Abstract: The present invention relates to a technique of preventing idling rotation of a submersible pump used for delivering liquefied gas, such as liquefied ammonia, liquid hydrogen, liquid nitrogen, liquefied natural gas, liquefied ethylene gas, or liquefied petroleum gas. A fluid-path switching apparatus (5) includes: a flow-passage structure (45) having a first flow passage (41), a second flow passage (42), and a third flow passage (43); and a valve element (47) for allowing the third flow passage (43) to selectively communicate with the first flow passage (41) or the second flow passage (42). The first flow passage (41) communicates with a discharge outlet (1b) of the submersible pump (1), the second flow passage (42) communicates with an interior of the suction vessel (2), and the third flow passage (43) communicates with a discharge port (8) of the suction vessel (2).

Abstract: The present invention relates to a pump casing and a pump apparatus. The pump casing (5) includes a suction nozzle (100) with formed a suction port (12). The suction nozzle (100) slopes downward toward the suction port (12).

Abstract: The present invention relates to a sealing system for a pump configured to pressurize a volatile liquid, such as liquid ammonia. The sealing system (2) includes a stuffing box (35) forming a barrier chamber (30) and a pump-side seal chamber (43), a mechanical seal (20) arranged in the barrier chamber (30), and a barrier-gas supply system (32) for supplying a barrier gas into the barrier chamber (30). The barrier gas has a pressure higher than a pressure of the volatile liquid in the pump-side seal chamber (43). The pump-side seal chamber (43) is located between an impeller (7) of the pump (1) and the mechanical seal (20). The barrier-gas supply system (32) includes a pressure control valve (50) configured to maintain a constant difference between pressure in the barrier chamber (30) and pressure in the pump-side seal chamber (43).

Abstract: Provided is a canned motor in which vaporization of the handling liquid is reduced in a case where a rotor rotates at high speed. A canned motor 10 includes a stator 18 disposed in a stator chamber 26, a rotor 14 disposed in a rotor chamber 12, and a stator can 7 enclosing the rotor 14. Furthermore, the canned motor 10 includes a stator chamber inlet portion 43 configured such that a cooling liquid for cooling the stator 18 flows into the stator chamber 26, and a stator chamber outlet portion 44 configured such that the cooling liquid flows out from the stator chamber 26.

Abstract: The present invention relates to a sealing system for a pump configured to pressurize a volatile liquid, such as liquid ammonia. The sealing system (2) includes a stuffing box (35) forming a barrier chamber (30) and a pump-side seal chamber (43), a mechanical seal (20) arranged in the barrier chamber (30), and a barrier-gas supply system (32) for supplying a barrier gas into the barrier chamber (30). The barrier gas has a pressure higher than a pressure of the volatile liquid in the pump-side seal chamber (43). The pump-side seal chamber (43) is located between an impeller (7) of the pump (1) and the mechanical seal (20). The barrier-gas supply system (32) includes a pressure control valve (50) configured to maintain a constant difference between pressure in the barrier chamber (30) and pressure in the pump-side seal chamber (43).

Abstract: A vortex prevention device is capable of preventing creation of air entrained vortex and also provides a double suction vertical pump having such a vortex prevention device. The vortex prevention device is used in combination with the double suction vertical pump which is installed in an open channel and has an upper suction opening and a lower suction opening. The vortex prevention device includes a plate member as a vortex prevention structure arranged above the upper suction opening. The plate member is arranged away from the upper suction opening such that a passage is formed between the plate member and the upper suction opening.

Abstract: A vortex prevention device is capable of preventing creation of air entrained vortex and also provides a double suction vertical pump having such a vortex prevention device. The vortex prevention device is used in combination with the double suction vertical pump which is installed in an open channel and has an upper suction opening and a lower suction opening. The vortex prevention device includes a plate member as a vortex prevention structure arranged above the upper suction opening. The plate member is arranged away from the upper suction opening such that a passage is formed between the plate member and the upper suction opening.

Abstract: A submerged turbine generator is operated by a working fluid, such as liquid nitrogen, liquefied natural gas, or liquid ethylene, to generate electric power. The submerged turbine generator includes a shaft, a casing, a turbine having a runner fixed to the shaft, a generator having a rotor fixed to the shaft and a stator surrounding the rotor, and bearings for rotatably supporting the shaft. The runner is rotated integrally with the shaft by the pressure of the working fluid introduced into the casing. The shaft includes at least two members.

Abstract: A canned motor includes a rotor having a rotor core and a rotor can covering an outer circumferential surface of the rotor core, and a stator fixedly disposed around the rotor with a radial gap defined therebetween and having a stator core and a stator can covering an inner circumferential surface of the stator core. The rotor core has at least one groove defined in an outer circumferential surface thereof and extending longitudinally thereof. The rotor can has a portion pressed into the groove and held in intimate contact fully with the outer circumferential surface of the rotor core.

Abstract: A canned motor has a rotor having a rotor core and a rotor can covering an outer circumferential surface of the rotor core, and a stator disposed around the rotor with a gap left therebetween for rotating the rotor, the stator having a stator core and a stator can covering an inner circumferential surface of the stator core. The stator core has a plurality of slots defined therein at circumferentially spaced regular intervals and having respective open ends opening at the inner circumferential surface of the stator core, and a plurality of windings disposed in the slots, respectively. The slots include respective winding chambers with the windings housed therein, respective constricted throats disposed radially inwardly of the winding chambers, and respective stiffener chambers spaced radially inwardly from the constricted throats. A plurality of stiffeners are housed in the stiffener chambers, respectively.

Abstract: A turbomachinery includes an attachment structure of an impeller to a rotational shaft which does not incur looseness even when it is subjected to temperature cycles, and which can be obtained without increasing manufacturing costs. The rotational shaft has the impeller at an end portion thereof. A cylindrical member is provided concentrically of the rotational shaft at the end portion for holding the impeller. The impeller is fitted inside the cylindrical member by shrink fitting.

Abstract: A high temperature pump is compact in size, reasonable in manufacturing cost and capable of stable pumping operation. The high-temperature motor pump includes a pump portion for pumping a liquid, a motor portion integrated with the pump portion for driving the same, and a rotatable shaft for transmitting rotation of the motor portion to the pump portion. A magnetic bearing is provided within the motor portion for supporting one end of the rotatable shaft by actively controlling a position thereof in a radial direction. A hydrostatic bearing is provided within the pump portion for supporting the other end of the rotational shaft in a radial direction by using a hydrostatic pressure of a portion of the liquid pumped by the pump portion.

Abstract: A high-temperature motor pump is operated by a method wherein coolant is supplied in a manner to maintain the temperature thereof sufficiently high to keep its viscosity at a low level for smoothly flowing in a narrow gap between a rotor and a stator. Thus, the coolant performs a cooling function without frictional loss, and thereby the motor pump is stably operated with little energy loss.

Abstract: A structure for centering and connecting two members includes a first member having an engagement opening, and a second member having an engagement projection which has an outer peripheral surface substantially corresponding to an inner peripheral surface of the engagement opening. Small protrusions extend radially outwardly and are equidistantly disposed along a circumferential direction on the outer peripheral surface of the engagement projection. Straight notches are formed in the outer peripheral surface on both axial sides of each small protrusion to provide elasticity. When the engagement projection is fitted into the engagement opening, the small protrusions are elastically urged against the inner peripheral surface of the engagement opening. In this way, even when the two members have different thermal expansions, no play or no excessive stress is generated between the two members.