EP3921057A1

EP3921057A1 - Filter-changeover method and dedusting system

Info

Publication number: EP3921057A1
Application number: EP20705618.5A
Authority: EP
Inventors: Christoph Vetter; Martin SCHUNK
Original assignee: Vesch Technologies GmbH
Current assignee: Vesch Technologies GmbH
Priority date: 2019-02-05
Filing date: 2020-02-04
Publication date: 2021-12-15
Also published as: DE202019000538U1; WO2020160837A1

Abstract

Established de-dusting systems with cyclones and high-efficiency air filters usually have, on the outside, freely guided feed and discharge lines terminating on opposite sides. This makes construction, operation, maintenance and repair unnecessarily complicated and cost-intensive. Despite the long-term need for more efficient designs with improved costs and lower operating risk, such designs are not available on the market. The problem addressed by the invention is that of improving a dedusting system such that the need is covered. The problem is solved by a surrounding housing in which all connections are arranged adjacent to one another on a single surface; it is thus possible, for the first time, to propose a more efficient and cost-effective form of module which, in addition, ensures a lower risk of accident and injury during operation. Further developments and advantageous applications are possible on this basis. In the field of industrial dedusting with stringent to extremely stringent requirements, the dedusting system claimed provides considerable potential for savings to be made in installation, operation and maintenance and, at the same time, allows easier and more robust process management.

Description

l

Procedure for filter change and dedusting system

The present invention is in the general field of purification of

industrial media - here gas flows - settled.

Industrial process gases are often contaminated with impurities and must be freed from them before the process gas can be exported and / or recycled.

Particulate contaminants, here in particular aggressive or toxic dusts and very fine dusts, are removed via systems which are referred to as dedusting systems in the present document.

Depending on the type and average particle size, dedusting systems provide various assemblies and measures with which the respective particles are removed from a media flow. For example, DD 140 711 A1 suggests arranging ionization electrodes in the cleaning area, which can charge a symmetrically divided raw gas flow in its particles in opposite directions and then allow the charged particles to agglomerate electrostatically. DE 29 12 326 C2 proposes connecting a wetting device in parallel to a product stream, in which a mixing tube is in turn connected to at least one liquid and one polyelectrolyte tank; Liquid and polyelectrolyte can be mixed in a controlled manner via flow meters and control valves and can remove dust through direct wetting in the

Binding product stream with simultaneous polymerization in a matrix. DE 34 09 836 A1 suggests passing fluctuating volume flows through a cyclone with fluidized bed ionization bodies; Particles contained in the raw gas are tribostatically charged in the frictional contact and are agglomerated through their static charge; the larger the volume flow, the larger the fluidized bed; this ensures that there is always the same number of tribostatically active surface per volume unit. WO 87/03214 A1 proposes connecting a dust meter to a raw gas flow; Dust that binds pollutants can be added in excess of stoichiometry and then separated using a bag filter or multi-cyclone on the outflow side. DE 91 1 013 B suggests designing multicyclones as a group of small cyclones connected in parallel in order to make all volume fractions more uniform

CONFIRMATION COPY treat and dedust more effectively. CH 343 761 A suggests structuring such multicyclones in a grid-like manner to save space. DE 23 51 613 A proposes that a dust-laden gas stream should not be applied, partially or entirely, to two different cyclones in a regulated manner, in order to achieve a constant efficiency with a higher gas load or a higher efficiency with the same gas load. DD 104 028 A5 suggests adding fine dust and suspended matter to filter surfaces

agglomerate and to clean the filter surfaces at regular intervals, whereby a constant amount of fine dust can be continuously separated without the flow resistance over the filter surfaces increasing too much due to thick layers of dust.

The present invention relates to dust extraction systems according to the preamble of the independent claims. Dedusting systems are known in principle, but have considerable structural differences depending on the type of dust and product. For example, DE 25 02 806 B2 discloses a dust removal system for a wide belt sander; In this case, material is naturally fed in from the side, while the clean gas is sucked in on the top, guided over the milling machine, sucked off with dust and fed to a dedusting assembly. In principle, the purpose is dust removal, but a housing that is closed to the outside is not usual and not possible for this purpose. In contrast, the present invention relates to vertical, gravity-assisted dedusting systems with closed gas flow guidance.

Generic dedusting systems provide a basically closed power supply; Generic dedusting systems comprise a first connection for a gas flow feed, a second connection for a gas flow outlet and a dust separation device arranged between the connections. The dust is guided and separated here in a closed stream.

From DE 2 248 258 A, a generic dedusting system is known in which a gas flow loaded with particles is connected via a first connection to a

Gas flow feed can be supplied. A vertical dust separation device arranged between the connections separates and guides the particles this gravity-assisted to pick up dust. The dedusted gas flow can be discharged via a second connection for the gas flow outlet.

A disadvantage of the generic dedusting systems is that they have lateral connections. These connections are often arranged on opposite sides, which corresponds to the typical, usual use of dust extraction systems. As a result, a generic dedusting system cannot be inserted flush into basically matching, U-shaped niches or installed in corners.

Another disadvantage is that in the case of a factory structure that is customary in industry, the lines are routed in bundles on the ceiling side. Dedusting systems with connections on opposite side walls require two scaffolds to be set up at one connection point each in the context of connection and maintenance in order to make, operate and integrate them into the plant's media system at the position of the respective flange or welded connection to be able to wait.

A further disadvantage is that in established, generic dedusting systems, lines and line sections are freely routed between the assemblies of the dedusting system. During maintenance, this harbors the risk that maintenance technicians may unintentionally or inappropriately misuse cables as handles or load points and thereby damage them at an early stage. There is also the risk that a falling tool may bounce off the lines during maintenance work and get inside a device or between assemblies. Such a design also leads to problematic undercuts, which make efficient and complete cleaning of the housing, as is usual in the context of production in clean rooms, difficult or impossible.

The object of the present invention was therefore to overcome the disadvantages of the prior art and to provide a method for safe filter replacement. In particular, it is an object of the invention to provide a dedusting system which, despite the generic basic structure and mode of operation, is able to constructively provide a more efficient option for integration and maintenance with less risk during maintenance. A generic system that takes this long-standing need into account is the Not known to inventors. She was also in the relevant vertical market

Dedusting systems for raw gases polluted with dust and fine dust are not available.

This problem is solved according to the features of the independent claims. Advantageous embodiments emerge from the dependent claims and the following description.

A preferred dedusting system in which the method can be used comprises a first connection for a gas flow feed, a second connection for a gas flow outlet and a dust separation device arranged between the connections. In this case, the dedusting system preferably comprises at least one cyclone and at least one suspended matter filter. In addition, the dust extraction system preferably has a completely enclosing housing and all (that is to say the aforementioned) connections are arranged in particular on a surface of the housing in a corner adjacent to one another. In the dust separator, the dust is filtered through a filter cell, whereby the dust collects in the filter cell.

