DE977558C - Transparent filter insert for breathing apparatus - Google Patents

Description

ISSUED FEBRUARY 2, 1967

B 46830 VIb / 61 b

The invention relates to a transparent filter insert for breathing apparatus with automatic Display of the state of exhaustion, the exhaustion being indicated by the color change of an indicator layer is displayed on part of the adsorbent medium.

Filter cartridges of this type in which a certain indicator layer is applied to part of the adsorbent material is applied to the exhaustion of the filter element compared to a certain Indicate harmful gas are known per se. However, such filter cartridges have the disadvantage that they can only be used if the occurrence of only one very specific one Harmful gas is possible, as z. B. may be the case in industrial companies. Can on site different types of harmful gases occur in the filter insert, the known filter inserts are unusable, since the user of the respiratory protective device is not responsible for every possible exhaustion of the The filter insert causes one of the harmful gases to replace the filter insert will. This disadvantage is both for the use of the filter insert in industrial plants, but especially important for use in war and catastrophes, since the The type of harmful gases that may occur cannot be determined in advance.

The object of the invention is to eliminate this disadvantage and to create a filter insert that in the case of the possible occurrence of various harmful gases, exhaustion for the user of the respiratory protective device of the filter insert shows against one of the possibly existing harmful gases, so

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that the latter can replace the exhausted filter element with a new one.

Different types of indicator layers that contrast the exhaustion of a filter by changing color Show certain harmful gases or types of harmful gases are known. With filters for protection against acid gases it is z. B. known, the adsorption medium representing the activated carbon with a alkaline coating with Congo red as an indicator to ίο provided. When exposed to acidic gases, it strikes Indicator from red to blue, this blue coloration being constant. For filters to protect against alkaline gases, it is known that the adsorption medium representing the activated carbon body with a acidic coating, with Congo red also being used as an indicator. Upon exposure alkaline pollutant gases show a color change from dark blue to red.

To solve the problem it is proposed according to the present invention that different Zones of the adsorption medium with different types of pollutant gas groups appealing, known indicator layers are coated.

The selection of the different types to be arranged side by side in one filter insert at the same time Indicator layers are used for the intended purpose of the filter insert vote, the number of different indicator layers to be arranged side by side at the same time in the case of warfare agent filter cartridges for military purposes, of course, is greatest because the type of pollutant gases that may occur cannot be determined in advance for this application can.

One way of technical implementation of the invention is that not all of the Filling necessary absorption medium is coated with an indicator layer, but that only two or more thin layers of coated absorption medium near the mouthpiece are provided will. For example, if the entire layer of the absorption medium has a thickness of 30 mm has, a 5 to 10 mm thick layer near the mouthpiece can be provided with various types of indicators exist in superimposed layers or in adjacent sectors, and in such a way that each layer or each sector has a different type of cladding and thus an indication contains. In this way, a specific indication is created for several different pollutant gases. If the color change has occurred in a shift or in a sector, the filter element applies as exhausted. When stacked on top of one another, the indicator layers must be thin overall so that the absorption medium is used to the last.

The individual differently sheathed zones of the absorption medium can be mixed or in the direction of the airway separated from each other so that they are introduced as thin-walled Layer against the inner surface of the filter element wall. The separation of the jacketed from the uncoated coal can be in a simple mechanical way by means of permeable Partitions are made. Once the mixture or a layer of coated charcoal is near the mouthpiece discolored, the filter is used up.

Protection for the particular type of arrangement claimed in the context of the present invention the absorption media provided with various types of indicator layers in layers or Sectors should only apply within the framework of the main claim.

Some exemplary embodiments of the invention are shown in the drawings.

Fig. Ι shows a conventional view of a filter container Design, the wall of which is partially transparent, with several near the mouthpiece Layers of absorption media provided with different types of indicator layers are provided are;

FIG. 2 shows the filter container according to FIG. 1, here those with different types of indicator layers provided zones of the absorption medium are sectors of a layer;

Fig. 3 is a section along the line AB in Fig. 2;

4 shows the arrangement of the absorption medium provided with various types of indicator layers in zones, which represent the sectors of a circular ring, and

Fig. 5 is a section on the line Ct-D in Fig. 4.

Fig. Ι shows a view of a filter container 1 conventional design with a circular cross-section, at least in the part designated by 2 of its essentially cylindrical circumference is transparent. The assigned to this peripheral part 2 The cylindrical interior space 3 is filled with activated carbon which is the absorption material. With 4 is denotes the cylindrical interior of the filter container 1, which contains the usual HEPA filter. S is the part of the filter container 1 provided with the corresponding external thread in the usual way, with which it can be screwed into the breathing apparatus. There are several in area 2 near the mouthpiece thin layers 7, 8, 9 of variously coated activated carbon separated according to the type of coating arranged one behind the other.

In Figs. 2 and 3, an embodiment is shown in which only one near the mouthpiece, from with various indicators encased absorption medium existing top layer 6 provided, which is divided into eight different sectors 10 to 17, of which each individual sector is one contains certain type of encased absorption medium.

4 and 5 show an embodiment in which one of the outer circumference of the absorption medium forming, the inner surface of the wall of the filter container in the direction of the airway adjacent layer 18 is provided in any thickness of coated absorption medium, wherein this ring cross-section having layer 18 is divided into ring sectors 19, 20, 21 and 22, of

each of which contains a certain type of jacketed absorbent medium. The one from the ring cross-section Having layer 18 enclosed cylindrical interior space 23 is with normal activated carbon filled.

The separation of the individual layer or sector zones of the differently coated medium from each other and optionally from the other uncoated absorption media in all cases by means of gas-permeable walls.

Claims (5)

PATENT CLAIMS: ι. Transparent filter insert for breathing apparatus with automatic display of the state of exhaustion, the exhaustion being indicated by a change in color of an indicator layer on part of the absorption medium, characterized in that different zones of the absorption medium are encased with different types of indicator layers that respond to different types of harmful gas groups and are known per se. 2. Filter insert according to claim 1, characterized in that that the part of the absorption medium provided with different types of indicator layers of two or more thin, arranged near the mouthpiece, according to the different Indicator layer types separate layers (7, 8, 9) of the absorption medium. 3. Filter insert according to claim 1, characterized in that that the part of the absorption medium provided with different types of indicator layers consists of a layer (6) of the absorption medium, which is divided into sectors (10 to 17), the indicator layer of the absorbent material in the individual Sectors the same, but different from sector to sector. 4. Filter insert according to claim 1, characterized in that that the part of the absorption medium provided with different types of indicator layers is an annular layer (18) surrounding the absorption medium and resting against the inside of the filter insert, which is shown in Ring sectors (19 to 22) is divided, the indicator layers of the absorption medium the same in the individual sectors, but differ from sector to sector. 5. Filter insert according to claim 1 to 4, characterized in that with different types Layers (7,8,9) or sectors (10 to 17; 19 to 22) provided with indicator layers the absorption medium through suitable partitions, e.g. B. Sieves, from each other and from not jacketed absorption medium are separated. Considered publications:
USA. Patent Nos. 1,537,519, 1,725,893. 1 sheet of drawings © 609 771/4 1.67