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The people near Fuzhou should be relatively wealthy in the whole province, especially since Geng Jingzhong focused on the development of Houyu Port. A large number of people here have jobs, and their lives at home are much better. This is a small plain, and farming is the most basic, and even if you can work in a workshop, no one will abandon their own land. Forsaking is a great sin in the eyes of the people. After continuing to wander around a few villages, Geng Jingzhong took his guards back home.

Geng Jingzhong walked around with the guards all day, and he recorded all the problems he found that needed to be improved in the booklet he carried with him. At the same time, combined with the memories of later generations, I also thought of a lot of good ideas. For example, encourage the people to develop breeding, pig and cattle raising. Breeding animals, such as raising pigs, must have a pigsty, this thing has been seen since childhood, these special buildings in later generations are very reasonable, and now they can also be used immediately.

For the problem of village sanitation, Geng Jingzhong thought of an excellent method, and it is completely achievable with the current technical conditions. In later generations, there is a thing that can often be seen in the countryside, which is not only environmentally friendly and hygienic, but also provides energy for the people, and that is the biogas digester. In the technical conditions of later generations, there are many types of biogas digesters, and the effects are also different. What Geng Jingzhong can remember is only one of them, and it is also the one built by his father in his own family in later generations - a fixed arched biogas digester.

Early the next morning, Geng Jingzhong called a group of masons and dug a big pit on the side of the public toilet in the barracks. Construction of the biogas digester begins. He saw the whole process of building the digester with his own eyes. At that time, he himself was already in the first year of junior high school. Although many years have passed, I remember every step clearly.

There are three types of digesters: cylindrical, spherical and ellipsoidal. Geng Jingzhong has only seen a cylindrical type, so he began to build according to this one. After the construction of this type of pool, the upper gas chamber of the tank body is completely closed, and with the continuous generation of biogas, the biogas pressure will be increased accordingly. This increasing air pressure forces a part of the liquid in the digester to enter the water pressure room that communicates with the tank body, causing the liquid level in the water pressure room to rise.

So. There is a water level difference between the liquid level between the water pressure room and the liquid level in the biogas digester, which is called "water pressure" (those who have used or seen the biogas digester will know that it is the value displayed by the U-shaped tube biogas pressure gauge). When using gas, turn on the biogas switch, and the biogas is discharged under water pressure; When the biogas decreases, the liquid between the water pressure returns to the tank, so that the water level difference decreases continuously, and the pressure of the biogas is also reduced accordingly. This type of tank that uses part of the material liquid to move back and forth to cause repeated changes in water pressure to store and discharge biogas, so this kind of biogas digester also has a name for hydraulic biogas digester.

The smell of the public toilet is still a little flushed. Even Geng Jingzhong has already made the military camp clean up very well. After the pit was dug, the masons first laid gravel on the bottom of the pit. Fill the cracks of gravel with a one-to-four cement mortar, and then pour the bottom of the pool with cement, sand, and gravel in a one-to-three concrete ratio, with a thickness of about one centimeter, all of which were said by the town's instructors in person.

Although the pit wall is also made of masonry, the inside of the digester must still be sealed. The biogas digester constructed of a combination of brick and concrete cannot meet the requirements of leakage prevention only by relying on the structural layer, and the tank body must be sealed to prevent air and water leakage. The sealing layer of the biogas digester adopts two kinds of seven-layer method and three-layer method, and the gas storage chamber and the feed pipe part in the tank adopt the seven-layer method; The bottom of the pool, the wall of the pool, the pressure room, and the passage of the discharge port adopt a three-layer approach. Finally, a sealed lid was added to the pit, and a feeding port was left.

The skills of these masons are really good, the sketches drawn by Geng Jingzhong can be understood at a glance, according to the construction requirements, there is no trace of misery, and under the pleasure, Geng Jingzhong rewarded them heavily. The whole construction process only took one day, which is also thanks to the cement, otherwise it would not be possible to use lime. Although this thing is ready for the time being, it can't be used yet, and the cement inside hasn't dried yet!

The digester is not very large, and the total volume is only about 12 cubic meters. But this is only Geng Jingzhong's real yàn version, and if there is no problem, it can be promoted to various villages. However, even if it is applied to the countryside, it is still different from this practical version, after all, there are no pigs in the barracks, and the problem of pig houses must be considered in the villages.

The excrement from the pit was discharged directly into the pit through the guò ditch, and some rotten vegetable leaves, rotten fruits, and straw used to make a fire were also poured into the feed port. The soldiers passing by the public toilet didn't know what Geng Jingzhong was doing, why did he make the dung pit so troublesome, in their opinion, it was okay to put a lid on the manure pit, why bother to toss it so much, it would take bricks and stones to come down like this, and it would take labor, it was really thankless. In addition, the smell of the manure pit here is so bad, it is really incomprehensible that the dignified son should come here to stay all day.

But Geng Jingzhong didn't explain much to them before it was done, and still asked the masons to continue the construction, and after the construction was over, he checked again and made sure that there was no problem, and then he began to have people connect a copper pipe to a small hole in the lid of the pit. Here, Geng Jingzhong can use copper pipes extravagantly, which is also for the sake of safety. Although the people are now richer, they are still able to afford to use copper pipes. Moreover, with copper pipes, I am also worried that some thieves will steal the copper and melt it down for money.

