Reactor device for passivating filter residues, filter device for filtering particles from feed gas stream, and method for operating reactor device

Abstract

The invention relates to a reactor arrangement (1) for carrying out a chemical reaction between a filter residue (3) and an oxidizing agent in the context of at least one passivation process in order to reduce the chemical reactivity of the filter residue (3), the reactor arrangement (1) having a reactor space (5) enclosed by a reactor housing (4), the invention relates to a reactor device (1) having a reactor space (2), which has a filter device connection (6) for producing a fluidic connection between the reactor device (1) and the filter device (2), and a collection chamber connection (8) for producing a fluidic connection between the reactor device (1) and a collection chamber (9) for receiving passivated filter residue (3), the reactor space (5) is further divided by a reactor base (40) into a reaction chamber (11) and a discharge chamber (12). In order to improve reactor devices (1) known in the prior art, it is proposed that the reactor base (40) is designed to be movable between a first operating position, in which the reactor base (40) forms part of the reaction chamber (11), and a second operating position, in which the reactor base (40) forms part of the discharge chamber (12), in which the reactor base (40) forms part of the reaction chamber (11). And the division can be canceled during the movement of the reactor bottom (40).

Description

Technical Field

[0001] The present invention first relates to a reactor apparatus for performing a chemical reaction between filter cake and oxidant in the scope of at least one passivation process to reduce the chemical reactivity of the filter cake, wherein the reactor apparatus has a reactor space surrounded by a reactor shell, the reactor space having a filter device interface to establish a fluid technical connection between the reactor apparatus and the filter device, and a collection chamber interface to establish a fluid technical connection between the reactor apparatus and a collection chamber for receiving the passivated filter cake.

[0002] Furthermore, the present invention relates to a filtration apparatus for filtering particles from a feed gas stream, comprising a filter device having one or more filter elements on which filter cake accumulates during filtration. The filtration apparatus also comprises a reactor device for performing a chemical reaction between the filter cake and an oxidant within at least one passivation process to reduce the chemical reactivity of the filter cake. The reactor device has a reactor space surrounded by a reactor shell, the reactor space having a filter device interface for establishing a fluid-technical connection between the reactor device and the filter device, and a collection chamber interface for establishing a fluid-technical connection between the reactor device and a collection chamber for receiving the passivated filter cake. Further, the reactor device is arranged below the filter device so that the filter cake can also be transported from the filter device to the reactor device by gravity. The reactor device has an expansion chamber into which the filter cake can be moved against gravity to assist passivation.

[0003] Furthermore, the present invention relates to a method for passivating filter residue in a reactor apparatus having a reactor space, wherein the reactor space is airtight and the passivation is carried out in the reactor space during a first passivation process under a time-limited oxidant input. Background Technology

[0004] Reactor devices of the aforementioned type are known in the prior art. They are used to passivate filter cake typically received from filter devices. The reactor device is particularly operated in combination with an upstream filter device and a downstream collection chamber for receiving the passivated filter cake.

[0005] For example, a reactor device is known as a separable space within a filter device, in which the filter material is treated to reduce the remaining reactivity. In this regard, see DE 10 2021 116 264 A or WO2022 / 268497 A1.

[0006] Regarding the background of the invention, it should be noted that the passivated filter residue obtained by such a reactor device is typically, but not exclusively, generated during metal printing processes, such as laser sintering or laser melting, and also, for example, by so-called 3D laser printing equipment. In this method, process gas is introduced into the printing chamber during a circulating process, which is then regenerated in a filter device to target impurities (e.g., soot) generated during metal printing, particularly due to intense heat. The filter material collected in the filter device remains highly reactive, thus posing a risk of fire or ignition of flammable materials.

[0007] In the metal printing process, it is therefore preferable to introduce an inert gas, such as argon or nitrogen, as the process gas into the printing chamber. This ensures that the atmosphere within the printing chamber is free of or substantially free of oxygen to prevent reaction. For example, refer to DE 10 2017 206 792 A1 for the metal printing equipment itself. Filtering devices for metal printing equipment are described, for example, in DE 20 2012013 036 U1.

[0008] Impurities generated during metal printing are collected by a filter device to prevent them from entering the environment. The filter residue is typically composed of highly reactive materials. Consequently, there is an increased risk of ignition during disposal when leaving the protective gas atmosphere provided by the inert process gas.

[0009] In the prior art, it is also known to passivate filter cake using flame retardants, that is, to transform it into a state where it can no longer ignite or burn objects that pose a fire hazard. For example, disposable filters are also used for passivation, and these filters are disposed of when a predetermined fill level is reached. In particular, such disposable filters are passivated by impregnation with water and / or oil. Flame retardants, such as lime or gaseous particles, can also be blown into the filter, so that the entire surface of the filter is wetted and the flame retardant is mixed with the filter cake located on the filter. Summary of the Invention

[0010] In view of the above-mentioned prior art, the technical problem to be solved by the present invention is to provide an alternative reactor device and an alternative method, by which the reactor device and method can reliably passivate filter cake, thereby not generating problematic waste.

[0011] One possible solution to the aforementioned technical problem is provided by a reactor device in which the reactor space is divided into a reaction chamber and a discharge chamber by the bottom of the reactor, wherein the bottom of the reactor is designed to be movable between a first operating position and a second operating position, wherein the bottom of the reactor forms part of the reaction chamber in the first operating position and part of the discharge chamber in the second operating position, and the division can be cancelled during the movement of the bottom of the reactor.

[0012] Therefore, the reactor space can be divided into a reaction chamber and a spatially separate discharge chamber by means of the reactor bottom. In one feasible embodiment, the reactor bottom is, for example, an opening cover disposed in a partition wall constructed between the reaction chamber and the discharge chamber, which is pivotable from a first operating position to a second operating position. In the first operating position, i.e., when the partition wall is closed, the reactor bottom faces the interior of the reaction chamber and is therefore part of the reaction chamber. In the second operating position, i.e., when the partition wall is open, the reactor bottom, for example, pivots to the interior of the discharge chamber, wherein the back side of the opening cover facing away from the reactor bottom, for example, contacts the inner wall of the discharge chamber.

[0013] According to another feasible embodiment, the reactor bottom may be, for example, a translationally or rotatably movable portion of the reactor shell, capable of moving from the reaction chamber to the discharge chamber. The reactor bottom may be designed to be flat or curved, particularly in its edges, such that the reactor bottom forms a shape-matched (or shape-corresponding) fit with the reactor shell of the reactor space. Preferably, the reaction chamber has a filter device interface, and the discharge chamber has a collection chamber interface. The passivated filter cake can thus be directly fed into the reaction chamber of the reactor space from the filter device interface, while the discharge chamber can discharge the passivated filter cake to a subsequent collection chamber through the collection chamber interface. The filter cake inlet and outlet are thus directly and correspondingly provided to the corresponding chambers of the reactor space.

[0014] Furthermore, the bottom of the reactor may have at least one receiving area for filter cake. This receiving area is preferably distinguished from other parts of the reactor bottom by its shape. For example, the receiving area is a recess or material void in the bottom of the reactor, in which filter cake can or preferably accumulates after being introduced into the reactor space or after being agitated, for example based on the flow conditions and / or structural conditions within the reactor space.

[0015] According to one feasible implementation, the bottom of the reactor is part of a shaft arranged in the reactor space that is rotatable relative to the reactor shell. This shaft can be supported, in particular, on the reactor shell. The shaft is arranged within the reactor space and connected directly or indirectly to the inner wall of the reactor shell such that the reactor space has two spatially separated chamber sections: a reaction chamber in which the passivation reaction takes place, and a discharge chamber in which the passivated filter residue is received after the passivation process is complete and discharged into a collection chamber.

[0016] The shaft, or at least one receiving area for filter cake formed on its circumferential surface, is located within the reaction chamber in a first rotational position of the shaft and is capable of moving within the reactor shell to a second rotational position by rotation of the shaft, allowing the filter cake located within the receiving area to enter the discharge chamber from the reaction chamber. If the shaft has multiple receiving areas for filter cake distributed circumferentially, it may also have multiple rotational positions in which the corresponding receiving areas are located within the reaction chamber or at least partially within the discharge chamber of the reactor space.

[0017] The reactor bottom or shaft can be directly or indirectly connected to the inner wall of the reactor shell using a receiving area for receiving filter cake, with seals or adapter components arranged in between, such as sleeves as will be suggested below, if necessary. The reactor bottom or shaft spatially separates the reaction chamber containing the still reactive filter cake from the discharge chamber containing the passivated filter cake, with the discharge chamber providing a transition to the collection chamber for the passivated filter cake.

[0018] The reactor unit is preferably connected to the filter unit via a flow channel and an airtight valve, particularly a butterfly valve. A valve is also preferably present between the reactor unit and the collection chamber connected through its collection chamber interface. Further valves may be present downstream of this valve, which are open, for example, during reactor unit operation and only closed before the collection chamber is removed. Thus, these additional valves serve as a convenient, but not necessarily necessary, supplementary device to retain any residue of passivated filter cake in the inlet line of the reactor unit or collection chamber when the collection chamber is separated from its interface.

