Filtration device for separating a particle-loaded liquid, filtration system, filtration plant, and method for separating a particle-loaded liquid

Abstract

The invention relates to a filtration device (31, 31') for separating a particle-loaded liquid (39) into a particle-reduced permeate (38) and a particle-enriched retentate in a filter chamber (34) comprising a filtration membrane (10), through which the liquid (39) flows or can flow in a flow direction and which separates the permeate side (11a) of the filter chamber (34) of the filtration device (31, 31') from the retentate side (11) of the filtration device (31, 31'); a pump device (33), by means of which the pressure of the liquid on the permeate side (11a) and on the retentate side (11) can be set, wherein the pump device (33) comprises a pump membrane (1) in a pump chamber (32), said pump membrane (1) being oscillatable by means of a drive means (8) via a pump tappet (7), and the supply chamber (2) of the pump chamber (32) is fluidically connected to the filter chamber (34); a supply line (37) for supplying the liquid (39) to the supply chamber (2); a permeate discharge line (12); and a retentate discharge line (36). The filtration device (31, 31') is characterized in that a sealing chamber (35) with a sealing space (5) is provided between the drive means (8) and the pump chamber (32), and at least one part of a wall of the sealing chamber (35) is formed by a sealing membrane (6). The invention additionally relates to a filtration system (30) comprising at least two filtration devices (31, 31'), to a filtration plant, and to a method for separating a particle-loaded liquid (39).

Description

[0001] Filtration device for dividing a particle-laden liquid, filtration system and filtration plant as well as

[0002] Method for dividing a particle-laden liquid

[0003] Description

[0004] The invention relates to a filtration device for dividing a particle-laden liquid into a particle-reduced permeate and a particle-enriched retentate in a filter chamber according to the preamble of claim 1, as well as to a filtration system according to claim 17 and a filtration plant according to claim 20. Furthermore, the invention relates to a method for dividing a particle-laden liquid into a particle-reduced permeate and a particle-enriched retentate according to claim 22.

[0005] Filtration devices and filter processes are known in various forms in the prior art. A special form of filtration device and filter process is membrane filtration, in which particles are separated from a viscous mixture according to size and molecular weight. Membrane filtration separates the mixture into a permeate, which comprises the particles and substances penetrating the membrane, and a retentate, which represents the solution retained by the membrane. The permeate can also be referred to as filtrate. The membrane separates the retentate side from the permeate side.

[0006] DE 10 2016 003 335 A1 discloses a filtration device with a filter membrane and a pump membrane for setting a filter medium into an oscillating movement, wherein by the forward stroke of the pump membrane a pressure can be built up on a retentate side of the filter membrane and a negative pressure can be formed on the filtrate side of the filter membrane, so that filtration takes place, and during the reverse stroke of the pump membrane a pressure can be built up on a filtrate side and a negative pressure can be formed on the retentate side, so that the filtrate moves back from the filtrate side to the retentate side.

[0007] This type of filtration device has proven to be effective in increasing the concentration of particles in a particle-laden liquid. This particle-laden liquid, or the retentate with an increased particle concentration, can then be processed into pellets in a filter press, as is known, for example, from DE 10 2021 128 622 A1.

[0008] However, a problem with membrane filtration, particularly in the filtration devices described above, is sealing the filtration device from its environment. On the one hand, it may be necessary to prevent any particle-laden mixture from escaping from the filtration device to the outside, for example, in the case of toxic or explosive media or components. On the other hand, it must be prevented that air or other gaseous media are sucked into the devices by the movement of the pump membrane. Air in the filtration device has a negative impact on the required pumping capacity for the particle-laden liquid in the filtration device. In particular, pumping the liquid or viscous mixture into the filter chamber may be impossible if there is too much air in the filtration device. In addition, the air dampens the pressure required to generate the permeate.

[0009] Particularly problematic here is the sealing of the pump tappet, which sets the pump diaphragm in motion and thereby achieves the corresponding pumping action. Mechanical seals, stuffing box packings and similar shaft seals are well known for sealing pump tappets, but these have a small gap between the seal and the pump tappet, which means that air ingress cannot be ruled out. To effectively prevent air ingress, water barrier seals are usually used. In these, a water barrier chamber with excess pressure is formed downstream of the sliding seal. However, water barrier seals are complex and require more space. In addition, the generation of excess pressure in the water barrier chamber requires a separate line routing with a corresponding pump.

[0010] It is therefore an object of the present invention to provide a filtration device and a filtration system as well as a filtration plant and a method for dividing a particle-laden liquid, which ensures a sealing of the filtration device, in particular the filter chamber, in a simple and reliable manner.

[0011] This and other objects are achieved by a filtration device according to claim 1, a filtration system according to claim 17, a filtration plant according to claim 20, and a method according to claim 22. Advantageous embodiments of the filtration device are set out in claims 2 to 16. Advantageous embodiments of the filtration system are set out in claims 18 and 19. An advantageous embodiment of the filtration plant is set out in claim 21. Advantageous embodiments of the method are set out in claims 23 to 26.

[0012] The filtration device and the filtration system are designed, in particular, to carry out a filtration process. A filtration process can be carried out, in particular, with a filtration device according to the invention, a filtration system according to the invention, or a filtration plant according to the invention.

[0013] As a first solution to the aforementioned objects, a filtration device for dividing a particle-laden liquid into a particle-reduced permeate and a particle-enriched retentate in a filter chamber is specified, comprising a filtration membrane through which the liquid flows or through which it flows in a flow direction, which separates a permeate side of the filter chamber of the filtration device from a retentate side of the filtration device. Furthermore, the filtration device comprises a pumping device by means of which a pressure of the liquid on the permeate side and on the retentate side can be determined. The pumping device comprises a pumping membrane in a pumping chamber, which can be set into an oscillating motion by means of a drive means via a pump plunger, and a feed chamber of the pumping chamber is fluidically connected to the filter chamber.In addition, the filtration device comprises a supply line for the liquid into the feed chamber, a permeate outlet and a retentate outlet.

