BRPI0802403A2 - mobile fire extinguishing apparatus and prevention of the formation of explosive atmospheres indoors - Google Patents

Abstract

MOBILE FIRE EXTINGUISHING APPARATUS AND PREVENTING THE FORMATION OF EXPLOSIVE ATMOSPHERES IN CLOSED ENVIRONMENTS The present invention relates to a mobile apparatus for extinguishing fires and preventing the formation of explosive atmospheres in closed environments called a gas flow cannon, intended for intervention in fire cells in closed environments or small outbreaks in the open, such as vehicular fires, among others.

Description

MOBILE FIRE EXTINCTION APPARATUS AND PREVENTION DEFORMATION OF EXPLOSIVE ATMOSPHERES IN CLOSED ENVIRONMENTS

Technical Field

The present invention describes a mobile apparatus for extinguishing fires and preventing the formation of explosive atmospheres in closed environments known as gas flow cannon, intended for intervention in indoor fire cells or small open source outbreaks such as vehicular fires, among others. .

Previous Techniques

The techniques commonly used to prevent and combat fires in confined or non-confined environments, such as those caused by short circuits in electrical networks and equipment, small outbreaks such as vehicular fires, among others, consist of the use of equipment such as small extinguishers that contain as a fire fighting agent. extinguishing water, gas pressurized and CO2 as an extinguishing agent, which in addition to exposing its users to the effects of gas, smoke and gases derived from the burning of existing materials or equipment, put them in direct contact with the high temperatures in the environments where the fire is occurring, In addition to presenting low storage volumes of the extinguishing agent, which greatly hinders its use, thus presenting low efficiency when used in large spaces or confined areas.

Another alternative is the use of a network. Hydro or mobile units, which are limited in their use due to the difficulty of access to certain confined areas or difficult to access as is the case of pipes, where by the characteristics of the fire and by being water conducting electricity makes it inefficient in combat.

The proposed innovation concerns an apparatus designed to intervene in fire cells of varying sizes in closed environments, or small outbreaks such as vehicular fires. The artifact, called a gas flow cannon, is composed of the arrangement, with varying possibilities of geometric shapes, of carbon dioxide jets biphasic nozzles, or other liquefied gas with similar curve phase diagram, that is, same physicochemical properties. . The cannon of gas streams allows to launch high pressure jets with high and low speed.

In the gun, the high pressure jets are aligned to form fast, high mechanical thrust flows and high concentrations of the extinguishing agent with the aid of low speed jets. Low-velocity carbon dioxide streams are formed by projecting the high-pressure jets through suitable firing nozzles onto steel plates that act as deflecting elements. Variations in the baffle angles can force the gas into a previously studied circulation to enable fire cell interventions until the end of the extinction process.

Flows must come from liquid-phase carbon dioxide stocks, as flows of up to approximately one thousand US gallons per minute (three thousand seven hundred eighty-five liters per minute) are required, with contents of up to seventy percent snow. of sublimation. Such a feature of the substance is part of the process to be described.

By aligning some of the direct firing nozzles, i.e. without the deflectors and others as low speed secondary jets, a high concentration turbulent extinguishing compound flow can be obtained in nearly seventy percent of sublimation snow. This flow generates a directed push, which has the power to intervene in the dynamics of the fire cells, allowing the displacement of overheated pockets of gases and smoke. Such movement becomes a practical way to prevent phenomena such as violent expansions formed by late ignition of overheated gases called "flashover".

At the same time as the mechanical attack, the enclosed spaces of fire cells, commercial and industrial premises may be filled with high concentrations of extinguishing agent. This will force a reduction in relative oxygen concentration and low temperature as a function of the heat absorbed in the sublimation vaporization. The combination of factors allows the parameters within which to extinguish fires and to prevent the formation of explosive atmospheres of various materials, mixtures and chemical substances that do not show incompatibility with the extinguishing agent.

