US1649120A - Heat exchanger - Google Patents

Description

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W. H. KNISKERN LMSMZ HEAT EXCHANGER NMA, 35, 2

W. H. KNISKERN HEAT EXCHANGER Filed Aug. 16, 21.923

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W. H. KNISKERN HEAT EXCHANG'ER Filed Aug. 16. 1925 5 Sheets-Sheet 3 ATTORNEYS Patented Nov. 1.5, 1927.

AUNITED STATES PATENT OFFICE.

WALTER H. KNISKERN, OF SYRACU'SE, NEW YORK, ASSIGNOR TO ATMOSPHERIC NITROGEN CORPORATION. OF SYRACUSE, NEW YORK, .A CORPORATION OF NEW YORK.

HEAT Examens.

rangement in which any pressure-diffe' ential between the heat exchanging gases .o .fluids in the apparatus is utilized to maintain the M same in anoperative condition. A further object of the invention is to provide anv improved packing and gland whereby a satisfactory connection between the nest of tubes and the shell containing the same is insured.`

2o Other objects of the invention will from the description hereinafter. y

In the accompanying drawings, which illustrate an example of the invention without defining its limits` Fig. 1 is a sectional 25 elevation of a heat exchanger embodying the invention; Fig. 2 is an enlarged, fragmentary section thereof; Fig. 3 is an enlarged cross-section of one of the tube elements; Fig. 4 is an enlarged detail section of an improved gland and packing arrangement; Fig. 5 is a horizontal section on line 5-5 indicated on Figs. 1 and 6 and Fig. 6 is a fragmentary vertical section on line 6-6 of Fic'. 5.

s shown in the drawings the apparatus may comprise a shell 10 preferably cylindrical in form and of predetermined length suitable for the intended purpose and provided at opposite'ends with removable heads 11 and 12` respectively, secured in place, for instance, by means of bolts 13. Each head is provided with inlet and outlet openings which, in the present case. have been indicated respectively as 14 and 15 in the head 11 and 16 and 17 in the head 12. The shell 10 may be supported in its operative posi tion in any suitable manner as by means of a conventional supporting bracket 18.

Within the shell 10 is located the improved tube nest, which, as shown in Fig. 2, comprises tubes 19, rolled or expanded into or otherwise connected at their opposite ends with tube sheets 20, said sheets being connected with plates 21 by means of bolts 22 and appear held in spaced relation thereto by means of the rings or spacers 23 through which the bolts 22 pass as shown in Fig. 1, the sheets 20, plates 21, and spacers 23 forming units which .may be termed headers. A gas-tightcoiidition is maintained at this point by using a ground joint between the rings 2.3 and the tube sheets 2() and the plates 21. (lore-rods 24 extend lengthwise of the tubes 19 and. are provided at regular spaced intervals with projections 25 extending outwardly from said rods 24 into contact with the interior surfaces of the tubes 19 as shown in Fig. .2; the projections 25 as shown in the drawings may be arranged in pairs lengthwise ofthe rods 24 and preferably so that the projections ofI one pair are out of registry with .the projections of adjacent pairs,f said projections serving to maintain the cores centrally within the tubes 19 and to maintain uniform annular spaces 26 therein for the lpassage of gases or other fluids. By substituting core-rods of' different dimen-v sions, the interchanger may readily be adapted for'diieriiig degrees of heat interchange according to the resultant variation in gas velocity. As shown in 2 some of the core-rods 24 may be supported by resting upon the bottom plate 21 while others of said cores that is, those which lie above the outlet 1 may be suspended from the upper g5 tube sheet 20 in any suitable manner; for instance, the upper ends of the last-mentioned group of core-rods may be flattened as indicated at 24a inFig. 2te provide rigid devices spanning the openings of tubes 19 and having a transverse width materially less than the internal diameter of the tubes whereby the full area for gas passage is, at the same time, maintained. If desired baffle plates 27 and 27a may be located in registry 95 with the openings 14 and 17, respectively.

