US1720536A - Heat exchanger - Google Patents

Description

J. W. YOUNG July 9, 1929.

HEAT EXCHANGER Filed May 27, 1927 3 Sheets-Sheet WITNESSES mvemog J.W. YounQ BY OIHWLM ATTORN EY J. w. YOUNG HEAT EXCHANGER July 9, 1929.

Filed May 27. 1927 3 Sheets-Sheet 2 GI. PA ATTORNEY INVENTOR I J-W. Younq WITNESSES J. W. YOUNG HEAT EXCHANGER July 9, 1929.

Filed May 192'? 3 Sheets-Sheet 5 Fig.1.

INVENTOR J-w' FRQB.

WITNESSES:

ATTORNEY Fatented July 9, 1929.

UNITED STATES PATENT OFFICE.

JOHN WILLIAM YOUNG, OF MANCHESTER, ENGLAND, ASSIGNOR TO WESTINGHOUSE ELECTRIC & MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA.

HEAT EXGHANGER.

Application filed May 27, 1927, Serial No.

This invention relates to heat exchangers, particular'ly air preheaters for furnaces, and consists in apparatus of this nature comprising a series of annular or similarly shaped clnin'ibers juxtaposed one against another with provision for causing the fluids, between which the transference of heat is desired, to

circulate, )referably in opposite directions, through a .ternate chambers.

According to one construction the heat exchai'lger comprises a casing of substantially cylindrical ttorm, disposed about a furnace ol'ltake and divided by transverse partitions into a series of chambers each of which is divided by a battle or partition extending between the casing and the flue, one chamber of each pair of adjacent chambers communieating with the exterior of the casing adjacent one side of the battle and with the line adjacent; the other side of the battle, while the other of said chambers communicates with the exterior of the casing upon opposite sides oi the battle. The casing is advantageously formed with a tangential projecting 5 portion through which the chambers communicate with the exterior of the casing, and the fluids enter adjacent chambers through inlets in said tangential portion arranged so that the fluids pass in opposite directions 3% through adjacent chambers. Such an apparains maybe readily constructed from a number of similar sections assembled together and moreover may, if desired, be made almost entirely of sheet metal, so that the manufacture i comparatively simple.

lVhere the heat exchanger is intended for use with fluids which may contain suspended solid matter, as in the case of an air preheater for the air necessary for the combusl tion of solid or pulverulent fuel in aturnace, utilizing the heat of the line gases leaving said furnace, means is preferably provided for separating and collecting any solid products of combustion which might be in the flue gases. Such separating device may comprise lateral openings in certain of the chambers through which the solid matter may be ej ected, a collecting chamber being also provided to collect the solids and permit the escape of any gases which pass out therewith.

In a modified construction the heatexchanger comprises a casing of substantially cylindrical form disposed about the line and divided into a series of concentric chambers by partitions which extend around the 194,787, and in Great Britain June 16, 1926.

greater part of the cylindrical portion of the casing, one chamber of each pair 01' ad'acent chambers communicating with the us at one end and with the exterior of the casing at the other end, and the other chamber communicating with inlet and outlet openings in the external walls of the casing.

These and further features of the invention will be more readily understood from the following description with reference to the accompanying drawings in which two constructional forms of the invention are illustrated more or less diagrammatically and wherein:

Fig. 1 is a sectional elevation corresponding to line I-I of Fig. 2, showing an air preheating and smut catching apparatus according to the invention applied to a flue 01' chimney Fig. 2 is a plan corresponding to Fig. 1;

Figs. 3 and 4 represent horizontal crosssections through any two adjacent chambers 01 the pro-heater shown in Figs. 1 and 2;

Figs. 5-and 6 are a plan and side elevation respectively, showing an arrangement of boiler-house plant embodying the invention; and,

Figs. 7 and 8 are, respectively, a plan and front elevation illustrating a modified construction of heat-exchanger according to the invention arranged for preheating the air supply for the furnace of a steam generator.

Referring more particularly to Figs. 1 to 6, the air preheater shown comprises a casing l of substantially cylindrical form disposed about an olitake 2 and divided by a large number of transverse partitions 3, whereby a plu rality of juxtaposed chambers of more or less annular form are provided. As seen from Figs. 3 and 4 which represent two adjacent chambers, 4L, 5 intended for the passage of the flue gases and air blast respectively, the chamhers are themselves divided by battles or partition walls 6, 7 extending between the easing 1 and the wall of the flue 2, the chamber 4 comn'iunicating with the exterior of the easing through an inlet 8 adjacent the battle 6 on one side and with the flue 2 through an outlet 9 adjacent the other side of the battle, while the chamber 5 communicates with the exterior of the casing through inlet and outlet apertures 10, 11 respectively, upon opposite sides of the baflie 7. i 4

