Production of particulate materials
AssigneeImperial Chemical Industries PLC
InventorsRaymond Oliver, Anthony R. N. Fairclough, Alejandro M. Antonini, Robert J. Munro, Lynn W. Lipscombe
Life of this patent
Estimating the term…
Abstract
A process for producing solid particles by drying a spray of liquid droplets. The droplets are formed by projecting a liquid formulation as a plurality of jets J (FIG. 6) in such a way that each jet breaks up into droplets of narrow size distribution. Prior to the onset of coalescence the droplets are contacted with a gas flow (G) which is arranged to reduce coalescence by disrupting slip streaming of the droplets and/or accelerating the droplets.
Claims22
A process for the production of solid particles, comprising:
- projecting from a body of liquid an array of mutually divergent jets;
- disturbing the jets to cause break up thereof into streams of droplets of narrow size distribution;
- contacting the array of resulting droplet streams with a gas flow which has a magnitude exceeding the magnitude of the velocity at which the jets are projected to reduce coalescence of the droplets in each stream;
- and causing or allowing the droplets to solidify at least partially while in flight.
Apparatus for producing solid particles, comprising:
- means for discharging liquid formulation from a body of the liquid as an array of jets;
- means for disturbing the jets to cause break up thereof into an array of droplet streams comprising droplets having a narrow size distribution;
- means for contacting the droplet streams with a gas flow which has a magnitude exceeding the magnitude of the velocity at which the jets are projected so that, prior to the onset of coalescence, the droplets in each stream are dispersed to reduce coalescence thereof;
- and means for effecting at least partial solidification of the droplets while in flight.
A method of spray drying a liquid formulation to produce a particulate product, comprising:
- (a) projecting the liquid formulation from a vessel containing the same as an array of downwardly directed jets;
- (b) generating acoustic waves within the liquid contained by the vessel in such a way as to disturb the jets substantially simultaneously to cause them to break up into streams of droplets having a narrow size range;
- (c) prior to the onset of droplet coalescence, contacting said streams of droplets with a turbulent gas flow to reduce droplet coalescence;
- and
- (d) as the liquid droplets descend within the tower, effecting at least partial solidification of the liquid droplets by interaction with said gas.
Spray drying apparatus for producing solid particles, comprising:
- (a) a tower;
- (b) means located at an upper portion of the tower for discharging liquid formulation from a vessel containing the same as an array of downwardly directed jets of predetermined velocity and diameter;
- (c) means for disturbing the jets to cause break up thereof into an array of droplet streams comprising droplets having a narrow size distribution;
- (d) means for introducing a gas flow into the tower with a velocity of magnitude in excess of that of the jets and in such a way that the gas contacts the droplet streams prior to the onset of coalescence, thereby dispersing the droplets in each stream to reduce coalescence thereof;
- and
- (e) means for effecting at least partial solidification of the droplets as they descend within the tower.
A process for the production of solid particles, comprising:
- projecting from a body of liquid an array of mutually divergent jets while applying pressure pulses to said body of liquid formulation so that the jets are simultaneously subjected to said pressure pulses and are thereby caused to break up into droplets of narrow size distribution;
- contacting the array of resulting droplet streams with a gas flow to reduce coalescence of the droplets in each stream;
- and causing or allowing the droplets to solidify at least partially while in flight.
A process for the production of solid particles, comprising:
- projecting from a body of liquid an array of mutually divergent jets from a curvilinear surface, the jets being encompassed between a pair of imaginary conical surfaces which intersect the curvilinear surface;
- disturbing the jets to cause break up thereof into streams of droplets of narrow size distribution;
- contacting the array of resulting droplet streams with a gas flow to reduce coalescence of the droplets in each stream;
- and causing or allowing the droplets to solidify at least partially while in flight.
Dependencies are inferred from the claim text.