RU2817915C1 - Combined fire extinguishing installation with air-mechanical hybrid foam of medium expansion or sprayed water - Google Patents

Abstract

FIELD: fire-fighting equipment.

SUBSTANCE: invention relates to fire-fighting equipment, to manual and stationary devices for generation of air-mechanical hybrid foam of medium expansion rate or sprayed water. In installation combined fire extinguishing, comprising a cylindrical housing, a mesh cassette installed inside the housing and a nozzle with a connection pipe for supplying a fire extinguishing substance, housing is made of metal thin-walled with annular projection concave inside the housing on the side of foam jet or sprayed water outlet and with annular projection outward from the nozzle side, mesh cassette is made of three coaxially installed with interference one inside the other inner, intermediate and outer annular rims with side cylindrical surfaces and two meshes arranged with a gap relative to each other, one of which is fixed by its edges in the gap between the mating side surfaces of the outer and intermediate rims, and the other is fixed by its edges in the gap between the mating side surfaces of the intermediate and inner rims, and the nozzle is attached to the housing by means of centring stops. At the same time cassette of meshes is installed inside the housing on the side of the nozzle with thrust against the annular projection concave inside the housing and is located so that the mesh fixed by the edges between the outer and intermediate rims faces the nozzle, and the mesh fixed by its edges between the intermediate and inner rims faces towards the foam jet outlet.

EFFECT: increasing the efficiency of extinguishing emergency transport, forest, industrial and other fires.

10 cl, 18 dwg, 1 tbl

Description

Field of technology

The invention relates to fire-fighting equipment, to manual and stationary devices for generating air-mechanical hybrid foam of medium expansion or sprayed water and can be used when extinguishing various forest, emergency transport, emergency industrial and other large-scale fires, in particular when extinguishing flammable and combustible fires liquids, liquefied natural and hydrocarbon gases (LNG and LPG), solid combustible materials, vehicles and industrial technical equipment, as well as for creating light and heat shields and cooling in areas of accidents, catastrophes, natural disasters, for degassing and decontamination, camouflage of civilian objects and military purposes.

State of the art

It is known that the most effective modern fire extinguishing agent is air-mechanical hybrid foam of medium expansion, consisting of polydisperse bubbles with a thickened (watered) shell - reduced (low) expansion foam, and bubbles with a thinned (dehydrated) shell - high (medium) expansion foam , forming, when mixed in the process of joint movement, a hybrid foam of medium expansion [RU 2757106, A62C 5/02, publ. 10/11/2021, BI 29; RU 2757479, A62C 5/02, publ. 10/18/2021, BI 29].

There are known generators of air-mechanical foam of medium expansion in portable and stationary design options, however, most of the well-known generators of medium expansion foam by other authors provide foam jets with a range of up to 10 m, which limits their use when extinguishing large-scale fires due to the high risk of personal working in the fire zone composition of fire departments.

A mobile multi-purpose foam generating unit is known for generating foam mainly at nuclear fuel cycle facilities, including a container for water or a foam concentrate solution, a pump with an electric motor, a comb for connecting air-foam generators (foam generators) with an average expansion rate of K = 20-200 and fire nozzles, pipelines, hoses and fittings, is additionally equipped with low expansion foam generators (K<20) and high expansion foam (K=200-1000), working with two types of mesh (conventional - flat or metal fabric - volumetric weaving), and a valve is installed on the comb, allowing smoothly regulate the flow of the foaming solution supplied to the high-expansion foam generator at a flow rate of 0.5-10 l/min. In addition, the container is equipped with a lid designed to seal it when creating a pressure of up to 6 atm. These features provide increased versatility of the installation [RU 2308996 A62S 27/00, A62S 5/02 Publ. 27.10.2007].

The disadvantage of the device according to RU 230899 is its significant weight and dimensions, low performance and the impossibility of its use when extinguishing fires in industrial and low-rise buildings in urban and rural settlements, extinguishing forest and landscape fires.

A device previously developed by the applicant’s authors for forming a jet of medium expansion foam with increased range is known, according to which, in order to increase productivity, efficiency and increase the efficiency of fire extinguishing by creating a combined jet of foam of medium expansion and increasing the range of the jet of medium expansion foam up to 20 m, a foaming agent solution is supplied to the mesh in the body of the foam generator to produce a jet of foam of medium expansion with increasing expansion and decreasing density in the direction from the center to the periphery by means of a means or means located on the mesh or inside the mesh cassette for redistributing the amount of foaming solution on the surface of the mesh, made in the form of a ring, rings, ring nozzles or other means located inside the mesh cassette and/or on the surface of the mesh or mesh cassette on the supply side of the foaming solution jet or on the foam outlet side. The body of this foam generator is made in the form of a hollow cylinder, to which a nozzle or other means of forming a jet of foam solution is attached on the supply side of the foam agent solution, and a mesh is attached inside the body on the foam outlet side. The body of the foam generator has a length of 0.3 to 1.5 times the distance from the means for forming a jet of foam solution to the mesh. The foam generator additionally contains a diffuser in the form of a hollow cylinder, fixed in the body of the foam generator directly behind the mesh on the side of the foam outlet and made with a length of 0.1 to 0.9 times the diameter of the diffuser and a free cross-sectional area less than the cross-sectional area of the mesh [RU 2170123 A62C 5/02 Publ. 07/10/2001].

