工業污水處理的PLC控制

電氣自動化論文編號:ZD261 論文字數:10859,頁數:29

目     錄
概 述..............................................6
  1.1   設計課題的目的和意義..............................6
 1.2  我國水資源基本情況..................................6
 1.3  水污染概述..........................................6
第二章 工業污水的處理系統..................................7
 2.1  污水處理工藝流程簡介................................7
 2.2  控制系統的設計......................................7
 2.2.1  機械處理段的自動控制系統.......................7
 2.2.2  生化處理段的自動控制系統.......................8
 2.2.3  污泥沉淀濃縮處理段的自動控制系統...............8
 2.3  控制系統的實現......................................9
 2.3.1  系統硬件構成...................................9
 2.3.2  系統軟件......................................10
 2.4  控制系統的功能和工作狀態...........................11
 2.4.1  手動狀態（MAN）................................12
 2.4.2  自動狀態（AUTO）...............................12
 2.4.3  自診斷........................................12
第三章 可編程序控制器概述.................................13
 3.1  可編程序控制器的歷史...............................13
 3.2  可編程序控制器的基本結構...........................13
 3.3  可編程序控制器的特點...............................14
 3.4  PLC的應用范圍.....................................14
 3.5  可編程序控制器的工作原理...........................14
第四章 系統控制方案設計...................................16
 4.1  流量控制...........................................16
 4.2  中和處理...........................................17
 4.3  溫度處理...........................................18
 4.4  水位控制...........................................18
 4.5  按下起動按鈕.......................................19
 4.6  程序系統 ..........................................20
第五章 可編程序控制器系統的抗干擾措施.....................22
  5.1  控制系統中干擾及其來源............................22
  5.2  可編程序控制器的工作環境..........................22
  5.3  I/O端的接線.......................................23
設計總結..................................................24
參考文獻..................................................25
致    謝.................................................26
附錄1 污水處理的PLC系統梯形圖..............................27
附錄2 PLC與現場器件的系統接線圖...........................28

摘要
 由于一個城市的工業門類較多，廢水排量大，因此城市污水處理是一個非常復雜而龐大的工程。污水中BOD、COD、SS、、，堿及有機磷、盼、氯化物、硫化物、石油、苯、三氯乙醒、甲醇絡離子等濃度較高。若不經處理直接排放則不僅影響人民的健康，危害農業的和工業的生產，也嚴重污染自然水體，因此必須對污水進行綜合治理，以使其達到國家排放標準。污水廠為例，說明其工藝流程及實施方案。如圖所示，污水被粗格柵房清除，然后入曝氣沉淀池，吸砂機吸出的沉砂送到分離器，沉砂連同水一起排入輸砂槽，與沉沙一起處理，然后污水排入曝氣池，曝氣池中設有溶解氧測定儀，根據水質的變化及污水中溶解的含量控制調節進氣量，再經中間沉淀池，到最終沉淀地等多道工序刮泥，除砂，調節溶解氧進入量，使污水達到國家排放標準。
 目前污水處理的PLC控制系統在國內外已經得到廣泛應用。此次設計的工業污水凈化處理系統的工藝流程為：
 按下啟動按鈕，啟動并運行攪拌器；
 打開凈化反應池的進水閥，使工業午睡流入凈化反應池，并檢測流量；
 水位在正常范圍內，開始測量酸堿度并測量水溫；
流量、酸堿度和水溫的數字信號送給PLC，進行中和處理，水溫調節以及進水閥開口度的調節；
 檢測水位并調節排水閥，控制處理好水的排出。
關鍵詞：污水處理   PLC  控制系統

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