Let's talk about it again, why didn't I think of cooling the head with water, or the boss dared to think about it.

The formulas on the blackboard are one after another, and many technicians have been unable to keep up with his rhythm.

Determine the diameter of the head and nose (F)

F = (0.25 ~ 0.30)Dd (Dd < 80 mm)

F = (0.18~0.25)Dd (Big Head)

But not less than 16 mm.

- Determine the radius of the arc of the head (Rd) by the following formula: The length of the arc segment is calculated as follows:

The radius of the arc is:

The range of the arc radius value Rd is between 300 ~ 900 mm. Do not take the upper limit of the arc radius value of the 2-segment head.

Example: Given the given conditions, the basic parameters of the 2-stage header are calculated. Given the calculated roll pitch E = 177.2 mm.

Hu Wenkai answered questions while eating, and his hand had become greasy and slippery after turning the microphone countless times.

It took more than two o'clock to end the discussion of seamless steel pipes, and he picked up the microphone and said: "Yang Siliang and Zhou Haiquan are responsible for tackling key problems in the seamless steel pipe factory. The person concerned can leave and go back. ”

No one in the audience walked away, and Hu Wenkai said again.

"Boss, we want to continue to listen to the process of the fertilizer plant, it is good for us to touch the bypass, anyway, the equipment of the fertilizer plant will be manufactured from us."

"Okay, if you want to listen, you can stay, I'm afraid of delaying your time to go back."

"Boss, we are here today, and the ferry said that we would cross the river overnight."

Hu Wenkai did not delay in this matter, and after sorting out his thoughts, he knocked on the table and talked about the fertilizer factory.

"Fertilizer, an agricultural multiplier, is rarely used in China, and there is almost no fertilizer, who made the fertilizer? Does anyone of you know? ”

"The boss made it." This caused laughter in the audience.

Hu Wenkai shook his head, these turtles are because of the incomplete domestic literature.

"In the early 17th century, scientists began to study the relationship between plant growth and soil. At the beginning of the 19th century, the German J. Liebig studied the relationship between plant growth and certain chemical elements. In 1840, he explained that the nutrients needed for the growth of crops were obtained from the soil, and he determined the significance of the elements nitrogen, calcium, magnesium, phosphorus, and potassium for the growth of crops, and predicted that the nutrients needed for crops would be produced in factories. Soon his prophecy was confirmed. ”

"In 1840, Liebig treated bone meal with dilute sulfuric acid to obtain a slurry that was better than bone meal. Soon, the Englishman J.B. Rolls used sulfuric acid to decompose phosphate rock to make a solid product called superphosphate. In 1842 he built a factory in England, the first fertilizer plant. In 1872, wet phosphoric acid was first produced in Germany, which was used to decompose phosphate rock to produce heavy superphosphate, which was used as a purification agent in the sugar industry. ”

"In 1861, carnallite potash was first mined in Stasfurt, Germany. Shortly before that, Liebig had announced that it could be used as potash fertilizer, and that within two years potash mines had been mined in 14 places. At the end of the 19th century, ammonia from coal gas began to be recovered to make ammonium sulfate or ammonia water for nitrogen fertilizer. In 1903, Norway built a factory to fix nitrogen in the air by the arc method and process it into nitric acid, and then neutralized it with lime to make calcium nitrate nitrogen fertilizer, which was industrially produced two years later. In 1905, lime and coke were used as raw materials to make calcium carbide (calcium carbide) in an electric furnace, and then reacted with nitrogen to make nitrogen fertilizer - calcium cyanide (lime nitrogen)"

"Nitrogen fertilizerIn 1913, the Haber method of synthesizing ammonia from hydrogen and nitrogen was built for the first time in Germany. It paved the way for the development of the nitrogen fertilizer industry. Its production technology is not perfect enough, the price is relatively expensive, most of it is used in industry, and a small amount is used to make nitrogen fertilizer. Today we are reinventing this production process to make it much more synthesized. ”

The drawings of the reactor were hung on wooden boards, and the chemical process was started in a particularly expensive and unsafe industry.

"Two steps, one for gas production and one for compression and liquefaction separation. Feedstock gas preparation makes crude feedgas containing hydrogen and nitrogen from coal feedstock. For solid raw coal and coke, syngas is usually produced by gasification. ”

"The second-stage reformer is one of the most critical pieces of equipment in ammonia plants. The process gas medium after a period of conversion. It is still necessary to further convert the process raw gas in the second-stage reformer furnace to achieve the methane (CH4) content of less than 0.9% after hydrogen steam reforming, and the process medium after the conversion contains high heat energy, which can be recovered by the downstream waste heat boiler and generate high-temperature steam."

"Purification purifies the crude raw gas, removes impurities other than hydrogen and nitrogen, mainly includes the transformation process desulfurization and decarburization process and the gas refining process, carbon monoxide transformation process In the production of synthetic ammonia, the raw gas prepared by various methods contains CO, and its volume fraction is generally 120 The two components required for synthetic ammonia are H2 and N2, so CO in the syngas needs to be removed. The transformation reaction is as follows: CO+H2O→H2+CO2 ΔH=-41.2kJ/mol, because the CO transformation process is a strong exothermic process, it must be carried out in stages to facilitate the recovery of the reaction heat, and control the residual CO content at the outlet of the transformation section. The first step is the high-temperature shift, which converts most of the CO into CO2 and H2; The second step is the low-temperature shift, which reduces the CO content to 0.3 right. ”

"Therefore, the CO shift reaction is both a continuation of the raw gas production and a purification process that creates the conditions for the subsequent decarbonization process. In order to prevent the poisoning of the catalyst in the production process of synthetic ammonia, it must be removed before the ammonia synthesis process, the steam reforming method with natural gas as raw material, the first process is desulfurization, which is used to protect the conversion catalyst, and the partial oxidation method with heavy oil and coal as raw materials determines the position of desulfurization according to whether the carbon monoxide shift uses sulfur-resistant catalysts. There are many types of industrial desulfurization methods, usually using physical or chemical absorption methods, commonly used are low-temperature methanol washing method (Rectisol), polyethylene glycol dimethyl ether method (Selexol), etc. ”

Hu Wenkai gradually talked about the key point of today, stopped and asked: "Have you signed a confidentiality agreement with the company?" ”

"After signing, I will get an extra two yuan a month, boss, don't worry, I won't betray the company's interests if I sell my wife." Someone below said it loudly.

