US2046481A - Heat exchanger - Google Patents

Description

July 7, 1936. J pR|E 2,046,481

HEAT EXCHANGER Filed March 15, 1955 4 Sheets-Sheet 2 O O ZQZ Icbb ATTORNEY5 J. PRICE HEAT EXCHANGER July 7, 1936.

Filed Mlarch 15, 1935 4 Sheets-Sheet 3 ELEE ATTORNEYS J. PRICE July 7, 1936.

HEAT EXCHANGER Filed March 15, 1935 4 Sheets-Sheet 4 }VENTOR M ATTORNEY Patented July 7, i936 orrica MAT EXCHANGER ware Application March 15, 1935, Serial No. 11,183

' 13 Claims. (01. 257-242) This invention relates to improvements-in heat exchangers, an object of the invention being to provide improved structural features suitable for heat exchangers of various types but especially useful in constructing heat exchangers of the type having parallel fluid passages for the hot and cold fluids, the passages being arranged side by side with a heat transferring material disposed between the passages to conduct heat from one passage to the other.

For many heat exchanger installations, particularly in the oil refining industry, it is necessary to employ apparatus which can be readily taken apart to permit the necessary cleaning of the fluid passages. It is also desirable tohave as few joints as possible, thus reducing the danger of leakage to a minimum and the joints should be of such a nature that when leakage does occur it will be at once apparent to the attendants and furthermore it should be possible to tighten a leaky joint without interfering with other parts of the apparatus. The above obj ects- I and others may be attained by employing the present invention which also contemplates such a construction and arrangement of the end connecticns that these connections and walls of the fluid passages communicating therewith are the only parts of the apparatus in contact with the fluid inside the apparatus. For certain duties alloy steel of high cost per pound is necessary for all points of contact with the fluid in the passages and by utilizing the present invention it isnecessary to use this expensive'material only for the elements forming the fluid passages and the end connections. .According to my invention the several parts may be so constructed and arranged that it is impossible for fluid to escape from one fluid passage into another fluid passage; .where D the apparatus."

The heat exchanger unit embodying my invention may include a billet head. having a fluid passage extending therethrough and an end connection' in direct communication with this pas- 55 sage and so associated therewith that a forcefit fluid tight joint is formed between the end connection and the wall of the fluid passage.

Where this construction is employed the end of the fluid passage is preferably tapered and this tapered surface may be directly engaged by an end connection having a complementary tapered portion. Detachable means may be employed for securing the end connection in place so that it forms a fluid-tight joint at the point of contact between the and connection and the fluid passage. The billet head may support a compression screw plate, or the like, and this plate may be provided with a numberof set screws or studs adapted to engage the end connections to clamp them against the ends of the passages extending through the billet heads. In a. multiple unit heat exchanger the several billet heads may be interlocked by keys, or the like, to provide a rigid structure including all of the stationary heads and the end connections associated therewith. The multiple unit apparatus may include a number of floating heads mounted in superimposed relation with one head resting upon another and. the fluid-tight joints in the floating heads may be of the same type as the joints in the stationary heads. Where each unit includes two separate fluid passages, separate return bend conduits are provided for forming the end connections for these passages and these conduits may be clamped directly against the ends of the passages with the joint preferably formed by complementary tapered surfaces directly engaging each other to provide a force-fit joint. In such a heat exchanger the heat is transferred from the fluid in one passage to the fluid in an adjacent passage through a heat conducting medium disposed between the passages. This medium may be of any desired form, for example it may consist of a large number of metal plates or fins mounted ontubular members which form the fluid passages. A'single unit may include four such tubes with each of the connecting heat conducting plates spanning each of the four tubes to tie them totaken on line 2-2 of Fig. 1), of the apparatus shown in Fig. 1;

Fig. 3 is a left end elevation of the apparatus shown in Fig. 1;

Fig. 4 is a plan view of the apparatus shown in Figs. 1, 2 and 3;

Fig. 5 is a diagonal section View of a portion of the apparatus. taken on line 55 of Fig. 3;

Fig. 6 is a diagonal section view of a portion of the apparatus, taken on line 6--6 of Fig. 3;

Fig. '7 is a transverse section view of a portion of the apparatus, taken on line 'I'I of Fig. 1;

Fig. 8 is a transverse section'view of a portion of the apparatus, taken on line 8-.8 of Fig.1;

Fig. 9 is an end view of a multiple unit heat exchanger illustrating a typical arrangement of a group of units to provide parallel flow of one fluid through the apparatus and series flow of the other fluid.

