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Post by coldspaces on Jul 29, 2014 6:02:30 GMT
Eeeek. That's a whole bunch of watts. I hope it ok. I think it is. The windings still check the same other than the continuity to ground has gone up to 5.8k ohms. It is either working hard from a restriction or maybe dragging mechanically from lack of oil or previous wear.
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Post by allan on Jul 29, 2014 13:36:43 GMT
I realized that I neglected to mention that yesterday when this unit really started to run hot it was also drawing double the watts it had been. 300 watts as opposed to the 150 it had been running at for more than a week. Heating the evap. coil up only caused the watts to climb to over 400 and start cycling the overload I have on it. Looks like I will have to bring home the so2 recovery machine from storage(small freezer)and find out what is really restricted. Might be good to check hi side pressure while this is going on. Right before my DR 3 died it had 105# head pressure in about a 75 degree room. And that was during a regular run cycle. Would be informative to compare to your pressure.
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Post by coldspaces on Jul 29, 2014 16:09:01 GMT
I did check and had 75 psi but at the time I also had a fan blowing on the condenser and the evap was heated above ambient. If the filter is blocking it may have been higher pressure on the inlet side.
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Post by coldspaces on Aug 2, 2014 4:08:55 GMT
Well I recovered the charge on this machine this week. Amazing just how well the freezer works,I got all but 2-3 oz out. Removed the filter and found I could blow nitrogen right through it. It looks like if I have a restriction it is in the float seat or even possibly the strainer at the float inlet if my machine has one. I did go ahead and cut open the filter drier for you all. As you will see it is a bead type desiccant held in place with a spring to prevent movement of the beads and stop dusting of the desiccant. At lest that's the way the sales literature tells it. I had no idea till I cut this one open just how little desiccant it has in in. They sell it as having lots of capacity before it plugs because of the fiberglass filter medias. I had no idea it was almost all fiberglass. Gonna have to stop buying these. This filter was only in this unit a few months and run time was only a few weeks but it looks almost new still. The burnt fiberglass is from when they made it and welded the shell. The only thing I see that may not be normal is the metal mesh outlet piece appears to have a slight dusting of a white material. Here is the final filter that is denser and was up against the metal mesh piece. It has none of the white residue at all on either side. Not sure what I am seeing on the metal but if it was dusting of the desiccant beads the final filter would have to have trapped some. Best I can tell the so2 did not hurt this filter drier.
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Post by allan on Aug 2, 2014 12:17:39 GMT
Well I recovered the charge on this machine this week. Amazing just how well the freezer works,I got all but 2-3 oz out. Removed the filter and found I could blow nitrogen right through it. It looks like if I have a restriction it is in the float seat or even possibly the strainer at the float inlet if my machine has one. I did go ahead and cut open the filter drier for you all. As you will see it is a bead type desiccant held in place with a spring to prevent movement of the beads and stop dusting of the desiccant. At lest that's the way the sales literature tells it. I had no idea till I cut this one open just how little desiccant it has in in. They sell it as having lots of capacity before it plugs because of the fiberglass filter medias. I had no idea it was almost all fiberglass. Gonna have to stop buying these. This filter was only in this unit a few months and run time was only a few weeks but it looks almost new still. The burnt fiberglass is from when they made it and welded the shell. The only thing I see that may not be normal is the metal mesh outlet piece appears to have a slight dusting of a white material. Here is the final filter that is denser and was up against the metal mesh piece. It has none of the white residue at all on either side. Not sure what I am seeing on the metal but if it was dusting of the desiccant beads the final filter would have to have trapped some. Best I can tell the so2 did not hurt this filter drier. Love your recovery method! Gonna use it on the red DR1 to clean the needle and seat. Was this DR running full factory nameplate charge?
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Post by coldspaces on Aug 2, 2014 17:57:48 GMT
It had 5 lbs 6 oz so2 in it.
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Post by blackhorse on Sept 23, 2014 20:45:02 GMT
This has been an interesting read; I had the convenience of not having to wait for the results at each step along the way. Can't wait to see how it turns out. The attempts I made to clear the float valve on my CK TXV conversion didn't help a bit, neither did the magnet. Since it's part of the deck and I didn't want to ruin the appearance I didn't try any surgical interventions on it. (That unit has the best factory-original paint of any unit I have). I don't even know that it's clogged, I rather suspect the linkage between the float and the needle may have just worn through. The float valves I have opened had worn about half way through the pivot pins, and they probably didn't have the total hours on them that this unit has.
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Post by allan on Sept 23, 2014 23:10:38 GMT
This has been an interesting read; I had the convenience of not having to wait for the results at each step along the way. Can't wait to see how it turns out. The attempts I made to clear the float valve on my CK TXV conversion didn't help a bit, neither did the magnet. Since it's part of the deck and I didn't want to ruin the appearance I didn't try any surgical interventions on it. (That unit has the best factory-original paint of any unit I have). I don't even know that it's clogged, I rather suspect the linkage between the float and the needle may have just worn through. The float valves I have opened had worn about half way through the pivot pins, and they probably didn't have the total hours on them that this unit has. Wow that's interesting news about the float linkage. I have opened a lot of CA and DR floats and been amazed that there seems to be no wear at all! I have never opened a CK though. Is there some reason a CK would wear out linkage more than the other models??
