GB2545765A

GB2545765A - Portable radon filtration apparatus

Info

Publication number: GB2545765A
Application number: GB1611118.9A
Authority: GB
Inventors: Cipollone Rita
Original assignee: Global H&s Ltd
Current assignee: Global H&s Ltd
Priority date: 2015-12-23
Filing date: 2016-06-27
Publication date: 2017-06-28
Anticipated expiration: 2036-06-27
Also published as: GB2545716B; GB2545765B; GB201522759D0; GB2545716A; GB201611118D0

Abstract

An air-purifying respirator comprises mask means 1, for supplying filtered air to a user of the respirator and radon (Rn) filtration means 5 for filtering air prior to being conducted to the mask means. An air circulation means (7, Fig 3) is provided for capturing ambient air, and conducting the air to the filtration means and mask means. The radon filtration means is configured to adsorb radon from the ambient air before supplying radon-filtered air to the mask means. The use of an air-purifying respirator to adsorb radon from ambient air is also disclosed. The respirator may adsorb radon and radioactive particles from air before supplying radon-filtered air to a mask user to breathe. Further inventions directed to an apparatus for regeneration of a filtration means, the apparatus characterised by enclosure means, for receiving a filtration means and means for supplying a washing fluid; an air-purifying system characterised by a respirator and a regeneration apparatus; a method for regenerating a filtration means from a respirator; an isobaric process for the separation of radon from a mixture of gases comprising helium; an isobaric process for the separation of radon from air; a portable filtration apparatus for the separation of radon from air and a method for removing radon from air characterised by providing a housing having dust filters and radon filter, are also disclosed.

Description

Portable Radon Filtration Apparatus

The present invention provides a fan powered respirator mask having the function of removing Radon and radioactive particles from air.

Radon is formed as one intermediate step in the normal radioactive decay chains through which thorium and uranium decay into lead. Unlike all the other intermediate elements in the aforementioned decay chains, Radon is gaseous. Radon is a radioactive and naturally-occurring gas which constantly comes out from soil through the surface of the earth’s crust into the atmosphere, which becomes enriched with Radon gas and a mixture of its isotopes known as 222Rn (Radon), 220Rn (Thoron), 219Rn (Actinon). However, given its relatively short half-life, of about 3.8 days, Radon gas concentration has low concentrations in the earth’s atmosphere, varying from 1 to 100Bq/m3, where Bq is Becquerel and m is metres. On the contrary, significant Radon concentrations can accumulate indoors or in confined spaces, where there is little or no exchange of interior air with external air, and in areas below the soil level. Radon gas is about eight times heavier than air and tends to accumulate in holes or in other depressions.

The problem of air enriched with Radon is particularly exacerbated in areas of considerable Radon effluence, i.e. volcanic areas or zones rich in uranium ores, phosphate rock, shales, igneous and metamorphic rocks, such as granite, gneiss and schist, where Radon concentration can achieve levels even higher than 10,000 kBq/m3.

It has been calculated that exposure to Radon, its isotopes, and its decay products is the cause of more than 20,000 deaths in the European Union; furthermore, Radon is the second biggest cause of lung cancer after cigarette smoke. This adverse statistic also results from professional exposure to Radon, where workers may enter poorly ventilated indoor sites or be in confined spaces with high concentration of Radon.

Basic confined space equipment is generally used to guarantee air to workers, and includes a ventilating fan that introduces fresh air. Alternatively, other systems and methods are used to eliminate Radon from air and are based on the capacity of Radon to be adsorbed on a substrate. Active carbon is currently one of the best substrates in terms of cost/effectiveness ratio for separation, although other possible usable substrates are known, such as silver exchanged zeolite (from European Patent Application EP 1752206A1). Among the types of active carbon, the best results are obtained from coconut-derived ones, having mean granulometry of 3.5 mm, 450-550 kg/m3 density, 1000-1200 m2/g superficial area.

The affinity of Radon for active carbon has been previously exploited for the measurement of Radon concentration in the air, measuring the gamma radioactivity emitted by the active carbon after the accumulation of Radon decay products.

