Multi-medium filter backwashing technology

Abstract

The invention relates to the field of water treatment, in particular to a multi-medium filter backwashing technology. The multi-medium filter backwashing technology is characterized by adopting the following steps of: carrying out minor gas washing for 10-20 seconds until a filter material can just not flow out of a water outlet, falling on a bed, and carrying out gas washing for 240 seconds; carrying out minor backwashing for 50-60 seconds until water is filled in the filter and can just not flow out of the filter, pausing for 180 seconds, and carrying out backwashing for 600 seconds; and pausing for 300 seconds, and carrying out forward washing for 900 seconds. The multi-medium filter backwashing technology has the advantages of shortening bed falling time and backwashing technology time and increasing the efficiency by 50% or so; gas at the bottom of the filter and in the center of the filter material is discharged through minor backwashing so as to prevent filter material loss; a series of problems of backwashing strength control difficulty, filter material mixing, great filter material loss amount and the like are solved, and the quality of produced water is ensured; the amount of backwashing water is reduced, energy sources are saved, and the cost is reduced; and the full automatic control operation of the technology process is realized.

Description

technical field [0001] The invention relates to the field of water treatment, in particular to a multi-media filter backwashing process. Background technique [0002] In the production process of titanium dioxide, the desalted water station is used to provide desalted water. If the annual output of titanium dioxide is 100,000 tons, the desalted water station must provide 720 tons of desalted water per hour to meet the demand. The desalinated water system is divided into two main processes of pretreatment and desalination, and the multi-media filter is the first-level treatment equipment of the pretreatment process. The water quality of the multimedia filter directly affects the normal operation and production cost of the desalination station. [0003] The multi-media filter is filled with several specifications of quartz sand and anthracite to remove colloid, suspended matter and organic matter in the raw water, so that the water quality meets the requirements of use. Th...

AI Technical Summary

Problems solved by technology

[0005] The backwashing process has the following disadvantages: it is difficult to get off the bed, it takes a long time, and it takes more than 1 hour

Backwashing is carried out directly after air washing. If the backwashing intensity is high, a large amount of filter material will be carried out, resulting in loss of filter material; if the backwashing intensity is low, the backwashing effect will not be achieved, affecting the quality of the produced water, and it is difficult to operate and control.

The main reason: there is gas at the bottom of the filter and in the middle of the filter material after air washing, and direct washing after backwashing will cause mixed layers of filter material and fine filter material will be carried out from the produced water, resulting in loss of filter material and seriously affecting the quality of produced water

After manual operation, the automatic control operation is performed, which increases the complexity of the operation