US3216487A

US3216487A - Regenerators

Info

Publication number: US3216487A
Application number: US221032A
Authority: US
Inventors: Brian M Gallagher
Original assignee: Solar Aircraft Co
Current assignee: Solar Aircraft Co
Priority date: 1962-09-04
Filing date: 1962-09-04
Publication date: 1965-11-09
Anticipated expiration: 1982-11-09

Description

1985 B. M. GALLAGHER 3,215,437

REGENERATORS Filed Sept. 4, 1962 4 Sheets-Sheet 1 j INVENTOR firz'anj f. G'aZlay/zer BY MF M ATTORNEYS 1965 B. M. GALLAGHER 3,216,437

REGENERATORS Filed Sept. 4, 1962 4 Sheets-Sheet 2 INVENTOR Bria/21 1. 6a ll a lz 62" BY Aim MEM ATTORNEYS Nov. 9, 1965 B. M. GALLAGHER 3,216,437

REGENERATORS Filed Sept. 4, 1962 4 Sheets-Sheet 3 #2 ii i l===: mu: iiiiiisii M i; iisiiim I'll s: 1 s w a: i; iisisi ii i: Q ii INVENTOR I I s! EM!!! flaw/11. @zza /W BY/JWMZ/M ATTORNEYS Nov. 9, 1965 B. M. GALLAGHER 3,216,487

REGENERATORS Filed Sept. 4, 1962 4 Sheets-Sheet 4 224 04 f4 A22 INVENTOR Brz'azzlflallayker BY JMM M ATTORNEYJ United States Patent 3,216,487 REGENERATORS Brian M. Gallagher, San Diego, Calif., assignor to Solar Aircraft Company, San Diego, Calif, a corporation of California Filed Sept. 4, 1962, Ser. No. 221,032 17 Claims. (Cl. 165-9) This invention relates to rotary gas regenerators and, more specifically, to improved means for preventing leakage between the high pressure air and low pressure gas sides of rotary regenerators.

Regenerators of the type to which the present invention relates include a housing divided by in internal partition into a high pressure air chamber and a low pressure gas chamber (generally termed the air side and the gas side) and a hollow, cylindrical drum or matrix fashioned of heat transfer elements supported in the housing and rotated by a drive connected to an external power source, normally the turbine output shaft. Heated gases, usually turbine exhaust gases at a relatively low pressure, are introduced into the gas side of the regenerator where they give up their heat to the rotating matrix. The heated portion of the matrix then passes from the gas side to the' air side where it gives up the heat acquired from the gases to air introduced into the air side, generally by a turbinedriven compressor at a pressure substantially higher than that in the gas side. From the regenerator, the heated air is delivered to the turbine combustion chamber.

Use of such regenerators has long been advocated because of the significant increase in turbine efficiency effected by imparting to the combustion air otherwise wasted heat energy recovered from the turbine exhaust gases. However, the lack of effective sealing means for preventing the leakage of the relatively high pressure air into the low pressure gas side of the regenerator has generally precluded the use of such devices.

The sealing means most commonly employed heretofore for controlling such leakage has been a system of sealing shoes arranged on the inner and outer sides of and in rubbing contact with the rotating matrix. In the prior art regenerators, it has been the general practice to maximize the area of contact between the matrix and the sealing surfaces of the shoes to provide as effective a seal as possible. This approach has decided disadvantages.

First, rotary regenerators operate at such elevated temperatures that the rotating matrix undergoes substantial axial thermal growth during regenerator operation. Because the inner surface of the matrix is (in the conventional construction) contacted first by the hot gases entering the regenerator, the temperature at his surface may be as much as 800 F. higher than the temperature at its outer surface. Because of this temperature differential, the axial thermal growth of the matrix at its inner surface exceeds the growth at its outer surface, causing the inner matrix surface to assume an inwardly bowed configuration. This results in the formation of gaps between the matrix and the sealing shoes. Consequently, air can readily leak from the high pressure side past the matrix into the low pressure gas side of the regenerator. The deflection problem is particularly acute in the prior art regenerators since the heat transfer elements of the matrix are also the elements maintained in rubbing contact with the sealing shoes. These elements are necessarily made of a material having low heat conductivity and such materials have high coefiicients of thermal expansion and the amount of bowing or deflection is therefore large.

