Venturi Desuperheater and Annular Venturi Desuperheater
Principle of Operation
Fig. 6980 Annular Venturi Orifice Desuperheaters eliminate the accumulation of unvaporized water in the pipeline. Water droplets that fail to vaporize immediately after injection must fall back into the high-velocity throat region of the desuperheater where it again comes into contact with the steam until completely vaporized. They can be installed horizontally or vertically – depending on operating conditions.
Fig. 6950, Fig. 6940 and Fig. 6940M Venturi Desuperheaters and Fig. 6985 Annular Venturi Desuperheaters reduce steam temperature by bringing superheated steam into direct contact with water. The steam is cooled through the evaporation of the water. These desuperheaters are recommended for use under a wide range of conditions, including steady and variable flows. They can be installed horizontally or vertically up. When installed vertically up, turndown ratio can be increased substantially.
Fig. 6950, Fig. 6940 and Fig. 6940M Venturi Desuperheaters and Fig. 6985 Annular Venturi Desuperheaters are normally used in areas where atomizing steam is not available. Turndown ratio is dependent upon a wide variety of factors, such as installation (horizontal or vertical), amount of residual superheat, and piping. Depending on exact flow conditions, units are capable of 20% to 2% flow variation. Pressure drop normally varies between 2 psi and 10 psi.
Fig. 6980 offers increased turndown capacity in comparison to other desuperheaters. The only maintenance necessary to keep the S&K Annular Venturi Orifice Desuperheater operating properly is the removal of scale due to evaporation.
Both Venturi Desuperheater and Annular Venturi Desuperheater units can be installed in either the horizontal or vertical position. There are no moving parts, are made of heavy duty construction; no special pipe supporting or thermal sleeve required.