As shown in Fi 1 a tube 28 is screwthreaded into the ttom plate 21 and depends therefrom into the opening 17 in which suitable packings held in place by suitable devices 29 are located to provide a fluid-tight connection. A similar tube 30 is screwthreaded into the upper plate 21 and extends into the opening 14 of head 11 which is shown as provided at the inner` end of opening 14 with an annular shoulder 14* surrounding the tube 30. The connection between the latter and the head 11 is, however, preferably made by the improved land and packin arrangement shown in etail in Fig. 4 an which comprises a. first ring 31 which surrounds the tube `30 and rests against an annular shoulder 32 formed thereon (or on 14* of 11). A series of s ht packing rin 33 and 34 alternately beve led 1n opposite irections rest against each other and against the bevelled face of the ring 31; a second rin 35 having one of its faces bevelled rest against the terminal packing ring 34 in the resent case, andin turn, is engagled by a and 36 screwed u n the externa ly screwt readed end 37 of t etube 30 (or into 11 if a shoulder thereof is used for ring 31%. All of the rings 33 and 34 are preferab y made of steel and the faces of the rings are cut at an an le as shown so that as pressure is applied t ereto by the` adjustment of the sleeve nut36, alternate rings 33 and 34 will make contact res tively with the tube 30 and with the hea 1'1`and thereby provide a satisfactory connection. This arrangement is independent of the external ange and pipe connection 38 whereby a pipe 39 extending from a source of fluid supply may be connected with the apparatus. t will be understood that similar pipes 39, 39 and 39 constituting inlet and outlet pipes are likewise connected with the apparatus in the well-known way.

In utilizing the heat exchanger a gas or other fluid passes into the apparatus through the inlet 16 and circulates throu h the shell 10 upon the outside of the tu 19 and passes out through the outlet 15 while a gas or other iluidat a different temperature is caused to llow through the pipe 39 and tube 30 and through the annular's aces 26 interiorly -of the tubes 19 and fina ly passes out through the tube 28 and pi 39.

If the heat exchanging uids are at different pressures, the one at the higher pressure is introduced at 16 and the one at the lower ressure at 14, throughlthe pipes 39 and tube 30. This condition often exists and the rcssure differential may be considerable as or exam le where the heat exchanger forms part o a reaction system in which the heat exchan ng fluids are respectively those going to an thosecoming from the reaction vessel or vessels.- B thus passing the gas or other fluid of a A igher pressure outside of the tubes 19 and the gas or other fluid of a lower pressure throu h the tubes2 the tendcncy of anypressure iferential in the ap#` paratusis to press the tube sheets toward the plates 21 which ressure is resistedl by the spacers 23", whic are from one totwo thousandths of an inch shorter than'the ring 23 is thick. The spacers may beof'any suitable ty e and as shownv com rise vmembers rovi ed at one of their en with reduce portions adapted to fit into suitable recesses located for this purpose, on the lmay be duplicated at o plates 21; in order to make the s acera 23 reversible the aforesaid redu portions site ends thereof, as shown m Fig. 1. he bulging of the tube sheets 20 and ofthe plates 21, because of pressures in the apparatus, is thereb resisted and the pressure differentials emselves are utilized to maintain these parta of the a paratus in an emcient condition.

The ow of gases ma obviously be reversed so that 15 and 1 are used as inlets and 16 and 14 as outlets.

The arran ment f core-rods 24 'within the tubes 19 is such that uniform annular s aces 26 are maintained within said tubes -t rough which the gas or other fluid passes For this purpose baille plates 40 extend trans'- versely across the tubes 19 in a manner to divide the spaces therebetween into a sinuous passage as shown in Fig. 1. In the illust-rated example these baille plates 40 are supported by means of sections 41 located 1n registry with each other and extending between the baille plates as shown in Fig. 6; in order to clamp the baille plates 40 in place, angle irons 42 may be riveted to the sections 41 and to alternate baille plates 40 as shown in Fig. 6, the intermediate-plates 40 being clamped between the opposed edges ofcontiguous sections 41. The latter sections 41, as shown in Fig. 5, are spaced from the shell 10 and form spaces 43, said sections preferably following 4the yinterior form of said shell and being referably relatively small in width, as sma as the angle irons 42 willallow. Io prevent the gases from-passing through the s aces 43 between thc sections 41 and thev ell 10 and to force said gases to pass between the tubes and over the surfaces of the baille plates 40,ilanges 44 are provided whereby the spaces 43 are formed into dead spaces and'closed against communication with the sinuous passage defined by the baille plates 40. These flanges 44 may be of any suitable construction and arrangement and in the illustrated example extend between the sections 41 and comprise integral portions of said sections 41 which project from opposite ends thereof. As shown 1n Fig. 5, these flanges 44 sufficiently prevent the gases from finding a ready p along only an etlicient jointbetween the pi e 30 and the head 11, but also forces and olds the packing in position between the shoulder 32 et the tube 30 and the gland 36. Fur` therinore, with the arrangement set f orth and illustrated, the desirable free vmovement of the tube nest within the pressure shell which is necessary to compensate for Atemperature changes in said tube nest is obtained and at the same time the detachable relation between the tube 30 andthe head 1l is maintained throughout the life ot the apparatus so as to permit of the ready disconnection ot the parts when, for any rcason, this is required as the rings 33, 34 neither freeze nor disintegrate: i