When all nozzles are actuated against deflectors, that is, with low speed jets, an inert space volume is formed in front of the cannon in the position immediately ahead. This configuration allows you to fight small outbreaks such as vehicular fires or parts of electrical equipment.

The Gas Cannon can be mounted on several bases, such as:

(a) at the end of robotic arms mounted on mobile units, with remote control of the nozzle valves and deflector actuators;

b) Extendable rod of telescopic type mounted on a mobile unit c) On small utility machines with the dimensions of a mechanical forklift, for operation in large electrical equipment such as: forced lubrication bearings, turbocharger systems and commercial storage sheds;

d) At the end of mechanical ladders used by firefighters;

e) At the end of robotic arms of assembly and production lines, I allow robots to be integrated into the factory fire fighting system.

In all cases, the guns are used in various configurations of the nozzles, load distribution geometry and deflector firing orientation, according to the characteristics of each application. The cannon allows to attack the focus of fire of three conjugated forms:

1 Reduction in relative oxygen concentration available for acombustation;

2 cooling;

3 Displacement of overheated vaporized charge by high pressure and speed jets.

Detailed Description of the Invention

The Gas Flow Cannon consists of three parts: (1) Firing Cannon

An artifact consisting of a set of high-pressure firing nozzles that allow to decompress large flows of carbon dioxide, or similar, that produce turbulent jets at high speeds. In front of each nozzle is a 304 stainless steel plate with thicknesses of four and eight millimeters, which acts as a deflector element. The deflectors must be positioned close to the inner face of the nozzles and are coupled to a actuator that can be mechanical, electric, electromechanical or hydraulic, which allows to change the angle in relation to the jet.

When the deflectors are parallel to the firing nozzle, the high speed jet is projected in a straight line. In this way, a long zone of forced dispersion is formed, capable of displacing masses, gasses and smoke.

If the baffles are forced on the jet the forced dispersion region will be shortened. With inclination of approximately thirty grauss a moderate speed jet will be formed, with approximately ninety degrees of inclination, in relation to the axis of the firing nozzle. With the inclination of the deflector between forty-five and fifty degrees a large curtain-shaped biphasic material cell will be formed with up to seventy per cent deneve of sublimation. The combination of the firing nozzles and the variations in the deflector angles allows the gun to be used in various firefighting situations, under the conditions and environments previously mentioned.

(2) Control Module

The control module is made up of a console with the trigger nozzle actuating valve commands and the actuator controls of the baffle assembly. In this document, the deflector actuators are designed with hydraulic systems and valves operated by compressed air, although they may be of various types, as noted above.

(3) Transfer Lines

In the event that the gun and the control module are used unarticulated, the two parts shall be connected by rigid or flexible transfer lines capable of resisting the extinguishing agent characteristics and the physical parameters of the operation. modalities of use cited in items "a", "b", "c" and "e" of the summary. If the gun is used coupled to the control module, as in the "d" mode, there is no need for transfer lines.

The operation of the cannon to meet the proposed objectives is based on four elements:

1 When firing high pressure biphasic jets (greater than fifty Kgf. / Cm2) composed of gas and concentrations of up to seventy per cent of sublimation snow of the extinguishing agents;

2 In controlling the speed and dispersion of jets by means of movable baffles;

3 In the distribution geometry of the gun's nozzles;

4 Cannon mobility according to the dynamics and environments of the fire cells.

In the Gas Flow Cannon, high-pressure jets with different velocities fulfill different functions for attacking and extinguishing fire cells. The dynamic characteristics of the jets are:

A - High Speed Jets

The high speed jets that make up the Cannon come from sources of high pressure (> 50 Kgf./cm2), low temperatures (> -50 ° C) and liquid phase stocks. The nozzles for directing the shots must be mounted on the cannon frame. Formed dispersal plumes have very characteristic zones as described in the dispersion models. In the vicinity of the source the mass of gas travels at a high speed, and the movement of the molecules is dominantly oriented by the position of the nozzles. This movement reaches a distance proportional to the trigger pressures and flow rates. From there follows the dispersion movement that is oriented by environmental conditions, with a progressive mixing of the extinguishing gas with the air and other gases present, which determines an elevation gradient of the extinguishing agent concentrations in adjacent positions.