In order to preserve, as far as possible, the stream line flow of the gases, the battles, 6, 7

are arranged to inerge tangentially with the circular Walls of the casing and flue, and for the convenient attachment of the gas or air supplytrunks the casing 1 is formed with a tangential. proj ecting. portion through which the chambers communicate with the exterior of the casing as is readily seen from Figs. 2 to 4. By this arrangement also the inlet and outletopeiiings in each chamber are as remote as possible circumterentially, and the direction of new, whicli-ijsindicated by arrows in Figs; 3 an are reversedin alternate chant. bets thatthe advantages of contra-flow of s and air are availed of.

1F dr the-purpose of removing any solid matter harried the flue gases, the'outer wallet each chamber 4 is provided with an wette -e12 somewhat in. advance of the out- 9 adjacent said aperture is a deflef eXtending inwardly of the casing 1 ,vaind collecting con'ipartment- 1a ft the. 1. The compartment 14 terminates at as; lower end in a discharge hopper 15, and at the upper end communicates tliijou with the chimney or flue 2. angenient the flue gas enters v chambers and due to the furnace which may be natural, induced force-d, or. forced and induced, is caused to 'p'a'ss pidly therearoiind to the outlets comv iicz itiitg with the flue. Owingto the speed with wli ili the nae gas traverses the gas ny solid suspended matter there'- in i's .th 'ownagainstthe outer wall of the through the apertures 12 therein to the collecting compartment from which it is either fed directly back to the furnace or removed periodically for this purpose. Any flue gas "out with the solid products of combu 't'on expands into the collecting compartt, 14.- where its velocity is reduced and from whichit passes back through pipe 16 to at; ake 2. y

desire a jacket 17 may. be provided U d outside of easing 1,. said acket for/the passageof air or flue gas and F ating with some or all of the chambersfl ornot, as may be preferred. In Fig. 1 it isjshiown independent of the chambers 4 erelycons titutes anofi'take gas jacket co nunicating with the flue 2a the top and vtliijugh a, passage 18 near the bottom.

In the above description it is assumed that the ap'piarati'is is located around a vertical part of {theofltakeso thatthe apparatus as a whole isveaishiasa the compartments hori'zjo This however is not essential as the apparatus as a whole may be horizontal or inclinedjaccording to practical requirements. In the above construction the inner wall of the a paratus is constituted by an existing part o f a furnace ofitake and the outer wall one art with the yarious inlet and out let branches formed therein as may be most and is deflected by the plates 13 convenient for practical purposes, by cutting the wall and bending back portions thcrcoi', by the addition of suitable walls or passages, or by a combination of these expedicnts. The

apparatus may however be sectionalized, that able number of compartments or sections.

The apparatus may thus be readily taken apart for repair or for cleaning purposes if desired; where the construction is not sectionalized however, steam jets may be advantageously employed for this latter purose.

Figs. 5 and 6 illustrate the above described apparatus erected in the upper part of a boiler liouse around the bottom of an ollitake 2. -An induced draught fan 19 driven by a motor 20 it adapted to draw the flue gases from the boiler furnace through the uptake 21 ofan economizcr 22 and to force them through a flue gas supply trunk attached to the inlet 8 of the preheating apparatus, around the chambers 4; of which they pass to the ofitake 2 as previously described. At the same time, air is drawn through the inlet 10, which is open to the atmosphere, around the chambers 5 where it is heated and is drawn out through the air trunk 24 by means of a forced draught fan of the boiler [urnace. Naturally, in some cases, the tans may be dispensed with, the circulation being etfected by the natural draught. A by-pass 2:) provided with a damper 526 is also provided between the economizer 22 and the line 2, and a similar damper 26 or other regulating dcvicc may if desired be provided in the uptake 21, whereby the flow of the flue gasesthrough the preheating apparatus or directly to the chimney 2 may be controlled.

In the modified form of the apparatus shown in Figs. 7 and 8,21 casing 1 of substantially cylindrical form is arranged around a flue or chimney 2 and divided into series oi concentric chambers by partitions indicated by dotted lines 3' which extend around the greater part of the cylindrical portion of the casing from an annular branch or extension, butterminate somewhat short of the junction of the annular and tangential portions of the. casing. Alternate chambers 5 are closed at each end, and the remaining chambers 41; communicate at one end with an inlet 8 associated with a boiler 01 economizer uptake 21 with or without an induced draught tan driven by a motor 20, and at the other end with the undivided portion of the casing which communicates directly with the flue 2' through an outlet 9'. By this arrangement it will be apparent that the hot gases leaving the furnace will be caused to travel along alternate compartments to the undivided porlUU (ill

tion of the casing and from thence to the chimney or flue.

