AU1674401A - Process and movable and transportable unit for producing breathable air - Google Patents

Description

AUSTRALIA

Patents Act COMPLETE SPECIFICATION

(ORIGINAL)

Class Int. Class Application Number: Lodged: Complete Specification Lodged: Accepted: Published: Priority Related Art: Name of Applicant: Air Liquide Sante (International) Actual Inventor(s): Didier Beauvois, Robert Montausier, Thierry Duboudin Address for Service: PHILLIPS ORMONDE FITZPATRICK Patent and Trade Mark Attorneys 367 Collins Street Melbourne 3000 AUSTRALIA Invention Title: PROCESS AND MOVABLE AND TRANSPORTABLE UNIT FOR PRODUCING BREATHABLE

AIR

Our Ref: 635619 POF Code: 1290/329618 The following statement is a full description of this invention, including the best method of performing it known to applicant(s): -1- The present invention relates to a modular movable unit or assembly for producing air breathable by human beings, which can be used on an industrial site where an operation causing the pollution of the ambient air, by smoke, dust, vapor or the like, is carried out, particularly in an enclosed area, room or structure.

Many industrial operations, such as maintenance, cleaning, repair and manufacturing operations or the like, generate or are carried out in areas contaminated by various atmospheric pollutants or impurities such as gases or smoke, dust, aerosols, radioactive particles, volatile solvents and/or the like, which become mixed with the ambient atmospheric air and thereby create health risks for the operators working on the industrial sites where these operations are carried out.

By way of examples, mention may be made of asbestos-deflocking sites which generate asbestos dust 20 and particles liable to be carcinogenic, sites where painting operations are carried out or else sites where the welding or cutting of metal workpieces is carried out with substantial smoke emission or else sites where the dismantling of nuclear plants is carried out.

It may be easily imagined that the health risks for the operators are even greater when the work or operation is carried out in an enclosed room, structure or area, that is to say in which no or very little normal replenishment of air takes place, for example in 0000 30 the case of asbestos deflocking in the cellar of a building or a welding operation using a coated ooee electrode in the hold of a ship under construction or undergoing repairs or maintenance.

In the light of the foregoing, so as to prevent the operators from inhaling excessively high quantities of atmospheric impurities, it is recommended, or indeed is mandatory, for operators to wear breathing masks or the like.

2 In addition, when the masks are simply fitted with filters, on the one hand, these filters often become fouled by the accumulation of impurities, especially dust, which further reduces the filtration effectiveness and, on the other hand, certain particles are not stopped.

To alleviate this problem, it is recommended to use work masks supplied with breathable gas, that is to say to use pure or purified air for supplying breathable air to the work station or stations, that is to say the operator or operators, so as to allow them to breath sufficient air to ensure correct oxygenation of their lungs and hence the fewest possible impurities.

To do this, it is possible either to use air conveyed by an existing compressed-air mains for supplying masks worn by the operators or to provide the operators with personal air supplies, such as highpressure bottles.

However, this is not always possible or has certain drawbacks.

Thus, in the first case, all industrial sites are not endowed with a compressed-air mains and, in the second case, the personal air supplies are, on the one hand, necessarily limited in terms of capacity, i.e. in volume, and, on the other hand, wearing one or more air supplies causes fatigue in the operator and restricts his ability to move around.

In addition, the application often requires 30 both substantial air flow rates, for example from 0.1 to 100 m 3 generally from 0.5 to 10 m 3 per consumer, and an air production system that can be moved from one point to another on the actual work site, for example from one room to another or from one building to another.

Thus, the problem that then arises within the context of the present invention is how to improve the devices or units for producing breathable air so as to provide a unit which can be easily moved over any work I 3 site, which is simple to connect and to turn on, which is capable of operating both indoors and outdoors, which is applicable to various types of work and capable. of producing at least about 60 to 80 m 3 /h of air, corresponding to about 6 to 8 masks supplied with a continuous flow.

The solution provided by the present invention is therefore a movable and transportable unit for producing breathable air, which comprises at least one first subassembly and one second subassembly, said first and/or second subassemblies comprising connection means allowing the first subassembly and the second subassembly to be connected to each other, to enable the unit to operate, and allowing the first and second subassemblies to be disconnected from each other, so as to enable said first and second subassemblies to be transported or moved independently of each other: the first subassembly forming an air supply system which includes air compression means used for 20 compressing air to a pressure of greater than 1 bar; and the second subassembly forming a compressedair treatment system comprising: .compressed-air treatment means used to remove at least some of the impurities liable to be found in the compressed air delivered by the air compression means; and Scontrol means used to control at least the oooo* air treatment means and/or the air compression means.

