Abstract: A pumping system for performing a hydraulic fracturing operation includes an inlet conduit extending from a manifold, wherein a pair of inlet valves disposed along the inlet conduit, a fluid pump including an outlet configured to be inserted into the inlet conduit, and a connector assembly including an engagement member having a first position configured to lock the outlet within the inlet conduit and a second position configured to unlock the outlet from the inlet conduit. The pumping system additionally includes a pair of branch conduits extending from the inlet conduit, a pair of branch valves, wherein one of the pair of branch valves is disposed along each of the pair of branch conduits, and a dump conduit extending from the pair of branch conduits, wherein a dump valve is disposed along the dump conduit.

Abstract: A system, method, and apparatus for the collection of surgical/wound fluid from a subject patient with the capability of simultaneous fluid removal from a plurality of such wounds and/or wound through the utilization of a single pump device worn by such a patient. Such a system, method, and apparatus allow for such a single pump device to collect surgical/wound fluid within a single site collection component attached to or associated with such a single pump device. Multiple fluid transfer lines may be incorporated with the single pump device leading to such plurality of wounds and/or wound sites for greater versatility and comfort for the subject patient, as well as cleaner removal capabilities than in the standard apparatus systems and method currently undertaken within the industry.

Abstract: A subsea installation for heating a two-phase liquid/gas effluent circulating within a subsea casing, includes a plurality of heated pipe sections which are successively connected to one another by curved pipe sections to form a heating coil, each heated pipe section being inclined with respect to the horizontal at an angle comprised between 2 and 10° in order to promote a distributed flow regime of the two-phase effluent and being provided with an induction heating system.

Abstract: A hydraulic arrangement for an agricultural or industrial utility vehicle includes a main hydraulic circuit, a main hydraulic pump, a charge pump, a lubricating hydraulic circuit, a gearbox lubricating hydraulic circuit, a shifting hydraulic circuit, and a gearbox pump. Hydraulic fluid can be fed to the main hydraulic circuit by the main hydraulic pump. Hydraulic fluid can be fed to the main hydraulic pump by the charge pump. At least a part of the hydraulic fluid delivered by the charge pump can be fed to the lubricating hydraulic circuit. Hydraulic fluid can be fed to the shifting hydraulic circuit by the gearbox pump. At least a portion of the hydraulic fluid delivered by the charge pump can be fed to the gearbox lubricating hydraulic circuit.

Abstract: A method of making a personal care composition that involves using a mixer to combine a personal care composition chassis with microcapsules. The mixer has a housing, a first fluid inlet, a second inlet, a fluid outlet and a rotor connected to the housing. The rotor has blades positioned within the housing to define cells between neighboring blades and the housing. The personal care composition chassis, which includes surfactants and water, is advanced along a flow path from the first fluid inlet toward the fluid outlet, while the microcapsules are transferred from the second inlet to the flow path by rotating the rotor. Air in the microcapsule composition is directed from inside the cells toward the second inlet, and the microcapsule composition is combined with the personal care composition chassis to form the personal care composition. The personal care composition is advanced from the outlet.

Abstract: An HVAC system includes a single compressor, a pair of condensers, a reheat heat exchanger, an evaporator, and an expansion device. Within the system, the refrigerant exiting the compressor is separated into two portions. In the cooling mode, the first and second portions of the refrigerant are directed from the compressor through the two condensers in parallel. In the reheat mode, the first portion of the refrigerant is directed through the first condenser, while the second portion of the refrigerant is directed through the reheat heat exchanger. The system also may include a head pressure control device that is designed to maintain the compressor discharge pressure within a desired range by adjusting the condenser fan speed.

Abstract: A compact cooling and boosting gas turbine system provides combined cooling, heating, and electrical power with high energy efficiency. The system has a pressure booster and a turbo-compressor. The pressure booster includes a fuel inlet, a fuel outlet, and a piston, and is in fluid communication with a gas turbine engine. The pressure booster also includes a coolant inlet, a coolant chamber, and a coolant outlet, and is in fluid communication with a closed pressurized coolant flow. The turbo-compressor includes a compressor and a turbine, and is in fluid communication with a water input flow and with the closed pressurized coolant flow. A coolant flow control valve controls the closed pressurized coolant flow. The system is configured to provide a cold water flow for a first position of the flow control valve and to provide a hot water flow for a second position of the flow control valve.

