| 摘要 |
1453410 Paper-making apparatus ESCHER WYSS GmbH 23 Sept 1975 [2 Oct 1974] 38978/75 Heading D2A In a paper-making machine, such as the cylinder machine shown, having a stock inlet 1 and a tank 30 for collecting stock overflowing from the wire or screen at the inlet, the tank having a return line 26, the pressure in a vacuum box 11 is controlled in accordance with the level of stock in the tank 30 whereby the web forming on the wire or screen is uniformly dewatered. As shown the level is sensed by a pressure sensor 23 whose output is compared at 21 with a reference value and used to control a valve 18 in the vacuum line 17 to the vacuum box 11. The output of the senser 23 may also be used on line 22' to control the action of a refiner and drier. The volume flow rate of stock to the inlet 1 is maintained constant by a senser 8 whose output controls the speed of a motor 6 for a pump 5 in the stock supply line. |
