Shotgun product cooler efficiency

[Odin]

Hi guys,

Maybe you can help me out. I am trying to find some calculations or rules of thumb on how to design the right size shot gun product condenser. Say you have a 3 inch wide product cooler of around 1 foot long ... how much would that knock down? Maybe 5 to 6 KW? Maybe much more? Just guessing here, so correct me where I am wrong. And how about 2 feet? What amount of cooling water per minute are needed?

Or we should turn it around. How much cooling water per minute is needed in a 1 foot 3 inch shotgun per 1 KW energy input? That would make it easy, because it would give us a number we can work with. "If 1 KW takes X amount of water, 10 KW would take X times 10 ..."

Looking forward to your input!

Odin.

[tropik]

I have no scientific input but I have a shotgun condenser. 2"x20" on a 15.5 gal boiler. It can take a lot of heat. Actually I would scortch in my boiler before getting vapor past my condenser.

[Odin]

What kinda wattage you put into the boiler? And how many liters of cooling water do you use?

Odin.

[Prairiepiss]

Odin mine is 3" 16" long. The condenser portion is 11" long with 5 11" 1/2" tubes and 4 11" 3/8" tubes. One of the 3/8" tubes has a 1/4" tube running through it. For my parrot vent. I have never tried pushing it to the limit. With the fu man plate and packed section. Running cm mode. I have pushed it at 4000 to 4500 watts. My 2" column will flood before the condenser gets overloaded. I've never really pushed it at all in pot still mode. I guess I should try to at least once. And as far as flow. I've never measured it. I use tap water and just turn it up til the water coming out is warm.

[wv_cooker]

Odin wouldn't the condenser calc from the parent site help. 2' condenser 4 tubes equal 8' of 1/2 inch tubing enter into calc see how much flow per hour and how much power etc. etc.

http://homedistiller.org/calcs/cond_calc

[Odin]

I tried that WV, but the thing does not seem to make sense. Just try it for yourself: if you raise the temperature of cooling water out, there is more heating of that cooling water, so total length should be less ... instead it gets longer. Not sure we can trust it.

Odin.

[Prairiepiss]

And the calculator won't be accurate for a shotgun. The shotgun is somewhat more efficient then a liebig. Kinda. You also get into the difference in mass of the cooling water. Since most shotguns will hold more water then a liebig. Bla Bla Bla. You get the picture.

[wv_cooker]

Well shucks just trying to take the easy way out. Yea I can see the surface area of the volume of water in the chamber of a shotgun being more efficient than a coil or liebeg. More dang math to learn lol.

[sambedded]

I tried that WV, but the thing does not seem to make sense. Just try it for yourself: if you raise the temperature of cooling water out, there is more heating of that cooling water, so total length should be less ... instead it gets longer. Not sure we can trust it.

OK Almost all power you pumping to heater should be caries away by cooling water. (except the power carried out by ambient air , on my setup i'm loosing around 300watt)
One liter of water heated on 1 C consume 4,186 watts of heating. So if you have 1 liter/sec flow rate and 1C difference between in and out you will utilize 4186 watt . Or you can have 0.1 liter per second flow rate if you have 10C difference.

You are right Odin, if you rase cooling water out temperature with the same flow rate it will carry more energy. But flushing out power is only one part of cooler job. It also has to TRANSFER that energy from vapor to water. Transfer rate proportional to cooling area and temperature difference. If you increasing out water temperature you are decreasing transfer rate. It means you need to increase area (ie length if you keep same diameter) to compensate it.

I don't know how accurate that calculator but it's logic is correct.

One more thing to consider - as soon as vapor start condensing on cooler pipe walls it creates a film of liquid. And ransomer rate metal-liquid-vapor is much less than just metal-vapor. To make cooler work more efficient you need remove that liquid ASAP. it means same condenser installed vertically works more efficient when mounted vertically because force of gravity remove liquid from the walls faster.

[Odin]

Yes, Sam, I think I now understand the logic. And thanks for giving me some numbers.

So ... let's see if I got this one right.

4 kw needs one liter of water per second. Temp water in will be 15 degrees C, temp water out ... 16 degrees C.

Or you put in 0.1 liters and water temp out will not be 16, but 25 degrees C. But ... aren't we missing out on the fact warmer cooling water is less effective? It feels like there should be some kinda X-factor compensating for that.

I mean, we can say water out can be 60 degrees C, thus creating 45 degrees of temp difference between water in and water out. But 60 degrees water won't do much cooling ...

Odin.

[sambedded]

Yes. Hot water not so efficient cooler. So, To have bigger temperature difference you need a more efficient (ie bigger) shotgun/Liebig.

[wv_cooker]

I think we are missing flow rate as a factor Odin. If the water just lays in the condenser the temp will just continue to rise so flow rate becomes the issue. If we add more power one of 2 things needs to happen (or probably both). We need to increase the surface area of the condenser and we need to remove the hot water, so we need more pipe but we also need to increase the coolant flow rate. It seems in my thinking that surface area and flow rate are important to keeping the coolant in temp low. So it seems the questions are how much surface area, coolant flow rate, and coolant temp in do we need to hold coolant temp out at x if we apply x amount of power. Boy I hope I said all of that right lol.

[Odin]

Well ... it sounded right, WV!

I am currently thinking of a dual solution of one big pre-condensor, then some pipe, then a smaller shotgun.

Odin.

[wv_cooker]

Well ... it sounded right, WV!

I am currently thinking of a dual solution of one big pre-condensor, then some pipe, then a smaller shotgun.

Odin.

Well you usually speak better English than I do so I will take your word for it, lol.

I have noticed several folks doing things similar lately, like putting cute little liebegs on LM rigs before take off. It has had me to thinking we can't control what happens from the boiler up through the column but we can from the condensers to take off.

[Odin]

Always felt 180 degrees the other way around on that topic. Like we can control what happens in the column, yet not afterwards.

Just me.

Anyhow, I solved the puzzle that was bothering me. Thanks! With your guys' input!

Odin.

[wv_cooker]

Well see there's that better English than mine again lol. We can't control the Temperature in the column but once it reaches a condenser we can control the returning reflux is more what I should have said. You have to point these Hillbilly's occasionally lol.

Now are you gonna through us a bone and enlighten us on this big discovery?

[googe]

Have to agree, I have always run the still and never touched cooling.

[Odin]

If we look at it from a different point of view ... how much energy can a dephlag handle?

Odin.

[googe]

Just less than a pc, all a deflag has to do is knock down vapor to stabilize the column. 10 mini deflags would = one large one, try running 10 mini deflags though lol.

[Odin]

Not sure I understand "just less than a pc" Googe!

Hope you can explain ...

Odin.

[googe]

You asked "how much energy can a deflag handle" as a deflag is designed to be a type of pre condenser for the nature of the still, it can handle just less energy than a pc for a pc is designed to knock down all in coming vapors. There all the same, contact with vapors is the determining factor that makes them.what they are in the scope of the still there being used on.

[wv_cooker]

Hey guy's Bushman has a topic going on Deph's let's carry this discussion over there and help him out.

http://homedistiller.org/forum/viewtopi ... 17&t=42954

We might be able to add some new words or something to his discussion lol.

Thanks

[Odin]

Good idea!

Odin.