CA1168226A - System for recovering heat from a first liquid and using it to heat a second liquid - Google Patents
System for recovering heat from a first liquid and using it to heat a second liquidInfo
- Publication number
- CA1168226A CA1168226A CA000392560A CA392560A CA1168226A CA 1168226 A CA1168226 A CA 1168226A CA 000392560 A CA000392560 A CA 000392560A CA 392560 A CA392560 A CA 392560A CA 1168226 A CA1168226 A CA 1168226A
- Authority
- CA
- Canada
- Prior art keywords
- tank
- liquid
- outlet
- inlet
- heat
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F24—HEATING; RANGES; VENTILATING
- F24D—DOMESTIC- OR SPACE-HEATING SYSTEMS, e.g. CENTRAL HEATING SYSTEMS; DOMESTIC HOT-WATER SUPPLY SYSTEMS; ELEMENTS OR COMPONENTS THEREFOR
- F24D17/00—Domestic hot-water supply systems
- F24D17/02—Domestic hot-water supply systems using heat pumps
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
- Y02B30/00—Energy efficient heating, ventilation or air conditioning [HVAC]
- Y02B30/52—Heat recovery pumps, i.e. heat pump based systems or units able to transfer the thermal energy from one area of the premises or part of the facilities to a different one, improving the overall efficiency
Landscapes
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Heat-Pump Type And Storage Water Heaters (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
A system holds waste or process water (or other liquid) that possesses readily recoverabl heat, removes the heat by means of a heat pump and transfers it to another liquid, e.g., water to be heated for domestic use. The holding tank is shaped to permit it to be cleaned readily periodically, and thermal stratification in the tank containing the liquid being heated is promoted by a separator plate.
A system holds waste or process water (or other liquid) that possesses readily recoverabl heat, removes the heat by means of a heat pump and transfers it to another liquid, e.g., water to be heated for domestic use. The holding tank is shaped to permit it to be cleaned readily periodically, and thermal stratification in the tank containing the liquid being heated is promoted by a separator plate.
Description
SYSTEl~l FO~ ~CO~T~.P~I~G HEAT FROM A FIRST
LIQ~ID AND USING IT TO HEAT A SECO~D LIQUID
BACKGROUND OF THE INVENTION
At the present time it is not common practice to recover the heat that is present in domestic waste hot water. Hot water from bath tubs, showers and sinks simply is sewered resulting in a great deal Of recoverable energy literally "going down the drain". In accordance with this invention, there is provided a system for the recovery of this energy. While the system will be hereinafter described as one in which heat is recovered from waste water in a house and used to heat water for domestic operations, it is to be understood that this is exemplary only. The liquid containing heat to be recovered may be other than water and may be derived frcm other than a domestic operation. For example, it may be industrial liquid waste. Likewise, the li.quid to be heated may be other than water and may be for other than domestic use. However, the system hereinafter described was conceived for use in a domestic environment for recovering heat from waste water and using the same to heat water, and the invention thus will be so described.
SUMMARY OF THE INVENTION
Various aspects of this invention are as follows:
P system for recovering heat from a first liquid, and using the heat recovered to heat a second liquid comprising: a first storage tank for said first liquid, said first tank having a top, a bottom and side walls, a first outlet located in the bottom of said first tank, an overflow weir located within said first tank adjacent ~aid top thereGf, a second cutlet from said first tank for said first liquid, said second outlet 35 being located nearer said top than said bottom of said first tank but below the level of said overflow weir, a riser channel connecting said second outlet and a part of said first tank adjacent said bottom thereof in liquid-flow relationship to permit relativel~ cold first liquid at the bottom of said first tank to be displaced and to discharge from said first tank via said second outlet upon introduction of fresh first liquid into said first tank, means for introducing said first liquid into said first tank via a first inlet at a location above said bottom of said first tank but below the level of said first liquid established in said first tank by said second outlet, a third outlet from said first tank for said first liquid and a second inlet into said first tank for said first liquid, said third outlet being closer to said top than to said bottom of said first tank and said second inlet being closer to said bottom than said top of said first tank, valve means for opening and closing said first outlet, means for controlling the opening and closing of said valve means, rinsing means for directing rinsing liquid against the interior. surface of said first tank, the portion of said first tank at the level of said first liquid established in said first tank by said second outlet being inclined inwardly and being in the path of rinsing liquid from said rinsing means, whereby material in said first liquid which accumulates on said portion of said first tank can be readily removed therefrom by the combined action of rinsing and the influence of the force or gravity; a second storage tank for said second liquid, said second tank having a top, a bottom and side walls, means including a first inlet for intr~du:ing said second liquid to be heated into said second tank adjacent said bottom thereof, electrical heating means for heating said second liquid located in 30 the upper part of said second tank, a first outlet from said second tank for said second liquid, and a second inlet into said second tank for said second liquid, said second inlet being located below said electrical heating means and above said first outlet, said first outlet 35 being located between said second inlet and said bottom of said second tank, and a second outlet from said second tank for said second liquid, said second outlet being located above said electrical heating means; and a heat pump including a compressor, condenser and an evaporator, llti~
means for circulating said first liquid from said first tank via said third outlet of said first tank in heat exchange relationship with said evaporator and back to said first tank via said second inlet of said first tank, whereby heat in said first liquid so circulated is given up to a heat exchange fluid in said evaporator, and means for circulating said second liquid from said second tank via said first outlet of said second tank in heat exchange relationship with said condenser and back to said second tank via said second inlet of said second tank, whereby heat in said heat exchange fluid in said condenser is given up to said second liquid.
