Compressor packing
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For the packing seals of piston compressors, I’ve seen ones that use nitrogen for sealing as well as those that use lubricating oil. How do they achieve sealing? What is the structure inside? As shown in the figure
Hehe, just wait; this thing needs to be replaced frequently. You’ll know once it’s time. Ask the maintenance staff at any time; they all know. :)
Inside is the seasoning box; this one should be for 9 dishes, with each dish’s filling consisting of radial rings, tangential rings, and flow-blocking rings.
Search online and you’ll find it. When replacing the filler, pay close attention to how it’s installed and how to adjust the gaps; after doing it a couple of times by yourself, you’ll get the hang of it
Packing seal ring: composed of a throttle ring set + a main seal ring set + an air leakage seal ring + a nitrogen seal ring. In the diagram, the first set at the flange is the nitrogen sealing ring, which is filled with nitrogen for protection. Next is the leak-sealing ring. The latter groups are the main sealing rings, which serve as the rings that provide sealing in the packing assembly. Finally, there is the throttle ring, whose purpose is to throttle and reduce pressure.
Just follow what was said on the sixth floor. Then check how the liquid flows, how the oil flows, and how the nitrogen flows; use air to blow into the holes, or blow with your mouth, and feel it
Just take a look at the drawings or disassemble it to find out. Based on the photos, if what the poster is referring to as a nitrogen seal involves the two larger-diameter pipes at the top and bottom, then strictly speaking these nitrogen pipes (our compressors use ammonia or water; we have never used nitrogen – could the poster be mistaken?) do not serve a sealing purpose; rather, they are used for cooling the filler ； The smaller pipes are lubrication pipes, used to lubricate the packing.
There are four pipes in total: the supply water for the packing cooling water and the return water for the packing cooling water； Nitrogen supply for packing seal, packing leak collection tube ； If there is oil lubrication, there is also an oil injection pipe
Nitrogen provides sealing, while oil serves a lubricating purpose. Most packing seal rings are three-leaf designs made of polytetrafluoroethylene; springs are used to hold the piston rod in place. The sealing principle combines throttling with sealing effects. Multiple sets of seal rings are used to gradually reduce the air leakage pressure. There is an air leakage hole located two sets away from the cover side, which is connected to an air collection tube that leads to the liquid collection tank and then to the flare. The outer two sets serve as nitrogen seals – 1 kilogram of nitrogen is introduced here, and it escapes along with the air leakage; the nitrogen acts as a barrier in this area. The specific sealing structure can be seen once it is disassembled. Oil is a lubricant used to extend the lifespan of the packing ring.