Still Sizing and Bainmarie Heating

Robin123

Hello,

I'm looking to start up a Distillery making Vodka and Gin from Cows Milk and would love some pointers on sizing and designing the still setup.

We are looking to have 1800L of 6% wash 4 days a week.

We have a 300kW wood chip boiler on site which has excess heat we would love to use to heat our still if possible in a bain-marie style pot. (The maximum Temp we can get out of this is 92°C)

I would be great to see what size , style etc people would recommend for doing this on a 5 day week.

Many thanks

hudsonbaydistiller

hey robin not sure if it helps but we heat a baine marie with the hot water from our wood boiler . here is the down side . we can circulate water in the jacket at around 180 , this takes forever to get the product up to temp , at least 12 hours . so our solution is we strip into the spirit still , by time its full we have the hot water bring it up to around 160 . when its time to run it we close the valves from the hydronic system open valves to prv and drop the water level in the jacket to about a third . we then use 3 elements in the jacket to heat from 160 to what ever temp we want to run the still .

it is slow but it does bring us up to 160 for free . the hydronic water circulates in the jacket to what ever we want because it on its own loop controlled by its pump .

hope that makes sense .

tim

Robin123

Hi Tim, Yes that was the method I had thought of as well, but I was going to fill the pot through a heat exchanger to speed up the initial heat up time. Then as you do close off the loop to the woodchip boiler and run electric elements.

Smaug

So as a general rule of thumb we would say that you'll need 70 watts per liter for a 1 hour heat up. So 35 watts per liter will get you to a 2 hour heat up while spending 63,000 watts. So you do have enough heating power to keep heat up times respectable.

What heating medium are you using? Do you run with a PRV or are you attempting to run open to the atmosphere? At 15 psi you should be able to achieve 121 C

Smaug

With a 12" / 18 plate column, if you keep 50% you'll get about 156/750 ml bottles (per run) and the run will take about 4 hrs,,,,not including heat up time.

If you keep 60% you'll get about 187/750 ml bottles per run.

Robin123

Okay so you dont think I will need a Heat exchanger to pre heat the wash?

so is that 63kw/H for heat up? what would the maths be for time and kws for the actual distillation?

We are just using hot water with very little pressure, I have been told the boiler can run up to abit more under pressure but I think it was only up to 106C

Smaug

Well you'll need to run up to "low (15 psi) pressure to get the kettle to perform heat up in a timely manner. The thing is that at atmosphere, you will never get past 100 C and will likely be leaving alcohol in your kettle.

Can you confirm if you have a low pressure kettle rating @ 15 psi?

Robin123

I dont have any equipment apart from our boiler just now, I was hoping to have a full SD setup when the time comes!

Smaug

Got any pics you can post? Any markings on the kettle.

Robin123

By Kettle do you mean our Woodchip Boiler?

Smaug

Kettle meaning the vessel used to hold and boill your beer, must, or low wines.

Robin123

We do not yet have a kettle yet. We would be looking at getting a bain marie style kettle heated on a closed loop from a heat exchanger with a air gap in the kettle to allow for expansion when we close off the heat exchanger and use electric elements to get up to our final temp.