US3246687A

US3246687A - Thermal actuated sector plate

Info

Publication number: US3246687A
Application number: US356127A
Authority: US
Inventors: Jensen Arthur; Eugene D Krumm
Original assignee: Air Preheater Co Inc
Current assignee: Alstom Power Inc
Priority date: 1964-03-31
Filing date: 1964-03-31
Publication date: 1966-04-19
Anticipated expiration: 1983-04-19
Also published as: ES311196A1; NL144731B; DE1501619A1; DE1501619B2; NL6504073A; GB1058627A

Description

April 19, 1966 A. JENSEN ETAL. 3,246,687

THERMAL ACTUATD SECTOR PLATE Filed March 3l, 1964 2 Sheets-Sheet 1 i fw A. .JENSEN ETAL THERMAL ACTUATED SECTOR PLATE April 19, 1966 Filed March 3l, 1964 2 Sheets-Sheet 2 ,iff/far Janie/1 United States Patent O 3,246,687 THERMAL ACTUATED SECER PLATE Arthur Jensen and Eugene B. Krumm, both of Wellsville, NSY., assiguors, by mesne assignments, to The Air Preheater Company, inc., a corporation of Delaware Filed Mar. 31, 1964, Ser. No. 356,127 l2 Claims. (Cl. 165-9) The present invention relates to heat exchange apparatus and particularly to an arrangement that precludes interference between relatively movable parts thereof when thermal conditions induce the deformation of the several parts.

In rotary regenerative heat exchange apparat-us of the type herein defined a cylindrical rotor has compartments carrying heat transfer material which are first exposed to heating gases and then to cool air or other cooling fluid in order that the heat absorbed from the heating gas may be transferred to the cooler air. The rotor is surrounded by a housing having end or sector plates formed with openings that provide for the flow of heating gases and air through the element carried by the rotor. To prevent mingling of the two liuids, radial partitions that form the rotor compartments and the end edges 4of the rotor are provided with sealing members -that are maintained in sealing relationship with the imperforate portions of the sector plate.

The seal-ing members are usually mounted in such a manner that they will resiliently accommodate to a limited degree the twisting and bending that accompanies normal thermal variations within the rotor.

Under certain conditions of operation as during startup, shut-down, or cleaning operation when the ow of air or other cool fluid through the heat exchanger has been substantially curtailed, the temperature of the heat exchanger may rise rapidly to a point well beyond the ytemperature for which the apparatus has been designed so that the limit of thermal accommodation is exceeded. When this condition obtains, relatively movable parts of the sealing members and rotor housing are moved into direct interference one with another so as to cause excessive wear, binding and even breakage of the parts. Such wear may necessitate the shutdown of the apparatus and the repair of the sealing members or related parts before normal operation may be resumed.

It is therefore the principal object of this invention to provide for .automatic actuation of housing structure in a rotary regenerative heat exchanger whereby excessive temperature changes within t-he apparatus will move interfering housing structure away from cooperating sealing means when abnormal temperature conditions cause excessive xpansion or deformation of the several parts.

It is a further object of this invention to provide for an arrangement that precludes interference of the rotor and surrounding housing during abnormal temperature conditions, and when normal conditions have been restored,

Awill return with the rotor to its original setting without necessitating a manual readjustment or reset.

The present invention is therefore directed to a particular housing arrangement that precludes interference between relatively movable parts of rotary heat exchange apparatus that is subjected to abnormal conditions of temperature.

vThe invention will be more clearly understood upon consideration of the following detailed description of an illustrative embodiment thereof when read in conjunction with the accompanying drawings in which:

FIGURE 1 is a sectional elevation in diagrammatic form showing a rotary regenerative heat exchanger involving the invention.

FIGURE 2 is a sectional elevation normal to tha-t of 3,246,687 Patented Apr. 19, 1966 ICC FIGURE l illustrating conventional flow passageways through apparatus of the invention.

FIGURE 3 is an enlarged detail View showing in simplilied form an embodiment of the invention.

FIGURE 4 is a slightly modied form of the apparatus.

FIGURE 5 is a view of the apparatus as seen from line 5 5 of FIGURE 1, and

FIGURE 6 is an enlarged sectional view showing a further modied form of the apparatus.

In the drawings the numeral 10 designates the cylindrical shell of a rotor that is customarily divided into a series of sector shaped compartments by radial partitions or diaphragms 12 which extend between the rotor shell and a central rot-or post 14. The rotor compartments so formed are packed with a perforate mass of heat t-ransfer material such as spaced metallic plates 16 and the entire rotor is rotated labout its axis by a motor and reducing gear arrangement illustrated at 1S.

