# US 2014/0151005 A1 · Method for extraction heat from an effluent, especially waste water, circulating in a conduit, heat exchanger and material for implementing said method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0151005 A1 - Document ID: US20140151005A1 - Status: Published application - Kind: A1 - Application number: 14/130,930 - Filed: 2012-07-03 - Published: 2014-06-05 - Earliest claimed: 2011-07-06 - Assignees: Lyonnaise Des Eaux France - Inventors: Frederic Duong - Web page: https://patentgrep.com/patent/US20140151005A1 ## CPC - F28D 1/06: with the heat-exchange conduits forming part of, or being attached to, the tank containing the body of fluid - C04B 14/324: {Silicon carbide} - C04B 30/02: containing fibrous materials - E03F 3/04: Pipes or fittings specially adapted to sewers (manufacture of concrete tubes B28; pipes or pipe fittings in general F16L) - F28D 7/0008: {the conduits for one medium being in heat conductive contact with the conduits for the other medium} - F28D 7/103: {consisting of more than two coaxial conduits or modules of more than two coaxial conduits} - F28D 21/0012: {the heat being recuperated from waste water or from condensates} - F28F 1/40: the means being only inside the tubular element - F28F 21/04: of ceramic; of concrete; of natural stone - C04B 2111/56: Compositions suited for fabrication of pipes, e.g. by centrifugal casting, or for coating concrete pipes - C04B 2201/32: for the thermal conductivity, e.g. K-factors - E03C 2001/005: {Installations allowing recovery of heat from waste water for warming up fresh water} - F28F 2275/02: by using bonding materials; by embedding elements in particular materials - F28D: HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT (fluid heaters having heat generating means and heat transferring means F24H; furnaces F27; details of heat-exchange apparatus of general) - C04B: LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE {(roofing granules E04D7/005)}; CERAMICS (devitrified glass-ceramics C03C10/00); REFRACTORIES; TREATMENT OF NATURAL STONE - E03F: SEWERS; CESSPOOLS - F28F: DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION (water and air traps, air venting F16) - E03C: DOMESTIC PLUMBING INSTALLATIONS FOR FRESH WATER OR WASTE WATER (not connected to either water-supply main or to waste pipe A47K; devices of the kind used in the ground E03B, E03F); SINKS ## Abstract The invention relates to a method for extracting heat from an effluent (2) circulating in a conduit (1), especially a waste water collector, according to which a heat exchanger (E) is installed, at least in the bottom of the conduit, said heat exchanger (E) lying in the effluent and being formed by coating tubes (3) with sufficiently heat-conductive concrete cast around the tubes intended for the circulation of a heat-transfer fluid, the heat exchange with the effluent of the conduit being carried out through the moulded coating. The concrete (4) of the coating consists of a least 50 weigh % of silicon carbide, a load of needles made of a heat-conductive and mechanically resistant material, a binding agent and the remainder of alumina, metal powder or carbon. ## Claims ### Claim 1 A method for extracting heat from an effluent flowing along a pipe, notably a sewer, the method comprising installing, at least in the bottom of the pipe, a heat exchanger (E) which is immersed in the effluent the heat exchanger (E) being formed by coating tubes with a sufficiently thermally conductive concrete poured around tubes through which a heat-transfer fluid is intended to circulate, the exchange of heat with the effluent of the pipe taking place through the cast coating, wherein the coating concrete is made up of at least 50% by weight of silicon carbides of an acicular filler of needles of a thermally conductive and mechanically strong material, of a binder and the rest being alumina, metallic powder or carbon. ### Claim 2 (depends on 1) The method as claimed in claim 1, wherein the acicular filler of needles represents more than 2% by weight. ### Claim 3 (depends on 1) The method as claimed in claim 1, wherein, the needles of the acicular filler are made of metal, particularly of carbon steel or of aluminum, or are made of carbon. ### Claim 4 (depends on 1) The method as claimed in claim 1, wherein the diameter of the needles is less than five-tenths of a millimeter for a length generally of less than 10 mm. ### Claim 5 (depends on 1) The method as claimed in claim 1, wherein the needles are ferritic needles. ### Claim 6 (depends on 1) The method as claimed in claim 1, wherein: a layer of thermally insulating material is placed between the tubes and a wall of the pipe, a layer of conductive concrete is placed in contact with the tubes, between the tubes and the effluent, and, at the surface, a layer of abrasion-resistant material is placed in contact with the effluent. ### Claim 7 (depends on 1) The method as claimed in claim 1, wherein an intermediate mesh made of metal or synthetic fibers is spread over the tubes, prior to the pouring of the coating material, over the entire extent of a portion of the exchanger so as to enhance mechanical strength and/or improve heat transfer. ### Claim 8 (depends on 1) The method as claimed in claim 1, wherein the tubes are ringed. ### Claim 9 (depends on 1) The method as claimed in claim 1, wherein the tubes are made of plastic. ### Claim 10 (depends on 1) The method as claimed in claim 1 wherein the tubes are flexible. ### Claim 11 An exchanger for extracting heat from an effluent flowing along a pipe, notably a sewer, installed at least in the bottom of the pipe so that it is immersed in the effluent, the exchanger comprising tubes embedded in a thermally conductive concrete poured around tubes through which a heat-transfer fluid is intended to circulate, the exchange of heat with the effluent of the pipe taking place through the cast coating, wherein the coating concrete is made up of at least 50% by weight of silicon carbide, of an acicular filler of needles of a thermally conductive and mechanically strong material, of a binder, the rest being alumina, metallic powder or carbon. ### Claim 12 (depends on 11) The exchanger as claimed in claim 11, wherein the tubes embedded in the concrete are ringed tubes. ### Claim 13 (depends on 11) The exchanger as claimed in claim 11, wherein the ringed tubes are made of plastic. ### Claim 14 (depends on 11) The exchanger as claimed in any one of claim 11, wherein the tubes are flexible. ### Claim 15 (depends on 1) A material for implementing a method as claimed in claim 1, the material comprising a mixture made up of at least 50% by weight of silicon carbide, of an acicular filler of needles of a thermally conductive and mechanically strong material, of a binder, the rest being alumina, metallic powder or carbon. ### Claim 16 (depends on 15) The material as claimed in claim 15, wherein the acicular filler of needles represents at least 2% by weight. ### Claim 17 (depends on 15) The material as claimed in claim 15, wherein and the acicular filler of needles are made of metal, particularly of carbon steel or of aluminum, or are made of carbon.