PDA

View Full Version : Air Compressor aftercooler/manifold



Gamble
09-02-2016, 11:32 AM
I want to do this to help cut down on moisture and add a little volume to it. Have a few questions because I'm not sure where to start.

* Does diameter of the pipe/tube matter?

*Copper or black pipe?

*Welded or soldered (if copper)

*air inlet/outlet are they supposed to be on the top or bottom?

*Horizontal or vertical?

Is there a science behind this as to what works best or is it that anything is better than nothing?

Then when it's all said and done, I want to get the rapidair kit to go around the garage. This way I can always have the cnc table hooked up, 1 for blowing air, 1 on the other side of the garage to fill up tires, DA sander and a misc port. This way I don't have to keep plugging and unplugging things
https://www.amazon.com/Rapidair-90500-Master-2-Inch-100-Feet/dp/B0015A11U2/ref=sr_1_2?ie=UTF8&qid=1472830094&sr=8-2&keywords=rapidair


Here is a pic for those that don't know what I am talking about
http://67-72chevytrucks.com/vboard/attachment.php?attachmentid=1304007&d=1411316378

76GMC1500
09-02-2016, 12:38 PM
Don't mention soldered copper air pipe here.

That said, steel pipe has poor heat transfer so definitely use copper. Just don't solder it, braze it. 15% sil-phos is ideal. It's used on air conditioning systems running at 350 psi. I would do S curves with a downhill slope into your receiver where the water can be separated out. The one pictures with the low points with drains is wrong.

Straight copper tube has little surface area, see if you can find something with gill rings. Better yet, get an air conditioning condensor from the junk yard and put a fan on it.

Jawslandshark
09-02-2016, 07:22 PM
I have black pipe run throughout my shop and various separators and Motor Guard filters, also have a auto drain on the tank that goes off every 20 minutes to purge. My plasma is hooked up for the table about 20 ft from the compressor and have a Motor Guard on it also. Been wondering if should just buy a refrigerated air dryer. I am also curious what people have done and if just spending the money on a dryer is the way to go. I really don't have a water problem but when in drain the feed drops a little water does come out.

Ypop
09-02-2016, 10:19 PM
76GMC1500 is correct. How I would run air lines is go to the ceiling and would be to slope all lines to air tank.(1 inch per 6 feet should work) Then for your drops to each machine or air hose use a "T" facing to the ceiling then 2 90 degree to go down that way all water/moisture runs back to the tank. Use auto drain on the tank this should cut down on water/moisture in the lines. Also use larger pipe 1 inch or larger for pipes along ceiling three quarter inch or half inch for your drops.

Ypop
09-02-2016, 10:36 PM
1500101 like this

CEP
09-03-2016, 06:12 AM
Here is how I have my air system.

John T
09-03-2016, 07:17 AM
. I want to get the rapidair kit to go around the garage. This way I can always have the cnc table hooked up, 1 for blowing air, 1 on the other side of the garage to fill up tires, DA sander and a misc port. This way I don't have to keep plugging and unplugging things
https://www.amazon.com/Rapidair-90500-Master-2-Inch-100-Feet/dp/B0015A11U2/ref=sr_1_2?ie=UTF8&qid=1472830094&sr=8-2&keywords=rapidair


That rapidair kit looks pretty good.

fittings look similiar to the sharkbite plumbing fittings (water)

I used them on new kitchen sink install... honestly expected leaks... since it was such an easy assembly... push/click/done.
But it's been great.

DSW
09-03-2016, 07:23 AM
Straight copper tube has little surface area, see if you can find something with gill rings. Better yet, get an air conditioning condensor from the junk yard and put a fan on it.

Alum finned radiator pipe is easy to locate, both new and used. You simply cut it to length with a saw and then peal off the alum fins so you can solder/braze the copper pipe.

jpump5
09-03-2016, 07:52 AM
I like sweated copper.
The less steel in an air system the better.
I'm rebuilding equipment at work
now because it was connected
without a filter and
rust scale from steel pipe got
into valve spools.

MX442
09-03-2016, 07:10 PM
I am in the process of setting up an air piping system in my garage right now. I have a few comments to add.


Is there a science behind this as to what works best or is it that anything is better than nothing?
A little bit of Meteorology 101. To turn water vapor from a gas to a liquid state, it has to be chilled to the dew point. With that said, your air dryer system will need to chill the air below the ambient temperature, and hopefully down to the dewpoint to reach 100% saturation to separate water from air. The easiest way would be a refrigerated air dryer. Otherwise, a little science is involved. Rapid expansion after passing through a venturi, or passing through a cooler will chill the compressed air.

