US2651508A - Heat exchange apparatus for liquids containing solids - Google Patents

Description

W. M. BREADY Sept. 8, 1953 HEAT EXCHANGE APPARATUS FOR LIQUIDS CONTAINING SOLIDS Filed NOV. 4, 1949 2 Sheets-Sheet 1 r INVENTOR. W/LL/HM M BREHDY m m ,L M

' ATTORNEYS Sept. 8, 1953 w. M. BREADY 2,651,503

HEAT EXCHANGE APPARATUS FOR LIQUIDS CONTAINING SOLIDS Filed Nov. 4 1949 2 Sheets-Sheet 2 ATTORNIEYS Patented Sept. 8, 1953 UNITED "STATES Parent crews HEAT EXCHANGE APPARNDUS FORLXLIQUID'S CONTAINING ESQLIDS lit-his invention relates :to heat exchange safpiparat-us for 'liquids containing 'solids.

I-t isa primaryobject ofithefinveritionito obtain high efilciency of heat transfer notwithstanding that one ofthe liquids involvediin the transfer of heat may :be '"carrying :large :quantities f foreign r-mat'ter, such as would clog any conventional .heat exchanger.

To obtain high ieiiicienc-y of :heat transfer, a high velocity (if fiowzis desirable. The required velocities may be i'achieve'd only if the-passages through which the flow'oceursiaremf restricted capacity in proportion to :the amount or liquid handled. The present invention :provides a heat "exchange :apparatus in which,

throughout the various sections hi the app aratus, iiiowo'ccurs-at high velocity through parallel tubes of small cross section,t-.stoppages being precluded by the uniformity of such cross'section sand the "absence "of any shoulders against which foreign matterfmaylodge. Itisia'veryiimpmtantrfeature :of the apparatus disclosed that where the liquid is admitted and divided Eto pass through ft'he multipletubes "of heat exchanger section's,rmeans is provided for backwash :so that angy raccumul'ations of solids at this point can be discharged Containing Solids.

The foregoing and other :objects of :the invention will he more app arent ffromthe follow-ing disclosure thereof with reference :to the accompanying drawings, wherein:

Fig. 1 is a view in side elevation ahd part'iaily in section showing apparatus embodying the mvvention.

Fig. 2 is a detail View in enlarged axial section through one of the-heat exchanger in'iets.

"Fig. 3 is a fragmentary detail view taken in section through a portion of the heat exchanger.

Fig. 4 is a detail view in perspective of one 'of the connectors between heat exchanger section's.

Fig. 5.is a fragmentary.sideelevationof air'nodifled embodiment of the heat exchanger arranged for automatic 'backwashing.

Fig. 6 is a view .in end elevation of thexiev ice shown in Fig. 5. s

Fig. 7 is an enlarged detail view siront eelevation of the backwash control valve and its 10peratin'g mechanism. I

. Fig. 18 :is a :further enlargedidetail viewii-n'transworse section through the control valve.

l l dla ims. (Cl. 2 57- 2 97") .Fi-g. :9 isra view .in side elevation-showing a further modified for-m of the heat exchanger.

iFig. I0: is a :diagrammaticvi-ew in side elevation showing-the:connections'of my improved heat-exichan'ger. for special fuses.

For ;purposes of :exemplification, the device is illustrated ior'laundry :use, where the hot waste water, entering -the-heat exchanger at approximatelytlfiotigives lofi its heat :to clear water eniterin rthe exchangertat iobF, The-waste water temperature at the point of discharge has been a'educedlfrom '1-60-*F.-:to .-E.-,rand the fresh water temperature has been increased from 40 F. to appiroximately .The installation of such z-awdev-ice in a laundry seduces afiuel costs approximately :a "third and makes about the same mercentage increase in available iboi-ler capacity. However, in a laundry, the waste water :is extremely :difiicult to "handle without stoppages, sincelit-contains not only such ."forei-gn material :as buttons and the like which 603111 Eb'E ==elimmated by s'scr'eens, but also a large .aamount of such iforeign material as lint which grasses rthroug h the screens in-to the :heat e'xch-anger.

