US3266564A

US3266564A - Liquid metal rotary heat exchanger

Info

Publication number: US3266564A
Application number: US344120A
Authority: US
Inventors: Sabatiuk Andrew
Original assignee: Curtiss Wright Corp
Current assignee: Curtiss Wright Corp
Priority date: 1964-02-11
Filing date: 1964-02-11
Publication date: 1966-08-16
Anticipated expiration: 1983-08-16

Description

Aug. 16, 1966 A. SABATIUK LIQUID METAL ROTARY HEAT EXCHANGER 5 Sheets-Sheet 1 Filed Feb. 11, 1964 INVENTOR ANDREW EAEIATIUK ATTORNEY Aug. 16, 1966 A. SABATIUK 3,265,564

LIQUID METAL ROTARY HEAT EXCHANGER 3 Sheets-Sheet 2 Filed Feb. 11, 1964 INV NTOR. ANDREW EKEATIUK ATTORNEY Aug. 16, 1966 A. SABATIUK LIQUID METAL ROTARY HEAT EXCHANGER 5 Sheets-Sheet 5 Filed Feb. 11, 1964 i l v m Iv Qn ww 7/ /l|.|W HlM\l l// V N7 /A vm D D W M \Nw Nw \yw H M M S C C Hn l l N Hill! "u H "Ilillflh Lilli HFIIIIJIIIIIhHHH lhrlllhnh "4 N a i 1 HEBMEIEHEBEEHEm -a Maw Y INVENTOR. AN DREW EAEIATILM Y B *6 3mm LEI I E ATTEIRNEY United States PatentO This invention relates to gas turbine engines and in particular to a means for utilizing the heat of the exhaust gases to reduce the fuel consumption.

Gas turbine engines are being used in increasing quan- 1 tities for auxiliary power drives, generation of electricity, pumping of liquids and gases,,and as prime movers in aircraft, marine and automotive vehicles. However, one of the principal disadvantages of the gas turbine engine lies in'its poor fuel economy at part-power load conditions. It has long been recognized that the use of regenerativecycles in gas turbine engines presents a promising means of achieving good part-load fuel economy. In the regenerative-cycle, heat from the exhaust gases from the gas turbine engine is removed and transferred to the incoming air prior to introduction of said air into the combustion zone. By this means, the air for combustion is preheated which thereby improves the combustion process with a resulting reduction in the fuel consumption. In the past, however, the conventional heat exchange systems used for carrying out the regenerative-cycle have suffered from serious drawbacks in that they were of excessive weight and volume resulting in cumbersome and awkward engine configurations and further were of complex design.

It is a prime object of the present invention to provide a novel and improved heat exchanger of the rotary type for a gas turbine engine which is relatively light in weight, simple in construction and has improved heat exchanging effectiveness. The invention is generally carried out by providing a rotary heat exchanger which is rotatable relative to the compressor and turbine of the gas turbine engine and is provided with a plurality of circumferentiallyspaced hollow blade-like members each of which has a liquid metal sealed therein. The liquid metal in each of the blade members is acted upon by centrifugal forces due to the rotation of the rotary heat exchanger which urges the liquid metal to flow radially outwardly relative to its respective blade member. The radially outer portion of each of the blade members is exposed to the flow of the relatively hot exhaust gases for flow thereover while the radially inner portion of each blade member is exposed to the fiow of the relatively cool compressed air for flow thereover. This results in variation in the temperature of the liquid metal sealed in the blade member and therefore the centrifugal forces on the different density portions causes circulation of the liquid metal. If the exhaust gases and compressor air flow are in opposite directions relative to the axis of rotation of the blade members, then the liquid adjacent one edge .of each blade member becomes relatively warm compared to the temperature adjacent to the other edge of the blade member whereby in response to the centrifugal forces, the liquid will flow radially outwardly along the cooler edge and radially inwardly along its hotter edge. Thus, there will be a circulation of the liquid metal in each blade member between its radially outer and inner portions wherein heat will be absorbed by the liquid metal in the radially outer portion from the exhaust gases and given oft by the liquid metal to the relatively cool compressed gas in the radially inner portion. Therefore, the compressed gases introduced into the combustion zone will be preheated prior to mixture with the fuel and combustion thereof which will result in a more complete burning of the fuel-air mixture, particularly during part-load operation, with a resultant 3,266,564 Patented August 16, 1966 improvement in the specific fuel consumption of the engine over the entire power range.

