1) A new concept for a magnetic-drive pump called MONSUN is presented which aims to address weaknesses in intermittent flow conditions. 2) The MONSUN design locates the radial slide bearings farther outside the pump casing than traditional designs to avoid dry running conditions. It also includes a lubrication reservoir to lubricate the bearings during liquid tear-off situations. 3) Test results showed the MONSUN design was able to limit temperature rise in the bearings to under 10°C during intermittent flow, whereas traditional magnetic drive pumps often fail under such conditions, making MONSUN more reliable and durable.

1. InnovationInnovation
A completely new concept
of a magnetic-drive pump

2. Subdivision of the presentationSubdivision of the presentation
1.) Weakness of the magnetic-drive pumps in
classical design in cases of intermittent flow
(quasi-dry running)
2.) New concept to locate the radial slide bearings*
3.) New concept of a close coupled pump*
4.) New concept to absorb the axial thrust
by the magnetic coupling itself*
5.) Photo of the magnetic-drive pump
type MONSUN * applied for patents

3. Intermittent flow and itsIntermittent flow and its
consequencesconsequences
 The intermittent flow is one of the most frequent and
gravest cause for breakdowns of centrifugal pumps.
 Losses at the rate of some millions of € are resulting from
those failures, to the pleasure of the after-sales service
departments of the pump manufacturers.
 Especially the magnetic-drive pumps often are not worth a
repair (economical total loss).
 To achieve a competitive advantage many pump
manufacturers are trying to find technologies to prevent
those kinds of damages.

4. Reasons for intermittent flowReasons for intermittent flow
 Emptying of the suction tank (as shown)
 Low plant resistance (pump operates far right on its curve)
 Closed suction valve
 Dirty filters or plugging in front of the pump
 High gas content (e.g. caused by swirls)

5. The problem zone of classicThe problem zone of classic
magnetic coupled pumpsmagnetic coupled pumps
Slide bearings
radial far inside
Low
circumferential
speed
No real sliding,
but mixed
friction
Need for high
grade,
wear resistant
materials

6. Intermittent flow: What happensIntermittent flow: What happens
inside the pump?inside the pump?
The liquids tear-of is displayed in the Q-H-
diagram as quick reduction of the volume flow
along the plant resistance curve !

7. Intermittent flow: What happensIntermittent flow: What happens
inside the pump?inside the pump?

8. Intermittent flow: What happensIntermittent flow: What happens
inside the pump?inside the pump?

9. Intermittent flow: What happensIntermittent flow: What happens
inside the pump?inside the pump?

10. Intermittent flow: What happensIntermittent flow: What happens
inside the pump?inside the pump?

11. The bearings lie fully dry, though a rest of liquid is
circulating in the pump:
Quasi dry run
Remaining radial forces act upon the bearings,
which are not lubricated anymore:
Hot run
Intermittent flow: What happensIntermittent flow: What happens
inside the pump?inside the pump?

12. Other state-of-the-art designs (1)Other state-of-the-art designs (1)
Bearings still fully
in the “problem
zone”

13. Bearings still fully
in the “problem
zone” as well
Other state-of-the-art designs (2)Other state-of-the-art designs (2)

14. The shaft less pump as right wayThe shaft less pump as right way
CORRECT:
Slide bearings to
the outside!!!
„Shaft less
concept“
DISADVANTAGEOU
S: Thin isolation
shell is used as
bearing (Emergency
and start-up
bearings still
required)
DISADVANTAGEOU
S: Bearings difficult
to reach
SUBOPTIMAL:
Why not even
farer to the
outside??
WHY NOT
THERE ?

15. Shaft less concept MONSUNShaft less concept MONSUN
Sliding bearings
radial outside to
the maximum
possible
Magnetic driver
positioned at the
inside
Simple bearing
geometries
possible due to
real sliding
Impeller and drum
bearings form one
single unit

16. Direct access to the bearingsDirect access to the bearings
Option: temperature
control
Option: flushing
- very simple

17. Liquid tear-ofLiquid tear-of
Bearings are located in
the wetted area

18. Very low static head
Bearings lie dry
Liquid tear-of – worst caseLiquid tear-of – worst case

19. The solution : A lubricationThe solution : A lubrication
reservoirreservoir
Rotating lubrication
reservoir
Circular partition wall
prevents empting of the
lubrication reservoir

20. Cooling stream from
electrical motor
Cooling rips at the
casing guide the friction
heat away
Cooling of the lubrication reservoirCooling of the lubrication reservoir

21. ConventionalConventional
closed coupled designclosed coupled design
Advantage: Short axial
dimension
Disadvantage: The
assembly of the magnetic
driver requires the final
assembly of the electrical
motor.

22. Ball bearings located
inside the isolation shells
opening: large bearing
distance.
Pump is premountable
and not depending on
variants. Good for
stockholding!
MONSUNMONSUN
ball bearing conceptball bearing concept

23. Universal shaft endUniversal shaft end
Alternatively: Journal
part of a coupling…
… or shaft end of a
standard pump
Flywheel mass

24. MONSUN 50-200MONSUN 50-200
New magnetic coupling
acts additionally as
magnetic thrust bearing
Dynamic throttling
gab regulates
axial position of
the rotor as well

25. MONSUN 50-200MONSUN 50-200
Temperature sensor
(Option)
1500 1/min:
Δt10min´= 2,5 °C
3000 1/min:
Δt10min = 10 °C
Temperature rise
of emergency reservoir
related to speed:
(ca. values for water)

26. Classic magnetic couplingClassic magnetic coupling
Same polarity in
axial direction

27. Axial reset capability of the classicAxial reset capability of the classic
magnetic couplingmagnetic coupling
Number of green
triangles is
important
100 N
100 N

28. 400 N
100 N
Alternating
polarity in axial
direction
Axial reset capability of theAxial reset capability of the
MONSUN type magnetic couplingMONSUN type magnetic coupling

29. MONSUN type magnetic couplingMONSUN type magnetic coupling
 Low losses of transferable nominal torque (circa 80% of classic coupling).
 Increasing the axial reset forces by a multiple.

30. MONSUN asMONSUN as
standard pump (ISO 2858)standard pump (ISO 2858)
MONSUN 32-200

31. MONSUN in closed coupled designMONSUN in closed coupled design
MONSUN 32-200 F

32. End of the presentationEnd of the presentation