The disadvantages of the device according to RU 2170123 are the complexity of the design of the means or means for redistributing the amount of foaming solution on the surface of the mesh, as well as the lack of information about the features of fastening the mesh in the device and about the design of the mesh cassette.

There is a known method, previously developed by the authors of the applicant, of forming a jet of medium-expansion foam with increased range and a device for its implementation, according to which increasing the productivity, economy and efficiency of fire extinguishing with combined medium expansion foam while simultaneously simplifying the manufacture, transportation and use in fire extinguishing systems, when receiving a jet of foam, a jet of foam concentrate solution is supplied to the mesh in the foam generator body under pressure RP in front of the nozzles from 0.4 to 1.2 MPa. In a device for forming a jet of medium expansion, containing a housing and a mesh located in the housing, the body of the foam generator is made in the form of a hollow cylinder or two or more half-cylinders connected to each other by planes, while a mesh is fixed inside the body on the foam outlet side, the body of the foam generator has a length from 0.3 to 1.5 distances from the means for forming a jet of foaming agent solution to the mesh, and the means for forming a directed jet of foaming agent solution is made in the form of a nozzle or nozzles or other means for forming a directed jet or jets, located or located at a distance from the mesh, determined by formula, where A is the distance from the center of the nozzle or other means of jet formation to the mesh, m; Rs - radial mesh size; tgα/2 is the tangent of half the opening angle of the foam solution jet; α is the angle of opening of the foam solution jet at the exit from the nozzle or other means of forming a directed jet [RU 2180607, A62C 5/02, publ. 03/20/2002 Bulletin. No. 8].

The disadvantages of the device according to RU 2180607 and other known foam-generating devices are the lack of information about the features of fastening the mesh in the device, about the design and manufacturing technology of the mesh cassette as a determining design factor of reliability and influence on the quality of the resulting foam.

The closest in technical essence and achieved technical result (prototype) is the medium expansion foam generator GPS-200 in accordance with GOST R 50409-92, containing a conical generator body made of cast aluminum alloy AK7 or other alloys with a nozzle on the foam outlet side and a conical collector (confuser) from the supply side of the sprayed foam solution to the grids, a grid cassette in the form of a ring, covered along the end planes with a metal mesh with a cell size of 0.8 - 1 mm, a vortex-type centrifugal sprayer with a GM-70 connecting head attached to the body by means of three stands [GOST R 50409-92 Medium expansion foam generators. Technical conditions. Official publication. Gosstandart. Moscow. 8 p. (prototype)].

The GPS 200 generator (prototype), according to its operating principle, is a portable water-jet ejector apparatus.

The nozzle in the GPS-200 generator is designed to form a foam flow after a grid cassette into a compact jet and increase the flight range of medium-expansion foam up to 10 m.

The vortex-type sprayer in the GPS-200 generator has six windows located at an angle of 12°, which causes swirling of the flow of working fluid and ensures that a sprayed stream of foam solution is obtained at the output, covering the entire surface area of the grid cassette.

The GPS-200 generator (prototype) functions as follows: The sprayed stream of foaming agent solution emerging from the atomizer, due to ejection and the reduced pressure created inside the housing, sucks in atmospheric air through a conical collector (confuser) and mixes with it in the housing.

A mixture of droplets of foaming solution and air falls on the mesh cassette.

On grids, deformed drops form a system of stretched films, which, enclosed in limited volumes, form first elementary (in the form of individual bubbles) and then mass foam.

With the energy of newly arriving droplets and air, the mass of foam is pushed out of the foam generator and with the formation of a jet of air-mechanical foam of medium expansion with a multiplicity of 100 + 30, obtained as a result of intensive mixing in the GPS-200 generator in a certain proportion of three components: water, foaming agent and air [Moiseev Yu., N. Kharlamov R.I., Kolbashov M.A.. Fire-technical and emergency rescue equipment. Tutorial. - Ministry of the Russian Federation for Civil Defense, Emergency Situations and Disaster Relief. Federal State Budgetary Educational Institution of Higher Education Ivanovo Fire and Rescue Academy of the State Fire Service. Ivanovo, 2017, pp. 36-38].

The main technical disadvantage of the GPS-200 generator (prototype) is the insufficient (only about 8-10 m) range of medium expansion foam supply, as well as insufficient operational reliability. In particular, the probability of failure-free operation of GPS-200 for 50 hours of operation, or failure-free operation of GPS-2000 for 25 hours of operation, specified in GOST R 50409-92 (p. 7, clause 2.19) is 0.993 at a nominal pressure of the foam concentrate solution in front of the sprayer of 0.0, 4-0.6 MPa ((4-6 kg/cm ² ) proves the relatively low reliability of GPS foam generators, due to the possible destruction of the grid cassette with the tearing of the grids from their fastening points with the cessation of their normal operation as a result of the dynamic pressure of the flows acting on the grids. This significantly limits the scope and effectiveness of the GPS-200 generator and increases the risk of danger for fire personnel.

A common disadvantage of the known water-foam fire extinguishing devices is that the known stationary and mobile devices for generating medium-expansion foam with relatively low reliability and the inability of normal operation at high pressure of the foam solution or water supplied to them have a relatively low operating efficiency due to insufficient range and generation productivity and supplying medium expansion foam.

At the same time, in the well-known publicly available sources of information about medium-expansion foam generators, there is practically no information about the design features and manufacturing technologies of mesh cassettes or mesh packages and fastening in the mesh body, which are the main working element of medium-expansion foam generators, loaded by the dynamic pressure of the flow of foam concentrate solution or water.

