US1617083A - Heat exchanger - Google Patents

Description

J. PRICE HEAT EXGHANGER Feb. 8 1927.

Filed Sept. 29, 1925 3 Sheets-Sheet 1 nl un 1,617,083 Feb 8 1927 J. PRICE HEAT EXCHANGER Filed Sept. 2S, 1925 3 Sheets-Sheet 2 m INVENToR .l Maf/Mi, ZM

i ATTORNEYS J. PRICE HEAT EXCHANGER Feb. 8 1927.

Filed Sept. 29, 1925 3 Sheets-Sheet 3 .INVENTOR M /e/ic@ av /0 ./QW /fmgf ZM afg' ATTORNEYS Petenred Feb. e, 1927.

UNITED STATES PATENT OFFICE;

JOSEPH PRICE, 0F NEW YORK, Y., -ASSIGNOR T0 THE GBISCOM-'RUSSELL COMPANY, 0F NEW' YORK, N. Y., A CORPORATION 0F DELAWARE.

HEAT EXCHANGER.

Applicationiled September 29,1925. Serial No. 59,260.

This invention relates to heat exchangers adapted particularly for cooling and liquefying the vapors resulting from the distillation of petroleum and more generally for coolingr gases and liquids of any kind.

In localities such, for example, as the oil fields of Oklahoma, where the water available for cooling purposes contains relatively large amounts of various salts which crystallize out of the water and form scaly deposits, a great deal of difficulty has been experienced in operating heat exchangers. In this region the conventional type of tube and shell heat exchanger is unsuitable because of the carbonate and sulfate scales in the cooling Water. Some refining plants have even resorted to the treating of the circulating water to remove the objectionable salts, such as is man times-done economically in the preparatlon of boiler feed water. However, the tremendous volume of circulating water required in a refining plant renders this treatment extremely expensive and undesirable.

The object of the present invention is to provide an improved surface type heat exchanger which is substantially self-scaling, and 1s commerciall practicable because of its simple construction and low cost of manufacture.

According to this invention, the heat exchanger consists of assembled units, each comprising a pair of headers which are held by suitable spacers. Tubes, preferabl arranged in a relatively shallow layer o two or more rows, are connected to each pair of headers. The medium to be cooled iows through the headers and tubes. The spacers should be made of a metal having a lower coeilicient of expansion than the metal of the tubes. Steel may be used for the spacers and a non-ferrous metal such as admiralty metal or brass for the tubes. The spacers prevent the separation of the headers when the tubes are elongated by expansion due to the passage of a hot medium therethrough. The tubes are bowed slightly so that a relatively small elongation of the tubes by expansion produces a relatively large deformation and thereby exerts a loosening eifect upon the scale deposited on the outside of the tubes.

The units are assembled into a heat exchanger, preferably, by stacking in an appropriate rack which can conveniently be made of relatively light structural steel. The cooling water containing the salts, which deposit on the outside of the tubes and form the scale, is sprayed over the surface of the tubes of the several units. The water can be collected for recirculation when desirable. The rack is preferably so constructed as to leave the tier of horizontal units exposed to the atmosphere, thus securing an added cooling effect, but the tier may be enclosed ifY found desirable.

The invention is illustrated by way of example in the accompanying drawings in which- Figure 1 is a view partially in side` elevation, partial] in section, of a heat exchanger constructed 1n accordance with the present invention;

Figure 2 is an end changer;

Figure 3 is an enlargedhorizontal section through one of the heat exchanger units taken on the line 3-3 of Figure 4;

Figure 4 is an enlarged longitudinal section taken through the heat transferring elements of a heat exchanger including a smaller number of units than that shown in Figure 1;

Figure 5 is an enlarged fragmentary section, taken transversely of the heat exchanger and longitudinally through the headers, showing also a modified form of spraying device;

Figure 6 is a transverse section on line 6 6 of Figure 3;

Figure 7 is a transverse vertical section through a modied form of heat exchan er.

