SOLID BOWEL SCREW CENTRIFUGE

Description

[0001] The invention relates to a solid bowl screw centrifuge according to the preamble of claim 1.

[0002] A solid-bowl screw centrifuge (also called a decanter) can be used to separate a solid phase from a suspension. Optionally, the suspension, once cleared of solids, can be separated into different liquid phases in a design with two liquid outlets. Solid-bowl screw centrifuges are ideally suited for processing relatively high solid concentrations in the feed stream, are relatively robust, achieve excellent separation results, and ensure effective drying of the solids.

[0003] Known solid-bowl screw centrifuges with a frame that is non-rotatable or non-rotating during operation have a rotatable or rotating rotor, which in turn has a bowl and a screw that rotates at a speed different from that of the bowl. For the discharge of the solids, essentially radially aligned solids discharge openings are provided in a conical section of the bowl.

[0004] If the energy loss caused by the discharge of solids from the bowl of the solid bowl screw centrifuge is to be as small as possible, the radius on which the solids discharge openings are located in the drying zone or in the conical section of the bowl must be as small as possible.

[0005] If a solid-bowl screw centrifuge is to be operated in such a way that the so-called pond depth – this results from the difference between the inner diameter of the bowl and the diameter of the liquid weir to which the suspension extends inside the bowl – is as large as possible, this requires the solids to be discharged as close to the axis of rotation as possible. For this purpose, the radius at which the solids discharge openings are located in the drying zone or in the conical section of the bowl must be as small as possible. KR 101 422 567 B1 is cited for the technological background. EP 0 490 270 A2, JP 2005 254 190 A, EP 2 422 882 A1, and DE 31 47 404 A1 are also cited for the technological background.

[0006] In conventional state-of-the-art solid bowl screw centrifuges - as shown, for example, in DE 10 2018119 279 A1 - the outlet opening for the solids is usually located essentially radially aligned in the outer shell of the bowl at the end of the drying zone or the conical section of the bowl.

[0007] One reason for this is that the distance between the drum bearings determines the critical speed of the rotating system, thus limiting the drum length. To utilize the full length between the bearings for the separation and drying zone of the drum, the solids are typically ejected radially through the conical drum wall.

[0008] WO 2018 / 202358 A1 discloses screw-in solids discharge sleeves, whereby both the pond depth and the discharge diameter can be changed by the screw-in depth of the discharge sleeves.

[0009] A disadvantage of the technical teaching of WO 2018 / 202358 A1 is that it is not possible to set a discharge diameter smaller than the smallest diameter of the conical section of the drum. Similar problems occur in the generic WO 03 / 031073 A1.

[0010] The aim of the invention is to reduce these problems.

[0011] The invention solves this problem by the subject matter of claim 1.

[0012] According to the invention, the drum is designed in the region of the conical section or the drying zone in such a way that solid Fe is transported by means of the screw to a solid discharge drum cover, which forms the end of the conical section in the axial direction of the drum, in order to leave the drum through several axially or substantially axially aligned openings in the solid discharge drum cover, wherein a cover element, in particular a cover plate, with openings is attached to the solid discharge drum cover having the solid discharge, in particular to its conical section, which openings correspond to the openings of the solid discharge drum cover, in particular of the conical section.

[0013] In this way, the discharge diameter of the solids discharge can advantageously be designed smaller than the smallest inner diameter of the conical section of the bowl. In this way, the effective openings for the solids discharge are located in the solids discharge bowl cover within, preferably completely within, the smallest inner diameter of the conical section of the bowl. In this way, the energy loss caused by the discharge of solids from the bowl of the solid-bowl screw centrifuge can be kept very low. Furthermore, a solid-bowl screw centrifuge according to the invention can advantageously be operated with the greatest possible pond depth.

[0014] The axially or substantially axially extending openings in the conical section of the solids discharge drum cover for solids discharge are oriented at a greater angle than the cone angle of the inner conical region of the drum and / or the outer conical region of the screw. Preferably, the angle is even 90° to the axis of rotation or more than 45°, in particular more than 60°, to the axis of rotation of the drum. It can preferably be provided that the one or more openings for solids discharge are formed in the conical section of the solids discharge drum cover, wherein it can then further preferably be provided that the conical section of the solids discharge drum cover has a cone angle of more than 45°, in particular more than 60°, to the axis of rotation.

[0015] It can further be provided that in the conical section of the solids discharge drum cover the openings are arranged on a pitch circle with a diameter d1 which is smaller than the smallest diameter of the inner conical section of the drum.

[0016] According to the invention, the openings in the solids discharge drum lid are preferably each partially covered by a replaceable cover element, in particular a replaceable cover plate, in which aperture-like openings can be formed. Using multiple cover elements, in particular cover plates with differently positioned and / or dimensioned openings, a simple and thus advantageous adjustment option for the solids discharge openings is created. In this way, the openings of the respective cover element, in particular cover plate, define the "effective" openings through which the solids can leave the drum at the drum lid.

[0017] According to one embodiment, the aperture-like openings can be arranged circularly on a partial circle with a diameter d1 and have an opening diameter d2.

[0018] It can then advantageously be provided that both the diameter d1 and the diameter d2 can be changed by exchanging the respective cover plate. For this purpose, cover plates with different opening arrangements must be provided. In this way, the solids outlet can be easily adjusted over a wide range and thus individually and easily adapted to the specific conditions of the respective application of the solid bowl screw centrifuge. The cover plate can advantageously be arranged on the outside of the bowl cover, where it is easily exchangeable. However, it can also be arranged internally.

[0019] According to another embodiment of the invention, it can be provided that a sleeve or disc is rotatably mounted in each of the openings of the solids discharge drum cover. It can also advantageously be provided that each sleeve or disc has an opening, which is preferably formed eccentrically in the sleeve / disc. This creates a simple and therefore advantageous adjustment option for the solids discharge. It is also advantageous if and that the diameter on which the respective opening is located can be changed by rotating the respective sleeve / disc around its center point, which lies on a diameter d3. In this way, the radius on which the center point of the opening of the solids outlet lies can be easily changed over a wide range and can thus be individually and easily adapted to the specific conditions of the respective application of the solid bowl screw centrifuge.

[0020] In a preferred embodiment of the invention, the solids discharge drum cover has a cylindrical section, which, according to an additional refinement, can be attached to a drum shaft section. This results in an advantageously simple attachment of the solids discharge drum cover to the drum, which also allows the solids discharge drum cover to be retrofitted to state-of-the-art solid-bowl screw centrifuges without major modifications.

[0021] According to a variant, it can further advantageously be provided that a screw shaft section or a pin that can be coupled to such a screw shaft section is formed in the conical section of the solids discharge drum cover. In particular, the integrated screw shaft section of the solids discharge drum cover results in advantageously simple assembly of the screw shaft bearing, which also allows the solids discharge drum cover to be retrofitted to state-of-the-art solid bowl screw centrifuges without major modifications. If the screw shaft section is integrally formed on the conical section of the solids discharge drum cover, the result is a solids discharge drum cover that is advantageously easy to manufacture, for example by forging or casting, and that can be completely machined in a single setup.

[0022] According to an optional development, the cylindrical section of the drum has a length L 1 and the conical section of the drum has a length L 2, where L 1 and L 2 added together is the length LT of the drum and the drum bearings for supporting the drum in the housing are spaced apart by a distance LL, where the distance LL between the drum bearings is smaller than the length LT of the drum. Due to this advantageous arrangement of the drum bearings, the critical speed of the drum can be in a higher speed range than in state-of-the-art solid bowl screw centrifuges. This advantageously increases the separation performance of the solid bowl screw centrifuge without having to increase the volume of the drum.

[0023] Further advantageous embodiments of the invention can be found in the subclaims.

[0024] The invention is described in more detail below with reference to the drawings using exemplary embodiments. Features described in connection with these exemplary embodiments can also be used in other—not shown—embodiments of the invention and are therefore also usable as features in claims. They show: Figure 1: a schematic view in section of a solid bowl screw centrifuge according to the invention; Figure 2: in a) view of the solids discharge drum cover of a first embodiment of the drum of the solid bowl screw centrifuge from Fig. 1 , in b) a sectional view of the enlarged detail of the solids discharge drum cover according to Fig. 2a and the conical section of the bowl; Figure 3: in a) View of a solids discharge bowl cover of another design variant of the bowl of the solid bowl screw centrifuge from Fig. 1 , in b) a sectional view of the enlarged detail of the solids discharge drum cover according to Fig. 3a and the conical section of the drum; Figure 4: a schematic sectional view of a prior art solid bowl screw centrifuge;

[0025] First, the construction of the Fig. 4 described in Fig. 1 is further developed according to the invention.

[0026] Fig. 4 shows a solid bowl screw centrifuge with a frame 100 which is non-rotatable or non-rotating during operation - which can preferably be designed as a type of housing - and a rotor 200 which is rotatable or rotating during operation.

[0027] The rotor 200 has a rotatable drum 210 with a horizontal axis of rotation D. 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 coincides with the axis of rotation of the drum 210.

[0028] The drum 210 has a cylindrical section 211 with a length L 1 and an axially adjoining conical section 212 with a length L 2 . The cylindrical section 211 is closed here by a substantially radially extending drum cover 213. In the conical section 212 with the length L 2 , the drum is preferably conical on the inside and outside (relative to the drum shell).

[0029] The screw 230 also has a cylindrical section 231 and an axially adjoining conical section 232. It is arranged within the drum 210. During operation, the screw 230 can be rotated at a speed different from that of the drum 210.

[0030] An inlet pipe 214 extends into the drum 210, running concentrically to the rotational axis here, and opens into a distributor 215 through which a suspension Su to be processed can be guided radially into a centrifugal chamber 216 of the drum 210. The inlet pipe 214 can either be guided into the drum 210 from the side of the cylindrical drum section 211 or it can be guided into the drum 210 from the side of the conical drum section 212.

[0031] One or more liquid outlets 217 may be formed in or on the drum cover 213. These can be configured in various ways, such as openings in the drum cover 213 that have a type of overflow weir, or in another way, such as a paring disc.

[0032] At least one solids discharge 218 is formed at the end of the conical section 212.

[0033] The drum 210 is designed as a solid-shell drum. In the rotating drum 210, at least one liquid phase Fl is clarified from solids Fe.

[0034] The at least one liquid phase FI exits the liquid outlet 217 at the drum cover 213. The solids Fe, however, are transported by the screw 230 toward the solids discharge 218 and ejected from the drum 210 there.

[0035] A first drum shaft section 220, which is connected in a rotationally fixed manner to the drum 210, can be axially connected to the drum cover 213 or to the actual drum 210, and a second drum shaft section 219, which is also connected in a rotationally fixed manner to the drum 210, can be axially connected to the conical drum section 212.

[0036] A first worm shaft section 234, which can be connected to the worm 230 in a rotationally fixed manner, is axially connected to the cylindrical section 231 of the worm 230. The conical section 232 is mounted on a bearing 235. This bearing 235 can be mounted on a second worm shaft section 233.

[0037] A drive device, which may have one or two motors, is used to drive the rotor 200. At least one gear 310 can be connected downstream of the drive device 300. Two pulleys 320, 330 are schematically shown here, indicating that the gear 310 can have at least two interfaces for feeding a respective torque from the motor or motors into the gear 310 to drive the drum and the screw. Alternatively (not shown here), the rotor can also be driven in another way.

[0038] The gear 310 rotates Fig. 4 (and preferably also according to the variants of the invention) on the one hand, the drum 210 and on the other hand, the worm 230. For this purpose, the transmission 300 can have two output shafts. The first output shaft can be non-rotatably coupled to the first drum shaft section 220 or directly coupled to the drum 210. The second output shaft, on the other hand, can be directly or indirectly non-rotatably coupled to the first worm shaft section 234 or directly to the worm 230.

[0039] The drum 210 can be rotatably mounted by two drum bearings 221, 222 arranged axially offset in the direction of the rotation axis. The term "bearing" should not be defined too narrowly in this respect. Each of the bearings 221, 222 can consist of one or more individual bearings, which are then arranged axially directly adjacent to one another, so that they can each be considered functionally as a single bearing.

[0040] The drum bearings 221, 222 can advantageously be arranged between the drum 210 and the frame 100 or one or more elements connected to the frame, so that the drum 210 can be rotated relative to the frame 100. This also applies to all other variants shown. The drum bearings 221, 222 are preferably arranged radially between the drum 210 and the frame 100 or one or more elements connected to the frame.

[0041] The screw bearings 235, 236, however, can be arranged radially between the screw 230 and the drum 210, so that the screw 230 can be rotatable relative to the drum 210.

[0042] In a possible design variant (not shown), one of the screw bearings 235 in the area of ​​the solids discharge 218 can be omitted. This can be provided, for example, with a vertical arrangement of the decanter.

[0043] Preferably, after Fig. 4 - as well as after Fig. 1 and further variants of the invention - one or even both drum bearings 221, 222 can be arranged within the axial region that lies between the solids discharge 218 and the liquid outlet 217 of the drum 210 or directly adjacent to a region of the liquid outlet 217 and / or a solids discharge 218 of the drum 210. The drum bearings 221, 222 are then positioned radially outward on the drum 210 or radially or axially outward on or on the drum cover 213.

[0044] If one of the drum bearings 221, 222 is arranged within the axial region lying between the solids discharge 218 and the liquid discharge 217 of the drum 210, the other of these bearings - the other of the drum bearings 221, 222 - can be arranged outside this axial region.

[0045] It can be provided that the drum bearings 221, 222 for supporting the drum (210) in the housing (100) are spaced apart by a distance LL, wherein the distance LL of the drum bearings 210 from one another is smaller than the axial length LT of the drum.

[0046] In a preferred embodiment, the above features can also be used for the solid bowl screw centrifuge of the Fig. 1 and other figures, as well as further variants of the invention. However, the solids discharge and preferably also the storage can be designed differently.

[0047] The solids discharge 218 can be arranged in the solid bowl screw centrifuge according to the state of the art in Fig. 4 be designed such that the openings of the solids discharge 218 are aligned radially or substantially in the radial direction of the drum 210.

[0048] The solids discharge 218 of the solid bowl screw centrifuge is Fig. 1 and 2 and 3, are preferably designed such that the openings 224 of the solids discharge 218 are aligned axially or substantially in the axial direction of the drum 210. They are also preferably located within the smallest diameter of the conical region 212 of the drum, relative to the inner shell or inner diameter.

[0049] The conical section of the solids discharge drum cover can thus either extend at a right angle to the rotation axis or be arranged at an angle of more than 45°, in particular more than 65°. The openings can also be located in another conical drum section whose conicity angle to the rotation axis is greater than 45°, in particular more than 65°.

[0050] During operation, solids in the rotating drum are first conveyed from a suspension rotating radially outside in the drum from the cylindrical region into the conical region 212 of the drum 210 and from there further conveyed or pushed radially inwards to the solids discharge 218.

[0051] For this purpose, a solids discharge drum cover 223 adjoins the conical section of the drum 210 in the axial direction, axially closing off the conical section 212 of the drum 210. The solids discharge drum cover 223 can be conical in its entirety or in sections. The conicity angle of the conical section 226 is greater, in particular more than 10° greater, than the conicity angle in the conical section of the drum. The solids discharge 218 can be designed such that the openings 224 of the solids discharge 218 are aligned axially or substantially in the axial direction of the drum 210.

[0052] The solids discharge drum cover 223 may have one or more, for example four, openings 224 that form the solids discharge. These openings may be formed as window-like, circumferentially closed openings in the conical section of the solids discharge drum cover 223.

[0053] According to a variant that is structurally simple to implement, it can advantageously be provided that the solids discharge 218 is located in the conical section 212 of the drum 210 behind the drum bearing 221 in the axial direction relative to the cylindrical section 211 of the drum 210. It can also advantageously be provided that the solids discharge 218 is located behind the screw bearing 235 in the axial direction relative to the cylindrical section 211 of the drum 210.

[0054] In Fig. 2a and Fig. 2b a variant embodiment of the solids discharge 218 is shown, which has openings 224 which are aligned in the axial or substantially axial direction.

[0055] A cover plate 225 is attached to the solids discharge drum cover 223, either inside or preferably outside. The cover plate 225 can be replaceable, in particular, attached to the rest of the drum 210, in particular to the solids discharge drum cover 223. The cover plate 225 can be replaceably attached to the solids discharge drum cover 223 using fastening means such as screws. The cover plate 225 can be conical in shape.

[0056] The solids discharge drum cover 223 has openings 224 with an area F1. Corresponding openings 229 are formed in the cover plate 225. This means that the openings completely or at least partially overlap and are aligned with each other. These openings 229 can have an area smaller than the area F2. The cover plate 225 configured in this way acts like a diaphragm.

[0057] Thus, the size and / or location of the solids discharge 218 or the size and / or location of its openings 229 - when the drum is at a standstill - can be easily changed by exchanging the cover plate 225 with the openings 229 for a cover plate with openings 229 of a different area and / or arrangement.

[0058] The aperture-like openings 229 are arranged on a pitch circle with a diameter d1 and have an opening diameter d2. Depending on requirements, both the diameter d1 and the diameter d2 can be changed by replacing the respective cover plate 225. Thus, when the cover plate 225 is replaced, the solid Fe exits the drum 210 through these aperture-like openings 229 at a variable diameter in the axial direction of the drum 210.

[0059] The solids discharge drum cover 223 can have one or more further advantageous features according to optional further developments.

[0060] Thus, the solids discharge drum cover 223 can have a conical section 226 in which the openings 224—here, the four openings 224—can be formed. The solids discharge drum cover 223 can further have a cylindrical section 227 adjoining the conical section 226, preferably axially in the direction of the cylindrical section of the drum.

[0061] Thus, it may have a cylindrical portion 227 in addition to a conical portion 226. According to an advantageous further development, it may then be fastened with the cylindrical portion 227 to the drum shaft portion 219, preferably arranged axially next to the drum bearing 221.

[0062] The conical section 226 may be connected internally to an axial pin which may be inserted into the worm shaft section 233 or which may even serve as the worm shaft section 233 in a simple and surprisingly compact and practical embodiment.

[0063] In a further embodiment of the solids discharge 218 according to the invention Fig. 3a and Figur 3b In the solids discharge drum cover 223, a plurality of openings 224 are formed. In one or more, in particular each, of the openings, a sleeve, aperture, or disk 228 can be rotatably mounted. The outer diameter of the sleeves 228 thus preferably corresponds to the inner diameter of the preferably circular openings 224. The sleeves 228 are preferably arranged rotatably in the openings 224. This rotational position can be fixed by fixing means (not shown). Preferably, each sleeve, aperture, or disk 228 has an opening 229', which can be arranged / formed / aligned eccentrically in the preferably circular sleeve or disk 228. By rotating the respective sleeve 228 around its center point, which can lie on a diameter d3, the diameter on which the center point of the respective opening 229' lies can be changed.Through the respective opening 229' in the respective sleeve 228, the solid Fe thus exits the drum 210 at a variable diameter in the axial direction of the drum 210.

[0064] The solids discharge drum cover 223 can, moreover, be used like the solids discharge drum cover of the Fig. 2 be designed. Bezugszeichenliste

[0065] 100 housings 200 Rotor 210 Drum 211 Cylindrical section 212 Conical section 213 Drum cover 214 Inlet pipe 215 Distributor 216 Centrifugal chamber 217 Liquid outlet 218 Solids discharge 219 Drum shaft section 220 Drum shaft section 221 Drum bearing 222 Drum bearing 223 Solids discharge drum cover 224 Opening 225 Cover plate 226 Conical section 227 Cylindrical section 228 Sleeve 229, 229' Opening 230 Worm 231 Cylindrical section 232 Conical section 233 Worm shaft section 234 Worm shaft section 235 Worm bearing 236 Worm bearing 300Drive device 310Gearbox 320Pulley 330Pulley A 1 Distance A 2 Distance DRotation axis L 1 Length L 2 Length LL Distance drum bearing LT Length drum SuSuspension FeSolids FlLiquid phase F1Area F2Area d1Diameter Pitch circle d2Opening diameter d3Diameter

Claims

1. Solid-bowl screw centrifuge having a housing (100) and a rotor (200) rotatably mounted in the housing (100), comprising at least the following: a. a rotatable drum (210) having an axis of rotation (D), wherein the drum (210) has a cylindrical portion (211) and a conical portion (212), b. at least one liquid outlet (217) arranged in the cylindrical portion (211) of the drum (210), and c. at least one solids discharge (218) arranged in the conical portion (212) of the drum (210), d. a screw (230) rotatable relative to the rotatable drum (210) at a differential speed and arranged within the drum, wherein the drum (210) and screw (230) together form the rotor (200), e. at least two drum bearings (221, 222) for mounting the drum (210) in the housing (100), f. at least a first screw bearing (236) for mounting the screw (230) in the drum (210), g. wherein the drum (210) is designed in the region of the conical portion (212) or drying zone such that solid matter Fe is transported by means of the screw (230) up to a solid-discharge drum cover (223), which forms a termination of the conical portion (212) in the axial direction of the drum (210), in order to leave the drum (210) through a plurality of axially or substantially axially aligned openings (224) in the solid-discharge drum cover (223), and h. wherein the openings (224) in the solid-discharge drum cover (223) are located within, preferably entirely within, the smallest inner diameter of the conical portion (212) of the drum (210), characterized in that i. a cover element, in particular a cover plate (225), with openings (229) corresponding to the openings (224) of the solid-discharge drum cover, in particular of the conical portion (226), is fitted to the solid discharge drum cover (223) having the solid discharge (218), in particular to its conical portion.

2. Solid-bowl screw centrifuge according to claim 1, characterized in that the solid-discharge drum cover (223) has a conical portion (226).

3. Solid-bowl screw centrifuge according to claim 1 or 2, characterized in that the solid-discharge drum cover (223) has a cylindrical portion (227).

4. Solid-bowl screw centrifuge according to claim 2 or 3, characterized in that the one or more openings (224) for solids discharge are formed in the conical portion (226) of the solid-discharge drum cover (223).

5. Solid-bowl screw centrifuge according to claim 2, 3 or 4, characterized in that the conical portion (226) of the solid-discharge drum cover (223) has a cone angle that is greater than the interior cone angle of the conical portion of the drum.

6. Solid-bowl screw centrifuge according to one of the preceding claims 2 to 5, characterized in that the conical portion (226) of the solid-discharge drum cover (223) has a cone angle of more than 45°, in particular more than 60°, to the axis of rotation (D).

7. Solid-bowl screw centrifuge according to one of claims 2 to 6, characterized in that in the conical portion (226) of the solid-discharge drum cover (223) its openings (224) are arranged on a pitch circle with a diameter d1 which is smaller than the smallest diameter of the conical portion (212) of the drum (210).

8. Solid-bowl screw centrifuge according to one of the preceding claims, characterized in that the cover plate (225) is designed to be exchangeable.

9. Solid-bowl screw centrifuge according to one of the preceding claims, characterized in that the openings (224) in the solid-discharge drum cover (223) have a larger diameter than the openings (229) of the cover plate (225).

10. Solid-bowl screw centrifuge according to one of the preceding claims, characterized in that in the conical portion (226) of the solid-discharge drum cover (223), a screw shaft portion (233) is formed, or in that it can be coupled thereto.

11. Solid-bowl screw centrifuge according to one of the preceding claims, characterized in that the aperture-like openings (229) are arranged circularly on a pitch circle with a diameter d1 and have an opening diameter d2, so that both the diameter d1 and the diameter d2 can be changed by replacing the respective cover plate (225).

12. Solid-bowl screw centrifuge according to one of the preceding claims, characterized in that a screw shaft portion (233) is formed in the conical portion (226) of the solid-discharge drum cover (223), or in that it can be coupled thereto.

13. Solid-bowl screw centrifuge according to one of the preceding claims, characterized in that the cylindrical portion (226) of the solid-discharge drum cover (223) is fitted to a drum shaft portion.

14. Solid-bowl screw centrifuge according to one of the preceding claims, characterized in that a rotatable sleeve (228) is rotatably mounted in each of one or more of the openings (224).

15. Solid-bowl screw centrifuge according to claim 14, characterized in that each sleeve (228) has an opening (229') which is arranged eccentrically in the sleeve (228), and in that by rotating the respective sleeve (228) about its center point, which lies on a diameter d3, the diameter on which the center point of the respective opening (229') lies can be changed.

16. Solid-bowl screw centrifuge according to one of the preceding claims, characterized in that the cylindrical portion (211) of the drum (210) has a length L1 and the conical portion (212) of the drum (210) has a length L2, wherein L1 and L2 added together is the length LT of the drum (210).

17. Solid-bowl screw centrifuge according to one of the preceding claims, characterized in that the drum bearings (221, 222) for the bearing of the drum (210) in the housing (100) are spaced apart by a distance LL, wherein the distance LL of the drum bearings (210) from one another is smaller than the length LT of the drum.

18. Solid-bowl screw centrifuge according to one of the preceding claims, characterized in that the solids discharge (218) is located axially outside the two drum bearings of the drum.