The capacity of Radon and its isotopes to be absorbed by active carbon has been used for the filtration of Radon gas from air to solve the problem of Radon contamination in the air of a cleanroom for scientific experiments. See for reference "Low Background Techniques and Experimental Challenges for Borexino and its Nylon Vessels. Andrea Pocar. A dissertation presented to the faculty of Princeton University in candidacy for the degree of Doctor of Philosophy. November 2003". In this case, the system used is based on the VS A (Vacuum Swing Adsorption) technique, that is an alternation of cycles of high and low pressure, to favour respectively the adsorption on the active carbon and the desorption of Radon from them. Said technique is capable of handling high air flows and is applicable to air or Nitrogen containing Radon in activity concentrations that are constant and lower than 10 kBq/m3. However, since an appropriate full-scale plant, which is capable of treating between 85 and 170 m3/h of air, where m is metres and h is hours, requires an amount of charcoal in the 200 to 250 kg range, where kg is kilogrammes, heavy steel tanks and vacuum/pressure pumps, this technique is not suitable for portable devices and cannot provide protection for relatively short or occasional exposure to Radon-polluted air in narrow environments.

Basic Personal Protective Equipment (PPE) for such a purpose are respirators/self-contained air packs. The need to wear various self-contained breathing apparatus while working in hostile environments is well documented, but wearers often suffer from breathing resistance and a short lifespan of the air cylinder. Despite the fact that major advances have taken place in the design of respirators, it is still widely recognized that "psychological" problems continue to exist.

Alternatively, disposable particulate respirators and active powered respirators can, in principle, provide the function of air filtering, but none are appropriate or effective for Radon gas contamination. A search for Patents describing the use of affinity substrates for Radon in portable devices retrieves Patents that describe a Zeolite based disposable particulate respirator filtration media, which is able to protect the wearer from inhalation of the progeny of Radon but not from Radon per se (as exemplified in US Patent Application US2015/0238784 Al) and a nasal mask which consists of a main body having two activated carbon pieces (US Patent Application US2004/0211425 Al). In this latter case, the object of the invention is to provide a nasal mask having an air filtering function, which, by placing a filtration device in the main body of the mask, can achieve bactericidal and/or bacteriostatic effects. It is not aimed at, nor suitable for Radon separation.

According to an aspect, the present invention provides an air-purifying respirator, comprising: mask means, for supplying filtered air to a user of the respirator; radon filtration means, for filtering air prior to being conducted to the mask means; air circulation means, for capturing ambient air, and conducting such air to the filtration means and mask means, wherein the radon filtration means is configured to adsorb radon from the ambient air before supplying radon-filtered air to the mask means.

Preferably, substantially all, if not all, Radon from the ambient air is removed.

Preferably, the filtration means comprises activated carbon, preferably activated carbon derived from coconut.

Preferably, the filtration means is a self-contained, interchangeable unit.

Preferably, the filtration means and circulation means are contained in a portable housing and, most preferably, is a rucksack.

Preferably, the filtration means comprises a labyrinthal arrangement of passageways and partitions so as to define an elongate pathway from an inlet to an outlet of the filtration means.

Preferably, the filtration means comprises a housing and one or more partitions providing an internal tortuous pathway from an inlet to an outlet of the filtration means.

Preferably, the filtration means additionally comprises a filtration media.

Most preferably, the filtration media is activated carbon.

Preferably, the air-purifying respirator additionally comprises a particulate filter, through which ambient air is first conducted, prior to being conducted to the radon filtration means. Preferably, the circulation means provides a positive pressure to the mask means.

Most preferably, a porous fibreglass bung is located at a respective inlet and an outlet of the filtration means.

According to a second aspect, the present invention provides an apparatus for regeneration of a filtration means, the apparatus comprising: enclosure means, for receiving a filtration means; means for supplying a washing fluid; means for bringing the washing fluid into contact with the filtration means; and means for heating and controlling a temperature of the enclosure means, wherein, in use, the application of heating and washing is capable of desorbing undesirables adsorbed on the filtration means into the washing fluid and, thereby, regenerating the filtration means for further use.

Preferably, the filtration means is radon filtration means, and the application of heating and washing is capable of desorbing Radon from the filtration means into the washing fluid.

