Improvement Feasibility Analysis of Mining Hard Hat

Coal is one of the most important sources of energy in the world today. Since most of coal is buried deep in the ground, the mining of coal must be carried out by excavating the mine. Although the degree of mechanization has reached a certain height, coal mining still cannot achieve pure mechanized mining, and people must go deep underground for mining. In mines, a complex and dangerous environment, safety equipment for underground personnel is particularly important. Underground safety equipment includes safety helmets , miner's lamps, self-rescuers, etc. Among them, helmets are particularly important for protecting the body's most important part, the head's protective equipment.

I. Analysis of the status of mine safety helmets

The mine environment is very complex. The depth of the mine ranged from tens of meters to a few thousand meters. The thick rock strata above it. Despite the support of underground support, it is still difficult to ensure absolute safety. Roof disasters are also one of the common disasters in mines. The head is the most critical part of the human body, so head protection is essential in almost every dangerous situation.

The main function of the helmet is to protect the head from the impact from above and to ease the impact. Its protection principle is: forming a certain gap between the cap and the top of the head, this gap will play a certain buffer to the impact from the upper part. At the same time, the spherical glossy cap can redirect the falling objects from above to avoid impact on the head.

On the other hand, downhole safety comes not only from the threat above the head, but mine gas is also a hazard. The content of harmful gases in the underground air is large, and at the same time it is doped with ore dust. Breathing this air for a long time will cause great harm to the human body. "Scoutosis" is an occupational disease commonly found among miners. It is caused by mine gas that has been mined by miners for a long time.

Considering both of the above considerations, the helmet can only protect the head from impact damage and will not provide any protection against harmful gases in the mine.

Second, mine safety helmets to improve the perspective

(A) Respiratory filtration device

After the above analysis is known, the helmet mainly protects the head from harm. However, for the common occupational disease in the underground personnel, “silicosis disease”, there is currently no equipment to play a role in preventing the disease. Therefore, with reference to the design of the gas mask, breath filtration can be added to the helmet.

In the process of coal mining, a large amount of ore dust will be generated. In addition, the effect of mine ventilation will cause a large amount of dust to be released from the air, and underground personnel will breathe in this environment for a long time, posing a great risk of “silicosis”. Silicosis is mainly due to long-term inhalation of free silica dust, resulting in pulmonary interstitial fibrosis, and silicosis nodules-based diseases, severe cases can affect lung function, loss of labor ability, and even develop pulmonary heart disease, Heart failure and respiratory failure.

In addition to mine dust, harmful gases in mines are also harmful to the human body. These harmful gases include methane, carbon monoxide, carbon dioxide, hydrogen sulfide, sulfur dioxide, ammonia, nitrogen dioxide, and the like. For example, long-term inhalation of trace amounts of carbon monoxide will reduce human emotions, simple response time, digital span, manual agility, digital decoding, and visual preservation. Carbon monoxide, carbon dioxide and other gases have been inhaled for a long time and have a great impact on people's lungs, and they easily induce lung cancer. Long-term inhalation of hydrogen sulfide and sulfur dioxide may cause hyposmia, neurasthenia syndrome, and autonomic dysfunction; long-term inward injection of ammonia may induce pulmonary edema, respiratory distress syndrome, etc., and respiratory tract irritation may occur. Long-term inhalation of nitrogen dioxide can easily cause respiratory diseases such as bronchitis, bronchitis, and pharyngitis. These all threaten the physical health of underground personnel.

To sum up, the introduction of respiratory filtration devices must have two functions: one is to filter mineral dust, and the other is to filter harmful gases.

(B) Positioning System

The positioning of underground personnel plays an important role in both management and rescue.

The existing underground personnel positioning system is based on modern radio coding communication technology, applying signaling technology and wireless transmission and reception technology in modern radio communication technology, combined with popular data communication, data processing and graphic display software and other technologies . The system can timely and accurately reflect the status of underground personnel and mobile devices in the ground to the ground computer system, enabling managers to keep track of the total number and distribution of downhole personnel and mobile equipment; the system can track the situation of cadres and shifts, downhole, and every miner. Wells, wells, and trajectories allow for more rational scheduling and management.

This positioning system is a micro computer system composed of main functional circuits such as data wireless acquisition, display, control, storage, infrared remote control, communication, watchdog, and power supply. Mainly through the motherboard, communication board, wireless transceiver board and power board and other circuit board formed an organic whole. The main board is the main control circuit; the communication board is used for data communication with the ground central station; and the wireless transceiver board carries the data communication between the substation and the external personnel carrying the card. Its working principle is: the system personnel position the substation's wireless transceiver data board to transmit the low-frequency encrypted data carrier signal to the outside via the transmitting antenna; the identification card carried by the person enters the low frequency transmitting antenna working area and is activated (does not enter the transmitting antenna. The work area identification card does not work. At the same time, the encrypted information carrying the target identification code is transmitted via the high-frequency transmitting module in the card; the receiving antenna receives the carrier signal sent from the identification card and is received and processed by the sub-station main board and then extracted. The target identification code is sent to the ground monitoring computer through the long-distance communication line to complete the automatic tracking and positioning management of the mine personnel.