[0019] After the chemically reactive filter cake leaves the filter device, it first enters the reaction chamber of the reactor device through the filter device interface, and accumulates under gravity on the bottom of the reactor or the surface of the shaft, that is, in the area provided for receiving the filter cake. This receiving area, as will be described in detail later, can be, for example, an annular edge region of a groove, a material void, a hole, or an arch.

[0020] The spatial separation of the reactor space into the reaction chamber and discharge chamber, achieved through contact between the shaft and the reactor shell, ensures that the filter cake remains within its designated area, the reaction chamber, as long as passivation is not complete. This allows the filter cake to come into contact with the oxidant, particularly oxygen, and to undergo a chemical reaction only within the reaction chamber. As long as the filter cake remains separately contained within the reaction chamber, it will not accidentally enter other areas of the reactor unit, especially the discharge chamber, and react uncontrollably there, potentially causing damage to the reactor unit or the entire system comprising the filter unit, reactor unit, and collection chamber.

[0021] Once filter cake accumulates in the reaction chamber, especially in the receiving area, the valve between the filter unit and the reactor unit is closed. This valve can be located, in particular, in the area where the filter unit interfaces. The reaction chamber is then evacuated until a predetermined negative pressure is reached. Then, an additionally installed gas inlet valve is opened, allowing air, especially from the immediate external environment of the reactor unit, to flow into the reaction chamber.

[0022] Alternatively or supplementally, pressurized air, preferably ambient air, can also be used. For example, it can be compressed air from a commonly used compressed air network of the operating facility to which the reactor unit is connected. However, similarly, as a supplement or alternative to the compressed air in the compressed air network, a compressed air storage device can be provided from which compressed air can be fed. This compressed air storage device can then be filled from the compressed air network as described, or supplementally or alternatively filled via a compressor. Ambient air, or the oxygen it contains, is used as the oxidant for the filter cake passivation reaction. The oxidant can flow directly toward the accumulated filter cake through a predetermined direction, for example, a gas inlet designed as a hole within the reactor shell, particularly preferably directly into the receiving area. Thus, the filter cake is agitated within the reaction chamber of the reactor unit and preferably distributed throughout the entire available volume. Therefore, the reaction does not occur only in the receiving area, but preferably throughout the entire reaction chamber of the reactor unit.

[0023] Once the specified pressure, particularly ambient pressure, is reached within the reaction chamber, the gas inlet valve closes, thereby stopping the input of the oxidant. It is then preferable to wait until the filter cake re-aggregates in the receiving area. The passivation process can then be repeated, especially if it is determined that the filter cake is not fully passivated but still retains some chemical reactivity. The relative state of the filter cake can be determined here, for example, by measuring the pressure or temperature within the reaction chamber. The measured values ​​are compared, for example, with a reference value. This reference value could be the pressure or temperature within the reaction chamber before the oxidant flows in. If the temperature and / or pressure rises above the reference value when the oxidant flows into the reaction chamber, the filter cake can be considered not fully passivated or at least not sufficiently passivated. Once the temperature and / or pressure no longer rise when the oxidant flows in, the filter cake has reached a harmless passivation state. The relevant reference value for which sufficient passivation can be considered can, in principle, be specified by the reactor manufacturer or user.

[0024] One alternative to controlling the passivation state of the filter cake is to first specifically determine and specify the amount of oxidant required to reliably passivate the filter cake. The required number of passivation cycles can then be determined based on this amount, such that the total amount of oxidant required reacts with the filter cake.

[0025] Alternatively or additionally, the oxidant may be heated before flowing into the reactor to activate the reaction of the filter cake. This can, for example, advance the passivation reaction, thereby shortening the reaction time within the reactor. Heating of the oxidant can be achieved, for example, by equipping the walls of the oxidant inlet pipe with heating elements or designing it as a heat exchanger. The temperature of the inlet oxidant can be, for example, ambient temperature or a temperature higher than ambient temperature.

[0026] Alternatively or supplementarily, an ignition spark can be specifically generated to initiate combustion and thus a reaction. This could involve, for example, a piezoelectric spark generator, a spark plug, or an ignition electrode.

[0027] Once the desired passivation state of the filter cake is reached after one or more passivation cycles, it is preferable to wait this long until the passivated filter cake settles in the receiving area. Then, the reactor bottom is moved from the previous first operating position to a second operating position. Depending on an exemplary design where the reactor bottom is part of a rotatable shaft, the shaft may be rotated 90 degrees. Subsequently, the valve or multiple valves located between the reactor unit and the collection chamber are opened, allowing the passivated filter cake to flow from the discharge chamber of the reactor space into the collection chamber.

[0028] After removing the filter cake from the discharge chamber of the reactor space, the bottom or shaft of the reactor can be cleaned, especially the area with the receiving zone. This cleaning can be carried out, in particular, using an inert gas. Additionally, the support locations can also be cleaned. The reactor unit can then be used for other passivation processes, which are initiated by re-vacuuming the reaction chamber of the reactor unit.

[0029] To evacuate the reactor space, an oil-lubricated vacuum pump can be used, in particular. According to one feasible implementation, the gas drawn from the reactor space can be guided through an oil bath of the vacuum pump for filtration, thereby depositing any present dirt particles and filter cake. An oil filter is typically used for depositing dirt particles or filter cake. A particular advantage of this design is that particles with indistinct passivation states are selectively drawn from the reactor space and transported to the oil in the vacuum pump, where the filter cake is ultimately passivated by the oil, achieving a safe state. The dirt particles or passivated filter cake are then disposed of by periodically changing the oil or replacing the oil filter.

[0030] Additional separators can be placed before the potentially oil-lubricated vacuum pump to further filter the gas during intake. This avoids the need for overly frequent oil changes.

[0031] Furthermore, one or more support locations of the vacuum pump can be specifically cleaned or prevented from contamination using airflow, and if necessary, with inert gas. For this purpose, it is preferable to install nozzles appropriately aligned with the support locations.

[0032] Furthermore, regarding the rotatable shaft, it is suggested that the shaft be supported on the reactor shell of the reactor apparatus. Therefore, it is preferable to construct support positions for the shaft on the reactor shell. Particularly preferably, the reactor shell has two support positions opposite each other relative to the center of the reaction chamber, thereby reliably holding the shaft in its position without tilting.

[0033] Regarding the shaft, it is also suggested that it have different outer diameters along its axial extension. For example, the axial section of the shaft in the support region can have a smaller diameter than the section of the shaft in the circumferential region having a receiving area for filter cake. In particular, the dimensions and shape of the shaft, especially its circumferential profile, are coordinated with the internal shape of the reactor space, thereby enabling direct or indirect contact between a portion of the shaft and a portion of the inner wall of the reactor space to form a reaction chamber and spatially separate it from the discharge chamber and the reactor space. Additional sealing devices can be provided between the shaft and the reactor shell if necessary.

[0034] Furthermore, it is suggested that the reaction chamber has a sleeve, which is pressed against the circumferential portion of the shaft having the reactor bottom by spring force, connecting the shaft to the reactor shell. More preferably, the shaft is rotatable between an open position and a locked position while maintaining contact with the sleeve. Thus, the sleeve constitutes a fitting component between the surface of the shaft and the inner wall of the reactor space. The sleeve is particularly designed as a cylindrical member, its shape fitting snugly onto the circumferential surface of the shaft, i.e., at the location where the receiving area for filter cake is provided. The wall of the sleeve surrounds the circumferential portion of the shaft having the receiving area for filter cake. Furthermore, the sleeve is also, particularly its shape-fitting, abutting against or embedded within the inner wall of the reactor shell at its opposite ends.

[0035] To achieve a shape-matched fit with the circumferential surface of the shaft, the sleeve may, for example, have different lengths in its circumferential direction along its axial extension. According to a feasible design, when viewed from the axial direction of the shaft, the end profile of the sleeve is, for example, arc-shaped, and especially concave. When viewed in the direction of rotation of the shaft, i.e., perpendicular to the axis of rotation, the end profile of the sleeve is straight. Importantly, the shape of the end opening of the sleeve corresponds to the shape of the circumferential surface of the shaft, thereby producing a sealing fit between the sleeve and the shaft.

