| Crop straw, such as rice straw, wheat straw and corn stover is the main by-product of agricultural production, such as annual crops straw amount to billions around the world. Our country is agricultural country, more power to utilize straw resources. In recent years, in order to promote the rapid development of the national economy, our government has introduced a number of favorable agricultural policies, followed by increasing food production and straw yield. Although there are many places on the comprehensive utilization of straw recycle various attempts, but because of the existence of many problems, the phenomenon of large area of open burning straw, it not only waste resource, but also caused serious pollution, also increased the number of social security risks.Crop straw is a kind of organic matter, for coking coal handling system, crop straw is make the fullest use of these agricultural waste as one of the effective ways of biomass resources. Straw diameter is much smaller than the timber, the use of a direct way to ignite charcoal, easy to ashes, charcoal produced low carbon content. On the basis of these problems, this paper developed a thermal radiant straw carbonization furnace and control unit. The main work is completed as follows:1. According to the characteristics of straw combustion, this paper proposes a new type of thermal radiation straw carbonization furnace structure. Crop straw with screw push into stationary furnace cavity, the straw into the furnace chamber is not direct contact with fire, but in the upper chamber of biomass burning gas to provide result straw pyrolysis and complete carbonized under high temperature and radiation. On the carbonization furnace is divided into the upper cavity and inferior vena, cavity with a chimney, inferior vena have feed trough and discharge chute. Peripheral parts including ignition device, feeding device, air supply device and water spray device. According to the principle of fluid mechanics, this paper analyzes the gas flow direction within the furnace chamber; Coking furnace in stable working state is obtained by experiment, when the furnace chamber of general temperature range each point.2. According to the working principle and control demand of crops straw carbonization furnace, coking control system hardware system is designed. System consists of data acquisition module, communication module, data processing and the electromagnetic valve, motor control module and other parts. Introduces in detail introduced the ATmegal6 minimum system, power supply circuit, temperature signal collection circuit, the design of the control signal output circuit, communication interface circuit, and introduces the anti-interference measures in the design of PCB.3. Design the software of the control system of coking furnace system, it includes the control system of the machine PC application program and touch screen, use the Modbus communication protocol between two modules. PC application implements automatic detection, temperature PID temperature control, communications with touch screen, and other functions; With MCGS development platform as a touch screen, the design of the window, equipment control, operation strategy and real-time database, the user window. Touch screen for the user, has the good man-machine interactive performance. Can realize the whole system of the coking furnace multi-point detection and control of environmental parameters, PC to accept lower machine transmission of data and display in real-time database, the PC can send instructions down a machine, modify the parameters of the upper and lower.4. The straw carbonization control system for coking test for many times, the amount of carbon production according to the different control temperature and carbon content, and the results of analysis of the temperature of carbonization. The test shows that the control system is stable and reliable operation can satisfy the control requirements of continuous carbonization process of control system. |
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