US2781174A - Dual heat-hot water tankless system - Google Patents

Description

Feb- 12, 1957 G. J. SMITH DUAL. HEAT-HOT WATER TANKLEss SYSTEM Filed April 27, 1954 CLDMW Haug-. m

NM NM nited tees The present invention is'crected to av dual system adapted to furnish heat: for het; waterY supply and heat for heating thepremises.

Systems of this, kind haveY previously been Vused but in general they consisted essentially of a boiler and radiation whereby heat in the form of' hot Water is caused to circulate through apiping system to the radiation andi return it tothe boiler. Purely asan adjunctV thereto there was provided a take-oi in the nature of a heat exchanger which was intended to heat water stored in a tank for obtaining theL requisite temperature for domestic and other uses of such water. Usually the take-oil consisted of a chamber of relatively small size through whichthe water from the boiler was adapted to circulate. The chamber contained a coil through which the. water for the hot water supply circulated and such Water was stored in a relatively large storage tank.

To a certain extent, such a dual system was satisfactory but; there Vwere numerous disadvantages inherent in such a-system. For instance, the heating of the hot water supply was slow and the temperature to which it was raised was variable. If a large or continuous demand for hot water occured, the Vsystem could not supply'the hot water at the. proper temperatures. It is highly desirable in modern installations, and particularly in such applications asrestaurants andY the like, to have'a large supply of hot Water at a high and uniform temperature in order that the dishesand other articles Washed or rinsed with such water shall beself-drying without the necessity of usingtowels or dish cloths. For this purpose it was generally necessary to install a separate hot water supply system at considerable additional expense both of installation and of operation.

'lhe present invention is intended and adapted toV overcome the diticulties and disadvantages inherent in dual systems of the type described, it being among the objects of the invention to provide a h ot water heating system combined with radiation heating for the premises, which is small, compact, low in cost of installation and economical in operation and maintenance.

t is also among the objects of the present invention to provide a dual systemA whereby hot water at uniform and high temperature is` supplied continuously Without the necessity of a large storage tank for said hot water and to prevent high temperature deterioration, and' radiation loss. Y

It is further among the objects of the present invention to provide a system in which water is heated in a boiler to a very high temperature and which water is tempered both for'heating purposes and for the hot water supply, the operation therefor being substantially automatic.A

In practicing the invention there is provided a boiler and awater heater with a connection from the boiler to the heater and return. The heater contains coils so that cold Water may enter the coils and be heated to a high temperature and then conducted to one or more mixing valves which are thermostatically controlled where the hot water is blended with suicient cold water to give a atent 2,'73l,l71i Patented Feb. 12,1957

2, temperature desired at the operative level. Usually there are two such mixing valves so arranged that hot water at two diierent and uniform temperatures 'are obtained.

TheY connection from the boiler to the water heater has a branch leading to the radiator and supplied with a thermostatic mixing valve. vThev return water from the radiator enters a mixing valvewhich is setto blend the 'return water withthe hot water togive it the -desired tem.-

perature for the radiator. Various controls are provided at various points so that the operation of-'the system is practically automatic.

In the accompanying drawing constituting a part hereof and in which like reference characters indicate like parts, the single figure is an elevational View, partly diagrammatic and partly in cross-section, illustrating one form of the invention.

The boiler 1 which maybe heated by gas, oil or other fuel, and being of anysuitable type having heating surfaces therein for heating water, has, a pipe connection 2 extending from the top thereof. A pipe 3 Vconnected therewith leads intoA and through` pipe 4 and the water heaterchamber 5. From the bottom of the heater a pipe 6 connects with Vpipe 7 returning the water. to the lower part' of the boiler. In operation, the water ows from the boiler'to the heater and return by convection currents induced by the heat. An air chamber (not shown), positioned atA the endof pipe 8 is provided to take up the expansion of the water in, the system asV is well known. In place thereof, there may be provided an expansion tank 9 at a high level connectedV to pipe 4 and having, a Vcut-ott valve Ill'. Tank 9 is also provided with'a draw-olf valve I1; Boiler responsive thermostat 12 of the immersion type, for control of the, heat in the boiler, is provided' in heater S. ln connection 2 is a surface boiler responsive thermostat 13 and also contained in said connection isathermometer or tridicator 14. An automatic water vent 15 is inserted in the connectionV between pipes 3V and 4.

