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Compressor Set up - Zig Zag vs. "Knock out drum" and Loop vs. Deadend

OntarioMark

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Jul 26, 2012
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Hi,

I am working on setting up a small air compressor in my garage. I have read a fair number of threads on the subject. I wish to cool air coming off of my compressor before it gets distributed. I know that one option is to put some zig zag lines on the wall. I have seen some good posts with photos of that design. I have also seen some suggest that a kind of "knock out drum" can be an alternative to the zig zag. The suggestion as I understand it is to take a 2" or 3" pipe about 48" long, place it vertically on the wall, on the side near the bottom of the pipe have a 1/2" or 3/4" inlet for a flexible line from the compressor, have at the top of the pipe a 1/2" or 3/4 outlet, and from there run to your separator, regulator and the rest of your system. The effect of the big pipe is to allow the air to cool and moisture to drop out. From what I have read, that one big pipe can be as effective as the zig zag and take up far less wall space.

My questions then:

1. Have I got the description of how to lay out the "knockout drum" right? Am I missing anything?

2. Is this set up as effective as the zig zag?

3. If you have the "knock out drum" system on your wall, could you please post a photo? I found only two in my search of various threads. I am a simple guy. The more I see, the better I understand. Usually.

One other question about set up of the air system. This is in regard to a loop of piping versus a dead end system. From what I have read, it seems some say that if the air system is only going to be used by a single user, then there is no advantage to having a loop system. In other words, without having more than one user at a time, there is no advantage to having the air able to come to a drop from both directions.

My question: Is this correct?

Thanks for your input.
 
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sberry

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I want to ask first, what is the intention here? The reason is,,, we see this often and with the internet it becomes a glob of good ideas and now it seems its a must have despite the rest of us working the last 40 years without it.
One other question about set up of the air system. This is in regard to a loop of piping versus a dead end system. From what I have read, it seems some say that if the air system is only going to be used by a single user, then there is no advantage to having a loop system. In other words, without having more than one user at a time, there is no advantage to having the air able to come to a drop from both directions.

My question: Is this correct?
This is a perfect example of it. I don't use a loop and I am in a 80x80 building, the loop is another great idea someone seen at work in a GM plant covering acres and they bring it home to their "huge" 30x40 pole barn. Its not really a single user vs multiple issue and a single 1/2 pipe line will deliver more air than your comp will be able to put out.
There is no advantage and maybe some drawbacks as it makes for difficulty in driving condensate to a collection point.
 

sberry

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I am a simple guy. The more I see, the better I understand. Usually.
Ok, how big is the building, this is somewhat fundamental in a couple aspects but usually in hydrant and end user design.
I havnt kept track of the threads, there were a couple that had really good fundamentals and that is where to start. Don't boither with a whoile slew of hydrants, a hose reel or 2 located right and maybe a fixed whip at a bench, you do not need drops every 4 ft with several couplers and valves. Pick a good spot for a regulator and filter, put a ball valve on the tank the same size as comes out of the comp, a hose to a 1/2 black pipe and run a stick or 2 to the filter/regulator, install a t on it, plumb a hose reel to it using the screwed connections and leave a port to put a whip or additional equipment on and go from there.
This is your first comp, hook it up get it working, run the feeds with a hose if you have to and pipe after. Many and from what I have seen maybe most waste a lot of time and resources for stuff built in and often never used.
Avoid the temptation to include every idea you can find ever see before you ever get started. Real things you need can be added after if it becomes the case.
 

woodzy

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Mine is a simple 1/2 copper line wrapped around a 5 gallon bucket. I built a couple supports to hold it up and it caused all the air to cool before it gets to the tank.

If you look at the color of the pipe, you can see it goes from dark to shinny as the air cools.



air%20compressor_zps5m2df49u.jpg
 

Brian_WK

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Mine is a simple 1/2 copper line wrapped around a 5 gallon bucket. I built a couple supports to hold it up and it caused all the air to cool before it gets to the tank.

If you look at the color of the pipe, you can see it goes from dark to shinny as the air cools.




Wouldn't this work better if you had a trap and a drain at the bottom of the loops. So you could keep the moisture out of the tank? Seems like the way it is ran as the air cools and condenses it will just drip water down into the tank. Using the cooling effect to pre remove moisture before entering the tank is the only benefit I can see from these loops and to reduce load on an air drier.

Brian
 

Brian_WK

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What would it hurt dripping back in the tank?

Nothing.
It just seems like if you are going to go through all the trouble to cool the air you might as well get rid of some of the moisture to keep it from rusting the tank and working the air drier.

Brian
 

woodzy

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I have been using this for 16 years on the same compressor and I don't have an air dryer. Never seen moisture in the line. I just drain the tank once in a while (probably not as often as I should).
 

James E

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I like the idea of that coil but I would think that when you're using a lot of air, the flow would carry the condensed moisture through the line to your tool. It seems like the water that condensed near the top of the coil would never have an opportunity to dribble down into the tank as long as you were using air.