Referring now to these drawings, and rst to Figure 3, the unit of which the heat exchanger is made comprises the headers l() and 11, between which extend the tubes 12. The headers are of shallow elongated boxlike construction as shown in Figure 4 and are ada ted to receive only a relatively few rows o tubes 12. Two horizontal parallel rows of tubes are preferable. These tubes are secured in apertures 13 in each of the headers in any appropriate manner, such for example as by expanding the ends of the tubes with a suitable tool, or by welding. It is better to secure the tubes by the expansion method than by welding inasmuch as individual tubes can then be readily replaced if desired. Opposite the apertures 13 are corresponding apertures 14 through view of the heat ex-` the outside walls ofthe headers which are normally fitted with threaded plugs, readily removable, however, when it becomes necessary after long and continuous operation of the heat exchanger to clean the interiors of the condenser tubes 12.

The tubes 12 instead of being straight are slightly bowed out of a straight line so that, when the headers 10 and 11 are held in fixed position and the tubes are subjected to elongation by heat expansion, a relatively large deformation of the tubes will occur. Similarly, the subjection of the tubes to cooling causes them to shorten and straighten out. Either such elongation or shortening of the tubes produces a distortion of the tube surface that cracks or loosens any scale which may have formed on the outside surfaces of the tubes. In the drawings the bowing of the tubes has been somewhatv exaggerated for the sake of clcarness but the amount of bowing used in practice is relativel slight. The smaller the degree of bow wit 'n such limits as necessary to protect the tubes from rupture, the greater is the surface distortion for the same amount of elongation or shortening.

In order to maintain the position of headers 10 and 11 fixed with respect to one another while the tubes 12 are being subjected to distortion, the spacers and 16 extend longitudinally of the condenser element one on each s.' de of the tubes 12 and are firmly secured at their ends to the headers 10 and 11. These spacers are made of steel angle bars having a face somewhat wider than the layer of tubes as may be seen in Figure 4 so as to form a'certain degree of protection for the tubes against mechanical injury. The spacers are secured to the headers 10 and 11 by bolts 17, by welding or by any appropriate means.

Intermediate the headers 10 and 11, three transverse bars 18 pass above, between and below the two rows of tubes 12 and are welded at their opposite ends 19 to the spacers 15 and 16 (see Figures 4 and 6). These bars pass in close proximity to the surfaces of tubes 12 but are not fastened to the tubes. They are relatively rigid and, when the tubes are subjected to elongation, compel the bowing thereof to take place in a single horizontal plane, the tubes moving slightly laterally with respect to bars 18 and coming in contact therewlthif there is any tendency of the tubes to twist or warp or move in any other than the horizontal dlrection.

The headers 10 and 11 are provided with projecting portions 20 and 21- res ectivel and these lprojections are provi ed Wit 1 anged or other suitable couplin s 22 by which connections for conveying t e vapor or other flnidtoand from the umts are made. These projections may be placed at any conven'ent point longitudinally of the headers but they are preferably located at the center. Headers 10 and 11 are absolutely identical when projections 20 and. 2l are centrally placed. Hence the same header can be used at both ends of the heat exchanger unit and the unit will be assembled with the projections 20 and 21 extending either in the same or opposite directions depending upon convenience.

Referring now to Figures l and 2 of the accompanying drawings there is here shown a com lete heat exchanger constructed of the units described. In this heat exchanger a rack comprising upright posts 23 of steel connected by longitudinally extending angle bars 24 and by cross members 25 supports the several units one above the other with their respective layers of tubes 12 in horizontal position. The horizontal flanges of the angle frame members 15 and 16 form conven ent means for supporting the units upon the horizontal bars 24.

The connecting projection 20 of the uppermost unit is turned upward and connecting projection 21 downward, those of the next lower unit in the o posite directions, and so on down through tlie heat exchanger, so that the units are connected in series with one another from top to bottom. It will be noted that even with this reversal of the connect ng projections, the units are identical with one another and in order to connect them as shown in Figure 1, it is only necessary to arrange adjacent units upside down with respect to one another. Inasmuch as there are no right and left connections and inasmuch as these units are identical one with another, it is only necessary to add on or take olf un'ts when it is desired to change the capacity of the heat exchanger.