[0036] The sleeve is preferably pressed against the circumferential surface of the shaft by the restoring force of a spring element. This achieves a spatial, but not necessarily airtight, separation between the reaction chamber and the discharge chamber of the reactor space. The sleeve is preferably shape-matched, connected on one side to the shaft and on the other side to the inner side of the reactor shell. This spatial separation ensures that the filter cake is selectively contained within a predetermined area, i.e., the reaction chamber, so that it reacts only there with the oxidant, preferably oxygen. Therefore, the filter cake will not accidentally enter other areas of the reactor apparatus. The spring element is preferably designed as a helical spring, resting against the sleeve's end facing away from the shaft. Particularly preferably, the spring element allows the shaft to rotate about its axis of rotation while maintaining contact between the shaft surface and the sleeve, even when the shaft rotates away from the reactor shell and the sleeve. It goes without saying that the exemplary helical spring mentioned is only one possible implementation of a spring element that presses the sleeve against the circumferential surface of the shaft with spring force. Alternatively, leaf springs or other spring elements may also be used, for example. In principle, the sleeve itself can also be designed as a spring element, for example, using a flexible but relatively rigid material. For instance, the sleeve can also be folded like an accordion.

[0037] The advantage of the sleeve elastically resting against the shaft is that it can also compensate for wear or abrasion on the circumferential surface of the shaft and / or the sleeve that may occur due to friction between the components. Therefore, the spring allows for automatic calibration of the contact, thereby compensating for any possible clearance.

[0038] Furthermore, it can be specified that the longitudinal axis of the sleeve is oriented perpendicular to the axis of rotation of the shaft. According to this design, at least a partially open end of the sleeve can be fitted onto the circumferential surface of the shaft to define a circumferential region therewith having a receiving area for filter cake. The inner wall of the sleeve simultaneously forms part of the inner wall of the reaction chamber, and if necessary, together with other parts of the reactor shell. Therefore, the inner wall of the reaction chamber is formed by the circumferential region of the shaft's circumferential surface surrounded by the sleeve, the inner wall of the sleeve itself, and, if necessary, one or more portions of the inner wall of the reactor shell.

[0039] According to one feasible embodiment, the at least one receiving area has a recess. This recess is specifically a concave depression on the circumferential surface of the shaft. The recess forms a collection tray for filter cake, which accumulates on the circumferential surface of the shaft due to gravity. The particularly concave construction of the recess ensures that when the oxidant flows into the reaction chamber, the filter cake is lifted on the circumferential surface of the shaft and circulates within the reaction chamber, thereby mixing the filter cake with the oxidant and achieving a preferably particularly uniform reaction. This allows the filter cake to be passivated particularly quickly and completely. Relatedly, it is particularly advantageous that the gas inlet opening for allowing the oxidant to enter the reaction chamber is arranged such that the oxidant flows towards the receiving area and selectively lifts the filter cake from the receiving area.

[0040] After the passivation process, especially after multiple passivation cycles, the shaft rotates about its axis of rotation to remove the filter cake located in the receiving area from the receiving area and transfer it to the discharge chamber of the reactor space. By rotating the shaft, the receiving area of ​​the shaft shifts relative to the sleeve or a portion of the inner wall of the reactor shell (especially in the absence of an intermediate sleeve). The rotation of the shaft creates a gap between the circumferential portion of the shaft having the receiving area and the sleeve or reactor shell that previously contacted that circumferential portion. This creates a flow connection between the reaction chamber and the discharge chamber of the reactor space, allowing the passivated filter cake to flow from the reaction chamber into the discharge chamber. This is preferably assisted by pre-vacuuming the discharge chamber. The filter cake located in the discharge chamber can then exit the discharge chamber through the collection chamber interface toward the connected collection chamber. For this purpose, it is preferable to optionally evacuate the reactor space, including the discharge chamber, again. Furthermore, the receiving area of ​​the shaft where the previously collected filter cake was purged with inert gas. For this purpose, the corresponding valve is opened.

[0041] If the shaft has a plurality of recesses formed sequentially in the circumferential direction, for example, the first recess can be located in a first rotational position in which the first recess is fluidly separated from the discharge chamber of the reactor space in the reaction chamber, while the second recess of the shaft is located in a second rotational position in which the second recess has a flow connection to the discharge chamber, thereby allowing the second recess to be emptied into the discharge chamber of the reactor space.

[0042] According to an alternative embodiment, the at least one receiving region may have a through-hole extending transversely to the axis of rotation and an arched portion constructed on at least one circumferential portion of the shaft and extending transversely to the circumferential direction of the shaft. In particular, the arched portion may be a raised portion protruding radially from the edge region of the end face of the shaft relative to the circumferential surface. In contrast to the aforementioned embodiment, the receiving region for filter cake is therefore not formed by a recess in the shaft material, i.e., not by a depression, but by an arched portion extending in the axial direction of the shaft. Therefore, the arched portion extends transversely to the convex profile inherent in the cylindrical shaft. In other words, the shaft therefore also has a curved profile when viewed from a direction perpendicular to the axis of rotation. In particular, this profile descends towards the end face of the shaft. The shaft with the arched portion also has a through-hole extending transversely to the axis of rotation through the shaft. This through-hole does not penetrate the arched portion extending transversely to the circumferential direction of the shaft.

[0043] According to a particular embodiment, the shaft has arched portions extending transversely in the circumferential direction in two opposing circumferential regions. Therefore, these arched portions are opposite to each other relative to the shaft's axis of rotation and relative to the through-hole.

[0044] The method of draining filter cake from the reaction chamber using a through-hole involves the through-hole moving relative to the filter cake collected in the annular contact area between the inner wall of the sleeve or the reactor shell and the circumferential surface of the shaft as the shaft rotates. Thus, with further rotation of the shaft, the filter cake is transferred from the reaction chamber to the discharge chamber in the reactor space. This is achieved by scraping the filter cake located at the edge of the arch from the edge region on the end side of the sleeve or the edge region on the end side of the inner wall of the reactor shell corresponding to the edge region of the arch (if there is no intermediate sleeve). The filter cake then falls into the discharge chamber through the through-hole.

[0045] In this embodiment, it is particularly advantageous to provide one or more inlet openings for the oxidant within the sleeve or reactor shell, through which the oxidant can flow into the reaction chamber circumferentially, particularly along the circumferential direction of the cylindrical sleeve. This causes the filter residue located at the annular edge of the arch (which accumulates at the edge of the sleeve due to the arch) to be conveyed into the reaction chamber circumferentially and off-axis, particularly along a helical flow path.

[0046] In both the first embodiment with a recess in at least one circumferential portion of the shaft, and the second, last embodiment with an arch and through-hole formed in the circumferential portion, a single receiving area for filter cake can be provided only along the circumference of the shaft, or multiple receiving areas can be provided. If multiple receiving areas are provided, it is advantageous that, for example, the first receiving area for receiving filter cake points towards the reaction chamber, while the second receiving area is at least partially located outside the reaction chamber and already has a flow connection to the discharge chamber leading to the reactor space. Furthermore, in the case of multiple receiving areas, it is advantageous that the shaft does not need to rotate back and forth or complete a 360-degree rotation between two passivation cycles; rather, for example, for a design with four receiving areas along the circumference, only a 90-degree rotation is required to start a new passivation cycle. Therefore, one, two, three, four, or even more receiving areas can be provided in the circumferential direction of the shaft. In the case of the embodiment with the arch and through-hole, two receiving areas that are mirror-symmetrically opposed to each other with respect to the axis of rotation of the shaft are particularly recommended.

[0047] According to a preferred embodiment, the reactor shell may have, in particular, a tubular extended chamber into which filter cake can be moved against gravity to aid passivation. This extended chamber is designed as a dead zone, into which the filter cake, flowing through the filter device interface in height dimension, is moved solely for passivation. Due to its dead-zone design, the extended chamber has only a filter cake inlet and no filter cake outlet. The extended chamber is arranged relative to the reaction chamber such that filter cake raised in the reaction chamber rises into the extended chamber but does not flow into the filter device interface, only passing alongside it. The volume of the extended chamber advantageously complements the volume of the reaction chamber, thereby providing more ambient air or oxidant for the passivation of the filter cake.

[0048] In cases where a sleeve is arranged intervening between the shaft and the reactor shell, it can be specifically stipulated that the extended chamber extends beyond the sleeve and connects to the reaction chamber. Here, the extended chamber is constructed spatially separately from the filter device interface. The extended chamber forms a volumetric expansion of the reaction space provided by the reaction chamber for passivating the filter cake. It is particularly advantageous here that the extended chamber is not connected to the reaction chamber via the filter device interface, but is spatially separated from it, such that the reaction chamber and the extended chamber together form a single volume to which the filter device interface is connected to transfer the filter cake from the filter device into this common volume. The extended chamber can, for example, be formed by a tubular flow channel that is closed at the ends. The extended chamber is, for example, a tube with end closures having flanges with integrated sensor devices, such as the previously suggested temperature and / or pressure sensors. The extended chamber extends the reaction space for the passivation process because it provides a larger air volume in which the filter cake can be agitated. Therefore, the passivation process can proceed significantly faster compared to cases with smaller available air space.

