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AFM Stainless Steel Pressure Filters

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General details
AFM Filtration media
pH control, heavy metal and iron removal
Oxidation and maintenance of redox potential
Mixed Bed Filtration
Leachate treatment
Stainless steel filters filter specification
DIN standard polyester pressure filters

Bacterial Implications

In cases where the bacterial quality of the product water is of ultimate importance, stainless steel filters are the nest choice. Plastic has a microporous structure which can become contaminated by bacteria and fungi. This is often observed as a discoloration which can sometime be seen on the out-side of the the filter shell. Stainless steel filters no not suffer from this problem since they are less prone to bacterial contamination, and can easily be disinfected.

General details

The catalytic pressure filter is manufactured from 316 stainless steel, and is designed for heavy duty industrial use in water and waste water treatment. The filter is designed to be very strong and virtually maintenance free.

The shell of the filter is constructed from stainless steel with a false bottom internally near the base of the shell. As opposed to using laterals, the stainless steel filter uses wedge wire plates on the base of the structure. The wedge wire prevents the filter media from escaping from the filter and provides for an extremely strong structure.

The filter is designed to operate up to flowrates of 100 cubic metres of water per hour, however any flowrate up to 100 cubm/hr can be used. Generally the slower the water is passed through the filter, the better the filtration performance. The rate of filtration depends upon the choice of filtration media, the type of water to be filtered, and the desired results that you wish to achieve,  in this respect there is more information presented the filter media section at AFM Filtration media

pH control, heavy metal and iron removal

In addition to the AFM, MagpHlow can be added to the filter, this product is composed of magnesium oxide that dissolves in the water in direct response to the pH of the water. The maximum pH that can be developed by the magpHlow is pH 8.3.

When magpHlow are used in the catalytic sand filter, iron and heavy metals will precipitate out of solution on the surface of the magpHlow. On back-flushing the filter the iron and metals will be removed by the action of the sand ( or AFM) on the surface of the magpHlow.

Oxidation and maintenance of redox potential

The addition of ozone to water increases the redox potential of water and starts to oxidise any particles or metals in the water. The ozone will also oxidise bacteria, viri and parasites. Ozone (O3) works by degrading back to oxygen (O2) and a free radical of oxygen. It is the action of the free radicals that is responsible for the oxidation reaction attributed to ozone.

A catalyst can be added to the filter media, and a small amount of hydrogen peroxide can be added to the water prior to the filter. Hydrogen peroxide is H2O2 and it degrades to water (H2O) and a free oxygen radical. The radical is exactly the same as the product produced by ozonation.

Ozone is unstable and degrades to oxygen and the free radical very quickly, however hydrogen peroxide is very much more stable that ozone, it therefore requires to action of the catalyst to initiate the reduction step. In this manner we have mimicked the action of an ozonation system without the use of ozone.

Mixed Bed Filtration

The fused silica ( AFM) magpHlow and catalyst can all be added to the one stainless steel filter. The unit will mechanically remove solids down to 10 microns, and smaller particles by electrostatic attraction. The magpHlow will provide pH buffering and will reduce the concentration of heavy metals. The catalyst in conjunction with hydrogen peroxide will keep the filter clean, it will also start to oxidise metals, organics, bacteria, fungi and parasites. In this manner it mimics an ozonation system.

Filter specification

The filter is termed a horizontal unit which measures 1.2m in diameter and 2.5m in length. the height of the structure is 1.5m.

 

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Last modified: May 26, 2008