EP3337576B1 - Fire extinguisher - Google Patents

Description

The invention relates to a fire extinguisher with outlet channel and mixing device according to the preamble of claim 1, known by the CA 1 266 073 A and US 4830790A He has an extinguishing agent container, from which when using the fire extinguisher the extinguishing mixture consisting of an extinguishing agent and additional fluids through a mixing device with mixing chamber and ventilation chamber (21) out. After the mixing chamber, the extinguishing mixture is mixed and foamed in a subsequent aeration level of the ventilation level by air jets drawn in from outside. In this case, the mixing device on two perforated plates, which lie in a common radial plane to each other and touch each other; the last plate in the direction of flow has a single hole which partially covers the holes of the first plate.

Here is the extinguishing mixture-wie US 4,830,790 A in column 3, lines 19-26 - leaving the hole of the second plate tapering towards each other, then expanding into a multi-turbulent spray and thereby creating the suction pressure to aspirate the ambient air.

US 5 613773 A shows a mixing device for producing foams with two plates 112, which consist of one piece and have smaller inlet openings 122 and larger outlet openings 123, which communicate flush with each other, partially overlapping and form steps and sharp corners to create a Koanda effect.

Particularly suitable for foam formation are the foam-forming surfactants, e.g. Fluorine surfactants. However, these are particularly harmful and should not get into the sewage or groundwater. However, they have been indispensable so far to achieve a good extinguishing performance that meets the requirements.

Extinguishing foam should have a certain coherence and stability, so that the fire is stifled and can not "burn through" by the applied foam carpet, one tries to improve the foaming. This is mainly due to the interference of air.

The unsatisfactory quality of the extinguishing foam produced is attributable to inadequacies of the mixing devices in the systems known from the prior art.

Starting from fire extinguishers with the known mixing device, it is therefore an object of the invention to improve the foam formation without the use of surfactants and in particular fluorine and also without the use of a pressurized gas of more than 50bar gas and in particular to ensure that at sufficient throw a thick impenetrable foam carpet on the fire, eg let the surface of a burning liquid lay.

This is solved according to plate in claim 1 by inclined holes in the second perforated plate.

The holes of the second perforated plate have to deviate from the axial direction. In this case, the housing inner cross-section of the mixing chamber in several radial planes through perforated plates (32, 33) is filled, which repeatedly divide the incoming Löschgemischstrom into individual beams and give these individual jets one of the turbulence and mixing conducive direction by the first flow-through hole plate a variety of the current direction extending holes in fine distribution and the following perforated plate also have uniformly distributed holes whose axes also have a directional component in the direction of flow, but are inclined to, in the limit case in the circumferential direction concentric to the cylinder axis of the mixing chamber cylinder level, or even with an additional radial direction component radially inward or radially outward.

On the one hand a good mixing of the components-extinguishing agent, foaming agent and air- on the other hand, a significant increase in volume of the foam and finally a stabilization of the foam is guaranteed. In particular, the developments of the subclaims are characterized by simple, robust design and surprising effectiveness and lead in their selection and summation to an unexpected optimization of foam formation.

The invention serves to produce a plurality of isolated stream threads, which are interrupted and laid again and again in the direction of flow. The result is a kind of turbulent flow of the extinguishing mixture with an unlimited number of spaces between the current strands and interruptions of the current strands in Current direction with the finest distribution in the current direction and over the entire cross section of the extinguishing mixture stream.

It is particularly important that ambient air is supplied to the extinguishing mixture stream in the ventilation chamber without further technical aids. As a result, there are no space restrictions to arrange a largest number of air inlet holes on the circumference of the jacket of the ventilation chamber. As a result, air is flowed through the multiple split extinguishing mixture stream over its entire cross section and the air is included as a plurality of air bubbles in the extinguishing mixture when it is combined in the extinguishing foam outlet again into a closed jet of extinguishing foam.

To generate the negative pressure and suction of the ambient air, the flow velocity of the expelled by the expanding propellant extinguishing mixture is increased by the flow path is narrowed below the ventilation level of the ventilation chamber, in particular by a collar (claim 2).