Problem solved and technical result

An inventive problem that has not been properly resolved to date, hindering the increase in productivity and efficiency of modern fire extinguishing methods and equipment, is that the known foam generators of medium expansion or bulky, complex and low-tech to manufacture, or do not provide the required efficiency in extinguishing large and fast-moving fires. reasons for insufficient performance and range, since it is known that when extinguishing large-scale industrial, forest, emergency transport and emergency industrial fires, controlled, rapid and uniform coverage of the entire fire-hazardous area with fire extinguishing agents is required, preferably air-mechanical (water-air) foam of medium expansion from the most remote positions .

The technical problem to be solved by the claimed invention is the need to quickly prevent fires and explosions, reduce the intensity of combustion and extinguish fires through the rapid formation and long-range distribution of air-mechanical (water-air) foam of medium expansion or sprayed water over large areas of fire of flammable liquids, solid flammable materials, liquefied natural and hydrocarbon gases (LNG and LPG), when and where to prevent fires and extinguish fires, prompt coverage of the entire fire-hazardous area with a fire extinguishing agent is required, as well as cooling and fire protection of buildings, structures, machinery, equipment, flammable and adjacent to the fire explosive materials. This is possible only if there is a sufficient number of long-range generators of medium-expansion foam or sprayed water in various manual and stationary designs, which are structurally simple and technologically advanced to manufacture, but convenient and effective in operation, which is not observed at present.

The technical result achieved by implementing the claimed invention is to increase the efficiency of extinguishing emergency transport, forest, industrial and other fires through the creation, mass production and widespread practical use of structurally simple, technologically advanced and reliable in operation combined hybrid extinguishing installations medium expansion foam or sprayed water with increased range.

Disclosure of the invention

The problem is solved and the required technical result is achieved by the fact that in the proposed combined fire extinguishing installation, containing a cylindrical body, a grid cassette installed inside the body and a nozzle with a connection pipe to the fire extinguishing agent supply pipeline, according to the invention

the body is made of thin-walled metal with an annular protrusion concave into the body on the side where the foam jet exits and with an annular protrusion convex outwards from the nozzle side,

the mesh cassette is made of three coaxially installed with interference one inside the other inner, intermediate and outer annular rims and two tensioned and located with a gap relative to each other, one of which is fixed by the edges in the gap between the mating side surfaces of the outer and intermediate rims, and the other is fixed edges in the gap between the mating side surfaces of the intermediate and inner ring rims,

and the nozzle is attached to the body by means of three centering stops.

In this case, the mesh cassette is installed inside the body on the nozzle side with a stop in the annular protrusion concave inside the body and is located so that the mesh fixed with its edges between the outer and intermediate rims faces towards the nozzle, and the mesh fixed with its edges between the intermediate and inner rims faces towards the jet outlet foam.

Besides

A shut-off valve is installed on the connection pipe to the fire extinguishing agent supply pipeline.

and the nozzle is equipped with a connecting pipe for supplying a fire extinguishing agent to the nozzle in the form of a foaming agent solution or water.

In this case, the installation

manufactured with the ability to form and supply hybrid foam of medium expansion with an expansion of 50 + 20 or sprayed water at a distance of 15 + 3 m to the fire zone.

is made manually and contains a handle attached to the body, is made with the possibility of installation on a fire escape, foam lift, manipulator, automobile, rail, air, watercraft or all-terrain vehicle or trailer, gas and oil production platform or fastening on a stationary platform,

or manufactured with manual or remote control or oscillation.

In addition, the connection pipe to the fire extinguishing agent supply pipeline is equipped with a quick-detachable/detachable connection with rotary eccentric clamps of the camlock type, or a connecting head or flange, and the installation additionally contains means of rotation in vertical and/or horizontal planes with a manual or linear drive with electric, pneumatic - or a hydraulic motor with the ability to connect them to a remote control system for their operation using a remote control or radio signals from the remote control system.

Brief description of drawings

The invention is illustrated by drawings, where in Fig. 1-18 the design of the proposed installation is disclosed in detail and where the features and capabilities of operation in manual and stationary versions of the device are shown, including those shown in the drawings: a thin-walled metal cylindrical body 1, on which there is a an annular recess 2, and on the nozzle side an annular protrusion 3; nozzle 4 with a connection pipe to the pressure pipeline for supplying the fire extinguishing agent in the form of an aqueous solution of foaming agent or water; stops 5, ensuring fixation and centering of the nozzle along the axis of the body; a grid cassette 6 installed inside the body of an original design, a handle 7 for operating the device in its manual version; shut-off valve 8 installed on the connection pipe to the pressure pipeline for supplying the fire extinguishing agent; means for fastening the connection pipe to the fire extinguishing agent supply pipeline 9; mesh cassette 6 containing inner 10, intermediate 11 and outer 12 coaxially located one inside the other annular rims, in the spaces between which meshes 13 and 14 located with a gap relative to each other are fixed with places 15 for spot welding of the outer and inner with the intermediate rims; plastic protective rings 16 along the edges of the body; screws or self-tapping screws 17 fixing the position of the net cassette inside the housing; screws or self-tapping screws 18 for fixing the position of the stops 5, ensuring fixation and centering of the nozzle along the axis of the body, a pipe with a tap 19 for supplying the fire extinguishing agent (foaming agent solution or water) to the nozzle 4.

In fig. 1 shows a photo of the installation with a GM-50 connecting head (Weight: 3.5 kg).

