JPH0299078A - Respiration apparatus - Google Patents

Abstract

PURPOSE: To eliminate cooling operation of a respiration device before use, by composing a radiating element by a material with phase transition temperature at a specific temperature and capable of performing at least one heat absorptive solid/solid or solid/liquid phase transition. CONSTITUTION: In order to protect each human being from harmful environment, respiratory gas is supplied from a respiratory gas supply source to individual human being and the gas is cooled by a radiating element made of a material with the phase transition temperature 20-100 deg.C and capable of performing one of heat absorbing solid/solid or solid/liquid phase transition. The material can be a polymer of an organic compound such as camphene, naphthalene or stearic acid or, for example, a metal alloy such as Wood's metal (50% of bismuth, 25% of lead, 12% of tin and cadmium 12.5%). A preferable material is wax, more preferably wax with a melting point of 20-100 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to breathing apparatus, and more particularly to a breathing apparatus having a heat sink for cooling breathable gas.

BACKGROUND OF THE INVENTION Respiratory apparatus for protecting an individual from the effects of a harmful environment may consist of a filter that removes toxic or harmful substances from the air in the harmful environment, such that it can be inhaled by the individual. becomes. During fire-related emergencies, this type of filter is required to remove harmful gases such as carbon monoxide as well as soot and smoke particles. This type of breathing apparatus can have the disadvantage that the air drawn in through the filter becomes hot in a fire-related emergency.

Additionally, if the filter removes toxic or harmful gases due to an exothermic reaction, the air is further heated.

Respiratory equipment that protects individuals from harmful environments prevents toxic or harmful gases (e.g. - carbon oxides) from recirculating breathing gases.
It may consist of a closed-loop or partially closed-loop breathing system with a filter to remove. As this breathing gas circulates, it can become increasingly heated, especially if the filter removes toxic gases by exothermic reactions.

Heat sinks for cooling breathing gas are known, which use liquid/gas, solid/gas and solid/liquid endothermic phase transitions.

For example, UK Patent Application No. 2,122,907 relates to the use of forced vaporization of liquids; UK Patent Application No. 2.038 relates to the use of forced vaporization of liquids;
．． No. 188 relates to the use of solid carbon dioxide or ice, and British Patent Application No. 2,151,490 relates to the use of ice water. Heat sinks of this type have the disadvantage that they are difficult to store and may require cooling, especially before use.

[Means for Solving the Problems] Therefore, according to the present invention, a breathing system comprising a means for supplying breathable gas to an individual and a heat sink arranged to remove heat from the breathable gas is provided. A breathing apparatus characterized in that the heat sink is made of a material capable of undergoing at least one endothermic solid/solid or solid/liquid phase transition having a phase transition temperature between 20°C and 100°C. provided. Preferably, the phase transition temperature is between 40°C and 80°C.

Further, according to the present invention, when protecting an individual from a harmful environment, a respirable gas is supplied to the individual from a respirable gas source, and the gas is supplied to the individual from a breathable gas source, and the gas is supplied to the individual from 20°C to 100°C, preferably from 40°C to 80°C. A method of protection is provided which consists in cooling a gas by means of a heat sink made of a material capable of undergoing at least one of an endothermic solid/solid or solid/liquid phase transition with a phase transition temperature of .

The breathable gas supply means may consist of at least one filter capable of removing toxic or noxious gases originating from the environment or from the air inhaled from a closed loop or partially closed loop breathing gas source.

The material can be a polymer, an organic compound such as camphene, naphthalene or stearic acid, or an organic compound such as Woods Metal (50% bismuth, 25% lead).
%, 12.5% tin and 12.5% cadmium). Preferably the material is wax, most preferably the wax is between 20°C and 100°C
It shall have a melting point of This wax is animal-based,
It can be a vegetable or mineral wax, most preferably a microcrystalline wax. The wax may be a mineral wax having reference number Gera Wax 1301 and supplied by Gera Wax Ltd, Chorley, Lancashire.

