JP2007289951A - Bearing device for centrifugal separator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To shield a middle space between a cylindrical drum hub and bearing blocks to prevent entry of impurities. <P>SOLUTION: A basket 1 is rotatably fixed to and coupled with a drive shaft 3 coupled with a drive unit 12 extending along a rotating axis 6 in the bearing blocks 4, 7, 8, 9, 20, 24 through a basket hub 2 and a suspension device 21 of the basket 1 in a bearing device for the basket 1 of a centrifugal separator arranged around the rotating axis 6. The basket 1 is supported in the bearing blocks 4, 7, 8, 9, 20, 24 in such a way that a bearing force generated by a dynamic force is substantially separated from the drive shaft 3. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a countermeasure for a bearing of a drive shaft for a rotary basket and to sealing of the bearing. The rotating basket is a component of a centrifuge, in particular a vertical scraper centrifuge.

  This type of centrifuge is an example of a means for performing the separation of a solid / liquid mixture into its solid and liquid components. During centrifugation, i.e. the separation process for separating the solid components from the liquid, the solid / liquid mixture is rotated. Centrifugal forces acting on solids and liquids will increase the sedimentation rate. Unlike the sedimentation of the solid components of the mixture due to gravity acting on the particles, the solid particles are moved away from the axis of rotation by the action of a centrifugal force in a plane perpendicular to the axis of rotation. The particles are collected in a filter that is mounted rotationally about the axis of rotation. The filter is most often placed in a basket jacket made in a cylindrical fashion, or even the basket itself is designed as a filter. The basket is provided with a passage opening for liquid ejected away from the outer wall of the basket in the direction of the stationary housing of the centrifuge. The following process steps take place in a separation process for the separation of the solid components of the solid / liquid mixture in a centrifuge.

  The centrifuge is filled with a solution containing solid particles to be separated through a filling device such as a filling pipe. The solution is sent inside the basket. In a further stage, a centrifugation step is performed to separate the liquid from the solid particles. The particles are deposited as a cake inside the outer wall of the basket, and the liquid is discharged through an opening provided in the basket for discharge purposes and collected in a container surrounding the basket. The cleaning process can remove residual solution from the filter cake. The cleaning solution is sprayed onto the filter cake. The cleaning liquid is removed from the filter cake by rotation. Furthermore, any residual solution in the filter cake is drained by the cleaning process. This type of solution should often not be detected in the filter cake for health or environmental reasons, or in view of the flammability of the product and its further throughput. After the cleaning process, the filter cake is removed from the inside of the basket outer wall, which is called scraping in the industrial arts. For this purpose, the scraping means moves along the inner wall of the basket rotating at low speed and removes the cake of the filter. The filter cake exits the centrifuge space in the vertical scraper centrifuge by discharging downward through an opening in the bottom of the centrifuge. Thereafter, the inside of the outer wall of the basket is cleaned so that the residual layer can be removed.

  Bearing devices for rotary baskets of vertical centrifuges with drive shafts are known from the prior art, the devices being arranged along a substantially vertical axis of rotation of the rotary basket. The basket includes a basket hub that is rotatably fixedly coupled to the drive shaft and supports the rotating basket. The first bearing functions to absorb the force generated by the rotating motion of the basket. At least one second bearing serves to absorb forces acting in the direction of the rotation axis. The drive shaft is pivotally supported on the stationary housing portion of the centrifuge, which is referred to below as the flute tube. The flute tube extends along at least a portion of the drive shaft. The first and second bearings are disposed between the drive shaft and the flute tube.

  Furthermore, it is known from the prior art to provide a gap between a fixed flute tube and a rotating basket hub. A bearing for transmitting force is located at the end of the drive shaft connected to the storage basket hub. A guide bearing is disposed near the end of the drive shaft and is coupled to the drive device. A V-belt pulley is typically flanged to the end of the drive shaft and supports a V-belt that is driven by an electric motor. Thus, the guide bearing is disposed between the drive shaft and the flute tube. Therefore, the inner diameter of the flute tube is only slightly smaller than the outer diameter of the bearing attached to the drive shaft.

  A problem caused by prior art bearing devices is that the shaft is subject to both torsional and bending strains. In addition, the shaft must also absorb dynamic forces introduced into the shaft by the operation of the storage basket. In particular, high speed sliding centrifuges with speeds in the range of 700 rpm to 2,700 rpm result in alternating high bending stresses, which necessitates the determination of a sufficient dimensional shape of the shaft. The required shaft diameter then makes it necessary to select a corresponding large bearing, thereby increasing the inner diameter of the basket hub. Therefore, the solution from the prior art has a significant peripheral speed due to its inner diameter, so it is necessary to place the bearing directly on the shaft. Furthermore, the seals must likewise be placed directly on the shaft or via a sleeve that has the smallest possible diameter and moves with the shaft. Because the peripheral speed increases as a result of the required allowable shaft diameter, the seal generates very high frictional heat, so it cannot even be reduced to an acceptable amount via grease lubrication of the seal, As a result, the sealing material fails. Even PTFE lip seals can only withstand temperatures in the range of up to 250 ° C. due to grease lubrication, in which the failure due to oxidation reactions (seal combustion) occurs.

