EP3740290B1

EP3740290B1 - Silenced head for fire extinguishing gas discharge

Info

Publication number: EP3740290B1
Application number: EP19701326.1A
Authority: EP
Inventors: Thomas Andreas; Philippe SCHMITZ
Original assignee: Luxembourg Patent Co SA
Current assignee: Rotarex SA
Priority date: 2018-01-21
Filing date: 2019-01-18
Publication date: 2021-10-20
Anticipated expiration: 2039-01-18
Also published as: EP3740290A1; LU100679B1; WO2019141819A1

Description

Technical field

The invention is directed to the field of gas discharge, more particularly to the discharge of fire extinguishing gases. Even more specifically, the invention is directed to gas discharge nozzles and heads thereof.

Background art

Prior art patent document published EP 1 151 800 A2 discloses a silenced nozzle head for discharging fire extinguishing gases. The nozzle head comprises a body forming a cylindrical cavity housing filter elements made of porous material, and a perforated disk closing the cavity. The filter elements are made of sintered material and are two superimposed thick disks housed in the cavity. The body comprises a cylindrical wall that can be provided with apertures forming lateral or radial discharge passages. The massive construction of the filter element occupying most of the cavity generate a counter-pressure and a pressure drop for the gas being discharged there through.
Prior art patent document published EP 2 818 207 A discloses also a silenced nozzle head for discharging fire extinguishing gases. The nozzle head comprises a base with an opening forming a gas input, a closed wall made of porous material and extending longitudinally from the base so as to form a distal opening, a front wall made of porous material closing the distal opening of the closed wall, and a fastening ring arranged against an outer face of the front wall and attached to the base by longitudinal screws. Similarly to the previous reference, the cavity housed a filter element made of porous material causing a counter-pressure and a pressure drop for the gas being discharged there through. The closed wall shows an increased thickness at the location of the screws which extend through the wall. This renders the manufacturing of the wall more complex and expensive. Other prior art documents are US 2014/069663 A1 and JP 2017 104560 A .

Summary of invention

Technical Problem

The invention has for technical problem to provide a head for a gas discharge, in particular for a fire extinguishing gas discharge, that causes a reduced pressure while reducing the noise generated when discharging the gas.

Technical solution

The invention is directed to a silenced head for a gas discharge, in particular for a fire extinguishing gas discharge, comprising: a base with an opening forming a gas input; a closed wall made of porous material and extending longitudinally from the base so as to form a distal opening; a front wall made of porous material closing the distal opening of the closed wall; a fastening ring arranged against an outer face of the front wall and attached to the base by longitudinal screws; wherein the ring comprises a ring portion and webs extending radially from the ring portion so as to form contact surfaces for the front wall.
According to a preferred embodiment, the webs extend radially to the centre of the ring portion.
According to a preferred embodiment, the webs are three or more.
According to a preferred embodiment, the webs form with the ring portion apertures with a total cross-sectional area that is larger than 50%, preferably larger than 60%, of the area of the outer face of the front wall.
According to a preferred embodiment, the webs are integrally formed with the ring portion.
According to a preferred embodiment, the webs and apertures are formed by machining.
According to a preferred embodiment, the ring has an outer diameter and the webs have a minimum width that is larger than 5% and/or less than 10% of said outer diameter.
According to a preferred embodiment, the closed wall shows an inner side delimiting a cavity of the silenced head, the screws being located in the cavity.
According to a preferred embodiment, the screws are located radially distant from the closed wall.
According to a preferred embodiment, the closed wall is cylindrical with a constant wall thickness.
According to a preferred embodiment, the base is a circular plate with an outer edge forming a shoulder housing the closed wall.
According to a preferred embodiment, the base comprises threaded nuts formed in or attached to the circular plate at locations radially between the opening and the shoulder.
According to a preferred embodiment, the ring portion of the ring has an outer edge forming a shoulder housing the front wall and the closed wall.
According to a preferred embodiment, the screws are located on the ring at a junction between the ring portion and the webs.
According to a preferred embodiment, the opening of the base is configured for receiving a gas discharge nozzle.
According to a preferred embodiment, the silenced head further comprises the gas discharge nozzle, said nozzle comprising a first series of discharge holes oriented radially and a second series of discharge holes oriented obliquely with regard to a radial plane and the longitudinal axis.
According to a preferred embodiment, the porous material of the closed wall and/or of the front wall is a metallic sintered material.