Abstract: A fuel system including a fuel tank, a first pump fluidly coupled to the fuel tank configured for distributing fuel from the fuel tank throughout the fuel system, and a second pump fluidly coupled to the first pump by a pressure regulating valve and configured for driving fuel to an engine.

Abstract: A fluid supply system supplying multiple fluid consumers of a vehicle with fluid, the fluid supply system including: a first pump supplying a first fluid consumer, arranged in a first supply circulation of the vehicle, with fluid; a second pump supplying a second fluid consumer, arranged in a second supply circulation of the vehicle, with fluid; and a directional control valve adjustable between a first valve position and at least one other, second valve position and preferably includes an electromagnetic device for adjusting. The directional control valve allows the fluid to be delivered from the second pump into the first supply circulation in the first valve position and separates the first supply circulation from the second pump, or allows the fluid to be delivered from the second pump into the first supply circulation only to a restricted extent as compared to the first valve position, in the second valve position.

Abstract: The invention relates to a screw pump (1), in particular a double screw pump, s comprising a multiple-piece housing (2, 7, 15, 21) and at least two coupled rotors (3, 3a) which form chambers with in each case at least one thread-shaped profile (4, 4a) which is configured at least in regions with helical channels (5, 5a) and with dividing walls (6, 6a) which delimit the channels (5, 5a), wherein the rotors (3, 3a) perform an opposed rotor rotation, and the dividing walls (6, 6a) engage into one another in a gearwheel-like manner, a running housing part (7), wherein the running housing part (7) encloses the rotors (3, 3a) without contact, wherein the rotors (3, 3a) form, with the running housing part (7), at least one conveying chamber (8, 8a) for the fluid to be conveyed, wherein the conveying chamber (8, 8a) migrates axially along the rotor axis (10, 10a) and conveys the fluid from a suction chamber (11) into a pressure chamber (12), a suction-side connector element (13) which is connected fluidically to the

Abstract: A method for controlling a compressor towards an unloaded state, in which the compressor includes a compressor element (2) with an inlet (5), in which in the unloaded state, a residual flow (QD) is suctioned via the inlet (5) towards and into the compressor element (2), and in which for a transition from a loaded state of the compressor to the unloaded state, the inlet (5) of the compressor element (2) is partially closed in successive discrete transitional steps.

Abstract: A multistage Roots pump comprise a plurality of pump chambers in a pump housing. They constitute respective pump stages, wherein each pump stage comprises two two-toothed rotary pistons. The pump stages are separated from each other by partition walls. In the partition walls essentially radially extending connecting ducts are arranged. The connecting ducts are connected with an inflow chamber whose inflow opening has a larger cross-section than the connecting ducts.

Abstract: The invention concerns a method and an apparatus for operating a multi-phase pump which has a suction-side inlet (10) and a discharge-side outlet (20) and which pumps a multi-phase mixture charged with solids, comprising the following steps: a. pumping a multi-phase mixture into a discharge-side separation chamber (45), b. separating a gaseous phase from a liquid phase and a solid phase in the separation chamber (45), c. separating the liquid phase from the solid phase in the separation chamber (45), and d. supplying a portion of the liquid phase freed from the solid phase to the suction side.

Abstract: A low cost scroll device and methods of manufacturing the same are described. The scroll device includes, for example, a drive pin hole and bearing bores machined into a scroll of the scroll device from the same side as the involute of the scroll; idler shaft assemblies with no more than one bearing in the orbiting scroll for mechanically coupling the orbiting scroll to the fixed scroll; and an epoxy coating applied using a process that requires assembly of the scroll device only once.

