Hydrocyclone apparatus for centrifugally separating solids from a suspension

Abstract

The invention relates to a hydrocyclone device (1) for centrifugal separation of solids from a suspension, comprising at least one first hydrocyclone (2.1), at least one second hydrocyclone (2.2) and a common feed chamber (10) with a feed opening (10a) for introducing a suspension feed stream into the common feed chamber (10) and a plurality of flow outlets (11.1, 11.2, 11.3, 11.4) corresponding to the first and second hydrocyclones (2.1, 2.2) for leading respective shares of the suspension out of the common feed chamber (10) into first and second inlets (4.1, 4.2) of the first and second hydrocyclones (2.1, 2.2), wherein the common feed chamber (10) is designed as an annular chamber to which the feed opening (10a) is connected in order to form a circulation.

Description

[0001] This invention relates to a hydrocyclone apparatus for centrifugally separating solids from a suspension, comprising: at least one first hydrocyclone having a first separation chamber, a first inlet tangentially connected to the first separation chamber for inputting a first portion of the suspension feed stream into the first separation chamber, a first lower overflow outlet for outputting the separated heavy components or heavy fractions, and a first upper overflow pipe for outputting the depleted suspension fractions; at least one second hydrocyclone having a second separation chamber, a second inlet tangentially connected to the second separation chamber for inputting a second portion of the suspension feed stream into the second separation chamber, a second lower overflow outlet for outputting the separated heavy components, and a second upper overflow pipe for outputting the depleted suspension fractions; and a common supply chamber having a supply port for introducing the suspension feed stream into the common supply chamber and a plurality of outlets corresponding to the plurality of first and second hydrocyclones, the outlets being used to draw corresponding portions of suspension from the common supply chamber to the first and second inlets of the first and second hydrocyclones.

[0002] Patent document WO 2018 / 091173 A1 describes a hydrocyclone device for purifying a suspension of fibrous materials, which has multiple hydrocyclone chambers with circular cross-sections. Each of these chambers has an inlet and a light component outlet at one end and a heavy component separator at the opposite end. The inlets are connected to a common supply port through a common supply chamber, and the light component outlet is connected to a common light component discharge port through a separate outlet pipe that passes through the common supply chamber.

[0003] Patent document US 3,543,931 describes a hydrocyclone device having multiple hydrocyclones, to which a fluid suspension is supplied via a common supply chamber. Multiple hydrocyclones are arranged linearly side-by-side in two parallel rows, wherein the supply chamber has two straight supply channels arranged parallel to each other, the tops of which decrease in height continuously.

[0004] Patent document DE 828 346 describes a method for purifying a non-uniform liquid mixture, particularly pulp. Purification is achieved by forming an annular vortex band of the mixture within a vertical cylindrical vortex chamber. Multiple cylinders arranged in a circular pattern are supplied tangentially through a common circular, gradually tapering conduit, and the purified pulp is similarly extracted through a circular, widening conduit. In the lower part of the cylindrical vortex chamber, the downward movement of the annular band is blocked by the bottom of the cylinders. The portion rich in heavy impurities is extracted at the bottom height, while the remainder of the mixture is extracted at the center of the upper part of the chamber. The portion rich in heavy impurities is extracted laterally and outward, preferably tangentially relative to the cylindrical chamber wall, using the centrifugal force generated by the vortex motion.

[0005] The technical problem to be solved by the present invention is to provide a hydrocyclone device for centrifugally separating solids from a suspension, which can be operated with high reliability and has a compact structure. Furthermore, improvements in the separation effect are sought where necessary.

[0006] This technical problem is solved by a hydrocyclone device for centrifugally separating solids from a suspension, comprising:

[0007] - At least one first hydrocyclone, having a first separation chamber, a first inlet tangentially connected to the first separation chamber for inputting a first portion of the suspension feed stream into the first separation chamber, a first lower overflow outlet for outputting the separated heavy component (or heavy fraction), and a first upper overflow pipe for outputting the depleted suspension portion (or suspension fraction).

