Calorimetry device

Abstract

Calorimetry Device A calorimetry device (1), particularly for studying the fire behavior of materials, configured to allow the guided movement of at least one cone calorimeter (2) between a first position (P1) located away from a sample to be tested and a second position (P2) in which the cone calorimeter (2) is positioned opposite said sample to be tested. Figure for abbreviation: Fig. 1

Description

Title of the invention: Calorimetry device Technical field

[0001] The present invention relates to a calorimetry device, in particular for studying the fire behavior of materials, an associated system and method. Prior art

[0002] A cone calorimeter or cone calorimeter is a measuring instrument for studying the fire behavior of a material "on a small scale", that is to say on the scale of the material. Such an instrument makes it possible, for example, to evaluate the behavior of a material in conditions close to those of a fire.

[0003] It comprises a device of generally conical shape (also called heating resistor, spiral, furnace or radiant cone) generating radiant illumination (also called thermal flux density or radiative flux density or heat flux density, expressed in kW.m2) to which the material to be tested is subjected.

[0004] Different parameters can be measured when using a cone calorimeter such as the mass loss rate (MLR) of the material or the heat release rate (HRR) released by the material via a calorimetric measurement by oxygen depletion for example.

[0005] In certain cases it is necessary to be able to move from a zero heat flux density (absence of radiative illumination) to a controlled non-zero density (presence of controlled radiative illumination) to which the sample of material to be tested is subjected.

[0006] To do this, it is known to position a cone calorimeter opposite the material to be tested and to use a removable cover ("insulating shield" or "screen" in English) which can be placed between the cone calorimeter and the material to be tested.

[0007] However, when placed between the cone calorimeter and the material to be tested in order to obtain an absence of illumination, the cover heats up rapidly over time. The cover then itself generates uncontrolled illumination on the material to be tested and therefore no longer fulfills its function correctly.

[0008] Similarly, when the cover is removed in order to obtain controlled illumination, the regulation system used leads to fluctuations in the illumination generated which therefore do not allow perfectly controlled illumination to be obtained.

[0009] It is also necessary in certain cases to be able to move from one non-zero controlled radiant illumination level to another in order to vary the level of illumination to which the sample to be tested is subjected.

[0010] Devices have been proposed for varying the level of illumination to which the sample to be tested is subjected, however with a variation whose speed is very slow and poorly controlled. Statement of the invention

[0011] The invention aims to further improve the devices and methods used to study the fire behavior of materials, and in particular to overcome all or part of the above drawbacks. It achieves this by means of a calorimetry device, in particular for studying the fire behavior of materials, configured to allow the guided, and in particular automated, movement of at least one cone calorimeter between a first position remote from a sample to be tested and a second position in which the cone calorimeter is positioned opposite said sample to be tested.

[0012] By "cone calorimeter positioned in front of the sample to be tested" is meant a cone calorimeter positioned so that the axis of the cone is, on the one hand perpendicular to the exposed face of the sample, and on the other hand aligned with the center of the exposed face of the sample.

[0013] By "cone calorimeter in a position remote from the sample to be tested" is meant a cone calorimeter positioned sufficiently remote from the sample so that the sample does not receive the radiative irradiance generated by the cone calorimeter.

[0014] The device can allow the cone calorimeter to be moved in a guided manner from the first to the second position so as to move respectively from a zero heat flux density to a controlled non-zero density to which the sample to be tested is subjected. Conversely, the device can allow the cone calorimeter to be moved in a guided manner from the second to the first position so as to move respectively from a controlled non-zero heat flux density to a zero density to which the sample to be tested is subjected. The invention can thus make it possible to avoid the screen of the prior art and the associated drawbacks.

[0015] The device can be configured to allow the guided, and in particular automated, movement of at least one other cone calorimeter between a third position remote from the sample and the second position.

[0016] Preferably, the distance between the first and second positions and / or between the second and third positions is chosen to be sufficient so that the radiative illumination generated by a cone calorimeter in the first or third position does not disturb the sample.

