a wet wet chiller

[drsuperheat]

In a case like this I would take my best guess at a reasonable number of hours and double it. What I have seen in the past is that if a compressor runs wet for more than a few minutes it will die sooner or later. If they just get flooded, never ran and is dehydrated in a few days they are usually ok. You may want to just put replacing the compressors on your bid. Also a few other unwelcome surpises will pop up. If you have to do it, do it on a T&M basis.

The guys are right, you will own this job. A year from now when the same junior engineer decides he needs colder water again, you'll get a call: "ever since you fixed that thing it hasn't been right, and now it shut down". Sell him a new one if you can and tell the Bozo who adjusted the controls to stay away from it.

[trimble]

If you haven't bid the job yet, and absolutely can't sell him a new chiller, do it on a T&M basis only.

[no8no3]

I did one last year that was full of water also, replacement was out, due to the way they allocate their machinery budget. We replaced the compressors, plate evap, and removed the condenser coil(air cooled) and accumulator, and everything else that would hold freon or water, and placed them in a powder coating oven at 250 degrees for 24 hours. Installed everything back and THEN took the dehydrateing steps that you mentioned. This 30 ton unit was repaired and is running fine today, for the nominal sum of 34,000.00 about 4 grand over new. Total hours 44 for 1 man.

This price included a hot gas by-pass, and tamper proof freeze stat. This was and still is the worst decision this company ever made, and possibly the company that i worked for also. You simply do not favor the customer by repairing this unit. I've got 30 years in this biz, and it took me 44 hours. how long do you really think it will take you? If you do nothing else, at least show your boss this thread...we all cannot be wrong...and good luck.

[Chomper]

He is the BOSS!

[aaronforprez]

yeah,

thanks chomper.

ok, well i've started so it's balls to the walls now.
i'll keep you updated with how things are going.

maybe my boss will fire me if this doesn't go well...

i wonder how that conversation would go

[aaronforprez]

this is a pic of the new evap and suction filter i'm adding and some other parts. (i thought i'd post some pics on the website once)

[nowonder]

I've been at this for a long long time and unless youbare in pakistan or some other hell hole you are anging a anchor around your neck, be very carefull here, good luck

[freonrick]

those drier cores look like standard cores. you need high moinsture removal cores.

[seaboard]

Earlier you said the compressors have a 1/4" fitting near the bottom. It is probably an access fitting to drain excess oil from the compressors. Since you have compressors in tandem they have to have an oil equalizer. If this fitting is near the level of that line, it's not a drain. "Baking" the compressors in a low temp oven to remove moisture sounds like a very good idea. All I can say is good luck, I think you are going to need it. Keep us posted on it no matter what happens and I for one will resist the urge to say "I told you so". Either way (whether you encounter many problems or not), it will be a learning experience for all of us as well as yourself and that's what were here for.

[R12rules]

Let me get this straight.


1) you are the boss. You make the decisions to go for it or turn the job down. Is that correct?

2) you are working on time & materials here, not on a bid? Is that correct?

3) you are going to be following the advice of step by step clean up, as outlined above?

4) the plant manager has informed you of his intent to keep this machine and NOT buy new?

5) The plant manager has been informed the cost of repair will EXCEED the cost of replacement. Correct?

6) you realize that a vacuum pump is not a magical insturement! That it accomplishes NOTHING unless it is clean and is filled with fresh dry vacuum pump oil!

If you dare to hook up a vacuum pump, or a pair of them ... which is the better idea. If you put them on this system and do not include the use of that dry ice tank, The Welch, then you are just kidding yourself.
I dont care how often you change the vac pump oil. I dont care HOW OFTEN you change that oil ... even if you CLEAN the pump out, "thuroughly", with each oil change .... that pump can only remove some moisture IF the oil is dry. Cause once that vac pump oil becomes wet ... it is only wasting electricity. And all the time that that pump is running, that chiller system is NOT online!
And that will be to your dread!

Welch offers a dry ice/ alcohol slurry cold trap.
Cat No. 1402H-14 which comes with 1/2" I.D. connections.

Welch Rietschle Thomas
7301 N. Central Ave.**P.O. Box 183**Skokie, IL 60076-0183 USA
Phone: 847/676-8800**Fax: 920/451-4397

When ever I hear stories about leaving a pump on the system for extreme lengths of time, "UN-ATTENDED", it just makes me wonder what the tech has on their mind.

This may not be the case if you have a "known to be dry system" ... if you are just removing free air at the first and then any small amounts of moisture ... and you are properly measuring this amount of moisture ... so that your vac pump(s) are NOT running long periods of time with "wet oil" . Then that would be the exception, rather than the rule.
That Welch dry ice tank is the only apperatus I have ever heard of which will inhibit the direct transfer of moisture from within the wet system ... into the vac pump.
And I use the word "inhibit" to mean that it is not a 100% trapping of all free airborn moisture.

In the pix I saw what looked like awful big sweat fittings on that drier shell.
I also remember you mentioned a suction filter.

What are you doing about LIQUID FILTERS?
Suction filters are for prevention of garbage returning to the compressors.
Moisture is best captured from refrigerant when it is filtered in the liquid line and when the liquid line is located in a very cold environment!
For example, a walk in box. Install the liquid line filter drier inside the refrigerated space.
This way you have the best of BOTH worlds.
It is cold and it is in the liquid line.

This is certainly NOT an application for throw away steel driers. Sweat or flare.

You need to go with the Big Boys here.
At least a twin or three drier core shell would be in order.




I heard something about two compressors in tandem.
Is that correct?
If so, how has the system been operating without the one compressor.
Tandems, to my understanding, do NOT work well alone.
(snicker, snicker)

I guess you have contacted the manufacturer of both the compressors themselves and the maker of the chiller and discussed clean up proceedures, at great length!
I hope, I hope, I hope, I hope, I hope, I hope, I hope, I hope, I hope, I hope, I hope, I hope, I hope, I hope, I hope, I hope, I hope, I hope, I hope, I hope, I hope, I hope, I hope, I hope, I hope, I hope, I hope, I hope, I hope, I hope, I hope, I hope, I hope, I hope, I hope, I hope, I hope, I hope, I hope, I hope, I hope, I hope, I hope, I hope, I hope, I hope, I hope, I hope, I hope, I hope, I hope, I hope, I hope, I hope, I hope, I hope, I hope, I hope, I hope, I hope, I hope, I hope, I hope, I hope, I hope, I hope, I hope, I hope, I hope, I hope, I hope, I hope, I hope, I hope, I hope, I hope, I hope, I hope, I hope, I hope, I hope, I hope, I hope, I hope, I hope, I hope, I hope, I hope, I hope, I hope, I hope, I hope, I hope, I hope, I hope, I hope, I hope, I hope, I hope, I hope........

[Edited by R12rules on 07-18-2004 at 12:26 AM]

[dschwab9]

Originally posted by R12rules
I heard something about two compressors in tandem.
Is that correct?
If so, how has the system been operating without the one compressor.
Tandems, to my understanding, do NOT work well alone.
(snicker, snicker)

2 circuits, each with two compressors in tandom. 4 compressors total. One circuit still working according to a previous post.

[R12rules]

Ahhhhhh-soooo .....

Boy that was a buncha posts .... I figured I'd lose something in there.



Hermetics in tandem .... whoever came up with THAT idea should have to fix em for as long as fools manufacture them.
Sheesh.

[nowonder]

what breed of hog is this?