High Filtration Speed Industrial Gravity Rapid Sand Filter Water Treatment Device

High Filtration Speed Industrial Gravity Rapid Sand Filter Water Treatment Device

A rapid sand filter is a water treatment device that uses sand or other grainy media to filterout the 

solid particles suspended in water. These suspended solids include dirt and other organic matter 

that cause water to appear cloudy or turbid. Rapid sand filtration is commonly used by municipal 

water treatment plants to clean surface and ground water intended for drinking water. It is also 

used to treat sewage and industrial wastewater containing biological contaminants before these 

waters are discharged to the environment.

Rapid sand filtration takes place in a tank containing one or more layers of grainy media, such as

 sand, anthracite or hard coal, garnet, magnetite, or other minerals. The total media depth typically 

ranges from 2-6 feet (about 0.6-1.8 meters). In many systems the incoming water, or influent, enters near 

the top of the tank and

 flows downward through the media. The outgoing water, or effluent, leaves through a drainage 

system called the underdrain that lies underneath the filter media bed.

As the influent travels through the rapid sand filter, many of the water-borne suspended solids become 

trapped above or within the pores between grains. This straining

 process is the primary mechanism by which solids are removed from the water. In addition, 

suspended solids are adsorbed onto the surface of the grains due to intermolecular attractive

 forces. Other physical, chemical, and biological processes also enhance solids removal during

 filtration.

The effectiveness of a rapid sand filter is highly dependent on the characteristics of the influent and 

the grainy media. Important influent properties include the concentrations, types, and particle charges

 of the suspended solids in the water. The depth of the media bed and the particle charges, sizes, and 

shapes of the grains are also crucial.

Smooth round grains crowd closely together and create very small pores. More jagged grains may 

produce larger pores, but are better at snagging solids as they pass by. Typically, layers of different 

grains are used to take advantage of multiple removal mechanisms.

Over time, the media bed of a rapid sand filter becomes clogged with accumulated solids. At this point,

 the filter is cleaned through a process called backwashing. Wash water is pumped upward through the

 bed to dislodge the solids and rinse them out of the tank. As the wash water is drained, the granular 

media settle back into their original layers, and the filter is ready to be used again.

 
Generally speaking, if your filter is a quartz sand filter, it usually has two main functions:
1. To reduce suspended solids (turbidity). Otherwise, as the system is running, suspended solids

increases, which will exacerbate the deposition and other problems.
2. Degreasing. Especially the oily turbid circulation, such as steel rolling and continuous casting,

has high oil content and is easy for breeding microorganism and blocking the nozzles.

Technical description of by-pass filter for the industrial circulating water
Flow filter flow is designed according to 5% to 10% of the total circulation volume (the by-pass filter

flow of the cooling water is designed by 10 % of the circulation volume and the by-pass filter flow of

chilled water is designed by 5% of the circulation volume) and the filtration rate is designed by 20 —

3Smih according to water quality of the system. Specific to corrosive suspended solids of the

circulating water system as well as the control, our technical support team has designed a variety of manual/automatic by-pass filtrating equipment in line with customer demand.

Back-washing status

With the continuous accumulation of impurities in the filter layer, head loss will continue to increase.

The factory setting with backwash once in24 hours , when it reaches the setting time, automatic back

-washing will be started to clean accumulated impurities.
The working principle is back-washing recoil and surface cleaning.
 

Specifications: