METHOD FOR CLEANING MODULES OF A FILTER DEVICE AND MODULE FOR FILTRATION

Description

Field of invention

[0001] The invention relates to a method for cleaning filter devices of a module for filtering fluids and a module for carrying out this method. State of the art

[0002] Various filter systems are known that, for example, filter fluids for industrial purposes and discharge the filtered fluid. Since continuous filter operation is desirable for industrial applications to maximize machine efficiency, it is advantageous to minimize filter cleaning times. To maintain continuous filter operation despite occasional filter failure, several filter modules can be used in parallel, feeding filtrate into a central collection line. This simultaneously increases the amount of filtrate. Such a filter system is disclosed, for example, in WO 2013 / 048801 A1. This system comprises a filter module arrangement consisting of a container with a filter cartridge and a collector coupled to one end of the container, the collector head comprising a housing with an open upper and lower end and an end cap.A section that fits a complementary structure defined by the interior of the entire open top end of the housing, so that it engages removably with the housing and end cap, defines a passage through which liquid can flow out of the container. The filter module arrangement enables a manifold arrangement used to convey liquids to and from a filter system comprising several such modules. However, disadvantages of existing filter cleaning solutions include their reliance on backflushing, which involves the complex reversal of the flow direction and the use of filtrate to rinse the filters against the main filtration direction. The inherently long flow paths result in a significant pressure drop in the piping system and poor fluid distribution, thereby reducing process efficiency and increasing process times.This, combined with the use of filtrate, the product of the filtration process, ultimately leads to a reduction in machine efficiency. Efforts are underway to use filter systems that allow backwashing within a single flow chamber. This reduces the backwash path and provides a compact module with a filtrate-generating module area and a backwashed module area. However, the flat membrane filters used in this approach result in poor flow distribution, as the fluid only flows in and out over a small portion of the filter surface. Consequently, a large part of the filter is not adequately cleaned. Furthermore, the flow path of the filtrate, which is fed into the module via the filtrate collection line that normally discharges the filtrate, is also very long, leading to significant flow losses.

[0003] DE 101 64 555 A1 discloses a method for operating a cross-flow microfiltration device that makes it possible to maintain continuous filtration operation during the cleaning phase. The method provides that at least one filter module is temporarily disconnected from the unfiltrate feed and / or discharge and operated in backwash mode, while simultaneously the remaining filter module(s) are operated in filtration mode, with a portion of the filtrate produced by these filter modules being diverted for backwashing.

[0004] DE 10 2017 208 730 A1 discloses a filter device and a method with at least one module package comprising several, in particular at least three, modules for crossflow filtration, which have a first unfiltrate connection at a first end of the module and a second unfiltrate connection on the opposite side of the module, as well as at least one filtrate outlet. The device includes a valve arrangement configured such that each individual module can be selectively supplied with unfiltrate from either the first or the second unfiltrate connection.

[0005] CN 111087045 A discloses a filter module in which both a water inlet pipe and an air inlet pipe are connected to the water outlet opening of the end head component. The air inlet pipe is located on one side of the water outlet opening and has an inner upper surface adjacent to the water outlet opening and an inner lower surface away from the water outlet opening. An air outlet branch pipe is provided inside the air inlet pipe, extending from the inner bottom surface of the air inlet pipe towards the water outlet opening and connecting the air outlet branch pipe to the water outlet opening. Description of the invention

[0006] The object of the invention is to provide a method for cleaning the filter elements of a fluid filtration module and a module for implementing this method, enabling efficient and cost-effective cleaning of the filter elements. The fluid to be filtered is preferably a liquid, in particular water, although gas, for example nitrogen, can also be used for the cleaning process.

[0007] This problem is solved by a method according to claim Error! Reference source not found. and through a module according to claim Error! Reference source not found.. Further features that elaborate on the invention are contained in the dependent claims.