The limitation of this positioning system is that the signal is transmitted using a radio and the radio has poor penetration. We have all experienced the loss of signal in cell phones in tunnel culverts because tunnel culverts blocked the propagation of external signals. If the radio communication can be smooth downhole, multiple signal transfer stations are needed. Once a signal station fails, the communication will be interrupted. In the event of an accident, this situation cannot be avoided. On the other hand, the deeper the mine is, the larger the scale, the more signal transfer stations are needed, and the higher the required cost is. Furthermore, downhole personnel need to carry identification cards for transmitting and receiving signals with them, and identification card failures and losses are also difficult to avoid.

Third, the feasibility of mine safety helmet improvement program

(A) The material and shape of respiratory filtration device

1. Breathing filter material

Gas masks worn by firefighters are mainly used to filter the smoke and toxic gases in the fire scene. The mine environment is similar to this environment.

Gas masks mainly use a material called "activated carbon." Activated carbon is a very good adsorbent. It uses charcoal, bamboo charcoal, various kinds of fruit shells, and high-quality coal as raw materials. It crushes, sieves, activates, rinses, dries and filters raw materials through physical and chemical methods. A series of processes such as processing and manufacturing. It has the dual characteristics of physical adsorption and chemical adsorption, and can selectively adsorb various substances in the gas phase and liquid phase. Although activated carbon is a very fine carbon particle, it has a large surface area and there are finer capillaries in the carbon particle. This capillary has a very strong adsorption capacity, due to the large surface area of ​​the carbon particles, it can fully contact with gas impurities. When these gas impurities collide with the capillary, they are adsorbed and act as a purifier. For the filtration of mineral dust, activated carbon can play a very good role. At the same time, the chemical adsorption characteristics of activated carbon can also effectively filter harmful gases. Activated carbon has a wide range of sources of materials and is simple to process. It can be described as “affordable”.

2. The shape of respiratory filtration device

Although the mine environment is similar to the fire environment, the harmful substances are far less than the latter. Therefore, protective masks for mining do not need to be as bulky and tight as gas masks. They can be designed to be light and easy to pick, such as masks. This resembling mask-like breath filtering device is light and easy to carry and can be attached to the helmet as an integral part of it; or as a removable part, it will be easy to clean and replace.

The above analysis may indicate that it is entirely feasible to add respiratory filtration devices on the helmet .

(B) Positioning System Forms and Technical Measures

1. The form of positioning system

The characteristics of the existing positioning system have been analyzed above. The system is huge and requires huge hardware support, which inevitably brings huge capital investment.

The ideal positioning system should be in the form of a small transmitting/receiving device on the helmet (the inside can contain personal information of the person). It only needs a transceiver device on the ground to monitor the situation of the underground personnel. Even if a mine accident occurs, as long as the device on the helmet is not damaged, a signal can be sent out. This signal can include the personal information of the person as well as the location, site conditions, etc., which is much more convenient for rescue. In short, it is to achieve ground-downhole direct communication. Transmitting/receiving devices mounted on hard hats need to be small and versatile and can be achieved at the current state of the art but may result in higher costs.

2. Positioning system technology

In order to achieve direct ground-downhole communication, it is more difficult with existing technologies. Because all current wireless communications use electromagnetic waves, electromagnetic waves can only travel in a straight line, and it is difficult to penetrate such a thick layer of media. Electromagnetic waves have electromagnetic radiation, and long-term acceptance of such radiation can also have adverse effects on human health.

In theory, the "neutrino" spread can be chosen. The neutrino is a kind of basic particle and has a strong penetration ability. Neutrinos emitted from the sun can easily penetrate the earth. However, neutrinos only participate in very weak weak interactions, and they traverse the Earth’s thick material. Only one of the 10 billion neutrinos reacts with matter, so neutrino detection is very difficult. So far, the neutrino is still in a very preliminary stage of research. There are still many mysteries that have not been revealed. Although the "neutrino" is still in the low-level stage of research, it has a broad application prospect, which indicates a research direction for the future development of communication technology.

From the perspective of feasibility, the most ideal positioning device is to be realized. It still needs further development and research of science and technology.

Fourth, summary

Although the current Chinese miners have been well protected in terms of labor, the accidental casualty rate of Chinese coal mines still ranks first in the world. This is related to the management system of coal mines. On the other hand, the level of labor and equipment is low. Chinese coal mines should extensively absorb advanced foreign experience, use new technologies and new methods, improve the working equipment of miners, ensure the health and safety of workers, and ultimately enable the overall development of the Chinese coal industry.

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