1. A grey water heat recovery apparatus in which heat is transferred between a grey water stream and a fresh water stream, wherein said apparatus comprises:
a heat exchanger having at least a first pass and a second pass, the first pass and second pass being mounted in series;
the heat exchanger having a gravity-fed grey water flow path, said grey water flow path including a first portion in said first pass, and a second portion in said second pass, said first portion in said first pass being upstream of the second portion in said second pass, said grey water flow path having a source inlet, and a drain outlet;
said grey water flow path having an intermediate portion lower than said drain outlet;
said heat exchanger having a pressure-fed fresh water flow path, said fresh water flow path being segregated from said grey water flow path;
said fresh water flow path having a first portion in said second pass, and a second portion in said first pass, said second portion of said fresh water flow path being downstream of said first portion of said grey water flow path;
said fresh water flow path of said heat exchanger being at least predominantly immersed in said grey water flow path; and
said fresh water flow path having a fresh water source and a fresh water outlet, both said fresh water source and said fresh water outlet being positioned at respective heights higher than said drain outlet of said grey water flow path; and
said heat exchanger being free of fresh water wall penetrations of said grey water flow path lower than said drain outlet of said grey water flow path.
2. The apparatus of claim 1 wherein said first pass and said second pass are of substantially the same size and are mounted side-by-side.
3. The apparatus of claim 1 wherein said heat exchanger has more than two passes, and said more than two passes are mounted in a side-by-side bundle.
4. The apparatus of claim 1 wherein:
said first pass includes a first shell defining an outer wall of a first portion of said grey water flow path;
said second pass includes a second shell defining an outer wall of a second portion of said grey water flow path;
said first portion of said fresh water flow path is nested within said second shell; and
said second portion of said fresh water flow path is nested within said first shell.
5. The apparatus of claim 4 wherein said first shell has a resting sump fluid level, and said second portion of said fresh water flow path has an entrance to and an exit from said first shell, both of said entrance and said exit being at a level at least as high as said resting sump fluid level.
6. The apparatus of claim 4 wherein said first shell has at least a first closure fitting; said second portion of said fresh water flow path has an entrance to and an exit from said first shell; both of said entrance and said exit being carried through said first closure fitting.
7. The apparatus of claim 4 wherein said first shell is made from a cylindrical pipe; said cylindrical pipe has a first end and a second end; said cylindrical pipe has at least a first plug fitting; said first closure fitting mates with said first end of said cylindrical pipe; said second portion of said fresh water flow path has an entrance and an exit; and said entrance and said exit of said fresh water flow path are mounted through said first closure fitting.
8. The apparatus of claim 1 wherein:
said first pass includes a first plastic cylindrical pipe defining an outer wall of a first portion of said grey water flow path;
said second pass includes a second plastic cylindrical pipe defining an outer wall of a second portion of said grey water flow path;
said second portion of said fresh water flow path includes a first coil nested within said first shell;
said first portion of said fresh water flow path includes a second coil nested within said second shell;
said second coil having a fresh-water source connection fitting;
said second coil being connected in series to said first coil; and
said first and second coils being made of metal.
9. The apparatus of claim 8 wherein:
each of said first and second coils is a copper coil;
each of said first and second cylindrical plastic pipes is predominantly upstanding;
each of said first and second plastic pipes has a bottom end closure;
each of said first and second plastic pipes has a top end closure;
each of said first and second coils has a counter-direction leg, whereby each of said first portion and said second portion of said fresh water flow path has first and second terminations, and said first and second terminations pass through the top end closure of said first and second cylindrical plastic pipes, respectively;
said top end closures of said first and second cylindrical plastic pipes being higher than said drain outlet of said grey water flow path; and
said first and second cylindrical plastic pipes and said first and second coils extending downwardly of said drain outlet whereby said cylindrical plastic pipes define first and second sump portions, and said first and second coils are predominantly submerged in said second and first sump portions.
10. The apparatus of claim 1 wherein said apparatus is circumscribed by an external housing in which both of said first and second stages are enclosed, with grey water and fresh water connection fittings being externally accessible.
11. In combination, the grey water heat recovery apparatus of claim 1 and a water heater, the fresh water flow path of the grey water heat recovery apparatus being upstream of the water heater, the water heater having supply conduits to at least a first hot water load, and the grey water flow path of the heat recovery apparatus of claim 1 being mounted to receive grey water from at least said first hot water load.
