US2879749A - Hot water system - Google Patents

Description

March 31, 1959. v I EWY 2,879,749

' HOT WATER SYSTEM Filed April 24, 195'? 2 Sheets-Sh ee t i l 1 N 1 1 I E 1w Q a a Q I lg l 351g 57' 4 U i N' 5 I x:

INVENTOR.

H Tromvtys' March 31, 1959 D. LEWY HOT WATER SYSTEM 2 Sheets-Sheet 2 Filed April 24, 1957 wrulaila INVENTOR. flaw/1. 443w? A TTGRNEYS United States Patent O HOT WATER SYSTEM Daniel Lewy, Chicago, Ill., assignor to The Patterson- Kelly Co., Inc., East Stroudsburg, Pa.

Application April 24, 1957, Serial No. 654,694

3 Claims. (Cl. 122-32) This invention relates to storage water heaters, and more particularly to an improved packaged water storage tank and heater device adapted to be installed with improved facility in an institution having available a supply of steam for heating water, such as for example in connection with equipment used in a commercial laundry. The invention is particularly applicable to advantage where the demand for hot water is sudden and erratic and disproportional to the normal operational requirements.

Thus, one of the objects of the invention is to provide an improved device as aforesaid which will provide the required quick large volume hot water supplies without use of a corresponding boiler steaming capacity, thereby avoiding need for exorbitant boiler capacities and/or excessive steam pressure drops adversely affecting operation of other equipment served by the same boiler.

Another object of the invention is to provide an improved water storage and heater device as aforesaid which is adapted to receive both live steam from a suitable standby source and waste steam and hot condensate from associated steam-operated equipment or the like; for automatically maintaining the storage water at the desired temperature while drawing upon the live steam source only as needed in addition to the waste steam and condensate, to maintain the supply water at the specified temperature.

Other objects and advantages will appear in the specification hereinafter.

Generally stated, the invention contemplates a method of heating water at a constant rate and at a uniform temperature and storing it in an accumulator tank; thus having it available to supply sudden demands in large quantities intermittently over short periods of time. The system consists of a heater-condenser unit, a pump, a control valve, and an automatic steam valve; all of which control the rate of heating of the water before it enters the accumulator tank proper. The heater portion takes just enough steam so that the water always enters the accumulator tank at the same temperature. The condenser or preheater portion absorbs the heat from the flash returns of the various steam heated machines in the plant, exhaust from any auxiliaries, and available trap returns. It also receives the flash and condensate from the trap of the live steam heater portion of the unit. This condenser portion is arranged to deliver the condensate to the boiler return system. In this way there can be no losses due to leaky traps because whatever additional heating elfect is obtained from such leaks reduces the amount of live steam that will be allowed through the. automatic steam control valve. Furthermore, since the condenser is vented to theatmosphere, no trap in the entire plant has to discharge against any back pressure thereby allowing them to free all machines quickly and effectively of all condensate. This makes it possible for them to perform at maximum efiiciency.

2,879,74tl Patented Mar. 31 1959 The pump takes the cold water from the bottom of the tank and pushes it through the condenser-heater, and into the top of the accumulator tank. Thepump is selected to have broad water delivery characteristics, and the valve is used to adjust the rate of flow of water through the heat exchangers. This is an important part of the system.

The invention may be practiced for example in combination with a storage water tank of any suitable shape with suitable outlet for delivery of hot water to the water-consuming equipment, such as for example in connection with the laundry industry or the like. A tube bundle type heat exchange unit extends into the tank in the upper level thereof and is sheathed bya casing enclosing the tube bundle except at one end thereof. The tube bundle comprises banks of horizontally return-bent tubes arranged in vertically stacked but spaced relation; the vertical stack of tubes being divided into upper and lower banks each having right and left hand terminals fitted to a tube sheet (Figs. 1, 3, 4). A fluid flow pattern control manifold is associated with the tube sheet to separate the flows of the upper and lower tube banks, and to separate the flows entering and leaving the tubes at the opposite right and left hand portions of the tube sheet, as illustrated in Figs. 2 and 4. The tank is also arranged to be supplied with fresh or cold make-up water as occasion demands.

