Separation device for separating particles, processing machine, use of a separation device and method for separating particles

Abstract

The invention relates to a separation device for separating particles from a carrier liquid contaminated with the particles, wherein the separation device has a feed device, a sedimentation tank and a discharge device along a flow direction, and the feed device has a feed cross-section and a feed length, wherein the contaminated carrier liquid can be received in the sedimentation tank for separating the particles.Further contaminated carrier fluid is fed by means of the feeding device along a feeding axis with a feeding flow over the feeding length along a gravitational direction into a lower region of the carrier fluid held in the sedimentation tank, arranged in the direction of gravity, and a clear liquid relieved of the particles by sedimentation of the particles is discharged from the sedimentation tank by the discharge device along a discharge flow in an upper region of the carrier fluid arranged against a gravitational direction, wherein the feeding axis is arranged inclined relative to the gravitational direction at a feeding angle, so that the feeding direction is inclined at a feeding angle to the gravitational direction and thus a feeding wall of the feeding cross-section along the gravitational direction is provided as a pre-sedimentation surface for the particles.

Description

[0001] The invention relates to a separation device for separating particles from a carrier liquid contaminated with the particles, wherein the separation device has a feed device, a sedimentation tank and a discharge device along a flow direction, and the feed device has a feed cross-section and a feed length, wherein the contaminated carrier liquid can be received in the sedimentation tank for separating the particles.Further contaminated carrier fluid is fed by means of the feeding device along a feeding axis with a feeding flow over the feeding length along a direction of gravity into a lower region of the carrier fluid held in the sedimentation tank, arranged in the direction of gravity, and a clear liquid, freed of particles by sedimentation of the particles, is discharged from the sedimentation tank by means of the discharge device along a discharge flow in an upper region of the carrier fluid, arranged against a direction of gravity. The invention further relates to a machine tool for the mechanical, in particular machining, processing of a workpiece, the use of a separation device for a machining process, and a method for separating particles from a carrier fluid contaminated with particles by means of a separation device.

[0002] Known separation devices for removing particles from contaminated carrier fluids are used, for example, to reduce the load on cooling lubricants used in machining processes or on biologically contaminated carrier fluids through sedimentation, i.e., to remove the particles. One known method involves feeding the contaminated carrier fluid into a container with gravity, significantly slowing the flow by means of a cross-sectional expansion, and then allowing the carrier fluid to slowly rise against gravity, causing the particles to settle. This allows clear liquid to be skimmed off the top of the container. However, such processes are often very space-consuming and require large containers and typically several sedimentation stages to ensure sufficient particle removal.Furthermore, sufficient particle separation often cannot be achieved.

[0003] Furthermore, it is known, for example, to use flocculants to agglomerate the corresponding particles and to promote, improve or accelerate flocculation and thus separation of the particles from the contaminated carrier liquid by sedimentation.

[0004] However, achieving complete or nearly complete removal of particles from the carrier fluid requires the intensive use of flocculants, which is difficult to implement both in terms of potential environmental impact and cost. Furthermore, the dosage must be monitored to ensure that excess flocculant does not remain in the clarified fluid. Otherwise, for example, if the clarified fluid is returned to a machine tool, particles could clump together within the tool, potentially clogging pipes or other machine components.

[0005] The purpose of the invention is to improve the state of the art.

[0006] The problem is solved by a separation device for separating particles from a carrier liquid contaminated with the particles, wherein the separation device has a feed device, a sedimentation tank and a discharge device along a flow direction, and the feed device has a feed cross-section and a feed length, wherein the contaminated carrier liquid can be received in the sedimentation tank for separating the particles.Further contaminated carrier fluid is fed by means of the feeding device along a feeding axis with a feeding flow over the feeding length along a gravitational direction into a lower region of the carrier fluid held in the sedimentation tank, arranged in the direction of gravity, and a clear liquid relieved of the particles by sedimentation of the particles is discharged from the sedimentation tank by the discharge device along a discharge flow in an upper region of the carrier fluid arranged against a gravitational direction, wherein the feeding axis is arranged inclined relative to the gravitational direction at a feeding angle, so that the feeding direction is inclined at a feeding angle to the gravitational direction and thus a feeding wall of the feeding cross-section along the gravitational direction is provided as a pre-sedimentation surface for the particles.

