Siheyuan: I eat melons while doing scientific research

Chapter 1247 is too thorough! (5k views yesterday)

Although the comrades from Beijing Steel Plant present here have no chance of coming up with this furnace brick design in the short term, they still have the ability to evaluate and assess the results.

This thing looks reliable!

It seems that we can catch up with the international mainstream of 500-800 furnace lifespan.

The comrades remained silent, focusing solely on memorizing.

It sounds simple, but it actually takes a long time. After all, the material ratios and firing processes are all crucial. This is an engineering implementation, and the requirements for specific data and processes are much higher than those for theoretical analysis.

Just like the total FeO content in slag, Gao Zhendong can vaguely say it's below 15%.

However, the maximum allowable impurity content in a brick, the firing temperature, and the firing time must be precisely determined; otherwise, a small difference could lead to a huge disparity.

After finishing his explanation, Gao Zhendong glanced at his watch and said, "Oh, it's noon. Well then, let's go eat, and continue this afternoon." It had taken quite a while; even after all that time, he still hadn't finished speaking, or rather, he had only said about half of it.

However, this amount of time is still worthwhile compared to the 14 years that these technological measures actually took.

In fact, due to various reasons and the problems of domestic converters themselves, the proportion of our converter steelmaking in the total steel production was not high in the early stages.

Being able to advance this process is of great significance to both Gao Zhendong personally and to society.

After hearing his words, the comrades from Beijing Steel Plant were still eager for more, including Zheng Liangshu from the Third Branch Plant and relevant comrades from the Technical Department. They were even more enthusiastic than those from Beijing Steel Plant.

Compared to his direct involvement in materials, Chief Engineer Gao's expertise in steel smelting technology is rarely seen, only occasionally revealing its brilliance.

But when this "occasional" moment does appear, it is always so stunning.

But you still have to eat. People need to eat, and you'll get hungry if you skip a meal.

"How about... Chief Engineer Gao, Factory Director Zheng, we ask the canteen staff to bring the food over? We'd like to take this opportunity to digest what you just shared; walking around like this is such a waste of time."

Gao Zhendong and Zheng Liangshu exchanged a glance and nodded: "That's fine, but the taste might be a little off when it's delivered."

One of the comrades got up and went out to make a phone call to the canteen.

The comrades at Jinggang Steel Plant, including those from the Technical Department of the Third Plant, did indeed save the time they would have spent on their way to meals. Including the time spent waiting for their meals to be delivered, they spent the rest of the time, except for about ten minutes shoveling their food down their throats, reviewing their notes. They would occasionally exchange and proofread their notes, since no one could guarantee that they had made any mistakes or recorded everything correctly when taking notes.

Occasionally, when someone felt they hadn't remembered something clearly, they would ask Gao Zhendong a question or two. Fortunately, Gao Zhendong would write the numbers on the blackboard as he spoke, otherwise it would have taken the comrades even longer.

Seeing that it was almost time, and that the comrades really had no intention of taking a break, Gao Zhendong and the other canteen staff cleared away the tableware and greeted Director Fan, saying, "Let's continue."

"Okay, okay! Keep going." Actually, they had been itching to get started for a while, but since Gao Zhendong hadn't made a move, they were too embarrassed to urge him.

"Even with good refractory materials, I think our work is not over yet. As I just mentioned, this is the result of a combination of chemical and physical processes. Therefore, we still need to think of more ways to further extend the service life of the furnace based on good materials, and strive to catch up with the international advanced level, or even surpass them!"

Chief Engineer Gao is really ambitious; he wants to surpass others right from the start! But considering Chief Engineer Gao's past, this doesn't seem so outrageous.

He's an expert at surpassing the most advanced international standards!
"Alright, Chief Engineer Gao, you lead the way, we'll follow!" Director Fan's words were very skillful, perfectly reflecting both his attitude and his position.

