CA2611709A1 - Drainpipe heat exchanger - Google Patents
Drainpipe heat exchanger Download PDFInfo
- Publication number
- CA2611709A1 CA2611709A1 CA002611709A CA2611709A CA2611709A1 CA 2611709 A1 CA2611709 A1 CA 2611709A1 CA 002611709 A CA002611709 A CA 002611709A CA 2611709 A CA2611709 A CA 2611709A CA 2611709 A1 CA2611709 A1 CA 2611709A1
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- CA
- Canada
- Prior art keywords
- heat exchanger
- heat
- conduit
- heat transfer
- cold water
- 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.)
- Abandoned
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Classifications
-
- E—FIXED CONSTRUCTIONS
- E03—WATER SUPPLY; SEWERAGE
- E03C—DOMESTIC PLUMBING INSTALLATIONS FOR FRESH WATER OR WASTE WATER; SINKS
- E03C1/00—Domestic plumbing installations for fresh water or waste water; Sinks
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F28—HEAT EXCHANGE IN GENERAL
- F28D—HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT
- F28D21/00—Heat-exchange apparatus not covered by any of the groups F28D1/00 - F28D20/00
- F28D21/0001—Recuperative heat exchangers
- F28D21/0012—Recuperative heat exchangers the heat being recuperated from waste water or from condensates
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F28—HEAT EXCHANGE IN GENERAL
- F28D—HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT
- F28D7/00—Heat-exchange apparatus having stationary tubular conduit assemblies for both heat-exchange media, the media being in contact with different sides of a conduit wall
- F28D7/0008—Heat-exchange apparatus having stationary tubular conduit assemblies for both heat-exchange media, the media being in contact with different sides of a conduit wall the conduits for one medium being in heat conductive contact with the conduits for the other medium
-
- E—FIXED CONSTRUCTIONS
- E03—WATER SUPPLY; SEWERAGE
- E03C—DOMESTIC PLUMBING INSTALLATIONS FOR FRESH WATER OR WASTE WATER; SINKS
- E03C1/00—Domestic plumbing installations for fresh water or waste water; Sinks
- E03C2001/005—Installations allowing recovery of heat from waste water for warming up fresh water
-
- 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]
- Y02B30/56—Heat recovery units
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- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Hydrology & Water Resources (AREA)
- Public Health (AREA)
- Water Supply & Treatment (AREA)
- Heat-Exchange Devices With Radiators And Conduit Assemblies (AREA)
Abstract
The present invention is a jacket-type heat exchanger which may, for example , be used to replace or fit over a section of drainpipe to heat fresh cold water using th e waste heat in the drainwater. Normal cold water pressure is used to create an internal-expandi ng force on the inner thermal contact wall of the jacket, which, in turn, creates an enormous heat - transfer clamping force on the drainpipe for fast heat transfer. A longitudinal gap in the jacket (or a two-piece jacket) enables clamping movement. An external sleeve resists bulging of the outer jacket wall. The heated cold water is plumbed to a faucet or water heater so as to reduce hot water use, which, in turn, reduces energy use and related environmental damage. Double- wall construction and venting for visible leak detection satisfies plumbing code requirements. A horizontal embodiment discloses a two-piece plastic-copper drainwater heat exchanger. U se on vehicular exhaust pipes is also contemplated for providing instant interior heat and/or motor warm-up.
Description
SPECIFICATIONS
FIELD OF THE INVENTION
A heat exchanger for use on drain- or exhaust pipes for heat recovery and in particular for drainwater heat recovery in buildings and from individual plumbing fixtures such as sinks and for use over existing drainpipes that cannot have their flow interrupted by their temporary removal/
replacement. Heating cold water to make hot water for cleaning and then discarding the heat along with the dirty hot water is expensive, wasteful and environmentally damaging. It is estimated that in North America some $15 billion dollars is spent annually on fuel to heat water.
The fuel's exhaust and the discarded heat in the used hot water contribute doubly to global warming and a lower standard of living. Speeding up heating of vehicle occupants using waste exhaust heat is also contemplated.
BACKGROUND OF THE INVENTION
A shortcoming of traditional drainwater heat recovery (DHR) methods is cost effectiveness.
This can be partly attributed to the poor use of the heat transfer surface area of the expensive copper tubing used. Even more so if laid horizontally which is often necessary.
Traditionally, copper tubing is wrapped around a vertical copper drainpipe to make the DHR
heat exchanger. It operates on a l long-known heat exchanger design called Falling Film.
(In Falling Film heat exchangers, a liquid is made to flow, ideally, in an even, tubular film or sheet clinging to the entire inner vertical tube wall. More information on falling film heat exchangers can be found at: The Chemical Educator, Vol. 6, No. 1, published on Web 12/15/2000, 10.1007/s00897000445a, 2001 Springer-Verlag New York, Inc., and, US patent #
4,619,311 to Vasile discloses a equal volume Falling Film DHR heat exchanger.) The traditional DHR is in many ways ideal for DHR because it allows the passage of large solids and other matter contained in a building's drainwater without blockage.
Cold water to be heated first passes through the outer coiled tubing at the same time as when drainwater is 'falling' down the inside straight tube. Thus showering and sink rinsing are the principal modes for such DHR devices because only then is cold water flowing into the hot water exactly while the drain taking away the now-dirty hot water.
However the traditional coil-on-tube design results in a narrow spiral contact patch totaling less than a third of the available surface area of the expensive coiled copper tubing. Thus the use of copper tubing makes DHR cost-ineffective in many applications especially where hot water use is low. Further, the long length of the coil (up to 100 feet) and the fact that it flattens somewhat as it is wound, creates internal resistance to flow and an unwanted drop in water pressure which necessitates larger, more expensive tubing, and/or multiple.
parallel coils, both of which add to cost.
In the instant invention, instead of tubing, sheet copper is used. This dramatically lowers cost, increases contact area, and eliminates pressure drop. For example, in a 5 foot long, 4 inch diameter drainpipe, only 2/3 the weight of copper is needed for the cold water exchanger and, a much higher percentage of that copper surface is used for heat transfer.
Further, the instant invention allows for very compact, small diameter DHR (i.e., a 11/a inch diameter sink drainpipe) for individual fixtures and appliances which is not practical with wrapped tube designs due to the bend radius limitation of suitably sized outer tubing. Thus with the instant invention DHR is made significantly more cost effective and more widely usable.
