An explosionproof container for the storage and transport of in particular pyrotechnic material

Abstract

 A container (1) for the storage or transport of pyrotechnic material, such as fireworks or explosives, e.g. a standard container of steel, is protected against exploding in case of unintentional ignition of the pyrotechnic material, said container being provided with at least one opening (7) which is closed by a hatch or a plate (8). Each hatch or plate is locked in the associated opening by locking means, which are adapted to be released at an internal pressure against the hatch which is lower than the pressure that can make the container explode, whereby the hatch opens or jumps off so that the generated pressure may be discharged through the openings.
Further, the container (1) is equipped internally with pipes (6) with nozzles (4) to provide a water mist particularly around the openings, whereby flames from the burning material are prevented from bursting out of the openings, and the fire in the material is possibly extinguished. The water connections of the pipes are arranged on the outer side of the container.
The control of the arrangement for providing a water mist is controlled by pressure and/or temperature sensors inside the container, which may be set so that the water mist is provided at the same time as the hatches are released.
The openings may be covered by a roller blind (22) of a fireproof material in case of a fire to ensure that no burning material escapes through the openings.

Description

The prior art

[0001] The invention relates to a container for the storage and transport of in particular pyrotechnic material, such as fireworks or explosives, where means are provided to protect the container against explosion in case of unintentional ignition of the pyrotechnic material. A container for this purpose may be a standard container made of steel and having an entry gate which is hinged to the container itself and locked by a pawl which engages a locking device.

[0002] The means for protecting the container are intended to ensure that the container cannot explode with consequent injury of people and material. The known protections of this type most frequently consist of a weakened location on the container or its equipment which, in case of unintentional ignition of the pyrotechnic material, yields and provides an opening through which the pressure may be discharged.

[0003] US 2002/0020323 A1 discloses a container or a closure for a pyrotechnic propellant, where this measure comprises a casing of a combustible mixture which, in the state of storage, is arranged externally on the container, and which is ignited in case of unintentional ignition of the propellant during storage. The ignited combustible mixture heats the container and makes the container wall so soft that it bursts during the impact from the pressure increase from the burning propellant, thereby relieving the pressure and avoiding an explosion.

[0004] US 2002/0144620 A1 relates to a small cylindrical container for pyrotechnic material which is closed at the end by a cover. The cover is configured with an annular weakened line concentric with the periphery of the cover. The weakened line extends all the way round near the periphery of the cover, apart from a small area which is left with full thickness. In the event of unintentional ignition of the stored material, the innermost portion of the cover is torn loose along the weakened line by the pressure from the combustion of the ignited material, whereby the pressure is relieved. The torn part of the cover remains connected with the container through the small of portion of full thickness.

[0005] In this and similar arrangements, the cover is destroyed completely, with the risk that flames from the combustion burst out of the opening which is left in the container by the part blown out of the cover.

The object of the invention

[0006] The object of the invention is to provide a container of the mentioned type, wherein the arrangement for protection against explosion is more expedient, as the container or its parts are not necessarily destroyed, and the risk that flames burst out of the container is minimum.

[0007] This is achieved by a container of the type stated initially, which is characterized in that the container, as defined in claim 1, is provided with at least one opening which is closed by a hatch or a plate firmly locked in the opening by locking means, which are adapted to be released by an internal pressure on the cover or the plate which is lower than the explosion pressure of the container.

[0008] Hereby, no weakening or damage is imparted to the container itself or its cover, it being the hatch or the plate which opens or jumps off in the event of an inadmissible pressure when the releasable lock opens. This releasable lock may be adapted to release exactly at the desired pressure. Especially for use for large containers, such as standard containers, this arrangement is expedient, as the container itself is not damaged.

[0009] When, as stated in claim 2, the container is additionally provided with means, such as nozzle pipes, for providing a water mist, and whose water connections are arranged on the outer side of the container, it is possible to ensure that flames from the ignited pyrotechnic materials do not burst out of the opening when the hatch is released. The water mist is often sufficient to extinguish the fire in the pyrotechnic material.

[0010] As stated in claim 3, the means for providing a water mist may be controlled by a pressure switch and/or a temperature switch which is arranged inside the container. With a suitable setting of this or these switches it may be ensured that the water mist is released at the same time as the hatch or the plate is opened by the internal pressure in the container.

[0011] As stated in claim 4, the hatch or the plate may be provided with a device which allows it to be released from the opening, but to remain firmly connected with the container.

[0012] As stated in claim 5, this device may be a hinge which allows the hatch to open by rotation, but holds it firmly to the container.

[0013] As stated in claim 6, the device may be a wire or chain connection between the hatch and the inner side of the container.

[0014] As stated in claim 7, the releasable lock may be a snap lock, or, as stated in claim 8, a spring-loaded latch which disengages at the desired pressure.

[0015] The hatch or the plate may also be held in place by compression springs which are so adapted as to be compressed at the desired pressure, as stated in claim 9. Finally, as stated in claim 9, the hatch or the plate may be glued into position by a gluing, whose strength is adapted such that the gluing breaks at the desired pressure.

