces.

6. A rotary regenerative heat exchanger according to claim 5, wherein the further fluid paths are secondand third separated paths; wherein there are firstsaid sector plates bounding the first path for hot gas through the rotor to impart heat to heat exchange media within the sector of the rotor in register with saidfirst path, and further said sector plates defining said second and third paths for fluidthroughheat exchange media in the sectors of the rotor in register with said further paths; and wherein said first sector plates divide the first fluid path from said second and third fluid paths and the further sector plates separate said second and third fluid paths from one another.

7. A rotary regenerative heat exchanger according to claim 5, wherein said further fluid flow paths comprise second, third and fourth paths, and wherein first said sector plates separate said first fluid path from second and third fluid paths through the rotor, and a first set of said further sector plates separates said second fluid path from said fourth fluid path and a second set of said further sector plates separates said third fluid path from said fourth fluid path.

8. A heat exchanger according to any one of claims 5 to 7, wherein the or each sector plate is substantially parallel-sided over substantially the whole of the extent from the rotor hub to the periphery.

9. A heat exchanger according to any one of claims 5 to 7, wherein the width of a said sector plate decreases towards the periphery of the rotor.

10. A heat exchanger according to any one of claims 5 to 9, wherein the sector plates are shaped to provide sealing contact simultaneously with more of the first mentioned and secondary vanes in said outer annulus than they seal with the first mentioned vanes over the inner annulus.

11. A rotary regenerative heat exchanger substantially as hereinbefore described with reference to and as illustrated in Figures 1 to 3 of the accompanying drawings.

12. A rotary regenerative heat exchanger according to claim 11 when modified substantially as hereinbefore described with reference to Figure 5 or Figure 6 of the accompanying drawings.

13. A rotor for a rotary regenerative heat exchanger substantially as hereinbefore described with reference to, and as illustrated in, Figures 3 to 6 of the accompanying drawings.

STATEMENT UNDER ARTICLE 19

The enclosed new pages 10 to 12 show amendments to clarify the scope of claims 1 and 5. Specifically: -

At lines 7 and 8 of the enclosed new page 10 there is an amendment adding the expression "the adjacent face of the respective one of" before "first" at line 7 of the originally filed page 10;

At lines 1 and 2 of the new page 11 there is an amendment comprising the addition of the wording "the adjacent surface of a respective one of" inserted after "against" in line 31 of originally filed page 10;

At line 3 of new page 11 the word "surface" has been inserted after "plate" at line 1 of original page 11;

At line 6 of the new page 11 the wording "plates" at line 4 of original page 11 has been expanded to read "plate surfaces".

The importance of the present invention is that the provision of the additional seals on the daily extending vanes of the rotor is able to provide for an increase in the number of lines of simultaneous sealing where the rotor is sweeping the adjacent (planar) surface of a sector plate of the stator.

Various of the prior art references show additional radially extending vanes over certain annular regions of the rotor, including the radially outer annular region, but none of them shows that the additional vanes in question can carry seals which simultaneously wipe the sector plate of the stator so as to provide for the increased sealing effect between the opposing sides of the sector plate. As explained in the description of the present application, in the passage starting at line 30 of page 5 and ending at line 2 of page 6, Figure 3 shows that there are simultaneous seals along four of the radially extending vanes 14, 15 of the rotor at the radially outer pan, whereas there are only two simultaneous seals over the radially inner part, and thus the sealing effect will be improved over the radially outer region.

Although FR-A-1448690 shows, in Figure 1, a larger number of radially extending vanes 28 in the radially outer segment 23 than in the radially inner segments 22, 21, 20 and 19 (for example six supplementary vanes in outermost segment 23 and only two supplementary vanes 24 in innermost segment 19), these vanes do not effect simultaneous contact with the sector plates. On the well known Rothemuehle arrangement the vaned structure shown in Figures 1 to 6 is the stator and the sector plates and inlet and outlet funnels rotate relative to it. We are told, at the foot of the right Viand column of page 1 and near the top of the left hand column of page 2, that there are sealing or closing members or elements which slide over the extreme edges or terminals of the radial walls or partitions and the arcuate or curved walls or partitions of each sector. In other words, the sector plate will have a distinct line seal which engages with the radially extending supplementary vanes 28, 27, 26, 25 and 24 and with the supplementary arcuate partitions between these successive annular sections, and there will therefore be only one of the vanes 28, or 27, or 26, or 25, or 24 which at any one time is sealing with a part of the stator plate. In accordance with the present invention, each of the additional vanes will itself wipe over the surface of the stator plate and hence there will be several such supplementary vanes simultaneously sealing to prevent flow from a hot region at one side of a sector plate to a cooler region at the other side of that sector plate.

Nowhere in any of the prior art is there any suggestion of the step of increasing the number of simultaneous seal lines by virtue of a redesigning of the structure.