Bokakob still question

[hankfrank]

So, I've been reading a lot here and I'm going to build a bokakob reflux still I just had a question before I get started.
In the designs that are shown online the top of the column has a cap (blue) on it with small hole in it (circled in red). I've seen a few other stills that leave that open, is there any benefit to putting a cap on there and only leaving a hole? Isn't that dangerous?

Thank You
Hank

[alkoholics]

i beleive that the hole is for the thermometer

[Dnderhead]

vent---leave open

[brewmaker1]

Listen to Dnderhead. The top has to be well vented so no pressure can build up. You will be adjusting output flow with the valve. If any pressure can build up in the column, it can do one of two things. Either blow apart or force everything out the output. If the valve is closed down for reflux equilibrium, pressure will build until something gives. If the valve is open the pressure will try to push liquid and vapor through the output tube like a pot still, but with such a small takeoff tube it will still be dangerous.

[Tatt2d]

vent---leave open

Exactly what Dndr said...

Without that vent you run the risk of pressurizing your column/boiler. The condenser is suppose to knock down any vapors so you aren't steamin out the top. But...
With it plugged, and you run into a problem with your cooling water, you turn it into a pressure cooker.

EDIT: Brewmaker beat me to the punch and made it sound better

[hankfrank]

I've got a second question, for the flow of water through the condenser coils is hooking a hose to a regular faucet and letting it run at a controlled rate enough or do I need an external aquarium pump or something to pump water through it?
Sorry if this is a foolish question I just didn't see anything written about this and I'm trying to figure out the whole process before I get too far into building.

Thanks,
Hank

EDIT: Thank you for the quick and informative help, I appreciate it.

[HookLine]

A cap on the column is not a problem if there is a hole in it.

You can run your coil condenser straight from the tap no problem, it only needs a low flow rate. It does mean you use a lot more water overall than a pump and reservoir recirculating system.

[rad14701]

Figure roughly 1/2 quart/liter of water per minute to cool most stills or maybe a slight bit more... So roughly 8 - 12 gallons of water per hour... You can decide from there whether to just use tap water and let it run down the drain or to utilize a water vessel and a small pump...

[Freedave]

hank,

you did not ask this but i thought I'd mention it if you don't already know. the better bokakob design has two slant plates soldered in the column in order to better collect the condensate for either takeoff or reflux. don't have a shortcut for you but maybe you will find it or someone will post it.

also make the packed part of the column as long as possible.

have fun.

[bourbonbob]

Like the boys said, leave the top vented, no need for a cap. If you find you are loosing vapour through the vent? stuff a pot scrubber in it.

[Husker]

A cap soldered on to a condenser is nice. I like them that way. It provides some support for the condenser.

However, like has been mentioned several times, MAKE SURE IT HAS A HOLE. That hole is for pressure release. I like to put a thin hammered copper disk over that hole (just a little bigger than the hole). That way I can easily spot if the condenser is not knocking down all the vapors (the disk will move).

If you look at the New-Distiller's mini FAQ http://homedistiller.org/forum/viewtopi ... =15&t=5166" onclick="window.open(this.href);return false;" rel="nofollow you will find a better upgrade to this still design (2 plate mini) The 'mini' can be upgraded in size (2") for usage with a keg.

H.

[Dnderhead]

A marble works (bigger than hole), just sit it on the hole . moves freely if it needs to and does not fall off.

[hankfrank]

I'm going to put a second plate over the plate that catches the distillate (the green line in the picture) that will be the take off so that my control of how much reflux is going back down the column is more controlled, my question is this, I'm going to use a large pot as my boiler and mount the column and head on the lid, while I'm at it I figure I may as well build a pot still on a second lid cause why not get all my construction done at one time? but do I need to build a pot still head or does this second plate with the the reflux valve fully open and nothing in the column do the same thing? I guess the question is is there enough difference to make a second pot still head worth having for whiskey making down the road?

Thank you again for your help I'd be lost without it.

Hank

[rad14701]

hankfrank, several members use the Bokakob dual slant plate column head as a pot still stripping head... There are several topics dedicated to the construction... Several even have a detachable reflux column... You simply open the take off needle valve so you collect 100% of the condensate with 0% reflux...

The current design I'm running, see the link in my sig, is a variation on the same theme as the Bokakob dual slant plate column except it uses two reducers and a stand pipe...

ALSO SEE:

http://homedistiller.org/forum/viewtopi ... =17&t=5829

http://homedistiller.org/forum/viewtopi ... =17&t=8845

[tracker0945]

To get the full benefit from a pot head, it's best to remove all restrictions possible, this would mean plates, packing etc.
I found it easier to make a completely different head and just swap it over where your column attaches to your boiler.


Cheers.

[Husker]

I agree with tracker. Using a inline head to simulate a pot can be done, but it is not the same as a true pot still head.

H.