Anodizing Plant Division
Pulse Rectifier
Advantages of using pulse rectifiers in anodizing
With the use of pulse rectifiers, the oxide quality is better than the one obtained with a conventional rectifier, as proved by the tests on abrasion, efficiency (ISO 321 O) and corrosion (Kestern ich).
So it is possible (without disadvantages) to work with a current density higher than conventional rectifiers. Thus the use of pulse rectifiers gives a benefit of 20- 25% time saving compared with the conventional ones.
CHOICE OF CURRENT VALUE (AMPERE)
The pulse rectifiers are characterized by 3 values.
— Base current
— Pulse current = base current x 1,5
— Average current = 1,35 x base current
Example:
– Base current = 2000 A
– Pulse current = 2000 x 1,5 = 3000 A
– Average current = 2000 x 1,35 = 2700 A
Therefore:
lf the size of a pulse rectifier is chosen with the same average current of a conventional rectifier a better oxide quality is obtained, but without any time saving.
lf the size is chosen with the same base cur- rent as a conventional rectifier, also a 20 – 25% time saving is obtained.
MAX. VOLTAGE
The pulse rectifiers are provided for a 22 V max. voltage (instead of 20V max. as for conventional rectifiers) to have the possibility of pulse superposing.
TECHNICAL FEATURES
Control:
By means of SCR set on primary or secondary side
Rectifier circuit:
Six-phase provided with interphase transformer.
Main transformer: according to IEC 742 standard “Safety isolating transformers”
General switch:
Magnetothermic or magnetic (automatic) type
Cooling:
Air cooling: by means of ventilator and air filters (max. ambient temperature: 45°C. Protection IP20.
On request: closed loop air cooling by means of air/water exchanger (IP54)
Protections:
- Max. current: by means of electronic device and automatic general switch
- Max. temperature: by means of thermostats inside the main transformer windings and on the diode cases.
Voltage/current control:
Constant current and (or) constant voltage control
Accuracy ± 1 o/o against ± 10% network variation and load variation from 10% to 100%.
Optionals:
- lnterfacing with external PLC (by means of opto- insulated cards)
- APC -Anodizing process computer:
- Automatic survey of the surface to be anodized
- Pre-setting of anodizing current density
- Pre-setting of the requested number of microns
Automatic printout of anodizing parameters. Further technical details in our brochure “APC”-Anodizing Process Computer.
Feel free to ask to our commercial department
service@italtecno.com