Zhou Haiquan, Hu Bin, and Tian Zhiliang walked to the rostrum to report that all the technicians who came today had been screened and signed a confidentiality agreement, and Hu Wenkai nodded and continued.

"At 400 °C, when the pressure exceeds 200MPa, without using a catalyst, ammonia can be synthesized smoothly, but in actual production, too much pressure requires a large amount of power, and the material requirements will also increase, which increases the production cost, therefore, affected by the power material equipment, the current synthetic ammonia plant is best to use 20MPa ~ 50MPa, using iron catalyst, iron catalyst at 500 °C is the most active, which is also the reason why synthetic ammonia is selected at 500 °C."

"Boss, please explain the iron catalyst in detail."

"The main body is ferric tetroxide. The main component was Fe3O4, and the contents of K2O, Al2O3, CaO, and MgO in the co-catalyst were less than 9% of the total mass of the catalyst, and the CoO was also increased by the low-pressure catalyst."

"Boss, we still don't understand, please explain in detail" The audience is arguing, but this is more difficult, he also watched it last night before he vaguely knew something, anyway, according to the book.

"The main body of the catalyst in the oxidized state is magnetite, and its stoichiometric formula is FeO.Fe2O3 or Fe3O4. The crystal structure is similar to that of spinel (MgAl2O4) (more than 90% of which are magnetite with an inhomogeneous complex system with an inverted spinel structure). It is the result of the accumulation of tetrahedral and octahedral structures. Two types of gaps are formed: tetrahedral gaps and octahedral gaps. Trivalent metal ions occupy half of the tetrahedral space and half of the octahedral space, and divalent iron ions occupy the octahedral space (Fe3+(Fe2+, Fe3+)). A single cell of magnetite (the smallest building block of a crystal) is composed of 32 oxygen ions and 24 iron ions, i.e. 8(Fe3O4). ”

"According to the crystallography principle, each cell of 32 oxygen atoms packed in a face-centered cube has 64 tetrahedral gaps and 32 octahedral gaps. As mentioned above, most of the rest are empty except for 24 occupied by iron ions, so cocatalysts can be added to occupy these voids to form interstitial solid solutions. Moreover, substances with similar chemical formulas, with the same structural type and similar particle (ion, atom or molecule) radius, can undergo homocrystaltic substitution to form a replacement solid solution, for example, trivalent aluminum can replace part of the ferric iron to form a replacement solid solution. ”

It's too difficult, it's hard to say it yourself, and if you ask it, you'll be beaten into the original shape, steel is familiar to you, and chemical industry is rarely involved in the unless * class.

"Who in the audience understands, come up and answer for me, it's really tiring after a day."

One person was pushed out of the crowd, a young man in his twenties who had never been seen before, tall and thin, with shaggy hair.

"Come on, Wu Wenhao, hurry up." The northwest corner of the audience shouted loudly.

Hu Wenkai walked off the stage, dragged the young man onto the stage, handed over the stage to him, and hid under to smoke.

Wu Wenhao picked up the microphone and wiped it on his clothes and said: The catalyst will induce a change in the chemical reaction, and make the chemical reaction faster or carry out the chemical reaction in a lower temperature environment. The iron catalyst mentioned by the boss just now is a kind of catalyst, and the normal catalyst uses a long-short mode to facilitate the increase or decrease of the contact area.

Hu Wenkai clapped his hands in the audience, this guy is an expert, and he will be exposed as soon as he speaks.

"According to what the boss just said, we can launch an iron catalyst that is a mixture of ferric tetroxide and alkaline materials."

Hu Wenkai's heart was shocked, this guy is a demon, I read from the book, and he can draw conclusions from it, or he has already researched it.

On and off the stage, he asked and answered, from air liquefaction to remove impurities to water and gas, and the notes were passed one by one, and Wu Wenhao answered them with ease.

Finally, Hu Wenkai came to the stage to announce the formula: using selected natural magnetite as raw materials, in addition to iron components, it also contains additives that can promote catalytic reactions. Generally, it is an oxide of aluminum, potassium, calcium, magnesium and other elements, which is called an accelerator or co-catalyst In addition, the catalyst also contains a very small amount of impurities that are attracted with the raw material or the production process. Ea, sulfur, phosphorus and chlorine, etc. The product is obtained by using a resistance furnace or induction furnace to solder natural or synthetic magnets and additives, then cool and crush to a suitable particle size. Catalyst before use. It must be reduced with syngas containing hydrogen and nitrogen to become porous and highly active grains. The normal operating temperature range is 425 to 525 C.

Subsequently, Hu Wenkai appointed Wu Wenhao as the leader of the leading group for the construction of the fertilizer plant on the spot, and the problems were solved through centralized discussion. I don't know anything about chemical industry, so there is no need to get involved.