GB2119037A

GB2119037A - A sealing system for a regenerative heat exchanger

Info

Publication number: GB2119037A
Application number: GB08217348A
Authority: GB
Inventors: Stanislaw Michalak; Bernd Hermanns
Original assignee: L&C Steinmueller GmbH
Current assignee: Hitachi Zosen Inova Steinmueller GmbH
Priority date: 1982-04-22
Filing date: 1982-06-15
Publication date: 1983-11-09
Also published as: JPS58187795A; FI822108A0; ZA824549B; ATA220082A; NL8202465A; FR2525719A1; AT373066B; SE8203534L

Abstract

A regenerative heat exchanger has a rotor 6 rotatable in a housing 7, the gap between the rotor and the housing being sealed by parallel flexible rows of bristles 12, 12'. The bristles 12, 12' extend from a stop 11 which is attached to the housing 7 through a connecting element 13. The connecting element 13 can be made resilient and/or adjustable. <IMAGE>

Description

SPECIFICATION Sealing system for a regenerative heat exchanger having a rotor The invention relates to a sealing system fora regenerative heat exchanger having a rotor rotatable in a housing.

In known regenerative heat exchangers having rotors equipped with a heat storage composition, such as the Ljungström system for example, the rotors are equipped with seals in the form of strips or consisting of sheet-metal segments. The purpose of these sealing systems is to reduce the leakage rate between the various gas zones to a minimum. For this purpose, the seals are so disposed that a constant gap, which is as small as possible, is maintained between the rotor and the housing of the heat exchanger.

During operation, a deformation ofthe rotor occurs as a result ofthe differences in temperature so that the gap must either be designed with a certain reserve, that is to say widerthan desired, or be provided with a complicated compensation system in accordance with DE-AS 1945485 and DE-AS 2809948.

The use of various sliding seals is also known. Thus the DE-OS 2952085 describes a system in which low-wear sliding seals of graphite or ceramic are proposed. The DE-AS 26 12298 describes a sliding seal which contains carbon as a basic constituent and is supplemented by a further auxiliary seal of resilient material, for example silicone rubber.

These known areal sliding seals have relatively high frictional resistances and tend towards incrustation in systems containing dust.

It is the object ofthe invention to provide a sealing system between the rotor and the housing of a regenerative heat exchangerthrough which the gap between rotor and housing and hencethe leakage rate is restricted to a minimum, expensive compensation systems are dispensed with, andthefrictional resistance and the risk of incrustation are reduced.

According to the invention, this problem is solved in that brushlike elements with parallel, flexible rows of bristles are disposed in the gap between the rotor and the housing ofthe regenerative heat exchanger.

In a further development of the invention, it is proposed that the parallel, flexible rows of bristles should be connected by rows of bristles extending transversely.

In contrast to the conventional sealing systems, an almost complete sealing between rotor and the housing of the heat exchanger can be achieved by the brushlike elements because the parallel, flexible, dense rows of bristles can slide directly on the rotor in the sealing zones.

The leakage rate th rough the brushes can easily be further reduced by providing a plurality of parallel rows of brushes. The sealing effect which can be achieved in this case is achieved not only by the flow resistance of the individual rows of brushes. In addition, the leakage rate is reduced by the progressive expansion and throttling ofthe gas stream between the individual rows of brushes, as is known from the use of conventional labyrinth seals.

Afurtheradvantageoftheconstruction of the sealing system according to the invention is that the surface of the rotor is constantly cleaned in the sealing zones by the sliding ofthe brushes, an advantage which is very important particularly during use in gases which contain dust or are corrosive.

Thiseffectcan be increased by resilientmounting of the brushlike sealing elements on the heat exchanger housing. In this case, it is also easily possible deliberately to adjust or alter the pressure of the rows of bristles against the sealing surfaces of the rotor.

Because of the low frictional resistance, there is no risk of the rotor jamming.

Depending on the limiting conditions such as temperature and corrosiveness, fibres of different materials, such as glass, steel, carbon or plastics material for example, are used for the brushes.

An embodiment ofthe invention will now be described by way of example with reference to the accompanying drawings, in which: Figure 1 shows a view of a cross-section of a Ljumgström beatexchangerwith a conventional sealing system, Figure 2 shows an isometric miew ofthe heat exchanger illustrated in Figure 1, Figure 3 shows an isometric view of the brushlike element used as a seal in the heat exchanger according to the invention, Figure 4 shows a portion of an isometric view of the brushlike element in the installed state between rotor and housing of the heat exchanger, Figure 5 shows an isometric view of the element illustrated in Figure 3 in conjunction with the radial wall ofthe rotor of the heat exchanger.

Figures 1 and 2 show diagrammatically in different forms of illustration, an example of a Ljungström heat exchanger with a conventional sealing system, consisting of a ring seal 1 and radial seal 2 of the rotor 3.

The radial seal 2 consists of the sealing plate 4 and the radial wall 5. The ring seal 1 of the rotor 3 is effected by reducing to a minimum the gap between the annular wall6ofthe rotor3andtheannularwall7ofthe housing 8. Forcertain constructions, the ring seals 1 are equipped with sealing elements 9 of sheet metal.

Figure 3 shows a brushlikesealing elementl0 consisting of the strip 11 and the bristles 11 and 12'.

Figure 4shows a ring seal 1 in an embodiment according to the invention with brushlike seals consisting of strip 11 and bristles 12, 12' which brush againsttheannularwall 6ofthe rotor and reducethe flow through of the gap 14 between the rotor and the housing. The strip 11 is connected to the annularwall 7 of the heat exchanger housing by a connecting element 13. This connecting element 13 can be made resilient and/or adjustable so that the sealing elements 10 with the rows of bristles 12, 12' slide with a certain fixed or adjustable pressure againstthewall 6 of the rotor 3.

Figure 5 shows the radial seal 2 in an embodiment according to the invention wherein the sealing plate 4 is equipped in brushlike form with bristles 12, A fixed or adjustable pressure of the rows of bristles 12, 12' againstthe radial wall 5can be effected as with the ring seal.

Claims

1. Asealing system for a regenerative heat exchanger having a rotor rotatable in a housing and having brush-like elements mounted in the gap between the rotor and the housing, characterised in thatthese elements are mounged on the housing in theform offlexible rowsof bristleswhich are parallel overthe circumference ofthe housing and which are connected byflexible rows of bristles parallel to the axis and extending transversely.

1. Asealing system for a regenerative heat exchanger having a rotor rotatable in a housing, characterised in that brushlike elements with parallel, flexible rows of bristles are disposed in the gap between the rotor and the housing of the regenerative heat exchanger.

2. Asealing system as claimed in claim 1, characterised in thatthe parallel, flexible rows of bristles are connected by rows of bristles extending transversely.

3. A sealing system for a regenerative heat ex- changer having a rotor rotatable in a housing, substantially as hereinbefore described with referenceto any of Figures 3,4 and 5 ofthe accompanying drawings.

New claims or amendments to claimsfiled on 14 March 1983.

Superseded claim 1.

Original claim 3 re-numbered claim

2.