Pu Lei said: "I will go to the mining city to install equipment recently. When I have the chance, I will ask where this stone is."
"I think it's better not to look for it. We don't know how to use it."
"I'll keep an eye on this."
A few days later, Pu Lei went to the mining city. He mainly went to repair the coal mining machines in the mining city. This shearer adopts a horizontal-axis drum cutting mechanism, and the coal loading device consists of a loading arm and a coal shoveling plate. The left and right drum rotation is driven by an AC motor to drop coal. The left and right robotic arms are also driven by two AC motors. The scraper conveyor operates. The loading arm pushes the coal cut by the drum onto the conveyor of the coal handling device.
However, when inspected with a thermal imaging instrument, some devices showed high temperatures. I don’t know if it was a motor or bearing failure. If the temperature is too high, it may cause spontaneous combustion of coal.
The ignition point of coal depends on its volatile content. The ignition temperatures of several coals are roughly: anthracite -550~700℃; bituminous coal -400~550℃; lignite -300~400℃.
Pu Lei and Duan arrived at Licheng. He said: "You stay up there and don't go down. It's very dangerous to go down. I'll go down and have a look. If there's any problem, I'll use the communication device to contact you."
Duan Zhu said: "Okay."
He descended into the deep mine and followed the tunnel. Passing by mudstone, limestone, and sandstone, we saw some colorful stones embedded in the walls.
He thought, "What are these?"
He picked out a few pieces and looked at them. It is dense and massive, grape-shaped, and has a concentric structure. The colors are distributed in strips, concentric rings, and dendrites, and are white, gray, brown, black, and blue. Waxy luster, translucent, with shell-shaped fractures.
"This should be agate. It seems that this part of the wall has fallen off. The stones are also exposed."
Agate is generally in the shape of irregular blocks, nearly oblate or cylindrical. Red, orange-red to deep red and milky white, off-white. Streaks white. translucent. The surface is flat and smooth, with a glassy luster; some are uneven and have a waxy luster. The body is light, hard and brittle, and easily broken. Concentric circular ripples with the stress point as the center can be seen in the cross section, resembling a shell. It has sharp edges and corners that can scratch the glass and leave scratches. Quick friction is not easy to heat.
I don't know why there is some vibration around here. It is possible that large mechanical vibrations caused these walls to peel off. These agates appear here and there.
Pu Lei got on the rail car and went down, forward, down, forward, almost to the position of the shearer.
There are gray and black walls next to it. He just looked at these agates. The main component of agate is silica, which often forms repeated layers due to alternating with hydrated silica. Because it is mixed with oxidized metals, its color can range from very light to dark. Agate can be made artificially by using salts such as iron, cobalt, and nickel, allowing them to naturally penetrate into the silicic acid gel. Natural agate may also be generated under similar circumstances.
Agate has a long history. About 100 million years ago, underground magma erupted in large quantities due to changes in the earth's crust. When the lava cooled, steam and other gases formed bubbles. The air bubbles become sealed as the rock freezes, creating holes. After a long time, the holes are immersed in a solution containing silica and condensed into silica gel. The soluble components of the iron-bearing rock enter the silica gel, and finally the silica crystallizes into agate.
When he arrived at the location of the coal shearer, Pu Lei took out some testing equipment, including a vibration sensor, a temperature sensor, and a voltmeter. The vibration amplitude was not very large, and he did not see anything abnormal. The motor and transmission should be fine.
"What's the problem?"
He shut down the machine again, took apart the end cover, motor, gears, and bearings, but found no problems.
There was no mobile phone signal in the mine, so he used the communication device to talk to Duan Zhu, "I don't see any problems with this machine. The temperature is not high at the moment. I don't know what the problem is."
"Then the company and I will report it immediately."
After a while, Duan Zhu used the communication device to say: "The company said that the remote sensor over there also saw that the temperature of the machine is normal. Come back first."
After Pu Lei took pictures of the machine, he was about to come up.
But just some distance away. Duan Zhu used the communication device to talk to him again: "Wait a minute, the company's remote sensor now shows that the temperature of the machine has increased."
"What's going on? I have to stay there, otherwise the temperature will rise. This machine also only needs maintenance personnel to arrive, and it will be fine as soon as the maintenance personnel arrive."
Duan Zhu said: "I don't know. Peng Qing from the company called me just now. She was looking at the monitoring parameters in the management center."
"Okay. Let me think about it."
After much thought, he realized that he himself was not a source of low temperature and would not cool down the machine by getting close to it. What's the reason?
"Could it be these agates?"
He placed the agate far away from the machine and measured it with a temperature sensor. He also asked Duan Zhu: "What is the temperature now?"
Duan Zhu said: "The temperature is getting higher."
His own temperature sensor also detected that the machine was getting hotter.
"That's really the reason for these agates."
This agate and heat distribution stone are similar, or opposite. Affect the nearby temperature distribution, such as causing the temperature of the machine to drop. Then, the stones in other places should affect its temperature, causing it to rise.
Thermal distribution stones and gravity stones may be a similar situation. The space near it is not continuous. There are many jumping points in the middle. Gravity stones change the propagation of nearby light. The heat distribution stone changes the heat distribution in the nearby space. The temperature in some places increases and the temperature in some places decreases. The heat in the middle is not continuously conducted.
"Then what should we do? We can only temporarily place a few of these agates nearby so that the temperature of the machine does not rise too high. Then take away a research."
He walked from the rail car to the elevator, walked out of the mine, and said to Duan Zhu, "On the way, I picked up a few agates. I used these agates to stabilize the temperature temporarily. This may be a kind of heat distribution stone."
Duan Zhu said: "Okay then. I can still pick up such strange stones. Have you found anything else?"
"The temperature of the machine has increased. I don't know if there are other heat distribution stones nearby. I guess there are."
Duan Zhu said: "Then let's investigate again when we come back?"
"Yes. It's so winding down here that it's not easy to walk."
Duan Zhu remembered the industry his original boss was in.
Duan Zhu, Sun Shiji, and Wu Tian originally worked in a home machinery company. Later, I thought about developing Shengshi City or Huixiang City, so I gave up my original job.
Boss Liang Ting said: "The things we do here are not big. You have been here for a year, and you have always been here. I also try my best to make friends. If anything happens in the future, we will still help each other."
Duan Zhu said: "I'm living a good life here. I'm so sorry that I resigned."
Liang Ting said: "It's nothing, just hire more employees. And we don't necessarily need a lot of employees."
Duan Zhu said: "I also learned a lot from you here."
Liang Ting said: "Yes, you have at least seen hundreds of parts, designed several new devices, and have experience in electromechanical control."
Duan Zhu said: "Which field does Mr. Liang plan to pursue in the future?"
Liang Ting said: "Power-assisted machinery. I may have to discuss it with you in the future. Young people have flexible minds and come up with many ideas. I mainly refer to the three of you. Not all young people are so creative. In mechanical design I can help you in this regard if necessary.”
