Li Ruoyu straightened up, sat on the edge of the bed and began to speak: "The highly automated concrete mixing plant controlled by computer is a fully automatic concrete mixing equipment composed of batching device, aggregate conveying device, powder conveying device, water supply and additive system, metering system, mixing system, electric control system and air control system. Although there are many forms of mixing host, but roughly divided into two forms, one is self-falling, the other is compulsory, and the compulsory type is divided into vertical shaft and horizontal shaft, for the automatic concrete mixing building, it should be a double-shaft compulsory mixer that is more suitable for our country. This mixer has good mixing quality and high production efficiency, and can complete good mixing in an ideal time for dry hard, semi-dry hard, plastic and various proportions of concrete. ”

Gou Ancai took over the conversation and said, "Xiao Li is right! The promulgation and implementation of our national standard GB10171-88 concrete mixing plant classification and GB10172-88 concrete mixing plant technical conditions have incorporated the development and production of concrete mixing plant into the track of standard management, laying the foundation for the future development of our own concrete mixing building. In the requirements of product technical standards and ready-mixed concrete standards, the technical indicators of concrete mixing buildings have reached the level of developed countries. Since the eighties, China's concrete machinery has had two strategic product structure adjustments. The first is the upgrading of concrete mixers in the early eighties, and the drum mixer is replaced by double-cone reverse transformation, vertical shaft and horizontal shaft compulsory concrete mixer. Second, the recent development of three cars on the first floor, namely concrete mixing building, concrete mixer truck, boom concrete pump truck and bulk cement truck, the strategy of China's commercial concrete machinery up, now is the time for us to vigorously introduce foreign advanced products and combine their own conditions for development. ”

Li Ruoyu nodded and said: "Chief Engineer Gou, we should seize this opportunity, these national-level strategies reflect the deep-seated requirements of the steady, sustainable and comprehensive development of the concrete and concrete machinery industry." We can be jointly developed by scientific research institutes and production enterprises, and timely introduce foreign advanced concrete pump and concrete mixer truck technology, so that China's design, manufacturing capacity and level of commercial concrete machinery have been greatly improved, and the same is true for concrete mixing buildings. As long as the quality of the domestic production of concrete mixing building is improved, it can gradually replace the imported mixing building, and the responsibility on the shoulders of your Donghua Construction Machinery Factory is heavy! I am very optimistic about you, maybe you can design and manufacture China's first automatic control concrete batching plant. ”

Gou Ancai was also very encouraged when he heard this, and said happily: "I hope so!" Comrade Xiao Li, let's talk about it, what are the key technologies of the mixing building for automated production? ”

Li Ruoyu looked at everyone and said slowly: "The most critical things in the automated production and mixing building are several, one is the programmable logic control device, also known as PLC; the second is industrial computers, also called single-chip microcomputers; The third is automated production control software. These three pieces are the core things of the automatic production of concrete mixing building, and tomorrow we need to pay the most attention to these three pieces in the process of inspection. ”

Li Ruoyu continued with a smile: "In fact, PLC has been born in 1969, and since its birth, the programmable logic control device has been valued by more and more engineers and technicians with its extremely high performance-to-price ratio and a series of advantages that people have agreed on. It is widely used in automobile production, oil production, home appliance manufacturing plants and other industrial control system places, and is one of the important technologies for the development of modern manufacturing industry. It provides a good control system for industrial production, and the realization of automatic control system for mixing equipment in the concrete production process is also a matter of recent years. The programmable controller has high reliability, perfect functions, simple and intuitive programming, which can effectively make up for the shortcomings of the relay control system. ”

Gou Ancai then asked: "Comrade Xiao Li, I have also heard of the PLC and industrial computer you mentioned, but I have never understood how these things are automatically controlled in the automated production and mixing building. ”

Seeing that everyone was looking at him curiously, Li Ruoyu said with a solemn expression again: "The measurement and control system of the automated production concrete batching plant is mainly composed of the monitoring and management part of the upper industrial computer, the PLC on-site control part of the lower computer and the measurement part of the single-chip weighing system. The communication unit with the computer can complete the collection and processing of the number of products, and can be transmitted to the number area of the PLC, and the computer can also directly read and write the number of the number area inside the PLC, and can also monitor the program execution status. It can be seen that through the communication between the PLC and the computer, it can be convenient to complete the selection of concrete ratio parameters, and also make the debugging of the PLC control system put aside the unintuitive and inconvenient lack of stuffing of the program, and the debugging, parameter modification and fault handling have realized the man-machine operation dialogue, and the control system is more perfect, which is the most ideal control method in the field of automatic control at present, that is, the use of industrial computer for the number of management level, PLC for the number of control level, PLC and computer communication form a centralized and distributed control system for network management sites. ”

In order to make the PLC complete the on-site control function of the entire production process of the concrete batching plant, the PLC needs to collect the weight signal of each scale and the switching signal provided by other sensors and travel switches, and after processing, output the control signal of the actuator such as the solenoid valve and the motor. The software program design adopts a modular structure, which has the advantages of clear structure, convenient debugging, easy maintenance and easy expansion. The whole system is composed of modules such as sampling, weighing, keyboard scanning, display, program setting, communication, and switching output. Li Ruoyu finished talking about the control system of the automated production of concrete mixing building in one breath, but most of the people present did not understand it, after all, they were not engaged in this, and only the two leaders of Donghua Construction Machinery Factory roughly understood what was going on.

Shu Ming, director of Donghua Construction Machinery Factory, said loudly: "After listening to Comrade Xiao Li's explanation, now I understand what we should do!" Our country's concrete mixing equipment is now too backward, and even can not manufacture the mixing building used in the commercial concrete batching plant, our Donghua Construction Machinery Factory should be the leader of the domestic concrete machinery industry, and strive to design and manufacture China's first modern concrete mixing building as soon as possible. ”

Cheng Nantong said happily when he heard this: "Okay! Good! Good! Our engineers and technicians must have the courage to dare to fight! I believe that this inspection and introduction of foreign advanced concrete mixing building will definitely give birth to our own automated production of concrete mixing building! ”

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