[0008] - At least one second hydrocyclone, having a second separation chamber, a second inlet tangentially opening into the second separation chamber for inputting a second portion of the suspension feed stream into the second separation chamber, a second lower overflow outlet for outputting the separated heavy components, and a second upper overflow pipe for outputting the depleted suspension portion; and

[0009] - A common supply chamber having a supply port for introducing a suspension feed stream into the common supply chamber and multiple outlets corresponding to multiple first and second hydrocyclones, these outlets being used to draw a corresponding portion of the suspension from the common supply chamber into the first and second inlets of the first and second hydrocyclones, wherein

[0010] i. The common supply chamber is designed as an annular cavity, and the supply port is connected to the annular cavity to form a circulation, wherein the supply chamber (10) is arranged above the hydrocyclones (2.1, 2.2) and the radial extension is less than the common radial extension of the hydrocyclones (2.1, 2.2).

[0011] The feed port can be connected eccentrically to form a circulating flow. The eccentric arrangement or orientation of the feed port here means that the suspension feed flow into the annular cavity through the feed port is not radially directed towards the center, but rather eccentrically, particularly off-center. In particular, the feed port can be connected tangentially to the feed cavity to form a circulating flow. In this respect, the suspension feed flow into the annular cavity can be tangential.

[0012] Hydrocyclones are designed to separate at least one heavy component from a suspension. The suspension includes a carrier liquid, such as water, in which solid particles are dispersed. The heavy component can be separated at the lower outlet of the hydrocyclone based on the flow characteristics of the solid particles in the carrier liquid. The remaining suspension after the heavy component has been separated can be referred to as the depleted suspension fraction. Therefore, after the heavy component has been separated, the depleted suspension fraction includes the carrier liquid and, if necessary, residual solid particles. The depleted suspension fraction may or may not contain residual solid particles.

[0013] Essentially, in the first operating mode of a hydrocyclone, the lean suspension portion can constitute qualified material. In this respect, qualified material is the portion intended to be used as a product or intermediate product. In this first operating mode, the separated heavy components constitute heavy component waste. Heavy component waste can be discarded or further processed relative to the lean suspension portion representing qualified material. For example, in the case of a hydrocyclone used in papermaking, heavy components might include, for example, sand, glass fragments, or metal parts to be sorted out. The solid particles constituting qualified material in the remaining lean suspension portion can include desired fibrous particles, which can be used in the exemplarily mentioned papermaking process.

[0014] Conversely, in a different second operating mode of the hydrocyclone, the separated heavy components can constitute qualified material. In this second operating mode, the qualified material, for this purpose, is the portion intended to be used as a product or intermediate product. In this second operating mode, the depleted suspension portion constitutes what is called light component waste. Light component waste can be discarded or further processed relative to the separated heavy components representing qualified material. For example, in the case of a hydrocyclone used in papermaking, it may be desirable to separate the finest particles with a particle size smaller than the particle size distribution suitable for papermaking.

[0015] Regardless of the actual orientation of the hydrocyclone in space, the outlet mechanism for the heavy components is generally referred to as the lower overflow port (or downflow device), and the outlet mechanism for the remaining depleted suspension portion, i.e. the remaining suspension containing qualified materials, is generally referred to as the upper overflow port (or upflow device).

[0016] In the separation chamber, the suspension introduced into the hydrocyclone through the inlet is made into a vortex, so that heavy components can accumulate near the walls of the separation chamber and can be discharged from there. The separation chamber typically has a tapered shape that tapers gradually towards the downward overflow outlet; that is, at least the inner wall of the separation chamber is designed to be tapered. However, a design with cylindrical separation chamber walls is also feasible.

[0017] A hydrocyclone device comprises at least two hydrocyclones, namely at least one first hydrocyclone and at least one second hydrocyclone. However, in general, a hydrocyclone device can have any number of individual hydrocyclones. A ring arrangement allows for a particularly compact construction. For example, a hydrocyclone device with three individual hydrocyclones or four individual hydrocyclones arranged in a ring is particularly advantageous.

[0018] When multiple hydrocyclones are combined into a common hydrocyclone apparatus, a common supply chamber is used, and if necessary, a common outlet, in which the lean suspension portions of the individual hydrocyclones are merged into a common qualified material stream. The common outlet of the hydrocyclone apparatus for merging the qualified material stream can be particularly designed as an outlet cavity, to which the overflow pipes of each hydrocyclone are flow-technically connected. In the outlet cavity, the multiple lean suspension portions are merged into a common qualified material stream and guided away from the hydrocyclone apparatus, for example, through an outlet pipe fitting flow-technically connected to the outlet cavity. To achieve a particularly compact configuration, the common outlet is arranged radially centered between the hydrocyclones.