Moreover, great convenience in manufactur` ing results because it is only necessary to manufacture one type of unit.

The vapor or other Huid to be cooled is fed to the heat exchanger through the pipe 26 in which is a controlling valve 27. The cooling water under the control of valve 28 in a pipe 29 flows into a distrbuting pan 30 which is shown in section in Figures 1 and 2 in order to bring ont the lurality of apertures 31 extending throng out the area of the bottom of this pan. The distributing tray 30 is supported upon one set of the longitudinal bars 24 above the uppermost unit. By means of apertures 31 the water is sprayed upon the outside surface of the tubes 12, striking first the tubesof the uppermost unit and thence droppinvf downwardly into contact with the subsequent layers of tubes. The water dripping over the surfaces of the tubes is collected at the bottom of the tier by means of a pan 32, which also is conveniently supported upon one set of the bars 24,- and flows out through pipe 33, either to waste or to be recirculated over the pfpes after' appropriate cooling.

As the vapor oi" other fluid passes downwardly through the series of units it is cooled, and flows out of pipe 34 which is .connected to the flanged coupling 22 of the bottom element. lVhen condensing oil vapor, it maybe desirable to draw oil separate cuts at different temperatures and for this purpose one or more intermediate outlet pipes 35 maybe connected to one or more of the headers 10 or 11 or any of the units deired. ln order to make this connection it is only necessary to'drill a hole 36 (see Figure 4) in one of the fiat sides of one of the headers 10 or 11, -and around this opening, drill and tap suitable holes for tap bolts 37 for the purpose of securing in place a flanged' connection 38. Any of the headers 10 and 11 can be drilled in this manner so that it is not necessary to provide a specially constructed .header where it is desired to withdraw condensate at an intermediate temperature.

In the heat exchanger shown in Figures 1 and 2, the stack beingof an open frame work construction and merely servin to support the several units, the atmosp 1ere is free to circulate around and between the tubes and facilitate the cooling of the vapor or other fluid. If desired, however plates 39 may be secured to the rack along each side so as to prevent the spattering of the cooling water as it,flows down over the tubes. These plates may be seen in Figure 5. Also, instead of the distributing tray .30 aplurality of longitudinally arranged pipes 40, as

l shown in the same figure, may be used.

These pipes are provided along their lower surfaces with apertures 41 by which the cooling water is sprayed upon the tubes.

' Y heat exchanger.

As an additional modification of the construction the rack containin the units as shown in Figurel may be p aced in a tank 42 as shown in Figure 7 in which case the tank will contain cooling water and the tubes will be submerged therein, Appropriate means can be provided to produce a continuous circulation of the cooling water in tank 42.

Referring again to Fi re 1 a steam supply pipe 43 provided with a valve 44 is connected to the inlet pipe 26 for the vapor at a point between control valve 27 and' the This is for the purpose of removing the scale which collects in large quantities upon the surfaces of the condenser tubes 12.` Steam at a relatively high temperature, say for example steam at 100 pounds gauge pressure is admitted through valve 44 after closing the valve 27 to shut ofi the vapor supply and valve 28 to shut oti' the cooling water supply. This sudden admission of steam at a temperature considerably above the normal workingtem- 'active again, or upon the stream of steam by a stream of cold water.

The application of steam through pipe 43 is made periodically whenever an incrustation of scale has built up on the surfaces of the tubes to such anextent as to appreciably reduce the efficiency of the heat exchanger.

The steaming operation1 however, requires only from l to 3 minutes time and therefore affects the operation of the apparatus to so small an extent that it can be repeated at extremely frequent intervals without dilii- 35 culty.

It will be noted that the force tending to separate headers 10 and l1 of each condenser element is resisted entirely by the spacers 15 and 16 of each particular unit. 90

That is, the stress which occurs in the spacers of any one element is entirely independent of the stress that may occur in any of the other units. Hence, if some of the units. for example, the upper units, are suh- 05 jected to a higher` temperature than the lower units, no appreciable stress results in the heat exchanger as a whole. This is an important feature inasmuch as it provides a structure which is rugged and which is not 1110 liable to damage during the cle-scaling operation at the hands of an unskilled operator.

