Abstract: A centrifugal pump for conveying a fluid includes a pump housing, an impeller to convey the fluid from an inlet to an outlet, a shaft to rotate the impeller, a first sealing device to seal the shaft at a suction side, a second sealing device to seal the shaft at a discharge side, a balance drum connected to the shaft between the impeller and the second sealing device, the balance drum defining a front side facing the at least one impeller and a back side facing the second sealing device, a relief passage between the balance drum and a stationary part, a balance line connecting the back side with the suction side, a discharge opening arranged at the relief passage between the front side and the back side, and a connecting line connecting the discharge opening with the first sealing device.

Abstract: A multistage pump for conveying a fluid includes an outer pump housing, at least first and last stages arranged in the outer pump housing. Each stage includes a stage casing, an impeller, and a diffuser. A pump inlet supplies the fluid to the impeller of the first stage and, a pump outlet discharges the fluid. Each impeller is mounted to a pump shaft in a torque proof manner, and the impellers are arranged one after another on the pump shaft. The last stage includes a collector with a collector chamber to receive the fluid from the diffuser of the last stage. The first stage includes guide channels to receive the fluid from a diffusor and to guide the fluid to the impeller of the next stage. The collector chamber is displaced in the axial direction with respect to the diffusor of the last stage.

Abstract: An intake device for a pump includes an inlet section extending in a first direction for guiding a fluid, an outlet section for delivering the fluid to an inlet of the pump, the outlet section extending in a second direction perpendicular to the first direction, and a diverting section for diverting the fluid from the first to the second direction, the diverting section connecting the inlet and outlet sections, and having a bottom wall opposing the an outlet opening and a back wall opposing an inlet opening, the inlet section tapering towards the diverting section to decrease a cross sectional area of the inlet section, the diverting section includes a splitter member arranged on the bottom wall that tapers in the second direction towards the outlet opening, and the outlet section includes an essentially bell shaped reducing part for decreasing a cross sectional area of the outlet section.

Abstract: A flow machine includes a rotor rotatably arranged about an axis of rotation in a rotor space of a housing. For energy exchange between a flow energy of a flowing fluid and a mechanical rotational energy, the fluid can be supplied to the housing of the flow machine in so as to bring the fluid into flowing contact with the rotor for the energy exchange and can be led out of the housing of the flow machine. A flow guiding element running about the axis of rotation in a peripheral direction of the rotor is disposed in the rotor space between an inner wall of the rotor space and the rotor in such a way that the rotor is surrounded by the flow guiding element over a predeterminable axial width.

Abstract: A pump for conveying a highly viscous fluid includes a casing with at least a first inlet and an outlet for the fluid, and an impeller for conveying the fluid from the inlet to the outlet. The impeller is arranged on a rotatable shaft for rotation around an axial direction, and includes a front shroud facing the first inlet of the pump. The casing includes a stationary impeller opening for receiving the front shroud of the impeller and has a diameter. The front shroud and the stationary impeller opening form a gap having a width in a radial direction perpendicular to the axial direction, and the ratio of the width of the gap and the diameter of the impeller opening is at least 0.0045.

Abstract: An intake device for a pump includes an inlet section extending in a first direction for guiding a fluid, an outlet section for delivering the fluid to an inlet of the pump, the outlet section extending in a second direction perpendicular to the first direction, and a diverting section for diverting the fluid from the first to the second direction, the diverting section connecting the inlet and outlet sections, and having a bottom wall opposing the an outlet opening and a back wall opposing an inlet opening, the inlet section tapering towards the diverting section to decrease a cross sectional area of the inlet section, the diverting section includes a splitter member arranged on the bottom wall that tapers in the second direction towards the outlet opening, and the outlet section includes an essentially bell shaped reducing part for decreasing a cross sectional area of the outlet section.

Abstract: A pump for conveying a highly viscous fluid includes a casing with at least a first inlet and an outlet for the fluid, and an impeller for conveying the fluid from the inlet to the outlet. The impeller is arranged on a rotatable shaft for rotation around an axial direction, and includes a front shroud facing the first inlet of the pump. The casing includes a stationary impeller opening for receiving the front shroud of the impeller and has a diameter. The front shroud and the stationary impeller opening form a gap having a width in a radial direction perpendicular to the axial direction, and the ratio of the width of the gap and the diameter of the impeller opening is at least 0.0045.

Abstract: A volute shaped pump casing for a centrifugal pump includes a chamber for housing at least one impeller rotatable around an axis of rotation and a volute shaped chamber which forms a flow channel and which contains a splitter rib for dividing the flow channel formed wherein in a section perpendicular to the axis of rotation a mean camber line is positioned equidistantly between an inner and outer surface of the splitter rib, where the thickness of the splitter rib is varied along the mean camber line and for the mean camber line unwrapped to a straight line there is a maximum in the thickness, s, of the splitter rib, wherein said maximum is positioned at a distance L from the leading edge of the splitter rib, and wherein the distance L is in the range between 1.4 times the maximum thickness s and 6 times the maximum thickness s.