[0019] In a particularly compact embodiment, the common outlet or outlet cavity is radially arranged within the supply chamber. Preferably, the supply chamber and the outlet cavity are arranged to at least partially overlap axially above the hydrocyclone. Thus, the supply chamber is arranged to coaxially surround the outlet cavity radially outward through an axial section.

[0020] When multiple hydrocyclones are combined into a common hydrocyclone device, a common supply chamber can also be used. A common supply port, such as a supply pipe fitting, is connected to this common supply chamber in a flow-technical manner. Through this common supply port, the initial suspension from which the heavy components are to be separated, and if necessary, the light components, is fed into the hydrocyclone device. In this case, multiple outlets, such as outlet pipe fittings, in the inlets of each hydrocyclone are located away from the common supply chamber in order to divide the feed suspension flow as evenly as possible into individual suspension portions and distribute or lead it out to all hydrocyclones.

[0021] The common supply chamber is designed as an annular cavity, and the supply port is particularly eccentrically or tangentially connected to the annular cavity to form a circulation, thereby realizing a hydrocyclone device for centrifugal separation of solids from a suspension, which can be operated with high reliability and, if necessary, can also have improved separation performance.

[0022] By feeding the suspension stream, particularly eccentrically or tangentially, into the annular cavity to form a circulation, the suspension feed stream is conveyed through a defined annular channel flow, which is sequentially guided to all inlets of all hydrocyclones in the hydrocyclone apparatus. This prevents the suspension feed stream from entering the large cavity uncontrolled or uncertainly, as is known in the prior art. Specifically, on the one hand, such a large cavity causes high pressure loss due to the sudden expansion of the flow cross-section when the suspension feed stream enters the cavity from the feed inlet; on the other hand, the entering suspension feed stream diffuses uncontrollably within the large cavity, accompanied by corresponding local vortices and / or dead zones, in which the flow may almost or completely stagnate. In this respect, undesirable vortices and / or dead zones can cause and promote sedimentation and agglomeration, which can block the flow path in the hydrocyclone apparatus, leading to undesirable disturbances and malfunctions. By designing the common supply chamber as an annular cavity, with the supply port tangentially connected to this annular cavity, sudden expansion of the flow cross-section and thus high pressure loss can be prevented or at least significantly reduced, local vortices can be prevented, and / or dead zones can be largely or completely avoided. Therefore, the risk of sediment and agglomeration in the hydrocyclone unit is reduced, and the likelihood of disturbances and malfunctions in the hydrocyclone unit is thus reduced. This improves operational reliability. Furthermore, the desired separation effect can be improved due to less sediment and agglomeration and lower pressure loss. Particularly in the aforementioned papermaking process, the suspension feed flow may contain solid particles with significantly deviated shapes from spherical forms, such as small sticks or threads, which imply a higher risk of sedimentation, agglomeration, and / or clogging.

[0023] The common supply chamber can be designed as a circular annular cavity with an annular main flow channel wall. This circular annular cavity with an annular main flow channel wall not only facilitates uniform and unobstructed flow of the suspension feed within the supply chamber but also promotes the most uniform distribution of the suspension feed to each inlet of each hydrocyclone in the hydrocyclone device. This improved uniform distribution of the suspension feed also enhances separation at each hydrocyclone, as all existing hydrocyclones are subjected to at least approximately the same suspension fraction with at least approximately the same throughput. The annular main flow channel wall prevents the formation of a central dead zone in the supply chamber.

[0024] The height of the flow cross-section at the supply port matches the height of the flow cross-section in the annular section of the annular cavity, where the supply port connects to the annular cavity. This means that the top wall section of the supply pipe can transition flush with, for example, the top wall section of the annular cavity. Similarly, the bottom wall section of the supply pipe can also transition flush with the bottom wall section of the annular cavity. In some cases, minor height differences that are unavoidable in structural design can be mitigated through gradual wall transitions. This also prevents, or at least largely avoids, unwanted vortices. Imposing an eccentric, and especially tangential, flow into the annular cavity avoids sudden flow deflection and also helps to prevent unwanted vortices.