[0017] The distance between the first and second positions and / or between the second and third positions may be greater than or equal to twice the diameter of the calorimeter. cone, better greater than or equal to three times the diameter of the cone calorimeter, for example greater than or equal to 40 cm, better 60 cm.

[0018] Preferably, the distance between the second and third positions is substantially equal to that between the first and second positions.

[0019] The device can be configured to allow the cone calorimeters to be positioned successively one after the other in front of the sample. This other cone calorimeter advantageously has characteristics different from the first.

[0020] The device may be configured to allow the simultaneous movement and at the same speed of one of the cone calorimeters from the first to the second position and of the other cone calorimeter from the second to the third position and / or the simultaneous movement and at the same speed of one of the cone calorimeters from the second to the first position and of the other cone calorimeter from the third to the second position.

[0021] One of the cone calorimeters can radiate a first predefined heat flux density and the other cone calorimeter can radiate a second predefined heat flux density, different from the first.

[0022] Preferably, the first and second heat flux densities are non-zero.

[0023] The device can allow the flux density to be varied automatically. heat to which the sample is subjected by automatically selecting the cone calorimeter according to the heat flux density to which the sample is to be subjected.

[0024] The device can thus make it possible to vary the level of illumination to which the sample is subjected in a controlled manner.

[0025] The first heat flux density may be greater than the second or vice versa, and the device may be configured to allow the sample to be successively subjected to the first and then the second heat flux density.

[0026] The first heat flux density may be greater than or equal to 55 kW.m2, preferably between 55 and 85 kW.m2, and the second heat flux density may be less than or equal to 55 kW.m2, preferably between 35 and 55 kW.m2.

[0027] In one example, the first heat flux density is equal to 85 kW.m2 and the second heat flux density is equal to 42.5 or 55 kW.m2. In another example, the first heat flux density is equal to 75 kW.m2 and the second heat flux density is equal to 55 kW.m2. In yet another example, the first heat flux density is equal to 55 kW.m2 and the second heat flux density is equal to 35 kW.m2.

[0028] The difference in absolute value between the first and second heat flux density can be between 10 and 50 kW.m2, better between 15 and 45 kW.m2.

[0029] The ratio between the first and second heat flux density can be between 1.1 and 2.5, better between 1.2 and 2.1.

[0030] The device may be configured to allow the sample to be subjected to the first heat flux density for a predefined exposure time tj and then to the second heat flux density for a predefined exposure time t2.

[0031] The guidance can be linear or rotary.

[0032] The device may comprise at least one support arranged to receive the cone calorimeter(s). Linearly guided support

[0033] The support can be guided in translation along a guide axis, in particular horizontal or vertical. For reasons of space, a horizontal or vertical guide axis can be preferred.

[0034] The support can be mounted on slides, in particular with balls or rollers, preferably with balls.

[0035] The slides may include stops allowing the sliding of the cone calorimeter(s) to be stopped in predefined positions, the positioning of the stops along the slides being adjustable in particular.

[0036] The slides may further comprise shock absorbers associated with the stoppers, making it possible to absorb shocks when the cone calorimeter(s) slide.

[0037] Alternatively, the support is mounted on a conveyor, in particular a motorized, belt or band conveyor, such as a treadmill. Rotating guided support

[0038] The support, in particular a carousel, can be guided in rotation around an axis of rotation, in particular vertical or horizontal. Moving the calorimeter(s)

[0039] The movement of the cone calorimeter(s) from one position to another can be carried out in an automated manner. This can make it possible to vary in a controlled manner the heat flux density to which the sample is subjected and thus to improve the repeatability and / or reproducibility of the measurement of parameters such as the mass loss rate of the sample or the heat flow rate.

[0040] The movement of the cone calorimeter(s) from one position to another can be carried out in a motorized manner.

[0041] The device may comprise at least one actuator, in particular electric, hydraulic or pneumatic, preferably electric, configured to allow the movement of the cone calorimeter(s) from one position to another in less than 5 seconds. This may make it possible to improve the accuracy of the measurement of parameters such as the extinction time (“time-to-extinguishment” in English).

