| 摘要 |
An airlock comprising a duct 2 and valve means 4, 6, which valve means is/are operable to assume an open or closed condition in response to the flow of particulate material e.g. tobacco through the duct. During periods of continuous material flow, the rate of material supply and the rate of material removal are controlled relative to one another in order to ensure that a body of particulate material is maintained within the duct. <IMAGE> |
