Filter insert, flue gas filter, treatment device and use of the flue gas filter

Abstract

In a filter insert (1) for a flue gas filter, comprising - an insert housing (2) with an inlet (3) and an outlet (4) which are connected to allow fluid flow, - at least two filter stages arranged between the inlet (3) and the outlet (4), it is proposed that this further include ◯ a first of the filter stages (5) which is designed as a liquid separator and has a separating element (8), ◯ a liquid collection device (9) which in use is arranged lower than the liquid separator 8 and is spatially separated from a second of the filter stages 6, ◯ a liquid guiding device (10) designed to guide liquid from the separating element 8 into the liquid collecting device (9), ◯ and a spacer (11) that keeps the first filter stage (5) at a distance from the second filter stage (6) downstream in the direction of flow (SR). Furthermore, a flue gas filter, a treatment device, and the use of a flue gas filter are described.

Description

[0001] The invention relates to a filter element for a flue gas filter, the flue gas filter itself, a treatment device comprising the flue gas filter, and a use of the flue gas filter. The filter element comprises an insert housing with an inlet and an outlet, which are connected to allow fluid flow, and at least two filter stages arranged between the inlet and the outlet.

[0002] Smoke filters, known from the state of the art, are used in medical technology. In minimally invasive procedures, which offer the advantage of less trauma for the patient, or in endoscopic examinations, as well as during laparotomies, high-frequency (HF) surgical devices such as the electrocautery are employed. This surgical instrument is used, among other things, for ablation (tissue removal) and cauterization (tissue burning) using electric current. The use of electromagnetic waves from lasers, such as the excimer laser, or vibrating high-frequency blades, so-called ultrasonic dissectors, is also replacing the classic scalpel in many medical, especially laparoscopic, procedures. Advantages of this new generation of surgical devices include, among others...the coagulation of opened blood vessels that occurs when tissue is cut, and is caused by heat-induced denaturation of proteins.

[0003] The fumes produced during the use of the described medical technology are considered harmful to health according to in vitro and in vivo studies. Depending on the type and duration of a procedure, the medical personnel involved are exposed to these fumes for several hours. This can lead to acute intoxication, causing symptoms such as headaches, nausea, or irritation of the mucous membranes. Beyond these potential pathological consequences, the generated fumes can also cause odor nuisance and impaired vision for the medical personnel. Therefore, in addition to compromising workplace safety, the fumes also pose a risk to the patient.

[0004] To minimize exposure to flue gases and the associated risks, flue gas extraction using flue gas filters and appropriate filter elements is essential. The extraction devices commonly used for this purpose incorporate a flue gas filter. This filter comprises a liquid separator and a separate filter element that filters both particulate and gaseous substances. In practice, the filter element is often a combination of an ULPA filter (Ultra Low Penetration Air) and an activated carbon filter. The filter element is positioned separately from the liquid separator to prevent contamination of the subsequent filter stages by the liquid and to ensure the flue gas filter functions correctly during operation.However, the separate arrangement results in a large space requirement for the flue gas filter and thus for the treatment unit, as well as complicated handling, which makes compliance with hygiene standards more difficult. Furthermore, the previously described multi-part arrangement leads to an increased amount of waste due to the necessary disposal of the separate flue gas filter components.

[0005] The invention is based on the objective of creating a generic filter insert that avoids the described disadvantages. Furthermore, the invention is based on the objective of creating a flue gas filter and a treatment device, each with the filter insert, that require less space and are easier to handle. The invention is also based on the objective of creating a use for the filter insert.

[0006] This problem is solved by a filter insert according to claim 1, a flue gas filter with the filter insert according to claim 16, a treatment device with the filter insert according to claim 17, and the use of a filter insert according to claim 18. Advantageous embodiments are the subject of claims 2 to 15.

[0007] According to the invention, the filter element comprises a first filter stage and a second filter stage. The first filter stage is designed as a liquid separator and includes a separating element. The filter element also includes a liquid collection device, which, in operation, is positioned lower than the liquid separator and is spatially separated from the second filter stage. Furthermore, the filter element includes a liquid guide device designed to direct liquid from the separating element into the liquid collection device. Finally, the filter element includes a spacer that maintains a distance between the first filter stage and the second filter stage, which is located downstream in the flow direction.