A long stretch of copper or drop legs will not cool the air to the dewpoint to reach 100% separation of water all by itself. Though, it will cool the compressed air from high temperature down to the ambient temperature. Other means, such as water traps, filters, or coalescence is still required if you need 100% dry air. Unless you are painting, I would just run your piping to where you need it. At the end, add a drain leg. Then add drop leg to a water trap/filter, and a manifold to hook up multiple tools and hoses. For most home hobbiests, this is probably adequate, and falls into "anything is better than nothing".

This is overkill, but I need 100% dry air for painting and media blasting. I built my own "chiller" with a 20' coil of 3/4" copper in a 5 gallon bucket filled with cold water. Add ice blocks if you need it colder. After getting the chill, the air passes into a 3 gallon expansion tank, then the output is filtered with a Motorguard M60 filter. Most of the water is collected in the 60 gallon compressor tank, the rest is collected at the 3 gallon expansion tank. The filter is always bone dry. Works great. However, it is a pain to setup and use. I would rather have a refrigerated dryer if I could find a decent unit at an affordable price. Occasionally I see them on CL in the $500+ range.

The rapid air kits make it much easier to setup and change down the road. However, they may not come with enough fittings to customize to your needs. There is an added expense for every valve, manifold, and fitting you add to the system. The 1/2" kits are push lock fittings. Though rated for high PSI, my personal preference is not to use them. The 3/4" kit uses compression fittings, and the added volume is a bonus.

In the end, I am using 3/4" L copper. Initially, the pipe is more expensive at about $2 per foot. But for 50' of copper + fittings, the end price isn't much more than the rapid air 3/4" 100' kit that I don't need an extra 50' of pipe.

metalman21
09-04-2016, 03:24 PM
I reworked my neglected air system last winter to eliminate water, oil and contamination for my spray painting. Side benefit was dryer air for the shop air tools. I decided to do without any added electric components like a refrigerated dryer or timed tank drains. I figured I can add a refrigerated unit if needed but so far the system works great.
I have an old Curtis 5HP on a verticle 80 gallon tank, approximately 18 CFM. I installed an auto drain because I would forget to drain it sometimes and when I did I would get a gallon or more of water out of it! There is always going to be water in the tank no need to store extra.
The auto drain:
1500991
The whole idea to getting water out of compressed air is to get it to condense out of vapor into liquid so it can be removed. All the additional pipe, coils, radiators you see people using are serving as condensers to various degrees. Though researching I found that at least 25' is a rough minimum between the compressor and the first drop where air is used to help the water to condense. I only had about 20' and it was not enough distance between the compressor and the first drop in the shop where I use a trap/regulator to run air tools, should have seen the gunk in that trap! I had limited space to add a condensing coil of sorts so I had to figure out a way to stuff more pipe in. I built one with four 5' tubes side by side all sloping away from the compressor. Each tube slopes 1/8" in 5' and the unit is in line horizontally with the pipe on the ceiling, 20' of extra pipe in 5'.
The condenser:
1501001
I dropped down from there to a bulk trap tank, followed by two side by side 5 micron filters. Seems to work, the only place I get a small amount of water is from the bulk tank and the first filter.
The bulk trap and filters:
1501011
After that if feeds the shop regulator then runs about 25' more (small slope) to another drop before the paint regulator. Here it runs through two side by side .01 micron coalescing filters, a 10lb desiccant can, another 5 micron filter to catch any desiccant dust, the regulator, then a 38' paint hose.
The second set-up:
1501021
Then through the wall to the filter and regulator:
1501031
Everything is installed with shut off valves and pipe unions so I can isolate and remove components easy for service.
So far this is working great and the desiccant life is good despite the nasty hot humid summer. I can regenerate the color indicating desiccant when needed in the shop stove.
Hope this helps.

04chase
09-04-2016, 07:21 PM
first post but here is my cheap project cooler that i ddint want to run a ton of line for

used the biggest hayden oil cooler with some 3/4 SS line and welded an AN aluminum male flare on the output of the head to the hose .I used two AN too NPT adaptors for the cooler in/out and tank return. costs was about 160 for the cooler and some fittings i had as well as the lines.

