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Summary 1. Under the leadership of teachers from xx Institute, we conducted base practice mobilization, practice scheme layout and factory status introduction in the simulation room 1, which made us understand the tortuous course of a factory and the difficulty of doing one thing. At ten o'clock in the morning, Mr. Li Liang, a senior teacher in the practice base, gave us factory-level safety education before leaving the factory. Through bloody accident education, we are reminded of the danger of chemical production and the huge personal injury and property loss caused by negligence. After that, we learned the importance of safety education and the relevant national safety laws and regulations.
Safety first, prevention first. Don't hurt yourself, don't hurt others and don't be hurt by others.
Four principles of accident handling: the cause of the accident is unclear, the person responsible for the accident does not handle it, the perpetrators do not educate, and preventive measures are not implemented. Speaking of which, let me think, if everyone can do as required, the accidents caused by human factors should be reduced a lot.
Then Mr. Li Liang described the three "zero" management goals of the practice base: zero work injury, zero disaster and zero pollution. Because the production equipment has been discontinued. And it is reformed to make it suitable for students to simulate operation. However, in order to be closer to the actual production, the production operations of some factories are still going on. The teacher still carefully explained the discipline during the internship.
Tell us where we are not allowed to enter casually and where smoking is forbidden. What are the unsafe factors? When entering the site, you must wear safety helmet and work clothes.
1 During the internship, all actions should be arranged by the instructor, and actions without authorization are not allowed.
Go to work on time, never be late or leave early.
Strictly abide by the rules and regulations of factories and workshops, and do not operate on-site equipment, electrical appliances, instruments and valves without permission.
4 4 Prohibition; Smoking is strictly prohibited in the factory; No games, mobile phones, newspapers and magazines. It is forbidden to escape, take off the post and sleep in the post. It is forbidden to insert personal USB flash drives and other mobile devices into the computer in the central control room. Five or five are not allowed; Do not enter the training place without wearing work clothes; You are not allowed to enter the work site without wearing a helmet. High heels with spikes are not allowed. Don't be late and leave early; Don't make any noise.
Attention: Pay attention to the dress. Don't let your hair hang freely, don't wear jewelry or high heels. 7 It is forbidden to touch valves, instruments and buttons. Pay attention to environmental protection and maintain the environmental sanitation of the factory. 9 batch into the factory, so as not to interfere with the normal production operation. After that, I did safety education on labor protection, safety technology, fire prevention, explosion prevention, gas prevention and how to escape. Let's understand the different meanings of safety signs and safety colors. Different colors of storage tanks contain different gases. Personal protective equipment in different jobs. And told us to wear acid-proof gloves, rubber boots and dust masks when collecting maleic anhydride.
Fire prevention is the most important project in production. The teacher introduced in detail how to choose fire extinguishers in different environments. The position of fire extinguisher in maleic anhydride production device is explained in detail. And remind us to pay attention when visiting the workshop. We are deeply impressed by multimedia and vivid examples. And conduct safety inspection before leaving the factory.
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Yesterday afternoon, we made a process introduction. Today, our task is to watch the technological process in groups. We assembled at the entrance on time, put on our helmets and pants, and lined up to enter the homework area under the guidance of the teacher. The teacher first showed us all kinds of equipment to see if we could know each other. We took a cursory look at all kinds of display instruments. It is worth noting that all kinds of pipes and cylinders are wrapped very thick. At first, I thought it was to look good during my internship. Very clean. Wondering what's in it.
Later, the teacher took us to introduce the equipment one by one, only to know that the thick protection is to keep the pipeline warm. Because most of them are carried out in high temperature environment. Otherwise, there will be a lot of heat loss. For over an hour, the teacher gave us a preliminary understanding of the equipment mentioned in yesterday's class. But when I saw two rows of * * * eight traps. It is not clear how it works. The teacher asked us some questions about the flow direction of equipment and processes. But no one will answer. Then the teacher led us to briefly introduce the catcher's equipment, let's pay attention to the difference of display instruments. Four-piece set, a common combination in chemical industry, is introduced to us. When in use, open the front valve first and then open it. When closing, close the front valve first, and then close the rear valve. When the pipeline fails, use the bypass switch. Then introduce us to the function of the design blasting hole and the details of other equipment. Finally, the teacher talked about the improvement of production technology in a private factory in Shijiazhuang, which saved the human labor of carrying and transferring to the hydrolysis tank. Remind us that people who engage in equipment must be familiar with the production process in order to improve the process equipment. Only in this way can we keep innovating.
