Drizzling is a dosing system developed by ALIT for the passivation of aluminum parts. Similarly to other
materials, aluminum surfaces must be treated to be durable over time, as they are naturally subject
to oxidation and corrosion.
2. DRIZZLING
Drizzling is a dosing system developed by ALIT for the passivation of aluminum parts. Similarly to other
materials, aluminum surfaces must be treated to be durable over time, as they are naturally subject
to oxidation and corrosion. In the specific case of aluminum, various surface treatment processes can
fulfil this purpose. One of the most significant and widespread is certainly coating, which is the last
(but not least) step of a chemical process that includes several intermediate stages in which parts are
degreased, deoxidized, and passivated. This is where ALIT TECHNOLOGIES’ Drizzling dosing system
can make a difference. Combined with chrome-free chemicals, such as ALFICOAT 748/3, developed by
Alufinish GmbH with nanotechnology components, it guarantees excellent passivation results in terms
of both corrosion resistance and paint adhesion.
HOW IT WORKS
Drizzling consists of a dosing panel for automatically
managing the demineralized water coming from a
feed tank and the amount of passivating chemical
product, in order to apply an optimally concentrated
solution on the material to be treated. The use
of special atomizing nozzles and compressed air
enables it to produce and evenly distribute a light
mist of chrome-free solution.
ADVANTAGES
• no need for a recirculating passivation tank: thanks to the low volume of solution sprayed onto the workpieces,
a tank is no longer required to collect the solution for continuous recovery and re-spraying;
• ever-clean solution: thanks to the reduced volumes of atomized solution, the Drizzling system allows using an
ever-fresh, “disposable” solution;
• no disposal of passivating solutions due to their ageing;
• ever-fresh, contaminant-free solution;
• possibility of converting chromate conversion coating lines to chrome-free lines easily and with guaranteed success;
• minimum space requirements, as the demineralized water feeding tank can be installed outside the line, if a process tank
cannot be used. Moreover, the system only features one spraying bar with a minimum footprint of about 30 cm in length,
which can be easily mounted within an existing tunnel.
3. DEMINERALIZED WATER SUPPLY
• Demineralized water tank
• Demineralized water level control in the tank
DOSING SYSTEM WITH PLC
• Flow and conductivity control of incoming
demineralized water
• Conductivity control of the mixed solution
(indirect concentration measurement)
• Product level control in the drum
KEY COMPONENTS
• minimum level alarm in the demineralized water tank
• alarm in case the conductivity of the incoming demineralized water is too high
• alarm in case the incoming demineralized water flow is too low
• alarm in case the conductivity of the water-product solution lies outside the optimal range
• minimum level alarm in the drum containing the product to be dosed
• alarm in case the outlet flow is too low for each nozzle (OPTIONAL), if a nozzle is clogged
DISTRIBUTION SYSTEM
• Flow adjustment and control of the water-product
solution for each sector of the spraying bar
SPRAYING BAR
• For tunnel heights of 2 to 8 meters
• Electronic flow control of the water-product
solution for each nozzle (OPTIONAL)
PLC DEMINERALIZED
WATER FLOW
CONDUCTIVITY CONTROL OF THE
INCOMING DEMINERALIZED WATER
CONDUCTIVITY CONTROL
OF THE MIXED SOLUTION
ALARMS
FLOW ADJUSTMENT AND CONTROL
OF THE WATER-PRODUCT SOLUTION
4. Via Cavalieri D’Italia, 7
37047 - San Bonifacio (VR) - Italy
Phone +39 045 245 6638
Fax +39 045 853 8097
info@alit-tech.com
www.alit-tech.com
ALIT Technologies
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Images are for illustrative purposes only
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Information is provided based on our best knowledge and awareness at the time
of printing and it reflects our experience in our laboratory and in practice. This
information should only be considered as a recommendation to be adapted to
any specific needs. Since the use of our products and systems is not subject to our
influence, we cannot offer any type of guarantee or insurance.