CN112203727A

CN112203727A - Breathing protective mask and filter housing for a breathing protective mask

Info

Publication number: CN112203727A
Application number: CN201980038167.8A
Authority: CN
Inventors: S·丹克特
Original assignee: Draeger Safety AG and Co KGaA
Current assignee: Draeger Safety AG and Co KGaA
Priority date: 2018-06-06
Filing date: 2019-05-14
Publication date: 2021-01-08
Also published as: EP3675969A1; WO2019233708A1

Abstract

The invention relates to a filter receptacle (16) for receiving a filter element (14) for a breathing mask. On the input side (18), the filter receptacle (16) comprises two flat impact elements (22, 24) which are arranged at a distance from one another and parallel and are arranged in front of the accommodated filter element (14). Each crash element (22, 24) comprises a plurality of longitudinal webs (26.1, 26.2) between which an opening (Ö 1, Ö 2) is formed. Each opening (Ö 1) in the one crash element (22) is arranged laterally offset with respect to each opening (Ö 2) in the other crash element (24) so that at least one curved fluid channel (F1, … …) is formed.

Description

Breathing protective mask and filter housing for a breathing protective mask

The present invention relates to a filter housing capable of housing at least one filter unit. The filter receptacle and the received filter unit belong to a breathing mask.

With the aid of such a breathing protective mask, the user can stay in an environment in which the ambient air is contaminated with droplets and/or particles and/or harmful gases and work there. The or each filter unit of the respiratory protection mask filters harmful substances from the ambient air. Thereby providing the user with cleaned ambient air. Optionally, the user carries his own source of breathing air, such as an oxygen cylinder. The breathing protective mask can be used, for example, in painting lines or in mining or on construction sites or for rescue in the case of fire.

The filter housing 7 of the document DE 93001811U 1 has a front panel 22 with a plurality of air inlet openings 23 on the input side. Behind the front plate 22, a plurality of impact plates 24 are arranged, wherein each impact plate 24 is arranged behind an air inlet opening 23. The fluid entering through the air inlet opening 23 is deflected by the collision plate 24.

The sealed filter housing a of the document DE 734496 accommodates a filter d and has an access opening in the form of an access nipple b. Viewed in the direction of entry, a plurality of impingement lamellae c are arranged behind the entry nipple b one behind the other, wherein each impingement lamella c is formed by a fan-shaped blade. The greater the distance from the flow axis (Str) the greater the free cross-section. The crash lamellae c are arranged offset one behind the other. Thereby, the air flowing through is deflected a plurality of times and the particles are thrown onto the collision sheet c.

Fig. 6 of document WO 2017/004313 a1 shows a breathing protective mask (respirator 300) with two filter housings (filter cartridge houses 60) each accommodating a filter cartridge 1. Each filter housing 60 has a front side (front side 61) and a rear side (rear side 62), respectively. The portion (second housing port 65) on the rear side 62 has an area 63 with a number of air passages and can be opened and closed relative to the remainder (first housing port 64) of the filter housing. A portion 56 of the remainder 64 has a region 52 with a plurality of openings and presses the filter cartridge 1 into a receiving structure 66, see fig. 9 and 11. The openings in said areas 63 and 52 can be coordinated with each other, but this is not essential.

The object on which the invention is based is to provide a filter receptacle for receiving a filter element for a breathing protective mask, which filter receptacle protects the received filter element against contamination and is of simpler construction than known filter receptacles which comprise a contamination-protection device.

The invention is achieved by a filter receptacle with the features of claim 1. Advantageous embodiments are specified in the dependent claims. As used herein, references to features in respective dependent claims indicate further configurations of the subject matter of the independent claims and should not be construed as a disclaimer of independent specific protection for the combination of features of the respective dependent claims as referred to back. Furthermore, in view of the interpretation of the claims, further embodiments of the features in the dependent claims should be taken as a starting point: no such limitation is present in the respective preceding claims. The filter receptacle according to the invention can receive at least one filter element, wherein the filter receptacle and the filter element belong to a respirator mask.

The input side of the filter receptacle is directed toward the incoming fluid. On this input side, the filter receptacle comprises at least two flat impact elements. The two or at least two crash elements are arranged parallel to one another and at a distance from one another. The two crash elements are arranged one behind the other, as viewed in the inflow direction of the inflowing fluid, so that a front crash element and a rear crash element are formed. The or each received filter element is arranged behind the rear impact element and thus behind both impact elements.

