Automated Water Distiller Gets An Overhaul

automated_water_distiller_stillduino_v2

One thing we love about the hacking community is the drive that most people have to revamp and rework their “finished” projects. A few weeks ago, we wrote about a water distilling rig that [Kyle] hacked together, which allowed him to automate his distillation process. He took his project back into the workshop and tweaked a few things, giving us the heads up when he was finished.

He got his hands on a new distillation unit and decided that he wanted to transfer over his automation setup. He cleaned things up by ditching most of the components from his first distiller, including the toy clock tower dial (which we happened to think was pretty fun). The same relays and Arduino were used in the second version of the still, but he reworked all of his code to make use of his new control interface.

The new model sports an LCD panel that allows the user to interact with the machine via a push button rotary encoder. Now he can easily navigate through a series of menus that enable him to set the distillation quantity and start time, leaving the distiller to do the hard work. The still also does a quick safety check each time it starts up, to ensure that things are in good working order before firing up the heating element.

[Kyle] says he will continue to tweak the distiller, though we think it looks great already.

Continue reading to see a quick video of his Stillduino v2 in action.

[youtube=http://www.youtube.com/watch?v=_eGcrKX39Zw&w=470]

19 thoughts on “Automated Water Distiller Gets An Overhaul

  1. I can’t think of any more features to add.
    It’s going to be a real challenge to fill 20K of the free space with [quality] short quotes if I don’t come up with anything or get a good suggestion.

  2. @therian… you are a sad sad troll to pick on ethanol. Maybe you need to plant less trees, and have a moderate amount of ethanol on occasion.

    In any case… nice “water” distiller. No… really… I know it just distills “water”. I do believe you.

    “Water”

  3. Kyle: Might I suggest a feature that checks the water levels against the amount you’ve programmed the timer for? The whole time I watched that video, I was wondering if it had any such thing.

  4. This is much better than the over-done junker they started with the last time we saw a distiller on here. Dont get me wrong, I’m sure it worked, but why dump more money into electronics than the thing will even be worth over a year? A simple electronic timer shut-off would have been fine last time – though for learning I’m sure it was worth it. KISS in the end, make it work forever :)

  5. @Az
    This is a concern of mine, also. Here is a brief description of how I operate it. A chamber with a heating element must be removed from behind the door on the left. The heating element must remain submerged in water at all times while distilling to prevent it from burning out worse. So, water is filled to a level just above the element. Then, the vessel that is to be distilled into is filled with water, then poured into the chamber. The top of the chamber is sealed, then slid back into the unit. When it reaches the back, the heating element connects with a 3-pole plug and a steel pipe inserts into a hole with an o-ring at the top of the chamber. I can now place the collection vessel under the drip on the right side, then set it to distill however much the vessel’s volume is.

    A problem I see with sensors to detect water level is that 1) this operates at high temperatures, 2) minerals and other compounds are left behind from the distillation process that builds up on the inside of the boiling chamber, casing it to periodically need cleaning.

    I don’t know of any sensor that is suited to work in this environment. If you happen to know of any, please share, because I would not like to see what happens if it were to run dry.

    If I had the steel-welding expertise and the money, in addition to making sure there was an adequate amount of water, I would make the filling and emptying automatic, with the use of electrically actuated ball valves (which can handle high heat and don’t require pressure to operate). If I were to go that far, I would also put in a electronic 3-way valve that diverts the outflow of distilled water to discard the first ~50 ml, so I would be free from having to use carbon post-filtration.

  6. …I forgot to mention that there is no need for measuring if I distill its maximum, 3 liter, amount. I just fill the boiling chamber to the mark at the top.

    @Life2Death
    “This is much better than the over-done junker they started with the last time we saw a distiller on here.”

    This distillation unit works the exact same way the last one does. You could have used an electric timer for this one as well.

    “Dont get me wrong, I’m sure it worked, but why dump more money into electronics than the thing will even be worth over a year? A simple electronic timer shut-off would have been fine last time”

    The first build you refer to was made with salvaged parts from a previous project, so there was no cost.
    If you want to talk about worth, you have to agree it is a subjective thing. Some value clean water more than others. I think that putting this much effort into making pure water available shows something about it’s value to me.
    Shai-hulud shall thou see.

  7. Finally! The kids toy timer is gone. What’s in there now? An Omron PID timer or something otherwise industrial grade? This looks MUCH better and MUCH more solid.

  8. I wonder if there is a viable hobbyist solution to the problem of monitoring the boiler fill level… I can’t think of anything that could tolerate the heat other than a mechanical float made entirely of metal.
    The industrial tank level monitors I’m familiar with are for low temperature high volume storage tanks and aren’t available in a hobbyist form factor.

    Keep working at this project because that metal-shelled unit looks ripe for modification!

  9. Seeing this project has made me want to replicate it. I bet if it could be fully automated that it could really effectively save a lot of cash on bottled water with zero inconvenience. The largest issue has already been addressed in previous comments, that of monitoring the water level in the boiler and in the vessel. The only other piece I can think of would be to hook it directly to a water line to automatically re-fill itself as needed. Keep a gallon of clean, fresh water always handy… And maybe a way to even keep that separately chilled.

    Awesome hack, for V1 and for V2

  10. nice project, you could try using a non intrusive water level detector such as thesehttp://www.omega.co.uk/literature/transactions/volume4/T9904-14-RAD.html but i think they are outside the scope of the project.

    does the water boil?

    how about just a thermistor on the side for low water detecting? i’m sure it would show up on thermal imaging so maybe a non contact thermometer http://www.maplin.co.uk/infrared-thermometer-223005 would work.

  11. @Kyle:
    To determine the level of the water in the boiler, you could use capacitive sensing. Because the dielectric constant (static relative permittivity) of air is about 1.0, while water has a dielectric constant of more than 50 (depending on temperature), capacitance changes can provide a very accurate indication of water level with no moving parts and potentially usable at high temperatures.

    Methods of Detecting Water Level in Steam Boilers describes a number of different types of level sensors, including capacitance probes.

    There are different types of capacitive level sensors. Some use the conductivity of the liquid being measured, along with the conductive boiler shell as a conductive path to the sensing element, which is a single conductor with a PTFE insulating shield. Below the surface of the liquid, the only dielectric contributing to capacitance is the PTFE shield. Above the surface of the liquid, the PTFE shield and the surrounding air contribute. This seems like it would require more signal processing to get accurate results. I think it would be easier to get good results with a two-terminal type of capacitive sensing element.

    Wikipedia’s level sensor article discusses capacitive level sensing.

    Here is a DIY water level sensor.

  12. Why not use weight sensing? There’s reasonably inexpensive pressure sensors you can use for that purpose and there’s not going to be too much variation in the weight of the liquid you put in.

    If you can weight the device & water to distill without the output receptacle then it’s a pretty straightforward operation. You can have a calibration routine that you run when there is no liquid at all. The shutoff temperature you set to that calibration + (# of G it takes to cover element * 8.328676) + weight of empty receptacle.

    The sensors SparkFun sells are about $21 and have a 3% error rate so you should set the minimum to the above * 1.03 but it still seems pretty straightforward.

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