A method for operating a pump, for conveying a fluid from a low-pressure side to a high-pressure side of the pump includes determining a current rate of change of pump vibrations and comparing the current rate of change with a limit for the rate of change or determining a current vibration of the pump and comparing the current vibration with a vibration amplitude limit for the vibration, storing the limit for the rate of change or the vibration amplitude limit in a surge controller, providing a control signal when the current rate of change reaches the limit or when the current vibration reaches the vibration amplitude limit, and changing a control variable of the pump by the control signal, such that the vibration is reduced and an unstable operating state of the pump is avoided.

There is provided an apparatus (30) and method for conditioning the flow of a mixed phase flow from a supply pipe (101) from a hydrocarbon well. The apparatus (30) comprises an elongate reservoir (11) having a first end for receiving a multi-phase fluid flow from the supply pipe and a second closed end, there being provided a gas outlet (02) from the upper part of the first end, a liquid separation region downstream of the first end, and a liquid outlet (12) from the lower part of the liquid separation region; and a gas-liquid mixer to which the gas and liquid outlets are connected such that the separated gas and liquid may be recombined. The reservoir (11) may accommodate surges of liquid such that the flow rate from the liquid outlet is relatively invariant over time compared to that of the flow received by the apparatus.

There is provided an apparatus (30) and method for conditioning the flow of a mixed phase flow from a supply pipe (101) from a hydrocarbon well. The apparatus (30) comprises an elongate reservoir (11) having a first end for receiving a multi-phase fluid flow from the supply pipe and a second closed end, there being provided a gas outlet (02) from the upper part of the first end, a liquid separation region downstream of the first end, and a liquid outlet (12) from the lower part of the liquid separation region; and a gas-liquid mixer to which the gas and liquid outlets are connected such that the separated gas and liquid may be recombined. The reservoir (11) may accommodate surges of liquid such that the flow rate from the liquid outlet is relatively invariant over time compared to that of the flow received by the apparatus.

A snow thrower impeller assembly (24) includes a mounting slot (84) for a wiper (70). The wiper includes a wiper portion (86) that slides into the mounting slot to mount the wiper to the impeller (54). The wiper contacts an interior wall (56) of an associated impeller housing during rotational operation of the impeller in order to limit a gap (74) between an impeller blade (66) and the interior wall. The wiper can move radially inward and outward to remain in contact with the interior wall without input from the operator. Another embodiment of the impeller assembly includes impeller blades with a first portion (116) and a second portion (118). The second portion extends at a non-zero angle from the first blade portion of the impeller blade.

A snow thrower impeller assembly (24) includes a mounting slot (84) for a wiper (70). The wiper includes a wiper portion (86) that slides into the mounting slot to mount the wiper to the impeller (54). The wiper contacts an interior wall (56) of an associated impeller housing during rotational operation of the impeller in order to limit a gap (74) between an impeller blade (66) and the interior wall. The wiper can move radially inward and outward to remain in contact with the interior wall without input from the operator. Another embodiment of the impeller assembly includes impeller blades with a first portion (116) and a second portion (118). The second portion extends at a non-zero angle from the first blade portion of the impeller blade.

A diffuser for a fluid compression device includes at least one vane mounted on a hub. The at least vane includes at least one opening (5) starting at a distance ranging between 10% and 60% of the axial length of the vane. The diffuser can be used in a fluid compression device also including a housing, at least one impeller within the housing, the impeller including at least one vane, the diffuser being arranged within the housing, upstream or downstream from said impeller.

A diffuser for a fluid compression device includes at least one vane mounted on a hub. The at least vane includes at least one opening (5) starting at a distance ranging between 10% and 60% of the axial length of the vane. The diffuser can be used in a fluid compression device also including a housing, at least one impeller within the housing, the impeller including at least one vane, the diffuser being arranged within the housing, upstream or downstream from said impeller.

The disclosure includes controlling a pressure ratio for a compressing system, comprising introducing a quantity of liquid into an input stream to create a multiphase input stream, compressing the multiphase input stream with a centrifugal compressor to create a discharge stream, measuring a parameter of the discharge stream, wherein the discharge parameter corresponds to a pressure ratio for the centrifugal compressor, when the parameter exceeds a first predetermined point, increasing a pressure ratio of the centrifugal compressor by increasing the quantity of liquid introduced, and when the parameter exceeds a second predetermined point, decreasing the pressure ratio by decreasing the quantity of liquid introduced.

The disclosure includes controlling a pressure ratio for a compressing system, comprising introducing a quantity of liquid into an input stream to create a multiphase input stream, compressing the multiphase input stream with a centrifugal compressor to create a discharge stream, measuring a parameter of the discharge stream, wherein the discharge parameter corresponds to a pressure ratio for the centrifugal compressor, when the parameter exceeds a first predetermined point, increasing a pressure ratio of the centrifugal compressor by increasing the quantity of liquid introduced, and when the parameter exceeds a second predetermined point, decreasing the pressure ratio by decreasing the quantity of liquid introduced.

A method for operating a pump, for conveying a fluid from a low-pressure side to a high-pressure side of the pump includes determining a current rate of change of pump vibrations and comparing the current rate of change with a limit for the rate of change or determining a current vibration of the pump and comparing the current vibration with a vibration amplitude limit for the vibration, storing the limit for the rate of change or the vibration amplitude limit in a surge controller, providing a control signal when the current rate of change reaches the limit or when the current vibration reaches the vibration amplitude limit, and changing a control variable of the pump by the control signal, such that the vibration is reduced and an unstable operating state of the pump is avoided.