Thermal fluid system for still heating(?)

[Simon13]

Hey Guys,

I'm in the process of sorting out a new heating system for my pot stills.  I have been running direct gas firing and am uprgading the system.  I had my stills made with steam coils as it was always the intention.

Steam is the easy option as it is widely used in the industry.   Thermal fluid seems to have a lot of advantages over steam but I cant find any distilleries that use a thermal fluid system.  You do get food grade thermal fluid, like you get additives for steam...

only issue is I cant find any distiller who uses thermal fluid.  does no-one use it because no-one uses it or am I missing something?

*HOGA do make an electric thermal fluid system for distilling but I cant find anyone who uses it.  

[Skaalvenn]

Other than initial price I can't think of a single advantage that baine Marie has.

I've been running electric baine marie for almost 4 years, initially with heating oil but now with propylene glycol, which seems to work better.

It got me started, it has made some fine spirits, but the slow startup time and high cost to run ($900 monthly electric bills) mean that it's time that I suck it up and upgrade to steam.

[bluestar]

Disadvantage of bain marie is as @Skaalvenn suggests. But there are other advantages. Primarily, being able to distill items that would be to heavily "cooked" if heating with steam, because you need to keep the temperature lower than boiling point at the pot wall. Typically, this is true for absinthe, for example. Could also be true for grappas and other fruit brandies done on fruit mash instead of clear wine.

[MG Thermal Consulting]

Your could - if you are using a chiller to chill the system condenser- tie into the refrigeration, add a refrigerant to glycol heat exchanger and preheat the glycol with hot refrigerant gas. 

[Southernhighlander]

I've sold over 170 baine marie oil stills to distilleries. Aside from what Bluestar mentioned I can't think of any advantages that baine marie oil has over steam.  Also if you are thinking about circulating the oil, there is no reason to do that.  The systems that circulate the oil are expensive and steam works much better in that situation.

 

[Patio29Dadio]

Spent a good deal of time looking into this and changed my direction from Baine Marie to NG-fired low pressure steam.  However, it added about $65k to my budget for a 36HP 1.4M BTU/hr low pressure steam boiler installed in my near-communist-controlled state.

If you are thinking of Baine Marie because you don't have access to NG or propane, or you want to keep your capital outlays low, I would suggest you look into the alternative of electric-powered steam.  The Sussex EX steam boiler looks like a good option to me.  The largest of these is 18.2 HP which translates into about 600K BTU/h I think.   The cost of the boiler alone is about $16-17k.  You will also need about $7 in extras including the condensate return and the blow-down separator.  The neato thing about these Sussex EX boilers is that they are a lower amp draw than others I considered.   480V/3PH/60HZ SUPPLY VOLTAGE, 217 AMPS.   240V/3PH/60HZ, 434 AMPS.   The 11 HP version is  480V/3PH/60HZ SUPPLY VOLTAGE, 130 AMPS.   240V/3PH/60HZ, 260 AMPS and looks to be close to 400K BTU/h.   I think this smaller unit should power a 150G still to get up to temp faster than the Baine Marie.  It is probably $20k or so all in not including the cost of installation.   Consider the cost of the Baine Marie components, the electrical installation costs and the boiler installation costs... do a spreadsheet.

Gas steam is certainly going to be more affordable long-term for most... assuming you have gas.

[Simon13]

Apologies gentlemen,  I'm looking at a gas powered boiler heating thermal fluid system that circulates the thermal fluid through the existing steam coils.

A number of breweries in recent years have taken on thermal fluid systems.  

 

Hoga make an electric one for their stills.  I am looking at similar but with a gas powered boiler.

[Simon13]

http://www.hogacompany.com/hogaboiler27.htm

 

above is the only example I can find of a thermal fluid system for circulating hot oil through steam coils.  As far as I can tell, its pretty new and they've just sold their first one to a distillery in Ireland.  Speaking to a local engineer who specialises in boilers for distilleries says he would be worried about contamination issues in the event of a leak, but then food grade thermal fluid exists.

Its a pretty massive outlay for us to upgrade.  A gas boiler with steam would be the safe option but thermal fluid claims better energy efficiency, safety and less maintenance... also al little more flexible for style as it can be run hotter and slower if you want more caremelisation  and maillard reaction or faster and lower for a more even heating pattern.

I'm pretty keen but i'm worried about making the wrong decision with the massive costs involved.

[Hudson bay distillers]

what does that system cost in comparison to a low pressure steam boiler . we use a hydronic system that  heats our house ,the distillery , the mash tun , and stills . we can hold vessels at 150 f with the hot water and then get the last bit of heat we need with steam injection into the mash tun and with steam jacket on the stills . we tested useing oil and found it way to much of a mess to work with , and very hard to back off if you over shoot a temp that your targeting . 

tim 

[MG Thermal Consulting]

What do you do for a chiller?  I have been working on a high temp heat recovery chiller system design but there would be some add-on to get mashing temp reached without a small steam boiler or hot water boiler to reach high enough water temperatures. 

[Southernhighlander]

2 hours ago, Simon13 said:

http://www.hogacompany.com/hogaboiler27.htm

 

above is the only example I can find of a thermal fluid system for circulating hot oil through steam coils.  As far as I can tell, its pretty new and they've just sold their first one to a distillery in Ireland.  Speaking to a local engineer who specialises in boilers for distilleries says he would be worried about contamination issues in the event of a leak, but then food grade thermal fluid exists.

Its a pretty massive outlay for us to upgrade.  A gas boiler with steam would be the safe option but thermal fluid claims better energy efficiency, safety and less maintenance... also al little more flexible for style as it can be run hotter and slower if you want more caremelisation  and maillard reaction or faster and lower for a more even heating pattern.

I'm pretty keen but i'm worried about making the wrong decision with the massive costs involved.

Thermal fluid systems that use circulation have been around for well over 80 years and you could use any of them to circulate through coils.  If circulating hot fluid systems were better than steam they would be the standard instead of steam.  Just my 2 cents.

[MG Thermal Consulting]

Paul,

That's the point I am, too, Paul.  If I sell a heat recovery chiller to make hot glycol, it's still needs some electric heater add for a hot glycol tank, and that buries my price.  I think the smaller distilleries should be able to work without a steam boiler, but it's a matter of making everything add together plus the cost payback on the utility that's the trick. Cheaper to buy gas for a boiler than the electricity input, especially if the customer doesn't have three phase power.

[Southernhighlander]

43 minutes ago, MG Thermal Consulting said:

Paul,

That's the point I am, too, Paul.  If I sell a heat recovery chiller to make hot glycol, it's still needs some electric heater add for a hot glycol tank, and that buries my price.  I think the smaller distilleries should be able to work without a steam boiler, but it's a matter of making everything add together plus the cost payback on the utility that's the trick. Cheaper to buy gas for a boiler than the electricity input, especially if the customer doesn't have three phase power.

I agree.  if you have a small distillery, electric over heat transfer fluid, self contained in a jacket with no pump, makes sense in the short run if you have a small budget and want to expand later, however circulating heat transfer  systems are usually pretty expensive.  Your heat recovery systems are a great idea though.

 

[MG Thermal Consulting]

Yep, I agree and sometimes dangerous with hot glycol or oil flying around in pipes (no more than steam, I suppose).

[Simon13]

Good point on backing off the power having lag because of the thermal mas of the oil although  I do run very slow as a rule.  Interesting points all.  Might be best to play it safe and go with the steam option.