A storage tank for a liquid, said tank having a top, a bottom and side walls, a first outlet located in 15 the bottom of said tank, an overflow weir located within said tank adjacent said top, a second outlet from said tank for said liquid, said second outlet being located ..~,
LIQ~ID AND USING IT TO HEAT A SECO~D LIQUID
BACKGROUND OF THE INVENTION
At the present time it is not common practice to recover the heat that is present in domestic waste hot water. Hot water from bath tubs, showers and sinks simply is sewered resulting in a great deal Of recoverable energy literally "going down the drain". In accordance with this invention, there is provided a system for the recovery of this energy. While the system will be hereinafter described as one in which heat is recovered from waste water in a house and used to heat water for domestic operations, it is to be understood that this is exemplary only. The liquid containing heat to be recovered may be other than water and may be derived frcm other than a domestic operation. For example, it may be industrial liquid waste. Likewise, the li.quid to be heated may be other than water and may be for other than domestic use. However, the system hereinafter described was conceived for use in a domestic environment for recovering heat from waste water and using the same to heat water, and the invention thus will be so described.
SUMMARY OF THE INVENTION
Various aspects of this invention are as follows:
P system for recovering heat from a first liquid, and using the heat recovered to heat a second liquid comprising: a first storage tank for said first liquid, said first tank having a top, a bottom and side walls, a first outlet located in the bottom of said first tank, an overflow weir located within said first tank adjacent ~aid top thereGf, a second cutlet from said first tank for said first liquid, said second outlet 35 being located nearer said top than said bottom of said first tank but below the level of said overflow weir, a riser channel connecting said second outlet and a part of said first tank adjacent said bottom thereof in liquid-flow relationship to permit relativel~ cold first liquid at the bottom of said first tank to be displaced and to discharge from said first tank via said second outlet upon introduction of fresh first liquid into said first tank, means for introducing said first liquid into said first tank via a first inlet at a location above said bottom of said first tank but below the level of said first liquid established in said first tank by said second outlet, a third outlet from said first tank for said first liquid and a second inlet into said first tank for said first liquid, said third outlet being closer to said top than to said bottom of said first tank and said second inlet being closer to said bottom than said top of said first tank, valve means for opening and closing said first outlet, means for controlling the opening and closing of said valve means, rinsing means for directing rinsing liquid against the interior. surface of said first tank, the portion of said first tank at the level of said first liquid established in said first tank by said second outlet being inclined inwardly and being in the path of rinsing liquid from said rinsing means, whereby material in said first liquid which accumulates on said portion of said first tank can be readily removed therefrom by the combined action of rinsing and the influence of the force or gravity; a second storage tank for said second liquid, said second tank having a top, a bottom and side walls, means including a first inlet for intr~du:ing said second liquid to be heated into said second tank adjacent said bottom thereof, electrical heating means for heating said second liquid located in 30 the upper part of said second tank, a first outlet from said second tank for said second liquid, and a second inlet into said second tank for said second liquid, said second inlet being located below said electrical heating means and above said first outlet, said first outlet 35 being located between said second inlet and said bottom of said second tank, and a second outlet from said second tank for said second liquid, said second outlet being located above said electrical heating means; and a heat pump including a compressor, condenser and an evaporator, llti~
means for circulating said first liquid from said first tank via said third outlet of said first tank in heat exchange relationship with said evaporator and back to said first tank via said second inlet of said first tank, whereby heat in said first liquid so circulated is given up to a heat exchange fluid in said evaporator, and means for circulating said second liquid from said second tank via said first outlet of said second tank in heat exchange relationship with said condenser and back to said second tank via said second inlet of said second tank, whereby heat in said heat exchange fluid in said condenser is given up to said second liquid.