The embodiment of my invention illustrated in Figs. 1 to 8 inclusive comprises a multiple unit heat exchanger consisting of three units A, B and C arranged in a vertical stack. Each' unit comprises four tubes I, 2, 3 and 4 (see Figs. 1 and '7). These four tubes are arranged in close proximity to each other and the ends of the tubes are mounted in a stationary billet head 5 at one end of the apparatus and in a movable billet head 6 at the other end of the apparatus. The tube ends may be expanded or otherwise permanently secured in the billet heads and the ends of the tubes are preferably enlarged to form tapered surfaces adapted to receive corresponding tapered pipe connections or conduits. For example, the tube I has an enlarged tapered end I engaging the tapered end 8 of the pipe connection 9. The other end of this tube I is likewise enlarged to form a tapered end I6 engaging the tapered end II of a return bend conduit I2 which serves to connect the tube I with the tube 4. The return bend conduit I2 is provided with lugs I3 and I4 having openings therein adapted to receive bolts I5. These bolts engage threaded holes in the billet head 6 and by tightening these bolts the conduit member I2 may be clamped firmly against the enlarged ends of the tubes I and 4 to form force-fit joints between the ends of the conduit and the ends of these tubes. In like manner a shorter return bend conduit I6 serves to interconnect tubes 3 and 2. This end connection I6 has a tapered portion I'I adapted to engage the enlarged tapered end I8 of the tube 2 and a similar joint is formed between this end connection and the end of the tube 3. The end connection I6 is clamped in position by means of a yoke member I9 and bolts 20 (see Fig. 6) which engage screw threaded holes in the floating head 6. The yoke member I9 engages lugs I6 on the end connection I6 and it will be understood that when the bolts 20 are tightened the end connection I6 is firmly clamped against the ends of the tubes 3 and 2.

The floating billet heads 6, mounted one on another, are not tied together in any way and accordingly each of these billet heads may move freely in the event temperature changes cause the tubes of one unit to expand or contract more than the tubes of another unit. The stationary heads 5 however are preferably tied together or interlocked by some suitable means such as the keys 2I. The tube 2 of the unit A is connected to the tube I of unit'B by means of an end connection 22 having tapered ends engaging the enlarged tapered ends of the tubes associated therewith. A similar end connection 23 interapparatus.

connects tube 4 of unit A with' tube 3 5r unit B (see Fig. 2). A pipe connection 24 communicates with the end of tube 3. A compression screw plate 25 is mounted on the billet head 5 by means 25 and the stationary heads 5 and it will be under-.

stood that by tightening these screws the end connections may be clamped firmly against the ends-of the passages-through the billet heads to provide a fluid-tight force-fit joint between the end of each passage and the end connection associated therewith. With the stationary heads 5 interlocked by means of the key 2|, or the like,

the stationary head assembly including the heads 5 and the plates--25 the'pipe connections 9 and 24 and the end connections 22- and 23 constitute a rigid assembly for the stationary end of the Any desired number of individual units may be mounted one above another in the manner illustrated in Figs. 1 to 3. The bottom unit C has its tube 4 connected to a pipe con- The compression screw plate 25 for nection 29 and a similar pipe connection 30 communicates with the tube 2 of the bottom unit.

The apparatus described above may be arranged for either concurrent flow or countercurrent flow of the separate fluids through the apparatus. For example, 'if countercurrent flow is desiredfthev pi'pe connection 29] may be employed as an inlet for one fluid and'the pipe connection'24 as the inlet for t he other fluid. The fluid entering through the connection 29 will passin ageneral upward direction through the apparatus, first entering thetube 4. of the bottom unit C-and then passing through an end connection I2 into tube I of the bottom unit 0; it then passes upward through a connection 22 into the tube 2 of unit B and the fluid then flows through end connection I6 of unit B to tube 3 of this unit B, then through an end connection 23 to tube 4 of unit A then through end connection I 2 of unit A, through tube I of unit 'A, from which it is discharged through the pipe connection 9.