A further disadvantage of the prior art large contact area rubbing type seals is that in this type of seal, the pressure drop across the sealing area results in the imposition of a unit rubbing load on the matrix of approximately one half the pressure difierentiial between the air and gas sides of the regenerator. Since the pressure in the air side may be as high as 40 p.s.i.g. and the pressure in the gas side as low as 0.9 p.s.i.g., high magnitude rubbing loads result. The imposition of high loads on the matrix causes its surfaces to smear and thereby block the flow passages between the heat transfer elements of the matrix. The result is an unacceptable high pressure drop across and early mechanical failure of the matrix.

In the present invention, the disadvantages of the prior art large contact area rubbing seals are eliminated by employing a labyrinth seal provided by the coaction of substantially conventional sealing shoes and a matrix of unique construction.

The novel matrix provided by the present invention is formed from heat transfer members of material having low heat conductivity. Arranged in pairs at equal intervals between and supported independently of the heat transfer members with one element adjacent each of the matrix surfaces are seal elements of material having a low coefficient of thermal expansion. The seal elements are free from contact with the heat transfer elements and have a width radially of the matrix but a fraction of the latter. Additionally, the seal elements have narrow sealing edges extending radially beyond the inner and outer edges of the heat transfer elements into contact with the sealing surfaces of the inner and outer sealing shoes.

As a result of this unique matrix construction, the heat transfer elements never contact the sealing shoes even though their inner surfaces bow inwardly as they are heated and smearing of the matrix surfaces with the attendant blockage of the flow passages between the heat transfer elements is eliminated, minimizing the pressure drop across the matrix and significantly prolonging its useful life.

Since the seal elements are formed from material having a low coefficient of expansion, since they are relatively narrow so that the differential temperature between their edges is relatively small, and since they are not connected to and therefore move independently of the heat transfer elements, bowing of these elements with the resultant formation of leak-permitting gaps is, for all practical purposes, eliminated. Further, the interval between elements is preferably selected so that there will always be three elements in contact with the sealing surface of each shoe. The result is a highly effective labyrinth seal between the matrix and the sealing surface. Additionally, the air and gas flowing through the matrix exert pressure on the edges of the seal elements opposite their sealing edges, forcing the elements in contact with the sealing surfaces.

It will be apparent from the foregoing discussion that it is an object of the present invention to provide improved rotary regenerators for gas turbines.

Another object of the present invention resides in the provision of rotary regenerators having improved sealing means for eliminating leakage from the high pressure air side to the low pressure gas side of the regenerator.

A further object of the present invention resides in the provision of rotary regenerator matrices which are less subject to mechanical failure than those of the prior art.

It is another object of the present invention to provide rotary regenerators having labyrinth type sealing means between their high pressure air sides and low pressure gas sides.

Another specific object of the present invention is the provision of rotary regenerators having rotating matrices, sealing shoes on the inner and outer sides of the matrices, and sealing spacers incorporated in the matrices and cooperating with sealing surfaces on said sealing shoes to prevent leakage from the high pressure air sides to the low pressure gas sides of the regenerators while maintaining the heat transfer elements of the matrices free of contact with the sealing surfaces.

In conjunction with the preceding object, it is another object of the present invention to provide improved matrices for rotary regenerators in which the heat transfer elements and sealing spacers are independent members.

Anotherv object of the present invention is the provision, in rotary regenerators, of sealing means between the high pressure air side and the low pressure gas side which will remain effective despite the distortion resulting from the temperature differentials encountered during regenerator operation.

Yet another object of the present invention resides in the provision of rotary regenerator matrices amenable to the employment of heat transfer members of materials having lower thermal conductivity than has heretofore been possible.

In conjunction with the above object, it is another object of the present invention to provide rotary regenerator matrices having sealing members formed of mate rials having lower coefficients of expansion than has heretofore been possible.

Other objects and further novel features of the present invention will be apparent from the appended claims and as the ensuing detailed description and discussion proceeds in conjunction with the accompanying drawing, in which:

FIGURE 1 is a vertical section through a rotary regenerator constructed in accordance with the principles of the present invention;

FIGURE 2 is a fragmental section through the regenerator of FIGURE 1, taken substantially along line 22 of that figure, and illustrates the mechanism provided for supporting the regenerator matrix for rotational movement within the regenerator housing;

FIGURE 3 is a sectional view of the regenerator of FIGURE 1, taken substantially along line 3-3 of FIG- URE 2, and illustrates details of the matrix-supporting rollers shown in FIGURE 2;

FIGURE 4 is a sectional view of the regenerator of FIGURE 1, taken substantially along line 44 of FIG- URE 2, andillustrates the arrangement employed in the present invention for preventing leakage from the high pressure air side to the low pressure gas side of the regenerator;