[0049] Furthermore, it is recommended that the reaction chamber and / or expansion chamber and / or sleeve have at least one temperature sensor and / or at least one pressure sensor and / or at least one interface for introducing gas into the reaction chamber. In particular, it is recommended that the interface for introducing gas be oriented relative to the receiving area, preferably inclined relative to the bottom of the reactor, such that the filter cake located in the receiving area is agitated within the reaction chamber and / or expansion chamber.

[0050] The at least one temperature sensor and / or pressure sensor is used to monitor the passivation process within the reaction chamber. If the pressure or temperature measured within the reaction chamber exceeds a specified reference value or range, it can be considered that the passivation of the filter cake is not yet complete and that residual chemical reactivity posing a fire hazard still exists. The at least one temperature sensor or the at least one pressure sensor can be located in different positions within the reaction chamber. For example, an arrangement can be specified in the area for receiving the filter cake or in the area of ​​the sleeve connecting the shaft to the reactor shell. Alternatively, an arrangement can be specified away from these areas, for example, in an expansion chamber connected to the reaction chamber, i.e., connected to a portion of the reaction chamber opposite the area for receiving the filter cake.

[0051] As previously described, the interface for introducing the oxidant into the reaction chamber is preferably oriented relative to the receiving area of ​​the shaft such that the filter cake located in the receiving area encounters the introduced oxidant as early as possible, thereby being able to be lifted into the reaction chamber and / or expansion chamber. Preferably, the inlet opening, such as a valve, is inclined relative to the shaft such that the oxidant is introduced in a direction toward the receiving area.

[0052] Furthermore, the reactor apparatus may have a metering device connected to the filter device interface of the reactor apparatus, the metering device being configured to separate a first component of the total amount of filter cake from at least a second component of the total amount of filter cake and transfer them to the reaction chamber of the reactor apparatus. This metering device may in particular be a gate or impeller gate defined by a valve. In the case of an impeller gate, the metering device may preferably have an impeller housing and an impeller, wherein the impeller is closed at least at its end by discs axially subjected to a spring force.

[0053] The metering device quantifies the filter cake flowing in from the filter unit, thereby transferring it in separate portions to the reaction chamber of the reactor unit. This metering device is preferably operable multiple times to transfer the filter cake to be passivated in portions to the reactor space, where it reacts with the oxidant. A valve is preferably provided between the metering device and the reactor space.

[0054] According to a particularly simple design, the metering device can be designed as a gate defined by valves. This arrangement can simply consist of two valves and the space between them. The space between the valves can thus determine the quantity determined for each metering stroke of the metering device. However, it is particularly preferred to use an impeller gate, which has an impeller housing and an impeller capable of rotating relative to it, the impeller having one or more impeller chambers. The impeller chambers can, for example, extend within a certain angular range, such as 90° or 180°, and in the remaining angular range, can have a closed design such that only one impeller chamber is formed. Accordingly, to form multiple impeller chambers, the closed area can also alternatively be designed as one or more impeller chambers. The impeller gate is preferably oriented such that it is slightly inclined at a defined starting position, i.e., the bottom surface of the impeller chamber is not horizontally oriented, but slightly inclined, thereby allowing the filter cake in the impeller chamber to be discharged from the impeller chamber by gravity. This ensures that the entire metered filter cake quantity is controlled to be delivered from the corresponding impeller chamber without any filter cake remaining in the impeller gate. Preferably, the metering device is designed such that only a portion of the impeller rests against the impeller housing to prevent filter cake from getting stuck between the impeller and the impeller housing. If filter cake still accumulates in the gap between the impeller and the impeller housing, it can be released by excessive rotation exceeding 180 degrees.

[0055] According to a particularly preferred embodiment, the disc can be pressed against the impeller in the axial direction by means of a spring element, thereby sealing the end side of the impeller. This preferably ensures a form-fitting and friction-fitting connection between the disc and the impeller. The disc here forms part of the impeller housing. The spring-loaded disc also specifically defines the axial position of the impeller. At the same time, the disc prevents filter cake from leaving the predetermined area. Furthermore, the position of the disc will automatically adjust when the impeller or impeller housing components wear due to mutual friction. In addition, pressing the disc by the spring element further enables the impeller to rotate relative to the impeller housing.

[0056] One or more support locations within the impeller housing, particularly the impeller's support locations within the impeller housing, can also be flushed with gas, especially the inert gas already mentioned. For this purpose, one or more suitable nozzles are also provided in this area, which can be specifically targeted at the support locations.

[0057] Furthermore, a reactor apparatus is proposed for performing a chemical reaction between filter cake and an oxidant within at least one passivation process to reduce the chemical reactivity of the filter cake. The reactor apparatus has a reactor space surrounded by a reactor shell, the reactor space having a filter device interface for establishing a fluid-technical connection between the reactor apparatus and a filter device, and a collection chamber interface for establishing a fluid-technical connection between the reactor apparatus and a collection chamber for receiving the passivated filter cake. The reactor space has a rotatable shaft and a sleeve with end-side regions pressed against a circumferential portion of the shaft, the sleeve connecting the shaft to the reactor shell and forming a reaction chamber spatially separated from the discharge chamber of the reactor space. The proposed rotatable shaft is particularly suitable for conveying filter cake collected in the circumferential portion of the shaft from the reaction chamber to the discharge chamber. Conveying is achieved here by rotation of the shaft about its axis of rotation. The shape-matching fit of the sleeve on the corresponding circumferential portion of the shaft, together with the reactor shell, preferably defines a portion of the volume of the reactor space of the reactor apparatus in which the filter cake can be passivated. As the shaft rotates, sleeves are correspondingly disposed in subsequent circumferential portions of the shaft. Particularly preferably, the shaft has a receiving area, such as a groove, in one or more circumferential portions for collecting filter cake, in which the filter cake can accumulate. This groove rotates from the reaction chamber to the discharge chamber during shaft rotation, where evacuation can occur. During rotation, the spatial separation between the reaction chamber and the discharge chamber is temporarily eliminated.

[0058] In particular, the rotatable shaft can be designed to rotate between a first and a second operating position, wherein a circumferential portion of the shaft forms part of a reaction chamber in the first operating position and part of a discharge chamber in the second operating position, wherein the separation between the reaction chamber and the discharge chamber can be cancelled during shaft rotation.

[0059] In addition to the aforementioned proposed reactor apparatus, a filtration device for filtering particles from a feed gas stream is also proposed, wherein the filtration device is designed to have a filter device having one or more filter elements on which filter cake accumulates during filtration, and the filtration device also has a reactor device for performing a chemical reaction between the filter cake and an oxidant within the scope of at least one passivation process to reduce the chemical reactivity of the filter cake, wherein the reactor device (1) has a reactor space surrounded by a reactor shell, the reactor space having a filter device interface to establish fluid between the reactor device and the filter device. The device includes a technical connection and a collection chamber interface to establish a fluid technical connection between the reactor device and a collection chamber for receiving passivated filter cake. The reactor device is further arranged below the filter device so that filter cake can also be transported from the filter device to the reactor device by gravity. The reactor device has an expansion chamber into which filter cake can be moved against gravity to assist passivation. The filter device interface and the collection chamber interface can be closed to perform the passivation process. The expansion chamber is designed as a dead zone, into which filter cake can be moved solely for passivation as it flows through the filter device interface in height.

[0060] The proposed filtration device includes a reactor unit, which can be designed according to one or more of the embodiments exemplified above. A filter unit is connected upstream of the reactor unit. Furthermore, a metering device may be provided between the filter unit and the reactor unit, for example, to quantify the filter cake collected in the filter unit and continue to deliver it to the reactor unit.

[0061] Filtering devices, for example, capture impurities generated during metal printing to remove them from the process gas, which is primarily and preferably guided as recirculated air, and capture them as filter cake in a corresponding filter. The proposed filtration apparatus may have only one or more such filter devices. It is also possible to specify the use of multiple filter units arranged in parallel, integrated into the filtration apparatus, for example, via common inlet and outlet valves.

[0062] Furthermore, a method is proposed for passivating filter residue in a reactor device having a reactor space, wherein the reactor space is airtight and the passivation is carried out in a first passivation process with a time-limited input of oxidant in the reactor space, wherein the passivation is repeated in a second passivation process or other passivation processes based on the pressure reached in the reactor space during the first passivation process or the temperature reached in the reactor space during the first passivation process.

[0063] The second passivation process, or other passivation processes, can preferably be carried out after the filter cake has re-aggregated on the bottom of the reactor space. For each passivation process, it is preferable to introduce an oxidant back into the reactor space, wherein the introduction of the oxidant is used to agitate the filter cake.

[0064] The proposed method preferably includes filling the reaction chamber of the reactor space with filter residue, introducing an oxidant into the reaction chamber, mixing the filter residue with the oxidant to reduce the chemical reactivity of the filter residue, moving the reactor bottom, which is used to divide (or partition) the reactor space into a reaction chamber and a discharge chamber, from a first operating position to a second operating position, in which the reactor bottom forms part of the reaction chamber and in which the reactor bottom forms part of the discharge chamber, wherein the division is canceled during the movement of the reactor bottom, and also includes dredging the filter residue located in the reaction chamber into the discharge chamber and / or a collection chamber connected to the discharge chamber.