The tube bundle is substantially enclosed within an elongate housingjoined at one of its ends to the tube sheet and manifold and being open at its other end interiorly of the tank. A water circulator pump draws Water from the lower section of the tank and delivers it to one end of the casing through which it travels in heat exchange relation around the tubes prior to discharge from the open end of the casing into the upper section of the tank. It then circulates down and around into the circulator pump and up into the heat exchange unit again except as the heated water may from time to time be drawn from the tank through the hot water outlet. The lower bank of tubes is arranged to be fed with waste steam or hot condensate delivered from associated steam operated equipment, and to deliver the liquid condensate therefrom to the associated steam generating boiler' water supply system, or for other disposal as may be preferred. The top bank of tubes is arranged to receive and circulate the supply of live steam from the associated steam generator equipment, according to requirements for additional heat energy to maintain the hot water supply delivery at the prescribed temperature; the condensate exiting from the live steam tube bank being then redirected through the lower tube bank for further heat extraction purposes, and ultimately issuing from the manifold with the previously mentioned condensate for delivery to the associated steam generator water supply system.

Thus, because the system provides for return of' all of the condensate to the steam generating boiler,'practically no boiler water make-up is required, thereby'minimizing boiler scaling and maintenance problems. Furthermore, the constant circulation of the stored water in the tank as explained hereinabove, provides minimum and uniform steam demand, thereby avoiding peak demands for live steam from the generating system such as would otherwise rob other steam heated equipment connected to the boiler in a system wherein the boiler capacity would otherwise be adequate. Still further, the device of the present invention increases the heating efficiency of the overall system. p

The device may be readily constructed in package form, fully self-contained and requiring minimum floor space, and is suitable for installation in any out-of-way 1 thereby improving'its'= e'flicienc'y and life span. The above and other objects of the'apparatus of the invention will be apparent from detailed descriptions of exemplary embodiments of the invention in storage water heater units as illustrated in the accompanying drawings wherein:

Fig. l is a' longitudinal sectional view through a water storage heater of the invention; 7

Fig. 2 is an end elevational view thereof; Fig. 3 is. a fragmentary horizontal sectional view taken along line III-III of Fig. l, and showing a portion of the connecting piping in planview;

I Fig. 4. is" a section',,on"an enlarged scale, taken along line IV-IV'of Fig. l; and a Fig..5. is a section, onan enlargedscale, taken along IIineV-V ofFig.1 i i As illustrated in Figs. the .water storage supply tank is illustrated at 10 as 1 5 of the drawing herewith,

.being generally of cylindrical form and supported to lie horizontally as upon spaced standards 12-12; but it is to be understood that'the tank may in lieu thereof be provided of any other preferred shape or form and may stand in upright attitude and be otherwise supported in any other manner if preferred. In any case, the tank 10 will include generally acold water supply conduit connection as indicated at 14 and a heated water outlet con nection as indicated at 15. A manhole and detachable cover therefor is indicated at'16 will also be provided as is customary in the art to provide access to the interior of the tank for maintenance and cleaning purposes and the like. i

The heat exchange device of the present invention is illustrated in the drawings herewith as comprising an elongated casing 20, which is welded at its forward end to the throat portion 22 of a flanged opening 24 formed in the front end of the tank 10. A tube sheet 25 into which are mounted the terminal ends of a lower bank of reverse bent tubes 26 as well. as the terminal ends of an upper bank of reverse bent tubes 28, is provided for attachmentto the flanged tank opening; the left and right hand ends of the tubes 26 being designated in Fig. 4 at 30-31 respectively, while the corresponding left andright hand ends of the tubes .28 are illustrated at 32-33 in Fig. 4. Baflle plates 34-36 (Fig. 1) disposed vertically and alternately. occupying upper and lower portions of the, casing 20, function simultaneously ,as vertical supports for the tubes 26-28 and as liquid passageway guide devices so ,as to cause the water circulating through the casing .to pursue a zig-zag path throughthe casing and around theheat exchange tubes 2 6'28, .as indicated by the directional arrows in Fig.

-. The baflles. 34-36 also control the velocity of the circulating water.

