RU199698U1 - GENERATOR OF BURNING AND GLOWING PARTICLES FOR POOR-VENTILATED AREAS - Google Patents

Abstract

The utility model relates to the field of environmental protection, mainly in the design of means for localizing and extinguishing natural fires, and can be used to study the penetration of burnt particles into ventilation openings, the vulnerability of roofing elements and other elements of buildings and structures. containing a frame, a flow-through working part fixed on it, equipped with a furnace, a gas burner, an ignition system and measuring windows, a receiving hopper for loading natural combustible material (PGM), a screw dispenser with an electric drive for feeding the PGM into the furnace, a centrifugal fan connected by its outlet with a flow-through working part, characterized in that the receiving hopper is equipped with a duct smoke suppression fan, the outlet of which is in communication with the lower part of the PGM receiving hopper.

Description

The utility model relates to the field of environmental protection, mainly in the design of means for localizing and extinguishing natural fires, and can be used to study the penetration of burnt particles into ventilation openings, the vulnerability of roof elements and other elements of buildings and structures.

Known installation "NIST Dragon", developed at the National Institute of Standards and Technology (USA), allows you to generate smoldering and burning organic particles that are formed as a result of wildfires [1]. The unit has a working section, in which two burners are installed, connected to a regulated propane gas source, a 1.5 kW fan powered by a gasoline electric generator, and a flexible hose 15 cm in diameter to create an air flow in the working section. The unit is equipped with a refractory mesh that protects the burners from the ingress of particles of combustible material.

Known generator of burning and smoldering organic particles of a smaller scale "Continuous Feed Baby Dragon" for experimental studies in laboratory conditions [2]. The unit has a working part made of galvanized or stainless steel 0.8 mm thick, a receiving hopper for loading the PGM, a 0.4 kW fan, a propane burner connected to a combustible gas source, and a flexible hose for air supply. The SGM is fed into the combustion zone by a special conveyor that is not part of the installation.

A common disadvantage of the described technical solutions is the lack of a receiving hopper for natural combustible material (NGM). To reload the PGM, it is necessary to cool the case, because inside the working part, the temperature reaches 1200 ° С, remove the upper part of the installation, which entails an increase in labor costs. In addition, during the operation of the installation, the smoke from the combustion particles of the PGM spreads from the flowing working part of the installation to the interior of the room and to the work area of the operators, which worsens the working conditions and poses a threat to safe work.

Based on the NIST Dragon design, Portugal has developed a Firebrand Generator Device [3]. Loading of combustible material for modeling burning and smoldering particles is carried out periodically through a specially withdrawn funnel on the side of the device.

The disadvantage of the device is the impossibility of long-term continuous supply of PGM when modeling the so-called "fire rain", which is falling burning and smoldering particles, and studying its effect on the ignition of the ground cover and combustible structural elements of buildings. Also, during the operation of the installation, smoke and combustion products arising in the working part of the installation spread inside the room, including in the area of operation of the operators, which poses a threat to the safe work of people.

Known generator of burning particles "Full scale continuous Firebrand Dragon" [4]. The generator has a device for continuous supply of combustible material, connected to the main body of the installation, a working part made of galvanized steel, a centrifugal fan, a gasoline electric generator, a flexible hose connected to a fan that creates a stream of burning particles, two propane burners connected by a copper tube to a source combustible gas with a flow regulator. The burners are equipped with a refractory mesh that protects the burner from extinguishing due to the ingress of particles of combustible material.

The disadvantages of the known device include the low service life of the working part of the generator, made of steel 0.8 mm thick, capable of deforming or collapsing during repeated or prolonged operation at high temperatures, the complexity of preventive and repair work. As in the analogs presented above, a characteristic disadvantage of the design is the ingress of gaseous products of combustion of the PMG into the operator's work area, as well as the spread of smoke into other rooms of the building, which poses a threat to the safe evacuation of people.