A storage tank for a liquid, said tank having a top, a bottom and side walls, a first outlet located in 15 the bottom of said tank, an overflow weir located within said tank adjacent said top, a second outlet from said tank for said liquid, said second outlet being located ..~,
2;~ .
nea-er said top than said bottom of said tank but below the level of said overflow weir, a riser channel connecting said second outlet and a part of said tank adjacent said bottom thereof in liquid-flow relationship to permit relatively cold liquid at the bottom of said tank to be displaced and to discharge from said tank via said second outlet upon introduction of fresh liquid into said tank, means for introducing liquid into said tank via a first inlet at a location above said bottom of said tank but below the level of liquid established in said tank by said second outlet, a third outlet from said tank for said liquid and a second inlet into said tank for said liquid, said third outlet being closer to said top than to said bottom of said tank and said second inlet being closer to said bottom than said top of said tank, valve means for opening and closing said first outlet, means for controlling the opening and closing of said valve means, rinsing means for directing rinsing liquid against ~he interior surface of said tank, the portion of said tank at the level of said liquid established in said tank by said second inlet being inclined inwardly and being in the path of rinsing liquid from said rinsing means, whereby material in said liquid which accumulates on said portion of said tank can be readily removed therefrom by the combined action of rinsing and the influence of the force of gravity.
!, BRIEF DESCRIPTION OF THE DRAWINGS
This invention will become more apparent from the following detailed description, taken in conjunction with the appended drawing, which is a schematic 5 representation of a complete waste water recovery and utilization system constituting an aspect of this invention.
DETAIL~D DESCRIPTION OF THE INVENTION INCLUDING
THE PREFERRED EMBODIMENT
Referring to the drawing, the system is composed of a waste water holding tank 10, a heat pump 11, a hot water tank 12 and various controls including controls 13.
Tank 10, which should be well thermally 15 insulated (thermal insulation not shown) and appropriately constructed to resist corrosion, has a top 14, a bottom 15 and side walls 16. The tank is generally cylindrical in cross-section, but adjacent top 14 side walls 16 slope inwardly, as seen at 17, for a purpose 20 that will be outlined in greater detail hereafter.
An outlet 18 is located in bottom 15 of tank 10, it being noted that bottom 15 is of conical configuration sloping towards outlet 18 so that all of the water in tank 10 can be drained therefrom via outlet 18. A valve 19 for opening and closing outlet 18 is provided.
Within tank 10 is an overflow weir 20. It is located adjacent top 14 and, in an emergency, functions to permit excess water in tank 10 to overflow from the tank and to discharge to waste via a waste pipe 21.
T, There is a second outlet 22 for water in tank 10. It is located r.earer top 14 than bottom 15 but below the level of overflow weir ?0 and is connected in liquid-flow relationship with the lcwer part of tank 10 via a riser channel 23. In this manner relatively cold water from the lower part Gf tank 10 can be displaced by waste water entering the tank. The displaced water overflows from outlet 2 and discharges into waste pipe 21. It will be seen than the level of outlet 22 determines the level 24 of water in tank 10. Riser channel 23 preferably is thermally insulated from waste water in tank 10 by thermal insulation 25. This also may be accomplished by making riser channel 23 a separate pipe that is kept well away from side wall 16 of tank 10.
Waste water is introduced into tank 10 from a pipe 26 via an inlet 27. Inlet 27 preferably is located at a point about /3 of the depth of tank 10. It must be noted, in this connection, that the waste water introduced into tank 10 is not always hot. For example, if cold water were being run in a sink, the waste water going into tank 10 would be cold. Therefore the location of inlet 27 relative to thermal stratification within tank 10 must take this into consideration.