[0025] The annular cavity can be designed to have a gradually decreasing flow cross-section starting from the supply port along the flow direction of the suspension.

[0026] A gradually decreasing flow cross-section can be adapted to the continuous separation of the suspension fraction in a hydrocyclone. In this respect, the gradually decreasing flow cross-section can be adjusted such that, during or after the suspension fraction is separated into the inlet of the hydrocyclone as the suspension feed flow passes through the annular channel of the annular cavity, the flow cross-section is reduced according to the remaining, unseparated suspension fraction, so that the flow velocity is maintained at least to a large extent or completely.

[0027] Therefore, the reduction in the flow cross-section can be adapted to the reduction in the volumetric flow rate of the suspension in the annular channel, which is due to the suspension portion of the suspension feed flow being diverted to one of the outlets of the first and second inlets relative to (or guided by) the first and second hydrocyclones.

[0028] The annular cavity can be designed to have a gradually decreasing flow cross-section along the flow direction of the suspension, i.e., the height of the flow cross-section of the annular cavity is continuously or stepwise reduced along the flow direction.

[0029] The height of the flow cross section of the annular cavity can be reduced along the flow direction by designing the top cover wall section of the annular cavity to sink continuously or gradually along the flow direction.

[0030] The height of the flow cross section of the annular cavity can be reduced by lowering the top cover wall section of the annular cavity. In this respect, the top cover wall section of the annular cavity can also be helical.

[0031] Alternatively or additionally, the height of the flow cross section of the annular cavity can be reduced along the flow direction by designing the bottom wall section of the annular cavity to rise continuously or in stages along the flow direction.

[0032] In addition, as an alternative or supplement to the design of the sinking of the top wall section of the annular cavity and / or the rising of the bottom wall section of the annular cavity, the distance between the opposite side wall sections of the annular cavity may be continuously or stepwise reduced if necessary, so as to continuously or stepwise reduce the flow cross-section of the annular cavity along the flow direction.

[0033] The annular cavity may have a recirculation channel section located downstream of the last outlet along the flow direction of the suspension in the annular cavity. The last outlet is used to draw the last portion of the suspension from the common supply cavity to the last hydrocyclone. The recirculation channel section draws the remaining suspension in the annular cavity back into the annular section of the annular cavity, and the supply port is connected to the annular section.

[0034] Impurities, especially heavy and / or light components that are not part of the qualified material, can be introduced into the newly flowing suspension feed stream through the recirculation channel section, and these impurities are resuspended therein and diverted from the top cover area, which may otherwise accumulate in the top cover area of ​​the annular channel.

[0035] The recirculation channel section of the annular cavity can be designed to place the residual suspension as the bottom layer below the suspension feed flow.

[0036] By placing the residual suspension as a bottom layer under the new suspension feed stream, it is particularly easy to mix impurities with the new suspension feed stream and especially easy to draw impurities away from the top cover area of ​​the annular channel.

[0037] The supply port can be connected to an annular section of the annular cavity between two directly adjacent outlets of the two inlets leading to the first and second hydrocyclones. This arrangement causes the suspension feed flow to be deflected into an annular flow in the first annular section before the first suspension fraction is diverted from the annular channel. In this respect, by arranging the supply port between two directly adjacent outlets of the two inlets leading to the first and second hydrocyclones, the suspension feed flow is prevented from being discharged directly into the first hydrocyclone before the annular flow is formed.

[0038] The outlets can be arranged on the feed chamber at equal circumferential distances and branching off from the annular cavity. By arranging the outlets at equal circumferential distances, the suspension fraction is distributed at equal intervals within the annular flow path. This further contributes to consistent separation in each hydrocyclone. In the corresponding flow section of the annular channel between two outlets, the suspension feed stream, or the remaining suspension feed stream, can become homogenized again after passing through one outlet, after which a new suspension fraction is separated at the next outlet.

[0039] The transition regions from the annular cavity to the outlet can have rounded profiles. These rounded profiles can be formed by a large radius at the transition surface of the wall section of the annular cavity. This also minimizes potential flow separation or vortices, thereby reducing or completely preventing sudden pressure losses in the flow path. Furthermore, hard edges are avoided or prevented to avoid hard inflows, which could, in some cases, cause suspended impurities to accumulate and deposit.

[0040] The rounded profile of the transition area has a radius between 5 and 50 mm, especially between 20 and 30 mm.