v The other fluid in passing downward through the apparatus follows the followingpath: pipe conmotion 24, tube 3 of unit A, end connection I6 of unit A, tube 2 of unit A, end connection 22, tube I of unit B, end connection I2 of unit B, tube '4 of unit B, end connection 23,. tube 3 of unit C, end connection I6 of unit C, tube 2 of unitC and pipe connection 30. The heat transfer from the fluid in oneconduit to the fluid in the other conduit takes place through intervening heat conducting material which in the form illustrated in Figs. 1 to8 inclusive consists of a large number of metal plates or fins 3I each provided with four openings to receive the four tubes of each unit. These fins or plates preferably engage the tubes in such a manner as to form a tight joint between the fins and the tubing thereby facilitating the transfer of heat from the tubes to the fins and vice versa. If the tubes 2 and 3 of each unit carry the hot fluid and tubes I and 4 the ,cold fluid then the heat is transferred from the tubes 2 and 3 through the metal fins or plates 3| to the fluid in the tubes I and 4.

If it is desirable to provide some support for the center portions of the tubes this may be acabove. The flow of the fluids will be in general concurrent if the connections for one of the fluids are reversed, for example, as by making the pipe connection 29 an outlet and pipe connection 9 an inlet for one of the fluids.

In Fig. 9, I have illustrated an assembly of three stacks of heat exchanger units embodying my invention. This Fig. 9 shows one of several ways in which the several units may be in terconnected. In Fig. 9 the arrangement is such that one of the fluids flows in a general downward direction in three parallel paths, entering the apparatus through the three pipe connections 24 and leaving the apparatus through the three pipe connections 30. The other fluid flows in a general upward direction entering the apparatus through the pipe connection 29' and leaving the apparatus through the pipe connection 9'. The arrows indicate the direction of flow of each fluid and it will be noted that the fluid entering through the pipe connection 29' flows in succession through the units C, C2, C3, B3, B2, B, A, A2 and A3. All of the units may be of identically the same construction and the end connections 22, 23 and 22' may be of'identical form and dimensions. The end connections 22' serve to interconnect the units of one vertical stack with the unitsof an adjacent vertical stack and it will be understood that the arrangement illustrated in Fig. 9 is such that one of the fluids flows in a single stream through the apparatus while the other fluid flows through the apparatus in three parallel streams.

It is apparent from the above description that by utilizing my' invention it is possible to have a single joint between the end of each straight fluid passage and the adjacent end of the end connections associated therewith. This is advantageous for it reduces the number of joints to a-minimum and accordingly the danger of leakage is likewise reduced to a minimum. It will also be noted that the return bends or end connections and the straight passages are the only elements in direct contact with the fluids inside the tubes and'accordingly where it is necessary to employ expensive high grade material for all parts coming in contact with the fluids the cost of the apparatus may be kept within reasonable limits by utilizing my invention. It is unnecessary, for example, to employ expensive material for the billet heads for no portion of any billet head comes in contact with the fluids passing through the apparatus. Each unit is of compact construction and, as clearly illustrated in Fig. 9, the center to center distance between units is so small that it is possible to interconnect adjacent units with short lengths of tubing. The same size connection may be employed whether it is used for connecting a unit to another unit above the same or toy a unit located at one side of the same. In Fig. 9 it will be noted that with the exception of the corner units,

'each unit is connected to at least three other units and in some instances one unit is connected to four other units. There are relatively few parts which require accurate machining and accordingly the manufacturing operations are not expensive. The use of an individual compression screw plate for each unit is advantageous for it facilitates joint adjustments and repairs. The apparatus is preferably so constructed that it is impossible for leaks to occur from one conduit to another and it will be noted that in the apparatus shown in the accompanying drawings any leakage through any one of the joints is from the inside of the conduit to the outside of the apparatus. Such leakage may be easily detected by an attendant and the compression scre'ws tightened to stop the leakage. By employing curved end connections it is possible to avoid the use of any sharp right angle turns in the separate fluid passages and this reduces to a minimum the danger of erosion where the apparatus is used for handling fluids which have a tendency to cause erosion of the walls of the passages. An additional advantage of importance is that by avoiding sharp right angle turns, the loss in pressure of the fluid passing through the exchanger is reduced.

