The Chemical Metering And Dispensing System Based On Flow Measurement

The additive metering and distributing process is an important part of dyeing and finishingindustry, the accuracy and efficiency of the process has a direct effect on the quality of products.While automation is highly developed nowadays, the traditional method of additive metering anddistributing can not meet the need of this industry as before. The chemical metering anddispensing system based on flow measurement can remedy the shortcomings of the traditionalones and has a great potential in the future.In chapter one and two, according to the study of the traditional metering and distributionmethod, in view of its shortcomings, and refer to the level of development both at home andabroad, I designed the chemical metering and dispensing system based on flow measurement,and the working process is designed either, and the automation of this system is realized byprogramming.In chapter three, the nonlinearity relationship of the flow and the motor frequency isanalyzed, and the function of the relationship is summarized by the method of mathematicalstatistics. This function can be the rule of frequency conversion in this system. At the other time,the accuracy and efficiency in the measurement process is analyzed, using the frequencyconversion control, and in view of the response time and the error caused by it, a set of flowregulation methods are designed to give consideration to both accuracy and efficiency of thesystem. With detailed theoretical calculations and analysis, the effects of the different strategiesare analyzed and compared.In chapter four, by analyzing the expert PID algorithm and the integral separation PIDalgorithm in flow measurement system, and the building of the analysis mathematic model of thesystem, the effects of the two algorithms are simulated.In chapter five, software are designed in the programmable logic controller for the flowregulation strategy, and experiments on different control targets are accomplished. With theanalyze of the experiment results, the practicability of the system is proved. In chapter six, the research achievements and the lack of work are summarized, and thefollowing-up studies are proposed.