An outlet 28 and an inlet 29 for waste water from tank 10 that is recirculated are provided in side wall 16, the former being closer to the top of tank 10 (where the water is hotter) and the latter being closer to the bottom of tank 10 (where the water is colder).
A rinsing device 30, which may be like the rotating arm of a dishwasher or a tubular ring provided with spaced apart openings therearound through which water can spray, is provided for rinsing the interior surface of tank 10. It is arranged so as to direct its spray against inwardly sloping section 17 and weir 20, 35 these components being at substantially the same level, namely the level 24 of water in tank 10. Because of this, scum and solid waste material accumulate thereon, and the inward lope of section 17 and weir 20 assists in the removal of such scum by the rinsing action and under the influence of gravity.
Hot water tank 12 also is cylindrical in cross-section, should be thermally well insulated and should be constructed to be corrosion resistant. It has a top 30, bottom 31 and side walls 32. Water to be heated is introduced, e.g., from city mains, from a pipe 33 via an inlet 34 located adjacent bottom 31 (the coldest water always should be introduced into the lowest point of a hot water tank).
A conventional electrical resistance heater 35 is located in the upper part of tank 12 along with a thermostat 35a that controls the supply of power to heater 35.
In the lower part of tank 12 there are provided an outlet 36 and an inlet 37, the latter being located below heater 35, and above outlet 36 and preferably about one-half way along the depth of the lower part of tank 12, the former being located adjacent bottom 31. A
thermostat 39 also is provided.
An outlet 40 for hot water from tank 10 is provided in top 30 above heater 35.
A sacrificial corrosicn ar.cde 60 is provided, as is conventional, to reduce corrosive attack on the tank welds or any other exposed metal surfaces.
An important feature Gf tank 12 is the provision of a separ~tor 61 that assists in the thermal stratification of the water in tank 12. Separator 61, which may be a circular plate that spring fits into 30 glazed over lugs 62 on the inner wall of tank 12, is located below heater 35 and well above inlet 37.
Separator 61 divides tank 12 intc ar. upper resistance heater section and a lower preheater section and prevents bulk circulation between the two sections. However, it 35 is provided with a small opening 63 sufficient to permit water to flow from the lower sectiGn to the upper section and out of tank 12 via outlet 40 in response to demand.
Heat pump 11 is essentially conventional in nature and includes a compressor 41, condenser 42 and l.~t;~Z.~4~
evaporator 43. P~efrigerant vapour from compressor 41 flows past a manual-reset high pressure circuit breaker 44 into condenser 42. Condensed refrigerant exits condenser 42 and flows through a liquid line filter-drier 45 and a thermostatic ccntrol valve 46. Now at reduced pressure, the refrigerant traverses evapGrator 43 and the refrigerant vapour from evaporator 43 is returned to compressor 41 via an optional low pressure cut-out 47.
A dual head magnetically driven pump employing one head 48 to circulate waste water from tank 10 over evaporator 43 in heat exchange relationship therewith and the other head 49 to circulate water from tank 12 to be heated over condenser 42 in heat exchange relationship therewith is provided. With this arrangement the water in each pump head is isolated from the motor by magnetic coupling, and hence the waters are isclated and cannot contaminate each other.
Optionally, the condensing refrigerant in condenser 42 may be isolated from the water being heated by a double-walled condenser optionally having an indicator dye between the double walls. The indicator dye would colour the hot water in the event of a rupture in the dye/water interface indicating possible contamination of the hot water by the refrigerant.
In cperation, waste water flows into tank 10 via pipe 26 and inlet 27 displasing cold water from the bottom of tank 10 via riser channel 23, outlet 2, and waste pipe 21. In the event that channel 23 s~.ould become plugged or should be urable to accom~odate the 30 volume of water being displaced by waste water coming into tank 10, overflow over weir 20 will occur, but operation in this mode is not desirable, of course, since the hottest water in tank 10 will be at the top of the tank.
Water from tank 10, if sufficiently warm, is circulated by pump 48 and gives up heat to the refrigerant in evaporator 43, the warmest ~ater fro~ the top of tank 10 being used for this purpose. The resulting cold water is returned to tank 10 via lower inlet 29, which is below inlet ~7. The extracted heat 'rom this water is transferred in condenser 42 to water from tank 12 being circulated by pump 49. In this manner the water in the lower (preheater) section of tank 12 is heated to a temperature that is determined by the setting of thermostat 39. This thermostat usually will be set to the same temperature, e.g., 130F, as that of thermostat 35a. When the desired temperature is reached, thermostat 39 inhibits operation of heat pump 11.
