Abstract: A liquid pump for conveying sensitive materials from a first to a second location through a main duct. The pump has a first segment through which secondary liquid flows with the materials. An inlet orifice receiving primary liquid from a plenum has a convex or Coanda surface and injects primary liquid into the main duct downstream of the first segment. The primary liquid intercepts the convex surface substantially tangentially and is turned through an angle to one more closely resembling the angle of the longitudinal axis of the pump. The first segment has a fustro-conical control surface which diverges outwardly immediately adjacent the outlet end of the first segment. The inside diameter of the outlet end of the first segment immediately before the control surface is substantially identical to the inside diameter of the second segment immediately downstream of the Coanda surface. Liquid directing vanes are positioned in the plenum just prior to the inlet orifice.

Abstract: A valve control system for an air displacement type pump operates the inlet or outlet valve in accordance with the pressure differential between the inlet line and the main pump chamber or the outlet line and the main pump chamber respectively such that the inlet valve is open when the pressure in the pump chamber is less than the pressure in the inlet line and the outlet valve is opened when the pressure in the chamber is greater than the pressure in the outlet line.

Abstract: The invention provides an apparatus and method for handling a solid/liquid mixture, for example for conveying fish immersed in a fish/water mixture. The apparatus has a receiving chamber to receive the mixture through an inlet valve thereof when the chamber is subjected to low pressure, and to discharge the mixture through an outlet valve thereof when pressure in the chamber is increased. A quantity sensor is responsive to a pre-determined quantity of mixture within the chamber to isolate the chamber from low pressure when the pre-determined quantity is reached. The inlet and outlet valves are responsive to pressure differences thereacross. The inlet valve is positioned adjacent an upper portion of the chamber above maxium upper level of mixture within the chamber and has seat clearing structure to clear the inlet valve of solids when flow therethrough ceases. Inlet and outlet flow sensors are responsive to flow through the inlet and outlet valves respectively.

Abstract: A self clearing bladder valve is provided by concentric flexible and expandable bladder sleeves, the inner sleeve defining the passage through the valve. Flushing fluid is directed into an annular chamber between the bladder sleeves and through apertures through the inner sleeve into the passage for material passing through the valve to lubricate the passage and tend to force material out of the passage. The flushing fluid is delivered to the chamber between the bladder sleeves more quickly than it escapes through the apertures to the pressure in the annular chamber increases forcing the inner sleeve into the passage to restrict same as it is being flushed by fluid. Normally the flushing fluid will be directed into the annular chamber and through the apertures into the passage immediately before the valve is fully closed.

Abstract: A pump for pumping a slurry of frail material is provided by a rigid chamber which is connected to a source of negative air pressure when an inlet valve is open and an outlet valve closed to suck the slurry through the open inlet valve into the chamber, the amount of slurry in the chamber is sensed and when it reaches a preset amount a controller is triggered to disconnect the source of negative pressure and close the inlet valve, and then admit air under positive pressure to the chamber, then open the outlet valve to drive the contents of the chamber through the outlet by replacing a significant amount of the contents with air. The controller then causes the air pressure in the chamber to be reduced and closes the outlet valve, and then reconnects the chamber to the source of negative pressure and then opens the inlet valve to commence a second cycle. The inlet and outlet valves are bladder type valves to protect the frail material and permit simplified operation.

Abstract: Apparatus has a receiving chamber subjected to low pressure to receive solid/liquid mixture through inlet valve thereof. The chamber also has outlet valve to discharge the mixture, an admitting valve to raise pressure in the chamber, and quantity sensing structure responsive to predetermined quantity of mixture within the chamber. The inlet valve is positioned above a predetermined upper level of mixture within the chamber, and a riser constrains the mixture to move initially upwardly and then, optionally, downwardly prior to discharging through the inlet valve. The riser is shaped to cause solids that might otherwise tend to rest initially adjacent the inlet valve, when the mixture flow therethrough ceases, to fall under gravity either forwardly through the inlet valve, or backwardly towards mixture within the delivery duct.