According to a third aspect, the present invention provides an air-purifying system, the system comprises: a respirator; and a regeneration apparatus, the respirator comprises: mask means, for supplying filtered air to a user of the respirator; filtration means, for filtering air prior to being conducted to the mask means; air circulation means, for capturing ambient air, and conducting such air to the filtration means and mask means, the regeneration apparatus comprises: enclosure means, for receiving the filtration means; means for supplying a washing fluid; means for bringing the washing fluid into contact with the filtration means; and means for heating and controlling a temperature of the enclosure means, wherein the respirator is capable of filtering ambient air so as to remove undesirables through adsorption within the filtration means and supplying treated air to a user of the respirator, and the regeneration means is capable of regenerating the filtration means of the respirator, through the application of heat and the washing fluid, which desorbs the undesirables from the filtration means into the washing fluid.

Preferably, the system is for respective adsorption and desorption of radon from a filter, such that the respirator is capable of filtering radon from ambient air through adsorption within the filtration means and supplying treated air to a user of the respirator, and the regeneration means is capable of regenerating the filtration means of the respirator, through the application of heat and the washing fluid, which desorbs radon from the filtration means into the washing fluid.

Preferably, the air-purifying respirator additionally comprises a particulate filter, through which ambient air is first conducted, prior to being conducted to the radon filtration means. Preferably, the invention includes one or more respirator and/or regeneration apparatus features form the first and/or second aspect.

According to a fourth aspect, the present invention provides use of an air-purifying respirator to adsorb radon from ambient air, the respirator comprising: mask means, for supplying filtered air to a user of the respirator; radon filtration means, configured for filtering air prior to being conducted to the mask means; air circulation means, for capturing ambient air, and conducting such air to the filtration means and mask means, wherein the radon filtration means adsorbs radon from the ambient air before supplying radon-filtered air to the mask means for said user to breathe.

Preferably, the air-purifying respirator additionally comprises a particulate filter for filtering the ambient air prior to conducting such air to the radon filtration means.

Preferably, the invention includes one or more respirator features from the first aspect.

According to a yet further aspect, the present invention provides a method for regenerating a filtration means from a respirator, the method comprising: separating the filtration means from the respirator; treating the filtration means, which has been used to purify air and has radon or undesirables adsorbed thereon, through the application of heat and a washing fluid and thereby regenerating the filter by desorbing radon or undesirables therefrom; and re-connecting the filtration means to the respirator.

The present invention also relates to an isobaric process for the separation of Radon from a mixture of gases comprising Helium, wherein the process comprises: adsorption of Radon from the mixture of gases on a substrate; heating the substrate to detach Radon from the substrate; washing the substrate with washing fluid to detach Radon from the substrate; and cooling the substrate.

Preferably, the process comprising any one or more or combination of the group comprising: heating the substrate to detach Radon from the substrate and, subsequently but together, washing the substrate whilst additionally heating the substrate; constant temperature washing of the substrate after heating; cooling the substrate whilst washing the substrate; subsequent cooling without washing; and/or after cooling, pausing the process in readiness for starting again.

The present invention also relates to an isobaric process for the separation of Radon from air, wherein the process comprises: adsorption of Radon from air on a substrate; heating the substrate to detach Radon from the substrate; washing the substrate with washing fluid to detach Radon from the substrate; and cooling the substrate.

With respect to the above-mentioned isobaric processes, relating to separation of Radon from Helium and Air, respectively, further details of the processing apparatus and parameters are disclosed in UK Patent Application GB1522759.8.

The present invention also relates to the following. A portable filtration apparatus for the separation of Radon from air, capable of adsorbing Radon on a substrate and delivering purified air into a face piece, while retaining Radon on the substrate, comprising a portable housing, a fan powered by a battery which is capable of pushing air from an air inlet to the face piece, passing through one or more dust filters and one or more Radon filters containing Radon adsorbent material.

Preferably, Radon adsorbent material includes but is not limited to activated carbon. A second apparatus able to regenerate the above substrate implementing Radon removal using the temperature increase of the substrate and a carrier gas for Radon desorption and removal without need to regulate pressure or to replace the substrate.

Preferably, said portable housing is rucksack-shaped.

Preferably, the face piece is made by a helmet made of light material (e g. of fibreglass or plastic polymers) having a panoramic tip-up visor.

Preferably, Radon absorbent material is embodied in a metal housing or other material suitable for high temperature desorption.