FIGURE 5 is a fragmental sectional view .of the regenerator, taken substantially along line 5-5 of FIG- URE 2, illustrating the relation of the matrix to the matrix-supporting rollers;

FIGURE 6 is a sectional view of the regenerator, taken substantially along line 6-6 of FIGURE 5, and illustrates the sealing shoes employed in the present invention;

FIGURE 7 is a view, to an enlarged scale, of a portion of FIGURE 6, showing one of the spring-biased sealing strips employed to effect a seal between the inner sealing shoe and the regenerator housing;

FIGURE 8 is a sectional view through the sealing strip of FIGURE 7 and is taken substantially along line 8-8 of FIGURE 7;

FIGURE 9 is a fragmentary plan view of the novel matrix provided by the present invention;

FIGURE 10 is a sectional View of the matrix of FIG- URE 9, taken substantially along line 10--10 of that figure, and illustrates a modular type heat transfer segment employed in the matrix;

FIGURE 11 is a sectional view of the matrix of FIG- URE 9, taken substantially along line 11-11 of that figure, and illustrates a loose pack type heat transfer segment employed in the matrix;

FIGURE 12 is a sectional view of the matrix of FIG- URE 9, taken substantially along line 1212 of FIG- URE 10, and illustrates the manner in which the seal matrix 30 which is formed of a number of multi-element heat transfer segments and which may be rotated by any desired source of power, normally the turbine with which the regenerator is employed. In operation, heated gases, I

normally the exhaust gases from the turbine, are introduced through aninlet 32 into the gas side 28 of the regenerator where they flow through and heat the rotating matrix 30 and pass out an outlet 34. At the same time, air is introduced, generally by the turbine compressor, through an inlet 36 into the air side 26 of the regenerator where it flows through and absorbs heat from the matrix 30 and passes through an outlet 38 to the turbine combustion chamber. The rotating matrix 30, therefore, alternately extracts heat from the turbine exhaust gases and gives up this heat to the turbine combustion air which, being thus preheated, raises the operating efficiency of the turbine.

The turbine exhaust gases flow into the gas side 28 of the regenerator at a relatively low pressure, commonly on the order of 0.9 p.s.i.g. The combustion air, on the other hand, is delivered to the air side 26 of the regenerator at a much higher pressure, generally on the order of 40 p.s.i.g. Because of this substantial pressure differential, the combustion air will tend to leak to the gas side 28 of the regenerator between: (1) the outer surface 40 of the rotating matrix and regenerator housing 22, (2) the inner surface 42 of the matrix and the edges 44 (only one of which is shown) of internal partition 24, (3) the ends of the matrix and the end walls of the regenerator housing, and (4) the peripheral edges of the sealing shoes and the regenerator housing and internal partition. It is with a novel sealing arrangement for preventing such leakage that the present invention is primarily concerned. As shown in FIGURE 1, sealing arrangements indicated generally by numeral 45 are employed at both the upper and lower sides of internal partition 24. Since thesealing arrangements at both locations are identical, only .that at the'upper side of partition 24 will be described.

Referring next to FIGURE 2, the sealing arrangement provided by the present invention includes an inner sealing shoe carrier assembly 46 providing an inner shoe 47 having a sealing surface 48.adjacent the inner surface 42 of matrix 30, an outer sealing shoe 50 carried by carrier assembly 46 and providing a sealing surface 52 ad-.

jacent the outer surface 40 of matrix 30, and a matrix construction including

seal elements

54 and 56 which cooperate with the sealing surfaces 48 and 52 of the sealing shoes to provide a highly effective labyrinth seal between matrix 30 and the sealing surfaces. Leakage around the ends of matrix 30 is prevented by end seal' from

end members

68 and 70, a top member 72 extending between

end members

68 and 70, and shoe assembly 47 extending between

end members

68 and 70 in spaced relation to top member 72. Shoe assembly 47 provides the sealing surface 48. Shoe carrier 46 is pivotably mounted in regenerator housing 22 by outwardly directed bosses or

trunnions

76 and 78, formed on

end members

68 and 70 respectively. Boss 76 extends through a circular aperture 80 in the end wall 82 of regenerator housing 22 while boss 78, which is diametrically slotted at 79 and then plugged at 83 to form a passage for seal strip 66, extends through a circular aperture 84 in an end cap assembly 86 fastened over an enlarged diameter aperture 88 in the vertical wall 90 of the regenerator housing. Cap assembly 86 is detachably fixed to regenerator housing side wall 96 by pins 92 and by socket head cap screws 94 and nut-like fasteners 96 and may be removed to gain access to the internal components of the regenerator.