[0065] The method is executed as suggested, first by introducing filter cake into the reaction chamber of the reactor space. This can be achieved, for example, by means of the previously suggested metering device arranged in a flow channel between the filter unit and the reactor unit. For example, the filter unit filters out impurities generated during the metal printing process from the process gas; these impurities are still highly reactive and therefore pose a risk of ignition or fire hazard. The filter unit receives and stores these impurities, which are then passivated by the reactor unit suggested herein. For example, during filter cleaning, the filter cake can fall into the impeller chamber of the impeller gate or directly into the reaction chamber of the reactor unit. Alternatively or additionally, a pressure differential can be created between the filter unit and the reaction chamber or the metering device to transport the filter cake to the reaction chamber. Alternatively or additionally, the filter cake can also be specified to be supported by an airflow, such as an inert airflow flowing from the filter unit to the reactor unit. Finally, the filter cake can also be drawn from the filter unit or the metering device into the reaction chamber of the reactor unit.

[0066] After the filter cake is transferred to the reaction chamber, it is preferable to first wait until the filter cake is almost completely accumulated in the pre-designated receiving area of ​​the shaft. Then, an oxidant, such as ambient air, is introduced into the reaction chamber, preferably via a nozzle or opening that directs the oxidant directly towards the receiving area. The filter cake and oxidant are then mixed in or around the receiving area, with the filter cake being agitated, particularly throughout the entire gas volume of the reaction chamber or, if necessary, any additional extended chambers. By mixing the filter cake with the oxidant, a chemical reaction begins, which can be further promoted by preheating the oxidant if necessary. This chemical reaction reduces the reactivity of the filter cake; sometimes, a single passivation cycle is not sufficient for complete passivation, but rather multiple consecutive passivation cycles must be performed to reduce the reactivity of the filter cake below a predefined reference value or range for residual reactivity. This reference value or range gives a residual reactivity that will no longer cause the filter cake to ignite or pose a fire hazard to other objects.

[0067] After one or more successive passivation processes, the process is paused until the filter cake re-accumulates in the receiving area of ​​the shaft. The shaft is then rotated to a rotating position where the receiving area is at least partially outside the reaction chamber and has a flow connection to a discharge chamber leading to the reactor space. Through this flow connection, the passivated filter cake can flow from the reaction chamber into the discharge chamber. Preferably, the filter cake located in the receiving area is completely emptied into the discharge chamber of the reactor space and / or into a collection chamber connected to the discharge chamber via a collection chamber interface in this manner.

[0068] To examine the chemical reactivity of the filter cake located in the reaction chamber, it may be specified that temperature and / or pressure be measured at one or more locations. This temperature or pressure provides a conclusion about the remaining reactivity of the filter cake, as the temperature or pressure will rise when the still chemically reactive filter cake comes into contact with the oxidant.

[0069] In particular, it is further suggested that after the filter cake is mixed with the oxidant, the temperature and / or pressure in the reaction chamber and / or expansion chamber be detected and compared with a reference value, wherein if the temperature and / or pressure is higher than the reference value, the oxidant is introduced into the reaction chamber again without removing the filter cake from the reaction chamber or introducing new filter cake into the reaction chamber, so that the same filter cake undergoes the passivation process again, and wherein the receiving area is at least partially removed from the reaction chamber only when the temperature and / or pressure is lower than the reference value.

[0070] The passivation process can be repeated until the filter cake reaches the desired passivation state. Here, as recommended, the passivation state is determined by temperature and / or pressure measurements. For reference, the temperature and / or pressure that can be measured in the reaction chamber, sleeve, or expansion chamber during oxidant inflow can be used. If the temperature and / or pressure increase during oxidant inflow, the filter cake can be considered not yet sufficiently passivated. Once the temperature and / or pressure no longer increase during oxidant inflow, the filter cake has generally reached a reliable passivation state.

[0071] As an alternative to the aforementioned method, the amount of oxidant required to reliably passivate the filter cake can be measured. The number of individual oxidant additions required in the reaction chamber to completely passivate the filter cake can then be calculated. Furthermore, the oxidant can be heated before flowing into the reactor space to initiate the chemical reaction. This allows the reaction to be started or stopped more quickly if necessary. The temperature of the input oxidant can be, for example, ambient temperature or a higher temperature. Attached Figure Description

[0072] The present invention will be explained in more detail below with reference to the embodiments. In the accompanying drawings:

[0073] Figure 1 A system with a filter unit, a metering unit, and a reactor unit is shown;

[0074] Figure 2 In accordance with Figure 1 The measuring device is shown in the longitudinal section cut by plane II;

[0075] Figure 3 It shows along Figure 2 Longitudinal section of Line III;

[0076] Figure 4 It shows according to Figure 1 The longitudinal section of plane IV of the reactor apparatus shown;

[0077] Figure 5 It shows along Figure 4 The longitudinal section of the V-line in the middle;

[0078] Figure 6 It shows that according to Figure 5 The reactor device has its shaft in the second rotational position;

[0079] Figure 7 It shows that according to Figure 6 The reactor device, with the shaft in a subsequent rotating position;

[0080] Figure 8 Another implementation of the axis of the reactor space is shown;

[0081] Figure 9 It shows along Figure 8 The cross-section of line IX in the middle;

[0082] Figure 10 It shows that according to Figure 9 The reactor device has its shaft in the second position;

[0083] Figure 11 It shows that according to Figure 10 The reactor device has its shaft in the third rotational position;

[0084] Figure 12 A reactor device with an expanded chamber is shown. Detailed Implementation

[0085] Figure 1 A filtration device, which is only an example, is shown, having a filter device 2, a metering device 7, and a reactor device 1. This filtration device is connected, for example, downstream of a metal printing device (not shown) to filter contaminated process gases during the metal printing process and, by means of the reactor device 1, passivates the filter residue 3 collected in the filter device 2 so that the chemical reactivity of the filter residue 3 is no longer sufficient to spontaneously combust or ignite a fire hazard when in contact with oxygen.

[0086] The system shown can be used not only in relation to metal printing equipment, but also in other industrial equipment that produces reactive filter residue. The exemplary structures subsequently shown, particularly reactor 1 and metering device 7, are not affected by this.

[0087] For example, in metal printing, it is preferable to regenerate the process gas within the printing chamber. To do this, a process gas, such as a protective gas like argon or nitrogen, is blown into the printing chamber and then extracted again. This can be done, for example, using a pump or a blower designed as a side-channel compressor. The extracted process gas is filtered within a filter device 2 to remove harmful substances, which subsequently form filter cake 3, etc.

[0088] Regarding the method for cleaning the filter device 2 and the filter device 2 itself, reference is made, by way of example only, to patent document DE 10 2019 132 349 A1 (US 2022 / 0362691 A1). The contents of that patent application are incorporated herein in their entirety into the disclosure of this invention, and also for the purpose of incorporating the features of that patent application into the claims of this invention.

[0089] To clean the filter of filter device 2 and remove filter residue 3 deposited on the filter during the filtration of process gas, filter device 2 can be placed in regeneration operation. For this purpose, filter device 2 can first be removed from the process gas passage and cleaned, for example, by a separate pump or side-channel compressor that generates negative pressure within filter device 2. Once a predetermined pressure is reached, for example, a flushing medium is directed to the filter wall so that it flows through the filter wall in the opposite direction to the filtration process. A detailed description of the filtration and regeneration process of such filter device 2 is available, for example, from patent document DE 10 2021 116 264 A (also disclosed as WO 2022 / 268497 A1). The contents of that patent application are incorporated herein in their entirety into the disclosure of this invention, with the aim of incorporating the features of that patent application into the claims of this invention.

[0090] The filter unit 2 is connected to the reactor unit 1 or the metering device 7 via an airtight valve 32, such as a butterfly valve. After the metering device 7, between the metering device 7 and the reactor unit 1, another valve 33, also designed as a butterfly valve, is provided. During filter cleaning, filter cake 3 is fed into the metering device 7 through the open valve 32. Then, the valve 32 is closed, and the reactor unit 1 is evacuated with the valve 33 open until the valve 32 is blocked. The metering device 7 is then operated so that the filter cake 3 is fed into the reactor unit 1. Inside the reactor unit 1, the filter cake 3 is then treated within the scope of a passivation process until its chemical reactivity drops below a predefined reference value or reference range and no longer poses a fire risk. Before performing the passivation process, the valve 33 is closed, and ambient air is preferably introduced into the reactor unit 1 as an oxidant.

[0091] After the passivation process is complete, another valve 34 located downstream of reactor unit 1 is opened to convey the passivated filter residue 3 from reactor unit 1 into collection chamber 9. Another valve 35 is located between reactor unit 1 and collection chamber 9, downstream of valve 34. This other valve 35 can be closed when collection chamber 9 needs to be removed from the system. Therefore, valve 35 serves as an additional safety device. However, in principle, valve 35 can be omitted, as the preceding valve 34 is sufficient to prevent air from entering reactor unit 1.

