Pусский
With continuous improvement of energy saving and emission reduction requirements for modern industrial production, use of single-end bellows-type mechanical seals and auxiliary systems can no longer meet the requirements, and four main problems have been exposed. This article first introduces two of them:
1.During operation of high-temperature oil pump, varied working conditions often occur. Pump evacuation, misoperation, artificial flow adjustment, etc. all make the mechanical seal under varied working conditions. When pressure of the sealed medium fluctuates violently，mutual impact of friction pairs occurs, causing damage to the end faces, thereby affecting sealing effect; if operating pressure of the sealed cavity fluctuates and becomes negative instantly, the bellows shrinks and cannot be restored in time,oil film formed between rotary face and stationary seat’s friction pairs is destroyed, causing sudden leakage failure.
2.Once the flushing system fails, the very high temperature of working medium, coupled with frictional heat of end faces of friction pairs will cause end faces temperature to rise sharply, causing the end face liquid film to vaporize and cause dry friction, which can cause the mechanical seal to fail in a short time;
Secondly, high temperature can also reduction of performance of graphite ring, and melting of impregnant may occur in severe cases;
Thirdly, when rotary face and stationary seat use materials like tungsten carbide and graphite,high temperature can also cause ring grooves on the surface of the graphite ring (stationary seat), and tungsten carbide (rotary face) is also easy to fall off;
Finally, the friction pair has a large thermal deformation at high temperature, which changes the friction state of the end face, leading to premature failure of the mechanical seal.
1.During operation of high-temperature oil pump, varied working conditions often occur. Pump evacuation, misoperation, artificial flow adjustment, etc. all make the mechanical seal under varied working conditions. When pressure of the sealed medium fluctuates violently，mutual impact of friction pairs occurs, causing damage to the end faces, thereby affecting sealing effect; if operating pressure of the sealed cavity fluctuates and becomes negative instantly, the bellows shrinks and cannot be restored in time,oil film formed between rotary face and stationary seat’s friction pairs is destroyed, causing sudden leakage failure.
2.Once the flushing system fails, the very high temperature of working medium, coupled with frictional heat of end faces of friction pairs will cause end faces temperature to rise sharply, causing the end face liquid film to vaporize and cause dry friction, which can cause the mechanical seal to fail in a short time;
Secondly, high temperature can also reduction of performance of graphite ring, and melting of impregnant may occur in severe cases;
Thirdly, when rotary face and stationary seat use materials like tungsten carbide and graphite,high temperature can also cause ring grooves on the surface of the graphite ring (stationary seat), and tungsten carbide (rotary face) is also easy to fall off;
Finally, the friction pair has a large thermal deformation at high temperature, which changes the friction state of the end face, leading to premature failure of the mechanical seal.
