Methods and apparatus for material processing using atmospheric thermal plasma reactor

Patent metadata

Field	Value
Publication number	US-2016347641-A1
Application number	US-201615235715-A
Country	US
Kind code	A1
Filing date	Aug 12, 2016
Priority date	Mar 31, 2014
Publication date	Dec 1, 2016
Grant date	—

Abstract

Methods and apparatus provide for: producing a plasma plume within a plasma containment vessel from a source of plasma gas; feeding an elongate feedstock material having a longitudinal axis into the plasma containment vessel such that at least a distal end of the feedstock material is heated within the plasma plume; and spinning the feedstock material about the longitudinal axis as the distal end of the feedstock material advances into the plasma plume, where the feedstock material is a mixture of compounds that have been mixed, formed into the elongate shape, and at least partially sintered.

First claim

1 - 13 . (canceled)

14 . A method, comprising:
producing a plasma plume within a plasma containment vessel from a source of plasma gas; feeding an elongate feedstock material having a longitudinal axis into the plasma containment vessel such that at least a distal end of the feedstock material is heated within the plasma plume; and spinning the feedstock material about the longitudinal axis as the distal end of the feedstock material advances into the plasma plume, wherein the feedstock material is a mixture of compounds that have been mixed, formed into the elongate shape, and at least partially sintered.

15 . The method of claim 14 , wherein the feedstock material is a glass batch material.

16 . The method of claim 14 , wherein the plasma plume is of a substantially cylindrical shape, and is of sufficient thermal energy to cause the distal end of the feedstock material to melt.

17 . The method of claim 16 , wherein step of spinning the feedstock material about the longitudinal axis includes spinning at a sufficient speed to cause the melt to separate from the distal end of the feedstock material, in response to centrifugal force, and to form respective substantially spherical droplets.

18 . The method of claim 17 , further comprising controlling a rate at which the feedstock material spins, thereby controlling a size of the droplets.

19 . The method of claim 17 , wherein the size of the droplets is one of: (i) between about 10 um-5000 um; (ii) between about 50 um-2000 um; (iii) between about 100 um-1000 um; (iv) between about 50 um-200 um; and (v) about 100 um.

20 . The method of claim 14 , wherein the rate of spinning the feedstock material is one of: (i) between about 500 rpm-50,000 rpm; (ii) between about 1000 rpm-40,000 rpm; (iii) between about 1400 rpm-30,000 rpm; (iv) between about 2000 rpm-20,000 rpm; and (v) between about 5000 rpm-10,000 rpm.

21 . The method of claim 14 , further comprising controlling a temperature of the plasma plume thereby controlling a size of the droplets.

22 . The method of claim 21 , wherein the plasma plume has a temperature ranging from one of: (i) about 9,000 K to about 18,000 K; (ii) about 11,000 K to about 15,000 K; and (iii) at least about 11,000 K.

23 . The method of claim 17 , wherein the plasma plume is of sufficient thermal energy to cause the droplets from the feedstock material to thermally react.

24 . The method of claim 23 , wherein at least one of:
the thermal reaction includes at least partially melting the droplets of material, the thermal reaction includes at least partially melting at least one of the droplets of material and one or more further materials thereby forming coated droplets of material, and the thermal reaction includes at least partially melting the droplets of material to form substantially homogeneous, spheroid-shaped intermediate particles.

25 . The method of claim 14 , further comprising producing the feedstock material by substantially continuously receiving, mixing, pressing, and at least partially sintering precursor compounds into the feedstock material as the feedstock material is fed into the plasma containment vessel.

26 . The method of claim 25 , wherein the pressing step includes pressing the mixed precursor compounds to between about 20 psi-200 psi.

27 . The method of claim 25 , wherein the heating step includes heating the pressed precursor compounds to between about 500-1000° C.

28 . The method of claim 25 , wherein the feedstock has a diameter of one of: (i) between about 5 nm-50 mm; (ii) between about 10 mm-40 mm; and (iii) between about 20 mm-30 mm.

Assignees

• Corning Inc

Inventors

• Boughton Daniel Robert

Classifications

• H01J37/32082

  Radio frequency generated discharge (H01J37/32357, H01J37/32366, H01J37/32394 and H01J37/32403 take precedence) · CPC title

• C03B19/109 Primary

  Glass-melting furnaces specially adapted for making beads · CPC title

• H01J37/32614

  Consumable cathodes for arc discharge · CPC title

• H05H1/30

  using applied electromagnetic fields, e.g. high frequency or microwave energy (H05H1/28 takes precedence) · CPC title

• H05H1/42

  with provisions for introducing materials into the plasma, e.g. powder or liquid {(arc stabilising or constricting arrangements H05H1/3405; coaxial protecting fluids H05H1/341)} · CPC title