Moving bed filter

Abstract

A moving-bed filter able to continuously run for treating water is composed of cylindrical tank, water distributor, filtering bed, fairing unit, air distributor, filtering material delivering pipe, gas separator, washer, filtering material distributor and the regulating valve for the washing water.

Description

technical field [0001] The invention relates to a water treatment device, more specifically a filter device for removing suspended solids in water, especially a moving bed filter capable of continuous filter operation. Background technique [0002] As one of the means of removing suspended solids in water, filtration is not only widely used in urban or industrial sewage advanced treatment and sewage reuse treatment, but also in urban and industrial water supply treatment ( Such as tap water, industrial fresh water, boiler feed water), circulating cooling water treatment and other processes commonly used equipment. [0003] The mechanism of the filter to remove suspended solids is mainly to use the tiny pores inside the filter bed to trap particulate pollutants in the water. Its working process includes two processes: filtration and filter material cleaning. According to different conditions such as filter material, filtration speed, water flow direction, bed depth, water fl...

AI Technical Summary

Problems solved by technology

US4126546 discloses a moving bed filter, the filter material circulation riser is arranged in the center of the filter, the main problem is that the riser occupies the filter space, the result not only affects the filtering effect, the filter material is not evenly distributed after washing, and the equipment Installation, maintenance and start-up operation are more difficult

In the moving bed filters disclosed in US5462654, US4891142, etc., the filter material circulation riser is also arranged in the center of the filter, the filter material is in the same flow direction as the water flow, and the drainage is arranged in the wire mesh structure in the filter material layer; its parallel flow makes The interception effect of suspended solids in wastewater is poor, and suspended solids are easy to pass through the screen structure with the filtered water, not only the quality of the effluent is poor, but also easy to cause the screen to be blocked; the water flow in the filter space under the screen structure is weak or even stops, resulting in "dead corners", Does not play a filtering role, and the filter space utilization rate is low

US5746913, US5277829, etc. disclose a kind of moving bed filter, and the filter material circulation riser is arranged outside the filter, and its drainage adopts the cofferdam overflow mode, and the overflow area occupies part of the section of the filter, and the filter material is circulated back to the filter bed. The position deviates from the center of the filter; due to the existence of the overflow area, the water flow distribution in the transverse section of the filter tank is uneven; because the filter material falls back and deviates from the center of the filter, the filter material forms an uneven accumulation slope in the filter , that is, the height of the filter material layer is different, which aggravates the uneven distribution of water flow; the uneven distribution of water flow will cause the filter material to not be fully utilized, and the quality of the effluent water will be affected

In addition, the above-mentioned filters also have the following common disadvantages: 1. The air distributors of the filter material riser are all arranged at the bottom of the riser. When the filter runs for the first time, it can smoothly lift and circulate the filter material. After stopping for some reasons, it is very difficult to restart; the reason is that the filter material accumulated in the riser is densely packed, and its height is greater than the height of the filter bed inside the filter. As a result, there is a large resistance in the riser, and air is easy to enter when restarting In the filter tank with low pressure and through the filter bed, the filter material cannot be lifted and circulated

2. The air in the process of lifting and circulating the filter material is not separated, and directly enters the scrubber with the filter material, which will not only have a greater impact on the washing due to the high speed, but also the amount of filter material entering the scrubber is uneven and the size is not uniform. 1. Affect the washing effect of the filter material and the water quality of the effluent

3. The washing of the filter material adopts a simple liquid-solid countercurrent method, the structure of the scrubber is unreasonable, the distribution of the filter material in the scrubber is uneven, it cannot fully contact with the washing water, the washing water is easy to short circuit, not only the amount of washing water is large, but also the washing The effect is difficult to guarantee, which will affect the quality of effluent water

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