Abstract: A vacuum pump system for evacuating a chamber, in particular a lock or a process chamber, is provided that includes a main vacuum pump preferably configured as a screw pump. An inlet of the main vacuum pump is connected with the chamber to be evacuated. As seen in the feeding direction of the main vacuum pump an auxiliary vacuum pump is arranged which is in particular a Roots pump. An outlet area of the main vacuum pump is connected with a main outlet on the one hand and an inlet of the auxiliary vacuum pump on the other hand. Further, an outlet of the auxiliary vacuum pump is connected with the main outlet.

Abstract: A system for subsea pumping or compressing includes an ESP (electrical submersible pump), a flowline jumper, a connector part in either end of the flowline jumper, and a truss structure or longitudinal rib-arrangement that acts as a stiffening arrangement. The ESP may be arranged in the flowline jumper which may be orientated in a substantially horizontal direction. The stiffening arrangement may function to ensure that the ESP shaft is straight at all times during lifting, installation and operation. The system may also include a load limiting arrangement for limiting or eliminating the load on structure and seabed supporting the system.

Abstract: An algae-based powdered fuel is configured to be fluidized in a gas stream. The algae-based powdered fuel is manufactured by drying an algae slurry to produce a powdered composition and then comminuting the powdered composition to produce the fuel. The algae-based powdered fuel can be combusted in a gas turbine to generate electricity and/or to propel an aircraft.

Abstract: A gas control apparatus includes an upper housing to which a second piezoelectric pump is joined, a lower housing to which a first piezoelectric pump is joined, and a diaphragm. The upper housing includes a discharge hole through which gas is discharged. The lower housing includes introduction holes through which gas is introduced, an opening, a first valve seat, a second valve seat, and a third valve seat. The diaphragm is sandwiched between the upper housing and the lower housing, and is fixed to the upper housing and the lower housing so that the diaphragm contacts the first valve seat, the second valve seat, and the third valve seat. The diaphragm divides an inner space of the upper housing and the lower housing to define valve chests together with the upper housing and the lower housing.

Abstract: A multistage reciprocating air compressor compresses air to an elevated pressure level discharge with an intermediate pressure level discharge for use in blow molding of PET bottles and similar products. The air compressor has a first, second and third reciprocating piston stages with first, second and third actuators operable in response to respective sensed discharge pressure levels from the discharges to actuate inlet unloading elements.

Abstract: The invention provides a high pressure water injection pump system, comprising at least two water injection pump units connected in series, each pump unit comprising a motor in a motor compartment operatively connected to drive a pump in a pump compartment, distinctive in that at least the pump units following the first pump comprises a choke compartment arranged between the pump and motor compartments, a leakage seal arranged between the pump and choke compartment, the choke compartment having an outlet; and the motor compartment of at least the pump units following the first pump unit is dimensioned according to a lower pressure class than the operatively connected pump compartment.

Abstract: A system is provided that includes a torch power unit that includes a compressor and a controller configured to adjust output of the compressor in response to feedback comprising compressor output, or altitude, or atmospheric pressure, or a combination thereof. A method is provided that includes adjusting operational parameters of a torch power unit to account for environmental conditions affecting performance of the torch power unit. A method of manufacturing a portable cutting torch system is also provided. Another system is provided that includes a plasma cutting circuit, a compressor, a motor coupled to the compressor, an interface, and an environmental feedback controller.

Abstract: A multistage vacuum pump unit can save a power requirement and prevent the gas discharged outside of the unit from flowing-back inside the pump unit. A plurality of vacuum pumps are connected in series to form the multistage vacuum pump unit. A suction inlet of a first stage vacuum pump thereof is connected to a to-be-vacuumized container so that the space inside of the container becomes under a high vacuum condition. In an operating method, part of the gas discharged into a first intermediate passage from the first stage vacuum pump is branched during a low vacuum operation, and discharged toward an air atmosphere through a low conductance line provided with check valves that prevent the branched gas from flowing back.