[0014] The filtration device according to the invention is characterized in that a sealing chamber with a sealing space is arranged between the drive means and the pump chamber, wherein at least part of a wall of the sealing chamber is formed by a sealing membrane.

[0015] By creating a sealing chamber, a completely reliable and cost-effective seal is achieved between the pump chamber and its surroundings, eliminating the need for an expensive and maintenance-intensive water seal. In particular, the sealing membrane enables a solution that corresponds to the pump membrane, creating synergistic effects. This allows for a simple seal of the drive chamber, in which the drive mechanism is located, without limiting the functionality of the filtration devices.

[0016] The filtration device can be used, for example, for dewatering metal hydroxide sludge or for phosphate recovery from liquid manure. Alternatively, the filtration device can also be used for the filtration of liquids, such as beer, for the partial demineralization of sodium sulfate-containing wastewater after wastewater treatment, or for prefiltration in seawater desalination or drinking water filtration. A preferred embodiment of the filtration device is characterized in that the sealing membrane is arranged on a wall surface facing away from the pumping chamber. In particular, the sealing membrane forms the wall surface of a wall surface facing away from the pumping chamber.

[0017] Advantageously, the sealing diaphragm and the pump diaphragm are arranged one behind the other in parallel planes. Particularly preferably, the sealing diaphragm and the pump diaphragm are arranged in alignment with each other. This arrangement in alignment achieves better synchronization in the movement of the two diaphragms. In particular, the aligned arrangement allows the sealing diaphragm and the pump diaphragm to be operated with a single pump tappet.

[0018] The drive means is preferably a linear drive or eccentric drive, which is operatively connected to the pump diaphragm via the pump tappet. The linear drive or eccentric drive is designed and intended to impart an oscillating movement to the pump diaphragm. The choice of drive means depends on the specific requirements and possible uses. A linear drive is particularly advantageous in this case, as it enables an oscillating movement of the pump diaphragm in a simple manner.

[0019] A preferred embodiment of the filtration device is characterized in that the linear drive is an electric drive, a hydraulic drive, or a pneumatic drive. Alternatively, or preferably additionally, the eccentric drive comprises an eccentric disc on which the pump tappet is arranged directly or indirectly.

[0020] Preferably, at least one valve is arranged in the supply line, the permeate discharge line, and / or the retentate discharge line. The valve is designed, in particular, to close the supply line, the permeate discharge line, and / or the retentate discharge line. Thus, a corresponding pressure can be built up in a supply line and / or discharge line or a pressure loss can be prevented, for example, in the filter chamber. The filter chamber can also be isolated from the supply of particle-laden liquid by the valves.

[0021] In a further preferred embodiment, the supply chamber of the pumping chamber is separated from a filtrate chamber of the pumping chamber by the pumping membrane. Separating the pumping chamber into a supply chamber and a filtrate chamber results in two pumping chambers with opposing pressure gradients. Thus, two pumping systems are created, each performing the opposite process.

[0022] Advantageously, a partition wall is arranged between the filtrate chamber and the sealing chamber, through which the pump tappet is guided in a sealing manner. The partition wall separates the filtrate chamber and the sealing chamber, forming two separate spaces, each with its own function.

[0023] Alternatively or preferably additionally, the partition wall is rigid.

[0024] In yet another preferred embodiment, the permeate outlet is connected to the filtrate chamber and / or to the permeate side of the filter chamber. This allows the permeate to be pumped out of the filtrate chamber via the pumping device and the corresponding movement of the pump membrane without any additional equipment.

[0025] Yet another advantageous embodiment is characterized in that the sealing membrane and / or the pumping membrane are designed as a plate membrane or a rolling membrane. These two types of membranes are particularly suitable for the intended use. Preferably, the sealing membrane has a larger surface area than the pumping membrane. Particularly preferably, the sealing membrane has a larger diameter than the pumping membrane.

[0026] Advantageously, the retentate can be periodically discharged via the retentate drain after a number of forward and reverse strokes of the pump diaphragm by building up an overpressure that is greater than the overpressure generated by the forward stroke of the pump diaphragm. For this purpose, an outlet valve is arranged in the retentate drain, which opens after the number of forward and reverse strokes of the pump diaphragm or when a certain overpressure is reached.

[0027] A preferred embodiment is characterized in that the filtration device comprises a pressure accumulator that can be filled with a liquid medium, in particular with particle-laden liquid or permeate or retentate. The liquid medium can be pumped into the pressure accumulator via a medium supply line through the sealing space of the sealing chamber and a pressure accumulator line. The sealing chamber thus also serves as a pumping device for pumping the liquid medium into the pressure accumulator. Furthermore, this results in an even better seal against the environment by means of the sealing chamber.

[0028] Particularly preferably, check valves are arranged in the medium supply line and / or the pressure accumulator line. The check valves prevent, in particular, the liquid medium from flowing back through the sealing chamber by means of the sealing membrane during the pumping process. In particular, the liquid medium can only be supplied to the pressure accumulator once a corresponding pressure has been generated in the medium supply line.

