Abstract: A displacement pump arrangement, method for operating the displacement pump arrangement and a control device for controlling the displacement pump arrangement provide rotational-speed-variable control of an expeller pump unit for feeding a fluid. The arrangement includes an expeller pump and a drive, the drive being composed of an electric drive motor and a frequency converter, and a control device. The control device controls a state value such as a final pressure of the expeller pump a setpoint value. The control device detects state values of a control variable are supplied by the drive, in particular relating to the position, rotational speed and torque of the drive motor, and adjusts the displacement pump output to reach the setpoint value without using sensors.

Abstract: A magnetic material is provided, the magnetic material including a powder composite material sintered from at least one magnetizable alloy powder of a high energy density, and fibers admixed with the powder composite. The fibers may be aligned in one direction to improve at least one of high-melting, high-modulus and high-strength material properties.

Abstract: A device and a method for monitoring rotating components in centrifugal pumps or systems which comprise centrifugal pumps is provided. The device includes a first unit which is located on or in the component to be monitored having at least one component property sensor, a sensor signal evaluation unit, a transmitting unit for transmitting analysis results to a receiver arranged spatially separate from the monitored component, and a source for supplying power. The device further includes a second unit having a receiver unit, a transmitted signal evaluation unit, and a sensed component property display and/or information communication element. The analysis result transmission from the first unit to the second unit is acoustic.

Abstract: A slide ring seal for high circumferential velocities for sealing liquids with little or no electrical conductivity, such as low-salt feed water for feed water pumps including a pair of slide rings, one of which is rotationally fixed and the other of which rotates with a rotating component. The slide rings have interacting sliding surfaces which form a region loaded with the liquid to be sealed relative to a sealing gap. One ring is formed of material with satisfactory electrical conductivity and the other of low conductivity material. The seal is arranged in a dead-end circuit of a rotating component to be sealed and is connected to a cooling system. A metering device is provided in the circuit for introducing a substance as a function of a slide ring seal leak to maintain the electrical conductivity of the liquid between 3 and 500 ?S/cm.

Abstract: A method for delivering a fluid using a centrifugal pump (11). Machines (1, 6) and/or apparatus (3, 8), which influence the pressure and/or the temperature of the fluid, are disposed upstream of the centrifugal pump (11). At the inlet to the centrifugal pump (11), the fluid is regulated to achieve a specific entry state. According to the invention, the entry state of the fluid is regulated by using the machines (1, 6) or apparatus (3, 8) such that, in the centrifugal pump (11), the fluid only takes on states in which the compressibility factor of the fluid has already reached or exceeded the minimum thereof.

Abstract: A centrifugal pump including a rotor and a housing surrounding the rotor, the housing having a connection on the pressure side and another on the intake side, respectively. The housing surrounding the rotor is constructed as a composite part in which a first thin-walled layer (5) defines the inner configuration of the housing, and at least one second layer (11) provides structural stability to the housing.

Abstract: A rotor mounting on one end of a shaft, particularly a shaft end of a centrifugal pump unit, in which an adjusting surface and at least one contact surface are constructed on the shaft end, and in which a rotor hub is provided at least on the end facing the shaft with a central bore having an internal thread. The rotor hub is attached to the shaft end by a screw connection. The shaft has a central bore (16) having an internal thread (17) at least on the end facing the rotor hub (12); a threaded pin (18) constructed as a separate component is disposed in both central bores (13, 16) in a connecting, torque-transmitting and force-transmitting manner, and the rotor is aligned on the shaft solely by the adjusting surfaces (20) and contact surfaces (21).

Abstract: A disinfecting device having an outlet (2, 42) for a flowing liquid, particularly water, and a UV irradiator (6), preferably a UV-C radiator (16) or one or more UV-C emitting light emitting diodes, and an electric power supply (7), such as a battery, turbine driven generator or a solar module, for supplying the UV irradiator with up to 25 V alternating voltage or up to 60 V direct voltage. The outlet may be constructed with a reflective interior, and a controller for regulating liquid temperature, liquid pressure and/or liquid flow rate and/or an aerator (14) for introducing air into the flowing liquid may be integrated into the device, which may be a plumbing fixture such as a water spigot.

Abstract: A pitot tube pump having a hydraulic chamber, a fluid supply line, a fluid discharge line, and a drive, in which the supply line, the discharge line and the drive are all arranged on the same side of the hydraulic chamber. A pitot tube preferably is mounted in the hydraulic chamber on a shoulder of a fixed shaft in communication with the discharge line. The drive is preferably an electric motor with a stator which is connected in a rotationally secure manner to the fixed shaft, and a rotor which forms a part of the hydraulic chamber or which is connected in a rotationally secure manner to the hydraulic chamber.

Abstract: A method and an apparatus for producing biogas from organic matter including a container (1) which is charged with fermentation substrate by a delivery system (13). At least one stirring mechanism (2) is arranged in the container. The feedback value of at least one measurable variable is detected and transmitted to a control unit (4). A reference variable is also provided to the control unit. The control unit calculates the deviation of the feedback value from the reference value, and actuating variables which modify the power input of the stirring mechanism and/or the composition of the container contents and/or the flow behavior of the container contents are adjusted as a function of the deviation.

