JET-VAC® Venturi Desuperheaters protect processes and equipment
JET-VAC Venturi Desuperheaters reduce the temperature of vapors flowing in a pipeline by heat transfer through evaporation. Liquid injected at the throat of the venturi is atomized into small droplets by the high vapor velocity. Superheated vapor is cooled by evaporation of the droplets as they flow downstream.
JET-VAC Desuperheaters are used in chemical plants and refineries.
- Desuperheating Steam
To be used as steam desuperheating liquid, steam condensate must contain no dissolved solids that could deposit on the pipe walls. The condensate enters slightly downstream of the venturi throat where it is sprayed into the vapor flow at a minimum pressure of 5 to 10 psi above steam line pressure. This achieves a relative velocity between condensate and steam that produces the smallest droplet size. Superheated steam temperature may be reduced to a practical 5° to 10°F above saturation. Velocity of flow and required heat reduction determine how far downstream this occurs. In many cases, the distance is less than 20 feet.
- Desuperheating hydrocarbons
The relatively small latent heat of hydrocarbons requires much more liquid in the desuperheating process than high-temperature steam. JET-VAC Venturi Desuperheaters introduce the required amount of liquid through a series of nozzles paralleling the vapor flow. Counter flow is not necessary to break hydrocarbons into small droplets as their surface tension is less than water.
- Design and fabrication standards
JET-VAC Venturi Desuperheaters are designed and fabricated in accordance to the ASME Boiler and Pressure Vessel Code and may be stamped if required. Carbon steel is used up to approximately 750°F, low alloy steels up to 1000°F and high alloy steels at greater temperatures.