[0029] Alternatively or preferably additionally, the liquid medium in the pressure accumulator has a pressure greater than 1 x 10 5 Pa, preferably greater than 3 x 10 5 Pa, particularly preferably greater than 6 x 10 5Pa. The required or desired pressure of the liquid medium in the pressure accumulator depends in particular on the selectivity of the filter membrane and / or the filtering task and / or the pressure resistance of the filter membrane. In particular, the pressure of the liquid medium in the pressure accumulator depends on a transmembrane pressure, which results from the movement of the pump membrane in the closed hydraulic system in the filtration device as the range of the largest pressure difference. Preferably, the pressure of the liquid medium in the pressure accumulator should be above the transmembrane pressure. For particles in the micrometer range, a pressure in the pressure accumulator of slightly over 1 bar, which is 1 x 10 5Pa may already be sufficient, whereas for the filtration of smaller particles, for example, in the nanometer range, the liquid medium in the pressure accumulator should be brought to a higher pressure. The pressure can be determined, for example, using a pressure gauge on the pressure accumulator.

[0030] An advantageous embodiment is characterized in that the liquid medium can be directed into the supply chamber and / or the filter chamber via a pressure accumulator discharge line, wherein a valve is arranged in the pressure accumulator discharge line. The liquid medium can be directed into the supply chamber and / or the filter chamber via the pressure accumulator discharge line and its connection to the supply chamber and / or the filter chamber. This enables cleaning, in particular, of the filter membrane in the filter chamber, since a coating, also known as fouling or scaling, can form on the filter membrane over time, impairing filtration.

[0031] Particularly preferably, the supply chamber and / or the filter chamber, in particular the filter membrane, is cleaned via the pressure accumulator drain through the liquid medium. This is preferably done by a pressure pulse from the liquid medium. In conjunction with the pressurized liquid medium in the pressure accumulator, a pressure pulse can be generated by opening the valve in the pressure accumulator drain, which enables effective and rapid cleaning and / or rinsing of the supply chamber and / or the filter chamber. In particular, deposits can form on the filter membrane and the filter membrane can become clogged during the filtration process. The pressure pulse can be used to quickly and easily clean the filter membrane and in particular its filter surfaces of adhering particles, so that improved filtration is subsequently possible again. In particular, cleaning takes place along the filter membrane.Preferably, the outlet valve on the filter chamber is also opened for this purpose to drain the liquid medium used for flushing and / or cleaning. The pressure pulse of the liquid medium is preferably characterized by the liquid medium being directed into the feed chamber and / or the filter chamber at a high flow velocity, for example, in the range of 2 m / s to 5 m / s.

[0032] An advantageous embodiment is characterized by the fact that a pressure-increasing device, in particular a hydraulic pressure booster, is arranged in the accumulator line downstream of the sealing chamber and upstream of the accumulator. This pressure-increasing device allows the accumulator pressure to be increased several times over the pump pressure.

[0033] Preferably, the pressure accumulator is designed to be fed by a plurality of filtration devices and to discharge the liquid medium from the pressure accumulator into the plurality of filtration devices.

[0034] A further solution is provided, comprising at least two filtration devices as described above, wherein the filtration devices share a common drive. The individual filtration devices are thus coupled to one another via the common drive, thereby increasing the throughput while minimizing the use of resources. Furthermore, pressure fluctuations within the filtration system are minimized, and pressure pulses can be smoothed during the filtration process.

[0035] Preferably, the two filtration devices in the filtration system are arranged diametrically opposite each other. A preferred embodiment of the filtration system is characterized in that the drive means is arranged substantially in the center of the two filtration devices. This achieves a symmetrical structure of the filtration system. The drive means is preferably arranged in a drive chamber.

[0036] According to a further advantageous embodiment of the filtration system, the sealing chambers of the two filtration devices are connected to each other via a compensating connection. This allows pressure equalization between the two sealing chambers, whereby the sealing space of the sealing chambers becomes depressurized. A valve is preferably arranged in the compensating connection, allowing the compensating connection to be closed as needed, in particular to build up pressure in a sealing chamber. The compensating connection can, in particular, be a hose or a thin channel.

[0037] Furthermore, the aforementioned object is also achieved by a filtration system comprising at least two filtration systems as described above, in particular at least two filtration systems according to an advantageous embodiment thereof, or more than two filtration devices as described above, in particular advantageous embodiments thereof. A filtration system as described above allows the overall throughput to be increased and synergy effects to be utilized.

[0038] A preferred embodiment of the filtration system is characterized in that the filtration systems are operatively connected to a pressure accumulator, and in that the filtration system has at least one pressure accumulator for the filtration devices. A pressure accumulator can thus be used for multiple filtration systems and thus for multiple filtration devices, thereby reducing the technical complexity of the filtration system. In particular, the pressure accumulator can be filled with liquid medium by all filtration devices connected to it, and all filtration devices connected to it can be supplied with liquid medium for cleaning from the pressure accumulator.

[0039] The drive means as well as the valves and check valves as well as other elements of the filtration devices or the filtration system or the filtration plant are preferably operatively connected to one another via a control system.

[0040] Furthermore, the aforementioned object is also achieved by a method for dividing a particle-laden liquid into a particle-reduced permeate and a particle-enriched retentate using a filtration device as set forth above, or a filtration system or a filtration plant as described above, or an advantageous embodiment thereof. The method comprises the following steps: a) Opening a supply line for the liquid, so that the liquid flows on a retentate side substantially orthogonally onto a filter membrane in a filter chamber; b) Opening a permeate outlet for the permeate, so that the permeate flows through the filter membrane on a permeate side and out of the filter chamber and via a permeate outlet, wherein the opening of the supply line and the permeate outlet is effected via valves; c) Generating a pressure of the liquid on the retentate side by means of a pump membrane in a pump chamber,wherein the pump membrane is moved by a drive means, d) generating a pressure of the liquid on the permeate side through the pump membrane, which pressure is smaller in magnitude than the pressure of the liquid on the retentate side; e) closing the inlet line for the liquid, f) closing the permeate outlet, wherein the closing of the inlet line and the permeate outlet is effected via valves, g) generating a pressure of the liquid on the retentate side through the pump membrane, h) generating a pressure of the liquid on the permeate side through the pump membrane, which pressure is greater in magnitude than the pressure of the solvent on the retentate side, so that the flow direction of the liquid, in particular of the permeate, through the filter membrane is reversed compared to process steps a) to d), i) repeating process steps a) to h),wherein the pressure of the liquid on the retentate side is greater in magnitude than on the permeate side in a time average over the repetitions of process steps a) to h), and j) after a certain number of repetitions of process steps a) to i), opening an outlet valve in a retentate discharge line for the retentate and, if necessary, repeating process steps a) to j).

