Rectifier Systems and Polarization Rectifiers for chlor-alkali industry

Heavy-duty rectifier systems and polarization rectifiers for the chlor-alkali industry.

To manufacture products for sanitation, disinfection, cleaning and medical treatment such as chlorine, sodium hypochlorite, caustic soda and PVC, to supply green energy and hospitals.


FRIEM supplies heavy-duty rectifier systems and polarization rectifiers for the chlor-alkali industry that produce chlorine, sodium hydroxide (caustic soda), calcium hydroxide, potassium hydroxide, hypochlorite, chlorate, etc.

These chemicals are in fact used to manufacture solvents, plastics, medicines, pesticides, disinfectants, soaps and are significantly used in the pulp and paper and aluminium industries.
In these applications, the DC current typically varies in the range of 1kA to 10kA for hypochlorite and water chlorination, up to 50kA for chlorine and caustic soda membrane plants, up to 100kA for chlorate and chlorine mercury plants.

Chlor-alkali plants are characterized by an aggressive and polluted atmosphere and by the intensive use of electric energy. These conditions require a specific industrial design of the equipment, which must be capable of operating continuously at the full load delivering the highest efficiency.

FRIEM’s rectifier systems grant the highest level of robustness, reliability, efficiency and longest lifespan, both in indoor and outdoor installation.

A unique experience and know-how in the chlor-alkali industry

Essential to support Customers in defining the most effective layout and topology of the rectifier systems and during the entire lifespan of the equipment:

  • Load variability through On Load Tap Changer and thyristors;
  • independent current-voltage control of two electrolysers with one rectifier group 12 pulse;
  • reduced energy consumption and harmonic distortion thanks to plant’s configuration up to 48 (or more) pulses, optimized power factor and low losses equipment;
  • highest reliability thanks to N-1 redundancy of diode and thyristors;
  • optimized use of manpower during installation, commissioning, start-up and operation thanks to 100% factory-tested equipment and FRIEM’s typical modular design.



MOBILITY Knowledge into efficiency


Knowledge into efficiency

SERVICE A partner to our Customer


A partner to our Customer

ENERGY Working now for the future


Working now for the future