[0008] In a method according to the invention for cleaning a filter device of a module for filtering fluids, wherein the module has a feed line with at least two separate feed channels that convey the fluid to the filter device, wherein the filter device has a filter inlet area for each feed channel that is specific only to that feed channel, a filtrate chamber, and a filtrate line that has one or more filtrate channels and that receives and discharges the filtrate from the filtrate chamber, the feed line leading to a module is divided so that at least one first feed channel conveys a fluid to the filter device and at least one second feed channel discharges the fluid from the filter device simultaneously. This ensures that when the fluid is discharged through a feed line, the particles located in the filters are washed out by the fluid.In particular, when the supplied fluid is filtered through the associated filter and directed into the filtrate chamber, and then exits only through the filter belonging to the outgoing supply line, this filter is cleaned extremely thoroughly. This also works in reverse. Therefore, if the fluid for cleaning the filter unit is conveyed directly from the supply lines to the filter unit, the complex process of filling a filtrate channel connected to the module is unnecessary. Furthermore, the fluid's path and the number of elements through which the fluid flows are minimized. Additionally, by clever throttling, simultaneous backflushing of one side and provision of filtrate at the outlet can be achieved. An advantage of the invention is that the space requirement is significantly reduced, as only one module is needed instead of two. Consequently, the connection effort is also reduced.Furthermore, special backwashing procedures, such as the cross-backwashing procedure, can be carried out.

[0009] A further advantage of the invention is that by reducing the backwash path, poor flow distribution during backwashing can be avoided. The fluid required for backwashing is provided, and in particular filtered, in the immediate vicinity of where it is used. This results in a more homogeneous flow distribution within the module, thus avoiding areas of the filter system with significantly different levels of contamination and uniformly reducing the clogging of the filter element membranes.

[0010] Preferably, in the method for cleaning a filter element of a fluid filtration module, a first feed channel conveys fluid through the filter element to a second feed channel. Hollow fiber membranes are preferably used as filter elements. The filter element is cleaned by the fluid flowing past the inner walls of the fibers without the fluid being filtered by the hollow fiber membrane itself. Because the fluid is conveyed past the filter membranes rather than through them, the filter cleaning is not as thorough but is significantly faster. In another preferred embodiment, the fluid is filtered by the filter element before being discharged through the at least second feed channel and cleans the filter during backwashing. This thoroughly removes the particles from the filter.

[0011] In further methods according to the invention, the fluid is preferably filtered through the filter device before being discharged in the second feed channel. This ensures that the part of the filter device to be cleaned is cleaned with filtrate. The cleaning process is thus significantly more effective.

[0012] In further methods according to the invention, the fluid is preferably filtered through the filter device before being discharged in the second feed channel. This ensures that the part of the filter device to be cleaned is cleaned with filtrate. The cleaning process is thus significantly more effective.

[0013] A method according to any of the preceding claims, further comprising the step of closing one or more feed channels, in particular by means of a valve. Closing one or more feed channels allows for very simple control of the filters to be cleaned.

[0014] The filters of several modules connected in series can be cleaned simultaneously using the first and second feed channels, making the process more efficient. Two or more modules can also be connected in parallel.

[0015] In further methods according to the invention, the fluid is preferably filtered through the filter device before being discharged in the second feed channel. This ensures that the part of the filter device to be cleaned is cleaned with filtrate. The cleaning process is thus significantly more effective.

[0016] The invention also relates to a module for filtering fluids, comprising a feed line for conveying fluid, a filter device comprising a filter element configured to filter the fluid conveyed from the feed line to the filter device, a filtrate chamber for receiving the fluid filtered by the filter element, and a filtrate channel that receives and discharges the filtrate from the filtrate chamber, wherein the feed line has at least two separate feed channels and the filter device has a filter inlet area for each of these feed channels, specific to that channel, where the fluid enters the filter element of the filter device. This module enables the method according to the invention and the advantages described therein.

[0017] The filter element can include a hollow fiber membrane. These are suitable for both types of filter cleaning, making the module more flexible.

[0018] The feed channels are preferably formed at least partially from two separate tubes and / or as a single tube in which the separation of the feed channels is formed by a separating element. Furthermore, the module can include a head element in which the feed channels are formed by separate chambers and which adjoin the filter device.

[0019] The chambers preferably each have two connection openings, allowing the fluid to flow into the chamber and at least partially out. Preferably, the connections between the at least one separating element and the areas adjacent to it are sealed against the fluid by means of a sealing element.

[0020] At least one feed channel preferably has a recess for gas discharge. This is particularly useful when cleaning the filters or when initially filling them with fluid. This recess is formed on the upper side of the feed channel(s) (with respect to the direction of gravity).

