Hop pellets in heat exchanger

[oppigards]

When pumping the last wort from whirlpool through the plate heat exchanger some hop pellets get caught in the heat exchanger. I do not get rid of it iwth current CIP pump so I have to screw it down and clean each plate. SO know I´m going to place a sieve before the heat exchanger. Is this a common solution? I might have a to small CIP pump? Or should the goal be to have a wort absolute free from hops?

[Diamond Knot]

Oppigards,

We use a converted beer keg in between the kettle and the heat exchanger. The keg has an open top so there is open, easy access to the inside. On the side is a tri-clamp fitting and there's one at the bottom side of the keg as well.

We attach a tee on the inside and attach (2) nylon fine mesh bags to act as in-line filters to collect pellet residue and trub so it will not pass to the heat exchanger. Originaly, we used this process to put hop pellets in the bags to create an in-line hopback to create more hop aroma for our IPA. The bags work well, but have to be replaced every so often due to rips and tears.

After finishing the brew, we would backflush the heat exchanger with 180F hot water. At each keg washing, we would backflush hot caustic through it as well. The heat exhanger is portable and on a cart in our process.

As well as all this works, we still remove the heat exchanger plates on a periodic basis to clean any film and debris.

Regards,

[Tbrew]

Pelletized hops added during boil or in Whirlpool(WP) during transfer should not be able to rapidly clog your heat exchanger(HE). Opening up your HE should be a bi-yearly or quarterly event not weekly. Sounds like you might first see if you could limit the amount of trub(including hops) that is getting drawn from the WP.

If flat bottom WP
First, do you have a compact trub pile that resists collapse? If not try a kettle fining like Irish moss(carageenan). I find the refined versions work much better (Quest Whirlfloc is one). Strong boil is also important. Also the less objects projecting into the tank the better. Can anything be removed or altered to allow maximum whirlpool effect?

If cone bottom
Is your draw off port at the correct height? If not, weld a tri-clover ferrule in the tank and place an elbow on it. Now adjust the elbow up or down to optimize. This arrangement can be adjusted for brews with a lot of hops or little thus maintaining wort quality while maximizing yield.

As Diamond Knot suggests when CIP'ing the heat exchanger use reverse flow (or at least pre-rinse in reverse). This will remove lots of material that would not make it through the first pass zone.

Hope that helps.

[Alex T]

Hi,

Both breweries I have worked at have had strainers in the line prior to the heat exchanger. I believe the first place I worked didn't have one initially and then blocked the heat exchanger in no time.

There should be strainers you can buy with DIN, BSM or triclover connections which you can have cut into your wort line - suggest contacting your local filtration company for some ideas.

Cheers,

Alex

[tarmadilo]

I've always used the transfer pump, rather than a c.i.p. pump, and like the others, done a backflush rinse and then a backflush cleaning of the heat exchanger.

Our heat exchanger was always pretty clean when we'd open it up for an inspection!

Cheers, Tim

[oppigards]

Thanks for the advices. I have not thought of rinsing/cleaning the H/E in the reverse direction before. I will try that next time with a better pump. I will also try to use an inline sieve.

[damoller]

I have brewed on 2 types of systems. Specific Mechanical and LVC. These two are quite different but they produce the same results. I had no problem with hops in the chiller. Are you doing proper rests before and after whirlpooling?

[Sir Brewsalot]

I haven't typically used a rest before or after whirlpooling, and am interested in hearing what others do, and for how long.

It could explain quite a bit, now that I'm thinking about it. Cone formation is not what I'd call structurally sound - but since I'm a newbie, I don't have much to compare it to.

Cheers,
Scott

[Diamond Knot]

Originally posted by Sir Brewsalot
I haven't typically used a rest before or after whirlpooling, and am interested in hearing what others do, and for how long.

It could explain quite a bit, now that I'm thinking about it. Cone formation is not what I'd call structurally sound - but since I'm a newbie, I don't have much to compare it to.