[0007] By tilting the feed axis, the feed direction is aligned at an angle relative to the direction of gravity. This also causes the feed flow to be inclined at an angle relative to gravity, thus enabling pre-sedimentation of the particles at the feed wall of the feed cross-section, either laterally or at least obliquely to the feed flow. In particular, this allows particles to agglomerate into pre-sediment even before the actual sedimentation in the sedimentation tank, significantly improving, facilitating, and / or shortening the sedimentation process. This approach therefore makes it possible to achieve complete or at least nearly complete separation of particles from the carrier liquid in a single container. Furthermore, the flocculant dosage can be adjusted accordingly.

[0008] The following terms should be explained in this context:

[0009] A "separation device" refers to a device, particularly one that operates by means of sedimentation, for separating particles from a liquid. Such separation devices are used, for example, to clean a carrier fluid in machining processes or biological processes, where, for instance, abrasive particles or other contaminants are separated from a cooling fluid or a cooling lubricant used in a machining process. Similarly, suspended solids can be precipitated and separated from liquid or partially liquid biological masses, for example, in a bioreactor or to prepare the biological mass for treatment in a bioreactor. In this context, "separation" refers specifically to the removal or extraction, particularly the settling or sedimentation, of particles from the carrier fluid.In this context, "particles" can refer to particles deliberately introduced through a technical process and carried away by the carrier fluid, such as metal shavings. However, such particles can also include contaminants of other kinds. Generally, these particles are solids carried within the carrier fluid. In liquid biomass, suspended solids such as plant matter can also be present as particles. These particles primarily occur as insoluble solid components within the carrier fluid.

[0010] The "carrier fluid" is a liquid, such as water or another liquid medium. The carrier fluid can also be, for example, a cooling-lubricating emulsion like those used in machine tools, or an aqueous liquid for a bioreactor or from agriculture. It should be noted that the "contaminated" carrier fluid contains and carries corresponding particles and would generally be described as "dirty" or "used up." The contaminated carrier fluid is then successively relieved of the particles by the separation device, whereby the particles are successively removed or separated from the contaminated carrier fluid, and the resulting technically "clean" or "usable" liquid medium, at least partially free of particles, is referred to as "clear fluid."It should be noted in this context that the clear liquid need not be completely clear in the optical sense, but rather, for example, in a technical sense, it is considered "clean" or "purified" for reuse in the process and contains fewer particles than the contaminated carrier liquid. It should also be noted that, as is common in process engineering, the transitions between the contaminated carrier liquid and the clear liquid can be gradual and / or continuous.

[0011] The "flow direction" refers to the general flow direction of the carrier fluid through the separator, whereby this flow direction need not be linear. The flow direction is defined in relation to a local flow direction, which can vary as the carrier fluid flows through the separator, for example, meandering.

[0012] A "feeding device" refers to a device used to supply the contaminated carrier fluid, particularly a fluid-carrying device, which can be, for example, a pipeline or a system of pipelines. The feeding device can also be designed as a filling hopper or other type of dispensing device for the contaminated carrier fluid, such as a filling ramp. A "sedimentation tank" is a container in which the contaminated carrier fluid is calmed, particularly by means of flow stabilization, and its flow velocity is slowed. This causes particles in the contaminated carrier fluid to sink due to gravity and, for example, to agglomerate, thus increasing their size and allowing these particles or agglomerated particles to settle in the sedimentation tank. This process is generally called "sedimentation."

[0013] A "discharge device" refers, for example, to a pipeline, an overflow or other fluid-carrying device in which clear liquid is then discharged from the sedimentation tank and / or from the separation device, particularly after the sedimentation of the particles has taken place.

[0014] The feeding device has a "feed cross-section," meaning a cross-section of the feed that is oriented orthogonally or at least substantially orthogonally to the local flow direction and the feed axis, and a "feed length" along the flow direction, i.e., along the feed axis. The feed length refers to the length that the feeding device has along the flow direction, for example, from an inlet of the feeding device to a transition point of the feeding device into the sedimentation tank.

