Richter MNK Series - Manual (Page 5)

Series MNK, MNK-B, external flushing Page 5
9230-060-en Revision 02
TM 6778 Edition 05/2007
Table 2 and 3 for series MNK-B
The following always applies: No inadmissible tem-
peratures may be introduced into the motor and the
specifications of the motor manufacturer must be ob-
served.
The temperature limits of the fluid given in Table 3
only apply when motors are used where the motor
manufacturer permits at least the following tempera-
tures for the motor flange and motor shaft:
Table 2
Temperature
class
Motor flange Motor shaft
T6 70 °C 70 °C
T5 70 °C 80 °C
T4 75 °C 85 °C
T3 80 °C 100 °C
T2 80 °C 100 °C
T1 80 °C 100 °C
At the same time the specified max. admissible ambi-
ent temperature of 40 °C must not be exceeded.
Table 3
Temperature class acc. to EN
13463-1
Limit value of the temperature of the liquid
Lining material PP PE-UHMW PFA/PTFE
Can material 2) CFK-F CFK-F CFK-F CFK-H
T6 (85° C) 75°C 1) 75°C 1) 75°C 1) 75°C 1)
T5 (100° C) 80°C 90°C 90°C 1) 90°C 1)
T4 (135° C) 80°C 90°C 125°C 1) 125°C 1)
T3 (200° C) 80°C 90°C 150°C 180°C
T2 (300° C) 80°C 90°C 150°C 180°C
T1 (450° C) 80°C 90°C 150°C 180°C
1) The limit values specified for the temperature of the medium at
the pump inlet are determined for the most unfavourable case
(high speed, low flow, low heat capacity of the medium, ....).
Under favourable operating conditions the limit values specified
may be increased by up to 5 K after consultation with the
manufacturer.
2) The can material has been list in the data sheet.
In the case of motors with the type of protection "in-
creased safety", no or low temperature entries are
generally permitted for the motor shaft and motor
flange related to an ambient temperature of 40 °C.
In these cases the max. admissible medium tempera-
ture is 20 K above the temperature which may be
introduced into the motor.
e.g.: Max. motor shaft temperature: 60°C
Max. motor flange temperature: 65°C
This results in a maximum medium temperature for
the pump of 80 °C (60 °C + 20 K).
5.1.3 Minimum flushing flow
The required flushing medium flow depends on the
amount of heat to be dissipated and the quantity of
lubricant needed for the plain bearings. The amount of
heat to be dissipated is determined by the friction val-
ues of the plain bearings and the inner magnet as-
sembly and by the specific heat capacity of the flush-
ing medium used.
The following formulas may be used to calculate the
required flushing medium flow. It should be noted
that the flushing flow must never be set lower than
the minimum value also given. The higher value is
always decisive.
Q
flushing quantity [l/h]
n pump speed [rpm]
For groups, see installation and operating manuals
of the relevant pump in Section 1.
Group 1.1
Q =
2
1500
n
x 10 (but min. 15 l/h)
Group 1.2
Q =
2
1500
n
x 15 (but min. 20 l/h)
Group 1.3
Q =
2
1500
n
x 20 (but min. 25 l/h)
Group 2
Q =
2
1500
n
x 30 (but min. 30 l/h)
The values determined apply to the flushing medium
water with a specific heat capacity of 4187 J/kg * K.