Industrial Multi-Media Filters & Sand Filters
Water filtration solution for removal of suspended solids, small particles, and floating contaminants to protect equipment and meet discharge requirements.
Sand filters are used to remove suspended solids from water. H2K industrial sand filters are designed to remove larger suspended solids (50-100 microns), using a single size of filtration media. The coarseness of the filtration process can be determined by adjusting the size of the filter sand. The effective size of each granule of sand typically varies from 0.35mm – 1.2mm. Industrial sand filters can use graded support media layers or be installed directly over or on a distribution plate or header/lateral under-drain.
Multi-Media Sand Filters are an industrial water filtration solution for removing suspended solids of finer sizes. These filters utilize multiple layers of filter media to accommodate greater solids loading and finer particle removal. Industrial multi media filters typically are able to filter particles down to 10-25 micron and can achieve as low as 5 micron filtration depending on filter vessel sizing and arrangement. As water flows downward through the bed, it encounters layers of filtration media with decreasing porosity. Successively smaller particles are removed by each layer, providing true depth filtration and increasing the filters capacity considerably over a sand filter. Multimedia filters are also sometimes referred to as dual media, anthracite, granular media, multi-layer or pressure filters. Multi media filters use graded support media layers over the under-drain to prevent the layers from migrating into each other during backwashing.
Dissolved Iron Removal uses a specialty manufactured filter media to reduce iron, manganese, hydrogen sulfide, and heavy metals from water through oxidation and filtration. H2K uses a variety of specialty media including Manganese Greensand, Katalox Light, and Filox-R for water filtration. These manufactured filter media use a manganese dioxide coating deposited on the surface of a fine-grained media. The manganese dioxide acts as a catalyst in the oxidation reduction reaction of iron and manganese.
Typical Filtration Applications:
Sizing of industrial sand filters:
H2K Technologies is a custom industrial sand filter manufacturer and our engineering team will support your project from initial design to turnkey system startup. Multi-media & sand filter design is different for every project and depends on properties of the process that requires water treatment.
- Concentration of solids: Higher suspended solids concentration will require lower sand filter loading rates and larger diameter vessels.
- Discharge limits and destination: The required effluent concentrations in the process stream helps determine the size of the filter vessels. Vessel diameter will increase as the restrictions get tighter for discharge allowances.
- Size of particles to filter: The loading rate required to adequately filter solids from the process stream needs to be lower for smaller sized solids. Finer filter sand and multiple layers of media are necessary for suspended solids removal below 10 microns.
- Source of backwash water: Filter backwashing is used to clean the filters and flush out the suspended solids that have been removed in the media bed. Backwash cycles can be designed either self-source or outside-source. Self-source backwashing uses water filtered by the duty filters. Outside source backwash uses an external source of clean water, such as a domestic water line or a storage tank.
Self-Source Automated Backwash is achieved by using the filtered water from the duty vessels and diverting over to a standby vessel. We manufacture turnkey sand filter systems with stock and custom designs. Self-source systems typically use three filters to allow enough flow for 12-15 gpm/ft2 of filter bed surface backwash flow rate. All cells are backwashed in sequence and an independent backwash water supply is not required. The filtration process will continue during the backwash cycle so the system is not “down” while backwashing. Sand filter backwash cycles are typically ten minutes per filter and are typically required between daily and weekly. H2K industrial sand filter systems are easy to operate and maintain, a pressure sensor, timer or manual initiation can be used to initiate the backwash cycle.
Air Scour utilizes pressurized air for backwash assist of filter media layers of the vessel. Air scour before the backwash cycle breaks up the sediment from the filtering media allowing it to be backwashed out easily. Air scour is typically done through a separate header which will be installed above the support bed.
Hydrocarbon or polymer loading in the process water can foul or blind the media bed permanently requiring media replacement. Hydrocarbons in particular will adhere to anthracite, so we do not recommend it be used when hydrocarbons are present. High residual concentrations of polymer should be eliminated and require more frequent backwashing to allow it be removed before forming a layer that is too thick to break up and backwash out of the filter bed.
Recommended Service Flow Rates based on filter bed surface area.
— 2-4 gpm/ft2 – Typical municipal loading rate for long bed life and 20 to 40 micron nominal filtering with less than 5 to 10 psi pressure drop when the bed is clean
— 4-7 gpm/ft2 – Typical industrial loading rate for large particle loading, long bed life and 20 to 40 micron nominal filtering with less than 5 to 10 psi pressure drop when the bed is clean
— 7-10 gpm/ft2 – Low loading industrial filtration for 40 to 100 micron nominal filtering with up to 10 to 20 psi pressure drop
— 10-15 gpm/ft2- Utility filtration only (no micron rating estimate) with up to 25 to 30 psi pressure drop
Recommended Backwash Flow Rates based on filter bed surface area
— 12-15 gpm/ft2 – Typical multi-media filter backwash flow rate
— 15-20 gpm/ft2 – Typical sand filter only backwash flow rate
Recommended Air Scour Flow Rates based on filter bed surface area.
— 2-4 cfm/ft2 – Typical sand/multi-media filter air scour flow rate
See our attached sizing program to estimate which multi-media filter vessels from H2K Technologies would meet your water filtration needs.
450 gpm acid resistant multi-media filter with automatic self-source backwash for lead filtration from wastewater stream. Custom fiberglass construction was required for this filter system to resist acid loading from upsets in a clarifier upstream. This turnkey filter system included (3) 6’ diameter filter vessels, PVC manifold and piping, pneumatically operated diaphragm valves, locally mounted control panel, and skid for entire system.
120 gpm Multi-media filter system with automatic self-source backwash and ASME rated vessels. System designed for wastewater from painting line which required suspended solids filtration before discharge. This turnkey filter system included (3) 3’ diameter filter vessels, PVC manifold and piping, PVC pneumatically operated diaphragm valves, locally mounted control panel, and system skid.
Dissolved iron removal
800 gpm Iron filter with automated self-source backwash and ASME rated vessels. This turnkey filter package removed dissolved iron and manganese from an industrial process using manganese greensand. The completed system includes (4) 8’ diameter filter vessels with schedule 40 carbon steel piping, fittings, and pneumatic-actuated cast iron valves.
25 gpm Industrial sand filter with FRP pressure vessels and automatically operated self-source backwash. Wastewater from plant processes filtered for suspended solids before discharge to sewer. The completed system, included (3) 18” diameter filter vessels with PVC manifold and piping, pneumatically operated diaphragm valves, locally mounted control panel, and packaged system skid.