[0042] Such speed of movement is advantageous because it makes it possible to vary in a very short time the level of illumination to which the sample is subjected (either passage from a zero density of heat flux to a controlled non-zero density to which the sample is subjected or vice versa, or passage from one controlled non-zero density to another by passing from one calorimeter to another).

[0043] The device may comprise a control unit for controlling the actuator.

[0044] In a variant, the control unit allows the actuator to be actuated according to predefined time sequences of operation. For example, the control unit controls the actuator so that the latter is in a first step inactive for a duration corresponding to the predefined exposure time tj during which the sample is subjected to the first heat flux density, then in a second step active so as to allow the heat flux density to which the sample is subjected to vary from the first to the second heat flux density, then in a third step inactive for a duration corresponding to the predefined exposure time t2 during which the sample is subjected to the second heat flux density.

[0045] In another variant, the control unit allows the actuator to be actuated no longer according to predefined durations but according to the occurrence of events, such as ignition, self-ignition, extinction or self-extinction of the sample. For example, the sample may be subjected to a first heat flux density so as to allow self-ignition of the sample. When self-ignition occurs, the control unit actuates the actuator so that the sample is subjected to a second heat flux density, lower than the first, so as to allow self-extinguishment of the sample. When self-extinguishment occurs, the control unit actuates the actuator so that the sample is subjected to a third heat flux density, higher than the second, so as to allow self-ignition again.

[0046] The cone calorimeter(s) may be oriented vertically or horizontally.

[0047] By "vertically oriented cone calorimeter" is meant a cone calorimeter whose cone axis is horizontal. This means that the exposed face of the sample, i.e. subjected to the heat flux density emitted by the cone calorimeter, is located in a vertical plane.

[0048] By "horizontally oriented cone calorimeter" is meant a cone calorimeter whose cone axis is vertical. This means that the exposed face of the sample, i.e. subjected to the heat flux density emitted by the cone calorimeter, is located in a horizontal plane.

[0049] The device may comprise at least one fixed sample holder capable of receiving the sample, the cone calorimeter(s) being movable relative to the sample holder.

[0050] Preferably, the sample holder is positioned such that the distance between the sample placed in the sample holder and the cone calorimeter positioned opposite the sample is in a range from 20 to 100 mm. The device may be configured to allow said distance to be varied within said range.

[0051] As specified in ISO 5660-1, the sample to be tested may have dimensions of 10 cm x 10 cm and a maximum thickness of 5 cm. The sides and the unexposed face of the sample may be covered with aluminum foil.

[0052] The sample holder may be placed on a balance allowing the mass of the sample to be measured continuously. This may make it possible to determine the rate of mass loss of the sample as a function of time, even when the heat flux density to which the sample is subjected varies from one value to another, in particular when the cone calorimeters are positioned successively one after the other opposite the sample.

[0053] The device may comprise at least one thermal sensor positioned opposite the sample so as to measure the surface temperature of the sample almost continuously. The positioning of the thermal sensor may allow the measurement when a cone calorimeter is positioned opposite the sample since the measurement takes place through the orifice of the cone.

[0054] The thermal sensor can allow on the one hand a non-intrusive temperature measurement and on the other hand a temperature measurement of a larger surface unlike a measurement carried out with a thermocouple placed on the sample which only provides a point temperature measurement.

[0055] The thermal sensor may comprise an infrared camera, in particular a multispectral one. The use of a multispectral infrared camera has the advantage of being able to measure the temperature of the sample even when the latter is ignited since such a camera is capable of carrying out temperature measurements through the flames.

[0056] The camera can be equipped with an optical bandpass filter, in particular at 2564 cm1, making it possible to block the emission bands of the combustion gases generated during the combustion of the sample, in particular carbon dioxide and water vapor.

[0057] The device may be configured to allow the guided, and in particular automated and / or motorized, movement of a number of cone calorimeters greater than two, for example, three, four, five or six cone calorimeters.