Turning now to the controls, a timing device 70 controls the opening and closing of valve 19 by operation of a valve actuator 71 and holds valve 19 open until the entire contents of tank 10 have drained followed by an automated spray rinse controlled by a controller 72.
Valve 19 is closed by timing devlce 70 and actuator 71 after the rinse water has drained away. As previously noted, the hot water rinse removes surface rim and bottom deposits from the interior of tank 10 prevent their accumulation.
A level sensor 73 inhibits operation of heat pump 11 if tank 10 is not full, while a thermostatic control 74 shuts off heat pump 11 if the surface waste water is tco cool for worthwhile heat recovery.
While preferred em~odiments of the invention 25 have been disclosed herein, those skilled in the art will appreciate that char,ses and modifications may be made therein without departing from the spirit a~d scope of this invention as defined in the appended clai~s.
nea-er said top than said bottom of said tank but below the level of said overflow weir, a riser channel connecting said second outlet and a part of said tank adjacent said bottom thereof in liquid-flow relationship to permit relatively cold liquid at the bottom of said tank to be displaced and to discharge from said tank via said second outlet upon introduction of fresh liquid into said tank, means for introducing liquid into said tank via a first inlet at a location above said bottom of said tank but below the level of liquid established in said tank by said second outlet, a third outlet from said tank for said liquid and a second inlet into said tank for said liquid, said third outlet being closer to said top than to said bottom of said tank and said second inlet being closer to said bottom than said top of said tank, valve means for opening and closing said first outlet, means for controlling the opening and closing of said valve means, rinsing means for directing rinsing liquid against ~he interior surface of said tank, the portion of said tank at the level of said liquid established in said tank by said second inlet being inclined inwardly and being in the path of rinsing liquid from said rinsing means, whereby material in said liquid which accumulates on said portion of said tank can be readily removed therefrom by the combined action of rinsing and the influence of the force of gravity.
!, BRIEF DESCRIPTION OF THE DRAWINGS
This invention will become more apparent from the following detailed description, taken in conjunction with the appended drawing, which is a schematic 5 representation of a complete waste water recovery and utilization system constituting an aspect of this invention.
DETAIL~D DESCRIPTION OF THE INVENTION INCLUDING
THE PREFERRED EMBODIMENT
Referring to the drawing, the system is composed of a waste water holding tank 10, a heat pump 11, a hot water tank 12 and various controls including controls 13.
Tank 10, which should be well thermally 15 insulated (thermal insulation not shown) and appropriately constructed to resist corrosion, has a top 14, a bottom 15 and side walls 16. The tank is generally cylindrical in cross-section, but adjacent top 14 side walls 16 slope inwardly, as seen at 17, for a purpose 20 that will be outlined in greater detail hereafter.
An outlet 18 is located in bottom 15 of tank 10, it being noted that bottom 15 is of conical configuration sloping towards outlet 18 so that all of the water in tank 10 can be drained therefrom via outlet 18. A valve 19 for opening and closing outlet 18 is provided.
Within tank 10 is an overflow weir 20. It is located adjacent top 14 and, in an emergency, functions to permit excess water in tank 10 to overflow from the tank and to discharge to waste via a waste pipe 21.
T, There is a second outlet 22 for water in tank 10. It is located r.earer top 14 than bottom 15 but below the level of overflow weir ?0 and is connected in liquid-flow relationship with the lcwer part of tank 10 via a riser channel 23. In this manner relatively cold water from the lower part Gf tank 10 can be displaced by waste water entering the tank. The displaced water overflows from outlet 2 and discharges into waste pipe 21. It will be seen than the level of outlet 22 determines the level 24 of water in tank 10. Riser channel 23 preferably is thermally insulated from waste water in tank 10 by thermal insulation 25. This also may be accomplished by making riser channel 23 a separate pipe that is kept well away from side wall 16 of tank 10.
Waste water is introduced into tank 10 from a pipe 26 via an inlet 27. Inlet 27 preferably is located at a point about /3 of the depth of tank 10. It must be noted, in this connection, that the waste water introduced into tank 10 is not always hot. For example, if cold water were being run in a sink, the waste water going into tank 10 would be cold. Therefore the location of inlet 27 relative to thermal stratification within tank 10 must take this into consideration.
