US2981521A

US2981521A - Rotary disc regenerator

Info

Publication number: US2981521A
Application number: US679955A
Authority: US
Inventors: Ted C Evans; Charles A Lyle
Original assignee: Air Preheater Co Inc
Current assignee: Alstom Power Inc
Priority date: 1957-08-23
Filing date: 1957-08-23
Publication date: 1961-04-25
Anticipated expiration: 1978-04-25

Description

April 25, 1961 T. c. EVANS ETAL 1,521 ROTARY DISC REGENERATOR Filed Aug. 25, 1957 2 Sheets-Sheet 1 April 25, 1961 T. c. EVANS ETAL ROTARY DISC REGENERATOR 2 Sheets-Sheet 2 Filed Aug. 23, 1957 f f N[ ma United States PatentO 2,981,521 ROTARY DISC REGENERATOR Ted C. Evans and Charles A. Lyle, Wellsville, N.Y., as-

signors to The Air Preheater Corporation, New York, N.Y., a corporation of New York Filed Aug. 23, 1957, Ser. No. 679,955 8 Claims. (Cl. 257267) The present invention relates to heat exchangers and particularly to heat exchangers of the rotary regenerative type where a rotor including a rotatable heat absorbent element is caused to rotate alternately through streams of' hot and cold fluid wherebyone of the streams will impart heat to the heat absorbent element while the other abstracts heat therefrom. The rotatable heat absorbent element is surrounded by a housing having end plates formed with openings which provide for the flow of heated gas and cooler air, and to preclude the flow of gas or air through the clearance space between the rotor and housing without passing over the heat absorbent element it is customary to provide the rotor with circumferential seals that bear. against adjacent surfaces of the end plates or other stationary parts of the housing. Radial sealing members mounted on the partitions forming the compartments prevent crossflow of fluids over the ends of the rotor.

. Usually the rotor is subjected'to a substantial temperature gradient whereby the structural components thereof warp and distort to the extent that effective sealing between the rotor and enclosing housing is difficult if not impossible to obtain. This is true where the pressure of the two fluid streams differ but little, however, where the pressure of the two fluids passing through the heat exchanger differ consider-ably, it is much more diflicult toprovide an efficient seal even though more effective sealing means becomes a necessity.

It is therefore a primary object of this invention to provide a rotaryregenerative heat exchanger whose sealingsurfaces are not subject to the usual excesses of I thermal distortion.

Thepresent invention relates particularly to a form of "regenerative heat exchanger that permits relative distortion of the rotating parts without; impairing the sealing relationship therebetween. i 1

"The invention-relates also'to a form of sealing arrangement' for a rotary regenerative heat exchanger that is uniquely eflicient and freefrom the usual difficulties of alignment and adjustment, and the invention further relates to sealing means for a rotary regenerative heat exchanger that simultaneouslyserves as support bearing therefor.

. The invention will bebmt understood upon consideration of the following description of an illustrative embodiment thereof when read in conjunction with the following drawings in which:

Figure 1 is a sectional elevational view in diagrammatic form of a rotary regenerative heat exchanger constructed according to this invention.

Figure 2 is a plan viewof the device as seen from section 2--2 of Figure 1.

Figure 3 is an enlarged fragmentary view of the rotor assembly in perspective.

Figure 4 is an enlarged view showing the construction details of the rotor housing.

7' Figure 5 is a plan view showing the general arrangement of the sealing ring. A

With respect to Figure l which shows a regenerative heat exchanger including a rotor '10 mounted for rota tion about its axis in a housing 12 through which hot and cold fluids are directed in heat exchange relation. Hot

. ter than that of the rotor.

gaseous fluid is supplied to inlet 14 where it is directed through the intervening element of rotor 10 to which ittransmits heat before being exhausted through outlet 18.- Relatively cool gaseous fluid is delivered to inlet 22 where it is directed through the intervening element to absorb heat therefrom before being exhausted through outlet port 2-4. I The rotor comprises a central shaft '26 fitted with a shoulder 28 which is adapted to support a lower rotor end wheel including a hub portion 32 and a rim 34 spaced apart by a series of radially extending spokes 36.