This oriented displacement zone is the part that is efficient for producing a mechanical thrust and imposing an oriented displacement of the gaseous mass and suspended particulate matter present in the environment such as smoke and overheated vapors. High-speed jet firing towards heat accumulation points and dynamic flame decirculation is an effective resource for penetrating fire cell environments.

This initial movement is important because the buildup of overheated flammable vapors that do not ignite due to a local oxygen deficiency or the shape of the environment where the fire occurs can cause late ignition. This can occur by sudden oxygenation, such as opening a door, or raising the temperature by accumulating the heat generated.

In the first case the resulting phenomena are the so-called "back draft", in the second case there are the turbulent expansions that resemble the explosions of vapor clouds, which are called "flashover". The interventions of the guns allow to interrupt the dynamics that create the conditions for the occurrence of these phenomena, reducing the combustion rate of the fire load and interfering with the cycles that feed the fire, which are:

1 Release and accumulation of volatile substances present in the fire load;

2 Flame aeration; 3 Circulation of the generated thermal radiation.

Although allowing the immediate intervention in the fire cell, the high speed jets that make up the direct firing of the cannon are not sufficient to enable the concentration of extinguishing agent and the cooling of the environments. Despite effectively performing mechanical intervention in the fire cells, the high-speed jets crawl in their turbulent motion, the air around the firing cannon flow promoting their mixing to the extinguishing agent. This mixture occurs over the entire high speed zone of the flow.

The existence of the air spill zone can be proved when the inert gas extinguishing agent is replaced by another similar behavior, but with ignition potential. The fire jet phenomenon that occurs as a final consequence of igniting a pressurized flammable fluid leakage, well illustrates the dynamics of dragging and mixing.

Fire jets are scenarios described as potential accidents of flammable liquefied gas installations such as propane and butane.

The dynamics of diffusion of the fluid that is emitted in biphasic flow and feeds the fire jet has been described in equations that allow predicting their behavior.

The temperatures and dimensions of the flames formed along the forced dispersion line of the flammable fluid are only possible due to the rate of air mixture. This velocity of mixture formation has as main energy the turbulent movement of the emission source.

Likewise, the high-speed extinguishing agent jets that are fired from the cannon will carry air creeps and this will make it difficult to raise the concentration of inert gas within the environment. Trailing flows have been identified and measured during short campaigns, in experimental shots were taken (5). Using a devazão cannon equal to one hundred US gallons (three hundred and seventy-eight and a half liters) per minute of carbon dioxide, shots were fired against open source and open air thermal source. With the support of oxygen meters it was possible to register the drag.

If people are trapped at points behind the main fire cell or in difficult-to-reach rooms, the high-speed jet may only be used for its mechanical thrust. Keeping aeration of the high-speed jets, ie by not activating the deflectors, can only force the movement of smoke and overheated vapors out of the environment without reaching the extinction parameters. This maneuver of slowly raising extinguishing agent concentrations in the environment with mechanical displacement of smoke and overheated gases would create a condition to allow relief personnel access to victims at critical points.

The configuration mentioned in the previous paragraph also forms a security zone immediately behind the cannon. In this position, the air drag carried out by the high speed jets induces an air current towards the flow, creating a windward situation. In the case of victims in the windows of burning buildings, the positioning of the gas flow cannon can join the fire cell in the room and generate a windward zone where the victim can breathe normally.

