Technical information

Page: 40
VL Series Portable Chillers, 2 to 40 Tons UGH021/0301
5.7 PROPER CLEANING PROCEDURE FOR BRAZED PLATE
EVAPORATORS
A. The brazed plate evaporator is
made of stamped stainless steel
plates, furnace brazed together
with copper based joints. The
complex geometry of the flow
passages promotes turbulent flow
which gives high efficiency and
reduces fouling by mineral
deposits. Large solids such as
plastic pellets or chunks of mineral
deposits will collect at the water
inlet port at the evaporator and
restrict flow through some of the
passages. If this possibility exists, Conair recommends filters or
strainers be added to the “from process” line. If the evaporator
becomes fouled there are a couple of methods for cleaning.
B. To begin, remove the piping to the “water in” port at the
evaporator. Remove any solids that have collected at this point.
Then backflush the evaporator to remove any solids that may be
trapped between the plates (see backflush procedure next page). If
there are mineral deposits adhered to the plates, the evaporator
must be backflushed with a mild acid solution (5% phosphoric or
5% oxalic acid is recommended.) After cleaning rinse with clear
water before returning to service. Continue with step C on next
page.
B
RAZED PLATE HEAT EXCHANGER
(EVAPORATOR)
FREON OUT
FREON IN
ORIGINAL WATER OUT PORT
BACKFLUSH WATER IN PORT
(SUPPLY BACKFLUSHING WATER
FLOW TO THIS PORT)
ORIGINAL WATER IN PORT
BACKFLUSH WATER OUT PORT
(ROUTE WATER TO PROPER
SEWER OR DRAIN CONTAINER)
Typical evaporator installation
Figure 5.7A