A submersible pneumatic canister pump system for pumping liquid from a tank or underground location by incorporating a valve inside the pump for preventing air from exiting with the liquid discharge. The floating-ball valve is located near the lower end of the pump and communicates with the discharge pipe. When liquid level approaches the lower end of the pump, a ball of lighter density than the liquid rests on a seat and prevents further discharge of liquid and the passage of air out of the pump. Also various pump control arrangements can be used to operate the pump and a quick-passage check valve can be used to enhance operation.

A submersible reverse osmosis desalination apparatus and method employs airlift to remove desalinated water from the apparatus via as annular flow regime over a substantial portion of the product water discharge conduit. Use of a high air fraction for airlift operation and an annular flow regime significantly lowers the weight of the product water column, as well as the backpressure on the downstream side of the osmotic membranes and at the bottom of the discharge water conduit. This permits deployment of the apparatus at reduced depths and in many eases closer to shore. In preferred embodiments the apparatus relies wholly upon hydrostatic pressure to drive seawater through the osmotic membranes, and continuously desalinates seawater and delivers pure water to the discharge water conduit without using any submerged moving parts subject to wear or breakage.

A submersible reverse osmosis desalination apparatus and method employs airlift to remove desalinated water from the apparatus via as annular flow regime over a substantial portion of the product water discharge conduit. Use of a high air fraction for airlift operation and an annular flow regime significantly lowers the weight of the product water column, as well as the backpressure on the downstream side of the osmotic membranes and at the bottom of the discharge water conduit. This permits deployment of the apparatus at reduced depths and in many eases closer to shore. In preferred embodiments the apparatus relies wholly upon hydrostatic pressure to drive seawater through the osmotic membranes, and continuously desalinates seawater and delivers pure water to the discharge water conduit without using any submerged moving parts subject to wear or breakage.

A pump is disclosed. The pump including an outer casing having a cavity therein; a pump assembly positioned in the cavity of the outer casing, the pump assembly including: a discharge tube; a check valve operably connected to the discharge tube by a coupling; and a multi-float control assembly, the multi float control assembly including a bottom float check valve operably connected to the discharge tube by the coupling and an upper float check valve connected to a vent.

A pump is disclosed. The pump including an outer casing having a cavity therein; a pump assembly positioned in the cavity of the outer casing, the pump assembly including: a discharge tube; a check valve operably connected to the discharge tube by a coupling; and a multi-float control assembly, the multi float control assembly including a bottom float check valve operably connected to the discharge tube by the coupling and an upper float check valve connected to a vent.

A desalination brine dispersal apparatus and method employ airlift to remove, oxygenate and disperse brine from a desalination apparatus. The apparatus includes a brine removal conduit having a brine inlet that receives brine from the desalination apparatus, a plurality of brine outlets submerged in seawater and one or more air introduction points located at depths below the brine outlets. The supplied air oxygenates and moves brine through the brine removal conduit and outlets via airlift and disperses the brine into seawater away from the brine removal conduit. The apparatus avoids the formation of concentrated, high shear brine plumes and can disperse brine into seawater over a wide area well away from the brine removal conduit.

A desalination brine dispersal apparatus and method employ airlift to remove, oxygenate and disperse brine from a desalination apparatus. The apparatus includes a brine removal conduit having a brine inlet that receives brine from the desalination apparatus, a plurality of brine outlets submerged in seawater and one or more air introduction points located at depths below the brine outlets. The supplied air oxygenates and moves brine through the brine removal conduit and outlets via airlift and disperses the brine into seawater away from the brine removal conduit. The apparatus avoids the formation of concentrated, high shear brine plumes and can disperse brine into seawater over a wide area well away from the brine removal conduit.

A desalination brine dispersal apparatus and method employ airlift to remove, oxygenate and disperse brine from a desalination apparatus. The apparatus includes a brine removal conduit having a brine inlet that receives brine from the desalination apparatus, a plurality of brine outlets submerged in seawater and one or more air introduction points located at depths below the brine outlets. The supplied air oxygenates and moves brine through the brine removal conduit and outlets via airlift and disperses the brine into seawater away from the brine removal conduit. The apparatus avoids the formation of concentrated, high shear brine plumes and can disperse brine into seawater over a wide area well away from the brine removal conduit.

A desalination brine dispersal apparatus and method employ airlift to remove, oxygenate and disperse brine from a desalination apparatus. The apparatus includes a brine removal conduit having a brine inlet that receives brine from the desalination apparatus, a plurality of brine outlets submerged in seawater and one or more air introduction points located at depths below the brine outlets. The supplied air oxygenates and moves brine through the brine removal conduit and outlets via airlift and disperses the brine into seawater away from the brine removal conduit. The apparatus avoids the formation of concentrated, high shear brine plumes and can disperse brine into seawater over a wide area well away from the brine removal conduit.

An apparatus having a plurality of pressure exchangers. Each pressure exchanger includes a first conduit and a second conduit and is operable for pressurizing a low-pressure dirty fluid via a high-pressure clean fluid. Each first conduit conveys the high-pressure clean fluid into a corresponding one of the pressure exchangers and to an adjacent one of the pressure exchangers, and each second conduit conveys a pressurized dirty fluid out of a corresponding one of the pressure exchangers and from the adjacent one of the pressure exchangers. The first conduits collectively form at least a portion of a high-pressure clean fluid manifold distributing the high-pressure clean fluid among the pressure exchangers, and the second conduits collectively form at least a portion of a pressurized dirty fluid manifold combining pressurized dirty fluid collectively discharged from the pressure exchangers.