  A structural solution from the prior art consists of placing the seal in close proximity to the basket suspension at the shaft so that the peripheral speed in the seal area is allowed as an upper limit for the seal. It will surely stay below the speed. Such a structural limitation provides a solution, in which the seal is arranged between the shaft and the fixed housing part, i.e. the component, hereinafter referred to as the flute tube. A seal is placed in the immediate vicinity of the bearing so that the shaft area sealed against the area between the drive bearing and the one or more bearings closest to the storage basket suspension is limited as much as possible. The The seal thus has the function of sealing the bearing against impurities and sealing against the discharge of the lubricant necessary to lubricate the bearing. Lubricant is fed to the bearing by a lubricant bore inside the flute tube. These lubricant bores are disadvantageous because their production is labor intensive and / or expensive. In particular, in the case of a centrifuge with a larger geometry where the shaft is used with an overall length longer than 1,000 mm, a long passage bore with a small diameter is technically complicated to manufacture. is there. In addition, these bores need to be designed to prevent occlusion during operation, which would otherwise include a storage basket and a cleaning basket for cleaning the lubricant bore under certain circumstances. This is because the bearing itself needs to be disassembled.

  A further disadvantage is based on the possibility that all kinds of impurities can enter the bearing space by the gap according to the prior art embodiments. These impurities are generated, in particular, when the centrifuge is withdrawn and by particles entering the gaps by flushing or cleaning agents. When changing the product, it is necessary to flush the entire centrifuge space. The inner centrifuge space is submerged, which can cause dust, impurities, etc., to enter and stay in the gap between the basket hub and the flute tube, and thereby between the rotating basket and the flute tube. There is a risk of clogging the intermediate space. As a result, the frictional resistance associated with hard crystalline products, in particular, can increase, which can lead to dynamic forces during operation that can lead the bearing into the bearing, which in extreme cases can cause the bearing to Unacceptable bearing distortions that can lead to failure can cause problems during start-up, as well as product contamination due to contaminating particles carried out of the gap during operation. In particular, it is necessary to completely prevent product contamination for the food industry and pharmaceuticals. However, in the case of prior art structural solutions, there must be a gap between the storage basket hub and the flute tube. On the other hand, sealing of the gap is not possible due to the high peripheral speed of the storage basket due to the problems described above. On the other hand, since the storage basket is supported in a cantilever fashion on the shaft, it cannot be sealed successfully, thereby causing the storage basket to bias up to a few millimeters around its rest position during operation. become. Even the highest performance lip seal can only tolerate a dynamic eccentric distance of up to 0.1 mm at 1,000 rpm. This eccentric distance further decreases as the speed increases, and is only acceptable up to 0.05 mm at 3,000 rpm. It arises based on the above description, and the open gap between the flute tube and the basket hub cannot currently be eliminated from the structural style.

  Further problems of impurities include corrosion that can adversely affect all parts of the bearing block, which is the whole of the flute tube, bearings, seals, and the connecting parts to which it is attached and centered, and in particular this type of impurities. The occlusion caused by can be adversely affected when it is impossible to access the inspection without disassembling the basket from the drive shaft or further disassembling the bearing block. Corrosion can also adversely affect the bearing seal, if it affects the working medium in a strongly acidic or basic range, which can also adversely affect the seal in continuous operation, thereby Long term sealing cannot be ensured. It is clear that PFTE seals are said to be sufficiently resistant to chemical products, but abrasive particles, together with chemically reactive materials, produce frictional forces due to high peripheral speeds, especially If this type of highly reactive material acts permanently on the seal for a longer period of time, it will show a large strain on any seal.

