What is carbon dioxide blasting?
Carbon dioxide blasting means that carbon dioxide changes from liquid carbon dioxide to gaseous state at high temperatures, causing rock fractures to achieve the purpose of mining. . Different from the mechanism of explosive explosion, the process of carbon dioxide explosion is that the highly compressed carbon dioxide inert gas in the blasting tube expands rapidly when heated, breaks through the bursting disc, rushes out from the vent hole, and creates a strong impact on rocks, breaking rocks and The process of an object. The whole process absorbs heat and does not produce harmful gases. Kaiqiang's carbon dioxide fracturing equipment is currently widely used in various engineering constructions, tunnel and trench excavation, mining, road construction groundbreaking operations, underwater blasting operations, etc.
Advantages of carbon dioxide blasting:
1. Environmental protection: Construction operations can be carried out in directional blasting, which will not cause damage to the surrounding environment or produce toxic and harmful gases, and can better improve the working environment. , higher safety factor.
2. Practical and effective: The blasting force is large and controllable, and can completely replace the application of traditional explosive blasting in mining and other fields.
3. The assembly, filling, transportation and installation processes are safe and reliable, and there is no need to deal with squibs. Carbon dioxide is an inert gas, does not produce chemical reactions, has no open fire or gas explosion, and is safe and efficient.
4. The operation is simple and fast: the price of carbon dioxide on the market is low, safe, and fast to fill. Replacing different types of fixed-energy rupture discs and heating activators can control the working pressure of expansion blasting, so it can adapt faster. Different construction working environments can truly adapt construction plans to local conditions, improving construction efficiency.
5. More economical and affordable: Kaiqiang’s complete set of carbon dioxide fracturing system equipment can be used repeatedly for more than 5,000 times. The cost of use is low, it is recyclable, and the maintenance is simple and efficient.
6. Fast construction operations: The filling, installation and blasting operations of the carbon dioxide cracking equipment are simple, and the blasting preparation time is short, so the construction operations can improve its work efficiency.
What is the inert gas content of a mixed gas that is non-explosive?
What is the inert gas content of a mixed gas that is non-explosive?
Add in the mixed gas Inert gases (such as nitrogen, carbon dioxide, water vapor, argon, helium, etc.), as the content of inert gases increases, the explosion limit range decreases. When the concentration of inert gas increases to a certain value, the upper and lower explosion limits tend to be consistent, so that the mixed gas does not explode.
What are the changing trends in the explosion limits of gases containing inert gases and what are their practical applications in engineering
Brainstorming in the right way
< p> Helium plus carbon dioxide will explodeIt is impos ***le!
Helium is an inert gas
Carbon dioxide is not very reactive either< /p>
What are the factors that affect the explosion limit
Various flammable gases and flammable liquid vapors have different explosion limits due to their different physical and chemical properties.
The explosion limits of a flammable gas or flammable liquid vapor are not fixed. They are affected by factors such as temperature, pressure, oxygen content, inert medium, and container diameter.
Effect of temperature
When the original temperature of the mixed gas increases, the lower explosion limit decreases, the upper limit increases, the explosion limit range expands, and the explosion risk increases.
As the temperature of the mixture increases, the intramolecular energy of the mixture increases, which accelerates the burning rate. Moreover, due to the increase in the internal molecular energy and the accelerated burning rate, the mixture originally contained excess air (below the lower explosion limit) or combustibles. The content of the mixture that cannot spread the flame (above the upper explosion limit) becomes a content that can spread the flame, thereby expanding the explosion limit range.
Effect of oxygen content
As the oxygen content in the mixture increases, the explosion limit range expands, especially the explosion upper limit increases even more. A comparison of the explosion limit ranges of flammable gases in air and pure oxygen is shown in Table 1-3.
Standard 3§ Explosion limit range (%) of several flammable gases in air and pure oxygen Table 1-3
Influence of inert media
If non-combustible inert gases (such as nitrogen, water vapor, carbon dioxide, argon, helium, etc.) are mixed into the explosive mixture, as the volume fraction of the inert gas increases, the explosion limit range shrinks, and the content of the inert gas increases to A certain value makes the mixture non-explosive. In general, the impact of inert gases on the upper explosion limit of a mixture is more significant than on the lower explosion limit. Because the increase in the inert gas content means that the oxygen content is relatively reduced, and the oxygen content in the upper limit is already very small, so a slight increase in the inert gas content will have a great impact, causing the explosion upper limit to drop significantly.
Influence of original pressure
The original pressure of the mixture has a great influence on the explosion limit. As the pressure increases, the explosion limit range also expands, especially the upper explosion limit increases significantly.
Container
The material and size of the filling container have an impact on the explosion limit of the material. Experiments have shown that the smaller the diameter of the container tube, the smaller the explosion limit range. For the same combustible material, the smaller the pipe diameter, the smaller the flame spread speed. When the diameter of the pipe (or flame channel) is small enough, the flame cannot pass through. This distance is called the maximum fire extinguishing distance, also called the critical diameter. When the pipe diameter is smaller than the maximum fire extinguishing distance, the flame cannot pass through and is extinguished.