Materials can be included in the heat sink having tortuous passageways through which breathable gases can flow. The material can be contained in a heat sink consisting of one or more closed vessels in heat exchange relationship with a breathable gas. The container may form several compartments of a honeycomb structure. The container can be a plurality of interconnected cavities formed between two press sheets.

The material can be contained in a plurality of containers, such as a heat sink consisting of a sphere in heat exchange relationship with the filter and/or catalyst material of the breathing apparatus.

According to the present invention, there is provided a protective hood or suit arranged to cover an individual's head, the protective hood or suit comprising a breathing apparatus as described above. A protective hood or suit may be arranged to enclose all or part of an individual's body. The protective hood or suit may be made of heat-resistant plastic material.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention will now be described by way of example only and with reference to the accompanying drawings in which: FIG.

FIG. 1 shows a schematic cross-sectional view of an individual wearing a protective hood with a breathing apparatus consisting of a filter pack with a heat sink according to the invention; FIG. 2 shows the filter pack of FIG. FIG. FIG. 3 is an exploded view of the heat dissipation configuration as shown in FIG. 2. Figure 4 shows the second
FIG. 4 is a cross-sectional view of a portion of the heat sink as shown in FIG.

FIG. 1 shows a schematic cross-sectional view of an individual 1 wearing a protective hood 2. FIG. The hood 2 is constructed from a transparent, heat-resistant plastics material 4 and has a neck seal 3, which in use forms a substantially air-tight seal with the individual's neck. the hood 2 has a filter pack 5;
In use, air can be inhaled by the individual through this. The hood may have more than one filter pack.

The filter pack 5 of FIG. 1 is shown in a high-level cross-sectional view in FIG. do. The filter pack 5 comprises a layer of particle removal filter 8 and a layer of adsorbent and catalytic materials 9, 10.11 designed to remove or render harmless airborne toxic or harmful substances from the environment outside the hood in use. It consists of

Filter pack 5 includes a heat sink 12 . The heat sink 12 has a honeycomb structure with several passages 13 through which, in use, the air 17 that is inhaled by the individual through the filter pack 5 is transferred from the outside environment 16 to the hood. 0 that can pass to (I'I!115)
The honeycomb compartments 19 around the passages 13 are sealed and contain a wax 14 having a high heat capacity, for example supplied by Kerax Ltd., Chorley, Lancashire, reference number Gera Wax 1301. The wax has a latent heat capacity of about 2205 per gn and undergoes at least one phase transition between 50°C and 75°C; the wax has a solid/liquid phase transition as well as a solid/solid phase transition in this temperature range. It is believed that a phase transition can occur. The inner surface of the filter pack 5 has a layer of refractory flame/thermal material 18 adjacent to the inside 15 of the hood.

In use, the individual 1 wears the hood 2 on his or her head so that the neck seal 3 forms a substantially air-tight seal with the neck. The individual 1 inhales air 17, which may come from the outside environment 16 of the hood and be heated via the fire-related emergency lick filter pack 5. Filter 8
, adsorbents 9, 10 and catalyst 11 remove or render harmless toxic or noxious substances in the inhaled air by reactions, at least some of which are exothermic. The inhaled air 17 passes through the passage 13 in the heat sink 12 and then passes through the passage 13.
is cooled by heat exchange with the wax 14 in the sealed honeycomb compartment 19 around it, with which the wax undergoes at least one phase change and thus absorbs heat. When an individual exhales, at least some of the exhaled air returns through the filter pack 5, thereby cooling the heat sink 12.

3 and 4 show how a heat sink 12 like that of FIG. 2 is made. FIG. 3 shows, in an exploded perspective view, two end brakes 20, 21 and a bee structure 22, which together form the heat sink 12. FIG. 4 shows a portion of the heat sink 12 in association with the wax 14 in a cross-sectional view transverse to the compartment axis of the bellows structure 22. 16. Ocmx 11. The heat sink was made using two sheets 20.21 of 50 micrometer thick aluminum foil in Ocn+.

