HYDROCLOGICAL ARRANGEMENT FOR CENTRIFUGAL SEPARATION OF SOUNDS FROM A SUSPENSION

Description

[0001] The invention relates to a hydrocyclone arrangement for the centrifugal separation of solids from a suspension, comprising at least one first hydrocyclone with a first separation chamber, a first inlet opening tangentially into the first separation chamber for feeding the suspension into the first separation chamber, a first underflow for discharging a separated heavy fraction and a first overflow pipe for discharging a depleted suspension fraction, at least one second hydrocyclone with a second separation chamber, a second inlet opening tangentially into the second separation chamber for feeding the suspension into the second separation chamber, a second underflow for discharging a separated heavy fraction and a second overflow pipe for discharging a depleted suspension fraction,and a common outlet for the depleted suspension fractions of both the at least one first hydrocyclone and the at least one second hydrocyclone.

[0002] WO 2018 / 091173 A1 describes a hydrocyclone arrangement for cleaning a fiber suspension with several hydrocyclone chambers of circular cross-section, into which an inlet and a light part outlet open at one end and a heavy part separator at the opposite end, wherein the inlets are connected to a common inlet via a common inlet chamber and the light part outlets are connected to a common light part outlet via separate outlet lines leading through the common inlet chamber.

[0003] DE 199 63 284 A1 describes an arrangement for controlling the operation of a hydrocyclone or a hydrocyclone arrangement, in which the shape of the discharge jet in the downstream flow of at least one hydrocyclone is detected using a probe, and the probe signal is fed to the control valve in the upstream flow line of the hydrocyclone or the upstream flow line of a hydrocyclone battery for adjusting the volume split. The upstream flow of each hydrocyclone is connected via a flexible hose serving as the upstream flow line to a common collection chamber, which is designed separately from the hydrocyclones.

[0004] The object of the invention is to provide a hydrocyclone arrangement for centrifugally separating solids from a suspension, which has an improved separation effect.

[0005] The problem is solved by a hydrocyclone arrangement for centrifugal separation of solids from a suspension, comprising: at least one first hydrocyclone with a first separation chamber, a first inlet opening tangentially into the first separation chamber for feeding the suspension into the first separation chamber, a first underflow for discharging a separated heavy fraction and a first overflow pipe for discharging a depleted suspension fraction, at least one second hydrocyclone with a second separation chamber, a second inlet opening tangentially into the second separation chamber for feeding the suspension into the second separation chamber, a second underflow for discharging a separated heavy fraction and a second overflow pipe for discharging a depleted suspension fraction, as well as a common outlet for the depleted suspension fractions of both the at least one first hydrocyclone and the at least one second hydrocyclone, wherein the common outlet is arranged within a common inlet housing of the hydrocyclone arrangement and the first overflow pipe and the second overflow pipe are each assigned a deflection device arranged within the inlet housing, which is designed to deflect the depleted suspension fraction emerging in the axial direction in a direction with a radial directional component, so that the depleted suspension fractions are each introduced into the common outlet with these radial directional components.

[0006] Hydrocyclones as such are designed to separate at least one heavy fraction from a suspension. The suspension comprises a carrier liquid, such as water, in which solid particles are dispersed. Depending on the flow behavior of the solid particles in the carrier liquid, a heavy fraction can be separated at an underflow of the hydrocyclone. The residual suspension, from which the heavy fraction is separated, can be referred to as the depleted suspension fraction. The depleted suspension fraction accordingly comprises the carrier liquid and any remaining solid particles after the heavy fraction has been separated. The depleted suspension fraction can contain remaining solid particles or be free of solid particles.

[0007] In principle, in a first operating mode of the hydrocyclone, the depleted suspension fraction can form an accept. The accept is therefore the fraction to be used as a product or intermediate. In such a first operating mode, the separated heavy fraction then forms a heavy reject. The heavy reject can be discarded with respect to the depleted suspension fraction representing the accept or can be subjected to a further process. For example, when hydrocyclones are used in paper production, the heavy fraction can comprise sand particles, glass splinters, or metal parts that must be sorted out. The solid particles forming the accept in the remaining depleted suspension fraction can comprise the desired fiber particles, which can be used for the paper production mentioned as an example.The depleted suspension fraction freed from the heavy fraction can therefore form a good substance.

[0008] In a different, second operating mode of the hydrocyclone, however, the separated heavy fraction can form the accept material. In this second operating mode, the accept material is the fraction to be used as a product or intermediate. In such a second operating mode, the depleted suspension fraction then forms what is known as a light reject. The light reject can be discarded with regard to the separated heavy fraction, which represents the accept material, or it can be subjected to a further process. For example, when using hydrocyclones in paper production, it may be desirable to separate ultrafine particles that have smaller grain sizes than the grain size distribution appropriate for paper production. The heavy fraction separated from the suspension feed stream can therefore form an accept material.

