Calcium Buildup in HLT

[KaskaskiaBrew]

Our water is insanely hard. Our calcium level is 97ppm and our bicarbonates are 456ppm. In order to drop the ph, we acidify the water in the HLT the night before with phosphoric acid while it's heating and that drops the ph to manageable levels. The problem is that it leaves a thick white shell of calcium around the whole interior of the tank. I've looked everywhere and I can't find an easy way to get rid of it. I thought about using Lactic acid instead to create less precipitates but I've also read that it could add flavors to the beer that phosphoric acid doesn't. Is there any easy way to get rid of this calcium shell or even prevent it from happening?

Cheers,

[brewmaster 2011]

Have you tryed to boil the water in your kettle and whirlpool it the day before you brew? I do it with the spring water I use for one of my beers. It helps get the bicarbonate out of solution. Then I cip the kettle with a nitro/phosphoric acid blend to get any calcium build up off the wall, then i add lactic acid to the water to bring down the ph.

[KaskaskiaBrew]

Normally I recirculate the HLT while it's heating but I can give it a whirl in the kettle. I've also thought about switching to Lactic acid so the calcium didn't drop out so I might give it a shot too. Thanks for the response.

Cheers,

[meadman]

We have a 1000 gal. dairy tank for our HLT, and we had over 1/2 inch of build-up. I CIP'ed about 40 gallons of water with a heavy dose of Ultra-Niter, then let it soak over night, then get in with a drywall knife to scrape of the build-up.
Use about 1 gallon of ultra niter, if I remember correctly.
But the overnight soak seemed to do the trick. Sorry I didn't check the ph.

Hope that helps.

[redwood_]

Normally I recirculate the HLT while it's heating but I can give it a whirl in the kettle. I've also thought about switching to Lactic acid so the calcium didn't drop out so I might give it a shot too. Thanks for the response.

Cheers,

Only hearsay, but have you heard of a threat of lactic maintaining a sour taste over a certain dosing threshold? Will a direction substitution of the same volume leave you with overly sour brewing water?

Just something someone said to me, no practical application to back this up.

[brewmaster 2011]

that depends on the buffering capacity of the water.

[dick murton]

The trouble is that calcium phosphate is almost totally insoluble so you will end up with sludge / scale almost whatever you do. However, we used to treat water with HsSO4 to achieve a pH of 7 and then trickle it (cold) down a degassing tower. This seemed to precipitate the sulphate out faster to get a slightly softer sludge which could be removed periodically. Perhaps blowing purified air through the treated water would work almost as well. Unfortunately I am not aware of anything that really shifts CaPO3 - EDTA maybe? Or perhaps try suspending some removable rough stainless plates in the tank and hope that most settles on these and can be bashed off periodically.

But unless it is causing a big problem with capacity or downstream, I wouldn't worry too much.

[petebearvalley]

If the buildup is real thick, try using a rubber mallet to crack it. But don't pound on it hard enough to dent the stainless. Once you get some bare metal with some edges, I've found a 3000-3500 psi presssure washer works wonders. Try to get under it by working around the edges. Make sure to wear full eye protection as scale will be flying everywhere.

[TGTimm]

We have a similar problem, due to similar, if not worse, water. We periodically--about every three months--clean our 1,500 g HL system. We begin by manually shoveling out the calcite from the bottom of the vessels (usually a couple of 5 g buckets full--we're paving our parking area with it). If wall deposits are too thick, I then climb in and pressure-wash the walls (my FAVORITE job!). We finish with a wash of sulfomic acid (Wesmar DSR) solution @ ~140 deg. I don't know the exact concentration, but a couple of lbs at a time, until the solution actively and rapidly dissolves calcite--test with residue from step 1. We recirculate and wash with the acid solution for about an hour, then rinse... rinse... rinse. The sulfomic acid has a distinctly soapy smell, so it's pretty easy to tell when you've rinsed enough. This process takes between 4 and 6 hours, and uses LOTS of H2O.

And guess what we're doing tomorrow?

PS: I installed a control system to keep our HL temp at or below 195 F. Before, we were boiling the HL, and the calcite accumulation was ridiculous. Now, it's bad, but within limits.

If you really have a problem with carbonate hardness, look into a whole-plant RO system. Not cheap, but it will give you, essentially, distilled H2O (Portland water). If you want hard (Burton) water for brewing, add your own chems (this is what most of the big boys do)!

