JPH04256848A - Apparatus for observing burning and smothering extinguishment of sodium - Google Patents

Abstract

PURPOSE:To conduct the experiment for the burning and smothering extinguishment of sodium quickly, simply and safely by anybody and to observe the experiment clearly. CONSTITUTION:An observing container 10 whose inside can be isolated from an atmosphere is provided. A crucible 12 is provided in the container 10. A gas feeding system controls the air (b) for burning which is supplied to the lower part of the observing container 10 and nitrogen gas (c) for fire extinguishment with a three-way solenoid valve 46. An exhaust system is connected to the upper part of the observing container. A high-frequency induction heating device heats sodium 28 in the crucible 12. These parts are provided. The observing container 10 has the vertical structure wherein the opening parts at both upper and lower ends of a heat resisting glass tube 14 are covered with a cap plate 16 and a bottom plate 18.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an observation device used in sodium combustion experiments and suffocation extinguishing experiments. More specifically, the present invention relates to a sodium combustion/suffocation extinguishing observation device that employs a high-frequency induction heating method and is designed to allow experiments to be repeated in a short period of time.

0002

BACKGROUND OF THE INVENTION Fast breeder reactors use liquid sodium (metallic sodium or sodium alloy) as a reactor coolant. Sodium is a highly active substance, and when it ignites, it emits high temperatures and white smoke of sodium oxide. For extinguishing a fire, the method generally used is to cover the sodium surface to block air. For this reason, we conduct sodium combustion experiments and suffocation extinguishing experiments in order to give visitors a correct understanding of the chemical properties of sodium, and to train staff and business partners.

[0003] Combustion experiments are conducted in a combustion chamber (for example, about 4 m x 4 m x 3 m in height) that has a closed structure and is equipped with exhaust gas treatment equipment. Sodium is placed in a combustion dish, and a worker uses a propane gas burner to heat it to ignition temperature and combust it.

[0004] In the suffocation fire extinguishing experiment, sodium is placed in the bottom of a steel cylindrical container that has a nozzle with a stop valve for supplying air and nitrogen gas and a nozzle with a stop valve for exhaust, and a glass container is placed in the top of the cylindrical container. This is done using a device equipped with a lid plate (which also serves as an observation window). First, the inside of the container is made into a nitrogen gas atmosphere, and the sodium at the bottom is heated together with the container to the ignition temperature using a propane gas burner. Once the ignition temperature is reached, the container is filled with air and ignited. Once combustion begins, the air supply is shut off and nitrogen gas is quickly filled to suffocate the fire.

[0005]

[Problem to be solved by the invention] First, in the case of combustion experiments, the work is carried out in a wide air atmosphere in a combustion chamber, so
The drawback was that it dissipated a lot of heat and took a long time to raise the temperature (about several tens of minutes). In addition, the combustion chamber has a sealed structure and is equipped with exhaust gas treatment equipment.
If the door of the combustion chamber was partially opened during observation, smoke would sometimes leak out to the visitors outside the door, creating a risk for the visitors to inhale the combustion smoke. Furthermore, since the heating work is carried out in the atmosphere, workers are required to wear safety equipment such as protective clothing, and the work is hard, accompanied by sweating, especially in the summer.

Next, in the case of the suffocation extinguishing experiment, since the sodium was heated in a steel cylindrical container, it still took several tens of minutes to raise the temperature to the ignition temperature. In addition, the sodium vapor generated during that time adheres to the observation window and solidifies, causing the glass to fog up.When combustion begins, a large amount of smoke is generated, so even if the exhaust is exhausted, the interior is filled with smoke, so the inside of the container is only kept for a short time. The disadvantage was that it was not possible to observe the The next experiment could not be carried out unless the observation window was thoroughly cleaned once the temperature of the container and sodium had cooled to room temperature. Therefore, experiments using one container could only be carried out once or twice a day.

[0007] For the reasons mentioned above, in both combustion experiments and suffocation extinguishing experiments, when there are a large number of visitors, it is difficult to allow each person to view the experiment. Also, experiments could only be carried out by people who were accustomed to the work. As a result, there was a risk of giving viewers an impression that was far from the reality, such as poor workability and sodium being dangerous and difficult to handle.