15012311501241

i have more pics but it reduced output temps from 200 degrees to under 100 degrees . measure at aluminum output line and input to the compressor tank. this is a husky 7.5 hp 80 gallon compressor.

mikecwik
09-04-2016, 08:22 PM
I sourced my Coolerd from throw away air conditioners and dehumidifier and fridges. All it costed me was stopping to pick up someone else's junk. Now I got exchangers for a tig cooler, air compressor, outside wood burner plus copper and aluminum for the forge. Splash guards for the mill mills and lathes heavy duty cords, new crucible. Plus a couple bucks from what I scrapped.

N2 Welding
09-05-2016, 11:00 AM
Interesting thread.

pantelones
09-09-2016, 06:45 PM
it reduced output temps from 200 degrees to under 100 degrees . measure at aluminum output line and input to the compressor tank. this is a husky 7.5 hp 80 gallon compressor.

Man we have killing our compressor and tools... I kind of trusted my dad knowing what's what with the compressor set up - but damn, an oil cooler w/ fan, and long copper radiator would have dropped temps and given more run time before hitting the duty cycle.

Pete.S.
09-09-2016, 08:50 PM
Just keep in mind that a lot of bends and small orifices for the air to pass through means that the cubicfeet per minute will take a significant hit.

I took a class on pneumatic design a couple of years ago and they gave us some tables on how bends and different diameter piping would affect the volume per minute of air. It was a lot more than I had imagined.

metalman21
09-10-2016, 09:18 AM
Just keep in mind that a lot of bends and small orifices for the air to pass through means that the cubicfeet per minute will take a significant hit.

I took a class on pneumatic design a couple of years ago and they gave us some tables on how bends and different diameter piping would affect the volume per minute of air. It was a lot more than I had imagined.
You are right about that. Ran across information and tables regarding that but without training the formulas can be hard to apply. Especially if one doesn't have the patience or time to study it :blush:. When I was done revamping the shop system there were almost as many elbows as a box of mac and cheese. The spray guns, air tools are all working OK. If I made any unqualified suggestions to anyone setting up an air system it would be; if in doubt go larger. IE if your not sure for example about 1/2" pipe use 3/4". Avoid restrictions like under-rated CFM filters with reduced pipe sizes. Re-purposed coolers/radiators for condensers would be better off with tubing as close as possible to the main pipe size.
Of course this advise all comes out of the T&E handbook, (trial & error) and is worth exactly what you paid for it :).

Teggy1
09-14-2016, 10:23 AM
I built a similar after cooler out of copper pipe. I believe I have just under 50' of 3/4" pipe in mine, which I routed directly off the cylinder head to the wall cooler. When running long periods, the temperature at the head is roughly 325 deg. (it's an old worn out Campbell Hausfeld), and the tank inlet is right at ambient, or slightly higher.

I bought the copper on sale, but by the time I had the fittings, solder (I believe it was 95 tin or something, not your standard plumbing solder), and my time, I think it would have been a wash to purchase a used industrial air dryer (which I just recently did). If you have the room, the 200 CFM range air dryers go cheap on auctions. I purchased an Ingersoll Rand for less than 300 bucks, the fan didn't want to turn, which required new bearings (many of these fans use standard skate bearings, only a couple bucks a piece) and a 20 dollar contactor to start the compressor. All said and done, I'll have less than 350 bucks into a refrigerated air dryer, that I will never have to worry about capacity, have air that has a dew point in the mid 30 deg range, for little more than I spent on copper pipes/fittings/valves on the wall.

bevis28
09-14-2016, 11:18 AM
Interesting thread.

Times 2

Jawslandshark
09-21-2016, 12:36 AM
I want to give 04Chase some thanks for showing his cooler design, after seeing it and looking at mine I thought what the hell that looks much better than what I have, just some copper tubing ran across the back. So over to trusty Amazon and they had the one size smaller unit for $127. It came in today so I took my crap down and put this one on. Holy crap what a differnce, coming out of the head it's so hot it will burn you bad, other side of the cooler feels like the air temp in my shop. Now Brand X posted a link for a deal on an IR refrigerated cooler so I bought that also, my air seems perfect now.

My home made whatever you call it never worked this good, I really did not expect the results achieved from either one of these units. Thinking back how did I ever work with all this other junk, I know I had lots of Motor Guard filters! I also ordered some new filter housings and filters that were bigger than what came stock on my compressor, this also seems to have made it quieter and shorter run times. I have always neglected my compressor, wish I would have done this all sooner.