Filtering and pumping on a small scale

UPDATE 11/19/2012: Added video to the end of this post.

Yesterday I pumped and filtered over 1000 gallons and all my equipment worked really well with no hitches and me working all by myself (per usual). As I was learning about commercial scale cidermaking I would have been overjoyed to find all the filtering and pumping details in one place so here they are for any other aspiring cidermakers.

The big spaceship looking thing in the middle is a lenticular filter housing, made by Pall. It uses SupraDisc media, 12″ in diameter, three stacked on top of each other. In my operation, I only filter to 7 microns nominal which is considered a coarse filtration.

The filter housing is pricey and the media is too. I’ve never used a plate and frame filter but from the discussions I’ve had with brewers, lenticular filters are much easier to use, waste no cider, are easier to set up and break down and do a very good job. I am certainly happy with it.

The cider is pumped from one container to another, through the filter. I use valves on each end of the filter. The input valve is used to control the flow and thus the pressure buildup in the filter housing. Too much pressure forces the little bits that I’m filtering deep into the media, reducing the life of the media. A valve on the outlet lets me move from one target container to another without all the cider pouring out of the housing. In addition to the two valves, I use two pressure gauges. It is the difference between the inlet and outlet pressure that determines how far you’re pushing crap deep into the filter. My Pall technical representative say to keep the two pressures within a few PSI of each other. The last bit-n-bob on each end of the filter are sight glasses. These aren’t really necessary but they’re very helpful so I can see how clear my cider is getting as well as debugging any foaming/loss of suction problems I might have. Sight glasses are pricey fittings but are worth it to me.

I’ll discuss my use of plastic HDPE IBCs for my primary fermentation tanks in a future blog post. They’re tough, inexpensive, readily available and with some modifications and adapters, are easy to use with standard tri-clamp fittings. In yesterday’s rackings, I transferred from these containers to my PaperIBCs. Both containers had hoses attached directly.

After I get everything hooked together (except connecting the source and target containers on each end), I hook the inlet hose up to a garden hose and run a whole bunch of water through it. I store the filter media soaked in a sulfite solution – they’re wet all the time. I pump water through the filter until I can’t taste or smell sulfite any more, and can’t taste or smell filter media. One area to improve upon is doing a quick ripper free sulfite test to ensure thorough flushing. Then I run a bunch of gallons of sanitizer through the system, purge via CO2, then hook up the containers at both ends and begin sucking cider. Despite doing my best to purge water before sucking cider, the first few gallons look mostly like water but it very quickly transitions to straight cider.

All this setup time means that once I start filtering, I like to do as much as I can. Yesterday I filtered one batch of Deliverance Ginger and three batches of Hallelujah Hopricot. Breakdown of the whole kit is pretty quick. I reverse the position of the pump so it’s pumping backwards through the filter housing and run about 150 gallons of water through it on full-blast. My pump is a 1 HP 3450 RPM Thomsen #4 so it puts out some serious water. It’s that high pressure backflushing that is crucial to prolonging the life of the filter media.