After discovering the suspected "gongjing" in Zigong, Li Su and his party were stationed in the local area and started engineering rectification on the spot.

Li Su despised the name of the township that was originally not shitty, so he changed it casually and asked to change the township to "Gongjing Township", indicating that the officials here will be directly under the jurisdiction of the Yanjing officials from the Yizhou Muslim in the future.

Of course, Chen Shi had no objection, so he asked the county and county books to adjust accordingly. Xu An, the hometown elder, became the "Gongjing Township elder", and immediately changed the sign of Fu Chuan (the township chief of 100 stones had no official seal, only Fu Chuan).

The salt workers and craftsmen in the entire town were mobilized and mobilized, and the craftsmen from Jiangyang County also invested in rectification and tried to develop the construction technology of "sealed gas pipelines" in full swing.

Li Su didn't understand technology. He only knew in his mind that special sealants would have to be used in future generations to achieve airtightness. Therefore, when looking for local methods, he thought that the craftsmen should first make trouble. Even if the craftsmen fail, they could still teach Li Su some lessons and let him adjust the direction of his efforts. He just wanted to ensure that the acceptance standard was checked and not let the tofu project get away with it.

Four or five days have passed, and several initial attempts have failed one after another.

The first way the craftsmen thought was to directly tie the bamboo joints of the bamboo with animal leather - this was what the county blacksmith thought of. Because the Han Dynasty blacksmiths had learned to sew materials such as leather, pig bladder, beef tripe, and then tied to the air-supply bamboo tube to blow the iron furnace. They naturally felt that since they could blow the air, they could seal the gas.

Unfortunately, the results of the experiment were not ideal. During Li Su's acceptance, he strictly asked people to repeatedly ignite the outside of the seam of the bamboo tube, and occasionally it could still be ignited, indicating that a gas leaked out. The leather bag itself has a certain airtightness, but the seams of the leather and bamboo are not tied tightly enough, and the fitting cannot reach the tightness level of the airtight project, which is too dangerous to use for a long time.

At first, Chen Shi pleaded with the craftsmen, thinking that as long as 70% or 80% of the energy can be transmitted to the stove, it doesn’t matter if it leaks slightly by 20% or 30%.

But Li Su knew how much the risk of "gas leakage" was. If a big accident happened, the death was not the most serious. The key was that it would cause locals to fear the development and research on the use of natural gas? Maybe there would be technical regressions in the future.

"No! Absolutely no! What we want is not to consume part of the gas until the salt stove is boiled? What we want is to ensure that almost all the gas is controllable!" Li Su refused firmly.

After the blacksmiths' blower skin replacement method failed, the second one was the county masons who came up with the idea of ​​"directly building mud seals to paste the broken bamboo joints with mud"? It's not surprising that they would think so? Because it is also sealed when building stoves and forgings, the kilns are also built.

But Li Su is still very cautious? Let them do a pilot first, continue to test, and ensure safe results before they can be implemented.

Moreover, Li Su instinctively rejects this approach? Because he thinks that the pipe is directly buried in the clay clay? If it is difficult to repair and replace it in the future, it will be smashed. Moreover, the clay will easily crack after being used for a long time, and the durability of the bamboo is not good. The lifespan of the two materials is different? The difficulty of replacement logistics is definitely a nightmare.

Moreover? There was basically no porcelain in the Han Dynasty, only pottery, celadon and white porcelain were explored by the Jin Dynasty, Southern and Northern Dynasties, and the Sui and Tang Dynasties matured. This shows that the demand for kilns in the Han Dynasty was very low, and the airtight quality was difficult to satisfy Li Su.

After four or five days of operation, this method failed in the air leakage experiment, and the bamboo joint interface could actually catch fire. In fact, if you think about it, you will know that mud is so tight? Even waterproofing is not possible. In the future, the house must be decorated with a special anti-seepage layer. This means that natural mud or concrete is loose and leaky.

After failing three or four methods, Li Su also roughly summarized the airtight characteristics of various materials in this era? Comparing various materials with the characteristics of airtight materials he had seen in later generations, he finally had some clues.

...

Another five days later, after many failures, after Li Su personally adjusted his thinking, the solution that seemed to have the most chance of success finally reached the sprint stage.

A group of supervisors were like facing a great enemy and were guiding on the spot. Even the prefect Chen Shi occasionally visited the factory.

"Do it quickly. This time, you must strictly follow the governor's requirements and do not cut corners! This linen is not dense enough. If you say that, you should find the linen with the densest weft as the base cloth."

"While it's hot, brush the pigskin glue on it. You won't put your hands in and try to see if it's hot enough! It's not conducive to the tight linen, and it's too cold or not."

"Wrap the bamboo tube tightly, and then apply glue to the inside several layers, and then wrap it tightly. The outer layer of raw paint is stupid! It is cooler to apply raw paint than to apply pig skin glue, so it doesn't have to be so hot!"

The craftsmen were busy carefully and compactly. After several hours of rectification, they finally tinted out a test gas pipe that was more than twenty meters long.

This time, the sealing base material they chose was a linen that was not favored at the beginning - the linen itself was actually not airtight and too loose, and it was not even a preferred item in the category of fabrics.

However, because silk is more likely to age and has a short lifespan, the most important thing is that the silk is too smooth and lacks friction to hold the bamboo tube tightly, so silk cannot be used.

