工业污水处理的PLC控制

文档编号:ZD261 文档字数:10859,页数:29

摘要
 由于一个城市的工业门类较多，废水排量大，因此城市污水处理是一个非常复杂而庞大的工程。污水中BOD、COD、SS、、，碱及有机磷、盼、氯化物、硫化物、石油、苯、三氯乙醒、甲醇络离子等浓度较高。若不经处理直接排放则不仅影响人民的健康，危害农业的和工业的生产，也严重污染自然水体，因此必须对污水进行综合治理，以使其达到国家排放标准。污水厂为例，说明其工艺流程及实施方案。如图所示，污水被粗格栅房清除，然后入曝气沉淀池，吸砂机吸出的沉砂送到分离器，沉砂连同水一起排入输砂槽，与沉沙一起处理，然后污水排入曝气池，曝气池中设有溶解氧测定仪，根据水质的变化及污水中溶解的含量控制调节进气量，再经中间沉淀池，到最终沉淀地等多道工序刮泥，除砂，调节溶解氧进入量，使污水达到国家排放标准。
 目前污水处理的PLC控制系统在国内外已经得到广泛应用。此次设计的工业污水净化处理系统的工艺流程为：
 按下启动按钮，启动并运行搅拌器；
 打开净化反应池的进水阀，使工业午睡流入净化反应池，并检测流量；
 水位在正常范围内，开始测量酸碱度并测量水温；
流量、酸碱度和水温的数字信号送给PLC，进行中和处理，水温调节以及进水阀开口度的调节；
 检测水位并调节排水阀，控制处理好水的排出。
关键词：污水处理   PLC  控制系统

Industrial wastewater treatment PLC control
 As a city more categories of industrial wastewater discharge, therefore municipal sewage treatment is a very complex and large projects. Sewage in BOD, COD, SS, alkali and organic phosphorus, I hope, chlorides, sulfides, oil, benzene, Peter triclosan B, methanol concentration higher Tongxinluo ions. If not treated directly emissions not only affect the health of people and endanger agricultural and industrial production, but also serious pollution of natural water, it is necessary to carry out comprehensive treatment of sewage, and to make it reach the state emission standards. Wastewater treatment plant as an example to illustrate the process and the implementation of the programme. As shown, the sewage was removed rough grid, and then into the aeration sedimentation tanks, sand suction aspiration of the desilting machines to the separator, desilting together with the water discharged into the trough lose sand, sand and dealt with, Then the sewage into the aeration tanks, aeration pond with dissolved oxygen detector, according to the changes in water quality and sewage dissolved in regulating the content of the feed rate control, then the middle sedimentation tanks, and to the final sedimentation processes, such as multi-channel scratch mud, Desanding, regulating access of dissolved oxygen, the sewage reached state emission standards.
 At present sewage treatment in the PLC control system has been widely applied at home and abroad. The industrial design of the sewage purification process for the treatment system:
 Press the start button and up and running blender;
 The open-purification tank valve, the inflow of industrial nap purification tank, and to detect flow;
 The water level in the normal range, and begin measuring pH and temperature measurement;
 Flow, pH and temperature digital signal gave PLC, and in the processing, as well as temperature-regulating valve opening of the regulation;
 Detection and regulate water drainage valve, the control handle from the water.
Key words: sewage treatment PLC Control System

目     录
概 述..............................................6
  1.1   设计课题的目的和意义..............................6
 1.2  我国水资源基本情况..................................6
 1.3  水污染概述..........................................6
第二章 工业污水的处理系统..................................7
 2.1  污水处理工艺流程简介................................7
 2.2  控制系统的设计......................................7
 2.2.1  机械处理段的自动控制系统.......................7
 2.2.2  生化处理段的自动控制系统.......................8
 2.2.3  污泥沉淀浓缩处理段的自动控制系统...............8
 2.3  控制系统的实现......................................9
 2.3.1  系统硬件构成...................................9
 2.3.2  系统软件......................................10
 2.4  控制系统的功能和工作状态...........................11
 2.4.1  手动状态（MAN）................................12
 2.4.2  自动状态（AUTO）...............................12
 2.4.3  自诊断........................................12
第三章 可编程序控制器概述.................................13
 3.1  可编程序控制器的历史...............................13
 3.2  可编程序控制器的基本结构...........................13
 3.3  可编程序控制器的特点...............................14
 3.4  PLC的应用范围.....................................14
 3.5  可编程序控制器的工作原理...........................14
第四章 系统控制方案设计...................................16
 4.1  流量控制...........................................16
 4.2  中和处理...........................................17
 4.3  温度处理...........................................18
 4.4  水位控制...........................................18
 4.5  按下起动按钮.......................................19
 4.6  程序系统 ..........................................20
第五章 可编程序控制器系统的抗干扰措施.....................22
  5.1  控制系统中干扰及其来源............................22
  5.2  可编程序控制器的工作环境..........................22
  5.3  I/O端的接线.......................................23
设计总结..................................................24
参考文献..................................................25
致    谢.................................................26
附录1 污水处理的PLC系统梯形图..............................27
附录2 PLC与现场器件的系统接线图...........................28

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