The vacuum pump for
transporting hot petroleum products shall be preheated evenly before starting.
Preheating can be accomplished by circulating hot oil through a pump, and the
temperature of the pump shell shall not be 40 ℃ lower than the working
temperature of petroleum products. The cracking feed pump, on average, should be
preheated for about 8 hours.
If the vacuum pump is preheated unevenly,
it will occur: (1) the deflection of the vacuum unit and the distortion of the
shaft; (2) the cracks on the pump housing; (3) the rotating parts of the rotor
are stuck.
During the circulation of hot oil, there should be no dead
angle in the vacuum pump, especially in the lower part of the pump casing, where
the cold oil products will gather; otherwise, the upper part of the pump casing
will be hotter than the lower part. Hot petroleum products shall be free to
circulate along the entire surface of the pump casing.
In fact, the
measurement proves that when the temperature difference between the lower shell
wall and the upper shell wall of the outer pump shell is 180 ℃, the distortion
of the outer bearing relative to the pump center line is equal to 5mm; in this
case, the distance between the bearing centers is equal to 2m.
In order
to prevent the rotor from being stuck due to temperature expansion of parts in
axial and radial directions, sufficient axial and radial clearance (axial
clearance of 4-7mm) shall be reserved.
Water Ring Vacuum Pump
Water Ring Vacuum Pump manufacturers
industrial vacuum
pumps,vacuum furnaces
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