[0041] Preferably, the retentate is removed in process step j). Preferably, process steps c) to h) can be carried out several times in succession, in particular before carrying out process step i).

[0042] Preferably, the pump chamber and the filter chamber are sealed off from the drive means by a sealing chamber between the drive means and the pump chamber, wherein at least a part of the wall of the sealing chamber, in particular the part of the wall towards the drive means, is formed by a sealing membrane.

[0043] According to an advantageous embodiment of the process, a flushing quantity of permeate that is pumped from the permeate side to the retentate side in process steps g) and h) corresponds to a portion of a filter quantity of the liquid that is pumped from the retentate side through the filter membrane to the permeate side in process steps c) and d). In particular, the flushing quantity amounts to up to 80% of the filter quantity, preferably up to 50% of the filter quantity, particularly preferably up to 30% of the filter quantity, most preferably at least 10% of the filter quantity. Thus, when the flow direction is reversed, less liquid is pumped back to the retentate side, so that the concentration of particles in the liquid on the retentate side increases after each repetition of process steps a) to h).

[0044] A preferred embodiment of the process is characterized in that the drive means, in particular the pressure to be generated by the pump membrane on the retentate side and on the permeate side, and / or the valves and / or the outlet valve are controlled via a controller. The controller coordinates the individual process steps and optimizes filtration.

[0045] Particularly preferably, the filter membrane and / or the filter chamber are cleaned using a liquid medium, in particular using the particle-laden liquid or the permeate or the retentate, in particular by a pressure pulse of the liquid medium from a pressure reservoir. Thus, the filter membrane can be freed from a deposit formed on the filter membrane from time to time, also referred to as fouling or scaling, and / or the formation of the deposit can be prevented, in particular through regular cleaning.

[0046] Further advantageous features and embodiments are explained below using exemplary embodiments and the figures. They show:

[0047] Figure 1 shows a filtration system in a first embodiment; and

[0048] Figure 2 shows a filtration system in a second embodiment with a

[0049] Pressure storage for the permeate; and

[0050] Figure 3 shows the filtration system from Figure 2 in a further embodiment.

[0051] Figure 1 shows a first embodiment of a filtration system 30. The filtration system 30 comprises two filtration devices 31, 31', which are arranged diametrically opposite one another. The filtration devices 31, 31' are essentially identical in design, which is why only one filtration device 31, 31' will be discussed in detail below. The drive chamber 40, in which the drive means 8 is arranged, is formed between the two filtration devices 31, 31'. By means of the filtration devices 31, 31', a particle-laden liquid 39 is divided into a particle-reduced permeate 38 and a particle-enriched retentate.

[0052] The filtration device 31, 31' comprises a filter chamber 34 in which a filter membrane 10 is arranged, as well as a pump device 33, which is formed by a pump chamber 32 and a sealing chamber 35 together with the drive means 8. A pump membrane 1 is arranged within the pump chamber 32 and divides the pump chamber 32 into a feed chamber 2 and a filtrate chamber 3. The pump membrane 1 is connected to the drive means 8 via a pump tappet 7 and performs an oscillating movement through the movement of the pump tappet 7. The movement of the pump membrane 1 generates a pressure in the feed chamber 2 and a negative pressure in the filtrate chamber 3 during a forward stroke, and vice versa during a reverse stroke, when a negative pressure is generated in the feed chamber 2 and a pressure in the filtrate chamber 3. The pressure can be determined by the stroke of the pump membrane 1, whereby the pressure on the retentate side 11 is slightly higher than the pressure on the permeate side 11a.

[0053] A supply line 37 for the particle-laden liquid 39 opens into the supply chamber 2. This liquid 39 is pumped through the fluidic connection of the supply chamber 2 to the filter chamber 34 into the filter chamber 34 for filtration by means of the pumping device 33. Furthermore, a valve 13 is arranged in the supply line 37, by means of which the supply line 37 into the supply chamber 2 can be separated.

[0054] The filter membrane 10 arranged in the filter chamber 34, through which the liquid 39 can flow in one flow direction or through which the liquid 39 can flow in one flow direction, separates a permeate side 11a from a retentate side 11 of the filter chamber 34. The filter chamber 34 also has an opening 34a at which an outlet valve 9 is arranged. The retentate on the retentate side 11 of the filter chamber 34 is discharged via the outlet valve 9 via a retentate discharge line 36. The retentate is periodically discharged into a receptacle 39a via the retentate discharge line 36 after a number of forward strokes and reverse strokes of the pump membrane 1 by building up an overpressure which is greater than the overpressure generated by the forward stroke of the pump membrane 1 by opening the outlet valve 9.In this case, the receptacle 39a also serves as a reservoir for the particle-laden liquid 39, so that the permeate 38 is fed back into the particle-laden liquid 39, which, however, increases the concentration of particles in the particle-laden liquid 39. The opening 34a is located on the side of the filter chamber 34 facing away from the pump chamber 32.