The extinguishing mixture tends by its cohesion to reunite even on a short flow path. This is prevented by the measure according to claim 3. The arranged in a radial plane of the aeration chamber, the cross-section filling close-meshed wire mesh fulfills a multiple function: on the one hand, it forms the narrowing of the flow path, which is required to generate the negative pressure of the extinguishing mixture; On the other hand, this wire grid leads to the entire cross section of the extinguishing mixture to a loosening, increase in volume, increase the flow velocity and thus to increase the negative pressure.

The foam formation according to the invention is supplemented and reinforced by a further measure according to claim 4. It serves to further increase the volume of the now already foamed extinguishing mixture by their further mechanical loosening, which in turn is associated with an increase of the exit velocity. For this purpose, a wire mesh with intersecting metal or plastic wires is placed in the radial plane of the mouth of the ventilation chamber.

In the following the invention will be described by means of exemplary embodiments.

• Fig. 1 den Längsschnitt durch einen Feuerlöscher (ohne Löschventil)
• Fig. 2, 3 und 4 Detailansichten des Auslaßventils mit aufgesetzter Belüftungskammer
• Fig.4A Aufsicht auf die Überwurfhülse nach Fig.4

Show it:

• Fig. 1 the longitudinal section through a fire extinguisher (without extinguishing valve)
• Fig. 2, 3rd and 4 Detail views of the exhaust valve with attached ventilation chamber
• 4A Watch over the cap sleeve after Figure 4

In all drawings, the same reference numerals are used for similar parts. The description applies to all figures, unless special features of a single figure are explicitly highlighted.

FIG. 1 shows as a fire extinguishing system a hand fire extinguisher with the extinguishing agent container. 1

This pressure-resistant container 1 of the hand-held fire extinguisher has a circular-cylindrical open neck 2. In this neck fits the collar 4 of a closure head 3, which is pressure-resistant manner by means of a clip, not shown, on the container 1. The closure head 3 has a hose nozzle 5 for attaching the extinguishing hose 15 with the metering valve attached to it -in this application consistently referred to as extinguishing valve 10- on. The hose nozzle is connected via outlet channel 6 and riser 7 with the interior of the container. The riser 7 extends substantially to the bottom of the container, so that the container can be completely emptied.

The container 1 is filled with the extinguishing agent, e.g. Filled with water. It is pressurized by a print cartridge 8 in which a pressure medium / blowing agent (nitrogen or carbon dioxide) is stored. The print cartridge 8 is mounted in the mouth of a pressure channel 9 on the closure head such that it protrudes into the container with the closure head.

The volume of the print cartridge is 1/10 to 1/60, preferably in the range between 2% and 4% of the volume of the extinguishing agent and the volume of the extinguishing agent.

To open the print cartridge 8 - as here only schematically indicated - a valve plate which closes the print cartridge 8, destroyed by means of a percussion plunger 11. The percussion ram is guided in alignment with the central axis of the print cartridge 8 and to the also aligned rising branch 13 of the pressure channel sliding and sealing at the same time in the closure head.

The pressure channel 12 is guided in the closure head U-shaped. On its free mouth, a pressure tube 9 is set, which is connected to the filling opening 19 of the sub-tank 14 via an inlet valve-not shown-pressure-resistant.

The inlet valve is a check valve which is opened by spring pressure in its closed position and by pressurizing the pressure tube 9 (or the inner extinguishing agent container).

On its other outlet side 22 of the secondary tank 14 is closed by a valve device 23, here a predetermined breaking point, down.

The predetermined breaking point is created by a weakening of the jacket, which propagates in particular on a generatrix. At internal pressure of the sub-tank 14, the sub-tank opens to the outside here.

The secondary container 14 has on its back along a common generatrix a recess and forms on its periphery a constriction 20. The secondary container 14 nestles with the indentation to the riser 7 and is secured in the region of these constrictions by means of a cable tie 20 on the riser 7 ,

To the function:
When the pestle 11 is knocked down in the manual fire extinguisher, the rupture disk (not shown) is broken and the print cartridge 8 is opened.

The predetermined breaking point of the secondary container 14 is now designed so that it opens under the now emerging pressure. As a result, the liquid-the foaming agent-is expelled from the secondary container into the extinguishing agent container, where it mixes with the extinguishing agent. Also, the extinguishing agent container is pressurized.

