TEŠ 6 – Design Documentation for Construction Permission for Water Pumping Plant, Water Treatment Facility, Bypass Filtration Station and Ammonia Water Plant

Sipro Engineering was involved in the design for construction permission for 600 MWe block 6 of Thermal Power Plant Šoštanj (Slovenia). Sipro developed the design of mechanical installations, technology and equipment and the design of electrical installation and equipment, for the following technological parts:

  • Water pumping plant
  • Water treatment facility
  • Bypass filtration Station
  • Ammonia Water Plant

Water pumping plant is located by the Paka river. Designed capacity of the new Pumping plant is 1.500 m3/h. The water is pumped from the Paka river, but in case of low stream flow from the lake of Družmir.

New Water pumping plant consists from following systems and equipment:

  • Mechanical water gates
  • Valves in river water intake
  • Rotating sieve with the capacity 1.400 m3/h
  • Pumps for water supply to the new decarbonizing plant
  • Pumps for water supply to technological consumers
  • Pumps for backup washing of the rotating sieve
  • I&C and electrical equipment
  • Electrical power supply for the consumers


Picture 1: Reactor

The water treatment plant with the capacity of 1.200 m3/h is based on decarbonizing with dosing of:

  • Lime milk – 8 % concentrated suspension of lime (dosing into reactor)
  • Iron tetrachloride (4 % FeCl3, dosing into reactor)
  • Polyelectrolyte (dosing into reactor)
  • Hardness stabilizer (dosing into cooling water pipe)
  • Bio dispersant (dosing into cooling water pipe)

Main technological parameters of the decarbonizing plant are:

  • Reactor
  • Settler (sludge basin)
  • Decarbonized water basin
  • FeCl3 dosing station
  • Polyelectrolyte dosing station Nr. 1
  • Polyelectrolyte dosing station Nr. 2
  • Water hardness stabilizer station
  • Lime milk dozing station (dosing tanks and dosing pumps)
  • Centrifuge Nr. 1 and Nr. 2
  • Decarbonized water pumps
  • Washing pumps
  • Sludge pumps
  • Cleaned water pumps
  • I&C and electrical equipment
  • Power supply and distribution

Bypass filtration facility with sand filters assures filtration of approximately 5 % of condenser cooling water. The facility consists of:

  • Sand filters
  • Circulating pumps of cooling water through filters
  • Filters washing pumps
  • Fans for sand filters
  • Back up washing water pump
  • Auxiliary systems
  • I&C and electrical equipment
  • Power supply and distribution

For the purpose of NOx reduction in the exhaust gases of the boiler the catalytic cleaning system (DeNOx reactor) for unit 6 as well as unit 5 has been used. For the purpose of catalytic reaction the ammonia water is supplied into the system. Ammonia water with the concentration of 25 % is used, 1.500 to 2.000 l/h, about 45 % for unit 5 and about 55 % for unit 6.

The components of ammonia plant are:

  • Wagon decanting facility (decanting platform with railway track, drainage reservoir, cover, four discharge units, valves)
  • Truck decanting facility (decanting platform with the drain to collecting drainage tank, cover, connections for truck cisterns discharge, connection for underground drainage tank discharge, flexible hoses…)
  • Ammonia water pumping station (lime for wagon cisterns or truck cisterna discharge, pumping line for the consumers, drainage reservoir 50 m3)
  • Double wall overhead reservoir of the capacity 1.000 m3 for the ammonia water storage with the connections and auxiliary equipment
  • Underground drainage reservoir for discharging of the facility or its sectors
  • I&C and electrical equipment
  • Power supply and distribution

Project Manager for technology and mechanical design: Matjaž Pleteršek

Project Manager for electrical and I&C design: Franc Katič