FR3127569A1 - Real-time detection system for volatile chemical compounds in protective equipment - Google Patents

Abstract

This real-time detection system (2) of at least one volatile chemical compound, and/or of at least one mixture of several volatile chemical compounds, comprises a gas collection device (6) configured to be placed in a protective equipment, a gas detector (8), and a main circuit (10) configured to fluidically connect the gas collection device (6) and the gas detector (8). Figure for abstract: Fig 1

Description

Real-time detection system for volatile chemical compounds in protective equipment

The present invention relates to the safety of operators handling products harmful to the health of said operators.

In particular, the present invention relates to the detection of volatile chemical compounds in protective equipment, for example protective gloves, so as to verify and guarantee the proper sealing provided by said protective equipment.

In general, the invention applies to all gas detection systems positioned behind a protective element in order to verify the effectiveness of said protective element.

Prior techniques

The protective equipment, and in particular the protective gloves used by operators to protect themselves from chemical products, for example volatile organic compounds, are generally chosen and used without any tests other than those of the manufacturer being systematically carried out. carried out to check the permeation of said protective gloves before handling harmful compounds.

Thus, an operator may have to use protective gloves that are not very suitable and may be permeable to certain allergenic or carcinogenic substances, for example acetone, toluene or benzene.

In addition, the impermeability of a glove, even compatible with a chemical product being handled, may depend on the contact time between the glove and said chemical product, the mechanical tensions exerted on the glove by the gestures of the fingers (stretching of the material by example), temperature, humidity of the hand, etc.

Similarly, a glove does not have the same behavior vis-à-vis a sum of substances as vis-à-vis each of the substances taken independently. That is to say that a glove resistant to a compound A and a compound B will not necessarily be resistant to a mixture composed of A and B.

The passage of the chemical through the glove can be done slowly without the operator noticing it. During the permeation of a volatile chemical product, the gaseous phase of said product is present with the liquid phase in the glove and the operator is then exposed.

The object of the present invention is therefore to overcome the aforementioned drawbacks and to provide a system for the real-time detection of a vapor phase of a volatile chemical compound so as to alert an operator during his work phases of the presence of a protection flaw in his protective gear.

The subject of the present invention is a system for the real-time detection of at least one volatile chemical compound, and/or of at least one mixture of several volatile chemical compounds, comprising a gas collection device configured to be placed in a protective equipment, a gas detector, and a main circuit configured to fluidly connect the gas collection device and the gas detector.

Thus, the positioning of a gas collection device directly in the protective equipment and connected to a gas detector allows an operator to know if the products he is handling pass through the wall of his protective equipment, allowing him to better protect themselves.

Advantageously, the protective equipment comprises a protective glove.

In one embodiment, the detection system further comprises a circuit for supplying air to the gas collection device, the main circuit comprising a main tube and a pump configured to circulate a fluid from the supply circuit in air to the gas detector through an internal passage of the gas collection device, said gas collection device comprising at least one perforation configured to connect the internal passage to the external environment of the gas collection device, so that the circulation of fluid in the internal passage creates a suction in the at least one perforation from the external environment towards the internal passage.

Advantageously, the air supply circuit comprises an air purification system and a supply tube connecting the air purification system and the gas collection device.

Advantageously, the air purification system comprises activated carbon.

In one embodiment, the gas collection device is configured to be disposed within a protective glove of the protective equipment, the gas collection device comprising a ring configured to be inserted around a finger of a hand inserted into the protective glove, the ring comprising a first end piece connected to the power supply circuit and a second end piece connected to the main circuit, the first and the second end piece being connected by the internal passage formed in the ring.

Advantageously, the ring comprises a first annular face comprising the first end piece and the second end piece, and a second annular face comprising a plurality of regularly spaced perforations, the perforations having a diameter of between 0.1 and 2 millimeters.

In a particular embodiment, the main tube and the supply tube are chemically resistant, are made of a material comprising a fluoropolymer, and have a length greater than 40 centimeters.

Advantageously, the gas detector comprises a photoionization detector and/or a semiconductor gas sensor, the gas detector being configured to emit a signal when a volatile chemical compound harmful to human skin is detected.

The invention also relates to protective equipment comprising the real-time detection system for a volatile chemical compound as defined above.

The invention also relates to a method for using the detection system as defined above and/or the protective equipment as defined above, the method comprising the following steps:

- Verification of the correct operation of the gas detector and calibration of said gas detector according to the volatile chemical compound to be detected;

- Installation of the gas collection device in a protective glove of the protective equipment;

- Sealing of the wrist of the protective glove and verification of the absence of signal emitted by the gas detector;

- Handling of chemical compounds;

- Stopping the step of handling chemical compounds when the gas detector emits a signal or when no signal is emitted by the gas detector (8) at the end of the manipulation;

- Removal of the gas collection device outside the protective glove in an environment away from chemical compounds; And

- Cleaning of the detection system.

Other aims, characteristics and advantages of the invention will appear on reading the following description, given solely by way of non-limiting example, and made with reference to the appended drawings in which:

is a schematic view of a real-time detection system for volatile chemical compounds according to the invention;

is a schematic perspective view of a ring of a detection system according to the invention;

is a schematic perspective view of a first annular part of the ring according to the ;

is a schematic perspective view of a second annular part of the ring according to the ; And

is a schematic representation of the steps of the method for using the real-time detection system for volatile chemical compounds according to the invention.

Detailed description of at least one embodiment

Schematically represented on the a detection system 2 in real time of volatile chemical compounds according to the invention.

By volatile chemical compounds is meant any compound having a gaseous phase, also called vapor phase, in equilibrium with the liquid phase of the compound. In particular, the vapor phase of a volatile organic compound in protective equipment, a sign of permeation of the liquid phase through said protective equipment, must be detected by the detection system in order to best protect the operator. In the embodiment represented, the protective equipment comprises a protective glove 4. It can also comprise a suit, and/or boots. Only the protective glove 4 is shown.

The detection system 2 comprises a gas collection device 6, a gas detector 8 in real time and a main circuit 10 configured to fluidically connect the gas collection device 6 and the gas detector 8.

The gas collection device 6 is configured to be placed in a protective glove 4 and comprises an internal passage 12 and at least one perforation (not shown on the ) opening on the one hand into the internal passage 12 and on the other hand into the protective glove 4. Preferably, the device 6 for collecting gas comprises several perforations configured to recover a gas present in the external environment of the device 6 gas collection, for example the inside of the protective glove 4, the gas being able to flow to the gas detector 8 passing through the internal passage 12 then through the main circuit 10.

In particular, the main circuit 10 comprises a main tube 13 configured to contain the gas circulating between the gas collection device 6 and the gas detector 8, and a pump 14 configured to circulate a gas in said main tube 13.

The gas detector 8 comprises for example a photoionization detector and/or a semiconductor gas sensor. These technologies allow the detection of several types of harmful compounds.

The gas detector 8 is for example configured to emit a signal, for example light or sound, when a volatile chemical compound considered harmful to human skin is detected above a predefined concentration threshold. Additionally, gas detector 8 includes a computer configured to record the measurements made by gas detector 8.

In some embodiments, gas detector 8 includes pump 14.

The detection system 2 further comprises a circuit 16 for supplying air to the device 6 for collecting gas. This air supply circuit 16 comprises a supply tube 18 connecting the gas collection device 6, and in particular the internal passage 12, with the ambient air. The internal passage thus connects the supply tube 18 and the main tube 13.

The pump 14 is configured to draw in ambient air, circulate it from the air supply circuit 16 to the internal passage 12 of the device 6 for collecting gas, then from the internal passage 12 to the main tube 13 until to the gas detector 8. For example, the pump 14 and the tubes 13 and 18 are configured to deliver a flow rate of 0.1 to 0.5 liters per minute.

The circulation of air in the internal passage 12 creates a slight depression at the level of the junction of the perforations with the internal passage 12, thus promoting the suction and the collection of gas present in the protective glove 4. The gases sucked in by the perforations then flow to the gas detector 8.

Optionally, the air supply circuit 16 comprises a purification system 20 of the ambient air. The supply tube 18 is configured to connect the purification system 20 and the internal passage 12.

