How to repair compressor crankcase vibration?
Thread Content
Our factory manufactures 6MD32-180/320 hydrogen-nitrogen compressors. Since their installation, the first-stage cylinder on the low-pressure side has experienced extremely high vibration levels. Importantly, the cylinder does not vibrate in the direction of piston movement back and forth, but rather it shakes from side to side, with a very large amplitude. Some time ago, the manufacturer’s technical staff came to provide guidance, but they didn’t point out where exactly the problem lay We successively replaced the piston support rings, adjusted the coaxial alignment of the cylinder and the crosshead, as well as the coaxial alignment between the motor and the crankshaft. We also checked the clearances of the moving parts in the low-pressure side crankcase, but no abnormalities were found. Later, it was discovered that the foundation of the machine frame had sunk, which indicated that the root cause of the problem lay in the foundation itself – its strength was not sufficient. At that time, we resolved this by installing pipes within the foundation, filling those pipes with dry sand, and using concrete to isolate them at the top and bottom. Now, those pipes are separated from the foundation; the machine frame’s shims are placed directly on top of those pipes, causing the pipes to move around. The corner bolts need to be tightened every week. This machine poses a serious safety hazard ； Next, our factory plans to completely eliminate the potential hazards associated with this equipment. It’s not possible to build a new foundation from scratch, as that would take too much time. Please share your ideas – is there any effective solution that can be implemented in a relatively short period of time? :(
I think the foundation can be partially demolished and the pipes can be re-installed for reinforcement
In addition to eliminating the causes of the underlying problems, I’m not sure whether there is vibration at the inlet section. If the vibration is severe, an expansion joint can be installed before the inlet connection flange to eliminate the factors that cause such vibration: handshake
OP, it seems that the machines in your factory are not operating well. Is this also from the Shen Gas Plant?
Let me introduce the basic information on the compressors here for your reference. The anchor bolts are double-ended studs, and holes are provided at the bottom of the foundation to allow for the removal of the nuts beneath the anchor bolts. The anchor bolt holes are filled with sand. Below the anchor bolts, a 40mm steel plate is used to connect to the foundation; this steel plate is fixed in place with nuts and is separate from the foundation. Place shims around the anchor bolts at the top, and carry out secondary grouting. It was designed this way, and that’s how it was done. Not bad.