초록 ▼

The operation of a centrifugal pump which pumps a liquid or suspension (e.g. 8-12 percent consistency) containing gas is controlled to minimize pump power consumption, or to vary the pump flow rate. The suspension is rotated within the pump so that a gas bubble is created at a central part of the pu

The operation of a centrifugal pump which pumps a liquid or suspension (e.g. 8-12 percent consistency) containing gas is controlled to minimize pump power consumption, or to vary the pump flow rate. The suspension is rotated within the pump so that a gas bubble is created at a central part of the pump, and gas is discharged from the gas bubble, at a gas discharge pressure. The differential pressure between the suspension inlet and the gas discharge is determined, and the head and/or discharge flow rate of the pump are controlled by controlling the differential pressure so determined. The discharge flow rate may be maintained constant utilizing a control valve and flow meter in the pump discharge line, in which case controlling the discharge of gas from the gas bubble controls the head, and minimizes power consumption for a given flow rate. Alternatively the flow rate is controlled by controlling the gas discharge, with no control valve in the pump discharge line being provided.

대표청구항 ▼

A method for controlling the operation of a centrifugal pump pumping a suspension having a consistency of about 8-12 percent and containing gas, the pump having an inlet suspension pressure, a pressure head, and a suspension discharge flow rate, comprising the steps of: (a) effecting rotation of the

A method for controlling the operation of a centrifugal pump pumping a suspension having a consistency of about 8-12 percent and containing gas, the pump having an inlet suspension pressure, a pressure head, and a suspension discharge flow rate, comprising the steps of: (a) effecting rotation of the suspension within the pump so that a gas bubble is created in a central part of the pump; (b) discharging gas from the gas bubble in the pump central part, at a gas discharge pressure; (c) rotating the pump impeller at a speed sufficient to effect fluidization of the suspension, and effecting discharge of the fluidized suspension at a flow rate; (d) determining the differential pressure between the suspension inlet pressure and the gas discharge pressure; and (e) controlling the head and/or discharge flow rate of the pump by controlling the differential pressure determined in step (d). A method for controlling the operation of a centrifugal pump pumping a liquid or suspension containing gas, the pump having an inlet liquid or suspension pressure, a pressure head, and a liquid or suspension discharge flow rate, comprising the steps of: (a) effecting rotation of the liquid or suspension within the pump so that a gas bubble is created in a central part of the pump; (b) discharging gas from the gas bubble in the pump central part, at a gas discharge pressure, to an air vessel; (c) determining the differential pressure between the liquid or suspension inlet pressure and the gas discharge pressure, the gas discharge pressure measured in the air vessel; (d) controlling the head and/or discharge flow rate of the pump by controlling the differential pressure determined in step (c); and (e) at pump start up, or when a rapid differential pressure change is desired, feeding air at a controlled pressure and flow rate－from a source independent of the pump gas discharge－to the air vessel.