US1782409A

US1782409A - Heat exchanger

Info

Publication number: US1782409A
Application number: US240957A
Authority: US
Inventors: Stanley J Chute
Original assignee: Griscom Russell Co
Current assignee: Griscom Russell Co
Priority date: 1927-12-19
Filing date: 1927-12-19
Publication date: 1930-11-25
Anticipated expiration: 1947-11-25

Description

Nov. 25, 1930.

s. J. CHUTE HEAT EXCHANGER Filed Dec. 19,- 1927 2 Sheets-Sheet l a 0 o o o 0 INVENTOR 125 ATTORNEYS 5. J. CHUTE HEAT EXCHANGER Nov. 25, 1930.

2 sheds-sneer 2 Filed D60. 19, 1927 INVENTOR 2 t 71?; ATTORNEYS Patented Nov. 25, 1930 UNITED STATES 4 STANLEY J. CHUTE, 0F RIDGEWOOD, NEW JERSEY, ASSIGNOR TO THE GRISCOM-RUSSELT;

COMPANY, OF NEW YORK, N. Y.,

A CORPORATION OF DELAWARE HEAT EXCHANGER This invention relatesto apparatus for heating or cooling fluids in which the heat is transferred from one fluid to another- The apparatus is particularly applicable to the transfer of heat unaccompanied by-condensation or vaporization of either fluid, but it may be used also as either a condenser or a boiler. The apparatus is of that type in which one of the fluids, for example, the fluid to be cooled, is passed through a tubular shell and the other fluid, which may be termed the working fluid, is passed through a plurality of tubes, that is, a tube bundle ,or tube nest positioned within the shell. A

One object of the invention is to provide an apparatus of this character of small exterior dimensions but having a relatively long path of movement for the fluid in the shell, whereby thefluid to be cooled in its passage through the apparatus is kept in continuous motion at a sufliciently rapid rate tomost effectively utilize the cooling surface and at the same time obtain the desired drop in temperature of the fluid to be cooled.

A further object of the invention is to construct an apparatusof this character providing a plurality of passes for the fluid in the shell in which that fluid in its travel throughout the length of a given pass is maintained in continuous motion in the samedirection instead of in a zig-zag direction with a reversing motion as heretofore practiced, thereby avoiding the fluid friction and loss of pres sure which result when the rate offiow is sufliciently rapid tocfliciently utilize the heat transferring surface.

Another object of the invention is to provide a heat exchanger having a shell that is divided into passes of semi-circular cross section, with a balfle structure for causing the fluid in the shell to flowcontinnously in the same direction instead of in a zig-zag direction as heretofore customary, particularly in heat exchangers having passes of this shape.

A further object of the invention is to pro vide a heat exchanger which is of simpleconstruction and low in cost-of manufacture, the long walls of the passages for the fluid in the shell being formed of thin metal shaped to form a baflie of approximately helical shape extending from end to end of each pass through the shell or casing.

A further object of the invention isto provide a heat exchanger having a plurality of passes for the fluid in the shell inwhich provision is made throughoutthe length of each pass ii or maintaining the fluid in continuous motion in the same direction, and in which the bundle or nest of tubesfor the entire tubular shell, including both the baffles for dividing the shell into parallel passes, and the battles for causing continuous rotary motion, may be removed from the shell as a unit. A further object of the invention is to provide a heat exchanger having a plurality of passes for the fluid in the shell in which the tubes and other parts of the apparatus can freely expand and contract without straining the apparatus or loosening the joints between the several parts. i

In the accompanying drawings have illustrated an embodiment of myinvention actual use. 4

In these drawings: Fig. 1 is a longitudinal section taken vertially through the heat exchanger,

Fig. 2 is a somewhat enlarged transverse vertical section taken on line 2-2 of Fig. 1; Fig. 3 is'a perspective view of two adjacent baflle plates for one of the passes, the tube which has been found highly satisfactory in holes in these plates being omitted for the sake of clearness;

Fig. 4 is a front view oftwo adjacent batfle plates joined together as changer; V v Fig. 5 is a plan or top view of these two bafiles showing the joining oi'the upper pore tion of one baflie to the next; and y Fig. 6 is a side view of these hafiles.