  It is therefore well known from the prior art to provide a flushing nozzle in the gap between the cylindrical drum hub and the bearing block. The arrangement of these flushing nozzles is complex due to the limited space available for the bearing blocks. In addition, flushing nozzles can become unusable due to clogging caused by impurities, so that all the problems specified so far can be caused by this improved solution. For the reasons mentioned above, an intermediate space between the basket hub and the bearing block, since the gap is not easily accessible for cleaning and subsequent inspection and therefore a correspondingly long repair time must be taken into account. Flushing and / or flooding is disadvantageous. Product replacement is only for products used in the pharmaceutical or food industry, for example, when it can be proved that no traces of the batches or other impurities mentioned above can be detected at all in the equipment that processes the product. It can be carried out. Thus, gaps where such products remain and / or where impurities may accumulate are avoided as much as possible. As the above example of a centrifuge shows, if it is not possible to eliminate this type of gap for structural reasons, it may be analytical according to the regulations for pharmaceuticals or pharmaceutical precursors. It is necessary to prove that the gap has been completely cleaned by the process, and the process reproduces the actual relationship in the gap, for example by determining the concentration of impurities and / or the composition of impurities. Within this type of test, a sample is taken, for example, from one of the surfaces that delimits the gap and the purity is determined by laboratory analysis.

  This type of analysis is not practically possible without prior disassembly of the basket and centrifuge bearing blocks, according to prior art embodiments. The design of the bearing block is pre-determined by mechanical distortion due to operating in the hypercritical speed range and multiples beyond the critical speed range of the drive shaft. Therefore, in order to ensure the required smoothness of sliding in operation, the greatest possible care must be taken when disassembling the bearing block and basket. In particular, if a small batch of a different type of each product needs to be centrifuged, the overall repair time for a new product, including the cleaning and analysis described above, is a significant fraction of the cycle time, if not the main part. Occupy part. Thus, the centrifuge remains in a non-productive state that is not productive for an extended period of time, thereby making it a considerable cost disadvantage.

  Accordingly, one object of the present invention is to shield the intermediate space between the cylindrical drum hub and the bearing block so that impurities are prevented from entering the intermediate space.

  Another object of the present invention is to reduce the component of the force acting on the shaft.

  The object is met by the features of claim 1. The bearing device according to claim 1 for a centrifuge basket arranged around a rotating shaft is connected to a drive unit extending along the rotating shaft in the bearing block via a basket hub and a basket suspension. A basket that is rotatably fixed to the drive shaft.

  The basket is supported in the bearing block such that the bearing force generated by the dynamic force is substantially disconnected from the drive shaft.

  Combined static and dynamic forces act on the drive shaft in the operating state. Dynamic forces include forces that change over time. However, unbalanced forces can also be exposed to changes caused by movement, which can in particular have the following causes: The filter cake is deposited in the basket by progressive separation of the solid / liquid mixture, and it is not expected that the filter cake will always be distributed evenly over the entire perimeter of the basket. Therefore, in general, the center of mass of the filter cake does not lie on the axis of symmetry of the basket, which is the rotational axis of the drive shaft. This dynamic force, which varies with time and generally increases with increasing degree of deposition, is similar so that the drive shaft does not need to absorb this force as described in the preferred embodiment below. Then, it is guided into the flute pipe through a bearing.

  A seal for sealing the gap between the bearing block and the basket hub is provided for the bearing device in accordance with one preferred embodiment.

  According to one preferred embodiment, at least one first bearing is provided for a bearing device for absorbing dynamic forces generated by the rotational movement of the basket and at least one second bearing is driven. Provided for guiding the shaft.

  According to one preferred embodiment, the bearing device comprises a bearing block and a flute tube arranged coaxially around the drive shaft. At least one bearing is disposed between the flute tube and the basket hub.

  According to one preferred embodiment for the bearing device, the basket hub is rotatably fixedly attached to the first end of the drive shaft via a basket suspension. At least a second bearing is disposed near the second end of the drive shaft or flute tube, the second end being connectable to the drive unit.

  According to one preferred embodiment for the bearing device, the drive shaft is arranged along a substantially vertical axis of rotation. The drive shaft has in particular a shaft diameter in the range of 10 to 300 mm, the shaft diameter being in particular between 10 mm and 150 mm, preferably in the range of 50 mm and 150 mm, and the drive shaft is in the range of 400 mm to 1500 mm. Having a length, in particular from 400 mm to 1,000 mm, in particular from 500 mm to 800 mm, preferably from 600 mm to 700 mm, the basket diameter reaching from 300 mm to 2500 mm, in particular from 300 mm to 2,000 mm, Preferably it exists in the range of 400 mm to 1,600 mm.

  Due to the arrangement of the bearings, the horizontal and unbalanced forces of the bearing basket are absorbed by the flute tube. The drive shaft can essentially be designed for absorption of torsional forces guided by the drive means when the centrifuge is started and stopped, thereby determining its dimensional shape with a substantially smaller shaft diameter. Sometimes sufficient can be found, which allows the shaft diameter to be reduced to one third of the original shaft diameter.

  Due to the reduction of the shaft diameter, the diameter of the flute tube becomes smaller and at the same time the peripheral speed is lower, which on the one hand contributes to increasing the product life of the bearing, on the other hand, the flute tube, And / or significantly reduce the peripheral speed between the stationary surface sealed on the basket hub and the moving sliding surface, thereby providing a completely new bearing device.