In fig. 2 – photo of the installation with a connecting flange (Weight: 5 kg)

In fig. 3 – photo of the installation with a shut-off valve and a GM-50 connection head (Weight: 4.5 kg)

In fig. 4 – photo of the installation with a shut-off valve, a pipe with a valve 19 for supplying foam concentrate to the nozzle and a connecting head GM-50 (Weight: 4.5 kg)

In fig. 5 – photo of the installation with a shut-off valve, a built-in foam agent supply pipe, a GM-50 connecting head, a hose for supplying the foam agent solution to the ejector and a soft fabric backpack with a container for the foam agent solution (Weight: 3.5 without foam agent solution, 19 kg when loaded with the solution foaming agent)

In fig. 6 – photo of the installation with a shut-off valve, an ejector built into the nozzle, a foam agent supply pipe, a GM-50 connecting head, a hose for supplying the foam agent solution to the ejector and a metal backpack with a container for the foam agent solution (Weight: 3.5 without foam agent solution, 31.5 kg in equipped condition with a foaming agent solution).

In fig. 7 – photo of a fire extinguishing system with five installations on a rotation unit (Weight: 35 kg)

In fig. 8 – 11 – diagrams of sections at individual stages of manufacturing a grid cassette.

In fig. 12, 13 – cross-sectional diagrams of a finished grid cassette, suitable for installation in the generator housing of the installation.

In fig. 14 – map of irrigation of combined foam of average expansion generated by a jet at a productivity of water or foaming agent solution of 2 l/s and an operating pressure in the pressure pipeline of 0.6-0.8 MPa (6-8 kg/cm2).

In fig. 15 – map of the radius of the installation with a water or foam solution capacity of 2 l/s and an operating pressure in the pressure pipeline of 0.6-0.8 MPa (6-8 kg/cm2).

In fig. 16, 17 – photos of tests of the PURG UKTP device when extinguishing forest fires.

In fig. 18 – photo of using the installation in the fire extinguishing system of a residential or industrial premises.

Carrying out the invention

The combined fire extinguishing installation proposed by the invention, hereinafter - an installation containing an original design of a medium expansion foam generator, hereinafter - a generator containing a cylindrical body, an original design of a grid cassette and a means of connecting to a pressure pipeline for supplying a fire extinguishing agent (foaming agent solution or water) is a new design a modification of an installation previously produced by the applicant under the commercial designation “Combined fire extinguishing installation PURGA 2” (“UKTP PURGA 2”), where the number 2 indicates the productivity of the installation for an aqueous solution of foaming agent or water 2 l/s.

The installation proposed by the invention is intended for use in extinguishing various forest, emergency transport, emergency industrial and other large-scale fires, in particular when extinguishing fires of flammable and combustible liquids, liquefied natural and hydrocarbon gases (LNG and LPG), solid combustible materials, transport means and industrial technical equipment, as well as for creating light-heat-protective screens and cooling in areas of accidents, catastrophes, natural disasters, for degassing and decontamination, camouflage of civilian and military objects.

The characteristic design, which is in a cause-and-effect relationship with the achieved technical result, are the distinctive features of the proposed installation, which contains a generator of original design, including a cylindrical body with a diffuser attached to it, a grid cassette installed inside the body of the original design and a means of supplying a fire extinguishing agent (foaming agent solution or water ) on the grid cassette, as well as the means of connection to the pressure pipeline for supplying the fire extinguishing agent, are:

- The presence of a technologically advanced thin-walled metal cylindrical body of the generator with an annular protrusion concave into the body on the side of the foam or sprayed water outlet and with an annular protrusion convex outward on the nozzle side, which can not only increase the rigidity and strength of the generator case, but also simply and reliably fix there is a grid cassette in the housing, and also simply and reliably attach the fixing and centering stops of the nozzle to the generator housing with a means of quick-detachable or permanent connection of the installation to the pressure pipeline for supplying the fire extinguishing agent (foaming agent solution or water).

- Possibility of manufacturing and using almost the same simple and technologically advanced, but convenient and efficient to use installation design in manual and stationary versions;

- The presence of a generator located inside the housing at an optimal distance from the nozzle of a grid cassette of original design, structurally formed by three coaxial outer, intermediate and inner ring rims located with interference one inside the other with cylindrical side surfaces and two located at an optimal distance from each other (about 20 mm) tightly and evenly stretched meshes, tightly and securely fixed edges in the gaps between the mating side surfaces of these three coaxially tensioned rims installed one inside the other with possible additional fixation by spot welding and the said annular rims to each other, and the said meshes with the rims. This original design of the grid cassette provides not only a tight, uniform tension of the grids, rigid and reliable fixation of the grid cassette and, accordingly, the grids inside the body at an optimal distance from the nozzle, but also ensures the effective formation of a long-range combined jet of medium expansion hybrid foam or sprayed water using two grids , located with an optimal gap relative to each other;

- Placing a grid cassette inside the body so that the mesh fixed between the outer and intermediate rims faces the nozzle, and the mesh fixed between the intermediate and inner rims faces the outlet of foam or sprayed water, allows not only to significantly increase the reliability of the design and long-term normal operation of the device in extreme conditions even with a pressure at the inlet of the fire extinguishing liquid up to 1.2 MPa (12 kg/cm ² ), but also the formation and delivery of a combined jet of hybrid foam, medium expansion foam or sprayed water over a distance of more than 15 m;

- Optimal proportions of overall dimensions (the version without a shut-off device has a length of about 430 mm, the diameter of the generator body is 220 mm and the height with the handle is 280 mm, and the version with a shut-off valve has a length of 600 mm, the height with the handle is about 280 mm, the diameter of the generator body is 220 mm) and the optimal distance between the nozzle and the screen cassette (about 360 mm). This allows, with a water (foaming agent solution) productivity of about 2 l/s, an optimal operating pressure at the fire extinguishing liquid inlet of 0.6-0.8 MPa and a control pressure of 1.2 MPa (12 kg/cm ² ), to form a supply to a distance more than 15 m combined jet of hybrid foam of medium expansion or sprayed water with increasing expansion and decreasing density in the direction from the center to the periphery.

