Soon, Section Chief Tang got the news from the factory laboratory that the factory laboratory not only has glycerol of chemical purity, but also has a quantity of 8,000 milliliters. So he immediately asked the lab to send 5,000 milliliters.

Then he took a 6H drawing pencil and a bottle of quick-drying paint from the warehouse of the equipment maintenance department and sent them to Guo Yonghe.

"Expert Guo, all the materials you need are ready."

Wen Qingyan said impatiently: "Now you can start repairing the printed circuit plug-in board, right?" ”

"It's time to go!"

Guo Yonghe nodded and said: "But since repairing printed circuit boards is a very delicate job, I still need someone to help me."

Speaking of this, he looked at Li Weijin, "Director Li, you go outside and call Hu Dongqiang over and ask him to give me a beating." ”

He was invited by Hu Changzheng, and at this time, he naturally wanted to call Hu Dongqiang in and let him have a chance to perform in front of Wen Qingyan, the deputy factory director.

Li Weijin didn't dare to respond, but just looked at Wen Qingyan with his eyes and the attitude of the deputy factory director.

"Who is Hu Dongqiang?"

Wen Qingyan remembered that there didn't seem to be any personnel surnamed Hu in the equipment department, so he asked out loud.

"Director Wen, Hu Dongqiang is a student of the Department of Mechanical Engineering of Zhongtian University, and he is interning in our equipment department." Li Weijin reported in a low voice.

"Oh, Expert Guo was invited by his father, right?"

Wen Qingyan nodded, "Director Li, go and call him in!" ”

Since Wen Qingyan agreed, Li Weijin naturally no longer hesitated and immediately ran out quickly.

Soon, he brought in Hu Dongqiang, who was surprised and delighted.

"Expert Guo, thank you!"

Hu Dongqiang thanked Guo Yonghe repeatedly, of course he understood how rare this opportunity Guo Yonghe fought for him. As long as Guo Yonghe can repair the printed circuit board, he, as Guo Yonghe's assistant, will definitely be credited.

With this merit and performance, after a little activity, even if Zhang Jianshe is dissatisfied with him, he can't object to the equipment department to keep him.

"Director Wen,"

Guo Yonghe continued, "The delicate work of repairing printed circuit boards is easily disturbed by the outside world, so the working environment must be very quiet and not too many people.

"So except for Hu Dongqiang, who started the work, the scene can only let Director Li and Section Chief Tang, who are more familiar with the equipment and tools of the equipment maintenance department, stay, and the rest of the people need to wait outside."

"That's no problem with that!"

Wen Qingyan immediately agreed, waved his hand and ordered: "Director Li, Section Chief Tang, the two of you stay on the scene to assist Expert Guo, and the rest of you will go to the lounge outside with me and wait!" ”

Even Wen Qingyan had to go out to wait outside, even if Zhang Jianshe was unwilling, he didn't dare to say anything, so he could only obediently follow the other personnel in the equipment maintenance department to accompany Wen Qingyan to wait outside.

Seeing Hu Dongqiang carefully running over and locking the door, Guo Yonghe couldn't help laughing, and secretly said in his heart that this little Hu really has eyes.

"Section Chief Tang,"

Guo Yonghe asked: "Your equipment maintenance department should have a low-temperature thermostat and a high-temperature thermostat, right?" ”

"Yes, yes, both!"

Section Chief Tang nodded again and again.

As the equipment maintenance department of a large central enterprise such as Zhongtian Aluminum Plant, how can there be no common maintenance equipment such as low-temperature thermostat and high-temperature thermostat?

Soon, he led Guo Yonghe to the front of the low-temperature thermostat and the high-temperature thermostat.

"Xiaohu, can you operate this equipment?"

Guo Yonghe pointed to the two thermostats.

"Yes, yes, I've seen it in the school lab!"

Hu Dongqiang hurriedly replied.

"Okay, you first pour 2,500 milliliters of glycerol into the low-temperature thermostat, and use the rapid heating function to heat the glycerol to 180 degrees." Guo Yonghe commanded.

"Yes!"

Hu Dongqiang responded and operated according to Guo Yonghe's instructions.

"Expert Guo, may I ask what you are doing in this step?"

Li Weijin and Section Chief Tang glanced at each other, and in the end, Li Weijin couldn't hold back the curiosity in his heart and asked out loud.

Since Guo Yonghe asked Li Weijin and Section Chief Tang to stay and watch, he naturally did not intend to keep his operation secret.

"Director Li, didn't Director Zhang mention that the disassembly of the PLCC is more tricky, and asked me how to remove the PLCC on the magnetic circuit that is open to the circuit?"

He explained with a smile: "At present, the role of this low-temperature thermostat and high-temperature thermostat is exactly the same as the special brazing thermostat device for disassembling PLCC developed by the German company Wilo.

"Because the soft brazing joints of PLCC's components are thoroughly cleanable. The glycerol solution has a high boiling point, good thermal stability, and good soft brazing, so it can make full use of its properties to replace the PLCC special brazing hot plate device developed by the German Wilo company through different combinations of operation in the low-temperature thermostat and the high-temperature thermostat.

"The function of this low-temperature thermostat is called low-temperature heating, after heating the glycerol solution to 180 degrees Celsius, the PLCC that needs to be disassembled on the printed circuit plug-in board can be infiltrated into it for preheating.

"Let the temperature of this PLCC reach 180 degrees......"

As soon as I said this, I saw that Hu Dongqiang's side had completed the operation, and the temperature on the LCD temperature display on the low-temperature thermostat was rising steadily.

"Xiaohu, pour the remaining 2,500 milliliters of glycerol into the high-temperature thermostat, and then use the rapid heating function to heat the temperature of the high-temperature thermostat to 210 degrees Celsius!"

Guo Yonghe commanded.

"Yes!"

Hu Dongqiang answered, and went to open the high-temperature thermostat again.

"Director Li,"

Guo Yonghe turned around and continued to explain to Li Weijin:

"The heating on the side of the high-temperature thermostat is called melt heating. Because when the temperature of the glycerol solvent reaches 210 degrees Celsius, the PLCC manifold is infiltrated into the brazing joint, and the brazing agent on the soft brazing joint will be dissolved in the glycerol solvent, and then the PLCC manifold can be safely removed from the printed circuit board.

"Because the glycerol solvent itself has good thermal stability and good brazing properties, I can re-braze the PLCC manifold intact after I weld the open circuit above the magnetic circuit under the PLCC manifold block......

"I see!"

Li Weijin and Section Chief Tang suddenly realized, no wonder Guo Yonghe was so confident, it turned out that it was because he had mastered the secret of glycerol solvent!

"Expert Guo, thank you for sharing selflessly!"

Section Chief Tang bowed to Guo Yonghe sincerely, "If you hadn't told this mystery, I'm afraid I would never have thought that a combination of glycerol solvent plus low-temperature thermostat and high-temperature thermostat could solve the problem of safe disassembly of PLCC manifolds!" ”