Accordingly it is one object of the invention to provide a novel and improved heat exchanger mechanism for utilizing heat in the exhaust gases to preheat the combustion air and more particularly it is an object of the invention to provide such a novel and improved heat exchanger mechanism for a gas turbine engine.

It is a further object of the invention to provide a rotary heat exchanger which is relatively simple in construction with improved operating performance.

It is still another object of the invention to provide a rotary heat exchanger which is relatively simple in construction with improved operating performance.

It is still another object of the invention to provide a rotary heat exchanger having a heat transfer liquid sealed therein under free convection circulation in response to the centrifugal forces on said liquid.

Other objects and advantages of the invention will become apparent .on reading the following detailed descrip tion withthe accompanying drawings wherein:

FIG. 1 is an axially sectional view of a gas turbine engine embodying the present invention,

FIG. 2 is an enlarged partial sectonal view of the rotary heat exchanger of the invention, as viewed from the exhaust end of FIG. 1, 5

FIG. 3 is a sectional view taken along line 3-3 of FIG. 2 showing the liquid metal circulation path,

FIG. 4 is a sectional view taken along line 44 of FIG. 3, and showing a single element of the rotary heat exchanger of the invention,

FIG. 5 is a sectional view taken along line 5-5 of FIG. 3; and

FIG. 6 is a schematic view of the air flow in and out of the rotary heat exchanger of the invention.

Referring now to FIG. 1 of the drawing, a gas turbine engine is schematically illustrated at 10 and comprises a duct-like housing 12 having an air compressor 14 journaled within said housing adjacent to its forward end. The air compressor 14 receives air through an annular air inlet 16 and delivers compressed air to a combustion chamber 18 where said compressed air is mixed with fuel supplied for example through nozzles 20 for combustion therein. The resulting combustion gases are directed by a nozzle or guide vane structure 22 which may comprise a plurality of stator blades, to the rotor blades 24 of a turbine rotor 26 for driving said rotor. A shaft 28 drivably connects the turbine rotor 26 with the air compressor 14 and in addition is connected through a suitable reduction gear box 27 to a thrust producing air propeller 25. Therefore, it will be seen that the propellers will be driven by the turbine rotor 26 for providing the gas turbine engine with a forward propulsive thrust. The gas turbine structure so far described is conventional and it should be understood that the invention may be embodied in gas turbine engines other than the turbo-prop type illustrated.

As statedabove, the primary purpose of the invention is to provide a novel and improved heat exchanger mechanism, Referring again to the drawings, a heat exchanger mechanism 30 of the rotary type is illustrated as being supported for rotation relative to the compressor 14 and the turbine rotor 26. The rotary heat exchanger 30 may be supported on an annular stationary housing member 32 surrounding the shaft 28 and has suitable bearings 34 and 36 between said annular member 32'and the hub portion 38 of the rotary heat exchanger 30. The bearings 34 and 36 support the rotary heat exchanger for end thrust and gyroscopic forces acting on said rotary heat exchanger.

The rotary heat exchanger 30 in itself comprises a plurality of circumferentially-spaced, radially-extending blade elements 40. Each of the blade elements 40 is hollow and is filled with a liquid metal such as sodium or the like and is sealed permanently. Some inert gas may also be contained in the hollow space in each of the blade elements 40 to permit expansion of the liquid metal. The interior of each of the blade elements 40 is provided with bafiles or partitions 42 which form circulation passages for a liquid metal. The partitions 42 may be formed in the interior of the blade elements 40 by crimping the blades with alternate crimps on opposite sides thereof. It will also be apparent that the partitions 42 serve to prevent high pressure gas from collapsing the hollow blade members 42 due to a differential in gas pressure on each side of the blade elements. The blade elements 40 are each suitably fixed to the rotary heat exchanger mechanism hub portion 38 through a slot arrangement in the hub portion 38 which receives an enlarged portion 44 on each of the blade elements (FIGS. 2-4). A shroud interconnecting the radially-outer portions of the blade members may also be provided to provide additional support to the heat exchanger blade elements 40, if necessary.