[0009] Using an additional centrifugal separation chamber on the hydrocyclone, an additional light fraction can optionally be separated from the suspension fraction depleted of the heavy fraction. The additional light fraction can be discharged via an optional discharge pipe on the hydrocyclone, separately from the suspension fraction depleted of the heavy fraction and the light fraction. Further solid particles may remain in the remaining depleted suspension fraction. These additional solid particles contained in the remaining depleted suspension fraction can also form an accept. In this context, the heavy fraction can form a heavy fraction reject, and the light fraction can also form a light fraction reject.For example, when using hydrocyclones in paper production, the heavy fraction may comprise sand particles, glass splinters, or metal parts that need to be sorted out, and the light fraction may comprise plastic particles, particularly expanded polystyrene particles, which may also need to be sorted out. The solid particles forming the accept in the remaining depleted suspension fraction may comprise the desired fiber particles, which can be used for the paper production mentioned as an example.

[0010] Regardless of the actual orientation of the hydrocyclone in space, the discharge device of the heavy fraction is generally referred to as the underflow and the discharge device of the remaining depleted suspension fraction, ie the residual suspension containing the accepts, is generally referred to as the overflow.

[0011] In the separation chamber, the suspension introduced into the hydrocyclone via the inlet is subjected to a vortex flow, allowing the heavy fraction to accumulate near the wall of the separation chamber and be discharged from there. The separation chamber usually has a conical shape that tapers toward the underflow, meaning at least the inner wall of the separation chamber is conical. However, designs with circular-cylindrical separation chamber walls are also possible.

[0012] The hydrocyclone arrangement comprises at least two hydrocyclones, i.e., at least one first hydrocyclone and at least one second hydrocyclone. However, in general terms, the hydrocyclone arrangement can comprise any number of individual hydrocyclones. Hydrocyclone arrangements with, for example, three individual hydrocyclones or four individual hydrocyclones are particularly suitable.

[0013] When several hydrocyclones are combined into a common hydrocyclone arrangement, a common outlet is used, in which the individual depleted suspension fractions from the individual hydrocyclones are combined into a common accept stream. The common outlet for the combined accept stream from the hydrocyclone arrangement can, in particular, be designed as an outlet chamber to which the overflow pipes of the individual hydrocyclones are fluidically connected. In the outlet chamber, the multiple depleted suspension fractions are combined into the common accept stream and are led away from the hydrocyclone arrangement, for example, via an outlet pipe connection fluidically connected to the outlet chamber.

[0014] If several hydrocyclones are combined into a common hydrocyclone arrangement, a common inlet casing can also be used, to which a common inlet nozzle is fluidically connected. Through this inlet nozzle, a feed suspension—that is, the initial suspension from which the heavy fraction and, if applicable, the light fraction are to be separated—is fed into the hydrocyclone arrangement. The inlets of the individual hydrocyclones then lead away from the common inlet casing, so that the feed suspension flow is distributed as evenly as possible among all hydrocyclones.

[0015] By assigning a deflection device arranged within the common inlet housing of the hydrocyclone arrangement to each of the first overflow pipe and the second overflow pipe, which deflection device is designed to deflect the depleted suspension fraction exiting in the axial direction in a direction with a radial directional component, so that the depleted suspension fractions are each introduced into the common outlet with these radial directional components, a compact hydrocyclone arrangement can be created that has an improved separation effect. The respective overflow pipe of each hydrocyclone is fluidically connected to a respective dip pipe of the hydrocyclone. The respective overflow pipe can be formed integrally with the respective dip pipe or co-form the dip pipe, or can be designed as a separate line section.An assembly comprising at least the first and second overflow pipes, as well as the common outlet or the common outlet chamber, can be made from one or more molded parts, in particular two molded parts.

[0016] The common outlet is arranged within the common inlet housing of the hydrocyclone arrangement, and the first overflow pipe of the at least one first hydrocyclone and the second overflow pipe of the at least one second hydrocyclone are each assigned a deflection device arranged within the inlet housing, which is designed to deflect the respective depleted suspension fraction exiting in the axial direction in a direction with a radial directional component, so that the depleted suspension fractions are each introduced into the common outlet with these radial directional components.