  The basket hub is supported on the flute tube, and the basket hub can be supported on the flute tube over its entire length, thereby ensuring the guidance of the basket hub so that it There will be some improvement. The basket hub is supported along its entire length by the support of the basket hub in the flute tube. This support results in a fairly tight tolerance between the basket hub and the flute tube so that the gap between the basket hub and the flute tube is completely possible. Since the basket hub cantilever support can be eliminated, the smoothness of the basket hub slip can be improved by this support.

  The reduced outer diameter also results in a reduction in peripheral speed, thereby reducing the frictional heat generated in the operating state, so that a lip seal can be used for gap sealing.

  The rotation of the basket is in the range of 500 rpm to 3,000 rpm. A range of 750 rpm to 1,600 rpm is particularly preferred, and normal bearing lubrication is considered sufficient for up to 900 rpm, and oil lubricated bearings can be used above 900 rpm.

  According to one preferred embodiment for the bearing device, the gap can extend from at least the first to the second bearing.

  According to one preferred embodiment, the basket comprises at least one discharge opening for carrying out the filter cake, the opening being arranged in the vicinity of the gap, and dust and / or particles and / or liquids. Ingress of drops and / or gas can be prevented by the seal.

  According to one preferred embodiment of the bearing device, the bearing can be lubricated by a bore in the flute tube, which can be connected to a lubricant supply means outside the basket of the centrifuge.

  According to one preferred embodiment of the bearing device, a moving sliding surface disposed on the jacket surface of the basket hub, and a fixed sliding surface disposed oppositely formed on the jacket surface of the flute tube. There is a seal between.

  According to one preferred embodiment for the bearing device, at least one of the seals is made as a shaft seal and / or a lip seal and / or a peripheral seal.

  According to one preferred embodiment for the bearing device, a lip seal is arranged around the outer jacket surface of the basket hub.

  According to one preferred embodiment for the bearing device, the peripheral speed in the operating state at the contact surface of the seal against the moving sliding surface is below 100 m / s, in particular below 75 m / s, in particular below 50 m / s. , Preferably below 40 m / s for grease lubrication and / or at least 10 m / s, especially at least 5 m / s, especially at least 1 m / s for dry run It is preferable.

  According to one preferred embodiment for the bearing device, an interposition means is provided for the generation and maintenance of an inert gas body in the space inside the basket hub sealed by the seal.

  In particular, a vertical centrifuge can be provided in a bearing device according to one of the above embodiments. Vertically arranged centrifuges are particularly suitable for small to medium batches with frequently changing product specifications, whereas horizontally arranged filtration scraper centrifuges It is preferably used for large throughputs of suspension that always occur in continuous operation. The area of application of filtration centrifuges covers a wide range of particle sizes from 0.1 μm to 10,000 μm, in particular from 1 to 5,000 μm, preferably from 1 to 1,000 μm. In particular, the suspension to be centrifuged has a solid content of more than 10%, preferably more than 20%, in particular more than 25%.

  This type of sealing problem occurs in a vertical centrifuge with both top and bottom discharges, where it is a small, lightweight particle container such as a fine dust or emulsion, or the like Thus, the filter cake material can always move into the gap between the storage basket hub and the drive shaft flute.

  The present invention will be described in more detail with reference to the drawings.

  It should be mentioned in advance that reference numbers above 100 belong to the embodiments already disclosed in the prior art.