[0008] Integrating the liquid separator into the filter element, in combination with a different filter stage, offers the advantage of a space-optimized filter element when installation space within a flue gas filter is limited. By using a single filter element instead of various separate components for flue gas filtration, the contamination risk of the individual components, as well as the flue gas filter as a whole, is reduced. This is because only the insertion of a single filter element is required, rather than the assembly and connection of multiple components. The inventive arrangement of the liquid collection device and the spacing of the filter stages reliably ensures that the second filter stage is not contaminated, particularly by liquids.

[0009] The fluid flows from inlet to outlet. The first filter stage, downstream of the inlet, is designed as a liquid separator such that liquid from the fluid flowing through the separator element is separated and transported by the fluid guide, similar to a drain, to the liquid collection device. The separator element can be directly welded, glued, clamped, or otherwise connected to the filter element housing. Advantageously, the separator element is connected to a frame that completely or partially surrounds it and is in turn connected to the filter element housing. The connection between the separator element and the frame and / or the filter element housing is designed to be completely sealed, ensuring that the fluid necessarily passes through the separator element in the first filter stage.In one embodiment, an injection-molded or applied seal can surround the frame and / or the insert housing for this purpose. Additionally or alternatively, an integrated labyrinth seal can be provided in the frame and / or the insert housing to prevent contamination of the subsequent filter stage. The portion of the frame facing the liquid collection device can be designed to be raised compared to the rest of the frame. This raised section prevents liquid from being forced through the separator element. This is advantageous, among other things, in the event of backflow of the discharged liquid.

[0010] Furthermore, the liquid collection device is positioned lower than the liquid separator in such a way that it is at least partially located below the separating element, allowing the separated liquid to drip or flow into the lower liquid collection device by gravity. Additionally, any flow generated during the separation of the liquid can accelerate the separation or drainage of the liquid with this arrangement of the liquid collection device.

[0011] The liquid collection device can advantageously include a storage medium that serves to absorb the separated liquid and retain it within the device. This medium can be, in particular, a sponge, granules, spheres, nonwoven fabric, or foam. Materials such as zeolite, silica, or a superabsorbent polymer can be used for this purpose. The storage medium can also be permanently attached to the liquid collection device to prevent leakage of the storage medium and the liquid it contains. For this purpose, the storage medium can, for example, be glued, welded, or clamped into the liquid collection device. In one embodiment, the storage medium is designed as a mat that extends within the liquid collection device at least below the first filter stage.The storage capacity of the storage medium and the liquid collection device can differ. For example, the liquid collection device can have a higher capacity than the storage medium. This ensures that no liquid escapes from the liquid collection device when the storage medium reaches its maximum capacity and contaminates, for instance, the second filter stage. The storage capacity of the storage medium and / or the liquid collection device is particularly 500 ml, preferably 250 ml, and most preferably 175 ml. In one embodiment, the storage capacity of the storage medium and / or the liquid collection device is 25 ml, preferably 12 ml, and most preferably less than 10 ml. A maximum capacity of 25 ml is particularly advantageous for minimizing the required installation space.This is advantageous for operations and / or treatments with relatively low fluid shedding, such as minimally invasive or endoscopic procedures, which are usually performed in smaller operating rooms or treatment rooms.

[0012] Furthermore, the liquid collection device is separated from the second filter stage in such a way that the liquid collected by the liquid collection device cannot contaminate the second filter stage. For this purpose, the greatest possible spatial distance within the filter element can be used. In one embodiment, the liquid collection device can extend below the filter stages over the entire length of the element housing, particularly the horizontal length. In an alternative embodiment, the liquid collection device can be positioned spatially upstream of at least the second filter stage, against the direction of flow.

[0013] The liquid guidance device can encompass the separating element completely or partially. In one embodiment, the liquid guidance device extends into the liquid collecting device. Advantageously, the opening of the liquid guidance device overlaps with the liquid collecting device, thus forming a leakage guard.