[0055] On the permeate side 11a of the filter chamber 34, a permeate outlet 34b is arranged, through which the permeate 38 is directed via the permeate discharge line 12 into a receptacle 38a. The permeate discharge line 12 has a branch that opens into the filtrate chamber 3 of the pump chamber 32. Furthermore, a valve 14 is arranged in the permeate discharge line 12 to shut off the permeate discharge line 12 from the receptacle 38a. By connecting the permeate discharge line 12 to the filtrate chamber 3, the permeate 38 is pumped out of the filter chamber 34 to be discharged into the receptacle 38a.

[0056] According to the invention, a sealing chamber 35 for sealing the pump chamber 32 is formed between the pump chamber 32 and the drive chamber 40, in which the drive means 8 is arranged. The sealing chamber 35 adjoins the drive chamber 40 on the one hand and the filtrate side 3 of the pump chamber 32 on the other hand and has a sealing chamber 5. A rigid partition wall 4 is formed towards the filtrate chamber 3 and has a passage for the pump tappet 7. For sealing, a sliding seal is arranged in the passage for the pump tappet 7, whereby a sufficient seal is achieved between the filtrate chamber 3 and the sealing chamber 5 of the sealing chamber 35. The sealing chamber 35 further comprises a sealing membrane 6, which forms part of the wall of the sealing chamber 35. In the present case, the sealing membrane 6 is located on the side of the sealing chamber 35 facing away from the filtrate side 3 of the pump chamber 32 and forms a wall surface towards the drive chamber 40.The pump tappet 7 is connected to both the pump diaphragm 1 and the sealing diaphragm 6, whereby they always perform a common, in particular parallel, movement.

[0057] In this case, the sealing diaphragm 6 and the pump diaphragm 1 are arranged in parallel planes, one behind the other, aligned. The sealing diaphragm 6 and the pump diaphragm 1 are each designed as plate diaphragms and are essentially identical to each other. This particularly improves the storage and availability of spare parts, since a plate diaphragm can be used both as the sealing diaphragm 6 and as the pump diaphragm 1. Alternatively, the diaphragms can also be a rolling diaphragm.

[0058] The sealing chamber 35 with the sealing membrane 6 provides a simple seal for the pump chamber 32, and in particular its filtrate side 3. This eliminates the need for a costly water seal, making the filtration system 30 simpler and requiring less maintenance. In particular, the sealing chamber 35 with its sealing space 5 prevents air or other gaseous media from the environment from being sucked into the filtration system 30.

[0059] To avoid pressure pulses caused by compression or decompression of a medium located in the sealing space 5 of the sealing chamber 35, the two sealing spaces 5 of the sealing chambers 35 of the filtration devices 31, 31' are connected to one another via a compensating connection 15. The compensating connection 15 can, for example, be a line or a hose through which the two sealing spaces 5 of the sealing chambers 35 are fluidically connected to one another. Due to the oscillating movement of the sealing membranes 6 of the two filtration devices 31, 31', which follow the movement of the pump membranes 1, a pressure equalization always occurs between the two sealing spaces 5 of the two filtration devices 31, 31'. This also makes the movement of the pump tappet 7 overall smoother, whereby the pumping processes become more uniform.

[0060] The filtration system 30 with two filtration devices 31, 31' thus, on the one hand, utilizes synergy effects, since some elements, such as the drive 8 or the receptacles 38a, 39a, only need to be present once. On the other hand, the opposing oscillating movement of the elements prevents pressure fluctuations and energy losses, making the system particularly efficient.

[0061] The embodiment shown in Figure 2 is constructed in the area of ​​the filtration system 30 essentially analogously to the filtration system 30 shown in Figure 1; in particular, it also comprises two filtration devices 31, 31'. Therefore, reference is made to the detailed description of Figure 1.

[0062] In addition, the filtration system 30 in Figure 2 comprises a pressure reservoir 26 for a liquid medium, in this case for the permeate 38, by means of which a simple and rapid cleaning of the feed space 2 and the filter chamber 34, in particular the filter membrane 10, is enabled. Due to the division of the particle-laden liquid 39 by means of the filter membrane 10, particles can become trapped on or in the filter membrane 10, thereby reducing the filter performance. In particular, a coating can form on the filter membrane 10, which is referred to as fouling or scaling. Therefore, it is necessary to clean the filter membrane 10 from time to time. This can be done particularly effectively if the filter membrane 10 is cleaned with a pressure pulse of a liquid medium.The present filtration system 30 is therefore particularly suitable because, in addition to the pressure accumulator 26 and some lines, other necessary devices, such as a pumping device for pumping permeate 38 as a liquid medium into the pressure accumulator 26, are already present in the filtration system 30.

[0063] To fill the pressure accumulator 26 with permeate 38 as a liquid medium, the filtration system 30 comprises a medium supply line 17, by means of which permeate 38 is conveyed from the receptacle 38a into the sealing space 5 of the sealing chamber 35. Alternatively, the retentate or the particle-laden liquid 39 or another medium, for example, water, can also be used as the liquid medium. By forming a wall with a sealing membrane 6, the sealing chamber 35 not only seals the retentate side 11 and permeate side 11a of the filtration device 31, 31', but also functions as a pumping system, by means of which the permeate 38 is pumped into the pressure accumulator 26 as a liquid medium.

[0064] To generate a pumping process, the equalizing connection 15 between the sealing chambers 35 of the filtration devices 31, 31' should be closed to avoid pressure loss when pumping permeate 38 as a liquid medium with the sealing chamber 35 in the pressure accumulator 26. This is achieved in this case via a shut-off valve 16 in the equalizing connection 15.