As further illustrated in FIGS. 24, each of the blade elements is provided with a plurality of axially-extending, radially-spaced fin members 46 which provide for heat transfer between the liquid metal in the interior of the blade elements 14 and the gases which pass over said fin elements 46.

Annular gas seals

48 and 50 are provided at each axial end of the heat exchanger 30, respectively, in a gas seal housing structure 52 and 54, respectively, which support said

seals

48 and 50 for sealing engagement against annular housing portions 56 and 58 (FIG. 1) adjacent each axial end of the heat exchanger 30, respectively.

The seal housing structure 52 and 54 may be formed by plates 68 and 70 suitably secured to the blades 40 or fins 46, as by brazing or the like, with the plates being formed to provide a box-like housing at each axial end of the heat exchanger 30 and having an opening therein to permit the

seal members

48 or 50 to protrude therefrom. A movable gas seal piece is provided in each of the seal housings 52 and 54 with said seal pieces extending slightly circumferentially beyond the width of each blade member its fins and, when the heat exchanger 30 is assembled, the seal pieces of each blade member mate with the seal pieces carried by an adjacent blade element to form the continuous

annular seals

48 and 50.

The

movable gas seals

48 and 50 may be biased into engagement with the

engine housing portions

56 and 58 by springs 64 and 66 (FIG. 3) or the like. However, the

seal members

48 and 50 may be carried by the

housing portions

56 and 58 for sealing against an annular portion of the rotary heat exchanger mechanism 30 instead of the arrangement shown. As illustrated in FIGS. 2, 4 and 5, the plates 68 and 70 extend in a circumferential direction so that they are immediately adjacent a plate member 68 or 70 extending from an adjacent blade element 40 in the assembled unit and in the region of the seal housings 52 and 54 the plate members 68 and 70 are in abutting relationship so that the gas seal housings 52 and 54 for each blade member 40 at each axial end of the heat exchanger mechanism 30 mate to form a continuous annular housing, as partially illustrated in FIG. 2. The metal plates 68 and 70 from each of the blade elements 40 overlap a circular member 72 which also extends over the entire axial dimension of each of the blade elements 40 to form a radial seal between the metal plates 68 and 70 and said circular member 72. The circular members 72 are each formed from an associated portion of a separation plate 74 which is positioned intermediate of each of the blade elements 40 as viewed in the circumferential direction and also extend over the entire axial length of the heat exchanger mechanism 30. The separation plates 74 serve to prevent the blade elements 40 from bulging as a result of pressure differentials by allowing them to mutually support each other through said separation plates rather than letting the fin members of each of the blade members 40 mesh together. As illustrated in FIG. 2, the separation plates 74 are provided in the radially upper portion of the heat exchanger mechanism 30 which is the high pressure side of said mechanism. However, it should be understood that the seal means illustrated is only meant to be exemplary of a type of seal means which may be used with the present invention and the invention is not intended to be limited to the specific seal means shown and other suitable seal means such as a labyrinth type seal may be used.

It will be apparent from the above description that the

movable seal members

48 and 50 and their related construction and the metal plates 68 and 70 with the circular section members 72 serve as a partition means to divide the rotary heat exchanger 30 into a radially inner portion and a radially outer portion with each of said portions being sealed from one another by the prior-mentioned construction so that gas leakage between the two portions will be prevented.

Referring to FIGS. 1 and 6, a row of stator blades 76 is positioned intermediate the compressor 14 and the rotary heat exchanger mechanism 30 with said stator blades 76 being disposed so as to provide a high tangential component to the axial flow of air (solid arrows in FIG. 1) leaving the compressor 14. This high tangential component of compressor air is directed at the blade elements 40 of the rotary heat exchanger mechanism 30 and will impart a rotation to said heat exchanger mechanism relative to the compressor 14 and the turbine 26 with the velocity of said rotary heat exchanger being relatively low as compared to the velocity of the compressor, for example, due to the fact that the relative velocity of the rotary heat exchanger will be of a magnitude equal to the tangential component of the compressor air flow. This relatively low flow velocity of the air relative to the rotor blade elements 40 is favorable for effective heat transfer between the liquid metal in the hollow blade elements 40 and the air passing over the surfaces of said blade elements 40. Means may be provided for adjusting the angle of the stator blades 76 relative to the axial flow of air from the compressor 14 to thereby change the tangential component of the air flow relative to the rotor blades 40 of the rotary heat exchanger. By this means the rotational speed of the heat exchanger may be changed and thus the circulation of the liquid metal can be controlled for varying the effectiveness of the heat exchanger.

