Abstract: Included are electric submersible pump assemblies, methods of use, and systems incorporating said electric submersible pump assemblies. An example electric submersible pump assembly comprises an electric submersible pump comprising a pump intake, a storage chamber in fluid communication with the discharge side of the electric submersible pump, and a tubing configured to allow for fluid communication between the pump intake and the storage chamber such that fluid may flow from the storage chamber into the pump intake.

Abstract: A reverse osmosis system includes a membrane unit, an energy recovery device, high and low pressure inlet lines, and a concentrate line. The membrane unit has a membrane, an inlet for receiving a feed fluid, a permeate outlet for discharging a permeate fluid and a concentrate outlet for discharging a concentrate fluid. The energy recovering device has a turbine portion, a turbine inlet and a turbine outlet, a pump portion, a pump inlet and a pump outlet, a motor, and a motor control unit for controlling the motor. The low pressure inlet line is connected to the pump inlet for supplying the feed fluid at a low pressure. The high pressure inlet line connects the pump outlet with the inlet for supplying the feed fluid at a high pressure. The concentrate line connects the concentrate outlet with the turbine inlet for supplying the concentrate fluid to the turbine portion.

Abstract: Turbine pumps can include: an inlet port; a first discharge port; a body defining a flow path extending from the inlet port through a raceway to the discharge port; and a turbine impeller disposed in the raceway. In some pumps, the body further defines an channel providing a fluid connection between a raceway outlet and the discharge port. In some pumps, an outlet angle defined by the inlet port, an axis of the turbine, and the discharge port is between 30 and 180 degrees.

Abstract: A bearing housing for a turbocharger is disclosed. The bearing housing includes a first end proximate to a turbine wheel of the turbocharger and a second end proximate to a compressor wheel of the turbocharger. The bearing housing further includes a central chamber disposed between the first end and the second end and configured to house, at least, the shaft. The bearing housing further includes an oil drain disposed radially outward of the shaft and configured for directing oil out of the bearing housing and an oil core disposed radially outward of the shaft and radially inward of the oil drain, the oil core configured for communicating oil towards the oil drain and having an inner wall. The bearing housing includes one or more strakes protruding radially inward from the inner wall, the one or more strakes configured to direct oil within the oil core towards the oil drain.

Abstract: A rotor blade according to an exemplary aspect of the present disclosure includes, among other things, a platform, an airfoil that extends radially from the platform, a first cooling core that extends at least partially inside the airfoil, a second cooling core inside of the platform, a first cooling hole that extends circumferentially between a mate face of the platform and the second cooling core, a second cooling hole that extends between a gas path surface of the platform and the second cooling core, the second cooling core radially disposed between the gas path surface and a non-gas path surface, and the second cooling core circumferentially disposed between the first cooling core and the mate face. A method of cooling a blade is also disclosed.

Abstract: An active clearance control system of a gas turbine engine includes a multiple of blade outer air seal assemblies and a multiple of rotary ramps. Each of the multiple of rotary ramps is associated with one of the multiple of blade outer air seal assemblies. A method of active blade tip clearance control for a gas turbine engine is provided. The method includes rotating a multiple of rotary ramps to control a continuously adjustable radial position for each of a respective multiple of blade outer air seal assemblies.

Abstract: This disclosure relates to a control system and method for the centrifugal compressor. The system, for example, includes a controller configured command an adjustment of at least one of (1) a flow regulator and (2) a speed of a shaft in order to provide safe, efficient compressor operation. Centrifugal compressors are used to circulate refrigerant in a chiller via a refrigerant loop. Centrifugal compressors operate efficiently before reaching a condition known as surge.

Abstract: A water supply apparatus for the supply of water to a machine tool, including a water pump, a water accumulator device, a suction line, a supply line and a valve device reversibly adjustable into a first and a second position. The water pump is positioned downstream of the valve device. A first connecting line, a second connecting line and a return line are provided. Here, in the first position, the first connecting line, the second connecting line and the return line are connected to one another such that water can be conveyed from the water pump, from the first connecting line, from the second connecting line, from at least a part of the suction line and from at least a part of the supply line into the return line, and, in the second position, the first connecting line, the second connecting line and the return line are not connected to one another.

