Cleaning plate heat exchangers
in the sugar industry
Your recipe for maintaining high thermal efficiency
Even in a well-controlled, optimized sugar process, to maintain their high heat
transfer efficiency, your Alfa Laval plate heat exchangers (PHEs) need regular
cleaning to remove fouling and scaling.
The good news is that the job can be done easily by inline chemical cleaning.
Compared to cleaning shell-and-tubes, it requires very little manpower and, due
to the low hold-up volumes of the PHEs, much less chemicals.
It’s a piece of cake!
How often you clean your PHEs depends on your sugar process, and which
positions the PHEs occupy in the process. Here are some typical cleaning
procedures – if you need more detailed information, our specialists can provide
a recipe for the optimum PHE cleaning procedure for your process:
Backflushing
For fibrous media, regular backflushing is recommended for a few minutes every
couple of hours.
Removing organic substances
Circulate hot water at 85°C for an hour, circulate alkaline cleaning agent with a pH
of 12 or higher, at 85-100°C for 4 hours, then rinse with hot water for 30 minutes.
Keep an eye on the pH.
Removing scale
Circulate hot water at 85°C for an hour, circulate acid cleaning agent with a pH of
3.5 or lower at 70°C for 4 hours, then rinse with hot water for 30 minutes. Keep
an eye on the pH.
If it’s not broken don’t fix it!
It’s not normally necessary to open
your PHEs – in fact they should
not be opened unless there is a
clear reason to do so.
If the pressure drop and performance are back to normal after
the cleaning process, there is no
reason to routinely open the PHE.
Precautions worth taking
If a PHE is about to be taken out
of service, round off the cleaning
cycle with a short alkaline cycle,
followed by rinsing with water. This
ensures that no acid is left in the
unit that could cause corrosion
during standstill.
Acid cleaning agents must be
weak solutions, such as, for
example, phosphoric acid and
sulphamic acid. Under no circumstances should hydrochloric acid
be used.
Alfa Laval CIP
Optimum cleaning efficiency is ensured by using a dedicated Alfa Laval CIP (Cleaning-in-Place) system. Our CIP chemical cleaning agents are efficient, non-corrosive
to plates and gaskets and have minimum environmental impact. They contain
additives that make the cleaning faster and more efficient at a lower temperature
and with a lower concentration of chemicals.
Always at your
service
Field service
Although it seldom happens, a
plate heat exchanger may need
repair. Alfa Laval’s team of field
engineers can be summoned
at short notice and are fully
equipped to make the repair on
site – quickly and safely.
Performance agreements
Alfa Laval CIP chemicals and additives
Alfa Laval offers performance
agreements on four different
service levels – ranging from
simple ad hoc repairs to performance optimization at high
efficiency levels. This structure helps make it easy and
convenient to maintain high
heat exchanger uptime. The
service levels are optimized
for different applications
and the demands they place
on cleaning and preventive
maintenance.
AlfaCaus: An alkaline cleaning agent containing tensides and a complex builder.
Service centers
AlfaPhos: An acidic cleaning agent containing tensides, a complex builder
and an inhibitor.
Alfa Laval’s 50+ service centres
worldwide are on stand-by
in the unlikely event of more
serious damage to a plate heat
exchanger. The experience
and specialized tools of the
service centre will help get the
damaged unit back in operation
in the shortest time possible.
The centre, often working
closely with the field engineers,
can help organize the dismantling, packaging and transportation of the heat exchanger.
AlfaAdd: A tensides additive.
Tensides enhance the efficiency of the cleaning. The complex builder prohibits the
precipitation of salts. The inhibitor protects the stainless steel from corrosion by
repassivating the steel surface.
PPI00402EN 1004
How to contact Alfa Laval
Up-to-date Alfa Laval contact details for all countries are
always available on our website at www.alfalaval.com
Alfa Laval reserves the right to change specifications without prior notification.