US1994779A - Heat exchange apparatus - Google Patents

Description

March 19, 1935. D. R. McNEAL HEAT EXCHANGE APPARATUS Filed April 16, 1932 a/fifl INVENTOR.

,', .1 v ATTORNEYS.

Patented Mar. 19, 1935 UNITED STATES PATENT OFFICE 1,994,779 .nEA'r EXCHANGE APPARATUS Application April 16,1932, Serial No. 605,619

7 Claims.

This invention relates to heat exchange apparatus and is especially concerned with a relatively simple and inexpensive small exchanger particularly suitable for cooling air or other gases.

.5 In considering some of the objects of the invention, it should first be noted that in a great variety and a large number of instances, it is desirable to employ a relatively small size heat exchange device, preferably connected directly into a gas or air supply line, it being noted that for many purposes it is highly desirable that the exchanger employed be of the straight-line or direct connection type. That is, for example, in an air supply line extended from a pressure reservoir to some point of use, it is desirable to employ a small size exchanger (usually a cooler) and at the same time maintain direct or straight-line communication through the air line. Heretofore, in many cases where such use was apparent, the cooler desired could not be employed as a practical matter, either because of the complication of apparatus heretofore provided for the purpose, or because of the relatively great expense which the cooler necessitated in installation and maintenance.

It is with apparatus adapted to overcome the foregoing difficulties and disadvantages that the present invention is concerned. An object of this invention, therefore, is to provide a relatively g inexpensive and simple heat exchange device especially adapted for direct connection in an air or gas supply line, particularly for the purpose of cooling the air or gas.

The invention also contemplates a cooler which maintains straight-line or direct communication through the supply line.

A still further object of the invention resides in the arrangement of the cooler parts, or at least a major portion thereof, in such manner that they may readily and conveniently be formed of standard tubing stock and the like.

The manner in which the foregoing objects and advantages are attained, together with others which will occur to those skilled in the art, will be more apparent from a consideration of the following description making reference to the accompanying drawing, in which Figure 1 is a longitudinal sectional view through a heat exchange device constructed in tially as indicated by the section line 1-1 on Figure 2;

Figure 2 is a sectional view taken substantially as indicated by the section line 2-2 on Figure 1; and

accordance with this invention, taken substan- Figure 3 is a fragmentary sectional view of one end of a modified exchanger device.

Referring first to the showing of Figures 1 and 2, the gas or air line with which the exchanger is to be associated is indicated as being broken and provided with opposed end portions 4 and 5. The various parts of each end of the device are entirely similar to those employed at the opposite end so that a description of one and only need be considered. It should be borne in mind in connection with this fact, however, that it is of advantage in a simplified and inexpensive heat exchange device to employ as many duplicate parts as possible since this materially reduces expense in manufacture, repair, etc.

Referring then specifically to the parts of the device shown at the left of Figure 1, it will be seen that the pipe connection 4 is threaded into a cylindrical part 6 formed integrally with a base or disc 7 which constitutes a tube sheet. This part may conveniently and readily be machined, as by drilling and the like, from standard bar material, it being noted that the cooler sizes to which this invention is especially adapted vary from approximately one to six inches in overall diameter.

A nest of relatively small diameter tubes 8 terminate in the sheet 1 and communicate with the interior of the cylindrical portion 6, this cylindrical portion thus constituting a header for communication between the pipe 4 and the tubes 8. Surrounding the tubes 8 I have provided a tubular shell or casing 9 which may conveniently be cut from standard or stock tubing, and at each end, the header device 6-7 fits into the shell so as to provide a chamber surrounding the tubes in which a heat transfer medium may be circulated.

A cylindrical or annular member 10 is applied externally of the tube 9 at each end thereof, it being noted that this part may also be cut from stock tubing and welded, brazed or soldered in place as indicated by the reference numeral 11. This collar or annular member performs three major functions. In the first place it serves to reenforce the end of the casing 9. Secondly, it provides suflicient depth or thickness of material for a threaded connection 12 with which a pipe 13 for the heat transfer medium cooperates. The shell 9, of course, is also apertured, as at 14, in alignment with the threaded aperture 12 to provide for communication with the interior of the casing.

To perform its third major function, the collar 10 is preferably extended outwardly beyond the end of the tube 9 in order to cooperate with the cylindrical portion of the header device to form an annular packing groove or chamber therebetween. Packing material or a packing ring 15 is illustrated in Figure 1 as occupy this cavity, and a gland or tightening device 16 is provided for the purpose of maintaining the joint tight. The gland may be drawn up by means of bolts 17 taking into lugs 18 attached to collar 10. The bolts 17 -also cooperate with the wings or ears 19 formed on the gland 16.