The honeycomb structure 22 is also made of aluminum and has a thickness of 0.0
The walls of the compartment are 25 m111 thick, the wall-to-wall distance is 3.2 m+, and the length of the compartment is 5rrIrrl.
And so. These dimensions were chosen to provide efficient heat exchange between the air and wax. To construct the heat sink, a sheet 21 was bonded to the honeycomb structure 22 using an epoxy resin adhesive that is stable up to temperatures of about 150°C.

The required compartments were then filled with heated wax such as Kerax, Chorley, Lancashire, reference number Kerawax 1301. As shown in Figure 4,
Some compartments 24 were left empty. A second sheet was then bonded onto the honeycomb structure 22. The passage 13 through the heat sink is made by piercing the sheet 20.21 adjacent to the empty compartment 24 using a sharp punch of diameter 11, ensuring that it is precisely aligned. The first sheet 21 was pierced before loading the compartment with wax, and then the second sheet 20 was bonded to the honeycomb structure. The heat sink was annealed by heating to 80° C. and then left to cool to room temperature for 16 hours.

Other cooling rates, 1°C/min, 10”C/min, and 20°C
/min can also be used. It is believed that this results in the formation of a microcrystalline structure of wax with a high latent heat capacity. The resulting heat sink contained approximately 35 g of wax. It is recognized that a protective hood as shown in Figure 1 may have two such heat sinks or one large heat sink containing about 100 g of wax.

In other embodiments, the material can be contained in a plurality of internal bond cavities formed between two pressed sheets. Heat sinks of this type are made by pressing regularly arranged interlocking recesses into two aluminum sheets coated with lacquer on one side and polypropylene on the other. The sheet was then aligned with the recess and cooperated to form an internal bonding cavity with the inner polypropylene coating. Po4.

The sheets were welded together using lipropylene. Load the cavity with wax through the internal coupling passage and then seal the inlet.

Finally, holes were punched in the sheet between the cavities to create passageways for air to pass through.

[Brief explanation of drawings]

1 shows a schematic cross-sectional view of an individual wearing a protective hood with a breathing apparatus consisting of a filter pack with a heat sink according to the invention; FIG. 2 is a cross-sectional view of the filter pack of FIG. 1; FIG. FIG. 3 is an exploded view of the configuration of the heat sink as shown in FIG. FIG. 4 is a cross-sectional view of a portion of the heat sink as shown in FIG. 2 or 3. FIG. 1...Individual 2...Protective hood 3...
Neck seal 4...Plastic material 5...Filter pack 7...Refractory flame/thermal material 8...Particle removal filter 9
...Adsorbent layer 10...Adsorbent layer 11...
- Layer of catalyst material 12...heat sink 13...passage 15...inside of hood 17...air 19...compartment 21...end plate 24...empty compartment 14 ... Wax 16 ... External environment of hood 18 ... Refractory flame/thermal material 20 ... End plate 22 ... Honeycomb construction

Claims (7)

[Claims] (1) A breathing apparatus consisting of a means for supplying breathable gas to an individual and a heat radiator arranged to remove heat from the breathable gas, the heat radiator having a temperature of 20°C.
A respiratory device characterized in that it consists of a material capable of undergoing at least one endothermic solid/solid or solid/liquid phase transition with a phase transition temperature of ~100°C. (2) The respiratory apparatus according to claim 1, wherein the phase transition temperature is 40°C to 80°C. (3) The respiratory apparatus according to claim 1 or 2, wherein the material is a metal alloy. (4) The respiratory device according to claim 1 or 2, wherein the material is wax. (5) The breathing apparatus according to claim 4, wherein the wax is a mineral wax. 6. A breathing apparatus according to claim 1, wherein the means for supplying breathable gas comprises at least one filter capable of removing toxic or noxious gases from the air inhaled from the environment. (7) A method for protecting an individual from a harmful environment, which comprises supplying the individual with a breathable gas derived from the breathing apparatus according to any one of claims 1 to 6. (8) A protective hood disposed to cover an individual's head, the protective hood comprising the breathing apparatus according to any one of claims 1 to 6.