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CA-3055104-C - IMPROVEMENTS IN GAS STORAGE DEVICES

CA3055104CCA 3055104 CCA3055104 CCA 3055104CCA-3055104-C

Abstract

A device for dispensing oxygen under pressure. The device comprises a canister filled with activated carbon and oxygen at a pressure of between 4 and 20 barg, when measured at room temperature. The canister is sealed with a valve assembly allowing release of oxygen from the canister on actuation of the valve assembly. To ensure the activated carbon does not react with the oxygen generating carbon monoxide, the device further comprises a catalyst that hinders the presence of carbon monoxide.

Inventors

  • Joe Michael Barratt
  • Matthew James Sygrove

Assignees

  • SIMPLY BREATHE LTD

Dates

Publication Date
20260505
Application Date
20180219
Priority Date
20170301

Claims (8)

  1. 12 CLAIMS 1. A device for dispensing oxygen, which is stored under pressure, comprising a canister filled with at least 40% activated carbon, by vol, and oxygen, which is absorbed by the activated carbon and stored at a pressure of between 4 and 20 barg, when measured at room temperature, which canister is sealed with a valve assembly allowing release of oxygen from the canister on actuation of the valve assembly, wherein the device further comprises a catalyst which converts carbon monoxide to carbon dioxide at ambient temperature to hinder the presence of carbon monoxide.
  2. 2. A device as claimed in claim 1 wherein the catalyst comprises manganese dioxide and copper oxide.
  3. 3. A device as claimed in claim 2 wherein the catalyst is Hopcalite.
  4. 4. A device as claimed in any one of claims 1 to 3 wherein the activated carbon is derived from coconut shell or a coal base.
  5. 5. A device as claimed in any one of claims 1 to 4 wherein the activated carbon has a density of from 0.4 - 0.5 g cm-3.
  6. 6. A kit comprising a device as claimed in any one of claims 1-5 together with a mask, mouthpiece and/or nose piece.
  7. 7. A kit as claimed in claim 6 further comprising a connector.
  8. 8. A device as claimed in any one of claims 1-5 further comprising a regulator and/or counter for monitoring gas usage from the device.

Description

1 IMPROVEMENTS IN GAS STORAGE DEVICES [0001] This invention relates to improvements in gas storage devices and more particularly to devices filed with e.g. oxygen or carbon dioxide. It also relates to an 5 improved method of storing gases, particularly, oxygen, carbon dioxide, nitrogen or air, in a device, and to the storage device per se. BACKGROUND [0002] Traditionally canisters filled with gasses are either filled with a compressed gas or utilise a propellant, such as HFA-134a, to facilitate discharge. Such systems suffer from a 1 O number of disadvantages. [0003] By way of example, GB2411812 discloses a pet behaviour correction device comprising a canister filled with a pressurised inert condensed gas, in the form of a hydrofluorocarbon (HFC). In use the gas is discharged, towards the head of e.g. a dog, to generate a hissing sound. However, such a device has a number of limitations including: 15 the undesirable nature of HFC's (environmental damage) giving rise to their legislative phase out, the fact that their liquid nature limits the orientation of use (they don't function effectively when inverted), and on depressurisation rapid cooling occurs, which can be distressing (and potentially harmful) for pets if activated too close to the animal, and if triggered accidentally, in e.g. a user's pocket, can give rise to freeze burns. 20 [0004] Alternative propellants may be used to replace HFC's but, for example, hydrocarbon gases, such as butane, are highly flammable and also suffer from volatile substance abuse potential. Many of the propellants will also leave residue deposits which in applications such as gas dusters can cause damage to sensitive electronic equipment. A gas duster is a device that is used to clean hard to reach surfaces, such as the grooves 25 and crevices in equipment and electronic or sensitive appliances that can't be accessed or cleaned using conventional solvents. [0005] However, because air and its components including oxygen, nitrogen and carbon dioxide are not readily liquefied, only a small quantity of gas can be stored without the need to provide reinforcement for excessively high pressure. 30 [0006] WO2005/0547 42 discloses a storage container for a gas comprising a sealed vessel containing an amount of activated carbon and a gas which is adsorbed thereon. [0007] One such gas is oxygen. [0008] Containers filled with compressed oxygen may be used for a range of applications, such as, for example, therapeutic or sport enhancement purposes. Confirmation copy 2 [0009] The use of activated carbon as a storage means enables greater volumes of gas to be stored in a given volume. For oxygen this is about two to three times that obtained by compression alone, at the same pressure, depending upon the grade of activated carbon. [0010] Typically the gas is stored at a pressure of from 4 -17 barg (measured at room 5 temperature), and the container typically contains at least 40%, by volume, of activated carbon. However, some canisters can withstand pressures of 20 barg. [0011] The device may be adapted to receive a mask, mouthpiece and / or nose piece and typically comprises a valve assembly which allows filling and dispensing. It may also contain a filter between the activated carbon and a valve of the valve assembly. 10 [0012] The device may be connected to the mask, mouthpiece and/ or nose piece via a connector, for example tubing, and these components may be sold separately or as a kit of parts. [0013) Where the device is filled with oxygen at pressures above about 8 barg it is desirable to use a high activity carbon (one having an activity of above 60% CTC (carbon 15 tetrachloride)), although a lower activity carbon may also be used, particularly at lower fill pressures. [0014] Applicant has determined that devices comprising activated carbon, which are filed with oxygen or air under pressure, contain not insignificant amounts of carbon monoxide (concentrations of over 100 ppmv) as a result of a reaction between the 20 activated carbon and oxygen. Whilst not inherently dangerous at these levels carbon monoxide has a binding affinity for haemoglobin which is 250 times greater than oxygen. In consequence even relatively low levels of carbon monoxide can negate the benefits obtained from breathing pure oxygen. Indeed at concentrations of 200 ppmv carbon monoxide can cause headache and nausea. 25 [0015] An aim of the present invention is to ensure that oxygen or air delivered using activated carbon is substantially free of carbon monoxide. [0016] A second, and independent aspect, is to manage heat affects associated with the filling of canisters with a gas, which aspect is not limited to oxygen. Indeed this second aspect can be a greater problem where the gas is carbon dioxide due to the much greater 30 volumes (as much as 25 times that of compressed carbon dioxide) that can be adsorbed in canisters filled with activated carbon, the adsorption being exothermic. [0017] Indeed, where the