Before Starting The Bmex; Startup And Operation; Bmex; Flow Control And Balancing - Grundfos BMEX Series Montage- Und Betriebsanleitung

8. Before starting the BMEX

Check the following:
• Oil level (BME hp feed pump only).
See section 7.1.5 Monitoring of oil lubrication
• Belt tension (BME hp feed pump only).
See section 14. V-belt tension.
• Greasing (BME hp feed pump only).
See section 18. Motor bearings, BME hp feed
• Power supply in accordance with nameplate.
• Free movability (BME hp feed pump only).
Rotate the motor and pump shafts manually by means of the
V-belt.
• Pipework according to the diagram, fig. 16.
• Slacken the foundation bolt nuts.
In addition, flush all pipes to remove all impurities before
connecting the system units.
A1
CV1
V5
V2
P3
P4
FM1
LP
V1
P1 P2
Fig. 16 Example of piping and instrumentation
Pos. Description
P1 Sea-water feed pump
P2 Cleaning/flush pump
P3 BME hp feed pump
P4 BM hp circulation pump with variable-frequency drive
V1 Three-way valve for feed water and cleaning
V2 Control valve for controlling pressure and flow
V3 Low-pressure reject-water valve
V5 Control valve for controlling pressure and flow
V6 Cleaning/flush valve
CV1 Non-return valve
FM1-3 Flowmeter for balancing the system
X1 X-Changer module
HP High-pressure switch
LP Low-pressure switch
S1 Pressure relief valve
system.
pump.
HP S1
A1
FM3
V6
FM2
X1
V3

9. Startup and operation

9.1 BMEX

This section and the subsequent subsections make references to
the piping and instrumentation diagram, fig. 16.
To start up the BMEX system, proceed as follows:
1. All valves should be in their normal operating positions.
2. Start the sea-water feed pump (P1). The feed flow (max. 6
bar, min. 2 bar feed pressure) through the X-Changer module
may or may not cause the rotor to begin to rotate. This
rotation will be confirmed by a humming noise.
3. Vent air from the system.
4. After the X-Changer has run with sea water for 5 to 10
minutes, start the BM hp circulation pump (P4). See section
9.7 BM hp circulation pump. Rotor speed will increase and
remaining air will be released from the X-Changer. Vent any
remaining air from the system.
5. Start the BME hp feed pump (P3). See section
feed pump. The BMEX system pressure will increase to the
point where the permeate flow will equal the flow from the
BME hp feed pump.
The sound pressure level from the X-Changer will increase.
Small variations in sound pressure level and rotor speed are
normal.
6. The system is running.

9.2 Flow control and balancing

Flow rates and pressures in a typical BMEX system vary slightly
over the life of the system due to temperature variations,
membrane fouling or feed salinity variations. The X-Changer rotor
is powered by the flow of fluid through the unit. The speed of the
rotor is self-adjusting over the operating range of the X-Changer
module.

9.3 High-pressure flow control

The flow through the BM hp circulation pump (P4) is adjusted with
control valve (V2) or a variable-frequency drive to control the flow
rate of the high-pressure sea-water discharge from the X-
Changer module and high-pressure brine inlet to the X-Changer
module. The high-pressure sea-water discharge flow equals the
high-pressure brine inlet flow.

9.4 Low-pressure flow control

The low-pressure reject-water valve (V3) on the discharge side of
the system must be adjusted to control the flow rate of the low-
pressure sea-water inlet and low-pressure brine discharge (min. 1
bar back-pressure). This valve also adds back-pressure on the X-
Changer module required to prevent destructive cavitation. The
low-pressure sea-water inlet flow equals the high-pressure brine-
reject water inlet flow.
9.8 BME hp
11