# US 4,400,332 A · Electrostatic dispersal of liquids > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 4,400,332 A - Document ID: US4400332A - Status: Granted - Kind: A - Application number: 06/328,131 - Filed: 1981-12-07 - Granted: 1983-08-23 - Earliest claimed: 1979-05-22 - Assignees: The Secretary of State for Industry in Her Britannic Majesty's Government of the United Kingdom of Great Britain and Northern Ireland - Inventors: Ian E. Pollard; Keith C. Hawkins - Web page: https://patentgrep.com/patent/US4400332A ## CPC - F02M 27/04: by electric means, {ionisation, polarisation} or magnetism - B01F 23/2133: {using electric, sonic or ultrasonic energy} - B05B 5/0255: {spraying and depositing by electrostatic forces only} - Y10S 261/55: Reatomizers - Y10S 261/80: Electrical treatment - F02M: SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF - B01F: MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING (mixing paints B44D3/06) - B05B: SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES (spray-mixers with nozzles B01F25/72; processes for applying liquids or other fluent materials to surfaces by spraying B05D) - Y10S: TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS ## Abstract A liquid such as a hydrocarbon fuel is sprayed electrostatically into a gas tream. Spraying is achieved by supplying the liquid to a porous member having a plurality of termini within an electrostatic field. The electrostatic field strength is enhanced at the termini so that liquid which soaks through the porous member to the termini breaks up under the influence of the locally high electrostatic field into a stream of droplets which are repelled by their charge away from the termini. The droplets become finely dispersed in a passing gas stream. The invention finds particular application as an electrostatic carburettor for dispersing petrol into an air stream for combustion in an internal combustion engine. The invention can also be utilized for re-dispersing fuel droplets deposited on the wall of an air/fuel intake. ## Claims ### Claim 1 Apparaus for the dispersal of liquid into a gas stream, comprising: at least one member formed of inherently porous material and being sufficiently porous that the liquid can soak therethrough and having a plurality of termini; means for supplying said liquid to said porous member; means for establishing an electric field in the vicinity of the termini on said porous member, said electric field causing liquid at said termini to be electrostatically dispersed from said termini; and means for directing a flow of gas past said termini so as to entrain and remove liquid electrostatically dispersed from said termini. ### Claim 2 Apparatus for dispersing liquid into a gas stream, comprising a plurality of porous members each such member being of generally annular form, each member having a plurality of termini directed radially therefrom; a plurality of tubular members, located one between each pair of adjacent annular porous members, means for holding the porous members and tubular member together to create an assembly defining a fluid reservoir therein; means for supplying said liquid to said reservoir; means for establishing an electric field in the vicinity of the termini on each of said porous members said electric field causing liquid at said termini to be electrostatically dispersed from said termini; and an annular duct wall surrounding said assembly of porous members and tubular members for constraining said gas stream to flow in the space between the duct wall and the assembly of porous members and tubular members for entraining and removing liquid electrostatically dispersed from termini. ### Claim 3 A carburetor for dispersing a liquid fuel into a gas stream comprising: at least one member formed of inherently porous material and sufficiently porous that said liquid fuel can soak therethrough and having a plurality of termini; means for supplying said liquid fuel to said porous member; means for establishing an electric field in the vicinity of the termini on said porous member, said electric field causing liquid at said termini to be electrostatically dispersed from said termini; and means for directing a flow of gas past said termini so as to entrain and remove liquid fuel electrostatically dispersed from said termini. ### Claim 4 (depends on 3) Apparatus according to claim 3, comprising a series of porous members each porous member having a plurality of termini, successive members being disposed adjacently along the line of flow of the gas. ### Claim 5 (depends on 3) Apparatus according to claim 3 wherein the termini are separated by at least 2 mm. ### Claim 6 (depends on 3) Apparatus according to claim 3 wherein the porous members are of a material selected from the group comprising ceramics, zeolites, fabrics, paper and sintered metals. ### Claim 7 (depends on 3) Apparatus according to claim 3 wherein the gas is constrained to flow within a duct and the termini of each porous member project radially outwardly into the duct. ### Claim 8 (depends on 7) Apparatus according to claim 7 wherein the duct is of substantially circular cross-section and the termini project radially outwardly into the gas which is constrained to flow between the duct and each porous member. ### Claim 9 (depends on 3) Apparatus according to claim 3 wherein said means for directing a flow of gas comprises a duct having walls within which the gas is constrained to flow and wherein the means for supplying said liquid comprises a sump into which liquid deposited on the duct walls can drain. ### Claim 10 (depends on 9) Apparatus according to claim 9 wherein the porous member extends into the sump and liquid therein is drawn to the termini by capillary action. ### Claim 11 A method of dispersing liquid into a gas stream, comprising the steps of: supplying the liquid to a member formed of inherently porous material and having a plurality of termini; permitting the liquid to soak through the porous member to the termini; simultaneously establishing an electric field in the vicinity of the termini, the field having such a magnitude as to cause said liquid to become electrostatically charged at said termini and to be driven off from said termini as a stream of droplets; and providing a flow of gas past said termini so as to entrain said droplets within said flow of gas. ### Claim 12 (depends on 11) A method as claimed in claim 11 further comprising the step of drawing the liquid through the porous member to the termini by capillary action. ### Claim 13 (depends on 11) A method as claimed in claim 11 wherein said step of establishing an electric field comprises the step of establishing a cyclically varying electric field. ### Claim 14 (depends on 11) A method as claimed in claim 11 wherein said step of establishing an electric field comprises the step of establishing an electric field having a magnitude of at least 100 KV/m. ### Claim 15 (depends on 14) A method as claimed in claim 14 wherein said step of establishing an electric field comprises the step of establishing an electric field having a magnitude on the order of 1 MV/m. ### Claim 16 (depends on 11) A method as claimed in claim 11 wherein said step of providing a flow of gas comprises the step of providing a flow of air. ### Claim 17 (depends on 16) A method as claimed in claim 16 wherein said step of establishing an electric field comprises the step of establishing an electric field having a magnitude less than about 3 MV/m. ### Claim 18 (depends on 16) A method as claimed in claim 16 wherein said step of supplying the liquid comprises the step of supplying a hydrocarbon fuel. ### Claim 19 (depends on 18) A method as claimed in claim 18 wherein said step of supplying the liquid comprises the step of supplying petrol.