US2579211A

US2579211A - Regenerative heat exchanger

Info

Publication number: US2579211A
Application number: US129261A
Authority: US
Inventors: Raymond K P Stevens; Cox Martin
Original assignee: Power Jets Research and Development Ltd
Current assignee: Power Jets Research and Development Ltd
Priority date: 1948-08-23
Filing date: 1949-11-25
Publication date: 1951-12-18
Anticipated expiration: 1968-12-18

Description

Dec. 18, 1951 R. K. P. STEVENS ETAL REGENERATIVE HEAT EXCHANGER Original Filed Aug. 23, 1948 2 SHEETS-SHEET l )matin C94 inve/:lors

O B3, l f lnw, mmwmdmmf im flor/Icy.)

Dec. 18, 1951 R. K. P. STEVENS ETAL REGENERATIVE HEAT EXCHANGER Original Filed Aug. 23, 1948 Patented Dec. 18, 1951 REGENERATIVE HEAT EXCHANGER Raymond K. P. Stevens, Farnham, and Martin Cox, Cove, Farnborough, England, assignors to Power Jets (Research and Development) Limited, London, England, a British company Original application August 23, 1948, Serial No. 45,756. Divided and this application November 25, 1949, Serial No. 129,261. In Great Britain May 20, 1948 5 Claims. (Cl. 257-6) 1 This application is a division of prior copending application Serial N o. 45,756, filed August 23, 1948, entitled Regenerative Heat Exchangers, and also relates to regenerative heat exchangers of the kind wherein heat absorbing and heat transmit- 5 drop across the sealing contact face of the eleting matrix members are rotatable in a casing ment. The abutting interfaces of the elements partitioned by dividing members extending across may be provided with sealing means to prevent the face of the matrix members into fluid paths leakage of the high pressure fluid between them. for a fluid at a high temperature and a fluid at For example the abutting elements may be a lower temperature so that the members as they l tongued andv grooved or the abutting elements rotate absorb heat from the high temperature may be provided with abutting grooves and a fluid and transmit the heat to the lower temdumbbell sectioned sealing element positioned perature fluid and in which the dividing members with the bell ends in the grooves. The faces of are each provided with movable sealing contact each element contacting the sides of the grooves members extending longitudinally thereof in l may also be provided with sealing means to pregrooves therein for movement towards and vent the high pressure leaking into the groove. away from the face of the matrix members and The invention will now be described by way of biassed to contact the face to limit the loss beexample only with reference to the accompany tween the two fluid streams. drawing in which:

In the regenerative heat exchanger as del0 Figure 1 is a divided and sectioned perspective scribed above the velocity of ow of the two fluids, view of a regenerative heat exchanger with dlwhich may be, for example, the products of comviding members or plates and rotatable matrix bustion from a furnace and the combustion air discs according to the aforesaid copending apfor the furnace, is generally low and the presplication Seria] No. 45,756. sure diiference and the temperature diierence Figure 2 is a sectioned perspective fragmenbetween the two fluids is never v ery great so that tary view showing the sealing contact elements of the provision of an effective seal between the the dividing plates in yieldable sections. two fluid flows is a comparatively simple matter. In Figure 1 a regenerative heat exchanger has When, however, the pressure difference and an outer cylindrical casing Il) with tangentially the temperature difference and the velocity of arranged uid inlet and outlet connections; two ow are much greater, such for example, as beinlets Il and I2 and one outlet I3 for the cold tween the compressed combustion air and the high pressure fluid and one inlet I4 and two hot exhaust gases of a gas turbine plant the prooutlets I5 and I6 for the hot low pressure fluid. vision of an effective seal is much more difficult The cylindrical casing is provided with removable and the seals devised so far are not effective. end covers I1 and I8.