Abstract: A centrifugal compressor includes a housing that accommodates a wheel. The housing includes an air intake space formed on an entrance side of the wheel; a flow passage to guide fluid compressed by the wheel to the outside of the housing; a return flow passage opened on each wall surface of the air intake space and the flow passage to circulate a part of the fluid in the flow passage to the air intake space without passing through the wheel; and an introduction portion provided in the air intake space, and having an inner peripheral surface that forms a flow passage to guide the fluid from the outside of the housing to the wheel. A downstream end of the inner peripheral surface in a flowing direction of the fluid is located radially inward of the wall surface of the housing.

Abstract: A ported-shroud centrifugal compressor for a turbocharger includes an inlet-adjustment mechanism in an air inlet for the compressor, operable to move between an open position and a closed position in the air inlet. The inlet-adjustment mechanism includes an axially elongated ring. In the open position, the radially outer surface of the ring is spaced from a tapering inner surface of the air inlet so that air can flow in an annular passage between the tapering surface and the ring, and the ring opens the ported shroud. In the closed position, the ring abuts the tapering surface to close off the annular passage and to close off the ported shroud. Movement of the inlet-adjustment mechanism from the open position to the closed position is effective to shift the compressor's surge line to lower flow rates.

Abstract: A second recirculation passage recirculates blow-by gas at an upstream section, which is upstream of an impeller of a turbocharger in an intake passage. A first passage branches and extends from a downstream section, which is downstream of the impeller in the intake passage. A second passage that forms part of the second recirculation passage connects the first passage and the upstream section to each other. A third passage, which is provided separately from the second passage, connects the first passage and the upstream section to each other. A change mechanism changes, in different manners, the flow rate of compressed gas recirculating to the upstream section through the second passage, and the flow rate of compressed gas recirculating to the upstream section through the third passage.

Abstract: A marine pumping system includes a pump for providing a cooling fluid to, for example, an internal combustion engine. The pumping system includes a pump, a reservoir separate from and upstream of the pump for storing cooling fluid, and plumbing downstream of the pump configured to maintain cooling fluid in the reservoir during non-operation of the pump. The reservoir and plumbing configuration minimize dry run time of the pump.

Abstract: An example system includes a diaphragm pump having a suction port and a discharge port, a urea suction line fluidly coupling a urea supply to the suction port, and a urea discharge line fluidly coupled to the discharge port. A recirculation line fluidly couples the urea discharge line to the urea suction line, and has a flow regulator operationally coupled thereto. A controller is configured to interpret a prime loss condition of the diaphragm pump, and to provide a flow regulator command in response to the prime loss condition.

Abstract: This disclosure relates a water pump, a system for cooling internal combustion engine components including a water pump, and a method for operating an internal combustion engine including a water pump. The water pump, system and method provide protection of the pump impeller during dry pump operation, such as when a watercraft engine is started while the watercraft is out of water, by dispensing fluid from a reservoir to the pump's impeller chamber. The fluid enters the chamber via a controllable flow path and interacts with the impeller and chamber walls to cool and lubricate the impeller.

Abstract: An exhaust-gas turbocharger (1), having a turbine (2) and a compressor (3) which is connected to the turbine (2) via a bearing housing (4) and which has a compressor housing (5). The compressor housing has a valve flange (6), provided with a valve seat (11), for an overrun air recirculation valve and has a connecting duct (9) which opens out at one end (9A) in a compressor inlet (7), a valve flange chamber (14) into which the other end (9B) of the connecting duct (9) opens out being arranged between a valve orifice (10) of the valve flange (6) and a valve seat orifice (13) of the valve seat (11). The valve flange chamber (14) is provided with a buffer volume (15).

Abstract: A vacuum pump comprises a molecular drag pumping mechanism and a regenerative pumping mechanism. A rotor element of the molecular drag pumping mechanism surrounds rotor elements of the regenerative pumping mechanism.

Abstract: A gas turbine compressor is disclosed. The compressor includes a compressor housing, guide vanes, rotor blades, and valve-controlled blow-in openings for stabilizing the compressor flow by air that is blown in. The air flow is detected by pressure sensors and the valves are controlled as a function thereof.

Abstract: A filter and pump unit is proposed for the filtering out of particles from a fluid, there being a filter housing (2) which bounds a filter space (3) and has an inlet (21) and also an outlet (22) for the fluid to be filtered as well as a filter element (4) provided in the filter space (3), the filter element demarcating an inlet region (31) from an outlet region (32) of the filter space (3), with the inlet region (31) communicating with the inlet (21) and the outlet region (32) communicating with the outlet (22), there also being an impeller (5) which, as part of a rotary pump, can pump the fluid from the inlet region (31) through the filter element (4) into the outlet region (32), characterized in that a flow connection (6) is provided between the outlet region (32) and the impeller (5) so that at least a part of the fluid can flow back from the outlet region (32) to the impeller (5). Furthermore, a method for the filtering out of the particles from a fluid is proposed.

Abstract: A bearing arrangement includes a bearing outer element that defines a first plurality of races opening radially inwardly, a bearing inner element that defines a second plurality of races opening radially outwardly, and a bearing middle element defining a third plurality of races at its radially outer surface thereof and a fourth plurality of races at its radially inner surface thereof. Rolling elements are receivable in the races. The bearing middle element includes an axial protrusion at least at one end thereof that can be received in a housing with respect to which the bearing outer and inner elements are rotatable.

Abstract: An apparatus for controlling the temperature of a component, which is situated in use in a gas stream, provides a nozzle to create a jet of air at an angle to the gas stream, the jet being directed into the region of the stagnation point of the component so as to control the temperature of the component. The invention is particularly suited to preventing or reducing the formation of ice on vanes of gas turbine engines, but may also be applied to other components, and may equally be used in situations where a component is to be cooled rather than heated.

Abstract: The invention relates to a turbocharger (1) having a turbine (2); and having a compressor (3) connected to the turbine (2) by means of a bearing housing (4), the compressor comprising a compressor housing (5), which has a reference surface (BF) perpendicular to a turbocharger axis (AL), and a valve flange (6) equipped with a valve seat (11) for a wastegate valve and a connecting channel (9) to a compressor inlet (7), wherein the valve flange (6) has a flange surface (8) that is disposed at a calculable angle (?) to the reference surface (BF) in a tilted manner, and wherein the connecting channel (9) has a channel axis (AK), which is disposed at a calculable angle (?) in a tilted manner.

Abstract: The exhaust within an exhaust gas recirculation (EGR) system should be purged to allow for access to the components of the EGR system. A system and method for purging the EGR system is provided. The system and method may incorporate a purge gas supply that may include: at least one pressurized cylinder, a storage tank, a compressor, or a benign fluid source. The system and method may drive the exhaust out of the EGR system.

Abstract: There is provided a compressor (10) and an associated method for controlling a recirculation flow to control surging in the compressor. The compressor includes a housing (12) and a compressor wheel (16) mounted therein. A recirculation passage (41) receives compressed air from the compressor and recirculates the compressed air to an inlet passage (20) of the housing and, in particular, to leading edges (32) of blades (18) of the compressor wheel. An adjustable flow control device (60) is configured to control the flow of the compressed air through the recirculation passage to control a surge characteristic of the compressor. For example, the flow control device can include one or more valves (V1, V2, V3), each of which can be adjusted by an actuator (64).

Abstract: An air cooled bearing comprising means for imparting a swirl component to the cooling air flowing toward the bearing. By imparting a swirl component to the cooling air the amount of work imparted on the cooling air by the rotating cage and rolling elements of the bearing can be reduced and in some cases substantially eliminated.

Abstract: A centrifugal pump comprising a pump body (1) housing an impeller (3) keyed onto a motor shaft (4) and provided with a suction mouth (7) and a discharge mouth (8) capable of being made to communicate with, respectively, a suction pipe (9) and a discharge pipe (10). Between the suction mouth (7) and the suction pipe (9) there is provided a chamber (22) that communicates with a tank (11) situated at a level higher than the level of the pump, said tank being interposed between the discharge mouth (8) and the discharge pipe (10) and in communication with both of them and communicating also with the chamber (22) through a recirculation duct (28) having a section smaller than the section of the suction pipe (9).

Abstract: A gas-supplying apparatus for a fuel cell, which generates electric power due to an electrochemical reaction between oxygen and hydrogen, during which water is produced, and which has respective gas passages within the duel cell according to the present invention comprises a gas-sucking means which supplies supply gas of the fuel cell provided on the downstream of the gas passage in a gas-flowing direction; and a pressure controller which controls the pressure of the supply gas within the fuel cell, provided on the upstream of the gas passage, whereby the water produced during the course of said electrochemical reaction is discharged. When the cell voltage is decreased, the apparatus of the present invention recovers the cell voltage by making the negative pressure large to accelerate the discharge of the produced water with minimized power consumption.

Abstract: A turbocharger having a bypass port compressor, with a center channel that flows directly into the compressor wheel, and an annular channel which acts as a bypass and provides flow either into or out of the compressor wheel, with an inner deflector having at least a first surface substantially perpendicular to the annular channel and extending radially into the annular channel, and at least a second surface substantially parallel to the annular channel and extending axially along the annular channel, such that line-of-sight transmission of sound from the annular channel is eliminated, and sound waves are instead dampened or canceled, reducing noise emissions from the compressor.

Abstract: In a centrifugal compressor, a housing is provided which has an annular treatment cavity in a shroud wall. The shroud wall has a first opening providing communication between an installed zone of an impeller and the treatment cavity, and a second opening providing communication between the treatment cavity and a zone upstream of the first opening so as to circulate air a during a low-flow-rate operation. Louvers are arranged in the second opening in circumferentially equidistantly spaced apart relationship with each other and inclined reversely to a rotative direction of the impeller so that the air a sucked to the treatment cavity is, when discharged through the second opening, subjected to directional flow guide action with a whirling direction reverse to the rotative direction of the impeller.

Abstract: A glass product machining apparatus comprises a grindstone rotatable around an axis by means of a motor, moving table movable under the grindstone in the cross direction of the grindstone, frame for supporting the grindstone for up-and-down motion, lift, guides, supporting arms, pressure cylinder supported on the frame, and dressing machine for dressing or truing the grindstone. The pressure cylinder serves to apply a fixed elastic load to the grindstone as the grindstone shifts its position upward. A glass panel is located on the moving table. The panel moves together with the table. When the panel passes under the grindstone, an outer peripheral surface of the grindstone is brought into contact with the surface of the panel with a fixed force of pressure by the pressure cylinder. The grindstone relatively moves along the curved surface of the panel as it grinds the panel surface.

Abstract: A gas compression system and method according to which product gas is introduced into and compressed in, a compressor. A portion of the compressed gas is discharged to external equipment, and a portion of the gas is trapped in response to deactivation of the compressor. The trapped gas is passed back to the deactivated compressor.

Abstract: A turbocharger system for an internal combustion engine is provided with a plurality of turbochargers. Each turbocharger includes a rotatable shaft; a turbine having turbine wheel carried by the shaft, an inlet and a variable nozzle at the inlet; and a multi-stage compressor. The multi-stage compressor includes a first compressor wheel carried by the shaft, an axially extending first inlet associated with the first compressor wheel, a radially extending first outlet associated with the first compressor wheel, a second compressor wheel carried by the shaft, an axially extending second inlet associated with the second compressor wheel, a radially extending second outlet associated with the second compressor wheel, and a interstage duct fluidly interconnecting in series the first outlet associated with the first compressor wheel with the second inlet associated with second compressor wheel.

Abstract: A turbocharger system for an internal combustion engine is provided with at least one rotatable shaft and a multi-stage compressor. The multi-stage compressor includes a first compressor wheel carried by a corresponding shaft, an axially extending first inlet associated with the first compressor wheel, a radially extending first outlet associated with the first compressor wheel, a second compressor wheel carried by a corresponding shaft, an axially extending second inlet associated with the second compressor wheel, and a radially extending second outlet associated with the second compressor wheel. An interstage duct fluidly interconnects in series the first outlet associated with the first compressor wheel with the second inlet associated with the second compressor wheel. At least one bypass duct is provided, with each bypass duct fluidly interconnecting the first outlet with the first inlet; the first outlet with an ambient environment; and/or the second outlet with the first outlet.

Abstract: An internal combustion engine is provided with at least one intake manifold and a turbocharger. The turbocharger includes a rotatable shaft; a turbine having a turbine wheel carried by the shaft; and a multi-stage compressor. The multi-stage compressor includes a first compressor wheel carried by the shaft, an axially extending first inlet associated with the first compressor wheel, a radially extending first outlet associated with the first compressor wheel, a second compressor wheel carried by the shaft, an axially extending second inlet associated with the second compressor wheel, a radially extending second outlet associated with the second compressor wheel, and an interstage duct fluidly interconnecting in series the first outlet associated with the first compressor wheel with the second inlet associated with the second compressor wheel. The second outlet is fluidly coupled with the intake manifold.