"I think we should try to lower the tapping temperature and reduce thermal erosion as much as possible without affecting the quality of the steel. At the same time, we should try to keep the temperature stable and the changes orderly and controllable throughout the entire steelmaking process. I've seen that the temperature control of this furnace is problematic. This places too high a demand on the thermal shock resistance of the materials. Even if the materials have good thermal shock resistance, the consumption will increase after such an ordeal."

Thermal shock is actually an analogy, similar to mechanical vibration, referring to drastic temperature changes, with rapid and repeated alternations between hot and cold. It's like a person staying at the same height isn't so uncomfortable, but if they are rapidly jolted up and down, they can't withstand it.

Speaking of this, Director Fan knew where the problem came from: "This is mainly due to our insufficient automation control capabilities. With your support in this area, we are confident that we can control this problem."

At this point, he couldn't help but admire Gao Zhendong's decisiveness in solving the automatic control system problem right away. With this basic condition, many problems could be alleviated or controlled, not only the steelmaking process and the quality of steel output, but also peripheral problems like those mentioned earlier, which could be solved easily.

As a modern scientific researcher, Gao Zhendong leans more towards "industrialized production" than "manual" methods.

In reality, unless it's something extremely special that automatic control technology can't yet meet the requirements, or the production volume is too small and investing in an automatic control system would be too costly, or there are other reasons such as sentimental culture and the scarcity requirements needed for hype, such as scraping operations being the first type, hand-carving rocket propellant being the result of both, and the Japanese having a bunch of "XX Immortals" being the last type.

Apart from that, in the vast majority of cases, industrialized products can outperform handmade ones.

Therefore, Gao Zhendong's idea has always been to use automatic operation whenever possible, because automatic operation has advantages in ensuring consistency and high/low limits. As for manual operation, from a purely technical point of view, the lower limit is extremely low, and in most cases, the upper limit is not necessarily very high either.

“Yes, this is a very specific question, closely related to reality, so we won’t go into too much detail here. Just know that we are moving in this direction,” Gao Zhendong said. “Next, we need to think about something very important, which is the maintenance of the converter during its use.”

"maintain?"

"Yes, in fact we can perform some simple maintenance during the operation of the converter, which can greatly slow down the erosion of the furnace lining and extend the furnace life. These maintenance are relatively simple and have high economic and time efficiency benefits compared to a complete overhaul and replacement of the furnace lining."

Gao Zhendong's words make sense, but what makes sense may not be applicable in practice.

“Chief Engineer Gao, the theory is sound, but there are difficulties in practice. Although the erosion rate is fast for the furnace's age, the actual reduction in thickness is a relatively slow process. We can't just add more lining at any time, and this operation is also very time-consuming. All things considered, there aren't many benefits. Besides using asphalt to repair the furnace, we don't have many other maintenance methods, but asphalt repair has limited effectiveness against permanent erosion,” said a colleague from Beijing Steel Plant.

Asphalt furnace repair involves adding asphalt to the furnace and sintering it, primarily to replenish the carbon lost during oxidation and decarburization.

Gao Zhendong nodded: "You're right, that kind of maintenance method is indeed unsuitable, but we can use the residual waste from the steelmaking process to complete this maintenance."

"Is that even possible?" The comrades were dumbfounded. Chief Engineer Gao's thinking was too far-fetched!

"Chief Engineer Gao, can this really work?"

Gao Zhendong laughed: "How will we know if we don't try? For example, I think there's a method we can consider, which is slag splashing to protect the furnace."

This term is easy to understand: it refers to splashing steel slag onto the furnace wall during steelmaking to protect the furnace lining.

But it is precisely because it is easy to understand that the comrades reacted so strongly.

"This won't do, will it? Slag splashing during the steelmaking process is already a major cause of furnace lining erosion, and you're deliberately spraying it upwards?"

"The reason we reduced the FeO weight in the slag earlier was to reduce the slag's erosion of the furnace lining. Why is it reversed now?"

"..."

Director Fan glanced at his comrades and said, "You guys are young."