[0014] In one embodiment, a third filter stage can be included, which is arranged downstream of the second filter stage in a flow direction and is configured differently from both the first and second filter stages, wherein the liquid collection device is spatially separated from the third filter stage. This arrangement increases the functionality of the filter element and provides the third filter stage with a particularly large spatial separation from the liquid collection device, thereby minimizing the risk of contamination of the third filter stage as much as possible.

[0015] In a further embodiment, the second or third filter stage can be designed as a particle filter or an adsorber. Preferably, the second and / or third filter stage can be designed as a particle filter. In this case, particulate filters such as EPA (Efficiency Particulate Air) or HEPA (High Efficiency Particulate Air) filters are used. The use of an ULPA (Ultra Low Penetration Air) filter is particularly advantageous. Compared to the filter variants mentioned above, the latter has a higher filter classification and thus a better separation efficiency, which is a measure of the effectiveness of the fluid purification. The particle filter used can be in a pleated form, similar to a bellows. This allows for the largest possible surface area for filtration.In one embodiment, the particle filter can be made of fiberglass fabric, and the filter seams can be sealed, for example, by beads of adhesive. An intermediate wall located within the housing, and in particular one enclosed by it, can serve to fix the filter stage. Alternatively, the filter stage can also be fixed between the particle filter and the housing using adhesives. A combination of different fixing methods is advantageous.

[0016] Alternatively or additionally, the second and / or third filter stage can be designed as an adsorber. The use of an adsorbent preferably leads to the accumulation of substances dissolved in a fluid on the surface of the adsorber. The adsorber can also be in a pleated form, similar to a bellows. Activated carbon can advantageously be used as the absorbent. Granulated activated carbon is particularly advantageous. This results in a lower differential pressure with respect to the flow velocity than when using a bed of activated carbon, where the differential pressure refers to air resistance. This has the advantage that the activated carbon, and thus the filter element, requires less space. In one embodiment, the activated carbon is surrounded on both sides by a casing material, with the seams of the casing material, for example, a nonwoven fabric, being laminated or filled with reactive PU foam or similar material.The bellows are sealed, preventing the activated carbon from escaping into the interior of the insert housing. Alternatively and / or additionally, the bellows, similar to a particle filter, can be tightly bonded to the insert housing all around. Alternatively and / or additionally, an adsorber in the form of loose fills, foams, or other structures can be used.

[0017] In an advantageous embodiment, a particle filter can be used as the second filter stage and an adsorber as the third filter stage, or vice versa.

[0018] Advantageously, in one embodiment, the separation element can be designed as a coalescer for the coagulation of liquid droplets. The liquid droplets coagulated on the separation element follow gravity and are guided by the liquid guide into the liquid collection device, or drip into it. The coalescer material is preferably a synthetic material. The randomly laid material preferably has a thickness of 5 to 30 mm. Advantageously, the material has a gradient structure from coarse to fine. The thickness and / or the gradient structure can be achieved by combining different materials / layers. The coalescence effect can be enhanced or optimized by a hydrophobic and / or hydrophilic coating and / or combinations thereof on the material.

[0019] In another embodiment, the separating element can be designed as a hydrophobic sieve. The sieve is formed by a perforated, net-like structure or a mesh-like or grid-like fabric. Due to the hydrophobic material properties, liquid cannot pass through the separating element and is guided into the liquid collection device via the liquid guide or drips into it. In one embodiment, a gradual increase in the hydrophobicity of the sieve can be provided. The separating element is, in particular, essentially flat or curved, especially curved against the flow direction.

[0020] In one embodiment, the separating element is inclined against the flow direction. This means, in particular, that a surface of the separating element facing the inlet is angled at an angle of less than 90° to the flow direction. In a preferred embodiment, the positioning against the flow direction is understood to mean that, in contrast to its standard arrangement, the separating element is pivoted about a pivot axis perpendicular to the flow direction, located in the region of the end of the separating element facing the liquid collection device. An inclination angle of 80° to 87° is particularly advantageous. This allows liquid droplets to drip directly from the separating element into the liquid collection device under the influence of gravity, without requiring a disproportionate amount of installation space.This promotes rapid drainage of the liquid, preventing liquid-induced film formation on the separator element and positively influencing the differential pressure. Furthermore, it reduces or eliminates the risk of liquid droplets being forced through the separator element, thus preventing contamination of the subsequent filter stage.