ZIn 217118 mstallationsshown, the usual sum-p 1D :is .provideii ibe'low zthe :l'evel of the laundry floor I l .a'finto'thisz-sump, through the :pipe :12, is led-all of the Waste water from the washing machines. QSuc'h "water zusual ly enters through the :-'aperture 1:3 :inte 2a memovableascreen receptacle is which 171 81383111 of the :ioreign matter. The remaining water, with iconsiderable ilint, issues through ith'e stop iscreening wall 15 of receptacle i4 and is ipicke'd sup sbyzone o'f the rlntakepi es 1 6 leading to the motor driven :puinp 1H.

Hhelpump outlet Lpipe x i-*8 is desirably equipped "withtapressuresgaugei! 9 zanclfthermometer 2t. vIt :iis 'coupled'through "valves 12:1 and 212 to the .re- :spective terminals 23, :24 ref :a :h'eat exchanger zwhich-icomprises any desired ."number or jacket ii-pee 7.2 5., is, n21, 22:9, 311, through which the ll-lot waste water ipa sses Fin parallel :copper tubes 3|, such as those shownz-i "Fig. =2.

Each Jacket ifie Z6 desirably ihas "a terminal ii'an ge '32 at feachzofcitssen'ds. "Itheiianges may conveniently be welded to the pipes. 1A iclos-ure id 1; ip'refiera'bly registering with the flange 32 and 3111 ."face contact therewith, sup'ports the ends :of theftu'bes 31., 'b'ei ng Fproviided twith apertures 3111 which the irrespective :tu'bes fare fixed. each tube extends ire'ctilinearly through the gasket nine 26 in s p ate'd relation to the pipe and to the other tubes. best shown in in s.

its 2 and '3; the tube tends :mav project slightly 3 beyond the outer face of the closure disk 33 wherein they are mounted.

Co-acting with closure disk 33 is another flange or disk. Fig. 2 shows at 34 a terminal flange on fitting 23. In each of the intermediate couplings, as shown in Fig. 3, there is a disk at 35 which supports a series of elbowed tubes 36 in registry with the ends of tubes 31, the corresponding ends of tubes 36 being preferably slightly countersunk in the supporting disk 35 so that,

when the disks 33 and 35 are assembled, the

ends of the respective straight and elbowed tubes will be in substantial abuttingcontact. In each case, an annular series of bolts 31 passes through registering openings in the flanges and disks to maintain them in assembly. Connections between the heat exchange tubes of the various heat exchanger sections are made in like manner.

Heat exchanger jacket pipe 25 and heat exchanger jacket pipe 30 are respectively provided with external connections at 3B and 39. At the end opposite the external connection 38, jacket pipe 25 has a coupling 49 which connects it with jacket pipe 26. At the opposite end of jacket pipe 26, a coupling 41 connects jacket pipe 26 with jacket pipe 21. Similarly, there is a connection at 42 between jacket pipes 21 and 28, a coupling at 43 between jacket pipe 28 and jacket pipe 29, and a coupling at 44 between jacket pipe 29 and jacket pipe 30, the latter being at the end or jacket pipe 36 remote from its external pipe connection 39.

Between the valve 2| and the fitting 23 there is a pipe connection through valve 45 to an outlet pipe 46 which leads to a waste pipe 41. The outlet pipe 46 may be provided with a thermometer at 48, and it has a connection through valve 49 with the heat exchanger fitting 24.

With valves 22 and 45 closed, water pumped from the sump ill will pass upwardly through valve 21 and fitting 23 into the heat exchanger tubes 31 in the first heat exchanger jacket pipe 25. Thence, it will flow in parallel through such tubes and through the corresponding elbowed tubes and the heat exchanger tubes of successive sections of the heat exchanger until it issues through fitting 24 and valve 49 to pass to waste through pipe 46 and waste pipe 41.

It will be observed that the means of assembly as herein disclosed conveniently provides readily assembled and disassembled butt connections between the successive tubes traversed throughout the heat exchanger system so that there are no pockets or exposed raw edges upon which lint carried by the water might catch and build up. Each sequence of tubes is interiorly smooth and of continuously constant cross section. The individual tubes being small in diameter, the liquid is forced to travel through the system at high velocities, scouring the interior tube walls and thereby assuring heat transfer with high efficiency through the tube walls into the liquid contained in the jackets.

