基于PLC的液体混合控制系统(论文).docVIP

河北农业大学 本科毕业论文 题 目： 学 院： 专业班级：学 号： 学生姓名： 指导教师： 指导教师： 二O年 月 日 摘 要随着科技的发展，PLC 的开发与应用把各国的工业推向自动化、智能化强大的抗干扰能力使它在工业方面取代了微型计算机，方便的软件编程使他代替了继电器的繁杂连线，灵活、方便，效率高。本次设计主要是对两种液体混合搅拌机 PLC 控制系统的设计，在设计中针对控制对象：三只传感器监视容器高、中、低液位，设三电磁阀控制液体A、B输入与混合液体C输出，设搅拌电机M。搅拌机是一种将两种或多种以上材料搅拌混合的系统对搅拌机的控制，关系到产品的质量，工艺流程是：启动后开阀放出混合液体C，低液位后延时2S放空后关阀，放入液体A经低液位再注入至中液位，关A，放液体B至高液位，关B，启动搅拌电机M，搅6S后停，开阀放出混合液体C，低液位后延时2S放空后关阀，又重复上述过程，要求工作过程中按下停止后搅拌器不停止工作，对当前混合操作处理完毕后才停止搅拌器。本设计采用德国西门子S7系列S7-200PLC以液体混料控制系统为中心，从控制系统的硬件系统组成，软件选用到系统的设计过程 （包括设计方案、设计流程、设计要求、梯形图设计、外部连接通信等），旨在对其中的设计及制作过程做简单的介绍和说明。 关键词：液体混料装置，自动控制，PLC，电动机，传感器ABSTRACT With the development of science and technology, the development and application of PLC puts the countries of industry into automation and intelligence. Strong anti-interference ability to make it in the industry replaced the micro-computer to facilitate software programming to enable him to replace the relay of complex connections, flexible, convenient and efficient. The system is mainly of two liquids mixing and blending machine PLC control system, for controlling the object in the design: three sensors high, medium and low level, The three solenoid control liquid A, B input and the mixed liquid C output, set stirring motor M. Mixer is a two or more above the mixing material system, on the mixer control, related to the quality of the product, process is: A post placed in the liquid to be injected by the low level of liquid level, the relevant .A up to high level of liquid B, cut off B, start stirring motor M, after mixing 6S stop, open mixed liquid release valve C, the low level off after the delay after 2S emptying valve, then repeat the process, the course work is required. Press the Stop button to stop working immediately after the mixer is not on the current operations have been disposed of to stop mixing blender. This design uses the Germen Siemens to li