Abstract: A purge solution for removing water-based dehydrated paint residues from a paint delivery system includes 2–15 total weight percent of a purge concentrate diluted with solvent. The concentrate includes 20–99.5 total weight percent of a C4 alcohol or an alkoxylated C4 alcohol, and 0.5–30 total weight percent of an amine.

Abstract: A purge solution for removing water-based dehydrated paint residues from a paint delivery system includes 2-15 total weight percent of a purge concentrate diluted with solvent. The concentrate includes 20-99.5 total weight percent of a C4 alcohol or an alkoxylated C4 alcohol, and 0.5-30 total weight percent of an amine.

Abstract: A process for recovering quantities of carbonyl compound material from spent solvent-in-water emulsions derived from paint overspray treatment and capture systems in which the spent solvent-in-water emulsion is removed from the paint overspray treatment and capture system and fed into a reaction vessel. The reaction vessel employed includes an outer housing defining a reaction chamber and a plurality of mixing blades movably positioned in the reaction chamber. The surface area of the mixing blades are maintained at a temperature sufficient to generate volatilized carbonyl compound. The interior of the reaction vessel is maintained under a vacuum. The spent solvent-in-water emulsion is processed in the reaction vessel for an interval sufficient to generate volatilized carbonyl compound.

Abstract: A process for recovering organic solvent material from a hydrophilic liquid derived from paint overspray treatment operations in which the solvent-in-water emulsion initially contains 1-50 weight percent of an organic liquid having a boiling point of at least 150.degree. C., a vapor pressure less than 0.5 Torr at 20.degree. C.; and water, and the spent hydrophilic liquid additionally contains paint solid material derived from the paint overspray treatment system in which the recovery process includes the steps of(a) removing the spent hydrophilic liquid or a portion thereof from the paint spray booth;(b) feeding the spent hydrophilic liquid into a reaction vessel, the reaction vessel operating at a pressure less than about 100 mm/Hg and at a temperature sufficient to volatilize the organic liquid component of the hydrophilic liquid; and(c) separating a portion of said volatilized organic liquid from the spent hydrophilic liquid after introduction of the spent hydrophilic liquid into the reaction vessel.

Abstract: A composition for treating oversprayed paints that contains an effective amount of a carbonyl compound such as alcohol esters and alcohol ester derivatives in water together with a suitable emulsifier. The carbonyl compound is capable of dissolving paint while remaining non-reactive with water. The alcohol ester employed has the general formula: ##STR1## The alcohol ester derivative employed has the general formula: ##STR2## R' and R" are a substituted or unsubstituted linear alkyl group containing 1 to 8 carbon atoms, R and R"' are linear or branched alkyl groups containing 1 to 10 carbon atoms, and R and R"' are either identical or different alkyl functionalities.

Abstract: A method for detackifying oversprayed paint solids in a paint spray booth utilizes an oil-in-water emulsion as the hydrophilic fluid for capturing and detackifying oversprayed paint, which emulsion contains a certain nonionic surfactant, which surfactant greatly improves detackification performance when the paint formulation being sprayed is a low VOC formulation, and particularly a two-component formulation. The nonionic surfactant is an ethoxylated C.sub.8-10 alkyl phenol having an HLB value of from about 4.5 to 15.5.

Abstract: In a method of recovering volatile organic paint carrier from paint spray booths and also collecting, detackifying, and dispersing paint solids obtained from paint overspray in said paint spray booths, which paint spray booths are of the type comprising a chamber, a duct system for passing air through said chamber, an exhaust system connected to said duct system, a sump containing a circulating hydrophilic liquid which is pumped onto a means for forming a liquid curtain of said hydrophilic liquid, said liquid curtain being contacted by oversprayed paint and volatile organic paint carrier; the improvement which comprises using as the hydrophilic liquid an improved oil-in-water emulsion maintained at a pH value ranging from 7.5-11.0, which emulsion consists essentially of the ingredients:(a) from 5-50 weight percent, of an organic hydrocarbonaceous liquid having a boiling point of at least 150.degree. C.;(b) from 0.

Abstract: A method of detackifying oversprayed paints chosen from the group consisting of high solids enamels, clear coats, two-phase urethane paints, and water or solvent borne base coats which comprises the contact of said oversprayed paint with an oil-in-water emulsion having:(a) 1-50 weight percent of a hydrocarbon oily liquid having a boiling point of at least 150.degree. C.;(b) 0.1-25 weight percent, based on the oily liquid, of an oil-in-water emulsifier;(c) the remainder, water;which emulsion has a pH of from 7.5-12.0 and then detackifying through said contact within a paint spray booth to form a detackified oversprayed paint particulate and then, collecting and dispersing said detackified paint particulate within the oil-in-water emulsion, thereby forming a spent oil-in-water emulsion containing at least 5 parts of detackified paint particulate per 100 parts of hydrocarbon oily liquid contained in said spent oil-in-water emulsion.

Abstract: In a process for removal of detackified oversprayed paint particles from paint spray booths of the type comprising a chamber, means for passing a wash stream capturing oversprayed paint particles across a liquid curtain and down through said chamber, a sump located at the bottom of said chamber and containing a circulating oil-in-water emulsion receiving said oversprayed paint particles from said wash stream, said oil-in-water emulsion comprised of:(a) 1-50 weight percent of an organic liquid having a boiling point of at least 150.degree. C.,(b) 0.1-30 weight percent, based on the organic liquid, of an oil-in-water emulsifier,(c) the balance, water, andsaid emulsion having a pH ranging between about 7.5-12.

Abstract: A method for the removal of over-sprayed paint solids which comprises contacting the over-sprayed paint solids with an oil-in-water emulsion until the emulsion is loaded with at least 5 parts by weight of paint solids per 100 parts by weight of the hydrocarbon liquid of the emulsion.

Abstract: A perturbed feedback control system for a process. Inputs to the process include a feed stream and a manipulated variable. The manipulated variable is controlled by a feedback controller. Measurements of a parameter measured "downstream" of the process are taken periodically and fed back to the controller. The feedback controller generates a control response on the basis of a comparison of the two most recent values of the downstream parameter. The comparison is made by calculating a perturbed set point which includes the values of the downstream parameter taken at the two most recent sampling periods. In a specific embodiment, the perturbed set point also includes measurements of the most recent and preceding values of the manipulated variable. A control response is applied to the manipulated variable by the feedback controller based on the value of the perturbed set point. The control system has been applied to optimize the feed rate of chemicals for sludge dewatering on a twin belt filter press.