[0017] The common inlet housing can have an inlet channel which surrounds a peripheral wall of the common outlet. A partial section of the peripheral wall of the common outlet can thus form part of the inner channel wall of the inlet channel of the common inlet housing. The common feed material can be fed to the hydrocyclone arrangement via the inlet housing, in particular with a tangential directional component, and divided between the first inlet of the at least one first hydrocyclone and the second inlet of the at least one second hydrocyclone and fed to all existing hydrocyclones of the hydrocyclone arrangement 1. The fed feed material flow or the divided feed material flows can thus flow past the deflection devices or between two adjacent deflection devices, i.e. through spaces between two adjacent outlet pipe sockets.The deflection devices can be designed, in particular, as rigid pipe bends. The rigid pipe bends can be directly connected to the (rigid) immersion tubes of the hydrocyclones, in particular, they can be formed integrally with them. Alternatively, the rigid pipe bends can also be directly connected to a (rigid) shell wall of the common outlet, in particular, they can be formed integrally with it.

[0018] Within the common housing arrangement of inlet housing and common outlet, the inner diameter D1 of the outlet pipe socket, via which the depleted suspension fractions of the at least one first hydrocyclone and the at least one second hydrocyclone jointly leave the outlet via the overflow pipes, can be smaller than the diameter of the common circumferential circle of the plurality of hydrocyclones.

[0019] The common outlet pipe joint transports the combined depleted total suspension fraction of the at least one first hydrocyclone and the at least one second hydrocyclone centrally, i.e., centrally, out of the housing of the common outlet in a vertical direction. The common outlet pipe joint can be directed vertically upward, i.e., arranged to lead upwards out of the hydrocyclone arrangement. Alternatively, the common outlet pipe joint can be directed vertically downwards, i.e., arranged to lead downwards out of the hydrocyclone arrangement.

[0020] If the depleted suspension fractions are each introduced into the common outlet with these radial directional components, the first and second overflow pipes can be introduced laterally, i.e. on an outer jacket wall of the common outlet, into the common outlet. The common outlet, in particular the common outlet chamber, can be designed to be significantly smaller in circumference than is possible in the prior art if straight overflow pipes are connected directly in a vertical or axial direction to an underside of the common outlet, in particular the common outlet chamber, as is the case, for example, in WO2018 / 091173 A1 mentioned at the outset. By designing the common outlet, in particular the common outlet chamber, a change in the flow cross-section at the transition from each overflow pipe to the common outlet orto the common outlet chamber can be made less abrupt or even avoided altogether, whereby a sudden pressure change in the flow path of the depleted suspension fraction to be discharged can be reduced or even completely prevented.

[0021] A significant widening of the flow cross-section would be accompanied by a significant reduction in the average flow velocity. The associated pressure losses would, in turn, negatively impact the separation efficiency of the heavy fractions to be separated in the separation chambers. If the dip tubes of the overflow pipes are short, a disruption of the flow vortices directly at the inlet of the overflow pipes into the outlet or outlet chamber would also cause the flow vortex in the dip tubes to slow down, which would also reduce the separation efficiency. Remaining vortex flows would continue from the dip tubes into the outlet or outlet chamber, and only there would the vortex energy be completely dissipated. This also results in pressure losses, which would negatively impact the separation efficiency of the heavy fractions to be separated in the separation chambers.

[0022] These disadvantages can be reduced or even completely eliminated if the first overflow pipe and the second overflow pipe are each assigned a deflection device which is designed to deflect the depleted suspension fraction emerging in the axial direction in a direction with a radial directional component, so that the depleted suspension fractions are each introduced into the common outlet with these radial directional components. As a result, abrupt jumps in the flow cross-section can be at least reduced or even completely avoided. The individual depleted suspension fractions of all hydrocyclones can be deflected via the first and second overflow pipes as long as the individual depleted suspension fractions are still guided separately and before they are combined in the centrally arranged outlet or into the centrally arranged outlet chamber of the hydrocyclone arrangement.

[0023] By combining the individual depleted suspension fractions of all hydrocyclones into a narrow outlet or into a narrow outlet chamber, a particularly space-saving arrangement is created on the hydrocyclone arrangement, not only for the discharge of the depleted suspension fractions from the hydrocyclone arrangement, but also for the inlet arrangement of the feed suspension stream.

[0024] The deflection devices can be designed to deflect the depleted suspension fraction guided in an axially extending dip pipe section of the respective overflow pipe by at least 30 degrees, in particular by at least 45 degrees, from the axial direction.

[0025] Each first overflow pipe and each second overflow pipe can be assigned a separate deflection device so that a respective deflection of each depleted suspension fraction can take place individually, i.e. separately or independently of each other.