[0021] The module further includes, in particular, a valve assembly with one or more valves, with which one or more feed channels and / or one or more filtrate channels can be closed. This allows the flow direction of the fluid and thus the filters to be cleaned to be easily controlled. The valve can, for example, be located in the head area.

[0022] The modules simultaneously act as collectors to distribute the corresponding flows to the modules connected in series, while maintaining any existing separation of the flows across modules arranged in series. Brief description of the characters

[0023] Figure 1a shows a module according to the invention for the filtration of fluids with feed channels formed in a tube and separated by a separating element; Figure 1b shows a vertical sectional view of the Figure 1a with a cut perpendicular to the separating element, in which both feed channels are visible inside the module; Figure 1c shows a vertical sectional view of the Figure 1a with a cut parallel to the separating element, in which both feed channels are visible inside the module; Figure 2a shows a module according to the invention for the filtration of fluids with feed channels formed in two pipes. Figure 2b shows a vertical sectional view of the Figure 2a with a cut perpendicular to the partition wall located in the module between the feed channels, in which both feed channels are visible inside the module; Figure 2c shows a vertical sectional view of the Figure 2awith a section carried out parallel to the partition wall located in the module between the feed channels, in which both feed channels are visible inside the module; Figure 2d shows an isometric view of two parallel connected modules according to the invention for the filtration of fluids; Figure 3a shows an abstract representation of the filtration process using a module according to the invention for the filtration of fluids. Figure 3b shows an abstract representation of a variant of the inventive method for cleaning filter devices of a module for filtering fluids, in which fluid is supplied via at least one supply channel, then filtered through a filter element, then used to clean another filter element and finally discharged via at least one supply channel adjacent to the other filter element; Figure 3cshows an abstract representation of a variant of the inventive method for cleaning filter devices of a module for filtering fluids, in which the in Figure 3b The procedure shown is carried out in reverse; 3D figure Figure 1 shows an abstract representation of a variant of the inventive method for cleaning filter devices of a module for filtering fluids, in which fluid is supplied via a feed channel, subsequently filtered through a filter element, then used to clean another filter element and finally discharged via at least one feed channel adjacent to the other filter element, wherein the fluid-discharging feed channel is located in a module that is connected in parallel to the other module in which the fluid-supplying feed channel is located; Figure 3eFigure 1 shows an abstract representation of a variant of the inventive method for cleaning filter devices of a module for filtering fluids, in which the filter device is cleaned by rinsing the fluid by passing the fluid along the filter membrane without filtering it; and Figure 3f shows an abstract representation of a variant of the inventive method for cleaning filter devices of a module for filtering fluids, in which the in Figure 3e The described procedure is carried out, with the difference that fluid is simultaneously supplied and removed in one module. Description of preferred embodiments

[0024] In the following, a module 10 for fluid filtration is described first, with directional references always referring to the corresponding figures. A basic embodiment of a module 10 for fluid filtration comprises a feed line 14 for conveying fluid. The feed line 14 has at least two feed channels 12 that convey the fluid to a filter unit 15. The feed channels can be configured as separate pipes or within a pipe by means of a partition. The feed channels also include a separate section in a head element 18. The filter unit 15 comprises several filter elements. The filter elements are preferably configured as a plurality of superimposed wound flat membranes or hollow fiber membranes arranged side by side, through which the fluid conveyed by the feed line is forced and which then absorb the components to be filtered from the water. Hollow fiber membranes are particularly preferred.The at least two separate feed channels 12 each have their own filter inlet area where the fluid enters the filter device 15.

[0025] Module 10 further comprises a filtrate chamber 16 for receiving the filtrate, i.e., the fluid filtered by the filter element, and a filtrate line 17, which may have one or more filtrate channels and which receives and discharges the filtrate from the filtrate chamber 16. The filtrate channel may be arranged off-center or centrally, with the off-center arrangement tending to result in greater flexibility in combining several modules 10 and the central arrangement tending to result in better flow conditions within the individual module 10.

[0026] In the embodiments shown here, the filtrate chamber 16 is designed as a cylindrical container. The feed lines can be located on either the top or the bottom, as exemplified in Figure 2d This is shown. This results in several different settings for the cleaning process, which is described below.