All this proves the confident achievement of the required technical result in the implementation and use of the invention, namely, the implementation of the invention provides the opportunity to increase the efficiency of extinguishing emergency transport, forest, industrial and other fires through the creation, mass production and widespread practical use of structurally simple, technologically advanced manufacturing and reliable operation of the installations proposed according to the invention with original generators of medium expansion foam with increased range.

As shown in the drawings, almost the same design of the installation can be implemented in manual and stationary versions, with a shut-off valve and without a shut-off valve, which allows you to quickly regulate the start-up by starting the formation and supply of foam or sprayed water and shutdown from work by stopping the supply of fire extinguishing agent substances on a grid cassette, with oscillating devices and with remote control in fire extinguishing systems, in a design for fresh and sea water.

The installation proposed by the invention can be equipped with standard quick-release connections (type TZA, Kamlok, flange connections, etc.), allowing them to be mounted and used on all types of domestic and foreign fire fighting equipment.

Standard and specially designed connections ensure quick and easy installation of the proposed installation or installations on stationary and mobile equipment and in fire extinguishing facility systems, as well as the possibility of using them either as barrels with connecting heads of the GM type according to GOST R 53279-2009, or as nozzles on stationary and auto-mechanical ladders, or as attachments for vehicle lifts, or as stationary installations with flange connections, etc.

If there are rotation units, the proposed installation can be produced with manual control, with wired or radio remote control for turning the generator in horizontal and vertical planes; with combined switchable manual and remote control.

The proposed installation can be mounted on mobile hand trucks, cars and car trailers, sea vessels, etc.

Thus, all individual essential features and the totality of essential features of the invention shown in detail in the drawings and in the description are essential and are in a cause-and-effect relationship with the technical result obtained from the use of the invention.

A grid cassette used in the generator, original in design, includes three coaxially installed with interference one inside the other: inner 10, intermediate 11 and outer 12 ring rims and two tightly stretched grids located with a gap relative to each other, one of which 13 is fixed by the edges in the gap between the mating ones the side surfaces of the outer and intermediate rims, and the other mesh 14 is fixed with its edges in the gap between the mating side surfaces of the intermediate and inner cylindrical ring rims, is made as follows (Fig. 8-13):

A mesh 14 is placed on the inner rim 10 (Fig. 8) and the intermediate rim 11 is pushed onto them from above with an interference fit in the coaxial axial direction until the inner rim 10 is completely inserted into the intermediate rim 11, ensuring tight tension of the mesh 14 onto the bottom of the inner rim 10 and tight fixation the edges of the mesh 14 in the gap between the mating side surfaces of the inner rim 10 and the intermediate rim 11 (Fig. 9).

Then I turn the workpiece obtained in this way by 180 ^° (Fig. 10), cut off the ends of the protruding edges of the mesh 14 flush and, using spot welding 15, additionally fix the edges of the inner rim 10 and the intermediate 11 rims and the mesh 14 to the indicated rims relative to each other (Fig. 10) .

On the inner 10 and intermediate 11 rims fixed by spot welding to each other with the edges of the mesh 14 (Fig. 10) located in the gap between the outer walls of the inner rim 10 and the inner walls of the intermediate rim 11 (Fig. 10), a mesh 13 (Fig. 11) is applied on top in a coaxial axial direction with interference, push the outer rim 12 onto them until the combined intermediate 11 and inner 10 10 rims with the edges of the mesh 14 are completely inserted into the outer rim 12, ensuring tight and uniform tension of the mesh 13 on the top of the intermediate rim 11 and tightly fixing the edges of the mesh 13 in the gap between mating side surfaces of the intermediate rim 11 and the outer rim 12 (Fig. 12, 13).

After this, the ends of the protruding edges of the mesh 14 are cut flush or turned outward and the edges of the inner rim 10 and the intermediate rim 11 (Fig. 10) and the mesh 13 with the indicated rims are fixed relative to each other by spot welding 15 to obtain variants of the finished mesh cassette suitable for installation in generator housing (Fig. 12, 13).

The mesh cassette can use a mesh with nominal dimensions of the cell sides in the clear of 0.8-1.12 mm in accordance with GOST 3826, made of wire with a diameter of 03.04 mm from high-alloy steel, or a mesh in accordance with GOST 6613 from semi-pompak wire with the same cell sizes and wire diameter.