Abstract: An air pump, including: two cylinders, a big one and a small one, which are telescopically fitted to each other. A head connects with the outlet end of the small cylinder. A pressure relief valve connects with the outlet end of the big cylinder. A first piston is fixed at the inlet end of the small cylinder and placed in the big cylinder. A first pipe, has one end fixed on the outlet end of the big cylinder, and the other passes through the first piston and placed inside the small cylinder. A first chamber with a passage communicating with the first pipe forms therein between the inside wall of the big cylinder and the outside wall of the first pipe. A second pipe, one end fixed at the outlet end of the small cylinder and communicating with the head in one-way air admission, has the other fit into the first pipe in a telescopicing way and communicating with it. A second piston, which is placed inside the small cylinder, fixes at the other end of the first pipe and the second pipe goes through it.

Abstract: A refrigerant cycle is provided with a multi-port compressor or compressor stages connected in series, and multiple condensers. A single evaporator communicates with the plurality of condensers. At least one of the plurality of condensers receives fully compressed refrigerant while the other condensers receive refrigerant at intermediate pressure. A control can optionally direct refrigerant to the condensers to achieve desired system heat rejection characteristics and operating conditions. One or multiple reheat coils may be associated with the evaporator and are arranged either in series or in parallel to provide a desired dehumidification function and reheat stages. One or several of the intermediate pressure condensers may be utilized for the reheat function as well.

Abstract: A method for analysis of solvent evaporation patterns includes: continuously evacuating the gas of a single-component or multicomponent solvent evaporated under desired evaporation conditions from an object containing the single-component or multicomponent solvent housed in an airtight container, with evacuation means from the airtight container to an exhaust path connected to an exhaust port of the evacuation means; sampling a gas at predetermined time intervals from a desired point between the airtight container and the outlet of the exhaust path with the continuous evacuation maintained; measuring the solvent gas contained in the sampled gas; and determining an evaporation pattern of the solvent from the object under the desired evaporation conditions, from results of the measurement.

Abstract: A multistage vacuum pump unit can save a power requirement and prevent the gas discharged outside of the unit from flowing-back inside the pump unit. A plurality of vacuum pumps are connected in series to form the multistage vacuum pump unit. A suction inlet of a first stage vacuum pump thereof is connected to a to-be-vacuumized container so that the space inside of the container becomes under a high vacuum condition. In an operating method, part of the gas discharged into a first intermediate passage from the first stage vacuum pump is branched during a low vacuum operation, and discharged toward an air atmosphere through a low conductance line provided with check valves that prevent the branched gas from flowing back.

Abstract: Provided is a liquid chromatograph pump system which sucks eluent from an eluent reserving container, and which feeds pressurized high pressure eluent into a column, wherein a plunger reciprocating in a cylinder is formed on its outer peripheral surface with a stepped part along the sliding direction of the plunger in the cylinder so as to define a working chamber between the stepper part and the inner wall surface of the cylinder, the flow rate of the liquid chromatograph pump being determined by the volume of the working chamber and the traveling speed of the plunger, thereby it is possible to stably feed a liquid at an extremely low flow rate, and to satisfactorily expel air bubbles upon a start of the liquid chromatograph pump system.

Abstract: A compressor assembly including a housing that encloses a sealed interior volume and defines an inlet opening and an outlet opening. Refrigerant is communicated from a suction line into the interior volume through the inlet opening. Refrigerant is communicated from the interior volume to a discharge line through the outlet opening. A first compressor mechanism is disposed within the interior volume and is adapted to compress the refrigerant. A first fitting is mounted on an exterior surface of the housing and is in communication with one of the inlet and outlet openings. The first fitting defines a first passageway for communicating the refrigerant between the one opening and a respective one of the suction and discharge refrigerant lines. The fitting further defines a first duct in communication with the first passageway. A first pressure relief valve is mounted in communication with the first duct.

Abstract: A multi-stage rotary compressor to reduce a driving load and prevent a malfunction due to an abrupt pressure rising. In the compressor of the type including first and second compressing units mounted in a hermetic casing thereof to compress a gas, the gas being primarily compressed in the first compressing unit and secondarily compressed in the second compressing unit, the interior of the hermetic casing is divided into a plurality of spaces including first and second pressure chambers. The first pressure chamber surrounds the first compressing unit and is kept at a discharge pressure of the first compressing unit, and the second pressure chamber surrounds the second compressing unit and is kept at a discharge pressure of the second compressing unit.