'l he materials of construction may be suitably varied in accordance with the temperature and other conditions and the nature of the heat exchanging fluids. For example, tor a nitiogen-liydiogen gas at high pressures and temperatures (used in ammonia synthesis) the rings 83, 34:, the tubes, the tube sheets, the plates, the spacers, the shell and the shell heads are preferably constructed of chrome vanadium steel or other suitable resistant alloy.

Various changes in the 'specific form shown and described may be made within the scope of the claims without departing from the spirit of my invention.

l. ln a heat exchanger, the combination of a vertical casing forming a conduit 4fora fluid, a nest of vertical tubes opening at their upper and lower ends into headers located within said conduit but having no communication with the conduit and arranged to convey a second fluid in heat exchange relation to said first fluid, connections establish'- ing communication between the exterior of the casing and the spaces within the tubes, one of said connections having a port opening into the lower of the two said headers beneath a plurality of said tubes and having a greater diameter than the sum of the diameters of said plurality of tubes, core-rods of substantially even external dimensions extending leiigthwise of said open-ended tubes and defining annular passages therein for said second li-luid, means within said openended tubes extendingr between the outer sur' face of each core-rod and the innei surface ot each tube for centralizing the core-rods in said tubes and for maintaining them in uniform spaced relation to said tubes, and a ,rigid device located exteriorly of the tubes,

at the upper end of each of those core-rods which are located above the aforementioned port, said rigid device s :inning its tube and having a transverse width materially less than the internal diameter of its tube, whereby each of said core-rods is suspended by the device in its open-ended tube without obstructing the accessibility at the points of suspension, of the free spaces within said tubes.'

2. In a. heat exchanger2 the combination of a vertical casing forming a conduit for a fluid, a nest of vertical tubes opening at their up er and lower ends into headers located within said conduit but having no communication with the conduit and arranged to convey a second fluid in heat exchange relation to said irst iuid, connections establishing communication between theexterior of the casing and the spaces within the tubes, one of said connections having a port opening into the lower of the two said headers beneath a plurality of said tubes and having a greater diameter than the sum of the diameters of said plurality of tubes, corerodsoi:l substantially even external dimensions extending lengthwise of said openended tubes and defining annular passages therein for said second fluid, projections extending outwardly from the surface of each core-rod at spaced intervals for centralizing each core-rod in its open-ended tube and for maintaining it in uniform spaced relation thereto, and a rigid projection located exteiiorly of the tubes at the upper end of each of those core-rods which are located above the aforementioned port, each rigid projection spanning its tube and having a transverse width materially less than the in- ,ternal diameter of its tube, whereby each of said core-rods is suspended by its projection in its open-ended tube without obstructing the accessibility, at the points of suspension, of the free spaces within said tubes.