As a prototype, a generator of burning and smoldering particles was selected according to the patent RU No. 183063 U1, which is the closest to the claimed utility model in terms of a set of essential features [5].

The known device contains a frame, fixed on it a flowing working part, equipped with a furnace, a gas burner, an ignition system and measuring windows. The device has a screw dispenser with an electric drive for supplying combustible material to the furnace and a centrifugal fan connected by its outlet to the flowing working part. The flow-through working part is made of steel pipes with a thickness of at least 4-5 mm, resistant to long-term high-temperature exposure, and the furnace is made with a lining of the walls with a high-temperature heat insulator.

The disadvantage of the device is the increased emission of smoke from the channel used to supply particles to the furnace part of the installation, and later from the receiving hopper, which makes it impossible to use it in poorly ventilated rooms. The design of the installation is such that the fan, which provides the flow of burning particles, creates an increased pressure in the flowing working part of the generator. Smoke and other products of combustion of PGM through the channel of the screw doser spread to the experimental room, including the operator's work area, which poses a threat to safe work and evacuation of people and should be taken into account when designing the smoke exhaust system. This circumstance makes it impossible to use the generator in laboratory conditions, or in rooms with low-power ventilation systems. Increased smoke is a side and undesirable effect also when working in semi-natural and natural conditions, since it is not the purpose of research and introduces additional "noise" when registering data through the measuring windows.

The technical challenge is to eliminate the effect of increased smoke emission through the particle feed channel and through the receiving hopper.

The problem is solved by changing the design of the generator of burning and smoldering particles, namely, by equipping the receiving hopper of the generator with a channel smoke suppression fan having a fixed connection with the receiving hopper and communicating with its lower part.

The generator of burning and smoldering particles for poorly ventilated rooms contains a frame, a flow-through working part fixed on it, equipped with a firebox, a gas burner, an ignition system and measuring windows. The device has a receiving hopper for loading natural combustible material, a screw dispenser with an electric drive for feeding combustible material into the furnace and a centrifugal fan connected by its outlet to the flow-through working part. The flow-through working part is made of steel pipes with a thickness of at least 4-5 mm, resistant to long-term high-temperature exposure, and the furnace is made with a lining of the walls with a high-temperature heat insulator. In one of the specific embodiments, the working part of the generator of burning and smoldering particles, including the firebox, can be made of pipe segments connected by flanges. Unlike the prototype, the generator receiving hopper is equipped with a duct smoke suppression fan, the outlet of which is in communication with the lower part of the PGM receiving hopper.

The essence of the proposed technical solution is illustrated by the drawings of FIG. 1, 2. FIG. 1 shows a general view of a generator of burning and smoldering particles for poorly ventilated rooms. FIG. 2 shows the receiving hopper of the generator and the duct smoke suppression fan fixedly connected to it. The numbers in the figures indicate: 1 - assembled frame; 2 - generator body (flow-through working part); 3 - receiving hopper of PGM; 4 - screw dispenser; 5 - fan (blower); 6 - gas burner; 7 - gas supply lever; 8 - duct smoke suppression fan, 9 - combustion mixture ignition system; 10 - gas supply hose; 11 - electric drive of the metering screw; 12 - firebox; 13 - exit of burning and smoldering particles, 14 - measuring windows.

The claimed device operates as follows. PGM is loaded into the receiving hopper 3. The air supply to the flowing working part 2 is switched on at low speeds of the fan 5 with an air flow rate of no more than 1 m / s. The gas supply valve on the cylinder (not shown in the diagram) is unscrewed by 1.5-2 turns, then, by pressing the gas supply lever 7 on the burner, a small supply of combustible gas is carried out into the flowing working part 2. The combustible mixture is ignited in the furnace for 12 s using a remote ignition system 9. After ignition, the supply of combustible gas is increased and the internal cavity of the furnace 12 is heated for 2-5 minutes. Then the fan speed is increased and the air speed is increased to 5-6 m / s. The operating temperature is regulated by changing the flow rate of the combustible gas. Before feeding the combustible material, a duct fan 8 is turned on, operating from a 220 V network. Then the electric drive of the auger 11 is turned on and the PGM is dosed from the hopper 3 into the furnace 12. The duct fan 8 creates a counterflow of air in the duct of the auger dispenser 4, preventing the flow of smoke from the flowing working part 2 into the receiving hopper of the PGM 3. The air supply from the fan 5 is increased to the required flow rate, preventing the PGM from falling onto the burner. If necessary, the supply of PGM from the bunker to the furnace can be carried out manually by turning the auger shaft when the power supply of the electric drive 11 is disconnected.

