US1813754A - Heat exchanger - Google Patents

Description

July 7, 1931. c. w. METZGAR I HEAT EXCHANGER Filed Nov. 22, .1928

ATTORNEY.

I Patented July 7, 1931 UNITED STATES PATENT OFFICE] CHESTER W. METZGAE, F EASTON, PENNSYLVANIA, ASSIGNOR TO INGERSOLL-RAND COMPANY, OF JERSEY CITY, NEW JERSEY, A CORPORATION OF NEW JERSEY HEAT EXCHANGER Application filed. November 22, 1928. Serial no. 321,151.

This invention relates to heat exchange apparatus, and more particularly to devices adapted to be used in conjunction with compressors for cooling the air between stages 3' of compression or between thefinal stage of compression and the storage receiver.

One object of the invention is to obtain a compact and eflicient cooling unit in which liquid conveying tubes may be arranged in close proximity to the walls of the heat exchanger.

Another object is to avoid the formation of what may be termed dead air pockets in the heat exchanger by means adapted to insure a state ofturbulence in the heat exchanger so that the fluid intended to be cooled will be brought into repeated and intimate contact with the surface of the cooling tubes.

Other objects will be in part obvious and in part pointed out hereinafter.

In the drawings illustrating a practical application of the invention and in which similar reference characters refer to similar parts,

Figure 1 is a longitudinal vertical section of a heat exchanger constructed in accordance with the practice of the invention,

Figure 2 is a transverse view taken so through Figure 1 on the line 2-2 looking in the direction indicated by the arrows,

Figure 3 is an enlar ed detail sectional elegation of one end 0 a heat exchanger, an

Figure 4 is a transverse view taken through Figure 1 on the line 44 looking in the direction indicated by the arrows. Referring more particularly to the drawings, A designates generally a heat exchanger having a casing B in which is disposed a group of cooling liquid conveying tubes C. The casing B comprises in this instance a tubular section D to one end of which is secured a head E and at the other end an extension F of substantially the same diameter as the tubular section D to accommodate a group of cooling tubes C. A 010- sure is provided for the outer end of the extension F in the form of a cover or head G which may be secured to the extension F in any suitable manner, as for instance by bolts H.

For convenience of illustration, only a single pass cooler is illustrated. It will, however, be apparent to those skilled in the art from the following description that the invention is also applicable to multi-pass coolers or heat exchangers.

According to the construction shown, the element intended to be cooled,'such as pressure fluid issuing from a compressor, enters the casing B through an inlet opening J formed in this instance in the extension F. The pressure fluid therefore enters one end of the heat exchanger and is caused to flow through the casing B along a serpentine path formed by baffles K which are in this instance disposed in staggered relationship with respect to each other throughout the a casing to cause the fluid to be brought well into contact with the surfaces of the cooling tubes C.

Any suitable number of bafiies may be provided for the purpose described and these baflles are so spaced with respect to each other and the sides or ends L of the baflies K over which the pressure fluid flows are preferably so spaced with respect to the bounding surface of the casing that substantiallythe same pressure may exist through out the entire area of the heat exchanger. In other words, the space between the ends L of the baflles K and the wall of the casing is preferably such that there is neither a substantial decrease nor increase in the pressure of the fluid during its course through the exchanger A.

After passing over the bafie K adjacent the head E of the heat exchanger, the pressure fluid will flow against a grid or separator O forming in this instance an inte- (g)ral portion of the head E. The separator may be in the form of a series of ribs P which, when the pressure fluid contacts therewith, will have the efiect of extracting moisture from the pressure fluid immediately before the exit of such pressure fluid through an outlet opening Q of the head E.

The ribs P may be arranged in any suitable manner in oppo ite sides 0f-the head E and between the opposed series of ribs, P

and on the bottom of the head E is a bridge 'jected, it is essential that means be provided to accommodate .the free elongation and con tractional movement of thetubes C. To this end the tubes are seated with one end in a tube plate V fixedly secured to the head E and at the other ends are inserted in what may be termed a movable tube plate W. The tube plate W lies within the confines of the casing and is preferably of sufliciently smaller diameter to enable it to move freely longitudinally of the casing in accordance with the degree of contraction and expansion of the tubes which it supports.

Secured to the tube plate V is a head X for cooling liquid, such as water, and into which the Water may be conveyed through a pipe Y leading from a suitable source of supply. The water is preferably introduced into the head X at a point near the uppermost 1portion of the said head X and may flow t rough a series of tubes C lying in the upper region of the heat exchanger and thence into a head Z bolted to the tube plate W or otherwise suitably securedthereto and forming a chamber I) through which Water may flow into lower rows of tubes and again be returned to the head X. The chamber In in the head Z and a chamber 0 in the head X may be suitably divided into any desired number of compartments wherewith adjacent rows of tubes 0 may communicate so that the direction of the flow of water may be repeatedly reversed until finally it reaches the lowermost portion'of the head X from whence it may be conveyed by means of a pipe d.

