# US 5,702,652 A · Controlled cooling of porous materials > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,702,652 A - Document ID: US5702652A - Status: Granted - Kind: A - Application number: 08/788,627 - Filed: 1997-01-24 - Granted: 1997-12-30 - Earliest claimed: 1990-05-31 - Assignees: Crain Industries, Inc. - Inventors: Michael A. Ricciardi; Anthony C. M. Griffiths - Web page: https://patentgrep.com/patent/US5702652A ## CPC - B29C 44/5609: {Purging of residual gas, e.g. noxious or explosive blowing agents} - B29C 35/16: Cooling {(cooling extruded material B29C48/911; cooling preforms for blow moulding B29C49/6427; cooling blown articles B29C49/66; cooling tyres during post cure inflation B29D30/0643)} - B29C 2037/90: {Measuring, controlling or regulating} - B29K 2105/04: cellular or porous - B29C: SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING (making preforms B29B11/00; making laminated products by combining previously unconnected layers which become one product whose layers will remain together B32B37/00 - B32B41/00) - B29K: INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR {MOULDS, } REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS ## Abstract Method and apparatus for cooling porous materials whereby first gases are passed through a porous material, such as polyurethane foam, in a first zone at a predetermined flow rate to cool the porous material and to remove volatiles therefrom in a first gas mixture which exits the porous material at a predetermined temperature. The first gas mixture is combined with second gases having a temperature which is lower than that of the first gas mixture to form a second gas mixture having a temperature which is sufficiently low to condense or sublime one or more of the volatiles. Thereafter, the second gas mixture is passed through the porous material to filter the condensed or sublimed volatiles thereon and to further cool the porous material. The flow rate of the heated gases is controlled to provide a controlled uniform cooling of the porous material, and additional filters may be utilized to remove particulate matter from either of the heated gases or the cold gases, or both. ## Claims ### Claim 1 A process for cooling polyurethane foam which comprises: passing first cooling gases through a first section of a polyurethane foam block in a first cooling zone at a predetermined flow rate to cool the foam and to remove volatiles therefrom; thereafter passing second cooling gases through the same foam block section in a second cooling zone at a predetermined flow rate to further cool the foam and to further remove volatiles therefrom; withdrawing at least a portion of the second cooling gases which exit the foam block section from the second zone; and recovering volatiles from the withdrawn portion of the second cooling gases. ### Claim 2 (depends on 1) The process of claim 1 wherein the volatiles include at least one of toluene diisocyanate, butylated hydroxy toluene, chlorofluorocarbons or other solvents or auxiliary blowing agents, and which further comprises recovering one or more of the volatiles in an adsorption system. ### Claim 3 (depends on 1) The process of claim 1 wherein the cooling gases comprise air or nitrogen and at least a portion of the second cooling gases which has passed through the foam block section in one cooling zone is recirculated for use as part of the cooling gases in one of the other cooling zones. ### Claim 4 A process for cooling polyurethane foam which comprises: passing first cooling gases through polyurethane foam in a first cooling zone at a predetermined flow rate to cool the foam and to remove volatiles therefrom; thereafter passing second cooling gases through the foam in a second cooling zone at a predetermined flow rate to further cool the foam and to further remove volatiles therefrom; withdrawing at least a portion of the second cooling gases which exit the foam from the second zone; recovering volatiles from the withdrawn portion of the second cooling gases; and removing condensed or sublimed volatiles from said portion of the second cooling gases prior to recovering the remaining volatiles. ### Claim 5 (depends on 4) The process of claim 4 which further comprises cooling the first cooling gases which exit the foam from the first zone and mixing the resultant cooled gases with the second cooling gases which exit the foam from the second zone to form a gas mixture and to condense or sublime volatiles therein. ### Claim 6 (depends on 5) The process of claim 5 wherein the condensed or sublimed volatiles are removed by recirculating and passing the gas mixture through the foam to deposit the condensed or sublimed volatiles thereon. ### Claim 7 (depends on 1) The process of claim 1 which further comprises passing cooling gases through the foam in a third cooling zone at a predetermined flow rate to further cool the foam and to remove volatiles therefrom. ### Claim 8 (depends on 7) The process of claim 7 which further comprises mixing the gases which exit the foam from the third cooling zone with the gases which exit the foam from the first cooling zone to condense or sublime one or more of the volatiles and to form a gas mixture, and passing the gas mixture through the foam to filter the condenses or sublimed volatiles therein. ### Claim 9 (depends on 8) The process of claim 8 which further comprises recirculating a portion of the cooling gases that exit the foam from the third zone as for mixing with the gas mixture. ### Claim 10 (depends on 8) The process of claim 8 which further comprises removing particulate matter from the gas mixture prior to mixing with the portion of the cooling gases that exits the foam from the third cooling zone of the foam. ### Claim 11 (depends on 8) The process of claim 8 which further comprises removing particulate matter from the gases which exit the foam from the third cooling zone prior to mixing with the gas mixture. ### Claim 12 A process for cooling polyurethane foam which comprises: passing first Cooling gases through polyurethane foam in a first cooling zone at a predetermined flow rate to cool the foam and to remove volatiles therefrom; adding an auxiliary reactant to the cooling gases for introduction into the foam to modify one or more properties thereof; thereafter passing second cooling gases through the foam in a second cooling zone at a predetermined flow rate to further cool the foam and to further remove volatiles therefrom; withdrawing at least a portion of the second cooling gases which exit the foam from the second zone; and recovering volatiles from the withdrawn portion of the second cooling gases. ### Claim 13 (depends on 1) The process of claim 1 which further comprises adding moisture to the cooling gases to accelerate the curing of the foam. ### Claim 14 (depends on 3) The process of claim 3 wherein the air is high humidity air to accelerate the curing of the foam. ### Claim 15 (depends on 2) The process of claim 2 wherein the adsorption system comprises a carbon adsorption bed. ### Claim 16 (depends on 1) The process of claim 1 which further comprises cooling the first cooling gases which exit the foam from the first zone by mixing the gases with the second cooling gases which exit the foam from the second zone to form a gas mixture and to condense or sublime volatiles therein. ### Claim 17 (depends on 16) The process of claim 16 wherein the condensed or sublimed volatiles are recovered by recirculating and passing the gas mixture through the foam to deposit the condensed or sublimed volatiles thereon.