Apparatus for mixing aqueous foam with a slurry of gypsum and water. A
cylindrical housing includes, in its upper end, an inlet for a slurry and
a helical diverter for directing the slurry in a downward spiral flow
path. An inlet for aqueous foam in located in said diverted and directs
the foam into the incoming slurry. An annular flow restrictor is located
in the lower end of the housing. Turbulence resulting from diversion of
the incoming slurry from linear flow to a downward spiral flow path and
from changes in spin diameter and speed through the flow restrictor
uniformly mix foam with the slurry.