[0021] The spacer for separating the first filter stage from the second filter stage downstream in the flow direction can be integrated into the insert housing as a separate component or be provided within the insert housing. Advantageously, the spacer is part of the first or second filter stage. In one embodiment, the first filter stage incorporates the spacer. In particular, the spacer is formed by the frame. Furthermore, a spacer can be provided between the second and third filter stages. This spacer can again be located on the second and / or third filter stage or be designed as a separate component. In one embodiment, the spacer can be formed by an intermediate wall located in the insert housing, in particular the intermediate wall used to fix the filter stages.

[0022] In one embodiment, the first filter stage is arranged at a distance of 2 mm to 25 mm from the second filter stage. A distance of 5 mm, or particularly 8 mm, between the two filter stages is preferred, especially with regard to the reduced installation space. A distance of 25 mm between the two filter stages is particularly advantageous to prevent contamination of the subsequent filter stage with liquid.

[0023] In one embodiment, an intermediate wall borders the insert housing on both sides. In another embodiment, the insert housing has an intermediate wall impermeable to liquid, which is arranged between the liquid collection device and the second filter stage. The intermediate wall extends, at least partially, between the liquid collection device and the second filter stage and is optionally enclosed by the insert housing. The intermediate wall can extend from an outer wall of the insert housing into an interior space of the insert housing.In one embodiment, the intermediate wall extends from the outlet-forming side of the insert housing against the flow direction, in particular to next to the first filter stage, wherein the intermediate wall is liquid-impermeable to two opposite longitudinal sides of the insert housing which extend in the flow direction and at least partially vertically, in such a way that at least the filter stages downstream of the first filter stage are located above the intermediate wall and the liquid collection device is located below the intermediate wall.

[0024] In another embodiment, the intermediate wall extends from the side of the insert housing, which in particular forms the base for the liquid collection device, perpendicular to the flow direction into the interior. Preferably, in this case, the intermediate wall forms a right angle relative to the flow direction, with the intermediate wall a liquid-tight seal against the insert housing. In an alternative embodiment, the intermediate wall can originate from the liquid collection device and connect to the insert housing in a liquid-tight manner, acting as a cover for the liquid collection device. In one embodiment, the frame can at least partially form an intermediate wall and / or at least partially form the liquid collection device.

[0025] In one embodiment, the liquid collection device has a cover at the end facing the second filter stage. This advantageously provides splash protection to prevent contamination of the subsequent filter stage. In one embodiment, the intermediate wall can merge into the cover. In another embodiment, the cover can be designed as a grid. This is advantageous when using a storage medium, for example, a granular or gel-like storage medium, so that if the storage medium has a diameter larger than the diameter of the grid mesh, the storage medium is retained in the liquid collection device.

[0026] In one embodiment, the fluid guide can be formed by a frame surrounding the separating element. In another embodiment, the frame forms the fluid guide wholly or partially. In an alternative embodiment, the fluid guide is formed by the insert housing. In a third embodiment, the fluid guide is attached as a separate component between or to the frame and / or insert housing. In a fourth embodiment, the fluid guide is formed by the intermediate wall.

[0027] In one embodiment, a further filter stage designed as a liquid separator, which is arranged upstream of the second filter stage in a flow direction and comprises a further separating element and a liquid guide device designed to direct liquid from the further separating element into a liquid collection device, may be included. Advantageously, it may be provided that a further filter stage designed as a liquid separator is arranged upstream of the second filter stage. This further filter stage comprises at least one further separating element. The first and the further separating elements may share a frame and / or a liquid guide device and / or a liquid collection device. The separating elements may be of the same or different types.In one embodiment, it can be provided that the separating element of the first filter stage is designed as a coalescer for the coagulation of liquid droplets and the further separating element of the further filter stage is designed as a hydrophobic sieve.