[0027] The filtrate enters the filtrate line 17 through outlet openings in the wall of the filtrate chamber (not shown). These outlet openings are arranged on the filtrate chamber 16, preferably near the fluid channel in the head element. The filtrate line 17 can be connected to the outlet openings by a connecting piece (not shown). Such connecting pieces are disclosed, for example, in the subsequently published European application EP 10 2020 116 184. The connecting element is a separate element, but it can also be formed as part of the filtrate chamber 16, as part of the filtrate line 17, or as part of the feed line 14, and be integral with these. The connecting element has, for example, two connecting flanges or connection points to which tubes of the filtrate line 17 can be attached.The connecting element encloses the filtrate chamber 16 at the outlet openings in such a way that a wall forms a comparatively narrow gap in front of the outlet opening(s). With the usual dimensions of such pipe arrangements, the gap is preferably 10 cm to 20 cm or less at its widest point, possibly even only 7 cm or less. Furthermore, the gap preferably tapers, particularly from the position furthest from the filter inlet area towards the filter (i.e., e.g., in...). Figure 1aupwards), i.e., near the filter inlet area, the gap is narrower so that less fluid can flow from the filtrate chamber 16 into the connecting element directly at the filter inlet area. The gap is provided at all outlet openings. However, where there is no gap, there are no outlet openings. The pipe wall of the filtrate chamber 16, which faces the diameter of the connecting element connected to the filtrate line 17, has no outlet openings 42. In the Figures 1a to 1cA first embodiment of a module 10 for filtering fluids such as water is shown. This preferred embodiment of a module for filtering fluids 10 comprises a feed line 14 for conveying fluid, a filter assembly 15 comprising a filter which is configured to filter the fluid conveyed from the feed line 14 to the filter assembly 15. Furthermore, the module has a filtrate chamber 16 for receiving the fluid filtered by the filter and a filtrate channel 17 which receives and discharges the filtrate from the filtrate chamber 16. The feed line 14 has at least two separate feed channels 12, and the filter assembly 15 has a filter inlet area for each feed channel 12 that is specific only to that feed channel.The filter element preferably comprises hollow fiber membranes, which in particular connect two filter inlet areas provided for supply lines 12 opposite each other with respect to the filtrate chamber 16. This makes it possible, in particular when using two parallel connected modules 1, to clean the filter device by flushing the fluid along these without filtering the fluid. This preferred embodiment is described in the [reference to be added]. Figures 3e and 3f schematically represented. This allows, for example, the use of higher fluid flow rates and higher fluid flow velocities.

[0028] In the Figures 1a and 1b In the module 10 shown for fluid filtration, two feed channels 12 connected to the module are combined in a single pipe. The in Figure 1aThe illustrated separating element 20 also extends into the head region 18, thus ensuring the separate supply of fluid to the filter unit 15. Preferably, the area between the separating element 20 and the areas adjacent to it is sealed against the fluid by means of a sealing element. This prevents bypass flow and allows for higher fluid flow rates and velocities. Such a seal can, for example, be an elastomeric seal shaped as a sealing lip, flat gasket, or wedge. The sealing element can be bonded or welded into the module. Alternatively, the seal can be incorporated directly as a second component during the casting process.In a particularly preferred embodiment, an elastomer seal is cast directly into a corresponding recess of the module, which is made of thermoplastic material, for example polyurethane. The associated advantages are a highly efficient manufacturing process and a high degree of sealing performance of the sealing element.

[0029] As an alternative to combining two feed channels 12 connected to a module 10 for fluid filtration into a single pipe, these can be connected via separate pipes, which in the Figure 2a is shown. In contrast to the connection of feed channels 12 grouped together in a single pipe, the manufacture of the pipes is less complex from a structural point of view, since it is not necessary to insert an extended separating element 20, which would be very costly. Otherwise, the embodiment differs in the Figures 2a-2d not from the embodiment in the Figures 1a - 1c .

[0030] In the head section 18 of module 10 for fluid filtration, the feed channels 12 are designed as separate chambers adjacent to the filter unit 15. Such chambers are found, for example, in Figure 1b and 2b shown. This allows, in particular, a more uniform introduction of the fluid into the filter element.