A manifold cover or bonnet as indicated at 40 bolts to the outer face of the tube sheet 25, and is provided with an internal horizontal partition rib 42 and a vertical partition rib 44. The ribs 42-44 are dimensioned to bear firmly against the tube sheet when the unit is in assembly so as to thereby internally divide the end face of the tube sheet and the fluid chamber portion thereof into four quadrants, as shown for. example in Fig. 4. Gaskets as indicated at 46 operate to fluid-seal the tube sheet to the tank flange 27 and the tube sheet to the manifold 40, when the parts, are bolted together as indicated at. 48. Thus, it will be appreciated that the tubes 26, 28 may be initially assembled upon the tube'sheet 25, and that this sub-assembly may then be slip-fitted finto'the throatportion 22 of the tank 10 and into the casing 20, and tube sheet and manifold assembly may then be firmly bolted to the tank flange 27 to complete the'mounting of the heat exchange unitin the tank.

portions thereof, as will be explained more fully hereinafter; while a water inlet connection into the interior of the casing 20 at its forward end is effected by means of an inlet connection through the throat 22, as indi cated at 50 (Fig. 1). Thus, a water circulating pump as indicated at 52 may then be mounted on the front end of the tank 10 adjacent its lower portion, and its inlet port connected as indicated at 54 to the interior of the tank 10 while its outlet port is connected as indicated at 56 to a conduit 58-1eading to the inlet port 50 of the casing 20. Thus, it will be appreciated the circulation caused by the pump 52 will draw water from the interior of the tank 10 and will force it upwardly through the conduit 58 and thenceinto the front end of the casing 20 wherefrom it will proceed rearwardly in a vertically zig-zag path as indicated by the directional arrows. When the water emerges from the rear end of the casing 20 it circulates eitherupwardly into the hot water outlet conduit 15 -or-downwardly into the "pump 52 again; depending upon whether the conduit 15 is at the moment open and drawing water from the tank end. In any case, it will be appreciated that the presence of the-bafiles 34-36 interiorly of the casing 20 will cause the water supply within the tank to be circulated in intimate heat exchange relation with the tubes 26-28.

As shown in'Figs. l-2, the heat exchange component of the device of the invention is arranged to be primarily energized by means of a waste steam and hot condensate conduit connection as indicated at 60 which communicates with the lower right hand quadrant portion of the manifold cover 40. Hence, waste steam and hot condensate delivered thereto from associated steam using equipment, such as in a commercial laundry or the like, will be permitted to circulate into the ends 31 of the tubes 26 and thence lengthwise-of the heat exchange casing 20 and then through the return portions of the tubes through their tube sheet connections 30 at the lower left quadrant portion of the manifold cover 40, thereby giving off heat to the water circulating through the casing portion 20, as explained hereinabove. Liquid condensate issuing from the tube ends 30 then passes from the manifold into an outlet conduit 62 leading to the associated steam generating boiler, where it is usefully employedfor the boiler feed water makeup purposes. This method of utilizing the returned steam condensate in the boiler feed water system substantially reduces the scaling and other maintenance problems associated with the steam generator boiling operation, and

will be appreciated by those versed in the art.

The heat exchange component of the device of the present invention also embodies means for drawing upon a live steam source from the associated system whenever the waste steam and hot condensate supply hereinabove referred to is insuflicient to maintain the supply water interiorly of the tank 10 at the prescribed temperature. For this purpose, a live steam inlet conduit asindicated at 66 (Fig. 1) is arranged to deliver live steam into a bypass manifold as indicated at 68, which comprises a three-valve housing wherein the center valve 69 is normally closed and the end valves 70-71 are normally open. Hence, live steam entering through the conduit 66 is caused to by-pass through a valve 72 which is automatically controlled by means of a solenoid actuator or the like as indicated at 74. The actuator 74 is in turn controlled by means of a temperature responsive bulb as indicated at 75 disposed interiorly of the water supply within the tank 10; the mechanism being so arranged that the valve 72 will be automatically opened whenever the thermometer 75 records a temperature in the supply water lower than that prescribed therefor.

