A pump device, in particular an immersible pump device, includes at least one heat exchanger unit which is in at least one operation state configured for a heat exchange between a cooling fluid and a liquid that is to be pumped and which includes at least one cooling duct and at least one shaft receptacle having an axial direction, wherein a cross section surface area of the cooling duct changes by maximally 200% at least over a major portion of a course of the cooling duct.

A rotordynamic pump for delivering continuous flow of fluids, such as blood, is provided. In one embodiment, the pump includes a stator housing having an inlet and an outlet. A rotor hub is disposed within the stator housing having a first, mixed-stage impeller and a second, axial-flow stage impellers. One or more stator vanes and extend radially inwardly from the stator housing. In one particular embodiment, the second stage impeller is disposed nearer to the outlet than to the inlet. The stator vanes may include a first set of stator vanes disposed between the first and second stage impellers, and a second set of stator vanes positioned between the second stage impellers and the outlet.

A rotordynamic pump for delivering continuous flow of fluids, such as blood, is provided. In one embodiment, the pump includes a stator housing having an inlet and an outlet. A rotor hub is disposed within the stator housing having a first, mixed-stage impeller and a second, axial-flow stage impellers. One or more stator vanes and extend radially inwardly from the stator housing. In one particular embodiment, the second stage impeller is disposed nearer to the outlet than to the inlet. The stator vanes may include a first set of stator vanes disposed between the first and second stage impellers, and a second set of stator vanes positioned between the second stage impellers and the outlet.

Techniques are provided for seal flush systems. A system may include a reactor circulation pump configured to circulate a slurry through a polymerization reactor. The slurry may include an olefin monomer, a catalyst, and a diluent. The system may also include a catalyst-inhibiting additive system configured to supply a catalyst-inhibiting additive to a seal of the reactor circulation pump and a seal flush system configured to generate a seal flush mixture and supply the seal flush mixture to the seal of the reactor circulation pump.

A nozzle for a fan assembly has an air inlet, an annular air outlet, and an interior passage for conveying air from the air inlet to the air outlet. The interior passage is located between an annular inner wall, and an outer wall extending about the inner wall. The inner wall at least partially defines a bore through which air from outside the nozzle is drawn by air emitted from the air outlet. The inner wall is eccentric with respect to the outer wall so that the cross-sectional area of the interior passage varies about the bore. The variation in the cross-sectional area of the interior passage can control the direction in which air is emitted from around the air outlet to reduce turbulence in the air flow generated by the fan assembly.

A nozzle for a fan assembly has an air inlet, an annular air outlet, and an interior passage for conveying air from the air inlet to the air outlet. The interior passage is located between an annular inner wall, and an outer wall extending about the inner wall. The inner wall at least partially defines a bore through which air from outside the nozzle is drawn by air emitted from the air outlet. The inner wall is eccentric with respect to the outer wall so that the cross-sectional area of the interior passage varies about the bore. The variation in the cross-sectional area of the interior passage can control the direction in which air is emitted from around the air outlet to reduce turbulence in the air flow generated by the fan assembly.

An impeller includes a hub, and a plurality of blades supported by the hub, the blades being arranged in at least two blade rows. The impeller has a deployed configuration in which the blades extend away from the hub, and a stored configuration in which at least one of the blades is radially compressed, for example by folding the blade towards the hub. The impeller may also have an operational configuration in which at least some of the blades are deformed from the deployed configuration upon rotation of the impeller when in the deployed configuration. The outer edge of one or more blades may have a winglet, and the base of the blades may have an associated indentation to facilitate folding of the blades.

An impeller includes a hub, and a plurality of blades supported by the hub, the blades being arranged in at least two blade rows. The impeller has a deployed configuration in which the blades extend away from the hub, and a stored configuration in which at least one of the blades is radially compressed, for example by folding the blade towards the hub. The impeller may also have an operational configuration in which at least some of the blades are deformed from the deployed configuration upon rotation of the impeller when in the deployed configuration. The outer edge of one or more blades may have a winglet, and the base of the blades may have an associated indentation to facilitate folding of the blades.

A method for controlling circuitry of a softstarter arrangement to operate an electric motor for driving a pump is provided, wherein the softstarter circuitry electrically connects the motor to electric mains. The method includes: (i) controlling the circuitry of the softstarter arrangement to accelerate the motor up to full speed in a forward direction; (ii) controlling the circuitry of the softstarter arrangement to decelerate the motor when the motor has run at full speed in the forward direction for a first period of time; (iii) controlling the circuitry of the softstarter arrangement to accelerate the motor up a specified speed in a reverse direction; (iv) controlling the circuitry of the softstarter arrangement to decelerate the motor when the motor has run at the specified speed in the reverse direction for a second period of time; and (v) repeating the steps (i)-(iv) one or more times.

A method for controlling circuitry of a softstarter arrangement to operate an electric motor for driving a pump is provided, wherein the softstarter circuitry electrically connects the motor to electric mains. The method includes: (i) controlling the circuitry of the softstarter arrangement to accelerate the motor up to full speed in a forward direction; (ii) controlling the circuitry of the softstarter arrangement to decelerate the motor when the motor has run at full speed in the forward direction for a first period of time; (iii) controlling the circuitry of the softstarter arrangement to accelerate the motor up a specified speed in a reverse direction; (iv) controlling the circuitry of the softstarter arrangement to decelerate the motor when the motor has run at the specified speed in the reverse direction for a second period of time; and (v) repeating the steps (i)-(iv) one or more times.