When so rotated, the heat absorbent material carried by the rotor is alternately positioned in a hot gas stream and a cool air stream in order that heat from the hot gas is transferred to the cool rair through the intermediary of the heat absorbent material. The hot gas enters the heat exchanger Ithrough .an inlet duct 22 and is discharged through an outlet duct 24. The air in turn enters the heat exchanger through an inlet duct 26 and is discharged, after passing over the element 16, through an outlet duct 28 to which an induced draft fan is usually connected. After passing over the heated plates and absorbing heat therefrom, the stream of then heated air is conveyed to its place of ultimate use.

A cylindrical housing 32 encloses the rotor in spaced relation thereto to provide an annular space 34 therebetween, while end or sector plates 36 at opposite ends of the rotor are provided with circumferentially spaced apertures that admit and discharge the streams of hot gas and cooler air. In order that the streams of gas and air do not bypass the rotor it is customary to provide circumferential seals 38 on the end edge of the rotor shell 10 and radial seals 40 on the end edge of the radial partitions 12 that confront the adjacent surface of the end plate in a sealing relationship.

According to the invention the sector plates 36 at each end of the rotor are divided into independent sector shaped parts, each of which is pivotally secured at its inner end 39 to adjacent housing ,structure whereby it may be freely pivoted about an axis normal t-o that of the rotor. Thus the radial outer end of each sector plate is free to be moved axially toward or away from the adjacent end of the rot'or a distance determined only by the proximity of the rotor and its surrounding housing. For optimum operation, th radial outer end of each sector plate is provided with sealing means that bridge the space between the sector plate and the adjacent housing structure to preclude the flow of luid through the space therebetween.

Situated in the annular space 34 between the rotor shell and rotor housing and lying radially outboard from the sector plates are thermally responsive elements arranged to move one or both -sector plates axially with respect to the adjacent end of the rotor to preclude interference therebetween. The thermally responsive elements each comprise an expansion means preferably in the form of a tube 42 that is lixedly secured at one end 44 to the housing structure and movably secured as by bellows 46 to the rotor housing at the opposite end of the rotor. The expansion tube traverses the lower sector plate 36 which is provided with a packing 48 to preclude liuid flow therethrough and an adjusting means to permit axial adjustment of the sector plate into an optimum space relationship with the rotor to preclude excess fluid flow therebetween. The expansion tube 42 is xedly secured to the upper sector plate whereby expansion or contraction of the tube 42 will move the upper sector plate away from or into a closer space relationship with the adjacent end of the rotor.

The expansion tube 42 is connected to the gas duct 50 at the gas outlet side of the rotor and is preferably supplied with a blower 52 that draws hot gas from outlet duct 24 and directs it through the expansion tube 42 to outlet duct 56 where it is exhausted to atmosphere or otherwise directed back into the system as desired. A control darnper 58 is positioned in the outlet end S6 of duct 42 to permit control of fluid flow therethrough. When pressure of the hot gas at its outlet 24 is such that a continuous flow of gas may be maintained through the tube 42 without the use of the auxiliary fan, the fan 52 may be dispensed with entirely and flow through tube 42 regulated solely by the control damper.

In apparatus of the type illustrated in FIGURE l having expansion tubes 42 for both sector plates 36, a single fan 52 may be used to supply a bifurcated supply line with hot gas from duct 50 in order that expansion tubes 42 at both sides of the rotor will be simultaneously subjected to the flow of hot gas from the outlet duct 56.

The expansion tubes 42 are preferably comprised of material having a coefficient of expansion somewhat greater than that of the rotor. By way of example, in a rotor comprised of open hearth steel an expansion tube of stainless steel would provide greater relative thermal expansion whereby a temperature variation of gas flowing therethrough would effect a relatively greater expansion of the tube than the adjacent rotor structure.

During normal operation hot gas entering the heat exchanger at 22 transfers asubstantial portion of its heat content to the heat transfer material 16 carried by the rotor before the then cooled gas is exhausted from the heat exchanger through the duct 24. Cold air entering through duct 26 absorbs heat from the heated elements 16 and is then exhausted through outlet duct 28 to its point of use.

