Multiple Heads Plunger Metering Pump
* Multiple pump heads are available.
*Widely used in all kinds of industry line, such as: Chemical, power, Nuclear, Medicine etc.
*Customrized inquirment can be get, such remote digital control, different material of the pump head, etc.
* The capacity flow can be up to 10000L/H
*The
pressure up tp
50Mpa
*The
flow can be adjusted from 0-100% while it's running or
stopped.
* Liquid temperature range is not over than 250 degree.
Multiple Heads Plunger Metering Pump,Two Heads Plunger Metering Pump,Double Stainless Steel Pump Head Metering Pump ,High Pressure Duplex Head Plunger Zhejiang Ailipu Technology Co., LTD. , https://www.alipu.com
(1) Causes of mine fires The causes of fires in mines can be divided into two types: one is fire caused by external fire source, called external fire; the other is caused by the physical and chemical properties of combustible minerals (mainly coal ). Fire, also known as internal fire. Therefore, mine fires fall into two categories: external fires and internal fires.
1. External causes of fires Most of the fires are caused by human factors, including obvious violations by underground personnel or due to negligence and improper operation. Such as the underground demolition of miner's lamp, blasting of the cannon, illegal welding or gas welding or the strict implementation of the prescribed preventive measures, and even illegal smoking in the underground, etc., may cause a downhole fire. Short-circuiting of underground electrical equipment or short-circuiting of equipment maintenance, causing arc sparks, can also cause downhole fires. There are also violations of operating procedures and illegal shooting, such as using open flames or power lines to shoot, gunpowder deterioration, paste guns, etc., can also be the cause of underground fires.
Sometimes the open flame caused by external causes is very small, but due to the limitation of air conditions in the roadway, it will cause a big fire; on the contrary, the burning or explosion of mine gas and coal dust will form a mine fire because it ignites downhole combustibles.
External fires generally occur near wellheads, underground rooms, mining faces, and wood-supported roadways with cables.
2. Internal fires Internal fires mainly refer to coal spontaneous combustion. When coal is self-igniting, it can oxidize heat when it comes into contact with air. If the heat dissipation condition is not good, it will cause spontaneous combustion. The internal fire mainly occurs in the goaf, the roof and the pressed coal pillars. The natural fire in the goaf accounts for 80% of the natural fire in the mine.
(II) Characteristics of mine fires 1. There are many electrical equipments in the underground, and there are many flammable materials such as pit wood. Especially in coal mines, coal and coal powder can be ignited everywhere, and the underground space is small, and there is obvious air in the roadway rl'. Flow, these conditions themselves determine the susceptibility of the fire.
2. In mines with a risk of gas and coal dust explosion, mine fires may cause gas and coal dust explosions, which will expand the disaster, which is one aspect of the seriousness and catastrophic fire in the underground.
3. Under the influence of the wind flow in the underground roadway, the fire in the underground is easy to spread and spread, which will not only cause a fire, but also cause a large number of harmful gases to diffuse underground, which seriously threatens the life safety of the miners. At the same time, due to the access conditions of the underground roadway, avoiding It is difficult for disaster victims to determine the location and situation of the disaster, and it is difficult to avoid and evacuate. In addition, the underground personnel are concentrated, which increases the catastrophicity of the underground fire; the downhole conditions also increase the difficulty of disaster relief.
4. There are many reasons for mine fires, so the nature of fires will also be diverse, such as electrical fires, oil fires, fires caused by gas explosions, and spontaneous combustion of coal. Therefore, the methods of disaster relief are different, and the complexity of disaster relief is also caused.
5. Downhole not only affects the fire, but also the fire will generate fire pressure, which will encourage the wind flow or change the flow direction of the downhole. This will make it difficult to judge the disaster situation and the fire situation. Therefore, after the fire is encountered in the underground, the correct judgment of the wind flow is also a key task of the mine fire emergency.
6. Generate a source of regenerative fire. The hot and volatile gas-containing smoke flows and merges with the fresh airflow of the adjacent roadway, and then burns, so that some regenerative fire sources may appear on the downwind side of the fire source.
What are the characteristics of mine fires?
   Fires that occur underground, as well as fires that occur near the wellhead but endanger the safety of the well, are called mine fires.