Screen Filtration

A screen filter is a type of filter using a fixed or flexible screen to separate sand and other fine particles out of water for irrigation or industrial applications. These are generally not recommended for filtering out organic matter such as algae, since these types of contaminants can be extruded into spaghetti-like strings through the filter if enough pressure drop occurs across the filter surface. Typical screen materials in industrial manufacturing, include stainless steel (mesh), polypropylene, and polyester. Drop SA selects the most eco-friendly material; thus, the stainless steel and polypropylene are preferred as more and easier recyclable materials.
Self-cleaning screen filters incorporate an automatic backwash cycle to overcome these limitations. Their ability to quickly remove contaminants from water before they leach their nutrients make such filters popular choices for recirculating aquaculture systems.

They have also become popular in closed loop industrial systems such as cooling tower, heat exchanger, and other equipment protection applications.
Similar devices with larger openings designed only to keep out large objects are called strainers. Stainless-steel strainers are used in industrial, municipal, and irrigation applications, and can be designed for very high flow rates. When paired with a controller and flush valve, a strainer can be fully automated. Suspended particles are gathered on the inside of the screen, and the flush valve opens to expel the buildup. This eliminates the need for manual cleaning of the strainer element.
There is a large variety on the decision of the mesh could be used based on the customized needs and requests. Briefly, those are: 80, 120, 140, 160 mesh (other upon request).

Disc filtration

A disc filter is a type of water filter used primarily in irrigation, similar to a screen filter, with the only difference that the filter cartridge wears a number of plastic discs stacked on top of each other aligned. Each disc is covered with small grooves or bumps. Each disc (or ring) has a hole in the middle, forming a hollow cylinder in the middle of the stack. The water passes through the small passages in between and the impurities are trapped at the outside part of the discs.
The filtration quality is based on the quantity and size of particles that the filtering element is capable of retaining. Higher quality filtration simply means cleaner water. This depends on the geometry of the channels, including the size, length, angle, and number of generated intersection points.
The discs are color coded to denote the level of filtration. Filtration quality is usually measured in microns, based on the smallest size particle filtered. Disc filters range varies in size from small units with a 3/4" inlet and outlet used for landscape drip irrigation systems to very large banks of multiple filters manifolded together used for filtering large volumes of water for agricultural and industrial applications.
Some disc filters, especially the smaller ones, must be taken apart and cleaned by hand. Many of the larger ones can be backflushed in such a way that the discs are able to separate and spin during the cleaning cycle. Disc filters can be used for many types of contaminants, including fine sand and organic matter. Disc filters used in agricultural irrigation are covered by the ISO 9912-2 standard.

Media filtration

A media filter is a type of filter that uses a bed of sand, gravel, crushed glass, geo-textile fabric, anthracite, crushed granite or other type of media to filter drinking water, swimming pools, aquaculture, irrigation, stormwater management, oil and gas operations and other applications. The system brings the water in the top of a container through a distributor which allocates the water evenly. The filter media start with fine sand on the top and then becomes gradually coarser sand in a number of layers followed by gravel on the bottom, in gradually larger sizes. The top sand physically removes particles from the water. The job of the subsequent layers is to support the finer layer above and provide efficient drainage.
When particles are trapped in the media, the differential pressure across the bed increases. Periodically, a backwash may be initiated to remove the solids trapped in the bed. During backwash, flow is directed in the opposite direction from normal flow. In multi-media filters, the layers in the media re-stratify due to density differences prior to resuming normal filtration. Drop SA offers media filters in many different sizes and types such as dual chamber media filters which allow the continuous operation of the filter. Also, we can provide automatic media filters which require limited human maintenance as the backwash is arranged automatically. You can find the analytical overview with the chemical and physical characteristics upon request.