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.

Abstract: A self-priming system for liquid pumps wherein a priming valve is provided to convey a quantity of priming liquid to the pump upon loss of pump suction. A pilot valve is provided to regulate the pressure against a piston which serves to maintain the priming valve closed. The pilot valve controls the liquid pressure exerted against the piston and thereby regulate the pressure level at which the priming valve will open. The pilot valve can be electrically actuated by means of a flow sensor including a diaphragm operated switch responsive to liquid flow.

Abstract: A self-priming pump system incorporating a priming valve to release a quantity of priming liquid upon loss of pump suction. The valve includes a piston connected to a valve member, the piston having an area greater than that of the valve member. Discharge line static pressure act upon the valve member and the piston and the difference in area results in a net force tending to open the valve. The valve is maintained closed by the pump discharge dynamic pressure acting through a conduit and upon the opposite face of the piston. The valve does not include any springs or other mechanical biasing means.

Abstract: A self-priming system for liquid pumps wherein a priming valve is provided to convey a quantity of priming liquid to the pump upon loss of pump suction. A pilot valve is provided to regulate the pressure against a piston which serves to maintain the priming valve closed. The pilot valve includes a bleed valve to vary the liquid pressure exerted against the piston and thereby regulate the pressure level at which the priming valve will open.

Abstract: A steam generation system employing a flash tank feeding low-pressure steam to a compressor controls surges in the compressor by calculating the amount of steam generated based on the temperature change and flow of water passing through the flash tank and modulates the flow rate in order to maintain the steam flow above a surge limit. If increasing the water flow rate is incapable of producing enough steam to avoid surges, a recycle control recycles steam from the output of the compressor back to the flash tank. A further embodiment of the invention permits using an auxiliary source of low-pressure steam to augment the steam produced in the flash tank while maintaining the total steam flow at a level sufficient to avoid surges. The steam flow may alternatively be derived from the differential pressure between outlet and inlet of the compressor.

Abstract: A pipe fitting for attachment to a hydrotherapy pump has an inlet and outlet having parallel offset axes, with a separate small hollow nipple extending from and communicating with the inlet. The nipple attaches to the pump at a location normally occupied by the pump freeze plug. The fitting permits complete drainage of the hydrotherapy pump after the pump is shut off.

Abstract: A surge control system is disclosed for centrifugal compressors which utilizes an algorithm to calculate a desired orifice differential pressure and compare the calculated result with an actual differential pressure. A controller is provided for operating a blow-off valve to bring the actual differential pressure to the calculated differential pressure.

Abstract: The pump unit (2) is provided with a valve (6) at the pressure side, which is arranged to open a connection between the pump and the pump station thus obtaining a circulation. The valve is arranged at the upper side of the pump housing and the outlet of the valve is directed opposite to the flow direction (A) in the pump housing (4) thus minimizing the risk of clogging.

Abstract: The load on the starting steam turbine or motor which drives the power recovery string of an FCC process is reduced on the order of 15% by increasing the specific volume of the air compressed by a fixed volume compressor in the string. The specific volume of the ambient air is increased by returning a portion of the compressed and thereby heated air to the inlet of the compressor in amounts sufficient to raise the temperature of the inlet air about 75.degree. F., or more.

Abstract: A method and device for reducing the noise produced in a turbo-machine by e interaction of the blades of a ring of rotor blades and the vanes of a ring of stator vanes, by the creation of a counter-noise of opposed phase. This is achieved by the injection of a fluid into the flow passage of the machine in which the blades and vanes are located. The injection is carried out through orifices located on stationary parts of the machine and equal in number to the vanes of ring of stator vanes, the flow through the orifices being modulated at the frequency of the noise to be reduced and with a phase difference which increase in an incremental manner from one orifice to the next. The phase of the modulated flows injected through the orifices is simultaneously regulated so that the acoustic waves created by the flows are substantially in opposition, with respect to phase, to those of the noise to be reduced.

Abstract: To provide reduction in temporary conditions of excess load on the thrust bearing, a labyrinth positioned contiguous to a leakage aperture in the high pressure side of a single stage overhung compressor rotor affords controlled leakage to a venting circuit in communication with a lower pressure system. A pressure switch responsive to pressure levels in the venting circuit prevents compressor start at pressures above the set point of the switch while a backpressure valve in the venting circuit when operative maintains a predetermined pressure level therein. When the thrust bearing is operating at speeds sufficient to enable acceptance of the load imposed by compressor pressure, an override solenoid valve serves to close the backpressure valve and operably shut the venting circuit.

Abstract: A high pressure pump including a cylindrical rotor carried within a cylindrical cavity provided in a housing. Inlet and outlet ports are provided for transporting fluid to and from the cavity. A plurality of circumferentially spaced concave semicircular chambers are provided on the periphery of the rotor. A pivotal member is carried closely adjacent the outlet port and rides along the curving wall of the chambers as the chambers pass the outlet port directing fluid transported in the chambers to the outlet port. The rotor is driven by an electric motor. A bypass valve is provided between the outlet and inlet ports for bypassing the flow of fluid therebetween when an obstruction appears in the outlet or when the pressure exceeds a predetermined value.

Abstract: A self-priming pump system having a repriming valve opened in response to variations in fluid movement through a reservoir that includes a flow restriction. A control system is provided that includes a first sensor for sensing pressure within the flow restriction, a second sensor for sensing pressure within a portion of the reservoir spaced from the flow restriction, and a control mechanism for comparing the sensed signals and for opening the repriming valve when the difference between the signals falls to or below a predetermined value.

Abstract: A compressor surge control system is provided for a compressor system in which recirculation of gas from the discharge outlet of the compressor to the suction inlet of the compressor is utilized to prevent surging of the compressor. The recirculation of gas from the discharge outlet of the compressor to the suction inlet of the compressor is substantially minimized by using a first controller to provide a floating set point for a second controller. This reduced recirculation substantially increases the efficiency of the compressor system.

Abstract: The inner compartment of a compressor for noxious fluids is isolated by means of the closure system when the compressor is stationary and disengaged from its driving means. The closure system is controlled by a magnetic attraction system, the external surface of which is uniformly constructed of magnetic material having a small thickness at the level of non-magnetic elements. A particularly noteworthy application of the system is in motor-compressor sets for the transfer of toxic and hazardous fluids employed in the nuclear engineering field.

Abstract: A surge control system for a centrifugal compressor having a recycle line between the discharge and suction, modulates flow in the line in accordance with molecular weight and temperature of the gas being compressed, pressure drop across the inlet orifice, and pressure drop across and power input to the compressor. The system is based on the standard relation that the product of the gas constant times the pressure drop across the inlet orifice divided by the suction temperature equals the pressure drop across the compressor.

Abstract: A low well yield control system and method for preventing over pumping of wells and other fluid reservoirs. The control is positioned in the reservoir and includes a plurality of relief valves which are opened to replenish liquid in the reservoir from the pumped liquid in the event the liquid level is lowered relative to a float.

Abstract: An axial inducer, which charges the inlet of a centrifugal impeller has a bypass loop connecting its inlet and outlet. A valve member for controlling bypass flow is positioned in the bypass loop. At low flows, the bypass loop permits the inducer to run closer to design flow conditions than would otherwise be possible and, consequently, generate less pressure rise, consume minimum power, and cause minimal heating of the fluid being pumped. An extension of the bypass valve member functions to restrict the centrifugal pump discharge area when the valve member is positioned to bypass flow to reduce recirculating flow in the centrifugal impeller and increase its efficiency.

Abstract: An inducer for a high speed centrifugal pump includes a shaft located upstream of the inlet eye of the centrifugal pump concentrically within an inlet bore; and further includes a plurality of axial blades on an inducer shaft for producing a boost pressure to the inlet of the centrifugal pump and wherein means are included to direct a spray of fuel in a direction radially of the longitudinal axis of the shaft immediately upstream of the blades to reduce the amount of fuel flow across the inducer with a resultant lowered pressure rise than would otherwise occur.

Abstract: A method and apparatus for protecting a dynamic compressor from surge. The method includes a first step for providing a simultaneous control of a smaller relief means and a main control member of a dynamic compressor or the driver thereof for changing the performance of the compressor. This combined action provides for the protection from surge and at the same time insures the invariability of the main control parameters of pressure, mass flow rate to the user, or the speed of rotation. The second step provides for controlling a larger relief means and provides for antisurge protection in those cases when the first step is not sufficient to protect the compressor from surge. Apparatus is also provided for automatically implementing the method.

Abstract: A method for starting a blower in the form of a single-stage radial fan installed in a pressure system such as the circulating cooling system of a turbogenerator in which the resistance of the pressure system is varying during the starting operation by means of a starting duct provided with a throttling element. The throttling element is closed at any desired blower speed ranging from 10 to 100% of its rated speed when the point of intersection between the pressure system characteristic, modified on the basis of the open throttling element, and the blower characteristic has been reached whereupon the desired point of operation conforming to the blower characteristic and the system characteristic will regulate itself automatically.

Abstract: A control system for preventing over-pumping of wells using submersible pumps. When the pump lowers the level of the water in the well, the control automatically diverts some or all of the water pumped back into the well to assure that sufficient water is available in the well for pumping. In this way, pump cavitation is eliminated and water is pumped from the well either at a rate equal to the capacity of the pump or, if the flow of water into the well is less than the capacity of the pump, at a rate equal to the flow of water into the well.

Abstract: A control system is disclosed for a cascade control of a dynamic compressor having a variable speed of rotation to maintain a constant pressure to a process. The method consists of a successive junction of control loops for controlling the speed of rotation, the flow rate of a compressor, the pressure in the delivery or in suction; the output signal of each outer loop being the input signal for the inner loop and each of the loops containing a compensating element to reduce the effects of large time constants of all inner loops.An automatic control system based on using the above method, distinguished by its great transient and steady state precision in maintaining a main controlled parameter, and by the high reliability of protection of the compressor from surge and from a dangerous increase of the speed of rotation.

Abstract: A centrifugal air compressor having first and second stages together with means for recirculation, at a predetermined low level of flow, air of compression from the second stage simultaneously to the inlet passage of the rotor of the first stage and to the discharge passage of the rotor of the first stage in such manner that the injected air is admitted tangentially to the inlet passage and in the direction of the prevailing flow to the discharge passage, with the result of improved flow stability through the compressor being obtained.

Abstract: A method and apparatus for sensing the velocity of a fluid flow, especially within the boundary layer of a fluid flow path through a compressor. A reference flow under constant pressure is established through an orifice dividing two plenum chambers, and directed through a flow sensing opening in a probe positioned in the flow to be sensed. The flow sensing opening is slightly larger than the orifice. A relative pressure indicator connected to the two plenum chambers indicates the velocity of the sensed fluid flow. The flow sensing opening is arranged so that the normal reference flow of fluid therethrough is in the same direction as the normally expected flow direction of the flow to be sensed.