ROTARY JOINT FOR STRONGLY CORROSIVE LIQUID

• Main Authors: OKUNISHI YASUYUKI, OKUMACHI EIJI
• Format: Patent
• Language: English
• Published: 26.11.2009
• Subjects: BASIC ELECTRIC ELEMENTS; BLASTING; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVEFUNCTIONING OF MACHINES OR INSTALLATIONS; HEATING; JOINTS OR FITTINGS FOR PIPES; LIGHTING; MEANS FOR THERMAL INSULATION IN GENERAL; MECHANICAL ENGINEERING; PIPES; SEMICONDUCTOR DEVICES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; THERMAL INSULATION IN GENERAL; WEAPONS

PROBLEM TO BE SOLVED: To provide a rotary joint capable of surely preventing contamination and leakage when streaming a strongly corrosive liquid such as hydrofluoric acid. SOLUTION: One first sealed space 7 and each pair of second and third sealed spaces 8 and 9 are formed between a case body 2 and a rotary shaft body 3 by partitioning with first to third mechanical seals 4, 5 and 6, and passages 15 and 16 formed in both the case body 2 and rotary shaft body 3 are communicated with each other through the first sealed space 7 to form a flow passage 10 for a strong corrosive liquid 1. A first sealed liquid 11 having the pressure lower than that of the strong corrosive liquid 1 is supplied to the second sealed space 8, and a second sealed liquid 12 having the pressure higher than that of the first sealed liquid 11 is supplied to the third sealed space 9. The first mechanical seal 4 is formed into a non-contact type mechanical seal which allows fine leakage of the strong corrosive liquid 1 from the first sealed space 7 to the second sealed space 8, and the second mechanical seal 5 and the third mechanical seal 6 are respectively structured to an end surface contact type mechanical seal. COPYRIGHT: (C)2010,JPO&INPIT