AB "Panevėžio energija"

Panevezys, Lithuania
2010

Supply of automatic vacuum deaeration system

Vacuum deaeration system capacity 37 m³/h
Nominal temperature of treated water before deaerator 75-80°С
Concentration of dissolved oxygen before deaerator > 8000 mkg/l
Concentration of dissolved oxygen after deaerator < 50 mkg/l

Chemically cleaned water with a temperature of 75-80°C goes to working nozzles of vacuum deaerator.

Vacuum deaerator may operate in three modes.

When deaerator works with load range up to 37m³/h feeding water goes to three deaeration nozzles. When deaerator works with load range up to 12m³/h feeding water goes to only one deaeration nozzle. The left nozzles can be activated or closed by the valve.

When the chemically cleaned water goes through the working nozzles it boils and then begins to discharge the dissolved corrosive gases (О2, СО2).

The pressure of vacuum deaerator is (-0,5÷-0,8) atm (by vacuum-gauge). Deaerating water flows after vacuum deaerator to hot well (volume is 5% of maximum rate during one hour V=2,5m³). Vacuum deaerators minimal installation height is 4 m above ground level.

Deaerating water goes from well to piping by gravity flow from the exhaustion side of the pump. The system is provided with two pumps, one working, another reserve; they are pumping the deaerating water to accumulator tank.

In accordance with pump output the water-level changes in a hot well. Level control works automatically by the frequency regulator and keep level on 20-30%.

To regulate the water-level in the deaerating tank as a primary device there is used pressure-difference transmitter.

Discharging corrosive gases are removed by the liquid-packed vacuum pump from deaerating column and deaerating tank to cold water tank. After vacuum pump discharge water and water mix with corrosive gases flow together to cold water tank, which is connected with atmosphere. The system has two pumps, one working, and another reserve. Cold process water with temperature 15-20°C is used as sealing water of vacuum pump. The cold water pumps from cold water tank, V=2 m³.