| 摘要 |
Apparatus for use in a multi-stage system in which a fluid being treated is passed in succession through a first stage A, a second stage B, a third stage C, etc. includes a controlled system of valved interconnections that permits the direction of flow within each stage to be reversed while preserving the original sequence ABC . . . in which the fluid progresses from stage to stage. The stages may be reaction chambers in which chemical or photo-chemical reactions are carried out or the stages may be filters that need to be reverse-flushed at intervals. In accordance with the invention, a second set of inter-stage connections is provided, in addition to the original connections used for forward flow. In the second set, the inlet and outlet ports are located at opposite ends of each stage from the inlet and outlet ports used in the original connections. Each inter-stage connection includes a valve, and the valves in the original set of interconnections are operated in unison, as are the valves in the second set of interconnections. The valves of the original set are all open and the valves of the second set are all closed for forward flow. For reversed flow, the valves of the original set are closed and the valves of the second set are open. |
