MN Still

[Myles]

Thought I would give you an update. This still is being built for one of the members here. Sorry in advance for the poor pictures - I will get some more light in there for you later.

100 litre 6 kW keg boiler.
Basic copper pot still
SPP 3" column mounted over a thumper.

This is just me working out positions so I can maximise the column.

The pot still is the one I showed on here previously - it got snapped up fairly fast!!!

I have since upgraded it a little bit.

It now has an SD brass tri clamp ferrule - these are going to be my standard option from this point onwards.
I also added a 1 to 3 bar pressure safety valve. I recommend that you connect the rear outlet port into a hose leading to a bucket of water. Just in case. The gate valve will be topped with a nice copper funnel - it is the refil port.

I replaced the product condenser for the pot still with a 7 core shotgun because we upgraded the boiler to 6 kW.

The coolant connectors were threaded into the shell and then silver soldered.

It polished up just fine. Only 3 pictures per posting!!

[Myles]

Because there are two bends and a joint in the vapour path the condenser can be rotated forwards in an arc to raise the product end. You will need a chair to sit on, as you can't get the product end to standard work top height. In the picture it is pointing towards the front of the keg and is not vertical.
We can't raise the boiler too much because we need the thumper to be positioned at the correct height for the overflow to work.

The product condenser has 7 tubes each 12 mm diameter and 500 mm long. You will need to build a suitable plinth to lift the thumper to the correct height - top ring just a bit above the top of the main boiler.

Main boiler has a drain valve out the front, the second valve is in the overflow line to the thumper - this will also work as a level indicator for the boiler.

I need to think about the vapour path to the thumper. There was going to be a valve at the bottom of the pot still, but this would stop you raising the condenser for convenience.
Possible options are to fit a 3 way valve above the condenser, or remove the condenser and replace with another section of tube to bridge to the thumper. A lot depends on how often you will switch between pot still and reflux column.

[Myles]

Here is the VM /LM head for the column.

76 mm column into 54 mm connector, the brass ferrules look good IMO. 35 mm vapour splitter with full bore VM valve and entry into the reflux condenser. The VM valve polished up nicely, and the weight balances out the reflux condenser quite well.

[chill]

I have to say that your work never fails to impress!

[Myles]

This build has changed a bit as it has developed, but that happens sometimes. The original pot still was fine for its intended use but now that it has been coupled to a thumper mounted column it is not quite right.

Oh it works fine as it is but due to the relative heights between the boiler and thumper the parot is going to be a bit low.

This gives you the basic impression.

The new 3 way valve (and it is a full bore 35 mm beast) certainly makes the switch between pot still and column easier. It also allows the angle of the pot still product condenser to be changed for convenience.

I will not know for sure until I get everything connected up, but if the parot is still a bit low, I will just extend the riser on the pot still to lift everything a bit higher.

Normally you would just raise the boiler a bit - but in this case we can't do that. The extended riser is no problem at all. On a pot still it can be any height you like - it makes no difference to the product and is simply adjusted for convenience. On our small stills there is not enough natural heat loss from the riser to change the flavour profile of the product.

[Myles]

I put this still together for a dry run and decided that I just did not like it. The pot still product condenser was too low for convenience.

So I took drastic action and made the pot still taller. It really does not matter and in this configuration the pot still condenser is a lot more convenient. Close in level to the condenser on the vodka column.

This is just a preview. Top outlet from the 3 way valve is for the thumper, bottom one is for the pot still.

A simple flick of the 3 way diverts the vapour, then you just need to change over the coolant valves and you have switched from pot still to vodka still.

[Myles]

Here you go MN, your still now looks like this. I was still adjusting the parrot when this picture was taken.

I have given you a needle valve and air cooled coil on the LM side of the still. I am not a big fan of LM, but some folks quite like it and it gives you the option to try it if you wish.

