Continuous removal of organic coating, e.g. resin, from steel pipe - involves heating pipe with a medium frequency induction coil and burning off to remove coating completely without thermally degrading steel

• Main Authors: REINEKING, KLAUS-JUERGEN., 4330 MUELHEIM, DE, HOFMANN, GEORG., 4000 DUESSELDORF, DE, FOERSTER, HERBERT., 4000 DUESSELDORF, DE
• Format: Patent
• Language: English; German
• Published: 24.02.1994
• Edition: 5
• Subjects: CLEANING; CLEANING IN GENERAL; CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATERTREATMENT OR WASTE MANAGEMENT; ELECTRIC HEATING; ELECTRIC LIGHTING NOT OTHERWISE PROVIDED FOR; ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULARARTICLES; INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS; MAKING GRANULES OR PREFORMS; PERFORMING OPERATIONS; PREPARATION OR PRETREATMENT OF THE MATERIAL TO BESHAPED; PREVENTION OF FOULING IN GENERAL; RECOVERY OF PLASTICS OR OTHER CONSTITUENTS OF WASTE MATERIALCONTAINING PLASTICS; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS; TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINSTCLIMATE CHANGE; TRANSPORTING; WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE, IN GENERAL

An organic coating on hollow metal bodies, esp. steel pipes, is removed where they have an epoxy undercoat and an ethylene-copolymer to coat, and the surface is cleaned off mechanically for renewed application of the organic coating. The metal wall is uniformly heated to at least 200 deg.C but max. 350 deg.C by induction heating at medium frequency, the coating is then immediately heated externally in the presence of oxygen so that it is thermally broken down at at least 400 deg.C but max. 550 deg.C but without causing the metal wall to exceed 400 deg.C. The product is then subjected to the mechanical cleaning. ADVANTAGE - The procedure is continuous. It effectively removes all coatings from the metal surface but without heating it enough to affect its properties.