This isn't to say that the comrades' enthusiasm for discussing issues was wrong, or that they shouldn't have openly opposed Gao Zhendong's opinions. If that were the case, what's the point of holding a technical exchange seminar? He was thinking that the real reason the comrades were so young was because they didn't understand Chief Engineer Gao. If he dared to say that, he must have a backup plan.

As expected, Gao Zhendong did not stop his comrades' heated discussion. Instead, he smiled and waited for them to finish expressing their opinions before saying, "I don't want you to splash slag and protect the furnace during the steelmaking process, but after the steel is tapped!"

"After the steel is tapped, what comes next is just slag?"

The comrades who had been vehemently opposing the call suddenly fell silent. They realized they had made a huge mistake—empiricism.

Thinking only of solving the problem during the steelmaking process, he instinctively focused on the slag produced during the steelmaking process, thinking of protecting it while refining it. Little did he know that Chief Engineer Gao had no such intention at all.

Gao Zhendong nodded: "Yes, the final slag, using the MgO in the final slag, is blown up with nitrogen and adhered to the wall. It's like each steelmaking process is repairing the furnace lining surface to a certain extent, slowing down the total erosion of magnesium oxide in the furnace lining itself, which can also extend the furnace life. Moreover, this action is done conveniently after steelmaking is completed."

As soon as he finished speaking, his comrades felt as if they had discovered a new path, that it was actually possible.

Although this method may seem like simply blowing away slag after steelmaking is finished, they actually know that without a thorough understanding of the entire steelmaking process and a deep knowledge of the erosion and protection mechanisms of the furnace lining, they would never have come up with such a method.

"This method is brilliant! It makes full use of the residual components and heat of the slag after steelmaking to directly generate a new protective layer. It's ingenious!"

"But won't the nitrogen splashing affect the steel?" At this stage, oxygen is out of the question, and we'll never use oxygen again. Only nitrogen can ensure that no troublesome reactions occur.

"Are you crazy? This is slag from the tapping of steel! No matter how much you brag, it has nothing to do with the quality of the tapped steel."

"Oh right, right, I'm being silly again. But what if the magnesium oxide content isn't high enough?" When refining different types of steel, the MgO content in the slag isn't necessarily the same, so if the content is too low, it won't be of any use.

Gao Zhendong interjected, "Add a little lightly calcined magnesium balls to adjust the MgO content in the slag to 8%~12%, and then perform nitrogen blowing."

The comrade who asked the question was overjoyed, and everyone happily wrote "lightly sintered magnesium balls, 8%~12%" in their notebooks. Those who work on the process all know that this is very important.

"This operation can be used for various types of steel, so it's quite versatile." Versatility is also very important.

"But the spray is not easy to control in terms of direction and range..." The angle, direction and height of the spray gun can only be controlled within a limited range, so the effect may not be the best. Although it is a little regrettable, the comrade who said this did not think it was a big problem. It's better than nothing. What more can you ask for?

"Are you stupid? Besides the spray gun, which can be controlled to some extent, the converter can actively change its tilt angle and rotation. Why should only the gun move? Let the converter move on its own! We can even develop an automatic program that doesn't require manual intervention. It automatically detects slag composition, adds lightly calcined magnesia balls, and automatically controls the converter and nitrogen gun to achieve the most complete coverage possible, ensuring high-quality furnace protection. It's also fast and doesn't delay things."

At this point, the comrades couldn't help but recall the brilliance of Chief Engineer Gao's initial focus on solving automatic control systems. Automatic control systems cannot solve fundamental problems, but they can implement solutions to those problems as effectively as possible.

"Wonderful, absolutely wonderful~~~~~~" Director Fan's exclamation was ambiguous, whether he meant the slag splashing protection of the furnace was wonderful, or wonderful in general, but the latter was probably more likely.

However, things are not that simple.

"Of course, this kind of maintenance, which involves some recycling of waste materials, has some effect, but it is limited by the waste materials and is not very targeted or universal. Therefore, we also need to have proactive maintenance methods to take the initiative in maintenance into our own hands!"