Preferably, regeneration of the absorbent material occurs by a high-temperature Radon desorption method. A method for removing Radon from air, comprising the steps of: providing a housing having a dust and/or particulate filter and Radon filter wherein Radon is adsorbed on a substrate and removed from air, an air inlet for receiving air into said filters and an air outlet for passing filtered air from the filters to an helmet through a flexible tube; providing fan means and connections for passing air from the air inlet towards the air outlet and for maintaining a positive pressure into the face piece. A portable apparatus used to adsorb a group of fluid in the form of gases, fogs or vapours that can be adsorbed and desorbed from an active carbon based substrate using temperature.

The present invention also provides an air-purifying respirator, comprising: mask means, for supplying filtered air to a user of the respirator; filtration means, for filtering air prior to being conducted to the mask means; air circulation means, for capturing ambient air, and conducting such air to the filtration means and mask means, wherein the filtration means is configured to adsorb undesirables from the ambient air before supplying filtered air to the mask means.

The present invention also provides an apparatus for regeneration of a filtration means, the apparatus comprising: enclosure means, for receiving a filtration means; means for supplying a washing fluid; means for bringing the washing fluid into contact with the filtration means; and means for heating and controlling a temperature of the enclosure means, wherein, in use, the application of heating and washing is capable of desorbing undesirables from the filtration means into the washing fluid and, thereby, regenerating the filtration means for further use.

The present invention describes a portable apparatus for Radon filtration and for its separation from air. During the phase of air purification, air is forced by a fan to pass through one or more dust and/or particulate filters and through one or more carbon filters. When, after several hours - for example, say, 2 to 4 hours - of continuous working, the carbon filter is exhausted, it can be regenerated to avoid its contamination by the radioactive particles generated by Radon decay. The formulas for calculating the maximum time of continuous use and the principle of regeneration are described in an earlier UK Patent Application, entitled “Improvements in or Relating to the Separation of Radon”, GB 1522759.8.

Briefly, Radon and its isotopes (later on simply referred to as "Radon") are separated from air with a process of adsorption and subsequent desorption of Radon without regulating the pressure. The adsorption and desorption processes are optimised to treat Radon-polluted air with a compact and portable device that occupies relatively small space exploiting a process that, at the same time, allows removal of Radon from air while reducing the production of radioactive waste.

The invention will now be disclosed, by way of example only, with reference to the following drawings, in which:

Figure lisa schematic drawing of a respirator worn by an operator;

Figure 2 is a schematic drawing of the filter unit showing various components with Figure 2a showing a front view and Figure 2b a rear view of the components;

Figure 3 is a schematic drawing of a filter showing the internal pathways and components; Figure 4 is a schematic drawing of further filters, a pump unit and a battery, shown in stippled line in Figures 2a and 2b; and

Figure 5 is a schematic drawing of a regeneration apparatus.

The appliance includes two main units: an apparatus for filtration, in other words a respirator, as shown in Figure 1, which contains an extractable filtration unit, as shown in Figure 2a and 2b, and an apparatus for regeneration of the extractable filtration unit, as shown in Figure 5. The apparatus for filtration consists of a light helmet 1, made from fibreglass or plastic polymers, with a panoramic tip-up visor 2, a tube 3, for connecting the helmet 1 with a filtration unit 5, a mantle 4 or other suitable device able to prevent non-purified air from entering the helmet 1, and a filtration unit 5 shaped as a backpack or another suitable case.

The filtration unit may be worn by an operator 0 by means of a safety harness 6.

As shown in more detail in Figures 2a and 2b, the filtration unit 5 includes a turbine motor unit 7, a rechargeable battery pack 16, connected with appropriate plugs 17 to a control and regulation unit (not shown), a three radioactive particulate filters 14 and a Radon filter 11. The particulate filters 14 are a dense net of fibrous material, for example paper- or mineral-fibres, such as fibreglass, rock-wool or other synthetic fibres, which traps particulates without adsorbing them. By placing the particulate filters 14 before the Radon filter 11, this avoids contamination of the Radon filter or even the lungs of a user, as it prevents pre-existing radioactive particulates from being conducted any further through the respirator. The Radon filter 11 is an active carbon filter.

