Cleaning or stripping of coated objects

• US 4,474,199 A
• Filed: 11/09/1982
• Issued: 10/02/1984
• Est. Priority Date: 11/19/1981
• Status: Expired due to Fees

• Current Assignee: L'Air Liquide Societe Anonyme Pour L'Etude et L'Exploitation Des Procedes Georges Claude (L'Air Liquide SA)
• Original Assignee: L'Air Liquide Societe Anonyme Pour L'Etude et L'Exploitation Des Procedes Georges Claude (L'Air Liquide SA)
• Inventors: Blaudszun, Bernd
• Primary Examiner(s): Bleutge, Robert L.
• Application Number:
  US06/440,433
• Time in Patent Office: 693 Days
• Field of Search: 202/170, 134/105, 134/122 R, 134/122 P
• US Class Current: 134/105
• CPC Class Codes: B08B 7/0092 by cooling
• CPC Class Codes: B44D 3/16 Implements or apparatus for removing dry paint from surfaces, e.g. by scraping, by burning chemical paint-removers C09D9/00
• CPC Class Codes: C23G 5/04 Apparatus

Abstract

The present invention relates to the cleaning or stripping of coated objects. The coating is dissolved in a receiver tank rendered inert by means of nitrogen, by a solvent and the mixture of solvent and coating product is transferred into a thickening tank swamped by a heated nitrogen flow. The nitrogen-solvent mixture is separated by cooling and condensation of the solvents extracted. The invention is applied to the stripping of objects coated with paints and varnish.

Claims

1. Apparatus for cleaning or stripping objects coated with varnish or paints, comprising:

at least one receiver tank for receiving said objects;

means for selectively sealingly closing said receiver tank;

a tank of inert gas;

an inert gas feed pipe having a first valve and connecting said receiver tank to said tank of inert gas;

a stripping agent tank;

a stripping agent feed pipe having a second valve and connecting said stripping agent tank to said receiver tank;

an exhaust pipe having a third valve and connecting said receiver tank to atmosphere through a heat exchanger and a separator, said inert gas tank being connected to said receiver tank via said heat exchanger; and

emptying means for selectively emptying said receiver tank.

2. Apparatus according to claim 1, wherein a first pump is provided in said stripping agent feed pipe and said emptying means comprise a second pump.

3. Apparatus according to claim 1, further comprising at least one thickening tank which is connected to said receiving tank through said emptying means;

a conduit having a fourth valve and connecting said inert gas tank to said thickening tank;

a discharge pipe connecting an upper part of said thickening tank to a second separator via a second heat exchanger; and

means for supplying a refrigerant fluid to said second heat exchanger.

4. Apparatus according to claim 3, wherein said second heat exchanger comprises an evaporator of a refrigerating set.

5. Apparatus acccording to claim 3, further comprising a return pipe for returning inert gas freed of condensed stripping agent from said second separator into said thickening tank.

6. Apparatus according to claim 5, wherein a heating device is installed on said return pipe.

7. Apparatus according to claim 3, wherein a blower is installed in said discharge pipe.

8. Apparatus according to claim 5, wherein said discharge pipe and said return pipe are disposed in heat exchange relationship in a recuperator.

9. Apparatus according to claim 3, wherein liquid outlets of said separators are connected to said stripping agent tank via stripping agent return means comprising a third pump.