It will be apparent from FIG. 1 that the sealed inner I portion designated at 78, of the rotary heat exchanger mechanism 30 has a radial dimension which coincides with the annulus of the compressor exit downstream of the row of stator blades 76 which is designated at 89. At the exit side of the rotary heat exchanger mechanism 30, the radially inner portion 78 has a radial dimension which coincides with the annulus of the combustion chamber entrance, designated at 82. Thus, it will be seen that the compressor air, as it leaves the compressor, has a sealed flow path through the radially inner portion 78 of the rotary heat exchanger mechanism and into the combustion chamber 18. A row of stator blades 84 is provided at the discharge end of the rotary heat exchanger mechanism 30 or in other words upstream of the combustion zone 18 and said stator blades 84 are disposed so as to return the tangential flow of air from the heat exchanger mechanism 30 to an axial flow prior to its entrance into the combustion chamber 18. Therefore, referring to FIG. 6, it will be seen that upstream of the rotary heat exchanger mechanism 30 or the blade elements 40 a row of stator blades 76 is disposed so as to receive the compressor air C and to provide a tangential component, AV (Absolute Velocity), from the axial flow of compressor air, designated RV (Relative Velocity) for imparting rotation to the rotary heat exchanger mechanism 30, designated RR, and a second row of stator blades 84 is positioned downstream of the rotary heat exchanger mechanism 30 to return the tangential component, AV, to an axial flow designated C. As also illustrated-in FIGS. 1 and 6, the combustion gases T (dotted arrow in FIG.- 1) which have an axial flow upon discharge from the turbine 26, are directed through a row of stator blades 85 prior to entry through the portion 88 of the heat exchanger with said blades 85 being disposed so as to provide a tangential component AV which acts on the blades 40 to aid in rotating the heat exchanger mechanism in a manner similar to the gases flowing through the heat exchanger portion 78. A row of stator blades 87 is provided at the downstream end of the heat exchanger portion 88 to return the tangential component AV to an axial flow, designated by arrow T. Rotation of the mechanism 30 may also be provided by the blade elements 40 alone for this purpose by orienting them so as to have an angular relationship relative to the flow of gases through each

portion

78 and 88. It should be understood that the invcntion is not limited to the means illustrated for imparting rotation to the rotary heat exchanger mechanism 30 and other means may be used such as, a mechanical drive geared from the turbine shaft 28, a drive imparted from the turbine exhaust or combustion gases instead of the compressor gases, or a bleed flow may be taken from either the compressor or exhaust gases to drive a separate turbine coupled to the rotary heat exchanger mecha- IllSm.

An annular duct 86 having an opening downstream of the turbine 26 is provided for receiving the combustion gases discharged from said turbine 26 (dotted arrows in FIG. 1) and directing said gases in a direction toward the upper portion 88 of the rotary heat exchanger mechanism 30. The duct 86 has a discharge opening which substantially coincides with the radical dimension of the upper portion 88 of the rotary heat exchanger mechanism so that the combustion gases will be directed through the upper portion 88 of the rotary heat exchanger mechanism and will be discharged therefrom into an annular duct 90 where the combustion gases will then be directed toward the exhaust end of the engine for discharge through an exhaust nozzle (not shown) and into the surrounding atmosphere. It will be seen, therefore, that the relatively cold compressor air will be directed through the rotary heat exchanger mechanism 30 in one direction and the relatively hot combustion gases will be directed through said rotary heat exchanger mechanism 30 in an opposite direction to the compressor air. FIG. I is merely illustrative of a system of ducts for directing the compressor air and combustion gases through the rotary heat exchanger mechanism and it should be understood that other configurations of duct work may be used with changes in the basic design of the gas turbine engine such as, for example, having the compressor at the rearward portion of the engine and the turbine at the forward portion.

