# US 12,180,605 B2 · Volatile organic compound recovery device and recovery method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,180,605 B2 - Document ID: US12180605B2 - Status: Granted - Kind: B2 - Application number: 17/420,360 - Filed: 2020-01-08 - Published: 2022-03-24 - Granted: 2024-12-31 - Earliest claimed: 2019-01-15 - Assignees: Mazda Motor Corporation - Applicants: Mazda Motor Corporation - Inventors: Yu Kato; Masafumi Shinoda - Web page: https://patentgrep.com/patent/US12180605B2 ## CPC - C25D 13/22: Servicing or operating {apparatus or multistep processes} - B01D 53/002: {by condensation} - B01D 53/265: {by refrigeration (condensation)} - B01D 53/38: Removing components of undefined structure - B01D 53/44: Organic components - B05B 16/40: Construction elements specially adapted therefor, e.g. floors, walls or ceilings (ceiling elements filtering inflow of air into the booth B05B16/60; walls specially adapted for promoting separation of excess material B05B14/44) - B05C 9/14: the auxiliary operation involving heating {or cooling} - B05C 11/10: Storage, supply or control of liquid or other fluent material; Recovery of excess liquid or other fluent material {(B05C1/0813, B05C5/0225, B05C17/002 and B05C19/06 take precedence)} - B05D 3/00: Pretreatment of surfaces to which liquids or other fluent materials are to be applied; After-treatment of applied coatings, e.g. intermediate treating of an applied coating preparatory to subsequent applications of liquids or other fluent materials (successively applying liquids or other fluent materials B05D1/36; drying ovens F26B) - B05D 3/02: by baking {(B05D3/04 takes precedence)} - B05D 7/24: for applying particular liquids or other fluent materials - C25D 13/04: with organic material - F26B 3/04: the gas or vapour circulating over or surrounding the materials or objects to be dried (F26B3/14 takes precedence) - F26B 15/12: the lines being all horizontal or slightly inclined - F26B 21/25: partly outside the drying enclosure - F26B 21/33: Humidity - F26B 25/006: {Separating volatiles, e.g. recovering solvents from dryer exhaust gases} - B01D 2257/708: Volatile organic compounds V.O.C.'s - B01D 2258/06: Polluted air - F26B 2210/12: Vehicle bodies, e.g. after being painted - C25D: PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR - B01D: SEPARATION (separating solids from solids by wet methods B03B, B03D; by pneumatic jigs or tables B03B; by other dry methods B07; magnetic or electrostatic separation of solid materials from solid materials or fluids, separation by high-voltage electric fields B03C; centrifuges, vortex apparatus B04; presses per se for squeezing-out liquid from liquid-containing material B30B9/02; treatment of water C02F, e.g. softening by ion-exchange C02F1/42; {arrangements of air intake cleaners in gas turbine plants F02C7/05} ; arrangements or mounting of filters in air-conditioning, air-humidification or ventilation F24F13/28) - 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) - B05C: APPARATUS FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL (spraying apparatus, atomising apparatus, nozzles B05B; plant for applying liquids or other fluent materials to objects by electrostatic spraying B05B5/08) - B05D: PROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL (conveying articles or workpieces through baths of liquid B65G, e.g. B65G49/02) - F26B: DRYING SOLID MATERIALS OR OBJECTS BY REMOVING LIQUID THEREFROM (drying devices for combines A01D41/133; racks for drying fruit or vegetables A01F25/12; drying foodstuffs A23; drying hair A45D20/00; body-drying implements A47K10/00; drying household articles A47L; drying gases or vapours B01D; chemical or physical processes for dewatering or like separating liquids from solids B01D43/00; centrifugal apparatus B04; drying ceramics C04B33/30; drying yarns or fabrics in association with some other form of treatment D06C; drying frames for laundry without heating or positive air circulation, domestic laundry-or spin-driers, wringing or hot pressing laundry D06F; furnaces, kilns, ovens F27) ## Abstract A recovery device for a volatile organic compound is a device for recovering the volatile organic compound in a coating drying oven which dries a coating film of a workpiece coated with a water-soluble coating. The coating drying oven includes: an evaporation zone in which moisture of the workpiece is evaporated; and a curing zone to cure the coating film. The recovery device includes: a first take-out passage for taking out first furnace air in the evaporation zone; a second take-out passage for taking out second furnace air in the curing zone; a mixing chamber configured to mix the first furnace air and the second furnace air to obtain mixed air; and a cooling recovery unit configured to cool the mixed air and recover, as a condensate, the volatile organic compound contained in the mixed air, together with the moisture. ## Claims ### Claim 1 A device for recovering a volatile organic compound in a coating drying oven into which a workpiece coated with a water-soluble coating is carried and which dries a coating film of the workpiece, the coating drying oven including: an evaporation zone into which the workpiece is