The purpose of the present invention is to eliminate the above-mentioned drawbacks of the prior art, and to provide an apparatus that allows anyone to conduct sodium combustion and suffocation extinguishing experiments quickly, easily, and safely, and that allows for clear observation. It is to provide.

[0009]

[Means for Solving the Problems] The present invention, which can achieve the above objects, includes an observation container whose interior can be isolated from the atmosphere, a crucible for sodium disposed in the observation container, and a crucible for burning and extinguishing gas. Combustion and suffocation extinguishing of sodium, which is equipped with a gas supply system that can control supply and stop to the observation vessel, an exhaust system connected to the observation vessel, and a high-frequency induction heating device that heats the sodium in the crucible from outside the observation vessel. It is an observation device.

For example, the observation container has a vertical structure in which the openings at both the upper and lower ends of a heat-resistant glass tube are covered with a lid plate and a bottom plate, respectively. Then, an inlet portion of the gas supply system is formed on the bottom plate of the observation container, and an outlet portion of the exhaust system is formed on the lid plate. The gas supply system is preferably constructed by connecting a combustion gas piping and a fire extinguishing gas piping to two inlets of a three-way solenoid valve, and connecting an outlet of the three-way solenoid valve to an observation container.

[0011]

[Operation] The observation container defines the combustion area to prevent combustion smoke and sodium vapor from leaking to the outside, and also defines the area filled with extinguishing gas for suffocation and extinguishing. The high-frequency induction heating device directly heats the sodium in the crucible from outside the observation container to raise the temperature to the ignition temperature. The gas supply system selectively introduces sodium combustion gas and fire extinguishing gas into the observation vessel. In addition, the exhaust system allows gas containing combustion smoke and sodium vapor to exit the observation vessel, making it easier to observe combustion and suffocation.

[0012] The vertically arranged heat-resistant glass tube makes it easy to observe the inside from the surroundings, and gas is introduced from the bottom of the observation container and smoothly exhausted from the top to prevent sodium vapor etc. from adhering to the glass. . The three-way solenoid valve allows the supply and stop of combustion gas and fire extinguishing gas to be controlled remotely.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is an explanatory diagram showing an embodiment of the sodium combustion/suffocation extinguishing observation apparatus according to the present invention. This device includes an observation container 10 whose interior can be isolated from the atmosphere, a steel crucible 12 installed therein, a combustion and fire extinguishing gas supply system, and an exhaust system for gases containing combustion smoke and sodium vapor. Equipped with high frequency induction heating equipment. Here, air is used as the combustion gas and nitrogen gas is used as the fire extinguishing gas.

The observation container 10 includes a heat-resistant glass tube 14 whose openings at both upper and lower ends are covered with a heat-resistant lid plate 16 and a bottom plate 18.
The flange-shaped peripheral portions of the cover plate 16 and the bottom plate 18 are connected by a plurality of pillars 20 to form a sealed vertical structure, which is supported on support legs 22. The high-frequency induction heating device includes a heating coil 24 installed at the outer lower part of the heat-resistant glass tube 14, and a high-frequency induction heating temperature control device 26 that controls the supply of electricity to the heating coil 24. The steel crucible 12 has a double structure, inside and outside, and stores sodium 28 inside its inner cylinder.
0 and placed at the center of the lower part of the observation container 10. A sensor section 34 of a thermometer 32 is inserted into the bottom of the crucible 12.

An inlet portion 36 for a gas supply system is formed in the center of the bottom plate 18 of the observation vessel 10, and an outlet portion 38 for an exhaust system for gas containing combustion smoke and sodium vapor is formed in the center of the lid plate 16. A stop valve 40 is provided at the outlet portion 38 of the exhaust system. The gas supply system includes an air pipe 42 and a nitrogen gas pipe 4.
4 are respectively connected to two inlets of a three-way solenoid valve 46, and an outlet of the three-way solenoid valve 46 is connected to the observation container 10. Furthermore, rotary flow monitors 48 and 50 are provided in the middle of both pipes 42 and 44. The three-way solenoid valve 46 is connected to the operation desk 5
It is connected to the combustion switch 54 and fire extinguishing switch 56 of No. 2.