  In the preferred embodiment of the prior art shown in FIG. 1, the bearing device comprises a basket 101 that is rotatably fixedly connected to the drive shaft 103 via a suspension device 121. The suspension device 121 is arranged at the first end 110 of the drive shaft, which in this embodiment has a conical shape. The conical shape was chosen so that the weakest possible notch effect leads to a weakening phenomena of the drive shaft 103. All direct diameter transitions of the drive shaft 103 are referred to as a weakening phenomenon, which results in the highest point of local load under the influence of the load, the highest point of these loads being the notch effect Matches. The drive shaft needs to absorb not only the full load and torsional force of the basket 101 but also the dynamic forces that arise due to the rotational movement of the basket and / or the drive shaft 103 itself. These dynamic forces introduce alternating bending stresses that vary periodically into the shaft, which can lead to fatigue failure, which is often the case for shaft shoulders with small transition radii, etc. It is known to have its beginning in a structural notch. The suspension device 121 is fixed so as not to rotate by a fixing element 138. The fixing element 138 is positioned by the cover 139. The drive shaft is rotatable about its axis of rotation 106 by a drive unit 112 not shown in more detail. Accordingly, the rotation of the drive shaft 103 can be transmitted to the basket hub 102 via the suspension device 121 of the basket 101 and / or to the basket jacket via the rib structure 126. Thus, the basket 121 is made as a rotationally symmetric component whose rotational axis coincides with the rotational axis 106 of the drive shaft. The drive shaft 103 is supported in a bearing block 122, and the bearing block includes a flute pipe 104 in addition to the bearings (107, 108, 109). The bearing block 122 further comprises a seal 118, with three shaft seals sequentially arranged in the illustrated embodiment. The seal 118 is received in the receiving means 120 attached to the flute tube via the screw connection 130. The receiving means 120 are designed as a series of flanges, each receiving one shaft seal, so that when assembled, the flanges are stacked on top of each other without a gap and are terminated against impurities that may be located in the gap 113. 131 and / or a sleeve element. The sealing action also includes sealing against the lubricant used for bearing lubrication being discharged into the gap 113. A sealing element 132 such as an O-ring can be provided between the flanges and / or between the flange and the termination element 131 or the sleeve element 133. The connector element 134 which is rotationally fixedly connected to the drive shaft 103 is provided with a sliding surface which, in terms of its surface properties, is sealed by a seal 118 designed as a shaft seal by frictional heat. Designed to be able to slide over this surface without being heated in an unacceptable manner. It is advantageous to place the sliding surface on the connector element 134 as making the sliding surface on the connector element 134 can be much simpler and more cost effective than on the drive shaft itself. . However, it is necessary to provide positioning means 135 for the connector element 134 which makes it possible to fix the connector element 134 on the drive shaft. On the one hand, the drive shaft and the connector element 134 ensure that the sealing effect of the seal is ensured and that no unacceptable pressing pressure acts on any position of the seal, which can reduce the sealing effect and / or cause the seal to overheat. Since there is a need to ensure that no misalignment occurs between the connector elements, there is a high demand for tolerances on the shape and position of this connector element. On the other hand, the mass distribution of the connector element 134 can be such that the center of mass is at the axis of rotation of the drive shaft 106 so that no dynamic forces, in particular unbalanced forces, are introduced into the shaft. The need for accuracy in manufacturing makes the entire bearing block more expensive.

  It is further necessary to provide the possibility of cleaning the gap 113 periodically to be free of impurities, or to prevent impurities from moving into the gap 113 by a continuously usable flushing process. In the illustrated embodiment, an infeed for a detergent designed as a tube 136 is shown, through which the detergent is introduced into the peripheral bore 137, and the peripheral bore is received by the receiving bore. Located in the boring block 122 between the means 120 and the termination element 131. An additional sealing element 132 is required to seal the peripheral bore 137 so as to eliminate the penetration of the cleaning agent into the bearing area. A nozzle (not shown) is arranged in the termination element 131 so that the cleaning agent can be discharged into the gap 113.

  Instead of periodic cleaning, measures can be taken to continuously guide the inert gas to the gap 113 through the peripheral bore 137 by the pipe 136 and the nozzle described above. The gap is continuously flushed with inert gas so that impurities are carried out of gap 113 by the flushing flow. This variant is used when reactive media are subjected to centrifugation, such as unwanted chemical reactions or even danger of explosion.

  The embodiment of the bearing device according to the invention shown in FIG. 2 consists of a basket 1 of a centrifuge, in particular a vertical centrifuge with a bottom discharge, the basket 1 comprising a basket hub 2 and a basket suspension 21. And is rotatably arranged on a drive shaft 3 connected to a drive unit 12 extending along the rotation axis 6 in the bearing block (4, 7, 8, 9, 20, 24). Seals (18, 19) for sealing the gap 13 between the bearing block (4, 7, 8, 9, 20, 24) and the basket hub 2 are connected to the basket hub 2 and the bearing block (4 on the drive side). , 7, 8, 9, 20, 24).

