US2919903A - Shell-tube heat exchange apparatus for condensate subcooling - Google Patents

Description

Jan. 5, 1960 L. H. VAUTRAIN ET AL SHELL-TUBE HEAT EXCHANGE APPARATUS FOR CONDENSATE SUBCOOLING Filed March 18, 1957 2 Sheets-Sheet 2 lNvENToRs L. H. vAuTRA//v F. H. MoRLfr, JR. BY i( ATTORNEYS United States Patent C,"

SHELL-TUBE HEAT EXCHANGE APPARATUS FOR CONDENSATE SUBCOOLING Lucien H. Vautrain and Fred H. Morley, Jr., Qkmulgee,

Okla., assignors to Phillips Petroleum Company, a corporation of Delaware Applicationv March 18, 1957, Serial No. 646,720

6 Claims. (Cl. 257-32)` Huid' passes throughk the tubes in indirect heat exchange with. Vapor to be condensed, it is sometimes` desired to withdraw condensate from the exchanger at a temperature below the-temperature at which the vapor Was condensed. Byso operating suchan apparatus, as ak condenser andas a, subcoolen, separate pieces of equipment to do these twefservces. are not required. The main object of subcooling`1 fa; condensate is` tovprevent flashing from occurring whemsuch a condensate is passed,y fromthe condensing heat` exchanger at the; heat exchange temperature to a peint, off lower pressure. Condensate formed at a` given temperature and pressure might be considered; approximately in equilibrium with thevapor phase from which itgwasprloduced'. It *isi obvious, then, it the pressure of this condensate is. reduced,` asl at the suction inlet oi atransf fer pump, while the condensate is maintained at approxi mttely its. condensation temperature, flash vaporizing may. occur.

Amainobject oi thisinventionis.to-proyide an apparatusifpr subcooling condensate, in the condenserV in which the. Condensateis produced.

Another. object of this inventionis totprovideta, single apparatus. for condensing` vapor and for subcooling the condensate-.to a. temperature below: the, condensation tem? peratune.

Sutillanother. objectof this. invention is to; providetasingle. apparatus in. which they condensation` and subcooling o'fgthefcondensate-is carried out', the apparatus beinglsubstantially no` more expensive tha-n1 a.. conventional con.- denser..

Still other objects and advantagesof, our.` inventionwill be realizedmpon reading they following. description which, taleirwitlitheI attached drawing, forms .a part,V of,V this disc llosllre-Y Inrthe drawing,

Figure l illustrates in diagrammatic, form, an1 elevational, view, partly, in sectioIL, of oneernbodirnent. of our invention.

Figure 2 isa sectionalview taken along the line 2-2 oflFigure-l;

Figure 3 isanelevational view, partly insection, of an,- otherembodiment ofA our invention.

Y Eigure:4l is asectional'view taken-along theline 4--4 ofiEigure-Si .Applicants have specifically` devised. a condenser for cendensing vapor and subcooling condensate. formed therein comprising, in combination, al horizontally. dis,- posednhell, a bundleofy condenser tubes insaidshell,` said condenser.: havingY a head end. andv a floating-end, an` inlet in thejupper portion of said shell. forf inlet of vapor to becondensed, aconduit disposed aroundnt leaspthe lower lportion of'said shell adjacent one end thereof, an outlet Patented Jan. 5, v1960 for uid in the lower portion of said conduit, a irst passageway at least near said one end of said shell for pas? sage of condensate to said conduit, a baille in said conduit intermediate said outlet for condensate and said passageway, said ba-le extending vertically in said conduit to a level intermediate the bottom and top of said bundle of tubes to maintain a body of condensate in con.- tact with the lower tubes of said bundle, a second passageway within said conduit and over the top level of said balile for overow of condensate from said body of condensate to said outlet for condensate, and an inlet and an outlet for coolant to and from said condenser tubes.