[0092] Reference Figure 2 and Figure 3The metering device 7, located upstream of the reactor device 1, will now be described first. The metering device 7 is designed here only as an impeller brake, by way of example only. Accordingly, the metering device 7 has an impeller housing 27 and an impeller 28 rotatably supported within the impeller housing 27. The impeller 28 preferably has a plurality of impeller chambers 31, for example, two, three, four, or more impeller chambers 31 arranged sequentially along the rotation direction of the impeller 28. The impeller 28 has two opposing end sides 29, one end side abutting against the impeller housing 27, and the other end side preferably abutting against a disc 30. The disc 30 is preferably subjected to a restoring force of a spring element 36 acting in the axial direction along the rotation axis 37 of the impeller 28, thereby pressing the disc 30 against the adjacent end side 29 of the impeller 28. The frictional fit between the disc 30 and the impeller 28, and between the impeller 28 and the adjacent shell walls of the impeller housing 27, acting along the axial direction of the rotation axis 37 of the impeller 28, ensures that the filter cake 3 does not escape from the impeller chamber 31 of the impeller gate into the environment. Furthermore, when friction between the impeller 28 and the disc 30 causes material wear, the position of the disc 30 will shift or recalibrate. The spring element 36 thus automatically readjusts the position of the disc 30, while the impeller 28, through the spring force of the spring element 36, still maintains rotation relative to both the impeller housing 27 and the disc 30.

[0093] Although not shown here, the impeller gate shown could be replaced by a gate consisting of two valves and the space between them as the metering device 7. The space between the valves determines the amount of filter cake 3 measured in each metering stroke of the metering device 7. Furthermore, other embodiments of the metering device 7 that can be used in conjunction with the reactor device 1 are also possible. The operating principle of the reactor device 1 remains unaffected.

[0094] exist Figure 2 and Figure 3 The metering device 7, designed as an impeller gate, functions as follows: First, it receives a portion of the total amount of filter cake 3 located in the filter device 2 into the first impeller chamber 31 of the impeller 28. To do this, the valve 32, located between the filter device 2 and the metering device 7, is first opened, allowing the filter cake 3 to fall into the impeller gate through the open valve 32. Then, the valve 32 is closed, and the metering device 7 is evacuated. Preferably, the evacuation of the metering device 7 is performed simultaneously with the evacuation of the reactor device 1 while the valve 33 located between the metering device 7 and the reactor device 1 is open. After evacuation, the impeller 28 of the metering device 7 is rotated about the rotation axis 37, thereby conveying the filter cake 3 stored in one or more impeller chambers 31 into the reactor space 5 of the reactor device 1.

[0095] Especially Figure 3 As can be seen, the impeller 28 here exemplarily has only two impeller chambers 31 opposite each other about the axis of rotation 37. When referring to Figure 3 When the upper first impeller chamber 31 is filled with filter residue 3, the opposite lower impeller chamber 31 is emptied towards the reactor device 1.

[0096] Furthermore, it can be seen that the metering device 7 is preferably configured such that the impeller 28 is slightly tilted in the initial position, so that the bottom of the impeller chamber 31 is not horizontally oriented, in which one of the impeller chambers 31 is filled. This helps to completely empty the impeller chamber 31 when the impeller 28 rotates 180 degrees, without leaving any filter cake 3 in the metering device 7. In addition, if a portion of the filter cake 3 is located in the gap between the impeller 28 and the impeller housing 27, this filter cake can be released by rotating more than 180 degrees. In addition, airflow can also be used to assist in the transport of the filter cake 3. According to another possibility, valve 32 can be opened first while valve 33 is closed first. Then, only the reactor device 1 can be evacuated without simultaneously evacuating the metering device 7. When the impeller gate is operated, the filter cake 3 falls onto the closed valve 33 and is drawn into the reactor device 1 after the valve 33 is opened until pressure equilibrium is reached between the filter device 2 and the reactor device 1.

[0097] In all the described embodiments, the support position of the metering device 7 can be flushed with protective gas after the filter cake 3 is discharged into the reactor device 1. This cleans the support position and conveys any filter cake 3 that may not have entered the reactor device 1 into the reactor device 1.

[0098] After the filter residue 3 leaves the metering device 7, it enters the reactor device 1. Especially as... Figure 1 As can be seen, reactor device 1 has a filter device interface 6 through which filter cake 3 can flow into reactor device 1. In the lower end region opposite to filter device interface 6, reactor device 1 has a collection chamber interface 8 in a similar manner, which connects to a collection chamber 9 for the final collection of passivated filter cake 3. Collection chamber 9 can be separated from reactor device 1 to allow disposal of the contained filter cake 3. Reactor device 1 also has an expansion chamber 23 (see...). Figure 1 and Figure 12 Its function will be described in detail later. The expansion chamber 23 has a closure 38, which is, for example, a flange.

[0099] Reference Figures 4 to 7 First, a first embodiment of a possible reactor device 1 will be described.

[0100] The reactor apparatus 1 has a reactor shell 4, in which a reactor space 5 is constructed. A rotatable shaft 10 is supported on the reactor shell 4, for example, passing through the reactor space 5, and relative to the axis of rotation of the shaft 10... Figure 4 and Figure 5The rotational position shown contacts a portion of the reactor shell 4, such that the reactor space 5 is divided by the shaft 10 into a reaction chamber 11 and a discharge chamber 12. A portion of the circumferential surface 14 of the shaft 10 forms the reactor bottom 40 of the reaction chamber 11.

[0101] However, as an alternative to the rotatable shaft 10, the reactor space 5 can also be divided into a reaction chamber 11 and a discharge chamber 12 by other structural measures, such as by a cover plate of the reactor bottom 40 forming the reaction chamber 11 or a translationally movable shell portion of the reactor shell 4.

[0102] To achieve contact between the circumferential surface 14 and the inner wall of the reactor shell 4, the shaft 10 has, for example, a different outer diameter in its longitudinal extension direction, i.e., parallel to its axis of rotation 18. The circumferential portion 13 with the largest diameter can be sealed relative to the reactor shell 4 by a sleeve 16. The sleeve 16 can be pressed against the circumferential surface 14 of the shaft 10 by a spring element 39. This establishes a connection with the reactor shell 4, which simultaneously separates the reaction chamber 11 from the discharge chamber 12 of the reactor space 5.

[0103] The sleeve 16 can be designed as a cylindrical hollow body, with its longitudinal axis 17 perpendicular to the rotation axis 18 of the shaft 10.

[0104] The circumferential portion 13 of the shaft 10 extending into the reaction chamber 11 has a receiving area 15 for introducing the filter residue 3 into the reactor device 1. The receiving area 15 is, for example, a concave material recess.

[0105] Especially Figures 5 to 7 It is evident that four such receiving regions 15 for the filter cake 3 are preferably formed on the circumferential surface 14 of the shaft 10. Here, every two receiving regions 15 can be positioned opposite each other relative to the axis of rotation 18 of the shaft 10. By rotating 90 degrees about the axis of rotation 18 of the shaft 10, it is always possible to move another receiving region 15 of another circumferential portion 13 of the shaft 10 into the reaction chamber 11. The corresponding circumferential portion 13 here, together with the inner wall of the sleeve 16 and the remaining inner wall of the reactor shell 4, forms the reaction chamber 11. At least one interface 26, for example two interfaces 26, can lead into the reaction chamber 11, through which an oxidant can be introduced into the reaction chamber 11. The oxidant here is oxygen or oxygen-containing ambient air.

[0106] like Figures 5 to 7 It can also be seen that the reaction chamber 11 may have at least one temperature sensor 24 and at least one pressure sensor 25, which are configured by the analysis device of the reactor device 1, such as a computer processor, to measure the temperature or pressure inside the reaction chamber 11. As will still be explained below, this is used to monitor the passivation process of the filter residue 3 inside the reactor device 1.

[0107] Reaction chamber 11 with the help of Figure 1 The extended chamber 23 shown is expanded in terms of the volume of gas it encloses.

[0108] The following description is based on the first embodiment ( Figures 4 to 7 The working principle of reactor device 1.

