SOLID BOWL SCREW CENTRIFUGE

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.

Claims

1-7. (canceled)

8. A solid bowl screw centrifuge for separating an inflowing suspension into at least one liquid phase and at least one solid phase, the solid bowl screw centrifuge comprising: a rotatable drum having an axis of rotation, wherein the rotatable drum has a cylindrical portion and a conical portion; at least one feed configured to receive a suspension; at least one liquid drain; at least one solid discharge; a screw arranged in the rotatable drum, wherein the screw is 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 or more screw bearings configured to bear the screw in the rotatable drum; 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 one respective chamber is configured so that a gas pressure is appliable to the at least one respective chamber by a gas source so that a current gas pressure is established in the 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, wherein the at least one respective chamber is pressurizable with the gas pressure by a control or regulating device and the gas source via a bore or line, wherein the control or regulating device is configured to vary a gas pressure in the at least one respective chamber, wherein the line has a pressure measuring device or a pressure sensor configured to measure or sense the current gas pressure in or outside the at least one respective chamber, and wherein the bore or the line comprises or forms an orifice plate.

9. The solid bowl screw centrifuge of claim 8, wherein the at least one sealing assembly comprises at least two sealing assemblies, wherein one of the at least two sealing assemblies is arranged on a first side of the at least one of the drum bearings and a second one of the at least two sealing assemblies is arranged on a second side of the at least one of the drum bearings, wherein the first side is opposite the second side, and wherein the sealing lips of the at least two radial shaft sealing rings are directed away from the at least one respective chamber in opposite directions.

10. 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.

11. The method of claim 10, further comprising: generating and outputting a message when the current state of wear exceeds a defined threshold value indicative that the at least two radial shaft sealing ring must be replaced.

12. 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.

13. The method of claim 12, further comprising: generating and outputting a message when the current state of wear exceeds a defined threshold value indicative that the at least two radial shaft sealing ring must be replaced.

Description

BRIEF DESCRIPTION OF THE DRAWING FIGURES

[0041] In the following, the invention is described in more detail with reference to the drawing by means of exemplary embodiments. The invention is not limited to these exemplary embodiments, but can also be implemented differently within the scope of the claims. In addition, individual features of the following exemplary embodiments can also be combined individually with other exemplary embodiments in each case, wherein:

[0042] FIG. 1 shows a schematic, sectional view of a solid bowl screw centrifuge;

[0043] FIG. 2 shows a section of a drum shaft bearing of a solid bowl screw centrifuge, in particular of the type shown in FIG. 1;

[0044] FIG. 3 shows a diagram illustrating the friction loss versus circumferential speed of a radial shaft sealing ring of the solid bowl screw centrifuge of FIG. 1;

[0045] FIG. 4 shows a measurement record of a first test with a radial shaft sealing ring pair on a first bearing FLT and a second bearing FS.

[0046] FIG. 5 shows a measurement record of a second test with a radial shaft sealing ring pair on a first bearing FLT and a second bearing FS.

[0047] The terms right, left, horizontal, vertical used in the following refer to the respective drawing plane.

DETAILED DESCRIPTION

[0048] FIG. 1 shows a solid bowl screw centrifuge having a frame that is not rotatable or rotating during operation and preferably a housing 100 and a rotor 200 that is rotatable or rotating during operation.

[0049] The rotor 200 has a rotatable drum 210 with an axis of rotation D that is horizontal here. However, the axis of rotation D can also be oriented differently in space, in particular vertically. The rotor 200 also includes a screw 230 arranged in the drum 210, the axis of rotation of which corresponds to that of the drum 210. In operation, the screw 230 can be rotated at a differential speed with respect to the drum 210.

[0050] The drum 210 has a portion 211 that is cylindrical here on the inside and outside, and a portion 212 that is conical here on the inside and outside that axially adjoins the cylindrical portion 211. The cylindrical portion 211 is terminated by a drum cover 213 that extends substantially radially.

[0051] Here, the screw 230 also has an at least externally cylindrical portion 231 and an at least externally conical portion 232 axially adjoining it. It is arranged inside the drum 210. The drum 201 is rotatable in operation. In addition, the screw 230 is rotatable in operation. Preferably, the two elements drum 210 and screw 230 are rotated at a differential speed with respect to each other during operation. One or more corresponding drives, e.g., electric motors, are used for rotation.

[0052] A feed pipe 214 extends into the drum 210, here concentrically to the axis of rotation, and opens into a distributor 215, through which a suspension Su to be processed can be fed radially into a centrifugal chamber 216 of the drum 210.

[0053] The feed pipe 214 may either be guided into the drum 210 from the side of the cylindrical drum portion 211, or it may be guided into the drum 210 from the side of the conical drum portion 212.

[0054] One or more liquid drains 217 may be formed in or on the drum cover 213. These can be formed in various ways, for example as openings in the drum cover 213, which have a type of overflow weir, or in other ways, for example as a peeling disc. In the area of, in particular at the end of the conical portion 212, at least one solid discharge 218 is formed.

[0055] As a rule, the drum 210 is designed as a solid bowl. In the rotating drum 210, at least the suspension is then clarified or separated into at least one liquid phase FI and a solid phase Fe. The at least one liquid phase FI exits the liquid drain 217 at the drum cover 213. The solid phase or the solids Fe are transported on the other hand by the screw 230 in the direction of the solid discharge 218, where it is ejected from the drum 210.

[0056] Axially adjoining the drum cover 213 or the actual drum 210 is a first drum shaft portion 220, which is non-rotatably connected to the drum 210. A second drum shaft portion 219 axially adjoins the conical drum portion 212 and is also connected to the drum 210 in a rotationally fixed manner. The cylindrical portion 231 of the screw 230 is axially adjoined by a first screw shaft portion 234, which is non-rotatably connected to the screw 230, and the conical drum portion 232 is axially adjoined by a second screw shaft portion 233, which is also non-rotatably connected to the screw 230.

[0057] Here, the axis of rotation D is aligned horizontally. The axis of rotation can also be aligned vertically or at an angle (not shown here). The drum and/or the screw can also be mounted on one side.

[0058] A drive device 300 with one or two motors (not shown here) is used to drive the rotor 200. At least one transmission 310 can be connected downstream of the drive device 300. Two belt pulleys 320, 330 are schematically shown here as an example, indicating that the transmission 310 can have at least two interfaces for feeding a respective torque of the electric motor or motors into the transmission 310 in order to drive the drum and the screw.

[0059] Alternatively (not shown here), the rotor can also be driven by other means, e.g., hydraulic motors, so that a transmission may not be required. The drive can also be provided by a combination of electric motor(s) and hydraulic motor(s), in which case other transmissions are used and the pulleys are completely or partially omitted.

[0060] Thus, the drive here rotates the drum 210 on the one hand and the screw 230 on the other hand. For this purpose, the transmission 310 here has two output shafts. The first output shaft is coupled in a rotationally fixed manner to the first drum shaft portion 220 or directly to the drum 210, and the second output shaft is coupled directly or indirectly in a rotationally fixed manner to the first screw shaft portion 234 or directly to the screw 230.

[0061] The drum 210 and the shaft are each rotatably supported by two drum bearings 221, 222 arranged axially in the direction of the axis of rotation. In this respect, the term bearing is not to be understood too narrowly. Each of the bearings 221, 222 may each comprise one or more individual bearings, which are then arranged axially directly adjacent to one another such that they can each be functionally regarded as a single bearing. The bearings 221, 222 can also be designed as bearings of various types, such as rolling bearingsin particular ceramic bearings, hybrid ceramic bearings, magnetic bearings or plain bearings.

[0062] The drum bearings 221, 222 are arranged between the drum 210 and the frame 100 or a part connected to the frame so that the drum 210 can be rotated relative to the frame 100. In this regard, the drum bearings 221, 222 are preferably arranged radially between the drum 210 and the frame 100 or a part connected to the frame.

[0063] In contrast, the screw bearings 235, 236 are arranged radially between the screw 230 and the drum 210 so that the screw 230 is rotatable relative to the drum 210. Here, the screw bearings 235, 236 are preferably arranged radially between the drum 210 and the screw 230.

[0064] In one possible embodiment variant (not shown), the one of the screw bearings 235 in the region of the solid discharge 218 may be omitted. In this case, the rotating screw centers itself independently, which is known, for example, in a vertical arrangement of the decanter.

[0065] Axially to the left and right of one of the bearings, in particular the drum bearingshere exemplarily next to the drum bearing 221 on the conical drum portion 212at least one sealing assemblyhere two sealing assembliesis arranged. This is intended to seal the respective bearing to which it is assigned, in particular against penetration of suspension or suspension constituents, during processing of the suspension. The bearing to be protected can be protected axially by one of the sealing assemblies or arranged between two sealing assemblies. Alternatively, it can also be protected axially on one side only by a single sealing assembly (not shown here).

[0066] The respective sealing assembly has, in each case, two radial shaft sealing rings 400a, b, and 400c, d, respectively, which are each arranged at a mutual axial distance to form a chamber 402a, b between the two radial shaft sealing rings 400a, b. Radially inwardly, the respective chamber 402a bounds the shaft 219 or a part of this shaft. Radially outwardly, it may be additionally bounded by the ring or sleeve portion 110. Here, one of the two sealing assemblies seals the drum bearing 221 axially against a collecting chamber 101 for the solid phase Fe and the other sealing assembly seals it axially towards the other side, e.g., towards the surroundings. In this respect, the respective sealing assembly 400 acts to protect the drum bearing 221, 222 against the ingress of constituents of the suspension Su from the corresponding axial side.

[0067] A radial shaft sealing ring 400 within the terms of this specification is a seal used to seal rotating elements, such as rotary shafts, particularly those rotatably supported in an annular or sleeve portion 110 of the housing 100.

[0068] To this end, the respective radial shaft sealing rings 400 include a sealing lip 401 that rests on the surface of the rotary shaft. The sealing lip 401 is designed to press radially on the shaft surface or a shaft sleeve 405, so that a sealing force is generated which acts on the shaft or the shaft sleeve 405 and thus a sealing effect is generated. A hose spring or screw spring may also be provided for this purpose. The radial shaft rings may have a reinforcing ring made of metal, for example. Outwardly, they are fixed in the ring or sleeve portion 110.

[0069] The above-mentioned bearing position is shown enlarged in FIG. 2. Axially to the left and right of the drum bearing 221, the four radial shaft sealing rings 400a, b, c, d are each arranged in pairs, thus forming two of the sealing assemblies here.

[0070] In particular, the radial shaft rings 400a, b, c, d may be fixed (radially outwardly) to a surrounding ring or sleeve portion 110, which may be an element of the frame or housing, for example.

[0071] The sealing lips 401 of one pair each of radial shaft sealing rings 400a, b and 400c, d, respectively, are here in contact with a respective shaft sleeve 405, which is fitted on the drum shaft portion 219. The shaft sleeve 405 forms in each case the running surface or counter-sealing surface of the pairs of radial shaft sealing rings 400a, b, c, d. The pairs of radial shaft sealing rings 400a, b or 400c, d are aligned in such a way that the sealing lips 401 of the respective pair face outwardly, i.e., face away from the respective chamber 402a, b.

[0072] The respective chamber 402a, b is bounded laterally by the sealing lips 401 of the two radial shaft sealing rings 400a, b and 400c, d, respectively, and radially inwardly by the drum shaft portion 219 and/or the respective shaft sleeve 405. Radially outwardly, it may further be bounded by the annular portion 110. A supply line for a gas opens into the chamber. This may be supplied from a gas source 600. The gas source may be a compressed air tank and/or a compressor.

[0073] It is advantageously provided that the respective sealing lips 401 of the radial shaft sealing rings 400a, b and 400c, d, respectively, of the respective chamber 402a, b are each directed away from the respective chamber 402a, b in opposite directions, so that the two sealing lips 401 can each be lifted radially outwardly by a gas pressure in the chamber. The sealing lips 401 describe a kind of arc transitioning from the radial direction to an axial direction, wherein they can abut the rotating element with the axial portion inside. The axial ends or portions of the two sealing lips 401 on one of the chambers 402a, b are thus directed outwardly away from each other. If they were directed inwardly toward each other, they could not be lifted by a gas pressure in the chamber 402a, b, but would actually be pressed more firmly against the rotating element as the gas pressure increased.

[0074] The gas source 600 may, for example, be provided downstream with a valve that can be controlled by the control and/or regulating device 500. The compressor 600 can also be controlled by the control and/or regulating device 500 (schematically indicated in FIG. 2 but not shown in detail).

[0075] A bore 403a, b in the ring or sleeve portion 110 opens into the respective chamber 402a, b here, to which a line 404a, b can be connected, which leads up to the gas source 600. Via the line 404a, b and here the bore 403a, b, the respective chamber 402a, b can be pressurized from the gas source 600, for example a compressed air source, with a gas pressure P.sub.zu, from which a current gas pressure P.sub.akt in the chamber 402a, b results.

[0076] It may have a pressure measuring device or a pressure sensor with which the gas pressure P.sub.akt in the respective chamber 402a, b can be measured or sensed. This may be provided, for example, in the respective line 404a, b. The gas for generating the gas pressure is provided by means of the gas source 600. This can be designed to be controllable.

[0077] As can be seen in FIG. 3, the contact pressure of the sealing lip 401 forms a parameter for the amount of friction losses. If a gas pressure P.sub.akt is now applied to the respective chamber 402a, b, the sealing lip 401 is lifted by the gas pressure P.sub.akt due to its shape and arrangement (sealing lip faces outwards). Thus, the gas pressure P.sub.akt counteracts the contact pressure of the respective sealing lip 401 and thus reduces the contact pressure of the sealing lip 401 on the shaft sleeve 405 or the drum shaft portion 219 and thus the friction losses.

[0078] In the case of a pair of radial shaft sealing rings 400a, b and 400c, d, respectively, each with an intact sealing lip 401, a certain gas pressure P.sub.akt=P.sub.max in the respective chamber 402a, b causes the sealing lip 401 to lift off the shaft sleeve 402 or the drum shaft portion 219. This then results in a corresponding gas leakage.

[0079] The gas pressure P.sub.akt can be changed with the aid of a corresponding control and/or regulating device, with which, for example, a valve downstream of the gas pressure source or a compressor (not shown here) is controlled. The gas pressure P.sub.akt can thus be increased in the respective chamber 402a, b with a new sealing lip 401 up to a gas pressure P.sub.max at which leakage begins.

[0080] As the wear of the sealing lip 401 progresses, the measured value for the gas pressure P.sub.max at which leakage starts becomes smaller and smaller and can be compared in the control and/or regulating device 500 (which is in particular a computer with interfaces and a memory) with reference values for the gas pressure P.sub.max at which leakage should start. From this, a conclusion can be drawn as to the state of wear of the respective sealing lip 401. In this procedure, pressure control and flow measurement are also required in addition to pressure measurement.

[0081] Alternatively, the gas volume/time supplied to the respective chamber 402a, b can be limited in each case by an orifice plate 406a, b at a constant feed pressure P.sub.zu>P.sub.max. In this case, a leakage gas flow results since the feed pressure P.sub.zu is greater than the leakage pressure P.sub.max so that, depending on the orifice plate opening, a relatively constant gas flow occurs which overcomes the respective sealing lip 401.

[0082] Behind the orifice plate or in the respective chamber 402a, b, a current gas pressure or leakage pressure P.sub.akt is set, which depends on the state of wear of the respective sealing lip 401. The measured value of this gas pressure in the respective chamber 402a, b can be compared with reference values in a control system and provides an indication of the state of wear of the respective sealing lip 401. A pressure regulating device and flow rate measurement are not required here.

[0083] FIG. 4 shows a measurement record of a test on a solid bowl screw centrifuge. The seal diameter in this test is 110 mm and the solid bowl screw centrifuge is operated at a speed of 6500 1/min. In this experiment with a pair of radial shaft sealing rings 400a, b and 400c, d, respectively, on a first bearing FLT, the gas pressure P.sub.akt in the chamber 402a, b between the pair of radial shaft sealing rings was lowered from 150 mbar to 8 mbar. The gas leakage thereby decreases from 980 Nl/h to 0 Nl/h, while the bearing temperature increases from 100? C. to 122? C.

[0084] FIG. 4 shows another measurement record of a further test with a pair of radial shaft sealing rings 400a, b and 400c, d, respectively, on a second bearing FS, in which the gas pressure P.sub.akt in the chamber 402a, b between the pair of radial shaft sealing rings was reduced from 145 mbar to 4 mbar. The gas leakage thereby decreased from 3000 Nl/h to 0 Nl/h while the bearing temperature increased from 58? C. to 70? C.

[0085] The relationship between increased frictional power of the respective sealing lip 401 and reduced gas pressure P.sub.akt in the chamber 402 a, b can be clearly seen here.

[0086] FIG. 5 shows a measurement record of another test on a solid bowl screw centrifuge. In this test, the seal diameter is 110 mm and the solid bowl screw centrifuge is operated at a speed of 6500 1/min. In this experiment with a pair of radial shaft sealing rings 400a, b and 400c, d respectively on the first bearing FLT, the gas pressure P.sub.akt in the chamber 402a, b between the pair of radial shaft sealing rings was increased from 50 mbar to 100 mbar. Gas leakage did not occur and the bearing temperature decreased from 122.5? ? C. to 115? C.

[0087] FIG. 5 shows another measurement record of a further test with a pair of radial shaft sealing rings 400a, b and 400c, d, respectively, on a second bearing FS, in which the gas pressure in chamber 402a, b between the pair of radial shaft sealing rings was increased from 50 mbar to 100 mbar. The gas leakage thereby increased from 980 Nl/h to 1700 Nl/h while the bearing temperature decreased from 69? C. to 61? C.

[0088] The relationship between the reduced frictional power of the respective sealing lip 401 at increased gas pressure P.sub.akt in the chamber 402 a, b can also be seen clearly here.

[0089] Thus, for the operation of a solid bowl screw centrifuge in which an inflowing suspension Su is separated in the rotating drum 210 into a solid phase Fe and at least one liquid phase FI, the following method is preferably given:

[0090] The gas pressure P.sub.akt in the respective chamber 401a, b of the respective sealing assembly with two radial shaft sealing rings 400a, b, c, d can be adjusted by the control and/or regulating device and by one or more components controllable by this control and/or regulating device, in particular valves and/or a compressor or the like as pressure source.

[0091] In this way, the respective chamber is thus subjected to a gas pressure P.sub.zu, which results in a gas pressure P.sub.akt in the chamber.

[0092] The gas pressure P.sub.akt can be increased by the control and/or regulating device up to a gas pressure P.sub.max at which gas leakage starts at a new sealing lip 401 of the respective radial shaft sealing ring 400a, b, c, d as it lifts off the shaft.

[0093] In this way, the wear at the sealing lip or lips of the respective radial shaft sealing rings 400a, b, c, d can be reduced.

[0094] In practice, for example, the feed pressure P.sub.zu and the orifice plate cross-section of the orifice plate can be selected so that a defined flow rate, for example a flow rate or flow of several hundred Nl/h to several thousand Nl/h, for example about 400 Nl/h (Nl/h: standard volume flow/h) per pair of radial shaft sealing rings (i.e., per chamber) is achieved. In the measurement report of FIG. 4, an example with 3000 Nl/h (with pressure regulation) is included. The amount of the leakage pressure P.sub.max corresponding to the defined flow rate of a new sealing assembly 400 can be stored as a reference valuee.g., in the control and/or regulating device 500.

[0095] The current leakage pressure P.sub.akt in or at the respective chamber can then be measured with a measuring device (not shown). This can be carried out continuously or at defined time intervals.

[0096] The currently measured leakage pressure P.sub.akt is then compared with the stored reference value(s). This can also be carried out continuously or at defined time intervals.

[0097] Thereupon, the current state of wear of the respective sealing assembly 400 can optionally be evaluated. This can be carried out in a simple manner, for example, by means of at least one value table stored in the control and/or regulating unit 500, in which corresponding value pairs of the respective leakage pressure P.sub.akt and the associated degree of wear are stored.

[0098] A message is generated if the current state of wear exceeds a defined threshold value, so that the respective radial shaft sealing ring 400a, b, c, d must be replaced.

[0099] This variant thus provides in a simple manner a measurability of the current degree of wear of the sealing lip 401, as well as an estimability or predictability of a total failure of a radial shaft sealing ring 400a, b, c, d, so that a predictive maintenance of the radial shaft sealing rings 400a, b, c, d is possible.

[0100] Although the invention has been illustrated and described in detail by way of preferred embodiments, the invention is not limited by the examples disclosed, and other variations can be derived from these by the person skilled in the art without leaving the scope of the invention. It is therefore clear that there is a plurality of possible variations. It is also clear that embodiments stated by way of example are only really examples that are not to be seen as limiting the scope, application possibilities or configuration of the invention in any way. In fact, the preceding description and the description of the figures enable the person skilled in the art to implement the exemplary embodiments in concrete manner, wherein, with the knowledge of the disclosed inventive concept, the person skilled in the art is able to undertake various changes, for example, with regard to the functioning or arrangement of individual elements stated in an exemplary embodiment without leaving the scope of the invention, which is defined by the claims and their legal equivalents, such as further explanations in the description.

LIST OF REFERENCE SIGNS

[0101] 100 Housing [0102] 101 Collecting chamber [0103] 110 Ring or sleeve portion [0104] 200 Rotor [0105] 210 Drum [0106] 211 Cylindrical portion [0107] 212 Conical portion [0108] 213 Drum cover [0109] 214 Feed pipe [0110] 215 Distributor [0111] 216 Centrifugal chamber [0112] 217 Liquid drain [0113] 218 Solid discharge [0114] 219 Drum shaft portion [0115] 220 Drum shaft portion [0116] 221 Drum bearing [0117] 222 Drum bearing [0118] 230 Screw [0119] 231 Cylindrical portion [0120] 232 Conical portion [0121] 233 Screw shaft portion [0122] 234 Screw shaft portion [0123] 235 Screw bearing [0124] 236 Screw bearing [0125] 300 Drive device [0126] 310 Transmission [0127] 320 Belt pulley [0128] 330 Belt pulley [0129] 400 Sealing assembly [0130] 400a, b, c, d Radial shaft sealing ring [0131] 401 Seal lip [0132] 402a, b Chamber [0133] 403a, b Bore [0134] 404a, b Line [0135] 405 Shaft sleeve [0136] 406a, b Orifice plate [0137] 500 Control and/or regulating device [0138] 600 Gas source [0139] D Axis of rotation [0140] Su Suspension [0141] Fe Solids [0142] FI Liquid phase [0143] P.sub.zu Feed pressure [0144] P.sub.max Maximum pressure [0145] P.sub.akt Current gas pressure, leakage pressure