  In the preferred embodiment shown in FIGS. 2 and 3, the bearing device comprises a basket 1 that is rotatably fixedly connected to the drive shaft 3 via a suspension device 21. The suspension device 21 is arranged at the first end 10 of the drive shaft which in this embodiment has a cylindrical shoulder. The suspension device is rotatably fixed and connected to the first end 10 of the drive shaft 3 by a key. It is preferred that the key connection is selected because less labor is required for production and therefore it can be produced more cost-effectively. By separating the dynamic and / or quasi-static force of the basket from the torsional force introduced into the drive shaft by means of the drive unit described above, the drive shaft can, at most, be completely immune to torsional force. It is only subjected to alternating bending stresses, which have no influence, thereby preventing unacceptable distortion of the structural notches. Thus, it provides a drive shaft design with a cost effective construction option that could not be used due to the combined distortion of the drive shaft as known from the prior art. Alternatively, measures can be taken so that the seat portion of the suspension device 21 of the storage basket 1 has a conical shape as disclosed in the prior art embodiments. The conical shape is chosen to achieve the weakening phenomenon of the drive shaft 3 with the lowest possible notch effect. The shape of the drive not only needs to absorb the full load of the basket 1 as well as the torsional force when the center of mass of the drive shaft is not on the axis of rotation, but also because of the rotational movement of the drive shaft 3 itself. Any dynamic forces that arise need to be absorbed. Periodically alternating alternating bending stresses are introduced into the drive shaft by these dynamic forces, which can lead to fatigue failure, and this type of fatigue failure is often found in structural notches. It is known to have a beginning. Thus, the deformation with a conical drive shaft portion for receiving the basket suspension 21 is particularly suitable for large centrifuges in which the force of the weight of the drive shaft 3 is not negligible with respect to torsional forces. The suspension device 21 is fixed in the same manner as the embodiment shown in FIG. 1 by a fixing element so as not to rotate. The fixing element of the basket 1 and the suspension device 21 are positioned by a cover.

  The drive shaft can be rotated about its axis of rotation 6 by a drive unit 12 not shown in more detail. In particular, an electric motor is provided as drive unit 12 and can be directly flanged to the drive shaft, or alternatively can be connected to drive shaft 6 by means of a transmission device, in particular belt drive 11. Thus, the rotation of the drive shaft 3 can be transmitted to the basket hub 2 via the suspension device 21 of the basket 1 and / or to the jacket 27 of the basket 1 via the rib structure 26. The basket 21 is thus produced as a rotationally symmetric component whose rotational axis substantially coincides with the rotational axis 6 of the drive shaft. The drive shaft 3 is supported in a bearing block 22 which comprises a flute pipe 4 in addition to the bearings (7, 8, 9).

  The bearing device according to FIG. 2 or 3 for a centrifuge basket arranged so as to be rotatable about an axis of rotation 6 comprises a basket 1 via a basket hub 2 of the basket and a suspension 21. Since the bearing block (4, 7, 8, 9, 20, 24) is rotatably fixedly coupled to the drive shaft 3 coupled to the drive unit 12 extending along the rotation axis 6, the bearing (7 , 8, 9) is considerably different from the prior art with respect to the centrifuge basket, whereby the basket 1 is mounted on the bearing block (4) so that the bearing forces caused by the dynamic forces are considerably separated from the drive shaft 3. , 7, 8, 9, 20, 24). Accordingly, in this embodiment, two bearings (7, 8) are arranged between the flute pipe 4 and the basket hub 2. The bearings (7, 8) are mounted where possible near the first end 10 of the drive shaft 3 so as to ensure the maximum possible sliding smoothness of the rotating storage basket 1. Dynamic forces resulting from the movement of the basket are guided into the flute tube 4 via bearings (7, 8). In particular, unbalanced forces are understood by these dynamic forces. These unbalanced forces vary with time during the start-up of the centrifuge and during the stop phase. During steady state operation of the centrifuge, the unbalanced force can be subject to periodic fluctuations due to the non-rotationally symmetric mass distribution of the basket 1 and can be changed by reloading the centrifuge. . The period duration corresponds to one rotation of the drive shaft. The time-varying unbalanced forces are due to the non-uniform distribution of the material separated on the basket 1 jacket 27 and / or these periodic liquid discharges through the basket jacket 27 openings. In addition to the unbalanced force that fluctuates, it can also act on the bearing. This time, however, all these forces are no longer absorbed by the drive shaft 3. This provides the advantage that a drive shaft 3 with a substantially smaller outer diameter can be used than was possible in the prior art for centrifuges of the same structure and dimensions.

  The bearing 9 is essentially a guide bearing and serves the function of guiding radial forces that may be caused by the movement of the basket hub 2 to the flute tube 4. The bearing 9 is also advantageously arranged between the basket hub 2 and the flute tube 4.

