US2036957A - Heat exchanger - Google Patents

Description

prll 7, 1936. n J, pR|E 2,036,957

HEAT EXCHANGER Filed Feb. 19, 1956 2 Sheets-Sheet l INVENTOR ATTORNEYS 2 sheets-Sheet 2 ENTOR ATTO R N EYS J. PRICE HEAT EXCHANGER April 7, 1936.

Filed Feb. 19, 1936 Patented Apr. 7, 1936 UNITED STATES PATNT ori-ica u Exeem Joseph Price, West New Brighton, N. Y., assigner to The Griscom-Russell Company, New York, N. Y., a corporation of Delaware Application February 19, 1936, Serial No. 64,631 11 Claims. (Cl. 257-236) 'I'his invention relates to heat exchangers and do not interfere with the normal movement of more particularly to improvements in heatexthe tubes during expansion and contraction changers of the type in which a pair of tube thereof but limit or restrict abnormal displacesheets or headers are interconnected by a ment of the tubes out of alignment or proper bundle of flexible tubes which, at least during spaced relation to each other. I may also pro- 5 normal operation of the apparatus, are bowed vide means for preventing any substantial lator laterally displaced. Heat exchangers of this eral movement of the tubes at right angles to type comprise one or more groups of bowed the planes in which theyare normally bowed. tubes, arched or bowed in one direction. If the My improved tube supporting apparatus may headers or tube sheets are rigidly secured in be mounted in a frame connected to the head- 10 spaced relation to each other, the expansion ers so that the headers, the tube bundle and the and contraction of the tubes with changes in supporting means constitute a unitary structure. temperature produce a exure of the tubes; con- The tube supporting elements for preventing traction of the tubes tends to straighten them abnormal displacement of the tubespreferably l5 out and expansion of the tubes tends to increase comprise a plurality of nat bars inclined at an 15 the bow or lateral displacement thereof. This angle corresponding with the inclination of exure of the tubes effectively removes any those portions of the tubes adapted to be enscale deposited on the tube surfaces. gaged by these bars, and the bars are prefer- It has been found that if the bundle of bowed ably mounted on supports which extend paral- 26 tubes is of considerable length some of the tubes lel to the tube sheets or headers. The bars are 20 may in the course of time become warped, or preferably threaded onto these supports and they may expand or contract more than other mounted in spaced relation to each other by tubes, with the result that the group of tubes spacers threaded onto the supports. The bars are no longer properly spaced from each other. and spacers may engage each other in such a This is particularly true with respect to bowed manner that the bars are inclined at an acute 25 tube heat exchangers in which the tubes are angle to the axes of the bar supports. This may normally arched or bowed upwardly, for in apbe accomplished in various ways but I prefer to paratus of this particular type some of the provide the bars with spacer-engaging surfaces tubes may sag more than others and after exextending at such an angle with respect to the 30 tended use the major portion of the tube bundle tube-engaging surfaces of the bars that these 30 may be out of alignment. It has been noted for tube-engaging surfaces are parallel to the porexample that in bowed tube heat exchangers in tions of the tubes engaged thereby when the which 1 O. D. Admiralty tubing is employed, bars are firmly secured in spaced relation to some of the tubes sag down out of their vereach other on the bar supports.

tically bowed position where the length of the The various objects and advantages of my in- 35 tube bundle exceeds approximately fteen or vention will be more apparent upon considering Sixteen feetthe following detailed descriptionof one em- AD Object 0f this invention iS tC' Provide means bodiment of the invention as applied to an evap for restricting. or limiting the movement of the orator, this embodiment of the invention being tubes of a bowed tube h eat exchanger,` in the illustrated in the accompanying drawings 1n 40 directialn olpioste tgl! that 1n which the tubes are which: norma y we y inven ion thus makes it possible to use long tube bundles without the tug'easotgrtlwltinlypvg ghzivg danger of having the tubes sag or otherwise beof my invention;