[0065] With each movement of the sealing membrane 6, permeate 38 is directed into the sealing chamber 5 of the sealing chamber 35 and fed to the pressure accumulator 26 via a pressure accumulator line 18. This also increases the pressure in the pressure accumulator 26, which can be determined via a pressure gauge 27. To prevent backflow of permeate 38 from the sealing chamber 5 into the receptacle 38a and from the pressure accumulator 26 into the sealing chamber 5, check valves 17a, 18a are arranged in the medium supply line 17 and in the pressure accumulator line 18. The check valves 17a, 18a close the pressure accumulator line 18 and the medium supply line 17 on one side, so that pumping out of permeate 38 by a backward stroke of the sealing membrane 6 from the pressure accumulator 26 or the pressure accumulator line 18 or the sealing chamber 5 is not possible.In order to conduct liquid medium into the filter chamber 34, the latter is connected to the pressure accumulator 26 via a pressure accumulator discharge line 19, wherein a valve 19a for opening and closing the pressure accumulator discharge line 19 is arranged in the pressure accumulator discharge line 19.

[0066] In the pressure accumulator line 18, a shut-off valve 24 and another check valve 25 are arranged in the supply line to the pressure accumulator 26 and upstream of the pressure accumulator outlet line 19. The pressure accumulator line 18 is also connected to the retentate outlet line 36 via a valve 22, which allows the pressure accumulator line 18 to be vented and, in the event of excessive pressure, to drain the liquid medium, in this case the permeate 38.

[0067] To clean the filter chamber 34 or the filter membrane 10, when the pressure in the pressure accumulator 26 is sufficient, the valve 19a and the outlet valve 9 are opened, preferably abruptly, creating a pressure pulse from the liquid medium flowing out of the pressure accumulator 26, in this case the permeate 38, which is fed to the filter chamber 34 via the pressure accumulator discharge line 19. The pressure pulse cleans the feed chamber 2, the filter chamber 34, and in particular the filter membrane 10 using the permeate 38. Preferably, the pressure pulse is further amplified by simultaneously performing a pre-stroke of the pump membrane 1 toward the filter chamber 34. The opening and closing of the valves 19a is effected, in particular, via a control system.

[0068] Figure 3 shows yet another embodiment of a filtration system 30, which is essentially based on the filtration system 30 from Figure 2. A key difference from the filtration system 30 shown in Figure 2 is that a device for increasing the pressure in the pressure accumulator 26 in the form of a hydraulic pressure booster 23 is arranged in the region of the pressure accumulator line 18. The hydraulic pressure booster 23 comprises two pistons 23a, 23b of different diameters, wherein the ratio of the diameters of the pistons 23a, 23b is, for example, 1:3. For pumping permeate 38 as a liquid medium into the pressure accumulator 26, a valve 21 is arranged in the pressure accumulator line 18, which, together with the valve 24 in the open position, enables the pressure accumulator 26 to be filled.

[0069] After filling the pressure accumulator 26 with permeate 38 as a liquid medium, the valve 21 is closed. Permeate 38 is then pumped from the pressure accumulator line 18 via the valve 20 into an annular space containing the piston 23a of the hydraulic pressure booster 23, causing this piston 23a to move toward the piston 23b or exert pressure on the piston 23b. The movement of the piston 23b, which is arranged on the side facing the pressure accumulator 26, increases the pressure in the pressure accumulator 26 until an end position of the piston 23b in the hydraulic pressure booster 23 is reached or the desired pressure in the pressure accumulator 26, which can be determined via the pressure gauge 27, is set. Due to the transmission in the hydraulic pressure booster 23, the pressure in the pressure accumulator 26 increases more slowly, but a significantly higher pressure can be achieved.

[0070] With the filtration device 31, 31' as described above as well as with a filtration system 30 as described above, a method for dividing a particle-laden liquid 39 into a particle-reduced permeate 38 and a particle-enriched retentate can be carried out, wherein the method comprises the following steps: a) opening the feed line 37 for the liquid 39 so that the liquid 39 flows on the retentate side 11 substantially orthogonally onto the filter membrane 10 in the filter chamber 34; b) Opening the permeate discharge line 12 for the permeate 38, so that the permeate 38 flows through the filter membrane 10 to the permeate side 11a and out of the filter chamber 34 via the permeate outlet 34, wherein the opening of the supply line 37 and the permeate discharge line 12 takes place via valves 13, 14, c) Generating a pressure of the liquid 39 on the retentate side 11 by means of a pump membrane 1 in the pump chamber 32, wherein the pump membrane 1 is moved via the drive means 8,d) generating a pressure of the liquid on the permeate side 11a by the pump membrane 1, which pressure is smaller in magnitude than the pressure of the liquid 39 on the retentate side 11; e) Closing the supply line 37 for the liquid 39, f) Closing the permeate discharge line 12, wherein the closing of the supply line 37 and the permeate discharge line 12 takes place via valves 13, 14, g) Generating a pressure of the liquid 38 on the retentate side 11 through the pump membrane 1, h) Generating a pressure of the liquid on the permeate side 11a through the pump membrane 1, which pressure is greater in magnitude than the pressure of the liquid 39 on the retentate side 11, so that the flow direction of the liquid, in particular of the permeate 38, through the filter membrane 10 is reversed compared to process steps a) to d), i) Repeating process steps a) to h),wherein the pressure of the liquid 39 on the retentate side 11 is greater in magnitude than on the permeate side 11a in a time average over the repetitions of process steps a) to h), and j) after a certain number of repetitions of process steps a) to i), opening the outlet valve 9 in a retentate discharge line 36 for the retentate and, if necessary, repeating process steps a) to j).

