Issues with the compressor’s discharge volume?
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There is a compressor in our unit whose exhaust volume never reaches the expected level. We checked it several times over, and later we replaced the cylinder as well as the piston rings, but the problem persisted for a while before it appeared again. We consulted some experts, who said that over time the piston rings can move up and down inside the piston, which in turn affects the exhaust volume. However, I personally think that the impact should be minimal. I wanted to come here and ask the experts if they can help resolve my doubts. Thank you in advance. Chemical Equipment and Machinery
Has the radial clearance between the piston and the cylinder increased? An increase in air leakage from the piston during compression can result in insufficient exhaust volume
This is another scenario: the pistons and cylinders that were replaced during this repair have resolved the issue, but there is still a problem – the gap between the top and bottom of the piston is large. Does this affect the volume of exhaust gas? What other impacts are there?
Excessive clearance in the piston leads to too much freedom of movement for the piston rings within their grooves, which results in rapid wear of these rings or even their breakage and detachment, thereby causing damage to the bottom of the cylinder
What is the cleanliness level of the compressed gas? Oil-free lubricated cylinder, gap control – how about external cooling? Is it often operating under no load? I think all of these can be considered.
This post was last edited by tiansf5936 on 2018-5-1 at 18:55. What is compressed here is natural gas, which contains a small amount of water; it is lubricated with oil, and an external oil injector is used for lubrication. Cooling is achieved through air cooling. There is no cooling when the compressor is not under load – at first it works fine, but then the exhaust volume decreases day by day, until eventually almost no exhaust is produced anymore. Also, isn’t it bad for the compressor to operate frequently without a load? I think the lighter the load, the less damage there should be, right? Why is the damage even greater?
Is it due to the intake and exhaust valves, or the filter pressure difference? Is it still poor compressor lubrication, or poor cylinder cleanliness causing abnormal wear?
Change cylinder? Is the cylinder’s surface finish within spec, is the ellipticity out of limit, or is it damaged? Why change? Is it because of the small displacement? What are the opening degrees of the inlet and outlet circuits? What are the inlet pressure and flow rate? Is the inlet filter clogged? Intake and exhaust temperature? Intake and exhaust pressure? Are the intake and exhaust valves leaking? What is the piston diameter, and what is the radial clearance between the piston and the cylinder? What is the material of the piston ring support ring? What are the side clearance, clearance at the opening, and the clearances at the top and bottom dead centers of the cylinder? What is the maximum compression ratio at runtime? Could you please provide the maintenance data? It will help everyone analyze the cause together
I just looked at the pictures. Since the compressor is oil-lubricated, the gap between the piston rings and the ring grooves in the compressor is filled with a mixture composed of lubricating oil and powder generated by the wear of the piston rings. Coupled with the high temperatures generated during gas compression, this mixture carbonizes to form gum-like substances, resulting in insufficient sealing pressure between the piston rings and the cylinder block and severe internal leakage. As a result, the volume of exhaust gas produced decreases over time.