If adverse conditions should obtain within the heat exchanger so as to result in overheating the rotor, the temperature of the hotgas at outlet 22 will increase accordingly. As the temperature of the gas exhausting from the heat exchanger increases a portion of the hot gas from outlet 24 directed through duct 50 and expansion tubes 42 causes them to expand. When the tubes 42 expand they carry with them the sector plates 36 that are securely attached thereto whereby the sector plates will be moved away from the rotor to provide space for its limited distortion.

Numerous variations of this basic arrangement may be readily-effected without departing from the spirit of the invention. Thus sector plates 36 at opposite ends of rotor may be fixedly secured to each thermal expansion member 42 in the manner illustrated in FIGURE 4 in order that an increase of temperature in the tube will cause it to expand axially in one or both directions and carry with it the ends of both sector plates. Inasmuch as the ends of expansion members 42 are resiliently mounted at spaced ends, movement of the rotor into contact with either end plate will cause the resilient mountings 46 to ex accordingly and thus accommodate axial movement of the expansion member 42 sufiicient to preclude damaging interference between the rotor and adjacent sector plates 36.

In heat exchange apparatus of the type illustrated in FIGURE 6 wherein axial sealing members 60 are held in sealing relationship with the outer surface of the rotor shell so as to preclude the-flow of uid through the annular space around the rotor, the expansion tubes 42 may be adapted to move the axial seals 60 radially away from the rotor and thus permit the rotor to freely expand as may be required when the temperature of the rotor is appreciably increased.

In this arrangement a bracket 62 mounted upon the inner surface of the rotor housing pivotally supports a bell crank 64 having its short arm pivotally connected to the expansion tube 42 and its long arm pivotally connected to the sealing member 60. When expansion tube 42 moves in response to an increase of temperature in the fluid owing therethrough it pivots the bell crank 64 about its pivot point whereby the axial sealing member 60 is moved radially outward and away from the adjacent peripheral surface of the rotor.

While the application of tubular members 42 to the device of the invention does constitute a specic form of the invention, it should be understood that suitable expansion rods or bars could also be used with certain modifications. It should be evident that various other changes may be made without departing from the spirit of the invention, and it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

We claim:

1. A regenerative heat exchange apparatus including a cylindrical rotor shell and a concentric rotor post spaced therefrom to provide an annular space therebetween, a mass of heat transfer material carried in said annular space, a housing surrounding the rotor in spaced relation having inlet and outlet ducts at opposite ends thereof for a heating fluid and a fluid to be heated, end plates intermediate the ends of the rotor housing and the adjacent ends of the rotor having imperforate portions between spaced apertures that direct the heating fluid and the uid to be heated through the heat transfer material carried by the rotor, actuating means positioned in the space between the rotor shell and rotor housing for moving said end plates axially away from the confronting face of said rotor, said actuating means comprising an axially disposed tube means connected to one of said end plates, and means for subjecting said tube means to a flow of hot gas from the outlet duct for the heating fluid whereby an increase of temperature at said outlet duct will cause an expansion of said tube means that moves the attached end plate away from the adjacent end of the rotor.

2. A regenerative heat exchange apparatus includ-ing a cylindrical rotor shell and a concentric rotor post spaced therefrom to provide an annular space therebetween, a mass of heat transfer material carried in said annular space, a housing surrounding the rotor in spaced relation having inlet and outlet ducts at opposite ends thereof for a heating fluid and a fluid to be heated, end plates intermediate the ends of the rotor housing and the adjacent ends of the rotor having imperforate portions between spaced apertures that direct the heating fluid and the fluid to be heated through the heat transfer material carried by the rotor, means for rotating the rotor about its axis, thermal expansion means extending axially through said annular space between imperforate portions of said end plates, and duct means connecting said thermal expansion means to the outlet duct for the heating fluid whereby said expansion means is subjected to a flow of gas at substantially the same temperature it is exhausted from said rotor.

3. A regenerative heat exchange apparatus having a rotor including a central rotor shell and a central rotor post, a mass of heat transfer material carried by the rotor, a housing surrounding the rotor in spaced relation having inlet and outlet ducts at opposite ends thereof for a heating Huid and a fluid to be heated, end plates intermediate the ends of the rotor housing and the adjacent end of the rotor having imperforate portions between spaced voids that direct the heating fluid and the fluid to be heated through the heat transfer material carried by the rotor, means for rotating the rotor about its axis, thermal expansion means extending axially between spaced end plates and fixedly secured thereto, duct means connecting said thermal expansion means to the outlet duct for the heating fluid, and means controlling fluid ow through said duct means whereby said thermal expansion means is continuously subjected to gas flow from the outlet duct for the heating fluid.