An outlet 28 and an inlet 29 for waste water from tank 10 that is recirculated are provided in side wall 16, the former being closer to the top of tank 10 (where the water is hotter) and the latter being closer to the bottom of tank 10 (where the water is colder).
A rinsing device 30, which may be like the rotating arm of a dishwasher or a tubular ring provided with spaced apart openings therearound through which water can spray, is provided for rinsing the interior surface of tank 10. It is arranged so as to direct its spray against inwardly sloping section 17 and weir 20, 35 these components being at substantially the same level, namely the level 24 of water in tank 10. Because of this, scum and solid waste material accumulate thereon, and the inward lope of section 17 and weir 20 assists in the removal of such scum by the rinsing action and under the influence of gravity.
Hot water tank 12 also is cylindrical in cross-section, should be thermally well insulated and should be constructed to be corrosion resistant. It has a top 30, bottom 31 and side walls 32. Water to be heated is introduced, e.g., from city mains, from a pipe 33 via an inlet 34 located adjacent bottom 31 (the coldest water always should be introduced into the lowest point of a hot water tank).
A conventional electrical resistance heater 35 is located in the upper part of tank 12 along with a thermostat 35a that controls the supply of power to heater 35.
In the lower part of tank 12 there are provided an outlet 36 and an inlet 37, the latter being located below heater 35, and above outlet 36 and preferably about one-half way along the depth of the lower part of tank 12, the former being located adjacent bottom 31. A
thermostat 39 also is provided.
An outlet 40 for hot water from tank 10 is provided in top 30 above heater 35.
A sacrificial corrosicn ar.cde 60 is provided, as is conventional, to reduce corrosive attack on the tank welds or any other exposed metal surfaces.
An important feature Gf tank 12 is the provision of a separ~tor 61 that assists in the thermal stratification of the water in tank 12. Separator 61, which may be a circular plate that spring fits into 30 glazed over lugs 62 on the inner wall of tank 12, is located below heater 35 and well above inlet 37.
Separator 61 divides tank 12 intc ar. upper resistance heater section and a lower preheater section and prevents bulk circulation between the two sections. However, it 35 is provided with a small opening 63 sufficient to permit water to flow from the lower sectiGn to the upper section and out of tank 12 via outlet 40 in response to demand.
Heat pump 11 is essentially conventional in nature and includes a compressor 41, condenser 42 and l.~t;~Z.~4~
evaporator 43. P~efrigerant vapour from compressor 41 flows past a manual-reset high pressure circuit breaker 44 into condenser 42. Condensed refrigerant exits condenser 42 and flows through a liquid line filter-drier 45 and a thermostatic ccntrol valve 46. Now at reduced pressure, the refrigerant traverses evapGrator 43 and the refrigerant vapour from evaporator 43 is returned to compressor 41 via an optional low pressure cut-out 47.
A dual head magnetically driven pump employing one head 48 to circulate waste water from tank 10 over evaporator 43 in heat exchange relationship therewith and the other head 49 to circulate water from tank 12 to be heated over condenser 42 in heat exchange relationship therewith is provided. With this arrangement the water in each pump head is isolated from the motor by magnetic coupling, and hence the waters are isclated and cannot contaminate each other.
Optionally, the condensing refrigerant in condenser 42 may be isolated from the water being heated by a double-walled condenser optionally having an indicator dye between the double walls. The indicator dye would colour the hot water in the event of a rupture in the dye/water interface indicating possible contamination of the hot water by the refrigerant.
In cperation, waste water flows into tank 10 via pipe 26 and inlet 27 displasing cold water from the bottom of tank 10 via riser channel 23, outlet 2, and waste pipe 21. In the event that channel 23 s~.ould become plugged or should be urable to accom~odate the 30 volume of water being displaced by waste water coming into tank 10, overflow over weir 20 will occur, but operation in this mode is not desirable, of course, since the hottest water in tank 10 will be at the top of the tank.