The secondary container contains the foaming agent. Fluorinated surfactants, which greatly reduce the surface tension of the water and on the one hand have excellent foaming properties and have a good extinguishing effect, but on the other hand damage the water, especially the groundwater, during extinguishment, were used for this purpose. Preference is therefore given to the use of fluorine-free foaming, but their foaming and extinguishing effect is worse, if they are not optimized by the mixing device according to the invention.

Alternatively to the preparation of the extinguishing mixture of extinguishing agent and foaming agent by storage of the foaming agent in a sub-tank, the foaming agent can also be added to the extinguishing agent immediately and filled into the extinguishing agent tank as a finished mixture. This alternative is particularly suitable for permanent pressure extinguishers on, in which the extinguishing agent container is placed after filling with the extinguishing mixture by filling with a suitable pressure medium / propellant gas under continuous pressure. This alternative is also useful for Aufladelöscher in which the pressure fluid / propellant -wie also described above stored in a print cartridge inside or outside of the extinguishing agent container and the print cartridge is opened only in case of fire in the extinguishing agent container and the already finished extinguishing mixture is expelled.

In the three alternatives described in each case when pressurizing the extinguishing agent container, the mixture of extinguishing agent and foaming agent (extinguishing mixture) supplied through extinguishing hose 15 to the extinguishing valve 10 which is actuated by a handle -opened and closed. By opening the extinguishing mixture can be sprayed on the fire site. In the case of fluorine-free foaming agents, a further treatment of the extinguishing mixture of extinguishing agent and foaming agent is carried out to improve foaming. It must be remembered that the extinguishing mixture forms a laminar flow substantially. It is therefore pre-empted a mixing device, which consists of the mixing chamber 18 and the ventilation chamber 21 placed thereon. The extinguishing mixture leaves this mixer as a foam.

It has been found that the foam still has a substantially worse extinguishing effect than when using fluorine-containing surfactants as foaming agents, when the extinguishing mixture stream is divided into individual streams in the mixing chamber and discharged in this form. The resulting foam dissolves over the burn site, e.g. burning liquid surface - thus has a lack of stability - and is not sufficient with its thickness to choke the flame - so has too little volume per unit weight-.

Surprisingly, it is possible by mixing this inadequate foam with ambient air in the subsequent aeration chamber 21 to increase the stability of the foam and the volume and thus its coverability so much that the quality of a compressed air mixture at pressures over 100baraufbereiteten foam is reached or exceeded.

In itself, the intake of ambient air to the extinguishing agent does not seem advised, since there is a risk that form in the extinguishing mixture large air caverns, which rather than prevent flame formation. However, it has been found that the air bubbles are so finely distributed in the foam and so tightly bound by the inventive measures, and that the Luftabkapselung the point of fire by the firmer and thicker foam carpet is so good that the Zumengung of air bubbles in fine distribution not is disadvantageous.

This jacket is firmly clipped to the outlet of the mixing chamber 18 by axially projecting hook 25, which just overlap an outer collar of the circular cylindrical mixing chamber.

The shell is provided with air inlet holes 26 on its circumference in a cross-sectional plane (ventilation plane). The inner cross section of the ventilation chamber shell is narrowed below -d.h .: upstream of the aeration level, such that this restriction has a venturi-like effect and, by increasing the flow velocity in the region of the air inlet holes, a negative pressure of less than atmospheric pressure results, which leads to the intake of the ambient air.

In Fig. 2 this constriction is designed as a circumferential collar, ie Venturi-type constriction 27, which has the effect of increasing the flow velocity while reducing the static pressure in the extinguishing mixture stream. The resulting negative pressure draws in the outside air / ambient air through the air inlet holes 26. As a result of this interference of air in as fine a distribution as possible, the volume of the escaping foam increases so considerably that the disadvantage of non-use of fluorine-containing surfactants is substantially eliminated.

A further increase in volume is achieved by the wire mesh 29, which is placed on the orifice 30 of the circular cylindrical housing of the ventilation chamber 21 and clamped by means of screw ring 31 on a small circumferential on the inner circumference of the shell collar.

The wire mesh 29 consists of thin, less than 1 mm thick wires of metal or plastic, which are laid with a density between 15 and 40 meshes, preferably 20 to 35 meshes per square inch to a rectangular grid. In this case, the cross section of the ventilation chamber 21 is between 20 and 50qmm, e.g. 35qmm.

This wire mesh 29 has the function of further mixing and mixing, in particular, the exiting foam jet enriched with air bubbles. It works but above all as a cross-sectional constriction and caused with the simultaneous increase in volume of the foam and an increase in the exit velocity and thus the throw of the foam.

In the execution after Fig. 3 occurs in place of the venturi-like constriction (27) as a narrowing the shell cross-section filling grid, preferably Drahtgitter28. 21 connected so that the front edge of the mixing chamber 18 and the opposite rear edge of the ventilation chamber 21 this circumferential Schlitz26 release. On the free rear end of the cylindrical shell 24 of the ventilation chamber 21, a cap sleeve 34 is screwed by thread pairing 35. The cap sleeve 34 extends axially beyond a cylindrical extension 36, which has the mixing chamber 18 at its front free end and which forms the front edge of the mixing chamber 18. The cap sleeve 34 has at its free end the circumferential hook 25, which engages behind the outer diameter stage of the cylindrical extension 36. At the inner cylindrical diameter stage of the cylindrical extension 36 is a thread into which a clamping sleeve 37 with its external thread can be screwed. The clamping sleeve 37 clamped by screwing up to the stop the wire mesh 29 against the radial surface of the diameter step of the cylindrical extension 36th

To connect the slot with the atmosphere, the diameter of the outer circumference of the cylindrical extension 36 is smaller than the inner circumference of the cap sleeve 34 and also forms the circumferential hook 25 paraxial passages 39, as the top down 4A shows. Thus, there is formed on the outer circumference of the extension 36, a cylindrical gap which connects the slot with the atmosphere.

The mixing chamber 18 has in all the described embodiments essentially the function to break the laminar flow of the extinguishing mixture into individual jets to divert these individual jets from the flow direction and to break it up into smaller pieces, drops, strands.

The cylindrical housing of the mixing chamber 18 is set on the one hand to the outlet of the extinguishing valve 10 and on the other hand connected by its own outlet with the ventilation chamber 21 -as described above. The cylindrical one Housing inner cross-section is filled in several radial planes by perforated plates 32, 33 which lie in the flow behind each other.

For this purpose, the holes may be distributed differently, e.g. be distributed in several concentric rings on their perforated plates. These rings can have different diameters from perforated plate to perforated plate, so that the rays of the first perforated plate do not hit holes of the second perforated plate. The holes of the second orifice plate have a direction different from the axial direction and are therefore inclined with respect to the axial direction in the circumferential direction inclined.

The holes of the perforated plate 32 are directed in the flow direction and distributed uniformly over the surface of the perforated plate. Perforated plates 32 divides the incoming extinguishing agent mixture stream into individual jets.

The holes of the downstream following perforated plate 33 are directed in the direction of flow and in addition also more or less transverse to it and evenly distributed over the surface of the perforated plate 33, but less than the number of holes. Perforated plate 32. Perforated plate 33 further divides the incoming single rays, redirects them and breaks them up into shorter pieces. Perforated plate 33 thus serves to give these individual jets a direction conducive to swirling and mixing and to chop them up.

By the described measures according to this invention, a foam carpet is produced without the use of fluorine-containing surfactants, which places itself on the fire, especially on burning liquid levels, and is so firm that at a few centimeters thick foam layer, the flames are permanently stifled.

It has been found that the foam formation depends on the flow rate of the extinguishing mixture of extinguishing agent and foaming agent. This flow rate is known to depend on the volume expansion of the propellant gas; It therefore appears necessary to provide a sufficiently large volume of propellant gas relative to the volume of the extinguishing mixture or of the extinguishing agent container. As a result, however, the amount of extinguishing mixture is reduced, which is disadvantageous for the extinguishing success. By using suitable propellant gases, the volume of propellant gas is kept small relative to the volume of extinguishing agent, and so small that the volume before expansion is between 2% and 4% of the volume of the extinguishing agent. This is mainly through the use of nitrogen reachable as propellant gas, which is stored until discharge in a print cartridge, preferably in the extinguishing agent container - see the description Fig.1 ,

reference numeral

1.