[0031] In the feed lines 12 of module 10, recesses 22 for gas discharge can be incorporated, particularly in the upward-facing area of ​​the chambers of the head element, to facilitate the ascent of the gas as a low-density fluid. The gas to be discharged can be, for example, air present in the lines before initial filling with fluid, or nitrogen used for cleaning. An advantage of these discharge recesses 22 is that the gas can be removed from the lines quickly and effectively, thus improving the fluid flow behavior, especially when the flow direction changes during cleaning.

[0032] Furthermore, a valve assembly comprising at least one valve can be provided with which one or more feed channels 12 and / or one or more filtrate channels 17 can be closed. This makes it possible, on the one hand, to implement special backflushing procedures, for example the one described in 3D figureThe cross-backwashing process shown is implemented. Furthermore, it enables the cleaning of modules 10 connected in series during the filtration process by preventing the contaminated fluid discharged from one module 10 from being conveyed to the next. Instead, the flow path is modified by appropriate valve positions so that the contaminated fluid can be temporarily removed from the process if necessary. Additionally, the use of a valve arrangement allows for a rapid response to fluctuating filtrate demand during the process. This is achieved by activating an additional feed channel 12 when demand increases and deactivating a feed channel 12 when demand decreases. In a particularly preferred embodiment, the valve is located in the head region, which further shortens the flow paths. In principle, shut-off valves are not required.It is sufficient to refrain from pumping fluid into one or more feed channels 12 and direct it to the filter unit 15. The pump pressure from the pumping feed channels 12 then forces the fluid and / or filtrate through the filter into the non-pumping feed channel(s) 12, thus cleaning it. A valve control allows the feed channels to be individually blocked, enabling more efficient and faster cleaning of the filters.

[0033] The head sections 18 can have not only inlet openings for the supply lines, but also outlet openings, so that several modules can be connected in series. The supply lines 12 thus convey the fluid to a multitude of filter devices 15 and filtrate chambers 16, which are arranged one after the other.

[0034] in the Figures 3a-3fThe module is shown schematically, with two filter units and corresponding feed lines arranged opposite each other and thus in parallel. This means that four feed lines are provided. Hollow fiber membranes are used as filter units 15 as an example. Figure 3a The normal operating procedure of module 10 is shown. The supply lines 12 carry the fluid to the filter units 15, where it is forced through the membrane and the fluid particles are trapped in the filter. The resulting filtrate is located in the filtrate chamber and is then transported away by the filtrate line 17.

[0035] The various cleaning processes can then be carried out using the described modules. A method according to the invention for cleaning filter devices 15 of a module 10 for filtering fluids comprises supplying and / or discharging fluid to the filter device 15 via several supply channels 12. This means that at least one supply line 12 conveys the fluid to the filter device 15 and another supply line 12 discharges the fluid conveyed there. When the fluid moves within the area of ​​the filter device 15, it is either moved through a porous area of ​​the filter device 15, for example the membrane, and thus filtered, or guided along the porous area and thus not filtered.

[0036] During the Figures 3b and 3cIn the illustrated embodiments of the method, the fluid is filtered. Here, the fluid exits a filter element of the filter device 15 via a first feed channel 12 towards the filtrate chamber 16. Subsequently, filtrate from the filtrate chamber 16 exits in the opposite direction via another filter element of the filter device 15 into the corresponding feed channel 12, thereby cleaning the other filter element. These embodiments also function with a non-parallel configuration of the module with only two feed channels.

[0037] In 3D figure A diagonal process is shown. Four feed channels are provided, but only two diagonally opposite ones are used; the others are closed, primarily by valves. This allows for targeted and more efficient cleaning of specific filters. Naturally, the flow direction can be reversed, or the [unclear] can be [unclear] 3D figureOpen feed channels 12 are closed and the open ones are closed to reverse the diagonal process.

[0038] An embodiment in which fluid is used to clean a filter device 15, but is not filtered, is described in the Figures 3e and 3f These embodiments, unlike the other cleaning methods, only function with a hollow fiber membrane, but not with a flat membrane. In this case, the fluid does not exit from the filter device 15 towards the filtrate chamber 16, but instead flows through the hollow fiber membranes to the opposite filter inlet area of ​​another feed line 12. The filter device 15 is thereby cleaned by the fluid flowing along the hollow fiber membranes, as the particles contained in the hollow fiber membrane are absorbed by the fluid.