SUMMARY OF THE INVENTION
In one embodiment, the instant heat exchanger invention sheet copper is formed into a tubular, hollow, pressurized jacket (with spaced inner and outer walls), and with a longitudinal gap or opening between the walls to allow for constriction by clamping onto a drain tube by exterior band clamps and by the effect of the internal pressure. Normal mains cold water supply maintains an internal pressurize inside the jacket heat exchanger. This pressure would balloon the inner wall of the jacket but instead the force is applied to the surface of the drainpipe about which it is installed thereby creating an enormous contact force between the jacket and the drainpipe for best thermal conduction. An outer sleeve (or shaped shoes for the horizontal embodiment)) and clamps restrains the outer jacket wall.
In one application the jacket is slid over and clamped onto the exterior of a conduit, such as a drainpipe, from which heat is to be transferred. In another it is pre-assembled with a drainpipe which then replaces a section of existing drainpipe. In yet another, it is in two halves which are assembled onto a drainpipe that remains in operation. A second embodiment for horizontal installation uses a flattened, half round, straight drain tube with the cold water heat exchanger taking the form of a flat, hollow, pressurized shallow trough located under the flat drain tube and bound to it with outer shaped restraining shoes and clamping bands. Internal water pressure again forces thermal contact therebetween. The trough may also be in the form of a flat, hollow rectangular tube. The flattened drain tube may be a composite of an upper plastic portion bonded to a lower copper portion to lower costs.
In use, a sink or bathtub-type shower may have the instant heat exchanger beneath it such that cold water is pre-heated before reaching the cold water faucet. In this way less hot water is needed to mix with the now-warm cold water to achieve the desired temperature.
Less hot water use saves energy and money and pollution, and, if electrically heated, lowers peak power demand.
The sheet copper should be creased diagonally where thermal contact will occur to serve as a vent for visible leak detection (a drip path onto the floor). The sheet is then formed into an "outline C shape", or, double walled hollow tube structure with a longitudinal gap. The outer wall of the jacket is punched to receive soldered-on pipe fittings for the cold water supply and the ends are sealed with "C" shaped rings of copper tubing, rod or twisted wire, dip-soldered into place between the tops of the walls. In another embodiment the fittings are attached to the jacket ends and the copper squeezed-close about the fittings and soldered. A thick, stiff plastic sleeve fits over the unit and band clamps around the sleeve completes the assembly.
The cold water pressure hydraulically clamps the jacket to the drainpipe which clamping movement is allowed by the longitudinal gap. This high-force hydraulic clamping maximizes heat transfer which increases with contact pressure. For example, if the drainpipe is 3 inches in diameter and the jacket 24 inches long and the cold water is at 50 pounds per square inch pressure, the contact force will be approximately:
3.14 (n) x 3 x 24 x 50 = 11,304 pounds, or 5'h tons of contact force!
Not only dose such an enormous force provide excellent heat transfer but it does so evenly over its entire length. This would be extremely difficult or impossible to achieve by any mechanical clamping method Where the instant invention is to be installed on an existing drainpipe already permanently in place, the jacket may be made in two halves (or hinged) with duplicate fittings to connect to the cold water supply. The plastic jacket would also be in two halves (or hinged).
In some cases only a lower half-jacket may be appropriate to reduce cost when using it on a horizontal drainpipe for example.
Use of the instant invention is also contemplated on vehicle exhaust pipes.
So, for example, a stainless steel model, with a metallic outer retaining sleeve, may be fitted to an exhaust pipe of a car to provide double-walled-safe, hot air to the car interior in cold weather. Although the internal pressure-clamp feature may be duplicated using compressed air and flow restrictors, the complexity along with the huge temperature differential available (some 500 degrees F) may obviate using only the simpler external clamping arrangement and internal fins to transmit the clamping force onto the inner wall of the jacket, especially since there is no scum or solids that would lead to blockage. The recovered heat can be used to heat the vehicle's interior and/or its motor and/or a heat storage medium.
In all embodiments, internal baffles, walls, dams (as in a weir) or fins can be incorporated to distribute fluid flow, optimize heat transfer and to distribute the external clamping force.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 shows an partial section end view of the central heat transfer portion of one embodiment where the fluid to heated or cooled is shown entering the cold water heat exchanger via a bottom fitting;
Figures 2, 3, 4 shows the same embodiment in a sequence of forming steps to seal of the two ends of the lower conduit against the internal pressure of, for example, a building's water supply;
Figure 5 shows the same embodiment in side view showing the sealed ends of the cold water heat exchanger, its lower fittings, and, the adapted ends of the drainwater heat exchanger that connect to regular drainpipes and where the right end of the drainwater heat exchanger is shown to have an added adaptor while the left end is shown to have been formed into a short cylindrical shape in both cases the flow path is flush such that there is no 'step-up' to impede drainwater flow out of upper conduit;
Figure 6 shows an adaptor for the drainwater heat exchanger formed, for example, from a suitable plastic material;
Figure 7 shows an end view of another embodiment where the drainwater heat exchanger's end's are formed to rectangular sockets to receive rectangular solder-type plumbing fittings and a plug, and where the excess material is closed off to be sealed by soldering at the same time that the fitting is inserted, and showing an internal distribution tube enclosed therein;
Figure 8 shows a copper solder-type fitting having one end formed to a rectangular shape for insertion in the formed end socket of the drainwater heat exchanger;
Figure 9 shows a copper plug to be soldered in the unused socket openings;
Figure 10 shows a side view of the same embodiment as figure 7 showing the end location of the drainwater heat exchanger fittings. Figure 11 shows a top view in section of a one-piece heat exchanger into which a drainpipe/exhaust would be inserted through from one end;
Figure 12 shows a top section view of a two-piece design for clamping about an already installed drainpipe/exhaust pipe;
Figure 13 shows a side view with the outer clamping sleeve and clamps in section and showing the fluid fittings and the location of the end sealing members;
Figure 14 shows a top view of the sealing ring member made from tube or rod although a stamped sheet design may be more economical in production;
Figure 15 show a side view of the sealing member;
Figure 16 shows a possible use of the joint flange where it has various notches to direct the cold water flow to be as even as possible over the inner wall so as to maximize heat transfer by maintaining the best temperature differential.
