Article written by FCX Performance, Inc
Pros:
Little maintenance needed
Save time on maintenance since the filters clean themselves!
With backwash filters, contaminants are collected on the outside of the filter media and are automatically cleaned off the media when differential pressure reaches 15 PSI. The filter is cleaned with either a reverse flow of filtered product (internal backwash) or an outside product (external backwash) that blows the solids off the media and dumps it down the drain.
Mechanically cleaned filters are typically cleaned by a spring-loaded brush (minimum of 200 micron) or a spring-loaded disc/wiper (minimum of 25 micron) which scrapes contaminants off the inside of the filter media and pushes them down into a purge chamber.
Since they are self-cleaning, maintenance is not required for manually replacing the filter media; however, they do require occasional preventative maintenance.
Lower operating cost
Not only can you save money on maintenance, but you can also save money by reusing your filter media and potentially save or reprocess product. Backwashing filters can repurpose most water or water-like fluids and dispose 1-5% of the inlet flow material. For example, a paper mill can use a backwashing filter and the backwash can be sent to upstream areas, closing the loop. Mechanically cleaned filters are optimal for industries with high value product because it only disposes 0.1-0.5% of inlet flow material.
Cons:
Must be able to dispose backwash and purge material
With 1-5% of material being consumed in backwash filters, it is essential that you have a designated location of disposing your contaminants. Additionally, despite not having to throw out as many products compared to a backwashing filter, you still need a location to dispose contaminants from the purge chamber of a mechanically cleaned filter. Overall, you must have a location to dispose of or reprocess backwash or purge material in order to have a self-cleaning filter.
Higher upfront cost
Both backwashing and mechanically cleaned filtration systems are more costly upfront compared to other systems. However, the high capital cost can make up for itself with the money you save in the long run with less maintenance, filter media costs and less overall product waste.