Cylindrical bushings 88 and 190, fixed in aperture 80 in regenerator housing end wall 82 and in aperture 84 in cap assembly 86 in surrounding relationship to trunni-

ons

76 and 78 respectively, promote free rotational movement of shoe carrier 46 in its mounting. The pivotable mounting of shoe carrier 46 permits it to pivot to maintain shoe sealing surfaces 48 and 52 normal to the sealing edges of the

seal elements

54 and 56 in matrix during operation of the regenerator.

Shoe assembly 47 of carrier 46 includes end blocks 102 and 104 which are disposed between bars 105 and 106 (FIGURES 3 and 4) fastened to end

members

68 and 78 by screws 107. Extending between and fastened to end blocks 102 and 104 are lower and upper

horizontal members

108 and 110 and a pair of spaced apart vertical

side wall members

112 and 114, all of these members being joined together as by brazing or welding. The hollow boxlike assembly thus formed is strengthened by transversely extending stiffener plates 116 fixed between

members

112 and 114. The top surface of the upper horizontal member 116 is the sealing surface 48 of the inner sealing shoe 47.

As was pointed out previously, a sealing strip assembly 62 is arranged between carrier 46 and the edge 44 of regenerator housing interior partition 24 to prevent air from leaking between the carrier and the partition to the low pressure gas side 28 of the regenerator. Sealing strip assembly 62 includes a pair of generally channelsectioned elongatd strips 118 and 120 (FIGURE 6) disposed in a slot 122 formed in and opening onto the lower surface of the bottom member 108 in shoe assembly 47. As is best shown in FIGURES 4 and 7, the webs 124 of

strips

118 and 120 contact the upper edge 44 of partition 24, providing a seal between the partition and carrier 46. Firm contact between the sealing strips and the partition is maintained by leaf springs 126 which extend between the ends of slot 122 in member 108 and the webs 124 of the sealing strips.

As is best shown in FIGURE 7, strip 118 is fixed to end member 68 of carrier 46 by a pin 128. Sealing strip 120 (see FIGURE 8) is fixed to the lower end of end sealing strip assembly 66 by a pin 130. Referring now to FIGURE 6, the adjacent inner ends of

strips

118 and 120 are joined by a resilient strip connector 132 which accommodates thermal expansion and distortion of the

strips

118 and 120 as the internal regenerator components are heated to elevated temperatures under operating conditions.

Returning now to FIGURES 4 and 6, the upper member 72 of carrier 46 comprises an upwardly opening channel which extends between and is fixed to end

members

68 and 70 as by brazing or welding. Leakage of air to the gas side 28 of the regenerator between outer sealing shoe and regenerator housing 22 is prevented by the sealing strip assembly 64 which is substantially identical to the sealing strip assembly 62 described above and which is mounted in the channel section upper member 72. Its component parts have been identified by reference characters identical to those employed in describing sealing strip assembly 62, but primed.

The outer sealing shoe 50, which is supported by carrier 46, includes a pair of L-sectioned

bars

136 and 138 which cooperate to form a downwardly opening channel and are welded or brazed to top member of carrier 46 and, at their ends, to the

carrier end members

68 and 70. This assembly is strengthened by bars 140 and 142 welded to the L-shaped

members

136 and 138 and to end

members

68 and 70.

Slidably mounted for movement radially of the matrix between L-sectioned

members

136 and 138 is an outer shoe assembly 144 which includes an open sided rectangular frame formed from side members 145 and 146 and end members 147 and 148 and strengthened by intermediate transverse spacers 149. Supporting blocks 150 fixed in notches 151 (FIGURE 6) at the ends of side members 145 and 146 support a longitudinally coextensive sealing member 152. The lower side of sealing member 152 is the sealing surface 52 which, as explained above, cooperates with the seal elements 56 in matrix 30 to prevent leakage of air to the low pressure gas side 28 of the regenerator between the outer surface 40 of the matrix and regenerator housing 22. Sealing member 152 is biased toward seal elements 56 by coil springs 154 which extend between the horizontal legs of L-sectioned

members

136 and 138 and transversely extending retaining channels 156 fixed to the upper side of sealing member 152.

End sealing strip assembly 66 is formed of three channel-sectioned

members

166, 168, and disposed between inner sealing shoe end member 70 and end cap assembly 86 in notch 79 in the end member (see FIG- URE 5). Leaf springs 172 bias the sealing strips into engagement with the end cap assembly.

