Grundfos BMST Series Installation And Operating Instructions Manual page 14

6.3.3 Startup
To start up a BMSX system, proceed as follows:
1. All valves should be in their normal operating positions.
2. Start the raw-water feed pump (1). When the raw-water feed
pump is started, the system is filled with water. Ensure that
the entire system is vented. The feed flow (17) (max. 10 bar,
min. 2 bar feed pressure) through the pressure exchanger
pump (23) may or may not cause the rotor to begin to rotate.
Rotation will be confirmed by a humming noise.
8
6
7
14
15
12
17
16
5
4
3
2
1
26
Fig. 24 Start the seawater feed pump
3. Adjust the concentrate valve (24) to the system flow.
4. Vent the system.
5. When you have filled the system with water and vented it,
then see the BM hp startup procedure.
The maximum flow rate of the pressure
Caution
exchanger must never be exceeded. See the
nameplate of the pressure exchanger.
The BM hp pump must not run against a closed
discharge valve for more than 5 seconds as this
will cause an increase in the temperature/
formation of steam in the pump which may
damage the pump and motor. If there is any risk
of the BM hp pump running against a closed
discharge valve or risk of no flow, ensure a
minimum liquid flow through the pump by
connecting a bypass/drain to the discharge side
of the pump. The drain can be connected to a
tank.
6. Start the BM hp pump (14).
14
18
19
13
21
20
22
23
24
25
8
6
7
14
15
12
17
16
5
4
3
2
1
26
Fig. 25 System pressure and flow, BM hp
The rotor speed will increase, and remaining air will be released
from the pressure exchanger. Vent any remaining air from the
system.
Adjust the frequency converter of the BM hp pump (14) on the
discharge side of the pressure exchanger (23) until the low-
pressure seawater inlet flow (17) equals the calculated seawater
flow (15).
8
6
7
14
15
12
17
16
5
4
3
2
1
26
Fig. 26 Balanced flows
To achieve a balanced flow through the pressure exchanger (23),
use the flowmeters installed on the low-pressure seawater inlet
pipe (17) and the high-pressure seawater pipe (15). All flows in
and out of the pressure exchanger (23) should be balanced to
within 5 % for optimum operation.
Operating the pressure exchanger with
unbalanced flows may result in contamination of
Note
the seawater feed by the concentrate and
consequently lower efficiency.
18
19
13
21
20
22
23
24
25
18
19
13
21
20
22
23
24
25