45 come displaced out of their normally bowed positions. A further object of the invention is Fig' 2 1s an enlarged transverse sectional View taken on line 2-2 of Fig. 1;

to provide means for thus restraining the movement of the tubes without interfering with Fig- 3 is an enlarged Section@ View of a pomo the free movement of the tubes in the direction of the apparatus shown m Flgs' 1 and 2i in which they are bowed. One embodiment of Fig- 4 is a' transverse Sectional View taken 0n 50 the invention comprises a series of supporting line 4 4 0f Fig- 1 and bars for engaging the tube bundles at points re- Fig. 5 is a fragmentay enlarged Sectional View mote from the ends thereof and from the center taken on line 5-5 of Fig. 1. of the tube bundle and these bars are prefer- The accompanying drawings illustrate a heat ablyrigidly mounted in such a way that they exchanger suitable for use as an evaporator, 55

and for other purposes, the apparatus comprisoutlet 3. The shell is provided with a removable cap 4 and the shell encloses a heat exchanger unit having an inlet 5 and an outlet 6. The heat exchanger unit comprises headers 1 and 8 interconnected by a bundle of bowed tubes 9. The ends of these tubes are expanded into openings in the headers or otherwise firmly secured thereto.

' In Fig. 1 the exible tubes 9 of Admiralty metal, or the like, are bowed upwardly. The tube bundle comprises vertically arranged rows of tubes bowed upwardly and the tubes are so arranged that the bundle may also be considered as comprising horizontal rows or tubes.

A frame extending between the headers 1 and 8 comprises transverse members I0, II, I2 and I3, the ends of these transverse members being secured to the longitudinal frame members I4, I5, I6 and I'I. The headers I and 8 are held in xed spaced relation to each other by means of tie rods I0', II", I2' and I3', which clamp the headers to the frame.

The headers I and 8 may be spaced a considerable distance apart to accommodate a relatively long tube bundle, and my invention contemplates providing means for insuring that all of the tubes of the tube bundle are properly positioned with respect to each other. With this object in view I have provided supports for the horizontal rows of tubes, these supports being shown at I8 and I9. Each of these supports comprises bottom and top crosspiec-cs 2B and 2I and a pair of screw threaded side rods 22 and 23 (see Fig. 2). These rods have threaded thereon a series of supporting bars 25 with short -sleeves or spacers24, interposed between them. These bars 25 are preferably inclined at an angle so that the upper surfaces thereof are parallel with the lower surfaces of the tubes at the point where the bars engage the tubes. Portions of the supporting bars 24 may be cut away to provide spacer-engaging surfaces 26 (see Fig. 3) that extend horizontally and therefore parallel with the ends of the spacers. When the nuts 2'I on the rods 22 and 23 are tightened to clamp the supporting bars 25 firmly against the spacers, the supporting bars 25 are securely held in place with their tube engaging surfaces parallel to those portions of the tubes engaged thereby. In this manner a rigid stationary support is provided for each horizontal row of tubes. With the transverse members 20 and 2I welded or otherwise permanently secured to the frame members I4, I5, I6 and I'I, the tube supports are rmly mounted on the frame, which is secured to the headers 'I and 8.

Referring to Fig. l, it will be noted that the tube supports I8 and I9 are located at points remote from the ends of the tube bundle, and remote from the center oi the tube bundle. These supports can be located in such a way that the center span of the tube bundle between these supports is not excessive in length. By using such supports the tubes are prevented from sagging beyond a certain point. It will be understood that temperature changes cause elongation or contraction of the tubes, and, with the headers held in xed spaced relation to each other, the tubes are exed whenever these temperature changes occur. Elongation of the tubes increases the bowing or arching of the tubes upward, and, when the temperature of the tubes is lowered, they contract and tend to straighten out. The

supports I8 and I9, however, prevent the tubes from sagging to an undesirable extent.

I may also provide means for maintaining the tubes in proper vertical alignment. In the accompanying drawings I have illustrated for this purpose three cages 28. 29 and 30, the cage 30 being shown in detail in Fig. 4. Each of these cages comprises a series of vertically arranged bars 3I secured to a crosspiece 32 at the bottom. The outer bars 3| may be welded or otherwise permanently secured to the frame members I4 and I5 and they may be secured to or integral with a top crosspiece 33 which is secured to the upper frame bars I6 and II. The upper ends of the bars 3I may be secured to the top crosspiece, although it may be convenient to secure some of these bars directly to the upper frame members I6 and I`I, as illustrated at 34 and 35 in Fig. 4. The bars 3| are located between the vertically arranged rows of tubes 9 and serve to prevent the tubes from becoming displaced laterally. If desired. diagonal crosspieces 3B, 3T. 38 and 39 may be employed as best illustrated in Fig. l. By using some means such as the cages 28, 29 and 30 for preventing lateral displacement of the tubes, and by employing the Supports I8 and I9, the flexible tubes are maintained in proper spaced relation to each other. The tubes are free to arch upwardly away from the supporting bars 25 but their lateral movement is restricted by the cages 28, 29 and 30 and the bars 25 prevent the tubes from sagging to an undesirable extent.