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Post by blackhorse on Sept 24, 2014 15:04:10 GMT
Structural differences, and total hours in service, would be the only variables I can think of. If a machine sat out 40 years or so in a garage somewhere it wouldn't have the same wear as one that saw nearly continuous service for 80 years. The drawings I've seen of the valves on the formate machines show a different mechanism too, more similar to the ones I've opened from the tubing-wound SO2 units, in that the float slides up and down on a rod. The ones with the float just floating basically free in the chamber (without the guide rod) above the linkage have little pins where the parts of the linkage pivot, the pins looked like a bit over 1/16 inch thick, and had very distinct grooves worn in them.
And of course rust and crud. I'm not much on destroying units that have any hope of returning to service; the ones I've vandalized most thoroughly were ones I found behind old abandoned canning factories that the roofs had fallen in and had trees growing in the floors, the units had been stripped of their tubing for copper salvage decades ago and left exposed to the weather. But just wonderful for research, and the old mineral oil had surprisingly kept the parts from locking up from rust. And none of those were burned out, and ran when I applied current for several seconds after I turned them by hand for a bit. Maybe they got scrapped just for being old when the canning factories closed, or had some other issue, I'll never know; they were in bits and pieces when I found them.
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Post by ChrisJ on Sept 24, 2014 19:23:55 GMT
Structural differences, and total hours in service, would be the only variables I can think of. If a machine sat out 40 years or so in a garage somewhere it wouldn't have the same wear as one that saw nearly continuous service for 80 years. The drawings I've seen of the valves on the formate machines show a different mechanism too, more similar to the ones I've opened from the tubing-wound SO2 units, in that the float slides up and down on a rod. The ones with the float just floating basically free in the chamber (without the guide rod) above the linkage have little pins where the parts of the linkage pivot, the pins looked like a bit over 1/16 inch thick, and had very distinct grooves worn in them. And of course rust and crud. I'm not much on destroying units that have any hope of returning to service; the ones I've vandalized most thoroughly were ones I found behind old abandoned canning factories that the roofs had fallen in and had trees growing in the floors, the units had been stripped of their tubing for copper salvage decades ago and left exposed to the weather. But just wonderful for research, and the old mineral oil had surprisingly kept the parts from locking up from rust. And none of those were burned out, and ran when I applied current for several seconds after I turned them by hand for a bit. Maybe they got scrapped just for being old when the canning factories closed, or had some other issue, I'll never know; they were in bits and pieces when I found them. Do you have any ideas on why the CA machines end up with their seats either eaten or worn so badly the machines cannot pull the evaporator down below 20F or so?
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Post by blackhorse on Sept 25, 2014 17:15:13 GMT
Do you have any ideas on why the CA machines end up with their seats either eaten or worn so badly the machines cannot pull the evaporator down below 20F or so? Can't say that I do, I could only SWAG* on that. *Scientific Wild Ass Guess (an actual legitimate engineering process) Formate seems to not be an extremely stable compound, my understanding is that the NCG problem mostly comes from the compound decomposing, formic acid being one of the decomposition products. Anything high-boiling in any system will collect at the expansion orifice, left behind as the liquid goes to gas; maybe it collects there and eats up the polished machined surface? Also once the valve starts passing vapor, the cavitation scouring might erode the seat more rapidly? It can sure eat the hell out of turbine vanes pretty quickly. To be perfectly honest, those machines run so deep into vacuum, the suction gas vapor is so rarefied, I'm amazed that they can breathe deeply enough to get as low temperature as they do. Testament to the design that they can do so at all after 80 years.
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Post by blackhorse on Sept 25, 2014 17:18:51 GMT
Is there anywhere on this forum, a detailed diagram, exploded view, deconstructed example, and/or explanation of the design, of this style of evaporator?
Thanks.
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Post by coldspaces on May 13, 2015 3:36:08 GMT
When I last had this unit running it showed signs that the float was maybe plugging up again. Trying to clean the garage up so I decided to get this DR2 off of the floor last night. Since it is now on the workbench I cut the line under the float to see if it is indeed plugged. This older unit has the feature where you can open the float manually and to my surprise when I did the float is not plugged at all. I had no trouble blowing through it when open and it even seals good when closed. It now looks like the float is sticking most likely due to worn out linkage.
This must be a very early DR2 as it does have the bolt together dome with the lead seal. It has a rebuild tag and the serial starts with 44. Could it have been rebuilt in 1944 while the war was still going on? I don't suppose we will ever know for sure. Seems like since it wasn't welded shut they would have been more likely to have tried to repair it as materials to build new would have been all going to the war effort.
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Post by Travis on May 13, 2015 6:10:28 GMT
The unit is an early one. I still have the cabinet. It has strap hinges. If you could've met the guy I got that from, you would realize it had a hard life.
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Post by coldspaces on May 16, 2015 4:42:10 GMT
Curiosity got the better of me and I have now started to disassemble this DR2. After lifting things open I removed most of the insulation so I could get in and cut the suction line. Compressor base ring is put together from underneath on this one, was done from above on Travis's DR3. Past the point of no return now on this one. If the inside of the compressor is as black as the suction line then it's a wonder I ever got it to start at all. Sure would be impossible to replace all the wiring on this one without getting the base loose from the top plate. Now that the compressor is upside down and all old wiring removed it checks over 2 meg ohms to ground. Wiring was in good shape for its age so I would think it would still check real low, used to be only 5-6K ohms to ground with 120 volts to the shell.
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