[0058] The invention also relates, according to another of its aspects, to a calorimetric system, in particular for studying the fire behavior of materials, comprising a calorimetry device as defined above, and at least one cone calorimeter, in particular two cone calorimeters.

[0059] The system may comprise a number of cone calorimeters greater than two, for example, three, four, five or six cone calorimeters.

[0060] The invention also relates, according to another of its aspects, to a calorimetric measurement method, in particular for studying the fire behavior of materials, in particular using the calorimetric system as defined above, comprising the step consisting of:

[0061] (a) Moving in a guided, and in particular automated, manner at least one calorimeter cone from a first position remote from a sample to be tested to a second position in which the cone calorimeter is positioned opposite said sample to be tested, or

[0062] (b) Moving in a guided, and in particular automated, manner at least one calorimeter cone calorimeter of a second position in which the cone calorimeter is positioned opposite a sample to be tested at a first position remote from said sample to be tested.

[0063] The method may comprise steps (a) and (b).

[0064] The method may further comprise the step of:

[0065] (c) Moving in a guided, and in particular automated, manner at least one other ca cone lorimeter from the second position to a third position distant from the sample, or

[0066] (d) Moving in a guided, and in particular automated, manner at least one other ca cone lorimeter from a third position away from the sample to the second position.

[0067] The method may comprise steps (c) and (d).

[0068] Steps (a) and (c) can be carried out simultaneously and at the same speed.

[0069] Steps (b) and (d) can be carried out simultaneously and at the same speed.

[0070] The cone calorimeter(s) may be carried by a support guided in translation along a guide axis, in particular horizontal or vertical, and steps (a), (b), (c) and / or (d) may be carried out by sliding the support along the guide axis.

[0071] The cone calorimeter(s) may be carried by a support, in particular a carousel, guided in rotation around an axis of rotation, in particular vertical or horizontal, and steps (a), (b), (c) and / or (d) may be carried out by rotating the support around the axis of rotation.

[0072] Steps (a), (b), (c) and / or (d) can be carried out in an automated and / or motorized manner.

[0073] The method may comprise at least one actuator configured to allow complete each step in less than 5 seconds. Brief description of the drawings

[0074] The invention may be better understood by reading the detailed description which follows, non-limiting examples of its implementation, and by examining the attached drawing, in which:

[0075] [Fig-1] [Fig.l] schematically represents an example of a calo- device rhymetry according to the invention, in front view,

[0076] [Fig.2] [Fig.2] represents the device of [Fig.l] after displacement of the ca cone lorimeter from first to second position,

[0077] [Fig.3] [Fig.3] schematically represents another example of a device for calorimetry according to the invention, in front view,

[0078] [Fig.4] [Fig.4] represents the device of [Fig.3] according to a different view,

[0079] [Fig.5] [Fig.5] represents the device of figures 3 and 4 according to a view still different,

[0080] [Fig.6] [Fig.6] schematically represents yet another example of calorimetry device according to the invention, seen from above, and

[0081] [Fig.7] [Fig.7] represents the device of [Fig.6] after displacement of the ca cone lorimeter from first to second position. Detailed description

[0082] [Fig. 1] shows an example of a calorimetry device 1 according to the invention, in front view. The device comprises a cone calorimeter 2 oriented vertically in a first position PI remote from a sample to be tested which is placed in a fixed sample holder 5 resting on a balance 6.

[0083] The cone calorimeter 2 is mounted movably so that it can move in a guided manner between the first position P1 and a second position P2 in which the cone calorimeter 2 is positioned opposite the sample. To do this, the cone calorimeter 2 is carried by a support 4 which is in the example considered guided in translation along a horizontal guide axis x.

[0084] The support 4, which is for example a sliding table, is mounted on ball slides. These slides are preferably metallic, in particular steel or aluminum. They can be double-stroke (or bidirectional).