carried and in which moisture of the workpiece is evaporated at a furnace temperature ranging from 80° C. to 120° C.; and a curing zone arranged downstream of the evaporation zone so as to cure the coating film at a furnace temperature ranging from 150° C. to 200° C., the device comprising: a first take-out passage communicating with the evaporation zone, the first take-out passage being for taking out first furnace air in the evaporation zone; a second take-out passage communicating with the curing zone, the second take-out passage being for taking out second furnace air in the curing zone; a mixing chamber configured to mix the first furnace air and the second furnace air to obtain mixed air; and a cooling recovery unit configured to cool the mixed air and recover, as a condensate, the volatile organic compound contained in the mixed air, together with the moisture. ### Claim 2 (depends on 1) The device of claim 1, wherein the cooling recovery unit includes: a cooler configured to cool the mixed air; a heater to which residual air obtained by removing the condensate from the mixed air cooled by the cooler is introduced, the heater being configured to heat the residual air; a return passage for returning, to the coating drying oven, the residual air heated; and a heat pump connecting the cooler and the heater, and configured to supply cold heat for cooling the mixed air to the cooler through heat exchange and supply hot heat for heating the residual air to the heater through heat exchange. ### Claim 3 (depends on 2) The device of claim 2, further comprising: an additional cooler arranged upstream of the cooler and configured to pre-cool the mixed air. ### Claim 4 (depends on 3) The device of claim 3, wherein the cooling recovery unit includes a moisture feeder configured to add additional moisture into the cooling recovery unit. ### Claim 5 (depends on 1) The device of claim 1, wherein the cooling recovery unit includes a moisture feeder configured to add additional moisture into the cooling recovery unit. ### Claim 6 A method of recovering a volatile organic compound in a coating drying oven into which a workpiece coated with a water-soluble coating is carried and which dries a coating film of the workpiece, the coating drying oven including: an evaporation zone into which the workpiece is carried and in which moisture of the workpiece is evaporated at a furnace temperature ranging from 80° C. to 120° C.; and a curing zone arranged downstream of the evaporation zone so as to cure the coating film at a furnace temperature ranging from 150° C. to 200° C., the method comprising: a first take-out step of taking out first furnace air in the evaporation zone; a second take-out step of taking out second furnace air in the curing zone; a mixing step of mixing the first furnace air and the second furnace air to obtain mixed air; and a cooling recovery step of cooling the mixed air and recovering, as a condensate, the volatile organic compound contained in the mixed air, together with the moisture. ### Claim 7 (depends on 6) The method of claim 6, further comprising: a return step of heating, and returning to the coating drying oven, residual air that has undergone the cooling recovery step and from which the condensate has been removed, wherein the mixed air is cooled and the residual air is heated by a heat pump that uses the mixed air as a heat absorption source and the residual air as a heat dissipation source. ### Claim 8 (depends on 7) The method of claim 7, further comprising: pre-cooling the mixed air before the mixed air is cooled by the heat pump. ### Claim 9 (depends on 8) The method of claim 8, wherein in the return step, the residual air heated by the heat pump is further heated and returned to the coating drying oven. ### Claim 10 (depends on 9) The method of claim 9, wherein the moisture contained in the mixed air has a weight absolute humidity of 21 g/kg or more, the mixed air contains the volatile organic compound at a concentration of 500 ppmC or more, the moisture contained in the residual air has a weight absolute humidity of 18 g/kg or less, and the residual air contains the volatile organic compound at a concentration of 80 ppmC or less. ### Claim 11 (depends on 10) The method of claim 10, wherein the water-soluble coating is an electrodeposition coating, and the workpiece is carried into the coating drying oven after being subjected to a rinsing step in which the workpiece subjected to electrodeposition using the electrodeposition coating is immersed into rinse water and rinsed. ### Claim 12 (depends on 6) The method of claim 6, wherein the water-soluble coating is an electrodeposition coating, and the workpiece is carried into the coating drying oven after being subjected to a rinsing step in which the workpiece subjected to electrodeposition using the electrodeposition coating is immersed into rinse water and rinsed. ### Claim 13 (depends on 7) The method of claim 7, wherein in the return step, the residual air heated by the heat pump is further heated and returned to the coating drying oven. ### Claim 14 (depends on 7) The method of claim 7, wherein the moisture contained in the mixed air has a weight absolute humidity of 