In order to reach the extinction parameters, the high speed jets must be complemented with low speed jets. These jets will fill with the extinguishing gas and its snow depletion the mechanical drag windows of the high-speed jets, forming an airless flow. This will make it possible to rapidly increase the extinguishing agent concentration and the effect of ambient cooling from a conjugated firing at a safe distance.B - Low Speed Jet

To fill the mechanical aeration windows of the high-speed jets, to counteract the effects of drag and consequent forced air mixing, gas flows with particular characteristics are required. Essentially low-speed jets formed from the direct collision of high-speed flow against a deflecting surface. The surface shall be molded of 304 stainless steel of thickness between four and eight millimeters or other material with cryogenic temperature resistance and preserving the strength characteristics.

The deflector has a dual function in forming the sealing jets:

1 Reduce the speed;

2 Redirect the trigger.

The first function of gas flow collision against the deflector is to reduce the flow velocity and shorten the dispersion zone dominated by the firing nozzle force. Thus, the impact-reduced gas mass initiates a new dispersion process, with rationing and flow redirection. In this process occurs the formation of a dispersion zone with high concentrations of gas and sublimation of sublimated material, in this case, carbonic snow.

The second function of the collision against the deflector is to direct the flow, directing it to the necessary points to provide a movable gas and smoke circulation blocking line. It is possible to scale the reduction in flow velocity, the size of the desaturation zone and the direction of firing by changing the shape of the deflector and the angle between the firing nozzle and the deflector surface. Joint actuation of some slow nozzle cannon nozzles allows forming a fluid flow wall capable of backing, by mechanical thrusting action and with the advance of the gas flow cannon, a considerable volume of smoke and flammable vapors. Talação cleans the environment and allows the advance of combat teams.

Unlike high-speed jets, which form high gas concentrations in the dispersion zone after the push-source dissipation of the trigger source, the low-speed jet forms high concentrations at short distances from the trigger point. In guns that fire against deflectors and produce low velocity flows the short dispersion plume forms and can be controlled by varying the angles of the deflectors.

The gas flow gun can be adapted to various element arrangements without changing the expected efficiency. For the purpose of the present invention, a cannon consisting of six firing nozzles with flow rates of fifty American gallons (one hundred and eighty-nine liters and one quarter) per minute was designed. The gun has hydraulic actuators for the baffles and trigger valves driven by the compressed air system. The artifact was designed with the distribution of firing quadratics in parallel alignment under the surface of a cylinder and two overlapping firing nozzles in advance of the four radials.

The gas cannon is formed by mounting the firing nozzles in a rigid structure with a central coupling axis, circular cross section and uniform linear density. The axle must be made of 304 stainless steel, or equivalent in characteristics, so that it can be fixed to different platforms. The hollow structure shall allow the attachment of all component elements:

1 Nozzles;

2 deflector support rods;

3 guides of hydraulic actuators;

4 couplings of the cargo hoses;

5 Deflectors;

6 Protective cover.

Mode ε System Operating Parameters

The gas cannon has five basic design parameters:

(a) number of trigger points (minimum of two);

(b) Jet flow (up to one thousand US gallons or three thousand seven hundred eighty-five liters per minute);

c) working pressure (approximately sixty kilograms square centimeter force);

c) spacing between the jets (depends on the geometry and dimensions of the jet);

d) activation time (minimum of three minutes).

In order to operate gas cannons efficiently, it is necessary to sequence the shots to compose the extinguishing environment. In closed environments, the attack on fire cells with high front nozzle jets shall be preceded by the opening of the trigger nozzles with the configuration of low speed jets, ie maximum emangulation deflectors. This procedure is necessary due to the high drag carried out by the high speed jet of the high speed jet, which was previously described. Initial activation of the high speed jets would favor flame generation, improve combustion efficiency and consequently increase heat flow. . Acceleration of combustion would reduce the relative efficiency of the gun. In fact, low speed jets need to be fired at the beginning of operation to promote saturation of the space adjacent to the main aeration zone of the high speed jet. Thus, when the low speed jets are first triggered, the initial motion of the high speed jets will have no effect on the dynamics of the fire focus other than the thrust of the air mass that lies between the front of the extinguishing feather and the limits of the fire. cell.

