Method and apparatus for feeding material into a plasma

Abstract

An apparatus for providing material feedstock into a plasma of a plasma torch includes a material feeding device having an input end and an output end. The output end of the material feeding device extends at least partially around the periphery of a plasma generated near the output end of the plasma torch. The material feeding device is oriented at an angle with respect to a central axis of the plasma torch.

1 . An apparatus for providing material feedstock into a plasma of a plasma torch, comprising:
 a material feeding device having an input end and an output end, the output end extending at least partially about a periphery of a plasma generated proximal to an output end of a plasma torch, the material feeding device being oriented at an angle with respect to a central axis of the plasma torch.   
     
     
         2 . The apparatus of  claim 1 , wherein the output end of the material feeding device includes a nozzle that has a flared cross sectional geometry extending at least partially about the periphery of the plasma to provide a substantially uniform dispersion of the material feedstock at least about a substantial portion of the entire periphery of the plasma. 
     
     
         3 . The apparatus of  claim 2 , wherein the nozzle provides substantially uniform dispersion of the material feedstock around at least half of the periphery of the plasma at a particular position about the periphery of the plasma. 
     
     
         4 . The apparatus of  claim 1 , wherein the output end of the material feeding device includes a plurality of nozzles positioned about the periphery of the plasma, the number and cross sectional geometry of the nozzles being selected to provide a substantially uniform dispersion of the material feedstock around a substantial portion of the entire periphery of the plasma. 
     
     
         5 . The apparatus of  claim 1 , wherein the material feeding device is designed to spread the material feedstock about the entire periphery of the plasma. 
     
     
         6 . The apparatus of  claim 1 , wherein the material feeding device is adjustable with respect to the central axis of the plasma torch to enable feeding of the material feedstock at different positions along the length of the plasma. 
     
     
         7 . The apparatus of  claim 6 , wherein the material feeding device feeds material about a substantial portion of the periphery of the plasma as well as a desired portion along the length of the plasma. 
     
     
         8 . The apparatus of  claim 1 , wherein the angle of the material feeding device with respect to the central axis of the plasma torch can be adjusted. 
     
     
         9 . The apparatus of  claim 1 , wherein the material feeding device is a conical hopper having the input end wider than the output end, and having a plasma torch liner configured to surround at least a portion of the plasma torch. 
     
     
         10 . The apparatus of  claim 9 , wherein the plasma torch liner forms a gap between both the input end and the output end of the conical hopper, the gap between the plasma torch liner and the input end of the conical hopper being larger than the gap between the plasma torch liner and the output end of the conical hopper so that material can be fed into the larger gap and exit the smaller gap into the plasma about substantially the entire periphery of the plasma. 
     
     
         11 . The apparatus of  claim 10 , wherein a first portion of the plasma extends outside the confines of the output end of the conical hopper and the respective end of the plasma torch, the material being fed about a periphery of the first portion of the plasma directly from the smaller gap at the output end of the conical hopper. 
     
     
         12 . The apparatus of  claim 10 , further comprising:
 a material swirl device positioned for operable communication with material in the conical hopper to assist in evenly distributing material within the conical hopper.   
     
     
         13 . The apparatus of  claim 1 , wherein the material feedstock is fed into the plasma by gravity. 
     
     
         14 . The apparatus of  claim 1 , wherein the material is fed into the plasma at a particular rate and velocity that does not appreciably disrupt the plasma and provides for uniform processing of the material by the plasma. 
     
     
         15 . An apparatus for uniformly providing material feedstock into a plasma of a plasma torch, comprising:
 a material feeding device installed proximate a plasma within a plasma torch, the plasma having a three dimensional shape that varies slightly over time during operation and having a desired and relatively consistent length, width, depth, shape and periphery, the material feeding device being in operable communication with a source of material to be fed into the plasma and the material feeding device also being capable of transferring the material to the plasma at a desired dispersion pattern that can vary based on a variety of factors, the material feeding device being designed and installed to enable substantially uniform dispersion of the material into the plasma at a position along the length of the plasma and at least about a substantial portion of the entire periphery of the plasma despite the variability of the shape and position of the plasma to utilize substantially all energy of the plasma, decrease variability of the plasma itself caused by inputting material into the plasma and decrease concentration of the material as it engages with and is processed by the plasma to provide for more efficient and consistent material processing to increase yield while avoiding additional processing to meet precise material specifications.   
     
     
         16 . A method of processing materials within a plasma torch, comprising:
 a) providing a plasma torch having a plasma established therein, the plasma having a relatively consistent but dynamic three dimensional shape that varies slightly over time during operation and having a desired and relatively consistent length, width, depth, shape and periphery;   b) providing a source of material to be fed into and processed by the plasma;   c) providing a material feeding device proximate a desired position of the plasma, the material feeding device being in operable communication with the source of material to be fed into the plasma; and   d) transferring the material, using the material feeding device, to the plasma at a dispersion pattern that can vary based on a variety of factors, the material feeding device being designed and installed to enable substantially uniform dispersion of the material into the plasma at a position along the length of the plasma and at least about substantially the entire periphery of the plasma.   
     
     
         17 . The method of  claim 16 , further comprising:
 e) monitoring an output of the plasma to determine if a desired processing of the material has been provided by the plasma;   f) adjusting the dispersion pattern of the material to the plasma if the desired processing of the material has not been achieved; and   g) repeating operations d)-f) as needed until the desired processing of the material has been achieved.   
     
     
         18 . The method of  claim 17 , wherein adjusting the dispersion pattern of the material to the plasma includes adjusting at least one of: material feed rate, material velocity, and position of the material feeding device with respect to the plasma. 
     
     
         19 . The method of  claim 18 , wherein the material feed rate and material velocity are selected to provide a smooth flow of material within a material feeding device in operable communication with the plasma torch and prevent any agglomeration of material within the material feeding device. 
     
     
         20 . The method of  claim 17 , wherein the plasma is a microwave plasma having an interior temperature at least several times higher than an exterior temperature and whereby power provided to the plasma only needs to be sufficient to enable the exterior temperature to provide the desired processing of the material so that any material that may make its way to the interior of the plasma is still processed as desired to provide the desired yield while conserving power and thus reducing costs.