Alfa Laval AlfaNova 400, Instruction Manual, Page: 19 / 260

Fault-tracing English
Plate Heat Exchanger 15 EN
EN
Fault-tracing
Pressure drop problems
The pressure drop has increased.
Action Result Correction
1 Check that all valves are open including non-
return valves.
• Measure the pressure just before and just
after the heat exchanger, and the flow rate.
For viscous media a membrane manometer
with a diameter of at least 30 mm should be
used.
• Measure or estimate the flow rate if possi-
ble. A bucket and a watch showing seconds
may be sufficient for small flow rates. For
larger flow rates, some type of flowmeter is
required.
– –
2 Compare the pressure drop observed with the
one specified for the actual flow rate (see data
printout). Is the pressure drop higher than
specified?
YES Check the temperature program, see
step 3.
NO If the pressure drop is corresponding
to the specifications, there is no need
for action.
If the pressure drop is lower than
specified, the pump capacity is
probably too small or the observation
may be wrong. See pump instruction
manual.
3 Check the thermometer readings. Do the read-
ings correspond to those specified?
YES The heat transfer surface is probably
clean enough, but the inlet to the heat
exchanger may be clogged by some
objects. Check the port area.
NO Heat transfer is obviously dropping
below specifications, because of
deposits on the heat transfer surface,
which at the same time also increases
the pressure drop, since the passage
becomes narrower.
If a Cleaning-In-Place (CIP) system is
available, follow the instructions and
use it to wash out the deposits.