DynaSand WWR can be used for final polishing in the final step of the purification of waste water. Due to continuous washing the DynaSand filter can purify waste water with high concentrations of particles, so that you get about 3-4 times higher capacity compared to backwashed sand filters. Washing of the filter media is adapted to load and flow.
Efficient wash water reduction and improved cleaning efficiency
With DynaSand you also get an effective cleaning water reduction by alternating periods with and without washing the filter sand. During a period without washing no washing water is produced and no air is consumed by the integrated airlift pump. Thereby you reduce both energy and wash water consumption. Additionally, you can achieve a better degree of purification with a stationary bed of sand.
Mechanical, chemical and biological purification
If you wish to precipitate phosphorus and increase the degree of purification of particles, you can use contact filtration with aluminium or iron salts as a flocculant. You can also combine the final polishing with filtration and biological denitrification in the same filter step.
Mechanical purification reduces particles, chemical purification reduces phosphorus and biological purification involves the removal of nitrogen.
The advantages of DynaSand WWR
¥ Low energy consumption
¥ Low wash water consumption
¥ No stop for backwashing
¥ Handles large variations of incoming susp and flow
¥ Handles high levels of suspended particles without requiring pre-treatment
¥ No need for a stand-by filter to compensate for the filter in the backwashing
¥ High reliability and low need for monitoring and maintenance
¥ No pumps and valves for the backwash
¥ No tank for rinsing water
¥ No collection tank for wash water
¥ No blowers for purge air
This is how DynaSand WWR works
The incoming water is led down to the inlet manifold in the filter bottom. Suspended solids are filtered out when the water flows upwards through the filter bed. The filtered water is directed to the drain conduit via the weir in the upper part of the filter. Using compressed air an airlift pump in the centre of the filter draws sand from the bottom up into the sand wash where the particles are separated from the sand. The sand bed moves downwards during washing. A valve in the wash water pipe opens during washing and a small portion of the filtrate is directed through the sand washer and used for washing the sand before being led away as wash water. The clean sand then falls down onto the filter bed and is re-used. Airlift pumps and filters are adjusted and controlled via a pneumatics cabinet.
Thanks to the intermittent operation of sand washing the amount of wash water is significantly reduced. Running the sand washing in cycles also reduces energy consumption significantly because of reduced air consumption. And since the sand bed is stationary during filtration, a higher degree of purification is also achieved.
A pressure sensor detects if the filter resistance increases due to the high susp load. An additional washing is done and the filter automatically returns to intermittent operation.
The respective filter is started and adjusted via the pneumatics cabinet that is supplied with the installation.
Two variants – one method
No matter how big or small your facility, we can adapt DynaSand to your circumstances. Smaller plants typically use standalone DynaSand filters while concrete installations are often used at larger works.
If you select a standalone DynaSand filter you get a device consisting of a cylindrical tank with a conical bottom and internal filter elements. The filter has flanged connections for inlet, filtrate and wash water. The filter system can consist of one or more filters depending on the desired capacity. If you select multiple filters they are connected to the pipework that distributes the incoming water and drains off filtrate and washing water.
If you want a facility with high capacity it usually takes the form of filter modules mounted in concrete tanks. The filter cells (each consisting of several filter modules) contain bottom cones in stainless steel or FRP and internal filter sections and have a common sand bed. Your facility can be designed for a virtually unlimited filter area allowing DynaSand to be used in both small and large facilities with very different capacities.