Abstract: A stirrer stand (10) for a submersible motor stirrer (12) composed of at least one base part (14) and a receiving part (16) for the submersible motor stirrer beyond which a guide member extends, which is used for guiding the submersible motor during assembly, the entire stirrer stand being produced from a single vibration-damping material.

Abstract: A rotor (11) with a squirrel cage and permanent magnets (19) mounted on and distributed around the circumference of the rotor, including a core stack extending over the entire rotor region with longitudinally continuous rotor slots extending over the length of the core stack. The squirrel cage is constructed with cage bars disposed, and preferably cast, in the rotor slots; short circuit rings connect the cage bars at both end faces of the core; and the radius of the rotor region is reduced by at least the radial thickness of the magnets. The radius of rotor (11) is reduced over the entire length between short circuit rings (17) such that the radial height of cage bars (15, 29) or cage webs (27) connected thereto is reduced. Also an electric motor or a radial pump having such a rotor, and methods of producing or operating such devices.

Abstract: A guiding device for submersible motor agitators having a guiding tube and a sliding carriage for carrying a submersible motor agitator. The guiding tube is held in a pivotable lower mount and in an upper mount composed of a bracket and an adjusting lug, and the angular position of the guiding tube can be adjusted via the adjusting lug. The sliding carriage, the adjustment lug and any optional connecting lug are dimensioned in such a way that the sliding carriage carrying the submersible motor agitator can be removed from the guiding tube without disassembling the guiding device.

Abstract: A slide ring seal for high circumferential velocities for sealing liquids with little or no electrical conductivity, such as low-salt feed water for feed water pumps including a pair of slide rings, one of which is rotationally fixed and the other of which rotates with a rotating component. The slide rings have interacting sliding surfaces which form a region loaded with the liquid to be sealed relative to a sealing gap. One ring is formed of material with satisfactory electrical conductivity and the other of low conductivity material. The seal is arranged in a dead-end circuit of a rotating component to be sealed and is connected to a cooling system. A metering device is provided in the circuit for introducing a substance as a function of a slide ring seal leak to maintain the electrical conductivity of the liquid between 3 and 500 ?S/cm.

Abstract: A boxless casting form which is separated horizontally and which is composed of a lower casting body (1)and an upper casting body (2). The casting bodies (1, 2) are formed of dry sand and define a casting cavity (9). Openings (3, 4) are introduced into the casting bodies (1, 2), and these openings (3, 4) are used to align the casting bodies horizontally and form a vertical guide passage for a rod-like guide element (5).

Abstract: An axially operating stirring element, preferably a propeller manufactured from sheet metal, having propeller blades arranged radially around an axis (A) and in which at least one propeller blade has a sharpened edge on the discharge or trailing edge side.

Abstract: A method for delivering a fluid using a centrifugal pump (11). Machines (1, 6) and/or apparatus (3, 8), which influence the pressure and/or the temperature of the fluid, are disposed upstream of the centrifugal pump (11). At the inlet to the centrifugal pump (11), the fluid is regulated to achieve a specific entry state. According to the invention, the entry state of the fluid is regulated by using the machines (1, 6) or apparatus (3, 8) such that, in the centrifugal pump (11), the fluid only takes on states in which the compressibility factor of the fluid has already reached or exceeded the minimum thereof.

Abstract: Method and apparatus for determining an operating point of a work machine and/or asynchronous motor driving the same, the operating point being characterized by the power consumed by and/or output rate of the machine, in which one or more operating point-dependent measurement variables of the machine are detected by sensors, and the measured values are evaluated and/or stored during operation of the machine. The operating point is determined without using electric measurement variables of the motor by determining a frequency linearly proportional to the fundamental tone of the machine through signal analysis, especially frequency analysis of a measured mechanical variable selected from pressure, differential pressure, power, vibration, and solid-borne or air-borne sound.

Abstract: A pitot tube pump having a hydraulic chamber, a fluid supply line, a fluid discharge line, and a drive, in which the supply line, the discharge line and the drive are all arranged on the same side of the hydraulic chamber. A pitot tube preferably is mounted in the hydraulic chamber on a shoulder of a fixed shaft in communication with the discharge line. The drive is preferably an electric motor with a stator which is connected in a rotationally secure manner to the fixed shaft, and a rotor which forms a part of the hydraulic chamber or which is connected in a rotationally secure manner to the hydraulic chamber.

Abstract: A centrifugal pump for delivering hot fluids, having a contacting shaft seal, a seal housing (13) for the shaft seal (14), and a return line (8) for a partial flow of the delivered fluid, in which no delivered fluid is discharged out of the seal housing (13); a separate housing cover (9) is disposed between the seal housing (13) and the pump housing (1); there is a contact surface which minimizes heat transfer between the seal housing (13) and the housing cover (9);, and the return line (8) is connected to the housing cover (9) and/or to the pump housing (1).