The effect of container size on the explosion limit can also be explained from the container wall effect. Combustion is the result of a series of chain reactions produced by free radicals. Only when the new free radicals are larger than the lost free radicals can combustion continue. However, as the diameter (size) of the pipe decreases, the probability of collision between free radicals and the pipe wall increases accordingly. When the size is reduced to a certain extent, that is, because the destruction of free radicals (collision with the wall) is greater than the production of free radicals, the combustion reaction cannot continue.
Regarding the impact of materials, for example, hydrogen and fluorine mixed in glassware can explode even in the dark at liquid air temperatures. In silver vessels, the reaction can only occur at normal temperatures.
Energy
The energy of the spark, the area of ??the hot surface, the contact time between the fire source and the mixture, etc., all have an impact on the explosion limit. For example, methane will not explode at any ratio to an electric spark with a voltage of 100V and a current intensity of 1A. For example, when the current intensity is 2A, its explosion limit is 5.9% to 13.6%; when the current intensity is 3A, it is 5.85% to 14.8%. Therefore, various explosive mixtures have a minimum detonation energy (generally occurring when close to chemical theoretical quantities).
In addition to the above factors, light also has an impact on the explosion limit. As we all know, the reaction between hydrogen and chlorine is very slow in the dark, but when exposed to strong light, a chain reaction occurs and leads to an explosion. Another example is the mixture of methane and chlorine, which does not react for a long time in the dark, but will cause a violent reaction when exposed to sunlight. If the ratio of the two gases is appropriate, it can explode. In addition, surface-active substances also have an impact on certain media. For example, at 530°C in a spherical vessel, hydrogen and oxygen have no reaction at all. However, when quartz, glass, copper or iron rods are inserted into the vessel, an explosion occurs.
Why do inert gases not explode?
Because inert gases cannot participate in chemical reactions, they will not produce chemical energy, and will not release huge energy inside the molecules, and explosions are Start from the inside so the inert gas doesn't explode.
The more inert gases contained, the greater the explosion limit of natural gas
The amount of inert gas contained in the system increases, the explosion limit range shrinks, the lower the explosion limit of inert... and The higher the explosion limit, the greater the explosion risk. ...This formula is used for the explosion limit of mixed gases such as coal gas, water gas, natural gas, etc.
The mixture of inert gas and CO2 contains
How much inert gas does the mixed gas contain? Explosive gas
Add inert gases (such as nitrogen, carbon dioxide, water vapor, argon, helium, etc.) to the mixed gas. As the content of the inert gas increases, the explosion limit range decreases. When the concentration of inert gas increases to a certain value, the upper and lower explosion limits tend to be consistent, so that the mixed gas does not explode.
Whether carbon dioxide blasters are explosives in criminal law
1. Carbon dioxide has superior chemical and physical properties and is very safe. The molecular formula of carbon dioxide is CO2. Its chemical value has stabilized and it can no longer participate in chemical reactions. It is a truly inert gas. Therefore, during the entire explosion process, it is just from carbon dioxide to carbon dioxide, and no harmful substances are produced.
2. No explosion will occur during production, storage, and transportation. Flammable liquefied gas can easily leak and burn and explode when exposed to fire. Carbon dioxide cannot burn. If it leaks, it can only deflate. Since the deflation absorbs a large amount of heat, it may cause local freezing of the surrounding area and will not explode.
3. Intelligent carbon dioxide cold blasting is cold blasting. The so-called "cold" means that carbon dioxide cold blasting is the process of turning liquid into gas. Therefore, it absorbs a large amount of heat from the surroundings, cooling the surrounding environment, and will not detonate gas. , coal dust. This feature is especially suitable for blasting operations in environments with explosive gases and dust such as gas and coal dust, such as coal mines, oil mines, etc.
4. The vibration generated by intelligent carbon dioxide cold blasting is weak and has very little destructive power. It is very powerful for protecting buildings and reducing impact factors that induce ground pressure. The detonation speed of smart carbon dioxide cold blasting is much lower than that of explosive detonator blasting, and the impact force is generally 400Mpa, which is far lower than the 1000-5000Mpa of explosive blasting. According to preliminary detection, the explosion velocity is about 3m/s. Generally, there is basically no destructive effect after 2-3 meters away from the blasting point.
5. No new harmful gases are produced during blasting. Unlike explosive blasting that produces a large amount of harmful gases such as carbon monoxide, carbon dioxide cold blasting is a physical reaction process. From carbon dioxide to carbon dioxide, there is no harm in blasting on the ground. Blasting, according to the detection of multiple projects, has never exceeded the standard above one meter, and only exceeded the standard for a short time near the tunnel floor (normal ventilation).
6. It cannot be used to commit explosion crimes. On the one hand, carbon dioxide cannot burn or explode. On the other hand, carbon dioxide cold explosion can only produce destructive effects in a closed space, and can hardly produce destructive effects in an open space.
Therefore, it is not considered an explosive under the criminal law.
Why do some documents claim that carbon dioxide is an inert gas?
No. Originally, rare gases were called inert gases, but now they are called noble gases because of the discovery of xenon compounds. .Carbon dioxide and nitrogen do not originally belong to this category