In the meantime, fresh water to supply the r laundry washing machines is entering through the external pipe connection at 39 and passing in counterflow to the waste water through the series of jackets from jacket 30 to jacket 25, passing through pipe 38 to the point of use.

In such a system, the only place where stoppages may develop due to the deposit of lint or other foreign matter is at the point where the fitting 23 provides communication between the relatively large cross sectional supply line and the parallel and small diametered tubes of the heat exchanger. To preclude the development of stoppages in fitting 23, the control valves are periodically reversed to backwash this fitting, the valves 22 and 45 being opened, and valves 2| and 49 closed. This immediately discharges through valve 45 to the sewer any lint which may have accumulated against the disk 33. Since very little time is required for backwashing, and since it is less desirable to have concurrent flow through the heat exchanger than to have counter-flow therethrough, the valves will ordinarily be left only briefly in the backwashing position and will thereupon be re-set to their original positions for counterflow. Obviously, the valves may be left in positions for concurrent flow if desired or, if it be desired that the fresh water enter at the top through pipe 38 and issue from the bottom through pipe 39, counter-flow may be achieved by simply setting the valves in a reverse position from that originally described, valves 22 and being open, and valves 2! and 49 closed during the period of normal operation.

It is also possible to re-arrange the tubes within the jackets so that a given set of tubes will extend forth and back with integral elbows as shown in Fig. 9. In this construction, the jacket pipes 50, 5! and 52 may be made exactly as above described, being provided with the terminal flanges 32 already mentioned. The header disk 53, however, is provided with elbowed tubes 54 which curve upwardly and elbowed tubes 55 which curve downwardly. The tubes within jacket 58 with which elbowed tubes 54 connect are extended through the jacket to elbowed tubes 58 mounted on header disk 51 and communicating with those tubes in jacket with which elbowed tubes connect. Thus, assuming there are six tubes within the jacket, three of these would be connected in series to three others, so that there would be three lines of tubes extending forth and back through any given jacket, similar connections being made to the other jackets in the series.

Instead of making the valve control manual, as above described in connection with Fig. l, the control may be automatic as suggested in Figs. 5, 6, 7 and 8. Figs. 5 and 6 also suggest a somewhat different arrangement of the heat exchanger sections, which is more compact in a vertical direction and which facilitates the application of the four-way valve disclosed in Figs. 5 to 8. It will, however, be understood that these features are separate and not interdependent, either the compact arrangement of the heat exchanger sections or the automatic control being independently usable without the other.

In the arrangement of Figs. 5 to 8, the heat exchanger sections 25, 26, 21, 28, 29 and 39 may be assumed to be identical in every way with those shown in Fig. 1 except that they are arranged in two tiers of three each instead of a single tier of six sections, the connection between sections 21 and 28 being horizontal. The fittings 239 and 249, corresponding to fittings 23 and 24 of Fig. 1, may comprise elbows communieating with passages 66, 61 at the sides of a fourway valve casing 68. Other passages 69 and 18 of such casing lead respectively to the pump line and the waste line 460, these corresponding respectively to pipes 16 and 46 of Fig. 1.

Within the valve casing 68 there is rotatably mounted a valve plug 15 having a pair of ninetydegree ducts 16 and 11 designed, as shown in ass-mos Fig. 8, to provide communication between pairs of'ports which are angularly proximate. As illustrated, the passage 76-- provides communication between ports 66 and 69; while the passage H simultaneouslyprov-ides communication between the ports 67 and 10. A ninety-degree rotation of the plug 15' will place ports '67 and 69' in communication with each other and will simultaneously place ports 66 and in communication with each other. The stem of the rotary valve plug projects at 1-8 and carries a segmental gear 19 meshing with reciprocable rack 8t; This rack is attached to a piston 81 movable in an air cylinder 32 with which air tubes 83, 84' communicate. These tubes, in; turn, are operated by a four-way valve 85 similar in construction to that already described, and having air supply connections at 86' and an air exhaust at 81. This valve has a control lever 88 operated in one direction "by spring 89 and in the other by solenoid 9,0 energized from time to time by a time switch 91. The spring normally holds valve '85 in a position to apply air below piston 81 to hold valve plug '15 in the position shown, wherein waste water flows from pipe 180 through passage 16 and port 66 to heat exchanger section 25 and is discharged from section 30 through passage 1"! to waste pipe 460.