The turbine motor unit 7, the rechargeable battery pack 16, the extractable radon filter 11, the particulate filters 14 and their components are contained in a case equipped with a lid 9 and all together make up the filtration unit 5.

The filtration unit 5 is connected to the helmet 1 through a tube 3 attached to the connector 12 which passes through a hole 10 of the lid 9. The filtration unit 5 may be connected to a safety harness 6 through an attachment 8.

The particulate filters 14 are mounted in special fittings on the turbine motor unit 7. Air sucked from an inlet at the bottom of the backpack is supplied to the helmet 1 with a pressure higher than the local atmospheric pressure, after passing through the filters 14, a connector 15 and the Radon filter 11. Air, through the appropriate connector 12 (better shown in Figure 3), is then conducted through the tube 3 to the helmet 1. Using a control button (not shown), that can be detached from the filtration unit 5, it is possible to regulate the rotation speed of the turbine 7, the operating lifespan of the battery 16, and the filters 11 and 14. The absorption phase is implemented in the portable filtration unit 5 containing the active carbon filter (or other appropriate substrate). The function of the filtration unit 5 is to deliver filtered and purified atmospheric air to the helmet 1 of an operator 0 working in an environment with Radon polluted air.

The apparatus is intended to be used in atmospheres containing appropriate Oxygen concentration (17-22%), but no toxic gases whose nature does not allow absorption and subsequent desorption on a substrate, and whose concentration is above their health risk level, and no explosive gases in concentration above their lower explosive limit. However, the use of the apparatus in explosive atmospheres may be allowed with specific preventative measures performed on the apparatus in order to avoid the ignition of explosive gases.

The Radon filter 11 includes a certain quantity of activated carbon or other suitable substrate, enclosed in a container (preferably made of aluminium or other lightweight alloy or polymers suitable for high temperature desorption). The quantity of substrate depends on the designed flow rate and the intended life/duration of the Radon filter. The shape of the filter case is optimised in order to guarantee both the ergonomic wearing of the device, and the best flow rate and length of the filter (see UK Patent Application No. GB 1522759.8 for calculation formulas).

As an option, the Radon filter 11 can be discarded without regeneration after one or more days of interrupted and/or partial use and after Radon decay, subject to local environmental rules. Ambient air is sucked through the filtration unit 5 by the motor-driven ventilator unit 7, which blows it into the helmet 1 worn by the user 0 - shown in Figure 1. Purification of air roughly consists of pushing the air through the particulate filters 14 and through the Radon filter 11 in order to remove radioactive particles and Radon, respectively. The purified air is then conveyed into the helmet 1 creating a positive pressure which allows the operator to breathe effortlessly and prevents the visor 2 from steaming up, and prevents external non filtered-air entering the helmet 1. By adjusting the supply voltage of the motor 7, supplied from the battery 16 through the plugs 17, it is possible to achieve two or more speeds, i.e. two or more different flow rates. The best flow rate is preferably between 120 and 1801/min (where 1 is litres and min is minutes) to guarantee positive pressure in the helmet 1, even during fast inspiration of the user.

The Radon filter 11 contained in the filtration unit 5 is made of metal (or other heat resistant material) and contains a substrate (preferably coconut-derived, active carbon) which is capable of binding Radon. The substrate is contained inside labyrinth-like pathways, as shown in figure 3, which create a long path inside the filter 11 where air can flow with appropriate speed whilst Radon is bound to the active carbon. The length of the air pathways inside the filter unit 11 can be calculated according to Formula 2 of GB1522759.8, where the slowdown coefficient of Radon (R), experimentally measured for air passing through coconut active carbon, is about 6,666 xlO'4. This coefficient varies with the composition of the gas passing through the substrate (e.g. air containing higher concentration of Carbon dioxide and/or other interfering gases results in a higher coefficient) and with the nature of the substrate (higher affinity substrates have lower "R" values). The length of the air path inside the Radon filter and the flow rate determine the duration/life of the Radon filter before it is considered exhausted. It is important to notice that this length, as well as the duration of the Radon filter before regeneration is needed, are not influenced, below the concentration of saturation of the substrate, by Radon concentration in air. The duration of the Radon filter before a regeneration is needed can be calculated using the following formula: t = L/Vr [FORMULA 1] where: t= time of maximum allowed use of the filter L= Length of the air path inside the filter Vr= speed of the Radon inside the column and where:

Vr= (Φ x R)/A [FORMULA 2] where: Φ = air flow rate through the filter R= slowdown coefficient of Radon A= section of the air path inside the filter

For example, according to said formulas, given a 2.40 m long air path inside the filter unit 11 and a flow rate of 1201/min (7.2 m3/h), the efficiency of Radon removal is guaranteed for about 4 hours. After 4 hours, the filter is no longer efficient and needs to be regenerated. If the filter is not regenerated promptly, there is the risk of contamination of the substrate from the Radon decay products. However, after complete Radon decay, the filter 11 is again able to bind Radon, but possibly should not be used (at least initially) because it is contaminated by radioactive particles. There is always some extent of contamination of the substrate during each cycle of use, even if the filter is promptly regenerated, and the filter 11 should not be used indefinitely. Hence the maximum number of cycles before the filter must be disposed has to be calculated. In GB1522759.8 it is possible to find formulas to calculate the amount of substrate needed in the Radon filter (Formula 3), the amount of Radon bound to the substrate (Formula 4), the filter operation lifetime and the maximum number of cycles of the Radon filter before the filter itself should be considered "radioactive" (Formulas 4,5,6,7,8,9). Those calculations are needed in order to guarantee that the decay of Radon inside the substrate does not cause an accumulation of long-living radioactive daughters (such as 210Pb) that would make the product classifiable as radioactive waste according to local regulations. For example, according to said formulas and presuming the use of the said filter at a flow rate of 120 1/min (7.2 m3/h) for 4 hours per day in an environment containing 10,000 Bq/m3 of Radon, a limit for non-radioactive disposal fixed to 1 Bq/kg, the number of cycles allowed with a single filter before its mandatory disposal is about 1700 (about 5 years if used every day for 4 hours).

The filtration device can be completed by adding other devices such as a remaining battery power gauge and related alarms, a remaining time of filter use gauge and related alarms, a filter life expectancy calculator and display, a Radon concentration in the filtered air gauge and related alarms, a remote controller and display, an inside display with indication of efficiency and residual power, instruments for alpha, beta and gamma ray detection; toxic and suffocating gas detection; and Oxygen and Carbon dioxide concentration, a harness for emergency rescue, communication tools, helmet cameras etc.

The desorption phase is fulfilled in a single or multi-filter desorption unit as shown in Figure 5, able to remove Radon from the filter 11 before its decay, by simply using heating and a carrier inert gas, without any need to regulate pressure.

In order to proceed with its regeneration, the exhausted filter 11 can be extracted from the filtration unit 5, using handles 13, after removing the tube 3 from the connector 12 and lifting up the lid 9.

The regeneration unit, identified by reference 19 is a thermostatic oven having a housing 21 equipped with a lid 20 so that, once the filter 11 to be regenerated is inserted therein, it is able to increase the temperature of the filter 11 while a carrier gas (washing fluid), preferably made of an inert gas like Nitrogen, Carbon dioxide, etc., preferably contained in a cylinder 22, is caused to flow in the filter 11, having passed through a supply tube 23 and a connector 24. The carrier gas is flowed through the filter 11 to increase the efficiency of the desorption of the radioactive gas, so as to carry the Radon out of the filter 11 and prevent, at the same time, possible explosive combustions of the substrate when Oxygen contained in air reacts with the heated substrate. The specific parameters for substrate regeneration using a high-temperature Radon desorption method are those described in UK Patent Application No. GB1522759.8. The regeneration unit may also include multi-filter capability, a timer, a thermostat, and an electric valve for controlling the supply of inert gas.