Strips

166, 168, and 170 are joined by a connector 174. These components of end sealing strip assembly 66 are substantially identical to the corresponding components in sealing

strip assemblies

62 and 64 and are, therefore, not deemed to require further elaboration. End sealing strip assembly 66, as noted previously, prevents air from leaking between the end of matrix 30 and regenerator housing cap assembly 86 to the low pressure gas side 28 of the regenerator.

At the opposite end of the regenerator, a gap 175 is left between end member 68 of shoe carrier 46 and regenerator housing side wall 82 to accommodate axial thermal growth of the sealing arrangement as the internal components of the regenerator heat up during regenerator operation. Annular sealing rings 176 and 177, disposed in annular grooves of end member 68, prevent the leakage of air through gap 175 to the gas side 28 of the regenerator.

Referring next to FIGURES 4 and 1013, the hollow cylindrical rotating matrix 30 is constructed from two types of heat transfer member segments, loose packs and modular segments, supported by circular end rings 178 and 180. The preferred embodiment of regenerator 20 has a matrix fabricated from 32 modular segments and 96 loose packs, there being three loose packs between each module.

Referring now specifically to FIGURES l1 and 12, each loose pack 182 consists of a stack or array of thin metallic leaves. In the preferred embodiment, a combination of flat leaves 184 and transversely convoluted leaves 186 is employed with the fiat leaves 184 interspersed between the convoluted leaves 186. Both the flat leaves 184 and the convoluted leaves 186 are fabricated from thin metal foil having low heat conductivity so that the heat transferred to the rotating matrix by the turbine exhaust gases in gas side 28 of the regenerator will not be dissipated before it can be transferred to the combustion air in the regenerators air side 26. Typically, the metal foil from which the flat and

convoluted leaves

184 and 186 are fabricated will have a thickness ranging from 0.001 to 0.005 inches and the convolutions in leaves 186 will have a depth on the order of 0.017 inch.

Longitudin ally extending, vertically spaced projections 188 and 190 (FIGURE 11) are formed on the ends of both the flat and

convoluted leaves

184 and 186. When the loose packs 182 are assembled into end rings 178 and 180, projections 188 extend between annularly extending, inner and

intermediate flanges

192 and 194 formed on the end rings and projections 190 extend between inter.- mediate flanges 194 and inwardly directed annularly extending flanges 196 formed adjacent the outer edges of the end rings. taposed flat leaves 184 of adjacent loose packs 182 are side plates 198(FIGURES 6, 12 and 13). Side plates 198 are provided with spaced, axially directed tabs defining notches 200 supportingly interfitted around the inwardly directed annular projections 194 on end rings 178 and 180. Side plates 198 are formed of metal'preferably with a thickness of about 0.050 inch.

Assembled into, matrix 30 adjacent the inner and outer edges of each side plate 198 are

identical seal elements

54 and 56. Because of this identity, only the seal elements 56 will be described in detail.

Seal element 56 (FIGURES 6 and 12) is a thin, narrow, elongated strip of metal having a low coefiicient of thermal expansion. Typically, element 56 is about 0.038 inch thick and has a central body width, in the radial direction, of 0.366 inch. Depending, outwardly directed feet 202, formed on the central body ends of element 56, extend into the spaces provided between the inner edge of the associated side plate 198 and the inwardly extending end ring flanges 192. Feet 202 space the opposing edges of the central body of element 56 from side plate 198 so that side plate 198 will not contact and distort the seal element even though the side plate is bowed or deflected radially by thermal expansion under normal operation condition.

Since the

seal elements

54 and 56 are fashioned from metal having a low coeflicient of thermal expansion and a relatively small width in the radial direction, radial bowing or curving of the seal elements under normal operating conditions will be inconsequential. As a consequence, gaps will not be formed between the sealing edges 204 of the seal elements and the sealing surfaces of the sealing shoes as in the prior art sealing arrange- Assembled into matrix 30 between the jux-,

ments. Side plate 198, being substantially thicker than

seal elements

54 and 56, prevent the heat transfer seg ments, as they swell under thermal expansion, from press-v ing against and distorting the seal elements.