In apparatus of this character it is desirable that substantially all the available space in the casing B be occupied by the cooling means, such as the tubes C in order to avoid the formation of dead air pockets in which pressure fluid of any temperature may remain substantially motionless and thus act as an insulator to preclude any additional cooling effect which might otherwise take place due to the temperatureof the atmosphere surrounding the heat exchanger. The present invention. contemplates the elimination of such dead air pockets and to this end the head Z is provided at its edge with an annular flange e of only small width in order that the chamber b for which the flange 6 forms a bounding surface may be in diameter only slightly smaller than the diameter of the casing B. The flange e in'this instance is adapted to encircle a boss f of the tube plate W and agasket 9 is disposed between the flange e and the tube plate W to seal the chamber b. By forming the flange e in the manner described the means whereby the head Z is secured to the tube plate W, such as the bolts 71, are insterted through the head Z at points within the inner surface of the flange 6. This arrangement will permit of the disposal of cooling tubes C at points close to the casing and therefore throughout substantially the entire area of the casing.

Formerly, in heat exchanging apparatus it has been customary to depend entirely upon the natural flow of the pressure fluid through the heat exchanger to cause agitation of the pressure fluid so that it may be uniformly distributed throughout the heat exchanger and brought into contact with the entire available cooling surfaces of the tubes C. While this was the desired result, it was found that in practice the main fluid stream followed the serpentine course hereinbefore referred to and that there were considerable areas in the casing in which pressure fluid remained comparatively dormant, thus insulating not only the casing of the heat exchanger but also considerable areas of the cooling tubes C. In order therefore to insure a desirable state of turbulence throughout the entire area .of the casing, the baflles K are provided with passages j for diverting a portion of the pressure fluid from the main fluid stream. The pressure fluid enters the passages j from the upstream side of the baffles and injects such pressure fluid laterally into the main fluid stream to insure its thorough agitation so that the pressure fluid comprisingthe main fluid stream will not only flow along its general course towards the outlet opening Q, but will be diffused and will therefore be brought into repeated contact with the surfaces of the cooling tubes C. The passages 7' may be of any suitable number and conformation and are preferably located on diametrically opposite sides of the tubes C, and for convenience ofrmanufacturing, they also preferably open into apertures in the baflles K through which the tubes C extend. The apertures 70 are of such diameter that the walls thereof may be in body contact with the tubes so that the tubes may be suitably supported at points intermediate their ends.

The operation of the device is as follows: Assuming the machine, such as a compressor, to which the heat exchanger may be attached to be in operation, compressed fluid entering the inlet opening J will -flow over the ends L of the bafiies K through the casing B and into the head E where, upon striln'ng the ribs, P, S and T of the separator, any moisture or other matter entrained by the fluid will be separated from the fluid. This scouring process preferably takes place just before the fluid leaves the casing through the outlet opening Q, from whence it may flow to a storage receiver, where only one unit is being utilized or, in case of a two pass exchanger, into the connected unit.-

During the course of the fluid through the casing B, fluid will enter the .passages j on the up-stream side of the baflies K and" will flow throughth'e'passages to be again injected in a longitudinal direction relativel5 1y to the casing into the main fluid stream. In this *way the fluid will be thoroughly agitate d to prevent the undesirable insulating efi'ect hereinbefore referred to.

I claim:

1. A heat exchanger, comprising a casing, tubes in the casingfor conveyin .cooling liquid, baflies in the casing arran e in stag gered relation with respect to eachother to I,

direct fluid flowing through the easing into 3 intimate contact with the tubes, and a separator integral with the casing for removmg' moisture entrained by the fluid intended .to

be cooled.

ing and inject it laterall into t e main stream for agitating the fluid and thus insure its intimate contact with the tubes.

6. A heat exchanger, comprising a casing,

baflies in the casing having apertures therein, liquid conveying tubes extending through the apertures, said tubes being supported against lateral movement intermediate their ends by the bafiles, and separate passages for each tube in the baflles adjacent 'the apertures and coalescing therewlth to divert a portion of the fluid flowing through the casinto the main stream for agitating the uid and thus insure its intimate .contact'with the'tubes.

In testimony whereof I have signed this specification.

2. A heat exchanger, comprising a casing having an inlet and an outlet opening, tubes in the casing for conveying cooling liquid 7 through the casing, baflles in the caslng,fpassages in the baflles to direct a portion 0 the fluid intended to be cooled longitudinally of the casing and in the direction of the outlet opening to agitate the main fluid stream and insure its intimate and repeated contact with the tubes, and a separator integral with the casing and in the same transverse plane as the outlet opening for removing moisture entrained by the fluid intended to be cooled.

3. A heat exchanger, comprising a casing,

tubes in the casing, for conveying cooling 4 liquid, a tube plate aflixed to the casing for supporting the tubes at one end, a movable tube plate in the casing to support the-ops -posite ends of the tubes and having a boss,

a head for the movable tube plate, a flange on the head to form a chamber for cooling hquid and encircling the boss to seal the chamber, and means lying within the inner surface of the flange for securing the head to the movable tube sheet.

4. A heat exchanger, comprisin a casing, tubes in the casing for convey ng cooling liquid, a tube plate aflixed to the casing for supporting the tubes at one end, a movable tube plate in the casing to support the opposite ends of the tubes, a head for the movable tube plate having an annular flange to form a chamber for cooling liquid, and bolts lying within the inner surface of the flange for securing the head to the movable tube plate.

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