The steam passing the valve 72 then flows through the manifold 68 and into a conduit system indicated at 76, and thence into the upper left hand quadrant portion of the manifold 40. The steam is then conveyed into the left hand end portions of the upper bank of bent tubes 28 and travels through the tubes 28 and thence in reverse direction back into the upper right hand quadrant portion of the manifold cover 40, while in the meantime transferring heat to the tubes 28 to assist in heating the supply water as it circulates through the casing 20 as explained hereinabove. Any excess steam and condensate issuing from the right hand end portions of the tubes 28 into the upper right hand quadrant portion of the manifold cover is then conducted by means of a conduit systern designated 80 which leads through another by-pass manifold device 82 (Figs. 2, 3) which is of identical construction to the manifold 68 previously referred to except that in the case of the manifold 82 the by-pass portion thereof leads through a steam trap device 84 which holds back the steam in the live steam supply system until it substantially condenses. This facilitates release of substantially the entire available heat in the steam supply, and therefore improves the efliciency of the system.

The hot condensate exiting from the manifold 82 is carried by a conduit system 8889 and down into the line of the conduit 60 delivering hot condensate into the lower right hand quadrant portion of the manifold cover 40 for heating of the lower bank of tubes 26, as explained hereinabove. It will be appreciated that whereas waste steam and hot condensate supplied to the unit from exhausts of other assoicated steam using equipment are circulated only through the lower bank of tubes 26, the live steam supply, whenever it is drawn upon as required to maintain the water supply at the proper temperature level, passes first through the upper bank tubes and therein gives up substantially its entire heat potential. Thereupon, the hot condensate issuing from the upper bank of tubes 28 is added to the other hot condensate supply line so that it then circulates through the lower bank of tubes; thereby insuring most eflicient use of the heat available to the unit.

As illustrated in Figs. 1 and 3, the by- pass manifolds 68, 82, include manually adjustable valve devices 71 and 72, whereby if for any reason it is preferred to by-pass the automatically controlled valve 72 or the steam trap 84, the center valve devices 69 of the manifolds may be opened while the two end valves 71 and 72 are closed against the associated by-pass conduit, whereupon the live steam supply will flow directly through the manifold 68 and through the upper bank of tubes 28 and thence through manifold 82 and through the condensate conduit system 88, 89 into the lower bank of tubes 26, and thence to be returned to the boiler feed water supply system as explained hereinabove.

A pressure relief valve as indicated at 90, and a drainoff valve device as indicated at 92 (Fig. 1) may be employed in conjunction with the tank, as well as any other preferred accessory devices, as is well understood in the art. For example, a vacuum breaker as indicated at 94 (Fig. 2), and an air valve, as indicated at 96 may be mounted in connection with the manifold cover 40 to break any vacuum in the tubes created by condensation of steam therein, and to release any entrained air and non-condensatable gases from the system, respectively. The pump 52 may of course be driven by any suitable power means, such as electric motor as indicated at 97, and is preferably of the constant speed and constant pressure type; the volume of output thereof being controlled by a valve as indicated at 98. The pump motor control switch box may be readily mounted on the end of the tank as indicated at 99 (Fig. 2). A pressure gauge may also be conveniently mounted on the pump suction line 54 as indicated at 100 and on the pump discharge as indicated at 101 (Fig. 2) as well as a thermometer 102. A valve 104 (Fig. l) is preferably provided in the pump suction line to permit the pump to be removed from the tank for maintenance purposes.

Thus, it will be appreciated that the mechanism of Figs. 1-5 provides a closed steam and condensate circulation system interiorly of the water tank. By virtue of this arrangement a condensate cooling element is provided to condense the flash in the condensate from high pressure steam as furnished via the conduit 66, as well as from other high pressure steam machines in the associated system. By transferring the heat from the condensate to the water supply in the tank 10 no flash steam is lost to the atmosphere from the condensate receiving tank; andthe temperature of the water is thus elevated by heat which would otherwise be lost, thereby effecting a fuel saving and alleviating peak loads on the steam generator boiler.

Thus, it will be appreciated that although only one form of the invention has been shown and described in detail, it will be apparent to those skilled in the art that the'invention is not so limited but that various changes may be made therein without departing from the spirit of the invention or the scope of the appended claims.

