Pressure Atomizing Desuperheaters reduce steam temperature by bringing superheated steam into direct contact with water. The steam is cooled through the evaporation of the water. Desuperheaters can be mounted either horizontally or vertically and are normally used for conditions where pressure losses must be minimized. These desuperheaters are a modification of the Attemperator Desuperheater with a relatively constant feed pressure, independent of the atomized flow rate, and achieve considerable higher turndown ratio.
The amount of liquid injected is adjusted via a control valve in the spillback line, whereby part of the flow is taken from the inlet flow rate and returned to the tank. The maximum atomized flow rate is achieved with the control valve closed. Uniform and fine liquid atomization is achieved across the entire control range.
Approach point as low as 6oC over saturation is possible.
Advantages
- High turn down ratio over 12:1
- Low pressure drop
- Vertical and Horizontal installation
- No moving part
- Heavy duty construction
- No special pipe support required
Disadvantages
- Coolant water retune pipeline required
Applications
- Used in shipboard service
- Control steam temperature to dryers in paper industry
- Heating system steam conditioning
- Process steam temperature control