Bain Marie Heat transfer oil

[junglejimmy]

Started my own distillery about 8 months ago in Australia, and after all this time I am finally about to get my License to manufacture alcohol. About to purchase a 400L Bain Marie Pot still and a 400L Bain marie mash tun. At this point steam generation is not an option as I would like to be up and running as soon as possible.

What are you guys thoughts on the bath medium. Water or Oil? I am looking for the most energy efficient option as electricity prices in Australia are some of the most expensive in the world.

I have found a local supplier of Heat transfer oil. http://www.hi-tecoils.com.au/product/heat-transfer-oils-12-90/. Is this Oil suitable?  I have seen that some guys use Mobil 46. I have come to understand that the number refers to the viscosity of the oil, where the higher number is more thick.

The Supplier says they can only do 32 or 64. Would the lower number be more suitable?

Thanks for your help!

[whiskeytango]

Water will never get hot enough.   You can use just about any heat transfer oil or even just fryer oil will do just fine at a fraction of the cost. 

 

[Southernhighlander]

Actually we have had some great luck running water in our Baine Maries lately.  At first we thought oil was far better and that is what our testing showed.  however when we did the testing the still  jacket was full of water.  We did some recent testing starting out with the jacket only 40% full of water. This worked a great deal better than our first testing with water and the heat up to operating temp time was only a little longer than oil and the run time was pretty much the same as oil.  We are running more testing next week with water.  So here is why we are getting better results with the jacket 40% full of water.  Even though the jacket is open, there is steam in the upper part of the jacket.  We start out with steam in 60% of the jacket and by the time that we were done 80% of the jacket was full of steam.  So you are probably asking, how the hell could 215 F steam heat a vessel almost as fast as 300 F oil.  Its because the oil has a terrible heat transfer coefficient and steam has one of the best heat transfer coefficients,  Much better that water and glycol.   

With 400 liters you should run 22,000 to 27,500 watts of power.  Also water is much safer than oil because it is not flammable like some of the oils.  Also water is not nearly as messy and it is much easier to keep water from leaking around your immersion heater connections.  Oil leaks where water would never leak because oil has a great deal less surface tension than water. 

Also you might consider pulling a little vacuum.  With just a little vacuum in the still you can get the boiling  point of ethanol down to 140F and then water is a much more viable heating solution with no need for steam.  The problem with a vacuum system is, how do you do the cuts from a closed system?  We have solved that problem but it is proprietary, however if you email me privately I will tell you how it can be done. 

We will start taking orders for our new vacuum stills next week.  They are truly amazing and really safe.  I think that they are going to change the face of the beverage distilling industry.  Also for our bigger vacuum stills, instead of a $30,000.00 steam boiler, all that you need is a $3,000.00 water heater or a  $5,000.00 hydronic boiler.  That's right, you will be able to fire these vacuum stills with a wood fired hydronic hot water boiler.  Also we are getting higher proofs with less column with these vacuum stills. 

You other equipment vendors better look out, because your world is about to change.

[bluestar]

We use a water bain marie, and agree, that what you are really doing, if you want to operate at higher temperature, is not running it as a bain marie at all, but heating the sidewalls with steam, and that is far more efficient for heat transfer than near-boiling water. So, ironically, you can get better heating at a lower water level. BUT, unlike a steam jacket where you control heating by adjust amount of steam flow, it is harder to control the bain marie because you are adjusting heating elements, these are what adjusts boiling rate, and this indirect control has more thermal lag.

[junglejimmy]

I am leaning towards using the heat transfer oil. It only cost around $800 AUD for a 200L drum. The smoking point for the oil is around 300C (572f), so getting enough heat to boil the distillate should not be a problem.

blustar, you said there would be thermal lag with the water bath steam option. Would there be the same problem with heat transfer oil.  I have no experience with bain marie systems to speak of, however, when cooking with oil on a stove top it seems very responsive to the heat input.