Advantages of the invention

The invention is particularly interesting in that it provides a gas discharge nozzle assembly that generates a limited counter-pressure and pressure drop while remaining silent, essentially by maximizing the surface of porous material and thereby limiting the flow speed of the gas.

Brief description of the drawings

Figure 1 is a perspective view of a silenced head according to the invention.
Figure 2 is an exploded view of the silenced head of figure 1.
Figure 3 is a top view of the silenced head of figures 1 and 2.
Figure 4 is a cross-sectional view of the silenced head of figures 1-3 along the longitudinal axis.

Description of an embodiment

Figure 1 is a perspective view of a silenced head for a gas discharge, in particular for a fire extinguishing gas discharge, according to the invention.
The silenced head 2 comprises a base 4 with a generally circular plate (not visible in figure 1), a gas inlet at the centre of the circular plate (at the bottom in figure 1), and an outer edge 4.1 forming a shoulder. For instance, a gas discharge nozzle 14 is mounted on the opening at the centre of the base 4. The silenced head 2 comprises also a circular wall 6 extending along the longitudinal axis 7 of the head 2, with a proximate edge 6.1 housed in the shouldered edge 4.1 of the base 4. The circular wall is preferably circular so as to form a cylinder. It is made of porous material, e.g. sintered metal, in order to act as a filter for diffusing the gas while reducing the amount of noise generated by the gas discharge.
The silenced head 2 comprises also a front wall 8 arranged in contact with the proximal edge 6.2 of the closed wall 6, in order to close the opening formed by said wall. The front wall 8, similarly to the closed wall 6, is made of porous material, e.g. sintered metal, in order to act as a filter for diffusing the gas while reducing the amount of noise generated by the gas discharge.
The silenced head 2 comprises also a ring 10 arranged on an outer face of the front wall 8. More specifically, the ring 10 comprises a ring portion 10.1 that can form a shoulder for receiving the front wall 8 and the distal edge 6.2 of the closed wall 6. The ring 10 comprises also webs 10.2 that extend in a radial plane, inwardly, from the ring portion 10.1. These webs 10.2 form support and contact surfaces for the front wall 8.
Eventually, the silenced head 2 comprises also screw 12 that extend essentially longitudinally through the ring 10 and the cavity formed by the closed wall until the base 4.
Figure 2 is an exploded view of the silenced head 2 of figure 1. The base 4 and the nozzle 14 are better visible than in figure 1.
We can observe the circular plate 4.2 of the base 4, with a central opening 4.3 delimited by a collar which can form an inner thread for engaging with a corresponding thread on the nozzle 14. Nuts with female threads 4.4 can be formed on, or attached to the circular plate 4.2, for engaging with the screws 12.
We can also observe that the front wall 8 comprises an outer edge 8.1 contacting the distal edge 6.2 of the closed wall 6. The front wall 8 comprises also openings 8.2 through which the screws 14 extend.
Figure 3 is a top view of the silenced head 2. We can observe the shape of the ring portion 10.1 and webs 10.2 of the ring 10. Each of the, for instance, three webs 10.2 extends essentially radially inwardly until the centre that corresponds to the longitudinal axis 7. The webs 10.2 and the ring portion 10.1 form then, for instance, three apertures 10.3 with a total cross-section area that is advantageously larger than 50%, preferably 60%, of the front wall 8 (figures 1 and 2) contacting the webs 10.2. The ring 10 is advantageously made of a single piece where the apertures 10.3 can be formed by machining. Other techniques can however also be considered. We can also observe that the hole in the ring 10, through which the screws 12 extend, are located at junctions between the ring portion 10.1 and the webs 10.2.
Still with reference to figure 3, the width of the webs 10.2 is advantageously less than 10% of the outer diameter d of the ring and/or more than 5% of said diameter d.
Figure 4 is a cross-section view of the silenced head 2 according to the arrows in figure 3. We can observe that the nozzle 14 comprises a first series of discharge holes 14.1 oriented essentially radially at a mid-height of the cavity formed by the base 4 and the walls 6 and 8. It comprises also a second series of discharge holes 14.2 oriented obliquely with regard to the longitudinal axis 7 and also a radial plane. The holes of the second series 14.2 can be oriented with an angle α with the longitudinal axis 7 that is more than 30° and/or less than 60°, more preferably more than 40° and/or less than 50°.
The gas being discharge can then be diffused both by the closed wall 6 and by the front wall 8 through the apertures 10.3. This means that the inner surfaces of the cavity able to diffuse the gas is maximized, leading to a reduced counter-pressure and pressure drop, while keeping the gas flow speed reduced and thereby the reducing the noise level.

