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.

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.

A pump-storage device includes a tank, a treatment container, and a vacuum pump. The treatment container includes a first chamber in communication with an inlet. The first chamber includes a bottom wall having a first valve intercommunicated with a second chamber. The second chamber includes a bottom wall having a second valve. The treatment container includes a first control valve having a first duct in communication with the first chamber, a second duct in communication with the second chamber, and a third duct in communication with the tank. The treatment container includes an actuation cylinder for actuating an actuation rod to extend or retract. A first valve plate and a second valve plate are mounted on the actuation rod for controlling opening and closing of the first valve and the second valve. The treatment container includes a second control valve in communication with the first chamber and the vacuum pump.

A vacuum pump comprises: a rotor; a stator; a first heating section configured to heat the stator cylindrical portion to a temperature for reducing product accumulation; an exhaust pipe provided at a housing storing the rotor and the stator to discharge gas discharged by the rotor and the stator to an outside of the housing; a second heating section configured to heat the exhaust pipe to a temperature for reducing product accumulation; and a gas passage container arranged in the housing, having an inlet port into which gas discharged through a gap between the rotor cylindrical portion and the stator cylindrical portion flows and an outlet port from which inflow gas flows to the exhaust pipe, and heated to a temperature for reducing product accumulation. A gas-inflow-side end portion of the exhaust pipe is inserted into the outlet port of the gas passage container through a clearance.

Disclosed is a self-priming fluid transfer system having an integral siphon line that draws trapped air bubbles out of a main fluid chamber over time and fluid cycles. The self-priming fluid transfer system may include a body structure and a siphon line. The body structure may include a chamber inlet and a chamber outlet. The main fluid chamber may receive and output fluid from the chamber inlet and the chamber outlet, respectively. The siphon line may be positioned at the periphery of the main fluid chamber and may include a priming inlet and a siphon outlet. The priming inlet may be positioned at or near a top wall of the body structure and may receive air bubbles from the main fluid chamber. The siphon outlet may be positioned at the chamber outlet and may output the air bubbles at the chamber outlet. Other examples may be described and claimed.

A quick no-water startup apparatus for a centrifugal pump includes, from top to bottom in sequence, one-way passages (1), a self-priming chamber housing (41), sliding devices (5), a self-priming chamber (4), chamber partition plates (2) a concave-convex impeller (3), inlet channels (6) connected on two sides of the self-priming chamber (4), a spring device (7) of an upper-side x-shaped gas-liquid separation device, the upper-side x-shaped gas-liquid separation device (8), upper and middle-side gas-liquid separation device connecting shafts (9), a middle-side gas-liquid separation device (10), lower-side backflow-type gas-liquid separation devices (11), v-shaped backflow channels (122), an inverted v-shaped inlet channel (121), and an inlet. The quick no-water startup apparatus of the present invention enables the centrifugal pump to directly enter a normal operating condition after no-water startup, and 36 times of air exhaust can be completed while the concave-convex impeller (3) in the self-priming chamber (4) rotates by a circle in the early stage. Besides, the apparatus is provided with the upper, middle, and lower gas-liquid separation devices to fully realize separation of gas and liquid, so that gas can be exhausted more quickly and the chamber is filled with water. Therefore, the working efficiency is significantly improved and the operation process is greatly simplified.

A quick no-water startup apparatus for a centrifugal pump includes, from top to bottom in sequence, one-way passages (1), a self-priming chamber housing (41), sliding devices (5), a self-priming chamber (4), chamber partition plates (2) a concave-convex impeller (3), inlet channels (6) connected on two sides of the self-priming chamber (4), a spring device (7) of an upper-side x-shaped gas-liquid separation device, the upper-side x-shaped gas-liquid separation device (8), upper and middle-side gas-liquid separation device connecting shafts (9), a middle-side gas-liquid separation device (10), lower-side backflow-type gas-liquid separation devices (11), v-shaped backflow channels (122), an inverted v-shaped inlet channel (121), and an inlet. The quick no-water startup apparatus of the present invention enables the centrifugal pump to directly enter a normal operating condition after no-water startup, and 36 times of air exhaust can be completed while the concave-convex impeller (3) in the self-priming chamber (4) rotates by a circle in the early stage. Besides, the apparatus is provided with the upper, middle, and lower gas-liquid separation devices to fully realize separation of gas and liquid, so that gas can be exhausted more quickly and the chamber is filled with water. Therefore, the working efficiency is significantly improved and the operation process is greatly simplified.

A sensing device for a centrifugal slurry pump having an impeller which rotates about an axis, the centrifugal slurry pump including a side liner and a main liner housed within an outer casing of the pump, the sensing device comprising; a body portion arranged to pass through the outer casing, wherein the body portion includes a sensor biased towards contact with either the side liner or the main liner of the pump.

The invention relates to a method of venting a synthetically commutated hydraulic pump (2). The connecting fluid conduits (8, 16), connecting said synthetically commutated hydraulic pump (2) with a fluid reservoir (7) is vented at least on start-up of the synthetically commutated hydraulic pump (2), using a fluid intake device (14, 17, 20) that connects to a fixed displacement pump (3).

A pump-storage device includes a tank, a treatment container, and a vacuum pump. The treatment container includes a first chamber in communication with an inlet. The first chamber includes a bottom wall having a first valve intercommunicated with a second chamber. The second chamber includes a bottom wall having a second valve. The treatment container includes a first control valve having a first duct in communication with the first chamber, a second duct in communication with the second chamber, and a third duct in communication with the tank. The treatment container includes an actuation cylinder for actuating an actuation rod to extend or retract. A first valve plate and a second valve plate are mounted on the actuation rod for controlling opening and closing of the first valve and the second valve. The treatment container includes a second control valve in communication with the first chamber and the vacuum pump.