  The bearing block 22 further comprises a seal 18 and the inlet opening to the gap 13 in the embodiment in which the shaft seal is sealed so that the bearing 9 can be sealed against impurities moving into the gap 13 through the inlet opening. Placed as close as possible. The seal 18 is made of a fixed sliding surface 17 which is part of the flute tube 4 and a movement made as part of the basket hub 2 or as a sleeve element 28 which is rotatably fixedly connected to the basket hub 2. It arrange | positions between the sliding surfaces 14 which do. The part of the gap 13 that is upstream and still accessible to particles from the filter cake 5 can be sealed by another seal, which is made as a lip seal 19 so that it is outside the basket. There should be no gaps in the filter cake being carried out. The lip seal 19 is received in a receiving means 20 attached to the flute tube via a screw connection 29. The receiving means 20 is made in particular as part of a tube or part of a sleeve, in which a recess for receiving at least one lip seal 19 is provided. The recess serves as a holder for the lip seal 19 and forms a sliding surface 16 to which the bottom surface of the recess is fixed, on which the lip of the lip seal 19 is located. The receiving means 20 is assembled such that the receiving means is directly attached to the flute pipe 4 by a screw connection part or to the flute pipe 4 via a flange connection part 23. The gap 13 is sealed against impurities by two seals (18, 19). The seal 19 is advantageously formed on the outside of a sleeve element 28 that is rotatably fixedly connected to the basket hub 2. The moving sliding surface 15 extends between the seal 19 and the sleeve element 28 so that the seal 19 can slide over the moving sliding surface 15. The advantage of placing the seals 18 and 19 on opposite sides of the sleeve element 28 is due to the formation of a maze-like passage between the two seals. Thus, any individual contaminating particles that pass through the lip seal can be trapped in the maze-like passage from the start, thereby preventing them from reaching the seal 18. Thus, some sort of sealing effect is provided by the maze-like passage. A sleeve element (28) is provided because the moving sliding surfaces (14, 15) can simply be produced. In particular, in the case of small centrifuges, the frictional heat generated at lower peripheral speeds is so low that it does not affect the unacceptable heating of the seal, thereby affecting the surface properties of the moving sliding surfaces (14, 15). Since it is not necessary to make such a high demand, at least the seal 18 can be provided directly between the flute tube 4 and the basket hub 2.

  Thus, complex and / or expensive comprising a sealing element 132 (see FIG. 1) between the flanges as described in the prior art and / or between the flange and the terminating element 131 or the sleeve element 133 The structure is no longer used. Since the seals (18, 19) can be placed at the entrance of the gap, the seal 118, which is rotatably fixedly connected to the drive shaft 103 and designed as a shaft seal, is overheated in a manner not allowed by frictional heat. Without the need for a connector element 134 with a sliding surface that can be slid over this surface and that also requires high surface properties.

  According to the embodiment of FIG. 2 or FIG. 3, it is no longer necessary to provide further cleaning possibilities for periodically cleaning the impurities in the gap 13, or the impurities are put into the gap 13 by a continuously usable flushing process. It is no longer necessary to prevent it from moving. The seal is placed at the gap inlet by disconnecting the force and thereby reducing the diameter of the drive shaft 3 and the flute tube 4, so that the particles of the filter cake that are unloaded are “entered” into the gap 13. There is no possibility and therefore any risk of contamination of the bearing device can be prevented.

  Since no impurities can enter the gap 13 during operation and in the assembled state, the deformation is also continuously flushed with an inert gas so that the impurities are carried out of the gap 113 along with the flushing flow. In addition, it is unnecessary to continuously introduce the inert gas into the gap 113 through the pipe 136 and the peripheral bore 137 described with reference to FIG. Thus, the centrifuge according to the present invention eliminates any further risk of unnecessary chemical reaction or further explosion as long as the function of the seal is ensured by sealing the area of the bearing device, so that the complex and / or the aforementioned It can be used for reactive and / or explosive media without expensive flushing. The seal is relatively easily accessible for inspection so that maintenance of the centrifuge is also simplified.

  FIG. 4 shows an overall view of the bearing device of the vertical centrifuge. The storage basket 1 is here shown unloaded. A discharge opening for the liquid is shown above the surface of the storage basket, said liquid leaving the basket by centrifugation through the discharge opening and being able to be collected in a housing arranged around the basket 1 . The basket 1 comprises a basket hub 2, which is supported on the flute 4 by means of a bearing device according to the invention. The drive shaft 3 is rotatably fixedly coupled to the basket 1 and is driven via a V-belt drive by an electric motor that functions as a drive unit. The V-belt drive can be made unnecessary by a deformation not shown. In this case, the drive motor is directly connected to the drive shaft 3 by the flange connecting portion.