In this embodiment, the gas detector 8 is less subject to ambient air pollution, which allows better detection of harmful gases. In particular, the purification system 20 is dimensioned according to the pollution of the ambient air, a polluted air meaning an air likely to disturb the gas detector 8.

In one embodiment, the air cleaning system 20 includes activated carbon.

Advantageously, the main tube 13 and the supply tube 18 are chemically resistant. For example, they are made and/or covered with a material comprising a fluoropolymer.

Preferably, the main tube 13 and the supply tube 18 have a length greater than 40 centimeters so as to supply the detection system 2 with air sufficiently distant from the area for handling harmful substances. More generally, the tubes 13 and 18 have a sufficient length to position the purification system 20, the pump 14 and the gas detector 8 on the arm, on the strap of a bag or on the back of the operator. Thus, the real-time detection system 2 is easily transportable and allows the detection in the field of harmful volatile chemical compounds.

In the embodiment illustrated in the , the device 6 for collecting gas comprises a ring 22 configured to be inserted around a finger of a hand 24 inserted in the protective glove 4. Thus, the ring 22 does not hinder the operator in his movements.

In various modes of implementation, the hand 24 is the hand of an operator when handling chemical substances, or a dummy hand or a robotic hand in the case of tests carried out without an operator.

Schematically represented on the an embodiment of a ring 22 of a detection system 2 according to the invention.

The ring 22 includes a first tip 26, also illustrated in the , connected to the supply tube 18 of the supply circuit 16. The ring 22 also comprises a second end piece 28 connected to the main tube 13 of the main circuit 10. The first end piece 26 and the second end piece 28 are hollow and fluidly connected by the internal passage 12 formed in the ring 22. The end pieces 26 and 28 are preferably positioned so as to be, when the ring 22 is slipped on a finger, on the back of said finger.

In one embodiment, the ring 22 comprises a first annular face 30 on which the first end piece 26 and the second end piece 28 are positioned. During the use of the detection system 2, the first face 30 is preferably positioned towards the wrist of the operator in order to facilitate the positioning of the main tube 13 and the supply tube 18.

The ring 22 also comprises a second annular face 32 on which the perforations 34 open. The second face 32 is preferably positioned towards the fingertips of the operator when using the detection system 2 so as to orient the perforations 34 to an area where the probability of vapor phase infiltration is high.

Advantageously, the perforations 34 are regularly spaced over the entire second face 32 of the ring 22 so that gas detection can be carried out for a vapor phase all around a finger.

In one embodiment, the perforations 34 have a diameter between 0.1 and 2 millimeters.

Advantageously, the number of perforations 34 is greater than five.

In various embodiments, the ring 22 is made using a three-dimensional additive manufacturing process. Alternatively, and as illustrated in the , the ring 22 is made by gluing or welding a first annular part 36 with a second annular part 38. The ring 22 is for example made of a plastic material.

Schematically represented on the a first annular part 36 of the ring 22. The first annular part 36 comprises for example the first annular face 30, the first and the second end pieces 26 and 28, as well as a positioning rail 40 configured to cooperate with the second annular part 38 to form the internal passage 12.

Schematically represented on the a second annular part 38 of the ring 22 configured to cooperate with the first annular part 36 illustrated in the to form the ring 22 illustrated in the .

The second annular part 38 comprises the second annular face 32, an open duct 42 made along the second annular part 38 and configured to form the internal passage 12, and the perforations 34 opening on the one hand onto the second annular face 32 and on the other hand in the open conduit 42.

The positioning rail 40 is less thick than the depth of the open conduit 42. Furthermore, the positioning rail 40 cooperates with the open conduit 42 so that the positioning rail 40, in the assembled configuration of the ring 22, is inserted into the open conduit 42, thus forming the internal passage 12.

Schematically represented on the the steps of a method of using the detection system 2 according to the invention.

Firstly, a step 44 of verification of the correct operation of the gas detector 8 is carried out according to the volatile chemical compound(s) to be detected. Optionally, a setting and/or a calibration is carried out so as to take account of the measurement conditions, for example the conditions of pressure, of temperature, or of the presence of sweat, these parameters being able to influence the detection.

