Dosing problems - too much cleaning?

[starbro]

Hi All,

Been having dosing pump problems and was wondering if it might be related to overcleaning the unit.

We use a Spodoni DCBL 100 4m2 horizontal leaf filter that's approaching 16 years old. We do 20bbls at a time, once a day.
After each use, we do a full cleaning regimen:
- 30 min caustic (~150 degrees)
- 5 min light acid (~150 degrees)
- rinse (~150 degrees)

Is this overkill? I continually have dosing pump problems, especially with the packing rings failing and was wondering if too much hot water and chemicals are beating up my seals too quickly?

I've replaced the piston, top check valve and packing rings (3 times for those in less than two years), but leaking has always been constant to some degree. Now I can't get enough pressure to actually dose. Wondering if the pump head needs to be replaced next?

Any thoughts?

Thanks,
Mike

[Alex T]

Hi,

I'm not sure if the CIP is the root cause of your problem, but in my experience you could probably get away with a weekly CIP, and just do a daily sterilisation with 85degC hot water prior to filtration. Will save you some time and chemicals at least. Just inspect thoroughly to ensure soil isn't building up, and strip it down for a big clean as needed.

Cheers,

Alex

[dereknobleluke]

Hey man. I currently use a DCBL 80 3 square meter. I filter 60 bbl brews twice a week. After each filter I strip all the plates off, spray off all DE from plates and rings. then rebuild and tighten nut. Backflush scavenger plate and top plates with municipal water. Then rinse all lines thoroughly with municipal water getting all DE out. Then use 1.5 % caustic at 80 degrees (much hotter than that and I ahve found I damage the guide veins within the pump head). I circ for 15 minutes. then rinse all lines thouroughly (but not running the pump) with hot water (160 F). Fill the bell twice with 160 F water, draining each time and use this drain water to clean off all the DE on th floor etc... Then fill bell with cold water, nuke it with Iodophore and keep everything packed in iodophore. I use a heavy concentration with the I4 and haven't noticed much staining. When I get ready to filte the next time, I simply drain this I4 through all the ports and then begin pre-coating, but use PAA on my water and deaerate as well....

Haven't had a probem and we test beers before the filter and after the filter and no micro picjup at all.....

[dick murton]

I assume you are using some sort of piston or diaphragm pump. These do wear out as the KG / Celite is so abrasive but I would have expected it to las linger than you are reporting. If you do decide to replace, consider replacing with a completely new peristaltic pump of suitable size as these don't need valve seals. You will need to provide a bypass to clean / flush out the lines effectively. Actually, that's a thought. Do you have a bypass fitted to flush the lines out properly, running through the pump at the same time to clear out the pump ?

The cleaning regime will soften seals if they are not suitable. Check with the pump / system supplier what the most aggressive cleaning regime can be without risk of rapid degradation.

[starbro]

Thanks for the replies! Put new packing in the pump head and the piston could barely move. Took some lube and hot water to get it going again, and then it still leaked (not as bad as the last packing, though.)
I'll price out a new pump head and make a decision to get a totally new pump, as this one could nickel and dime us pretty quick.