Depending on the case, the unit of the :o invention may include one or more of the following characteristics: it furthermore includes at least one third subassembly forming a system for storing air treated by the second subassembly, said second and/or third subassemblies which include linking means used to link the second subassembly downstream of the third subassembly in order to enable the third subassembly to 4 be supplied with air treated by the second subassembly, said linking means allowing said second and third subassemblies to be disconnected from each other so as to enable said second and third subassemblies to be transported or moved independently of each other; the air compression means are at least one air compressor, preferably a screw compressor; the compressed-air treatment means include at least one adsorption and/or catalysis container, preferably at least one adsorption container; where appropriate, the compressed-air treatment means include at least one permeation membrane or at least one membrane module; said first and/or second and/or third subassemblies include handling and/or movement means used for transporting or moving them, preferably at least one of said first, second and third subassemblies includes rolling means used for movement over the floor by rolling and/or slinging means used for overhead movement by means of at least one sling and/or means for transportation on a pallet; the third subassembly comprises a buffer tank, the buffer tank preferably including gas expansion means; the means for controlling the second subassembly comprise at least one programmable controller, the programmable controller preferably controlling the air compression means.

The invention also relates to the use of a unit according to the invention for supplying breathable purified air free of the smell of oil to one or more operators provided with breathing masks who are in a room or an area where an operation generating atmospheric impurities, especially gases, smoke, dust, volatile particles and/or aerosols, is carried out.

Preferably, the operation generating atmospheric impurities is a welding or cutting operation generating smoke, an asbestos-deflocking operation generating volatile dust, a painting operation and a dismantling operation.

The invention will now be described in greater detail with the aid of the appended figures, which are given by way of illustration but imply no limitation.

Figure 1 shows a movable and transportable unit for producing breathable air according to the invention, which comprises a first subassembly 1 forming an air supply system, a second subassembly 2 forming a compressed-air treatment system and a third subassembly 3 forming a system for storing air treated by the second subassembly 2.

The first 1 and second 2 subassemblies comprise connection means 9, such as a flexible hose or a gas line for example, allowing the first 1 and second 2 subassemblies to be connected to each other, to enable, on the one hand, the unit to operate and, on the other hand, to allow the first l1and second 2 subassemblies to be disconnected from each other when it is necessary to transport them or move them, independently of each other, to their operating or work site.

shown in detail in figure 2, the first subassembly 1 forms an air supply system which includes ee* *air compression means 4 used for compressing air to a 25 pressure of greater than 1 bar, preferably to a pressure of 4 to 15 bar, preferably from 5 to 13 bar, for a flow rate, for example, of about 100 m3/h to a few thousands of m 3 For this purpose, it is S"preferred to use a screw compressor 4 actuated by an electric motor 15 with a filter 14 placed at the outlet.

Moreover, the second subassembly 2 forms a compressed-air treatment system comprising compressedair treatment means 5 used to remove at least some of the impurities liable to be found in the compressed air delivered by the air compression means 4 and control means 6 used to control, via the connection cable 16, the air treatment means 5 and/or the air compression means 4, the control means 6 preferably controlling the 6 air compression means 4, as described in document EP-A-864 818.

As regards the third subassembly 3, this forms a system 7 for storing air treated by the second subassembly 2, for example a buffer tank having a volume of between 0.1 m 3 and 10 m 3 for example between 0.1 m 3 and 2 m 3 The second 2 and/or third 3 subassemblies include linking means 8 used to link the second subassembly 2 downstream of the third subassembly 3 in order to enable the third subassembly 3 to be supplied with air treated by the second subassembly 2, the linking means 8 being, for example, one or more gas lines.

Said linking means 8 allow said second 2 and third 3 subassemblies to be disconnected from each other so as to enable them to be transported or moved independently of each other.

Figure 2 shows that the compressed-air 20 treatment means 5 comprise two adsorption and/or catalysis containers 10, 11 making it possible to remove, by catalysis and/or adsorption, at least some of the gaseous impurities, especially the toxic gases likely to be present in smoke, for example NOx, SOx, C0 2 CO and ozone or moisture favorable to bacterial development.

o" For this purpose, it is possible to use, for example, the system described by document EP-A-875 277, S" which will be adapted so as to meet the NF EN12021 standard: Air comprim6 pour appareil de protection respiratoire [Compressed air for respiratory protection apparatus] (April 1999).

Preferably, the two adsorption and/or catalysis containers 10, 11 operate alternately and in a cycle, that is to say that one of the two containers is in production phase, producing purified air, while the other is in regeneration phase.

