Phenothiazine in prill form and method for making the same
AssigneeAvecia Limited
InventorDavid A. Vanzin
Life of this patent
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Abstract
Phenothiazine and its derivatives products are provided with a minimal level of fines or dust as a result of forming such products in prill form. The prills are generally spherical. Also provided is a method for reducing the level of powder in phenothiazine product which includes forming the phenothiazine product in prill form such that the prills have a generally spherical shape. The prill product achieves improved handling, flowability and dissolution times, while minimizing the generation of phenothiazine fines and dust, and the problems associated with worker exposure, irritation and sensitization to such fines and dust.
Claims26
A phenothiazine product, comprising
- a plurality of phenothiazine prills, wherein the prills are generally spherical and yellow.
A phenothiazine product, comprising a plurality of phenothiazine prills, wherein the prills are generally spherical, are yellow, have a melting point of 184.9° C. minimum, and the prills have a particle size distribution such that 99% of the prills have a size of from 500 microns to 2360 microns.
A phenothiazine product comprising a plurality of phenothiazine prills, wherein the prills are generally spherical, yellow, have a melting point of 184.9° C. minimum and a purity of 99.9% and a particle size distribution such that about 99% of the prills have a size of from 500 microns to about 2360 microns.
A phenothiazine product comprising a plurality of phenothiazine prills, wherein the prills are generally spherical, are yellow, have a melting point of 184.9° C. minimum, less than 1% by weight of the prills have a particle size less than 500 microns, and the product has a angle of repose of 25.
A method for making phenothiazine in generally spherical prill form comprising:
- (a) introducing molten phenothiazine feed into a jet priller capable of receiving a molten phenothiazine feed and passing the feed through at least one nozzle which has a plurality of holes to form molten phenothiazine droplets;
- and
- (b) cooling the droplets to form solid phenothiazine prills.
A method for making a phenothiazine product in generally spherical prill form comprising:
- (a) charging phenothiazine product to a holding vessel;
- (b) melting said product;
- (c) conveying the molten product to a receiver vessel;
- (d) feeding said molten product into the prilling head of a jet priller and forcing the molten product through said holes;
- (e) controlling the flow through the nozzles by means of a vibrating membrane so as to form 1-2 mm droplets of molten product;
- (f) permitting said droplets to immediately fall through a cryogenic freezing column so as to form solid prills;
- (g) further cooling said prills;
- and
- (h) removing any generated fines.
A method for making a phenothiazine product in generally spherical prill form comprising:
- (a) charging phenothiazine product to a holding vessel;
- (b) melting said product;
- (c) conveying the molten product at about 200° C. and a pressure of about 3.1 bars to a receiver vessel;
- (d) feeding said molten product into the prilling head of a jet priller having 100 nozzles with a nozzle diameter of 0.5 mm, each nozzle having 100 to 250 holes and forcing the molten product through said holes;
- (e) controlling the flow through the nozzles by means of a membrane vibrating at a frequency of 1005-1007 Hz so as to form 1-2 mm droplets of molten product;
- (f) permitting said droplets to immediately fall through a liquid nitrogen/nitrogen gas cryogenic freezing column so as to form solid prills;
- (g) cooling said prills further in a spiral fluid bed;
- and
- (h) removing any generated fines by means of a cyclone.
A method of making phenothiazine in prill form comprising:
- feeding molten phenothiazine into a nozzle which has a plurality of holes to form molten phenothiazine droplets, cooling the droplets with an inert gas or liquid to form solid yellow phenothiazine prills, and maintaining said prills in an inert nitrogen atmosphere.
Dependencies are inferred from the claim text.