DESCRIPTION

[001] Invention relates to fire suppressing gas generating devices, especially to a sealing of fire suppressing gas generating devices.

[002] A fire suppressing gas generating device is a non-pressurized container comprising gas generating grains or compound which, upon activation, generates the inert extinguishing agent, for example Nitrogen. The fire suppressing gas generating device is mainly utilized for extinguishing fire falling under Class A, Class B and Class C (EN2) within enclosed environments - enclosures.

[003] The international patent application No. WO 2019/035015 discloses a fire supressing gas-generating device. The device comprises a housing; a plurality of gas -generating grains; end caps attached to each side of the housing; an ignition device for ignition of said the gas generating grains; a multi-layer filter encompassing said plurality of gas-generating grains and disposed between the gas -generating grains and the housing. During discharge, generated gas tends to escape through connection of the housing and the end caps. The US patent application publications Nos. US2006/0207468 and US2006/0043716 disclose an embodiment trying to solve aforementioned problem by implementing a double housing design. This however increases manufacturing complexity and in case of misalignment of both housings during assembly, the aim of reliable sealing is not reached and generated gas and burning by-products may escape through the sealing. During discharge of a fire suppressing gas generating device considerable amount of pressure is built up and multiple burning by-products are generated. All this should be contained within the device. Therefore, reliable and easy to manufacture and implement sealing solution is necessary.

[004] In order to overcome aforementioned problems the following fire suppressing gas generating device was invented. A fire suppressing gas generating device comprises a cylindrical housing having two open sides and at least one discharge opening; a plurality of gas generating grains disposed in a stacked relationship within the housing; a multi-layer filter encompassing the plurality of gas generating grains. The open sides of the cylindrical housing are sealed by two end caps. Each end cap is fixed to each open side of the housing in result of which the cylindrical housing with end caps encloses the plurality of gas generating grains and the multi-layer filter disposed in the cylindrical housing. The device further comprises an ignitor positioned at one end cap and associated with the gas generating grain for ignition of the gas generating grain. The device further comprises at least one gas discharge channel. The gas discharge channel is connected to the discharge opening. The discharge channel comprises a burst plate arranged in the discharge channel so that the burst plate seals the inner volume of the fire suppressing gas generating device from the outer environment. The longitudinal axis of the gas discharge channel is generally aligned with the longitudinal axis of the discharge opening and generally orthogonal to the to the longitudinal axis of the cylindrical housing. The gas discharge channel comprises openings or nozzles with its longitudinal axis arranged generally orthogonal to the longitudinal axis of the gas discharge channel. The nozzles are arranged evenly around the gas discharge channel so that a discharged gas flow distributes evenly therearound creating thrust neutrality of discharged gas

[005] The multi-layer filter comprises an inner layer of steel mesh, an outer layer of steel mesh and multiple layers of steel wool and non-woven glass-fibre mat arranged therebetween.

[006] The device is characterized in that the end cap on the surface opposed to the multi-layer filter comprises at least one circumferential protrusion, which extends into the multi-layer filter when the end cap is fixed to the housing therefore sealing the inner volume of the cylindrical housing. Reliable sealing is created. The circumferential protrusion is arranged between the two layers of the multi-layer filter so that the layers of the multi-layer filter cover both sides of the circumferential protrusion. Moreover, the end cap is positioned at the multi-layer filter so that the entire end surface of the multi-layer filter is covered by the end cap.

[007] The circumferential protrusion of the end cap extends into and between the two layers of the multi-layer filter when the end cap is fixed to the housing in result of which reliable sealing of the inner volume of the cylindrical housing is created.

[008] The end cap on the surface opposed to the multi-layer filter comprises at least two circumferential protrusions. Each circumferential protrusion extends between two layers of the multi-layer filter when the end cap is fixed to the housing therefore sealing the inner volume of the cylindrical housing.

[009] The drawings illustrate generally, by way of example, but not by way of limitation, various embodiments of the invention.

[010] Fig. 1 is a perspective view of one embodiment of a fire suppressing gas generating device.

[Oil] Fig. 2 is a cross-sectional view of the fire suppressing gas generating device as seen in Fig. 1.

[012] Fig. 3 is a perspective view of an ignitor end cap (3) with two circumferential protrusions (34).

[013] Fig. 4 is a perspective view of an end cap (4) with two circumferential protrusions (34).

[014] Fig. 5 is a part of the cross-sectional view of the fire suppressing gas generating device having an end cap (3), wherein the end cap (3) is fixed to the cylindrical housing (1) and protrusions (34) of the end cap (3) extend into a multi-layer filter (6) forming a seal.

[015] Fig. 6 is a perspective view of an end cap (3) with one circumferential protrusion (34).

[016] A fire suppressing gas generating device comprises a cylindrical housing (1) having two open sides (11; 12) and two discharge openings (13). Plurality of gas generating grains (2) are disposed in a stacked relationship within the cylindrical housing (1) and a multi-layer filter (6) encompassing the plurality of gas generating grains (2) is arranged between the gas generating grains (2) and the cylindrical housing (1). The multi-layer filter (6) comprises an inner layer of steel mesh, an outer layer of steel mesh and multiple layers of steel wool and non-woven glass- fibre mat arranged therebetween. The device further comprises an ignitor (5) positioned at one end cap (3; 4) and associated with the gas generating grain (2) for ignition of the gas generating grain (2). The device further comprises two end caps (3; 4), wherein each end cap (3; 4) is fixed to each open side (11; 12) of the housing (1) in result of which the cylindrical housing (1) with end caps (3; 4) encloses the plurality of gas generating grains (2) and the multi-layer filter (6). Each from both end caps (3; 4) on the surface opposed to the multi-layer filter (6) comprises two circumferential protrusion (34), which extends into the multi-layer filter (6) when the end cap (3; 4) is fixed to the housing (1) therefore sealing the inner volume of the cylindrical housing (1). The circumferential protrusions (34) of the end cap (3; 4) extends into and between the two layers of the multi-layer filter (6) when the end cap (3; 4) is fixed to the housing (1) in result of which reliable sealing of the inner volume of the cylindrical housing (1) is created. The device further comprises two gas discharge channels (7), where each gas discharge channel (7) is connected to the respective discharge opening (13). Each discharge channel (7) comprises a burst plate (8) arranged in the discharge channel (7) so that the burst plate (8) seals the inner volume of the fire suppressing gas generating device from the outer environment. The longitudinal axis of the gas discharge channel (7) is generally aligned with the longitudinal axis of the discharge opening (13) and generally orthogonal to the to the longitudinal axis of the cylindrical housing (1). The gas discharge channel (7) comprises eight openings or nozzles (17) with its longitudinal axis arranged generally orthogonal to the longitudinal axis of the gas discharge channel (7). Eight nozzles (17) are arranged evenly around the gas discharge channel (7) so that a discharged gas flow distributes evenly therearound creating thrust neutrality of discharged gas (see Figs. 1 to 5).

[017] While the invention may be susceptible to various modifications and alternative forms, specific embodiments of which have been shown by way of example in the figures and have been described in detail herein, it should be understood that the invention is not intended to be limited to the particular forms disclosed. Rather, the invention includes all modifications, equivalents, and alternatives falling within the scope of the invention as defined by the following claims.