An annular end wheel spacer 38 having chamfered outer edges is fitted over the shaft 26 in concentric alignment with the lower rotor end wheel. The elements thus assembled provide a support platform for a series of sector shaped baskets of element 42 that are adapted to lie in radial abutment with their abutting sides superposed over the radial spokes 36 of the lower end wheel. The inner sides 44 of the baskets are arcuately formed to provide a composite annular member concentric with the end wheel spacer 38 when carried by the hub 32 of. the lower end wheel. The radially outer edges 46 of adjoining baskets are similarly formed to provide a composite shell which lies superposed on the rim 3!] of the lower end wheel. An upper end wheel similar to; the lower end wheel is aligned therewith on the rotor shaft 26 with the spokes 36 of both end wheels and the radially abutting sides of adjacent baskets in axial alignment.

The baskets of element 42 have an axial thickness substantially less than that of end wheel spacer 38 to provide space at each end of the element baskets for a flexible packing 48 which permits limited distortion of each basket without forcing similar distortion upon the adjacent end wheels. The packing 48 is placed completely around each basket to preclude any fluid passing through the space between it and the adjacent end wheels.

When thus assembled the rotor components are held in position by means of a series of adjustable bolts 52 through hub portions 32 of superposed end wheels and the intervening end wheel spacer 38. The rotor assembly thus described is maintained fixed to shaft 26 by a rotor nut 30 which clamps the rotor against the flange 28. The rims 34 of the spaced rotor end wheels are main tained positively spaced by an annular rotor shell 54.-- To permit a degree of relative distortion between'oppositely disposed end wheels not possible if the shell were inflexible, the rotor shell is formed from a metallic strip having lateral slots 56 originating from oppositesides thereof as illustrated in Figure 4. The slotted shell 54 is secured along opposite edges to the periphery of the parallel rims 34 by screws 58 or other means whereby each segment between slots 56 becomes integral with the outer rims 34 to maintain them in spaced relationship. The rotor is supported for rotation about its axis in a. cylindrical housing 12 having substantially greater diame- An annular end plate comprising a flange 60 extends completely around the inner periphery of the rotor housing and is integrally attached thereto to provide a surface supporting the rotor, while a web member 62 extends diametrically across the end plate to separate the air from the gas sides. The web 62 has an opening 64 concentric with the housing 12 in which shaft 26 is free to rotate.

An annular packing 66 having a diametric web in alignment with web 62 is superposed thereon to provide a Y flexible support for a lower sealing ring 68. The sealing ring 68 similarly has a diametric web 70 to separate air from the gas sides with a central opening 71 through which the shaft 26 is directed. T he-sealing ring is preferably formed from rigid material having a low coetiicient of friction such as carbon, since the lower sealing member-l. actually comprises a support bearing on which the lower Patented Apr. 25,- 1961-- rotor end wheel is supported for rotation about its axis.

stantial axial alignment with the diametric web portion of the lower sealing ring. A sealing cushion 72 having substantially the same configuration as the sealing rings 68 is then superposed thereon and compressed to bias the upper sealing ring into contacting relationship with the adjacent surface of the upper end wheel. The sealing cushion 72 is preferably formed from a resilient spongelike material which is chemically inert and capable of withstanding a wide range of temperatures to which the rotor may be subjected. In this respect a sealing cushion of silicone sponge material fulfills the necessary qualifications and is deemed entirely satisfactory for most applications.

The housing 12 is formed with an annular flange 76 somewhat below the upper surface of the sealing cushion 72 whereby the cushion 72 may be compressed between end plate flange 74 and flange 76 by tightening the bolts 78 that are evenly spaced around the periphery thereof.

Compression of the resilient sealing cushion 72 by tightening flange 74 of the upper end plate against housing flange 76 places a biasing force upon the upper sealing ring which is transmitted against the upper end wheel to provide a sealing fit that precludes the passing of fluid therebetween. This force together with the weight of the rotor acting against the lower sealing ring 68 similarly provides a sealing fit that effectively precludes fluid flow therebetween. If conditions should warrant horizontal installation of the rotor, the expansive force of the resilient cushion 72 when compressed is ample to maintain a sealing relationship between both sealing rings 68 and the relatively moving surfaces of the adjacent rotor end wheels.