FIGS. 1 and 3 illustrate the circulation of the liquid metal within the hollow blade elements 40. With the rotary heat exchanger mechanism 30 rotating about the axis A-A the liquid metal sealed within the hollow blade elements 40 will be acted upon by a radially outwardly directed centrifugal force designated at CF in FIG. 3. As the hot combustion gases, designated by the arrows T, pass through the upper portion 88 of the rotary heat exchanger mechanism 30 in one direction heat will be transmitted from said hot gases to the liquid metal within the hollow blade elements 40. As the relatively cold compressor gases flow in the opposite direction through the lower portion 78 of each blade element 40, heat will be transmitted from the liquid metal to the compressor gases. It will be apparent that the liquid metal at the axial end of the heat exchanger mechanism in both the

portions

78 and 88 adjacent the compressor will be at a relatively lower temperature than the liquid metal in both

portions

78 and 88 at the axial ,end of the heat exchanger adjacent the combustion chamber 18. Thus, there will be a differential in temperature and density of the liquid metal at each axial end of the heat exchanger and due to this differential, the higher temperature, lower density liquid metal at the combustion zone end of the heat exchanger, or the rearward portion,

will flow radially inwardly along the rearward wall and.

relatively higher temperature and lower density liquidmetal contained therein than the preceding path. Thus, there will be a differential in temperature and density of the liquid metal in each of the axially adjacent flow paths formed by the partitions 42 which will result in the liquid metal flow circulating in and out of the paths and guided by the partitions 42, as illustrated in FIGS. 1 and 3 with the flow being from front to rear in the radially outward portion 88 and rear to front in the radially inner portion 78.

From the above, it will be seen that the liquid metal, when it reaches the radially outward portion 88 of the rotor, will pick up heat from the hot combustion gases passing over this portion and as the liquid metal, which has been heated in the radially outward portion 88, flows to'the radially inward portion 78 of the rotor, heat will be transferred from said liquid metal to the relatively cold compressor air designated by arrows C in FIG. 3, passing through this region. It will be apparent that the liquid metal within each of the rotor blade elements 40, during operation, has a free convection circulation due the heat transfer from the hot combustion gases to the liquid metal and from the liquid metal to the relatively cold compressor air. from the hot combustion gases to preheat the relatively cold compressor air prior to its entrance into the combustion chamber 18.

As is well known, raising the temperature of the compressor air as it enters the combustion chamber for c0mbustion therein permits a more economical use of the fuel mixed with said compressor air, particularly at the part-load operating conditions. It should be particularly noted that the heat transfer from the hot combustion gases to the compressor air is brought about in complete absence of any pumps or other mechanical means for creating circulation of the heat transfer medium. It should also be noted that the device is a steady flow device using separate paths for the hot and cold gases which as a result simplifies the scaling mechanisms between the separate gas fiow paths. Further, the circulation of the liquid metal within the blade elements 40 is relatively simple and does not require any two-directional or flow reversal of the liquid metal in order to provide the heat transfer from the combustion gases to the compressor air. Another advantage of the invention lies in the fact that no separate storage is required for the liquid metal and therefore the problem of the liquid metal solidifyin at relatively low temperatures so as to make starting the system ditficult is avoided. It will also be seen that the design of the rotary heat exchanger mechanism will be compact and lightweight. The compactness of the rotary heat exchanger of the invention will permit a shorter overall engine configuration which will result in reducing critical speed problems and weight problems than, as for example, could be accommodated by a gas to air type heat exchanger.

From the above detailed description, it will be apparent that the invention provides for a novel and improved rotary heat exchanger mechanism which is compact, light in weight and has improved efficiency and economy over heat exchanger mechanisms of the prior art type. While In this manner, heat is transferred I have described my invention in detail in its preferred embodiment, it will be obvious to those skilled in the art, after understanding my invention that various changes and modifications may be made therein without departing from the spirit or scope thereof. I aim in the appended claims to cover all such modifications.

