GB2258404A

GB2258404A - A chemical cartidge for breathing apparatus

Info

Publication number: GB2258404A
Application number: GB9220172A
Authority: GB
Inventors: Volker Hunnebeck
Original assignee: Auergesellschaft GmbH
Current assignee: Auergesellschaft GmbH
Priority date: 1992-09-24
Filing date: 1992-09-24
Publication date: 1993-02-10
Anticipated expiration: 2012-09-24
Also published as: GB2258404B; GB9220172D0

Abstract

Chemical cartridge for breathing equipment comprising a casing 5 accommodating an oval container 3. A duct 6 is formed between the casing 5 and the container 3 in order to allow exhaled gas which enters the cartridge through an upper end to enter the container 3 via air permeable upper and lower end faces 4a and 4b and an air permeable side surface 4c. A chemical such as potassium peroxide accommodated within the container 3 converts the exhaled carbon dioxide and water vapour into oxygen. Gas flows out of the container via nozzles 7 having air permeable portions 7b which are interconnected via a cavity 8 having air permeable side walls 8b. A space 9 holding the chemical is formed between the bottom of the container and the cavity. The arrangement ensures uniform reaction by all of the chemical and a uniform distribution of temperature in the cartridge. <IMAGE>

Description

CHEMICAL CARTRIDGE FOR BREATHING APPARATUS The invention relates to a chemical cartridge for breathing equipment such as a gas mask of the type which contains a chemical which combines with carbon dioxide and water vapour in axhaled air which passes through peripheral surfaces of the chemical and is discharged through a tube.

A chemical cartridge of this kind is known from DE 26 35 376 C2. In this known embodiment, the chemical is bounded by a container and exhaled air flows through a top end face and a side surface of the container into the chemical, is converted into breathable air and travels through a peripherally perforated central tube into a respirator bag.

One disadvantage of this is that since the central tube is disposed at the centre of the chemical contents, the edge portions of the chemical near the bottom of the container are not completely flowed through by the exhaled air, and so the chemical is not used in an optimum manner.

The aim of the invention therefore is to improve a chemical cartridge of the initially mentioned kind so that all edge regions of the chemical are efficiently flowed through by the exhaled air and are fully used for oxygen production.

Thus according to the invention there is provided a chemical cartridge for gas mask and breathing equipment, comprising a chemical accommodated in a container which chemical combines with carbon dioxide and water to produce oxygen, exhaled air travelling through a top end face and a side face of the container into the chemical and being discharged through a tube wherein a) the exhaled air also flows into the chemical through a bottom end face of the container of the chemical cartridge, and b) two nozzles for discharging the exhaled air are provided together with a cavity connected between the nozzles for flow purposes, and the nozzles project into the chemical so that a space for holding the chemical exists between a bottom surface of the cavity and a bottom end face of the container.

The main advantage of the invention is that a given quantity of chemical for producing oxygen can be fully used and a required minimum holding time for the breathing equipment can be ensured.

Other advantageous features of the invention are disclosed in the sub-claims.

The invention will be examined in detail with reference to an embodiment shown in the drawings, in which: FIG. 1 is a diagram of the chemical cartridge according to the invention; and FIG. 2 is part of a view in the direction A of Fig.

1.

As shown in Fig. 1, the breathing apparatus operates on recycled air and comprises a chemical cartridge 1 which contains a chemical (potassium peroxide) which gives off oxygen when acted upon by carbon dioxide and moisture from exhaled air flowing through it.

The chemical 2 is disposed in an oval container 3 which has top and bottom perforated end faces 4a and 4b and a perforated side surface 4c. The surfaces 4a, 4b and 4c which bound the chemical contents constitute the exhaledair inflow surface. The container 3 is disposed in the casing 5 of cartridge 1. A passage 6 for exhaled air is formed between the inner wall of casing 5 and the two end faces 4a, 4b and the side surface 4c of the container 3.

The exhaled air outflow surface includes two nozzles 7 which project into the chemical 2 and comprise a short unperforated portion 7a and an adjacent air-permeable longer portion 7b which is perforated. The shorter un-perforated portion extends through the base surface 5a of the casing 5 the bottom surface of the container into the chemical 2, and is connected to a respirator bag (not shown in the drawings). The air permeable portions 7b of the two nozzles 7 are interconnected, for flow purposes through a cavity 8 bounded by air permeable side walls 8b. These permeable side walls constitute further exhaled air outflow surfaces. The side walls bounding the rectangular cavity 8 supported by the nozzles 7 projects from the base surface 5a into the casing 5 and thus leave a space 9 for holding the chemical 2.Due to this arrangement the nozzles 7a, 7b and the cavity 8 are completely surrounded by the chemical. This enables the exhaled air to flow through the bottom end face 4b of the container 3 into the chemical as well as through the top end face and the side surface 4c.

The shortest distance between a point on the air permeable peripheral surface of the nozzles and the top and side surfaces 4a and 4c respectively of the container 3 is approximately the same for all points on the said air permeable peripheral surface 7b.

The flow through the chemical cartridge 1 is indicated by arrows. The exhaled air flows only once through the chemical 2, which is heated by the reaction, so that the temperature of the exhaled air at the outlet 7a is low. The exhaled air flows through the chemical contents 2 from all sides, i.e. through a large inflow surface 4 including the two end faces 4a and 4b and the side surface 4c, whereas the outflow occurs through the two nozzles 7, i.e. over a small surface area. This advantageously brings about a uniform reaction by all the chemical, from the exterior towards the interior, together with uniform distribution of heat.

Claims

CLAIMS:

1. A chemical cartridge for gas mask and breathing equipment, comprising a chemical accommodated in a container which chemical combines with carbon dioxide and water to produce oxygen, exhaled air travelling through a top end face and a side face of the container into the chemical and being discharged through a tube wherein a) the exhaled air also flows into the chemical through a bottom end face of the container of the chemical cartridge, and b) two nozzles for discharging the exhaled air are provided together with a cavity connected between the nozzles for flow purposes, and the nozzles project into the chemical so that a space for holding the chemical exists between a bottom surface of the cavity and a bottom end face of the container.

2. A chemical cartridge according to claim 1, wherein the cavity is in the form of a chamber with closed sides.

3. A chemical cartridge according to claim 1 or claim 2, wherein the chemical is disposed in an insertable container having perforated end faces and a perforated side surface.

4. A chemical cartridge according to any preceding claim wherein the container is in a casing of the cartridge and a duct is formed between an inner wall of the casing and the end faces and the side surface of the container.

5. A chemical cartridge according to claim 4 wherein the nozzles each have a short air-tight portion and an adjacent air-permeable longer portion, the short portion extending through a base surface of the casing and the bottom end face of the container to project into the chemical.

6. A chemical cartridge according to claim 5 wherein the two nozzles are connected for air flow purposes in the region of the air-permeable tube portion by a cavity bounded by air permeable walls.

7. A chemical cartridge according to any preceding claim wherein the shortest distance between a point on an air permeable surface of the nozzles and the top and side surfaces of the container is approximately the same for all points on the said surface.

8. A chemical cartridge substantially as hereinbefore described with reference to figures 1 and 2.