And remember--it's the permanent hardness that contributes to good Burton water, not the carbonate hardness. Carbonates just end up depositing in your HL system.

I dream about things like this...

Timm.

[The Cellarman]

Acids

We have a 1000 gal. dairy tank for our HLT, and we had over 1/2 inch of build-up. I CIP'ed about 40 gallons of water with a heavy dose of Ultra-Niter, then let it soak over night, then get in with a drywall knife to scrape of the build-up.
Use about 1 gallon of ultra niter, if I remember correctly.
But the overnight soak seemed to do the trick. Sorry I didn't check the ph.

Hope that helps.

I have to agree. I run all of the cleaning/Sanitation for a production brewery. We use Ultra Niter (a mixture of nitric/phosphoric acid). When I started with the company all of the fermenters had calcium buildup. After a lot of CIP'ing for extended periods between 140*-155* it removed all of the calcium. This mixture also will re-passivate the stainless. The temperatures stated are where acids are most effective. We recieved our Ulta Niter from Birko.

Acids are what remove calcium build up. Any type of caustic or caustic soda will set the calcium and make it harder to remove.

Hope this helps a little bit more!

[Hazell]

We have a hot liquor system re-circulating through a heat exchange, heated by our boiler. Our water isn't too hard but we eventually get scale build up. In the past we have mostly emptied the tank (a couple hundred litres left) then added 10L nitric acid. We re-circulated back through the sprayball to clean the tank and more importantly, the heat exchange.

A water softener could help but teh ion exchange type might add too much chloride to your water, causing corrosion issues.

We've had leaks all through our HLT from our naturally high chloride levels. We've since let the scale grow over the leaking sections and it works really well to stop the leaks. We no longer acid clean the tank but just do the piping and heat exchange instead. We do this every 3 months.

I guess what I'm saying is...
1) The scale isn't too bad if it's only on tank walls but it will greatly affect the efficiency of heating elements and exchanges.
2) I think it's better to empty and de-scale occasionally rather than constantly add acid.
3) Watch for leaks when you remove the scale, its about all that holds our packaging plants HLT together right now!

[Dough In]

Build up on hearing elements

I have replaced many immersion heaters that have been totally destroyed by mineral build up. I agree with all above Birko ultra niter and routine maintenance is crucial.

[CaptainRedBeerd]

sulfamic acid.

it's one of the main ingredients in lime away and it's done wonders in our HLTs.

we try to run out production schedule to allow for maintenance days on Fridays. when that works out, we run a solution of sulfamic acid into the HLTs and let is sit for the weekend.

by Monday, a simple spray down is all that's needed.

[TGTimm]

DO NOT use nitric acid for de-scaling if you have anything but stainless steel in contact with the HL system!!

Nitric acid dissolves copper, mild steel, and many other metals--including the cladding on your heating elements. Try dropping a small piece of copper pipe or a penny into a nitric acid solution. Nitric acid is used in the brewery for passivating and cleaning SS tanks and vessels--not for mixed-metal systems. I'm not surprised that Hazel's HLT leaks after numerous cleaning cycles with nitric acid.

Sulfomic acid has a low activity for most metals, and this is why it's used in commercial de-scaler solutions. Sulfomic acid is also much cheaper than nitric.

Don't turn your electric heating elements on while de-scaling--unless you enjoy replacing them. We transfer our HL into another tank and then use it for the de-scaling process--this gives us hot water that would otherwise be wasted, and the water has already been de-calcified to some degree by heating before the acid is added--saving some acid and the elements.

As for build-up on the elements, using low-density or ultra-low density elements will eliminate or greatly reduce deposits on the elements--they'll last much longer than standard or high-density elements. If the elements are being buried in sediment, you need to clean more often or take the radical path of moving the elements higher in your HLT.

Low density elements are usually bent into a U-shape; ultra-low density elements are usually serpentine. Both have much more surface area for their heating rating (hence low density) than standard elements. Expansion and contraction during the heating cycles flakes the scale off the elements, leaving very little or no deposit.

Scale on the inside of a tank may not affect heating or performance, but it will flake off and end up on the bottom of the tank--possibly burying and destroying your elements and clogging your HL system plumbing and pump.