I claim as my invention:

1. A rotary heat exchanger including means for rotating said heat exchanger, said rotary heat exchanger comprismg:

(a) a hub member;

(b) a plurality of circumferentially-spaced heat exchanger elements secured to said hub member and extending radially theretrom with each said element including a plurality of interconnected substantially -shaped passages extending from one axial end of said element to the other;

(c) partition means disposed intermediate the radial length of said elements and extending circumferentially between said elements such that said partition means forms the inner wall of a first annular gas flow path across which the radially outer portions of said elements extend and said partition means with said hub member also forming the outer and inner walls respectively of a second annular gas flow path across which the radially inner portions of said elements extend;

(d) a plurality of radially-spaced heat exchange fin members secured to and projecting circumferentially from both the radially inner and radially outer portions of said elements into heat exchange relationship with the gases flowing though said flow paths; an

(e) a heat exchange liquid sealed within said elements for circulation through said passages in response to centrifugal forces acting on said liquid due to rotation of said heat exchanger for transferring heat between the radially inner and outer portions of said elements.

2. A rotary heat exchanger as recited in claim 1 wherein: Y

(a) said elements have a blade-like configuration and in one of said annular gas flow paths are angularly disposed relative to the direction of the gas flow through said annular gas flow path so that the gas flow acts on said elements to impart rotation to said rotary heat exchanger.

3. A rotary heat exchanger as recited in claim 1 further comprising:

(a) guide means including at least one interior partition disposed intermediate of the axial limiting walls of each element and extending radially between both said radially inner and outer portions of said element but terminating short of the radial limiting walls of each said element for guiding said heat exchange liquid around said interior partition between said radially inner and outer portions of said element during circulation of said liquid within said element.

4. A rotary heat exchanger as recited in claim 1 wherein:

(a) said heat exchange liquid comprises a liquid metal with said liquid metal being in a liquid state at least at temperatures above the ambient atmospheric temperature.

5. A rotary heat exchanger as recited in claim 1 wherein:

(a) said partition means includes seal means in sealing relationship with an outer body for preventing mixture of the gases in said first annular gas flow path with the gases in said second annular gas flow path.

6. A rotary heat exchanger supported in an outer body for transmitting heat from a hot fluid stream to a cold fluid stream with said outer body including passage means for separately guiding each of said fluid streams axially in opposite directions relative to each other and also ineluding means for rotating said heat exchanger, said rotary heat exchanger comprising:

(a) a rotor having a first radial portion disposed in the path of said hot fluid stream and a second portion radially inward of said first portion and disposed in the path of said cold fluid stream;

(b) partition means on said rotor intermediate said first and second portions for dividing said rotor into first and second annular flow paths;

(c) said rotor including a plurality of circumferentially-spaced heat exchanger elements extending radially outwardly from said second portion through said first portion and supported for rotation about the axis of said rotary heat exchanger with each said element including a plurality of interconnected sub stantially radially oriented liquid conducting passages disposed in axial relationship from one end of said element to the other;

(d) a plurality of radially-spaced heat exchange fin elements on the outer surface of said elements in heat exchange relationship with said hot and cold fluid streams; and

(e) a heat exchange liquid sealed in each of said elements which in response to rotation of said rotor and the difference in temperature of said hot and cold fluid streams is caused to circulate through said passages of said elements between said first and second portions for absorbing heat from said hot fluid stream and transmitting heat to said cold fluid stream.

7. A rotary heat exchanger as recited in claim 6 wherein said heat transfer material comprises a liquid metal with said liquid meta-l being in a liquid state at least at temperatures above the ambient atmospheric temperature.

8. A rotary heat exchanger as recited in claim 6 further comprising seal means on said rotor for sealing engagement with said outer body and said seal means being disposed so as to provide a gas seal between said first radial portion and said second portion for preventing mixture of said hot fluid stream with said cold fluid stream.

9. A rotary heat exchanger as recited in claim 6 wherein each said element comprises a blade-like member with each blade-like member having interior partitions therein for guiding said heat exchange liquid during circulation within said blade-like element.

10. A rotary heat exchanger for use in a gas turbine engine having an outer body including means for directing the compressor air and exhaust gases of said gas turbine engine axially in opposite directions, said rotary heat exchanger comprising:

(a) a rotor including a hub member and including means for rotating said heat exchanger relative to said gas turbine outer body;-

(b) a plurality of circum ferentially-spaced radially extending hollow elements secured to said h-ub memher for rotation therewith;

(c) partition means disposed intermediate the radial length of said hollow elements and extending between each of said hollow elements such that said partition means separates said rotor into first and second radial portions each of which defining a separate gas flow path through said rotor with said first radial portion being disposed in the path of said gas turbine combustion gases and said second radial portion being disposed in the path of said gas turbine compressor air;