Abstract: Progressive cavity pump assemblies including one or more mechanisms adapted to regulate intake pressure of the main pump between a minimum intake pressure and a maximum intake pressure. In one embodiment, the mechanism is a sealing member configured to open at a threshold pressure to discharge wellbore fluid and close after falling below the threshold pressure. In an alternative embodiment, the mechanism may be a regulator assembly that adjusts the volume of output from the charge pump to the interconnect according to the pressure in the interconnect.

Abstract: A multi-directional pump is disclosed generally comprising a housing with inlet and outlet ports, a pumping device disposed therein, a first chamber in fluid communication with the inlet port, and a second chamber in fluid communication with the first chamber. The first and second chambers are both in direct fluid communication with the outlet port, such that a double pumping effect is achieved while some of the fluid is compressed in multiple stages. In certain embodiments, one or more sealing mechanisms can be activated when particular conditions are desired in order to seal the first conduit by which the first and second fluid chambers communicate, or by which the second fluid chamber communicates with the inlet port, such that a standard double or single pumping effect is achieved.

Abstract: A screw vacuum pump which allows reduced power, lower inside gas temperature, and reduced discharging time. The pump has a pair of screw rotors rotatively engaged with each other in a pump casing to discharge a gas along a longitudinal direction of the pump. Each rotor has three types of helical teeth serially located in a longitudinal direction of the rotor and different from each other in theoretical displacement volume. A bypass conduit communicating with a delivery side of the pump is connected via a first check valve to a first intermediate space defined between the first helical teeth and the second helical teeth and via a second check valve to a second intermediate space defined between the second helical teeth and the third helical teeth. The gas is compressed at the third stage to half the first stage volume before a discharge port opens.

Abstract: A piston pump including an inlet manifold, and outlet manifold, and a piston ring sandwiched between the inlet and outlet manifolds. The inlet manifold has a first face and a second face with at least one outlet formed in the second face. The outlet manifold has a first face and a second face, and includes at least one inlet formed in the outlet manifold first face. The piston ring has an inlet face and an exhaust face, wherein the piston ring is sandwiched between said inlet manifold second face and said outlet manifold first face, and has at least one radially extending cylinder formed therein. The piston ring further includes an inlet passageway formed in the piston ring between the inlet face and the cylinder and in fluid communication with the inlet manifold. The piston ring also has an exhaust passageway formed therein between said cylinder and the exhaust face and in fluid communication with the outlet manifold inlet.

Abstract: A surface pump assembly having a pressure vessel containing a submersible pump and an industrial motor located at least partially external to the pressure vessel having a shaft or seal thrust chamber extending at least partially into the pressure vessel to connect to pump. The pressure vessel has an inlet connected to a fluid source and one or more bleed off or pressure relief valves. The pump has an intake to receive the fluid and a discharge connected to a discharge conduit.

Abstract: An oil free screw compressor having a low-pressure stage compressor body and a high-pressure stage compressor body. Power of a motor driven by an inverter is transmitted to the compressor bodies through gears. A low-pressure stage blow-off two-way valve is provided in a pipe branching off midway an air pipe connecting between the high-pressure stage compressor body and the low-pressure stage compressor body, and a high-pressure stage blow-off two-way valve is provided in a pipe branching off from a discharge air pipe provided on a discharge side of the high-pressure stage compressor body. During no-load operation, a controller gives a command to the inverter to make the rotational speed of the motor a set lower limit rotational speed, and also gives an open command to the low-pressure stage blow-off two-way valve.

Abstract: A multi-stage compressor comprises a gas compressor, a centrifugal blower having an input connected with a gas source and an output connected with the gas compressor and providing a flow of compressed gas as a first stage of compression to the gas compressor, and a power source mechanically connected with and driving both the centrifugal blower and gas compressor to provide multi-stage compression of said gas.