12. The apparatus of claim 1 wherein said apparatus includes a space filling member positioned to reduce flow path area of the grey water.
13. The apparatus of claim 1 wherein said apparatus includes at least one return, and said return is mounted within an obstructing member, and the grey water is restricted to flow in an annular region outside the obstructing member.
14. The apparatus of claim 1 wherein said apparatus includes a tube bundle, said tube bundle having an outlet and an inlet, both of said outlet and said inlet being located at one end thereof, whereby said tube bundle may be extracted from one end of said apparatus.
15. The apparatus of claim 14 wherein said tube bundle includes an inlet header, a return header, an array of feeder tubes extending between said inlet header and said return header, and a return; said inlet header is mounted concentrically about said return, said return passing though said inlet header free of fluid communication therewith.
16. A grey water heat recovery apparatus in which to transfer heat between a grey water stream and a fresh water stream, wherein said grey water heat recovery apparatus comprises:
a heat exchanger having a first pass and a second pass, said first pass and said second pass being connected in series;
said heat exchanger having a first side defining a grey water flow path, and a second side defining a fresh-water flow path, said grey water and fresh water paths being segregated from each other;
said grey water flow path being a gravity-feed flow path;
said fresh water flow path being a pressure-feed flow path;
said heat exchanger having a grey water flow path inlet and a grey water flow path outlet, at least a portion of one of said first pass and said second pass being lower than said grey water flow outlet whereby said heat exchanger defines at least a first grey water sump;
at least one of said first pass and said second pass including a first cylindrical pipe member through which to conduct the grey water stream, said first cylindrical pipe member defining a containment wall of at least a portion of said grey water flow path;
said first cylindrical pipe member having a grey water inlet and a grey water outlet;
said first cylindrical pipe member having a first end, and a first end member, said first end member defining a closure of said first end of said first cylindrical pipe member;
a first fresh water flow element nested within said first cylindrical pipe member, said first fresh water flow element extending axially within said first cylindrical pipe member;
said first fresh water flow element having an inlet and an outlet;
both said fresh water inlet and said fresh water outlet being mounted to pass through said first end member of said first cylindrical pipe member.
17. The grey water heat recovery apparatus of claim 16 wherein said first fresh water flow element includes a metal coil, said metal coil having a counter-direction leg, said fresh water flow element has first and second end connections, both of said first and second end connections of said metal coil passing through said first end of said first cylindrical pipe member.
18. The grey water heat recovery apparatus of claim 16 wherein said first and second cylindrical pipe members are each elongate are mounted together side-by-side in a predominantly upstanding orientation, and are mounted adjacent to at least one of (a) a main stack drain pipe; and (b) a water heater; the water heater having an overall height, and the heat recovery apparatus having an overall height, the overall height of the heat recovery apparatus being in the range of \u2154 to 32 of the height of the water heater.
19. The grey water heat recovery apparatus of claim 16 wherein one of:
(a) said first pass and said second pass are connected to define a single grey water sump in which the grey water outlet of the first pass is connected to a lower portion grey water entry of the second pass; and
(b) said first pass and said second pass are connected to define a first grey water sump in said first pass and a second grey water sump in said second pass, in which the outlet of the first sump is carried to a top portion entry into said second sump.
20. The grey water heat recovery apparatus of claim 16 in combination with a water heater, wherein said grey water heat recovery apparatus is connected as a fresh water pre-heater for said water heater.
21. The grey water heat recovery apparatus of claim 16 wherein said apparatus is circumscribed by an external housing in which both of said first and second stages are enclosed, said housing having a generally cylindrical shape, with grey water and fresh water connection fittings protruding from said housing and being externally accessible.
22. A grey water heat recovery heat exchanger comprising:
a first cylindrical plastic pipe for grey water with a first metal coil for fresh water nested therein; and a second cylindrical plastic pipe for grey water with a second metal coil for fresh water nested therein;
said first cylindrical plastic pipe having an inlet for grey water;
said second cylindrical plastic pipe having an outlet for grey water;
said first and second cylindrical plastic pipes being connected in series to conduct grey water from said first cylindrical plastic pipe to said second cylindrical plastic pipe;
said first metal coil being connected in series with said second metal coil, said first metal coil having a fresh water inlet, said second metal coil having a fresh water outlet, whereby said fresh water coils are mounted for counter-flow operation relative to said grey water conducting first and second cylindrical plastic pipes;
at least one of said first and second cylindrical plastic pipes defining at least a portion of a grey water sump in which at least a portion of one of said second and first metal coils is mounted.