[0028] According to the invention, a flue gas filter according to claim 16 is further comprised, comprising a filter inlet and a filter outlet, and a filter chamber in the flow direction between the filter inlet and the filter outlet. A filter element according to one of the preceding claims is arranged in the filter chamber such that, during operation, the flue gas flowing into the flue gas filter passes through the filter element. The filter element is sealed such that the flue gas flowing into the flue gas filter during operation passes through the filter element. In one embodiment, the filter element is detachably connected to the flue gas filter. This allows for regular replacement of the filter element to ensure the most hygienic working environment possible.

[0029] According to claim 17, a treatment device is claimed, comprising a tool designed to apply thermal treatment to a human or animal body, in particular for separating organic material, and a fume extraction device, wherein the fume extraction device has an intake port located adjacent to the tool, such that fume gases released during the thermal treatment are drawn through the intake port into the fume extraction device, wherein the fume extraction device includes a fume filter for cleaning the fume gases, and wherein the fume filter contains a filter element according to any one of claims 1 to 15. Such fume filters are used in the medical field, particularly in surgery, during surgical procedures.The use of the treatment device can include not only medical, especially surgical, procedures, but also cosmetic and other, including non-invasive, procedures or treatments where a thermal effect is achieved. The thermal effect can also be generated by a mechanical tool, such as the use of surgical motors in orthopedics or traumatology for performing sternotomies.

[0030] According to claim 18, the invention claims the use of a flue gas filter in a therapeutic, in particular surgical, field, wherein the flue gas filter includes a filter insert according to one of claims 1 to 15.

[0031] Further features, details and advantages of the invention will become apparent from the wording of the claims and from the following description of exemplary embodiments with reference to the drawings. The drawings show: Fig. 1 a longitudinal section view through a first embodiment of a filter insert, Fig. 2 a longitudinal section through a second embodiment of a filter insert, Fig. 3 a longitudinal section through a third embodiment of a filter insert, Fig. 4 a longitudinal section through a separating element and a liquid collection device, Fig. 5 a longitudinal section through a first filter stage, Fig. 6 a section of a front view of a separating element with frame, Fig. 7 a sectional view of a frame with a separating element, Fig. 8 a longitudinal section through a fourth embodiment of a filter insert, and Fig. 9 a longitudinal section through a fifth embodiment of a filter insert

[0032] Fig. Figure 1 shows a longitudinal section through a filter element 1 for a flue gas filter, which has an insert housing 2 with an inlet 3 and an outlet 4. When flue gas flows in the direction of flow SR through the inlet 3, the flue gas passes a separating element 8 of a first filter stage 5, which is connected to the insert housing 2 in a frame 15. Any liquid separated in this process is transported via a liquid guide 10 to the liquid collection device 9. Downstream of the first filter stage 5 is a second filter stage 6, which is kept apart from the first filter stage 5 by a spacer 11 attached to the frame 15. Downstream of the second filter stage 6 is a third filter stage 7.The three filter stages are spatially separated from the liquid collection device 9 by an intermediate wall 13, the liquid collection device 9 extending over the entire longitudinal axis and having a correspondingly large liquid intake capacity.

[0033] Fig. Figure 2 shows a longitudinal section through a filter insert 1 comprising an insert housing 2, an inlet 3, and an outlet 4. A separating element 8 of a first filter stage 5 is followed by a second filter stage 6 and a third filter stage 7. The separating element 8 is inclined at an angle opposite to the flow direction from the inlet 3 to the outlet 4 to allow the separated liquid to drip off. The liquid drips into a liquid collection device 9, which is located upstream of the three filter stages. Furthermore, liquid separated by the separating element 8 is directed by a liquid guide 10 into the liquid collection device 9. An intermediate wall 13 located below the separating element 8 separates the liquid collection device 9 from the second filter stage 6 and the third filter stage 7.Furthermore, a frame 15 surrounding the separating element 8 has a spacer 11 that separates the first filter stage 5 from the second filter stage 6. The liquid is guided over the frame 15 as a liquid guide 10.