Extinguishing agent container 1

Second

Neck 2

Third

Locking head 3

4th

Covenant 4

5th

Hose nozzle 5

6th

Extinguishing mixture channel 6

7th

Riser 7

8th.

Print cartridge 8,

9th

Pressure pipe 9

10th

Extinguishing valve 10

11th

Impact tappet 11

12th

ascending branch 13 of the pressure channel

13th

Extinguishing hose 15

18

Mixing chamber 18

19

Einfüllöffnung19

20

Cable tie 20

21

Ventilation chamber 21

22

Floor 22

23

Valve device predetermined breaking point 23

24

Coat 24

25

Hook 25

26

Air inlet holes 26

27

Venturi-type constriction (27)

28

Wireframe 28

29

Wireframe 29

31

Screw ring 31

32

Perforated plate 32

33

Perforated plate 33

34

Cap sleeve 34

35

Thread pairing 35

36

Extension 36

37

Thread 37

38

Clamping sleeve 38

39

cylindrical paraxial passage 39 qmm = mm ²

sq cm =

cm ²

Claims (5)

1. Fire extinguisher

   • with an extinguishing agent container (1) for the extinguishing agent and a secondary container (14) for a foaming agent,

   • with a extinguishing mixture channel (6), which is connected to the extinguishing agent container and in which the extinguishing mixture of extinguishing agent and foaming agent is expelled when using the fire extinguisher by pressurizing the extinguishing agent container by means of a propellant gas,

   • with a two-part mixing device, through which the extinguishing mixture is guided and which has:

   + a mixing chamber (18) which is mounted on the end of the extinguishing hose (15) connected to the extinguishing mixture channel (6), and

   + a ventilation chamber (21) having a jacket (24) which is constructed as a hollow cylindrical rotary body and which, on the one hand, is placed on the mouth of the mixing chamber (18) and the mouth of which, on the other hand, serves as an extinguishing foam outlet through which the extinguishing mixture in the foamed state is sprayed as an extinguishing foam,

   • wherein the housing inner cross-section of the mixing chamber (18), in several radial planes, is filled by perforated plates (32, 33), which lie one behind the other in the flow,

   ∘ with the first perforated plate (32) behind the extinguishing agent inlet (2), having a plurality of holes through which the extinguishing mixture flowing through is divided into a plurality of individual streams,

   ∘ and with the perforated plate (33) following downstream

   • and wherein the ventilation chamber (21) comprises, in a ventilation plane oriented as a radial cross-sectional plane, air inlet holes (26) which

   ∘ are arranged on the circumference of the jacket (24), and

   ∘ directed into the interior of the mixing device, and

   ∘ which connect the interior of the jacket with the ambient air in such a way that sucked-in air jets are directed in the ventilation plane onto the extinguishing mixture divided into individual streams,

   • the inner cross-section of jacket of the ventilation chamber (21) having a cross-sectional constriction between the aeration plane and said perforated plates,

   characterized in that
   the holes of the successive hole plates (32, 33) are not aligned and that the holes of the second hole plate have a direction different from the axial direction.
2. Fire extinguisher according to claim 1
   characterized in that
   the constriction of the jacket inner cross section of the ventilation chamber (21) is a venturi-like necking (27) by a collar running around on the inner circumference.
3. Fire extinguisher according to claim 1
   characterized in that
   the constriction is a grid (29) filling the jacket cross-section of the ventilation chamber (21), preferably wire grid made of metal or plastic wires, whose mesh size is in the range between 15 and 40 / cm², preferably 25 to 35 mesh / cm².
4. Fire extinguisher according to claim 1,
   characterized in that
   the mouth of the ventilation chamber (21) is provided with a grid (28) filling the outlet cross-section of the mouth, preferably wire grid of metal or plastic wires, whose mesh size is in the range between 15 and 40 / cm², preferably 25 to 35 mesh / cm².
5. Fire extinguisher according to claim 1,
   characterized in that
   the holes of the second perforated plate are inclined relative to the axial direction in the circumferential direction.

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