[0071] In process step j), the retentate is drained from the filter chamber 34 via the retentate drain 36. Process steps c) to h) can preferably be carried out several times in succession, in particular before carrying out process step i). Through process steps c) and d), a filtered amount of liquid is pumped from the retentate side 11 through the filter membrane 10 to the permeate side 11a, whereas in process steps g) and h), a flushed amount of permeate 38 is pumped from the permeate side 11a to the retentate side 11. However, the flushed amount is only a portion of the filtered amount, in this case only up to 50% of the filtered amount. The filtration devices 31, 31' as well as the filtration system 30 and the process are controlled by a controller (not shown), in particular the pressure generation on the retentate side 11 and the permeate side 11a.The control system controls, among other things, the drive means 8 and, in particular, the pressure generated on the retentate side 11 and on the permeate side 11a by means of the pump membrane 1. In addition, the control system also controls the valves 13, 14, as well as the other valves and the outlet valve 9, according to the process steps.

[0072] List of reference symbols

[0073] 1 pump diaphragm 21 valve

[0074] 2 Feed chamber 22 Valve

[0075] 3 Filtrate chamber 23 hydraulic pressure increase

[0076] 4 Partition 30 23a Piston

[0077] 5 Sealing chamber 23b piston

[0078] 6 Sealing membrane 24 Valve

[0079] 7 Pump tappet 25 Check valve

[0080] 8 drive means 26 pressure accumulators

[0081] 9 Outlet valve (retentate) 35 27 Pressure gauge

[0082] 10 filter membrane 30 filtration system

[0083] 11 Retentate side 31, 31' Filtration device

[0084] 11a Permeate side 32 pump chamber

[0085] 12 Permeate discharge 33 Pumping device

[0086] 13 Valve 40 34 Filter chamber

[0087] 14 Valve 34a opening

[0088] 15 Compensation connection 34b Permeate outlet

[0089] 16 Shut-off valve 35 Sealing chamber

[0090] 17 Medium supply line 36 Retentate discharge line

[0091] 17a Check valve 45 37 supply line

[0092] 18 Storage line 38 Permeate

[0093] 18a Check valve 38a Holder

[0094] 19 Accumulator discharge 39 particle-laden liquid

[0095] 19a Valve 39a Holder

[0096] 20 Valve 50 40 Drive chamber

Claims

Claims 1. Filtration device (31, 31') for dividing a particle-laden liquid (39) into a particle-reduced permeate (38) and a particle-enriched retentate in a filter chamber (34), with a filtration membrane (10) through which the liquid (39) can flow or through which it flows in a flow direction, which filtration membrane separates a permeate side (11a) of the filter chamber (34) of the filtration device (31, 31') from a retentate side (11) of the filtration device (31, 31'), with a pumping device (33), by means of which a pressure of the liquid on the permeate side (11a) and on the retentate side (11) can be determined, wherein the pumping device (33) comprises a pumping membrane (1) in a pumping chamber (32), which pumping membrane (1) is driven by a drive means (8) via a pump tappet (7) into a oscillating movement, wherein a feed chamber (2) of the pump chamber (32) is fluidically connected to the filter chamber (34),and with a supply line (37) for the liquid (39) into the feed chamber (2), a permeate discharge line (12) and a retentate discharge line (36), characterized in that a sealing chamber (35) with a sealing space (5) is arranged between the drive means (8) and the pump chamber (32), wherein at least part of a wall of the sealing chamber (35) is formed by a sealing membrane (6).

2. Filtration device (31, 31') according to claim 1, characterized in that the sealing membrane (6) is arranged on a wall surface facing away from the pumping chamber (32), in particular that the sealing membrane (6) forms the wall surface of a wall surface facing away from the pumping chamber (32).

3. Filtration device (31, 31') according to one of the preceding claims, characterized in that the sealing membrane (6) and the pumping membrane (1) are arranged one behind the other in parallel planes, in particular are arranged in alignment with one another.

4. Filtration device (31, 31') according to one of the preceding claims, characterized in that the drive means (8) is a linear drive or an eccentric drive which is operatively connected to the pump membrane (1) via the pump tappet (7) and which is designed and provided to set the pump membrane (1) in an oscillating movement.

5. Filtration device (31, 31') according to claim 4, characterized in that the linear drive is an electric drive, a hydraulic drive or a pneumatic drive and / or that the eccentric drive comprises an eccentric disc on which the pump tappet (7) is arranged directly or indirectly.

6. Filtration device (31, 31') according to one of the preceding claims, characterized in that at least one valve (9, 13, 14) is arranged in the feed line (37), in the permeate discharge line (12) and / or in the retentate discharge line (36), in particular for closing the feed line (37), the permeate discharge line (12) and / or the retentate discharge line (36).

7. Filtration device (31, 31') according to one of the preceding claims, characterized in that the feed space (2) of the pumping chamber (32) is separated from a filtrate space (3) of the pumping chamber (32) by the pumping membrane (1).

8. Filtration device (31, 31') according to claim 7, characterized in that a partition wall (4) is arranged between the filtrate chamber (3) and the sealing chamber (35) through which the pump tappet (7) is sealingly guided, wherein the partition wall (4) is preferably rigid.

9. Filtration device (31, 31') according to one of the preceding claims, characterized in that the permeate discharge line (12) is connected to the filtrate chamber (3) and / or to the permeate side (11a) of the filter chamber (34).

10. Filtration device (31, 31') according to one of the preceding claims, characterized in that the sealing membrane (6) and / or the pumping membrane (1) is designed as a plate membrane or rolling membrane.

11. Filtration device (31, 31') according to one of the preceding claims, characterized in that the retentate can be discharged periodically after a number of forward strokes and reverse strokes of the pump membrane (1) by building up an overpressure which is greater than an overpressure generated by the forward stroke of the pump membrane (1), via the retentate discharge line (36).

12. Filtration device (31, 31') according to one of the preceding claims, characterized in that the filtration device (31, 31') has a pressure accumulator (26) which can be filled with a liquid medium, in particular the particle-laden liquid (39) or permeate (38) or retentate, wherein the liquid medium can be pumped into the pressure accumulator (26) via a medium supply line (17) via the sealing space (5) of the sealing chamber (35) and a pressure accumulator line (18).