[0041] The inner walls of the supply port, annular cavity, and / or outlet can be designed, in particular, to be smooth walls and / or without internal components, protrusions, and / or steps. This can further prevent potential flow separation or vortices, thus eliminating concerns about sudden pressure losses in the flow path.

[0042] The annular cavity can surround the central axial channel in which a common outlet of the hydrocyclone device is arranged, through which the depleted suspension portions of at least one first hydrocyclone and at least one second hydrocyclone are discharged together.

[0043] In this arrangement, it is not necessary to guide the multiple individual outlets of the hydrocyclones through the annular cavity, which would create unfavorable internal components within the annular cavity. Instead, the overflow pipes of the individual hydrocyclones are merged into a common outlet, which, for example, a common outlet pipe, is guided along the outside of the annular cavity, more precisely, through an opening in the ear-shaped stalk of the solid annular body in the central part of the annular cavity's shell, i.e., through an axial channel.

[0044] The outer peripheral wall section of the outlet and / or the deflection device of the overflow pipe of at least one first hydrocyclone and at least one second hydrocyclone, i.e. the outer peripheral wall section of the pipe fitting, can respectively constitute the inner wall section of the annular cavity.

[0045] In this respect, the annular cavity can be constructed from a multi-piece cavity shell. Here, the upper half of the cavity shell can be designed in the style of a lid. A spiral top cover can be constructed in such a lid. The lower half and / or inner half of the cavity shell can be shaped such that, in this respect, on the inner side of the annular cavity, one or more inner wall sections simultaneously constitute the outer peripheral wall of the outlet and / or the outer peripheral wall section of the overflow pipe fitting.

[0046] Specific embodiments of the present invention are explained in detail in the following description with reference to the accompanying drawings. The specific features of these exemplary embodiments may constitute general features of the invention regardless of the specific context in which they are mentioned, and may be considered individually or in other combinations as necessary.

[0047] In the attached diagram:

[0048] Figure 1 A cross-sectional view showing a specific embodiment of the hydrocyclone device according to the present invention;

[0049] Figure 2 Shown from an obliquely upward view according to Figure 1 A partial sectional perspective view of a hydrocyclone device, in which the annular cavity is cut open;

[0050] Figure 3 The side view shows the following: Figure 2 A partial perspective view of a hydrocyclone device, showing a closed annular cavity;

[0051] Figure 4 A schematic diagram showing the unfolding of the annular cavity, which has a flow cross-section that continuously decreases along the flow direction; and

[0052] Figure 5 The specific values ​​in an example embodiment of an annular cavity are shown in tabular form, wherein the flow cross-section of the annular cavity decreases continuously along the flow direction.

[0053] Figure 1 A hydrocyclone apparatus 1 for centrifugally separating solids from a suspension is shown. The hydrocyclone apparatus 1 includes at least one first hydrocyclone 2.1, which has a first separation chamber 3.1, a first inlet 4.1 tangentially opening into the first separation chamber 3.1 for inputting a first portion of the suspension feed stream into the first separation chamber 3.1, a first lower overflow port 5.1 for outputting the separated heavy components, and a first upper overflow pipe 6.1 for outputting the depleted portion of the suspension.

[0054] The hydrocyclone device 1 further includes at least one second hydrocyclone 2.2, which has a second separation chamber 3.2, a second inlet 4.2 tangentially opening into the second separation chamber 3.2 for inputting a second portion of the suspension feed stream into the second separation chamber 3.2, a second lower overflow port 5.2 for outputting the separated heavy components, and a second upper overflow pipe 6.2 for outputting the depleted suspension portion.

[0055] In the illustrated embodiment, the hydrocyclone device 1 includes a common outlet 7, which is used for both the depleted suspension portion of at least one first hydrocyclone 2.1 and the depleted suspension portion of at least one second hydrocyclone 2.2.

[0056] The first overflow pipe 6.1 and the second overflow pipe 6.2 are respectively equipped with deflection devices 8.1 and 8.2, which are designed to deflect the axially overflowing portion of the depleted suspension to a direction with a radial component, so that the depleted suspension portion is introduced into the common outlet 7 with these radial components respectively.