Arcuate

sealing cushion retainers

82 and 84 are adapted to fit inside the

flanges

60 and 74 to restrain the resilient packing 66 and the seal cushion 72 when they are compressed and subjected to frictional contact with adjacent rotating parts. Holding clips 86 along the diametric dividers 62 similarly aid in restraining the diametric portion of packing 66 and seal cushion 72 so that cooperating sealing members are maintained in superposed relationship.

To further maintain axial alignment of the rotor super and lower guide bearings 92 are positioned concentrically within the housing at opposite ends thereof while rotation of the device is achieved by the use of any suitable means not here illustrated.

What we claim is:

1. A regenerative heat exchange device or the like having a cylindrical rotor carrying heat transfer material and a stationary housing surrounding the rotor to provide opposite ends of the latter with annular end plates formed with diametric web portions which afford circumferentially spaced openings for the flow of a heating fluid and a fluid to be heated to and through the rotor; sealing means at opposite ends of the rotor arranged to restrict fluid flow to the circumferentially spaced openings; and a biasing means comprising a sheet of heat resistant resilient sponge apertured to coincide with the openings in the end plates and positioned in continuous contact therewith to maintain the sealing means and the adjacent surface of the rotor in sealing relationship to preclude fluid flow therebetween.

2. A regenerative heat exchange device or the like of the kind defined in claim 1 including means axially compressing the resilient sponge to maintain the sealing means and the adjacent surface of the rotor in sealing relationship.

3. A regenerative heat exchange device or the like of the kind defined in claim 2 wherein the means axially compressing the resilient sponge expands it radially into contact with the rotor housing.

4. A regenerative heat exchange device as defined in claim 1 wherein the biasing means comprises a resilient silicone sponge.

5. A regenerative air preheater or the like having an upright rotor including a cylindrical shell carrying heat transfer material, and a stationary housing surrounding the rotor to provide opposite ends of the latter with end plates formed with circumferentially spaced openings for the flow of a heating fluid and a fluid to be heated to and through the rotor, one of said end plates comprising annular flange means contiguous with the annular inner surface of the housing and coextensive with the cylindrical shell of the rotor arranged to provide an annular support for the rotor permitting it to rotate about its vertical axis while simultaneously providing sealing means adapted to preclude the flow of fluid between the rotor and the surrounding housing.

6. A regenerative air preheater or the like having an upright rotor including a cylindrical shell carrying heat transfer material and a stationary housing surrounding the rotor providing opposite ends-of the latter with upsimultaneously providing a sealing surface at one end thereof; and annular sealing means at the axially remote edge of the rotor adapted to preclude fluid flow in-the annular space between the rotor and the rotor housing.

7. A regenerative air preheater or the like having a cylindrical rotor carrying heat transfer material and a stationary housing surrounding the rotor and provided at opposite ends of the latter with axially spaced end plates formed with diametric web portions which alford circumferentially spaced openings for the flow of a heat- T ing fluid and a fluid to be heated through the rotor, said rotor including an annular shell comprising a metallic strip alternately slotted from axially opposite ends thereof to permit its limited axial distortion without attendant buckling.

8. Regenerative heat exchange apparatus or the like having an annular housing surrounding a rotor that carries a mass of heat transfer material alternately between spaced ducts for a heating fluid and a fluid to be heated, said rotor comprising in combination a series of independent sector shaped baskets of perforate material arranged around a central rotor post to provide a composite annular matrix for the flow therethrough of the heating fluid and the fluid to be heated; a pair of support members axially spaced on said rotor post to support the sector shaped baskets therebetween, said support members including an annular rim joined to a central hub by radial spokes in alignment with the radial sides of the sector shaped baskets therebetween; and flange means carried by the inner surface of the annular housing coextensive with the annular rim of the adjacent support member adapted to simultaneously provide a bearing surface supporting the rotor and a sealing surface that precludes fluid flow between the rotor and surrounding housing.

References Cited in the file of this patent UNITED STATES PATENTS 2,666,625 Byerley Jan. 19, 1954 2,738,958 Hodge Mar. 20, 1956 2,818,934 Pennington Jan. 7, 1958 2,880,972 Williams Apr. 7, 1959 FOREIGN PATENTS 728,192 Great Britain Apr. 13, 1955 739,608 Great Britain Nov. 2, 1955