13. Filtration device (31, 31') according to claim 12, characterized in that check valves (17a, 18a) are arranged in the medium supply line (17) and / or the pressure accumulator line (18) and / or that the liquid medium in the pressure accumulator (26) has a pressure greater than 1 bar, preferably greater than 3 bar, particularly preferably greater than 10 bar.

14. Filtration device (31, 31') according to one of the preceding claims 12 or 13, characterized in that the liquid medium can be conducted into the feed space (2) and / or the filter chamber (34) via a pressure accumulator discharge line (19), wherein a valve (19a) is arranged in the pressure accumulator discharge line (19).

15. Filtration device (31, 31') according to one of the preceding claims 12 to 14, characterized in that cleaning of the feed space (2) and / or the filter chamber (34), in particular the filter membrane (10), takes place via the pressure accumulator discharge line (19) through the liquid medium, preferably by a pressure pulse of the liquid medium.

16. Filtration device (31, 31') according to one of the preceding claims 12 to 15, characterized in that a device for increasing the pressure in the pressure accumulator (26), in particular a hydraulic pressure increaser (23), is arranged after the sealing chamber (35) and before the pressure accumulator (26) in the pressure accumulator line (18).

17. Filtration system (30) comprising at least two filtration devices (31, 31') according to one of the preceding claims, which are preferably arranged diametrically opposite one another, wherein the filtration devices (31, 31') have a common drive means (8).

18. Filtration system (30) according to claim 17, characterized in that the drive means (8) is arranged substantially in the middle of the two filtration devices (31, 31').

19. Filtration system (30) according to one of the preceding claims 17 or 18, characterized in that the sealing chambers (35) of the two Filtration devices (31, 31') are connected to one another via a compensating connection (15), wherein a valve (16) is preferably arranged in the compensating connection (15).

20. Filtration system comprising at least two filtration systems (30) according to one of claims 17 to 19 or more than two filtration devices (31, 31') according to one of claims 1 to 16.

21. Filtration system according to claim 20, characterized in that the filtration devices (31, 31') are designed according to at least one of claims 12 to 16 and that the filtration system has at least one pressure accumulator (26) for the filtration devices (31, 31').

22. A method for dividing a particle-laden liquid (39) into a particle-reduced permeate (38) and a particle-enriched retentate in a filtration device (31, 31') according to one of claims 1 to 16 or a filtration system (30) according to one of claims 17 to 19 or a filtration plant according to one of claims 20 or 21, the method comprising the following steps: a) opening a feed line (37) for the liquid (39) so that the liquid (39) flows on a retentate side (11) substantially orthogonally onto a filter membrane (10) in a filter chamber (34);b) opening a permeate discharge line (12) for the permeate (38) so that the permeate (38) flows through the filter membrane (10) to a permeate side (11a) and out of the filter chamber (34) via a permeate outlet (34), wherein the opening of the supply line (37) and the permeate discharge line (12) takes place via valves (13, 14), c) generating a pressure of the liquid (39) on the retentate side (11) by means of a pump membrane (1) in a pump chamber (32), wherein the pump membrane (1) is moved via a drive means (8); d) generating a pressure of the liquid on the permeate side (11a) by means of the pump membrane (1), which pressure is smaller in magnitude than the pressure of the liquid (39) on the retentate side (11); e) closing the supply line (37) for the liquid (39), f) closing the permeate discharge line (12), wherein the closing of the supply line (37) and the permeate discharge line (12) is effected via valves (13, 14), g) generating a pressure of the liquid (39) on the retentate side (11) through the pump membrane (1), h) generating a pressure of the liquid on the permeate side (11a) through the pump membrane (1), which pressure is greater in magnitude than the pressure of the liquid (39) on the retentate side (11), so that the flow direction of the liquid, in particular of the permeate (38) through the filter membrane (10) is reversed compared to process steps a) to d), i) repeating process steps a) to h),wherein the pressure of the liquid (39) on the retentate side (11) is greater in magnitude than on the permeate side (11a) in a time average over the repetitions of process steps a) to h), and j) after a certain number of repetitions of process steps a) to i) opening an outlet valve (9) in a retentate discharge line (36) for the retentate and, if necessary, repeating process steps a) to j).

23. Method according to claim 22, characterized in that the pump chamber (32) and the filter chamber (34) are sealed off from the drive means (8) via a sealing chamber (35) between the drive means (8) and the pump chamber (32), wherein at least part of the wall of the sealing chamber (35), in particular the part of the wall towards the drive means (8), is formed by a sealing membrane (6).

24. The method according to claim 22 or 23, characterized in that a flushing quantity of permeate (38) which is pumped from the permeate side (11a) to the retentate side (11) in method steps g) and h) corresponds to a partial quantity of a filter quantity of the liquid which is pumped from the retentate side (11) through the filter membrane (10) to the permeate side (11a) in method steps c) and d), in particular that the flushing quantity is up to 80% of the filter quantity, preferably up to 50% of the filter quantity, particularly preferably up to 30% of the filter quantity, most preferably at least 10% of the filter quantity.

25. Method according to one of claims 22 to 24, characterized in that the drive means (8), in particular the pressure to be generated by means of the pump membrane (1) on the retentate side (11) and on the permeate side (11a), and / or the valves (13, 14) and / or the outlet valve (9) are controlled by a controller.

26. Method according to one of claims 22 to 25, characterized in that the filter membrane (10) and / or the filter chamber (34) is cleaned by means of a liquid medium, in particular by means of the particle-laden liquid (39) or the permeate (38) or the retentate, in particular by a pressure pulse of the liquid medium from a pressure accumulator (26).

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