ponedeljek, 26. september 2016

Measuring vapor pressure of butane

I built a miniature pressure chamber, in order to measure vapor pressure of butane at different temperatures.

I only have this mini Hobbymat MD65 tabletop lathe, which, of course, also has a very small chuck. I don't know how large a workpiece can be for this size of a chuck, to still be able to turn it safely, but I'd say 25-30mm at most (rather 25mm, to be safe). But this workpiece was 36mm in diameter, so I was only able to slightly tighten the chuck, since the 3rd jaw was only half of a key turn away from falling out. Of course I didn't want to damage the chuck by overtightening it in such extreme conditions. I was scared all the time that the jaw would fly out of the chuck, but it luckily didn't.

1. Removing oxide layer:







2. Cutting off a 20mm disk:



3.Facing off the rough edge:



4.Drilling a pilot hole (I need to buy centering bit):




Drilling holes on the edge (one hole every 60 degrees):



After drilling 16mm hole + smoothing out the rough surface, left after drilling.
O-ring grooves are not deep enough, since I don't have any face grooving tool - those grooves were
made by a thread cutting tool.




I forgot to take pictures, when making acrylic covers, however, I just drilled all six holes in square
piece of acrylic and bolted it to that aluminium part, then I used a lathe to make the covers round.
Those o-rings aren't meant to be used with butane and they deform a lot, when in contact with
butane, so there's some leakage, which could probably be fixed by using appropriate o-rings.





After drilling a hole and cutting 1/8 NPT, for pressure gauge:



Finished product:




Butane is a gas at room temperature, but it can be a liquid if under high enough pressure - for butane, that's a little over 2bar or 30psi, at room temperature.



Safety pressure test - pressure chamber was placed in some warm/hot water (50°C+), to see, if it
can withstand maximum pressure (for this pressure gauge). (pressure gauge was bought on ebay,
for about 3.5€ or approx. $4 + free shipping)



Chamber can simply be filled with "lighter fluid". When the butane is released into the atmosphere,
its temperature drops - that's what keeps it in liquid state, until it warms up and evaporates of course.
But if the pressure chamber is closed before that happens, the pressure will build up as the temp.
rises and this will keep butane in liquid state.

To see how I fill this pressure chamber with butane and do some vapor pressure tests, watch the video, below:



That's all, and thanks for reading/watching.

Best regards!

petek, 23. september 2016

Welcome to my blog!

Hi!

This is my blog about science and some random stuff. What kind of posts can you expect to see here?
Well, for example, I'll write about, how certain electronic circuit works and how you can make it yourself. Since I also have a Youtube channel, you'll also be able to watch a video about making or testing of that particular circuit. You can also expect some posts about chemistry, electrical experiments and other physics experiments + random, everyday stuff. Thanks for taking your time to read this, I'll start posting soon (maybe even later today, but if not today, you can expect a new post within a few days at most). I hope we'll have a great time together :)

If you're interested to see my Youtube channel, you can check it out, here: https://www.youtube.com/c/electronpower

Have a great day!