The method according to the invention is used for low-dust filter changes in a dedusting system with filter cells (at least one filter cell) which are loaded from above with dust-laden raw gas. The indication of the direction "from above" relates not only to the loading direction vertically from above, which is preferred due to the minimal dust emission, but also to the loading direction obliquely from above. The filter cell can therefore be mounted upright or at an angle, provided that its top (the side on which it is loaded with dust-carrying gas) points upwards.

The method comprises the steps: lowering and removing the filter cell, and closing the filter cell with a lid before or during the removal. In this case, at least the top of the filter cell is closed with a cover; the underside of the filter cell can also be closed with a further cover.

The procedure for low-dust filter change can be staggered according to the requirements of the user exposure. In the simplest case, the filter cells are “from above "loaded with the dust-laden raw gas. As a result, the collected dust does not fall out of the filter cell when the filter cell is lowered and removed. A throttle can preferably be used at this point in order to enable the filter cell to be slowly lowered regardless of the operating pressure of the compressed air network. This prevents the deposited dust from being whirled up by the jerky movement of the clamping device and thus further minimizes exposure when changing the filter. In order to provide additional protection for the user, the cell is closed (in particular permanently) with a cover during expansion. In order to avoid contamination of the environment by any dust deposits that may be in the system, it is particularly advantageous to continue aspiration by means of a fan, side channel compressor or vacuum pump during the change; as a result, air is sucked from the room into the system and contamination of the room is prevented. The dust sucked in during this extraction is collected in the next filter stage. This concept works for all but the last filter stage. In this case, a conservative filter change using Safe-Change can be used.

If an even higher level of user protection is required, the filter cell can be specifically wetted from above. By arranging the wetting nozzles over the entire area, the entire filter surface is wetted without significantly impacting the housing. In this way, the formation of crust-like deposits in the system is minimized. This procedure enables a high level of user protection without using Safe-Change. This application therefore also discloses, as a further procedural measure, the advantageous wetting of the filter cells with a binding agent or adhesive in order to permanently secure the dust in the cell. For this purpose, a binding agent, which gels or hardens on the cell, is applied with a nozzle system. A preferred binding agent is water, oil or a binding agent soluble in these liquids or a binding agent based on an oil or water solution. Particularly preferably, water or a water-soluble binder is applied directly via the wetting lines of the cell. Even with this one

In the process step, the aspiration can advantageously be left active in order to minimize contamination of the environment. According to a preferred method, while the filter cell is being changed, aspiration is carried out by a fan, a side channel compressor or a vacuum pump. The dust sucked in during this extraction is preferably collected in a respective next filter stage. A fan, for example, draws air from the room into the dust extraction system, but for this purpose the raw gas flap should be closed and air should enter through a cover that is opened to change the filter. The aspirating element (for example the fan or the vacuum pump) is preferably located in the interior of the housing of the dedusting system, this housing preferably having a closed housing wall in which only said cover is open. As a result, the air flow that is sucked in can be precisely defined with regard to its position, direction and strength.

According to a preferred method, the filter cells are wetted with a binding agent and / or an adhesive, particularly preferably with water or oil. This is preferably done before lowering the filter cell, since in this way dust can be securely bound and its escape prevented. The wetting ensures that dust is permanently secured in the cell. The wetting is preferably carried out by application with a nozzle system, a water-soluble binder being particularly preferably applied directly via the wetting lines of the cell. Depending on the type and size of the cell or the function of the nozzle, the nozzles can be arranged stationary or laterally movable. In particular, the nozzles can be mounted pivotably. For example, water, gel or adhesive is sprayed onto the open filter cell from above using 4 (in particular stationary and possibly pivotable) spray nozzles. A (fine) spraying or atomization of the binder / adhesive is preferred so that no dust is whirled up by the spraying.

A throttle is preferably used to lower the filter cell. Such a throttle should be set in such a way that the acceleration forces acting on it as a result of the lowering of the filter cell have a preset (very low)

Do not exceed limit value. This limit value depends primarily on the type of filter cell and the intended use of the expected dust, e.g. its particle size. According to a preferred method, before removing the filter cell,

in particular before it is lowered into the housing of the dedusting system, an access to the filter cell is opened, e.g. by opening or removing said

Cover, and the area between access and filter cell cleaned of dust, in particular using a liquid. The cleaning is preferably carried out by rinsing with the said liquid or using a damp cloth.

So that there is no dust when opening the access, e.g. Above mentioned cover flap, can swirl outwards, an aspiration by a ventilator, a side channel compressor or a vacuum pump takes place preferably already before opening the access. For example, before a cover is opened in front of a filter cell, a fan is switched on, which is intended to draw dust inward into the housing of the dust extraction system, in particular through the subsequent filter cells.

According to a preferred method, the filter cell is placed in an additional container, at least after it has been removed, and this container is then closed. Such a container is e.g. a sack or a box. The removed filter cell is therefore e.g. placed in a sack, which is then closed. This further reduces the risk of dust escaping.

According to a preferred embodiment, the cover is closed in that the cover is positively positioned in two parallel grooves in the area of the upper edge of the filter cell above the filter cell, in particular by pulling or pushing. These grooves are located on opposite sides of the filter cell and have their openings facing one another. In particular, the cover is so wide that it can be guided in both grooves. The grooves should be accessible from one side of the filter cell (“accessible side”) so that the cover can be pushed in. The side wall between the grooves has a slot on the accessible side which connects the two grooves so that the cover can be inserted on this side. The resulting opening should be closed when the filter cell is in operation, in particular with a plug or an edge of the cover, so that no dust can penetrate through it from the filter cell. Even if the grooves can run completely through one side, it is nevertheless preferred that they not be at the opposite end of the accessible side (“facing away side”) reach to the edge of the filter cell. For a secure fit of the cover on the opposite side, it is preferred that in the inside of the relevant

Side wall between the grooves, a groove is also introduced, which connects the grooves and enables a form-fitting holding of the cover on the opposite side in the grooves. Non-continuous grooves prevent the cover from slipping out to one side.

The filter cell can also be provided with grooves at its lower edge and closed with a cover, as described above. In this way, the filter cell can be closed all around.

With such an embodiment it is possible to slide the cover into the grooves before lowering the filter cell and thus to close the relevant side of the filter cell.

A preferred lid should be so stiff that it can securely close the filter cell. In particular when it is guided in grooves, however, it is advantageous if it is flexible enough that canting can be compensated for. It could also be advantageous to use a cover that is orthogonal to the

Direction of movement is more rigid than parallel to the direction of movement and e.g. present rolled and can be inserted into the filter cell when unrolling.