Abstract: An oil free screw compressor having a low-pressure stage compressor body and a high-pressure stage compressor body. Power of a motor driven by an inverter is transmitted to the compressor bodies through gears. A low-pressure stage blow-off two-way valve is provided in a pipe branching off midway an air pipe connecting between the high-pressure stage compressor body and the low-pressure stage compressor body, and a high-pressure stage blow-off two-way valve is provided in a pipe branching off from a discharge air pipe provided on a discharge side of the high-pressure stage compressor body. During no-load operation, a controller gives a command to the inverter to make the rotational speed of the motor a set lower limit rotational speed, and also gives an open command to the low-pressure stage blow-off two-way valve.

Abstract: An oil catching device and an oil pump for an internal-combustion engine are provided, having an oil catching housing which is arranged below a crankcase and which has at least two oil collecting spaces, in a first oil collecting space an oil pump being arranged which has two pump stages, at whose two suction stages one oil suction pipe, respectively, is connected. The first oil suction pipe reaches in the first oil collecting space in order to deliver the lubricating oil by way of the delivery side of the first pump stage to the consuming devices, and the second oil suction pipe connected with the second suction stage leads to a second oil collecting space. On its top side, the housing of the oil pump has an opening connected with the delivery side of the second pump stage, by way of which opening, the oil suctioned out of the second oil collecting space is delivered into the first oil collecting space. This achieves a defoaming of the suctioned-off lubricating oil.

Abstract: An oil free screw compressor includes a low-pressure stage compressor body and a high-pressure stage compressor body. Power of a motor driven by an inverter is transmitted to the compressor bodies through gears. A low-pressure stage blow-off two-way valve is provided in a pipe branching off midway an air pipe connecting between the high-pressure stage compressor body and the low-pressure stage compressor body, and a high-pressure stage blow-off two-way valve is provided in a pipe branching off from a discharge air pipe provided on a discharge side of the high-pressure stage compressor body. During no-load operation, a controller gives a command to the inverter to make the rotational speed of the motor a set lower limit rotational speed, and also gives an open command to the low-pressure stage blow-off two-way valve.

Abstract: A multi-stage manual hydraulic pump comprising a plurality of cylinders in tandem. A block holds each cylinder assembly. One or more cylinders are the high volume stage, one or more cylinders are the medium volume stage and the final cylinders are the low volume, high pressure stage. The pump utilizes check valves built into flow tubes that control the direction of fluid. A variable hydraulic piston and cylinder assembly in each high volume block and each medium volume block automatically turns off the vacuum and flow of fluid to each cylinder at a designated pressure. At the point of highest pressure only the smallest cylinder or cylinders are pumping fluid, where the effort expended is significantly reduced.

Abstract: A multi-stage pump has a housing defining a plurality of stages each having an internal rotor enclosure with each enclosure having a non-pumping inlet and outlet. A plurality of rotor assemblies are operatably contained in housing extending through all of the stages. The rotor assemblies and rotor enclosures are shaped to provide a smaller inlet volumetric delivery rate at the last (downstream or outlet) stage than at the first (upstream or inlet) stage. A plurality of fluid lines connect the non-pumping chambers to enable the pump to handle liquid so that, as the rotor assemblies are rotated, a fluid stream entering the pump inlet is subjected to a pumping action to transport the fluid stream to exit through the pump outlet.

Abstract: A multi-stage manual hydraulic pump comprising a plurality of cylinders in tandem. A block holds each cylinder assembly. One or more cylinders are the high volume stage, one or more cylinders are the medium volume stage and the final cylinders are the low volume, high pressure stage. The pump utilizes check valves built into flow tubes that control the direction of fluid. A spring and piston in each high volume block automatically turns off the vacuum and flow of fluid to each cylinder at a designated pressure. At the point of highest pressure only the smallest cylinder or cylinders are pumping fluid, where the effort expended is significantly reduced.

Abstract: A gas ballast system for a multi-stage positive displacement pump in which a first stage includes at least one positive displacement pump stage, is equipped with an inlet valve and an outlet valve, and is connected with the following stage by an intermediate vacuum chamber, with the gas ballast system including a first conduit for supplying gas into the intermediate vacuum chamber, and a second conduit for supplying gas from the intermediate vacuum chamber into a pump chamber of the first stage or to a suction region of the first stage.

