Automatic control of sludge discharge from pulse c

Automatic control of sludge discharge from pulse clarifier in water plant (2)

2 methods of sludge control

there are two methods of sludge control: regular sludge discharge and automatic sludge discharge

① set the sludge discharge time (H adjustable), and set the automatic timing sludge discharge according to the time. Between the sludge discharge cycle and the start time of sludge discharge. 6. The load system 1 of the plastic tensile testing machine must be checked: whether the appearance of the sensor is damaged can be determined by experience or by the analysis of operation data

② the structural feature of the pulse clarifier is that the sludge concentration chamber is of bucket type, which has the advantage that the sludge discharge is relatively uniform, and the bucket slope is conducive to sludge discharge. Therefore, the thickness of sludge in the sludge bucket can be monitored by the mud layer thickness gauge. The specific method is to monitor the turbidity of the muddy water layer at a certain depth in the clarifier. According to the measured turbidity of the muddy water layer and the turbidity data of the effluent of the clarifier downloaded from the central control room, through the analysis of the operating conditions, under the condition of ensuring that the turbidity of the effluent of the clarifier is in the best range, the best turbidity value of the muddy water layer at the beginning of sludge discharge and the most reasonable turbidity value of the muddy water layer at the end of sludge discharge are obtained, As the upper and lower limits of sludge discharge set by SS6 turbidimeter. (this setting value can be modified). When the turbidity of the muddy water layer reaches the upper limit set value, an early warning will be issued to start sludge discharge, although PLA and PGA can be made into a universal degradable multi filament suture, and the automatic sludge discharge valve will be automatically opened after a delay to start sludge discharge; When the turbidity of the muddy water layer drops to the lower limit setting value, an early warning of stopping sludge discharge will be issued, and the electric valve will be closed automatically after a delay to stop sludge discharge. When the effluent turbidity of the clarifier reaches the set value (an experimental data of 15 NTU) and the sludge discharge conditions are not met, an early warning message will be sent to inform the relevant personnel on site to increase the dosage of liquid medicine or take other measures, and the relevant parameters can be corrected if necessary

3 system characteristics and treatment of several technical problems in the design

① in the structural design of computer monitoring system, the relatively mature PLC technology is cited as the basis. PLC is specially designed to meet various control occasions. It has the characteristics of high reliability, flexible system configuration, convenient debugging and maintenance. Adopt the way that multiple PLC control units work at the same time and complete their specific functions respectively to disperse the risk. When one of them fails, it will not affect the completion of other functions of the system

② the PLC programmable controller of American AB company is used in the hardware design of this system. Electrical isolation measures shall be taken in the PLC control box to reduce power interference. All instruments and equipment are original imported products of HACH company of the United States. The instrument has self diagnosis function. If an instrument or system is tested to be abnormal, the display will display the error code indicating the cause of the fault and record it in the alarm record. The high-speed data communication link of AB company is also used for communication with the central control room, and special shielded twisted pair cable is configured, which has strong anti-interference, wide frequency band, fast transmission speed, simple laying and convenient system architecture

③ the software is developed by the industrial configuration software package. The software adopts module structure, with friendly interface and strong visibility. With the fully integrated and graphical development method, users can basically ignore the problem of how to program in the development process, and can focus on the analysis, planning and design of the process automation process. In addition, the software adopts a distributed structure, which is convenient for configuration. The connecting disc is bolted to the upper port of the experimental machine through the step hole, which is open and flexible, and has the advantages of high efficiency and practicality. The communication sub module adopts American a2 Experimental value B company's software, because the software connection is directly supported by Microsoft, it has its own uniqueness in dynamic data exchange with other data processing software, which not only improves the reliability of communication, but also enhances the flexibility of the system

④ real time curves and histograms of turbidity, flow, voltage, current, etc. are depicted in the application software programming of the central control computer. Each curve is composed of the 24h value of a certain parameter, which can clearly indicate the peak and trough of a certain parameter every day. In order to represent different curves in the same coordinate system, various curves are distinguished by different colors and can be clearly identified

⑤ the system is equipped with voice technology, which can report the working condition at any time. It is recorded and synthesized in Mandarin, solidified into the file, and the central control computer calls out the sound file to alarm according to the information sent by the control unit

⑥ because computer hard disk is a large capacity external storage medium, it often faces more than one user. It is precisely because of this open use that the data of each user becomes quite transparent, which goes against the wishes of users. Therefore, in order to ensure the security of the control system, an encryption method that restricts the user's use of operation authority is adopted in the central control room. It sets the user to different authority values to restrict who can't operate, who can only view data, and who can modify data according to the authority values. Before the central control computer needs to modify the data or control each control point immediately, the identity of the operator must be verified through the authority value, and the operation can be carried out only after it is verified to be correct. This is very important in practical work