According to a preferred embodiment, the lid is sealed in that a sealing liquid is applied to it. This can be done in particular by means of the nozzles, which can also be used to wet the filter cell. This type of sealing is particularly preferred when the cover is guided in grooves in the filter cell. In a simple case, the sealing can be done with water, the lid being wetted with water from above. This also binds any dust on the lid to it. However, a gel and / or adhesive can also be used for sealing.

In a particularly preferred embodiment, to close the filter cell, a cover is pushed into the above-described grooves in the filter cell until it reaches the opposite side. Thereafter, preference is given to the lid, at least in the areas of the grooves, a sealing liquid (for example an adhesive) is applied to the cover, preferably in such a way that the accessible slots of the grooves are closed or expired with the adhesive. This can be done with the same nozzles

happen, which are also used to wet the dust in the filter cell. If the filter cell is closed and sealed on both sides with lids, there is theoretically no need for additional containment of the filter cell.

According to a preferred method, to close the filter cell, the cover is pushed below the upper edge of the filter cell over the filter cell and, in particular, is guided in a form-fitting manner in a groove on the sides, with an outer sealing of the cover then preferably being carried out using a

Sealing liquid is made, wherein the sealing liquid is particularly preferably applied to the lid by means of a nozzle system.

A preferred dedusting system comprises at least one filter cell which is loaded with dust-laden raw gas from above (possibly also at an angle). It comprises a first connection for a gas flow feed, a second connection for a gas flow outlet and a dust separating device arranged between the connections. In addition, it includes a lowering device designed to lower the filter cell, and an access to the filter cell in the housing of the dedusting system for removing the filter cell for carrying out the method. The dedusting system is designed to close the filter cell with a lid before or during expansion. The dedusting system is thus designed to carry out the method according to the invention.

The dedusting system preferably comprises a fan, a side channel compressor or a vacuum pump which is positioned and controlled in such a way that when the filter is changed, air enters the interior of the filter cell through the access

Dust collector is sucked.

A dedusting system with two independent, parallel ones is preferred

Filter rods equipped. Here, when changing a filter cell in one

Filter strand the other perform the necessary function. A preferred dedusting system includes a first connection for one

Gas flow feed, a second connection for a gas flow outlet and a dust separation device arranged between the connections. The industrial, particle-laden and / or polluted gas stream - often also referred to as raw gas - is fed in a closed path via the first connection, dedusted via the dust separation device and returned to the industrial process and / or into the circulating air via the second connection or release the building ventilation. The connections are therefore designed for typical, industrial production processes and are suitable for clean and emission-free processing / dedusting.

The dedusting system preferably comprises at least one cyclone and at least one suspended matter filter. Particles can be separated off via the cyclone, while suspended solids, which often escape centrifugal separation, are separated off using the suspended solids filter. The combination of the two filters ensures dedusting that can meet high to highest requirements. The particulate filter comprises at least one filter cell.

In addition, the preferred dust extraction system has a completely enclosing housing and the connections (all of the connections mentioned or relevant here) are arranged on a surface of the housing in a corner adjacent to one another. A completely enclosing housing also encloses lines, projections and profiles, which in established dust extraction systems are often run freely along the housing. The outside of the housing is characterized by continuous, haptically smooth surfaces. Grip points necessary for operation and

Handles can be attached as an external device, but media-carrying lines, protrusions, shoulders and undercuts, which could allow inadmissible hooking or getting stuck, are not given. Only the necessary operating elements are specifically placed, attached and / or built in so that they are accessible. As a result, for the first time, a dedusting system can fit into an existing one

Niches are used. All arranged adjacent to one another

Connections allow integration into a typical industrial line via a singular connection point. Installation and maintenance can thus take place via a single connection point, which saves considerable time and costs in construction, maintenance and repair / replacement. The dedusting system preferably has at least one further assembly, the assembly selected from the group consisting of raw gas flap, multicyclone module, cyclone relaxation room, singular cyclone relaxation room, discharge flap, dust discharge flap, discharge container, discharge housing, discharge housing with viewing window, containment flap, containment flap -Measuring lances, DEHS module consisting of DEHS measuring lances in a housing, DEHS module consisting of at least one DEHS measuring lance and a filter wetting device, filter cassettes, clamping device, filter clamping device, filter module comprising filter cassettes and filter clamping device and safe-change frame and leak test device and maintenance cover, Wetting device, filter wetting device, fan, side channel blower, vacuum pump, radial fan, alternating field pump,

Volume flow probes, differential pressure sensors, differential pressure switches, silencers, interference silencers, pneumatic ball valves, switchable check valves, pressure reducers, oil separators, vent valves, dust collectors,

Level sensor, inductive level sensor, filter cell sensor, inductive

Filter cell sensor, mass sensor, load cell, pressure compensation line, signal lamp, control module, regulating module, regulating flap control, regulating flap group control, communication interface, frequency converter, graphic front end, wireless sender / receiver unit, digital network connection, potential-free contacts for signal exchange, sinusoidal filter, pneumatic valves, emergency shutdown, digital Data processing, mixing assembly, metering unit, solid-liquid mixing assembly, solid-liquid mixing assembly with metering unit and digital control interface, frame for low-dust filter change, tight fit test device, connection valve for test gases, gas detectors, dust detectors, temperature sensor, conductivity sensor, grounding control, Earthing control with fuse, explosion pressure relief, bursting disc, explosion suppression, overpressure safety valves, flooding device,

Hand shower, extinguishing system, rack system, removable inspection boards,

Removable side planks, adjustable feet, rollers, continuously variable control flaps, digital control unit with at least one sensor connection and volume flow control, fan with volume flow control, fan with

Volume flow control and digital control interface, vacuum control, fan with vacuum control, flap monitoring, flap monitoring with Control sensors, housing doors as storage space, switchable filter clamping device and stepless control.

The components listed here make it possible, individually or in combination, to improve the invention for special applications in dedusting technology. These are improvements for specific dust parameters, additional safety requirements beyond the legal minimum and requirements for sensors and signal exchange for better process control.

All (relevant) connections of the dust extraction system are preferred, including the first connection, the second connection and at least one further connection for media selected from the group consisting of electricity, gas, water,

District heating, compressed air, cleaning agents, process gases, inert gas, protective gas,

Extinguishing agents and binders; arranged on the top of the housing in a corner adjacent to each other. Consequently, at least a number of the aforementioned connections are arranged on the upper side of the housing in a corner adjacent to one another.

