Abstract:
A gasifier and gasifier system based on the gasifier, which contains as a major component, a novel feed system for feeding organic materials into the burn pile of the gasifier. The gasifier feed system is a horizontal auger driven feed system that feeds directly through a ceramic elbow into the furnace without having to auger the feed through significant vertical elevations.

Description:
This application claims priority from U.S. Provisional Patent application ser. no. 60/937,309, filed Jun. 27, 2007. 
    
    
     The invention disclosed and claimed herein is a gasifier and gasifier system based on the gasifier, which contains as a major component, a novel feed system for feeding organic materials into the burn pile of the gasifier. 
     The invention is useful for gasifying solid organic materials and using such gasified products for conversion to thermal energy. 
     Materials that can be gasified using this invention include, among other materials, biomass materials, such as forestry and agricultural residues, industrial waste materials, such as saw mill pulp and paper products, hydrocarbon based products and plastics, and the like. 
     BACKGROUND OF THE INVENTION 
     It has been known in the art for a long time to use industrial and agricultural solid organic by-products, such as forestry an agricultural residue and the like, as potential sources of large amount of chemical energy. Such organic materials are frequently referred to as “biomass” materials. There is a large library of patents and other publications dealing with gasifiers (retorts) and associated systems for creating energy from biomass materials. 
     Patents dealing with such systems are for example, U.S. Pat. No. 4,971,599 that issued to Cordell on Nov. 20, 1990; U.S. Pat. No. 4,691,846 that issued to Cordell, et al. on Sep. 8, 1987; U.S. Pat. No. 4,593,629 that issued to Pedersen, et al. on Jun. 10, 1986; U.S. Pat. No. 4,430,948 that issued to Schafer, et al. on Feb. 14, 1984; U.S. Pat. No. 4,321,877 that issued to Schmidt, et al. on Mar. 30, 1982; U.S. Pat. No. 4,312,278 that issued to Smith, et al. on Jan. 26, 1982; U.S. Pat. No. 4,184,436 that issued to Palm, et al. on Jan. 22, 1980, and U.S. Pat. No. 5,138,957 that issued to Morey, et al. on Aug. 18, 1992. 
     However, none of these patents deal with a horizontal auger system to deliver feed material to a discharge elbow that discharges directly to a burn pile in the gasifier. The prior art deals with vertical auger units and most of them deal with a double vertical auger system. The disadvantage to the use of vertical augers is that the inside vertical auger cannot be repaired while the system is on-line, and they have a tendency to burn up at the tip when dry fuels are fired, or when there is an upset in the system. This problem has been completely eliminated by the use of a single, horizontal auger firing into a ceramic discharge elbow for discharging directly into the burn pile. 
     The gasifier of the instant invention is less costly to build and operate, easier to maintain, has fewer moving parts and contains nearly 100% ceramic internals to prevent warping and contortion of metal parts that are used in the prior art devices. 
     SUMMARY OF THE INVENTION 
     In accordance with the present invention, there is provided a low cost to build, low cost to operate, easier to maintain, and relatively simple gasifier and system. The gasifier is used in a gasification system to provide recovery of energy from feed stock of forestry and agricultural residues, such as industrial waste materials such a pulp and paper products, hydrocarbon based products, such as plastic and the like, by gasification of such materials with the inventive gasifier and employment of the inventive system disclosed herein. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a full side view of a gasifier of this invention. 
         FIG. 2  is a partial cross sectional side view of a portion of the gasifier of  FIG. 1 , through line  2 - 2  of  FIG. 4 . 
         FIG. 3  is a cross sectional view of a portion of the gasifier of  FIG. 1 , through line  3 - 3  of  FIG. 4 . 
         FIG. 4  is a full top view of a gasifier system of this invention. 
     
    
    
