Self-Indexing Filter

A self-indexing filter is a system that uses filter paper to remove solids from water. The unit works by feeding a filter paper media off a roll and laying it on a mesh support that forms a trough. Water is either gravity-fed or pumped through an inlet where it is distributed across the width of the roll so that it is evenly released onto the paper. The water flows down the paper and settles into the base of the trough where the solids in the water are captured by the filter and the water falls through into a collection tray. The solids will eventually clog the filter media and cause the water level to rise. Once a pre-set level sensor is reached, the media will be ‘indexed’; new paper will be fed off the roll to replace the clogged media in the trough. The removed solids are trapped within and on the filter media and will stay with it as it is rolled out of the unit. The paper and solids will then dry and can be disposed.

Figure 1: Components of and incoming and treated water flows through a self-indexing filter

There are advantages and disadvantages to this system. The amount of paper necessary will depend on the amount of solids in the water; more solids will mean more paper being used. The paper traps the solids and both can be disposed of together. It is automated equipment and can be run with minimal operator input. The pore size of the media can range in size from less than 10 microns to 200 microns so it can be customized to a facility’s needs. This system is a proven technology and available from multiple suppliers.
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References

• Clearstream Filters Inc. (2009). Operation Manual Myco Self Indexing Unit. In Myco Media Filter. Retrieved April 29, 2016, from http://www.clearstream.ca/mmfmanual.pdf
• Water Maze. (2016). Mechanical Filtration. In Wastewater Technology. Retrieved April 29, 2016, from http://www.wmaze.com/wastewater-technology.aspx