Supplementary media in the area of dedusting allow the system to be improved; Electricity will enable a system control and a fan, compressed air for pneumatically operated flaps, ball valves or filter cleaning, water, cleaning agents or binding agents for cleaning the system or for wetting the filter cells in order to bind separated, toxic dust in the filter elements, special inert gases or extinguishing agents to control difficult components in the gas or solid phase. It is also advantageous for these supply lines

To bundle connections in one place, as the bundling of lines already described, which is typical for the industry, can come into play.

The housing of the dust extraction system is preferably cuboid and all (relevant) other assemblies required for operation and maintenance are accessible and operable on one side. This design allows the modular use of several systems in a network with large volume flows or with

Extraction of several process systems. Particularly in the pharmaceutical environment and installation in clean rooms, the required floor space is often a commercial factor that can significantly impair added value. The base and The system height is optimized by the cuboid shape. By arranging the assemblies required for maintenance and operation, accessible from one side, the minimum distance to the wall or other systems is also improved. It can also be set up in a niche or integrated into one of the walls.

On the outside of the enclosing housing, the dedusting system preferably has a full-surface, even stainless steel surface designed with grooves, the surface again being free of molded undercuts and, optionally, cuts or bores for viewing windows, switches, lines, connections, handles, hinges, housing locks , Signal lamps and controls. This embodiment facilitates cleaning of the outer surfaces and enables complete decontamination in the event of an accident at the installation site with the simplest of means. The current guidelines for good manufacturing practice (GMP) require as little undercut as possible. However, the inventors are not aware of any implementation of these guidelines in the sense of enclosing all of the elements mentioned in a closed housing and completely avoiding undercuts. Naturally, the outer skin has to be interrupted for some control elements and connections, but these elements are also grouped sensibly and haptically optimized. The present invention advantageously proposes such a consistent implementation for the first time.

The dedusting system preferably has at least two cyclones; preferably at least two cyclones of different capacities, particularly preferably four cyclones of different capacities. Several advantages can be realized by using multiple cyclones. First of all, a higher degree of separation can be achieved by using several small cyclones, especially for suspended matter with small grain sizes. Furthermore, if the volume flow falls below a limit, one of the cyclones can be separated from the process manually and / or in a controlled manner by actuating a shut-off valve, so that the degree of separation of the system cannot fall below a previously specified minimum degree of separation. The use of a single, correspondingly small cyclone is disadvantageous here if the differential pressure across the cyclone increases disproportionately as the volume flow increases and it can quickly no longer be overcome by conventional fans. The use of several cyclones of different capacities enables this balancing act to be advantageously set between the degree of separation and the differential pressure. The use of four Cyclones of different sizes according to the attached table enable the use of all cyclones in a range of +/- 15% of the designed volume flow and thus enables stepless passage of all volume flows between 85 and 1025 m ³ / h through staggered switching.

Similar optimization examples are possible for differently aligned volume flow ranges in which the disclosed cyclone group is scaled appropriately. When using several cyclones of different capacities, it is advisable to automate the control flaps including additional locking flaps (as shown in Fig.

4) in order to be able to switch quickly between the volume flow ranges and the stored logic by machine and to avoid streak formation in one of the cyclones, which is caused by the individual geometries

to compensate for different differential pressures. For this purpose are

additional volume flow measurements for each of the individual cyclones are particularly preferred. In the case of simple, slow-flowing applications, on the other hand, a particularly simple, manual control can also achieve a significant improvement over the established use of individual cyclones.

The dedusting system preferably has at least one filter module comprising a connection for differential pressure measurement on the inflow side and outflow side, a filter cassette, a pneumatic filter clamping device, a safe-change frame with C-profile grooves, a tight fit test device with a circumferential groove with a connecting line to the outside of the housing, and a Maintenance cover open. The use of filter cassettes enables the use of a large filter surface with an optimized, reduced installation space and thereby supports the basic concept of the invention of the minimal space requirement. By measuring the differential pressure across the filter cell, conclusions can be drawn about the loading of the filter with dust and the cells can be replaced in good time before the load limit is reached or the degree of separation decreases. The one-sided spring-operated pneumatic clamping devices ensure that the cells are always tightly connected to the frame when the compressed air is not applied and that no dust can pass the system past the filter cells. Furthermore, the compressed air actuation makes handling easier, since the necessary voltage does not have to be applied manually. The Safe-Change frame enables the discharge of the dust-laden filter cell and the introduction of the new filter cell without having to break the containment of the system. Ie the system remains permanently closed. By applying a slight overpressure to a groove within the frame, which is only sealed by the seal of the filter cell, a tight fit test device allows to check whether the filter seal prevents the dust from bypassing the seal all around. For this purpose, the leakage measured with a special measuring device must not exceed the permissible leakage of the filter cells used. The combination of these elements in one assembly makes it particularly advantageous to equip an embodiment according to the invention with any number of filter cells connected in series or in parallel. In this way, the overall degree of separation and the capacity of the system can be adjusted.

The dust extraction system preferably has at least one DEHS module, the DEHS module consisting of at least one DEHS measuring probe and a filter wetting device, the DEHS module being arranged on the inlet and / or outlet side of a filter module. DEHS measuring lances enable the in-situ measurement of the separation efficiency of a filter cell. Sampling is possible through measuring openings in the lance, distributed over the entire projected area of the filter. For this reason, a mixing section no longer has to be provided and the device is more compact and smaller. The filter wetting device enables the filter to be wetted before removal. This binds the dust and thus ensures a significant reduction in the dust released when changing the filter. Beneficial Methods to reduce the release of dust are: Closing the filter with a lid immediately after removal, changing the filter using protective bag changing technology (also called BiBo or Safe-Change), the combination of

Filter wetting and protective bag changing technology. All of these procedures are performed with the fan turned off.

The dedusting system preferably has a discharge housing with a viewing window and a pressure compensation element against ambient pressure, the discharge housing being connected on the inflow side via a discharge flap to the dust outlet side of the at least one cyclone or cyclone relaxation chamber and via a pressure compensation element against the system negative pressure with the inflow side of a DEHS module can be connected, a discharge container with an optional fill level sensor being arranged in the discharge housing; the discharge container is connected to the outflow side of the discharge flap in a separable manner via a containment flap; an optional flap monitoring system comprises sensors which are arranged on the discharge flap and pressure compensation element; the flap monitoring is connected to a control, the discharge flap and the pressure compensation element in turn being controllably connected to the control. This combination enables an advantageous dust discharge during operation. Through the

With the pressure equalization line, the discharge container is not sucked into the cyclone despite the prevailing negative pressure in the dedusting system. The discharge housing is preferably designed to maintain an increased negative pressure in order to compensate for pulsation peaks. I.e. A corresponding rigidity and gas density is introduced in order to be able to operate the system more robustly and with step control.