It is a figure of the bearing apparatus for centrifuges of a prior art. It is sectional drawing which penetrates the bearing apparatus for centrifuges by this invention. FIG. 3 is a detailed view of the bearing device according to FIG. 2. 1 is an overall view of a vertical centrifuge according to the present invention comprising a drive unit.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Basket 2 Basket hub 3 Drive shaft 4 Flute pipe 5 Filter cake 6 Rotating shaft 7, 8, 9 Bearing 10 First end of drive shaft 11 Second end of drive shaft 12 Drive unit 13 Gap 14, DESCRIPTION OF SYMBOLS 15 Sliding sliding surface 16, 17 Fixed sliding surface 18 Shaft seal 19 Lip seal 20 Receiving means 21 Suspension device 22 Bearing block 23 Flange connection part 24 Flange 25 Connection means 26 Rib structure 27 Jacket 28 Sleeve element 29 Screw connection Part 101 Basket 102 Basket hub 103 Drive shaft 104 Flute tube 105 Filter cake 106 Rotating shaft 107, 108, 109 Bearing 110 First end of drive shaft 111 Second end of drive shaft 112 Drive unit 1 13 Gap 114, 115 Moving sliding surface 116, 117 Fixed sliding surface 118 Shaft seal 119 Lip seal 120 Receiving means 121 Suspension device 122 Bearing block 123 Flange connecting portion 124 Flange 125 Connecting means 126 Rib structure 127 Jacket 130 Screw Connecting portion 131 Terminal element 132 Sealing element 133 Sleeve element 134 Connector element 135 Positioning means for connector element 136 Passage 137 Peripheral bore 138 Fixing element 139 Cover

Claims (15)

  A bearing device for a basket (1) of a centrifuge, wherein the basket (1) is rotatably arranged around a rotating shaft (6), a basket hub (2), and the basket (1) The drive shaft (3) connected to the drive unit (12) extending along the rotation axis (6) in the bearing block (4, 7, 8, 9, 20, 24) via the suspension device (21) ) In a manner such that the bearing force generated by the dynamic force is substantially decoupled from the drive shaft (3). 7, 8, 9, 20, 24).   A seal (18, 19) is provided to seal the gap (13) between the bearing block (4, 7, 8, 9, 20, 24) and the basket hub (2). The bearing device according to 1.   At least one first bearing (7, 8) is provided for receiving a dynamic force generated by the rotational movement of the basket, and at least one second bearing (9) is provided on the drive shaft (3). The bearing device according to claim 1, wherein the bearing device is provided for guidance.   The bearing block (4, 7, 8, 9, 20, 24) comprises a flute tube (4) arranged coaxially around the drive shaft (3), and at least one of the bearings (7, 8, Bearing device according to any one of claims 1 to 3, wherein 9) is arranged between the flute tube (4) and the basket hub (2).   The basket hub (2) is rotatably fixedly attached to the first end (10) of the drive shaft via the suspension (21) of the basket (1), and at least the second The bearing (9) is arranged in the vicinity of the drive shaft or the second end (11) of the flute pipe (4), and the second end (11) can be connected to the drive unit (12). The bearing device according to claim 1, wherein the bearing device is configured as described above.   The drive shaft (3) is arranged along the substantially vertical axis of rotation (6), the drive shaft having a shaft diameter in the range of 10 mm to 300 mm, in particular, the shaft diameter being Especially between 10 mm and 150 mm, preferably in the range of 50 mm to 150 mm, the drive shaft has a length of 400 mm to 1,500 mm, especially 400 mm to 1,000 mm, especially 500 mm to 800 mm, preferably 600 mm to 700 mm. The diameter of the basket is from 300 mm to 2500 mm, in particular from 300 mm to 2,000 mm, preferably in the range from 400 mm to 1,600 mm. Bearing device.   7. The bearing device according to claim 1, wherein the gap (13) extends from at least the first bearing (7, 8) to the second bearing (9). 7.   The basket (1) is arranged in the vicinity of the gap (13) and comprises at least one discharge opening for carrying out a filter cake, and dust and / or particles and / or droplets, and / or The bearing device according to claim 1, wherein gas intrusion can be prevented by the seal (18, 19).   9. Bearing lubrication can be performed by a bore in the flute tube (4), which can be connected to a lubricant supply means outside the basket (1) of the centrifuge. The bearing apparatus as described in any one.   A moving sliding surface formed on the jacket surface of the basket hub (2) and an opposed fixed sliding formed on the jacket surface of the flute tube. The bearing device according to claim 1, wherein the bearing device is arranged between the surfaces (16, 17).   11. At least one of the seals (18, 19) is made as a shaft seal and / or as a lip seal and / or as a perimeter seal. The bearing device described.   12. A bearing device according to any one of the preceding claims, wherein the lip seal is arranged around the outer jacket surface of the basket hub (2).   The peripheral speed of the moving sliding surface in the operating state on the contact surface of the seal is below 100 m / s, in particular below 75 m / s, in particular below 50 m / s, in the case of grease lubrication below 40 m / s. 13. And / or preferably at least 10 m / s, in particular at least 5 m / s, and preferably at least 1 m / s during dry runs. Bearing device.   Interposition means for generating and maintaining an inert gas body in the space inside the basket hub (2) sealed by the seal (18, 19) is provided. The bearing apparatus as described in any one.   A vertical centrifuge having the bearing device according to any one of claims 1 to 14.

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