Method for cleaning mixing devices

US4311531A · kind A · utility

Assignee

• Kraftwerk Union Aktiengesellschaft · DE

Inventors

• Dietmar Bege · Erlangen, DE
• Anwer Puthawala · Erlangen, DE

Key dates

• Filing date: Mar 7, 1980
• Grant date: Jan 19, 1982
• Expiry date: Mar 7, 2000

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B29C48/03
• WIPO field: Other special machines
• WIPO sector: Mechanical engineering

Abstract

Mixing devices such as worm machines used for embedding radioactive wastes in hot bitumen are cleaned to remove residual bitumen and salt incrustations in three successive operations: (a) Washing with a solvent for bitumen in a volume amount equal to about the free space of the device. (b) Rinsing with a water-soluble rinsing medium miscible with the solvent in a volume amount the same as (a). (c) Rinsing with demineralized water in a volume amount twice (b). Pumice gravel is used to absorb the solvent and rinsing medium and the resultant pumice embedded in bitumen and sent to ultimate storage.