Measuring gas pressure in a solid bowl screw centrifuge
AssigneeGEA Westfalia Separator Group GmbH
InventorsTorsten Franzke, Volker Knospe
Life of this patent
Estimating the term…
Abstract
A solid bowl screw centrifuge has a rotatable drum, a screw arranged in the drum and rotatable relative to the rotatable drum with a differential speed, one or more drum bearings for bearing the drum, a sealing assembly arranged between a drum shaft portion and the housing for protecting at least one of the drum bearings from an ingress of constituents of a suspension. Each sealing assembly includes at least two radial shaft sealing rings arranged with a mutual axial spacing so as to form at least one chamber. Respective radial shaft sealing rings are arranged such that their respective sealing lips are directed away from the respective chamber. A gas source having a gas pressure can impinge on the respective chamber.
Claims4
A method for operating a solid bowl screw centrifuge, which comprises a rotatable drum having an axis of rotation, a cylindrical portion, and a conical portion, a screw arranged in the rotatable drum and rotatable relative to the rotatable drum with a differential speed, at least one or more drum bearings configured to bear the rotatable drum in a housing, at least one sealing assembly arranged between a drum shaft portion and the housing, wherein the at least one sealing assembly is configured to protect at least one of the drum bearings against ingress of constituents of the suspension, wherein the at least one sealing assembly comprises at least two radial shaft sealing rings arranged at a mutual axial spacing to form at least one respective chamber, wherein the at least two radial shaft sealing rings are arranged such that sealing lips of the at least two radial shaft sealing rings are directed away from the at least one respective chamber, the method comprising:
- feeding a suspension into the rotatable drum;
- and
- separating the suspension, by the rotatable drum, into at least one liquid phase and at least one solid phase,
- wherein, during the separation, the method further comprises
- generating, by a gas source operatively connected to the at least one respective chamber via a bore or line, a gas pressure in the at least one respective chamber;
- increasing the gas pressure up to a gas pressure at which a radial contact of the sealing lips is overcome so that a gas leakage at the sealing lips of the at least two radial shaft sealing rings starts at a leakage pressure;
- measuring, by a pressure measuring device or pressure sensor, a current gas pressure in the at least one respective chamber;
- comparing the measured current gas pressure with at least one stored reference value;
- and
- determining or evaluating a current state of wear of the sealing lips or of the at least one sealing assembly based on the comparison of the measured current gas pressure and the at least one stored reference value,
- wherein the bore or the line comprises or forms an orifice plate.
A method for operating a solid bowl screw centrifuge, which comprises a rotatable drum having an axis of rotation, a cylindrical portion, and a conical portion, a screw arranged in the rotatable drum and rotatable relative to the rotatable drum with a differential speed, at least one or more drum bearings configured to bear the rotatable drum in a housing, at least one sealing assembly arranged between a drum shaft portion and the housing, wherein the at least one sealing assembly is configured to protect at least one of the drum bearings against ingress of constituents of the suspension, wherein the at least one sealing assembly comprises at least two radial shaft sealing rings arranged at a mutual axial spacing to form at least one respective chamber, wherein the at least two radial shaft sealing rings are arranged such that sealing lips of the at least two radial shaft sealing rings are directed away from the at least one respective chamber, the method comprising:
- feeding a suspension into the rotatable drum;
- and
- separating the suspension, by the rotatable drum, into at least one liquid phase and at least one solid phase,
- wherein, during the separation, the method further comprises
- generating, by a gas source operatively connected to the at least one respective chamber via a bore or line, a gas pressure in the at least one respective chamber through an orifice plate that limits a feed volume of gas from the gas source into the at least one respective chamber;
- setting a feed pressure of the gas upstream of the orifice plate to a gas pressure at which a radial contact of the sealing lips is overcome so that a gas leakage at the sealing lips of the at least two radial shaft sealing rings starts at a leakage pressure;
- measuring, by a pressure measuring device or pressure sensor, a current gas pressure in the at least one respective chamber;
- comparing the measured current gas pressure with at least one stored reference value;
- and
- determining or evaluating a current state of wear of the sealing lips or of the at least one sealing assembly based on the comparison of the measured current gas pressure and the at least one stored reference value,
- wherein the bore or the line comprises or forms the orifice plate.
Dependencies are inferred from the claim text.