If the people use it in the future, the bamboo pipe can be smoked and then carbonized on the surface, so that the anti-corrosion function can be achieved. Of course, at the joints of the bamboo pipe, some soil methods should be used to seal the connection. After the pipe was connected, Geng Jingzhong asked the blacksmith in the army to make an iron mouth, which was like a faucet in later generations, and was connected to the mouth of the pipe. However, the mouth of this faucet is facing upwards, unlike the faucet of flowing water, which is facing downwards.

The temperature here in Fujian is relatively high, after two days of dryness. This pool is ready to start the next new pool start-up action. The new pond is preferably started with pure cow and horse manure. Generally, it is cow and horse manure that is loaded into a quarter of the volume of the digester. However, before entering the pool, it is necessary to pile up outside the pool for five or six days, which is intended to enrich the strains and speed up the start-up. This step can be directly skipped here by Geng Jingzhong, and most of the horses transported back from the Wa Kingdom were sold, and many remained in the army for retention. Therefore, there are piles of horse manure and there is no need to prepare it at all.

Geng Jingzhong still remembers. When a new pool is started, warm water is required to start it. The water temperature is thirty or fifty degrees, and cold water should not be used to start, which will prolong the starting time. After the horse manure is in, seal the movable covers as required, and pay special attention to sealing the skylight to prevent air leakage. After doing this, Geng Jingzhong went back to the camp and continued to work on other things. Because the gas produced in the initial stage of start-up is exhaust gas, it cannot be burned at all, and must be discharged for one hour a day. Seven days or so in a row.

Seven days passed in the blink of an eye, and the exhaust gas was released for seven days in a row. Later, he didn't continue to open his mouth to deflate. After another two days, it felt that the time was almost up, so Geng Jingzhong led a large group of people to the biogas digester again, ready to let them look strange! In the past few days, Li Guangdi and others have also asked Geng Jingzhong several times, wondering what Geng Jingzhong is doing, mysterious and secretive. Geng Jingzhong never said anything, but told them that he would show them a strange thing.

When I came to the biogas digester again, I twisted the faucet, and then put the lit long wooden strip close to the faucet, and the iron mouth immediately "Whew!" A burst of fire erupted, and it continued to burn. The people who followed Geng Jingzhong to see the strange were immediately shocked, they didn't know what Geng Jingzhong had come up with, and they actually ignited this thing out of thin air without using wax or lamp oil.

"Dare to ask the son, what is this, you can make flames without firewood?" Although Lee Kwang Tei has seen a lot, he has never heard of putting some horse manure in a pond to light a fire!

Geng Jingzhong didn't explain to the people around him until this time: "This is the result of my hard work in the past ten days!" This thing is called a biogas digester, and the manure is introduced into the tank, and later some rotten vegetables, weeds and other things can be added to rot in the pool. The pond is hermetically sealed, and during the decomposition process it produces a gas called biogas, which can ignite. Later, the biogas produced in these digesters will be diverted to the sides of the road and lit at night to light up the road. In this way, there will be no need to light a brazier in the barracks! ”

"Not only our barracks, but also on both sides of the street, we can also lead it over, transform this thing and make it into a street lamp, so that everyone doesn't have to wear lanterns anymore when they go out! Also, this thing burns up, there is no smoke and dust at all, it is very clean, even the house in our army, you can use biogas to cook in the future! In this way, our room can be more hygienic! The most important thing is that after the use of the biogas digester, mosquitoes and flies will not be able to breed maggots in the manure tank in the future, and the mosquitoes and flies here will naturally be greatly reduced after the hot weather. Presumably, the brothers in the army have also suffered enough from mosquitoes! ”

When everyone heard this, they didn't believe that there were so many benefits, but when they looked at the covered biogas digester in front of them and the fire that was still burning, they had to believe it. "Is there really a god you say?" Wang Zhenbang was also a little dizzy, this thing is really unbelievable, it is on fire out of thin air, and I don't see what the biogas is at all!

Geng Jingzhong saw that many people were still in a daze, smiled and said, "It's not just that! The manure and rotten things in this pond are good waste materials, which are clean and fertile compared to manure, and they are regularly lifted out and put up in the fields to strengthen the fields and collect more grain! You say, "Wouldn't it be more advantageous to spread this thing to the people's homes?" ”

Li Guangdi reacted quickly enough, and quickly thought through the cause and effect. "Okay, this thing is really good! Not only can it make the army cleaner, but it also saves fuel, and the firewood and coal used in our army every day is not a small amount! I think the most important thing Shizi said is that it can reduce the breeding of mosquitoes, and I hate dead mosquitoes! ”

"Hahahaha!" Everyone laughed at the same time.

"In the future, we will build this thing in every barracks, this is only the first one, and there are still some imperfections. As for the promotion of this thing to various villages, let's not be in a hurry for the time being, let's use it for a while, while using it, while pondering, as much as possible to improve it, so that its gas output can be increased. The biogas produced by this digester is combustible, ignites when it meets fire, and if you are not careful, it will explode! Therefore, it is necessary to always be aware of the safety of use, and do not hold an open flame near the digester! After a month or two, it can be extended to various villages, and even if it is used for lighting at night, it can save a lot of lamp oil! ”

The soldiers nearby also nodded secretly when they heard this, most of them were from poor backgrounds, and the poor people's homes did not light up at night at all, and went to bed early. Just kidding, the poor don't have enough to eat, where can they get the money to buy lamp oil to light the lamp? (To be continued......)

PS: Come on, cheer yourself up! Come on, cheer up the brothers!