Solid bowl centrifuge

Abstract

A solid bowl centrifuge (1) for centrifugal processing of a suspension Su, wherein the suspension Su is separated into at least a liquid phase Fl and a heavy phase, in particular a slurry or sludge phase or a solid phase Fe, having at least the following features: a frame or housing (100); a rotatable drum (210) having an axis of rotation A and a separating space; a feed line (219) through which the suspension Su to be processed can be conducted into the separating space (216) of the drum (210); at least one liquid discharge (212) through which the liquid phase Fl is discharged from the drum; and at least one solids discharge (211) through which the heavy phase is discharged from the drum. This centrifuge is characterized in that an insert (230) is inserted in the drum (210) and connected to the drum (210) for conjoint rotation, such that the insert (230) rotates synchronously with the drum (210), wherein the drum (210) has a doubly conical inner contour (213) and wherein the insert (230) has a singly conical or doubly conical outer contour (231).

Description

[0001] Solid bowl centrifuge

[0002] The invention relates to a solid bowl centrifuge according to the preamble of claim 1.

[0003] In a solid-bowl screw centrifuge, during centrifugal processing of a suspension (Su) in a centrifugal field, a heavy phase—often a solid phase (Fe) or sludge phase—collects on the inner circumference of the centrifuge bowl. The solid phase is transported by a screw from the cylindrical portion of the bowl into the conical portion and then further to the solids discharge openings at the end of a conical section of the bowl.

[0004] For this purpose, the screw is driven at a speed differential to the bowl, so that the screw flight mechanically pushes the solids toward the discharge openings. The screw is mounted in the bowl. The magnitude of the differential speed and the pitch of the screw flight influence the speed of the solids transport to the discharge openings.

[0005] This design of a solid-bowl screw centrifuge has proven itself in practice for many years, but the production of the screw, especially the screw flight, is complex and therefore expensive. Furthermore, the screw must be mounted so that it can rotate within the bowl. The centrifuge drive must also be designed so that the bowl and the screw are driven separately, and the screw has a different speed than the bowl during centrifuge operation.

[0006] The object of the invention is to provide a solid bowl centrifuge which has advantageous separation properties - preferably similar to those of a conventional solid bowl screw centrifuge - but the transport of the heavy phase takes place with fewer rotating components.

[0007] The invention solves this problem by the subject matter of claim 1.

[0008] Accordingly, a solid bowl centrifuge is created for the centrifugal processing of a suspension Su, wherein the suspension is separated into at least one light liquid phase and one heavy phase, in particular a sludge phase or a solid phase (i.e., a clarification of the suspension of solids takes place), which has at least the following features: a frame and / or a housing which does not rotate and is stationary during operation; a rotatable drum with an axis of rotation, which has a separation chamber, an inlet line through which the suspension Su to be processed can be guided into the separation chamber of the drum, at least one liquid outlet through which the light liquid phase is discharged from the drum, and at least one solids discharge through which the heavy phase - i.e., the sludge phase or the solid phase - is discharged from the drum.

[0009] It is further provided that the drum has a double-conical inner contour, and that an insert is inserted into the drum, which is connected to the drum in a rotationally fixed manner - so that the insert rotates synchronously with the drum - wherein the insert has a single-conical or double-conical outer contour and wherein the separation space is formed in any case in sections between the insert and the drum.

[0010] It can preferably be provided that the drum diameter tapers continuously or in sections in a first conical section from a maximum inner diameter to the liquid outlet and continuously or in sections in a second conical section from the maximum inner diameter to the solids outlet.

[0011] The terms "conical sections" as well as "conical inner contour" and "conical outer contour" encompass a completely conical configuration, but also a conical configuration of the corresponding section or contour area that is at least partially conical, in particular over more than 50%, in particular more than 80% of the axial length. The cone angle can be constant in each case, but it can also vary. The conical sections can, for example, transition into cylindrical, tubular sections at their ends.

[0012] The term "solids discharge" should not be interpreted too narrowly. It describes the ability to discharge the heavy phase, especially a sludge or solid phase that is still somewhat moist, from the drum.

[0013] According to claim 1 and optionally claim 2, a rotating screw can be surprisingly easily dispensed with, requiring only a drive for the bowl. A possible additional screw drive can be eliminated. This creates a solid-bowl centrifuge that has advantageous separation properties similar to those of a conventional solid-bowl screw centrifuge, but is more cost-effective to manufacture than such a device.

[0014] It is advantageous and practical if the maximum outer diameter d of the insert is smaller than the maximum inner diameter D of the drum, thereby creating a constriction in the separation space between the insert and the drum. With such a design, the flow conditions in the drum can be particularly advantageously influenced to optimize the centrifugal separation process.