[0015] In connection with the invention, it can be assumed in particular that the contaminated carrier fluid is absorbed or at least absorbable in the sedimentation tank, wherein in particular a certain, especially constant or at least substantially constant, liquid level is maintained in the sedimentation tank or in the separation device, for example by means of overflows arranged at a corresponding height or by a respective control system.

[0016] The feeding device has a "feed axis," that is, an orientation of the feeding device, which essentially corresponds to the flow direction set within the feeding device. The feeding device need not be straight, and the feed axis is also not mathematically exact, but can be locally curved or defined differently from a straight orientation according to the technical purpose.The feed flow for particle separation is introduced into the sedimentation tank along the direction of gravity, commonly referred to as "downwards." As the contaminated carrier fluid escapes from the feed device into the free sedimentation tank, the flow cross-section widens, resulting in a rapid decrease in flow velocity. This promotes sedimentation at this point by preventing or at least reducing the entrainment of particles or agglomerated particles. The carrier fluid introduced during the process then leads to a subsequent flow in the sedimentation tank against gravity, i.e., "upwards." This widened and enlarged cross-section, combined with a correspondingly low flow velocity, allows the clear liquid to form through further sedimentation of the particles.In most cases, the relieved clear liquid is then suctioned, pumped out or overflowed in an upper area of ​​the sedimentation tank or at a surface of the liquid where the clear liquid is located.

[0017] According to the invention, the feed axis is arranged at an inclination relative to the direction of gravity at a "feed angle," meaning that the feed device is, for example, inclined to a vertical axis of the separation device, so that the flow within the feed device runs obliquely to the axis of gravity, i.e., inclined to the axis of gravity, thus enabling lateral settling of the particles on the feed wall of the feed cross-section. In this context, a "feed wall" can be, for example, the wall of a pipeline, although the wall of, for example, a U-shaped feed chute is also suitable for pre-sedimentation. A key aspect of the invention is that a respective wall is present below the feed flow as a sedimentation wall, on which particles can settle in the form of sediment.

[0018] It should be mentioned that "pre-sedimentation" describes a preliminary agglomeration and / or settling movement of the particles at the respective feed wall, while "sedimentation" describes the subsequent pooling and sedimentation of the larger particles that have already been agglomerated, for example, by pre-sedimentation.

[0019] In order to increase the area for pre-sedimentation and, for example, to carry out more efficient pre-sedimentation, the feeding device has one, two, three or more feeding cross-sections, wherein the respective feeding cross-sections are fluidically separated from each other within the feeding device by a respective feeding wall, whereby a respective feeding wall of the respective feeding cross-section is provided as a respective pre-sedimentation area for the particles, wherein the feeding device is in particular designed as a cross-sectional bundle, in particular as a tube bundle.

[0020] In this context, a "feed cross-section" refers to the respective cross-section of, for example, a pipe, a tube bundle, or another shaped fluid guidance element. For instance, a "cross-sectional bundle" can be formed from rectangular pipes, with the corresponding lower wall surfaces, namely the feed walls, serving as a pre-sedimentation surface for the particles.

[0021] It should be mentioned that the feed device is inclined in the direction of gravity and that the loaded carrier fluid passes through the feed device, particularly in a co-current flow, so that any particle agglomerations that may occur can be flushed into the sedimentation tank with the feed flow, thus automatically cleaning the feed device.

[0022] In one embodiment, the feed ratio of the feed cross-section or the respective feed cross-section to the respective feed length along the feed direction is 1:3, 1:4, 1:5, 1:10, 1:25 or 1:50. Such a selected "feed ratio", which describes the quotient of the respective feed cross-section to the respective feed length, ensures a uniform flow through the feed device with good sedimentation results.

[0023] According to a further embodiment, the feed cross-section or the respective feed cross-section has a maximum width of 100 mm, a maximum width of 75 mm, a maximum width of 50 mm, a maximum width of 40 mm, a maximum width of 25 mm or a width of 15 mm or 10 mm.

[0024] In this context, a "width" describes a reference dimension for the passage of the carrier fluid, for example the diameter of a pipeline, the reference diameter of an oval cross-section, the radius of an oval cross-section, or, for example, the distance between two plate-shaped boundaries of a rectangular pipe or a feed passage formed by, for example, plates.

[0025] According to one embodiment, the feed angle is configured between 10° and 80°, between 20° and 70°, between 30° and 60°, and particularly between 40° and 50°. Such a feed angle, which can be, for example, 40° or 45°, represents a technically promising ratio between the flow velocity in the feed device and the sedimentation tendency of the particles, whereby the feed angle can be adjusted based, for example, on the expected particle size. In particular, a feed angle of 15° to 45° has proven advantageous, depending on the geometric conditions in the sedimentation tank and / or the respective consistency and particle load of the carrier fluid. Angle specifications here refer to a full 360° angle.

[0026] To promote pre-sedimentation, a pre-calming zone and / or a post-calming zone are fluid-conductingly connected to the feed device along the flow direction upstream of the feed device or in an inlet area of ​​the feed device, wherein the pre-calming zone has a pre-calming cross-section that is expanded relative to the feed cross-section(s) and / or the feed device, and / or the post-calming zone has a post-calming cross-section that is expanded relative to the feed cross-section(s) and / or the feed device, in order to slow down the feed flow in the respective way.

[0027] In particular, the pre-stabilization zone and / or the post-stabilization zone is or are arranged essentially collinearly or collinearly with the feed axis and / or with the feed direction.

[0028] According to a further embodiment, the sedimentation tank has a cross-sectional constriction in the lower area arranged in the direction of gravity, wherein the cross-sectional constriction begins in particular above a lower end area of ​​the feed device.

[0029] The cross-sectional constriction is used, for example, to guide sedimented particles towards sediment removal. This cross-sectional constriction can, for instance, be funnel-shaped.

[0030] In a further embodiment, an admixture device for a flocculant or several admixture devices for several flocculants is arranged along the flow direction upstream of the feed device, wherein a respective flocculant can be added to the carrier liquid by means of the respective admixture device.

[0031] This allows the flocculant to be added before the feed device, enabling pre-sedimentation with significant utilization of the flocculant. Consequently, the subsequent sedimentation in the sedimentation tank and the resulting complete consumption of the flocculant prevent the discharge of excessively dosed flocculant from the clarified liquid.

[0032] In this context, an “adding device” can be, for example, a device operating by means of an injector principle, by sprinkling or dripping, or by means of a metering pump, which introduces a liquid or, for example, powdered flocculant into the flow of the contaminated carrier fluid.

[0033] A "flocculant" can be formed, for example, from metal salts or other hydroxide-forming substances, and is used in particular to cause the smallest particles in liquids to clump together. Flocculants form larger microflocs from smaller agglomerations, which can then be removed, for example, by filtration or sedimentation.

[0034] In this process, a static mixing device for mixing the carrier liquid with the respective flocculant can be arranged along the flow direction after the mixing device, after a mixing device and / or after the respective mixing device, so that a corresponding mixing is ensured even before the portion of the contaminated carrier liquid containing the flocculant enters, so that pre-sedimentation within the feeding device can be carried out in the best possible way.Alternatively or additionally, a reaction section can also be arranged downstream of the mixing device and in particular downstream of the respective static mixing device or downstream of the last static mixing device along the flow direction, wherein this reaction section provides a length along the flow direction along which the flocculant or the respective flocculant can react before the loaded carrier liquid containing the flocculant enters the feed device.

[0035] In another aspect, the problem is solved by a machine tool for the mechanical, in particular machining, processing of a workpiece, wherein the machining is supported with a carrier fluid, in particular a coolant, a lubricant or a cooling-lubricating agent, for the removal of machining heat and / or particles from the workpiece, comprising a separation device according to one of the previously described embodiments for separating the particles from the carrier fluid loaded with the particles.

[0036] Thus, for example, the separation device can be used to remove particles from the cooling lubricant of a machine tool, with the separation device occupying a particularly small installation space.

[0037] In particular, the carrier fluid, especially the coolant, lubricant, or cooling-lubricating agent, can be conveyed from the machine tool to the feed unit of the separator, whereby the clear fluid, now free of particles, can be returned to the machine tool via the discharge unit of the separator. This allows, for example, a closed-loop lubrication system for the corresponding machine tools, whereby the coolant / lubricating agent, now clean and ready for use, is returned to the machine tools. Any machining residues are separated in the process, provided the fluid passes through the separator.