(d) seal means disposed between said first and second radial portions of said rotor for sealing cooperation between said gas turbine outer body and said rotor so is to provide a gasseal between said gas flow P (e) a plurality of radially-spaced heat exchange fin members secured to and projecting from the outer surface of each said hollow element into heat exchange with the gascs flowing through said gas fiow p (-f) a heat exchange liquid sealed within each of said hol-low elements which in response to the centrifugal ior-ces on said liquid generated during rotation of said rotor and the difference in temperature between said gas tunbine combustion gases and compressor air circulates within said hollow elements between said first and second radial portions whereby heat is transferred from said combustion gases by said liquid to said compressor air for preheating said compressor air prior to combustion; and

(g) each said hollow element is provided with partit-ion means in the interior thereof 'for guiding said heat exchange liquid during circulation between said first and second radial portions.

11. A rotary heat exchanger as recited in claim 10 wherein:

(a) said partition means includes at least one radially extending partition disposed intermediate the axial limiting walls but terminating short of the radially limiting walls of each hollolw element so that the heat exchange liquid circulates radially inwardly along one axial limiting wall of said hollow element, around said interior portion, to said first-mentioned axial limiting wall.

12. A rotary heat exchanger as recited in claim \10 wherein:

(a) said heat exchange liquid comprises a liquid metal.

References Cited by the Examiner UNITED STATES PATENTS 1,739,137 12/1929 Gay 165-181 X 2,925,714 2/1960 Cook 60-39.5 1 X 3,007,685 11/1961 Hryniszak 165-104 X FOREIGN PATENTS 1,002,570 2/ 1957 Germany.

792,984 4/1958 Great Britain.

ROBERT A. OLEARY, Primary Examiner.

A. W. DAVIS, Assistant Examiner.

Claims

1. A ROTARY HEAT EXCHANGER INCLUDING MEANS FOR ROTATING SAID HEAT EXCHANGER, SAID ROTARY HEAT EXCHANGER COMPRISING: (A) A HUB MEMBER; (B) A PLURALITY OF CIRCUMFERENTIALLY-SPACED HEAT EXCHANGER ELEMENTS SECURED TO SAID HUB MEMBER AND EXTENDING RADIALLY THEREFROM WITH EACH SAID ELEMENT INCLUDING A PLURALITY OF INTERCONNECTED SUBSTANTIALLY U-SHAPED PASSAGES EXTENDING FROM ONE AXIAL END OF SAID ELEMENT TO THE OTHER; (C) PARTITION MEANS DISPOSED INTERMEDIATE THE RADIAL LENGTH OF SAID ELEMENTS AND EXTENDING CIRCUMFERENTIALLY BETWEEN SAID ELEMENTS SUCH THAT SAID PARTITION MEANS FORMS THE INNER WALL OF A FIRST ANNULAR GAS FLOW PATH ACROSS WHICH THE RADIALLY OUTER PORTIONS OF SAID ELEMENTS EXTEND AND SAID PARTITION MEANS WITH SAID HUB MEMBER ALSO FORMING THE OUTER AND INNER WALLS RESPECTIVELY OF A SECOND ANNULAR GAS FLOW PATH ACROSS WHICH THE RADIALLY INNER PORTIONS OF SAID ELEMENTS EXTEND; (D) A PLURALITY OF RADIALLY-SPACED HEAT EXCHANGE FIN MEMBERS SECURED TO AND PROJECTING CIRCUMFERENTIALLY FROM BOTH THE RADIALLY INNER AND RADIALLY OUTER PORTIONS OF SAID ELEMENTS INTO HEAT EXCHANGE RELATIONSHIP WITH THE GASES FLOWING THROUGH SAID FLOW PATHS; AND (E) A HEAT EXCHANGE LIQUID SEALED WITHIN SAID ELEMENTS FOR CIRCULATION THROUGH SAID PASSAGES IN RESPONSE TO CENTRIFUGAL FORCES ACTING ON SAID LIQUID DUE TO ROTATION OF SAID HEAT EXCHANGER FOR TRANSFERRING HEAT BETWEEN THE RADIALLY INNER AND OUTER PORTIONS OF SAID ELEMENTS.