| Lime is a modifying agent which is often used in mineral flotation process.Lime addition method adopts manual operation widely in domestic at present. mineral processing plants automatic control of lime addition which mainly adopts the method of constant lime milk level, by seting the valve open time to control the amount of lime addition. This control system requires more equipment, and lime milk easily bonds and block in the system pipeline. The changes of level fluctuation and lime milk concentration affect the lime addition and metering accuracy. Control systems generally use PLC, electromagnetic flow meter, nuclear density meter and other instruments and equipment. It is not only costly but also easier to be breakdown, and need frequent maintenance. Therefore, in this paper, I study an intelligent lime-milk preparation and addition control system based on the AVR, and put forward a technical method that can effectively solve the existing problem of lime-milk preparation and addition. I also design a controller of integration of measurement and control, intelligence, controlled stability, low-cost. It is of great significance to implement and popularize lime-milk preparation and addition automation in the beneficiation process, reduce the labor intensity, as well as improve mineral processing technology and economic indicators.First the article explains the development and status of lime-milk preparation and addition automation in the beneficiation process, analysis the current domestic main problems and shortcomings of lime operation in dressing process, and put forward a new overall solution. It is studied that the problem of current domestic main process and structure, characteristics, control requirements, and so on. It is presented as a technical method that weight measurement as the basic means is used for getting lime concentration, dosage and other data to control parameters, by processing and computing data. The all-around research was carried out in allusion to controller hardware design and development, control system hardware preparation, controller software development, system management software development, communications and software control system application, etc.In term of controller hardware design, with advanced microcontroller in the AVR ATMEGA 128 microcontroller to be the core,20X4 LCD2004 display unit, utilizing high-performance thin-film keyboard, together with the 4-way sensor signal amplifier and 16-bit AD converter,2 channels analogue signal output circuit,10 roads DI input and 12 roads DO output, etc.. Circuit also has a calendar, unlimited read-write data memory, RS-485 communication circuit etc., it constitutes an hardware system of which I/O port is rich enough, storage space is adequate and feature is rich, provides the superior hardware base for following system development.In term of controller software design and development, using ICC AVR 7.0 Programming Software for software design and development, these software include: System Management Software, Chip driver, Communication Software, Data calculation software, Control Software, and so on. Controller software and hardware constitute the intelligent controller, for the application and development of control system to provide core equipment. Controller with computer can make up a system network, and monitoring and control points can be easily extended according to requirement.In term of system monitoring and management, using the most famous domestic control configuration software—King View, it can easily configuration control system. The configuration include dynamic flow picture, operation panel screen, trend chart, data acquisition and recording, and so on. In order to enable the KingView to communicate with the intelligent controller, use C# language to develop a communications driver. Upper computer can be connected to as many as 32 controllers, consequently realizes the management of multiple controllers.In aspect of control system hardware integration, with the development of intelligent controller for lower control host, with a computer as upper management host, with a force sensor and a device as a quality testing equipment, it gets help from the feeder to control lime powder quantity, depends on the electromagnetic valve to control water and lime, by means of ultrasonic level meter detect lime compound tank and a lime milk storage tank level. Meanwhile I design a line output pipeline system with automatic flush feature. This provides reasonable hardware configuration for the exploitation.Finally, in this paper, I research the application exploitation, design a typical application system, introduce the monitoring system and method based on Kingview software. In addition, on the technology for the future development, I put forward my own views. |
PDF Full Text Request