An example of implementation.

At least 3 people were directly involved in the experiment. The generator of burning and smoldering particles for poorly ventilated rooms is prepared for operation. Before starting, it is necessary to place the generator on a fire site of sufficient size in a metal hangar (work in open areas is also possible), guided by fire safety measures. Fire extinguishing means are provided: a fire extinguisher, a container with water, a water supply hose. The flammable gas cylinder is installed at a distance of at least 3 meters from the installation, the gas supply hose 10 is connected to the burner 6. The operator prepares a site with samples of plant materials or other object of fire to study the ignition processes. Set up video and photography equipment, data recording devices, means for collecting burnt samples. The generator frame 1 is grounded, after which power is supplied to the installation.

The operator responsible for carrying out the experiments ignites the combustible mixture, controls the process through measuring windows 14. The second operator is engaged in the supply of combustible gas, regulation of the gas flow rate and shutdown of its supply. After the furnace warms up and the generator reaches the operating mode, the first operator increases the speed of the fan 5. At the same time, the third operator turns on the duct fan 8 and the electric drive 11 of the auger dispenser 4, observes the metered supply of the PGM to the furnace 2, where the material ignites in a hot gas stream. Burning and smoldering particles of PGM are emitted through exit 13.

The technical result consists in the fact that the duct fan prevents the penetration of smoke through the channel of the screw feeder and through the receiving hopper into a poorly ventilated room and into the area of operators' work. At the same time, the air aerates the PGM and improves the outflow from the bottom of the receiving hopper.

List of sources used:

1. Samuel L. Manzello, John R. Shields, Thomas G. Cleary / On the development and characterization of a firebrand generator / Fire Safety Journal 43 (2008), 258-268. http://dx.doi.org/10.1016/j.firesaf.2007.10.001.

2. Suzuki S. and Manzello, S.L., 2011. On the Development and Characterization of a Reduced Scale Continuous Feed Firebrand Generator. Fire Safety Science 10: 1437-1448. 10.3801 / IAFSS.FSS.10-1437.

3. Oliveira R., Quesada C, Viegas D.X., Freitas E., Raposo J. Firebrand generator system applied to wildland-urban interface research / Advances in Forest Fire Research. Book chapter. Coimbra, Portugal, November 17 - 21 .-- Coimbra, Portugal, 2014 .-- P. 759-765. -http: //dx.doi.org/10.14195/978-989-26-0884-6_84.

4. Samuel L. Manzello, Sayaka Suzuki, Experimentally Simulating Wind Driven Firebrand Showers in Wildland-urban Interface (WUI) Fires: Overview of the NIST Firebrand Generator (NIST Dragon) Technology, In Procedia Engineering, Volume 62, 2013, Pages 91- 102, doi: 10.1016 / j.proeng.2013.08.047.

5. Patent RU No. 183063 U1, IPC F24B 1/00, publ. 09/07/2018.

Claims (1)

A generator of burning and smoldering particles for poorly ventilated rooms, containing a frame, a flowing working part fixed on it, equipped with a firebox, a gas burner, an ignition system and measuring windows, a receiving hopper for loading natural combustible material (NGM), a screw dispenser with an electric drive to furnace, a centrifugal fan connected by its outlet to the flow-through working part, characterized in that the receiving hopper is equipped with a duct smoke suppression fan, the outlet of which is in communication with the lower part of the PGM receiving hopper.

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