By way of explanation, the references in the Figures can be summarised as the following: 0 operator 1 helmet 2 visor 3 connection tube 4 mantle 5 filter unit including Radon filter, particulate filter, fan, fan controller and battery 6 harness 7 fan motor unit 8 harness attachment for connecting the filtration unit to the harness 9 filtration unit lid 10 aperture through the lid 9 to allow the transit of the connection tube 3 11 Radon filter unit 12 connector for connecting the tube 3 to the radon filter 11 13 handles for handling the radon filter 11 14 radioactive particulate filters 15 connector for connecting the fan motor unit 7 to the radon filter 11 16 rechargeable battery 17 plugs for power supply to the fan motor unit 7 from battery 16 18 porous fibreglass bungs 19 desorption unit / regeneration unit 20 desorption unit / regeneration unit lid 21 desorption unit housing 22 inert gas cylinder 23 supply tube for supplying the inert gas from the cylinder 22 to the desorption unit / regeneration unit 19 24 connector for connecting the desorption unit / regeneration unit 19 to the radon filter 11 25 display and controls of the desorption unit / regeneration unit 19

Claims

CLAIMS 1. ) An air-purifying respirator, comprising: mask means, for supplying filtered air to a user of the respirator; radon filtration means, for filtering air prior to being conducted to the mask means; air circulation means, for capturing ambient air, and conducting such air to the filtration means and mask means, wherein the radon filtration means is configured to adsorb radon from the ambient air before supplying radon-filtered air to the mask means.
2. ) An air-purifying respirator as claimed in claim 1, wherein, substantially all, if not all, Radon from the ambient air is removed.
3. ) An air-purifying respirator as claimed in claim 1 or claim 2, wherein the filtration means comprises activated carbon, preferably activated carbon derived from coconut.
4. ) An air-purifying respirator as claimed in any preceding claim, wherein the filtration means is a self-contained, interchangeable unit.
5. ) An air-purifying respirator as claimed in any preceding claim, wherein the filtration means and circulation means are contained in a portable housing.
6. ) An air-purifying respirator as claimed in any preceding claim, wherein the filtration means comprises a labyrinthal arrangement of passageways and partitions so as to define an elongate pathway from an inlet to an outlet of the filtration means.
7. ) An air-purifying respirator as claimed in any preceding claim, wherein the filtration means comprises a housing and one or more partitions providing an internal tortuous pathway from an inlet to an outlet of the filtration means.
8. ) An air-purifying respirator as claimed in claim 6 or claim 7, wherein the filtration means additionally comprises a filtration media.
9. ) An air-purifying respirator as claimed in claim 8, wherein the filtration media is activated carbon.
10. ) An air-purifying respirator as claimed in any preceding claim, wherein the circulation means provides a positive pressure to the mask means.
11. ) An air-purifying respirator according to any preceding claim additionally comprising a particulate filter, through which ambient air is first conducted, prior to the radon filtration means.
12. ) An apparatus for regeneration of a filtration means, the apparatus comprising: enclosure means, for receiving a filtration means; means for supplying a washing fluid; means for bringing the washing fluid into contact with the filtration means; and means for heating and controlling a temperature of the enclosure means, wherein, in use, the application of heating and washing is capable of desorbing undesirables adsorbed on the filtration means into the washing fluid and, thereby, regenerating the filtration means for further use.
13. ) An apparatus as claimed in claim 12, wherein the filtration means is radon filtration means, and the application of heating and washing is capable of desorbing Radon from the filtration means into the washing fluid.
14. ) An apparatus for regeneration of a filtration means, substantially as herein disclosed, with reference to Figure 5 of the accompanying drawings and/or any example described herein.
15. ) An air-purifying system, the system comprising: a respirator; and a regeneration apparatus, the respirator comprises: mask means, for supplying filtered air to a user of the respirator; filtration means, for filtering air prior to being conducted to the mask means; air circulation means, for capturing ambient air, and conducting such air to the filtration means and mask means, the regeneration apparatus comprises: enclosure means, for receiving the filtration means; means for supplying a washing fluid; means for bringing the washing fluid into contact with the filtration means; and means for heating and controlling a temperature of the enclosure means, wherein the respirator is capable of filtering ambient air so as to remove undesirables through adsorption within the filtration means and supplying treated air to a user of the respirator, and the regeneration means is capable of regenerating the filtration means of the respirator, through the application of heat and the washing fluid, which desorbs the undesirables from the filtration means into the washing fluid.
