Jet for use in a jet mill micronizer
The current invention provides an improved jet nozzle suitable for use in a micronizing jet mill or retrofitting to an existing jet mill. The improved jet nozzle incorporates a coanda effect inducing element to enhance entrainment of particles to be ground within the vortex created by the micronizing jet mill. When the jet mill uses steam to generate the jet, use of the improved nozzle will reduce energy costs by increasing the efficiency of the jet mill.
1. A jet nozzle suitable for use in a micronizing jet mill and constructed and arranged to provide a gaseous jet that creates a supersonic zone for grinding friable materials, comprising:
a nozzle body having a first open end and a second open end with a passageway joining said first and second ends; and
a Coanda effect inducing element positioned within said passageway and extending outward from said second end of said nozzle, said Coanda effect inducing element extending outward from said second end of said nozzle for a distance sufficient to ensure development of a Coanda effect and thereby extend said supersonic grinding zone outward from said nozzle body.
2. The jet nozzle of claim 1 , wherein said Coanda effect inducing element has a geometric configuration corresponding to a geometric configuration of said second open end of said nozzle body.
3. The jet nozzle of claim 2 , wherein said second open end of said nozzle body has a slot-like configuration.
4. The jet nozzle of claim 2 , wherein said second open end of said nozzle body has a slot-like configuration defined by two longer, essentially inwardly hyperbolic sides and opposing generally rounded ends.
5. The jet nozzle of claim 1 , wherein said Coanda effect inducing element extends outwardly from said second open end a distance of from about 2.5 mm to about 38.1 mm and wherein said Coanda effect inducing element has a geometric configuration corresponding to a geometric configuration of said second open end of said nozzle body.
6. The jet nozzle of claim 3 , wherein an exterior surface of said Coanda effect inducing element and an interior surface of said second open end define a gap, and wherein the portion of said Coanda effect inducing element which conforms to the configuration of said second open end extends into said passageway a distance ranging from about ten times said gap to about 20 times said gap.
7. The jet nozzle of claim 3 , wherein said first open end of said nozzle body carries interior threads and an exterior surface of said Coanda effect inducing element and an interior surface of said second open end define an air passage, and said jet nozzle further comprises
a Coanda effect inducing element retainer positioned within the first end of said nozzle, thereby securing said Coanda effect inducing element within said passageway.
8. The jet nozzle of claim 7 , wherein said retainer has a passageway passing therethrough.
9. The jet nozzle of claim 1 , wherein said Coanda effect inducing, element is adjustably positioned within said passageway joining said first and second open ends of said nozzle body.
10. The jet nozzle, of claim 5 , wherein an exterior surface of said Coanda effect inducing element and an interior surface of said second open end define a gap, and wherein the portion of said Coanda effect inducing element which confirms to the geometric configuration of said second open end extends into said passageway a distance ranging about ten times said gap to about 20 times said gap.
11. The jet nozzle of claim 10 , wherein said second open end of said nozzle body has a slot-like configuration defined by two longer, essentially inwardly hyperbolic sides and opposing generally rounded ends.
12. A jet nozzle suitable for use in a micronizing jet mill and constructed and arranged to provide a gaseous jet that creates a supersonic zone for grinding friable materials, comprising:
a nozzle body having a first open end and a second open end with a passageway joining said first and second ends; and
a Coanda effect inducing element positioned within said passageway and extending outward from said second end of said nozzle, said Coanda effect inducing element extending outward from said second end of said nozzle for a distance sufficient to ensure development of a Coanda effect and thereby extend said supersonic grinding zone outward from said nozzle body, wherein said Coanda effect inducing element has a geometric configuration corresponding to a geometric configuration of said second open end of said nozzle body, and wherein said second open end of said nozzle body has a slot-like configuration defined by two longer, essentially inwardly hyperbolic sides and opposing generally rounded ends.
13. A jet nozzle suitable for use in a micronizing jet mill and constructed and arranged to provide a gaseous jet that creates a supersonic zone for grinding friable materials, comprising:
a nozzle body having a first open end and a second open end with a passageway joining said first and second ends; and
a Coanda effect inducing element positioned within said passageway and extending end outward from said second end of said nozzle, said Coanda effect inducing element extending outward from said second end of said nozzle for a distance sufficient to ensure development of a Coanda effect and thereby extend said supersonic grinding zone outward from said nozzle body, wherein said Coanda effect inducing element has a geometric configuration corresponding to a geometric configuration of said second open end of said nozzle body, wherein said second open end of said nozzle body has a slot-like configuration, and wherein an exterior surface of said Coanda effect inducing element and an interior surface of said second open end define a gap, and wherein the portion of said Coanda effect inducing element which conforms to the configuration of said second open end extends into said passageway a distance ranging from about ten times said gap to about 20 times said gap.