Then, a step 46 of fitting the gas collection device 6 into the protective glove 4 is carried out. soapy water, a hydroalcoholic gel is not indicated because it can distort the detection.

A step 48 of sealing the wrist of the protective glove is then carried out so as to avoid direct chemical compound infiltration.

Then, the operator performs a step 50 of manipulation of chemical compounds until a signal is emitted by the gas detector 8 during a step 52, or until the end of the manipulation if no signal is emitted by the gas detector 8.

A step 54 of removing the device 6 for collecting gas outside the protective glove 4 is then carried out in a clean environment at a distance from the chemical compounds.

Finally, a step 56 of cleaning the detection system 2 is carried out, for example by passing it through an oven.

Claims (10)

System for detecting (2) in real time at least one volatile chemical compound, and/or at least one mixture of several volatile chemical compounds, characterized in that it comprises a gas collection device (6) configured to be disposed in protective equipment, a gas detector (8), and a main circuit (10) configured to fluidically connect the gas collection device (6) and the gas detector (8). System according to claim 1, further comprising a circuit for supplying (16) air to the gas collection device (6), the main circuit (10) comprising a main tube (13) and a pump (14) configured to circulating a fluid from the air supply circuit (16) to the gas detector (8) via an internal passage (12) of the gas collection device (6), said gas collection device (6) gas comprising at least one perforation (34) configured to connect the internal passage (12) to the external environment of the gas collection device (6), such that the circulation of fluid in the internal passage (12) creates suction in the at least one perforation (34) from the external environment to the internal passage (12). System according to Claim 2, in which the air supply circuit (16) comprises an air cleaning system (20) and a supply tube (18) connecting the cleaning system (20) to the air and the device (6) for collecting gas. A system according to claim 3, wherein the air cleaning system (20) comprises activated carbon. A system according to any of claims 2 to 4, wherein the gas collection device (6) is configured to be disposed within a protective glove (4) of the protective equipment, and wherein the device (6 ) gas collection comprises a ring (22) configured to be inserted around a finger of a hand inserted in the protective glove (4), the ring (22) comprising a first end piece (26) connected to the circuit of supply (16) and a second endpiece (28) connected to the main circuit (10), the first and the second endpiece (26; 28) being connected by the internal passage (12) formed in the ring (22). System according to claim 5, in which the ring (22) comprises a first annular face (30) comprising the first tip (26) and the second tip (28), and a second annular face (32) comprising a plurality of perforations ( 34) regularly spaced, the perforations (34) having a diameter of between 0.1 and 2 millimeters. A system according to any one of claims 3 to 6, wherein the main tube (13) and the supply tube (18) are chemically resistant, are made of a material comprising a fluoropolymer, and have a length greater than 40 centimeters . A system according to any of claims 1 to 7, wherein the gas detector (8) comprises a photoionization detector and/or a solid-state gas sensor, the gas detector (8) being configured to emit a signal when a volatile chemical compound harmful to human skin is detected. Protective equipment, characterized in that it comprises the real-time detection system (2) of a volatile chemical compound according to any one of Claims 1 to 8. Method of using the detection system (2) according to any one of Claims 1 to 8 and/or the protective equipment according to Claim 9, characterized in that it comprises the following steps:

• Verification of the correct operation (step 44) of the gas detector (8) and calibration of said gas detector (8) according to the volatile chemical compound and/or the mixture of compound to be detected;
• Placing the gas collection device (6) in a protective glove (4) of the protective equipment (step 46);
• Sealing of the wrist (step 48) of the protective glove (4) and verification of the absence of signal emitted by the gas detector (8);
• Manipulation of chemical compounds (step 50);
• Stopping the step (50) of manipulating chemical compounds when the gas detector (8) emits a signal (step 52) or when no signal is emitted by the gas detector (8) at the end of the handling ;
• Removing the gas collection device (6) from outside the protective glove (4) in an environment away from chemical compounds (step 54); And
• Cleaning (step 56) of the detection system (2).