Advanced Media Filters – Amiad Dual Vortex Filter
A range of high efficiency filters that filter to produce a clean supply of water that is free of solids down to sub-micron levels and have a reduced bacteria count.
- 6 filter sizes, ranging up to 68m3/hr per vessel
- 0.45 – 10 micron nominal degrees of filtration
- 1 bar min operating pressure
- Stainless steel construction (ANSI 304 or 316)
- DWI & WRAS approvals
- Up to 99% filtration efficiency
- 5 times more flow than a conventional media filter = smaller plant footprint
- Short backwash times compared to standard media filters
- Low backwash volumes, reducing backwash loss of process water by up to 95%
- Multiple applications across many industries
- Side stream filtration of process & cooling water
- Highly effective swimming pool filtration
The Dual Vortex Filter (DVF) is a development on traditional media filters that brings a more effective solution for water filtration than was previously available.
The removal of microscopic contamination, such as iron oxide & manganese (magnetite) as well as bacteria, spoors & organic material.
This removal of biological loading from the water means that chemical dosing will be far more effective due to the reduced challenge it faces, thus saving money from the significant reduction in chemical use and providing a more environmentally friendly solution to water treatment.
The Filtering Process
Untreated water enters via the inlet which is located at the top of the vessel and is passed through the patented DVF vortex generator. This pipe has a dual outlet configuration inside the vessel which generates a double vortex. This allows for the solids to be suspended above the filter bed. This leaves the water being cleaned free to pass through the specially constructed media bed with less resistance whilst giving the filter bed longer life before backwashing is needed. The filter bed is constructed of 4 different grades of Active Glass media of which the coarse layer is used at the bottom, followed by 2 additional layers of support media and the special blend top layer. The cleaning process is achieved by backwashing the media.
The Self-Cleaning Process
Backwashing the filter bed is achieved by either a set time or, if backwashing is needed sooner, a pressure differential gauge which triggers backwashing when the pressure differential reaches the pre-set value.
Once this has been triggered, the self-cleaning process begins: The inlet valve shuts followed by the process water out valve. The backwash valve then opens followed by the drain valve. This forces the water being used for backwashing up through the nozzles at the bottom of the vessel, through the filter bed which lifts the solids from the top layer of the media. The unique nozzle design & layout ensures even flow distribution into the bottom media layer, to ensure even backwashing.
Once lifted off the bed it is discharged through the drain which is located at the top of the vessel. When the backwash is finished at a pre-determined time, the valves shut in reverse and filter process is resumed.
The backwash volume is typically so minimal that in the case of processes where the water is of monetary value (eg heated or chilled water, chemically treated water), a separate tank of backwashing water can be used so there are no losses from the process water.
The Control System
The Amiad AC controller which is used with the DVF Series allows for the backwash timings to be altered to suit the specific site requirements. It also allows for pumps to be added to the system to aid with process and/or backwash flow. There is also a manual backwash facility which will work in conjunction with the set time and differential pressure settings for the filters.
The self-cleaning cycle is initiated as a result of any of the followings:
• Receiving a signal from the pressure differential gauge
• Time interval parameter set at the controller
• Manual start
• Remote access