US3822739A

US3822739A - Multi-directional seal biasing means

Info

Publication number: US3822739A
Application number: US00329267A
Authority: US
Inventors: H Kurschner
Original assignee: Air Preheater Co Inc
Current assignee: Alstom Power Inc
Priority date: 1973-02-02
Filing date: 1973-02-02
Publication date: 1974-07-09
Anticipated expiration: 1991-07-09
Also published as: DE2403232A1; GB1406798A; DE2403232C2; DD114674A5; FR2216538A1; FR2216538B1

Abstract

A sealing arrangement for an air preheater that precludes fluid flow between a rotatable shaft and a relatively fixed element of a surrounding housing structure. The sealing arrangement is adapted to be simultaneously biased in an axial direction by a spring biased sleeve and in a radial direction by a spring biased cam to close a clearance space that would permit leakage of fluid therebetween.

Description

United States Patent Kurschner MULTl-DIRECTIONAL SEAL BIASING MEANS [451 July 9,1974

FOREIGN PATENTS OR APPLICATIONS 704,857 3/1954 Great Britain 165/9 Primary ExaminerAlbert W. Davis, Jr. Attorney, Agent, or Firm-Wayne H. Lang [57] ABSTRACT A sealing arrangement for an air preheater that precludes fluid flow between a rotatable shaft and a relatively fixed element of a surrounding housing structure. The sealing arrangement is adapted to be simultaneously biased in an axial direction by a spring biased sleeve and in a radial direction by a spring biased cam to close a clearance space that would permit leakage of fluid therebetween.

6 Claims, 4 Drawing Figures I MULTI-DIRECTIONAL SEAL BIASING MEANS SUMMARY OF THE INVENTION In a rotary regenerative heat exchange apparatus absorbent material rotates alternately between a hot and a cold fluid in order that heat absorbed from the hot fluid may in turn be transferred to the cold fluid flowing therethrough.

The rotor is surrounded by a housing formed with end plates at spaced ends and having openings therein that simultaneously direct the heating fluid and the fluid to be heated to and through spaced compartments This invention therefore proposes to provide a heat exchanger arrangement whereby each of the several fluids flowing therethrough may be effectively separated from each other and from the surrounding atmosphere.

BRIEF DESCRIPTION OF THE DRAWING FIG. I is a sectional elevation of a heat exchanger contracted in accordance with the invention.

FIG. 2 is an enlarged detail as seen from line 2-2 of FIG. 1 showing a sealing arrangement intermediate the rotor post and the surrounding rotor housing.

FIG. 3 is an enlarged cross sectional view showing details of the sealing means as seen from line 33 of FIG. 1.

FIG. 4 is an enlarged cross sectional view showing details of the sealing means as seen from line 4-4 of FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT The arrangement of the drawing shows a rotary regenerative heat exchanger having a rotor post 12 supported by bearings 14 and rotated about its axis by means of a drive motor 16 that is connected through suitable reduction gearing 18 to the rotor post. A mass of heat absorbent material 20 contained in independent, open ended frames or baskets around the rotor post are secured thereto to form a composite rotor or container 26 that upon rotation within the surrounding housing 28 is adapted to coincide with the spaced

openings

32, 34, 35 and 37 at opposite ends of sur rounding rotor housing whereby fluids passing through the housing are directed through the heat absorbent material carried in the rotor.

Circumferential seals 38 positioned around end edges of the rotor and radial sealing means 40 extending radially between baskets from the inner to the outer ends of the rotor are adapted to reach axially thereof a sufficient distance that enables them to bridge the space between the adjacent end parts of the rotor and the rotor housing.

To preclude fluid flowing into or out of the rotor housing through the space between the rotor post and the surrounding housing, post seals 42 are provided. These seals are simultaneously biased by a unique spring means inward against the rotor post and axially against the surrounding rotor structure to seal the clearance space therebetween.

Accordingly, the invention comprises one or more annular packing rings 45 that tightly surround the rotor post and are concentrically embraced by a composite retainer 48 comprised of arcuate shaped shoes in an end-to-end abutment that together form an annular retainer abutting the packing rings 45 and surrounding the rotor post. In order that the packing rings and composite retainer will not rotate along with the rotor post as it is rotated upon its axis, each of the several segments is provided with a pair of guides 54 that embrace an axially disposed pin 56 secured to the end plate of the fixed housing structure. Because of the looseness by which the guides embrace the pin 56, the segments of the annular retainer 48 abutting packing 45 are free to move radially inward into close contact with the rotor but are precluded from rotation therewith.

The arcuate segments of the retainer are each formed with a radial flange 58 having an axially disposed lip 62 at the end thereof to form an annular recess for a resilient sealing ring 64 that abuts the end plate of the housing to preclude any fluid flow between the inside and outside of the rotor housing.

The annular sealing rings 45 are preferably formed from a standard resilient, temperature resistant packing material of rectangular cross section to provide a maximum surface area for contact with an adjacent sealing ring and with the relatively movable surface of the rotor post.

The above defined sealing means is simultaneously biased axially into contact with the end plate of the rotor housing and radially inward into contact with the relatively movable rotor post by a unique spring means carried on each of several axially disposed pins 68 secured to the end plate of the rotor housing around the rotor post 12.

The above defined sealing means is simultaneously biased axially into contact with the end plate of the rotor housing and radially inward into contact with the relatively movable rotor post by a unique spring biasing means carried on each of several axially disposed pins 68 which is in turn secured to the end plate of the rotor housing around the rotor post 12.

The outer end of each pin 36 is drilled and tapped to accept an adjusting screw 72. A sleeve 74 having an annular abutment 76 secured thereto has an inner surface that slidably receives the pin. A flange 78 on adjusting screw 72 is sized to contact a spring means 82 coaxial with pin 68 that rests upon the sleeve intermediate the abutment 76 and flange 78.

Rotating the adjusting screw 52 in the threaded end of the pin screws the pin into thestud and places a bias upon spring 82 and a downward thrust upon the sleeve 74 which is transmitted to an actuating cam 84 pivoted to the end plate of housing 28.

A second spring 55 similar to spring 82 concentrically surrounds sleeve 74 but is separated from the first spring 82 only by the annular abutment 76. This spring 55 presses directly upon follower 52 which in turn rests upon the annular packing 45 and biases it axially against housing end plate 28. The follower 52 is apertured at one end 88 to slide readily upon the pin 68 and is formed to include an arcuate flange portion 92 that is normal thereto and sized to fit between the retainer 48 and the rotor post 12 so that it may freely force the packing 45 axially to preclude fluid flow between the retainer and the end plate. The sealing ring 64 also forms a relatively resilient seat that permits limited axial movement due to wear of the follower while seal biasing means 82 continuously compensates for any wear and forces sealing means tightly against the rotor 12.

The elements of the seal biasing means 48 and 52 are both comprised of arcuate segments that together form an annular member that encircles the rotor post while the packing members 45 and 64 are preferably elongate strips readily formed into an annular configuration.

Thus with a single seal biasing means that is readily accessible during operation, the sea] means may be simultaneously biased both axially and radially by a single biasing means to accommodate limited wear therebetween.

The invention described herein and illustrated in the accompanying drawings is believed to admit to many modifications within the ability of persons skilled in the art, all such modifications considered to lie within the spirit and scope of the appended claims.

I claim:

1. A regenerative heat exchange apparatus having a central rotor post, sectorial baskets in lateral juxtaposition around the rotor post adapted to comprise an annular rotor, a mass of heat absorbent material contained in the baskets of the rotor, housing means surrounding the rotor having inlet and outlet ports for a heating fluid and a fluid to be heated, means for rotating the rotor about its axis, sealing means around the rotor post intermediate said post and the surrounding rotor structure adapted to preclude fluid flow through the space between the rotor post and the housing, said sealing means comprising an annular packing intermediate the rotor post and the housing, means biasing the annular packing axially against the adjacent housing structure, means simultaneously biasing the annular packing radially into intimate contact with the rotor post to preclude the flow of fluid through the space therebetween that comprises a first axially movable spring member, means for applying the biasing force of said first spring member axially to said packing member, a second axially moavable spring member and movable along a common axis, and means translating the axial biasing force of said second spring member to a radial biasing force against the annular packing member whereby said packing member is simultaneously biased axially and radially so that it is continuously held tightly against the rotor post.

2. Regenerative heat exchange apparatus as defined in claim 1 indluding a single adjusting means, and means intermediate the spring member and the adjusting means whereby the first and second axially movable spring members are adjusted by the single adjusting means.

3. Regenerative heat exchange apparatus comprising a central rotor post, a rotor including sectorial baskets in juxtaposition around the center rotor post, a mass of heat absorbent element carried in the baskets of said rotor, housing means surrounding the rotor having inlet and outlet ports for a heating fluid and a fluid to be heated, means for moving the baskets of heat absorbent material relative to the heating fluid and the fluid to be heated, sealing means intermediate the rotor and surrounding housing structure to preclude the flow of fluid therebetween comprising a flexible packing, means biasing the flexible packing axially against the adjacent housing structure, means simultaneously biasing the flexible packing radially against the relatively movable rotor to preclude the flow of fluid therebetween including a sleeve member, an arcuate shoe abutting the outer surface of the packing member, means responsive to axial movement of said sleeve effective in moving the arcuate shoe radially inward comprising a series of axially disposed studs on the rotor housing surrounding the rotor post, and a cam means pivotally supported by the housing adjacent the axially disposed stud and aligned with the sleeve whereby axial movement of said sleeve against said cam produces a radial movement of the abutting arcuate shoe.

4. Regenerative heat exchange apparatus comprising a central rotor post, a rotor including sectorial baskets in lateral juxtaposition arranged around the rotor post, a mass of heat absorbing material carried in the baskets of the rotor, housing means surrounding the rotor having inlet and outlet ports for a heating fluid and a fluid to be heated, means for moving the baskets of heat absorbent material relative to the heating fluid and the fluid to be heated, sealing means intermediate the rotor and the surrounding housing structure adapted to preclude fluid flow through the space between the rotor post and the rotor housing comprising an annular packing at the ends of the rotor abutting the rotor post, axial stud means on the rotor housing co-axial with the rotor having the outboard end thereof drilled and tapped to receive an adjusting screw, and adjusting screw engaging each stud, a sleeve member with an annular abutment on the outer surface thereof slidably carried by each stud, a cam means on the rotor housing axially aligned with the sleeve member and having a portion thereof radially abutting the annular packing, a seal follower adjacent sleeve having a portion thereof axially abutting the annular packing, and spring means adjacent said sleeve to place a tension upon the cam means and the seal follower whereby the annular packing will be simultaneously biased in a radial and in an axial direction.

5. Regenerative heat exchange apparatus as defined in claim 4 wherein the spring means comprises an annular coil spring surrounding said sleeve and in abutment with the adjusting screw.

6. Regenerative heat exchange apparatus as defined in claim 4 wherein the spring means comprises a first coil spring surrounding the sleeve and intermediate the abutment and the adjusting screw, and a second coil spring intermediate the abutment and the seal follower whereby an axial bias is placed upon the seal follower and radial bias is placed upon the cam.