Abstract: An apparatus for measuring doses of dispensed products includes a first metering ring (20) mounted to rotate 5 around a rotation axis (1), and drive means (10) that drives the first metering ring to rotate around an axis (1). The drive means (10) is actuated each time the dispenser is actuated. The apparatus also has interlocking means (15, 22) that engage the drive means (10) with the first metering ring (20) after the dispenser has been actuated a predetermined number of times. The first metering ring (20) is driven to rotate once it is engaged with the drive means (10). The apparatus only counts the doses of dispensed product after the dispenser has been actuated a predetermined number of times.

Abstract: The invention relates to a centrifugal pump device, comprising a pump casing (1) having an inlet (2) and an outlet (3), an impeller device inside the casing (1) having one or more pump stages (5-7) with a common rotary shaft (4), and a non-return valve (8) between inlet (2) and outlet (3). The device is characterized in that the non-return valve (8) is provided on the discharge side of at least a first pump stage (5).

Abstract: Active recovery from a rotating stall operating condition in an axial flow compression system is accomplished by altering the temperature and/or density of the working fluid flowing in the inlet of the compression system once rotating stall is detected. A burner is used to increase the compressor inlet flow temperature and concomitantly reduce the inlet flow density. Alternatively, a low density gas such as helium is injected into the compressor inlet. The ingestion of high temperature gases or other low density gases into the compressor energizes a dynamic response from the compression system that induces rotating stall recovery.

Abstract: A control system prevents recurrence of surge in a dynamic compressor. An anti-surge valve bypasses flow and is operated by the control system between a low limit and a full open position. The low limit is initially established to be zero, or a fully closed anti-surge valve. In the event of a compressor surge, the system detects a position of the anti-surge valve at the onset of surge, and stores a position related to the detected position as a new low limit. The stored position is preferably the detected position plus a small increment in order to prevent recurrence of the surge event.

Abstract: A method is provided for equalizing fluid pressure in a primary fluid flow region, comprised of providing a modulating fluid flow region adjacent to the primary flow region and separating the two regions with a perforated wall. By controlling the fluid pressure in the modulating fluid flow region, and permitting fluid to flow between the perforated wall, the fluid pressure in the primary fluid flow region is equalized. This method is important in equalizing the air pressure in a turbine engine air inlet and thereby avoiding aerodynamic distortions in said inlet. Additionally, an apparatus is provided for equalizing the pressure in a primary fluid flow region.

Abstract: A method of operating a multistage turbocompressor or of monitoring the pump limit thereof, whereby the pump limit function is stored in the control unit in the form Y=m.F+b and the coefficients m and b are determined by the linear relationshipsm=m.sub.0 +m.sub.1.dT.sub.s +.SIGMA.m.sub.2i.dT.sub.rib=b.sub.0 +b.sub.1.dT.sub.s +.SIGMA.b.sub.2i.dT.sub.riwhere T.sub.s and T.sub.ri represent the intake temperature and the backcooling temperatures following coolers after each turbocompressor and dT.sub.s and T.sub.ri and reference temperatures T.sub.ref. The system automatically compensates for the shift of the pump limit with temperature and allows operation closer to the pump limit or boundary for stable aerodynamic operation.

Abstract: A compressor assembly (12,13) for a gas turbine engine (10) comprises a centrifugal compressor (12) having a variable cross-sectional area diffuser (13) located at its downstream end. When the cross-sectional area of the diffuser (13) is less than a maximum value, some of the air exhausted from the downstream end (24) of the compressor (12) is directed to the upstream end (23) thereof. Sufficient air is so directed as to ensure that the mean air velocity at the outlet (30) of the diffuser (13) remains substantially constant.

Abstract: Method and apparatus for operating compressors to avoid surges. The compressor is controlled by direct measurement of the rate of volumetric flow, Q, of gas through the compressor via the use of an acoustic flow meter, or other sonic velocity measuring device in combination with a standard flow meter and the measurement of the speed, N, of the compressor. The Q/N ratio is calculated electronically and output to a controller which, through a control circuit, operates a recycle valve in a by pass line leading from the discharge side to the suction side of the compressor. The Q/N ratio measured by the controller at compressor operating conditions is compared with a Q/N ratio at which surge will occur. When the measured Q/N ratio is less than the Q/N ratio at surge, the recycle valve will open and flow gas from the discharge side to the suction side of the compressor to avoid surge flow in the compressor.

