# US 4,396,055 A · Electrohydrodynamic inductively pumped heat pipe > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 4,396,055 A - Document ID: US4396055A - Status: Granted - Kind: A - Application number: 06/226,319 - Filed: 1981-01-19 - Granted: 1983-08-02 - Earliest claimed: 1981-01-19 - Assignees: The United States of America as represented by the Secretary of the Navy - Inventors: Archer S. Mitchell, Jr. - Web page: https://patentgrep.com/patent/US4396055A ## CPC - F28D 15/06: Control arrangements therefor - F04B 19/24: Pumping by heat expansion of pumped fluid - F28D 15/025: {having non-capillary condensate return means} - H02N 11/006: {Motors} - 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) - F04B: POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS (machines for liquids, or pumps, of rotary-piston or oscillating-piston type F04C; non-positive-displacement pumps F04D; pumping of fluid by direct contact of another fluid or by using inertia of fluid to be pumped F04F) - H02N: ELECTRIC MACHINES NOT OTHERWISE PROVIDED FOR ## Abstract An applied traveling potential wave induces a traveling wave of electrical harge in the liquid phase of a dielectric working fluid providing an electrical traction which pumps the working fluid from a condensing section to an evaporating section of an electrohydrodynamic inductively pumped heat pipe. In one embodiment, a surface electrical traction is induced along an open interface that extends along the liquid phase return flow circuit, and in another embodiment, the electrical traction is induced in the liquid bulk of an inhomogeneous dielectric working fluid along the liquid phase return flow circuit. ## Claims ### Claim 1 An induction pump for pumping a dielectric liquid along a flow path from a condensing section toward an evaporating section of a heat pipe, comprising: means for applying a traveling potential wave along said flow path along which said liquid is pumped from said condensing section to said evaporating section; and means for inducing a traveling wave of electrical charge in said liquid in selected phase relation to said applied traveling potential wave for pumping said liquid. ### Claim 2 (depends on 1) An induction pump for pumping a dielectric liquid along a flow path from a condensing section toward an evaporating section of a heat pipe, as recited in claim 1, wherein: said evaporating section evaporates said liquid forming a gas; and said inducing means comprising an interface between said gas and said liquid along said flow path along which said liquid is pumped. ### Claim 3 (depends on 1) An induction pump for pumping a dielectric liquid along a flow path from a condensing section toward an evaporating section of a heat pipe, as recited in claim 1, wherein: said inducing means comprises a liquid consisting of two immiscible dielectric fluids. ### Claim 4 (depends on 2, 3) An induction pump for pumping a dielectric liquid along a flow path from a condensing section toward an evaporating section of a heat pipe, as recited in claims 2 or 3, wherein: said applying means comprises a segmented electrode positioned along and spaced from said flow path along which said liquid is pumped. ### Claim 5 A method for pumping a liquid condensate along a flow path from a condensor toward an evaporator in a heat pipe, comprising the steps of: applying a traveling potential wave along said flow path along which said liquid condensate is pumped; and inducing a traveling wave of electrical charge in said liquid condensate in selected phase relation to said applied traveling potential wave for pumping said liquid condensate. ### Claim 6 (depends on 5) A method for pumping a liquid condensate along a flow path from a condensor toward an evaporator in a heat pipe, as recited in claim 5, wherein: said liquid condensate has a conductivity gradient; and further comprising the step of producing a discontinuity in said conductivity gradient of said liquid condensate. ### Claim 7 (depends on 6) A method for pumping a liquid condensate along a flow path from a condensor toward an evaporator in a heat pipe, as recited in claim 6, wherein: said evaporator evaporates said liquid condensate to a gas, and wherein said discontinuity is produced by providing an interface between said gas and said liquid condensate along said flow path along which said liquid condensate is pumped. ### Claim 8 (depends on 6) A method for pumping a liquid condensate along a flow path from a condensor toward an evaporator in a heat pipe, as recited in claim 6, wherein: said discontinuity is produced by employing a liquid condensate consisting of two immiscible fluids. ### Claim 9 A self-priming voltage controllable EHD inductively pumped heat pipe, comprising: a condensing section; an evaporating section; a tube connecting said condensing and evaporating sections; a plurality of electrode segments circumferentially disposed around and positioned along said tube; a working fluid having a liquid and gas phase; a first conduit disposed within said tube for guiding said working fluid in said gas phase from said evaporating section to said condensing section; a second conduit disposed within said tube for guiding said working fluid in said liquid phase from said condensing section to said evaporating section; and electrical means for generating a traveling wave of electric potential and inducing a corresponding traveling wave of electric charge in said liquid for pumping thereof from said condensing section to said evaporating section of said heat pipe. ### Claim 10 (depends on 9) A self-priming voltage controllable EHD inductively pumped heat pipe as recited in claim 9, wherein said working fluid is a homogeneous dielectric working fluid, and further comprising said first and second conduits having an open interface extending along the length of said tube. ### Claim 11 (depends on 9) A self-priming voltage controllable EHD inductively pumped heat pipe as recited in claim 9, wherein said working fluid consists of two immiscible dielectric working fluids.