PROCESS FOR CONTROLLING WATER FLOW USED DURING BACKWASHING FILTERS IN DRINKING WATER TREATMENT PLANTS AND CONTROL SYSTEM THEREOF

摘要

The invention relates to a process for controlling the water flow used for backwashing filters in drinking water treatment plants and to an equipment for carrying out the same. According to the invention, the process consists of the following stages: closing the cofferdam sills for stopping the water supply of the two tanks of the filter, opening the filtering gate 100%, lowering the water level in the tanks up to 10 cm above the sand filtering mass, closing the filtering gate, controlling the start of a first turbo-ventilator simultaneously with opening the air inlet valve, bubbling the sand for 3 minutes with a high volume of air for aeration, followed by the stage of mixed washing, with air and water, by opening the water inlet gate and starting a first washing pump simultaneously with starting a second turbo-ventilator and, when the water in tanks gets to 1/3 of the height, the second washing pump is started and, when the full-level mark is reached, an ultrasound sensor stops the two turbo-ventilators and the air intake valves are closed, the washing is continued for 20 minutes only with water, after which the washing pumps are stopped and the washing water inlet gates are closed, the cofferdam sills are opened for water inlet and the gate from the washing water pipe is opened for resuming the production. The claimed equipment used for backwashing uses an online-type turbidimetric probe, connected to the filter automation system and to the central process unit SCADA, which transmits, in real time, data on the turbidity of the water in the filtering tank, the turbidimetric probe being immersed in the filter in the direction opposite to the cofferdam gate for decanted water supply, the information taken over from the probe being processed by a controller which controls the end of the washing process by stopping the pumps, and, depending on the turbidity value, it reduces or extends the washing time.