[0015] In a particularly preferred embodiment of the invention, it is provided that a cross-sectional plane of the maximum outer diameter of the insert coincides with a cross-sectional plane of the maximum inner diameter of the inner contour of the drum at the constriction.

[0016] According to a further, particularly preferred embodiment of the invention, the constriction is formed by an annular gap. By designing the constriction as an annular gap, the width of the constriction can be easily adjusted by appropriate design measures.

[0017] Thus, according to another particularly preferred embodiment of the invention, a ring weir disc, in particular a replaceable ring weir disc, is arranged at the constriction, which can extend radially from the inside of the insert outward into the separation chamber. By replacing a ring weir disc with one of a different diameter, the maximum outer diameter of the insert can be changed. The replaceable weir disc allows for the option of a variable gap width or width of the constriction to be implemented in a structurally simple manner.

[0018] The drum can also have a single-conical or double-conical design on the outside, which is advantageous in terms of manufacturing but not absolutely necessary in terms of functionality. Preferably, the drum is rotatable by a drive motor, in particular an electric motor or hydraulic motor, and is rotated during operation.

[0019] Furthermore, according to another particularly preferred embodiment of the invention, the cone angle α of the first conical section can be 3 to 45° and the cone angle β of the second conical section can be 3 to 45°. This allows the geometry of the drum to be optimally adapted to the respective requirements for separating the suspension Su.

[0020] According to a further particularly preferred embodiment of the invention, it can then be provided that a first, liquid-outlet-side end - in particular a conical tip - of the insert is arranged axially in a region of the first conical section of the inner contour of the drum or which corresponds to an axial extent between 0 and 80% of the length L1 of the first conical section of the inner contour of the drum. The conical end of the insert can also be rounded or flattened, resulting in a virtual conical tip - the intersection point of the conical outer surface of the insert. This also allows the geometry of the insert to be very well adapted to the respective requirements for separating the suspension.Then, according to a further particularly preferred embodiment of the invention, it can be provided that a second, solids discharge-side end - in particular a conical tip - of the insert lies axially in a region of the second conical section of the inner contour of the drum, which corresponds to an axial extent between 0 and 80% of the length L2 of the second conical section of the inner contour of the drum. In this way, too, the geometry of the insert can be very well adapted to the respective requirements for separating the suspension, for example by selecting the cone geometry of the insert such that the cross-sectional area of ​​the channel between the insert and the inner contour of the drum remains essentially constant over the length L2. In this way, the heavy phase is not further compressed on the way to the solids discharge. The basis for the length dimensioning of the insert is the cross-sectional plane of the insert with the largest diameter d of the insert.This creates an easily implementable design specification for changing the insert geometry.

[0021] According to a further, particularly preferred embodiment of the invention, the insert is connected to the drum in a rotationally fixed manner via one or more (in particular, substantially radially extending) connecting spokes. The connecting spokes provide a method of rotationally fixed connection of the insert to the drum that is easy to manufacture and, with a suitable design of the spokes, which can be determined by a person skilled in the art numerically or experimentally, does not have to significantly influence the flow conditions in the separation chamber of the solid-bowl centrifuge.

[0022] In a further particularly preferred embodiment of the invention, the separation chamber is divided, starting from the maximum inner diameter, into a first separation chamber section (separation zone in the rotor) on the liquid outlet side and a second separation chamber section (drying zone in the rotor) on the solids discharge side. This advantageously and simply creates another advantageous option for efficient separation of the suspension Su.

[0023] It is preferred that the solid-bowl centrifuge has a control and / or regulating device. The control and / or regulating device can preferably be designed as a control unit of the centrifuge. It can have a microprocessor and a data memory as well as connections to actuators and / or sensors, and can preferably also have a data input device and a display. It can be provided with a computer program designed to control and / or regulate the operation of the centrifuge. The control or regulating device can be installed at the location of the centrifuge or at another location.

[0024] According to a further advantageous embodiment, a controllable feed pump can be provided in the feed line for feeding the suspension Su into the drum, which feed pump can be controlled by the control and / or regulating device. It can also advantageously be provided that the feed line is mechanically sealed from the drum in such a way that an inlet pressure can be built up in the separation chamber of the drum by appropriately controlling the feed pump. This is an advantageous measure for controlling the solid-bowl centrifuge in such a way that it can effectively fulfill its separation task during operation.

[0025] In a further advantageous embodiment, it can then be further provided that the separated light liquid phase is discharged from the first separation chamber section through a non-rotatable first discharge line, which is provided in a mechanically sealed manner with respect to the drum of the solid-bowl centrifuge. It is then advantageous and expedient if a controllable device, in particular a controllable control valve or a controllable positive displacement pump, is arranged in the first discharge line, which can be controlled by the control and / or regulating device such that the pressure in the first discharge line can be changed and adjusted by the controllable device. This is also an advantageous measure for controlling the solid-bowl centrifuge in such a way that it can effectively fulfill its separation task during operation.

[0026] By means of the controllable device, or preferably the actuator, control valve, or positive displacement pump in the first discharge line, both the volume flow and the pressure at which the light liquid phase leaves the separation chamber can advantageously be easily adjusted to the respective requirements. In particular, the pressure in the first discharge line can be easily adjusted so that the pressure in the first separation chamber section is always high enough to force the heavy phase over the maximum diameter of the insert, through the constriction, and possibly also out of the drum.

[0027] In a further advantageous embodiment, it can then be further provided that the discharge of the separated heavy solid phase from the second separation chamber section takes place through a non-rotatable second discharge line, which is provided in a sealed manner with respect to the drum. In this case, a further controllable device, in particular a controllable pump, which is connected to the control and / or regulating device can be arranged in the second discharge line, wherein the pressure in this second discharge line upstream of the pump can be changed and adjusted by controlling the controllable device with the control and / or regulating device. In this way, the pressure in the second separation chamber section of the drum can be adjusted. This is also an advantageous measure for controlling the solid bowl centrifuge such that it can effectively fulfill its separation task during operation.The adjustability of the pressure in the second discharge line allows the residence time of the solid in the separation chamber to be easily determined.

[0028] According to a further preferred embodiment, the pressure in the first discharge line can be in the range of 1 to 6 bar or adjusted to this range. This ensures that the pressure in the first discharge line and thus also in the first separation chamber section is high enough to effectively convey the heavy solid phase Fe out of the drum through the constriction (or, if applicable, via the weir plate arranged there).

[0029] Another particularly preferred embodiment of the invention also provides for the pressure in the second discharge line to be regulated within a range of -1 to +1 bar. A negative discharge pressure assists the removal of the heavy solid phase Fe by the pump sucking the heavy solid phase Fe out of the solid-bowl centrifuge. This advantageously allows the residence time of the solid phase in the separation chamber to be easily adjusted, thus allowing the degree of drying of the solid phase to be easily influenced.

[0030] In another particularly preferred embodiment of the invention, the pump in the second drain line is designed as a positive displacement pump. This advantageously makes the pump self-priming and, due to its design, can be used to build up pressure in the second drain line.

[0031] According to claim 25, the invention also provides a use of a solid-bowl centrifuge for centrifugally processing a suspension Su, wherein the suspension Su is separated into at least one liquid phase Fl and one heavy phase, in particular a sludge phase or a solid phase Fe. And according to claim 26, the invention provides a method for centrifugally processing a suspension Su using a solid-bowl centrifuge according to any one of claims 1 to 24, wherein the suspension Su is separated into at least one liquid phase Fl and one heavy phase, in particular a sludge phase or a solid phase Fe, characterized by the following steps:

[0032] A) Prepare the solid bowl centrifuge and rotate the bowl;

[0033] B) Introducing the suspension to be processed into the separation chamber of the drum with a feed pump through the feed line so that pressure is built up in the separation chamber,

[0034] C) Centrifugal separation of the suspension in the separation chamber into a light liquid phase and a heavy phase,

[0035] D) Discharging the separated light liquid phase from the first separation chamber section through the first discharge line, which is sealed against the housing and the bowl shell of the solid bowl centrifuge, and

[0036] E) Discharge of the separated heavy solid phase from the second separation chamber section through the second discharge line, which is sealed from the housing and the bowl shell of the solid bowl centrifuge.

[0037] The control valve in the first discharge line can be used to regulate the discharge pressure of the light liquid phase to a value high enough to hydraulically press the heavy phase through the constriction and out of the drum. For this purpose, a discharge pressure in the first discharge line can preferably be set within a range of 1 to 6 bar. Furthermore, a discharge pressure—particularly within a range of -1 to +1 bar—can advantageously be set in the second discharge line.

[0038] Further advantageous embodiments of the invention can be found in the subclaims.

[0039] 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:

[0040] Figure 1 shows a schematic sectional view of a solid-bowl centrifuge according to the invention with a horizontal axis of rotation. The following description of the figures describes an exemplary embodiment of a solid-bowl centrifuge. Features of this exemplary embodiment are suitable not only as a whole, but also individually for further developing the subject matter described in one or more of the main and subclaims.

[0041] Fig. 1 shows a schematic representation of a solid-bowl centrifuge 1 for processing a product or suspension Su in a centrifugal field. This centrifuge comprises a housing 100 that does not rotate during operation and a rotor 200 that rotates or rotates during operation, with a drum 210. The drum 210 is designed as a solid-bowl drum.

[0042] The drum 210 is driven into rotation by a single drive device 400. The drive device 400 is preferably embodied as an electric motor. However, it can also be designed differently, e.g., as a hydraulic drive. The drive device 400 is coupled to the drum 210 via a belt drive or directly. Optionally, the drive device can have a gearbox (not shown here).

[0043] The drum 210 is rotatably mounted in the frame and, in this case, also in the housing 100 by bearings 402, 403. The drum 210 can preferably have a horizontal axis of rotation A. However, the axis of rotation A can also be oriented differently—in particular vertically. The drum 210 is preferably designed as a solid-shell drum.

[0044] In the drum 210 rotating during operation of the solid bowl centrifuge 1, at least one incoming suspension is separated in the separation chamber into a heavy phase - often a still flowable, sludgy solid phase Fe - and into a liquid phase Fl.

[0045] For this purpose, the solid bowl centrifuge 1 has an inlet 217 for the suspension, at least one solids discharge 211 and at least one liquid outlet 212.

[0046] The drum 210 here has a double-conical inner contour 213. The drum diameter thus tapers in a first conical section 214 from a maximum inner diameter D - relative to the inner contour 213 of the drum 210 - in the axial direction towards the liquid outlet 212 and in a second conical section 215 from the maximum inner diameter D towards the solids discharge 211. The cone angle α of the first conical section 214 with the length L1 can preferably be between 3° and 45°. The cone angle β of the second conical section 215 with the length L2 can then preferably be between 3° and 45°. According to the exemplary embodiment shown, it can also be provided that α > β.

[0047] The drum 210 can also be configured with a double conical shape on the outside. This makes it particularly easy to manufacture. The drum 210 can also have a cylindrical, tubular section / attachment at one or both ends.

[0048] Instead of a rotating screw, an insert 230 is inserted into the drum 210, which can be connected to the drum 210 in a rotationally fixed manner via connecting spokes 2351, 2352. The insert 230 thus rotates synchronously with the drum 210. The solid-bowl centrifuge is thus designed without a screw, or rather, does not have a screw that rotates relative to the drum during operation.

[0049] Mounting the insert 230 in the bowl 210—similar to a screw—as in conventional solid-bowl screw centrifuges is therefore not necessary. A drive for the screw or a gear to generate a differential speed between the bowl 210 and the screw is therefore also unnecessary.

[0050] The insert 230 can have a single-conical outer contour on one side only or—as shown in Fig. 1—a double-conical outer contour extending from a maximum outer diameter d in opposite directions. The maximum outer diameter d of the insert 230 is smaller than the maximum inner diameter D of the drum 210. According to Fig. 1, the insert is thus designed to be conical or cone-tip-like in two opposite directions, starting from a largest diameter. Thus, two conical sections 233, 234 are formed.

[0051] The (outer) cone angles of these two conical sections 233, 234 of the insert are each greater than or equal to the corresponding cone angles α and β.

[0052] The conical tip of the first conical section 233 of the insert 230, on the liquid outlet side, lies axially along a length of the first conical section 214 of the inner contour 213 of the drum 210, which corresponds to 0 to 80% of the total length L1 of the first conical section 214 of the inner contour of the drum 210. A second, solids discharge-side conical tip of the second conical section 234 of the insert 230, on the other hand, lies axially along a length that corresponds to up to 0 to 80% of the length L2 of the first, second section 215 of the inner contour of the drum 210. It can also be provided that the second section 234 has a radial base wall and that no first section 233 is provided (single conical insert).

[0053] The cross-sectional plane of the insert 230 with the largest diameter d is chosen as the basis for the length dimensioning of sections 233, 234 of the insert 230 (and, on the other hand, the respective cone tip).

[0054] In this way, a separation space 216 is formed between the outer contour 231 of the insert 230 and the inner contour 213 of the drum 210.

[0055] The cross-sectional plane of the maximum outer diameter d of the insert 230 coincides here with the cross-sectional plane of the maximum diameter D of the inner contour 213 of the drum 210, forming a constriction 226 in the separation chamber 216. The constriction 226 is thus designed as an annular gap. A replaceable weir disk 232 can be attached to the maximum outer diameter d of the insert 230, so that the maximum outer diameter d of the insert 230 and thus the width of the constriction 226 and the annular gap can be changed. An annular gap height corresponding to 2% to 20% of the diameter D has proven advantageous.

[0056] The separation chamber 216 is divided, starting from the maximum diameter D of the inner contour 213 of the drum 210, into a first separation chamber section 2161 on the side of the liquid outlet 212 and a second separation chamber section 2162 on the side of the solids discharge 211. The first separation chamber section 2161 is in fluid connection with an inlet 217 of the suspension Su into the drum 210 and with the liquid outlet 212 of the light liquid phase Fl. The second separation chamber section 2162 is in fluid connection with the discharge 211 of the heavy solid phase Fe.

[0057] The suspension Su is fed into the drum 210 by means of a feed pump 218 connected to a feed line 219. The feed line 219 is sealed from the housing 100 and the drum shell of the solid-bowl centrifuge 1, so that the feed pump 218 can build up an inlet pressure in the separation chamber 216 of the drum 210. This feed pump 218 can be connected to a control and / or regulating device 300 via a further connecting section. The feed line can extend relatively far into the first conical section 214 and extend over more than 50% of the length L1. The feed line 219 can be designed as a tube. This can be designed as a stationary tube that does not rotate during operation.

[0058] At least one liquid outlet 212 is provided to drain the separated light liquid phase Fl from the first separation chamber section 2161. This can have a cylindrical pipe section concentric with the inlet line 219, which can extend virtually as an extension of the first conical section 214. The liquid outlet 212 also has a non-rotating first outlet line 220. This can be sealed from the housing 100 and the bowl shell of the solid-bowl centrifuge 1. The cylindrical pipe section 2141, which is concentric with the inlet line 219 and can extend virtually as an extension of the first conical section 214, can open into this outlet line 220. This concentric pipe section rotates. It can be sealed from the outlet line 220 with a seal 225, which can be a mechanical seal. In the area of ​​the pipe section 2141, one bearing 403 can also be provided.

[0059] As shown in Fig. 1, a control valve 221 or, alternatively, a positive displacement pump (not shown here) can be arranged in the first drain line 220. This control valve 221 or the positive displacement pump can be connected to the control and / or regulating device 300 via a wired or wireless connection. Through suitable control, the pressure in the first drain line 220 can be adjusted by the control and / or regulating device 300. This drain pressure is preferably set / regulated within a range of 1 to 6 bar.

[0060] The separated heavy solid phase Fe is discharged from the second separation chamber section 2162 through the solids discharge 212. This can be provided as an axial extension of the second conical section 215. The second conical section 215 can open into a second tubular (here partially conical and then cylindrical) discharge line 222. This second discharge line 222 can be designed as a pipe that is stationary during operation and does not rotate with the drum 210. This pipe can be sealed against the second conical section 215 of the drum 210. For this purpose, a seal 224 can be provided, which can be designed as a mechanical seal.

[0061] A pump 223 can be arranged in the second drain line 222. This pump can be connected to the control and / or regulating device 300 via a connecting line. It is provided that by controlling the pump 223, the pressure in this second drain line 222 can be adjusted by the control and / or regulating device 300. This pump 223 can be connected to a control and / or regulating device 300 via a further connecting line. The drain pressure is typically controlled or regulated within a range of -1 to +1 bar. The pump 223 is preferably designed as a positive displacement pump.

[0062] The respective connection routes (shown in dashed lines) can be configured as wireless or wired connection lines or connection data channels, etc. They can allow power and / or data transmission.

[0063] A negative discharge pressure means that the speed of pump 223 in the solids discharge is set so that the discharge of the heavy solid phase Fe is supported, i.e., pump 223 sucks the heavy solid phase Fe out of the solid-bowl centrifuge 1. A positive counterpressure means that the speed of pump 223 is set so that the discharge of the heavy solid phase Fe is slowed, i.e., pump 223 delays the discharge of the heavy solid phase Fe from the solid-bowl centrifuge 1 and thus extends its residence time in the solid-bowl centrifuge 1. This has the great advantage that the degree of drying of the solid phase can be easily influenced.

[0064] During operation, the suspension Su is first fed (pumped) into the separation chamber. Depending on the throughput and composition of the suspension Su, the pressure of the feed pump can be between 1 and 6 bar. The suspension then rotates with the drum. The design can also be such that the radial acceleration during operation, i.e., at operating speed, in the area of ​​the largest diameter D of the drum 210 is between 1000 g and 7000 g. The suspension is now cleared of solids.

[0065] The resulting heavy solid phase Fe is thrown to the largest diameter D in the separation chamber 216 by the centrifugal forces acting on it, while the further resulting lighter liquid phase Fl (or the clarified suspension) remains in the region of smaller diameters of the drum 210.

[0066] Due to the suspension Su pumped into the inlet 217, the constriction 226 acting as a throttle, the centrifugal force acting in the rotating drum 210 and the throttling by the control valve 221, a hydraulic pressure is built up in the liquid phase Fl in the separation chamber 216. The backpressure in the discharge 211 of the heavy solid phase Fe is relatively low compared to the pressure in the discharge 212, so that the heavy solid phase Fe is pressed over the replaceable weir disk 232 of the constriction 226 in the direction of the solids discharge 211. There, the heavy solid phase Fe is pressed from the rotating drum 210 into the stationary, second discharge line 222 or into the pump 223. The connection between the drum 210 and the second discharge line 222 is sealed by a seal 224. The seal 224 can be designed as a mechanical seal.

[0067] Since the path out of the drum 210 is blocked by the heavy solid phase Fe above the weir disk 232, the only path left for the light liquid phase Fl is in the opposite direction, i.e. in the direction of the liquid outlet 212.

[0068] In the liquid outlet 212, the light liquid phase Fl is pressed from the rotating drum 210 into the stationary first outlet line 220. The connection between the drum 210 and the first outlet line 220 is also sealed by a seal 225. The seal 225 can be designed as a mechanical seal.

[0069] With the control valve 221 in the first discharge line 220, the discharge pressure of the light liquid phase Fl can be regulated to a value large enough to force the heavy solid phase Fe over the weir plate 232 and out of the drum 210. This discharge pressure is—as already explained above—typically between 1 and 6 bar.

[0070] The pressure in the separation chamber 216 results from the pressure of the feed pump 218, the constriction 226 acting as a throttle, the centrifugal force acting in the rotating drum 210 and the throttling by the control valve 221.

[0071] As soon as the hydrostatic pressure of the light liquid phase Fl, which is located in the rotating drum 210 on a smaller diameter in the separation chamber 216 due to its lower density compared to the heavy solid phase Fe, is greater than the counterpressure exerted on the heavy solid phase Fe - which is located in the rotating drum 210 on a larger diameter in the separation chamber 216 - the heavy solid phase Fe is hydraulically conveyed in the direction of the solids discharge 211 and the pump 223 arranged in the second discharge line 222.

[0072] The pressure of the feed pump 218 for the suspension Su must be adjusted so that the hydrostatic pressure in the separation chamber 216 is overcome in order to be able to feed the suspension Su into it.

[0073] Some of the key advantages of this design are listed again: a rotating screw is not required, only the insert 230, which is significantly easier to manufacture than a screw and is fastened in the drum 210, is required; only one drive 400 is required for the drum 210, an additional screw drive can be omitted; a bearing for the screw in the drum 210 is also not required, since the insert 230 is connected to the drum 210 in a rotationally fixed manner and thus rotates synchronously with the drum 210; a gear for generating a differential speed between the drum 210 and the screw is therefore also not required; no centripetal pump is required to discharge the liquid phase Fl; and due to the hermetic design of the centrifuge, the design according to the invention meets high hygienic requirements.These advantages do not always have to be fulfilled together, but they are achieved particularly well in the embodiment shown.

[0074] List of reference symbols

[0075] 1 solid-bowl centrifuge

[0076] 100 housings

[0077] 200 rotor

[0078] 210 Drum

[0079] 211 Solids discharge

[0080] 212 Fluid drain

[0081] 213 inner contour

[0082] 214 first section

[0083] 2141 pipe section

[0084] 215 second section

[0085] 216 Separation room

[0086] 2161 first separation space section

[0087] 2162 second separation space section

[0088] 217 inlet

[0089] 218 Inlet pump

[0090] 219 Inlet line

[0091] 220 first drain line

[0092] 221 control valve

[0093] 222 second drain line

[0094] 223 Pump

[0095] 224 Seal

[0096] 225 Seal

[0097] 226 bottleneck

[0098] 230 deployment

[0099] 231 Outer contour

[0100] 232 Weir Disc

[0101] Section 233

[0102] Section 234

[0103] 2351 spoke

[0104] 2352 spoke

[0105] 300 Control and / or regulating device

[0106] 400 drive device

[0107] 401 belts

[0108] 402 Warehouse 403 Warehouse

[0109] A axis of rotation

[0110] Su Suspension Fe Solids

[0111] Fl liquid phase D diameter d diameter

[0112] L1 length L2 length a angle ß angle

Claims

Claims 1. A solid-bowl centrifuge (1) for the centrifugal processing of a suspension Su, wherein the suspension Su is separated into at least one light liquid phase Fl and one heavy phase, in particular a sludge phase or a solid phase Fe, having at least the following features: a. a frame and / or a housing (100); b. a drum (210) which is rotatable relative to the frame or housing and has an axis of rotation A and which has an internal separation space, c. an inlet line (219) through which the suspension Su to be processed can be conducted into the separation space (216) of the drum (210), d. at least one liquid outlet (212) through which the light liquid phase Fl is discharged from the drum, and e. at least one solids discharge (211) through which the heavy phase is discharged from the drum; characterized in that f. the drum (210) has a double-conical inner contour (213), g.an insert (230) is inserted into the drum (210) and is connected to the drum (210) in a rotationally fixed manner, wherein the insert (230) has a single-conical or double-conical outer contour (231) and wherein the separation space is formed at least in sections between the insert (230) and the drum (210).

2. Solid bowl centrifuge (1) according to claim 1, characterized in that the drum diameter tapers continuously or in sections in a first conical section (214) from a maximum inner diameter D to the liquid outlet (212) and in a second conical section (215) from the maximum inner diameter D of the drum (210) to the solids outlet (211).

3. Solid bowl centrifuge (1) according to claim 1 or 2, characterized in that a maximum outer diameter d of the insert (230) is smaller than the maximum inner diameter D of the drum (210), whereby an annular gap-like constriction (226) is formed in the separation space (216) between the insert and the drum.

4. Solid bowl centrifuge (1) according to claim 2 or 3, characterized in that a cross-sectional plane of the maximum outer diameter d of the insert (230) coincides with a cross-sectional plane of the maximum diameter D of the inner contour (213) of the drum (210) at the constriction (226).

5. Solid bowl centrifuge (1) according to one of the preceding claims, characterized in that an annular weir disc (232), in particular a replaceable annular weir disc (232), is arranged at the constriction (226), which extends radially from the inside of the insert (230) outwards into the separation chamber.

6. Solid bowl centrifuge (1) according to one of the preceding claims, characterized in that the cone angle α of the first conical section (214) of the inner contour (213) of the drum is between 3° and 45° and that the cone angle β of the second conical section (215) of the inner contour (213) is between 3° and 45°.

7. Solid bowl centrifuge (1) according to one of the preceding claims, characterized in that a first, liquid outlet-side end of the first conical section (233) of the insert (230) lies axially in a region of the first conical section (214) of the inner contour (213) of the drum (210) which corresponds to an axial extent between 0 to 80% of the total axial length L1 of the first conical section (214) of the inner contour of the drum (210).

8. Solid bowl centrifuge (1) according to one of the preceding claims, characterized in that a second, solids discharge-side end of the second conical section (235) of the insert (230) lies axially in a region of the second conical section (215) of the inner contour (213) of the drum (210) which corresponds to an axial extent of 0 to 80% of the length L2 of the second conical section (215) of the inner contour of the drum (210).

9. Solid bowl centrifuge (1) according to one of the preceding claims, characterized in that the insert (230) is connected to the drum (210) in a rotationally fixed manner via one or more connecting spokes (2351, 2352).

10. Solid bowl centrifuge (1) according to one of the preceding claims, characterized in that the separation chamber (216) has, starting from the maximum inner diameter D, a first separation chamber section (2161) on the side of the liquid outlet (212) and a second separation chamber section (2162) on the side of the solids discharge (211).

11. Solid bowl centrifuge (1) according to claim 10, characterized in that the first separation chamber section (2161) has the inlet (217) and the outlet (212) for the light liquid phase Fl.

12. Solid bowl centrifuge (1) according to claim 10 or 11, characterized in that the second separation chamber section (2162) has the discharge for the heavy solid phase Fe.

13. Solid bowl centrifuge (1) according to one of the preceding claims, characterized in that it has a control and / or regulating device (300).

14. Solid bowl centrifuge (1) according to one of the preceding claims, characterized in that a controllable feed pump (218) is provided in the feed line (219) for feeding the suspension Su into the drum (210), which feed pump can be controlled by the control and / or regulating device (300).

15. Solid bowl centrifuge (1) according to one of the preceding claims, characterized in that the inlet line (219) is provided in a sealed manner with respect to the drum (210) in such a way that an inlet pressure can be built up in the separation chamber (216) of the drum (210) by appropriately controlling the inlet pump.

16. Solid bowl centrifuge (1) according to one of the preceding claims, characterized in that the discharge of the separated light liquid phase Fl from the first separation chamber section (2161) takes place through a non-rotatable first discharge line (220) which is provided in a sealed manner with respect to the drum (210) of the solid bowl centrifuge (1).

17. Solid bowl centrifuge (1) according to claim 16, characterized in that a controllable device, in particular a controllable control valve (221) or a controllable positive displacement pump, is arranged in the first discharge line (220), which can be controlled by the control and / or regulating device (300) in such a way that the pressure in the first discharge line (220) can be changed and adjusted by the controllable device through the control and / or regulating device (300).

18. Solid bowl centrifuge (1) according to one of the preceding claims, characterized in that the discharge of the separated heavy solid phase Fe from the second separation chamber section (2162) takes place through a non-rotatable second discharge line (222) which is provided in a sealed manner with respect to the drum (210).

19. Solid bowl centrifuge (1) according to claim 16, characterized in that a further controllable device, in particular a controllable pump (223) is arranged in the second discharge line (222), which is connected to the control and / or regulating device (300), wherein the pressure in this second discharge line (222) upstream of the pump (223) is variable and adjustable by controlling the controllable device with the control and / or regulating device (300).

20. Solid bowl centrifuge (1) according to claim 19, characterized in that the pump (223) is designed as a positive displacement pump.

21. Solid bowl centrifuge (1) according to one of the preceding claims, characterized in that a connection between the drum (210) and the first discharge line (220) is sealed by a first seal (225), wherein this first seal (225) is preferably designed as a mechanical seal.

22. Solid bowl centrifuge (1) according to one of the preceding claims, characterized in that a connection between the drum (210) and the second discharge line (222) is sealed by a second seal (224), wherein this second seal (224) is preferably designed as a mechanical seal.

23. Solid bowl centrifuge (1) according to one of the preceding claims, characterized in that the rotor (200) is rotatable by a drive device, in particular a single drive device (400), which preferably has an electric motor or a hydraulic motor.

24. Solid bowl centrifuge (1) according to one of the preceding claims, characterized in that it is designed without a screw, or that it does not have a screw that can rotate relative to the bowl during operation.

25. Use of a solid bowl centrifuge for the centrifugal processing of a suspension Su, wherein the suspension Su is separated into at least one light liquid phase Fl and one heavy phase, in particular a sludge phase or a solid phase Fe.

26. A method for the centrifugal processing of a suspension Su with a solid bowl centrifuge according to one of claims 1 to 24, in which the suspension Su is divided into at least one light liquid phase Fl and one heavy phase, in particular a sludge phase or a solid phase Fe, is separated, characterized by the following steps: A) Prepare the solid bowl centrifuge and rotate the bowl; B) Introducing the suspension Su to be processed into the separation chamber of the drum with a feed pump (218) through the feed line (219) so that a pressure is built up in the separation chamber (216), C) Separation of the suspension in the separation chamber into a light liquid phase Fl and a heavy phase Fe, D) Discharging the separated light liquid phase Fl from the first separation chamber section (2161) through the first discharge line (220), which is sealed from the housing (100) and the drum shell of the solid bowl centrifuge (1), E) Discharging the separated heavy solid phase Fe from the second separation chamber section (2162) through the second discharge line (222), which is sealed from the housing (100) and the drum shell of the solid bowl centrifuge (1).

27. The method according to claim 26, characterized in that the control valve (221) in the first discharge line (220) regulates the discharge pressure of the light liquid phase Fl to a value which is large enough to press the heavy solid phase Fe over the constriction (226) and out of the drum (210).

28. Method according to claim 27, characterized in that a discharge pressure of between 1 and 6 bar is set in the first discharge line (220).

29. Method according to one of the preceding method claims, characterized in that a discharge pressure in a range of -1 to +1 bar is set in the second discharge line (222).

30. Method according to one of the preceding method claims, characterized in that the drum is rotated such that in the region of the largest diameter D of the drum (210) the radial acceleration during operation, ie at operating speed, is between 1000 g and 7000 g.

31. Method according to one of the preceding method claims, characterized in that the pressure in the inlet is adjusted by the inlet pump (218) so that the hydrostatic pressure in the separation chamber (216) is overcome in order to feed the suspension Su into the latter.

32. Method according to one of the preceding method claims, characterized in that during operation the control of the controllable devices and the feed pump are selected such that the hydrostatic pressure of the light liquid phase Fl, which is located in the rotating drum (210) on a smaller diameter in the separation chamber (216) due to its lower density compared to the heavy solid phase Fe, is greater than the counterpressure acting on the heavy solid phase Fe - which is located in the rotating drum 210 on a larger diameter in the separation chamber 216 - in order to convey the heavy solid phase Fe hydraulically in the direction of the solids discharge 211.

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