RU2530448C1 - Method of controlling gaseous medium in container containing combustible gaseous substances - Google Patents

Abstract

FIELD: physics.

SUBSTANCE: method of controlling a gaseous medium in a container containing combustible gaseous substances includes creating an inert atmosphere using an inert gas, holding the container until safe content of the combustible gaseous substance is established. The container, which is equipped with a detachable cover, is placed in a sealed vessel. A sphere is then placed in the free space formed between the walls of the sealed vessel and the container, said sphere being filled with helium and provided with a load, the weight of which is selected such that the helium-filled sphere with the load is in a suspended state in argon. Further, argon is fed into the free space between the walls of the sealed vessel and the container to displace air until the helium-filled sphere provided with a load rises to the boundary of the detachable cover and the mouth of the container. Argon supply is continued and the detachable cover of the container is opened by a height h=Δ, which is sufficient to release excess combustible or toxic gaseous products from the container into the sealed vessel with argon. The detachable cover is fixed over the mouth of the container by a spacer and is held in that position for a time x, which is determined by a mathematical formula.

EFFECT: designing a method of controlling a gaseous medium in a container for storing combustible or toxic gaseous products to provide a safe and stable atmosphere and environmental safety.

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Description

The present invention relates to the field of methods and means of controlling the content of combustible or toxic components and can be used to control and regulate the content of gaseous toxic or combustible substances in stationary or transported containers.

The urgency of the problem to be solved is based on improving the safety during transportation, storage and maintenance of containers containing combustible gaseous substances, the accumulation of which inside the container in excess of the maximum permissible concentrations can lead to ignition, explosion or environmental damage.

From the prior art there is known a method and device for controlling the gas environment of the cavities of working devices by dumping explosive and toxic gases into the atmosphere or to inter-equipment communications (RF patent No. 2422177, IPC A62C 3/04, publ. 06/27/2011), according to which dumping These gases are carried out using their transportation through the main gas pipeline, one end of which is connected to the unit for the supply of explosive and toxic gases, and the other is connected through a safety valve to the flare pipe oh for burning gases.

A known method of monitoring the gas environment of volumes and its regulation from the patent of the Russian Federation No. 2138856 (IPC G08B 17/107, publ. 09/27/1999), in which to prevent the occurrence of fire and explosion hazard due to gas leakage in various capacities of aircraft The method of selective measurement of hazardous gas contents is used, followed by comparison of the measured values with a reference constant and safe gas content in the reference chamber (hydrogen and oxygen).

The disadvantages of analogues include the inability for a long time to observe and control the parameters of the gaseous environment of containers containing toxic or combustible gaseous substances.

Known as a prototype of the claimed method of controlling the atmosphere of the afterburner by displacing an inert gas of a toxic material (RF patent No. 2035809, IPC H01M 8/04, publ. 05/20/1995), according to which a toxic liquid is removed from the afterburner after being purged with hydrogen. when inert gas enters this chamber.

The disadvantages of the prototype include the lack of the ability to ensure a safe and stable atmosphere and environmental safety of the environment by increasing the reliability of preventing the risk of fire, explosion or release of toxic gaseous products into the environment.

The objective of the authors of the invention is to develop a method of regulating the gaseous environment in a container containing gaseous combustible or toxic substances, to ensure the safety of the gaseous environment and environmental safety.

A new technical result provided by using the proposed method is to ensure the safety and environmental cleanliness of the environment by increasing the reliability of preventing the risk of fire, explosion or release of toxic gaseous products into the atmosphere.

These tasks and a new technical result are ensured by the fact that, in contrast to the known method of regulating a gaseous medium in a container containing gaseous combustible substances, including creating an inert atmosphere using inert gas, keeping the container until a safe content of combustible gaseous substance is established, according to the proposed method, the container equipped with a removable lid, placed in a sealed vessel, then in the free space formed between the walls of the sealed container oud and a container, immerse a ball filled with helium and equipped with a load, the mass of which is selected so that the ball filled with helium with the load is suspended in argon, then argon is fed into the free space between the walls of the sealed vessel and the container until air is displaced until when a ball filled with helium and equipped with a load rises to the boundary of the removable lid and the neck of the container, argon flow is continued and at the same time the removable lid of the container is opened to a height h = Δ sufficient to Product surplus combustible or toxic gaseous products from the container in a sealed vessel with argon, after which the removable cap is fixed on the container neck by means of spacers, it is kept in that position for a time τ, which is determined on the basis of mathematical formula:

$$\tau \ge \mathrm{1,2}\frac{W\delta }{D\ast F}\ln \frac{C_0}{\left[C\right]}\left(\mathrm{one}\right),$$

where W is the volume of the gas space of the container, m ³ ;

δ is the thickness of the junction of the lid and the neck of the container, m;

D is the diffusion coefficient of the gaseous combustible component in air, m ² / s;

F is the area of the gap between the removable lid and the neck of the container, m ³ : F = LΔ;

Δ is the gap between the removable lid and the neck of the container, m

C ₀ - concentration of combustible gaseous component,% vol .;

[C] - the maximum permissible concentration of a combustible gaseous component,% vol .;

The proposed method is illustrated as follows.

Figure 1 presents the device on which this method is implemented, where 1 is the container, 2 is the neck of the container, 3 is a removable cover, 4 are spacers for adjusting the lifting height of the removable cover, 5 is a vessel, 6 is a pipeline for supplying an inert gas, 7 - ball, 8 - cargo.

Container 1 contains combustible gas, which can accumulate when released from materials in the container (for example, polymers containing vapors of organic liquids, benzene, toluene, xylene, etc.).

