摘要 |
The proper pressure conditions are maintained within an atmospheric pre-steaming chips bin (10) used in the production of paper pulp. Extending upwardly from the top (14) of the chips bin is a vertical section (21) of conduit, an elbow section (22), and a horizontal section (23). A door guide (29) with a door opening (30) in it is disposed in the horizontal section and precludes passage of gas through the horizontal section except through the door opening. A pivot pin (32) mounts a door (31) at its top so that it normally assumes a vertical orientation closing off the opening, and it is adjustably biased into that orientation by a counterweight mechanism (48). The counterweight includes weight discs (58) which mount on a vertical section of rod having external screw threads (50), and a horizontal section of rod is connected by a flange (53) to a flange (47) of the pivot pin. The door remains closed unless the pressure differential between the chips bin and the surrounding environment is greater than about 2 psig, in which case gas may flow from the environment to the chips bin, or vice versa, to bring the pressure differential within the desired range. <IMAGE> |