Courtyard House: Starting with handing over the keys, the state helps me abuse birds.

The senior engineers exchanged glances, their eyes filled with shock.

They certainly understand these concepts: stirring Reynolds number, fluid dynamics similarity, dead zone, temperature gradient—these are all fundamental concepts in chemical engineering principles.

However, the five days and nights of continuous hard work caused them to fall into a fixed mindset, focusing only on adjusting process parameters while ignoring the most basic principles of engineering scale-up.

"Then... what do we do now?" Engineer Chen's voice trembled slightly. "The reactor has already been installed, and redesigning and manufacturing it will take at least three months..."

"No need to redo it." Xie Weihong walked to the drawing board, picked up a T-square and a pencil, and said, "Machin a detachable flow guide tube to be hoisted in through the manhole. The flow guide tube has an inner diameter of 800 mm, a height level with the liquid surface, and is made of 316 stainless steel with a wall thickness of 8 mm."

As he spoke, he quickly sketched a diagram, with precise lines and clear dimension markings.

"We'll modify the mixer. We'll remove the two symmetrical blades from the existing six-bladed slanted impeller and replace them with four blades, adjusting the blade angle to a 45-degree sweepback. Although it's not as good as a dedicated three-bladed sweepback type, the mixing efficiency can be improved by more than 70%."

The sketch was completed in five minutes, with all key dimensions, material requirements, and installation methods clearly marked.

"Also," Xie Weihong put down his pencil, "add three sets of gas distribution rings inside the reactor, located here, here, and here." He marked the three points on the diagram, "to ensure that the ammonia-nitrogen mixture is evenly distributed and to avoid local concentrations that are too high or too low."

An older engineer, who had been silent all along, suddenly spoke up: "How are the pore size and porosity of the gas distribution ring determined?"

"3 mm aperture, 15% opening rate, triangular arrangement." Xie Weihong said without hesitation, "The distribution rings must be made of 310S stainless steel, resistant to high-temperature hydrogen corrosion."

Engineer Chen took the sketch, his hands trembling slightly. He stared at the drawing for a full minute, then suddenly looked up, his eyes gleaming: "Feasible! This plan is completely feasible!"

"But the construction time..." the equipment team leader hesitated, "even if we work through the night, it will still take at least a week..."

"Three days," Xie Weihong said. "The guide tube can be manufactured in four sections and assembled on-site. The gas distribution ring is made by bending and welding existing stainless steel pipes. Modifying the agitator is even simpler; it can be disassembled and sent to the machining workshop, where it can be completed in eight hours."

He spoke with absolute certainty, specifying every time point down to the hour, as if he had already rehearsed the entire renovation process countless times in his mind.

The atmosphere in the control room changed.

The initial doubts and scrutiny vanished, replaced by excitement and enthusiasm. Several engineers gathered around the drawing board, engaging in a lively discussion about the sketches.

"The segmented design of the deflector is ingenious! It's easy to install and maintain in the future!"

"The gas distribution ring is well-chosen; it's positioned right above the catalyst bed, ensuring that the gas enters the reaction zone evenly!"

"The mixer modification solution is simple and practical, requiring no remanufacturing, saving time and effort!"

Qi Mingyuan stood on the outskirts of the crowd, his face flushing red and then pale. He had just been questioning the young man's abilities, but the man had pinpointed the crux of the problem they had been searching for for five days and five nights in just ten minutes, and even provided a complete and feasible solution. The difference... made him feel utterly ashamed.

He took a deep breath, walked up to Xie Weihong, and bowed deeply.

"Consultant Xie, I'm sorry. My attitude was poor just now, please forgive me."

Xie Weihong glanced at him: "It's right for those in technical fields to have questions. But before you have questions, you need to make sure you've done the groundwork properly."

These words were quite harsh, and Qi Mingyuan's face turned even redder, but he nodded vigorously: "You're right. I'll remember that."

"Alright, alright," Duan Chengyi said at the right moment. "Now that we've found the direction, let's get moving. Engineer Chen, please make the arrangements. What resources are needed? I'll coordinate them immediately."

