Vapor degreasing

Abstract: Chlorinated degreasing solvents are multicomponent liquids containing not only the chlorinated hydrocarbons with which their name is associated (e.g., trichloroethylene or [TCE], perchloroethylene or [PCE], 1,1,1-trichloroethane [TCA]) but also a number of organic additives included as corrosion inhibitors and antioxidants. The additives, such as 1,4-dioxane, are likely to be of significant public-health importance as ground water contaminants due to their toxicity, solubility, and mobility. Following their use in vapor degreasing systems by industry, chlorinated degreasing solvents will also contain about 25% solubilized oil and grease. A number of physical-chemical properties become especially important in the light of the multicomponent nature of these solvents. First, the higher aqueous solubility and lower sorption of the additives makes it reasonable to expect that faster moving plumes of these solvent additives will precede plumes of the chlorinated hydrocarbons. Second, due to high losses of chlorinated hydrocarbons by volatilization from vapor degreasers during years in the middle of the century, it is probable that background concentrations of these hydrocarbons are present in ground water flow systems due to their downwind washout. Finally, the solubilized oil and grease may cause profound changes to the wettability of aquifer materials contacted by the solvents during their subsurface migration.more » It is argued, therefore, that the wettability of aquifer materials contaminated by chlorinated degreasing solvents needs to be experimentally determined before remediation of DNAPL at each site, rather than being simply assumed as water wet.« less

Abstract: Chemical solvating, degreasing, stripping and cleaning agents. The agents are cleaning and solvating mixtures of dichloroethylene and alkoxy-substituted perfluoro compounds that contain six carbon atoms, with optionally highly fluorinated materials to retard flammability and/or other enhancement agents that improve and enhance the properties of the composition to accomplish its desired cleaning or solvating task. These other agents are one or more of the following materials: alcohols, esters, ethers, cyclic ethers, ketones, alkanes, aromatics, amines, siloxanes terpenes, dibasic esters, glycol ethers, pyrollidones, or low- or non-ozone depleting halogenated hydrocarbons. These mixtures are useful in a variety of solvating, vapor degreasing, photoresistant stripping, adhesive removal, aerosol, cold cleaning, and solvent cleaning applications including defluxing, dry-cleaning, degreasing, particle removal, metal and textile cleaning.

Abstract: Cleaning apparatus such as a degreaser tank is provided with a vapor zone divided into upper and lower portions by a wall and a closure member which cooperates with the wall so that the upper and lower portions of the vapor zone may be isolated from one another. During such isolation of the upper and lower portions of the vapor zone, vapors from the upper portion are removed to thereby facilitate introduction or removal of work pieces into the upper portion of the vapor zone while minimizing solvent losses to the atmosphere and minimizing exposure of workers to solvent vapors.

Abstract: The development of receptor models for the determination of the sources of an ambient air pollutant requires that the composition of the pollutant at the point of emission be known. For this study, composition information for 10 sources of volatile organic compounds (VOC) were evaluated and source fingerprints developed. The source categories include motor vehicles, gasoline vapor, petroleum refineries, architectural coatings, graphic arts, waste-water treatment, vapor degreasing, drycleaning, automobile assembly (including body painting), and polyethylene production. The fingerprints are presented for a group of 23 compounds. These compounds were selected for a variety of reasons including ease of measurement in the ambient environment, compound toxicity, reactivity, and usefulness in previous receptor modeling applications. In general, the data for sources of VOC are remarkably consistent from study to study. Because the profiles for many of the sources of VOC are controlled by physical and chemical pro...