Referring now to the drawing, and specifically to Figures 1 and 2, reference numeral 10 identities a shell. of the'heat exchanger. Reference numeral 11 identifies a disf tributor member 11, one edge of which is attached to the outer surface of the shell 10 at Welds 39 thereby forming an annular passageway or conduit 40 therebetween, The other edge of the annular member 11. is formed as a flange to which a coolant inlet and outlet member 21a is bolted by bolts 36. This coolant inlet and outlet end of the exchanger is herein termed the head end of the exchanger. The adjacent end of the shell 10 is llikewise termed the head end of the shell. The opposite end of the shell, and of the exchanger is termed the floatf ingfendtofvthe. shell, and of the exchanger. AnV inlet 1,2 i sA disposed in` the upper portion of the distributor memhersY 1-15 for inlet ot vapors tobe condensed. Reference numeral 15 identities a cut-outsection inl the upper head end portion offthe shell forIlSsage` o jf vapors from the conduit 40 into the upper tube section 18 of the condenser. A connectionV 13. is providedf in the lower portion of memberl 11a for outlet of condensate from the exchanger. The portion of the shell enclosed within member 11 is herein termed a sleeve and is identied by reference numeral 14. Reference numeral 16 identifies al cut-out portion inthe lower head end portion of the sleeve 14. This cut-out section 16 provides a passage ioroutlet of condensate from the lower tube portion of the condenser to the lower portion of conduit 40. The condenser tubes, as a whole, are herein termed a bundle of. tubes, which terminology is common in the condenser art. This bundle ofcondenser tubes is operatively complete in that it is asesmbled with a floating tube sheet 32 and a head end sheet 41 to support the tubes fluid tight. The, tubes of this` bundle are identified by reference nu-. meral 31; Since the inlet and outlet. to this exchanger are at the, same end a baffle 17 is provided to make certain that fluid to be condensed and condensate travel the full lengths of theupper tube portion 18 and theV lower tube portion 19.

InI the lower portion of the conduit 40 is provided an annular submergence dam 26. This annular submergence dam 26 is composed of two sections, section 26a and section 2612, as shown in Figure 2. One of these sections, for.

example section 26b in Figure 2, extends upward from the condensate outlet 13 to a level at whichit is desired to maintain liquid in the lower tube section 19. The section 26a ofthe annular darn extends up the other side ofthe conduit 40.10 the same level. As illustrated in Figure 2, they annular submergence dam 26 is illustrated as being composedof the two sections for purposesy of installation. Reference numeral 42 identities the line of. juncture of these two sections. At still a higher level inthe conf duit 40 are provided. separate baes 29. These baflles 29 are intended to provide a iluid tight separationfbetween the-upper. portionof conduit 40referred to hereinasthe vapor inlet portion, and the lower, portion of the con: duit, referred toas the liquid or iiuid.outletportion. Reif erence numeralZS identities` the condensate level inthe lower tube portion 19 of the condenser. As mentioned,

this condensate level is intended to be substantially the same level as the upper ends of the submergence dam 26. If it is desired to operate such an apparatus with a higher liquid level in the lower tube section 19, it is merely necessary to construct the apparatus so that the annular submergence dam rises to a higher level in the lower conduit 40. An opening 27 is provided in the bottom of the annular submergence dam 26 for drainage of liquid from the condenser at such a time as it is desired to disconnect a pipe from outlet 13. Cross baiiies 30 are provided in the upper tube portion 13 and lower tube portion 19 so that the vapor being condensed and the condensate follow tortuous paths for eflcient heat exchange.

Reference numeral 33 identities a iioating head cover 33 which covers the open ends of the tube at the oating head end of the exchanger while a shell cover 34 covers the floating end of the condenser and is attached to the shell by bolts 35.

The coolant inlet and outlet at the head end of the condenser, are provided with the coolant inlet and outlet member 21a. A bathe 20 is disposed at about a midpoint of this member to provide separate inlet and outlet coolant sections 22 and 21, respectively. Reference numerals 23 and 24 identify a coolant inlet and a coolant outlet connection to this section.

A drainage plug 38 is provided in case it is desired to drain the liquid from the exchanger Without disassembling the liquid outlet connection 13.

In the operation of the embodiment of our exchanger illustrated in Figures l and 2, coolant enters the apparatus by way of coolant inlet section 22 and ows to the right through the tubes of the lower tube section 19 and enters the tubes of the upper tube section at the oating head end of the exchanger. The coolant leaves the apparatus by way of the coolant outlet section 21.

Vapors to be condensed enter the apparatus through the vapor inlet connection 12 and pass through cut-out section 15 and contact the exterior surfaces of the tubes of this upper tube section 13. The vapors and condensate as produced therefrom follow a tortuous path formed by crossbafiiles 30 on passage through tube section 13. At the tioating head end fluid passes downward beyond the end of the long baie 17 and again follows a tortuous path formed by crossbafliles 30 from the oating head end to the fixed head end of the lower tube section. At the fixed head end of the lower tube section 19 liquid is held at the level indicated by reference numeral 23 by the positioning of the annular submergence dam 26. The condensate at this end of the condenser flows through the cut-out section 16 and over the submergence dam 26 in the lower conduit 40 and thence passes from the exchanger through the liquid outlet 13.

