KSB Magnochem-Bloc, Installation & Operating Manual

Page: 18 / 96

4 Description of the Pump (Set)
18 of 96
Magnochem-Bloc
Automation
Automation options:
▪ PumpDrive
▪
PumpMeter
4.5 Configuration and function
1
2 3 4 5 6 7 8
9 10 11 12 13 14 15
16
17
18
Fig. 5: Sectional drawing
1 Impeller 2 Discharge nozzle
3 Casing gasket 4,13 Circulation bore
5 Shroud gasket 6 Inner rotor
7 Outer rotor 8 Motor
9 Containment shroud 10,
14 Hydrodynamic plain bearings
11 Pump-end shaft 12 Casing cover
15 Pump casing 16 Shaft bore
17 Suction nozzle 18 Clearance gap
Function The fluid enters the pump axially via the suction nozzle (17) and is accelerated
outward by the rotating impeller (1). In the flow passage of the pump casing the
kinetic energy of the fluid is converted into pressure energy. The fluid is pumped to
the discharge nozzle (2), where it leaves the pump. The clearance gap (18) prevents
any fluid from flowing back from the casing to the suction nozzle.
Sealing Mag-drive pumps are characterised by the absence of a dynamic shaft seal
(mechanical seal, gland packing). The fluid handled is sealed to atmosphere
exclusively by means of static sealing elements: a gasket (3) between the casing (15)
and the casing cover (12), and a joint ring (5) between the casing cover (12) and the
containment shroud (9). The driving torque is transmitted from the motor (8) to the
pump shaft (11) indirectly via the magnetic coupling. The magnetic coupling basically
consists of the outer rotor (7) and the inner rotor (6). The containment shroud (9)
forms the shaft seal, separating the wetted from the dry pump section.
Magnetic coupling Magnetic couplings with permanent magnets transmit the driving torque without
slip, i.e. the motor and the pump run at the same rotational speed. The driving
torque generated by the motor is transmitted from the outer rotor (7) to the inner
rotor (6) via the magnetic field. It is part of the inner rotor assembly which runs in
product-lubricated bearings. The directly product-lubricated radial and axial plain
bearings (10, 14) are made of wear-resistant and chemically resistant silicon carbide.
The flow circulated through the magnetic coupling not only lubricates the bearings