Cotton is denser than linen and has better friction. However, the Han Dynasty white-folded flower (cotton) was just an ornamental plant, and cotton was not popular until the Southern Song Dynasty. In addition, the Indian long-tailed cotton has not been introduced in the country of toxicity. The domestic white-folded flower varieties are not suitable for spinning and weaving, and can only be used as a warm filling, so the cotton cloth option is not available before opening the Nanzhong Road.

If the base material is not good, use auxiliary materials to make up. The coating is sticky and dense enough. You can still use a linen base to make airtight tape.

Li Su uses two auxiliary materials: natural gelatin boiled with pig skin acts as an adhesive effect, and the raw paint brush produced by the sapphire tree ensures airtightness on the outermost layer, and double insurance should be enough.

The idea of ​​this idea is actually a reversal from modern materials - later generations include rubber, chemically synthesized airtight paint, and chemically synthesized super glue. If Li Su can't do these, he will try to choose pure natural substitutes that are close to their characteristics. This is a deduction that liberal arts students are likely to think of naturally.

"Ignite!" As Li Su made the order, the final plan also began the experiment in the production stage. The gas deliberately went far away and flew twenty feet away, and at the end it was forked into several bamboo tubes and divided into several stoves to cook the brine in the large iron pot, in order to test the worst and most extreme situations.

After boiling over a heavy heat for one and a half hours, hundreds of kilograms of brine in each pot were boiled dry, leaving dozens of kilograms of salt. After a rough calculation, you will know that the salt content of this brine is nearly 10%, which is three times more intense than that of sea water. It is worthy of being a concentrated deep well old brine.

The natural dissolution rate of salt is only a few 30%, so this is already very good. If you can dig out black, shiny and bitter braised with a depth of more than 500 meters, the highest mineral content can be close to 30%, almost reaching the natural limit, and it is so salty that it is so bitter that it is terrible.

But these are all the key, and everyone is more concerned about whether there is any leak.

Several salt workers took the torches and smoked them with open flames at each bamboo tube interface a few inches away. After removing the torches, there was no open flame residue.

"No air leak! Finally no air leak! Is this successful?" All the accompanying officials felt relieved.

"It's still the governor who knows the pig skin glue and raw lacquer. The governor is really a genre and genre technician who knows everything."

"Don't hurry, keep cooking for three or five days. Every half day, use a torch to test whether there is any air leakage at the interface. It will be counted if there is no leakage." Li Su was very steady and did not directly announce his success.

"You guys are careful and report any situation!" The county officials immediately ordered the merchants and salt workers in the salt farm to serve them and not make any mistakes.

After several days of trial cooking, the stability was finally confirmed. Li Su ordered a celebration banquet, then expanded production, and all the wells that had a tendency to dig out natural gas were transformed nearby, and gas pipelines were transformed.

In this way, these wells that salt workers dare not dig deep can be further digged, so that the output of gas and brine output can be increased, and the quality of the marinade can be better.

However, from pilot to mass production, there are definitely many minor problems during the running-in period, not only technology, but also management and cost control.

For example, some management officials calculated the cost and thought that the raw paint brushes of Nanzhong specialties were so thick and too expensive, so they wondered if they could reduce the number of paint layers.

The raw paint produced by natural sapphire is a resin that flows out like cutting rubber. Tropical high mountains are most suitable for cutting paint. The raw paint output in Shu is already good compared to other states, but it is still not as toxic as Nanzhonghe. Usually, it only takes a slight amount of wood paint to make paint, and Lisu used it to make airtight coatings repeatedly, which is relatively expensive.

Li Su of course strictly opposed the attempt to cut corners in this regard, and the officials' suggestions were suppressed.

But the matter was not finished. A few days after the start of construction, as the material loss was too large and the progress was slow, the salt officer found that a craftsman had secretly drunk the gelatin used for construction, and even whipped and punished the craftsman for this, so he asked the cost to be refunded.

Li Su was so amused and laughed when she heard about this, but after thinking about it, she felt that it was normal. In ancient times, people drank paste made of pure grain, not to mention gelatin cooked with pure pig skin. This is a typical "edible gelatin". In later generations, you can directly produce QQ sugar and kitchen gelatin slices.

The craftsman begged for mercy when he confessed his guilt, saying that he had never eaten such clean and odorless pig skin in his life. It was so delicious that he couldn't help it.

After hearing this, Li Su personally ordered that the stealing should be severely punished, but the treatment of craftsmen should also be improved to solve the slack work in this area from the source.

So Li Su transferred a batch of pepper powder to come over, and Gongjing Township originally produced salt, so he asked the chefs who followed the army to put heavy peppercorns to remove the fishy smell of the pork, marinate and roast it. In this way, most of the odor of the pigs fed from the toilet in the Han Dynasty was covered and removed.

Because Gongjing Township is going to renovate a fire well on a large scale, it requires a lot of pig skin to make glue, so the prefect Chen Shi transferred a large number of pigs from various counties to slaughter and get the skin. The pork was originally surplus, so Li Su set the rules: Any craftsman who needs to transform salt wells can eat two kilograms of salt-free pork every day. If you have meat, you will fundamentally prevent the pork skin glue from stealing.
Chapter completed!