ACCOlding to the present invention a seal- Two similar porous matrix members I9 and ing contact member of a dividing member of 2n of disc form are mounted for rotation within a regenerative heat exchanger of the kind dethe casing I0 on a shaft 2|. The, are splined scribed and in which the pressure difference beto the Shaft 2| (splines not shown) and are ISWEQH the IJWO fluids iS great iS made up 0f a 40 capable of relative axial movement on the splines. plurality 0f Sealing Contact elements Slidably The disc members I9 and 2o divide the casing l0 positioned in the groove 0f the dividing member into three chambers and each chamber is divided iP Closely abuttflg formation, t0 Provide a C011' diametrically by dividing members or plates 26. tinuous seal against the matrix face and a flush 21 and 23 which are supported in grooves.or slots ,rea Surfacg m the groove each element bemg 29 or 3D formed respectively in the casing III and individually movable towards and away from covers i1 and is. The two dividing plates 25 the matrix face and each being spring biassed and 2a adjacent the covers n and is are spring sufliciently to maintain it in contact with the urged towards one another by compression matrix face and each being provided With a, fluid Springs 3| and 32 arranged around the shaft 2| Passage extending therethrough from the Seal' 5o between the covers II and I8 and the plates 26 ing contact face to the rear surface within the and 28 respectively. The two matrix discs I9 and groove to collect high pressure fluid leaking past 20 are sandwiched between the central dividing the sealing contact face and to lead it to the rear plate 21 and the two dividing plates 26 and 21, surface in the groove to load it and urge the Hollow bosses 33, 34 and 35 are formed respecelement into contact with the matrix face. The tively on the dividing plates 26, 21 and 2li-through opening of the fluid in the sealing contact face from the side of the element adjacent the high pressure fluid in accordance with the pressure 3 which the shaft 2I passes. The bosses 33, 34 and 35 closely engage the matrix discs and the end covers I1 and I6 to prevent any leakage between the high and low pressure chambers. The bosses 33 and 35 are arranged to receive the springs 3I and 32 respectively.

The matrix discs I9 and 20 are each formed of a. corrugated strip 36 and a plain strip 31 of metal wound in a spiral on a central boss 36. A rir member 39 is placed around the spirally arranged strips 36 and 31. A labyrinth gland (not shown) may be machined on the outer surface of the rim 39. The dividing

plates

26, 21 and 28 may be arranged to rub against the matrix discs I9 and 20 to form the diametrical seal.

In Figure 2 of the drawings the dividing member or plate 26 is shown which is provided in the region adjacent to a face of a rotating matrix disc I9 or 20 with a number of sealing elements 60 abutting against one another and arranged diametrically across the face of the disc I9 or 20. The elements 6I) are preferably arranged for rubbing contact with the discs and the centrally located element or elements may be provided with an aperture for the shaft (not shown) on which the matrix discs are mounted. The ele.

ments 60 are made comparatively short relative to the diameter of the discs so that the seal as a whole is locally yieldable and can, therefore, adjust itself to any distortion of the matrix face. Each element 60 is provided with an axially extending tongue 6| arranged to slide freely in a groove 62 formed in the dividing member 26.

`Adjacent elements 60 are also provided with sealing means 63, 64 and 65 between their interfaces to prevent high pressure fluid passing between them. For this purpose each element 60 may be formed for tongue and groove sealing 63, 64, in one plane (e. g. the horizontal plane) and another form of sealing in another plane (e. g. the vertical plane) which may consist of a dumbbell shaped element 65 arranged half in one element 60 and half in another element 60 in slots 66.

It may be necessary to form seals between the tongues 6I of the sealing sections 60 sliding in the grooves 62 in the dividing

members

26, 21 or 28. Packing strips 61 arranged in grooves 68 formed in the tongue 6| of each element 60 will suffice. The strips 61 are spring loaded by springs 69.

The sealing elements 60 are forced against the face of the matrix disc by fluid pressure applied to the groove 62 behind the elements 60. Springs 10 may be arranged between the end of the'..'

tongue 6I and the end of the groove 62 to give an initial loading to each element 60. The ends of the springs 10 may be arranged in circular recesses 1I formed in the tongue 6I (as shown in Figure 2 of the drawing) or in the dividing plate 26 to hold them in position.

The fluid pressure which is used to force the elements 60 against the face of the matrix disc I9 or 20 may be obtained from the high pressure fluid stream passing through the heat exchanger. For this purpose a bleed duct or passage 12 is provided in one or more of the elements 60 extending through the element from the front thereof (i. e. from the rubbing face of the disc) to the rear thereof, the function of this duct 12 being to maintain the pressure existing in the groove 62 at the rear of the elements 6B and urging said element 60 towards the rubbing face at a value equal to that existing at a suitable point on the front of the sealing element 60 where it abuts against or is very close to the matrix face, for varying rotational speeds and pressure differences between the two fluid streams.

The position of the duct 12 from the high pressure side of the element may be selected to give the necessary pressure loading required to hold the element 60 against the matrix face (i. e. according to the pressure drop across the face of the element 60.)

