Design Of The Machine-harvested Cotton’s Humidity Detection And Control System Of Seed Cotton Dryer

As the key process, seed cotton drying has a huge impact on processing efficiency and quality. At present, most of the domestic seed cotton dryers refer manufacturing technology from abroad to research and produce, but the seed cotton humidity detection and automatic control technology in the drying process is still not very mature. Based on the design of machine-harvested cotton’s humidity detection and control system of seed cotton dryer, the humidity of the seed cotton can be decreased to suitable value better. On the one hand, it can prevent these problems caused by high seed cotton moisture: cotton fiber metamorphism, discoloration, and even spontaneous combustion in the process of storage and transportation, cotton brushed endlessly, cotton lap stalling, and blockage of the rib in the process of cotton ginning. On the other hand, it can prevent seed cotton bags breaking up and lint cotton fiber uniformity declining, the rate of short fiber increasing under the too low moisture regain. This article main research content is as follows:(1) Humidity detection system for seed cotton in the dryer integrated design scheme. The hardware of this system consists of a microprocessor unit, a reset circuit, a power supply circuit, a crystal oscillator circuit, a humidity acquisition circuit, an A/D conversion circuit, an alarm circuit, a display circuit, a clock circuit, a memory circuit, a key press circuit and a communication circuit. The core of the hardware is the microprocessor unit, it used STC12C5A60S2 chip as the control chip. The humidity acquisition circuit used the HIH3610 humidity sensor to collect cotton humidity value. The communication circuit used MCP2515 chip to complete communication. The clock circuit used DS1302 chip to record time. The display circuit used LM016 L chip to achieve display function. The memory circuit used 24LC64 chip to store data. In order to verify the effectiveness of the action, the power supply circuit and the key press circuit were equipped with state display function.The comparative test of absolute humidity between seed cotton and lint cotton is more persuasive because of their great difference. We can draw a conclusion for many times and calculating average value of each group by detecting their humidity. The error between measured and displayed value is in the range of ± 3%, relative error is less than 7%. It conforms to the system design standard, the needs of reliability and accuracy. And the system is very helpful to solve the problem that machine-picking cotton humidity is difficult to control.(2) Humidity control system for seed cotton in the dryer integrated design scheme. This program focuses on the lack of technologies in the complete processing lines for seed cotton quality control and adjusting key equipment operation status. Rational matching among various equipments in the complete processing lines has not been realized, which hinders the improvement of cotton processing quality, and negatively influences the overall safe operation rate of the entire line. The program conducts specialized researches in two aspects: host computer system and lower computer system. As the core of control system, host computer system uses configuration software to implement monitoring and control. It can not only display the running state of the key parts in real time, but also analyze, judge, feedback and optimize the collected signals. Using PLC as the core, lower computer system is mainly responsible for the sensor signal acquisition, processing and motor control. Practice shows that this system has friendly interface, stable operation and monitoring functions.