[0026] The deflection devices can be designed to deflect the depleted suspension fraction, which is guided in an axially extending dip tube section of the respective overflow pipe, by at least 65 degrees, in particular by 90 degrees, from the axial direction. This means that the suspension fraction is preferably deflected between 65 degrees and 90 degrees, in particular by exactly 90 degrees. However, slight deviations from this 90 degrees are also possible, provided that the effect according to the invention still occurs despite this deviation. Thus, the individual depleted suspension fractions can be deflected from their axial directions into radial directions.

[0027] The deflection devices can each be formed by a pipe bend which connects the respective axially extending immersion pipe section of the respective hydrocyclone with the common outlet.

[0028] By using pipe bends, the overflow pipes of all hydrocyclones can be easily connected to the outlet or outlet chamber. The size, especially the outer diameter of the outlet or outlet chamber, can be freely selected, as it is independent of the location, size, and arrangement of the individual hydrocyclones.

[0029] The flow cross-sections in the outlet or in the outlet chamber can be selected so that no sudden changes in flow cross-section and thus no sudden changes in flow velocity occur. In particular, the outlet or the outlet chamber can have a constant flow cross-section. A flow cross-section, in particular the narrowest flow cross-section of the outlet or the outlet chamber, can correspond to the sum of all individual flow cross-sections of the individual overflow pipes of the multiple hydrocyclones or the dip pipes of the multiple hydrocyclones. The flow vortices in the individual dip pipes of the hydrocyclones can also continue into the respectively assigned individual pipe bends, so that fewer negative effects occur in the separation chambers. The individual pipe bends can have the same flow cross-section as the individual dip pipes of the hydrocyclones.

[0030] An average radius of curvature at the respective pipe bend can correspond to one to three times the average radius of the immersion pipe section of the respective hydrocyclone.

[0031] For example, the outer radius of curvature of the respective pipe bend can essentially correspond to the radius of the immersion pipe section of the respective hydrocyclone. Alternatively, the average radius of curvature of the respective pipe bend can essentially correspond to the radius of the immersion pipe section of the respective hydrocyclone. In this case, the outer radius of curvature of the respective pipe bend is greater than the radius of the immersion pipe section of the respective hydrocyclone. In a further variant, the inner radius of curvature of the respective pipe bend can essentially correspond to the radius of the immersion pipe section of the respective hydrocyclone. In this case, both the outer radius of curvature and the average radius of curvature of the respective pipe bend are greater than the radius of the immersion pipe section of the respective hydrocyclone.

[0032] Each pipe bend can be followed by a straight pipe section in the direction of flow, which fluidically connects the respective pipe bend with the common outlet.

[0033] In a special configuration of the hydrocyclone arrangement, the respective straight pipe sections can be arranged at an angle of less than 90 degrees, in particular at an angle between 45 degrees and 20 degrees, for example 25 degrees, to the horizontal cross-sectional plane of the hydrocyclone arrangement or the hydrocyclones. Regardless of the actual spatial orientation of the hydrocyclones in space, the position of the horizontal cross-sectional plane means a position of the plane perpendicular to the axial extent of the hydrocyclones. The axial extent of the hydrocyclones results from the axis of rotation of the separation vortex flow of the respective hydrocyclone.

[0034] The hydrocyclone arrangement can have a common inlet housing for the at least one first hydrocyclone and the at least one second hydrocyclone, to which the at least one first inlet and the at least one second inlet are connected, wherein the deflection devices are arranged within the outer contour of the common inlet housing.

[0035] Due to the deflection devices, the common outlet or the common outlet chamber can be made significantly smaller, which means that more space is available to feed the common feed suspension within the common inlet housing and distribute it to the individual hydrocyclones.

[0036] The hydrocyclone arrangement may comprise at least three hydrocyclones, the cyclone axes of which are arranged parallel to one another and lie on a common circumferential circle of the hydrocyclone arrangement and the common outlet is arranged in the center of the circumferential circle between the at least three hydrocyclones.

[0037] The common outlet may comprise an outlet pipe socket which is designed to discharge the depleted suspension fractions combined in the common outlet from the common outlet to the outside of the hydrocyclone arrangement, wherein the inner diameter of the outlet pipe socket is smaller than the diameter of the common circumferential circle of the at least three hydrocyclones.

[0038] Thanks to the use of deflection devices, the outlet no longer needs to extend completely over all of the hydrocyclone's overflow pipes, but can be significantly smaller in circumference. The deflection devices can therefore bridge any existing distances between the overflow pipes and the outlet.