Each crash element comprises a plurality of longitudinal slats. At least one opening is formed between each two adjacent longitudinal strips of the crash element. This opening is permeable to the incoming fluid. It is possible to construct a plurality of penetrable openings between two adjacent longitudinal slats.

Each opening in the front impact element is arranged laterally offset with respect to each opening in the or at least one rear impact element, as viewed in the inflow direction of the fluid into the filter receptacle. By "laterally offset" is meant that, in the inflow direction, the longitudinal strips follow the openings and/or the openings follow the longitudinal strips. At least one fluid channel for the inflowing fluid is thus formed. This fluid channel leads through an opening in the front crash element and through a laterally offset opening in the rear crash element.

Due to the openings in the two impact elements, ambient air can reach the accommodated filter element starting from the input side. The filter element is capable of purifying the ambient air. The user is able to provide himself with purified breathing air on the basis of his own breathing efforts. Thanks to a breathing protective mask with the filter unit, the user does not need to carry a breathing air supply device.

However, not only gaseous ambient air but also solid and fluid particles, such as splash water, paint spray, dust particles or other coarse particles, which pass from the inlet side into the interior of the filter receptacle, arrive through the opening into the crash element. In the event that these solid and fluid particles reach the contained filter element, then they can contribute to contamination of the filter element. Thereby reducing the ability of the filter element to be used for filtration. Furthermore, the breathing resistance which must be overcome by the wearer of the breathing protective mask is increased.

One possibility for avoiding such undesirable effects is to protect the accommodated filter element by means of an externally accessible prefilter. The pre-filter filters out solid and fluid particles from the incoming ambient air. Due to the prefilter, the or each actual filter element arranged behind the prefilter, viewed in the inflow direction, can be used longer.

A disadvantage of such a prefilter is that the filter receptacle then has to have an additional receptacle for the prefilter. Furthermore, the prefilter has to be replaced relatively frequently, which leads to reduced availability due to the interruptions in operating time that are necessary for this purpose. The user must carry multiple prefilters with him.

The invention achieves the following advantages: the contained filter element is at least partially protected from solid and fluid particles without the need for a separate pre-filter. In contrast, at least two crash elements with laterally offset openings serve as prefilters themselves. The usability of a breathing protective mask with a filter housing according to the invention is increased because the prefilter does not have to be replaced. However, the present invention may also be used in combination with a separate pre-filter.

The pre-filter increases the breathing resistance and increases the weight of the filter receptacle, particularly as the pre-filter absorbs or otherwise receives particulates. The present invention also avoids this disadvantage. A further advantage of the filter holder according to the invention without a prefilter compared to a filter holder with a prefilter is that filter holders without a prefilter can be manufactured more easily. Since no receptacle for the prefilter needs to be installed when manufacturing the filter receptacle according to the invention.

Solid or fluid particles which flow into the interior of the filter receptacle according to the invention from the input side together with the ambient air cannot impinge on the received filter element along a straight path; but rather the particles are deflected laterally due to the laterally offset openings and the or a curved inflow channel. In many cases, the particles thus either rest adhesively or adhesively on the longitudinal webs or on other components of the filter receptacle or are reflected again by the filter receptacle. In other cases, the particles are at least deflected and impinge on the filter element with reduced kinetic energy. The filter receptacle itself serves as a first separation stage for fluid and solid particles.

The invention provides a plurality of degrees of freedom in order to adapt the filter receptacle to the given requirements. For example, the width of the longitudinal webs, the width of the openings, the lateral offset between the front and rear openings and the distance between the front and rear impact elements can be varied in such a way that, on the one hand, the breathing resistance is kept as low as possible and, on the other hand, as few particles as possible impinge on the accommodated filter element. The distance between the front impact element and the rear impact element is preferably between 1.5mm and 2.5 mm. The distance between two longitudinal strips and thus the width of the opening between the two longitudinal strips is preferably between 2mm and 3 mm.

Each opening of the rear impact element is preferably arranged behind a longitudinal slat of the front impact element. Due to the lateral offset, and in particular due to the preferred embodiment, no straight flow channels are formed from the outside to the accommodated filter element. But each fluid channel is bent at least once so as to deflect the incoming ambient air and preferably create a vortex. This solution further reduces the risk of the inflowing particles reaching the accommodated filter element.