[0038] In another aspect, the problem is solved by using a separation device according to one of the previously described embodiments for separating particles from a coolant, lubricant and / or cooling-lubricating agent contaminated with particles, in particular for a machining process.

[0039] In another aspect, the problem is solved by a method for separating particles from a carrier liquid contaminated with particles using a separation device according to one of the previously described embodiments, with the following steps: - Feeding the carrier fluid contaminated with particles into the feeding device, so that the carrier fluid contaminated with particles is fed in, - Pre-sedimentation of particles on the pre-sedimentation surface formed by means of a feed wall, so that particles are pre-sedimented, - Sedimenting the particles and / or the pre-sedimented particles in the sedimentation tank, so that the particles and / or the pre-sedimented particles are sedimented in the sedimentation tank, - Discharge of the clear liquid freed from the particles through the discharge device, so that the clear liquid freed from the particles is discharged, so that the particles are separated from the carrier liquid.

[0040] In this process, the feed flow is slowed down by a calming factor of 1:8, 1:10, 1:16, or 1:20 by means of the pre-calming zone and / or the post-calming zone, both before and after the feed device, and / or the discharge flow is slowed down relative to the feed flow by a calming factor of 1:8 to 1:10, 1:12 to 1:16, or 1:16 to 1:20. The "calming factor" refers to the ratio of the outgoing flow velocity to the incoming flow velocity. For example, a calming factor of 1:15 slows a flow from 15 cm / s to 1 cm / s, correspondingly by a cross-sectional expansion from 1 to 15 area units.

[0041] The invention will now be explained in more detail using exemplary embodiments. These will show... Fig. 1 A schematic representation of a cooling lubricant processing plant in a side view, Fig. 2 a cross-sectional view of the processing plant of the Fig. 1, Fig. 3 a schematic representation of a detail of a feed to the processing plant of the Fig. 1 and Fig. 2, as well as Fig. 4 A schematic representation of a mixing system for an inlet pipe of the processing plant of the Fig. 1 and Fig. 2.

[0042] A processing plant 101 serves to separate particles from a carrier fluid, wherein the carrier fluid is in this case a cooling lubricant for a machine tool, wherein the particles are carried along in the cooling lubricant as chips from a grinding process as well as as impurities from the process.

[0043] The processing plant 101 includes a container 103. The upper part of the container 103 is essentially cylindrical and has a cylindrical wall 105. Below the cylindrical wall 105, a conical wall 107 extends, forming a conical shape at the bottom of the container. The container 103 is designed to hold cooling lubricant up to a fill level 109.

[0044] The container 103 is mounted in a frame 111, which is made of standard steel profiles. A bracket 121 on an open upper side of the container 103 serves to hold internal components (see below for further explanation). Support profiles 123 support the conical wall 107 from the outside. A control cabinet 125 is used to control the processing plant 101 (control system not described in detail).

[0045] Inside, the container 103 has an upper chamber 131, a bottom chamber 133 and a sedimentation chamber 135, wherein the sedimentation chamber 135 is located in the cone apex in the lower part of the cone wall 107, the bottom chamber 103 is located inside the cone wall 107 and the upper chamber 131 is located inside the cylinder wall 105.

[0046] Contaminated coolant, for example, from a machining process, can be introduced into the container 103 via a feeder 140 through an inlet pipe 141. The feeder 140 is supported in the holder 121 by a chain 127 and hangs in the upper chamber 131 of the container 103. The medium entering from the inlet pipe passes into a pre-calming zone 145 of the feeder 140 and then flows through a tube bundle 146 towards a post-calming zone 149 of the feeder 140. The feeder 140 has a linear design, such that corresponding reference axes of the tube bundle 146 are aligned with a reference axis of the feeder 140, in this case along a feeder axis 117. The feeder 140 is aligned with the feeder axis 117 at a feeder angle 119 relative to a gravitational direction 115, i.e., relative to the direction of the acceleration due to gravity.In the example shown, this feed angle 119 is, for example, 20°, but can be adjusted by selecting a length of the chain 127.