 

[Southernhighlander]

1 hour ago, bluestar said:

We use a water bain marie, and agree, that what you are really doing, if you want to operate at higher temperature, is not running it as a bain marie at all, but heating the sidewalls with steam, and that is far more efficient for heat transfer than near-boiling water. So, ironically, you can get better heating at a lower water level. BUT, unlike a steam jacket where you control heating by adjust amount of steam flow, it is harder to control the bain marie because you are adjusting heating elements, these are what adjusts boiling rate, and this indirect control has more thermal lag.

With water we just set the temp control at 220F and let her roll.  Of course low pressure steam is always better so if a customer has the budget, we always suggest that they buy one of our low pressure steam boilers.  Also we have more than 100 baines marie stills running oil in distilleries.  Some of these are as large as 1200 liters running 66kW.  I think we have one electric 2000 liter Baine Marie running oil with over 110,000 watts of power.  You can run jacket oil temps of up to 350 F in our newest bain marie oil stills.  Of course our new vacuum stills change everything.  They make hot water heat a viable solution were you can run water jacket temps at 190F and distill like hell.

 

 

[bluestar]

On 2/9/2018 at 12:00 AM, Southernhighlander said:

With water we just set the temp control at 220F and let her roll.  Of course low pressure steam is always better so if a customer has the budget, we always suggest that they buy one of our low pressure steam boilers.  Also we have more than 100 baines marie stills running oil in distilleries.  Some of these are as large as 1200 liters running 66kW.  I think we have one electric 2000 liter Baine Marie running oil with over 110,000 watts of power.  You can run jacket oil temps of up to 350 F in our newest bain marie oil stills.  Of course our new vacuum stills change everything.  They make hot water heat a viable solution were you can run water jacket temps at 190F and distill like hell.

 

 

Yes, you can run the way you describe, but it is not the best way to do control. By setting the temperature to 220F, since boiling is 212F, and depending where your sensor is, you are keeping the unit on to superheat around the elements, to ensure you are driving steam. We did that originally, too. But that can be sensitive to the bain marie water levels, contents of the pot, agitation, etc. What you really want to control is power, since that will directly translate into steam production. So we use temperature control for when we are running below boiling, but often use power control when we are running during active part of distillation using steam heat. Whether you run controlling temperature or power, we find both have to be adjusted while you run the distillation, to reflect the need to get the contents of the pot at the same boiling rate as the residual alcohol content drops.

The advantage of oil is the precision of temperature control as a means to control heating rate. The disadvantage will be the slower response (increased thermal lag) when making changes in power. It can also increase scorching (since steam heat can't get much above 212F). On the other hand, if you can determine a set of repeatable parameters and rates for a distillation, then you can program the oil bath to optimally run that distillation, and large temperature corrections should not be required, mitigating some of the problems due to thermal lag.

[jbdavenport1]

On 2/9/2018 at 1:00 AM, Southernhighlander said:

With water we just set the temp control at 220F and let her roll.  Of course low pressure steam is always better so if a customer has the budget, we always suggest that they buy one of our low pressure steam boilers.  Also we have more than 100 baines marie stills running oil in distilleries.  Some of these are as large as 1200 liters running 66kW.  I think we have one electric 2000 liter Baine Marie running oil with over 110,000 watts of power.  You can run jacket oil temps of up to 350 F in our newest bain marie oil stills.  Of course our new vacuum stills change everything.  They make hot water heat a viable solution were you can run water jacket temps at 190F and distill like hell.

 

 

Paul:

 

Does running our bain maries on oil vs. water make a material difference in electricity use?

[Southernhighlander]

bluestar,

 

 

You can run proportional power control using our newer controllers as well as set point temp control so you can do it either way with water.  Also water in the jacket has several advantages when it comes to cooking mash.  You can heat with the jacket and steam inject from it at the same time.  Also you can use water in the jacket to crash cool, also water is less likely to cause sticking or scorching, however we have only had 2 customer complaints concerning scorching and in both cases they were not liqifieing their mash.  Once they started to liqify their corn mash the sticking and light scorching stopped.