Figure 17 shows a thin, flat cold water tube clamped against the flat lower surface of the drainwater conduit;
Figure 18 is a cross section of the same embodiment;
Figure 19 is a cross section showing how the drainwater heat exchanger may be a two piece design with the upper portion in plastic and the lower in sheet copper bonded together along the length, and, with tension walls of sheet copper to transmit the internal pressure in the cold water exchanger to the clamping structure;
Figure 20 is a side view of the same embodiment showing how the drainwater flow may be made to enter from the top at the inlet end and to collect in a cross tube arrangement outlet fitting at the exit end;
Figure 21 shows a perspective view of the outlet fitting;
Figure 22 is a top view looking into the vertical design for the top and bottom where the cold water is made to flow past a gap formed by an annular ring so as to sweep the entire heat circumference of the transfer surface area from bottom to top;
Figure 23 is a cross section side view of the same embodiment showing how the cold water inlet is located between the end cap and the annular flow dam- or weir ring;
Figure 24 is an end view of a horizontal drainwater heat exchanger's lower surface with a gully shape along the middle of the flow path to resist upward bulging;
Figure 25 shows the same embodiment shaped as an oval.
DETAILED DESCRIPTION OF THE INVENTION
Two basic embodiments are disclosed, vertical heat exchanger 100, and horizontal heat exchanger 200. One novel feature of the instant invention is the use of this internal water pressure to create very high thermal contact force with the drainwater heat exchanger to provide high performance heat recovery.
In Fig 1 vertical heat exchanger 100 has an upper drainwater heat exchanger 60 and a lower cold water heat exchanger 50 held tightly together with bands 12 (Figs 5,10) or a suitable sleeve (not shown). Drainwater heat exchanger 60 comprises wall 1 with drainwater A
flowing along b......,..a,:,.. .. . . . ..._. ... ....... .. ....... . . .
flattened bottom surface 1' of wall 1 to thereby form a hemicylinder that transfers heat to fluid B
which enters and exists cold water heat exchanger 50 via fittings 10, 11 or alternately via end fittings 80.
Cold water heat exchanger 50 is shown being made of flat sheet copper formed with longitudinal hems 4 that are solder joined to create a generally "C shaped"
hemicylindrical conduit with flat surface 5. Hem 4 also serves as a heat conductive fin and, as a result of the bend curvature 6, provides a longitudinal vent 6 to the ambient for leak detection.
In one embodiment, wall 2 of conduit 50 has wings 3 which contact the side of the drainwater heat exchanger 60 to create additional surface for heat transfer. In Figs 2, 3, 4 cold water heat exchanger 50 is shown having a short end portion of hem 4 folded flat in preparation for sealing the ends. The wings 3 are pinched closed and excess metal is pulled into additional seams 3'. In Fig 4 is shown a dotted line 2 that represents the original cold water heat exchanger 50 shape.
In Fig 7 is shown an alternate way of sealing the ends of cold water heat exchanger 50 so as to provide in-line connection sockets 33', 34'. The two sockets at each end (4 in total) are formed on each side of hem 4 using an appropriate mandrel about which the remaining wall 3 and wing 2 are squeezed to bring them together as a seam to be soldered. Appropriate surfaces can be 'tinned' with solder prior to the forming and soldering.
In Fig 8, fluid fitting 80 has rectangular end 33 inserted and soldered into socket 33' or 34' (at each end of cold water heat exchanger 50) or both, and has a round end 30 for connecting to standard plumbing. Fitting 80 may also be an end of a longer tube where installation conditions warrant. Alternatively one of the two rectangular shapes 33' and 34' may be blocked with a simple plug 34 as indicated in Fig 9. Interior to cold water heat exchanger 50 and inline with the socket 33' and/or 34' is a plastic fluid distribution tube 35' which extends full length and is closed at the far end and has cross apertures at intervals. The purpose of tube 35' is to direct fluid B to cause at least some second fluid to flow at least partially crosswise creating turbulence and evening out flow velocity across the width of cold water heat exchanger 50.
In Fig 5 horizontal heat exchanger 200 is shown having the upper drainwater heat exchanger 60 made from a flattened tube, and lower cold water heat exchanger 50 (for, say, cold water) formed of sheet material bound together by bands 12. In some uses the upper drainwater heat exchanger 60 may also be formed from sheet to reduce cost. In either case the ends of drainwater heat exchanger 60 can be adapted to connect with existing round drain pipes the right end of the drainwater heat exchanger having a separate, bonded-on adaptor 70, while the left end adaptor 70 is shown as having an integrally formed round end 20'. It is important that the drainwater heat exchanger provides a flush flow path especially at the exit end so that solids in the drainwater will not hook and collect at the region of transition from flat to round. This can be achieved by forming a recess in the "D' shaped end of the bonded on adaptor equal to the thickness of the drainwater heat exchanger material. The bonding region is shown at overlap 20'.
Fig 5 shows fluid B, such as cold water for a water heater, entering fitting 10 at the left to counterflow horizontally under the drainwater water heat exchanger 60 and exit via fitting 11 on the right having absorbed (or given up) heat from warmer (or colder) drainwater'. Drainwater A
flows horizontally with a first temperature A' at inlet on right side and a different temperature A"
at outlet on left side. Fig 6 shows adaptor 70 having a "D" shaped first end 20' for bonding to drainwater heat exchanger 60 and a round end 20 for connecting to existing drainpipe. Adaptor 70 may also be made of molded rubber with a shaped shoe 22 under the flat portion 20' to provide even clamping pressure.
In use, by connecting cold water heat exchanger 50 to a pressurized fluid supply, an enormous thermal transfer contact force is created between the flat surfaces of heat exchangers 50 and 60 and is restrained by bands 12 (or a sleeve, not shown) to provide exceptional heat transfer therebetween. For example, with a 4 inch wide flat that is 50 inches long and with a pressure of 40 pounds per square inch, the contact force is some 8,000 pounds. This force custom forms typically imperfectly flat surfaces 1' and 5 into intimate contact.
With the instant invention, horizontally flowing drainwater, whose valuable heat energy is normally wasted, can be cooled by this low profile heat exchanger 200 by heat transfer to the cold water supply of the water heater to thereby shorten the time it takes to fully heat hot water and which, in turn, saves energy and money and provides more hot water due to faster recovery after its use. It may also be used to cool a flow of warmer water feeding, for example, an ice cube maker, using colder drainwater from a ice-filled sink. In all figures the drainpipe or exhaust pipe is indicated as A and the fluid whose temperature is to be changed is B. Heat exchanger 20 may be used to heat or cool fluid B. Although gaps between surfaces are shown in the figures (for clarity) it is understood that there is intimate contact between heat transfer and clamping surfaces.