As best shown in FIGURE 11, the sealing edges 204 of

seal elements

54 and 56 extend beyond the inner and outer edges, respectively, of the heat transfer leaves 182 and 184. Thus, the heat transfer leaves are maintained out of contact with the sealing surfaces 48 and 52 ofthe inner and outer sealing shoes. This eliminates the smearing and consequent blockage of the fluid flow channels between the heat transfer elements, an objectional condition common in the prior art arrangements in Whichthe heat transfer elements are designed to sealingly contact the sealing surfaces 48 and 52. I

If the preferred number of loose packs and modular segments is employed, the sealing edges of three

seal elements

54 and 56 will always be in contact with the sealing surfaces 48 and 52 of the inner and outer sealing:

shoes

46 and 50, respectively. This provides a highly effective labyrinth seal, preventing air from leaking be tween matrix 30 and the sealing surfaces 48 and 52,to the low pressure gas side 28 of the regenerator. The labyrinth seal is made even more effective by the high pressure air in air side 26 of the regenerator which acts against the inner edges of

seal elements

54 and 56, forcing them radially outwardly and inwardly, respectively, thereby assuring firm contact between their sealing edges and sealing

surfaces

48 and 52.

Referring now to FIGURES l0 and 13, modular heat transfer segments 206, like loose packs 182, are formed from a stack of alternating flat and

convoluted leaves

184 and 186 fabricated from metal having low heat conductance. The convoluted leaves are tapered slightly in a radial inward direction so that a wedge-shaped segment which can be readily assembled into the hollow cylindrical configuration of matrix 30 will be obtained. (Tapering of the convoluted leaves is not necessary in the loose packs because the ends of the leaves are not rigidly fixed to the end rings and the leaves will tilt slightly and their convolutions will spread to provide the desired configuration during the assembly process). In the modular segments these leaves are fixed, as by brazing, to slightly tapered, wedge-like end blocks 210 (only one .of which is shown). As shown in FIGURE 10, leaf-supporting lugs 212 and 214 formed on the ends of both the flat and

convoluted leaves

184 and 186 extend into correspondingly configured

recesses

216 and 218 in the end blocks 210. Fixed to.

one side of each segment is a side plate 198 and seal ele- I 196 on the end rings and similar projections 222 on the end blocks extending between

end ring flanges

192 and 194. The modular segments 206 are retained in place by pins 224 which extend through aligned

apertures

226 and 228 in the end block 210'and the flanges of end rings 178 and 180, respectively.

Referring now to FIGURES 2, 3, and 5, the assembled matrix 30 is rotatably'supported in regenerator housing. 22 by a pair of rollers 230 which are, in turn, supported by the seal shoe carrier side members 68 and70. As is 1 best shown in FIGURE 5, the rollers 230 are located on opposite sides of end seals 58 and 60 (and outer sealing shoe 50), are rotatably mounted upon stub shafts 232 which extend inwardly from seal

shoe carrier members

68 and 70, and are retained in-place by end caps 233 (see FIGURES 2 and. 5) fixed to the stub shafts by Allen head screws (not shown). shoulders 234, formed on matrix end rings 178 and 180, rest and ride on the rollers 230 which thereby support the rotating matrix. As was pointed out above, matrix 30is continuously rotated vfrom an external source of power, generally the turbine output shaft. Gear teeth 236 (see FIGURE 5), formed on matrix end ring 178 engageable by a driving gear (not shown) rotate the matrix.

Wear bands 237 (FIGURES 2, 6, 10 and 11), fixed in notches 238 in the, outer edges of matrix end rings 178 and 180, engage the sealing surface 52 of outer sealing 7 shoe 50 and prevent the end rings from being eroded by rubbing contact with sealing member 152 as matrix 30 is rotated.

As was mentioned above, leakage of air around the ends of matrix 30 to the low pressure gas side 28 of the regenerator is prevented

byend sealing members

58 and 60. Turning now to FIGURES 5 and 6, end sealing. member 60 (and end sealing member 58 is identical) is a rectangularly sectionedblock ,of metal having a seal face 239 which engages the outer edge of matrix end ring below shoulder 234 of the end ring, a face 240 which engages the underside of annular shoulder 234, and a face 242 which engages the outer face of the end ring superjacent shoulder 234. The engaging surfaces of end sealing member 60and matrix end ring 180 are preferably case hardened or otherwise made wear resistant to accommodate the continuous rubbing contact between them.

End sealing member 60 is biased against matrix end ring 178 by a pairof coil springs 244 (FIGURE 6) which extend from seal shoe carrier member 70 into pockets or recesses 246 formed in end sealing member 60. A third spring 248, which extends from inner sealing shoe member 104 upwardly into a pocket 250 opening through the lower edge of end sealing member 60, biases the end Outwardly directed, vannular sealing member 60 into engagement with matrix end ring annular shoulder 234.

Transversely extending strips 251, fixed by cap screws 252 to end block 150 in outer sealing shoe 50 are separated from the end block by shims 253 disposed at two spaced points at each end. By varying the thickness of shims 253, sealing member 150 can be adjusted radially of the matrix 30 and canted to maintain sealing face 52 spaced uniformly .002 to .005 inches from the matrix peripheral face 40 defined by the seal elements 56 and end rings 178 and 180.