[0039] The smallest flow cross-sectional area of ​​the outlet pipe socket can be smaller than or equal to the sum of the flow cross-sectional areas of the overflow pipes of all hydrocyclones in the hydrocyclone arrangement. This ensures that the flow cross-sectional area in the flow path is not expanded, thus preventing pressure loss.

[0040] The deflection devices can be designed to deflect the depleted suspension fractions guided in the respective overflow pipes in a direction with a tangential directional component, so that the depleted suspension fractions are each introduced into the common outlet with a tangential directional component.

[0041] The energy from the flow vortices in the overflow pipes, especially in the dip pipes and possibly in the pipe bends, can be converted into a common vortex flow by a tangential feed into the common outlet or into the common outlet chamber, which can avoid through losses and further improve the separation effect of the hydrocyclones.

[0042] The deflection devices can be designed to introduce the depleted suspension fractions into the common outlet with a tangential directional component, in which the resulting flow angular momentum of the overall flow within the common outlet has the same direction as the individual flow angular momentum in the individual hydrocyclones.

[0043] By tangentially feeding the individual depleted suspension fractions into the combined outlet, a rotating flow can be generated in the outlet chamber, for example. Such a rotating flow in the outlet chamber can then optionally form an additional centrifugal separation chamber, from which, for example, undersize particles can be separated as a light fraction from the combined depleted suspension fraction. Such a device is also referred to as a light fraction cleaner.

[0044] The deflection devices may comprise guide plates which are arranged in the common outlet and which deflect the depleted suspension fractions guided in the respective overflow pipes within the common outlet in a direction with a tangential directional component, so that the depleted suspension fractions entering the common outlet are each diverted in a tangential directional component.

[0045] By means of the guide plates, alternatively or in addition to a tangential supply of the individual depleted suspension fractions entering the common outlet, a differently generated or, if appropriate, a supporting, in particular reinforced, vortex flow or rotation flow can be generated in the outlet, in particular in an outlet chamber.

[0046] The outlet can optionally be designed as an additional centrifugal separation chamber, with a coaxially arranged discharge pipe dipping into its center. This discharge pipe is designed to discharge a light fraction separated from the combined, depleted suspension fraction. This allows for additional light fraction separation in a compact design. The special design of the outlet chamber eliminates the need for an additional, separate centrifugal separator.

[0047] The discharge pipe can be routed downwards from the centrifugal separation chamber on a side of the separation chamber facing the hydrocyclone separation chambers. This allows for a space-saving routing for the discharge of the separated light fraction from the hydrocyclone arrangement.

[0048] Specific embodiments of the invention are explained in more detail in the following description with reference to the accompanying figures. Regardless of the specific context in which they are mentioned, specific features of these exemplary embodiments may represent general features of the invention, even when considered individually or in further combinations.

[0049] They show: Fig. 1 a sectional view of a concrete embodiment of a hydrocyclone arrangement according to the invention, Fig. 2 a partially sectioned perspective view of the hydrocyclone arrangement according to Fig. 1 in a view obliquely from above, Fig. 3 a schematic representation of a cross section through a first variant of a hydrocyclone arrangement with a common outlet and four hydrocyclones which are connected by means of four radially aligned deflection devices, Fig. 4 a schematic representation of a cross section through a second variant of a hydrocyclone arrangement with a common outlet and four hydrocyclones which are connected by means of four tangentially aligned deflection devices, Fig. 5 a schematic representation of a cross section through a third variant of a hydrocyclone arrangement with a common outlet and three hydrocyclones which are connected by means of three radially aligned deflection devices, and Fig. 6 a schematic representation in longitudinal section of a modified embodiment of a hydrocyclone arrangement with a downwardly discharging discharge pipe for a light fraction.

[0050] In the Fig. 1 A hydrocyclone arrangement 1 for centrifugally separating solids from a suspension is shown. The hydrocyclone arrangement 1 comprises at least one first hydrocyclone 2.1, with a first separation chamber 3.1, a first inlet 4.1 opening tangentially into the first separation chamber 3.1 for feeding the suspension into the first separation chamber 3.1, a first underflow 5.1 for discharging a separated heavy fraction, and a first overflow pipe 6.1 for discharging a depleted suspension fraction.

[0051] The hydrocyclone arrangement 1 also has at least one second hydrocyclone 2.2, with a second separation chamber 3.2, a second inlet 4.2 opening tangentially into the second separation chamber 3.2 for feeding the suspension into the second separation chamber 3.2, a second underflow 5.2 for discharging a separated heavy fraction and a second overflow pipe 6.2 for discharging a depleted suspension fraction.

