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Walnut Shell Media Recycling And ORF/AF Service


The purpose of walnut shell recycling/reconditioning is to remove the unwanted contaminants present in new and used media, reducing pressure differential issues at substantially reduced costs compared to using new media alone.
Why Recycling Is Often Better Than New
After a walnut shell filter has been in operation for months to years, the filter media wears and becomes rounded and more resilient. It would be advantageous to continue using this media, except that it contains small, worn fragments that plug the internal screens and that also promote surface load. New walnut shells have unwanted meat, husk, fines, and softer pellicle present. The concentration of these off-specification contaminants varies considerably in aftermarket shells. The backwash process wears down the off-specification material and should discharge the residue, however, the fine shell fragments do not always discharge from the filter and often end up plugging the internal screens. If the concentration of the fine shell fragments becomes too high, the filter will surface load the media and the internal screens, causing unwanted pressure differential. The recycling process removes the media from the filter vessel, adds high volumes of water and then passes it across a vibrating separator in order to remove the fines and, in turn, recover the appropriately-sized media. The on-specification media is then stored in bulk bags so that filter internals can be easily accessed and serviced. The media is then returned to the vessel once the internal service is complete, and the vessel placed back in service.
Internal Screen Cleaning and Filter Service


Once the filter media is removed and screened, it is stored in bulk bags so that the filter internals can be serviced. If fine shell fragments build up in the filter, they can plug internal screen assemblies, causing differential pressure drop. The differential pressure drop can accelerate the formation of scale build-up on, and under, screen panels. Non-fragmented media (after recycling/re-screening) reduces screen plugging, which in turn reduces pressure differential and scaling issues.

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