The operating cycles of the plant may be of the PSA (Pressure Swing Adsorption), VSA (Vacuum Swing 7 Adsorption) or TSA (Temperature Swing Adsorption) type, preferably operating in PSA cycles with a high adsorption pressure of between 1 bar and 20 bar and a low regeneration pressure of between 0.3 bar and 3 bar.

The air to be purified is, within the context of the invention, at a temperature of between OOC and It may be seen in figure 2 that the first subassembly 1 includes movement means used for transporting or moving it, namely rolling means used for movement over the floor by rolling, for example several wheels 21, and possibly slinging means, such as fastening hooks (not shown), used for overhead movement by means of at least one sling and by means, for example, of a crane or the like, or means for transportation on a pallet.

As shown schematically in figure 2, the means 6 for controlling the second subassembly 2 comprise at least one programmable controller 18 which controls the air compression means 4 via the cable 16.

Furthermore, this second subassembly 2 also includes an electrical part with an electric current o* transformer 30, for example for a 400 V/220 V Stransformer, a 24 V current supply 31 with several fuses 32, a phase inverter 40 and a lockable •switch/circuit breaker 41, for example of the 40 A and mA type.

Warning lamps 43 indicate (from the top down in S"the figure) that the power is on (green lamp), the standby period during preheating (yellow lamp), a general system fault (red lamp) and the need to actuate the phase inverter before starting the unit.

Furthermore, a start button 44 is used to start the unit and a counter 45 is used to keep account of the number of hours of operation of the subassembly 2 (separate from the subassembly 1) Commissioning requires an initial connection to 380/400 V supply, via the mains outlet 42 comprising three phases and one neutral, by an electrician or the 8 like, but the phase inverter 40 provided on the second subassembly 2 prevents any electrical manipulation upon an error observed after the connections have been made.

In addition, safety means moreover limit the consequences of any inversion in the electrical connections.

Thus, the unit also includes a circuit breaker 33 protecting the supply 31, a circuit breaker 34 protecting the transformer 30, a divisional circuit breaker 35 supplying the assembly i, a divisional circuit breaker 36 supplying the heater for defrosting the assembly 2, a phase inversion detector 37 preventing startup, a 380 V supply cable for the screw compressor and a radiator 39 for preheating the assembly 2.

During operation, the air compressed by the compressor 4 of the subassembly 1 is transferred to the second subassembly 2, via the hose 9, before being conveyed to the compressed-air treatment means 5 via a 20 line 56 for conveying air to be treated.

Provided on the line 56 are, in succession, a cyclone device 50 provided with a temperature alarm and/or with a purge 57, and two filters 51 and 52 o provided with purges, these filters serving to strip 25 the air of the impurities of the water and oil type S"which are removed via the condensate collector 53, the system 54 for treating the condensates and the line for removing the water stripped of oil.

*oo The treatment unit 5 and its operation are described in documents EP-A-864 818 and EP-A-875 277, to which reference may be made for further details.

By way of indication, it may simply be pointed out that, at the outlet of the adsorbers 10, 11 there is a line 81 which includes a calibrated orifice 80 and is used during the regeneration phases of the adsorbers 11, as shown in figure 2; the presence of such a calibrated orifice 80 allows the adsorber to be regenerated with a suitable flow of gas. A pneumatic valve or solenoid valve controlled by the controller 18 9 makes it possible, moreover, at the end of regeneration, to reduce the compression time and in this way, indirectly, to reduce the buffer volume 7 needed for the process.

A filter 90 is provided downstream of the adsorbers 10, 11 on the gas-conveying line 56, which enables the purified air to be brought as far as the buffer tank 7.

Moreover, the gas-conveying line 56 also includes a pressure sensor 91, a temperature sensor 93 and a pressure switch 92 indicating too low a pressure in the buffer tank 7, for example a pressure of less than 5 bar.

As regards the buffer tank 7, for example of 300 liters capacity, this is provided with an expansion/filtration assembly 70 and with coupling means for hoses 8 with suitable couplers, preferably "quick-release" couplers.

The hose 8 is connected onto the subassembly 3 20 at a calibrated orifice with a nonreturn valve 94, the diameter of the orifice being between 0.1 mm and 10 mm, for example about 0.5 mm, so as to prevent the hose 8 "from whipping when it is disconnected under pressure.

o Preferably, the three subassemblies 1, 2 and 3 are mounted on castors, which can be easily manipulated *e*by a person indoors, including in corridors, when going through doors, in goods elevators, etc., and outdoors.

Furthermore, they can be handled by a crane and oeeoe transported on pallets, and are joined together by coded hoses and cables.