The described arrangement is merely a convenient means of using electrical controls and pneumatic power supply from time to time to actuate the rotary valve plug 15 for reversing flow to backwash the coupling 230 by delivering water from the pump through pipe I80 and passage IE to port 61, whereby the waste water first enters heat exchanger section 13B and passes thence through the other sections to section 25, from which the water issues through valve plug passage 11 to port 70. and drainpipe 460. As already described, this backwashing arrangement will ordinarily continue for only a relativelysmall proportion of the time, the waste water being directed through the heat exchanger for'the greater proportion of the time in counter-flow to the direction in which the newly arrived water is passing through the jackets.

Fig. 1.0 diagrammatically illustrates a specialized application of a heat exchan er embodying this invention to distillery practice. Although the heat exchanger is greatly simplified in the diagrammatic showing, it will be understood to incorporate the continuous mult'i-tube now as above described to promote .a high coefiicient of heat transfer. In distillery practice, the heat exchanger is used primarily for cooling the mash and, incidentally, for mixing the proper amount of .slop with mash to get an approximate 80-20 mixture (eighty per-cent mash, twenty per-cent .slop). The disclosure exemplifies'how the efficient. heat transfer achieved by reason of multitube flow is used for cooling just as effectively as for heating, and it works with highly viscous semi-liquids, such as mash.

In distillery practice, the required cooling of a given quantity of slop has been accomplished in one and one-half hours through the use of this heat exchanger at 25-40 pounds pumping pressure, as compared with four and one-half hours required for the cooling of the same amount of material at 120-150 pounds pumping pressure according to previously existing practices. The reduction in the required cooling period isaccomplished with only fifty per-cent of the volume of cooling water at forty per-cent of-the previous -flow rate. At the same time, the yield of alcohol from grain was increased because of the coolin efilciency and because the disclosed arrangement is more readily maintained sterile, and pockets wherein secondary fermentation has previously occurred are eliminated through the use of this apparatus.

There are many other advantages. such as the provision of a supply .of topping .oifwater'to complete the volume, fill of the termentation tanks; the facility of steam sterilization; and adaptability for positive mechanical controls.

in such a distillery installation, the jackets. S2 and 93 are typical of any desired number of exchange sections, the tubes 94 and 95 being in continuous connection through the respectiv jackets in multiatube or parallel arrangement a already described. The incoming mash is 511119- plied through a pipe Q5 and subdivided at a header connection to enter the tubes of jackets 93. The mash may have, for example. a temperature of 146 F. The incoming slop is supplied through pipe 98. connected by header 980 to the. parallel tubesof jackets .92.

it is common practice to :innoculate the incoming mash with approximately twenty per-cent by volume of slop, but. the slop .must first be reduced to an appropriate temperature. By Way of example, the .slop may be assumed to enter through pipe 98 at 190 F. and to leave the m lt ple tubes :94 of jackets 9.2 through pipe 919 at a temperature of 110 FL. having been o ed by water supplied through pipe I00, valve lot, and pipe I02 at an assumed temperature of 6.0. The unneeded slop is discharged to waste through pipe i103, and the valve I04 is used to regulat the admission to the mash line 9.6 of the desired proportion of innoculating slop through the cross connection 105.. If somewhat less cooling of the slop is desired prior to inoculation, water at a t mperat r of approximat ly 100 may be su plied through pipe 102 to the jackets .92., by clos ing valve llll and adjusting valve L06 to use water which has already passed through Jackets 93. The cooling water for jackets 93 is taken from pipe 10.0 subject to the control of valve It! through pipe 108, and it issues from the serial- 1y connected jackets 9.3 through pipe I09 to valve 106, whereby it may be passed to the drain pipe H0 or to pipe I02, as is desired.

