LEAKAGE CONTROL SYSTEM FOR TREATMENT OF MOVING WEBS

摘要

Pressurized web treatment systems (1) include a moving web (2) that passes through a pressurized treatment chamber (7) having a sealing assembly (6A,6B) with a leakage control system. Leakage control is achieved by the cooperative effect of localized leak detectors (31A,31B) and leak reduction means that applies a local sealing force on the seal assembly responsive to a signal from the leak detectors such that increased sealing occurs in the vicinity of the leak. In particular, an air press for paper web dewatering has improved efficiency by virtue of the leakage control system, which features local leak detectors and local force generation means associated with a flexible seal assembly to reduce leakage at the edges of the stationary plenum of the air press. Local leak detection can be based on sonic measurement with microphones, detection of escaping tracer gas, optical signals, and other means. Other embodiments of web treatment systems include those for continuous production of activated carbon fabrics and steam and chemical treatment of textiles and other fibrous webs.