Deep sand filter

Abstract

The invention is a depth-type sand filter, the size of sand gradually diminishing with the flow direction of the normal filtering fluid. It leads the fluid to the inlet of the sand filter through the pipeline, firstly holds back big suspension through big sand area, then holds back medium suspension through medium sand area, finally eliminates most fine suspension through fine sand area, and then makes the fluid flow out from the outlet. It is composed of wall body, filtering sand and ground leak; the wall body is set with inlet and outlet, the ground leak is set under the wall body, the filtering sand is spread in the liquid flow direction in turn according to the size. It can adopt upflow and downflow modes. It can stably and economically run in a wide range. It is applied to economical sand filtering field, especially the field where the sand filter is used infrequently or discontinuously.

Description

technical field [0001] The invention belongs to a water filtering device, in particular to a deep type sand filter. Background technique [0002] Sand filters are simple and economical filters because the filter media is sand, which is cheap and readily available. Existing sand filters mainly include coarse sand filters and fine sand filters. The basic structure is that there are fine stones and larger stones on the bottom, and sand or fine sand on the top. The stone structure below is mainly designed for the convenience of collecting filtered water and backwashing. The coarse sand or fine sand above mainly plays a filtering role. The filtration accuracy of the sand filter is mainly achieved by the gap size of the coarse sand or fine sand. The normal flow direction of the filtered fluid of the existing sand filter is from top to bottom, and when the system is fouled to a certain extent or the filter pressure difference reaches a specified va...

AI Technical Summary

Problems solved by technology

[0003] The existing sand filter equipment has the following defects: 1. It belongs to the surface filter, that is, the filtration accuracy is mainly achieved by the size of the surface gap of the sand.

2. It is easy to be fouled and needs frequent backwashing to regenerate its filtration function

Because their utilization rate is relatively low, resulting in a huge waste of resources

3. The frequency of backwashing is high, which means that the normal operation time is short, and the operating efficiency is reduced. It also means that the utilization rate of water is reduced and the pollution environment caused by backwashing is increased.

4. Normal filtration and backwashing devices need to be installed in the same filter device, and equipment such as water distribution or air distribution must also be configured, which has a complex structure and high cost

5. Pumps and other power devices are required, and the consumption of power such as electricity means energy input and cost increases. It is not suitable or even impossible to use in general fields or areas where power distribution has not yet been achieved or where power costs are relatively high.

6. The requirements for equipment materials are relatively high, generally need to have anti-corrosion properties, such as stainless steel or carbon steel, etc., the cost is quite high

However, surface filtration generally has a small dirt-holding capacity and requires frequent flushing or backwashing to regenerate

Depth filtration generally has the advantages of large dirt-holding capacity, small filtration pressure difference, and long single service life, but it is generally not easy to regenerate or the effect of regeneration is not very good

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