DEVICE FOR EXTINGUISHING FIRE OR LIMITING FIRE OUTBREAKS

Abstract

A fire extinguishing device is for a motor vehicle. The fire extinguishing device includes an internal cavity containing a pressurized fire extinguishing fluid. The cavity is delimited by a wall, the wall having at least one barrier layer (b) containing a semi-aromatic polyamide composition (B).

Claims

1. A fire extinguishing device, comprising an internal cavity containing a fire extinguishing fluid, said cavity being delimited by a wall, wherein said wall comprises at least one barrier layer containing a semi-aromatic polyamide composition.

2. The device according to claim 1, wherein the semi-aromatic polyamide composition contains at least one semi-aromatic polyamide containing aliphatic diamine units in C6 to C12.

3. The device according to claim 1, wherein the semi-aromatic polyamide composition contains a semi-aromatic polyamide containing terephthalic acid and/or naphthalene dicarboxylic acid units.

4. The device according to claim 1, wherein the semi-aromatic polyamide is a polyphthalamide.

5. The device according to claim 1, wherein the polyphthalamide is selected from PA6T, PA9T, PA1 OT and PA12T.

6. The device according to claim 1, wherein the wall further comprises an external layer.

7. The device of claim 6, wherein the external layer comprises a thermoplastic polymer composition.

8. The device according to claim 7, wherein the thermoplastic polymer composition comprises an aliphatic polyamide composition.

9. The device of claim 8, wherein the thermoplastic composition comprises an elastomer.

10. The device as claimed in claim 6, wherein the external layer is adjacent to the barrier layer.

11. The device of claim 8, wherein the wall comprises an intermediate layer between the barrier layer and the external layer.

12. The device of claim 11, wherein the intermediate layer comprises a thermoplastic polymer composition.

13. The device of claim 12, wherein the thermoplastic polymer composition of the intermediate layer comprises an elastomer.

14. The device of claim 12, wherein the thermoplastic polymer composition of the intermediate layer comprises an ethylene vinyl alcohol copolymer.

15. The device according to claim 11, wherein the external layer comprises a thermoplastic polymer composition.

16. The device of claim 11, wherein the intermediate layer is adjacent to the barrier layer.

17. The device of claim 16, wherein the intermediate layer is adjacent to the external layer.

18. The device according to claim 15, wherein the wall comprises: a barrier layer comprising a polyphthalamide, an intermediate layer comprising an aliphatic polyamide in C6-C12; an external layer comprising an aliphatic polyamide in C6-C12.

19. The device according to claim 1, comprising a hollow tubular structure.

20. A battery pack comprising a fire extinguishing device as defined in claim 1.

21. A motor vehicle, comprising at least one fire extinguishing device according to claim 1.

22. A domestic apparatus, comprising at least one fire extinguishing device according to claim 1.

23. A motor vehicle, comprising a battery pack according to claim 20.

Description

FIGURE

[0143] FIG. 1 shows the cross-section of an example of a fire extinguishing device according to the invention in a tubular form with a double-layer wall comprising: [0144] a barrier layer (2), and [0145] an external layer (3) ensuring in particular a good mechanical behaviour.

[0146] The internal cavity (1) delimited by the double-layer wall contains a fire extinguishing fluid.

EXAMPLES

[0147] Materials and Methods

[0148] In the following examples 1 and 2, the burst pressure of different hose structures at different temperatures and their permeability were investigated.

[0149] The sealed test hoses (1, 2 and 3) of known and identical dimensions (400 mm long tube, 15 mm internal diameter, 18 mm external diameter, end fittings), each equipped with a different type of barrier layer, were filled to 80% with a fire extinguishing fluid (HFC236) and maintained for a given time at a given temperature. Empty sealed hoses were used as control samples.

[0150] The 3 hose structures tested have a wall thickness of 1.5 mm. They have a distinct composition, in particular different barrier layers.

[0151] Hose 1: the barrier layer is a 0.3 mm thick PA9T layer

[0152] Hose 2: The barrier layer is a 0.25 mm thick EVOH layer. The adhesive between the layers EVOH and the PA12 is a PA612 copolyamide.

[0153] Hose 3: this structure does not comprise a barrier layer. It is a single layer of PA612, 1.5 mm thick.

Example 1: Fusible Nature of the Hoses 1, 2 and 3

[0154] In order to assess the ability of the hoses to release the extinguishing fluid in the event of a fire departure, burst tests of the 3 walls were carried out in accordance with the standard SAE J2260.

[0155] The results are presented in Table 1 below.

TABLE-US-00001 TABLE 1 Bursting Bursting Internal/external pressure pressure diameter Structure at 80° C. at 125° C. Hose (mm)/(mm) of the wall [bar] [bar] 1 15/18 PA9T/PA12 40.4 26.1 2 15/18 PA6/EVOH/adh/PA12 42 28.5 3 15/18 PA6.12 35.8 28.8

[0156] It is noted that the wall structures tested have a property of melting at a greater or lesser pressure, under the combined effect of heat and the rise in pressure of the extinguishing fluid, and in particular under the effect of a temperature greater than or equal to 80° C., or even 125° C.

Example 2: Permeability Nature of the Hoses 1, 2 and 3

[0157] In order to assess the permeability of the different hose structures (1, 2 and 3), the weight of the test hoses was measured at regular time intervals at the set working temperature, until a steady state was reached, i.e. a stage where the weight of the test hoses no longer varied (deviation of less than 10% from the lowest value of the last 4 measurements).

[0158] The table below shows the results of the permeability test for hoses produced with different multi-layer walls.

[0159] The permeability tests were carried out at 80° C., at atmospheric pressure and at a wall thickness of approximately 1.5 mm.

[0160] The results obtained after a period of 25 days are as follows.

TABLE-US-00002 TABLE 2 Permeability HFC236 - 80° C. Hose Type [g/m/an] 1 PA9T/PA12 2 2 PA6/EVOH/adh/PA12 2.8 3 PA612 8.8

[0161] These results show that the wall 1 containing a PA9T/PA12 barrier layer has a permeability lower than 30% than that of the wall 2 containing an EVOH-based barrier layer and more than 4 times lower than that of the wall 3.

[0162] Consequently, the results show that for a fusibility nature equivalent to that of the wall 2, the wall 1, equipped with a barrier layer based on a semi-aromatic polyamide, will allow better storage of the extinguishing fluid over time and thus improve the efficiency of the fire extinguishing device.