Sealing elements constructed in the above described manner can conform fairly closely to any distortion of the matrix face and thereby limit leakage.

It will be understood that when the matrix is in the form of a. drum, through the wall of which the gases pass in the radial direction, the seal will lie along the cylindrical surface of the drum and its local yielding will take place in the radial direction.

We claim:

1. A. sealing contact member of a dividing member of a regenerative heat exchanger of the kind described and in which the pressure difference between the two fluids is great, comprising a plurality of sealing contact elements slidably positioned in the groove of the dividing member in closely abutting formation to provide a continuous seal against the matrix face and a flush rear surface in the groove, each element being individually movable towards and away from the matrix face and each being spring biassed sufficiently to maintain it in contact with the matrix face and each being provided with a fluid passage extending therethrough from the sealing contact face to the face within the groove to collect high pressure fluid leaking past the sealing contact face and to lead it to the face in the groove to load the element and urge it into contact with the matrix face.

2. A sealing contact member of a dividing member of a regenerative heat exchanger of the kind described and in which the pressure difference between the two uids is great, comprising a plurality of sealing contact elements slidably positioned in the groove of the dividing member in closely abutting formation to provide a continuous seal against the matrix face and a flush rear surface in the groove, each element being individually movable towards and away from the matrix face and each-'being spring biassed sufficiently to maintain it in Contact with the matrix face and each being provided with a fluid passage extending therethrough from the sealing contact face to the face within the groove to collect high pressure fluid7 leaking past the sealing contact face and to lead it to the rear surface in the groove to load the element and urge it into contact with the matrix face, and sealing means between the abutting faces of the elements to prevent high pressure fluid passing between said elements.

3. A sealing contact member of a dividing member of a regenerative heat exchanger of the kind described and in which the pressure difference between the two fluids is great, comprising a plurality of sealing contact elements slidably positioned in the groove of the dividing member in closely abutting formation to provide a continuous seal against the matrix face and a flush rear surface in the groove, each element being individually movable towards and away from the matrix face and each being spring biassed suiciently to maintain it in contact with the matrix face and each being provided with a fluid passage extending therethrough from the sealing contact face to the face within the groove to collect high prevent high pressure fluid passing between said elements comprising a tongue in one element, and a groove` in an adjacent element to receive the tongue, the tongue and groove being arranged to allow each element to move relatively to another towards and away from the matrix face.

4. A sealing contact member of a dividing member of a regenerative heat exchanger of the kind described and in which the pressure difference between the two'fiuids is great, comprising a plurality of sealing contact elements slidably positioned in the groove of the dividing member in closely abutting formation to provide a continuous seal against the matrix face and a flush rear surface in the groove each element being individually movable towargs and away from the matrix face and each bein spring biassed sutilciently to maintain it in contact with the matrix face and each being provided with a uid passage extending therethrough from the sealing contact face to the face within the groove to collect high pressure fluid leaking past the sealing contact face and to lead it to the rear surface in the groove to load the element and urge it into contact with the matrix face, and sealing means between the abutting faces of the elements to prevent high pressure uid passing between said elements comprising a channel slot in each abutting face of adjacent elements arranged to cooperate together to form a passage between adjacent elements and a dumbbell-sectioned element in said passage with a bell end in each channel slot to form a seal.

5. A sealing contact member of a dividing member of a regenerative heat exchanger of the kind' described and in which the pressure differs ence between thetwo fluids is great comprising a plurality of sealing contact elements, each having a sealing contact face for contacting the matrix face and a tongue projecting into the groove of the dividing member, said elements being positioned in closely abutting formation to provide with their sealing contact faces a continuous seal against the matrix face and a flush rear surface in the groove, each elementbeing individually movable towards and away from the matrix face slldably on its tongue in said groove and each spring biassed suillciently to maintain it with its sealing contact face in contact with the matrix face and each provided with a fluid passage extending therethrough from the sealing contact face to the rear surface of the tongue within the groove to collect high pressure iuid leaking past the sealing contact face and to lead it to the rear surface of the tongue in the groove to load the element and urge it into contact with the matrix face and sealing means between said tongue and saidgroove to prevent high pressure fluid leaking between said tongue and groove.

RAYMOND K. P. STEVENS. MARTIN COX.

REFERENCES CITED The following references are of record in the ie of this patent:

UNITED s'rA'rEsiPA'rEN'rs Great-ritain July 29, 1921