Figure 3 shows a top view of a unit according the invention in which it may be seen that the first 1, second 2 and third 3 subassemblies are placed on a transportation means 100 of the wooden pallet type.

In other words, the floor area of each subassembly 1 to 3 has been chosen so that the area of each of them does not exceed that of a European pallet, thus allowing low-cost transportation.

10 The arrangement of the three subassemblies 1, 2 and 3 on a metal support base, with or without reinforcement, is one possible option which is suitable for applications in which mobility in buildings is not necessary and where the cost of the transportation is less important.

The unit according to the invention is particularly suitable for supplying breathable air to one or more operators provided with breathing masks who are in a room or an area within which there is little natural aeration and ventilation, for example a cellar or a ship's hold, and in which an operation generating atmospheric impurities, particularly gases, smoke, dust, volatile particles and/or aerosols, is carried out, in particular a cutting or welding operation generating smoke, an asbestos-deflocking operation generating volatile dust, a painting operation and a nuclear-plant dismantling operation.

In general, the unit of the invention is usually installed on the outside of the work area where it picks up the ambient air and purifies it before sending it to the masks of the operators or workmen, via one or more flexible lines or the like.

e .Because of the air purification according to the invention, the operators breathing the air thus opurified are no longer inconvenienced by oil smells and by moisture, which are conveyed by the air, as has indeed been the case with the devices of the prior art.

Ehroughout the description and claims of the specification the word :comprise" and variations of the word, such as "comprising" and "comprises", is not intended to exclude other additives, components, integers or steps.

Claims (3)

1. A movable" and transportable-unit for producing breathable air, which cdmprises- at least .i.-ne first subassembly and one second subassembly, said first and/or second subassemblies comprising connection means allowing the first subassembly and the second subassembly to be connected to each other, to enable the unit to operate, and allowing the first and second subassemblies to be disconnected from "each other, so as to enable said first and' second subassemblies to be transported or moved independently of each other: the first subassembly forming an air supply system which includes air compression means used for compressing air to a pressure of greater than 1 bar; and the second subassembly forming a compressed-air treatment system comprising: 20 compressed-air treatment means used to remove at least some of the impurities liable C .to be found in the compressed air delivered by the air compression means; and control means used to control at least 25 the air treatment means and/or the air "d compression means

2. unit as claimed in claim 1, which furthermore includes at least one third subassembly forming a system for storing air treated by the second. subassembly, said second and/or third subassemblies which include linking means used to link the second subassembly downstream of the third subassembly. in order to enable the third subassembly to b.e supplied with air treated by the second subassembly, said linking means allowing- said second and 'third subassemblies to be disconnected from each other so as to enable said second and third subassemblies to be transported or moved independently of each other.

12- 3. A unit as claimed in either of claims 1 or 2, wherein the air compression means comprises at least one air compressor, preferably a screw compressor. 4. A unit as claimed in any one of claims 1 to' 3, wherein the compressed-air treatment means comprise at least one adsorption and/or catalysis container preferably at least one adsorption container. A unit as claimed in any one of claims 1 to 3, wherein the compressed-air treatment means comprise at least one permeation membrane or at least one membrane module. 6. A unit as"'claimed in any one of claims 1 to wherein said first and/or second and/or third subassemblies include handling and/or movement means used for transporting or moving them, preferably at least one of said first, second and third subassemblies includes rolling means used for movement over the floor by rolling and/or slinging means used for overhead movement by means of at least one sling and/or means 20 for transportation on a pallet. 7. A unit as claimed in one of claims 1 to 6, S. wherein the third subassembly comprises a buffer tank, the buffer tank preferably including gas expansion means. 8. A unit as claimed in one of claims 1 to 7, wherein the means for controlling the second subassembly comprises at least one programmable controller, the programmable controller preferably controlling the air compression means. 30 9. Use of a unit according to any one of claims 1 to 8, for supplying breathable purified air free of the smell of oil to one or more operators provided with breathing masks who are in a room or an area where an operation generating atmospheric impurities, especially gases, smoke, dust, volatile particles, or aerosols and/or radioactive particles, is carried out. Use as claimed in claim 9, in which the operation generating atmospheric impurities is a welding or cutting operation generating smoke, an 13 asbestos-deflocking operation generating volatile dust or a painting or nuclear-plant dismantling operation. 11. A unit according to claim 1 substantially as hereinbefore described with reference to any one of the drawings. 12. Use according to claim 9 or claim 10 substantially as hereinbefore described with reference to any one of the drawings. DATED: 30 January, 2001 PHILLIPS ORMONDE FITZPATRICK Attorneys for: AIR LIQUIDE SANTE (INTERNATIONAL) 0 Go 0O 0eO 0:: S