The construction of matrix 30 is not limited to the combination of modular and loose pack heat transfer segments described above. Alternatively, matrices fabricated entirely of modular or loose pack segments or of varying ratios of modular to loose pack segments may be employed. The difiiculty with employing only modular segments is that it may be difficult to fabricate sets of segments which will exactly fit into the matrix pattern due to the close tolerances required. While loose pack segments avoid this problem, they are more difiicult to handle than the modular segments. Thus, from a practical standpoint, a combination of modular and loose pack segments is preferred.

The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiment is therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

What is claimed and desired to be secured by Letters Patent is:

1. A matrix for a rotary regenerator, comprising: a plurality of elongated :heat transfer elements; means confining said elements into a hollow cylindrical configuration having concentric inner and outer surfaces defined by the opposed mating edges of the heat transfer elements; and sealing means including sealing elements arranged in generally parallel relationship to said heat transfer elements, said sealing elements being free of connection to and movable independently of the heat transfer elements and having edges protruding beyond said inner and outer surfaces, and means for preventing said heat transfer elements from expanding against and binding said sealing elements, said last-named means comprising side plates adjacent said sealing elements, said side plates being substantially thicker than said sealing elements.

2. The matrix as defined in claim 1, wherein said heat transfer elements are loosely assembled into plural-membered matrix segments and some of said elements are formed to provide passages between their opposite edges.

3. The matrix as defined in claim 1, wherein a portion of said elements are loosely assembled into plural-membered matrix segments and the remainder of said elements are assembled into modular matrix segments interspersed at intervals among said first-named segments.

4. The matrix as defined in claim 1, wherein said heat transfer elements are formed of material having low heat conductance.

5. The matrix as defined in claim 1, wherein the material from which said sealing elements are formed has a low coefficient of thermal expansion.

6. The matrix as defined in claim 3, wherein said modular segments have a tapered cross section to facilitate assembly of said segments into said cylindrical configuration.

7. The matrix as defined in claim 1, wherein a pair of sealing elements are associated with each of said side plates, said sealing elements being disposed adjacent the opposite edges of said plates.

8. The matrix as defined in claim 1, wherein the cefficient of expansion of the material from which the sealing elements are formed is substantially lower than that of the material from which the heat transfer elements are formed.

9. The matrix as defined in claim 1, wherein the dimension of said sealing elements in a direction normal to said inner and outer surfaces is a relatively small frac tion of the distance between said surfaces.

10. A modular segment for use in constructing a rotary regenerator matrix having a hollow cylindrical configuration, comprising: a plurality of elongated heat transfer elements disposed in side-by-side relationship, at least some of said elements being configured to provide passages extending between opposite edges of said segment, said heat transfer elements being free of connection and movable relative to each other; end members attached to said elements to retain them in side-by-side assembled relationship, said segment having the configuration of a wedge; a side spacer plate extending between and fixed to said end members on one side of said segment adjacent the outermost of said heat transfer elements; and inner and outer sealing elements fixed to and extending between said end members adjacent the opposite sides of said spacer plate, said inner and outer sealing elements having sealing edge portions extending radially beyond the inner and outer edges of said heat transfer elements.

11. A rotary gas regenerator, comprising: a housing, a :hollow cylindrical matrix comprising a large number of heat transfer elements assembled in side-by-side relationship rotatably mounted in said housing; internal partition means dividing said housing into first and second chambers, said partition means having openings therein for passage of said matrix between said chambers; means providing an inlet to and an outlet from each of said chambers; sealing shoes providing sealing surfaces on the walls of said openings adjacent the inner and outer sur faces of said matrix, said sealing shoes being mounted in said housing for movement about a line parallel to the rotation axis of said matrix, whereby said sealing shoes may pivot to maintain said sealing surfaces normal to the sealing edge of said seal means; and seal means in said matrix extending radially therefrom and cooperating with said sealing surfaces to prevent the passage of fluid from one to the other of said chambers, said seal means including members free of connection to and movable independently of said heat transfer elements in sealing contact with said sealing surfaces over substantially the entire length of said matrix.

