A self-priming, centrifugal pump comprising a first housing part having a front wall with an inlet, a second housing part having an outlet, an impeller rotatably arranged in the second housing part and a pump screw rotatably arranged in the first housing part, connected to the impeller and comprising a center body around which a helical blade is arranged for feeding the impeller with any gas that is present in the liquid, wherein the center body is arranged at a distance from a side of the front wall that faces the center body, such that a channel with a width of at least 12 mm is formed between the center body and the side of the front wall that faces the center body.

A self-priming, centrifugal pump comprising a first housing part having a front wall with an inlet, a second housing part having an outlet, an impeller rotatably arranged in the second housing part and a pump screw rotatably arranged in the first housing part, connected to the impeller and comprising a center body around which a helical blade is arranged for feeding the impeller with any gas that is present in the liquid, wherein the center body is arranged at a distance from a side of the front wall that faces the center body, such that a channel with a width of at least 12 mm is formed between the center body and the side of the front wall that faces the center body.

A vane arc segment includes ceramic matrix composite (CMC) fairing that has an airfoil section, a first single-sided platform at the outer radial end projecting from the suction side wall, and a second single-sided platform at the inner radial end projecting from the pressure side wall. The first single-sided platform is comprised of a fiber layer that extends from the airfoil section and turns into the first single-sided platform, and the second single-sided platform is comprised of the fiber layer that from the airfoil section and turns into the second single-sided platform.

Systems and methods described herein provide a smart vacuum priming system for centrifugal pumps. The vacuum priming system includes a vacuum pump, a suction assembly, an electromagnetic clutch assembly, and a pressure sensor. The suction assembly provides fluid communication between the vacuum pump and a float box of the centrifugal pump. The electromagnetic clutch assembly selectively engages the vacuum pump, such that a drive shaft of the centrifugal pump also powers the vacuum pump when the clutch is on. The pressure sensor indicates when the centrifugal pump is in a primed state based on a discharge pressure of the centrifugal pump. When the pressure sensor indicates the main pump is in the primed state, the electromagnetic clutch decouples the vacuum pump from the drive shaft. When the pressure sensor indicates the main pump is not in the primed state, the electromagnetic clutch couples the vacuum pump to the drive shaft.

A self-priming pump assembly comprises a series connection of a liquid ring pump functioning as a rotating displacement pump and a normally-priming centrifugal pump. The self-priming pump assembly improves the fluid mechanics conditions for the flow of fluids toward and into a return line through the inclusion of a first connection opening in the meridian plane of the centrifugal pump that possesses a bulge enclosing a sector of the longitudinal axis of the first connection opening, where the bulge is one-sided and oriented toward a rotary axis of the pump assembly, and the bulge continuously expands, directly or indirectly, the first connection opening toward the impeller plane. At its end section facing the impeller plane, a transitional surface of the bulge continuously transitions into the lateral boundary surface, or an inner peripheral wall of the ring channel adjoining the lateral boundary surface.

The present application relates to a sealing soft water recovery apparatus for a vacuum pump in a vacuum pressure swing adsorption oxygen generation system, including a water tank, a wet Roots vacuum pump, a steam-water separator, and a collecting sink which are sequentially connected, where the collecting sink is connected to the water tank by a delivery tube provided with a delivery pump; and the water tank is connected to the wet Roots vacuum pump by a water inlet tube provided with a solenoid valve for controlling the opening and closing of a water channel. The present application has the effects of recovering sealing soft water and saving resources.

The present application relates to a sealing soft water recovery apparatus for a vacuum pump in a vacuum pressure swing adsorption oxygen generation system, including a water tank, a wet Roots vacuum pump, a steam-water separator, and a collecting sink which are sequentially connected, where the collecting sink is connected to the water tank by a delivery tube provided with a delivery pump; and the water tank is connected to the wet Roots vacuum pump by a water inlet tube provided with a solenoid valve for controlling the opening and closing of a water channel. The present application has the effects of recovering sealing soft water and saving resources.

A self-priming pump is described that has a housing, an inlet, and an outlet. A first impeller has a first pump section that is arranged in a first chamber, and a second impeller has a second pump section that is arranged in a second chamber. A shaft section is provided between the pump sections, and has a shaft end and penetrates an opening in a housing wall. To improve the net positive section head of the pump, the shaft section between a constriction and the shaft end is formed to taper from the shaft end toward the constriction, and the first impeller and shaft section between the constriction and first pump section has a smooth contour.

Systems and methods described herein provide a smart vacuum priming system for centrifugal pumps. The vacuum priming system includes a vacuum pump, a suction assembly, an electromagnetic clutch assembly, and a pressure sensor. The suction assembly provides fluid communication between the vacuum pump and a float box of the centrifugal pump. The electromagnetic clutch assembly selectively engages the vacuum pump, such that a drive shaft of the centrifugal pump also powers the vacuum pump when the clutch is on. The pressure sensor indicates when the centrifugal pump is in a primed state based on a discharge pressure of the centrifugal pump. When the pressure sensor indicates the main pump is in the primed state, the electromagnetic clutch decouples the vacuum pump from the drive shaft. When the pressure sensor indicates the main pump is not in the primed state, the electromagnetic clutch couples the vacuum pump to the drive shaft.

A sealing ring gland receives a sealing ring. The sealing ring gland includes an inner wall surface which seals against an inner periphery of the sealing ring. An outer wall surface is radially offset from the inner wall surface and seals against an outer periphery of the sealing ring. The sealing ring is axially compressed between an upper wall surface and a lower wall surface of the sealing ring gland. At least one of the upper wall surface and the lower wall surface includes an expansion volume which provides space for the sealing ring to expand upon swelling of the sealing ring.