According to the invention, each crash element comprises a plurality of longitudinal slats. In one embodiment, the at least one impact element comprises a plurality of transverse slats. The transverse slats are arranged perpendicularly or obliquely to the longitudinal slats of the crash element. The longitudinal and transverse slats of the crash element preferably lie in one plane or one surface, so that a lattice structure is formed. According to this solution, the transverse webs of the crash element are mechanically connected to the longitudinal webs of the other or the further crash element, respectively. This solution results in a particularly high mechanical stability of the filter receptacle. The risk of damage or even breakage of the external impact element due to mechanical loads acting from the outside is reduced.

In addition to the at least two crash elements, the filter receptacle preferably also comprises a circumferential wall. This surrounding wall encloses the part with the two crash elements and the accommodated filter element, more precisely preferably completely. The surrounding wall is fixedly connected to at least one crash element, preferably to both crash elements. The surrounding wall and the two impact elements together at least partially enclose a space in which a filter element is or can be accommodated.

In a further development of this solution, the surrounding wall and the part with the two crash elements are integrally formed, which further improves the mechanical stability. Preferably, these components are even integrally formed, that is to say they are produced in a single process step at the time of production. The process steps include, for example, injection molding (Spritzgie beta-en) or casting around (Umgie beta-en). This solution results in a fast and cheap manufacturing.

Different geometries of the longitudinal webs and thus of the openings are possible, wherein the filter receptacle according to the invention can also have a combination of a plurality of geometries. By selecting the desired geometry, the filter receptacle can be adapted to the expected use conditions.

In one embodiment, the filter receptacle according to the invention is a filter housing. Furthermore, the filter housing comprises a counter element (gegeneelement) which is fixedly connected to the filter receptacle according to the invention. The filter receptacle and the counter element together enclose a space in a fluid-tight manner. In which space at least one filter element is or can be accommodated. Preferably, the filter element is fixedly connected to the filter receptacle, for example by means of a mounting foam (Montageschaum) or another adhesive connection (klebeverberbindug) or by adhesive welding (klebschweii beta. en).

A filter unit comprises a filter housing with a filter receptacle according to the invention and at least one filter element which is arranged in the interior of the filter housing. A respiratory protection mask comprises a mask body and at least one filter unit with a filter housing according to the invention. The mask body may be placed over the face of the wearer. The or each filter unit of the respiratory protection mask is in fluid connection with the interior of the mask body.

The invention is described below with the aid of examples. To this end, the attached figures show:

fig. 1 shows a respiratory protection mask with a mask body and two filter units;

fig. 2 shows a filter receptacle according to the invention in a sectional view;

fig. 3 shows a first embodiment of a filter receptacle in a perspective view;

fig. 4 shows a second embodiment of the filter receptacle in the direction of view from the inside;

figure 5 shows said second solution of figure 4 in a cross-sectional view;

fig. 6 shows a third solution of a filter receptacle in a perspective view;

fig. 7 shows a fourth solution of the filter receptacle in a perspective view;

FIG. 8 illustrates, in cross-section, the fourth solution of FIG. 7;

fig. 9 shows a fifth solution of a filter receptacle in a perspective view;

fig. 10 shows a sixth solution of a filter receptacle in a perspective view.

Fig. 1 shows a respiratory protection mask 10 that is configured as a "full face mask" and includes a mask body 12 that can be positioned over the face of a wearer and held on the head by a wearer, not shown. A respiratory protection mask 10 according to the solution may also be constructed as a "half mask" or a "quarter mask". By means of the respiratory protection mask 10, the user can stay in a contaminated environment without a separate supply of breathing air (atemuluftwersorging). The respiratory protection mask 10 filters out unhealthy droplets, particles and gases from the incoming ambient air. The user inhales the filtered air.

Furthermore, the respiratory protection mask 10 of fig. 1 comprises a centrally arranged filter unit 15 and two laterally arranged filter units 13. Each

filter unit

13, 15 comprises a filter housing 16 and a counter element 17, respectively. The filter receptacle 16 and the counter element 17 are firmly and fluid-tightly connected to one another, for example by a welded joint, and together form a filter housing which encloses an interior space in which at least one filter element 14 is accommodated. This filter element 14 is illustrated in fig. 2 and is configured, for example, as a particle filter or coarse dust filter. The filter element 14 is firmly mounted in the interior of the filter receptacle 16, for example by means of a mounting foam (Montageschaum) or other adhesive connection.

