| 摘要 |
<p>1533865 Valves BELOIT CORP 5 Dec 1975 [13 Dec 1974] 50056/75 Heading F2V [Also in Division D2] A paper-machine headbox system for controlling pressure fluctuations comprises a distribution chamber 15 for receiving stock under pressure and supplying it to a headbox and a pressure chamber 18 separated from the distribution chamber by a yieldable wall, means being provided for controlling air pressure in the pressure chamber. The yieldable wall may be a flexible diaphragm 21 which may also be used to control the release of air from the pressure chamber through ports 36, 34 and outlet 37 to the atmosphere, so that an increase of pressure in the distribution chamber restricts the air flow from the pressure chamber. Damping of the air flow is provided by a wall 29 within the pressure chamber and comprising material such as felt 32 supported by a perforate plate 30.</p> |