[0085] When the cone calorimeter 2 is in the first position P1 and radiates a predefined heat flux density, the sample is subjected to a zero heat flux density (absence of radiative illumination) since no cone calorimeter is in the second position P2 in front of the sample, as illustrated in [Fig.l].

[0086] The cone calorimeter 2 radiating a predefined heat flux density can slide from the first position PI to the second position P2 in the direction of the arrow indicated in [Fig.l]. We then arrive at device 1 shown in [Fig.2].

[0087] In [Fig.2], the cone calorimeter 2 is in the second position P2 so that the sample is subjected to a controlled non-zero density of heat flux (presence of controlled radiative illumination).

[0088] Thus, the sliding of the cone calorimeter 2 from the first position PI to the second position P2 makes it possible to move respectively from a zero heat flux density to a controlled non-zero density to which the sample to be tested is subjected.

[0089] Of course, the cone calorimeter 2 radiating a predefined heat flux density can slide from the second position P2 to the first position PI in the direction of the arrow indicated in [Fig.2]. We then arrive again at the device 1 shown in [Fig.l].

[0090] The support 4 can optionally accommodate another vertically oriented cone calorimeter 3 (not shown in Figures 1 and 2) mounted movably so as to be able to move in a guided manner between the second position P2 and a third position P3 remote from the sample. This results in the device 1 shown in [Fig.3].

[0091] In [Fig. 3], another cone calorimeter 3 carried by the support 4 is in the second position P2, in addition to the cone calorimeter 2 which is in the first position PI. The device 1 is configured to allow the cone calorimeters 2 and 3 to be positioned successively one after the other in front of the sample. This makes it possible to vary the heat flux density to which the sample is subjected by automatically selecting the cone calorimeter according to the heat flux density to which the sample is to be subjected.

[0092] To do this, the sliding of the cone calorimeter 2 from the first position P1 to the second position P2 takes place simultaneously and at the same speed as the sliding of the other cone calorimeter 3 from the second position P2 to the third position P3, in the direction of the arrows indicated in [Fig.3].

[0093] Of course, the device 1 is also configured to allow the simultaneous sliding and at the same speed of the cone calorimeter 2 from the second position P2 to the first position PI and of the other cone calorimeter 3 from the third position P3 to the second position P2.

[0094] As illustrated in Figures 4 and 5, the device 1 comprises an infrared camera 7 positioned opposite the sample so as to measure the surface temperature of the sample almost continuously. This makes it possible to determine the mass loss rate (MLR) of the material as a function of time.

[0095] [Fig. 6] shows another example of a calorimetry device 1 according to the invention, seen from above. In the example of [Fig. 6], the device 1 comprises a cone calorimeter 2 in the first position PI remote from the sample which is placed in the fixed sample holder 5 and another cone calorimeter 3 in the second position P2 in which the cone calorimeter 3 is positioned opposite the sample.

[0096] The cone calorimeters 2 and 3 are carried by a support 4 guided in rotation around a vertical axis of rotation z. The support 4, which is for example a carousel, allows the cone calorimeters 2 and 3 to move respectively from the first position P1 to the second position P2 and from the second position P2 to the third position P3. Said movements are carried out in the example considered by a 90° rotation of the support 4 in the clockwise direction according to the direction of the arrows indicated in [Fig.6]. This results in the device 1 shown in [Fig.7].

[0097] In [Fig. 7], the cone calorimeter 2 is in the second position P2 and the other cone calorimeter 3 is in the third position P3. The cone calorimeters 2 and 3 can move respectively from the second position P2 to the first position P1 and from the third position P3 to the second position P2 by rotating the support 4 90° counterclockwise in the direction of the arrows indicated in [Fig. 7]. This leads again to the device 1 shown in [Fig. 7].

[0098] Of course, the invention is not limited to the examples which have just been described. For example, the support arranged to receive the cone calorimeter(s) can be guided in translation along a vertical guide axis or even guided in rotation around a horizontal rotation axis.