Abstract: A compound gear pump includes an internal gear pump including an outer rotor having on the outer periphery external teeth, an external gear pump including a rotor having on the outer periphery an external teeth circumscribed with the external teeth of the outer rotor, and a guide face arranged on the outer periphery of the outer rotor and being adjacent to the external teeth of the outer rotor in the axial direction thereof.

Abstract: An oil-free two-stage vacuum pump includes first and second pump stages coupled in series. The first and second pump stages have discharge spaces capable of communicating with each other via a bypass passage. The bypass passage is provided with a pressure control valve which is closed when pressure in the bypass passage is lower than a predetermined pressure. This permits a reduction in scroll size. In addition, the pump is free from problems present in pumps with large scroll sizes such as drive shaft vibrations due to warping thereof at high speed rotation, noise and heat generation, and durability reduction due to causes such as non-uniform contact between stationary and revolving scrolls. Moreover, in a compression step in the first pump stage, withdrawn gas is under high pressure; the gas pressure in a sealed vessel is close to the atmospheric pressure in an initial stage of driving.

Abstract: A screw type dry vacuum pump having dual shafts is disclosed, whereby the process gas is transported through three compartments, a gas admittance pump section, a central drive motor section, and a gas discharge pump section. By placing the drive motor in the center of the pump, it becomes possible to design a pump having the dual shafts supported only at one end, thus enabling to mount the rotors at the free ends of the pump which are closed with end plates which can be removed easily for servicing the pump sections. Synchronous operation of the dual shaft pump by magnetic coupling enables to lower power consumption and to extend the range of operable pressures.

Abstract: A pump includes a high pressure portion and a low pressure portion. During low pressure, high volume operation, pressure produced in the high pressure portion of the pump is applied to drive a large area piston in the low pressure portion of the pump. Once the pressure in the high pressure portion of the pump raises to a cut-off pressure, at which time it takes excessive power to drive the large area piston, a cut-off valve opens to allow the high pressure portion of the pump to directly pump a relatively lower volume of fluid per stroke at a relatively higher pressure.

Abstract: An evacuating apparatus includes a first pump section disposed on a suction opening side, a second pump section for exhausting a smaller amount of gas than the first pump section, the second pump being disposed in an exhaust opening side, a plurality of rotors accommodated in a housing, bearings for supporting rotation of the rotors, a suction opening for drawing fluid and a first exhaust opening thereof both formed on the housing, and a plurality of motors for driving the rotors. In the apparatus, the first pump section is a pump of positive displacement type formed by utilizing a volume change of a space defined by the rotors and the housing, and the second pump section is a viscous-type pump formed by utilizing a relatively moving surface formed in a small gap defined between the rotors and the housing.

Abstract: An apparatus and method for dispersing a gas in a liquid and for increasing gas pressure of a gas from a supply pressure to a delivery pressure. A first pump pumps the liquid to produce a pressurized liquid stream. The gas is injected into the pressurized liquid stream through for instance, a piping tee. The gas injection produces a pressure drop within the gas and as a result, the first pump pumps the liquid stream so that it has a static pressure no greater than the injection pressure. A second pump pumps the resultant pressurized gas-liquid stream so that an outlet liquid stream is produced with the liquid having a greater head than that of the pressurized liquid stream and the gas having the increased delivery pressure.

Abstract: A vane compressor capable of obtaining a two stage compression. The compressor has a front and rear rotor 6a and 6b for defining, together with a cylinder bores 43 and 44, first and second operating chambers 39 and 40, respectively. A refrigerant from a first inlet opening 28 is sucked into the first operating chamber 39 by a rotation of the front rotor 6a for obtaining a first stage compression at the first chamber 39. The refrigerant is then introduced, via an intermediate pressure chamber 36, to the second operating chamber 40 for obtaining a second stage compression at the second chamber 40, which is discharged outwardly.