Abstract: A supervisory computer is provided for controlling a compressor wherein a computer generated set point manipulates flow in a recycle line from the compressor outlet to inlet. The supervisory computer manipulates the recycle flow so as to prevent the compressor from surging due to changes in flow rate, pressure or the molecular weight of the gas being compressed. The molecular weight of the gas is calculated on-line from actual measurements of flow, pressure, temperature and speed along with compressor performance data that is prestored in the computer. In addition the supervisory computer automatically maintains a minimum flow for the compressor that is as close as possible to the surge limit without danger of putting the compressor into surge due to changes in flow, pressure or molecular weight of the gas being compressed.

Abstract: A supervisory computer for a centrifugal compressor control system is disclosed which manipulates the set point of a controller for a valve in a recycle line from the compressor systems outlet to inlet. The supervisory computer manipulates the set point so as to both prevent surging and substantially minimize the recycling of compressed gas. The computer first determines the surge flow limit for the compressor based on prestored data from the compressors manufacture performance curves such as constant speed compressor curves, and the actual speed of the compressor. The controller then outputs a set point signal which periodically moves the control valve in incremental amounts toward the fully closed position. The periodic movement towards the closed position continues until the flow is close to the surge flow limit, or until the actual deviation of the setpoint flow and the actual process flow exceeds a desired high limit for this deviation.

Abstract: A side channel pump (10) has a pumping cavity (26) which includes an inlet port (78), a discharge port (80) and side channels (72,74). An impeller (54) is mounted for rotation in the pumping cavity. A reservoir (20) holds an ample supply of liquid for pump priming and pump cooling during periods of gas pumping. A bypass suction duct (24) carries liquid from the reservoir to the pumping cavity during priming, gas pumping and normal operating and a bypass return duct (22) returns some discharged liquid to the reservoir during gas pumping and normal operation. The reservoir acts as a heat sink to enable the liquid ring formed during gas pumping operation to absorb more heat and provide pump cooling.

Abstract: To achieve priming during start-up and repriming during operation, a self-priming pump system is provided. The self-priming pump system includes a discharge priming reservoir for storing priming liquid for a pump. The discharge priming reservoir has an inlet in communication with the outlet of the pump for receiving priming liquid from the pump and has an outlet in communication with the pump upstream of an impeller and downstream of a liquid supply reservoir for supplying the priming liquid to the pump. The self-priming pump system is operable to separate air from priming liquid in the discharge priming reservoir during recirculation of priming liquid. In addition, a priming valve is disposed between the discharge priming reservoir and the pump to control circulation of priming liquid through the self-priming pump system.

Abstract: The pump system provides for a more efficient operation of multistage centrifugal pumps operating at less than designed capacity. The system includes a flow meter located in the inlet conduit to the pump, a control valve is located in a discharge conduit that extends from the discharge of the first stage of the pump to the inlet conduit, and a connection between the flow meter and control valve whereby the control valve will open to bypass liquid from the first stage discharge to assure that flow through the first stage is greater than the value wherein the internal recirculation occurs. Thus, the pump is capable of circulating a substantially greater amount of liquid through the first stage of the pump when the demand volume at the pump discharge is substantially less than the design value.

Abstract: An adaptive gain surge control system (18) is disclosed for a centrifugal compressor (14) which reacts to both normal and emergency surge conditions by controlling a bypass valve (48) across the compressor (14) inlet and outlet in response to a variable gain (G) determined by the offset (d) of the surge control line from the surge line of the compressor.

Abstract: A relief valve system for a pump in which control means are responsive to the occurrence of an excessive pressure on the inlet or discharge side of the pump to relieve this condition by dumping excess pressure to atmosphere.

Abstract: An adaptive gain surge control system (18) is disclosed for a centrifugal compressor (14) which reacts to both normal and emergency surge conditions by controlling a bypass valve (48) across the compressor (14) inlet and outlet in response to a variable gain (G) determined by the offset (d) of the surge control line from the surge line of the compressor.

Abstract: As an improvement in an anti-surge control method for a multi-stage centrifugal compressor having interstage coolers, this invention comprises, when there is an imbalance of stage flows relative to surge, replacing recycle with warm expanded gas to the maximum extent possible that still achieves an energy saving as compared with not effecting such replacement.