Whirling spray nozzles of various types have been known for many years wherein a vortex motion is imparted to a liquid passing through the nozzle to produce a conical spray. It has been the general practice to utilize vanes of various construction within such nozzles to impart a vortical component of motion to the liquid. Nozzles of this type have been used for spraying a slurry or liquid containing a solid or particulate phase. Prior patents relating to these types of nozzles include the following: U.S. Pat. Nos. 1,309,597, 1,503,438, 2,747,936, 2,751,252, 3,275,248, 3,567,116 and 3,666,183. In general, while these patents disclose the use of vanes which impart a whirling motion to the liquid, they are not suitable for spraying a slurry in which the solid phase is composed of relatively larger particles and especially long, rough fibers as in the case of cellulose fibers used in the papermaking process. Such fibers have a great tendency to snag on the edges of the whirl vanes and to agglomerate because of their length and rough outer surface characteristics. Consequently, nozzle clogging readily occurs requiring relatively frequent equipment shutdowns.
It is the principal object of this invention to provide an improved vortex spray nozzle for a fibrous slurry which provides for uniform particle dispersion while overcoming the clogging tendency of spray nozzles heretofore available.
It is a further object of this invention to provide a nozzle of the above type which has maximum free passage or opening through the swirl imparting vanes whereby it is uniquely adapted for use in the papermaking industry where fibrous slurries are sprayed.