I claim:

1. A water heating device comprising a tank having a flanged aperture in a wall portion thereof, an elongate casing extending from said aperture inwardly of said tank, a heat exchange unit slip-fitted through said aperture and mounted within said casing, said heat exchange unit comprising vertically spaced banks of horizontal return bent tubes, said tubes being mounted at their terminal ends upon a vertical tube sheet carried by the tank flange, baflie means interiorly of said casing providing for support of said tubes therein and defining zig-zag pathways for water circulating through said casing, a water inlet port adjacent the front end of said casing and a water outlet port at the rear end thereof, pump means mounted upon said tank and drawing water from therewithin and delivering same into said casing inlet port and thence through said casing in zig-zag fashion around said baffle devices and around said tubes, manifold means carried by said tube sheet and defining four separate quadrant chambers in association therewith, a hot condensate inlet connection associated with a first quadrant portion of said manifold to feed hot condensate into corresponding ends of one bank of said tubes, a cold condensate outlet port in association with a second quadrant portion of said manifold receiving exiting cold condensate from the opposite ends of said tubes for delivery of said condensate to an associated steam generator boiler feed water supply, a live steam source connected into a third quadrant portion of said manifold for delivery of live steam into the other bank of bent tubes, and a hot condensate conduit connected to the fourth quadrant portion of said manifold to receive the condensate from said other bank of tubes subsequent to circulation of live steam therethrough, said hot condensate conduit being connected into the hot condensate inlet connection leading into said first quadrant portion of said manifold.

2. A water heating device comprising a tank, an elongate casing substantially disposed Within said tank, a heat exchange unit mounted within said casing, said heat exchange unit comprising banks of return bent tubes, said tubes being mounted at their terminal ends upon a vertical tube sheet, baflie devices interiorly of said casing providing for support of said tubes therein and defining zig-zag pathways for water circulating through said casing, a water inlet port adjacent the front end of said casing and a water outlet port at the rear end thereof, pump means for causing the water of said tank to circulate through said casing in zig-zag fashion around said baffle devices and around said tubes, manifold means carried by said tube sheet and defining four separate quadrant chambers in association therewith, a hot condensate inlet connection associated with a first quadrant portion of said manifold to feed hot condensate into corresponding ends of one bank of said tubes, a cold condensate outlet port in association with a second quadrant portion of said manifold receiving exiting cold ,4 condensate from the opposite ends of said tubes for delivery of said condensate to an associated steam genera- :tor boiler feed water supply, a live steam source connected into a third quadrant portion of said manifold for delivery of live steam into the other bank of bent tubes, and a hot condensate conduit connected to the fourth ,,quadrant portion of said manifold to receive the condensate from said other bank of tubes subsequent to circulation of live steam therethrough, said hot condensate conduit being connected into the hot condensate inlet connection leading into said first quadrant portion of said manifold.

3. A water heating device comprising a'tank having a flanged aperture in a wall portion thereof, an elongate casing extending from said aperture inwardly of said tank, a heat exchange unit slip-fitted through said aperture and mounted within said casing, said heat exchange unit comprising a plurality of return bent tubes, said :tu'bes-being mounted at their terminal ends upon a vertube sheet and defining four separate chambers in association therewith, a hot condensate inlet connection'associated with a first chambervportion of said manifold to feed hot condensate into corresponding ends of some of said tubes, a cold condensate outlet port in association with a second chamber portion of said mainfold receiving exiting cold condensate from the opposite ends of said tubes for discharge delivery of said condensate, a live steam source connected into a third chamber portion of said manifold for delivery of live steam into others of said tubes, and a hot condensate conduit connected to the fourth chamber portion of said mainfold to receive the condensate from said other tubes subsequent to circulation of live steam therethrough, said hot condensate conduit being connected into the hot condensate inlet connection leading into said first chamber portion of said manifold.

References Cited in the file of this patent UNITED STATES PATENTS 1,943,373 Del Mar Jan. 16, 1934 2,088,905 Hartmann Aug. 3, 1937 2,530,443 Walker Nov. 21, 1950 FOREIGN PATENTS 470,863 Canada Jan. 16, 1951 848,571 France July 24, 1939

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