21 g/kg or more, the mixed air contains the volatile organic compound at a concentration of 500 ppmC or more, the moisture contained in the residual air has a weight absolute humidity of 18 g/kg or less, and the residual air contains the volatile organic compound at a concentration of 80 ppmC or less. ### Claim 15 (depends on 7) The method of claim 7, wherein the water-soluble coating is an electrodeposition coating, and the workpiece is carried into the coating drying oven after being subjected to a rinsing step in which the workpiece subjected to electrodeposition using the electrodeposition coating is immersed into rinse water and rinsed. ### Claim 16 (depends on 6) The method of claim 6, wherein in the cooling recovery step, additional moisture is added into the mixed air. ### Claim 17 A device for recovering a volatile organic compound in a coating drying oven into which a workpiece coated with a water-soluble coating is carried and which dries a coating film of the workpiece, the coating drying oven including: an evaporation zone into which the workpiece is carried and in which moisture of the workpiece is evaporated at a furnace temperature ranging from 80° C. to 120° C.; and a curing zone arranged downstream of the evaporation zone so as to cure the coating film at a furnace temperature ranging from 150° C. to 200° C., the device comprising: a first take-out passage communicating with the evaporation zone, the first take-out passage being for taking out first furnace air in the evaporation zone; and a cooling recovery unit configured to cool the first furnace air and recover, as a condensate, the volatile organic compound contained in the first furnace air, together with the moisture, wherein the water-soluble coating is an electrodeposition coating, and the workpiece is carried into the coating drying oven after being subjected to a rinsing step in which the workpiece subjected to electrodeposition using the electrodeposition coating is immersed into rinse water and rinsed. ### Claim 18 A device for recovering a volatile organic compound in a coating drying oven into which a workpiece coated with a water-soluble coating is carried and which dries a coating film of the workpiece, the coating drying oven including: an evaporation zone into which the workpiece is carried and in which moisture of the workpiece is evaporated at a furnace temperature ranging from 80° C. to 120° C.; and a curing zone arranged downstream of the evaporation zone so as to cure the coating film at a furnace temperature ranging from 150° C. to 200° C., the device comprising: a take-out passage communicating with the curing zone, the take-out passage being for taking out furnace air in the curing zone; and a cooling recovery unit configured to cool the furnace air taken out from the curing zone and recover, as a condensate, the volatile organic compound contained in the furnace air taken out from the curing zone, together with the moisture, wherein the cooling recovery unit includes a moisture feeder configured to add additional moisture into the cooling recovery unit. ### Claim 19 A method of recovering a volatile organic compound in a coating drying oven into which a workpiece coated with a water-soluble coating is carried and which dries a coating film of the workpiece, the coating drying oven including: an evaporation zone into which the workpiece is carried and in which moisture of the workpiece is evaporated at a furnace temperature ranging from 80° C. to 120° C.; and a curing zone arranged downstream of the evaporation zone so as to cure the coating film at a furnace temperature ranging from 150° C. to 200° C., the method comprising: a first take-out step of taking out first furnace air in the evaporation zone; and a cooling recovery step of cooling the first furnace air and recovering, as a condensate, the volatile organic compound contained in the first furnace air, together with the moisture, wherein the water-soluble coating is an electrodeposition coating, and the workpiece is carried into the coating drying oven after being subjected to a rinsing step in which the workpiece subjected to electrodeposition using the electrodeposition coating is immersed into rinse water and rinsed. ### Claim 20 A method of recovering a volatile organic compound in a coating drying oven into which a workpiece coated with a water-soluble coating is carried and which dries a coating film of the workpiece, the coating drying oven including: an evaporation zone into which the workpiece is carried and in which moisture of the workpiece is evaporated at a furnace temperature ranging from 80° C. to 120° C.; and a curing zone arranged downstream of the evaporation zone so as to cure the coating film at a furnace temperature ranging from 150° C. to 200° C., the method comprising: a take-out step of taking out furnace air in the curing zone; and a cooling recovery step of adding additional moisture into the furnace air taken out from the curing zone, cooling the furnace air taken out from the curing zone and recovering, as a condensate, the volatile organic compound contained in the furnace air taken out from the curing zone, together with the moisture and the additional moisture.