In order to avoid the risk of gas fire during work with the container, in the proposed method, the container 1 is placed in a sealed vessel 5, equipped with a pipe 6 for supplying argon. Pre-prepare the rubber ball 7, which is filled with helium. A load 8 is attached to the ball, the mass of which is selected so that the ball filled with helium with the load is in a suspended (equilibrium) state in an argon atmosphere. The ball 7 with the load 8 is placed in the free space between the walls of the sealed vessel 5 and the container 1. Then, through the pipe 6, the argon supply is turned on, as a result of which air is displaced from the space between the vessel 5 and the container 1. As the air is displaced, the ball 7 will rise. Its rise to a height to the border of the removable lid and the neck of the container will indicate the absence of air in this zone and the presence of argon in it. After reaching this state, the removable lid 3 of the container 1 will be lifted by installing spacers 4 that provide a gap Δ between the lid 3 and the neck 2 of the container 1. The container 1 is held in a vessel with continuous argon supply for a time τ determined by formula 1.

The use of a helium-filled ball with a load to determine the moment of air displacement from the space between the vessel and the container simplifies the process of regulating the gaseous medium without involving complex control systems, and increases the reliability of preventing the risk of fire, explosion, or the release of toxic gaseous (if any) products into the atmosphere .

As shown by experimental studies, when using the proposed method, the safety and environmental cleanliness of the environment is ensured by increasing the reliability of preventing the risk of fire, explosion or release of toxic gaseous products into the atmosphere.

The possibility of industrial implementation of the proposed method is confirmed by the following example.

Example 1. In laboratory conditions, the proposed method is tested on a prototype device shown in figure 1, which is used as a metal container of cylindrical shape, having the following characteristics:

- the height of the inner cavity: h = 1620 mm;

- the diameter of the inner cavity of the container 1 d = 782 mm;

- the thickness of the junction of the cover 3 and the neck 2 δ = 40 mm

The temperature during the experiment was 21 ° C. In the container, originally filled with air, an initial hydrogen concentration of C ₀ = 6.6% vol. Was created, exceeding the lower ignition limit of this gas in the air, equal to [C] = 4.12% vol. The container was placed in a vessel equipped with a pipe for supplying argon. A rubber ball filled with helium was previously prepared. A load was attached to the ball, the mass of which was chosen in such a way as the junction of the container lid m so that the ball with the load in the argon medium was in equilibrium. The ball with the load was placed in the space between the vessel and the container. Then through the pipeline began to supply argon. Since the density of argon is greater than the density of air, the process of displacing air from the space between the vessel and the container has begun. As the air was displaced, the ball began to rise. After raising the ball to a height corresponding to the location zone of the junction of the container lid and the neck, the lid was undocked from the container and installed on spacers with a height of Δ = 80 mm, thereby creating a gap between the lid and neck of 80 cm. After that, without stopping the flow of argon, spent holding the container in the vessel for the time calculated by the formula (1) with the following parameter values:

- the volume of the gas space of the container W = 0.539 m ³ ;

- the thickness of the junction of the lid and the neck of the container δ = 40 mm;

- the length of the junction of the lid with the neck of the container L = 2,111 m;

- the height of the spacers Δ = 80 mm;

- the area of the gap between the lid and the neck of the container F = LΔ = 0,169 m ² ;

- the diffusion coefficient of hydrogen in air at a temperature of 21 ° C CD _diff = 7.4 * 10 ^-5 m ² / s;

- the initial concentration of hydrogen in the container C ₀ = 6.6% vol .;

- the permissible value of the concentration of hydrogen in the container [C] = 4.12% vol.

The estimated exposure time according to formula (1) was 15.2 minutes. In fact, the exposure lasted 15.5 minutes. After completion of exposure, an analysis of a sample of the gas medium from the cavity of the container for hydrogen content was carried out. According to the analysis, the hydrogen content was 3.8% vol.

The implementation of the above operations allowed for further safe handling of the container, in the internal volume of which there was originally a flammable gas environment.

Claims (1)

A method of controlling a gaseous medium in a container containing combustible gaseous substances, including creating an inert atmosphere using an inert gas, holding the container until a safe content of combustible gaseous substance is established, characterized in that the container equipped with a removable lid is placed in a sealed vessel, then in free space formed between the walls of the sealed vessel and the container, immerse a ball filled with helium and provided with a load, the mass of which is selected so that if the ball filled with helium was suspended in argon with the load, then argon is fed into the free space between the walls of the sealed vessel and the container to displace air until the ball filled with helium and equipped with the load rises to the border of the removable lid and the neck of the container continue to supply argon and at the same time open the removable lid of the container to a height h = Δ, sufficient to release excess combustible or toxic gaseous products from the container into a sealed vessel with argon, then fix the removable cover over the neck of the container by means of spacers, maintain it in this position for a time τ, which is determined on the basis of the mathematical formula:
$$\tau \ge \mathrm{1,2}\frac{W\delta }{D\ast F}\ln \frac{C_0}{\left[C\right]}\left(\mathrm{one}\right),$$

where W is the volume of the gas space of the container, m ³ ;
δ is the thickness of the junction of the lid and the neck of the container, m;
D is the diffusion coefficient of the gaseous combustible component in air, m ² / s;
F is the area of the gap between the removable lid and the neck of the container, m ³ ; F = LΔ; L is the length of the junction of the lid with the neck of the container;
Δ is the gap between the removable lid and the neck of the container, m;
C ₀ is the concentration of the combustible gaseous component, vol.%;
[C] - the maximum permissible concentration of a combustible gaseous component, vol.%.