Engineer Chen straightened his back, his tired face regaining its vitality: "I'll personally lead the team! The design team will produce the construction drawings within two hours, the equipment team will prepare the materials and machining, and the process team will refine the operating plan—all preparations must be completed before midnight tonight, and the renovation will begin first thing tomorrow morning!"

A chorus of responses rang out in the control room. The previously exhausted engineers, as if given a shot of adrenaline, sprang into action.

Some people started making phone calls to coordinate materials, some rushed out to notify the workshop, and some were already hunched over their desks drawing detailed diagrams.

Xie Weihong walked to the control panel, looked at the real-time data, and added: "After the modification is completed, the test run plan needs to be adjusted. Don't run it at full load directly. Start with 30% load, and after it stabilizes, increase it by 10% every four hours, gradually increasing it to full load."

He wrote down the test curve and control points on a piece of paper: "During the process, closely monitor the temperature distribution, add six temperature measuring points in the catalyst bed, I have marked the locations here. Control the pressure fluctuation within ±0.1 MPa, and increase the space velocity according to this curve."

He handed the paper filled with key points to Engineer Chen: "If we operate according to this plan, the conversion rate should be able to return to over 65%. If the control is precise, it's even possible to reach a pilot level of 68%."

"65%?!" Engineer Chen's voice trembled with excitement. "Consultant Xie, if we can really reach 65%, this process will be a complete success! Industrial production will be entirely feasible! Do you know what that means?"

He turned to face everyone in the control room, his voice soft but carrying immense weight: "With this technology, our country's fertilizer production can double! Grain production can increase by at least 20%! It can feed tens of millions more people a year!"

The room fell silent.

The rain was still falling outside the window, the raindrops pattering against the glass. But everyone in the control room had a glint in their eyes.

That was the light of hope, the meaning of dozens of days and nights of hard work, and the sense of responsibility born from the memories of countless people going hungry.

He couldn't continue.

Engineer Chen patted him on the shoulder, his voice firm: "Old Liu, we have it now. Let's work harder and get this process working as soon as possible, so that no one will ever go hungry again."

He turned to Xie Weihong and solemnly extended both hands: "Advisor Xie, on behalf of the project team and all the people waiting for their livelihood, thank you!"

Xie Weihong grasped the hands covered in calluses and burn scars and nodded.

For the next two hours, Xie Weihong stayed in the control room, answering all sorts of questions raised by the engineers in detail. From the welding process requirements of the guide tube to the pressure drop calculation of the gas distribution ring, and the handling of abnormal situations during the test run, he answered everything he knew without reservation.

Qi Mingyuan followed along closely, notebook in hand, afraid of missing a single word. He later confided to a colleague, "What Consultant Xie said was more practical than what I learned in four years of university. Every point hit the nail on the head; you could tell he'd actually worked in engineering."

At 5 p.m., all construction drawings were completed and the material list was finalized, and the workshop began processing the first batch of parts.

Duan Chengyi checked the time and said to Xie Weihong, "Weihong, you've worked hard today. I'll take you home. Get some rest for the next three days. We'll need you to be here to oversee the test drive."

Xie Weihong nodded, taking one last look at the control room. Engineer Chen was already asleep on the table, a pencil still in his hand; several young engineers were quietly discussing welding details; the clock on the wall ticked, recording every minute this group of people fought for the country's food security.

By the time I left the base, the rain had subsided. The factory area was brightly lit in the twilight, and the roar of machine tools could be heard from the workshops—the first batch of components for the guide tube were being processed.

On the way, Duan Chengyi remarked with emotion, "Engineer Chen and his team have really had a tough time. In the past six months, not a single member of the project team has had a weekend off, and working fourteen or fifteen hours a day has been the norm. When Engineer Chen's wife was hospitalized for surgery, he didn't even go back; he only said 'I'm sorry' on the phone."

He paused for a moment: "But they never complained. Engineer Chen often said, 'We fertilizer workers hold the rice bowls of ordinary people in our hands. If we can't hold onto our rice bowls, then everything we say is meaningless.'"