Distilling with the brew pi spark

Not sure if this is in the correct place?

Anyway I want the brew pi spark to control two 3500W heating elements in a still, does anyone see any problems using the brew pi spark for this?

The boiler will be a kegmentor 58L with two 3500W heating elements.

I’d be interested too. I did a small experiement on my euro-30. What I’ve done so far is to put a 1-wire thermometer into the fitting for a regular themometer in top of of the still and measure what is going on. Reading from a regular thermometer was always a bit difficult. I was going to move onto other matters once I had done some measuring.

In my case, it was very interesting to see the temperature slowly moving up for a period and then suddenly shoot up to a very level 79 before remaining very steady. This was with constant water flow. No fiddling needed with the water flow at all and I was getting around 93% alchohol. Towards the end, the temperature started to rise slighty, and my still is designed to essentially stop prooducing when getting to the end point of the run. The element simply doesn’t have enough power, by design, to push any more energy in for the temperature to continue rising.

So I decided my old, simple still balanced very easily and I didn’t really need to do any more.

I did try a test run with just water, setting up a brewpi fridge and the temperature to 77 and that worked fine with the element comming on as needed. The system reacted quite quickly to changing the fridge temperature, faster than I expected.

I probably don’t need to, but for the next run, I was going to try controlling the heating and keeping the temperature to 77 rather than the natural 79 using the brewpi. In my case I cannot increase the water flow any more from the design of the still.

I don’t see why you could do much the same with your rather larger setup. I’m not sure if it’s possible to drive each of the heaters seperately, but it would be neat to drive both up to the point of getting a good initially flow and then cutting back for the main run.

My cooling flow is very simply, but if you have a mains pump that would accept the controlling influence of the brewpi, that would make sense.

I’d be interested in seeing anything you come up with!

I think it would be very interesting to see how we can control a still with the Spark.

I think it would be interesting to use a 2 PIDs, where one measures the temperature in the top of the still and adjusts the setpoint for the PID at the bottom of the still.

I would not use the fridge settings for this, the HERMS wizard is much closed to what you want. The HLT would be the bottom of the still and the MT the indirectly heated top of the still. I don’t have experience with distilling, so can’t comment much.
But if you describe the ideal control scenario with all the bells and whistles that you would like, if maybe possible, then I can think of a block chain that would achieve it.

I’m brand new to distilling & haven’t got the still set up yet, It sounds promising, I will link this thread with another forum & see if some of the more seasoned distillers can offer some insight into a ideal control scenario, thanks for the input so far.

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Ok how does the Brewpi control the heating elements, is it either On or Off or does it manipulate the voltage to reduce the heat output?

Seems that this is the way it needs to work?

Everyone is pointing me towards a voltage controller, which sees crude to me?

We use PWM signals to get % output from an on/off actuator.
https://brewblox.netlify.com/user/all_blocks.html#analog-actuators

Had this reply on the other forum

You are much better off using that beer pi logic to hit a wattage and not a temperature. Power voltage cycles up and down a fair bit for me during a run and having a dead stable amount of watts applied would help column stability no end

You will find you tube vids of people running stills by controlling temp, this stuff needs to be put into the urban myth category. What you can’t tell from those vids is the taste of the product or as bluc said, the smearing evident

Ethanol and the other 30 odd Alcohols we deal with do have different boiling points, but they wont just boil off perfectly in order by setting the temperature. Some are bonded to each other, some form as other components dissapear of get broken down. This is what a reflux column is for, the constant phase changes up and down the column let the different components separate for us to draw off slowly and manually seperate by cuts

I would like to get a little more science into the discussion.

Of course we can run a constant amount of watts, but I would think a control system is better. So what do we want to control if it is not temperature? What do we measure?

Or is temp control failing because it is not stable enough in those Youtube vids? Is the temperature
maybe not equally distributed?
If we can measure it, we can control it. I don’t believe that not measuring is a better approach.

Hi Elco, I wish I knew enough about the process to answer, I sort of get the idea that the guys who distill do it by feel, but they don’t seem to like change, i will link to the topic on the other forum, maybe you could ask the questions on there? or at least have a read up on the actual processes involved? I did link to this topic but it seems they don’t wish to come & give any input.

http://aussiedistiller.com.au/viewtopic.php?f=60&t=13270

Typically experienced distillers want new people to focus on the taste and smell of the products comming out to let them know when to change the water flow etc, so to them its more of an art than a science. Other advice I’ve seen is to throw the thermometer away and reply on smelling/tasting the end result to judge where to make cuts. This is particularly true when using a pot still to fashion whiskey or rum. The contents of a fermented wash with these can vary a great deal in terms of content. Consider the difference between fermenting pure sugar vs a mash of your own fruits from the garden.

But with a reflux still where one is more focused on high proof alcohol and removing components of the origonal wash, I bet a brewpi would work well.

I suspect a number of people have tried to engineer their way into distilling and don’t get too much encouragement to apply science. I’d love to have a go at improving my final product using my reflux still and I do plan to try a hermes based wizard approach next time I need to do a run.

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