The mash entering at the assumed temperature of 146 F. through pipe 96 is, somewhat. reduced in temperature by dilution with F. slop as above described. In passing through the multitubes 95 of jackets 93, it is further cooled by the water of such jackets and leaves the heat exchanger through pipe H2 at a temperature of 66 F. to 68 F. enroute to, the fermenters.

Cooling water used in the heat exchanger passes to the drain or to points of further use through pipe H0, above described, or through pipe H3, which is the discharge pipe from serially connected jackets 92.

Where it is desired to flush the multiple tubes of the heat exchanger parts with cold water, this may be done through the cross connection provided at H4, from the water supply line 100 to the slop inlet line 98, the cross connection being controlled by valve I 15. The flushing water will be discharged either at 103 or 116, according to the setting of valves I04 and H1 respectively.

It will be understood that the foregoing is merely illustrative of a practical application of the invention to distillery usage, and that among the many other installations for which this type of 'heat exchanger is adapted are textile breweries, and the like.

It will further be obvious that any desired water and steam connections and thermometers, gauges, rate-of-flow controllers, meters and so forth can be added to the organizations disclosed.

What is claimed is:

1. In a heat exchanger, the combination with a plurality of jacket pipes closed at their ends and having lateral connections in series, of a plurality of tubes extending in parallel through each such jacket pipe and opening through said ends and provided externally of such pipes with tube-to-tube connections of substantially uniform cross section with the respective tubes, end jacket pipes in said series having end plates providing terminal mountings for the tubes within said pipes, and manifold fittings to said tubes externally of said jackets, said manifold fittings constituting the only substantial change in cross section of the passages formed by said tubes throughout the heat exchanger, supply and waste pipes having cross connections with said manifold fittings and connected therethrough with said tubes, and valves controlling said connections for placing either of said manifold fittings in direct communication with the supply pipe and either of said manifold fittings in direct communication with the waste pipe whereby fiow through said tubes may be reversed to back wash the manifold fittings of the end jacket pipes.

2. The combination set forth in claim 1 in which the respective jacket pipe ends comprise plates in which ends of said tubes are positioned, said plates constituting closures for the respective pipes, the connection between the tubes comprising complementary plates and elbowed tubes having their ends mounted in the respective complementary plates, the said complementary plates being connected to the plates first mentioned in positions to register the ends of the elbowed tubes with the tube ends mounted in the plates first mills,

mentioned.

3. The combination set forth in claim 2 in which certain of said tube ends project from their respective Plates and certain of said tube ends are countersunk in their respective plates in positions complementary to the said projecting tube ends to assist in maintaining the plates in registration and the tube ends in abutment.

4. A heat exchanger comprising a series of jacket pipes connected sequentially and provided internally with parallel tubes, fittings at the ends of the pipes constituting closures therefor and having the ends of the tubes mounted therein, complementary fittings connected with each of the fittings first mentioned, elbowed tubes at the ends of the respective pipes mounted in the complementary fittings and connecting certain of the tubes in the respective pipes with other tubes therein for flow forth and back through the tubes of the respective pipes, and other elbowed tubes at the opposite ends of the respective pipes connecting the ends of certain tubes of each pipe with the ends of certain tubes of another pipe whereby the tubes of the several pipes are connected in series.

5. In a device of the character described, the combination with a supply pipe and a waste pipe, of a heat exchanger comprising a series of jacket means, closures at the terminal ends of the terminal jackets, tube means extending in substantially uniform cross section throughout the series of jacket means to the closures, manifold fittings connected to the respective closures, and valve controlled connections from each of said fittings to the supply pipe and the waste pipe whereby flow through said tubes and fittings is reversible, said jacket means having supply and delivery connections.

6. The device of claim 5 in which the valves controlling said connections are manually operable.

7. In a device of the character described, the combination with a supply pipe and a waste pipe, of a heat exchanger comprising jacket means, closures at the ends thereof, tube means extending in substantially uniform cross section through the jacket means to the closures, fittings connected to the respective closures, and valve controlled connections from each of said fittings to the supply pipe and the waste pipe whereby fiow through said tubes and fitting is reversible, said jacket means having supply and delivery connections, the valves controlling said connections comprising time-controlled means including fluid pressure means interconnected with said timecontrolled means for reversing flow through said fittings and tubes at predetermined intervals.

