Works Filter NZ Ltd

Porous Ceramic Dual Media Filtration has a number of advantages:




* Increase in flows of up to 100%

* 100% increase in Run Times

* More efficient Backwashing

* Removal of floc carryover


These are achieved by:




* Higher head pressures on the fine media

* More "Filtration" Media

* Complete fluidisation of the media

* The use of surface charges


The PCDM-Filter won the 1995 ECNZ Rutherford award for energy efficiency, innovation, environmental friendliness, and commercial potential.



The PCDM-Filter has 3 key elements.
Silicon-Sponge is a modified Aluminium Silicate with a huge surface area and high porosity. The surface of the processed media has a high negative charge which attracts and retains positively charged materials including Alum floc carryover, Iron and Manganese. These are released in a short vigorous backwash which leaves the charge intact.
Silicon-Sponge has been added to existing filters to increase runtimes, prevent floc carryover and improve water quality. This extra top layer (in place of some sand or anthracite) provides immediate operational and commercial benefits at a modest cost.


PCDM-Nozzles are manufactured from Sodium Silicate and Titanomaganetite. They can be manufactured in any shape or porosity, and are chemically inert. The Nozzles are each capable of passing 50 Litres of water per minute, and they can be retro-fitted to existing filter bed floors using existing stems. Above floor collection systems are also available to improve water collection and backwashing.


By replacing all the support media in the filter, the nozzles allow fine media to be placed at the base of the filter. They can be designed for special applications including fluidisation of very dense media.


PCDM-Sand is very evenly graded to increase porosity and retain the small pore sizes. This allows more water through a finer "mesh" than any other sand media, improving the quality of filtration. The sand is unable to pass through the ceramic nozzles and sits at the base of the filter under a higher head of water.


Backwashing


The whole PCDM- Filter is fluidised during backwashing. This unique feature ensures the whole bed is cleaned thoroughly and eliminates any possibility of preferential flow paths forming in the media. Due to the distinctly different specific gravities of the media, the media can never mix, so short, vigorous automated backwashing cycles are possible, saving energy, water, and filter down time.


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Silicon Sponge


Attributes







* Effective filtration Media

* Negative surface charge

* High effective surface area

* Irregular surface texture

* Low specific gravity

* High abrasion resistance

* High floc retention

* Low aluminium and iron residual

* Easily backwashed

* Low backwash water volume


Uses




* Capping filters

* Replacement for anthracite or filter coal

* PCDM Filters

* Pressure filtration

* Gravity filtration

* Scalping filters


For a discussion on design and build, or for water treatment or waste treatment, call us.