[0016] To ensure to the greatest extent possible that parts of the pyrotechnic material cannot penetrate out of the provided opening, each opening may be covered internally by a mesh or a hollow plate, as stated in claim 10. In an embodiment, as stated in claim 11, a roller blind may be arranged at each opening, which is controlled by a smoke or temperature sensor, and which covers the openings in case of a fire. This ensures that neither flames nor material can burst out through the exposed openings.

The drawing

[0017] The invention will be explained more fully with reference to the drawing, in which

fig. 1

schematically shows a section of a storage and transport container according to the invention,

figs. 2-5

show various configurations of the releasable lock,

fig. 6

shows the control system for the water mist system, and

fig. 7

shows the arrangement with the roller blind.

Descrption of an exemplary embodiment

[0018] Figure 1 shows a container 1 with a door or gate 2 in which pyrotechnic material 3 is stored. The container has one or more openings 7 which are closed by their respective hatches or plates 8. In the embodiment shown, each of the hatches is secured to the container by a hinge 18. Each opening is covered by a mesh 10 which is to prevent pyrotechnic material from escaping through the opening in case of a fire when the hatch is open.

[0019] At the top in the container, a nozzle pipe is arranged to provide a water mist with nozzles 4, which communicates with an outer source of water 5 through a feed pipe 6.

[0020] The hatches are secured to the container wall by releasable locks. In case of unintentional ignition of the pyrotechnic material, the pressure in the container will increase, and when it has reached a determined value which is lower than the pressure at which the container explodes or is damaged, the releasable locks open, and the hatches rotate about the hinges to a position in which they expose an opening through which the pressure is relieved.

[0021] Figs. 2 - 5 show various configurations of the releasable locks. In figure 2, a peg 11 is mounted in a hole in the plate 8. Two or more rods 12 rest on the peg and on a face in the hole and lock the hatch. At the desired pressure, this lock is released, and the hatch is pressed out of the opening. Chains or wires 17 ensure that the hatch remains connected with the container.

[0022] Figure 3 shows a configuration where the hatch is held by compression springs 13 which are compressed and expose the opening at the desired pressure. Figure 4 shows a configuration where the hatch is held in place by sealant or glue, which gives a determined strength corresponding to the desired release pressure. Figure 5 shows a configuration with a hatch 8 which is hinged at 18 to the container wall 1, and which is held by a latch 16 provided with inclined faces so that it may be released from the locked position at the determined pressure.

[0023] Figure 6 shows the arrangement for providing a water mist in the container with nozzles 4, which are positioned around the openings in particular. A pressure and/or temperature sensor 19 controls the inlet valve 21 for water to the nozzles.

[0024] Figure 7 shows the arrangement with the roller blind 22 which is controlled by a smoke or temperature sensor, so that the blind rolls down and covers the openings in case of a fire or other heat generation in the container 1.

Claims

1. A container (1) for the storage and transport of in particular pyrotechnic material (3), such as fireworks, explosives or ammunition, in particular a standard container, which has an entry opening closed by a gate or door (2), and wherein means are provided to protect the container against explosion in case of unintentional ignition of the pyrotechnic material, said means providing an opening in the container in the event of a pressure increase in the container because of the ignition, through which opening the pressure may escape, characterized in that the container (1) is provided with at least one opening (7) which is closed by a hatch or a plate (8) firmly locked in the opening by locking means (12, 13, 15, 16) which are adapted to be released by an internal pressure on the hatch or the plate (8) which is lower than the explosion pressure of the container.

2. A container according to claim 1, characterized in that the container internally has means, such as nozzle pipes (6), for providing a water mist, and whose water connections (5) are disposed on the outer side of the container (1).

3. A container according to claim 2, characterized in that the means for providing a water mist are controlled by a pressure switch and/or a temperature switch (19) which is arranged inside the container (1).

4. A container according to claims 1 - 3, characterized in that the hatch or the plate is provided with a device (17, 18) which allows it to be released from the opening, but to remain firmly connected with the container.

5. A container according to claim 4, characterized in that the device is a hinge (18) which allows the hatch to open by rotation, but holds it to the container.

6. A container according to claim 4, characterized in that the device is a wire or chain connection (17) between the hatch and the inner side of the container (1).

7. A container according to claims 1-6, characterized in that the releasable lock is a snap lock (fig. 2).

8. A container according to claims 1-6, characterized in that the releasable lock is a spring-loaded latch which disengages at the desired pressure (fig. 5).

9. A container according to claims 1 - 6, characterized in that the hatch or the plate is held in place by compression springs (13) which are so adapted as to be compressed at the desired pressure.

10. A container according to any one of claims 1 - 9, characterized in that each opening is covered internally by a net or a hollow plate (10).

11. A container according to any one of claims 1-10, character- ized in that a roller blind (22) of a fireproof material is arranged at each opening, which is controlled by a smoke or temperature sensor, and which covers the openings in case of a fire.

Drawing