12. In a rotary gas regenerator; a housing; a hollow cylindrical matrix comprising a large number of heat transfer elements assembled in side-by-side relationship extending substantially the length of and rotatably mounted in said housing; partition means extending the length of said housing through the hollow interior of said matrix and dividing said housing into high and low pressure chambers; spaced first and second sealing means for preventing the passage of fluid from one to the other of said chambers, said first sealing means comprising means providing an inlet to and an outlet from each of said chambers; a first sealing shoe extending the length of and supported by said housing between said housing and a side edge of said partition, said sealing shoe having an aperture through which said matrix extends and means providing a sealing surface adjacent one side of said matrix; a second sealing shoe carried by said first shoe and providing a sealing surface adjacent the opposite side of said matrix; and sealing elements in said matrix cooperating with said sealing surfaces to form labyrinth seals between said partition and said matrix and between said matrix and said housing, said sealing elements being free of connection to and movable independently of the heat transfer elements.

13. The rotary gas regenerator as defined in claim 12, including resilient biasing means between said first and second sealing shoes to bias the sealing surface of said second shoe into engagement with said sealing elements.

14. The rotary gas regenerator as defined in claim 12', including sealing strips carried by said first sealing shoe between said shoe and said partition and housing, respectively, and resilient means between said shoe and said strips biasing said strips into engagement with said housing and said partition.

15. The rotary gas regenerator as defined in claim 12, wherein said first sealing shoe has end walls adjacent the ends of said matrix and including end sealing shoes and resilient means between said end walls" and said Sealing shoes biasing said sealing shoes into engagement with the I ends of said matrix.

16. ,The rotary gas regenerator as defined in claim 12, wherein said first sealing shoe and said regenerator housing have juxtaposed end walls and including a sealing strip between one of said sealing shoe end walls and the juxtaposed housing end wall and resilient means between said sealing shoe end wall and said strip biasing said strip into engagement with said housing end Wall, there being a space between the other sealing shoe end wall and the juxtaposed housing end wall to accommodate thermal expansion of said sealing shoes.

17. The rotary gas regenerator as defined in claim 12, including rollers carried by said first sealing shoe at the ends of said matrix and wherein said matrix includes end rings with flanges extending over and riding on said rollers.

References Cited by the Examiner UNITED STATES PATENTS 2,432,198 12/47 Karlsson et a1. 165-5 x 2,352,233 9/53 Hryniszak 1659 2,937,010 5/60 Collman et al. 1651O 3,043,568 7/62 KOlthOlf 1659 X 3,057,604 10/62 Bubniak et al. 1659 FOREIGN PATENTS 535,751 1/57 Canada. 750,303 6/56 Great Britain.

CHARLES SUKALO, Primary Examiner.

Claims

12. IN A ROTARY GAS REGENERATOR; A HOUSING; A HOLLOW CYLINDRICAL MATRIX COMPRISING A LARGE NUMBER OF HEAT TRANSFER ELEMENTS ASSEMBLED IN SIDE-BY-SIDE RELATIONSHIP EXTENDING SUBSTANTIALLY THE LENGTH OF AND ROTATABLY MOUNTED IN SAID HOUSING; PARTITION MEANS EXTENDING THE LENGTH OF SAID HOUSING THROUGH THE HOLLOW INTERIOR OF SAID MATRIX AND DIVIDING SAID HOUSING INTO HIGH AND LOW PRESSURE CHAMBERS; SPACED FIRST AND SECOND SEALING MEANS FOR PREVENTING THE PASSAGE OF FLUID FROM ONE TO THE OTHER OF SAID CHAMBERS, SAID FIRST SEALING MEANS COMPRISING MEANS PROVIDING AN INLET TO AND AN OUTLET FROM EACH OF SAID CHAMBERS; A FIRST SEALING SHOE EXTENDING THE LENGTH OF AND SUPPORTED BY SAID HOUSING BETWEEN SAID HOUSING AND A SIDE EDGE OF SAID PARTITION, SAID SEALING SHOE HAVING AN APERTURE THROUGH WHICH SAID MATRIX EXTENDS AND MEANS PROVIDING A SEALING SURFACE ADJACENT ONE SIDE OF SAID MATRIX; A SECOND SEALIG SHOE CARRIED BY SAID FIRST SHOE AND PROVIDING A SEALING SURFACE ADJACENT THE OPPOSITE SIDE OF SAID MATRIX; AND SEALING ELEMENTS IN SAID MATRIX COOPERATING WITH SAID SEALING SURFACES TO FORM LABYRINTH SEALS BETWEEN SAID PARTITION AND SAID MATRIX AND BETWEEN SAID MATRIX AND SAID HOUSING, SAID SEALING ELEMENTS BEING FREE OF CONNECTION TO AND MOVABLE INDEPENDENTLY OF THE HEAT TRANSFER ELEMENTS.