Pump Type ~ Reflux Condenser Tube ID ~ Backpressure

[NineInchNails]

I am in the process of constructing my 1st VM head and I'm trying to decide on coil material size vs what type of recirculating pump to use. I've been using the search function and reading all I can find on the subject, but can't seem to find what I'm looking for. Many are using either pumps rated for low-mid pressure (anywhere up to 20-60psi) and even pond/fountain pumps (low pressure). I see that many of you guys plumb a bypass valve in order to relieve excess pressure in order to not needlessly overburden the pump ... I see how that could be wise.

I get all that, but where I'm a bit boggled is that when making a basic coil ... at what ID tubing (+ tubing length) can one get away with using a pond/fountain pump and not require a pump capable of maintaining a decent pressure?

From what I've read many seem to agree that 1/4" OD copper tubing is typically used for 2" and smaller columns and 1/4" ID tubing is more commonly used with 3" and larger columns. I have been researching and found ways to help reduce back pressure, for instance making a Cold Finger and plumbing multiple coils to it.

I have a 3" SS column, will be using a propane burner, mostly copper mesh packing, 1” vapor take-off with 1” ss gate valve, and my Liebig will be 1" over 3/4". I'm thinking that I want approx a 9" long reflux condenser, and would very much like to keep it simple ... for instance just a double or triple wound coil. I would very much like to get away with being able to use either a 12v pump (with power supply) or even a basic pond/fountain pump for water recirculation to the condensers.

I have found some 12v Booster Pumps (diaphragm pumps) like these: http://www.aqq.com.tw/products_k-36.htm" onclick="window.open(this.href);return false;" rel="nofollow and these types of pumps can handle PLENTY of pressure, can run dry without harm, self priming, but their flow rate can vary anywhere around 0.33 - 0.1 gpm (depending on pressure) to 1.1 - 0.63 gpm (depending on pressure). Some models are capable of higher volumes, but these types of pumps are not exactly cheap though.

[squidd]

Jackson cross flow condenser.

Can be a build challenge, but maybe not compared to double or triple wound coils.
Highly efficient, and zero to minimal back pressure.
Head room increase.

HTH,
squidd

[NineInchNails]

Ahhhhh, I don't want to get that complex at this point. I'm sure just a basic coil will work well as a condenser right? I'm just wondering at what point would a higher pressure pump be required (taking into consideration tubing ID and length)?

For instance if a 1/4" ID copper coil approx 9" long would require a higher pressure pump ... I'd be content knowing that I have to start shopping for that type of pump. If a basic pond/fountain pump will more than handle a 1/4" ID copper coil including the Liebig then I have a multitude of options with regard to the type of pump.

I'm more or less wondering what you guys think with regard to pump performance in relation to tubing type/size.

For instance if in order to use a double wound coil with a low pressure pump would I have to step up a size with the copper tubing? If so would the condenser itself suffer performance wise?

At this point it's theoretical to me. I'm a newb.

[squidd]

In that case, Hook is your man.
Suggest a PM.

squidd

[NineInchNails]

Will do, but if anyone has some input please jump right in.

[rednose]

For my twins (a little more than hobby stills) I use 12V Shurflo diaphragm pumps each (about 100$).

I use solar panels to feed 'em.

Those are bullet prooved.

Joe

[NineInchNails]

For my twins (a little more than hobby stills) I use 12V Shurflo diaphragm pumps each (about 100$).

I use solar panels to feed 'em.

Those are bullet prooved.

Joe

That’s what I was leaning towards, but they aren’t exactly cheap. Those little diaphragm pumps are real quiet and made to run continuously for a LONG time.

[HookLine]

Just use a bypass valve to relieve excess back pressure.

[rednose]

Try to catch one of these:
http://cgi.ebay.com/ebaymotors/8000-543 ... ccessories" onclick="window.open(this.href);return false;" rel="nofollow

The guy has two and shipping inside US maybe about 15$.

For me doesn't make sense to buy a used one, the shipping is about 50$ no matter if new or used but I'm behind a steal for a new one to have in reserve just in case that one of 'em goes in holidays.

That’s what I was leaning towards, but they aren’t exactly cheap. Those little diaphragm pumps are real quiet and made to run continuously for a LONG time.

[rednose]

Here a 110V version of the shurflo brother, the flojet, for about 40$ shipping included and looking pretty good.

Makes almost a gal per minute what should be enough for a home still.

http://cgi.ebay.com/Flojet-R2100-Pump-h ... 45ecfab11a" onclick="window.open(this.href);return false;" rel="nofollow

One add: those pumps are self-priming and dry running, that means you can use 'em to pump air through your booze.

The hint from HL to use bypass is great for the high pressure version, the 110 version is low pressure.

[ozone39]

How about running a submersible pump on a VF (variable frequency) drive?? Would you still need the bypass valve, if you can control the motor speed (and flow) by dropping the hertz cycles???

[NineInchNails]

Just use a bypass valve to relieve excess back pressure.

Recirculating pump & reservoir coolant system.jpg

I saw that drawing earlier today in your thread about making condensers for people. Makes perfect sense especially for pond type pumps.

Thanks!

[NineInchNails]

rednose,

I checked out those pumps. One thing that concerns me about some of those ShurFlo pumps is that their specs state "for intermittent use". I didn’t check the specs for all of their different models though.

Those 'Booster Pumps' for Reverse Osmosis units are made to run 24/7 with or without backpressure and can also run dry (they are diaphragm pumps too). They are VERY similar to the kind you listed though.

Today I went out into the shop and grabbed 25' of 1/4" plastic Pex type hose and it wasn't that hard to blow through it at all. I think I might be just worrying too much because I’m getting close