ArcelorMittal Atlantique-Lorraine Dunkerque (France)

Introduction

ArcelorMittal Atlantique-Lorraine Dunkerque is one of the largest steelmaking facilities in Western Europe. It offers high value-added products and services.

Callenge

The importance of keeping cooling tower water in proper chemical balance is very important. Cooling tower treatment control systems can limit scale formation to improve efficiency, limit corrosion to increase the service life of the cooling water system and maintain a residual disinfectant level to reduce biological growth.

ArcelorMittal produce reverse osmosis water from industrial water to cool the rollers of the continuous casting steel mill.

To produce 180 m³/h of reverse osmosis water from industrial water, divided in different stages:

  • 2 ultrafiltration units with 2 filtration racks per unit
  • Buffer storage of 150 m³ ultrafiltration water
  • 3 reverse osmosis units each equipped with 2 racks of 6 membranes mounted in 2 tiers
  • Buffer storage of 1250 m³  osmosis water

Each of the 5 units alternate utilized for production and chemical washing.

All the instrumentation are used to monitor the water quality protecting the expensive membranes and measure and control the injection of different treatment chemicals.

Typical parameter for process water are conductivity, pH-value and the quantity of used biocides (disinfection chemicals).

  • Disinfection - may not affect the system and must remove microorganisms that can affect the system
  • Conductivity - water may be treated with chemical inhibitors to extend the saturation point of insoluble materials and prevent scaling and corrosion
  • pH-value - alkaline orthophosphate treatments can result in corrosion and in calcium phosphate scaling
  • Additional parameters are alkalinity/hardness or turbidity

Solution

Used Kuntze Instruments process technology:

  • 1 Krypton® Multi - Measurement of free chlorine, pH, conductivity, temperature.
  • 6 Krypton® DIS - Measurement of free chlorine
  • 5 Krypton® pR - Measurement of pH (Zirkon® pH Universal)
  • 6 Krypton® EC - Measurement of conductivity
    (LE44 c=0,05 cm-1)

Add. turbidity, hardness/alkalinity

The customer is satisfied with the equipment for his process water control. Especially the measurement of very low conductivity with tailor-made Krypton EC set-up, using the LE44 (c= 0,05 cm-1) probe.