[0109] When shaft 10 is in, for example Figure 4 At the initial position shown, filter residue 3 enters the reaction chamber 11 from the metering device 7. This reaction chamber is spatially separated from the discharge chamber 12 by the shape matching and frictional fit of the sleeve 16 on the circumferential portion 13 of the shaft 10. This spatial separation ensures that the filter residue 3 remains solely within the reaction chamber 11 of the reactor space 5 before any passivation treatment. Once the filter residue 3 accumulates under gravity in the concave receiving area 15 of the circumferential surface 14 of the shaft 10, the valve 33 located between the reactor device 1 and the metering device 7 is closed. The reaction chamber 11, along with the tubular expansion chamber 23, is then preferably evacuated until a predetermined pressure is reached. Air is then introduced into the reaction chamber 11 from the direct external environment of the reactor device 1 through the interface 26. The interface 26 here is, for example, a small hole or valve in the sleeve 16, which is inclined relative to the longitudinal axis 17 of the sleeve 16, such that the incoming ambient air preferably enters the receiving area 15 of the shaft 10 in a substantially straight line. This causes the filter cake 3 accumulated in the receiving area 15 to be agitated within the reaction chamber 11 and, if necessary, within the expansion chamber 23, and conveyed vertically, i.e., towards the expansion chamber 23 if necessary. Once a predetermined pressure or ambient pressure (which can be measured by pressure sensor 25) is reached within the reaction chamber 11 or the expansion chamber 23, the input of oxidant through interface 26 is stopped. Then, the process continues until the filter cake 3 accumulates in the receiving area 15 of the shaft 10.

[0110] The passivation cycle described above can be repeated until the filter residue 3 reaches a predetermined desired passivation state. Here, the passivation state can be determined by measuring the temperature or pressure within the reaction chamber 11 or the extended chamber 23. For this purpose, temperature or pressure measurements are taken during or shortly after the oxidant flows into the reaction chamber 11. If the temperature and / or pressure rises above a specified reference value or range, it can be inferred that the filter residue 3 is not sufficiently passivated, i.e., it still possesses residual chemical reactivity that poses a fire hazard. Therefore, the passivation cycle is repeated by bringing the same amount of filter residue 3 in the reaction chamber 11 back into contact with the oxidant. Once the temperature and / or pressure no longer rise, or at least no longer rise significantly, when the oxidant flows in, the filter residue 3 has reached a reliable passivation state as defined. The passivated filter residue 3 can then be transferred from the reaction chamber 11 to the discharge chamber 12 of the reactor apparatus 1.

[0111] Alternatively, to ensure complete passivation of the filter residue 3, the required amount of oxidant for complete passivation of the filter residue 3 can be determined in advance, and then the number of passivation cycles required to passivate the total amount of filter residue 3 in multiple successive passivation cycles can be calculated. If necessary, the reaction can be assisted by heating the oxidant before it flows into the reaction chamber 11. This can activate the reaction of the filter residue 3, thereby initiating passivation earlier and / or completing it more quickly. Heating of the oxidant can be carried out, for example, by means of heating elements that heat the walls of the reaction chamber inlet pipe. Preferably, the walls of the reaction chamber inlet pipe can also be designed as heat exchangers, for example, by guiding warm liquid through cavities in the walls. Alternatively, the oxidant can also be heated in a separate container or space outside the inlet pipe of the reactor apparatus.

[0112] Once the desired passivation state of the filter cake 3 is achieved and the filter cake 3 has accumulated in the designated location, i.e., the receiving area 15 of the shaft 10, the shaft 10 is rotated 90 degrees about the rotation axis 18 in the illustrated embodiment. Here, firstly (among other things) achieving... Figure 6 As shown in the intermediate position, in this intermediate position, the reaction chamber 11 has a flow connection to the discharge chamber 12 leading to the reactor space 5. The filter residue 3 accumulated in the receiving area 15 of the shaft 10 can leave the reaction chamber 11 through the gap created between the shaft 10 and the sleeve 16, and ultimately... Figure 7 The device moves toward the collection chamber interface 8, which establishes a connection with the collection chamber 9 when valves 34 and 35 are open.

[0113] Subsequently, if necessary, the receiving area 15 can be cleaned by blowing inert gas into the reactor space 5. The bearings of the shaft 10 can also be cleaned in this manner within the reactor space 5.

[0114] Figures 8 to 12 Another of several other possible embodiments of reactor device 1 is disclosed. First, as... Figure 8 As can be seen, in this embodiment, the reactor device 1 also has a reactor space 5 with a shaft 10, which can separate the reaction chamber 11 from the discharge chamber 12. A sleeve 16 is still arranged between the circumferential portion 13 of the shaft 10 and the reactor shell 4, and the sleeve is pressed against the circumferential surface 14 of the shaft 10 by the restoring force of the spring element 39.

[0115] Compared with the aforementioned implementation method ( Figures 4 to 7 Unlike the second embodiment, the shaft 10 does not have a recessed receiving area 15 for the filter cake 3 in the circumferential portion 13, but instead has an arched portion 21, such as... Figure 8As can be seen, the arched portion extends longitudinally along the axis of rotation 18 of the shaft 10. Thus, the circumferential portion 13 of the arched portion of the shaft 10 abuts against the annular end face of the cylindrical sleeve 16 not only in the circumferential bending direction of the shaft 10, but also laterally in that direction. Therefore, the arched portion 21 surrounding the shaft 10 forms an integral annular receiving area 15 for receiving filter residue 3.

[0116] The shaft 10 and the arched portion 21 are combined to have a through hole 20, which is, for example, perpendicular to the axis of rotation 18 of the shaft 10, i.e., extending through the shaft 10 in the direction of rotation of the shaft 10. The through hole 20 is spatially separated from the arched portion 21 or two opposing arched portions 21 relative to the circumferential surface 14 of the shaft 10. In particular, as Figure 8 As shown, the design scheme makes the through hole 20 have a longitudinal direction that extends perpendicular to the rotation axis 18 of the shaft 10, wherein the through hole 20 is centrally opened on the circumferential surface 14 of the shaft 10 between two opposite circumferential portion regions 13.

[0117] According to this embodiment, the receiving area 15 located on the circumferential surface 14 of the shaft 10 is emptied by rotating the shaft 10 about the rotation axis 18, thereby causing the end region of the through hole 20 to move into the end opening of the sleeve 16 and thus also into the reaction chamber 11. This allows the filter residue 3 located in the receiving area 15 to enter the discharge chamber 12 from the reaction chamber 11 through the through hole 20. This... Figure 10 and Figure 11 As shown in the image.

[0118] As previously mentioned Figures 4 to 7 As shown in the embodiment, the interface 26 for introducing the oxidant into the sleeve 16 or the reaction chamber 11 is tilted relative to the longitudinal axis 17 of the sleeve 16, so that the oxidant flow is directed in the direction of the arch 21 and an airflow is formed in the annular circumferential region of the arch 21. This airflow spirally agitates the filter residue 3 and the oxidant together in the reaction chamber 11 and the connected extended chamber 23.

[0119] As shown in the figure, the extended chamber 23 is preferably designed as a tube. It constitutes a dead zone, meaning that only inflow and outflow are possible, but no flow is allowed. In a specific arrangement, as shown in the figure, the extended chamber 23 preferably has a considerable height. Its longitudinal extension is preferably arranged vertically, and the longitudinal extension is a multiple of its lateral extension (with reference to the internal space). The filter residue 3 agitated during the reaction can be distributed along the entire longitudinal extension of the extended chamber 23, and then, especially without further replenishment of oxidant, it will re-aggregate on the bottom 40 of the reactor by settling. More preferably, the extended chamber 23 has a diameter perpendicular to its longitudinal extension, or a given maximum size for this purpose, which is larger than the given size of the bottom 40 of the reactor in the same direction. Preferably, this size is about two to three times larger, more preferably five times or less. It is known that the inlet to the reactor is closed during agitation during passivation. Together with the extended chamber 23, a closed space is formed in which passivation occurs. Here, the extended chamber 23 can be further arranged and extended such that the agitated filter cake 3 flows past the filter device interface 6 in height dimension during the agitation process.

[0120] Especially Figure 12 It is evident that sparks can also be generated to specifically initiate the passivation reaction or assist in the start of passivation. For example... Figure 12 As shown, sparks can be generated in the expanded chamber 23, but they can also be generated closer to the actual reactor space.

[0121] like Figure 12 As can be seen, in one feasible implementation, two ignition electrodes 41 and 42 are provided. In this embodiment, they are also preferably mounted on the closure 38 of the expansion chamber 23, i.e., close to the tube end of the expansion chamber 23, which is therefore preferably tubular.

[0122] Alternatively, a conventional spark plug or piezoelectric spark generator can be installed.