Water from tank 10, if sufficiently warm, is circulated by pump 48 and gives up heat to the refrigerant in evaporator 43, the warmest ~ater fro~ the top of tank 10 being used for this purpose. The resulting cold water is returned to tank 10 via lower inlet 29, which is below inlet ~7. The extracted heat 'rom this water is transferred in condenser 42 to water from tank 12 being circulated by pump 49. In this manner the water in the lower (preheater) section of tank 12 is heated to a temperature that is determined by the setting of thermostat 39. This thermostat usually will be set to the same temperature, e.g., 130F, as that of thermostat 35a. When the desired temperature is reached, thermostat 39 inhibits operation of heat pump 11.
Turning now to the controls, a timing device 70 controls the opening and closing of valve 19 by operation of a valve actuator 71 and holds valve 19 open until the entire contents of tank 10 have drained followed by an automated spray rinse controlled by a controller 72.
Valve 19 is closed by timing devlce 70 and actuator 71 after the rinse water has drained away. As previously noted, the hot water rinse removes surface rim and bottom deposits from the interior of tank 10 prevent their accumulation.
A level sensor 73 inhibits operation of heat pump 11 if tank 10 is not full, while a thermostatic control 74 shuts off heat pump 11 if the surface waste water is tco cool for worthwhile heat recovery.
While preferred em~odiments of the invention 25 have been disclosed herein, those skilled in the art will appreciate that char,ses and modifications may be made therein without departing from the spirit a~d scope of this invention as defined in the appended clai~s.
Claims (8)
1. A system for recovering heat from a first liquid and using the heat recovered to heat a second liquid comprising: a first storage tank for said first liquid, said first tank having a top, a bottom and side walls, a first outlet located in the bottom of said first tank, an overflow weir located within said first tank adjacent said top thereof, a second outlet from said first tank for said first liquid, said second outlet being located nearer said top than said bottom of said first tank but below the level of said overflow weir, a riser channel connecting said second outlet and a part of said first tank adjacent said bottom thereof in liquid-flow relationship to permit relatively cold first liquid at the bottom of said first tank to be displaced and to discharge from said first tank via said second outlet upon introduction of fresh first liquid into said first tank, means for introducing said first liquid into said first tank via a first inlet at a location above said bottom of said first tank but below the level of said first liquid established in said first tank by said second outlet, a third outlet from said first tank for said first liquid and a second inlet into said first tank for said first liquid, said third outlet being closer to said top than to said bottom of said first tank and said second inlet being closer to said bottom than said top of said first tank, valve means for opening and closing said first outlet, means for controlling the opening and closing of said valve means, rinsing means for directing rinsing liquid against the interior surface of said first tank, the portion of said first tank at the level of said first liquid established in said first tank by said second outlet being inclined inwardly and being in the path of rinsing liquid from said rinsing means, whereby material in said first liquid which accumulates on said portion of said first tank can be readily removed therefrom by the combined action of rinsing and the influence of the force of gravity; a second storage tank for said second liquid, said second tank having a top, a bottom and side walls, means including a first inlet for introducing said second liquid to be heated into said second tank adjacent said bottom thereof, electrical heating means for heating said second liquid located in the upper part of said second tank, a first outlet from said second tank for said second liquid, and a second inlet into said second tank for said second liquid, said second inlet being located below said electrical heating means and above said first outlet, said first outlet being located between said second inlet and said bottom of said second tank, and a second outlet from said second tank for said second liquid, said second outlet being located above said electrical heating means; and a heat pump including a compressor, condenser and an evaporator, means for circulating said first liquid from said first tank via said third outlet of said first tank in heat exchange relationship with said evaporator and back to said first tank via said second inlet of said first tank, whereby heat in said first liquid so circulated is given up to a heat exchange fluid in said evaporator, and means for circulating said second liquid from said second tank via said first outlet of said second tank in heat exchange relationship with said condenser and back to said second tank via said second inlet of said second tank, whereby heat in said heat exchange fluid in said condenser is given up to said second liquid.
2. A system according to claim 1 including means for assisting the thermal stratification of said second liquid in said second tank, the last-mentioned means comprising a separator located within said second tank below said electrical heating means and above said second inlet of said second tank, said separator inhibiting substantial movement of said second liquid from below said separator to above said separator but permitting a sufficient flow of said second liquid from said second tank via said second outlet of said second tank in response to demand.
3. A system according to claim 2 wherein separator comprises a plate having an opening therein.
4. A system according to claim 3 wherein the opening in said plate is centrally located.
5. A system according to claim 3 wherein said plate is snapped into position within said second tank.
6. A system according to claim 1 including means for thermally insulating said first liquid in said riser channel from said first liquid in said first tank.