8. A device of the character described comprising the combination with jacket means provided with terminal closures and a plurality of parallel tubes of substantially uniform diameter providing continuous parallel communication through the jacket means between the closures, inlet and outlet connections for the jacket means, fittings connected with said jacket means and having communication through said closures with said tubes, supply and waste pipes having cross connections with the respective fittings and connected therethrough with said tubes, and valves controlling said connections for placing either of said fittings in direct communication with the supply pipe and either of said fittings in direct communication with the waste pipe, said valves being manually operable.

9. A device of the character described comprising the combinationwith jacket means provided with terminal closures and a plurality of parallel tubes of substantially uniform diameter providing continuous parallel communication through the jacket means between the closures, inlet and outlet connections for the jacket means, fittings connected with said jacket means and having communication through said closures with said tubes, supply and waste pipes having cross'connections with the respective fittings and connected therethrough with said tubes, and valves controlling said connections for placing either of said fittings in direct communication with the supply pipe and either of said fittings in direct communication with the waste pipe, said valves comprising a power operator, and a time-switch having means interconnected with said power operator for the intermittent actuation of said operator in predetermined sequence to backwash said tubes and fittings.

10. The device of claim 9 in which said valves comprise a single rotatable plug having a-plurality of passages therethrough and a casing hav ing two inlets and two outlets with which said passages are alternately registrable in the rotation of said plug.

11. The combination with a heat exchanger comprising a plurality of jackets having inlets and outlets sequentially connected, of closures connected with the respective jackets, tubes having their ends mounted in said closures and extending in parallel through the respective 9 jackets, fittings communicating with said tubes at closures at the ends of the series of jackets, complementary fittings abutting the closures at the intermediate ends of the sequentially connected jackets and provided with elbowed tubes affording communication between the tubes of the jackets to which said complementary fittings are applied, the said tubes and elbowed tubes providing parallel conduits of substantially uniform cross section throughout the series of sequentially connected jackets, a supply pipe, a waste pipe, and a connection from each of said first mentioned fittings to each of said pipes, the said connections being valve controlled, the valve controlling said connections comprising a rotary plug valve having a pair of angularly offset passages and ports at substantially equal angular spacing and connected respectively with the supply pipe and one of said first mentioned fittings and the waste pipe and the other of said first mentioned fittings, in further combination with time-controlled switch, solenoid means and power operator interconnected with said solenoid means for the periodic oscillation of said valve plug for connecting the supply and waste pipes respectively with different fittings first mentioned, the periods being such that circulation through said tubes is largely in one direction with occasional reverse in direction whereby to back wash said fittings while maintaining circulation primarily in said one direction.

12. The device of claim 11 in which the several jackets are arranged in parallel tiers, the jackets at corresponding ends of the respective tiers being cross connected, and the tubes of such jackets being cross connected, the said valve being disposed between said tiers.

13. A heat exchanger installation in a laundry or the like having a hot water sump, a drain, a cold water supply line, and a cold water delivery line, such installation comprising a set of jackets connected in series and communicating with said supply and delivery lines to provide a continuous conduit therebetween, parallel tubes in the respective jackets connected in series with each other and providing smooth-walled conduits of substantially uniform cross section from one end of said series of jackets to the other, manifold fittings communicating with the parallel tubes at each end of said series, and means providing valve controlled communication between each fitting and the sump and drain respectively, the valves controlling communication through said last mentioned means being operable to control flow from said sump to either of said fittings and thence through said tubes and the other of said fittings to the drain.

14. The device of claim 13 in which the several jackets are disposed with the first and last jacket in immediate proximity to each other, said valve controlled communication means comprising a four-way valve having ports communicating with the respective fittings and the drain and sump, said valve being disposed intermediate said first and last jacket.

WILLIAM M. BREADY.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 390,960 Gustin Oct. 9, 1888 779,889 Todd Jan. 10, 1905 894,141 Herman July 21, 1908 1,856,072 Gordon May 3, 1932 1,864,879 Youker June 28, 1932 2,099,493 Mahoney Nov. 16, 1937 FOREIGN PATENTS Number Country Date 199,210 G at Brit n ne 1923

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