In Figs 11-13 heat exchanger 100 is a jacket(s) comprising an inner heat transfer wall 5 and outer retaining wall 2 spaced apart for fluid flow therebetween with minimal resistance. This space may be, say,'/a inch. The walls are contiguous and formed from a single piece of thin sheet metal (copper) using reversing bends 112 and lap joint 5'. This leaves a longitudinal opening or gap 111 between bends 112 to accommodate movement from external mechanical clamping forces and internal hydraulic clamping forces. The jacket may also be formed by extrusion in which case finning 115 (representative fins only, shown in Fig 11) and fluid control elements 114 may be easily included on the inner wall 5 and/or outer wall 2. Outer clamping sleeve 116 with gap 113 closes tightly around and distributes clamping forces from band or hose clamps 12 to prevent expansion or bulging of outer wall 2 from the internal pressure of fluid B such as that from a building's cold water supply. Inner wall 1 is however free to bulge against drainpipe 1 by that same internal pressure.
Joint 5' is a soldered lap joint and may include longitudinal joint flange 110 which can act as a fluid flow equalizer and a stabilizer/spacer for aligning the sheet metal during soldering. Inlets(s) and outlet(s) 11 are connections for fluid B whose temperature is to be changed.
Representative fluid control element 114 may be many in number and take various shapes such as mesh, rods, screen, angles, etc., such as to direct, for example, flow of fluid B over element 114 as indicated by dashed flow arrow 114', to help effect best heat transfer from inner wall 5 by the fluid 'sweeping' the surface of inner wall as fully as possible.
Element(s) 114 may also be used to create turbulent flow which is known to improve heat transfer. Element 114 may also be shaped and located to deflect fluid B inflow at inlet 10 to avoid erosion corrosion of the small area of the inner wall by the fluid impinging on it perpendicularly at full velocity.
Fig 12 shows the hollow, tubular nature of the heat exchanger 100 as fitted onto a vertical drainpipe A. Sealing rings 34 are shown in dotted line and are soldered into the annular space between the inner and outer wall ends at top and bottom. Although a tubular shape is shown, other shapes such as oval are contemplated where, for example, fitting clearance is a concern.
Figs 14 and 15 show the sealing member 34 which can be made from rolled rod, tube or twisted wire bundle to fit snugly into the annular space and have a gap 111' to coordinate with gap 111. They may be made by winding a long piece onto a mandrel of the correct diameter into the form of a coil spring and then sawing through the coil to free individual rings which are then made planar as in Fig 15. Dip soldering is a fast method of construction.
Fig 16 shows a method of using the longitudinal joint flange 110 as a flow controller by providing restriction to flow directly from fitting 10 such that fluid B is forced through spaced vias 120 to travel across inner wall 5 to reach outlet 11 thereby improving heat removal from drainpipe I. Flange 110 may also simply be more simply double-tapered (not shown) from full . . ... . _. . .. .:.v -.n..~~v_...e._...b.,._.._ _.. ....... .. , . .. .
width at the center tapering to nil at each end to even out flow along its length, especially if the fittings 10 and 11 are positioned centrally and opposite one another.
Fig 12 shows the cold water heat exchanger in two halves with inlets 10 and outlets 11 on each half. The outer sleeve 116 and clamps 12 are not shown. The outer sleeve 112 would of course be in two pieces either separate or hinged for ease of assembly onto the drainpipe in a building. The sealing rings 34 (not shown in Fig 12) would of course be four in number each being a half ring, one at each of the four ends.
Fig 17 shows another embodiment of horizontal heat exchanger 200 where the cold water heat exchanger 2 comprises a sheet copper duct or tube in the form of a flat, rectangular hollow strip or bar. It is sealed at each end and may have flow-forming controllers to ensure that the entering cold water flows as a flat sheet of water to the outlet so as to recover heat from the entire heat transfer surface area. Fig 18 shows a cross section of the same embodiment where the drainwater heat exchanger is shown to be a flattened, hemi-cylindrical tube 1 forced into intimate, conforming thermal contact therewith with shoes 130, 131 and clamp bands 12.
Fig 18 shows a cross-section of the heat exchanger 200.
In Fig 19 drainwater heat exchanger I is comprised of a trough-like lower portion in sheet copper through which heat transfer takes place and a U-shaped plastic upper portion bonded lb thereto, the two creating a hybrid drainpipe of rounded rectangular form. This heat exchanger is conceived as a low cost device for use where there are no large solids in the drainwater, more specifically for use under a shower or sink. Interior longitudinal supports lc act to transmit compressive load from cold water heat exchanger 2 to shoe 130 and bands 12 thereby maintaining a flat profile for the trough. Supports lc may be wavy to create a desirable turbulent flow. Supports Ic also act as fins to extend heat transfer surface area.
Fig 20 shows the same embodiment with different drainpipe connection fittings.
Inlet 200" is a vertical right angle inlet centered on plastic top la and outlet 200' is a horizontal right angle ...I.. .. . om =:-.:, -fitting shown in more detail in Fig 21, having an end cap and a slot 201 which matches the shape of the end of heat exchanger 1, la, lb (Fig 19) and is bonded and sealed thereto. A slight slope to outlet 200' carries away the final drainwater drips to drain heat exchanger 1 dry.
In Fig 22 vertical heat exchanger 100 has an inner heat transfer surface 5 and ring-shaped flow controller 110' dam which leaves an annular gap 120' adjacent heat transfer surface 5. End seals 34 (Fig 23) and flow controller 110 are spaced apart vertically creating a circular chamber so that fluid fitting 11 feeds fluid therebetween. Fluid B then must leave the chamber as a full curvilinear sheet flow B' against heat transfer surface 5 so as to sweep heated (or cooled) fluid towards the outlet which is similarly configured. This ensures that a maximum temperature differential can be maintained to optimize heat transfer. This annular flow control arrangement may be used to advantage in all the aforementioned heat exchangers. In the case of horizontal heat exchangers 200 the controller would take the form of a rectangular bridge held raised a small distance below the heat transfer surface by stand-off formations at the controller ends.
Figs 24 and 25 show variations on the profile of the flow surface 1' of the drainwater heat exchanger 1 with the purpose of stiffening the flow surface 1' to resist upward bulging from the expansive potential of the pressurized cold water exchanger below. The cold water exchanger 2 is shown to be conforming in shape so as to maintain maximum thermal contact.
FIELD OF THE INVENTION
A heat exchanger for use on drain- or exhaust pipes for heat recovery and in particular for drainwater heat recovery in buildings and from individual plumbing fixtures such as sinks and for use over existing drainpipes that cannot have their flow interrupted by their temporary removal/
replacement. Heating cold water to make hot water for cleaning and then discarding the heat along with the dirty hot water is expensive, wasteful and environmentally damaging. It is estimated that in North America some $15 billion dollars is spent annually on fuel to heat water.
The fuel's exhaust and the discarded heat in the used hot water contribute doubly to global warming and a lower standard of living. Speeding up heating of vehicle occupants using waste exhaust heat is also contemplated.
BACKGROUND OF THE INVENTION
A shortcoming of traditional drainwater heat recovery (DHR) methods is cost effectiveness.
This can be partly attributed to the poor use of the heat transfer surface area of the expensive copper tubing used. Even more so if laid horizontally which is often necessary.
Traditionally, copper tubing is wrapped around a vertical copper drainpipe to make the DHR
heat exchanger. It operates on a l long-known heat exchanger design called Falling Film.
(In Falling Film heat exchangers, a liquid is made to flow, ideally, in an even, tubular film or sheet clinging to the entire inner vertical tube wall. More information on falling film heat exchangers can be found at: The Chemical Educator, Vol. 6, No. 1, published on Web 12/15/2000, 10.1007/s00897000445a, 2001 Springer-Verlag New York, Inc., and, US patent #
4,619,311 to Vasile discloses a equal volume Falling Film DHR heat exchanger.) The traditional DHR is in many ways ideal for DHR because it allows the passage of large solids and other matter contained in a building's drainwater without blockage.
Cold water to be heated first passes through the outer coiled tubing at the same time as when drainwater is 'falling' down the inside straight tube. Thus showering and sink rinsing are the principal modes for such DHR devices because only then is cold water flowing into the hot water exactly while the drain taking away the now-dirty hot water.
However the traditional coil-on-tube design results in a narrow spiral contact patch totaling less than a third of the available surface area of the expensive coiled copper tubing. Thus the use of copper tubing makes DHR cost-ineffective in many applications especially where hot water use is low. Further, the long length of the coil (up to 100 feet) and the fact that it flattens somewhat as it is wound, creates internal resistance to flow and an unwanted drop in water pressure which necessitates larger, more expensive tubing, and/or multiple.
parallel coils, both of which add to cost.
In the instant invention, instead of tubing, sheet copper is used. This dramatically lowers cost, increases contact area, and eliminates pressure drop. For example, in a 5 foot long, 4 inch diameter drainpipe, only 2/3 the weight of copper is needed for the cold water exchanger and, a much higher percentage of that copper surface is used for heat transfer.
Further, the instant invention allows for very compact, small diameter DHR (i.e., a 11/a inch diameter sink drainpipe) for individual fixtures and appliances which is not practical with wrapped tube designs due to the bend radius limitation of suitably sized outer tubing. Thus with the instant invention DHR is made significantly more cost effective and more widely usable.
SUMMARY OF THE INVENTION
In one embodiment, the instant heat exchanger invention sheet copper is formed into a tubular, hollow, pressurized jacket (with spaced inner and outer walls), and with a longitudinal gap or opening between the walls to allow for constriction by clamping onto a drain tube by exterior band clamps and by the effect of the internal pressure. Normal mains cold water supply maintains an internal pressurize inside the jacket heat exchanger. This pressure would balloon the inner wall of the jacket but instead the force is applied to the surface of the drainpipe about which it is installed thereby creating an enormous contact force between the jacket and the drainpipe for best thermal conduction. An outer sleeve (or shaped shoes for the horizontal embodiment)) and clamps restrains the outer jacket wall.
In one application the jacket is slid over and clamped onto the exterior of a conduit, such as a drainpipe, from which heat is to be transferred. In another it is pre-assembled with a drainpipe which then replaces a section of existing drainpipe. In yet another, it is in two halves which are assembled onto a drainpipe that remains in operation. A second embodiment for horizontal installation uses a flattened, half round, straight drain tube with the cold water heat exchanger taking the form of a flat, hollow, pressurized shallow trough located under the flat drain tube and bound to it with outer shaped restraining shoes and clamping bands. Internal water pressure again forces thermal contact therebetween. The trough may also be in the form of a flat, hollow rectangular tube. The flattened drain tube may be a composite of an upper plastic portion bonded to a lower copper portion to lower costs.
In use, a sink or bathtub-type shower may have the instant heat exchanger beneath it such that cold water is pre-heated before reaching the cold water faucet. In this way less hot water is needed to mix with the now-warm cold water to achieve the desired temperature.
Less hot water use saves energy and money and pollution, and, if electrically heated, lowers peak power demand.
The sheet copper should be creased diagonally where thermal contact will occur to serve as a vent for visible leak detection (a drip path onto the floor). The sheet is then formed into an "outline C shape", or, double walled hollow tube structure with a longitudinal gap. The outer wall of the jacket is punched to receive soldered-on pipe fittings for the cold water supply and the ends are sealed with "C" shaped rings of copper tubing, rod or twisted wire, dip-soldered into place between the tops of the walls. In another embodiment the fittings are attached to the jacket ends and the copper squeezed-close about the fittings and soldered. A thick, stiff plastic sleeve fits over the unit and band clamps around the sleeve completes the assembly.
The cold water pressure hydraulically clamps the jacket to the drainpipe which clamping movement is allowed by the longitudinal gap. This high-force hydraulic clamping maximizes heat transfer which increases with contact pressure. For example, if the drainpipe is 3 inches in diameter and the jacket 24 inches long and the cold water is at 50 pounds per square inch pressure, the contact force will be approximately:
3.14 (n) x 3 x 24 x 50 = 11,304 pounds, or 5'h tons of contact force!
Not only dose such an enormous force provide excellent heat transfer but it does so evenly over its entire length. This would be extremely difficult or impossible to achieve by any mechanical clamping method Where the instant invention is to be installed on an existing drainpipe already permanently in place, the jacket may be made in two halves (or hinged) with duplicate fittings to connect to the cold water supply. The plastic jacket would also be in two halves (or hinged).
In some cases only a lower half-jacket may be appropriate to reduce cost when using it on a horizontal drainpipe for example.
Use of the instant invention is also contemplated on vehicle exhaust pipes.
So, for example, a stainless steel model, with a metallic outer retaining sleeve, may be fitted to an exhaust pipe of a car to provide double-walled-safe, hot air to the car interior in cold weather. Although the internal pressure-clamp feature may be duplicated using compressed air and flow restrictors, the complexity along with the huge temperature differential available (some 500 degrees F) may obviate using only the simpler external clamping arrangement and internal fins to transmit the clamping force onto the inner wall of the jacket, especially since there is no scum or solids that would lead to blockage. The recovered heat can be used to heat the vehicle's interior and/or its motor and/or a heat storage medium.
In all embodiments, internal baffles, walls, dams (as in a weir) or fins can be incorporated to distribute fluid flow, optimize heat transfer and to distribute the external clamping force.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 shows an partial section end view of the central heat transfer portion of one embodiment where the fluid to heated or cooled is shown entering the cold water heat exchanger via a bottom fitting;
Figures 2, 3, 4 shows the same embodiment in a sequence of forming steps to seal of the two ends of the lower conduit against the internal pressure of, for example, a building's water supply;
Figure 5 shows the same embodiment in side view showing the sealed ends of the cold water heat exchanger, its lower fittings, and, the adapted ends of the drainwater heat exchanger that connect to regular drainpipes and where the right end of the drainwater heat exchanger is shown to have an added adaptor while the left end is shown to have been formed into a short cylindrical shape in both cases the flow path is flush such that there is no 'step-up' to impede drainwater flow out of upper conduit;
Figure 6 shows an adaptor for the drainwater heat exchanger formed, for example, from a suitable plastic material;
Figure 7 shows an end view of another embodiment where the drainwater heat exchanger's end's are formed to rectangular sockets to receive rectangular solder-type plumbing fittings and a plug, and where the excess material is closed off to be sealed by soldering at the same time that the fitting is inserted, and showing an internal distribution tube enclosed therein;
Figure 8 shows a copper solder-type fitting having one end formed to a rectangular shape for insertion in the formed end socket of the drainwater heat exchanger;
Figure 9 shows a copper plug to be soldered in the unused socket openings;
Figure 10 shows a side view of the same embodiment as figure 7 showing the end location of the drainwater heat exchanger fittings. Figure 11 shows a top view in section of a one-piece heat exchanger into which a drainpipe/exhaust would be inserted through from one end;
Figure 12 shows a top section view of a two-piece design for clamping about an already installed drainpipe/exhaust pipe;
Figure 13 shows a side view with the outer clamping sleeve and clamps in section and showing the fluid fittings and the location of the end sealing members;
Figure 14 shows a top view of the sealing ring member made from tube or rod although a stamped sheet design may be more economical in production;
Figure 15 show a side view of the sealing member;
Figure 16 shows a possible use of the joint flange where it has various notches to direct the cold water flow to be as even as possible over the inner wall so as to maximize heat transfer by maintaining the best temperature differential.
Figure 17 shows a thin, flat cold water tube clamped against the flat lower surface of the drainwater conduit;
Figure 18 is a cross section of the same embodiment;
Figure 19 is a cross section showing how the drainwater heat exchanger may be a two piece design with the upper portion in plastic and the lower in sheet copper bonded together along the length, and, with tension walls of sheet copper to transmit the internal pressure in the cold water exchanger to the clamping structure;
Figure 20 is a side view of the same embodiment showing how the drainwater flow may be made to enter from the top at the inlet end and to collect in a cross tube arrangement outlet fitting at the exit end;
Figure 21 shows a perspective view of the outlet fitting;
Figure 22 is a top view looking into the vertical design for the top and bottom where the cold water is made to flow past a gap formed by an annular ring so as to sweep the entire heat circumference of the transfer surface area from bottom to top;
Figure 23 is a cross section side view of the same embodiment showing how the cold water inlet is located between the end cap and the annular flow dam- or weir ring;
Figure 24 is an end view of a horizontal drainwater heat exchanger's lower surface with a gully shape along the middle of the flow path to resist upward bulging;
Figure 25 shows the same embodiment shaped as an oval.
DETAILED DESCRIPTION OF THE INVENTION
Two basic embodiments are disclosed, vertical heat exchanger 100, and horizontal heat exchanger 200. One novel feature of the instant invention is the use of this internal water pressure to create very high thermal contact force with the drainwater heat exchanger to provide high performance heat recovery.
In Fig 1 vertical heat exchanger 100 has an upper drainwater heat exchanger 60 and a lower cold water heat exchanger 50 held tightly together with bands 12 (Figs 5,10) or a suitable sleeve (not shown). Drainwater heat exchanger 60 comprises wall 1 with drainwater A
flowing along b......,..a,:,.. .. . . . ..._. ... ....... .. ....... . . .
flattened bottom surface 1' of wall 1 to thereby form a hemicylinder that transfers heat to fluid B
which enters and exists cold water heat exchanger 50 via fittings 10, 11 or alternately via end fittings 80.
Cold water heat exchanger 50 is shown being made of flat sheet copper formed with longitudinal hems 4 that are solder joined to create a generally "C shaped"
hemicylindrical conduit with flat surface 5. Hem 4 also serves as a heat conductive fin and, as a result of the bend curvature 6, provides a longitudinal vent 6 to the ambient for leak detection.
In one embodiment, wall 2 of conduit 50 has wings 3 which contact the side of the drainwater heat exchanger 60 to create additional surface for heat transfer. In Figs 2, 3, 4 cold water heat exchanger 50 is shown having a short end portion of hem 4 folded flat in preparation for sealing the ends. The wings 3 are pinched closed and excess metal is pulled into additional seams 3'. In Fig 4 is shown a dotted line 2 that represents the original cold water heat exchanger 50 shape.
In Fig 7 is shown an alternate way of sealing the ends of cold water heat exchanger 50 so as to provide in-line connection sockets 33', 34'. The two sockets at each end (4 in total) are formed on each side of hem 4 using an appropriate mandrel about which the remaining wall 3 and wing 2 are squeezed to bring them together as a seam to be soldered. Appropriate surfaces can be 'tinned' with solder prior to the forming and soldering.
In Fig 8, fluid fitting 80 has rectangular end 33 inserted and soldered into socket 33' or 34' (at each end of cold water heat exchanger 50) or both, and has a round end 30 for connecting to standard plumbing. Fitting 80 may also be an end of a longer tube where installation conditions warrant. Alternatively one of the two rectangular shapes 33' and 34' may be blocked with a simple plug 34 as indicated in Fig 9. Interior to cold water heat exchanger 50 and inline with the socket 33' and/or 34' is a plastic fluid distribution tube 35' which extends full length and is closed at the far end and has cross apertures at intervals. The purpose of tube 35' is to direct fluid B to cause at least some second fluid to flow at least partially crosswise creating turbulence and evening out flow velocity across the width of cold water heat exchanger 50.
In Fig 5 horizontal heat exchanger 200 is shown having the upper drainwater heat exchanger 60 made from a flattened tube, and lower cold water heat exchanger 50 (for, say, cold water) formed of sheet material bound together by bands 12. In some uses the upper drainwater heat exchanger 60 may also be formed from sheet to reduce cost. In either case the ends of drainwater heat exchanger 60 can be adapted to connect with existing round drain pipes the right end of the drainwater heat exchanger having a separate, bonded-on adaptor 70, while the left end adaptor 70 is shown as having an integrally formed round end 20'. It is important that the drainwater heat exchanger provides a flush flow path especially at the exit end so that solids in the drainwater will not hook and collect at the region of transition from flat to round. This can be achieved by forming a recess in the "D' shaped end of the bonded on adaptor equal to the thickness of the drainwater heat exchanger material. The bonding region is shown at overlap 20'.