Claims

Silenced head (2) for a gas discharge, in particular for a fire extinguishing gas discharge, comprising:
- a base (4) with an opening (4.3, 14) forming a gas input;

- a closed wall (6) made of porous material and extending longitudinally from the base so as to form a distal opening;

- a front wall (8) made of porous material closing the distal opening of the closed wall (6);

- a fastening ring (10) arranged against an outer face of the front wall (8) and attached to the base (4) by longitudinal screws (12);
characterized in that the fastening ring (10) comprises a ring portion (10.1) and webs (10.2) extending radially from the ring portion (10.1) so as to form contact surfaces for the front wall (8).
Silenced head (2) according to claim 1, wherein the webs (10.2) extend radially to the centre of the ring portion (10.1).
Silenced head (2) according to one of claims 1 and 2, wherein the webs (10.2) are three or more.
Silenced head (2) according to any one of claims 1 to 3, wherein the webs (10.2) form with the ring portion (10.1) apertures (10.3) with a total cross-sectional area that is larger than 50%, preferably larger than 60%, of the area of the outer face of the front wall (8).
Silenced head (2) according to any one of claims 1 to 4, wherein the webs (10.2) are integrally formed with the ring portion (10.1).
Silenced head (2) according to claims 4 and 5, wherein the webs (10.2) and apertures (10.3) are formed by machining.
Silenced head (2) according to any one of claims 1 to 6, wherein the fastening ring (10) has an outer diameter (d) and the webs (10.2) have a minimum width (w) that is larger than 5% and/or less than 10% of said outer diameter (d).
Silenced head (2) according to any one of claims 1 to 7, wherein the closed wall (6) shows an inner side delimiting a cavity of the silenced head, the screws (12) being located in the cavity.
Silenced head (2) according to any one of claims 1 to 8, wherein the screws (12) are located radially distant from the closed wall (6).
Silenced head (2) according to any one of claims 1 to 9, wherein the closed wall (6) is cylindrical with a constant wall thickness.
Silenced head (2) according to any one of claims 1 to 10, wherein the base (4) is a circular plate (4.2) with an outer edge (4.1) forming a shoulder housing the closed wall (6), preferably wherein the base (4) comprises threaded nuts (4.4) formed in or attached to the circular plate (4.2) at locations radially between the opening (4.3, 14) and the shoulder (4.1).
Silenced head (2) according to any one of claims 1 to 11, wherein the ring portion (10.1) of the fastening ring (10) has an outer edge forming a shoulder housing the front wall (8) and the closed wall (6).
Silenced head (2) according to any one of claims 1 to 12, wherein the screws (12) are located on the fastening ring (10) at junctions between the ring portion (10.1) and the webs (10.2).
Silenced head (2) according to any one of claims 1 to 13, wherein the opening (4.3) of the base (4) is configured for receiving a gas discharge nozzle (14), the silenced head preferably further comprising the gas discharge nozzle (14), said nozzle comprising a first series of discharge holes (14.1) oriented radially and a second series of discharge holes (14.2) oriented obliquely with regard to a radial plane and the longitudinal axis (7).
Silenced head (2) according to any one of claims 1 to 14, wherein the porous material of the closed wall (6) and/or of the front wall (8) is a metallic sintered material.