In the evaporator illustrated in the accompanying drawings the liquid to be evaporated is supplied to the shell I through the fluid connection 2 and the vapors are discharged through the fluid connection 3. The heating medium is supplied to the heat exchanger unit within the shell this medium entering through uid connection 5 from which it passes through suitable connections 40 and 4I to a supply pipe 42 extending lengthwise of the heat exchanger unit to the header 'I. From this header 'l the heating medium passes through the bundle oi tubes to the header 8 and it is then discharged through the connections 43 and 44 and the fluid connection E. The heat exchanger unit rests on a track mounted in the lower portion of the shell this track comprising longitudinally extending rails 45 resting on transverse members 46 which may be secured to the shell.

While I have illustrated one typical application of my invention as applied t'o an evaporator it is to be understood that the use of my improvements is not confined to any specic type of apparatus but may be employed generally in the heat exchanger art. My invention is therefore not limited to the particular details of construction illustrated and described but includes such modications thereof as fall within the scope of the appended claims.

l. Apparatus of the type described comprising a pair of headers. means for holdi g said headers in xed spaced relation to each ot er, a plurality of rows of exible tubes interconnecting said headers. said rows of tubes being bowed in one direction, and a plurality of stationary bars for separately engaging each of said rows of tubes to restrict movement thereof in the opposite direction. v

2. Apparatus of the type described comprising a pair of headers, means for holding said headers in fixed spaced relation to each other, a plurality of rows of flexible tubes interconnecting said headers, said rows of tubes being bowed in one direction, and a plurality of stationary bars for separately engaging each of said rows of tubes to restrict movement thereof in the opposite direction, the said tubes being free to move away from said bars in the direction in which they are bowed.

3. Apparatus of the type described comprising a pair of headers, means for holding said headers in fixed spaced relation to each other, a bundle of flexible tubes interconnecting said headers, said tubes being bowed in one direction in parallel planes, means for preventing lateral movement of said tubes at right angles to said planes and stationary means for restricting movement of said tubes in the opposite direction in said planes.

4. Apparatus of the type described comprising a pair of headers, a frame secured to said headers, a bundle of flexible tubes interconnecting said headers, said tubes being bowed in one direction in parallel planes, means carried by said frame for preventing lateral movement of said tubes at right angles to said planes, and means fixed with respect to said frame for restricting movement of said tubes in the opposite direction in said planes.

5. Apparatus of the type described comprising a pair of headers, a bundle of flexible tubes interconnecting said headers, said tubes being 'bowed in one direction, supporting means for restricting movement of said bowed tubes in the opposite direction, said supporting means comprising a plurality of flat bars for engaging said tubes at a point remote from the ends thereof and from the center thereof, said bars being disposed parallel to those portions of the tubes engaged thereby.

6. In apparatus of the type described, a tube support for a plurality of rows of bowed tubes, comprising a pair of rods, a plurality of supporting bars one for each row of tubes, said bars being threaded onto said rods, and means for securing said bars to said rods in xed spaced relation to each other.

7. In apparatus of the type described, a tube support for a plurality of rows of bowed tubes. comprising a pair of rods, a plurality of supporting bars one for each row of tubes, said bars being threaded onto said rods, and means including spacers on said rods between said bars including spacers on said rods between said bars,

for securing said bars to said rods in fixed spaced relation to each other, said spacers and bars engaging each other so that the plane of each bar extends at an acute angle to the axis of one of said rods.

9. Apparatus of the type described comprising a pair of headers, a bundle of exible tubes interconnecting said headers, said tubes being bowed in one direction whereby portions thereof between one of the headers and the center of the tube bundle extend at an obtuse angle to said header, and a plurality of stationary at bars having tube-engaging surfaces for engaging said portions of the tubes, said surfaces being substantially parallel to said portions of the tubes.

10. Apparatus of the type described comprising a pair of headers, a bundle of exible tubes interconnecting said headers, said tubes being bowed in one direction whereby portions thereof between one of the headers and the center of the tube bundle extend atan obtuse angle to :aid header, a plurality of stationary ilat bars having tube-engaging surfaces for engaging said portions of the tubes, supports for said bars extending parallel to said header, and spacers on said bars, said spacers having surfaces at right angles to said supports for engaging said bars, and said bars having spacer-engaging surfaces extending at an angle to the tube-engaging sur-

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