Fig 5 shows fluid B, such as cold water for a water heater, entering fitting 10 at the left to counterflow horizontally under the drainwater water heat exchanger 60 and exit via fitting 11 on the right having absorbed (or given up) heat from warmer (or colder) drainwater'. Drainwater A
flows horizontally with a first temperature A' at inlet on right side and a different temperature A"
at outlet on left side. Fig 6 shows adaptor 70 having a "D" shaped first end 20' for bonding to drainwater heat exchanger 60 and a round end 20 for connecting to existing drainpipe. Adaptor 70 may also be made of molded rubber with a shaped shoe 22 under the flat portion 20' to provide even clamping pressure.
In use, by connecting cold water heat exchanger 50 to a pressurized fluid supply, an enormous thermal transfer contact force is created between the flat surfaces of heat exchangers 50 and 60 and is restrained by bands 12 (or a sleeve, not shown) to provide exceptional heat transfer therebetween. For example, with a 4 inch wide flat that is 50 inches long and with a pressure of 40 pounds per square inch, the contact force is some 8,000 pounds. This force custom forms typically imperfectly flat surfaces 1' and 5 into intimate contact.
With the instant invention, horizontally flowing drainwater, whose valuable heat energy is normally wasted, can be cooled by this low profile heat exchanger 200 by heat transfer to the cold water supply of the water heater to thereby shorten the time it takes to fully heat hot water and which, in turn, saves energy and money and provides more hot water due to faster recovery after its use. It may also be used to cool a flow of warmer water feeding, for example, an ice cube maker, using colder drainwater from a ice-filled sink. In all figures the drainpipe or exhaust pipe is indicated as A and the fluid whose temperature is to be changed is B. Heat exchanger 20 may be used to heat or cool fluid B. Although gaps between surfaces are shown in the figures (for clarity) it is understood that there is intimate contact between heat transfer and clamping surfaces.
In Figs 11-13 heat exchanger 100 is a jacket(s) comprising an inner heat transfer wall 5 and outer retaining wall 2 spaced apart for fluid flow therebetween with minimal resistance. This space may be, say,'/a inch. The walls are contiguous and formed from a single piece of thin sheet metal (copper) using reversing bends 112 and lap joint 5'. This leaves a longitudinal opening or gap 111 between bends 112 to accommodate movement from external mechanical clamping forces and internal hydraulic clamping forces. The jacket may also be formed by extrusion in which case finning 115 (representative fins only, shown in Fig 11) and fluid control elements 114 may be easily included on the inner wall 5 and/or outer wall 2. Outer clamping sleeve 116 with gap 113 closes tightly around and distributes clamping forces from band or hose clamps 12 to prevent expansion or bulging of outer wall 2 from the internal pressure of fluid B such as that from a building's cold water supply. Inner wall 1 is however free to bulge against drainpipe 1 by that same internal pressure.
Joint 5' is a soldered lap joint and may include longitudinal joint flange 110 which can act as a fluid flow equalizer and a stabilizer/spacer for aligning the sheet metal during soldering. Inlets(s) and outlet(s) 11 are connections for fluid B whose temperature is to be changed.
Representative fluid control element 114 may be many in number and take various shapes such as mesh, rods, screen, angles, etc., such as to direct, for example, flow of fluid B over element 114 as indicated by dashed flow arrow 114', to help effect best heat transfer from inner wall 5 by the fluid 'sweeping' the surface of inner wall as fully as possible.
Element(s) 114 may also be used to create turbulent flow which is known to improve heat transfer. Element 114 may also be shaped and located to deflect fluid B inflow at inlet 10 to avoid erosion corrosion of the small area of the inner wall by the fluid impinging on it perpendicularly at full velocity.
Fig 12 shows the hollow, tubular nature of the heat exchanger 100 as fitted onto a vertical drainpipe A. Sealing rings 34 are shown in dotted line and are soldered into the annular space between the inner and outer wall ends at top and bottom. Although a tubular shape is shown, other shapes such as oval are contemplated where, for example, fitting clearance is a concern.
Figs 14 and 15 show the sealing member 34 which can be made from rolled rod, tube or twisted wire bundle to fit snugly into the annular space and have a gap 111' to coordinate with gap 111. They may be made by winding a long piece onto a mandrel of the correct diameter into the form of a coil spring and then sawing through the coil to free individual rings which are then made planar as in Fig 15. Dip soldering is a fast method of construction.
Fig 16 shows a method of using the longitudinal joint flange 110 as a flow controller by providing restriction to flow directly from fitting 10 such that fluid B is forced through spaced vias 120 to travel across inner wall 5 to reach outlet 11 thereby improving heat removal from drainpipe I. Flange 110 may also simply be more simply double-tapered (not shown) from full . . ... . _. . .. .:.v -.n..~~v_...e._...b.,._.._ _.. ....... .. , . .. .
width at the center tapering to nil at each end to even out flow along its length, especially if the fittings 10 and 11 are positioned centrally and opposite one another.
Fig 12 shows the cold water heat exchanger in two halves with inlets 10 and outlets 11 on each half. The outer sleeve 116 and clamps 12 are not shown. The outer sleeve 112 would of course be in two pieces either separate or hinged for ease of assembly onto the drainpipe in a building. The sealing rings 34 (not shown in Fig 12) would of course be four in number each being a half ring, one at each of the four ends.
Fig 17 shows another embodiment of horizontal heat exchanger 200 where the cold water heat exchanger 2 comprises a sheet copper duct or tube in the form of a flat, rectangular hollow strip or bar. It is sealed at each end and may have flow-forming controllers to ensure that the entering cold water flows as a flat sheet of water to the outlet so as to recover heat from the entire heat transfer surface area. Fig 18 shows a cross section of the same embodiment where the drainwater heat exchanger is shown to be a flattened, hemi-cylindrical tube 1 forced into intimate, conforming thermal contact therewith with shoes 130, 131 and clamp bands 12.
Fig 18 shows a cross-section of the heat exchanger 200.