[0057] In this embodiment, the deflection devices 8.1 and 8.2 are designed to deflect the depleted suspension portion guided in the axially extending insertion tube sections 9.1 and 9.2 of the respective overflow tubes 6.1 and 6.2 by at least 90 degrees from the axial direction to the radial direction.

[0058] As especially in Figure 2 As shown, the hydrocyclone device 1 has a common supply chamber 10 with a supply port 10a for introducing a suspension feed stream into the common supply chamber 10. The supply chamber 10 also has a plurality of outlets 11.1, 11.2, 11.3, 11.4 corresponding to a plurality of first and second hydrocyclones 2.1, 2.2, which are used to draw a corresponding portion of suspension from the common supply chamber 10 into the first and second inlets 4.1, 4.2 of the first and second hydrocyclones 2.1, 2.2.

[0059] like Figure 2 As shown, the supply port 10a is connected to the annular section of the annular cavity between two directly adjacent outlets 11.1, 11.2, 11.3, and 11.4 of the two inlets 4.1 and 4.2 that lead to the first and second hydrocyclones 2.1 and 2.2.

[0060] Outlets 11.1, 11.2, 11.3, and 11.4 are arranged on the supply chamber 10 at equal circumferential intervals and branching off from the annular cavity.

[0061] like Figure 2 As shown, multiple transition regions from the annular cavity to the outlets 11.1, 11.2, 11.3, and 11.4 have rounded profiles. The rounded profiles of the transition regions have radii between 5 and 50 mm, particularly between 20 and 30 mm.

[0062] The inner walls of the supply port 10a, the annular cavity and / or the outlets 11.1, 11.2, 11.3 and 11.4 are preferably designed as smooth walls and / or without internal components, without protrusions and / or without steps.

[0063] As especially in Figure 1As shown, the annular cavity surrounds the central axial channel 14, in which a common outlet 7 of the hydrocyclone device 1 is arranged, through which the depleted suspension portions of at least one first hydrocyclone 2.1 and at least one second hydrocyclone 2.2 are discharged together.

[0064] The outer peripheral wall section of outlet 7 and / or the deflection devices 8.1, 8.2 of the overflow pipes 6.1, 6.2 of at least one first hydrocyclone 2.1 and at least one second hydrocyclone 2.2, i.e. the outer peripheral wall section of the pipes, respectively constitute the inner wall section of the annular cavity.

[0065] In this embodiment, the common supply cavity 10 is designed as an annular cavity, and the supply port 10a is tangentially connected to the annular cavity.

[0066] The common supply cavity 10 is designed as a circular annular cavity with an annular main flow channel wall. The shape of the annular cavity or the outer casing of the annular cavity may deviate from the ideal shape of the toroidal surface. The shape of the annular cavity may also deviate from the ideal toroidal surface due to the availability of additional optional features if necessary. For example, as in this embodiment, the top cover wall 12 of the annular cavity may be constructed as a spiral, especially in… Figure 3 As can be seen in the image, the cross-sectional profile of the annular cavity is not circular, which is also true in... Figure 1 As shown in the image.

[0067] The height of the flow cross-section of the supply port 10a matches the height of the flow cross-section in the annular section of the annular cavity, where the supply port 10a connects to the annular cavity. Therefore, the annular cavity is designed to have a gradually decreasing flow cross-section starting from the supply port 10a along the direction of suspension flow.

[0068] The reduction in the flow cross-section corresponds to the reduction in the volumetric flow rate of the suspension in the annular channel, which is due to the suspension portion of the suspension feed flow being diverted to one of the outlets 11.1, 11.2, 11.3, and 11.4 of the first and second inlets 4.1 and 4.2 relative to the first and second hydrocyclones 2.1 and 2.2, respectively.

[0069] In this embodiment, the annular cavity is designed to have a gradually decreasing flow cross-section along the flow direction of the suspension, that is, the height of the flow cross-section of the annular cavity is continuously reduced along the flow direction. Figure 4 The diagram below schematically illustrates the unfolded flow path along the flow direction within the annular channel.

[0070] To reduce the flow cross-section of the annular cavity, the top cover wall 12 of the supply cavity 10 is inclined downward along the flow direction. The width of the flow channel can be kept constant here.