23. The grey water heat exchanger of claim 22 wherein at least one of said first and second cylindrical plastic pipes has a first end closure, and the corresponding one of said first and second coils has first and second ends that both have run through said first end closure.
24. The grey water heat exchanger of claim 22 wherein said first and second cylindrical plastic pipes are elongate and in a predominantly upstanding orientation, and said grey water outlet of said second cylindrical plastic pipe is higher than a predominant portion of at least one of said first and second fresh water coils.
25. The grey water heat exchanger of claim 22 wherein:
said first and second cylindrical plastic pipes stand on a common base and are mounted together in a single mounting with both of said first and second cylindrical plastic pipes being in an upstanding orientation;
said first cylindrical plastic pipe has a first end and a second end, said first end being higher than said second end;
said second end of said first cylindrical plastic pipe having a closure;
said first end of said first cylindrical plastic pipe having a closure having first and second penetrations through which pass respective first and second ends of said second fresh water coil, said first and second penetrations being higher than said grey water outlet of said second cylindrical plastic pipe;
said second fresh water coil has a helical coil portion and a counter-direction leg portion, said helical coil having an outside diameter fitting within said first cylindrical plastic pipe to permit construction of said heat exchanger by axial insertion of said helical coil into said first cylindrical plastic pipe;
said second cylindrical plastic pipe has a first end and a second end, said first end being higher than said second end;
said second end of said second cylindrical plastic pipe having a closure;
said first end of said second cylindrical plastic pipe having a closure having first and second penetrations through which pass respective first and second ends of said first fresh water coil, said first and second penetrations being higher than said grey water outlet of said second cylindrical plastic pipe; and
said first fresh water coil has a helical coil portion and a counter-direction leg portion, said helical coil having an outside diameter fitting within said second cylindrical plastic pipe to permit construction of said heat exchanger by axial insertion of said helical coil into said second cylindrical plastic pipe.
26. The grey water heat exchanger of claim 22 wherein said apparatus is enclosed in a unitary cylindrical housing in which both of said first and second stages are enclosed, through which externally accessible grey water and fresh water connection fittings pass, the fresh water connection fitting extending through a top end of said cylindrical housing, and said grey water connection fittings extending through a sidewall of said cylindrical housing.
27. A grey water heat recovery assembly comprising the heat exchanger of claim 22 in combination with a grey water drainage system, a water heater, and a hot water distribution system, wherein:
said fresh water inlet of said heat exchanger is connected to a fresh water supply system downstream of a water meter;
said fresh water outlet of said heat exchanger is connected to an inlet of said water heater;
said water heater has an outlet connected to supply water to at least one of a hot water tap, a shower, a bath-tub, a clothes washer, and a dishwasher;
said grey water drainage system is connected to a drain of at least one of a sink; a shower, a bath-tub, a clothes washer, and a dishwasher;
said grey water drainage system is segregated from any sewage water system;
said grey water drainage system is connected to said grey water inlet of said first cylindrical plastic pipe;
said grey water drainage system includes an overflow bypass of said heat exchanger;
there is a grey water inlet filter mounted to intercept objects in the grey water carried by said grey water drainage system to said heat exchanger; and
said outlet of said second cylindrical plastic pipe drains into a sewage drain.
28. A grey water heat recovery apparatus comprising:
a first stage and a second stage mounted in series;
the first stage having a first plastic pipe;
the second stage having a second plastic pipe;
said first and second plastic pipes each being elongate and cylindrical,
said first and second pipes being connected in series and being bundled together side-by-side in an upstanding orientation;
each of said first and second pipes having an upper end and a lower end;
said first and second pipes defining a gray water path of a heat exchanger in which said first pipe is upstream of said second pipe;
said first stage has a first copper coil nested within said first pipe, said first copper coil having inlet and outlet terminations that extend from the upper end of the first pipe;
said second stage has a second copper coil nested within said second pipe, said second copper coil having inlet and outlet terminations that extend from the upper end of said second pipe; and
said first coil and said second copper coil being connected in series to define a fresh water flow paths of the heat exchanger, said second coil being upstream of said first coil.