From connection 2 there is a branch ltwlrichV leads into thermostatic mixing valveV 17. A pipe; 18 from said mixing valve connects into flow-control valve 19; RadiationZil isv connected to flow-control 19 and an air bleeder 21 is provided in the` system. Return pipe Z2 from radiation 243 connects with return pipe 23 whichl leads into pipe 7. A by-pass 24 from pipe 22 leads to mixing valve 17.

A cold water inlet pipe 25. controlled by valve 26 has a branch 27 leading` therefrom, the pipe. 25` connecting with coil 28 in heater 5. The upper end of coil'ZS is connected by pipe 29 to thermostatic rm'xing valve 3o.. A. branch 31 from pipe 25 also is connected into mixing valve 3tl. The exit pipe. 32 from mxingvvalve, 3.9, having avalve 33, leads to taps, machines; or,` the' like. for use of hot water. A branch from; exit pipe-32 yenters thermostatic mixing valve 35 together with branch 27. Said branch 34 has a check valve therein to prevent Water from mixing valve 35 backing up into pipe 32. Exit pipe 35 fro-m mixing valve 35, having a valve 37, leads to points of use of hot water.

reducing and relief valvefltl in the line. A pipe 41' connects to pipe 7 and a drain cocklZy is providedfor drain-v ing the System. A re-circulator 33 driven by motor 39 is inserted in return pipe23. y

In operation of the system it may be assumed that no heatingk of the radiationis required, in which case, owcontrol 19 and circulator V are not' in operation. The heat in the boiler is on dueto boiler responsive thermostat 12 until the temperature in heatery 5i isthe basic temperature generally maintained inthejsystem when no domandi is made on it. We may assume that hot Water from exit pipe 32 is to be supplied at say 180 F. for certain uses and that hot water from exit pipe 36 is to be used at a lower temperature, say 140 F. When, for example, valve 33 is opened, hot water from coil 28 'enters mixing valve 30jand i-s'blended with cold water from lead l31 thereby tempering the water to '180 F. for use. if at the same time or independently thereof, hot water at 140 F. is required, valve 37 is opened and water begins to flow first through mixingvalve 39 and then into mixing valve 35 where the waterA isV further tempered by cold water from branch 27 to give the proper temperature; When no water is beingusedandV the temperature in i ing the water therein to a relatively high temperature, a hot water heater at a level above said boiler, a connection from the top of said boiler to the .top of said heater, a return pipe from the bottom of said heater to the bottom of said boiler, whereby there is provided a closed circuit ilow of water between said boiler and heater, an inlet for cold water into the lower portion of said heater in indirect contact with and adapted to be heated byVV conduction by the water circulating through Vsaid heater; a hot water exit for said heated water at the Vupper portion of said heater and leading toY points of use, house heating radiation, a branch fromlsaid connection above said heater is the basic temperature, boilerrresponsiveV thermostat 12 will cut oii the heat fromthe boiler. Y

If it is necessary or desirable to heat the `radiation, the system is controlled by a thermostat (not'shown) whereby now-control 19 and vcirculator 3S are caused to function allowing hot water from connection 2 to enter mixing valve 17. At the same time coolwater from return pipe 22 flows through by-pass 24 into mixing valve 17 in the proper proportion to give an exit water temperature of the pre-determined degree. ows through pipe 18 and into the radiation.

Although l have described the invention setting forth a single,'specic embodiment thereof, various changes in the details of construction may be made within'the scope of the invention. VFor instance, the connection from the boiler to the heater need not be at the top of the heater, but may be in the bottom thereof at one side. The return pipe from the heater may be located in the bottom at the opposite side of the heater; or the heater may be so arranged that there Vis an air space atthe top thereof which replaces Ythe expansion-tank9. It also allows compression to' take place at high temperature of. the water and thus avoids a possible rupture of or damage to the system. Mixing valve 17 need not be automatic in'its operation, but it may be manually` operative in some cases.

These and other changes may be made without departing from the principles herein set forth, and the invention is to be broadly construed in accordance with the claims appended hereto.

What I claim is: Y

l. A combined hot water supply and heating system. comprising a water-containing boiler with means for heating the water therein to a relatively high temperature, a hot water heater at a level above said boiler, a connection from the top of said boiler to the topof said heater, a return pipe from the bottom of said heater to the bottom of said boiler, whereby there isV provided a closed circuit flow of water between said boiler and heater, an inlet ior'cold water into the lower portion of said heater in Vindirect Contact with and adapted to be heated byrcon-` duction bythe water circulating through said heater, a hot water exitvfor said heated water at the upper portion of said heater and leading to points of use, house heating radiation, a branch fromsaid connection above said boiler to Ysaid radiation, a return from said radiation to saidboiler and joining with said first return pipeat the bottomV of said boiler, a thermostatic mixing valve in said branch f between said connection and said radiation, a lay-passV from said'r'adiationl entirely above'the level of said boiler to said mixing-ivalv'e to permitmixing of radiation .return water with heated water passing through Vsaid mixing valve, and a Vbranch from said cold water inlet to saidrfirst return pipe, a hot water thermostatic mixing valvewin said exit and a lead from said cold water inlet to said hot water mixing valve, an outlet `for tempered water from said hot watermixing valve, a' second hot water thermostatic mixing valve with connections thereto from said tempered water outlet and said cold `water inlet,'and an exitV from said second hot water mixing valve to provide further tempered hot water.

2. A combined hot Water supply and heating system comprising a water-'containing boiler with means for heat- The water thus tempered boiler to said radiation, a return from said radiation to said boiler and joining with`said first return pipe at the bottom of said boiler, a thermostatic mixing valve in said branch between said connection and said radiation, a bypass from said radiation entirelyabove the level of said boiler f Vwater fromY said hot water mixing Valve, a second hot water thermostatic mixing valve with connections thereto fromV saidtempered water outletV and said cold water inlet, and an exit from said second hot waterA mixing valveito provide further tempered hot water, a circulator in the lower part of said radiator return, said heater returnpipe'entering 'saidY boiler at a point nearer than the entrance of said radiator return whereby the radiator Vreturn'water is'pumped past the said heater return entrance into the boiler, creating no back pressure Vin the heater return pipe.

3. A combined hot water supply and heating system comprising a watercontaining boiler with means vfor heating the waterY therein to a'relatively high temperature,

` a hot water heater atra level above saidboiler, a connection from the Vtop of said boiler to the top of said heater, Aa return pipe from the bottom of said heater to the Y Y inletforcold water into the lower portion of said heater in indirect contact'with and adapted to be heated bycon- Vduction by the water circulating through said heater,.a

hot water exitrf'or said heatedwater at the upper portion of said heater and Vleading to points of use, house heating radiation, arbranch from said connection Vabove said boiler to said radiation, a return from'said radiation tosaid boiler Vand joining with saidrrst return pipe at the bot-Y tom of said boilerna` thermostatic mixing valve in ksaid branch between said connection and'said radiation, a`

lay-pass fromfsaid radiation entirely above the Vlevel of said boiler to said mixing valveV to permit mixing Vof` yradiation return water withV heatedV water passing through said mixing valve, and a branch fromp'rsajd old'water; inlet to said iirst return pipe, a Yhot water thermostatic mixing Valve in said exit and ,a lead from said cold water inlet to said hot water mixingY valve, an outlet for Ytempered` water' from Vsaid Yhot water mixing valve, a second hot water' thermostatio mix-V ing Valve with connections thereto Vfrom Vsaid temperedY valve and said radiation. Y

Y (References onY fellewingpagel K Y References Cited in the file of this patent UNITED STATES PATENTS Lake Feb. 2, 1932 Glenn Mar. 15, 1938 Miller May 23, 1939 Moore Oct. 17, 1939 Moore June 29, 1943 Colby May 9, 1944 McLain July 23, 1946 6 Midyette July 18, 1950 Thrush Aug. 29, 1950 Berntson Jan. 25, 1955 Schoerner Oct. 25, 1955 OTHER REFERENCES Powers Bulletin No. 2581-1, June 1939, published by the Powers Regulator Company, Chicago, Illinois, pages

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