By constructing a heat exchanger in accordance with this invention 'a self-scaling condenser is provided at such low costof manufacture that it can be economically used in the numerous petroleum refining plants and in many other installations where bad circulating water conditions would materially increase themaintenance cost of conventional tube and shell heat exchangers.

In addition, the invention has an extremely important manufacturing advantage. It rovides a standard heat exchanger unit which can he manufactured in large quantities for stock and used for a variety of duties bv merely changing the number of units which are assembled in series or parallel.

I claim:

l 1. A heat exchanger for use with cooling water from which scale-forming substances deposit comprising a plurality of units, ear-h unit including a pair of headers connectedn f by tubes, said tubes being slightly bowed out of a straight line whereby a relatively small elongation of the tubes through heat expansion produces a 'relatively large deformation of the tubes and thereby exerts a loosening action on the deposited scale, said headers The resulting bowing of the 70 other, each of said units including a-paii" of headers connected by a vplurality of horizontally bowed tubes and spacers to hold the` headers of each unit 'from spreading, means for spraying water over the surface of the uppermost unit` and means for collecting the water from below the bottom unit. 3. A heat exchanger, comprising a verti- .cal frame-work having!I a plurality of pairs of longitudinal bars supported in vertically spaced relation by a pair of vertcals at each end thereof, each pair of said longitudinals supporting thereon a separate heat transferring unit slidably mounted at each end thereof, each unit including a pair of headers connected by tubes, said tubes being slightly bowed out of a straight line. Whereby a. relatively small elongation of the tubes through heat expansion produces a relatively large deformation of the tubes and thereby exerts a loosening action on the deposited scale, said headers of each unit being independently held in spaced relation by means for preventing the separation of the headers when the `tubes are subjected to a greater amount of elongation than said spacing means.

4. In a heat exchanger, the combination Aof an atmospheric sprinkler system comprising a box frame, an overhead source of water supported thereon, a sprinkler tray supported vertically beneath-saidA source and a collector-sump vertically beneath said sprinkler tray and a closed condensing conductor comprising a series of separate parallel horizontally bowed heat-transferring units supported vertically in the box frame and connected in vertical S-for'm` and having an inlet and an outlet.

5. In 'a heat exchanger of the class described, a heat-transferring element having an inlet header slidably supported in a horiz'ontal plane in a vertical framework and an outlet header slidably supported in the framework in the same horizontal plane, a spacer bar connectingr said headers and a pluralityof sets of heat-transferring tubes extending in parallel horizontal planes therebetween, eaeh set of tubes comprising a plurality of tubesr having a higher coelicient of expansion than said spacer bar and having a permanent bowl-shape in parallel horizontal planes, each set being rigidly maintained in a vhorizontal plane and separated from the adjacent set by a rigid transversely extending bar attached by its ends to the framework near the middle of the length `ot' the tubes, said outlet header having at/its bottom side a downwardly -projecting conduit supported by and fluidly connected to a similar and upwardly projecting conduit on the upper face of the inlet header of the next succeeding heattransferring element'.

6. A heat exchanger, comprising a vertical frame work` having-a plurality of pairs of longitudinal bars supported in verticall spaced relation in parallel planes by a pair of verticals at each end thereof, the topmost pair of said longitudinals supporting a water sprinkler and each succeeding pair of said longitudinale supporting a separate heat-transferrin,f ,r element slidably mounted at each end thereon, each of said heat-transferring elements having a conduit projecting` in opposite vertical directions from each end thereof, said conduits having means whereby the successive elements may be connected in series How relation at alternate ends from the top-most element downwardly through the vertical frame work, said topmost element having a two-way inlet connection to a source of fluid to'rbe treated and to 'a source of steam respectively` and the bottom-most element having a discharge connection, and the bottom-most pair of longitudinale support-ing a cooling water collecting sump. i

In testimony whereof I aiiix my signature.