In the afternoon, a theoretical class was arranged. Teacher Huang Yuhong introduced the process of hydrolysis, dehydration and drying. Hydrolysis part introduction:
A certain amount of water and activated carbon are added to the crude maleic anhydride in the hydrolysis kettle, and after heating and hydrolysis. The activated carbon is removed by a hot filter, cooled and crystallized, and then dried by a centrifuge to obtain a crude pyromellitic acid product. The crude anhydride obtained in the trap contains by-products and needs to be refined by hydrolysis, dehydration and sublimation. According to the quality of the crude product obtained in each trap, one or more times of hydrolysis are carried out respectively. Star that stirrer in the hydrolysis kettle, and quantitatively adde soft water into the hydrolysis kettle from a soft water tank through a soft water pump. Activated carbon is filled in the kettle, then steam is introduced, and it is heated and hydrolyzed under stirring, and a filter bag is installed in the filter. In order to prevent activated carbon from passing through and affect product quality.
Why do you want to add filter bags? The teacher also described the improvement process of installing filter bags in the device. A foreign trade enterprise wants a product, and the price given is twice the market price. However, only one person requested that the detection product is to detect the number of carbon-containing particles. This is the first time I've heard of this quality inspection requirement. The original production process is far from meeting the quality requirements through experiments. But in order to win the business, researchers in the factory began to choose filtration devices. Finally, choose to install multi-layer filter bags to remove activated carbon. But this increases the traffic resistance and makes the pipeline easy to block. Instead, check the condition of the filter bag regularly.
The hydrolyzed material enters a crystallization tank for natural cooling and crystallization, and then is dried by a centrifuge. Then, the materials in the hydrolysis process are evenly added into the stainless steel boat. Open the lid of the dehydration kettle, put the boat into the tube array and dehydrate in vacuum. By-products are left on board. The sublimated product adheres to the wall of the crystallization chamber of the kettle.
During drying, the hot air flows upward at the speed of 2040m/s by the blower, and the wet material is added by the feeder, so that the particles are suspended in the high-speed airflow. . Due to full contact, the material quickly removes moisture, and the dried material enters the cyclone separator at the outlet of the airflow pipe with the airflow, and the product is extracted from the lower part of the separator. The other is a vacuum conical rotary separator, which is used to dry materials.
Summary 2 This morning, we had a simulation training in the simulation room. Everyone has a computer. Under the guidance of the teacher, we began to simulate the driving process. Under the instruction, we open all kinds of valves and switches. Because this is the first operation. Really blindly follow, I don't know what every step is for. Slowly, I realized that our actual production control process is also like this. Interested in this control. But we gradually understand the process. When we want to complete the requirements quickly, some heating and cooling processes have to take time slowly. The more urgent it is, the less it can reach the specified temperature. I also realize that the start-up process of production is also very slow, which is why continuous production is needed. Until class is over. We have only fiddled with this car in one or two workshops.
In the afternoon, the arrangement is still a field visit and study. This time, the teacher introduced us to all kinds of equipment along the airflow direction, starting with the blower. And the function of each air duct. Then let's visit freely. Ask questions freely. I asked the teacher, don't we really need three traps? Why are there two rows of four in each row? Why is the first one wrapped in insulation? Are these traps different? Why do you use tee pipes for connecting pipes between traps? The teacher who asked me questions answered patiently. Only then do we know that the heat preservation is to prevent rapid cooling, and the crystallization is stable during the heat preservation process, and the obtained product has high quality and purity. While other by-products continue to enter the second stage due to different boiling points.
The tee pipe is used to prevent pipeline blockage caused by unstable temperature, and has an opening to check whether the pipeline is blocked regularly. Otherwise, there may be a danger of explosion due to blockage. This also makes it easy for us to distinguish which pipeline takes the products and raw materials. Also take us familiar with melting tanks and reactors, as well as matters needing attention. I feel that we think the problem is too superficial, and there are so many considerations in the design of safety protection. And remind us to pay attention to different colors and see what the difference is. Then tell us that the substances taken from different pipelines are different, and we can also see if there is danger. Green is the cold water route; Green is water and blue is air; Red is steam and so on.
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