What is a sand filter?
Sand filters are called tanks made of steel, concrete, fiberglass, etc., which are manufactured under atmospheric pressure. These tanks are often cylindrical and circular and sometimes square. As its name implies, pure sand is used in their beds.
Sand filters are typically used to remove all types of biologically suspended particles in water up to 50 microns in diameter. These impurities can include all kinds of organic matter, plankton, bacteria and particles resulting from corrosion, mud, paint, and so on. This cleanup is done in the early stages of industrial water treatment systems. Carbon filters are also often used in the water treatment path after these filters.
The sand filter system with physical water filtration eliminates suspended particles and turbidity in the water. In this machine, water containing turbidity is passed through a bed containing sand and silica grains. As water passes through the sandy bed, the water suspended between the sand particles and the water is almost free of suspended matter and turbidity. Sand filters are one of the best ways to reduce the concentration of suspended solids in water. These filters have a substrate consisting of one or more types of layers, each containing particles of rock, granite, or anthracite grains. The grain and size of these particles also differ.
Using Under pressure sand filter
The sand filter is used as an effective step in the water treatment process. There are four main types of this device: pressure sand filters, gravitational sand filters, upstream filters and slow sand filters. All four methods are widely used in the water industry worldwide.
The first two need fluculent chemicals (substances that accumulate all kinds of particles and substances in water) to work effectively. While slow sand filters can produce very high quality water by removing the pathogen from 90% to 99% (depending on the type), with a good taste and odor, without the need for chemicals. Sand filters, regardless of being used in water treatment plants, are also used for water treatment and purification in residential and other commercial areas.
The most common type of sand filter is the under pressure sand filter. This type of filter is often used in pools. And it can offer very acceptable speed while doing a good cleaning.
How does the sand filter work?
The way they work is that dirty water first enters the inlet through the filter tank. With the pressure of the pump, the water is directed downward. During the passage of water through the fine sands contained in the filter, waste and surplus and junk remain in it. Finally, clean water comes out of the nozzles with tiny holes coming out of the bottom of the tank.
As mentioned, sand filtration is mainly used to remove suspended matter. Its efficiency and performance can vary from 50% to 99.99%. Depending on whether other auxiliaries are used (such as coagulants or flucolents). In addition to suspended matter, they also remove COD, BOD, nitrogen and phosphate, as well as non-soluble metals from wastewater.
Technical Specifications Sand filter made by Farab Zist Faraz
Working pressure 3 to 7 bars and test pressure 10 bars.
Coating with 3 layers of anti-corrosion coating 250 to 400 microns including zinc rich, epoxy mio, polyurethane
Use fiberglass coating (FRP) for high corrosive waters and wet areas.
Produced in three types of manual, semi-automatic and fully automatic.
Accurate and scientific design based on water quality.
Contact our experts for more information on the price of sand filters and advice on designing and calculating sand filters and details of building and installing this water treatment system.