Method and apparatus for adding and mixing second cohesive powders in a fluidized bed blender

A method for blending a mixture of powdered ingredients comprising the steps of:

• (a) introducing a first powdered ingredient into a pressure-tight vessel;
• (b) establishing a fluidized bed of said first powdered ingredients in said vessel;
• (c) introducing a gas into an eductor to initiate pressurization;
• (d) thereafter adding a second powdered ingredient mixture to said eductor;
• (e) mixing the gas and second powdered ingredient mixture under pressure in said eductor;
• (f) conveying the gas and second powdered ingredient mixture under pressure to a comminuting mill and therein comminuting the second powdered ingredient mixture;
• (g) conveying under pressure the gas and comminuted second powdered ingredient mixture from the comminuting mill to the pressure-tight vessel;
• and
• (h) introducing a second powdered ingredient under pressure into said vessel and impinging the comminuted second powdered ingredient mixture against a deflection plate disposed within said fluidized bed of the first powdered ingredient and uniformly dispersing said second powdered ingredient mixture into said first powdered ingredient mixture contained in said vessel for thereby homogeneously blending the first and second powdered mixtures.

A method for blending a mixture of powdered ingredients comprising the steps of:

• (a) introducing a first powdered ingredient into a pressure-tight vessel;
• (b) establishing a fluidized bed of said first powdered ingredients in said vessel;
• (c) introducing a gas into an eductor to initiate pressurization of said eductor at a pressure of approximately 25 psig;
• (d) introducing a second powdered ingredient mixture to said eductor;
• (e) mixing the gas and second powdered ingredient mixture under pressure of less than about 5 psig in said eductor;
• (f) conveying the gas and second powdered ingredient mixture from said eductor at a pressure of from approximately 1 psig to approximately 3 psig, to a vortex mill and therein comminuting the second powdered ingredient mixture;
• (g) conveying the gas and comminuted second powdered ingredient mixture from the vortex mill to the pressure-tight vessel at a pressure of from approximately 3 psig to approximately 5 psig;
• and
• (h) introducing the comminuted second powdered ingredient mixture under pressure into said pressure-tight vessel and impinging same against a deflection plate disposed within said fluidized bed of the first powdered ingredient and thereby reducing to approximately 2 psig the pressure at which it is dispersed in said first powdered ingredient mixture contained in said vessel for homogeneously blending the first and second powdered mixtures.

A method for blending a mixture of powdered ingredients comprising the steps of:

• (a) introducing a first powdered ingredient into a pressure-tight vessel;
• (b) establishing a fluidized bed of said first powdered ingredients in said vessel;
• (c) comminuting within a comminuting mill a second powdered ingredient mixture;
• (d) transporting under pressure the comminuted second powdered ingredient mixture from the comminuting mill to said pressure-tight vessel;
• and
• (e) introducing the comminuted second powdered ingredient under pressure into said pressure-tight vessel impinging said comminuted second powdered ingredient mixture against a deflection plate disposed within said fluidized bed of the first powdered ingredient and uniformly dispersing said second powdered ingredient mixture into said first powdered ingredient mixture contained in said vessel for thereby homogeneously blending the first and second powdered mixtures.

A method for blending a mixture of powdered ingredients comprising the steps of:

• (a) introducing a first powdered ingredient into a pressure-tight vessel;
• (b) establishing a fluidized bed of said first powdered ingredients in said vessel;
• (c) comminuting within a vortex mill a second powdered ingredient mixture;
• (d) transporting the comminuted second powdered ingredient from the vortex mill to said pressure-tight vessel at a pressure of approximately 3.5 psig;
• and
• (e) introducing the comminuted second powdered ingredient under pressure into said vessel impinging said comminuted second powdered ingredient mixture against a deflection plate disposed within said fluidized bed of the first powdered ingredient and uniformly dispersing said second powdered ingredient mixture into said first powdered ingredient mixture contained in said vessel for homogeneously blending the first and second powdered mixtures.

A fluidized bed blending apparatus comprising:

• (a) a vertically-oriented pressure-tight mixing vessel;
• (b) means for introducing a first powdered ingredient into said mixing vessel;
• (c) a fluidizing grid for establishing a fluidizing bed in said mixing vessel;
• (d) at least one impingement device disposed above said fluidizing grid and including a deflection plate;
• (e) means for introducing a second powdered ingredient into said impingement device under pressure and directing it against said deflection plate, whereby said second powdered ingredient is uniformly dispersed into the fluidizing bed of said first powdered ingredient in said mixing vessel;
• and
• (f) a pressurized comminuting means for receiving a mixture of gas and powdered ingredients under pressure and effective for comminuting and mixing said powdered ingredients, and means for conducting said mixture of gas and ingredients under pressure from said comminuting means to said impingement device.

A fluidized bed blending apparatus comprising:

• (a) a vertically-oriented mixing vessel having a fluidizing grid disposed at the bottom thereof;
• (b) a cage-like impingement device mounted within the vertically-oriented mixing vessel and including an inlet for delivering a gas fed powdered material mixture under pressure to said impingement device;
• (c) conduit means for conveying a gas and powdered material mixture under pressure to said inlet of said impingement device;
• (d) a vortex mill effective for high pressure operation having an outlet for conveying a gas and powdered material mixture under pressure from said vortex mill to said conduit means connecting the vortex mill to the inlet of said impingement device and including an inlet for receiving a gas powdered material mixture under pressure and means for mixing and comminuting the powdered material introduced therein;
• (e) an eductor having a material feed inlet, a gas inlet, an internal blending chamber for initially blending a gas and powdered material mixture therein, and an outlet;
• (f) conduit means connecting said vortex mill inlet with said eductor outlet for conveying said gas and powdered material mixture under pressure from said eductor to said vortex mill;
• and
• (g) means for predeterminedly pressurizing the apparatus comprising the mixing vessel and vortex mill.