Sand Filter

Sand Filter

Sand filter

Sand filters are used as a step in the process of water and wastewater treatment and wastewater treatment packages. The filtration process is used as one of the most important and well-known methods in the treatment and clarification of water and wastewater. The basis of sand filters is the physical purification of water by trapping suspended particles in the bed layers of sand filters. Sewage enters from the upper part of the device and after passing through the bed layers of sand filters and performing the clarification process, it leaves the lower part of the filter. The sand filter absorbs all suspended particles larger than 50 microns. Each filter has a piping network with fittings and valves for inlet, outlet, backwash, air drain, barometer and inspection valves to access the filter.

 Accumulation of suspended particles in the filter bed causes an increase in water pressure drop during passage through the filter. When the pressure drop is too high, the filter is removed from the filtration path and rinsed. To flush the filter, the water flow is reversed to remove the filter contaminants as the substrate expands. Normally, the bed material of pressurized filters is sand, anthracite or diatomaceous earth. The depth and size of the filter are designed in such a way that there is enough space for expansion of the bed during reverse washing. Sand filters have the ability to separate suspended materials up to 50 microns in diameter.

Types of sand filters

Sand filters are classified into three main categories: pressurized sand filters, fast sand filters and slow sand filters. All three types are widely used in the water and wastewater  treatment industry wordwide.
Pressure sand filters
Due to the high speed of pressure sand filters, these filters are the most common type of sand filters. Pressurized sand filters are used to remove suspended solids up to 100 microns. The material of these filters is usually made of PP and the maximum useful height of silica in them is 100 cm.
Quick sand filters
Fast sand filters quickly remove relatively large suspended particles. These filters are classified into two general categories: fast pressure sand gravity and gravity filters. These
systems are commonly used as pre-treatment and supplemental treatment.
Slow sand filters
Unlike pressurized sand filters and fast sand filters that require pumps and sometimes coagulants and wastewater treatment using a physical process, slow sand filters are pressure-free processes and a biological process for separating suspended particles from Uses sewage. Wastewater treatment in this method is done with the help of microorganisms and does not require electricity.

Advantages of sand filters
  • High efficiency of wastewater treatment
  • Easy to install and operate
  • Used in various stages of wastewater treatment
  • Requires little space due to the cylindrical design
  • Resistant to chemical corrosives
  • Low installation and maintenance costs
  • Short washing time
  • Equipped with upper and lower visit valves
  • Equipped with vent valve and pressure gauge
  • Equipped with automatic reverse washing system 
Disadvantages of sand filters 
  •      Inefficient in removing soluble particles and salts
  •      High construction cost
  •      High energy consumption
  •      Requires skilled labor
Application of sand filters 
  •     Drinking water filter
  •     Return water treatment of cooling towers
  •     Surface water treatment
  •     Pre-treatment of wastewater treatment packages
  •     Motorhome facilities
  •     Oil and gas industry
  •     Petrochemicals and refineries
  •     Fisheries industry 
 Price of sand filter
Kashefan Nilfam Engineering Company is a supplier of sand filters with the best quality and the most appropriate price. The price of sand filters of Kashefan Nilfam Engineering Company depends on items such as body material and type of filter. Each of these factors has a significant impact on determining the final price of sand filters. For more information, please contact the sales experts of Kashefan Nilfam Engineering Company.