Management and Maintenance of Automation and Measuring Instruments in Sewage Treatment Plant

On-line measurement of operating process parameters of wastewater treatment plant

With the development of science and technology and the requirements of sewage treatment technology, there are more and more automated controls in the sewage treatment process, which requires the application of a large number of on-site online measuring instruments. In the sewage treatment process, the parameters that need to be measured are various, such as the inlet and outlet water temperature of the sewage treatment plant, the dissolved oxygen in the aeration tank, the pH value in the sewage, the sludge concentration, and the turbidity. There are many types of measuring instruments with different structures, so there are many classification methods. According to the energy and signal classification of the instrument, it can be divided into pneumatic instrument, electric instrument and hydraulic instrument. According to the installation method, it can be divided into rack-mounted instruments and panel-mounted instruments; according to the form of composition, it can be divided into unit combination instruments and base-type instruments; according to the measured parameters, it can be divided into pressure instruments and liquid level measuring instruments , Temperature measuring instrument, flow measuring instrument, composition analysis instrument.

2. Routine maintenance and management of measuring instruments

Compared with other production areas, the application of automatic detection instruments in the field of sewage treatment is much later. From design, construction, installation to daily management and the operation, repair and maintenance level of instrument personnel need to be further improved. For the daily maintenance, maintenance, regular inspection, calibration and adjustment of the online instrument of the sewage treatment plant, it is an important condition to ensure its normal operation.

From the previous introduction, we can see that there are many types of meters used in sewage treatment plants. The working principle and adjustment and calibration methods of each instrument are different. Therefore, for each specific instrument, you should first carefully read its use and maintenance operation manual, and operate according to the requirements of the respective instructions, which will not be described in detail here.

1. Instrument file and data management

Whether the data and files of an instrument are complete is of great significance to the judgment and handling of daily maintenance and faults. For each instrument, a resume must be established as a file. The content of the resume is as follows:

(1) Instrument position number (generally it should be consistent with the design drawing number);

(2) Instrument name, specification and model;

(3) Accuracy grade;

(4) Manufacturer;

(5) Installation location and purpose;

(6) Measuring range;

(7) Put into operation date;

(8) Verification and calibration records (calibration date, method, accuracy verification record);

(9) Maintenance records (including maintenance date, failure phenomena and treatment methods, and replacement parts records);

(10) Daily maintenance records (zero point inspection, range adjustment, inspection, visual inspection, regular cleaning, etc.);

(11) Original data (should include design, installation and other data, cable direction, signal transmission, and the certificate, inspection records, design parameters, use and maintenance instructions provided by the manufacturer).

2. Daily maintenance, maintenance and overhaul

For each online instrument, daily maintenance, maintenance, and overhaul should be carried out in accordance with the relevant information provided by the manufacturer. Generally speaking, daily maintenance work is divided into four parts, namely: daily patrol inspection, regular cleaning and cleaning, calibration and calibration; failure analysis and component replacement when there is a failure, and calibration after maintenance.