Cheers,
Scott

Scott,
We have a flat bottom direct fire kettle and my observation is that whirlpooling flat bottom kettles between 5 and 10 Bbls really doesn't ensure much. We whirlpool and settle for 15 minutes, but still use the hopback / in-line filter and get debris in the nylon bags.
I've seen much better results with slightly conical bottoms, such as those found in steam kettles. Books I've read on air cyclone design corroborate the fact that conical bottoms produce better centrifugal debris removal.

Just my $.02..............

[dick murton]

Just to add to all the previous comments

The key to achieving a good hop cone is the casting speed. According to the major suppliers the wort should enter the whirlpool approx a third of the way up the final wort depth, at approx 15 degrees from the tangent (inwards). You should tehn get a decent trub cone in the centre after about 10 to 15 minutes. You could start drawing off at high level after say ten minutes, and when this takeoff point is nearly uncovered, switch to one at the bottom on the periphery of the WP. If you leave it to settle to long, or the inlet speed is too low you will get a trub cone spreading out across the bottom.

Watch out that you are not adding so many hops that the sheer volume will not allow a clean peripheral area round the cone. Wort depth to diameter should be aroun 1:1, though you can cheerfull go somewhat outside these limits depending on your wort composition.

You should be able to obtain clear wort with vitually no hop debris passing through to the FV.

I agree with the use of copper finings providing you are not brewing to the Reiheitsgebot. They will also assist final beer vcarity prior to filtration, as they help protein sedimentation. A good rolling boil in a traditional copper is essential to help protein coagulation.

Back clean your heat exchanger at least as fast as you push wort through it. Check your HE is sized correctly. If it is too big, tehn the flow rate in the HE plates drops and allows the hops and protein carryover to be deposited here instead of the FV.

By all meand use a filter, but it shouldn't be necessary if the wort quality and equipment is OK.

If you let the trub cone cool, it should go so solid you can walk on it - but don't let is cool, as it is then a b***** to clean out.

Cheers

[Sir Brewsalot]

Thanks everyone. I'm getting a lot from this discussion. I never cease to be amazed at just how much I don't know. The more I learn, the more I learn I don't know.

I whirlpool in my brew kettle, which has a dished bottom - a bit of a compromise between conical (whirlpool) and flat (kettle). All my hops are pelletized, and I chuck in a handful of dried Irish Moss flakes with about 20 min to go in the boil. Batches are in the 7-10bbl range. Boil is VERY vigorous.

The cone I get is no where near 1:1 - more of a pancake really, at probably 8-10 in high and 4 feet plus in diameter. This is after a 20 min whirlpool, no rest, but a pretty slow transfer, which I suppose can act like a settling rest. To your comment Dick, yes, I get virtually no hop debris transferred to the FV - after the first 15 min of transfer, it's all plugging up the heat exchanger!

Last brew after a super slow xfer, I left it soaking in hot PBW overnight, (maybe pushed in backward - I can't recall), then a hot flush the next day. Hopefully that should improve things next time ... until it clogs up again mid way thru knockout.

Maybe I need to look at a way to put in an in-line filter/hopback - might be able to use the grant somehow.

Thoughts?

Thanks a whole mess!
Scott

[jipjanneke]

Just found this ... might be helpful for an easy filter?

http://www.rubberfab.com/gasket_screen.html

Also, you need to get your whirlpooling time (i.e. time from end of boil until all wort is cooled) down to less than two hours to avoid DMS flavour problems later...

[damoller]

Where in the tank are you running wort from? THe center of the dish or an side ouilet? The 2 types of systems I used specific has a cone bottom and draws wort from the top of the cone at the side. The JVC direct fired had a flat sloping bottom(toward the outlet) and the runoff outlet was recessed into the bottom at the low point in the slope.
In both systems the trub looked more like a large dog had deficated in there. Building a cone of large tube rod shaped coagulants in the center!
Dick gives the mechanical design required for the optimum coagulation. Speed iof the wort in the whirlpool is also important in the equation!

[damoller]

I used a 15 minute rest before and after the whirlpool. I ajusted this number up and down to see what would happen and increasing the rest did nothing but decreasing reduced coagulation and sedimintation!

[admin]

This discussion has been moved to Process and Techniques.