Once fired the firing of all the nozzles of the Cannon the process of extinction in three distinct ways ends.

1 The first is the increase in extinguishing agent concentrations in the environments;

2 The second is the reduction of heat available for volatile vapor-fueling substances that are fed to the fire by sublimation snow vaporization (571 KJ / Kg for carbon dioxide).

3 The third is the introduction of turbulent flow, with mechanical thrust capable of disrupting the mass and energy circulation cycles that maintain the fire.

In open-air operations the interference of the vector representing the local wind can be compensated by adjusting three factors: increased trigger flow rates; increased number of firing points, modification of firing directions by adjusting the deflectors. Triggering conditions must be pre-adjusted for locations. So cannons can be effective on point targets such as vehicular fires, and free-edge puddles up to six meters in radius and parts confined to dikes up to ten meters in radius. This is because the cannons generate a volume of inert space in the area immediately ahead of the trigger point. Another device for firefighting in confined pools is the induction of turbulent movement over the flames' base surfaces.

Due to the high working pressures of the system (greater than fifty Kgf./cm2) lower wind speeds (less than twenty kilometers per hour), they should not cause interference in the jet dispersion zone. For all the above mentioned maneuvers, the gas flow cannon and its motors must have multilayer thermal insulation, combining rigid and flexible materials.

The efficiency of the gun depends on the fact that the extinguishing agent stock is in liquid phase. For this the support stock should be maintained with a set of complementary equipment to balance the phases in the stock tank, within the working parameters. Likewise, pumps are required to print operating flow rates. This equipment can be packed in containers, and trucks, giving the firefighting system great autonomy. With moving stocks of up to twenty and double, the cannons can perform even in the event of a power outage and a fire hydrant break. These situations are common:

1 After natural disasters such as tornado earthquakes occur;

2 In locations with energy rationing;

3 In very prolonged droughts;

4 In locations with scarce water resources. In the case of large but enclosed environments such as storage sheds and buildings that protect large equipment such as turbines and generators, configurations should vary, depending on the possibilities of vehicles and devices over which cannon can be mounted.

The sublimated phase of the liquefied gases is at very low temperatures, which in the case of carbon dioxide is negative seventy two degrees Celsius. For this reason direct firing of the jets against specific parts of equipment and buildings without proper protection is avoided. The goal is to avoid the undesirable effects of a thermal shock, which can compromise the structures and alter the resistance characteristics of the materials.

Preferred Modalities

The proposed gas cannon system can be applied in the following ways:

1 - At the end of robotic arms mounted on mobile units, with remote control of the firing valves and the deflector actuators. Fire trucks with only two occupants could hit several outbreaks of urban fires;

2 - Extendable telescopic rod mounted on a mobile unit;

3 - About small utility machines with the dimensions of a mechanical forklift, for operation in large electrical equipment, such as: bearings with forced lubrication, turbo generator systems and commercial storage sheds;

4 - At the end of mechanical ladders used by firefighters 5 - At the end of robotic arms of assembly and production lines to allow the robots to be integrated into the factory fire fighting system;

6 - At the end of large hydraulic arms, with attached cameras, for use in firefighting in high buildings;

7 - At the end of hydraulic arms coupled to cargo helicopters with extinguishing tank of one thousand kilos for use in fire fighting in high buildings;

8 - Mounted at the end of robotic arms used in assembly lines, with remote control of firing valves and

baffle actuators. With changes in control software, robots can be integrated into factory fire brigades; 5- The assembly of three high-flow guns on the front blade, longer lift combinations, from a tracker utility or military vehicle, can compose a turbulence front and inert zone. The confluence of three vehicles with these characteristics approaching the same point, which converged the simultaneous firing, can generate an inert zone to extinguish a point-like focus of fire jet. Foggets have a defined aeration zone, and direct high-speed shooting with low-speed jet seals over the base of the flammable fluid source can extinguish the flame. With stock of extinguishing agents in carts, the configuration described above can extinguish fires in oil wells and keep the zone inert for the placement of control equipment. The operation can be performed by elaborating the proper safety planning. Description of the Figures

Figure 1 shows details of the cannon mounted with the main curtain firing nozzles (B), their respective adjustment baffles (C) and console details (A).