The medium expansion foam generator used in the proposed installation with the proposed mesh cassette is manufactured as follows (Fig. 1-4):

A rectangular blank is cut out of a thin-walled metal sheet of predominantly stainless steel or ordinary painted steel, from which a cylindrical body of the required dimensions is made by bending and welding, on which on one side (from the side where foam or sprayed water exits) an annular protrusion 1 concave into the body 1 is formed. with a radius of 3 to 5 mm, and on the other side (from the side of subsequent installation of the nozzle 4) an annular protrusion 3 convex outward is formed with a radius of 3 to 5 mm

A mesh cassette 8 made using the technology described in detail is installed inside the housing 1 on the side of subsequent installation of the nozzle 4 with an emphasis on the annular protrusion 2 concave inside the housing so that the mesh 13, fixed by the edges between the outer 12 and intermediate 11 rims, faces the direction of the subsequent installation of the injector 4. and the mesh 14 fixed by the edges between the intermediate 11 and inner 10 rims (Fig. 12, 13) was turned towards the exit of foam or sprayed water, which ensures maximum reliability and strength of the fastening of both the grid cassette in the generator housing and the grids in the cassette.

The grid cassette 6 in the housing is fixed from the outside with screws or self-tapping screws 17 (Fig. 17).

Protective plastic hoops 16 are put on the edges of the body both from the foam outlet side and from the side of the subsequent installation of the nozzle, the handle 7 is screwed to the body, and by means of stops 5 and screws or self-tapping screws 19, the centered along the axis of the body, a nozzle 4 with a connection pipe to the pressure pipeline for supplying the fire extinguishing agent with a shut-off valve 8, which is necessary in certain design options, installed on it (Figs. 3,4).

In a similar way, constructive variants of the proposed installation are made with various means of connecting the generator nozzle to the pressure pipeline for supplying the fire extinguishing agent (foaming agent solution or water).

Individual parts and assemblies of the inventive installation can be made from structural elements and materials commonly used in fire-fighting technology, using conventional equipment, using conventional technologies known and used in the field of modern fire-extinguishing and fire-explosion prevention technology.

The installation according to the invention functions as follows:

A solution of foaming agent or water from the pressure pipeline is supplied to the nozzle, from where, under a working pressure of 0.6-0.8 MPa, it is supplied to the central zone of the mesh cassette. At the same time, due to the ejection effect and vacuum created by a conical flow of a foaming agent solution or water, expanding along the direction of travel from the nozzle to the grid cassette in a cylindrical body, atmospheric air is sucked into the peripheral zones of the grid 13, inside the grid cassette between grids 13 and 14 drops of the foaming agent solution or water and peripheral air flows are mixed to produce, at the exit from the mesh cassette and from the diffuser, a jet of combined hybrid foam of medium expansion or atomized water with increasing expansion and decreasing density in the direction from the center to the periphery.

When a foaming agent solution is supplied to the grid cassette, a stream of combined air-mechanical hybrid foam of medium expansion is formed at the outlet of the generator, consisting of polydisperse bubbles with a thickened (watered) shell located in the central part of the flow - foam of reduced expansion, and bubbles with a thinned expansion located in the peripheral parts of the flow (dehydrated) shell - foam of increased expansion, which, when further mixed in the process of joint movement, forms a hybrid foam of medium expansion with increased fire-extinguishing properties and an increased supply range.

The combined flows of foam of medium expansion or sprayed water with increasing expansion and decreasing density in the direction from the center to the periphery, formed by the inventive installation, have a significantly increased range compared to homogeneous flows due to the presence of a central part of the flow with increased density and increased kinetic energy.

It is known that foam is the most effective and widely used fire extinguishing agent, which is a dispersed system consisting of cells - air (gas) bubbles, separated by films of liquid containing a foaming agent [GOST R 50588-2012. Foaming agents for extinguishing fires. General technical requirements and test methods].

The ratio of the volumes of the gas and liquid phases (per unit volume) of the foam determines the structure and its properties. If the volume of the gas phase _Vg exceeds the liquid volume _Vg by no more than 10-20 times (low expansion foam), the foam cells filled with gas have a spherical shape. In such foams, gas bubbles are surrounded by liquid shells of relatively large thickness. Spherical foams are characterized by a high liquid content and, therefore, low stability. Therefore, they are classified as metastable (conditionally stable).

In unstable foams, the so-called Plateau effect is observed: the liquid phase is removed from the partitions, flowing out under the influence of gravity, and rapid coalescence occurs (from the Latin coalesce - merging, uniting) - the merging of touching gas bubbles. In foam, a gas bubble cannot move freely in either a vertical or horizontal plane. It is as if “sandwiched” by other bubbles adjacent to it.

With an increase in the V _g /V _l ratio, the thickness of the liquid film separating the gas volumes decreases, and the gas cavity loses its spherical shape. Medium expansion foams, in which the V _g / V _l ratio is several tens or even hundreds, have a multifaceted shape. Moreover, the shape of polyhedra can be different - triangular prisms, tetrahedrons, irregularly shaped parallelepipeds. During the aging process of the foam, the spherical shape of the cells becomes multifaceted. Multifaceted foams are characterized by a low liquid phase content and are characterized by high stability. In such foams, individual bubbles are brought together and separated by thin “stretched elastic films.” These films, due to their elasticity and a number of other factors, prevent the coalescence of gas bubbles. As the separating films become thinner, the bubbles come closer together, adjacent to each other and acquire a clear polyhedral shape [Bobkov S.A., Baburin A.V., Komrakov P.V. Physico-chemical foundations of the development and extinguishing of fires: textbook. manual / M.: Academy of the State Fire Service of the Ministry of Emergency Situations of Russia, 2014. - 210 pp.].