in the heat ex-:

for nest of tu My improved heat exchanger will be described in its application to the cooling of oil, the coil passing through the shell, as referred to above, and the working fluid being passed through the interior of the tubes. It will be understood, however, that the oil may be passed through the tubes, and the working fluid through the shell if desired. It will be assumed that water is employed as the workin fluid.

eferring now to the accompanying drawings, the shell 10 in the embodiment illustrated in cylindrical in cross section and is made of steel of suitable thickness to withstand the pressure under which the oil to be cooled is circulated. At each end of the shell is provided with flanges 11 and 12 respectively, which can conveniently be annular rings cut from thick steel plates and secured to their respective ends of the shell by welding. Near the right hand end of the shell, as

viewed in Fig. 1, is a flanged inlet 13 for the passage of the oil to be cooled, and diametrically opposite the inlet 13 is a flanged outlet .14 by which the cooled oil is discharged.

The tube su porting plate 15 for the bundle lies 16 is clamped accordingly against the flange 11 at that end of the shell which is near the inlet and outlet for the oil to be cooled, this clamping being effected by the bolts 17 which also serve to secure a water head 18 to the outside of the tube sheet 15. The water head is divided into an inlet chamber 19 and an outlet chamber 20 by means of a artition wall 21. This partition terminates 1n the same plane as the flanges of the water head so that when the head is secured in place a fluid-tight joint will be made between the partition and the surface of the tube sheet 15.

A flanged inlet 22 communicates with the admission chamber 19, and a similar flanged outlet 23 is provided for the discharge chamber 20, and by means of these connections the working fluid is supplied to and discharged from the apparatus.

The tubes of the tube bundle 16 supportedin tube sheet 15 are arranged in concentric rows, with the tubes in alternate rows staggered as shown particularly in Fig. All of the tubes are expanded in thetube. plate 15 after the manner of boiler tubes to :pro

duce rigid and fluid-tight joints.

' At the opposite end ofthe-shell an end cap 24 is bolted to theflange 12. Fluid-tigh joints are providedbetween the end cap24ff "and the flange 12,:as well as in securin the 18 and tube sheet 15 to the ange water head all connected to a floatim head or return drum 25 whose cylindrical walls fit loosely in the shell and end cap 24 to permit free expansion and contraction of the water tubes. The return drum is composed of a tube sheet The water tubes" of the tube bundle, the left hand end of the heat exchanger are 26 and a cap 27 which is bolted thereto and which forms with the tube sheet a chamber connecting the open ends of all of the tubes so that the water entering the chamber from one portion of the tubes, is returned through the battles for causing the oil to travel twice throughout the length of the apparatus, and to assume during each of these longitudinal passes a continuous rotary motion in the same direction. This baflle structure also coniprises a longitudinal battle 28 which extends rom the inner surface of tube sheet 15 and terminates just short of the tube sheet 26 of the return drum. This baflle is a relatively thin metal sheet extending in the horizontal direction diametrically across the shell 10 and dividing the interior of the shell into two parallel passageways of equal area. The bafile may conveniently be made of sheet steel and is welded across its right hand end 29 where it meets the stationary tube sheet 15 so as to prevent the passage of the oil being cooled and so as tofirmly secure the baflle to the tube sheet for a purpose which will appear hereafter.

The passageway on the upper side of the longitudinal bafile is rovided with a continuous winding helical aflle 30 which extends from a point adjacent the inlet 13 to a point adjacent the end of the longitudinal bafile 28 at the opposite end of the apparatus. In-

' stead of making this helical baflle as a single unitary structure, each turn or vane is made of a separate sheet of metal of the shape shown in Figs. 3 to 6 inclusive. Each of these elements 31cons1sts of a semi-circular a outwardly from the aperture 32.

he. vanes 30 are-mounted in uniformly {spaced relation upon a core tube 35 which extends longitudmally'of the upper passage way above the longitudinal bafile 28. The

.vanes 30 are arranged with their bases 33 at an angle to the axis of the core tube 35, de-

pending upon the pitch which it is desired to give to the helical channel formed between the vanes. The bases 33 are then tackwelded to the surface of the lon itudinal baflle 28 so as to form a fairly close fit therewith. The upper portions of the vanes which have IUU has a circular aperture 32 located approximate1y midway: between the center of its ilstraight base 33 and the. outer edge of its i'se'mi-circular peripheryi The vanes are each litted or out along a straight line 34 extendbeen previously severed by the cut or slit 34; are now ofl'set so that a portion of one vane is brought into alignment with the opposite portion of the adjacent vane, and the edges of these two vanes are spot-Welded together,

as indicated at 3,6 in Figs. 1,3 and 5.

By thus positioning and joining the individual vanes a continuous helical battle is produced extending from a point adjacent the inlet 13 to a point adjacent the end of longitudinal bafiie 28 at the opposite end of the apparatus. A substantially helical channel is produced about the core tube 35 and between the vanes and extending throughout the pass above the longitudinal baflle 28. In order to maintain the vanes in the desired uniform spaced relationship a plurality. of stay rods 37 pass through the vanes near their peripheries as may be seen in Fig. 4 and extend substantially from tube sheet to the return drum 25. Spacing sleeves 38 are placed upon these rods between the vanes. A relatively large number ofstay rods are used for the sake of strength and to serve as oil deflectors.

. The battles on the lower side of the longitudinal baifle 28 are arranged substantially as described above in connection with the passageway on the upper side thereof, except that the direction of rotation of the oil chanucl 39 is reversed. Thehelical channel. between the vanes and. the upper pass is joined to the helical channel 39 of 'the lower passageway by the space 40 between the tube sheet 26 of the floating head and the end of the longitudinal baffle 28.

In operation the oil or other fluid to be cooled ispumped into the inlet opening 13 under suflicient pressure to force the oil through the helical passage at agood rate of flow. Although the passage is long, there is little friction loss for the reason that the direction of flow is continuous throughout the length of the helical channels both in the upper and lower passageways, and except for'the Water tubes andspacin rods is free from obstructions. T lne rapiil circulation causes all particles ofthe oil to be brought rapidly and repeatedly against the cooling surface under the circulating pressure without dependence upon convection so that the heating surface is maintained at its maximum efl'iciency of operation. This is a feature of particularimportance in oil coolers for the reason that there is not a great difference in temperature hetWeent-he oil to be cooled and the circulating water, as the water usually availablefor the purpose is seldom at a temperature below 60 or F.

It will be understood that the water tubes I of the tube bundle 16 pass through the apertures {11 in the vanes of the helical bat'fle members. These apertures may be made to fit the tubes closely, or they may be made somewhat larger than the outside diameter of the tubes for the purpose of securing an automatic scouring action lengthwise of the tubes as disclosed 111 Letters Patent of the United States No. 1,454,053, granted May 8,

1923, to Russell C. Jones and assigned to the same assignee as the-present application.

The core tube 35 and the corresponding core tube for the lower passageway are secured at their left hand endsto the tube sheet of the floating head .25, and at their right hand ends they are spaced slightly from the stationary tube sheet 15." By reason of this, if there happens to'be any difference in the coeiiicients-of expansion of themetal" of thecore tube, and of the metal of'the tubes of the tube bundle, the possibilityof strain on the tube joints is avoided.

The longitudinal bathe 28, as mentioned above, is firmly secured tothe stationary tube sheet 15, and the individual vanes forming the helical baffles in both the upper and lower oil passageways are individually Welded to the continuous longitudinal baflle 28 along their base. lines. Thespacing stay rods 37 which support the. outer edges of the helica bafii'e members are not attached to either tube sheet, thus avoiding the possibility of-stresses due to unequal expansion and contraction, but because the peripheries of the vanes are rigidly spaced by means of these rods, and because the bases of the vanes are secured to the longitudinalbaffle, the entire. baflie 'system possesses a remarkable degree of rigidity and strength.

It will'thus be understood that the entire baffleflsystem is made an integral part of the 1 tube bundle and can be removed with the-tube bundle and replaced in the shell without fear of damaging the vanes forming the helical bafflemembers. At the same time because semi-circular baffle members are secured to the longitudinal plate 29 along straight edges. the individual baffle members are permitted to flex slightly to the temperature stresses serve the additional function of baffles for impeding the circulation of the oil at the ,outer edge of the helical channel, therebv causing the. greater'flow ofthe oil through the portions of the channel occupied by the tubes. This is "an important feature of the construti'onfor itwould be impractical to arrange the tubes close to the outer edge of the tube sheet 15 on account of the employment of the floating head construction. \Vithout therods located adjacent the shell loo wall, there would be less resistance to the flow of the oil at the outer edge of the helical channels with the result that some of the cooling surface would be short-circuited.

It is to be understood that my invention includes all modifications of my improved apparatus which fall within the scope of the appended claims.

\Vhat I claim as new and desire to secure by Letters Patent of the United States is:

1. In an apparatus of the character described, a tubular shell forming a chamber for the fluid to be acted upon and having inlet and outlet passages for said fluid at one end of the shell, a plurality of tubes within the shell for the circulation of the working fluid, means for delivering and discharging the working fluid to and from said tubes, a flat longitudinal plate arranged diametrically across the interior of the shell and extending substantially from one end thereof to the other so as to cause the fluid to be acted upon to travel from the inlet to the opposite end of the shell and thence to return within the shell to the outlet, an elongated core member extending substantially centrally of the semi-circular chamber above said longitudinal plate, and a second similar core member positioned in the semi-circular chamber below the plate, a plurality of semi-circular sheets of thin metal each perforated centrally and arranged in spaced relation upon the core members in each of said semi-circular chambers, the bases of said bafile elements being placed against the flat surface of said longitudinal plate and arranged in substantially parallel relation at an angle to the axes of the core members, the battle elements each being severed radially-from the core member to their respective semi-circular edges, and the severed portions of each element being offset with respect to one another, the severed edge of one element being secured to the oppositely directed severed edge'of its adjacent element thereby forming a continuous substantially helical passageway throughout the length of each of said semi-circular chambers.

2. In an apparatus of the character described, a shell having a plurality of tubes extending therethrough, a tube sheet at one end of the shell for supporting said tubes, a longitudinal plate arranged diametrically across the shell and extending lengthwise thereof and secured to the tube sheet at one cud, a return drum freely movable at the opposite end of the shell including a tube sheet for supporting the tubes at that end, and supporting a core member extending longitudinally of the shell above said plate and a similar core member below said plate, and a plurality of half-circu1ar baflie elements threaded in spaced relation transversely upon said core members. said battleelements being each severed radially from the core member to their respective curved edges.

the severed portions of each element being offset with respect to one another and tho severed edge of one element being secured to the oppositely directed severed edge of its adjacent element, and the bases of said elements secured to the surfaces of said longitudinal plate, thereby forming a continuous substantially helical passageway within the shell from one end thereof to the other both above and below said longitudinal plate, inlet ing lengthwise of the shell and dividing the interior thereof into two semi-circular chain-- hers, an elongated core member extending centrally lengthwise of each of said chambers, a plurality of semi-circular bafile elements perforated to receive the tubes of the tube bundle and said core member, said elements being arranged in spaced parallel relation lengthwise of each of said SQIlll-(ll'tll ,7 lar chambers at an angle to the axes of the core members and having their bases secured to said longitudinal plate, each of said batllc elements being slit radially from the core member to the arcuate edge of the baflle. and the thus severed portions being otl'sct into alignment with similar portions of adjacent battles and secured thereto so as to form a substantially helical channel about the core member in: each of said se1ni-circular chambers. inlet and outlet connections for the shell at one end thereof, and means for connecting said helical passageways at the opposite end of the shell so as to form a continuous fluid path through the shell, and a plurality of stay rods extending longitudinally between the baflle members and arranged in spaced relation around the periphery thereof to support the edges of said members.

4. In an apparatus of the character described, a shell having a plurality of tubes extendin therethrough, a tube sheet at one end of t e shell, a longitudinal baflle arranged diametrically across the shell and extending lengthwise thereof and secured at; one end to the said tube sheet, a plurality of semi-circular battle elements mounted in spaced relation upon both sides of the longitudinal bafllc and secured thereto at their straight bases, a movable tube sheet at the opposite end of the shell, two core members secured to said tube sheet and extending lengthwise of the shell on the respective sides of the longitudinal battle through central perforations in the semi-circular battle elements, the said bafile elements being severed radially from the core member to their res ective curved edges and the severed portions of each element being offset with re- 5 spect to one another and the severed edge of one element being secured to the oppositely directed severed edge of its adjacent element, thereby forming continuous helical passage ways Within the shell on both sides of the longitudinal battle.

In testimony whereof I aifix my signature.

STANLEY J. CHUTE.