Manual Cleaning; Clean In Place (Cip); Detergents; Liquid Penetrant Testing - CIAT ITEX Manuel D'instructions

ENGLISH

5.3 - Manual cleaning

• Always wear safety glasses and protective gloves and follow
the instructions for the cleaning products used.
• Dispose of wastewater in accordance with prevailing envi-
ronmental protection regulations.
• Never use metal tools, abrasives, or corrosives.
• Use a soft, non-metallic brush and suitable detergent.
• A pressure washer may be used provided the necessary
precautions are taken to avoid damaging the gaskets.
• Soak the plates in a detergent solution if they are coated
with thick deposits.
• Thoroughly rinse the plates, and especially the gaskets, in
cold or lukewarm water.
• Degrease the plates before reinstalling them, especially if
one of the fluids circulated is a lubricant (e.g. oil).
• Carefully check the condition and sealing surfaces of the gas-
kets, the flatness of the plates, and the overall cleanliness.

5.4 - Clean in place (CIP)

• CIP is recommended if the heat exchanger requires frequent
cleaning or is hard to disassemble.
• CIP can be performed provided it is impossible for particles
to build up inside the heat exchanger. Likewise, if there is a
risk of the surfaces of the plates being damaged by parti-
cles, manual cleaning should be performed.
• The CIP procedure must be determined with a specialised
firm when the system is designed.
• After the first few cleanings, it may be necessary to open
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the heat exchanger in order to check the degree of cleanli-
ness, adjust the cycle time and determine the best product
concentrations.
Procedure
1) Completely drain all the circuits (if this is not possible, run
fresh water through the circuits until the process fluids
have been completely flushed out).
2) Clean with fresh water (with a low chloride content for the
stainless steel plates) at a temperature of around 40°C to
eliminate all traces of the process fluids.
Run this water in the opposite direction of normal operation.
An even better result can be obtained by running the water
alternately in one direction and then the other (this is advised
for steam applications or to eliminate residues such as fibres
and particles). The use of filters upstream of the heat exchan-
ger will reduce the need for this.
3) Completely drain the water from the circuits and connect
the CIP unit. Do not let the solution sit in the exchanger.
4) For even better cleaning, use a centrifugal pump installed
between the CIP and the heat exchanger. Circulate the de-
tergent solution in the direction opposite that of the fluids
so as to eliminate all traces of dirt.
5) Circulate a quantity of detergent solution at above the nom-
inal flow rate but without exceeding the maximum allowable
flow rate (determined by the nominal diameter).
6) Thoroughly flush both circuits with fresh water.

5.5 - Detergents

• Never use hydrochloric acid (HCl) or chlorinated compounds
with stainless steel.
• Never use phosphoric acid with titanium.
• Suitable detergents may be obtained from specialised firms.Specify
the plate and gasket types to obtain a detergent that will not remove
the protective oxide layer on the plates or destroy the gaskets.
• Nitric acid (HNO3) and sodium hydroxide (NaOH) may be
used to clean stainless steel and titanium plates.
• Polyphosphates may also be used.
Descaling
• Use a nitric acid (HNO3) or citric acid solution: 1.5% concen-
tration by weight, max. temperature 65°C (1.5% by weight
corresponds to 1.75 l of 62% HNO3 for 100 litres of water)
or a polyphosphate solution (NaPO4 or Na3PO4): 1.5% max.
concentration by weight, max. temperature 50°C.
Degreasing
• Degrease stainless steel or titanium plates with a sodium
hydroxide (NaOH) solution: 1.5% max. concentration by
weight, max. temperature 65°C (1.5% by weight corre-
sponds to 3.75 l of 30% NaOH for 100 litres of water).
• Do not use hydrochloric acid or water with a chloride con-
tent of over 300 ppm to clean stainless steel plates.
• Do not use phosphoric acid to clean titanium plates.
ENGLISH
Deposits:
Calcium
Recommended detergents: 4% nitric acid solution at 60°C
max. - 4% citric acid solution at 60°C max.
Oils and greases
Recommended detergents: paraffin or kerosene (as these
fluids may damage NBR and EPDM gaskets, limit the con-
tact time to no more than 30 minutes)
Sludges, metal oxides
Recommended detergents: 8% nitric acid solution at 60°C
max. - 4% citric acid solution at 60°C max.
Organic matter
Recommended detergents: 2% sodium hydroxide solution
at 40°C max.

5.6 - Liquid penetrant testing

• Corrosion, galvanic coupling and erosion can create holes
in the plates. As such damage is not always visible to the
naked eye, we recommend performing liquid penetrant
tests to check for holes or microcracks. CIAT's technical
support team can advise you on the appropriate products.
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