Claims

Claims

1. Calorimetry device (1), in particular for studying the fire behavior of materials, configured to allow the guided movement of at least one cone calorimeter (2) between a first position (PI) remote from a sample to be tested so that the sample does not receive the radiative illumination generated by the cone calorimeter (2), and a second position (P2) in which the cone calorimeter (2) is positioned opposite said sample to be tested.

2. Device (1) according to claim 1, being configured to allow the guided movement of at least one other cone calorimeter (3) between a third position (P3) remote from the sample so that the sample does not receive the radiative illumination generated by the cone calorimeter (3) and the second position (P2).

3. Device (1) according to claim 2, being configured to allow the cone calorimeters (2, 3) to be positioned successively one after the other in front of the sample.

4. Device (1) according to claim 2 or 3, being configured to allow the simultaneous movement and at the same speed of one of the cone calorimeters (2) from the first (P1) to the second (P2) position and of the other cone calorimeter (3) from the second (P2) to the third (P3) position and / or the simultaneous movement and at the same speed of one of the cone calorimeters (2) from the second (P2) to the first (P1) position and of the other cone calorimeter (3) from the third (P3) to the second (P2) position.

5. Device (1) according to any one of the preceding claims, comprising at least one support (4) arranged to receive the cone calorimeter(s) (2, 3), the support (4) being guided in translation along a guide axis, in particular horizontal or vertical.

6. Device (1) according to claim 5, the support (4) being mounted on slides, in particular with balls or rollers, preferably with balls.

7. Device (1) according to claim 6, the slides comprising stops allowing the sliding of the cone calorimeter(s) (2, 3) to be stopped in predefined positions, the positioning of the stops along the slides being in particular adjustable.

8. Device (1) according to any one of claims 1 to 4, comprising at least one support (4) arranged to receive the cone calorimeter(s) (2, 3), the support (4), in particular a carousel, being guided in rotation around an axis of rotation, notably vertical or horizontal.

9. Device (1) according to any one of the preceding claims, the cone calorimeter(s) (2, 3) being oriented vertically or horizontally.

10. Device (1) according to any one of the preceding claims and according to claim 2, one of the cone calorimeters (2) radiating a first predefined heat flux density and the other cone calorimeter (3) radiating a second predefined heat flux density different from the first, the device (1) making it possible to vary in an automated manner the heat flux density to which the sample is subjected by automatically selecting the cone calorimeter (2, 3) according to the heat flux density to which the sample is to be subjected.

11. Device (1) according to any one of the preceding claims, the movement of the cone calorimeter(s) (2, 3) from one position to another being carried out in an automated and / or motorized manner.

12. Device (1) according to any one of the preceding claims, comprising at least one actuator configured to allow the movement of the cone calorimeter(s) (2, 3) from one position to another in less than 5 seconds.

13. Calorimetric system, in particular for studying the fire behavior of materials, comprising a device (1) according to any one of the preceding claims, and at least one cone calorimeter (2), in particular two cone calorimeters (2, 3).

14. A calorimetric measurement method, in particular for studying the fire behavior of materials, in particular using the calorimetric system according to the preceding claim, comprising the step of: (a) Moving in a guided manner at least one cone calorimeter (2) from a first position (PI) remote from a sample to be tested in which the sample does not receive the radiative illumination generated by the cone calorimeter (2) to a second position (P2) in which the cone calorimeter (2) is positioned opposite said sample to be tested, or (b) Moving in a guided manner at least one cone calorimeter (2) from a second position (P2) in which the cone calorimeter (2) is positioned opposite a sample to be tested to a first position (PI) away from said sample to be tested.

15. The method of claim 14, further comprising the step of: (c) Moving in a guided manner at least one other cone calorimeter (3) from the second position (P2) to a third position (P3) remote from the sample in which the sample does not receive the radiative irradiance generated by the cone calorimeter (3), or (d) Moving in a guided manner at least one other cone calorimeter (3) from a third position (P3) remote from the sample in which the sample does not receive the radiative illumination generated by the cone calorimeter (3) to the second position (P2).

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