Abstract: A device allows a liquid to flow between two open structures with different liquid surface elevations separated by a wall. The device has a conduit with an inlet on one side of the wall and an outlet on the other side of the wall separated by a high point above the expected liquid surface elevation. The conduit also has two valved openings, one connected to a source of suction that can evacuate air from the conduit and the other connected to a vent. In one example, the conduit is formed between a pair of spaced transverse walls attached to an arched cover. The transverse walls each have a slot allowing the device to be placed on top of a dividing wall between two tanks with surfaces of the dividing wall defining part of the conduit. In an example with multiple conduits, one or more interior walls are provided between a pair of end walls and a cover over the interior and end walls may be provided in segments. To initiate flow, a conduit is evacuated of sufficient air to allow a siphon to develop.

Abstract: A device allows a liquid to flow between two open structures with different liquid surface elevations separated by a wall. The device has a conduit with an inlet on one side of the wall and an outlet on the other side of the wall separated by a high point above the expected liquid surface elevation. The conduit also has two valved openings, one connected to a source of suction that can evacuate air from the conduit and the other connected to a vent. In one example, the conduit is formed between a pair of spaced transverse walls attached to an arched cover. The transverse walls each have a slot allowing the device to be placed on top of a dividing wall between two tanks with surfaces of the dividing wall defining part of the conduit. In an example with multiple conduits, one or more interior walls are provided between a pair of end walls and a cover over the interior and end walls may be provided in segments. To initiate flow, a conduit is evacuated of sufficient air to allow a siphon to develop.

Abstract: Limitation of the number of cassettes in an assembly currently used for the production of permeate is obviated by grouping plural cassettes into racks one or more of which may be isolated while permeate production from the remaining racks is uninterrupted. Ancillary functions such as back-pulsing, chemical cleaning and testing for defects in membranes (“integrity testing”) in one or more racks may proceed while production of permeate continues. The number of racks in a bank is determined by the period of the overall filtration cycle, typically 15 min, in which filtration period the ancillary period is a minor portion, typically 30 sec. The racks make it possible to use automatic on/off valves which open and close quicker than larger ones. The resulting saving in time, energy, and equipment costs, which when back-pulsing with permeate is surprisingly economical, is even greater when a chemical cleaning solution is to be used.