The chambers 5 which are closed at each end communicate through an inlet 10 near the undivided portion oi the casing with the free atmosphere, and, near the end of the tangential portion communicate through an out let 11 with the air supply trunk 24% of the furnace or, if a forced draught tan is employed, with the suction oil. such fan, as shown in Fig. 6, by which arrangement it will be apparent that air for combustion will be caused. to travel around the casing in alternate chambers and in an opposite direction to that taken by the flue gases, extracting heat from the latter dining its passage.

While I have shown my invention in two forms, it will be obvious to those skilled in the art that it is not so limited,but is susceptible of various other changes and modifications, without departing from the spirit thereof, and I desire, therefore, that only such limitations shall be placed thereupon are imposed by the priorart or as are specifleally set forth in the appended claims.

l Vhat ll claim is:

1. In a heat exchanger, the combination oi a circular shaped casing; a plurality oi? annular plates disposed within the casing and forming therewith a series 0i transverselyextending, juxtaposed annular cha1nbers; means providing tor the flow of a heating fluid through alternate ones of said chambers; and means providing for the flow oft fluid to be heated through the remaining ones of said chambers, and in a direction contra to that of the heating fluid.

2. In an air preheater, the combination of a circular shaped casing; a plurality of annular plates disposed within the casing and :lorming therewith a series 0t transverselyextending, juxtaposed annular chambers; means providing for the flow of flue gases through alternate ones of said chambers; and means providing for the flow of air to be heated through the remaining ones of said chambers, and in a direction contra to that of the flue gases.

8. In an air preheater, the combination of a circular shaped casing; a plurality of annular plates disposed within the casing and forming therewith a series of transverselyextending, juxtaposed annular chambers; means providing for the flow of flue gases through alternate ones of said chambers; and, means providing for the flow of air to be heated through the remaining ones of said chambers, and in a direction contra to that.

of the flue gases; and means providing for the sepa ration of the solid products of combustion from the flue gas as it flows through the chambers.

i. In a heat exchanger, the combination of a fluid conduit; a circular casing surroundin said conduit; a plurality of annular plates disposedwithin the casing and forming in conjunction with the casing and conduit a series of transversely-extending, juxtaposed annular chambers; alternate ones of said chambers being provided with transverselyentending baflle members; means providing communication between said alternate chambers and said conduit at one side of said baflle members; and means providing communicajtion between said alternate chambers and the exterior of; said casing at the other side of said ballie members; baflle means arranged within the ren'iaining ones of said annular chambers and providing a separate inlet and outlet for each one or the said remaining chambers; means providing for the transmis sion of a fluid through said alternate chamhers; and means providing for the transmission of a second fluid through said renmining chambers; the temperature of said second fluid prior to its admission to the chambers, being diflerent from that of the iii-st named fluid.

5. In a heat exchanger, the combination of a fluid conduit; a circular casin surrounding said conduit; a plurality of annular plates disposed within the casing and forming its conjunction with the casing and conduit a series of titansverselyextending, juxtaposed annular chan' bers; alternate ones of said chambers being provided with transverselyextending baflie men'ibers; means providing comnmnication between said alternate chamhers and said conduit at one side oi: said bafl'le n'iembers; and means providing comnmnication between said alternate chambers and the exterior oiii said casing at the other side or: said baflle members; baflle means arranged within the remaining ones of said annular chambers and providing a separate inlet and outlet 'l or each one of the said remaining chan'ibers; and means providing for the transn'lission of a second fluid through said remaining chambers, and in a direction contra to the flow of the first mentioned fluid; the temperature oi said second fluid prior to its admission into the chambers, being ditt- 'iercnt from that of the first fluid.

6. In an air preheater, the combination oil? a fluid conduit; a circular shaped casing surrounding said conduit; a plurality of annular plate: disposed withinv the casing and forming with the casing and conduit a series oi transversely-extending, juxtaposed annular chambers; alternate ones of said chambers forming a set, and being provided with transversely-eatending baflle members; means providing communication between said altern ate chambers and said fluid conduit at one side of said baflle members; and means providing communication between said alternate chamhers and the exterior of said casing at the other side o'l said baliie members; the remaining ones of said chambers forming a second set, and being provided. with transversely extending baffle means; means providing inlet and outlet openings at opposite sides of the battle means in each one of the second set of annular chambers; means providing for the flow of flue gas through one set of said chambers; and means providing for the flow of air to be heated through the other set of said chambers and in a direction contra to the flow of flue gas.

