Process for spray forming of discrete particles
AssigneeSCM Corporation
InventorEdgar Joachim Beyn
Life of this patent
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Abstract
A process for forming an atomized stream of a sprayable substance in a conversion zone, which may be a drying zone or a congealing zone, and forming discrete particles of said stream in said zone. The present invention comprises intercepting the stream of atomized droplets with a fluent binder capable of agglomerating fines in the stream faclitating their collection. The invention is particularly described with reference to the spray drying of pigment particles.
Claims13
In a process for forming and collecting aggregate particles from a sprayable substance which comprises a fraction of normally solid particulate matter and a fraction of a fluent bonding agent in addition to the solid matter, said process including the steps of:
- a. atomizing said sprayable substance into a conversion zone;
- b. said sprayable substance during said atomizing step forming a pattern of droplets of various sizes including a first group of droplets of solid particulate matter and bonding agent having a droplet size within a range and a second group of droplets of finer size less than the sizes in said range;
- c. establishing in said conversion zone conditions for hardening said bonding agent and forming discrete aggregates of said first group of droplets having an ostensibly dry surface, said bonding agent on hardening having sufficient strength to bond the particulate matter to form said aggregates;
- the improvement comprising:
- 1. intercepting said pattern of droplets with a spray of an auxiliary fluent binder also hardenable under conditions of the conversion zone;
- 2. maintaining said auxiliary binder and said pattern of droplets in an agitated state to mutually engage said second group of droplets of finer size and said auxiliary binder prior to hardening of the auxiliary binder forming additional aggregates of said second group of droplets of finer size and said auxiliary binder;
- and
- 3. removing said resulting aggregates from said zone.
A process for forming and collecting dried, aggregate, pigment particles suitable for addition to a pigment or plastics system comprising the steps of:
- a. forming a fluent slurry of pigment particles in a fugitive vehicle, said slurry containing an organic thickener material capable on drying of bonding said pigment particles into aggregates, the resultant bond being destructible in the pigment or plastics system to which the aggregates are added;
- b. atomizing said slurry into a heating zone;
- c. said slurry during said atomizing step forming a pattern of droplets of various sizes including a first group of droplets of solid particulate matter and bonding agent having a droplet size within a range and a second group of droplets of finer size less than the sizes in said range;
- d. heating said droplets for the time and at a temperature in said heating zone sufficient to volatilize said vehicle and harden said organic thickener material forming discrete aggregates of said first group of droplets having an ostensibly dry surface, said bonding agent on hardening having sufficient strength to bond the pigment particles to form said aggregates;
- the improvement comprising:
- 1. intercepting said pattern of droplets with a spray of an auxiliary fluent binder also hardenable under conditions in the heating zone;
- 2. maintaining said auxiliary binder and said pattern of droplets in an agitated state to mutually engage said second group of droplets of finer size and said auxiliary binder prior to hardening of the auxiliary binder forming additional aggregates of said second group of droplets of finer size and said auxiliary binder;
- and
- 3. removing said resulting aggregates from said zone.
Dependencies are inferred from the claim text.