The main physical and chemical properties of the foam are:

multiplicity - the ratio of the volume of foam to the volume of the foaming agent solution contained in the foam;

dispersion – degree of bubble refinement (bubble size);

viscosity - the ability of foam to spread over a surface;

durability – the ability of foam to resist the process of destruction [ibid.].

Depending on the expansion ratio (K), foams are divided into four groups:

foam emulsions, K < 3;

low expansion foams, 3 < K < 20;

medium expansion foam, 20 < K < 200;

high expansion foam, K > 200 [ Sharovarnikov A.F., Sharovarnikov S.A. Foaming agents and fire extinguishing foams. Composition, properties, application. M.: Pozhnauka, 2005. - 335 p.].

The dispersion of the foam is inversely proportional to the average diameter of the bubbles.

It is known that the higher the dispersion, the higher the foam resistance and fire extinguishing efficiency. The degree of foam dispersion largely depends on the conditions for its production, including the characteristics of the equipment. The expansion ratio and dispersion of the foam determine the insulating ability of the foam and its fluidity. [Bobkov S.A., Baburin A.V., Komrakov P.V. Physico-chemical foundations of the development and extinguishing of fires: textbook. manual / M.: Academy of the State Fire Service of the Ministry of Emergency Situations of Russia, 2014. - 210 pp.].

The fire extinguishing properties of foam are:

insulating effect - preventing the entry of flammable vapors, gases or air into the combustion zone, causing the cessation of combustion;

cooling effect - due to the presence of a significant amount of liquid in predominantly low expansion foam.

The cooling effect of foam is due to the water released from the foam.

The insulating effect is due to the formation of a foam layer that prevents oxygen from reaching the fire zone, including:

separation effect, which consists in isolating the liquid from the vapor phase;

the displacement effect causing the isolation of the flammable substance from the air;

blocking effect in which foam prevents the evaporation of a flammable liquid.

Low expansion foams (3 < K < 20) Due to the significant amount of water in the interbubble partitions (in the Plateau-Gibbs channels), they predominantly exhibit a cooling fire extinguishing effect, which is caused by the cooling effect of the foam itself and the water released from the foam.

Medium expansion foam (20 < K < 200) due to the smaller amount of water in the interbubble partitions (in the Plateau-Gibbs channels), they predominantly exhibit an insulating fire extinguishing effect, caused by the creation of an atmosphere depleted in oxygen and saturated with water vapor above the combustion zone, which helps slow down and completely stop the combustion.

At the same time, due to the larger amount of water present in low-expansion foam and, accordingly, the greater density (weight per unit volume), low-expansion foam compared to medium-expansion foams can be supplied from longer distances, which significantly affects the safety of fire personnel during large-scale and explosive accidents with liquefied gases.

A characteristic distinctive feature of the proposed technical solutions is the production and use of hybrid water-air foam with an expansion ratio of 30 to 70 based on synthetic hydrocarbon foaming agents.

The authors in the applicant’s laboratory have experimentally established and theoretically substantiated that hybrid water-air foam with an expansion ratio of 30 to 70 is significantly different in its structure, viscosity, dispersity, rheological, thixotropic and other properties significant for explosion prevention and fire extinguishing from the known properties of low and medium expansion foams by based on hydrocarbon and fluorine-containing foaming agents.

It was revealed that as a result of turbulent shockless mixing of low-expansion foam bubbles and medium-expansion foam bubbles in the hybrid foam, average-sized foam bubbles are formed, larger in comparison with low-expansion foam bubbles, but with thicker water-containing Plato channels compared to medium-expansion foams -Gibbs.

As experimentally established by the authors, the structure of a hybrid foam with a multiplicity of 30 to 70 with water-air bubbles unique in its structure and fire-extinguishing properties allows not only to better contain the high temperature of the flame without significant destruction of the volume of the hybrid foam itself, that is, to more effectively isolate the surface of the fire, but also Deliver hybrid foam jets over significantly longer distances compared to medium expansion foam jets or combined low expansion and medium expansion foam jets.

The authors also experimentally established that when a hybrid foam with a multiplicity of 30 to 70 is exposed to the surface of a liquefied natural or hydrocarbon gas spill, a synergistic effect is manifested due to the simultaneous influence of several factors - cooling, dilution of atmospheric water vapor in the zone of evaporation and combustion of gas, thermal insulation and sharp reducing the concentration of gas and vapor of flammable liquids above the foam layer in the combustion zone until the rate of the chemical reaction decreases and the subsequent decrease in the flame temperature to the extinction temperature.

This is due to the average dispersion and thickening of the water-containing Gibbs-Plateau channels of the hybrid foam compared to low- and medium-expansion foams or compared to foam in combined low- and medium-expansion foam jets.

Full-scale tests of the proposed installation under the conditions of practical extinguishing of various real fires (Fig. 16-17) show a confident solution to the formulated problem (posed inventive task) and the real achievement of the required technical result - increasing the efficiency of extinguishing transport accidents, forestry, industrial accidents and other large-scale fires as a result of the creation, manufacture and practical use of the proposed installation, which is structurally simple, technologically advanced and reliable in operation, and also proves:

- simplicity and manufacturability of manufacturing, preparation for use, use, assembly/disassembly and repair of the proposed installation;

- simplicity and efficiency of operation;

- high reliability of operation for a long time (up to 7 years);

- the ability to generate with high productivity and a range sufficient for the safe work of fire personnel (20-25 m) to supply a jet of medium-expansion air-mechanical foam or sprayed water, which are most effective for extinguishing and preventing the spread of most fires;

- the possibility of manual and stationary use with the possibility of manual and automatic control, the ability to create automatic oscillatory movements in various angular ranges, ensuring prompt, fast and uniform coverage of the entire fire surface with medium expansion foam (photo 16-17).

