The high-temperature magnetic pump is a kind of non-contact torque transmission through a magnetic drive (magnetic coupling), so that the static seal replaces the dynamic seal, so that the pump is completely leak-free. Since the pump shaft and inner magnetic rotor are completely sealed by the pump body and the isolation sleeve, the leakage problem is completely solved, and the safety hazard of flammable, explosive, toxic and harmful media leaking through the pump seal in the refining and chemical industry is eliminated.
Composition of the pump
The high temperature magnetic pump consists of three parts: self-priming pump, magnetic drive and motor. The key component, the magnetic drive, consists of an outer magnetic rotor, an inner magnetic rotor and a non-magnetic isolation sleeve.
1. Permanent magnets:
Permanent
magnets made of materials have a wide operating temperature range
(-45-400°C), high coercive force, good anisotropy in the direction of
the magnetic field, and no demagnetization will occur when the same pole
is close to each other. It is a kind of Very good source of magnetic
field.
2. Isolation sleeve:
When
a metal spacer is used, the spacer is in a sinusoidal alternating
magnetic field, and an eddy current is induced on a section
perpendicular to the direction of the magnetic force line and converted
into heat.
3. 냉각 윤활유 흐름 제어
When
the high-temperature magnetic pump is running, a small amount of liquid
must be used to flush and cool the ring gap area between the inner
magnetic rotor and the isolation sleeve and the friction pair of the
sliding bearing. The flow rate of the coolant is usually 2%-3% of the
design flow rate of the pump, and the ring gap area between the inner
magnetic rotor and the isolation sleeve generates high heat due to eddy
currents. When the cooling lubricating fluid is insufficient or the
flushing hole is not smooth or blocked, the temperature of the medium
will be higher than the working temperature of the permanent magnet, so
that the inner magnetic rotor will gradually lose its magnetism and the
magnetic drive will fail. When the medium is water or water-based fluid,
the temperature rise in the annulus area can be maintained at 3-5°C;
when the medium is hydrocarbon or oil, the temperature rise in the
annulus area can be maintained at 5-8°C.
4. 일반 베어링
The
materials of magnetic pump sliding bearings include impregnated
graphite, filled PTFE, engineering ceramics, etc. Because engineering
ceramics have good heat resistance, corrosion resistance, and friction
resistance, the sliding bearings of magnetic pumps are mostly made of
engineering ceramics.
Since
engineering ceramics are very brittle and have a small expansion
coefficient, the bearing clearance must not be too small to avoid
shaft-holding accidents.Since the sliding bearings of high temperature
magnetic pumps are lubricated by the transported medium, different
materials should be used to make the bearings according to different
media and operating conditions.