Apparatus for injecting a gas into a liquid flow

Claim 1

Apparatus for injecting gas into a liquid flow, comprising: a conduit for containing a flowing liquid, said conduit including in sequence, separate converging, bottleneck, and diverging sections, said converging section having a fluid-receiving inlet and said converging, bottleneck and diverging sections joined end-to-end without concordance radii between the sections, to produce a turbulence effect in liquid flowing through said conduit, said converging section increasing the rate of flow of liquid from a point upstream of the converging section, and said bottleneck section having a reduced diameter compared to that of the converging section; a generally cylindrical outer wall having upstream and downstream ends joined to said converging and diverging sections, respectively, said outer wall disposed about said bottleneck section so as to form therewith an annular chamber elongated in the downstream direction, said outer wall having means for connection to a pressurized source of gas for introducing the gas into the chamber; said bottleneck section further including a wall defining a portion of said annular chamber, said wall containing a plurality of needle-mounting holes extending therethrough and inclined in the downstream direction; and a plurality of rigid hollow needles mounted in said wall generally throughout the length of said chamber, said needles inclined in the downstream direction and extending varying amounts into the interior of the bottleneck section so as to inject gas from said chamber at different points within the liquid flow.