This entire apparatus is so arranged as to provide countercurrent ow and indirect heat exchange with coolant. the condensate in the lower portion of the lower tube section 19 while the coolant, somewhat warmed, passes through the tubes of the upper tube section for condensation of the vapors. ln this manner liquid in the lower tube section 19 is cooled to a temperature below the condensation temperature of the vapors when the coolant enters the system at a temperature below the desired vapor condensation temperature. For example, if it is desired to condense vapors at, for example, a temperature of 100 F. at a pressure of, for example, 40 pounds per square inch gauge, the temperature of the inlet coolant is about 80 F. At the time the coolant issues from the tubes of the lower tube section 19 and enters the tubes of the upper tube section 18 its temperature is very near the desired condensation temperature of 100 F. In this manner condensation is achieved at a desired temperature while the condensate is subcooled. to a temperature below the condensation temper- The coolant of lowest temperature contacts VV'2,919,903 Y ature. Liquid so cooled when transferred by a pump will not dash or form vapor at the inlet of the pump under reduced pressure conditions ordinarily existing at the suction side of the pump.

ln Figure 3, reference numeral 50 identities a shell of a second embodiment of exchanger of our invention. Shell 50 is provided with a distributor member 51 at the vapor inlet end and an outlet member 52 at the oating end of the exchanger. Attached to the distributor member 51 at the upper portion thereof is a vapor inlet connection 53 and a uid outlet 54 is provided in communication with the lower portion of the outlet member 52. This shell is approximately like shell 10 described hereinabove relative to Figures l and 2 and is thus provided with a sleeve 55 at the head end and a sleeve 56 at the oating end. The floating end of the exchanger of Figures 3 and 4 is the condensate and uncondensed vapor outlet end. The main difference between the hereindescribed embodiments of exchanger is that in Fifrure l the vapor inlet and fluid outlet are adjacent the head end of the exchanger while in Figures 3 and 4 the vapor inlet is at the head end and the condensate and Uncondensed vapor outlet is at the floating end. Sleeve 55 is provided with an upper cutaway r section 57 and a lower cutaway section 58 while sleeve 56 is also provided with an upper cutaway section 59 and a lower cutaway section 60. The head end of the exchanger is provided with a coolant inlet and outlet assembly 62. This assembly is provided with a coolant inlet 64 and outlet 65. It also is provided with a pair of bailes 61 for directing ow of coolant 'through tubes 75. A baffle 69 is provided at the floating head end of the exchanger for directing ow of coolant at this point. Fixed tube sheet 63 and oating tube sheet 66 are provided as illustrated. At the oating head end of the exchanger are provided a lioating head cover 67 for assisting in directing flow of coolant in cooperation with the aforementioned oating head bafe 69. Shell cover 68 covers the entire iioating head end of the apparatus.

To maintain a level 78 of condensate in the condenser in order to be subcooled, i.e., cooled to a temperature below the actual condensation temperature, an annular submergence dam 70 is provided in the lower portion of the space 77 between outlet member 52 and the corresponding sleeve 53. This submergence dam 70 is, if desired7 constructed of two portions similar to those described relative to the submergence dam 26 of Figures lland 2. The upper ends of this submergence dam are disposed relatively high in space 77 in order to maintain an appreciable depth of liquid in the condenser for subcooling purposes. Liquid condensate leaves the floating head end of the condenser through cutaway space 61B and around the right-hand end of the sleeve 56 and enters space 77 on the side of submergence dam 70 adjacent the oating end of the condenser. When the level of the condensate reaches the top of the submergence dam 70, liquid overflows and passes from the condenser through fluid outlt 54. Uncondensed vapor, of course, remains in the upper portion of the condenser and is collected in the portion of space 77 not occupied by liquid and under the inuence of throughput pressure Uncondensed vapor issues from the condenser along with liquid through the iiuid outlet 54. A drain hole 71 is provided in the bottom portion of the annular submergence darn 70 for drainage of condensate from the condenser in case it is desired to do maintenance work thereon. A drain plug 74 in the lower portion of each annular member 51 and 52 is alsov provided for drainage purposes.

Crossbaftiles 76 are provided as illustrated in Figures 3 and 4 for forming a tortuous path through which Huid entering the condenser must travel prior to its exit there- .from to make certain that there has been eicient come fast between, vapor to, befccndeused and liquid w11- dasate with. asturies..