4. A regenerative heat exchange apparatus as defined in claim 3 wherein the thermal expansion means comprises a tubular member continuous with said duct means.

5. A regenerative heat exchange apparatus as defined in claim 3 wherein the thermal expansion means is comprised of material having a coefficient of expansion greater than that of the adjacent rotor structure.

6. A regenerative heat exchange apparatus as defined in claim 3 wherein the thermal expansion means is comprised of stainless steel.

7. A regenerative heat exchange apparatus as defined in lclaim 3 wherein the end plates lare pivotally secured to said housing at a point adjacent the rotor post.

8. A regenerative heat exchange apparatus having a rotor including a rotor shell and a central rotor post, a mass of heat transfer material carried by the rotor, a housing surrounding the rotor in spaced relation to provide an annular space therebetween, inlet and outlet ducts connected to said housing for a heating fluid and a fluid to be heated, end plates intermediate the ends of the rotor housing and the adjacent ends of the rotor, axial sealing means in said annular space confronting the rotor shell adapted to preclude fluid ow through said annular space, means for rotating the rotor about its axis, thermal expansion means, duct means connecting the outlet duct for the heating uid to said thermal expansion means, and means linking the expansion means to the axial sealing means whereby expansion of said expansion means moves the axial sealing means radially away from the rotor.

9. The regenerative heat exchange apparatus of claim -8 wherein the -greatest movement of said axial sealing means occurs at the end of the rotor adjacent the outlet duct for the heating fluid.

10. The regenerative heat exchange apparatus of claim 8 wherein the expansion means is adapted to impart the greatest degree of movement to that part of said axial sealing means lying adjacent the outlet duct for the heating fluid.

11. The regenerative heat exchange apparatus of claim 10 wherein said thermal expansion means comprises a metallic tube.

12. A regenerative heat exchange apparatus having a rotor including a cylindrical rotor shell and a central rotor post with an annular space therebetween, a mass of heat transfer material carried in said annular space, housing structure surrounding the rotor having inlet and outlet ducts for a heating fluid and a fluid to be heated, means for rotating the rotor about its axis, means sealingly engaging the outer surface of said rotor to preclude the ow of Huid thereby, and means responsive to the temperature of fiuid at the outlet for the heating fiuid arranged to move said means that sealingly engages the outer surface of said rotor out of engagement therewith.

References Cited by the Examiner UNITED STATES PATENTS 2/1959 Mudersbach et al. 165-9 1/'1965 Koch 165-9

Claims

1. A REGENERATIVE HEAT EXCHANGE APPARATUS INCLUDING A CYLINDRICAL ROTOR SHELL AND A CONCENTRIC ROTOR POST SPACED THEREFROM TO PROVIDE AN ANNULAR SPACE THEREBETWEEN, A MASS OF HEAT TRANSFER MATERIAL CARRIED IN SAID ANNULAR SPACE, A HOUSING SURROUNDING THE ROTOR IN SPACED RELATION HAVING INLET AND OUTLET DUCTS AT OPPOSITE ENDS THEREOF FOR A HEATING FLUID AND A FLUID TO BE HEATED, END PLATES INTERMEDIATE THE ENDS OF THE ROTOR HOUSING AND THE ADJACENT ENDS OF THE ROTOR HAVING IMPERFORATE PORTIONS BETWEEN SPACED APERTURES THAT DIRECT THE HEATING FLUID AND THE FLUID TO BE HEATED THROUGH THE HEAT TRANSFER MATERIAL CARRIED BY THE ROTOR, ACTUATING MEANS POSITIONED IN THE SPACE BETWEEN THE ROTOR SHELL AND ROTOR HOUSING FOR MOVING SAID END PLATES AXIALLY AWAY FROM THE CONFRONTING FACE OF SAID ROTOR, SAID ACTUATING MEANS COMPRISING AN AXIALLY DISPOSED TUBE MEANS CONNECTED TO ONE OF SAID END PLATES, AND MEANS FOR SUBJECTING SAID TUBE MEANS TO A FLOW OF HOT GAS FROM THE OUTLET DUCT FOR THE HEATING FLUID WHEREBY AN INCREASE OF TEMPERATURE AT SAID OUTLET DUCT WILL CAUSE AN EXPANSION OF SAID TUBE MEANS THAT MOVES THE ATTACHED END PLATE AWAY FROM THE ADJACENT END OF THE ROTOR.