[0047] The tubes of the tube bundle 146 are naturally significantly thinner than the diameter 342 of the feed 140. The pre-calming zone 145 and the post-calming zone 149 each occupy the entire cross-section of the diameter 342. Consequently, the liquid entering through the feed pipe 141 is first calmed in the pre-calming zone 145, then flows through the tube bundle 146 through individual tubes and enters a post-calming zone 149, where the fluid flow is further calmed. The liquid flows along a flow path 181 parallel to the feed axis 171. Upon exiting the feed 140 in the area of ​​a transition 150, a pre-sediment 151 is deposited from the introduced liquid, a process facilitated by a reverse flow 183 of the liquid in the area of ​​the bottom space 133 of the container 103.

[0048] It should be noted that a mixing system 401 with a proportioner 403 for flocculant is installed in the inlet pipe 141. The flocculant is mixed into a fluid stream 481 along a flocculant stream 483, so that the contaminated liquid flowing in the inlet pipe 141 is already contaminated with flocculant. It should be noted that, for example, static mixing elements (not shown) may be installed downstream of the proportioner 403, which promote the mixing of the flocculant with the liquid. A reaction section of, for example, 6-10 m in length can be arranged between the inlet pipe 141 and the proportioner 403, as well as any downstream static mixing element, in which the added and, if necessary, mixed flocculant can act before the corresponding liquid enters the feed 140.

[0049] Within the tube bundle 146, flocculation and settling of particles from the liquid occur, intensified by the flocculant. The resulting flocs settle on the tube walls 347, 349, 351, and 353 of the corresponding tubes within the tube bundle 146, forming the pre-sediment 151. This pre-sediment is carried away by the flow 181 towards the bottom space 133 in the container 103. Within the bottom space 133 of the container 103, the pre-sediment 151 then settles to form sediment 153 within a sedimentation cone 152 in the sedimentation chamber 135.

[0050] The coolant, now largely purified, then rises along an upward flow 185. The cross-section of the upper chamber 131 is significantly larger than the diameter 342 of the feed 140, thus generating a correspondingly slow upward flow 185. Here, further particles from the coolant settle, so that the coolant is almost completely free of particles in the upper part of the container 103. A discharge flow 187 in the area of ​​the surface of the fill level 109 is then directed into a discharge 190. The discharge 190 has a suction box 191 at the surface of the liquid, which then leads into a drain pipe 193 and to a pump 195. The pump 195 conveys the clarified liquid, i.e., purified coolant, through a clear water discharge 197, for example, back to a machine tool.The separated sediment 153 can then be discharged into a sediment container 163 via a sediment discharge 161, which is designed like a siphon, for example by opening a valve in the bottom area of ​​the container 103.

[0051] Additionally, a drain pipe 155 below the described fill level 109 can be used to provide a drain located further down, thus keeping the liquid level in the container 103 lower. The drain pipe 155 is arranged horizontally in the cylinder wall 105 and can, for example, be extended upwards by a 90° bend. The height of a subsequent straight pipe section (not shown) then defines the liquid level in the container. In this case, the outlet 190 can be used as an emergency drain to effectively prevent, for example, the container 103 from overflowing.

[0052] It should also be mentioned that the processing unit 101 can, for example, be integrated into a closed-loop system in a processing plant for, for example, the grinding of metal parts, so that contaminated coolant is introduced into the processing unit 101 through the inlet pipe 141 and appropriately cleaned liquid is fed back to the respective processing machines. Reference symbol list 101 Processing plant 103 containers 105 cylinder wall 107 Conical wall 109 Fill level 111 frame 115 Direction of gravity 117 Feed axis 119 Feed angle 121 holders 123 Support profile 125 Control cabinet 127 chain 131 Upper Room 133 Floor space 135 Sedimentation basin 140 feed 141 Inlet pipe 142 wall 143 Inlet pipe 145 Pre-calming zone 146 tube bundles 149 Post-calming zone 150 transition 151 Pre-sediment 152 sedimentation cones 153 Sediment 155 drain pipe 161 Sediment removal 163 sediment tanks 181 Flow through 183 Reverse flow 185 Updraft 187 Discharge flow 190 Deduction 191 Suction box 193 Drain pipe 195 pump 197 Clear water discharge 342 diameter 344 diameter 346 diameter 347 Pipe wall 348 Length 349 Pipe wall 351 Pipe wall 353 Pipe wall 401 Proportioning system 403 proportioners 405 Feed 481 Fluid flow 483 Flocculant stream

Images