16. ) An air-purifying system as claimed in claim 15, wherein the system is for respective adsorption and desorption of radon from a filter, such that the respirator is capable of filtering radon from ambient air through adsorption within the filtration means and supplying treated air to a user of the respirator, and the regeneration means is capable of regenerating the filtration means of the respirator, through the application of heat and the washing fluid, which desorbs radon from the filtration means into the washing fluid.
17. ) An air-purifying system, substantially as herein disclosed, with reference to Figures 1, 2a, 2b, 3, 4 and 5 of the accompanying drawings and/or any example described herein.
18. ) Use of an air-purifying respirator to adsorb radon from ambient air, the respirator comprising: mask means, for supplying filtered air to a user of the respirator; radon filtration means, configured for filtering air prior to being conducted to the mask means; air circulation means, for capturing ambient air, and conducting such air to the filtration means and mask means, wherein the radon filtration means adsorbs radon from the ambient air before supplying radon-filtered air to the mask means for said user to breathe.
19. ) A method for regenerating a filtration means from a respirator, the method comprising: separating the filtration means from the respirator; treating the filtration means, which has been used to purify air and has radon or undesirables adsorbed thereon, through the application of heat and a washing fluid and thereby regenerating the filter by desorbing radon or undesirables therefrom; and re-connecting the filtration means to the respirator.
20. ) An isobaric process for the separation of Radon from a mixture of gases comprising Helium, wherein the process comprises: adsorption of Radon from the mixture of gases on a substrate; heating the substrate to detach Radon from the substrate; washing the substrate with washing fluid to detach Radon from the substrate; and cooling the substrate.
21. ) An isobaric process as claimed in claim 20 comprising any one or more or combination of the group comprising: heating the substrate to detach Radon from the substrate and, subsequently but together, washing the substrate whilst additionally heating the substrate; constant temperature washing of the substrate after heating; cooling the substrate whilst washing the substrate; subsequent cooling without washing; and/or after cooling, pausing the process in readiness for starting again.
22. ) An isobaric process for the separation of Radon from air, wherein the process comprises: adsorption of Radon from air on a substrate; heating the substrate to detach Radon from the substrate; washing the substrate with washing fluid to detach Radon from the substrate; and cooling the substrate.
23. ) An isobaric process as claimed in claim 22 comprising any one or more or combination of the group comprising: heating the substrate to detach Radon from the substrate and, subsequently but together, washing the substrate whilst additionally heating the substrate; constant temperature washing of the substrate after heating; cooling the substrate whilst washing the substrate; subsequent cooling without washing; and/or after cooling, pausing the process in readiness for starting again.
24. ) A portable filtration apparatus for the separation of Radon from air, capable of adsorbing Radon on a substrate and delivering purified air into a face piece, while retaining Radon on the substrate, comprising a portable housing, a fan powered by a battery which is capable of pushing air from an air inlet to the face piece, passing through one or more dust filters and one or more Radon filters containing Radon adsorbent material.
25. ) Radon adsorbent material according to claim 24 includes but is not limited to activated carbon.
26. ) A second apparatus able to regenerate the substrate described in claim 24 implementing Radon removal using the temperature increase of the substrate and a carrier gas for Radon desorption and removal without need to regulate pressure or to replace the substrate.
27. ) Apparatus as defined in claim 24 wherein said portable housing is rucksack-shaped.
28. ) Apparatus as defined in claim 24 where the face piece is made by a helmet made of light material (e.g. of fibreglass or plastic polymers) having a panoramic tip-up visor.
29. ) Radon absorbent material according to claim 24 or claim 28 is embodied in a metal housing or other material suitable for high temperature desorption.
30. ) Regeneration of the absorbent material of claim 24, claim 28 or claim 29 which occurs by a high temperature Radon desorption method.
31. ) A method for removing Radon from air, comprising the steps of: providing a housing having dust filters and Radon filter wherein Radon is adsorbed on a substrate and removed from air, an air inlet for receiving air into said filters and an air outlet for passing filtered air from the filters to an helmet through a flexible tube; providing fan means and connections for passing air from the air inlet towards the air outlet and for maintaining a positive pressure into the face piece.
32. ) A portable apparatus as described in claim 24 used to adsorb a group of fluid in the form of gases, fogs or vapours that can be adsorbed and desorbed from an active carbon based substrate using temperature.
33. ) An air-purifying respirator, substantially as herein disclosed, with reference to Figure 1, 2a, 2b, 3 or Figure 4 of the accompanying drawings and/or any example described herein.