You have braided stainless hoses to form the flexible section between the condensers and whichever coolant supply hoses you choose to use. They end in 15 mm compression fittings so you can join to rigid copper coolant lines or flexible hoses that end with a stub of copper tube.

[Icefever]

WOW..what superb work there, I can only dream at the moment. I'm hoping to have a go next year. Keep the photo's coming...

[Myles]

And a controller to go with it.

I used a United Automation PSR-40 - good for 9 kW but it is only being used with 6 kW.

This is a basic manual controller with a minimalistic front panel. No displays as the pot scale will be calibrated. Just a rotary ON/OFF switch, a single pot and an indicator and fuse for the fan PSU.

[Myles]

And the item itself

At these sort of power levels you really do need a decent sized fan assisted heatsink.

For convenience I fitted the fan to the outside of the wall box. It does fit inside but you need to remove the circuit to change the fan. An external fit in this instance is more convenient. I could have used a bigger box but wished to keep it compact.

The supply and boiler cables are solid core 3 x 4mm CSA cores. That outer insulator is a robust plastic tube (score to length and bend and it cracks straight round the score mark). I recommend you use a cooker outlet connector and then a length of more flexible cable - possibly twin and earth - to make a 3 foot flexible length to the element.

[Almanac]

Very neat and tidy Myles I'm currently rebuilding my rather messy first built controller which was installed in a, not very attractive, wooden box which has become cumbersome and in the way. I'm reorganising my brewing/distilling space, in the light of experience, to try and remove some of the heavy lifting particularly transferring wash or low wines to the boiler and emptying said boiler of slops after a run. I'm going at it by repositioning the main still boiler and providing a wash lift

Plenty of work ahead and the neatness of your work has given me food for though out how I must tackle my own work a bit more professionally

AM

[Myles]

My own controller is built in a bigger box. 300 x 250 x 150 but it contains 2 different controllers and a switched 3 kW supply.

If you can spare the space the bigger enclosure gives you more room to play about with. It is easier to get the fans internal and still have room to change them when they wear out.

I know proper wall boxes push the price up, but sometimes it is worth it.

[Easydrinker]

As with all your builds Myles,your electronics are quite inspiring.
I am sure that I don't need to say,but do keep it up.
Robert.

[just sayin']

Thanks Myles. Your posts continue to fascinate, I hope you are never totally satisfied with your builds, I just love to watch your thinking as you work your way thru a project. Keep designing, building and refining new machines for our education and enjoyment. Again, thanks much, Myles!..............Just Sayin'

[Myles]

I finally got the box completed and did a vapour test of the still today. I added in two copper funnels as fill ports, each is above a gate valve. For the steam test I connected up the condenser and reflux condenser air vent to a garden hose to run the steam to outside.

Now this 6 kW element has 2 elements in the same body so I wired them in parallel. On my supply (220 v) they actually produce 5 kW max. Doing the maths suggests that on a 240 v supply they would actually pull 24 Amps equating to 5.7 kW, fairly close to the advertised 6 kW.

Interestingly with this module the up and down trigger points are so close together that there is no conduction below the up trigger. On my own component based circuit, once it is switched on it can be backed off to lower than the trigger point.

This was the linearity of the controller.

I charged the boiler with 50 litres of water. Time to boil from cold was 65 minutes. The keg is significantly hot in use so insulation would be a good idea to reduce warm up time. There were no leaks so I just blasted steam through the pot still at full power for 10 minutes and then switched over to the thumper.

Initial noise was disconcerting - almost like a chainsaw in use. However after 5 minutes the small charge that I had put in the thumper heated up and the noise dropped to a barely audible murmur. The diffuser that is fitted to the end of the vapour tube clearly works as intended. Another 5 minutes had the packing heated through with steam exiting the reflux condenser. Again there were no leaks and the thermowells I have fitted work fine. After 10 minutes of blowing steam through the packing I switched off and opened both refill ports. Will drain her down tomorrow.