The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 25, 1990
Filed:
Jun. 03, 1988
Jeffrey C Johnson, Birmingham, MI (US);
Andrew Slater, Troy, MI (US);
Haden Schweitzer, Troy, MI (US);
Abstract
A method and apparatus are disclosed for the treatment of paint sludge and for reducing volatile organic compound emissions from a paint spraybooth operation, thereby obtaining a recyclable material for use in new coating products. In such an operation, uncured paint resins mixed with volatile organic compounds are sprayed onto an article to be painted and at least a portion of the overspray is mixed with water to form a waste stream containing water, uncured paint resin, volatile organic compounds and inorganic substances. The method includes the steps of: removing a portion of the water and liquid volatile organic compounds from the waste stream; heating the resultant sludge to volatilize the residual water and liquid volatile organic compounds and to cure the uncured paint resin; collecting the residual solids stream, and removing all of the volatilized organic compounds from the resultant stream, thereby generating a volatile organic compound-free gas effluent. The amount of volatized organic compounds removed is at least about 5% of the volatile organic compounds input to the paint spraybooth operation. The apparatus includes a waste paint stream dewatering device and an enclosed rotary screw heat exchanger maintained in an inert environment; the apparatus also provides a system for adding a scouring aggregate to the sludge before heating and for removing the aggregate after heating. Finally, the apparatus includes a separator for removing entrained solids from the resulting gas stream, and provides a system for processing the gas stream to remove all volatile organic compounds.