It is possible to arrange two different filter elements 14 one after the other in the

filter housings

16, 17, for example, first a coarse dust filter and then a particle filter. The filter unit 13 can be designed as a particle filter which protects against particles in solid form and in fluid form (droplets) and acts as a splash protection against particles in fluid. The filter unit 13 can also be designed as a combination filter which likewise protects against particles in solid and fluid form and additionally against vapors and gases.

Each laterally arranged filter unit 13 is fastened to the mask body 12, for example, by means of a bayonet closure (bayonettverseschluss). This plug-in closure is preferably arranged in said counter element 17. The centrally arranged filter unit 15 is likewise fastened to the mask body 12 by means of a plug-in closure or, for example, by means of a screw closure (schraubversluss). Three of the

filter units

13, 15 are in fluid connection with the interior of the mask body 12.

Fig. 2 to 10 show different embodiments of the individual filter receptacles 16 according to the invention. The individual filter receptacles belong to a

filter unit

13, 15. The following components of the filter receptacle 16 are shown:

an inflow direction E along which the fluid flows from the outside into the filter unit 13 with the filter receptacle 16;

an output side 20 and an input side 18 with reference to the inflow direction E;

-a contained filter element 14;

a frontal impact element 22;

a rear impact element 24 and

a circumferential wall 29 on the outside of which a plurality of projections 30 are mounted, which facilitate the rotation of the filter receptacle 16.

The designations "forward" and "rearward" impact elements refer to the inflow direction E. The

crash elements

22 and 24 are arranged one behind the other, viewed in the inflow direction E. It is also possible for more than two crash elements to be arranged one behind the other.

The frontal impact element 22 comprises a plurality of frontal longitudinal slats 26.1, each of which extends in a longitudinal direction which is perpendicular to the drawing plane of fig. 2 and is arranged horizontally in the drawing planes of fig. 4 and 5. The rear crash element 24 comprises a plurality of rear longitudinal slats 26.2, which are arranged parallel to the front longitudinal slats 26.1. A slot-like opening Ö 1 is formed between two adjacent front longitudinal strips 26.1 and a slot-like opening Ö 2 is formed between two adjacent rear longitudinal strips 26.2. The opening Ö 1 of the front impact element 22 is laterally offset with respect to the opening Ö 2 of the rear impact element 24, as can be easily seen in the sectional view of fig. 2. Each front opening Ö 1 and at least one adjacent rear opening Ö 2 belong together in each case to a fluid channel F1, … … which is curved as a result of the lateral offset of the front opening Ö 1 with respect to the rear opening Ö 2. Each fluid passage F1, … … diverts the incoming airflow from the input side 18 at least once. This turning causes the flow of incoming ambient air to create a vortex (turbulante Verwirbelung).

The longitudinal webs 26.1 of the front impact element 22 are also offset laterally with respect to the longitudinal webs 26.2 of the rear impact element 24. In a viewing direction parallel to the inflow direction E, a rear longitudinal web 26.2 is present behind each front opening Ö 1, but no rear opening Ö 2 is present. The inflowing fluid, in particular the ambient air, can contain fluid droplets (flssigkeitstropfen) or larger particles, for example dust particles. The droplets or particles either strike the front longitudinal strip 26.1 or can pass through the front opening Ö 1 and then strike the rear longitudinal strip 26.2. In any case, the droplets or particles impinge on the longitudinal slats 26.1 or 26.2 or on areas outside the openings Ö 1, Ö 2. In many cases, the droplets or particles are deposited adhesively or adhesively on the longitudinal strips 26.1 or 26.2 or are reflected. In any case, the speed of movement of the droplets or particles is reduced, so that the droplets or particles do not impinge on the filter unit 13 at all or only at a relatively low speed.

In one embodiment, the frontal impact element 22 is fixedly connected to the surrounding wall 29, see fig. 2. The rear impact element 24 is fixedly connected to the front impact element 22. Or both impact

elements

22, 24 are directly connected to the wall 29. Preferably, the

crash elements

22 and 24 and the wall 29 are designed as single components, i.e. are designed in one piece, particularly preferably even integrally, i.e. the one

component

22, 24, 29 is produced in a separate process step, for example by injection molding.

The longitudinal strips 26.1, 26.2 and thus the openings Ö 1, Ö 2 can have different shapes. According to a first solution illustrated in fig. 3, each front longitudinal slat 26.1 has the shape of a bar, and each rear longitudinal slat 26.2 (not shown in fig. 3) likewise has the shape of a bar. The filter receptacle 16 of the first solution has a round shape and each

impact element

22, 24 extends in a plane.