[0123] List of reference numerals

[0124] 1. Reactor apparatus

[0125] 2. Filter device

[0126] 3. Filter residue

[0127] 4. Reactor shell

[0128] 5. Reactor Space

[0129] 6. Filter device interface

[0130] 7 Metering device

[0131] 8. Collection Chamber Interface

[0132] 9 Collection Room

[0133] 10 axes

[0134] 11 Reaction Chamber

[0135] 12 Discharge Room

[0136] 13. Some areas around the perimeter

[0137] 14 circumferential planes

[0138] 15 Receiving Area

[0139] 16 sleeve

[0140] 17. Vertical axis

[0141] 18. Rotation axis

[0142] 19 concavity

[0143] 20 through holes

[0144] 21 Arch

[0145] 22 Edge Area

[0146] 23 Expanded chamber

[0147] 24 Temperature Sensors

[0148] 25 Pressure Sensor

[0149] 26 Interfaces

[0150] 27 Impeller casing

[0151] 28 Impeller

[0152] 29 End side

[0153] 30 discs

[0154] 31 Impeller Chamber

[0155] 32 valves

[0156] 33 valve

[0157] 34 valves

[0158] 35 valve

[0159] 36 Spring elements

[0160] 37. Axis of rotation

[0161] 38. Enclosure

[0162] 39 Spring elements

[0163] 40 Bottom of reactor

[0164] 41 Ignition Electrode

[0165] 42 Ignition Electrode

Claims

1. A reactor apparatus (1) for performing a chemical reaction between filter residue (3) and an oxidant within the scope of at least one passivation process to reduce the chemical reactivity of the filter residue (3), wherein, The reactor device (1) has a reactor space (5) surrounded by a reactor shell (4), the reactor space having: a filter device interface (6) for establishing a fluid connection between the reactor device (1) and a filter device (2); and a collection chamber interface (8) for establishing a fluid connection between the reactor device (1) and a collection chamber (9) for receiving passivated filter residue (3), wherein the reactor space (5) is further divided by a reactor bottom (40) into a reaction chamber (11) and a discharge chamber (12), characterized in that the reactor bottom (40) is designed to be movable between a first operating position and a second operating position, wherein the reactor bottom (40) forms part of the reaction chamber (11) in the first operating position and part of the discharge chamber (12) in the second operating position, and the division can be canceled during the movement of the reactor bottom (40).

2. The reactor apparatus according to claim 1, characterized in that, The reaction chamber (11) has a filter device interface (6), and the discharge chamber (12) has a collection chamber interface (8).

3. The reactor apparatus (1) according to claim 1 or 2, characterized in that, The bottom (40) of the reactor has at least one receiving area (15) for filter cake (3).

4. The reactor apparatus (1) according to any one of the preceding claims, characterized in that, The bottom (40) of the reactor is part of a shaft (10) arranged in the reactor space (5), and in particular supported on the reactor shell (4), which is rotatable relative to the reactor shell (4).

5. The reactor apparatus (1) according to claim 4, characterized in that, The reaction chamber (11) has a sleeve (16) which is pressed against the circumferential portion (13) of the shaft (10) having the reactor bottom (40) by a spring force. The sleeve connects the shaft (10) to the reactor shell (4). More preferably, the shaft (10) is rotatable between an open position and a locked position while maintaining contact with the sleeve (16).

6. The reactor apparatus (1) according to claim 5, characterized in that, The longitudinal axis (17) of the sleeve (16) is oriented perpendicular to the rotation axis (18) of the shaft (10).

7. The reactor apparatus (1) according to any one of claims 3 to 6, characterized in that, The receiving area (15) has a recess (19), especially a concave recess.

8. The reactor apparatus (1) according to any one of claims 3 to 6, characterized in that, The receiving area (15) has a through hole (20) extending transversely to the axis of rotation (18) and an arched portion (21) constructed on at least one circumferential portion (13) of the shaft (10) and extending transversely to the circumferential direction of the shaft (10), in particular a raised portion protruding in the radial direction from the edge region (22) of the raised end side relative to the circumferential surface (14) of the shaft (10).

9. The reactor apparatus (1) according to any one of the preceding claims, characterized in that, The reactor shell (4) has an extended chamber (23) that is particularly tubular, into which filter residue (3) can be moved against gravity to aid passivation. The extended chamber (23) is designed as a dead zone, into which filter residue (3) can be moved solely for passivation as it flows through the filter device interface (6) in height dimension.

10. The reactor apparatus (1) according to any one of the preceding claims, characterized in that, The reaction chamber (11) and / or the extended chamber (23) and / or the sleeve (16) have at least one temperature sensor (24) and / or at least one pressure sensor (25) and / or at least one interface (26) for introducing gas into the reaction chamber (11), wherein, in particular, the interface (26) for introducing gas is oriented relative to the receiving area (15) and preferably inclined relative to the bottom (40) of the reactor so that the filter cake (3) located in the receiving area (15) is agitated in the reaction chamber (11) and / or in the extended chamber (23).

11. The reactor apparatus (1) according to any one of the preceding claims, characterized in that... A metering device (7) is connected to the filter device interface (6) of the reactor device (1), the metering device being configured to separate a first component of the total amount of filter cake (3) from at least a second component of the total amount of filter cake (3) and transfer it to the reaction chamber (11) of the reactor device (1), wherein the metering device (7) is in particular a gate or impeller gate defined by a valve, and wherein the metering device (7) preferably has an impeller housing (27) and an impeller (28), the impeller (28) being closed at least at the end side (29) by a disc (30) axially subjected to a spring force.

12. A reactor apparatus (1) for performing a chemical reaction between filter residue (3) and an oxidant within the scope of at least one passivation process to reduce the chemical reactivity of the filter residue (3), wherein, The reactor device (1) has a reactor space (5) surrounded by a reactor shell (4), the reactor space having: a filter device interface (6) for establishing a fluid connection between the reactor device (1) and a filter device (2); and a collection chamber interface (8) for establishing a fluid connection between the reactor device (1) and a collection chamber (9) for receiving passivated filter residue (3), characterized in that the reactor space (5) has a rotatable shaft (10) and a sleeve (16) pressed against a circumferential portion (13) of the shaft (10) with its end side region, the sleeve connecting the shaft (10) to the reactor shell (4) and forming a reaction chamber (11) spatially separated from the discharge chamber (12) of the reactor space (5).

13. The reactor apparatus (1) according to claim 12, characterized in that, The rotatable shaft (10) is designed to rotate between a first and a second operating position, wherein a circumferential portion (13) of the shaft (10) forms part of a reaction chamber (11) in the first operating position and part of a discharge chamber (12) in the second operating position, wherein the separation between the reaction chamber (11) and the discharge chamber (12) can be cancelled during the rotation of the shaft (10).

14. A filtration apparatus for filtering particles from a raw material gas stream, the filtration apparatus having a filter device (2) having one or more filter elements, wherein filter cake (3) accumulates on the filter elements during filtration, the filtration apparatus further having a reactor device (1) for performing a chemical reaction between the filter cake (3) and an oxidant within the scope of at least one passivation process to reduce the chemical reactivity of the filter cake (3), wherein, The reactor device (1) has a reactor space (5) surrounded by a reactor shell (4), the reactor space having: a filter device interface (6) for establishing a fluid connection between the reactor device (1) and the filter device (2); and a collection chamber interface (8) for establishing a fluid connection between the reactor device (1) and a collection chamber (9) for receiving passivated filter residue (3), wherein the reactor device (1) is further arranged below the filter device (2) so that the filter residue (3) can also be transported from the filter device (2) to the reactor device (1) by gravity, wherein the reactor device (1) has an expansion chamber (23) into which the filter residue (3) can be moved against gravity to assist passivation, characterized in that the filter device interface (6) and the collection chamber interface (8) can be closed to perform the passivation process, and the expansion chamber (23) is designed as a dead zone into which the filter residue (3) can be moved solely for passivation when flowing through the filter device interface (6) in height dimension.

15. A method for passivating filter cake (3) in a reactor apparatus (1) having a reactor space (5), wherein, The reactor space (5) can be sealed airtightly, and the passivation is carried out in the reactor space (5) in a first passivation process with a limited input of oxidant for a limited time. The passivation is characterized by being repeated in a second passivation process or other passivation processes based on the pressure reached in the reactor space (5) during the first passivation process or the temperature reached in the reactor space (5) during the first passivation process.

16. The method according to claim 15, characterized in that, The input of oxidant is used to agitate the filter cake (3).

17. The method according to claim 15 or 16, characterized in that, The second passivation process or other passivation processes are carried out after the filter residue (3) has re-aggregated on the bottom (40) of the reactor in the reactor space (5).

18. The method according to any one of claims 15 to 17, characterized in that... The following are the steps: The filter residue (3) is filled into the reaction chamber (11) of the reactor space (5); An oxidant is introduced into the reaction chamber (11); The filter residue (3) is mixed with an oxidant to reduce the chemical reactivity of the filter residue (3); The reactor bottom (40) used to divide the reactor space (5) into a reaction chamber (11) and a discharge chamber (12) is moved from a first operating position to a second operating position, in which the reactor bottom (40) forms part of the reaction chamber (11) and in the second operating position the reactor bottom (40) forms part of the discharge chamber (12), wherein the division is canceled during the movement of the reactor bottom (40); The filter residue (3) located in the reaction chamber (11) is emptied into the discharge chamber (12) and / or the collection chamber (9) connected to the discharge chamber (12).

19. A reactor apparatus (1), a filtration device, or a method for operating the reactor apparatus (1), characterized in that... One or more characteristic features of any of the preceding claims.

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