[0052] The hydrocyclone arrangement 1 comprises a common outlet 7 for the depleted suspension fractions of both the at least one first hydrocyclone 2.1 and the at least one second hydrocyclone 2.2.

[0053] According to the invention, a deflection device 8.1, 8.2 is assigned to each of the first overflow pipe 6.1 and the second overflow pipe 6.2, which deflection device is designed to deflect the depleted suspension fraction exiting in the axial direction into a direction with a radial directional component, so that the depleted suspension fractions are each introduced into the common outlet 7 with these radial directional components.

[0054] In the case of the present embodiment, the deflection devices 8.1, 8.2 are designed to deflect the depleted suspension fraction, which is guided in an axially extending dip pipe section 9.1, 9.2 of the respective overflow pipe 6.1, 6.2, by 90 degrees from the axial direction. As shown in Fig. 1 The depleted suspension fractions are accordingly diverted from their vertical flow directions into radial, ie horizontal, flow directions.

[0055] In the case of the present embodiment, the deflection devices 8.1, 8.2 are each formed by a pipe bend which connects the respective axially extending immersion pipe section 9.1, 9.2 of the respective hydrocyclone 2.1, 2.2 with the common outlet 7.

[0056] As particularly in Fig.1 and Fig. 2 As shown, the hydrocyclone arrangement 1 for the at least one first hydrocyclone 2.1 and the at least one second hydrocyclone 2.2 has a common inlet housing 10, to which the at least one first inlet 4.1 and the at least one second inlet 4.2 are connected. The deflection devices 8.1, 8.2 are arranged within the outer contour of the common inlet housing 10.

[0057] The common outlet 7 is arranged within the common inlet housing 10 of the hydrocyclone arrangement 1 and the first overflow pipe 6.1 of the at least one first hydrocyclone 2.1 and the second overflow pipe 6.2 of the at least one second hydrocyclone 2.2 are each assigned a deflection device 8.1, 8.2 arranged within the inlet housing 10, which is designed to deflect the respective depleted suspension fraction exiting in the axial direction in a direction with a radial directional component, so that the depleted suspension fractions are each introduced into the common outlet 7 with these radial directional components.

[0058] The common inlet housing 10 has an inlet channel that surrounds a peripheral wall of the common outlet 7. A partial section of the peripheral wall of the common outlet 7 can thus form part of the inner channel wall of the inlet channel of the common inlet housing 10. The common feed material is fed to the hydrocyclone arrangement 1 via the inlet housing 10, in particular with a tangential directional component, and distributed between the first inlet 4.1 of the at least one first hydrocyclone 2.1 and the second inlet 4.2 of the at least one second hydrocyclone 2.2, and fed to all existing hydrocyclones 2.1, 2.2 of the hydrocyclone arrangement 1. The supplied feed material flow or the divided feed material flows flow past the deflection devices 8.1, 8.2 or between two adjacent deflection devices 8.1, 8.2, iethrough gaps between two adjacent outlet pipe sockets 7a. The deflection devices 8.1, 8.2 can be designed, in particular, as rigid pipe bends. The rigid pipe bends can be directly connected to the (rigid) immersion pipes of the hydrocyclones 2.1 and 2.2, in particular, formed integrally therewith. Alternatively, the rigid pipe bends can also be directly connected to a (rigid) shell wall of the common outlet 7, in particular, formed integrally therewith.

[0059] Within the common housing arrangement of inlet housing 10 and common outlet 7, the inner diameter D1 of the outlet pipe socket 7a, via which the depleted suspension fractions of the at least one first hydrocyclone 2.1 and the at least one second hydrocyclone 2.2 jointly leave the outlet 7 via the overflow pipes 6.1, 6.2, is smaller than the diameter D2 of the common circumferential circle U of the plurality of hydrocyclones 2.1 and 2.2.

[0060] The common outlet pipe 7a transports the combined depleted suspension fraction of the at least one first hydrocyclone 2.1 and the at least one second hydrocyclone 2.2 centrally, ie centrally, out of the housing of the common outlet 7 in a vertical direction. The common outlet pipe 7a can, as in Fig. 1 shown, be guided vertically upwards, ie be arranged leading upwards out of the hydrocyclone arrangement 1. Alternatively, the common outlet pipe socket 7a can be guided vertically downwards, ie be arranged leading downwards out of the hydrocyclone arrangement 1.

[0061] A common inlet nozzle 10a is fluidically connected to the common inlet casing 10, as is particularly the case in Fig. 2 is shown, via which a feed suspension, ie the initial suspension from which the heavy fraction and optionally also the light fraction are to be separated, is fed to the hydrocyclone arrangement 1. The inlets 4.1, 4.2 of the individual hydrocyclones 2.1, 2.2 then lead away from the common inlet housing 10, so that the feed suspension flow is distributed as evenly as possible between all hydrocyclones 2.1, 2.2.