The containment flap is suitable for separating the dust discharge container from the cyclone and for safely sealing the collected dust in the discharge container. The discharge flap is advantageous initially as a connection to the process

interrupt. At the same time, the pressure equalization line can be closed by a shut-off device in order to prevent the aspiration of false air via the discharge housing when it is open. After this step, the discharge housing is under negative pressure and cannot be opened accidentally. The viewing window now allows you to check whether an accident has occurred in the discharge area. In the event of an accident, the discharge area can only be opened using suitable Protective equipment and acknowledgment of a corresponding query can be opened. If there is no accident, the user can contact the

Press the pressure equalization button to release the negative pressure in the discharge housing and start discharging the dust. To do this, he closes and separates the containment flap, removes the dust discharge container and replaces it with a new one. The opening process can then be carried out in reverse order to return to normal operation.

At this point, this application also discloses a discharge as a further procedural measure, in which instead of the containment flap with a simple dust discharge container, a containment flap with a film tube several meters long is used as an endless liner. In this case, a hose section can advantageously be separated with a suitable sealing tool and the containment flap is only used at the end of the hose in order to avoid the complicated safe-change process. This endless liner can preferably be provided with a permanently installed fill level sensor.

Furthermore, this invention discloses an advantageous, reusable rigid discharge container with a containment flap; this is better able to withstand the system negative pressure and therefore cannot be sucked into the cyclone. The container preferably does not require any single-use components and the separated product can be fed back into the process. This essentially improves sustainability.

The control of the negative pressure directly behind the raw gas flap enables automated opening of the raw gas flap when a minimum negative pressure is reached, whereby an unintentional backflow into the pipe of the raw gas connection is particularly advantageously effectively avoided. The controller therefore particularly preferably comprises a negative pressure sensor, the negative pressure sensor being arranged on the inflow side to the cyclone and on the outflow side to a raw gas flap.

In the dedusting system, a controller arranged in the housing is preferably connected to a fan arranged in the housing and a volume flow probe, the fan being arranged on the inflow side to all filters and on the outflow side with it an optional, arranged in the housing, silencer and the clean gas outlet is connected; wherein the volume flow probe is again arranged on the outflow side to the fan in an area of predominantly laminar flow; particularly preferably, the volume flow probe has, on the inflow side, an extended and / or diameter-tapering flow section with an optionally structured inner pipe surface. By using these components, a stepless control of the system volume flow is possible. This allows the precise setting of the negative pressure or volume flow at the suction point. The placement of the volume flow probe in a dust-free room allows it to be used with less maintenance. The use of a muffler in front of the clean gas outlet enables particularly low-noise operation, particularly preferably also in free-blowing circulating air operation. The flow velocity can be reproduced externally by optimizing the measuring section of the volume flow measurement.

Further advantages result from the exemplary embodiments. It goes without saying that the features and advantages described above and the following exemplary embodiments are not to be interpreted as restrictive. Additional, advantageous features and additional combinations of features, as they are explained in the description and established in the scientific field, can be realized both individually and in different combinations within the scope of the independent claims in the claimed subject matter without departing from the scope of the invention.

The figures illustrate by means of schematic sketches:

1 advantageous embodiment of a preferred dedusting system in the external view;

FIG. 2 advantageous embodiment according to FIG. 1 with the front panels of the housing removed;

3 shows a flow diagram illustrating the connections, lines and control loops of an advantageous embodiment of a preferred dedusting system.

4 control diagram, illustrating the automatic system of a multicyclone for the optimal use of several cyclones with control of the total volume flow.

5 shows a preferred exemplary embodiment for a method according to the invention for changing filters with little dust. As FIG. 1 illustrates, a preferred dedusting system has in an advantageous combination: a first connection 2 for a gas flow feed, a second connection 3 for a gas flow outlet and one between the connections

arranged dust separator. The industrial, particle-laden and / or polluted gas flow - often also referred to as raw gas - is shown in

fed in a closed path via the first connection 2, dedusted via the dust separation device and fed back into the industrial process via the second connection 3 or, alternatively, released into the surrounding atmosphere. The connections 2, 3 are therefore designed for typical, industrial production cycles and suitable for clean and emission-free processing / dedusting. Alternatively, recirculation mode is possible without a connected clean gas line.

In addition, the preferred dust extraction system has a completely enclosing housing 1 and all connections 2, 3 are arranged on a surface of the housing 1 in a corner adjacent to one another. A completely enclosing housing 1 also encloses lines, projections and profiles, which in established dust extraction systems are often freely guided along the housing. The housing 1 is characterized on the outside by continuous, haptically smooth surfaces. Gripping points and handling necessary for operation can be set up as external equipment, but lines, protrusions, shoulders and media-carrying

There are no undercuts that could allow unacceptable hooking or getting stuck. Only the necessary operating elements are specifically placed, attached and / or built in so that they are accessible. This means that for the first time a dedusting system can be used with a positive fit in existing niches.

All of the connections 2, 3 arranged adjacent to one another allow the

Integration into an industry-typical line via a singular connection point. Installation and maintenance can thus be carried out via a single connection point, which saves considerable time and costs in construction, maintenance and repair / replacement.

All connections 2, 3 of the dust extraction system, including the first connection 2, the second connection 3 and at least other connections for electricity, water and Compressed air are arranged on the top of the housing in a corner adjacent to one another.

Electricity is required for the system control and the fan 9, compressed air for pneumatically operated flaps and ball valves and water for wetting the filter cells in order to bind the separated dust in the filter elements. With these feed lines, too, it is advantageous to bundle the connections in one place, since this way the bundling of lines that is typical of the industry can be used.

The housing 1 of the dust extraction system is cuboid and all other assemblies necessary for operation and maintenance are accessible and operable on one side. This design allows the modular use of several systems in a network with large volume flows or when extracting several process systems. The floor space required is often a critical factor, particularly in the pharmaceutical environment and when installing in clean rooms

Decision factor. The cuboid shape minimizes your own area. By arranging the assemblies required for maintenance and operation, accessible from one side, the minimum distance to the wall or other systems is also minimized. It can also be set up in a niche or integrated into one of the walls.

On the outside of the enclosing housing 1, the dedusting system has a full-surface, even stainless steel surface designed with grooves, the surface again being free of molded undercuts and cuts or holes for viewing windows, switches, lines, connections, handles, hinges, housing locks, Has signal lamps and controls.