Abstract: An impeller for a centrifugal pump has at least one vane which has a lower side concavely curved in at least one part region and which has at least one kink line in at least one part region. The kink line extends at least substantially along a main direction of extent of the at least one vane. The vane is open in a V shape along the kink line in at least one part region in the direction of a surface normal of the lower side.

Abstract: A flow machine includes a rotor rotatably arranged about an axis of rotation in a rotor space of a housing. For energy exchange between a flow energy of a flowing fluid and a mechanical rotational energy, the fluid can be supplied to the housing of the flow machine in so as to bring the fluid into flowing contact with the rotor for the energy exchange and can be led out of the housing of the flow machine. A flow guiding element running about the axis of rotation in a peripheral direction of the rotor is disposed in the rotor space between an inner wall of the rotor space and the rotor in such a way that the rotor is surrounded by the flow guiding element over a predeterminable axial width.

Abstract: A volute shaped pump casing (1) for a centrifugal pump includes a chamber for housing at least one impeller (4) mounted on a shaft (2) for rotating the impeller around an axis of rotation (2a), a volute shaped chamber which forms a flow channel divided into a first volute (5.1) and a second volute (5.2), and a first channel (6.1) and a second channel (6.2) connected to the first and the second volute respectively. The first channel is also called long channel and the second channel is also called short channel. In the volute shaped pump casing (1), the first or long channel (6.1) is axially displaced with respect to the second or short channel (6.2) and/or with respect to the second volute (5.2).

Abstract: A volute shaped pump casing for a centrifugal pump includes a chamber for housing at least one impeller rotatable around an axis of rotation and a volute shaped chamber which forms a flow channel and which contains a splitter rib for dividing the flow channel formed wherein in a section perpendicular to the axis of rotation a mean camber line is positioned equidistantly between an inner and outer surface of the splitter rib, where the thickness of the splitter rib is varied along the mean camber line and for the mean camber line unwrapped to a straight line there is a maximum in the thickness, s, of the splitter rib, wherein said maximum is positioned at a distance L from the leading edge of the splitter rib, and wherein the distance L is in the range between 1.4 times the maximum thickness s and 6 times the maximum thickness s.

Abstract: A volute shaped pump casing (1) for a centrifugal pump includes a chamber for housing at least one impeller (4) mounted on a shaft (2) for rotating the impeller around an axis of rotation (2a), a volute shaped chamber which forms a flow channel divided into a first volute (5.1) and a second volute (5.2), and a first channel (6.1) and a second channel (6.2) connected to the first and the second volute respectively. The first channel is also called long channel and the second channel is also called short channel. In the volute shaped pump casing (1), the first or long channel (6.1) is axially displaced with respect to the second or short channel (6.2) and/or with respect to the second volute (5.2).

Abstract: An optical fiber pH sensor 100, 200, 300 is described, where a transducer mechanically couples a Bragg grating to a pH-sensitive hydrogel, said sensor comprising a central part 110, 210, 301 where are placed the optical fiber 121 containing a Bragg grating 122, the pH-sensitive hydrogel set of discs 130, and the mechanical transducer which is a spring 123 a beam 215 or still the optical fiber itself 121, the mechanical transducer assuring the strain on the Bragg grating 122. The change in hydrogel hydrodynamic volume resulting from a change of the pH of the medium introduces a force that is sufficient to cause a strain in the Bragg grating. The measure of the pH change is retrieved using the usual techniques for wavelength measurement. The pH sensor 100, 200, 300 of the invention is useful for the indirect evaluation and control of corrosion in petroleum wells and is suitable for multiplexing with other optical fiber sensors measuring the same or different parameters.

Abstract: Storable compositions and slurries for cementing oil and gas wells are described which comprise blast-furnace slag besides other additives which are usual in the cementing technique. The compositions and slurries are insufficiently activated (or are activated immediately before introducing them into the well), so that they can be stored for at least 72 hours (alternatively they may be stored indefinitely) without the setting of the composition and dispense with the addition of activation inhibitors. The use of the compositions and slurries in the cementing of oil and gas wells is also described.

Abstract: Storable compositions and slurries for cementing oil and gas wells are described which comprise blast-furnace slag besides other additives which are usual in the cementing technique. The compositions and slurries are insufficiently activated (or are activated immediately before introducing them into the well), so that they can be stored for at least 72 hours (alternatively they may be stored indefinitely) without the setting of the composition and dispense with the addition of activation inhibitors. The use of the compositions and slurries in the cementing of oil and gas wells is also described.

Abstract: Storable compositions and slurries for cementing oil and gas wells are described which comprise blast-furnace slag besides other additives which are usual in the cementing technique. The compositions and slurries are insufficiently activated (or are activated immediately before introducing them into the well), so that they can be stored for at least 72 hours (alternatively they may be stored indefinitely) without the setting of the composition and dispense with the addition of activation inhibitors. The use of the compositions and slurries in the cementing of oil and gas wells is also described.