That water drop idea would be much more effective with that coil in front of it, as the already-condensed water droplets in the cooled air would drop out of the air stream much more easily, allowing the cool, dry air to go up and out to the tool.

I'm about to plumb my compressor into the lines I built into my garage. I'm glad I saw Brian's coil before I did it.
 
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Finky198

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I really don't understand all the big debate on all these different methods for cooling air why waste all the time, money, effort, supplies making wall art with pipe :dunno:

if you run a minium of 15' of 1/2" or larger metal pipe (black or galv steel, or copper) with a slight slope and 1 drop before your Filter/ regulator you should see little to no moisture which should be more then suitable unless your running a body shop, plasma table, or sandblasting outfit... :evil:


I have an IR 7.5hp 80 with 40 gallon surge tank output to 3/4 hydraulic hose 48" of rise to 16' of 1" black iron pipe, it drops roughly 6" on the 16' span, which then drops 18" to a sharpe F88 filter/regulator.

I get less the 1oz of water out of the filter end, and about a 4-8oz at the compressor per day
 
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OntarioMark

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Thank you for the responses to date. They are helpful.

Regarding some of the inquiries, my garage is small, only about 24 feet by 16 feet. I mainly want to be able to just use basic air tools. Nothing has to reach too far. But I like to have things very neat and out of the way. I do not want to have to pull a hose far through the garage. I also like to try to just do things once rather than redo things down the road. So I am going to do a few well placed drops. One will include a hose on a reel so as to be able to take air outside.

If the loop is of no value, then I want to skip it. It would add a lot of work compared to where I would just run a dead end system.

I do not want to create wall art at all. However, given where I have to put the compressor and where an inlet or two is already needed, I cannot get a straight run of 15 or 20 feet before the first air consumer. That is why I am inquiring about the zig zag or the "knock out drum." (The reason for the quotes around the latter is that I think what I am looking to hear about is not really a knock out drum - which I think from what I have read usually involves a separate air tank in a more sophisticated system - but rather what I have seen one or two members use as a way of describing what they have done with a long thick vertically mounted pipe rather than the zig zag.) I wish to do the cooling on the wall where the piping will be compact and out of the way and placed before the first air consumer is reached.
 

PoorOwner

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I run straight with least turns as possible, run it where you want it, I have 20-30 feet of pipes and no moisture. But that depends how hard your compressor works to keep up.

I build based on this diagram and scale to my needs .. you know, it works really well without any loops or zig zags.
2035_L_1c34657a.jpg
 
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OntarioMark

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Here are some photos of what I found showing the "knock out drum" design. One design is from Falcon67, the other is from akdiesel, who both posted in 2012.
 

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CNGsaves

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^ ^ ^ With small garage . . . and you're leaning towards "knock out drum" . . . might as well be calling it the CORRECT terminology . . . .

It's a Franzinator . . . . and yes they work.

Use GOOGLE to search out ALL the threads on Franzinators in GJ.

Do this:
> > > > > > GOOGLE > > > > Franzinator site:garagejournal.com

You'll have LOTS of reading, and great examples!! :D
 

Finky198

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I run straight with least turns as possible, run it where you want it, I have 20-30 feet of pipes and no moisture. But that depends how hard your compressor works to keep up.

I build based on this diagram and scale to my needs .. you know, it works really well without any loops or zig zags.
2035_L_1c34657a.jpg

I also built my system using this diagram as a guide

This is a properly designed system all you need to do is scale it down to your stations. If you need additional length just double back with pipe and you will double your overall length giving you more then enough cooling capacity

I think the others big issue are bends ^^ which are highly constricting to flow and coupler/joint which are prone to leaks. The less complicated the system the better

I would save money on the artistic plumbing and extra fittings and buy a better water trap filter / regulator and some good hi flow couplers
 
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OntarioMark

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I guess my quotes around "knock out drum" and the explanation a few posts above about why I did that was just too subtle. In any event, thank you CNGsaves sincerely for clarifying the name of the device, and perhaps a little less sincere of a "thank you" for the Google lesson.:D Now off to do some searching.
 

akdiesel

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OntarioMark

The term "Knock Out Drum" is just that. We use the term at work for the same purpose. To knock out liquids in our gas stream. Enters the side and exits the top and also has a liquid drain valve that is triggered by a level switch. The phrase Franzinator came from (I believe) some one called Fran but don't quote me.
Three reasons for a knock out drum are to eliminate liquids in your air system, to give a little more air storage, and to protect the main tank from corrosion.
I feel the better set up is Compressor, Cooler, Coalescent Filter, Knock Out Drum, Main Tank, and then the air line. The coalescent filter is a bit like the knock out drum and may not be needed or vice versa. Both play the part in the JT (Joules Thompson) effect. Creating a pressure drop in the tank / bowl to help cool the air and knock out the liquids.
 
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