[0071] Upstream of the first outlet 11.1, i.e., in the region indicated by arrow P1, the flow channel has its initial flow cross-section. In the region indicated by arrow P2, at the height of the first outlet 11.1, the flow cross-section begins to decrease and is further reduced uniformly along the flow through the regions indicated by arrows P3 and P4, passing through the second outlet 11.2, the third outlet 11.3, and the fourth outlet 11.4. As indicated by arrow P5, a residual flow cross-section remains after the fourth outlet 11.4, through which the remaining suspension is guided back into the annular region of the annular cavity. In the hydrocyclone device shown with a total of four hydrocyclones, the fourth outlet is the last outlet.

[0072] In this respect, the annular cavity has a recirculation channel section 13 located downstream of the last outlet along the flow direction of the suspension in the annular cavity. The last outlet is used to draw the last portion of the suspension from the common supply cavity 10 to the last hydrocyclones 2.1, 2.2, and the recirculation channel section draws the remaining suspension in the annular cavity back into the annular section of the annular cavity, to which the supply port 10a is connected.

[0073] In this embodiment, the recirculation channel section 13 of the annular cavity is designed to place the residual suspension as the bottom layer below the suspension feed flow.

[0074] exist Figure 5 In the present invention, based on a specific embodiment of a hydrocyclone device 1 having four hydrocyclones 4.1, 4.2, 4.3 and 4.4 with defined structural dimensions, the main process parameters are shown in tabular form in conjunction with a schematic diagram of the flow channel of the annular cavity.

[0075] The cross-sectional area of ​​the flow channel in the annular cavity is 1830 mm at the supply port upstream of the first flow outlet 11.1. 3 And it continuously decreases to 840mm upstream of the fourth flow outlet 11.4. 3 Accordingly, the cross-sectional area of ​​the flow channel of the annular cavity upstream of the second flow outlet 11.2 is, for example, 1740 mm. 3 And upstream of the third flow outlet 11.3, for example, is 1290mm. 3 .

[0076] Due to the given structural design conditions of the hydrocyclone device 1 in this specific embodiment, the flow channel of the annular cavity has a height of 61 mm at the supply port upstream of the first flow outlet 11.1. In this case, the height of the flow channel continuously decreases to 28 mm upstream of the fourth flow outlet 11.4. Accordingly, the height of the flow channel of the annular cavity is, for example, 58 mm upstream of the second flow outlet 11.2 and, for example, 43 mm upstream of the third flow outlet 11.3.

[0077] When a lower flow rate is applied to the hydrocyclone device 1, the volumetric flow rate in the flow channel of the annular cavity is, for example, 450 l / min at the supply port upstream of the first flow outlet 11.1 and continuously decreases to 150 l / min upstream of the fourth flow outlet 11.4. This lower flow rate, for example, is only half and can imply a higher separation quality. Accordingly, the volumetric flow rate in the flow channel of the annular cavity is, for example, 350 l / min upstream of the second flow outlet 11.2 and, for example, 250 l / min upstream of the third flow outlet 11.3. After the fourth flow outlet 11.4, the volumetric flow rate in the recirculation channel section 13 is, for example, 50 l / min. In this case, a flow velocity of, for example, 4.1 m / s is generated in the flow channel of the annular cavity at the supply port upstream of the first flow outlet 11.1, which continuously decreases to 3.0 m / s upstream of the fourth flow outlet 11.4. Accordingly, the flow velocity in the flow channel of the annular cavity is, for example, 3.35 m / s upstream of the second flow outlet 11.2 and, for example, 3.25 m / s upstream of the third flow outlet 11.3.

Claims

1. A hydrocyclone device for centrifugal separation of solids from a suspension, comprising: - at least one first hydrocyclone (2.1) having a first separation chamber (3.1), a first inlet (4.1) for feeding a first share of the suspension of a suspension feed stream tangentially into the first separation chamber (3.1), a first underflow outlet (5.1) for outputting separated heavy components, and a first overflow pipe (6.1) for outputting a depleted suspension fraction; - at least one second hydrocyclone (2.2) having a second separation chamber (3.2), a second inlet (4.2) for feeding a second share of the suspension of the suspension feed stream tangentially into the second separation chamber (3.2), a second underflow outlet (5.2) for outputting separated heavy components, and a second overflow pipe (6.2) for outputting a depleted suspension fraction; and - a common feed chamber (10) having a feed opening (10a) for introducing the suspension feed stream into the common feed chamber (10) and a plurality of flow outlets corresponding to the plurality of first and second hydrocyclones for leading the respective shares of the suspension from the common feed chamber (10) into the first and second inlets of the first and second hydrocyclones, characterized in that the common feed chamber (10) is designed as an annular chamber, the feed opening (10a) being connected eccentrically or tangentially to the annular chamber so as to form a ring flow, wherein the common feed chamber (10) is arranged above the hydrocyclones and has a radial extension which is smaller than the common radial extension of the hydrocyclones.

