VACUUM CONTROL SYSTEM FOR DEWATERING A WEB OF PAPER

摘要

VACUUM CONTROL SYSTEM FOR DEWATERING FELTSABSTRACT OF THE DISCLOSUREA vacuum control system for the flat box section of apapermaking machine. The machine is of the type which includesa plurality of serially arranged boxes interconnected by aheader. Vacuum controllers are connected to a predeterminednumber of the boxes for controlling and producing desired vacuumconditions at the boxes. A web is passed over the boxes fordewatering purposes. A vacuum pump supplies vacuum to the boxesand dewaters the web passing thereover. Controls are providedwhich are connected to at least the last box and to the vacuumpump and responsive to a change in vacuum level or air flowdemand on the last flat box to correspondingly adjust thespeed of the vacuum pump and obtain desired vacuum at at leastthe last box.-14-