In Fig 19 drainwater heat exchanger I is comprised of a trough-like lower portion in sheet copper through which heat transfer takes place and a U-shaped plastic upper portion bonded lb thereto, the two creating a hybrid drainpipe of rounded rectangular form. This heat exchanger is conceived as a low cost device for use where there are no large solids in the drainwater, more specifically for use under a shower or sink. Interior longitudinal supports lc act to transmit compressive load from cold water heat exchanger 2 to shoe 130 and bands 12 thereby maintaining a flat profile for the trough. Supports lc may be wavy to create a desirable turbulent flow. Supports Ic also act as fins to extend heat transfer surface area.
Fig 20 shows the same embodiment with different drainpipe connection fittings.
Inlet 200" is a vertical right angle inlet centered on plastic top la and outlet 200' is a horizontal right angle ...I.. .. . om =:-.:, -fitting shown in more detail in Fig 21, having an end cap and a slot 201 which matches the shape of the end of heat exchanger 1, la, lb (Fig 19) and is bonded and sealed thereto. A slight slope to outlet 200' carries away the final drainwater drips to drain heat exchanger 1 dry.
In Fig 22 vertical heat exchanger 100 has an inner heat transfer surface 5 and ring-shaped flow controller 110' dam which leaves an annular gap 120' adjacent heat transfer surface 5. End seals 34 (Fig 23) and flow controller 110 are spaced apart vertically creating a circular chamber so that fluid fitting 11 feeds fluid therebetween. Fluid B then must leave the chamber as a full curvilinear sheet flow B' against heat transfer surface 5 so as to sweep heated (or cooled) fluid towards the outlet which is similarly configured. This ensures that a maximum temperature differential can be maintained to optimize heat transfer. This annular flow control arrangement may be used to advantage in all the aforementioned heat exchangers. In the case of horizontal heat exchangers 200 the controller would take the form of a rectangular bridge held raised a small distance below the heat transfer surface by stand-off formations at the controller ends.
Figs 24 and 25 show variations on the profile of the flow surface 1' of the drainwater heat exchanger 1 with the purpose of stiffening the flow surface 1' to resist upward bulging from the expansive potential of the pressurized cold water exchanger below. The cold water exchanger 2 is shown to be conforming in shape so as to maintain maximum thermal contact.
Claims (10)
1. A heat exchanger comprising:
an elongated conduit having spaced inner and outer walls;
said inner and outer walls being continuous and forming a longitudinal gap;
said inner wall being operative for heat transfer and being at least partial cylindrical so as to make intimate contact with at least a portion of a generally cylindrical tube carrying a first fluid for heat transfer;
said hollow conduit having connection means to a second fluid supply for heat transfer;
clamping means exterior to said outer wall to reduce said gap and thereby increase said intimate contact.
an elongated conduit having spaced inner and outer walls;
said inner and outer walls being continuous and forming a longitudinal gap;
said inner wall being operative for heat transfer and being at least partial cylindrical so as to make intimate contact with at least a portion of a generally cylindrical tube carrying a first fluid for heat transfer;
said hollow conduit having connection means to a second fluid supply for heat transfer;
clamping means exterior to said outer wall to reduce said gap and thereby increase said intimate contact.
2. The heat exchanger of Claim 1 where said second fluid supply is under pressure to further increase said intimate contact.
3. The heat exchanger of Claim 1 where two said hollow conduits are operatively inter-connected about a second conduit carrying a first fluid for heat transfer.
4. A heat exchanger comprising:
a hollow conduit having spaced upper and lower walls;
said upper wall being operative for heat transfer;
at least a portion of said upper wall being substantially flat for intimate contact with at least a portion of a second conduit for heat transfer having a flat heat transfer surface carrying a first fluid for heat transfer;
said conduit having connection means to a second fluid supply for heat transfer;
clamping means exterior to said outer wall to increase said intimate contact.
a hollow conduit having spaced upper and lower walls;
said upper wall being operative for heat transfer;
at least a portion of said upper wall being substantially flat for intimate contact with at least a portion of a second conduit for heat transfer having a flat heat transfer surface carrying a first fluid for heat transfer;
said conduit having connection means to a second fluid supply for heat transfer;
clamping means exterior to said outer wall to increase said intimate contact.
5. The heat exchanger of Claim 1 where said second fluid supply is under pressure to further increase said intimate contact.
6. The heat exchanger of Claim 1 where said hollow conduit is combined with said second conduit.
7. The heat exchanger of Claim 1 where said second conduit is an exhaust pipe.
8. The heat exchanger of Claim 1 where said inner and outer walls are formed from a single piece of sheet material.
9. The heat exchanger of Claim 2 where said conduit connects to a building's drainpipe.
10. The heat exchanger of Claim 2 where said second conduit has lower and upper portions and where said upper portion is a plastic.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA002611709A CA2611709A1 (en) | 2007-03-13 | 2007-11-30 | Drainpipe heat exchanger |
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA2583161 | 2007-03-13 | ||
| CA002583161A CA2583161A1 (en) | 2006-05-24 | 2007-03-13 | Waste heat exchanger |
| CA002611709A CA2611709A1 (en) | 2007-03-13 | 2007-11-30 | Drainpipe heat exchanger |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2611709A1 true CA2611709A1 (en) | 2008-09-13 |
Family
ID=39747244
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002611709A Abandoned CA2611709A1 (en) | 2007-03-13 | 2007-11-30 | Drainpipe heat exchanger |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA2611709A1 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101846473A (en) * | 2010-05-07 | 2010-09-29 | 佛山市顺德区华天成电器有限公司 | Composite tube for heat exchanger |
| FR3019277A1 (en) * | 2014-03-28 | 2015-10-02 | Ecogreenenergy | FLEXIBLE WALL EXCHANGER DEVICE |
| CN116164557A (en) * | 2023-03-02 | 2023-05-26 | 江苏凯乐汽车部件科技有限公司 | Automobile radiator and manufacturing process thereof |
-
2007
- 2007-11-30 CA CA002611709A patent/CA2611709A1/en not_active Abandoned
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101846473A (en) * | 2010-05-07 | 2010-09-29 | 佛山市顺德区华天成电器有限公司 | Composite tube for heat exchanger |
| FR3019277A1 (en) * | 2014-03-28 | 2015-10-02 | Ecogreenenergy | FLEXIBLE WALL EXCHANGER DEVICE |
| CN116164557A (en) * | 2023-03-02 | 2023-05-26 | 江苏凯乐汽车部件科技有限公司 | Automobile radiator and manufacturing process thereof |
| CN116164557B (en) * | 2023-03-02 | 2024-08-02 | 江苏凯乐汽车部件科技有限公司 | Automobile radiator and manufacturing process thereof |
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