3. In a heat exchanger, the combination of a vertical casing forming a conduit for 'a fluid, a nest of vertical tubes opening at 4their upper and lower ends into headers located within said conduit but having no conimunication with the conduit and arranged to convey a second-fluid in heat exchange relation .to said first iiuid, connections establishing communication between the ,exterior of the casing and the spaces within the tubes, one of said connections having a port opening into the lower of the two said headers beneath a plurality of said tubes and having a greater diameter than the sum of the diaineters of said plurality of tubes` core-rods of substantially even cylindrical dimensions depending into said open-ended tubes to define annular-passages therein for said second fluid, projections extending radially outward from the surface of each core-rod at spaced intervals for centralizing each core-rod in its open-ended tube and for maintaining it in uniform spaced relation thereto, and a flattened rigid projection lccated exteriorly of the tubes, lat the upper end of each of those core-rods which are lo cated above the aforementioned port, each rigid projection spanning its tube and hav'- ing a transverse width materially less than the internal diameter of its tube, whereby each of said core-rods therein is sus ended by its projection in its open-ende tube, without obstructing the accessibility, at the points of suspension, of the free spaces with said tubes.

4. In a heat exchanger, a shell having inlet and outlet openings a tube nest within said shell comprising tube sheets, a lurality of l. tubes having their opposite ends xed in said tube sheets, end plates connected with said tube sheets in fixed spaced relation thereto, upper and lower gas deflecting means asseeiated with said inlet and outlet openings respectively, core-rods extending lengthwise of said tubes to define annularfluid passages therein, some of said rods resting upon one end late to maintain them in position in the tu s free from interference with said upper defiecting means, flattened ends on others of said rods for suspending them in said tubes free from interference with the lower defiecting means and projections located at uniformly spaced intervals on said rods for centralizin them in said tubes and -for maintaining t em ir. spaced relation thereto. i

5. In a heat exchanger, the combination of a shell, a tube nest within said shell comprising a plurality of tubes, tube sheets for their opposite ends, an end plate located at a distance from one of said Atube sheets and connected therewith, meansfoi` fixing said tube sheets and end plate in spaced relation and for sealing the space therebetween to forma fluid-tight gas chamber between said tube sheets and end plate and spacers located at intervals between said tube sheets and end plate for maintaining the same against collapse toward each other by gas pressures effective against them from the outer sides thereof, said spacers` being of such dimensiens as to present no interference to the sealing effect of the said fixing and sealing means. i

6. In a heat exchanger, the combination of a shell, a tube nest within said shell comprising a pluralityi of tubes, tube sheets for their opposite en an end plate located at a distanee from one of said tube sheets and connected therewith, an annular member for fixing said tube sheets and end plate in spaced relation and for sealin the space therebetween to form a fluid-tight gas chamber between said tube sheets and end plate, and spacers located at intervals between said tube sheets and plate and connected with one of said elements for maintaining the same against collapse toward each other by gas pressures operative against them from the outer sides thereof, said spacers being of such' dimension as to prevent no interference to the sealing effect of the said fixing and sealing means.

7. In a heat exchanger, the combination of a. shell, a tube nest within said shell compi'ising tube sheets, a plurality of tubes having their opposite ends arranged in said tube sheets, an end plate spaced from one of said tube sheets and having a plurality of recesses, an annular member located between said tube sheets and end plate to space the same apart and to form a gas chamber therebetween, means for clamping said tube sheets and end plate against said member to seal said chamber and a lurality of spacers located between said tu e sheets and end plate to prevent the collapse thereof toward each other by pressures within said heat exchanger, and havinfr reduced ends fitted into the recesses of said.j end plate, said spacers being of such axial length as to present no interference to the clamping of the end plate gud tube sheets against said annular mein- 8. In a heat exchan er, the combination of a shell, a tube nest within said shell, a plurality of bafile-plates extending transversely across said tubes to divide the spaces therebetween into a sinuous passage, a plurality of sections extending between said ba'lllcplates to support the saine in spaced relation, and flanges extending between the scctions and said shell to provide dead spaces between said sections and said shell and to fotce the gases to pass through said tube ne 9. In a heat exchan er the combination of a shell, a tube nest within said shell, a plurality of baille-plates extending transversely across said tubes to divide the spaces therebetween into a sinuous passage, a plurality of sections extending between said bailleplates 'to support the same in spaced relation, and flanges extending from opposite ends of said sections into engagement with said shell to provide dead spaces between said sections and said shell and to force the gases to ass through said tube nest.

In testimony whereof I have hereunto set my hand.

WALTER H. KNISKERN.

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