Of course one of the biggest reasons that I like water in the jacket is because it is non flammable.  With all of the baine marie stills we have out there now, I worry about safety issues which is one of the main reasons that we are starting to push water and our new vacuum stills.

[Southernhighlander]

jb,

 

Your question is a very good one. I think that water uses less electricity because it has a better heat transfer coefficient.  We will collect some data on that during this weeks testing and I will let you know for sure.

[bluestar]

22 hours ago, Southernhighlander said:

You can run proportional power control using our newer controllers as well as set point temp control so you can do it either way with water.  Also water in the jacket has several advantages when it comes to cooking mash.  You can heat with the jacket and steam inject from it at the same time.  Also you can use water in the jacket to crash cool, also water is less likely to cause sticking or scorching, however we have only had 2 customer complaints concerning scorching and in both cases they were not liqifieing their mash.  Once they started to liqify their corn mash the sticking and light scorching stopped.

Of course one of the biggest reasons that I like water in the jacket is because it is non flammable.  With all of the baine marie stills we have out there now, I worry about safety issues which is one of the main reasons that we are starting to push water and our new vacuum stills.

I think we are violently agreeing ;-) We use water for the same reason.

[Southernhighlander]

1 hour ago, bluestar said:

I think we are violently agreeing ;-) We use water for the same reason.

I agree .

[jbdavenport1]

Is there anything in the jacket or in the finish of the interior wall of the jacket that would repent us using that hot water for future mash-ins?

[Southernhighlander]

No, there is nothing to prevent you from using water for future mashing.  You will need to get any oil cleaned out well if yuo have been using it with oil,.  If you go back to oil you will need to be extra careful to get all of the oil out.  Email me privately if you need instructions for getting all of the oil out.

[MG Thermal Consulting]

On 2/8/2018 at 12:20 PM, Southernhighlander said:

Actually we have had some great luck running water in our Baine Maries lately.  At first we thought oil was far better and that is what our testing showed.  however when we did the testing the still  jacket was full of water.  We did some recent testing starting out with the jacket only 40% full of water. This worked a great deal better than our first testing with water and the heat up to operating temp time was only a little longer than oil and the run time was pretty much the same as oil.  We are running more testing next week with water.  So here is why we are getting better results with the jacket 40% full of water.  Even though the jacket is open, there is steam in the upper part of the jacket.  We start out with steam in 60% of the jacket and by the time that we were done 80% of the jacket was full of steam.  So you are probably asking, how the hell could 215 F steam heat a vessel almost as fast as 300 F oil.  Its because the oil has a terrible heat transfer coefficient and steam has one of the best heat transfer coefficients,  Much better that water and glycol.   

With 400 liters you should run 22,000 to 27,500 watts of power.  Also water is much safer than oil because it is not flammable like some of the oils.  Also water is not nearly as messy and it is much easier to keep water from leaking around your immersion heater connections.  Oil leaks where water would never leak because oil has a great deal less surface tension than water. 

Also you might consider pulling a little vacuum.  With just a little vacuum in the still you can get the boiling  point of ethanol down to 140F and then water is a much more viable heating solution with no need for steam.  The problem with a vacuum system is, how do you do the cuts from a closed system?  We have solved that problem but it is proprietary, however if you email me privately I will tell you how it can be done. 

We will start taking orders for our new vacuum stills next week.  They are truly amazing and really safe.  I think that they are going to change the face of the beverage distilling industry.  Also for our bigger vacuum stills, instead of a $30,000.00 steam boiler, all that you need is a $3,000.00 water heater or a  $5,000.00 hydronic boiler.  That's right, you will be able to fire these vacuum stills with a wood fired hydronic hot water boiler.  Also we are getting higher proofs with less column with these vacuum stills. 

You other equipment vendors better look out, because your world is about to change.

I will be introducing a higher temperature heat recovery chiller where you can make both hot water and chilled water for a distillery.  It will use a new refrigerant which will allow the refrigerant to operate at higher condensing temperatures for the refrigerant and thus higher water temperature for the water used to condense it.