This embodiment facilitates cleaning of the outer surfaces and enables complete decontamination in the event of an accident at the installation site. The current guidelines for good manufacturing practice (GMP) therefore call for the minimization of the

Undercuts. However, the inventors are not aware of any implementation of these guidelines in the sense of all of the named elements in a closed housing

to include. Naturally, the outer skin must be used for some controls and Connections are interrupted, but these elements are also grouped sensibly, haptically optimized and reduced to a minimum.

In addition, FIG. 2 shows that the dedusting system has a multicyclone consisting of two cyclones 4 and three suspended matter filter stages 8. A separation of coarser particles is possible via the cyclones 4, while suspended solids, which often escape centrifugal separation, are separated off via the suspended matter filters. The combination of the two filters ensures dedusting that can meet high to highest requirements. The dedusting system has two cyclones 4.

Several advantages can be realized by using multiple cyclones. First of all, a higher degree of separation can be achieved by using several small cyclones, especially for suspended matter with small grain sizes. Furthermore, if the volume flow falls below a limit, one of the cyclones can be manually separated from the process by actuating a shut-off valve, so that the degree of separation of the system cannot fall below a previously specified minimum degree of separation. The use of a single, correspondingly small cyclone is not advisable, as the differential pressure across the cyclone increases disproportionately as the volume flow increases and it can quickly no longer be overcome by conventional fans.

The dedusting system has three filter modules 8 comprising a connection for differential pressure measurement on the inflow side and outflow side, a filter cassette, a pneumatic filter clamping device, a safe-change frame with C-profile grooves, a tight fit test device with a circumferential groove with a connecting line for

Housing outside, and a maintenance cover. The use of

Filter cassettes enable the use of a large filter surface with minimal installation space and thereby supports the basic concept of the invention of minimal space requirements. By measuring the differential pressure across the filter cell, conclusions can be drawn immediately about the loading of the filter with dust and the cells can be in good time before the maximum load is reached or the

Degree of separation can be exchanged. The unilaterally spring-actuated pneumatic clamping devices ensure that the cells are always tightly connected to the frame when the compressed air is not applied and that no dust hits the filter cells can happen over. Furthermore, the compressed air actuation facilitates handling, since the voltage required to maintain the pressure on the cell when the volume flow is applied does not have to be applied manually. The Safe-Change frame enables the discharge of the dust-laden filter cell and the introduction of the new filter cell without having to break the containment of the system. Ie the system remains permanently closed. By applying a slight overpressure to a groove within the frame, which is only sealed by the seal of the filter cell, a tight fit test device allows to check whether the filter seal prevents the dust from bypassing the seal around the circumference. For this purpose, the leakage measured with a special measuring device must not exceed the permissible leakage of the filter cells used. The combination of these elements in one assembly enables the invention to be equipped with any number of filter cells connected in series or in parallel. In this way the

Overall degree of separation and the capacity of the system are influenced.

The dedusting system also has four DEHS modules, the DEHS module consisting of three DEHS measuring lances and a filter wetting device, the DEHS module being arranged on the inflow side of a filter module. DEHS measuring lances enable the in-situ measurement of the separation efficiency of a filter cell. Sampling is possible through measuring openings in the lance, distributed over the entire projected area of the filter. The filter wetting device enables the filter to be wetted before removal. This binds the dust and thus ensures a significant reduction in the dust released when changing the filter. Known

Methods to reduce the release of dust are: Closing the filter with a lid immediately after removal, using a filter change

Protective bag changing technology (also called BiBo or Safe-Change), the combination of filter wetting and protective bag changing technology. All of these procedures are performed with the fan turned off.

Against this background, this invention also discloses an advantageous method for low-dust filter change: this is graded according to the requirements for user exposure. In the simplest case, the filter cells are loaded with the dust-laden raw gas “from above”. This causes the collected dust to fall

Do not lower or remove the filter cell from the filter cell. Preferably can on At this point a throttle can be used to slowly lower the

To enable filter cell independent of the operating pressure of the compressed air network. This prevents the deposited dust from being whirled up by the jerky movement of the clamping device and thus further minimizes exposure when changing the filter. In order to provide additional protection for the user, the cell is closed with a cover immediately after removal, in particular permanently. In order to avoid contamination of the environment by any dust deposits in the system, aspiration is allowed to continue using a fan, side channel blower or vacuum pump during the change. As a result, false air is sucked from the room into the system and thus contamination of the room is prevented. The dust sucked in during this extraction is collected in the next filter stage. This concept works for all but the last filter stage. In this case, a conservative filter change using SafeChange must be used. If an even higher level of user protection is required, the filter cell is specifically wetted from above. By clever

By arranging the wetting nozzles, the entire filter surface is wetted without unnecessarily impacting the housing. In this way the formation of

crust-like deposits in the system are minimized. This procedure enables a high level of user protection without using Safe-Change. This application also discloses, as an additional method measure, an advantageous wetting of the filter cells with a binding agent or adhesive in order to permanently secure the dust in the cell. For this purpose, a binding agent, which gels or hardens on the cell, is applied with a nozzle system. A water-soluble binder is particularly preferably applied directly via the wetting lines of the cell. In this procedure, too, aspiration is left active in order to minimize contamination of the environment.

The dedusting system has a discharge housing with a viewing window and pressure compensation button, the discharge housing being connected on the inflow side via a discharge flap 6 to the dust outlet side of the at least one cyclone 4 and via a pressure compensation flap with the inflow side of a DEHS module, again being connectable in the discharge housing a discharge container 7 with an optional fill level sensor is arranged; the discharge container 7 can be separated from the discharge side of the discharge flap 6 via a containment flap connected; an optional flap monitoring system includes sensors that are connected to

Discharge flap 6 and pressure compensation flap are arranged; the

Flap monitoring is connected to a control, the discharge flap 6 and the pressure compensation flap in turn being controllably connected to the control.

This combination enables dust to be discharged during operation. Through the pressure equalization line, the discharge container 7 is not sucked into the cyclone despite the prevailing negative pressure in the dedusting system. However, this means that the discharge housing must be suitable for holding this negative pressure. I.e. must have appropriate rigidity and gas density. The containment flap is suitable for separating the dust discharge container from the cyclone 4 and for safely sealing the collected dust in the discharge container 7. However, it is not available in a controllable manner. Therefore, the discharge flap 6 must first interrupt the connection to the process. At the same time, the pressure equalization line is closed by a ball valve to allow the aspiration of false air via the

To prevent discharge housing in the open state. After this step, however, the discharge housing is still under negative pressure and can therefore not yet be opened. The viewing window now allows you to check whether an accident has occurred in the discharge area. In the event of an accident, the discharge area may only be opened using suitable protective equipment. If there is no accident, the user can now release the negative pressure in the discharge housing using the pressure compensation button and start discharging the dust. To do this, he closes and separates the containment flap, removes the dust discharge container 7 and replaces it with a new one. The opening process can then be carried out in reverse order to return to normal operation. As an advantageous method measure, this invention thus also discloses a discharge in which instead of the containment flap with a simple dust discharge container 7, a containment flap with a film tube several meters long is used as an endless liner. In this case, one hose section can be fitted with a suitable

Sealing tool must be separated and the containment flap is only used at the end of the hose to avoid the complicated safe change process avoid. This endless liner can optionally be provided with a permanently installed level sensor.