In order to provide a more or less extended path of travel of the cooling medium through the shell 9, I preferably employ baille devices indicated at 2'7 in Figure 1, these baflies being arranged generally cross sectionally of the casing 9 at spaced points therealong, and further being alternately disposed to extend from opposite sides of the casing and thus provide passages 28 around which the cooling medium may flow as indicated by the arrow in Figure l. Spacing sleeves 27a may be employed to position the several bailies lengthwise of the cooler. The direction of flow of the cooling medium through the casing 9 is preferably generally reverse to the direction of air or gas flow through the cooling tubes 8. It is observed in this connection that the construction of the parts at opposite ends of the unit as counterparts, permits use thereof for air and cooling medium flow in either direction.

In the preferred arrangement, the cylindrical part 6 of the header means is flattened as indicated at 20 to facilitate assembly or the like by the use of a wrench, and in order to prevent relative rotation of the casing 9 and the tubes with their associated header means, the headers may be recessed as at 21 to receive a locking pin 22 conveniently threaded into the collar 10.

In the modification of Figure 3, the tubes 8 and their surrounding shell 9 remain exactly the same as in Figures 1 and 2. The packing or gland device 1511 and 16a also remains substantially the same in its relation to the casing 9, the collar 10a and the tube header device. In this instance, however, the cylindrical portion 6a of the header device is externally threaded adjacent its outer end to receive an internally threaded collar 23, and the tube or air line connection 5a is threaded into an end plate 24. The plate 24, in turn, is secured to the outer end of the header part 6a, preferably with packing 25 interposed therebetween. For the purpose ofattaching the plate 24, I employ bolts 26 extended through apertures therein and threaded into the plate or disc 23.

In considering some of the advantages of both forms of the invention illustrated, it is first to be noted that the tube element, including the tubes themselves and their associated header means, constitutes a single unit which is readily inserted or removed for purposes of initial installation or subsequent cleaning or repair. In accordance with Figure 1 it is necessary only to loosen the bolts 17, displace the gland 16 by sliding it over the associated pipe connection, and then similarly displace the sleeve or tube 9 in order completely to expose the tubes 8. If desired, of course, the pipe connections 4 and 5 may then be uncoupled and the entire unit is open to inspection, cleaning or repair. A similar but reversed procedure, of course, is followed in initially assembling'or re-assembling the several parts.

In accordance with the arrangement of Figure 3 the parts may readily be disconnected or taken down first by releasing bolts 26 and then unscrewing the ring 23. After removal of the ring 23, the casing 9 may then he slid off the end of the tube unit to gain access to any parts which may require cleaning or repair.

The showing of Figure 3 illustrates the manner in which a flanged pipe connection may be used to connect the cooler into an air or gas line.

One factor of major importance in attaining the objects and advantages hereinbefore referred to is involved in the arrangement of the heater in such manner that the air or gas to be cooled is passed through the straight-line tubes, the cooling medium being circulated between and around the tubes within the casing 9. Bearing in mind the fact that water or some other suitable liquid is ordinarily employed for cooling purposes, it will be seen that the foregoing arrangement does not necessitate the use of glands or slidably packed joints at points where they will be subjected to air or gas pressure. The only slidable joint which'need be provided with a gland or packing device is interposed between the header means for the tubes and the casing 9. The arrangement, therefore, is especially adapted to the cooling of air or gas by a liquid such as water, since the sliding joints between the two headers and thecasing 9 are subjected to water pressure only. Ordinarily, the water pressure need not be very high and, in any event, a joint of the character referred to may be much more efliciently packed as against leakage of a liquid than as against leakage of a gas.

The tubular formation of the several parts of .the device also permits use thereof even where air or gas under very high pressure is to be cooled. Further in this connection, the passage of the air to be cooled through the tubes rather than around them is desirable in reducing vibrations,

and consequent wear, which heretofore has resulted where the material being cooled is pulsating, as when it is delivered from a compressor. Certain features of such an arrangement, however, are not broadly claimed herein since they form a part of the copending application of D. Raymond McNeal, Serial No. 605,618, filed April 16th, 1932. These features, however, are or" especial advantage in a small size heat exchangerof the character to which this invention relates since they serve to further reduce the maintenance and replacement costs, it being borne in mind that heretofore such costs have prohibited the use of coolers or the like in many instances where they should be employed for emcient operation.

With further reference to the advantages of the present construction, attention is called to the fact that the operation of an air compressor normally results in a very substantial increase in the temperature of the air compressed. The temperature, indeed, may often reach values as high as 300 to 400 Fahrenheit. Compressor operation also results in the formation of oil and water vapor and this is carried with the air-as it is discharged, usually to a receiver or storage tank. Under certain vapor, pressure and temperature conditions, a very highly explosive mixture is produced and this has not infrequently caused serious explosions, as a result of which heavy damage and injuries have been incurred.

It will be seen from the foregoing that it is use. However, in accordance with the practice of the prior art, even where attempts were made to employ coolers in relatively small installations, such coolers could not be located closely adiacent tothe compressor on account of the excessive wear which resulted from the vibrations set up by the pulsations in the air discharged from the compressor.

This invention, however, in providing a cooler which is not subject to material wear as a result of air pulsations, and which further serves to reduce the magnitude of the pulsations, particularly bearing in mind the fact that the several parts of the cooler may be manufactured very inexpensively, makes it possible to employ a small size cooler disposed closely adjacent to an air compressor. The advantages of such an arrangement should be fully apparent from the foregoing comments.

In conclusion, attention is again directed to the fact that at least a major portion of the parts employed, in either embodiment of the invention, may conveniently and efliciently be cut, drilled or machined from stock tubing, sheeting and the like. In accordance with this invention, therefore, I have provided a heat exchange device especially suitable for small size installations such as are required, in many instances, for efiicient operation of air or gas supply lines.

I claim:

1. In combination with a substantially straight section of a fluid supply line, a. heat exchange device interposed in said section, said device ineluding a nest of tubes, tube supporting means at the ends thereof having means of connection into said section, a tubular shell surrounding said tubes, said shell and the tube supporting means being so relatively proportioned with respect to each other and with respect to the diameter of the fluid supply line as to permit uncovering of the tubes by sliding the shell over the tube supporting means at one end thereof to telescope with an adjacent portion of the Supp y line, to-

gether with means associated with said shell for circulating a heat exchange medium therein.

2; Heat exchange apparatus of the character described including in combination with opposed ends of a pipe line, header devices associated with the pipe ends, a plurality of tubes extended between the header devices to complete a substantially straight-line communication through said line, and a shell surrounding said tubes between said devices and cooperating with the latter to provide a chamber for a heat exchange medium, the shell being slidable endwise over a header device and associated pipe end to expose the tubes.

3. In heat transfer apparatus of the character described, a tubular shell, a nest of tubes in the shell, tube supporting means at one end of the shell having a disc-like portion constituting a tube sheet and a cylindrical portion, a member surrounding the shell and extended beyond the end thereof to provide a packing chamber at the end of the shell between said cylindrical portion and said member, and a packing element in said chamber.

4. In combination with an air line or pipe having threaded connection means, an elongated sub- V 3 stantially straight-line air cooling device adapted to be connected with said line in substantial alignment therewith, said device including a tubular shell, a plurality of relatively small diameter tubes extended lengthwise through the shell, means for circulating a cooling medium through the shell around said tubes, and a device fitting in said shell and having a substantially circular portion and a portion of cylindrical shape the latter of which is substantially regular as to its cylindrical shape throughout an extended length thereof, the circular portion being arranged to serve as a tube sheet, the cylindrical portion being open at an end thereof and further being threaded on its substantially regular cylindrical wall to cooperate with the pipe connection means, and the said device and the shell being so proportioned as to provide for axial displacement of the shell over said device.

5. In combination with an air line or pipe having an externally threaded end, an elongated substantially straight-line air cooling device adapted to be connected with said line in substantial alignment therewith, said device including a tubular shell, a plurality of relatively small diameter tubes extended lengthwise through the shell, means for circulating a cooling medium through the shell around said tubes, and a member fitting in said shell and having a substantially circular portion and a substantially cylindrical portion the latter of which is substantially regular as to its cylindrical shape throughout the length thereof, the circular portion being arranged to serve as a tube sheet, and the cylindrical portion being open at an end thereof and further being internally'threaded on its substantially regular cylindrical wall to cooperate with said externally threaded pipe end, and the cylindrical portion of said member and the said shell further being so proportioned as to provide for axial displacement of the shell over said member and the connected pipe end to expose the tubes.

6. Heat exchange apparatus of the character described including a pair of header devices each having means of connection with a pipe, a plurality of tubes extended between the header devices, at least one of the header devices having a cylindrical outside wall, a shell surrounding said tubes between said devices, the shell being formed of standard tubing stock of inside diameter such as to receive the cylindrical header, and a cylindrical member surrounding an end of the shell, the cylindrical member also being formed of standard tubing stock and projecting beyond an end of the shell to cooperate with the cylindrical wall of the header in forming an annular packing cavity at the end of the shell.

7. A heat transfer device including a nest of tubes, a cylindrical shell surrounding the tubes, a cylindrical member amending the shell adia'cent an end thereof and secured thereto to reinforce the shell, said cylindrical member and the shell being apertured to provide an opening for the passage of a heat transfer medium and the aperture in the member being threaded for connection with a pipe for said medium, whereby the cylindrical member serves as the means for connection with the pipe and also as a reinforcement for the shell. P

D. RAYMOND McNEAL.

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