29. The grey water heat recovery apparatus of claim 24 wherein said apparatus is enclosed in a unitary cylindrical housing in which both of said first and second stages are enclosed, through which externally accessible grey water and fresh water connection fittings pass, the fresh water connection fitting extending through a top end of said cylindrical housing, and said grey water connection fittings extending through a sidewall of said cylindrical housing.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
Having thus described the invention, what is claimed is:
1. A static mixer comprising:
a first grid comprising one or more crossing elements and one or more slots adjacent to each crossing element and a second grid comprising one or more crossing elements and one or more slots adjacent to each crossing element,
wherein said crossing elements of said first grid are arranged at intersecting angles to said crossing elements of said second grid; and
at least one elongated connector positioned between and secured to said crossing elements of said first grid and said crossing elements of said second grid.
2. The static mixer of claim 1, wherein said grids are arranged such that each crossing element of one grid intersects a slot in the other grid.
3. The static mixer of claim 2, wherein said crossing elements of said first grid are in a generally parallel relationship relative to one another.
4. The static mixer of claim 3, wherein said crossing elements of said first grid lie within a common plane.
5. The static mixer of claim 4, wherein said crossing elements of said second grid are in generally parallel relationship relative to one another.
6. The static mixer of claim 5, wherein said crossing elements of said second grid lie within a common plane.
7. The static mixer of claim 1, wherein said crossing elements are one of corrugated plates and tubes.
8. The static mixer of claim 1, wherein the static mixer comprises more than two grids.
9. The static mixer of claim 8, wherein each grid comprises crossing elements.
10. The static mixer of claim 9, wherein said crossing elements of each grid are arranged at intersecting angles to one another.
11. The static mixer of claim 10, wherein said connector is positioned between said crossing elements of each grid.
12. The static mixer of claim 1, wherein said crossing elements are one of metal, polymeric, ceramic construction or combinations thereof.
13. The static mixer of claim 1, wherein said connector extends continuously along the entire cross-sectional length of said static mixer.
14. The static mixer of claim 1, wherein said elongated connector is positioned so that it intersects with said crossing elements along at least some of their points of intersection.
15. The static mixer of claim 1, wherein said connector has crossing groves positioned along the lines of contact of said crossing elements with said connector, wherein said grooves provide a larger bonding surface and mechanical fitting for holding said crossing elements together.
16. The static mixer of claim 15, wherein said grooves are located in a first face of said connector and extend in relationship to said crossing elements of said first grid and wherein said grooves are located in a second face of said connector and extend in relationship to said crossing elements of said second grid.
17. The static mixer of claim 1, wherein said crossing elements are secured to said connector by one of welding, brazing, gluing and combinations thereof.
18. A method of constructing a static mixer, said method comprising:
(a) providing at least two grids;
(b) positioning one or more crossing elements and one or more slots adjacent to each crossing element in a first grid;
(c) positioning one or more crossing elements and one or more slots adjacent to each crossing element in a second grid;
(d) arranging said crossing elements of said first grid at intersecting angles to said crossing elements of said second grid;
(e) positioning at least one connector between said crossing elements of said first grid and said crossing elements of said second grid; and
(f) securing said connector to said crossing elements.
19. The method of claim 18, further comprising:
arranging said grids such that each crossing element of one grid intersects a slot in the other grid.
20. The method of claim 19, further comprising:
providing more than two grids.
21. The method of claim 20, further comprising:
positioning one or more crossing elements in each grid.
22. The method of claim 21, further comprising:
arranging said crossing elements of each grid at intersecting angles to one another.
23. The method of claim 22, further comprising:
positioning said connector between said crossing elements of each grid.
24. A static mixer assembly comprising:
a generally ring-shaped fluid flow conduit having a central axis, concentric inner and outer, radially spaced, circumferentially extending surfaces, said inner surface defining a fluid flow path which extends along said axis;
one or more static mixers located in said flow path, each static mixer having a first grid comprising one or more crossing elements and one or more slots adjacent to each crossing element and a second grid comprising one or more crossing elements and one or more slots adjacent to each crossing element,
wherein said crossing elements of said first grid are arranged at intersecting angles to said crossing elements of said second grid; and
at least one elongated connector positioned between and secured to said crossing elements of said first grid and said crossing elements of said second grid.
25. The static mixer assembly of claim 24, wherein said grids are arranged such that each crossing element of one grid intersects a slot of the other grid.