A sodium combustion/suffocation fire extinguishing experiment using this apparatus is conducted as follows. First, the inside of the observation container 10 is made into a nitrogen gas atmosphere. A high frequency current is supplied from the high frequency induction heating temperature control device 26 to the heating coil 24 to heat the sodium 28 . Since it is a high frequency induction heating method, only the conductor is heated, so the small amount of sodium 28 is intensively heated together with the crucible 12, and unnecessary parts are not heated. Further, the temperature of the crucible 12 is measured with a thermometer 32, and the heating temperature is automatically controlled based on the measured temperature. When the ignition temperature is reached, the combustion switch 54 on the operation desk 52 is operated to blow air into the observation container 10 to cause combustion. To extinguish the fire, operate the fire extinguishing switch 56 to change the gas flow path in the three-way solenoid valve 46, supply and fill the observation container 10 with nitrogen gas, and suffocate and extinguish the fire.

Gas for combustion or extinguishing (air or nitrogen gas) enters from the lower part of the heat-resistant glass cylinder 14 and is exhausted from the upper part, and since the gas flows outside the crucible 12, the central part of the heat-resistant glass cylinder 14 (the crucible Sodium vapor and combustion smoke generated at (and in the vicinity of) the glass cylinder wall become difficult to adhere to, and can be clearly observed from the side of the observation container 10. Further, by providing rotary flow monitors 48 and 50 in the middle of both pipes 42 and 44, the flow of air and nitrogen gas can be seen at a glance. Further, by making the crucible 12 have a double structure, sodium and combustion slag spilled from the inner cylinder can be collected in the outer cylinder, thereby preventing the inside of the observation device from becoming dirty.

[0018]

Effects of the Invention As described above, the present invention heats the sodium in the crucible placed in the observation container using the high-frequency induction heating method, so the sodium can be heated intensively, there is no danger of burns, and there is no switch. Since heating and temperature maintenance are performed automatically by simply adding the fuel, heating and ignition time can be shortened to a few minutes, resulting in labor savings and high efficiency. Furthermore, since the observation container can be completely isolated from the atmosphere, there is no danger of inhaling sodium vapor or combustion smoke for visitors, and it will be possible to clearly and repeatedly observe the sodium combustion and suffocation fire extinguishing process right in front of your eyes.

[0019] An inlet of the gas supply system is provided at the bottom of the observation container.
By forming the outlet sections of the exhaust system in the upper part, combustion smoke and gas containing sodium vapor can be smoothly exhausted, and there is almost no clouding due to adhesion to the glass cylinder wall, making observation easier. In addition, by connecting the combustion gas piping and fire extinguishing gas piping to the inlet of a three-way solenoid valve, and connecting the outlet of the three-way solenoid valve to the observation container, anyone can easily set sodium in the crucible. You will be able to easily experience heating, temperature raising, combustion, and fire extinguishing experiments. In particular, since visitors can manually operate switches to supply combustion gas for combustion and fire extinguishing gas, the conventional negative image that sodium is dangerous and difficult to handle can be dispelled.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of an embodiment of the sodium combustion/suffocation extinguishing observation device according to the present invention.

[Explanation of symbols]

10 Observation container 12 Crucible 14 Heat-resistant glass cylinder 16 Lid plate 18 Bottom plate 24 Heating coil 26 High frequency induction heating temperature control device 28 Sodium 38 Exhaust system outlet 42 Air piping 44 Nitrogen gas piping 46 Three-way solenoid valve

Claims (3)

[Claims] 1. An observation container whose interior can be isolated from the atmosphere, a crucible for sodium installed within the observation container, and a gas supply system that can control the supply and stop of combustion and extinguishing gases to the observation container. A sodium combustion/suffocation/extinguishing observation device comprising an exhaust system connected to an observation container and a high-frequency induction heating device that heats the sodium in the crucible from outside the observation container. [Claim 2] The observation container has a vertical structure in which openings at both upper and lower ends of a heat-resistant glass cylinder are covered with a lid plate and a bottom plate, respectively,
2. The apparatus according to claim 1, wherein the bottom plate of the observation vessel has an inlet portion for a gas supply system, and the lid plate has an outlet portion for an exhaust system. [Claim 3] A gas supply system is constructed by connecting a combustion gas piping and a fire extinguishing gas piping to two inlets of a three-way solenoid valve, and connecting an outlet of the three-way solenoid valve to an observation container. The device according to item 2.