7. A storage tank for a liquid, said tank having a top, a bottom and side walls, a first outlet located in the bottom of said tank, an overflow weir located within said tank adjacent said top, a second outlet from said tank for said liquid, said second outlet being located nearer said top than said bottom of said tank but below the level of said overflow weir, a riser channel connecting said second outlet and a part of said tank adjacent said bottom thereof in liquid-flow relationship to permit relatively cold liquid at the bottom of said tank to be displaced and to discharge from said tank via said second outlet upon introduction of fresh liquid into said tank, means for introducing liquid into said tank via a first inlet at a location above said bottom of said tank but below the level of liquid establish-ed in said tank by said second outlet, a third outlet from said tank for said liquid and a second inlet into said tank for said liquid, said third outlet being closer to said top than to said bottom of said tank and said second inlet being closer to said bottom than said top of said tank, valve means for opening and closing said first outlet, means for controlling the opening and closing of said valve means, rinsing means for directing rinsing liquid against the interior surface of said tank, the portion of said tank at the level of said liquid established in said tank by said second inlet being inclined inwardly and being in the path of rinsing liquid from said rinsing means, whereby material in said liquid which accumulates on said portion of said tank can be readily removed therefrom by the com-bined action of rinsing and the influence of the force of gravity.
8. A storage tank according to claim 7 including means for thermally insulating said liquid in said riser channel from said liquid in said tank.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000392560A CA1168226A (en) | 1981-12-17 | 1981-12-17 | System for recovering heat from a first liquid and using it to heat a second liquid |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000392560A CA1168226A (en) | 1981-12-17 | 1981-12-17 | System for recovering heat from a first liquid and using it to heat a second liquid |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1168226A true CA1168226A (en) | 1984-05-29 |
Family
ID=4121642
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000392560A Expired CA1168226A (en) | 1981-12-17 | 1981-12-17 | System for recovering heat from a first liquid and using it to heat a second liquid |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1168226A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4655278A (en) * | 1985-09-27 | 1987-04-07 | Cambridge Manufacturing Climate Control Products Inc. | Heat recirculation apparatus and method |
-
1981
- 1981-12-17 CA CA000392560A patent/CA1168226A/en not_active Expired
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4655278A (en) * | 1985-09-27 | 1987-04-07 | Cambridge Manufacturing Climate Control Products Inc. | Heat recirculation apparatus and method |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US5286351A (en) | Water distilling method | |
| US5304286A (en) | Water supply system | |
| US4207752A (en) | Method and apparatus for recovering heat from waste water | |
| CN207816068U (en) | A kind of bath water waste-heat recovery device and system | |
| CN105276665A (en) | Household heating supply system for domestic wastewater waste heat recovery | |
| CA1162917A (en) | System for recovering heat from a first liquid and using it to heat second liquid | |
| CA1168226A (en) | System for recovering heat from a first liquid and using it to heat a second liquid | |
| GB2060864A (en) | Method and plant for heat recovery from sewage water | |
| JP2002195651A (en) | Hot-water supply system utilizing waste heat | |
| JPS628695B2 (en) | ||
| JP2548667B2 (en) | Heat exchange device between dirty hot waste water and fresh water | |
| JPS57127745A (en) | Solar water heater | |
| GB2304877A (en) | Water supply with heat recovery | |
| CN206486921U (en) | A kind of intelligent environmental protection type house water system | |
| EP0059692A3 (en) | Combined refrigerator/water heater unit | |
| JPH0658624A (en) | Heat recovery device for waste water of bathroom | |
| CA1148934A (en) | Waste water heat recovery system | |
| EP0088055A1 (en) | Device for recovering heat from domestic water | |
| CN102980299A (en) | Waste-water waste-heat recycling water-heater | |
| JP3589026B2 (en) | Heat pump type bath hot water supply system | |
| CA1040945A (en) | Waste water heat recovery unit | |
| CN219489652U (en) | Heat collecting type household solar heating ultrapure water device | |
| CN208130810U (en) | A kind of film deamination and phase-separation system heat energy comprehensive utilization device | |
| KR200311555Y1 (en) | Water distiller with hot water supplyer | |
| CN201434523Y (en) | Solar energy multifunctional water heater |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |