Patent Grant
11590515
The present application claims priority from German Pat. App. No. DE 10 2019 117 721.9, filed on Jul. 1, 2019, the contents of which are incorporated herein by reference.
Various aspects of this disclosure relate to pusher centrifuges.
Pusher centrifuges are used in many applications in chemistry and in the processing of raw materials. In general, in a conventional pusher centrifuge, a solid portion and a liquid portion of a solid-liquid mixture are separated from each other in a filter drum device of the pusher centrifuge by means of a rotational movement and the solid portion is moved out of the filter drum device of the pusher centrifuge by means of an axial oscillating push movement. For this purpose, a conventional pusher centrifuge generally includes two electric motors, by which the generation of the rotational movement and the generation of the axial oscillating push movement are respectively caused, wherein for this purpose a respective torque of the two electric motors is indirectly transmitted by means of a belt to the filter drum device and to a hydraulic pump, by means of which a hydraulic pressure causing the axial oscillating push movement is generated.
In the following description, various aspects of the disclosure are described with reference to the following drawings:
Throughout the figures, identical or similar components are provided with the same reference signs.
The following detailed description refers to the accompanying drawings that show, by way of illustration, example details and aspects in which the disclosure may be practiced.
Various aspects of the present disclosure relate to a pusher centrifuge that is easier and less expensive to manufacture and to maintain.
The present disclosure describes a pusher centrifuge, including: a rotatable filter drum (e.g., rotatable about a filter drum longitudinal axis) having at least one drum body and having a push floor (e.g., piston) which is arranged in the filter drum, wherein the push floor and the at least one drum body are capable of being axially reciprocated relative to one another (in a longitudinal direction of the filter drum), a filter drum drive shaft (e.g., coaxial with the filter drum longitudinal axis) that is non-rotatably (e.g., rigidly and/or fixedly) connected to the filter drum (and that, for example, extends in a longitudinal direction of the filter drum) (in the present disclosure, “non-rotatably connected” means that the respective connected parts (e.g., the filter drum drive shaft and the filter drum) are connected to each other in such a manner that they are not rotatable relative to each other), a hydraulic push mechanism, for generating an axial oscillating push force (e.g., an axially oscillating axial push force), that is connected to the filter drum in such a way that the axial oscillating push force generated by the hydraulic push mechanism is transferred to the filter drum to thereby cause the relative reciprocating movement between the push floor and the drum body, a hydraulic pump for generating a hydraulic pressure including a pump input shaft and being in fluid-connection with the hydraulic push mechanism for supplying the hydraulic pressure to the hydraulic push mechanism to operate the hydraulic push mechanism to generate the axial oscillating push force, and a drive motor (e.g., a single (e.g., main) drive motor) having an output shaft connected to the pump input shaft and the filter drum drive shaft to transmit torque of the drive motor to both the pump input shaft and the filter drum drive shaft (in operation), wherein the output shaft of the drive motor is connected to the pump input shaft in a manner without an intermediate transmission conversion (e.g., without a reduction and/or change in transmission ratio (e.g., without intervening mechanical transmission conversion elements such as gearboxes or belt and pulley systems)) to thereby form a direct drive. For example, the output shaft of the drive motor is connected to the pump input shaft to directly drive the pump input shaft. For example, the output shaft of the drive motor is connected to the pump input shaft so as to be co-axially aligned with each other. For example, the output shaft of the drive motor is directly, e.g., directly co-axially, connected to the pump input shaft.
The output shaft of the drive motor may include a first output shaft and a second output shaft which, starting from the drive motor, extend from opposed (e.g., opposite) sides of the drive motor (e.g., coaxially to each other), wherein the first output shaft is connected to the pump input shaft in a manner wherein the first output shaft directly drives the pump input shaft. For example, the first output shaft is connected to the pump input shaft without an intermediate transmission conversion, e.g., without reduction and/or change in transmission ratio to thereby form a direct drive. For example, the first output shaft is co-axially or directly connected to the pump input shaft without intervening mechanical transmission elements such as gearboxes or belt and pulley systems. The second output shaft is connected to the filter drum drive shaft.
The (e.g., first) output shaft of the drive motor may be connected to the pump input shaft via a clutch.
The (e.g., second) output shaft of the drive motor may be connected to the filter drum drive shaft by a belt. The belt may be a V-belt, e.g., a ribbed V-belt, or a toothed belt. However, the (e.g., second) output shaft of the drive motor may also be connected to the filter drum drive shaft in a manner without intervening transmission elements (e.g., gearboxes or belt and pulley systems)(i.e., without an intermediate transmission conversion, e.g., without a reduction and/or change in transmission ratio) to thereby form a direct drive. In this respect, the (e.g., first) output shaft of the drive motor may be connected to the pump input shaft via a clutch as described above and the (e.g., second) output shaft of the drive motor may be connected to the filter drum drive shaft via a drive shaft clutch.
The drive motor may further include a drive pulley non-rotatably connected to the output shaft of the drive motor (as mentioned above, “non-rotatably connected” means that the drive motor and the drive pulley are connected to each other in such a manner that they are not rotatable relative to each other), and the filter drum drive shaft may further include a driven pulley, wherein the drive pulley and the driven pulley may be connected by means of a belt to connect the output shaft of the drive motor to the filter drum drive shaft. The driven pulley may be connected non-rotatably to the filter drum drive shaft or may be formed integrally (e.g., in one piece) with the filter drum drive shaft. The drive pulley may be non-rotatably connected to the output shaft of the drive motor or may be formed integrally (e.g., in one piece) with the output shaft of the drive motor.
Hydraulic pumps used in pusher centrifuges are usually available to match an electric motor that drives them, so that the motor operating speed matches the pump operating speed per se. This allows the direct drive between the drive motor and the hydraulic pump to be carried out without loss in accordance with various embodiments of the present disclosure. In contrast thereto, different rotation speeds are sometimes required for the filter drum of the pusher centrifuge depending on the matter to be centrifuged (e.g., a solid-liquid mixture to be centrifuged or a suspension to be centrifuged). Since the filter drum of the pusher centrifuge according to various embodiments of the present disclosure can be driven by the drive motor by means of a belt via respectively associated belt pulleys, a reduction or a transmission ratio between the output shaft of the drive motor and the filter drum drive shaft can be realized easily by exchanging the respective belt pulleys, so that the rotation speed can thereby be adjusted accordingly based on the requirements of a process.
The hydraulic pump, the clutch and the drive pulley (e.g., the belt looping the drive pulley) may be located on the same side of the drive motor. Starting from (e.g., starting with) the drive motor, the hydraulic pump, the clutch and the drive pulley (e.g., the belt looping the drive pulley) may be arranged in the following order: the drive pulley (or the belt), the clutch, the hydraulic pump (i.e., in the following order: the drive motor, the drive pulley (or the belt), the clutch, the hydraulic pump) along an axial direction (e.g., a longitudinal direction) of the output shaft of the drive motor. This means that along the axial direction of the output shaft of the drive motor, first the drive motor, then the drive pulley (or the belt looping the drive pulley), then the clutch and then the hydraulic pump are arranged. This may be advantageous in that the hydraulic pump requires and has only one input shaft due to its end position in this arrangement. In contrast to a hydraulic pump disposed in an intermediate position, where in addition to the input shaft of the hydraulic pump, an output shaft of the hydraulic pump is also required to transmit a torque, which leads or may lead to a more complex design including, for example, a more complex sealing device, which requires increased maintenance.
The clutch may be a non-releasable clutch. The non-releasable clutch may be a non-releasable flexible clutch (e.g., any of a jaw clutch, a denture clutch, a spring bar clutch or a cross-head clutch). The clutch may be a safety clutch, optionally a safety slip clutch. The clutch may be a safety clutch with overload protection, which has a predetermined breaking point, optionally in the form of a shear pin. The clutch may be a flexible clutch, optionally a flexible claw clutch. If the output shaft of the drive motor is connected to the pump input shaft by means of a non-releasable flexible clutch or by means of a flexible clutch, coaxial alignment differences (e.g., an axial error or an alignment error) between the output shaft of the drive motor and the pump input shaft (e.g., in operation) caused by assembly and/or manufacturing can be compensated, so that smooth operation of the hydraulic pump and the drive motor can be achieved in each case.
The output shaft of the drive motor and the pump input shaft may be at least substantially coaxial with respect to one another.
For example, the output shaft of the drive motor and the filter drum drive shaft are at least substantially parallel to each other and are not coaxial with respect to one another.
The drive motor may be an electric motor, e.g., a three-phase asynchronous motor. The electric motor may, for example, have an output of 160 kW±20% (e.g., 160 kW±10%, e.g., 160 kW±5%), but electric motors of any output may be used in the pusher centrifuge described herein, provided that their motor output is suitable for the field of application of the pusher centrifuge. The electric motor may be connected to a control device for controlling the electric motor and may be electrically connected to a power source for power supply. However, the drive motor is not limited to a motor powered by electric current. For example, the drive motor may also be designed as an internal combustion engine.
The filter drum drive shaft may include: an outer filter drum drive shaft formed as a hollow shaft, and an inner filter drum drive shaft axially movably supported in the outer filter drum drive shaft and connected to the filter drum and the hydraulic push mechanism in such a way that the axial oscillating push force is transmitted thereby from the hydraulic push mechanism to the filter drum to cause the relative reciprocating movement between the push floor and the drum body.
The relative reciprocating movement between the push floor and the drum body may be a reciprocating movement of the push floor relative to the at least one drum body (and/or vice versa). The pusher centrifuge may, for example, be multistage, the filter drum, e.g., then having several drum bodies corresponding to the number of stages, wherein the pusher centrifuge may, for example, be configured as a two-stage pusher centrifuge with an outer first drum body and an inner second drum body. The pusher centrifuge may accordingly include, e.g., a rotatable filter drum (e.g., rotatable about a filter drum longitudinal axis) having an outer first drum body and an inner second drum body and having a push floor which is arranged inside the filter drum in the inner second drum body and is fixedly (e.g., non-rotatably) connected to the outer first drum body, wherein the inner second drum body can be oscillated (or reciprocated in operation) relative to the push floor and the outer first drum body (in the longitudinal direction of the filter drum). However, the pusher centrifuge may also have three and even more stages with correspondingly three and even more drum bodies.
The inner filter drum drive shaft may be connected to the inner second drum body (e.g., non-rotatably). The outer filter drum drive shaft may be connected to the outer first drum body (e.g., non-rotatably). The push floor may be connected to the outer first drum body (e.g., non-rotatably) via rods extending axially through the inner second drum body.
The pusher centrifuge may further include: a feeding device with a feeding line via which a solid-liquid mixture to be filtered (e.g., a suspension to be filtered) can be fed into the inner second drum body and the outer first drum body (and thus into the filter drum), a solid discharge device by means of which a screened or filtered solid portion of the solid-liquid mixture can be discharged from the filter drum, and a liquid discharge device by means of which the liquid portion of the solid-liquid mixture can be discharged from the filter drum.
The example embodiments of the present disclosure described above make it possible to provide a pusher centrifuge with only one drive motor which is able to directly drive the hydraulic pump to generate a hydraulic pressure for generating the axial oscillating push force and which is able to (simultaneously) drive the filter drum, thereby being able to reduce both the manufacturing costs of the pusher centrifuge and the maintenance costs thereof. Furthermore, in contrast to conventional pusher centrifuges that have a drive motor in which two respective belts, for example, are needed to transmit a torque to a filter drum and to a hydraulic pump, the embodiments of the present disclosure do not require a second belt (and, according to an example embodiment, do not require a first and a second belt). Thus, for example, any of an associated bearing, an associated belt protection, an associated adjustment mechanism, an associated lubrication etc. is not needed (also, mechanical belt tensioning devices are not needed during maintenance work on the pusher centrifuge). As a result, the pusher centrifuge not only reduces costs, but may also have a more compact and more simple design as compared to conventional pusher centrifuges. Furthermore, another discovered advantage of the pusher centrifuge according to the present disclosure is an increased degree of efficiency compared to conventional pusher centrifuges. This efficiency advantage is attributed to the output shaft of the drive motor being connected to the pump input shaft of the hydraulic pump in a manner without an intervening transmission conversion element (e.g., gearbox), thereby forming a direct drive transmission. Furthermore, the direct drive-forming connection having no intervening transmission conversion element (e.g., gearbox) may reduce and/or avoid transverse forces, which may be generated by a belt drive and which may act on the hydraulic pump via the input shaft thereof, so that the pusher centrifuge according to the present disclosure may include a hydraulic system (i.e., the hydraulic pump, the hydraulic push mechanism fluid-connected thereto, etc.) which is more reliable in terms of operation with an increased service life. In addition, the installation effort and the installation costs of a pusher centrifuge may be reduced by means of the pusher centrifuge according to the present disclosure, since an electrical infrastructure (i.e., power supply wiring, safety boxes, etc.) is required for only one electric motor.
With reference to
Referring to
Since the connection “drive motor 17/hydraulic pump 13” is made by a claw clutch, which is mounted directly to the driving pulley 33 as described above (via the projection 37), only the clutch 29 (i.e., the claw clutch) has to be removed to change the belt 31, so that a gap is created, through which an old (e.g., worn) belt can be removed and through which a new belt can be inserted. This may facilitate and accelerate maintenance (e.g., drive maintenance) of the pusher centrifuge 1.
As shown in
The drive motor 17 is an electric motor, in this case a three-phase asynchronous motor, with an output of 160 kW±20% (e.g., 160 kW±10%, e.g., 160 kW±5%). The electric motor is connected to a control device (not shown in the figures) and electrically connected to a power source 39 by means of a power line 41.
The pusher centrifuge 1 shown in
As shown in
The embodiment of
As shown in
Referring to
With reference to
The pusher centrifuge 1 with the previously described filter drum drive shaft 9 (of
The push floor 7 is non-rotatably connected to the outer first drum body 5a via rods 51 extending axially through the inner second drum body 5b. The inner filter drum drive shaft 9b is non-rotatably (e.g., rigidly and/or fixedly) connected to the inner second drum body 5b. The outer filter drum drive shaft 9a is non-rotatably (e.g., rigidly and/or fixedly) connected at one (longitudinal) end thereof to the outer first drum body 5a and at another opposite (longitudinal) end thereof to the driven pulley 35. The hydraulic push mechanism 11 is configured (e.g., installed) in (e.g., inside) the driven pulley 35. For this purpose, the driven pulley 35 includes an accommodation space 35a for accommodating or receiving the hydraulic push mechanism 11. The hydraulic push mechanism 11 includes: a piston member 59 which fluid-tightly divides the accommodation space 35a into a first hydraulic pressure chamber 53 and a second hydraulic pressure chamber 55 and which is connected to the inner filter drum drive shaft 9b in a non-rotatable and axially fixed manner, a pilot control slider 57, and a main control slider (not shown in the Figures) which is controlled by means of the pilot control slider 57 to assume either a first position state or a second position state. A fluid guide (not shown in the Figures) is formed in the piston member 59, which is connected to the fluid line 47 so as to receive a hydraulic pressure from the hydraulic pump 13, and which is configured so that when the main control slider is in the first position state, the hydraulic pressure is supplied to the first hydraulic pressure chamber 53 (and a hydraulic pressure in the second hydraulic pressure chamber 55 is discharged) and, when the main control slide is in the second position state, the hydraulic pressure is supplied to the second hydraulic pressure chamber 55 (and a hydraulic pressure in the first hydraulic pressure chamber 53 is discharged). When the hydraulic pressure is supplied to the first hydraulic pressure chamber 53, an axial push force generated by the hydraulic pressure and acting on the piston 59 causes it (together with the inner filter drum drive shaft 9b and the inner second drum body 5b) to move axially toward the second hydraulic pressure chamber 55 (in a longitudinal direction of the filter drum drive shaft 9, to the right as shown in
The pusher centrifuge 1 may further include: a feeding device 61 having a feeding line 63, via which a solid-liquid mixture to be filtered (e.g., a suspension to be filtered) can be fed into the inner second drum body 5b and the outer first drum body 5a (and thus into the filter drum 3), a solid discharge device 65, by means of which a screened or filtered solid portion of the solid-liquid mixture can be discharged from the filter drum 3, and a liquid discharge device 67, by means of which the liquid portion of the solid-liquid mixture can be discharged from the filter drum 3.
Although the invention has been described by means of embodiments, the invention is not limited to these embodiments. Instead, the skilled person will also consider alternatives and modifications as covered by the invention, provided that they are within the scope of protection defined by the claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2019 117 721.9 | Jul 2019 | DE | national |
| Number | Name | Date | Kind |
|---|---|---|---|
| 3136721 | Gooch | Jun 1964 | A |
| 4381236 | Cox | Apr 1983 | A |
| 4944874 | Kobayashi | Jul 1990 | A |
| 5085443 | Richards | Feb 1992 | A |
| 20210001353 | Scherer | Jan 2021 | A1 |
| Number | Date | Country |
|---|---|---|
| 10 2011 055 513 | May 2013 | DE |
| 2633918 | Sep 2013 | EP |
| 2076701 | Dec 1981 | GB |
| Entry |
|---|
| European Patent Office, English abstract of DE10 2011 055 513 A1, printed on Jun. 19, 2020. |
| European Patent Office, English abstract of EP2633918 A2, printed on Jun. 19, 2020. |
| Deutsches Patent—und Markenamt, Office Action for Application No. 10 2019 117 721.9, dated Apr. 29, 2020. |
| European Patent Office, extended Examination Search Report for EP Application No. 20175188.0-1016, Nov. 16, 2020, pp. 1-6. |
| Number | Date | Country | |
|---|---|---|---|
| 20210001353 A1 | Jan 2021 | US |