It s houlclfv be realized that, in. case local conditions dictate, the4 vapor inlet'could, with a minimum of alteraticu; be. provided at the. iloating andV of the assembly While. the c'ouclensateand uncondensed vapor Outlet and annulai submergence. dam '7,0, could be provided at the 525@ had. lend of the condenser. "However, it is preferredfto.I constllli and operate the condenser in the fQm illustrated in Figures l3 and 4,

One the important advantages of the several embodiments o f our' invention is that full and complete use 1s madeA ofthe entire length of our condenser tubes irsri'th'el enchangers....I That point is important because condenser tubes,v are. very. expensive andv are ordinarily d igued tofmalte, full-use of the tubes,Y and in such cases where fullv use@ of the tnbes `is not achieved, condenser eilsisny, is less than' the desired, efienc'y vllt/laterials.of. construction gan, ingeneral, be selected from amongthose available in commerce, taking into account the,l corrosivo nature of materials being condensed as welllas. the coolant. In case, the exchangers are required to operate under pressure, account should be 'taken to design the condensers to. withstand required pressures.

Stressing. the point mentioned.` above relative to making use ofi the entire heat exchange. surfaces available, it should be pointed out that that is particularly the case in the subcooling in the liquid containing section of the condensers. By placing the submergence dams in the condensate outlet we are able to maintain a body of condensate in the entire tube section of the lower portion of the condensers. If the submergence dams were placed in the shell 50 with the tubes extending through openings in the dams, those portions of the tubes between the submergence dams and the condensate outlet would not be in eilective heat exchange with the condensate and thus condensate subcooling would not be the maximum.

While certain embodiments of the invention have been described for illustrative purposes, the invention obviously is not limited thereto.

We claim:

l. A condenser for condensing vapor and subcooling condensate formed therein comprising, in combination, a horizontally disposed shell, a bundle of condenser tubes in said shell, said condenser having a head end and a iloating end, an inlet in the upper portion of said shell for inlet of vapor to be condensed, an annular conduit disposed circumferentially around at least the lower portion of said shell adjacent one end thereof, an outlet for iluid in the lower portion of said conduit, a first passageway at least near said one end of said shell for passage of condensate to said conduit, an annular baille within and fitting the inner walls of said conduit intermediate said outlet for condensate and said passageway, said baflle extending vertically in said conduit to a level intermediate the levels of the bottom and top of said bundle of tubes to maintain a body of condensate in contact with the entire lengths of the lower tubes of said bundle, a second passageway within said conduit and over the top level of said baille for overflow of condensate from said body of condensate to said outlet for condensate, and an inlet and an outlet for coolant to and from said condenser tubes.

2. A condenser for condensing vapor and subcooling condensate formed therein comprising, in combination, a horizontally disposed shell, a bundle of condenser tubes in said shell, said condenser having a head end and a iloating end, an inlet in the upper portion of said shell near said head end for inlet of vapor to be condensed, an annular conduit disposed circumferentially around at least the lower portion of said shell adjacent one end thereof, an outlet for tluid in the lower portion of said conduit, a lirst passageway at least near said one end of said shell for passage of condensate to said conduit,

:an annular baflle within andfitting the inner walls of said uit intermediate. vsaid outlet for condensate and said passageway, said baille. extending vertically in said conduittoal level intermediate the, levels of the bottom and top ofisaid vbundley oftubes to maintain a body of condensate in contact with the entire lengths of the lower tubes of said bundle, a' second passageway within said conduit andY overI the top level of said baflle for overflow of condensate fromv said body of condensate to said outlet for condensate, and an inlet and an outlet for coolant to andA fromsaid condenser tubes.

' 3, A condenser for condensing vapor `and subcooling condensate formed therein comprising, in combination, ay horizontally disposed shell, a bundle of condenser tubes in said slrell,A said condenser having a head end and afloating. end, an` inlet and an outlet for coolant at said headend ofjsaidcondenser, an inlet in the upper portion of lsaid shell` near` said' head en d for inlet of vapor to be condensed, a horizontal first baille extending from the. head end of said bundle of tubes toward the iloating end dividing said shell into upper and lower sections, an annular, conduit disposed circumferentially around at least the lower portion of said shell adjacent said head en d, an outlet for fluidy in the lower portion of said conduit, a first passageway at least near said head end of.l said condensery for passage of condensate to said conduit,r a vertically disposed annular second baille within and fitting the inner walls of said conduit intermediate said outlet for condensate and said passageway, said second baille extending vertically in said conduit to a level intermediate the level of said first baille and the level of the bottom of said bundle of tubes to maintain a body of condensate in contact with the entire length of the lower tubes of said bundle, a second passageway within said conduit and over the top level of said second baille for overilow of condensate from said body of condensate to said outlet for condensate.

