Variable Eductor / Feed Lance
The Sundrop gasification process required dispersion of particulate material (e.g. rice husk) into a carrier stream of process gas. This dispersed mixture then needed to be injected directly into the hot zone of the solar furnace.
In our case neither the details of the particulate material behavior nor the exact process gas chemistry and volumes were known and so gas velocity, volume, and point of introduction relative to the feed screw all required control independent of the total mass transfer rate of process gas.
To accomplish entrainment of the particulate we designed an adjustable eductor comprised of a movable needle valve housing. Adjusting position and velocity through the needle valve allowed us to optimize for properties of the particulate feed.
Provision for additional flow external to the needle valve allowed us to balance the volume of flow to carry the mixture independent of the needle valve settings.
This mixture passed through a water-cooled lance into the reactor where it combined with additional process gas. This additional gas was required to balance process mixture and prevent reacted gases from rising around the lance assembly due to temperature driven buoyancy.
© 2019 Donna Kelley