7. In an air preheater, the combination of a fluid Conduit; a circular shaped casing surrounding said conduit; a plurality of annul ar plates disposed within the casing and forming with the casing and conduit a series --of transversely-extending, juxtaposed annular chambers; alternate ones of said chambers forming a set, and being provided with transversely-extending battle members; means providing communication between said set of alternate chambers and said fluid conduit at one side of said baflle members; and means providing communication between said a1 ternate chambers and the exterior of said casing at the other side of said baflle members; the remaining ones of said chambers for'i'ning a seconds set, and being provided with transversely-extending baflle means; means: providing inlet and outlet openings at opposite sides of the battle means in each one of the second set of annular chambers; means providing for the flow of flue gas through on'eset'of said chambers; means providing for the flow of air to be heated through the other set of said chambers and in a direction contra to the flow of flue gas; and means providing tor the separation of the solid products of combustion from the flue gas as it flows through the annular chambers.

8. In an air preheater, the combination of a fluid conduit; a circular shaped casing surrounding said conduit; a plurality of amin lar plates disposed within the casing and forming with the casing and conduit aseries of 'transversely-extendmg, uxtaposed annu- 1 lar chambers; alternate ones of said chambers forming a set, and being provided with transversely-extending baffle members; means providing communication between said alternate chambers and said fluid conduit at one side. of said battle members; and means providing communication between ,said alternate chambers and the exterior of said casing at the other side of said baflle members; the remaining onesot' said chambers forming a sechere through which the flue gas flows, and providing for the separation of the solid products of combustion from the flue gas.

9. In an air preheatcr, the combination of a fluid conduit; a circular shaped casing surrounding said ccnduit; a plurality of annular plates disposed within the casing and forming with the casing and conduit a series of transverselfy-extending juxtaposed annular chambers; alternate ones of said chan'ibers forming a set, and being provided with transversely-extending battle members; means providing communication between said alternate chambers and said. fluid conduit at one side of said baflle members; and means providing communication between said alternate chambers and the exterior of said casing at the other side of said bafile members; the rennin]- ing ones of said 'chanil'iers forming a second set, and being provided with traiisversely-extending bafile means; means providing inlet and outletopenin s at opposite sides of the baflle means in eac 1 one of the second set of annular chambers; means providing for the flow of flue gas through one set of said chambers; means providing for the flow of air to be heated through the other set of said chambers and in a direction contra to the flow of flue gas; and means for varying the amount of flue gas flowing through said chmnbers.

10.- In an air preheat-er, the combiimtion with an ofl take for the flue gases from a furnace; of a circular casing surrounding said ofltake; a plurality of annular plates disposed within said casing and forming with the casing and ofl'take a series of transversely extending, juxtaposed annular chambers; alternate ones of said chambers being provided with transversely-extending bafil'e members; means providing communication between said alternate chambers and the ofltake at one side of said battle members; and means providing for the introduction of flue gas into said alternate chambers at the opposite side of said battle members; battle menus extending transversely of the remaining annular chambers; and means providing air inlet and outlet means in the remaining chambers at opposite sides of said b'aflle means.

11. In an air preheuter, the combination with an oiitake for the flue gases from a furnace; of a circular casing surrounding said o'fltake; a plurality of annular plates disposed Within said casing and forming with the casing and olftake a series of transversely-extending, juxtaposed annular chambers; alternate ones of said chambers being provided with transversely-extcnding ballle members; means providing cmnmunication between said alternate chambers and the otftake at one'side of said bafiles; and means providing for the introduction of flue gas into said alternate chambers at the opposite side of said bafiie members; baffle means extendin'g transversely of the remaining annular chambers; means providing air inlet and outlet means in the remaining chambers at opposite sides of said baflle means; and means disposed at the periphery of said alternate chambers and providing for the separation of the solid products of combustion from the flue gas.

12. In an air preheater, the combination with an offtake for the flue gases from a furnace; of a circular casing surrounding said ofltake; a plurality of annular plates disposed within said casing and forming with the casing and ofl'take a series of transverselyextending, juxtaposed annular chambers; alternate ones of said chambers being provided with transversely-extending baflle members;

means providing communication between said alternate chambers and the ofl'take at one side of said baflles; and means providing for the introduction of flue gas into said alternate chambers at the opposite side of said baffle members; baflle means extending transversely of the remaining annular chambers; means providing air inlet and outlet means in the remaining chambers at opposite sides of said baffle means; and means for varying the amount of flue gas flowing through said chambers.

In testimony whereof, I have hereunto subscribed my name this tenth day of May, 1927.

JOHN WILLIAM YOUNG.

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