4. A condenser for condensing vapor and subcooling condensate formed therein comprising, in combination, a horizontally disposed shell, a bundle of condenser tubes in said shell, said condenser having a head end and a floating end, an inlet and an outlet for coolant at the head end of said condenser, an inlet in the upper portion of said shell near said head end for inlet of vapor to be condensed, an annular conduit disposed circumferentially around at least the lower portion of said shell adjacent said iloating end, an outlet for iluid in the lower portion of said conduit, a first passageway in the lower portion of said shell at least near said iloating end of said condenser for passage of condensate to said conduit, a vertically disposed annular baille within and iltting thc inner walls of said conduit intermediate said outlet for condensate and said passageway, said baille extending vertically in said conduit to a level approximately midway from the bottom to top of said bundle of tubes to maintain a body of condensate in contact with the entire lengths of the lower tubes of said bundle, and a second passageway within said conduit and over the top level of said baille for overflow of condensate from said body of condensate to said outlet for condensate.

5. A condenser for condensing vapor and subcooling condensate formed therein comprising, in combination, a horizontally disposed shell, a bundle of condenser tubes in said shell, said condenser having a head end and a iloating end, an inlet and an outlet for coolant at said head end, an annular conduit disposed circumferentially around said shell adjacent said head end, rst and second bailles disposed in opposite sides of said conduit separating said conduit into upper and lower portions, an outlet for iluid in the lower portion of said conduit, an inlet for vapor to be condensed in the upper portion of said conduit, a horizontal third baille extending from the head end of said tubes toward the iloating end dividing said shell into upper and lower sections, a ilrst passageway adjacent the head end of said shell for passage of vapor to be condensed from the upper portion of said conduit to the upper section of said shell, a second passageway adjacent the head end of said shell for passage of condensate from the lower section of said shell to said lower portion of said conduit, a vertically disposed annular fourth baffle within and fitting the inner walls of the lower portion of said conduit intermediate said outlet for condensate and said second passageway, said fourth bafe extending vertically in the sides of the lower portion of said conduit to a level intermediate the level of said third baffle and the bottom of said bundle of tubes so as to provide a body of condensate in contact with the entire lengths of the lower tubes of said bundle, a third passage within the lower portion of said conduit intermediate the top level of the fourth bafe in one side of said lower portion of said conduit and the corresponding baffle separating said upper and lower portions of said conduit for overflow of condensate from said body of condensate to said outlet for condensate.

6. A condenser for condensing vapor and subcooling condensate formed therein comprising, in combination, a horizontally disposed shell, a bundle of condenser tubes in said shell, said condenser having a head end and a floating end, an inlet and an outlet for coolant at said head end, a rst annular conduit disposed circumferentially around said shell adjacent said head end, an inlet in the upper portion of said first conduit for inlet of 8 vapor to be condensed, a first passageway in said shell adjacent said head end for passage of vapor from said first conduit into said shell, a second annular conduit disposed circumferentially around said shell adjacent said floating end, an outlet for fluid in the lower portion of said second conduit, a second passageway in the lower portion of said shell adjacent said floating end for passage of condensate to said second conduit, a third passageway in the upper portion of said shell adjacent said floating end of said condenser for passage of uncondensed vapors in said second conduit, a'vertically disposed annular bale within and fitting the inner walls of the lower portion of said second conduit intermediate said outlet for fluid and said second passageway, said bafiie extending vertically in both sides of said second conduit to a level approximately midway from the bottom to the top of said bundle of tubes to maintain a body of condensate in contact with the entire lengths of the lower tubes of said bundle, and said third passageway being at a level above the top level of both sides of said bae.

References Cited in the file of this patent UNITED STATES PATENTS 989,415 Quiggin Apr. 11, 1911 1,353,449 Braun Sept. 2l, 1920 1,509,782 Samuelson Sept. 23, 1924 2,254,189 Reed Aug. 26, 1941 /df//f UNITED STATES PATENT OFFICE CERTIFICATE oF CORRECTION.

2,919,903 January 5 1960 Lucien H,

Patent No Vautrafm1 et. al.

It is hereby certified that error appears in the printed specification tion and that the said Letters of the above numbered patent requiring correo d as corrected below.

Patent should rea Column line BL for ""lengtln" read lengths column 87 line lll for in" read into Signed and sealed this 9th day of August 1960.

(SEAL) Attest:

KARL Ha AXLINE ROBERT C. WATSON Commissioner of Patents Attestng Oiicer

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