The filter receptacle of the second solution, illustrated in fig. 4 and 5, has an oval and tapering shape. This solution adapts particularly well to the shape of the wearer's face. Fig. 4 shows a second variant of the solution in a viewing direction opposite to the inflow direction E, i.e. the inflow direction E is perpendicular to the drawing plane of fig. 4. Fig. 5 shows the second solution in a sectional view, and the inflow direction E is in the plane of the drawing of fig. 5. As can be seen in fig. 5, the two

crash elements

22, 24 are arched outward. The filter unit is better placed in the user's hand than a filter unit having a flat front surface. The curved longitudinal strips 26.1, 26.2 are likewise rod-shaped, but not parallel to one another. In contrast, two adjacent longitudinal strips 26.1 or 26.2 enclose an acute angle between them, which is preferably less than 10 °.

According to the second variant, the rear impact element 24 comprises, in addition to the longitudinal strips 26.2, transverse strips 27.2 which are fixedly connected to the rear longitudinal strips 26.2, so that a lattice structure is formed. A plurality of mechanical connecting elements 28 connect the transverse slats 27.2 to the front longitudinal slat 26.1 and extend parallel to the inflow direction E. Viewed in the viewing direction of fig. 4, the frontal impact element 22 is arranged behind the rear impact element 24, and the frontal opening Ö 1 and the filter element 14 are depicted by dashed lines. This solution results in a particularly high mechanical stability.

In a third solution, illustrated in fig. 6, the frontal impact element 22 comprises, in addition to the frontal longitudinal slats 26.1, transverse slats 27.1. The front openings Ö 1 thus form a matrix structure with rows and columns. The rear crash elements 24, which are covered by the front crash elements 22 in the illustration of fig. 6, can likewise have a matrix structure with rows and columns, or have another structure.

Fig. 7 and 8 show a fourth solution, in which the front longitudinal strip 26.1 and thus also the front opening Ö 1 radiate radially outward from the center point M. The inflow direction E is vertically oriented in the plane of the drawing in fig. 7 and is located in the plane of the drawing in fig. 8. The rear crash elements 24 can likewise have longitudinal slats radiating radially outward from a central point, or have another configuration.

In the fifth solution according to fig. 9, the front longitudinal strip 26.1 has a rounded or arched shape. This circle or circular arch is arranged concentrically around said centre point M. The rear impact element 24 can likewise have such a round or circular arch, or have another design. The filter receiving portion 16 again has an oval shape tapered in one direction.

In the sixth solution according to fig. 10, the front longitudinal strip 26.1 and the front opening Ö 1 formed thereby are again rod-shaped. A plurality of longitudinal slats 26.1 are arranged parallel to one another, the further longitudinal slats 26.1 radiating outwardly in a radial pattern from a central point M.

List of reference numerals:

10 breathing protective mask comprising a mask body 12 and two filter units 13

12 mask body of the respiratory protection mask 10

13 the filter unit of the respirator 10, which is arranged laterally and fastened to the mask body 12, comprises a filter receptacle 16, a counter element 17 and a filter element 14

14 filter element inserted into the filter receiving part 16

15 centrally arranged filter unit fastened to the mask body 12

16 filter housing, housing said filter element 15, comprising

impact elements

22 and 24 and a wall 29

17 counter element fixedly connected to the filter receiving part 16

18 input side of the filter housing 16

20 the output side of the filter housing 16

22 front impact element, comprising a plurality of front longitudinal slats 26.1

24 rear impact element comprising a plurality of rear longitudinal slats 26.2

26.1 longitudinal strip of the frontal impact element 22

26.2 longitudinal slats of the rear crash element 24

27.1 transverse web of the frontal impact element 24

27.2 transverse web of the rear crash element 24

28 mechanical connecting element between the rear transverse slat 27.2 and the front longitudinal slat 26.1

29 surrounding wall sections of the filter receptacle 16 are fixedly connected to the two

crash elements

22 and 24

30 on the outside of the wall 29

E direction of inflow of fluid into said filter unit 13

F1, … … extend through the fluid channels of the two

crash elements

22, 24 and are each guided through an outer opening Ö 1 and an inner opening Ö 2

M center point of the round frontal impact element 22 of the fourth solution.

Claims

1. A filter receptacle (16) for receiving at least one filter element (14) for a breathing mask (10),

wherein the filter receptacle (16) comprises at least two flat impact elements (22, 24) on the input side (18) directed toward the inflowing fluid,

wherein the two or at least two crash elements (22, 24)

-parallel to each other,

At a distance from each other, and

-one after the other and in front of the accommodated filter element (14) as seen in the inflow direction (E) of the inflowing fluid

Is arranged to be placed in a manner such that,

wherein each crash element (22, 24) comprises a plurality of longitudinal slats (26.1, 26.2),

wherein at least one opening (Ö 1, Ö 2) that is permeable to the inflowing fluid is formed between each two adjacent longitudinal webs (26.1, 26.2) of a crash element (22, 24),

wherein each opening (Ö 1) in one crash element (22), viewed in the inflow direction (E), is arranged laterally offset relative to each opening (Ö 2) in the other crash element (24), and

at least one fluid channel (F1, … …) is formed, which leads through an opening (Ö 1) in the one crash element (22) and through a laterally offset opening (Ö 2) in the other or the other crash element (24).

2. Filter receptacle (16) according to claim 1,

it is characterized in that the preparation method is characterized in that,

each opening (Ö 2) of the or a rear impact element (24), viewed in the inflow direction (E), is arranged behind a longitudinal web (26.1) of the front impact element (22).

3. Filter receptacle (16) according to one of the preceding claims,

it is characterized in that the preparation method is characterized in that,

the one crash element (24.2) comprises transverse slats (27.2) which are arranged vertically or obliquely on longitudinal slats (26.2) of the crash element (24.2),

wherein the transverse web (27.2) is mechanically connected to at least one longitudinal web (26.1) of the other or of the other crash element (22).

4. Filter receptacle (16) according to one of the preceding claims,

it is characterized in that the preparation method is characterized in that,

the filter receptacle (16) comprises a surrounding wall (29),

wherein the surrounding wall (29)

-surrounds the two crash elements (22, 24) and

is fixedly connected with at least one crash element (22, 24) and

wherein the surrounding wall (29) and the two impact elements (22, 24) together at least partially enclose a space for accommodating at least one filter element (14).

5. Filter receptacle (16) according to claim 4,

it is characterized in that the preparation method is characterized in that,

the surrounding wall (29) and the two crash elements (22, 24) are integrally formed, in particular produced by an injection molding method.

6. Filter receptacle (16) according to one of the preceding claims,

it is characterized in that the preparation method is characterized in that,

the opening (Ö 1, Ö 2) of at least one crash element (22, 24) and/or the or at least two longitudinal webs (26.1, 26.2) extend radially outward from the center (M) of the filter receptacle (16).

7. Filter receptacle (16) according to one of the preceding claims,

it is characterized in that the preparation method is characterized in that,

the opening (Ö 1, Ö 2) of the at least one crash element (22, 24) and/or the or at least two longitudinal webs (26.1, 26.2) are arranged parallel to one another or each enclose an angle of at most 10 °.

8. Filter receptacle (16) according to one of the preceding claims,

it is characterized in that the preparation method is characterized in that,

the opening (Ö 1, Ö 2) of at least one crash element (22, 24) and/or the or at least two longitudinal webs (26.1, 26.2) are arranged concentrically around a point (M) on the crash element (22, 24).

9. Filter receptacle (16) according to one of the preceding claims,

it is characterized in that the preparation method is characterized in that,

the openings (Ö 1, Ö 2) of at least one crash element (22, 24) and/or the or at least four longitudinal slats (26.1, 26.2) are arranged in rows and columns in a matrix-like manner.

10. A filter housing comprising

-a filter housing (16) according to any one of the preceding claims, and

-a counter element (17) connected with the filter housing (16),

wherein the filter receptacle (16) and the counter element (17) together completely enclose a space in a fluid-tight manner for receiving at least one filter element (14).

11. A filter unit (13, 15) comprising

The filter housing of claim 10, and

at least one filter element (14),

wherein the or each filter element (14) is accommodated in a space enclosed by the filter accommodation (16) and the counter element (17).

12. Respiratory protective mask (10) comprising

-a mask body (12) that can be placed on the face of a wearer of the respiratory protection mask (10), and

-at least one filter unit (13, 15) according to claim 11,

wherein the or each filter unit (13, 15) is in fluid connection with the mask body (12).