Constant Ph Of The Spray System

In the railway boxcar production and maintenance process, it is necessary to cleaning and detection for boxcars. In the traditional process, tap water is usually used as a cleaning fluid, but this likely to cause the boxcar to rust, the next step of production processes was seriously affected, this will resulting in longer working hours and efficiency is reduced. Boxcar is sprayed a layer of rust before cleaning in part of the covered wagon repair factory. Though this way can prevent boxcar from the rust problem, the cost is greatly increased. The spray system of constant pH value, in this paper, cleaning boxcar with Alkaline pH value of 11, not only rust problem is solved and technological level and efficiency is increased, but the significant economic benefit is achieved.The specific content of this article are written as follows:(1) Firstly, The sources and significance of this issue is elaborated, and research and development trends of control of delay systems are analyzed. Therefore, theoretical foundation is laid for the study of control method. Then, trends of the spray system of constant pH value are predicted.(2) In this section, process and works of the spray system of constant pH value to be discussed, the properties of pH value of the system being proposed, and mathematical model is established. Thus, laid the foundation for the next step of control theory analysis and simulation.(3) After reading and analyzing plenty of domestic and foreign literature, the modeling and control method of pH value are thoroughly studied. According to the existing process characteristics of pH value in the system, a new control method is proposed——Fuzzy-Smith control method. It combines fully the advantages of both methods. Fuzzy control does not need accurate mathematical model of controlled object, and Smith predictor control can be very good to compensate for delay systems. Then the simulation was conducted by MATLAB, the results show that the stability and dynamic performance of the Fuzzy-Smith control method is very good, and process requirements of the spray system of constant pH value are satisfied. (4) System software and hardware design is discussed in detail. Components are selected, and the features and functionality of these devices are introduced, PLC is used as the core controller, then system main circuit, PLC wiring diagram and electric control chart is given in this section. After that, main program, control subroutine and work flow chart are developed in the software design.(5) Commissioning and trial operation of the spray system of constant pH value are conducted. Then the effects of the system in the practical application is analyzed.The results of trial operation show that, this system is designed rationally, low cost and practical. It can be well applied to practice.