It will be noted that the embodiments of my invention illustrated in the accompanying drawings comprise units each having a head with four fluid passages extending therethrough in close proximity to each other in the center of the head. The bolts 26 secure marginal or corner portions of the plates 25 to corresponding portions of the head 5. The set screws 21 for clamping the end connections to the ends of the passages are located near the central portion of the plate 25. This arrangement is advantageous for the several passages may be grouped close together and the clamping screws may be adjusted without interfering with the fastening bolts 26. Furthermore, this arrangement is such that the end connection communicating with any one passage may be mounted on either side of one of the fastening bolts 26, as best illustrated in Fig. 9. In this figure it will be noted that the end connection for the upper left-hand passage of the lower right-hand unit extends horizontally, whereas the end connection for the corresponding passage of the unit above this lower right-hand unit extends vertically.

It is to be understood that my invention is not limited to the particular embodiments illustrated and described in detail but includes such modifications thereof as fall within the scope of the appended claims.

I claim:-

1. Apparatus of the type described comprising a supporting head, a fluid passage extending therethrough, a plate mounted on said head, an end connection for said passage and disposed between said head and plate, and means carried by said plate for detachably clamping said end connection to the end of said passage.

2. Apparatus of the type described comprising a supporting head, a, fluid passage extending therethrough, a plate, means for detachably mounting said plate on said head, an end connection for said passage, said end connection being disposed between said head and plate, and means carried by said plate for detachably clamping said end connection to the end of said passage.

3. A multiple unit heat exchanger comprising a separate head for each unit, a fluid passage extending through each head, a separate plae mounted on each of said heads, a return bend conduit for connecting a passage through one head with a passage'extending through an- 75 on said heads for detachably securing said conduit to the ends of said passages.

4. A multiple unit heat exchanger compris-v ing a separate head for each unit, a fluid passage extending through each head, a separate plate mounted on each of said heads, a return bend conduit for connecting a passage through one head with a passage extending through another head, means associated with the plates on said heads for detachably securing said conduit tothe ends of said passages and means for locking said heads together.

5. A multiple unit heat exchanger comprising a plurality of floating heads mounted one upon another, a; plurality of superimposed stationary heads, means providing a plurality of fluid passages between each pair of floating and stationary heads, means for interlocking the stationary heads and means for interconnecting the several passages to provide separate fluid conduits through the-heat exchanger.

6. A multiple unit heat exchanger comprising a separate head foreach unit, the said heads being provided with keyways, a fluid passage extending through each head, a separate plate mounted on each of said heads, a return bendconduit for connecting a passage through one head with a passage extending through another head, means associated with the plates on said head for detachably-securing said conduit to the ends'of said passages and key means cooperating with said keyways to lock said heads together.

'7. A multiple unitheat exchanger comprising an assembly of units each having two pairs of fluid passages, means'for separately interconnecting the ends of the passages of each pair at one end of each unit, and end connections for the other ends of said passages, the said units and end connections being arranged so that the passages of one unit'communicate with the passages in at least three other units.

8. A multiple unit heat exchanger comprising an assembly of units each having two pairs of fluid passages, means for separately interconnecting the ends of the passages of each pair at one end of each unit, and end connections for the other ends of said passages, the said units and end connections being arranged so that the passages of one unit communicate with the passages in four other units.

9. A multiple unit heat exchanger comprising an assembly of units each having two pairs of fluid passages, means for separately interconnecting the ends of the passages of each pair at one end of each unit, and end connections for the other ends of said passages, the said units and end connections being arranged so through said head in close proximity to each other near the center of said head, a plate, means for detachably securing marginal portions of said plate to marginal portions of said head, end connections for said passages, said end connections being disposed between said head and said plate, and means carried by said plate, near the central portion thereof, for detachably clamping said end connections to the ends of said passages.

11. Apparatus of the type described comprising a rectangular supporting head, four fluid passages extending through said head in close proximity to each other near the center of said head, a rectangular plate, means for detachably securing corner portions of said plate to corner portions of said head, end connections for 'said passages said end connections being disposed between said head andsaid plate, and means carried by said plate near the central portion thereof for detachably clamping saidend connections to the near the central portion thereof for detachably clamping said end connections to the ends of said passages, said detachable-fastening means being arranged so that the end connection associated with any one passage may be mounted on either side of one of said detachable fastening means. I

13. Apparatus of the type described comprising a supporting head, four fluid passages extending through said-head in close proximity to each other near the center of said head, a plate, a plurality of bolts and spacing means for detachably securing marginal portions of said plate to marginal portions of said head with the spacing means interposed between the plate and head, end connections for said passages said end connections being disposed between said head and said plate and means carried by said plate near the central portion thereof for detachably clamping said end connections to the ends of said passages.

JOSEPH PRICE.

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