Method and apparatus for treating objects in a closed vessel with a solvent
First Claim
1. In a method for the treatment of objects in a closed vessel with solvents for stripping enamel and removing coatings from the objects, in which the objects to be treated are treated for at least part of the time by immersion in solvents and subsequently washed by spraying in a solvent-free region of the vessel, the improvement which comprises that said method includes at least the following additional steps:
- a) as solvents after closure of the treating vessels, a treating agent mixture with at least a preponderance of a solvent such as methylene chloride, and an amount of water in excess of that required to form an azeotropic mixture is used;
b) the treating agent mixture is heated to the boiling point of the mixture;
c) at the end of the treatment time, the settling and, if necessary, condensing solvent is removed from the treating vessel;
d) water is heated in the treating vessel and evaporated, whereby the water acts as a heat carrier;
e) the solvent on or in the coating or enamel residues and the objects to be treated is distilled off azeotropically from the system with water and removed before the vessel is opened.
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Accused Products
Abstract
In a method, especially for stripping enamel and removing coatings from objects, the advantages of a solvent treatment are to be retained, without having to put up with the disadvantages of contaminating the environment. This is accomplished essentially by using in a closed treating vessel a treating mixture with at least a preponderance of a solvent with a proportion of water in excess of that required for an azeotropic mixture and carrying out the treatment while boiling the treating mixture. After the treating mixture is removed from the vessel, any solvent components still present are distilled off azeotropically from the system with water and removed before the vessel is opened.
124 Citations
7 Claims
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1. In a method for the treatment of objects in a closed vessel with solvents for stripping enamel and removing coatings from the objects, in which the objects to be treated are treated for at least part of the time by immersion in solvents and subsequently washed by spraying in a solvent-free region of the vessel, the improvement which comprises that said method includes at least the following additional steps:
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a) as solvents after closure of the treating vessels, a treating agent mixture with at least a preponderance of a solvent such as methylene chloride, and an amount of water in excess of that required to form an azeotropic mixture is used; b) the treating agent mixture is heated to the boiling point of the mixture; c) at the end of the treatment time, the settling and, if necessary, condensing solvent is removed from the treating vessel; d) water is heated in the treating vessel and evaporated, whereby the water acts as a heat carrier; e) the solvent on or in the coating or enamel residues and the objects to be treated is distilled off azeotropically from the system with water and removed before the vessel is opened. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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Specification