JOSEPH PRICE.

of cach element being` independent-ly held in spaced relation by means for preventing the separation of the headers when the tubes are subjected to a greater amount of elongation than said spacing means.

2. A heat exchanger comprising a plurality of units spaced vertically one above the other, each of said units including a pair ot headers connected by a plurality of horizontally bowed tubes and spacers to hold the headers of each unit from spreading` means for spraying Water over the surface ot' the uppermost unit` and means for collecting the water from below the bottom unit.

il. A heat exchanger, comprising a vertical frame-Work having a plurality of pairs of longitudinal bars supported in vertically spaced relation by a pair of vertirals at each end thereof, each pair of said longitudinals supporting thereon a separate heat transferring unit slidably mounted at earh end thereof, each unit including a pair of headers connected by tubes, said tubes being slightly bowed out of a. straight line. Whereby a relatively small elongation of the tubes through heat expansion produces a relatively large deformation of the tubes and thereby exerts a loosening action on the deposited scale, said headers of each unit being independently held in spaced relation by means for preventing the separation of the headers when the tubes are subjected to a greater amount of elongation than said spacing means.

4. In a heat exchanger, the combination ot an atmospheric sprinkler system comprising a box frame, an overhead source of Water supported thereon, a sprinkler tray supported vertically beneath said source and a collector-sump vertically beneath said sprinkler tray and a closed condensing conductor comprising a series of separate parallel horizontally bowed heat-transferring units supported vertically in the box frame and connected in vertical S-forin, and having an inlet and an outlet.

5. In 'a heat exchanger of the class described. a heat-transferring element having an inlet header slidably supported in a horizontal plane in a vertical framework and an outlet header slidably supported in the framework in the same horizontal plane7 a spacer bar connecting said headers and a plurality ot sets of heat-transferring tubes extending in parallel horizontal planes therebetween, cach set of tubes comprising a plurality of tubes having a higher coefficient of expansion than said spacer bar and having a permanent bowl-shape in parallel horizontal planes, each set being rigidly maintained in a horizontal plane and separated from the adjacent set by a rigid transversely extending bar attached hy its ends to the framework near the middle of the length ot the tubes, said outlet header having .fit/its bottom side a downwardly projecting conduit supported by and Huidly connected to a similar and upwardly projeeting conduit on the upper face of the inlet header of the next succeeding heattransferring element'.

G. A heat exchanger, comprising a vertical trarne Work, having a plurality of pairs of longitudinal bars supported in vertically spaced relation in parallel planes by a pair of verticals at each end thereof, the topinost pair of said longitudinale supporting a water sprinkler and each succeeding pair of said longitudinals supporting a separate heat-transferring element slidably mounted at each end thereon, each of said heat-transferring elements having a conduit projecting in opposite vertical directions from each end thereof, said conduits having means whereby the successive elements may be connected in series How relation at alternate ends from the top-most element downwardly through the vertical frame Work, said topmost element having a two-way inlet connection to a source of fluid to be treated and to a source of steam respectively, and the bottom-most element having a discharge connection, and the bottom-most pair of longitudinals supporting a cooling water collecting sump.

In testimony whereof I aflix my signature.

JOSEPH PRICE.

CERTIFICATE 0F CORRECTION.

Patent No. l, 617, 083.

Granted February `8, 1927, to

JOSEPH PRICE.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 3, line 74, after the word "upon" insert the words "following up"; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the else in the Patent Office.

Signed and sealed this 29th day of March, A. D. 1927.

M. J. Moore, Aeting Conmnsioner of Patents.

(ill

CliliTFChlE. ifi? CORRUUQN.

Patent No. l,6l7,083. Granted February 8, 1927, to

JOSEPH PRICE.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 3, line 74, after the Word "upon" insert the words "following up"; and that the said Letters Paten-f should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 29th day of March. A. D. [927.

' M. J. Moore, Sell. Acting Comniesioner of Patents.

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