[0062] The common outlet 7 comprises an outlet pipe socket 7a, which is designed to discharge the depleted suspension fractions combined in the common outlet 7 from the common outlet 7 to the outside of the hydrocyclone arrangement 1, wherein the inner diameter D1 of the outlet pipe socket 7a is smaller than the diameter D2 of the common circumferential circle U of the hydrocyclones 2.1, 2.2.

[0063] The smallest flow cross-sectional area of ​​the outlet pipe socket 7a can in particular be smaller than or at most equal to the sum of the flow cross-sectional areas of the overflow pipes 6.1, 6.2 of all hydrocyclones 2.1, 2.2 of the hydrocyclone arrangement 1.

[0064] As particularly in Fig. 4 As shown, in such an embodiment, the deflection devices 8.1, 8.2 can be designed to deflect the depleted suspension fractions guided in the respective overflow pipes 6.1, 6.2 in a direction with a tangential directional component, so that the depleted suspension fractions are each introduced into the common outlet 7 with a tangential directional component. The deflection devices 8.1, 8.2 can be designed to introduce the depleted suspension fractions into the common outlet 7 with a tangential directional component, in which the resulting flow angular momentum of the overall flow within the common outlet 7 has the same direction as the individual flow angular momentum in the individual hydrocyclones 2.1, 2.2.

[0065] In the case of the present embodiment, the hydrocyclone arrangement 1 comprises a total of four hydrocyclones, i.e. two first hydrocyclones 2.1 and two second hydrocyclones 2.2, whose cyclone axes A arranged parallel to one another lie on a common circumferential circle U of the hydrocyclone arrangement 1, wherein the common outlet 7 is arranged in the center Z of the circumferential circle U between the four hydrocyclones 2.1, 2.2, as is particularly shown in Fig. 3 und Fig. 4 The same applies to a hydrocyclone arrangement 1 with, for example, three hydrocyclones 2.1, 2.2, as shown by Fig. 5 is illustrated.

[0066] The Fig. 6shows a further embodiment in which the outlet 7 is designed as a further centrifugal separation chamber 12, into the center of which a coaxially arranged discharge pipe 11 dips, which is designed to discharge a light fraction separated from the combined, depleted suspension fraction. In this embodiment, the discharge pipe 11 is directed downwards away from the centrifugal separation chamber 12 on a side of the separation chamber facing the separation chambers 3.1, 3.2 of the hydrocyclones 2.1, 2.2. Alternatively, the discharge pipe for a light fraction could also be mounted at the upper end of the separation chamber.

Claims

1. Hydrocyclone assembly for the centrifugal separation of solids from a slurry, comprising: - at least one first hydrocyclone (2.1) which has a first separating chamber (3.1), a first inflow (4.1) which leads tangentially into the first separating chamber (3.1) and is intended for feeding the slurry into the first separating chamber (3.1), a first underflow (5.1) for discharging a separated-out heavy fraction and a first overflow pipe (6.1) for discharging a depleted slurry fraction, - at least one second hydrocyclone (2.2) which has a second separating chamber (3.2), a second inflow (4.2) which leads tangentially into the second separating chamber (3.2) and is intended for feeding the slurry into the second separating chamber (3.2), a second underflow (5.2) for discharging a separated-out heavy fraction and a second overflow pipe (6.2) for discharging a depleted slurry fraction, and - a common outlet (7) for the depleted slurry fractions of both the at least one first hydrocyclone (2.1) and the at least one second hydrocyclone (2.2), characterized in that the common outlet (7) is inside a common inlet housing (10) of the hydrocyclone assembly (1), and the first overflow pipe (6.1) and the second overflow pipe (6.2) are assigned a respective deflection device (8.1, 8.2), which is inside the inlet housing (10) and is designed to deflect the axially exiting depleted slurry fraction in a direction with a radial directional component, with the result that the depleted slurry fractions are introduced into the common outlet (7) in each case with these radial directional components.

2. Hydrocyclone assembly according to Claim 1, characterized in that the deflection devices (8.1, 8.2) are designed to deflect the depleted slurry fraction, which is carried in each case in an axially extending immersion pipe portion (9.1, 9.2) of the respective overflow pipe (6.1, 6.2), from the axial direction by at least 30 degrees.

