Liquid phase in a compressor
Liquid phase in a compressor
(OP)
Why exactly a liquid cannot be present in a gas compressor? A liquid will certainly damage the compressor, but why and how?
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Liquid phase in a compressor
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Liquid phase in a compressorLiquid phase in a compressor(OP)
Why exactly a liquid cannot be present in a gas compressor? A liquid will certainly damage the compressor, but why and how? Red Flag SubmittedThank you for helping keep Eng-Tips Forums free from inappropriate posts. Reply To This ThreadPosting in the Eng-Tips forums is a member-only feature.Click Here to join Eng-Tips and talk with other members! |
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RE: Liquid phase in a compressor
The speed at which gas travells in suction pipework is very fast. Therefore the liquid is like a projectile in suction pipework so fast it will damange the blades.
RE: Liquid phase in a compressor
I have seen a high speed compressor hit with 500 gallons of water. Not only was the blade destroyed, so was the shaft, the labyrinth seal, the bull gear assembly, the housing, all bearings including rear motor bearings.
When the manufacturer analyzed the metal of the shaft they were fairly amazed that the entire assembly hadn't come through the housing which would have seriously injured several people.
RE: Liquid phase in a compressor
jhqpinto:
First - and foremost - just exactly what type of compressor are you talking about? A centrifugal? A reciprocating type?
It makes a big difference on what the correct answer is.
RE: Liquid phase in a compressor
RE: Liquid phase in a compressor
RE: Liquid phase in a compressor
The main cause for compressor damage is due to the incompressibility of liquids (or better, less compressibility) and valves are the things that get damaged first.
Each type of compressor has its own ability to handle certain percentage of liquids. Recips are worst prone, scrolls are a bit better, then comes screws and cetrifugals can handle it better. Refrigerating centrifugals(as far as my experience) can handle the accidental liquid flows (definitely not 100%) to great extent and you don't have problems.
RE: Liquid phase in a compressor
What also happens is a liquid may enter the suction valve and because the valve is hot from the heat of compression, that liquid may vaporize (boil). The violent vaporization and localized cooling on the valve material can cause fatique in spots and the valve or parts of the valve will fail (typically the valve plates). All in all a recip can have a very very small drop of liquids.
If uou look at a reciprocating compressor and pump, there is no basic difference, suction valve, piston with sealing rings, back and forth, discharge valve, whats the difference. If you try to put liquids through a gas unit, it will fail. Put gas through a liquid unit, not a mechanical failure, it will just stop moving any thing. The diffence is in the valves and the area available to pass the fluid and open/close with the fluid.
The same is true for centifugals. Nothings really different except clearance areas. My favorite site had 3 3000 HP IR HHE compressors working in parallel on the same fluid as an 1000 HP Bingham splitcase pump I loved it.
RE: Liquid phase in a compressor
Gas in a plunger pump is not a trivial occurance either. Heat of compression causes really high temperatures that cause metal exapnsion that busts ceramic plungers in a couple of strokes.
David
RE: Liquid phase in a compressor
RE: Liquid phase in a compressor
I wonder what would happen to flooded screw compressors in a liquid carryover? I've seen some trip a few times on high liquid level in the KO, but I've never seen a slug of liquid make it to the machine. I'd guess with enough liquid the twin screws wouldn't be able to shove it through fast enough, the case would pressure up, and something would break, but that's just my guess. Anyone ever see liquids make it to a flooded screw?
RE: Liquid phase in a compressor
Jason:
First - and foremost - just exactly what type of compressor are you talking about? A positive displacement, rotary lobe of the Roots-Connersville type?
It makes a big difference. And what makes a difference also is what mechanical strength/tolerances/hp rating was built into the vacuum "pump" (actually a blower).