2. The hydrocyclone apparatus of claim 1, wherein, the common feed chamber (10) is designed as a circular annular chamber having an annular main flow passage wall.

3. The hydrocyclone apparatus of claim 1 or 2, wherein, the height of the flow cross section of the feed opening (10a) corresponds to the height of the flow cross section in the annular section of the annular chamber at which the feed opening (10a) is connected to the annular chamber.

4. The hydrocyclone apparatus of claim 1, wherein, the annular chamber is designed to have a gradually decreasing flow cross section in the flow direction of the suspension starting from the feed opening (10a).

5. The hydrocyclone apparatus of claim 4, wherein, the decrease of the flow cross section is adapted to a decrease of the volume flow of the suspension in the annular passage due to the separate diversion of the shares of the suspension of the suspension feed stream into one of the flow outlets relative to the first and second inlets of the first and second hydrocyclones, respectively.

6. The hydrocyclone apparatus of claim 4 or 5, wherein, the annular chamber is designed to have a gradually decreasing flow cross section in the flow direction of the suspension by continuously or stepwise lowering the height of the flow cross section of the annular chamber in the flow direction.

7. The hydrocyclone apparatus of claim 6, wherein, the height of the flow cross section of the annular chamber is lowered in the flow direction by designing a top cap wall section of the annular chamber to continuously or stepwise sink in the flow direction.

8. The hydrocyclone apparatus of claim 6, wherein, the height of the flow cross section of the annular chamber is lowered in the flow direction by designing a bottom wall section of the annular chamber to continuously or stepwise rise in the flow direction.

9. The hydrocyclone apparatus of claim 1, wherein, The annular chamber has a recirculation channel section (13) which is located downstream of the last flow outlet for the last share of the suspension from the common feed chamber to the last hydrocyclone in the flow direction of the suspension in the annular chamber and which leads the remaining suspension remaining in the annular chamber back into the annular section of the annular chamber, to which the feed opening (10a) is connected.

10. The hydrocyclone apparatus of claim 9, wherein, The recirculation channel section (13) of the annular chamber is designed to place the remaining suspension as a bottom layer under the suspension feed stream.

11. The hydrocyclone apparatus of claim 1, wherein, The feed opening (10a) is connected to the annular section of the annular chamber between two directly adjacent flow outlets which open into the two inlets of the first and second hydrocyclones.

12. The hydrocyclone apparatus of claim 1, wherein, The plurality of flow outlets are arranged on the feed chamber (10) at an equal circumferential distance from one another and branching off from the annular chamber.

13. The hydrocyclone apparatus of claim 1, wherein, The transition areas from the annular chamber to the flow outlets respectively have a rounded contour.

14. The hydrocyclone apparatus of claim 13, wherein, The rounded contour of the transition areas respectively has a radius of between 5 and 50 mm.

15. The hydrocyclone apparatus of claim 14, wherein, The rounded contour of the transition areas respectively has a radius of between 20 and 30 mm.

16. The hydrocyclone apparatus of claim 1, wherein, The inner wall of the feed opening (10a), the annular chamber and / or the flow outlets is designed as a smooth wall and / or without interior components, without protrusions and / or without steps.

17. The hydrocyclone apparatus of claim 1, wherein, The annular chamber encloses a central axial channel (14) in which a common outlet (7) of the hydrocyclone device (1) is arranged, through which the lean suspension portions of the at least one first hydrocyclone (2.1) and of the at least one second hydrocyclone (2.2) are jointly discharged.

18. The hydrocyclone apparatus of claim 17, wherein, The peripheral wall section of the common outlet (7) and / or the peripheral wall section of the deflection device of the overflow pipe of the at least one first hydrocyclone (2.1) and of the at least one second hydrocyclone (2.2) respectively constitute an inner wall section of the annular chamber.

Images