[0034] Fig. Figure 3 shows a longitudinal section through a further filter insert 1, comprising an insert housing 2, an inlet 3, and an outlet 4. A separating element 8 is held in a frame 15, which holds a further separating element 12 and includes a spacer 11 for spacing the subsequent second filter stage 6. The further separating element 12 differs in its design from the separating element 8. A liquid guide 10 directs the liquid separated by the separating element 8 and the further separating element 12 into a liquid collection device 9. The liquid collection device 9 is separated from the second filter stage 6 and the third filter stage 7 by an intermediate wall 13. The liquid is guided over the frame 15, which serves as the liquid guide 10.

[0035] Fig. Figure 4 shows, in a longitudinal section, a separating element 8 which is held in a frame 15. The frame 15 has a spacer 11 at each of its opposite ends. Separated liquid is directed via a liquid guide 10 into a liquid collection device 9. This has a storage medium 16 which absorbs the liquid, as well as a cover 14 to protect the separated liquid from contamination before the first filter stage 5 and subsequent filter stages.

[0036] Fig. Figure 5 shows a longitudinal section through a first filter stage 5. A separating element 8 is held in a frame 15, the frame 15 forming spacers 11 at opposite ends of the separating element 8.

[0037] Fig. Figure 6 shows a section of a front view of a frame 15 with a separating element 8, wherein the frame 15 has a raised section 17 to prevent backflow of separated liquid. The frame 15 is fixed to an insert housing 2. A liquid guidance device 10 has adjacent guide channels 18 for draining the liquid from the separating element 8 into a liquid collection device 9 (in Fig. (6 not shown). The surfaces of the guide channels 18 facing away from the liquid collecting device 9 are angled to the flow direction SR such that the liquid flows into the liquid collecting device 9 via the guide channels 18 due to gravity.

[0038] Fig. Figure 7 shows a sectional view of a frame 15 with a separating element 8, wherein a liquid guiding device 10 has adjacent guide channels 18 that direct the separated liquid into a liquid collecting device 9 (in Fig. (7 not shown) guide. Furthermore, the frame 15 forms two spacers 11.

[0039] Fig. Figure 8 shows a longitudinal section of a fourth embodiment, wherein a filter insert 1 is designed approximately annularly around an annular axis and has two separation elements 8, each held in a frame 15. The frames 15 each have a liquid guide 10, through which separated liquid is directed into a liquid collection device 9. The liquid collection device 9 is formed by the frames 15 and part of an insert housing 2. The frames 15 also function as an intermediate wall 13 for separating the separated liquid from a subsequent second and third filter stage 6, 7. Furthermore, the frames 15 serve as spacers 11 to distance the separation elements 8 from the second and third filter stages 6, 7.In this embodiment, the fluid flow direction SR is given axially into the ring through an inlet 3 into the filter insert 1 and approximately radially through the separating elements 8, the subsequent filter stages 6, 7, and an outlet 4 out of the filter insert 1. In an alternative embodiment, the separating element 8 can also be designed at least substantially ring-shaped. In a further embodiment, a filter insert 1, similar to the one described above, can be used. Fig. 8, be designed in a mirror-symmetrical manner with respect to a plane running perpendicularly through the inlet 3, so that this embodiment, unlike the fourth embodiment, comprises two second and third filter stages 6, 7 each.

[0040] Fig. Figure 9 shows a fifth embodiment of a filter insert 1, wherein an intermediate wall 13 serves to separate liquid located in a liquid collection device 9 from a subsequent second and third filter stage 6, 7. This differs from the first embodiment in Fig. 1, the intermediate wall 13 also serves as a spacer 11 to keep the second filter stage 6, which is downstream in the direction of flow SR, at a distance.

[0041] All embodiments and representations shown in the figures can include a storage medium 16 in the liquid collecting device 9.

[0042] The invention is not limited to one of the embodiments described above, but can be modified in many ways.

[0043] All features and advantages arising from the claims, the description and the drawing, including design details, spatial arrangements and process steps, can be essential to the invention both individually and in various combinations. Reference symbol list 1 filter insert 2 insert housings 3 Entrance 4 outlets 5 First filter stage 6 Second filter stage 7 Third filter stage 8 Separation element 9 Liquid collection device 10 Liquid guidance system 11 spacers 12. Additional separating element 13 Intermediate wall 14 Cover 15 frames 16 Storage medium 17 Frame increase 18 guide channels SR Flow direction

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