Issues with CIP recirculation on serving tanks - pump pulling air, "chugging"

[Ajchocholousek]

Hey all,

First post here, just joined the site! Also, fairly new to the brewing community. I just recently got bumped up to full-time assistant brewer at our relatively busy (1,200 bbl/yr) brewpub in Duluth, MN.

I'm looking for some advice here on CIP spins on serving tanks. We have 15bbl serving tanks that feed our taps and our general SOP for cleaning them between fills is to depressurize/vent, break it down, scrub all small parts, build it back up, rinse twice warm with floor pump and dosing tank through CIP arm, drain, push 50 gallons of acid in and then recirculate that for 60 minutes. Rise twice cold, then purge, sani (if needed - we don't sani if we are pushing a beer into it within 24 hours of acid cleaning), and cap or fill.

Sometimes (more often than not), I have trouble keeping the recirculation going smoothly. The pump pulls air and chugs and will eventually come to a stop. At that point, I usually let the liquid settle down in there and try it again. After a few shots, it usually goes.

I'm wondering what could be causing this either in my procedure or environmental conditions in the serving room. Sometimes I try keeping some positive pressure in the tank, by closing the zwickel before it has a chance to blow off all pressure while pushing acid into the tank. This seems to help a bit, but not everytime. It seems really inconsistent.

Anyone have any advice for a greenhorn in the industry??

Cheers!

[Dough In]

Primed pump?

Seems to me that your pump is not primed and that air is causing your issue. If the pump stops like you say that could lead to serious issues. Have you released the air in the pump?
Put a 90 elbow with a butterfly valve on the pump outlet and make sure you open the valve and let liquid flow through the pump head releasing all air out of the line. Also make sure you have enough liquid in the tank. not enough liquid could be creating a vortex at the bottom of the dish. There are stainless steel "crosses" (dont know what their called) that can be placed in the hole at the bottom of the dish that hinder a vortex from forming. Another way is to add more liquid so a vortex cant form.
Hope this helps

[dick murton]

You have a pump that is almost certainly not self priming, and cannot cope with the entrained gas in the supply to the pump. This is probably made worse by a couple of conditions. Firstly, the outlet of the tank is probably restrictive for CIP as it is designed to run beer out slowly to the serving points, not for CIP flow rates. Secondly, the I suspect the bottom of the tank is dish shaped, and this allows horrendous vortices to form. This can be overcome to some extent, as stated, by fitting a vortex breaker, typically a cross of stainless in the outlet. Sometimes this is fitted with a top plate, which helps reduce the vortices, but is not as hygienic - so not recommended for beer - OK for a CIP tank.

If you get a self priming pump, then it may not be capable of generating sufficient flow to spray the tank effectively.

The best, though unfortunately most complex solution is to have a separate CIP tank, with a properly sized delivery pump to the sprayhead, and a separate scavenge pump which runs CIP back into the CIP tank. It is common for the delivery flow rate to exceed the scavenge rate, so periodically you will need to stop the delivery pump and allow the tank to drain completely. For effective cleaning of the tank, the tank bottom should not be ponded continuously, as the area which is ponded is only soaked, not scoured (think of manually washing up your dinner dishes - you don't simply leave things to soak do you? You use a brush or cloth to scour the surface as well).

Simply putting top pressure on the tank means you have to have a bigger delivery pump to overcome the top pressure and achieve good spray action.

[Ajchocholousek]

Thanks for the replies, y'all.

I'm 99% sure that what is happening is indeed a vortex. I filled up a tank a little while ago and watched the water drain out and it was spinning like mad with a huge hole in the middle. I would be interested in exploring a vortex stopper, but I'm hesitant to install that directly into a serving tank, for the sanitation reason you alluded to.

The pump is fully primed when I start. I run liquid out of our dosing tank through the inlet and right up to fill the outlet, thus getting any air out the pump head itself. The hose going to the CIP arm, however is empty when I start. Is that an issue, potentially?

I may explore using our dosing tank as a "cip tank" to act as a buffer in between the tank and the pump rather than scavenging directly from the bottom valve of the tank. I wonder, though, how it would fill up the dosing tank seeing as it'd have to push up a little bit rather than just out and down like it does to the pump head. So my set up would be...

pump outlet > high pressure hose > CIP arm
bottom valve on tank >drain hose > back into next highest valve from bottom on dosing tank
dosing tank > hose > pump inlet

?

[Dough In]

Vortex hinder

Contact Premier Stainless in San Diego. They make them and they are of high quality SS. Easy to install and remove after CIP/Sani of Serving tanks. Not need in conical unitanks.
Cheers

[stephenstraub]

Thanks for the replies, y'all.

I'm 99% sure that what is happening is indeed a vortex. I filled up a tank a little while ago and watched the water drain out and it was spinning like mad with a huge hole in the middle. I would be interested in exploring a vortex stopper, but I'm hesitant to install that directly into a serving tank, for the sanitation reason you alluded to.

?

We just put an elbow in the bottom of the tank, kinda over the outlet to break the vortex. Pull it out after the cycle is done, make sure that any orings and such are not put in with the elbow. It's worked for years.

[fuelforthehate]

We just put an elbow in the bottom of the tank, kinda over the outlet to break the vortex. Pull it out after the cycle is done, make sure that any orings and such are not put in with the elbow. It's worked for years.

+1

I've also used a tri-clamp to break any vortex.

[lhall]

Just throw a 90 or tri-clamp fitting in the bottom of the tank to break up the vortex.

[Ajchocholousek]

We just put an elbow in the bottom of the tank, kinda over the outlet to break the vortex. Pull it out after the cycle is done, make sure that any orings and such are not put in with the elbow. It's worked for years.

Do you mean on the inside of the tank? "Above" the outlet? Is it secured somehow?


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[stephenstraub]

Do you mean on the inside of the tank? "Above" the outlet? Is it secured somehow?

Yep, just put it in the bottom of the tank. Once you find the right "arrangement," it works consistently. It is not secured. We use a DN40 male/female elbow & center the male flange over the hole.

[beerguy1]

One other thought I am not sure if you have a sight glass on the side of the tank. They are always filled with ait that goes right into the pump and can cause priming issues. We always shut the valve at the bottom of the sight glass so solution cannot flow thru then slowly open it to allow cleaning

[Ajchocholousek]

Thanks for all the help, y'all.

Basically I resorted to spinning with 75 gallons instead of 50 and it seems to spin first time, everytime now. So, although we are using a nominal amount more acid, we are wasting less time. Probably evens out.

Still curious, though, to those of you who are still following this and suggested a anti-vortex device such as a tri-clamp or an elbow: are you doing this on tanks that have low-level, front manways? Our tanks only have top accesss, so I'm not sure how I'd ever get the device in there and be able to remove it. the outlet pipe is welded to the hole in the bottom of the dish.

Anyway, hope everyone has a good new year.

Cheers.

[dick murton]

No problem. With a bit of care, you can make a vortex breaker which will fit securely in the hole, fit a rigid loop to the top and then use a hook device on the top to lower it in and position it securely, then lift it out after the end of the clean. I've used one with great success with an upstand device whilst covering at one place, but unfortunately didn't make any proper notes about the design, so can't give any more details. If you drop it in the bottom it is easy to retrieve an lift out or reposition.

[Coolhand]

My guess is that Mike was right, you're pulling in air from the sight glass. You should not have to put that much volume in the tank (nor do you want to pay for that much chemicals) to get it to circulate.

Justin