     THE INVENTION 
     Thus, in more detail, there is an improved gasifier system for pyrolizing organic material, the gasifier system comprising a gasifier having a cylindrical housing. The cylindrical housing has a steel sidewall and the sidewall is completely lined with a refractory material. The sidewall has a top and a bottom. 
     The top of the sidewall is closed and sealed with a monolithic dome, the dome comprising a steel-walled hemi-elliptical section. The hemi-elliptical section comprises a height to diameter ratio of at least 1 to 2 and the dome has a top and is completely lined with a refractory material. The dome has a syngas exit duct centered at the top and the bottom of the sidewall is fixed to a furnace bed. 
     There is a refractory lined ash removal system comprised of an air-locked ash removal auger, an ash lift conveyer and, an enclosed ash dumpster. 
     There is a refractory lined combustion system comprised of a tuyere plenum, a segmented ceramic combustion hearth contained in a refractory lined hopper, a tuyere manifold, a plurality of tuyeres leading from the tuyere manifold through the tuyere plenum to a burn pile area. 
     There is a retractable, all-ceramic lance ignition burner projecting from the outside of the tuyere plenum and through the tuyere plenum and into the segmented ceramic combustion hearth and above the burn pile area. 
     There is a refractory lined upper housing comprising the burn pile area and a feed system for feeding organic materials to the burn pile area. The feed system comprises a hopper for organic material, a conveyor for conveying organic materials to the feed hopper, and a horizontal auger contained in an auger housing for conveying organic material through a ceramic discharge elbow and into the burn pile area. 
     The auger housing connects the hopper and the discharge ceramic elbow, and the auger housing has a control valve associated with it to control air flow through the auger housing. 
     There is an air cooling system for the ceramic elbow and auger housing, and the air cooling system comprises an electrical fan and an air feed system, the air feed system comprising an air feed duct housed in a refractory lined housing. 
     The upper housing of the upper segment contains a burn pile height detector. 
     In addition to that Supra, there is contemplated within the scope of this invention to use a grate over the air-locked ash removal auger. Preferably this grate is a ceramic grate, and most especially, the ceramic grate is an oscillating ceramic grate system. 
     One of the major features of this invention is the gasifier feed system which is a horizontal auger driven feed system that feeds directly into the bottom without having to auger the feed through significant vertical elevations. 
     DETAILED DESCRIPTION OF THE INVENTION 
     Turning now to  FIG. 1  wherein there is shown a full front view of a gasifier system  1  of this invention showing a refractory lined combustion chamber  2  having a cylindrical housing  29  wherein the cylindrical housing has sidewalls  30  ( FIG. 2 ) that are completely lined with a refractory material  27  ( FIG. 2 ), a feed hopper  3 , a litter feed conveyor  24 , a tuyere air manifold  4 , an oscillating ceramic grate  5 , an ash auger  6 , an ash lift conveyor  7 , an enclosed ash dumpster  8 , a tuyere plenum  9 , a lance ignition burner  10 , a combustion air fan  11 , a feed tube  12  ( FIG. 4 ), a feed tube housing  13  ( FIG. 4 ), a pile control detector  14 , a syngas exit duct  15 , and a control valve  16 . The cylindrical housing  29  has a top  31  and a bottom  32 , the top  31  being surmounted by a monolithic dome  33  having the syngas exit duct  15  mounted thereon (See  FIG. 1 ). 
     The dome  33  has a hemi-elliptical section comprising a height to diameter ratio of at least 1 to 2 and the dome  33  is also completely lined with a refractory material (not shown). 
       FIG. 4  is a full top view of the gasifier system  1  of this invention wherein like numbers indicate like components, and  FIG. 2  is a full cross sectional view through lines  2 - 2  of  FIG. 4 . 
     The bottom  32  of the sidewall  30  of the cylindrical housing  29  of the combustion chamber  2  is fixed to a furnace bed, generally  34 , the furnace bed  34  comprises an upper segment  35 , a middle segment  36 , and a lower segment  37 . 
     As shown in  FIG. 4 , the lower segment  37  is a refractory lined ash removal system comprising an air-locked ash removal auger  6  and an ash auger housing  17  for the ash auger  6  and a flange  18  that permits the retention and removal of the auger  6  from the ash auger housing for replacement or repair, an ash lift conveyer  7 , and an enclosed ash dumpster  8 . 
     In  FIG. 2 , there is shown the components of the middle segment  36  which shows a fixed ceramic hearth  19  constructed of replaceable segments and a plurality of oscillating ceramic ash removal plates  20  located above the fixed ceramic hearth  19 . Situated above the oscillating ceramic ash removal plates  20  is the tuyere plenum  9  having side wall  21 , wherein there is located the retractable ignition burner  10 . Multiple tuyeres  23  are inserted through the side walls  21  and lead to a burn pile area, generally  40  in  FIGS. 2 and 3  and the tuyeres  23  are fed air or other gas from the tuyere manifold  4  located on the outside of the furnace  34 . The tuyeres  23  can be changeable inside diameter tuyeres and can be zoned, manifolded or single plenum, as shown herein, to inject air or flue gas into the tuyere plenum  9  as required by pulsing, steady or varying flow of the burning mass described infra. 
     The housing for the tuyere plenum  9  the burning chamber  22  is constructed of insulated wear/temperature lining  26 , retained with stainless steel alloy “Y” anchors as shown at  25  and is line with insulated fire brick lining  27 . It should be noted in  FIG. 2  that the combustion chamber  2  is constructed such that there is built into the walls thereof, a stabilizing reflective arch  28 . In addition, there is a retractable, all-ceramic lance ignition burner  10  projecting from the outside of the tuyere plenum  9  and through the tuyere plenum  9  and into the segmented ceramic combustion hearth and above the burn pile area  40 . 
     The novelty and essence of this invention is the delivery system for the burnable biomass material  41 . The upper segment  35  comprises a refractory lined upper housing  42  containing the burn pile area  40 . The upper housing  42  of the upper segment  35  contains a burn pile height detector  14 . 
     The feed system  43 , generally, comprises a system for feeding organic materials (biomass, litter, etc.) to the burn pile area  40 . The system comprises a hopper  3  for the biomass material  41 , a biomass material conveyor  24  for conveying the biomass  41  to the feed hopper  3 , an auger system  38  comprising a horizontal auger  44  contained in an auger housing  39 . 
     The auger housing  39  terminates inside of the furnace  34  in a ceramic feed elbow  45  that is directed upwardly from the terminal end of the auger housing  39  and allows the biomass material  41  to overflow and descend to the burn pile area  40 . The horizontal feed system  43  is possible because of the ceramic elbow  45 . It should be noted that the ceramic elbow  45  is preferred to be wider at the top  46  than at the bottom  47  to enhance the flow of biomass material  41  through the ceramic elbow  45 . 
       FIG. 3  also shows the accumulation of ash  48  and the general distillates  49  that are generated by the burning pile of biomass material  41 . 
     As can be observed from  FIG. 1 , in addition to the tuyeres  23 , air is introduced into the furnace  34  through a duct  50  using an auxiliary fan  11  to enhance the burning activity in the furnace  34 . This provide for an air cooling system for the ceramic elbow  45  and auger housing  39 . This system is comprised of an electrical fan and an air feed system that is integrated and controlled by the gasifier.