Furthermore, the invention discloses a reusable, rigid discharge container 7 with a containment flap that withstands the system negative pressure and thus cannot be sucked into the cyclone 4. The container preferably does not require any single-use components and the separated product can be fed back into the process. This essentially takes sustainability into account.

The control particularly preferably comprises a negative pressure sensor, the negative pressure sensor being arranged on the inflow side to the dedusting system and on the outflow side to a raw gas flap.

The control of the negative pressure directly on the outflow side to the raw gas flap enables automated opening of the raw gas flap when a minimum negative pressure is reached, which causes an unintentional backflow into the pipeline of the

Raw gas connection is effectively avoided.

In the dedusting system, a control arranged in the housing 1 is connected to a fan 9 and a volume flow probe arranged in the housing, the fan 9 being arranged on the inflow side to all filters and on the outflow side being connected to an optional silencer 10 arranged in the housing 1 and the clean gas outlet; the volume flow probe again being arranged on the outflow side to the fan 9 in an area of predominantly laminar flow; particularly preferably, the volume flow probe has on the inflow side a flow section optimized in terms of flow technology with an optionally structured inner pipe surface.

The use of these components enables the

System volume flow possible. This allows the precise setting of the negative pressure or volume flow at the suction point. The placement of the volume flow probe in a dust-free room allows a low-maintenance use and the use of components without ATEX approval. The use of a silencer 10 in front of the clean gas outlet enables operation in environments with strict

Requirements for the permissible noise level also in the freely blowing out Recirculation mode. By optimizing the measuring section of the volume flow rate measurement, the results can also be reproduced by external measurements.

According to FIG. 3, a dedusting system comprises, in an advantageous combination of assembled assemblies, a raw gas flap which seals off the system on the air intake side. Immediately afterwards there is a negative pressure sensor that only allows the raw gas flap to be opened when there is negative pressure in the dedusting system. Following this sensor, the volume flow is distributed over two calming and inlet sections. These sections can be closed or opened using a hand flap and thus optimally used according to the actual system volume flow. A multi-cyclone consisting of two individual cyclones is located next to the inlet sections. These enable the pre-separation of the dust and thus the dust load of the particulate filter to be minimized, which enables longer service lives.

The cyclones 4 end on the product outlet side in a relaxation space 5, which breaks the vortices of the cyclones 4 and at the same time acts as a temporary dust container during the change of the dust discharge container 7. This dust discharge container 7 is connected to the relaxation space 5 by means of a discharge flap 6 and a containment flap. In this way, the discharge container 7 can be safely separated from the process (discharge flap) and separated from the system safely or with little dust (containment flap). The dust discharge container 7 is located in the dust discharge housing, which can be provided with a negative pressure by means of a pressure equalization line and with the ambient pressure by means of a pressure equalization button. This enables both safe operation and the discharge of dust while the filter system is in operation. A viewing window in the dust discharge housing allows a visual check to see whether an accident has occurred. On the clean gas side, the cyclones 4 are connected to a common collecting line. This leads to the first DEHS module. A measuring aerosol can be applied to this in order to check the degree of separation of the filter cells in the installation situation after a filter change. The DEHS module also contains the wetting device for the following first filter stage 8. The first HEPA filter stage 8 is housed in a modular filter housing. This includes a clamping device that presses the filter cells securely against a sealing seat frame. Precisely this sealing seat frame, with which the permissible leakage through the seal can be verified with the aid of a suitable measuring device and a test pressure, and the filter cell itself, which absorbs the remaining suspended matter. The housing also has a Safe-Change frame for

Implementation of the procedure of the same name. The first filter stage 8 is followed by a DEHS module with measuring lances for in-situ measurement of the degree of separation of the first filter stage if a test aerosol has been applied before this stage. This structure is repeated for the filter stages 8 two and three. The pressure equalization line for the dust discharge housing described above is also connected to the DEHS module between stages two and three. This can be closed and opened by a pneumatic ball valve. Due to the positioning behind the filter stages 8 one and two, there is always a slightly higher negative pressure in the dust discharge housing than in the dust discharge container 7. As a result, the container, although made of a plastic and fabric mix, is always kept open and the dust can collect freely.

The fan 9 is located next to the fourth DEHS module. This ensures the necessary aspiration of the system and is frequency-controlled, so it can move to different operating points. Following the fan 9 is a

Measuring section in which the flow largely calms down for the volume flow measurement. The volume flow measurement itself is carried out using a volume flow probe. The signal from the volume flow sensor serves as the basis for the

Fan control. Subsequently to the. A silencer is located to measure the volume flow, which minimizes the blow-out noise of the system and for this reason is located directly in front of the clean gas outlet.

Against this background, the present invention also discloses three advantageous procedural measures A, B and C for operating the above-described dedusting system, which are the following advantageous procedural steps

enables: A) By using multiple cyclones, several advantages can be realized. First of all, a higher degree of separation can be achieved by using several small cyclones, especially for suspended matter with small grain sizes. Furthermore, if the volume flow falls below a limit, one of the cyclones can be manually separated from the process by actuating a locking flap, so that the degree of separation of the system cannot fall below a previously specified minimum degree of separation. The use of a single, correspondingly small cyclone is not advisable, since the differential pressure across the cyclone increases disproportionately as the volume flow increases and it can quickly no longer be overcome by conventional fans. The use of several cyclones of different capacities enables the finer adjustment of this balancing act between the degree of separation and the differential pressure. The use of four cyclones of different types in accordance with the attached table enables the use of all cyclones in a range of +/- 15% of the design volume flow and, through clever switching, enables continuous passage through all volume flows between 85 and 1025 m ³ / h. Similar optimization examples are possible for other volume flow ranges. When using several cyclones of different capacities, it is advisable to automate the control flaps including additional shut-off flaps as shown by way of example in Fig. 4 in order to be able to switch quickly between the volume flow areas and the stored logic and to avoid streak formation in one of the cyclones and the To compensate for different differential pressures caused by individual geometries in the required volume flows. For this purpose, additional volume flow measurements are necessary for each of the individual cyclones. With simple applications, even without this automation, a significant improvement can be achieved compared to the use of individual cyclones.