Gao Zhendong's words left the comrades speechless. "And what else? And you insist on taking the initiative to maintain it, right? We've already talked about the difficulties of taking the initiative to maintain it."

"What are your thoughts?" Director Fan asked, his face beaming with delight.

"In addition to asphalt repair, we use magnesium oxide-containing materials as the main component, with the addition of binders and additives. We spray it onto severely corroded areas before the steel has completely cooled down after steelmaking. We can even perform preventative spraying when the corrosion is not severe."

"Can this really work?" Spray painting technology was only basically perfected in the late 70s. People today probably haven't even thought about it, let alone seen it.

“It’s feasible. I’ve put it forward. We can use calcined magnesia and dolomite sand as the main materials, silicates and silica ash as binders, quicklime as sintering additives, and add a certain amount of water. When the furnace temperature is still high, we can spray it onto the coating surface. This way, we can make full use of the residual heat to adhere the coating to the furnace wall.”

There are several types of spraying, including wet, semi-dry, dry, and flame spraying. Gao Zhendong chose wet spraying. Although this method may cause cracks due to drying too quickly and may only adhere for a few months, this is not a problem at all.

LOL, with the current furnace lifespan, it won't even last a few months, so there's no need to even consider it.

At this point, the wet spraying method's adhesion rate of over 90%, as well as its ease of operation, simple technology, and low cost, become its biggest advantages.

Moreover, the materials used in wet patching are the easiest to obtain, which is very important for our current situation. Some spray patching formulas require silicon carbide, which is a bit too demanding for us now, as the sourcing and processing are quite troublesome. Steel is a bulk commodity, and even if it is only used for repairs, the amount used is very large.

The technology you choose doesn't have to be the best; you have to choose the most suitable one.

Listening to Gao Zhendong's words, wow, this is indeed Chief Engineer Gao's habit. He even came up with the paint formula!

He not only provided the recipe, but also the proportions!
He not only provided the mixing ratio, but also a set of processes including spraying pressure, spraying angle, temperature, water-to-solid ratio, viscosity, and spraying distance.

What is this? We don't even need to do our own research. We can just bring the equipment, adjust the spraying material, and start spraying.

Moreover, every component in this spray patch is very easy to obtain.

The whole process was incredibly smooth and effortless.

But as everyone knows, it's not really that simple; it's just that others have already done the work for us.

There is no such thing as a peaceful and tranquil life; it is Chief Engineer Gao who is carrying a heavy burden.

He really made us cry our eyes out.

Of course, that's a joke. What really made the comrades cry was something else: they discovered that things weren't as smooth sailing as they thought.

“This spray coating is very viscous, and the spraying pressure requires 0.4~0.7 MPa. Moreover, it is a solid-liquid mixture, so the pump we have may not be able to handle it,” said a colleague in charge of the process.

Factory Director Fan didn't seem to care much: "If it doesn't work, then we'll figure something out." They've already gone to such lengths; we should just solve this problem ourselves, otherwise, where would we put our faces?

Gao Zhendong laughed and said, "You know what, you really don't need to worry too much about this."

Oh? There's another surprise?

"This pump can be either a plunger pump or a screw pump. I don't know much about plunger pumps, but I do know where screw pumps are being developed, and they've succeeded! They've even developed twin-screw pumps now. Let me ask them for the technology on your behalf."

The sprayed material has a special form, so ordinary pumps are really not suitable. This is where the value of a screw pump increases significantly. And this is something that Gao Zhendong guided others to develop when they were working on man-portable disposable rocket launchers.

Given Gao Zhendong's situation, acquiring the technology for this product would be no difficult task. His contributions and status are undeniable, and at that time, steel was the top priority of domestic industry, if not the only one.

Factory Director Fan was really about to cry; he was so incredibly embarrassed! His support was absolutely overwhelming!
(End of this chapter)