Comparative tests of the medium expansion foam generator GPS-200 (prototype) and the proposed installation in the basic design version showed the following main technical and operational parameters and indicators, listed in Table 1:

Table 1.

The name of indicators GPS-200
according to GOST 50409-92
(prototype) Installation according to the invention Water capacity (foaming agent aqueous solution) [l/s] 2 2 Foam capacity [l/s] 200 140 Distance of medium expansion foam jet [m] 10 15-18 Height of medium expansion foam jet [m] 3 8 Inlet pressure [MPa (kg/ ^cm2 )] 0.4-0.6 (4-6) 0.6-0.8 (6-8) Foam ratio 100 + 30 50 + 20 dimensions Length 485 430 Width 350 280 Height 230 220 Weight [kg] 4.45 6

As shown by full-scale tests, the installation proposed by the invention, in comparison with known fire extinguishing means with medium expansion foam, is most promising in the process of eliminating large-scale fires:

at enterprises of the fuel, chemical, oil refining industries;

at enterprises of the forestry, woodworking and pulp and paper industries, in forests and on agricultural land;

when extinguishing post-accident fires of air transport on the ground, accidents, disasters in non-railway, sea and river transport;

when neutralizing and disposing of potent toxic substances.

The installation proposed by the invention makes it possible to implement new modern technologies for producing and supplying medium expansion foam or atomized water with increased range and spreading speed over the combustion surface, which allows:

reduce fire extinguishing time compared to traditional means in warehouses of ammunition and highly toxic substances;

significantly reduce the number of firemen directly involved in fire extinguishing;

reduce the risk to human health and life, since fire extinguishing can be carried out at a considerable distance from the burning object;

increase mobility and mechanization of the process of delivering water and foam to the combustion zone.

Taking into account the novelty of individual and aggregate essential features, the technical solution to the problem, the inventive step and the materiality of all general and particular features of the invention, disclosed in detail in the description and shown in the drawings, the technical feasibility and industrial applicability of the invention proven in the section “Implementation of the invention”, a confident solution to an actual problem , it has been proven that the required technical result has been confidently achieved in the implementation and use of the invention - increasing the efficiency of extinguishing emergency transport, forest, industrial and other fires through the creation, mass production and widespread practical use of structurally simple, technologically advanced and reliable in operation combined extinguishing with medium expansion foam or sprayed water with increased range.

This also proves that the proposed technical solutions to the current problem comply with all established patentability requirements for inventions, and also proves that the essence of the claimed invention is disclosed in the application documents with completeness sufficient for the implementation of the invention.

The analysis also shows that all the general and specific features of the invention are essential, since each of them is necessary, and together they are not only sufficient to achieve the purpose of the invention, but also allow the invention to be implemented industrially.

Claims (17)

1. A combined fire extinguishing installation containing a cylindrical body, a grid cassette installed inside the body and a nozzle with a connection pipe to the fire extinguishing agent supply pipeline, characterized by the fact that the body is made of thin-walled metal with an annular protrusion concave into the body on the side where the stream of foam or sprayed water exits and with an annular protrusion convex outwards from the nozzle side, the mesh cassette is made of three coaxially installed with interference one inside the other inner, intermediate and outer annular rims with lateral cylindrical surfaces and two meshes located with a gap relative to each other, one of which is fixed by the edges in the gap between the mating lateral surfaces of the outer and intermediate rims, and the other is fixed by its edges in the gap between the mating side surfaces of the intermediate and inner rims, and the nozzle is attached to the body by means of centering stops. 2. Installation according to claim 1, characterized in that The screen cassette is installed inside the housing on the nozzle side with an emphasis on the annular protrusion concave into the housing. 3. Installation according to claim 1, characterized in that the mesh cassette inside the housing is located so that the mesh fixed with its edges between the outer and intermediate rims faces towards the nozzle, and the mesh fixed with its edges between the intermediate and inner rims faces towards the exit of the foam jet. 4. Installation according to claim 1, characterized in that the connection pipe to the fire extinguishing agent supply pipeline is equipped with a quick-release/detachable connection with rotary eccentric camlock type clamps, a connecting head or a flange. 5. Installation according to claim 1, characterized in that A shut-off valve is installed on the connection pipe to the fire extinguishing agent supply pipeline. 6. Installation according to claim 1, characterized in that manufactured with the ability to form and supply hybrid medium-expansion foam with an expansion ratio of 50 + 20 or sprayed water to the fire zone at a distance of 15 + 3 m. 7. The installation according to claim 1, characterized in that it is made manually and contains a handle attached to the body. 8. The installation according to claim 1, characterized in that it is made with the possibility of installation on a fire escape, foam lift, manipulator, automobile, rail, air, watercraft or all-terrain vehicle or trailer, gas and oil production platform or fastening on a stationary platform. 9. Installation according to claim 1, characterized in that it is manufactured with manual or remote control or oscillation. 10. Installation according to claim 1, characterized in that it additionally contains means of rotation in vertical and/or horizontal planes with a manual or linear drive with an electric, pneumatic or hydraulic motor with the possibility of connecting them to a remote control system for their operation using a remote control or radio signals of the remote control system.