B) This invention also discloses a method measure for low-dust filter change: This is graded according to the requirements for user exposure. In the simplest case, the filter cells are loaded with the dust-laden raw gas “from above”. As a result, the collected dust does not fall out of the filter cell when the filter cell is lowered and removed. A throttle can preferably be used at this point in order to enable the filter cell to be slowly lowered regardless of the operating pressure of the compressed air network. This prevents the deposited dust from being whirled up by the jerky movement of the clamping device and thus further minimizes exposure when changing the filter. In order to provide additional protection for the user, the cell is closed with a cover immediately after removal, in particular permanently. In order to avoid contamination of the environment by any dust deposits in the system, aspiration is performed

Fan, side channel blower or vacuum pump kept running during the change. As a result, false air is sucked from the room into the system and thus contamination of the room is prevented. The dust sucked in during this extraction is collected in the next filter stage. This concept works for all but the last filter stage. With this one has to

Conservative filter changes using Safe-Change can be used. If an even higher level of user protection is required, the filter cell is specifically wetted from above. By clever arrangement of the

The wetting nozzle wets the entire filter surface without unnecessarily impacting the housing. In this way, the formation of crust-like deposits in the system is minimized. Through this procedure are high

User protection level possible without using Safe-Change. This application also discloses the wetting of the filter cells with a binding agent or

Adhesive to permanently secure the dust in the cell. For this purpose, a binding agent, which gels or hardens on the cell, is applied with a nozzle system. Particularly preferred is a water-soluble binder directly over the Wetting lines applied to the cell. In this procedure, too, aspiration is left active in order to minimize contamination of the environment.

C) At this point, this invention also discloses, as a further advantageous procedural measure, a discharge in which, instead of the containment flap with a simple dust discharge container, a containment flap with a film tube several meters long is used as an endless liner. In this case one can ever

The hose section can be separated with a suitable sealing tool and the containment flap is only used at the end of the hose in order to avoid the complicated safe-change procedure. This endless liner can optionally be provided with a permanently installed level sensor.

This invention also discloses a reusable rigid discharge container with a containment flap. This withstands the system negative pressure and can therefore not be sucked into the cyclone. The container preferably does not require any single-use components and the separated product can be fed back into the process. This essentially takes sustainability into account.

Established dedusting systems with cyclones and particulate filters show

on the outside regularly freely guided and on opposite sides ending supply and discharge lines. This means that construction, operation, maintenance and repair are unnecessarily complicated and costly.

Despite the long-standing need for more efficient construction methods with improved costs and lower operational risk, these are not available on the market.

The task is to improve a dust extraction system so that the demand is covered.

The solution is an enclosing housing in which all

Terminals are arranged on a surface adjacent to one another; For the first time, a more efficient and economical modular form is proposed, which also ensures a lower risk of accidents and injuries during operation. Further training courses and advantageous applications are possible on this basis. Figure 5 shows a preferred embodiment for an inventive

Process for low-dust filter change in a dust removal system as shown, for example, in FIGS. 1 and 2. The filter cells are loaded from above, so that dust is held in the filter cell by gravity alone.

In step I, a fan 9 is switched on, provided it was not switched on beforehand, so that aspiration through this fan takes place while the filter cell is being changed. The dust sucked in during this extraction can be collected by the air flow of the fan 9 in a respective subsequent filter stage.

In step II the filter cells are wetted with a binding agent, e.g. Water, or adhesive, to permanently secure the dust in the cell, preferably by application with a nozzle system, with a water-soluble binding agent being particularly preferably applied directly to the filter cell by means of wetting lines.

In step III, an access to the filter cell is opened and the area between the access and the filter cell is cleaned of dust, in particular using a damp cloth, in order to prevent dust from being whirled up.

In step IV, the filter cell is lowered and removed. A throttle is preferably used to lower the filter cell in order to prevent dust from being whirled up.

In step V the filter cell is closed with a lid. this happens

for example here at the end of the expansion of the filter cell but can also be done before expansion.

In step VI, the filter cell is placed in an additional container and this container is then closed.

In the field of industrial dedusting with high to the highest requirement profiles, the claimed dedusting system offers considerable savings potential in assembly, Operation and maintenance and at the same time enables simpler and improved secure process management.

Claims

Expectations

1. A method for low-dust filter change in a dedusting system with filter cells which are loaded from above with dust-laden raw gas, comprising the steps:

- lowering and removing the filter cell,

- Close the filter cell with a lid before or during removal.

2. The method according to claim 1, characterized in that during the change of the filter cell an aspiration is carried out by a fan, a side channel compressor or a vacuum pump, the dust sucked in during this suction preferably being collected in a respective next filter stage.

3. The method according to any one of the preceding claims, characterized in that, in particular before lowering the filter cell, the filter cells are wetted with a binding agent and / or adhesive in order to permanently secure the dust in the cell, preferably by application with a nozzle system, wherein particularly preferably a water-soluble binder is applied directly via the wetting lines of the cell.

4. The method according to any one of the preceding claims, characterized. that a throttle is used to lower the filter cell.

5. The method according to any one of the preceding claims, characterized. that before the removal of the filter cell, in particular before it is lowered into the housing of the dust extraction system, an access to the filter cell is opened and the area between the access and the filter cell is cleaned of dust, in particular using a liquid,

aspiration by a fan, a side channel compressor or a vacuum pump preferably already takes place before the access is opened.

6. The method according to any one of the preceding claims, characterized in that the filter cell is brought into an additional container at least after removal and this container is then closed.

7. The method according to any one of the preceding claims, characterized. that to close the filter cell the lid is below the upper edge of the

The filter cell is pushed over the filter cell, and in particular is guided in a form-fitting manner on the sides in a groove, with an outer sealing of the lid preferably then being carried out by means of a sealing liquid, the sealing liquid being particularly preferably applied to the lid by means of a nozzle system.

8. Dedusting system with at least one filter cell, which is loaded from above with dust-laden raw gas, comprising a first connection for a gas flow feed, a second connection for a gas flow outlet and a dust separation device arranged between the connections, additionally comprising:

- a lowering device designed to lower the filter cell,

- an access to the filter cell in the housing of the dedusting system to remove the filter cell,

wherein the dedusting system is designed to close the filter cell with a lid before or during expansion.

9. Dedusting system according to claim 8, characterized in that it comprises a fan, a side channel compressor or a vacuum pump, which is positioned and controlled so that air is sucked through the access to the filter cell into the interior of the dedusting system when the filter is changed.

10. Dedusting system according to claim 8 or 9, characterized in that the dedusting system has at least one cyclone and at least one HEPA filter, and preferably a completely enclosing housing, the connections preferably being arranged on a surface of the housing in a corner adjacent to one another.