[0039] In a preferred embodiment, where fluid is used to clean a filter device 15, several modules 10 are connected in series via the same feed channels 12. This allows the fluid to flow into a chamber located in the head element of the module 1 and to at least partially flow out. Particularly preferably, a feed channel 12 used for supplying fluid to one module 10 is also used for supplying fluid to a subsequent module 10, so that impurities present in the feed channel 12 used for draining fluid do not contaminate a subsequent filter device in the process. To enable this embodiment, modules 10 with two openings for each feed channel 12 are necessary to transfer a portion of the fluid supplied to or discharged from the module 10 to the subsequent module 10.

[0040] In a preferred embodiment, fluid is used to clean a filter device 15 and which is in Figure 3 As shown, several modules 10 are connected in parallel to each other by the same filter unit 15. This allows, on the one hand, the flow of fluid along a filter unit 15 without the fluid being filtered. On the other hand, it enables, in particular, special backwashing procedures, for example, the cross-washing procedure in the area of ​​a single filter unit 15. Reference symbol list

[0041] 10 Module for fluid filtration 12 Feed channel 14 Feed line 15 Filter unit 16 Filtrate chamber 17 Filtrate channel 18 Head area 20 Separating element 22 Recess

Claims

1. Method for cleaning filter devices (15) of a module for filtering fluids (10), wherein the module comprises a supply line with at least two separate supply channels that convey the fluid to the filter device (15) wherein the filter device (15) has a filter input area for each supply channel (12) that is specific to that channel, a filtrate chamber (16) and a filtrate line (17) that has one or more filtrate channels and that receives and discharges the filtrate from the filtrate chamber (16) in which multiple supply channels (12) of the module supply fluid to the filter device (15) and / or discharge it from the filter device (15) so that at least a first supply channel simultaneously conveys a fluid to the filter device and at least a second supply channel conveys the fluid away from the filter device.

2. Method according to claim 1, in which the fluid is conveyed unfiltered from a first supply channel (12) via the filter device (15) to the second supply channel (12).

3. Method according to claim 1, in which the fluid is filtered through the filter device (15) before being discharged through the at least second supply channel (12).

4. Method according to one of the preceding claims, further comprising the step of closing one or more supply channels (12), in particular by means of a valve.

5. Method according to one of the preceding claims, in which the filters of several modules (1) connected to each other in series with the first and second supply channels (2) are cleaned at the same time.

6. Method according to one of the preceding claims, in which at least two modules (1) are connected to each other in parallel.

7. Module for filtering fluids (10), comprising: i. a supply pipe (14) with at least two supply channels (12) for conveying fluid to a filter device (15); ii. the filter device (15) comprising a filter element, which is equipped to filter in each case the fluid conveyed by the supply pipe (14) to the filter device (15); iii. a filtrate space (16) for collecting the fluid filtered through the filter element; and iv. a filtrate channel (17), which collects and discharges the filtrate from the filtrate space (16); characterized in that the supply pipe (14) has at least two supply channels (12) separated from each other, and for each of these supply channels (12) the filter device (15) has a filter inlet region allotted to this one alone at which the fluid enters the filter device (15).

8. Module according to claim 7, in which the filter element comprises a hollow fibre membrane.

9. Module according to claim 7 or 8, in which the supply channels (12) are at least partially formed of two separated tubes and / or the separation of the supply channels (12) is formed by a separator (20) in one tube.

10. Module according to one of claims 7-9, furthermore comprising a head element, in which the supply channels (12) are formed by chambers separated from each other, which adjoin the filter device (15).

11. Module according to claim 10, in which the chambers each have two connection openings, so that the fluid can flow into the chamber and at least partially flow out.

12. Module according to one of claims 7-11, wherein the connections between the at least one separator (20) and the regions adjoining it is preferably sealed against the fluid by means of a sealing element.

13. Module according to one of claims 7-12, in which at least one supply channel (12) has an indentation (22) for discharging gas.

14. Module according to one of claims 7-13, furthermore comprising a valve device comprising a valve, with which a supply channel (12) and a filtrate channel (17) can be closed.

15. Module according to claim 14, in which the valve is provided in the head region.