3. Hydrocyclone assembly according to Claim 1 or 2, characterized in that the deflection devices (8.1, 8.2) are designed to deflect the depleted slurry fraction, which is carried in each case in an axially extending immersion pipe portion (9.1, 9.2) of the respective overflow pipe (6.1, 6.2), from the axial direction by at least 65 degrees.

4. Hydrocyclone assembly according to one of Claims 1 to 3, characterized in that the deflection devices (8.1, 8.2) are formed by a respective pipe bend, which connects the respective axially extending immersion pipe portion (9.1, 9.2) of the respective hydrocyclone (2.1, 2.2) to the common outlet (7).

5. Hydrocyclone assembly according to Claim 4, characterized in that an average radius of curvature on the respective pipe bend corresponds to one to three times the average radius of the immersion pipe portion (9.1, 9.2) of the respective hydrocyclone (2.1, 2.2).

6. Hydrocyclone assembly according to Claim 4 or 5, characterized in that adjoining the respective pipe bend in the flow direction is a respective straight pipe piece, which places the respective pipe bend in flow connection with the common outlet (7).

7. Hydrocyclone assembly according to one of Claims 1 to 6, characterized in that the hydrocyclone assembly (1) has, for the at least one first hydrocyclone (2.1) and the at least one second hydrocyclone (2.2), a common inlet housing (10) to which the at least one first inflow (4.1) and the at least one second inflow (4.2) are connected, and the deflection devices (8.1, 8.2) are inside the outer contour of the common inlet housing (10).

8. Hydrocyclone assembly according to one of Claims 1 to 7, characterized in that the hydrocyclone assembly (1) comprises at least three hydrocyclones (2.1, 2.2), the mutually parallel cyclone axes (A) of which lie on a common circumferential circle (U) of the hydrocyclone assembly (1) and the common outlet (7) is in the centre (Z) of the circumferential circle (U) between the at least three hydrocyclones (2.1, 2.2).

9. Hydrocyclone assembly according to Claim 8, characterized in that the common outlet (7) comprises an outlet pipe fitting (7a), which is designed to discharge the depleted slurry fractions merged in the common outlet (7) from the common outlet (7) and out of the hydrocyclone assembly (1), wherein the inside diameter (D1) of the outlet pipe fitting (7a) is smaller than the diameter (D2) of the common circumferential circle (U) of the at least three hydrocyclones (2.1, 2.2).

10. Hydrocyclone assembly according to one of Claims 1 to 9, characterized in that the deflection devices (8.1, 8.2) are designed to deflect the depleted slurry fractions, which are carried in the respective overflow pipes (6.1, 6.2), in each case in a direction which has a tangential directional component, with the result that the depleted slurry fractions are introduced into the common outlet (7) in each case with a tangential directional component.

11. Hydrocyclone assembly according to Claim 10, characterized in that the deflection devices (8.1, 8.2) are designed to introduce the depleted slurry fractions into the common outlet (7) in each case with a tangential directional component and, for the depleted slurry fractions, the resulting angular momentum of the overall flow inside the common outlet (7) has the same direction as the individual angular momenta of the flows in the individual hydrocyclones (2.1, 2.2).

12. Hydrocyclone assembly according to one of Claims 1 to 11, characterized in that the deflection devices (8.1, 8.2) comprise baffles, which are in the common outlet (7) and deflect the depleted slurry fractions, which are carried in the respective overflow pipes (6.1, 6.2) and are in each case inside the common outlet (7), in a direction which has a tangential directional component, with the result that the depleted slurry fractions entering the common outlet (7) are diverted in each case into a tangential directional component.

13. Hydrocyclone assembly according to one of Claims 1 to 12, characterized in that the depleted slurry fraction freed of the heavy fraction forms a product material.

14. Hydrocyclone assembly according to one of Claims 1 to 12, characterized in that the heavy fraction separated out of the supplied slurry stream forms a product material.

15. Hydrocyclone assembly according to one of Claims 1 to 14, characterized in that the outlet (7) is in the form of a further centrifugal separation space (12), into the centre of which dips a coaxial extraction pipe (11), which is designed to discharge a light fraction separated out of the merged, depleted slurry fraction.

16. Hydrocyclone assembly according to Claim 15, characterized in that the extraction pipe (11), on a separation-space side that faces the separating chambers (3.1, 3.2) of the hydrocyclones (2.1, 2.2), leads away downwards from the centrifugal separation space (12).

17. Hydrocyclone assembly according to Claim 15, characterized in that the extraction pipe (11'), on a separation-space side that faces away from the separating chambers (3.1, 3.2) of the hydrocyclones (2.1, 2.2), leads away upwards from the centrifugal separation space (12).