Figure 2 shows in exploded view, details of the assembly that makes up the cannon, console (A) with transfer lines, hydraulic actuator guides, load hose couplings and baffle support rods, firing nozzles (B) and adjustment baffles (C).

Figure 3 shows in side view and divided into two parts, the control module (A), the cannon with the nozzles (B) and respective deflectors (C).

Figure 4 shows in top view and divided into two parts, the control module (A), the cannon with the nozzles (B) and respective deflectors (C).

Figure 5 shows a control module consisting of a console with the trigger nozzle actuating valve controls and baffle actuator controls.

Figure 6 shows a front view of the console control module consisting of the trigger nozzle actuating valve commands and actuator controls on the baffle, trigger nozzle, and baffle actuators.

Figure 7 shows in exploded view the cannon with details of nozzles (B) and respective deflectors (C) mounted in parallel and angle to firing nozzles (B). Figure 8 shows in detail, nozzle (B) high speed with the respective deflector mounted in parallel.

Figure 9 shows in detail the velocity trigger nozzle (B) with its deflector mounted at an angle.

Figure 10 shows the rear view of the control module.

Figure 11 shows in front view the cannon with the trigger nozzles and respective deflectors.

Figure 12 shows the rear view gun with its firing nozzles.

Figures 13 and 14 show details of the cannon with some of the positions of the deflectors relative to the firing nozzles.

Claims (8)

1. MOBILE FIRE-EXTINGUISHING APPLIANCE EXPLOSIVE ATMOSPHERE FORMATION CLOSED ENVIRONMENT, characterized by a gas flow cannon that is composed of a console (A) with transfer lines, hydraulic dosing guides, loading hose couplings and rods of deflector supports, firing nozzles (B) and adjustment deflectors (C) mounted in a rigid structure with a central coupling axis, circular cross section and uniform linear density. The apparatus according to claim 1, characterized by the use of the assembly of high pressure biphasic jet firing nozzles composed of liquefied inert gas, which presents in the phase diagram the physicochemical characteristics similar to carbon dioxide, in a cannon flow. gas, which by varying the different velocities of the jets, controlling the parameters flow, pressure and discharge time, will produce volumes of inert atmosphere with strong heat absorption and displace the volumes of flammable vapors and smoke by mechanical thrust. APARATO according to claim 2, characterized by the use of high speed jets complemented by low speed jets to stop and intervene in large fire cells using a long zone of forced movement as a combat element. APARATO according to claims 2 and 3, characterized by the use of low speed jets generated by high speed jet projection against movable baffle plates which shorten the forced dispersion azone and raise the concentration of the extinguishing agent a short distance from the firing point, and these jets are complemented by high velocity by saturation of the atmosphere in the application space of the system with sublimation snow. 5. The apparatus according to claims 2, 3 and 4 characterized by the simultaneous and intensive use of three ways combating fire, reducing available oxygen, intensive heat absorption cooling and mechanical thrust displacement of smoke stocks and overheated evaporators produced by fire or vapors, and flammable gases generated from a leak. 6. APARATO according to claims 3 and 5, characterized by the use of articulated jet combinations of the extinction agent flows, which allow the generation of moving dynamic barriers that can make smoke masses recede in residential, commercial and industrial building sectors, enabling advance slowly into the fire cells. 7. Apparatus according to claims 2 and 5, characterized by the use of liquid phase extinguishing agent stock, in mobile systems and on various vehicles, with equipment for condensation and vaporization of the working fluid. 8. An apparatus according to claim 7, characterized by the preferred use of carbon dioxide as a working fluid.