System and Method for Waste Incineration

Abstract

Systems and methods for incinerating waste solids are disclosed. A fluidized bed of solid particles is provided at an elevated temperature in a reactor. The waste stream, comprising the waste solids and water, is passed onto the fluidized bed of solid particles. The fluidized bed of solid particles has a sufficiently elevated temperature to vaporize substantially all of the water into an offgas stream. The waste solids are mixed among the bed of solid particles. Sufficient heat and oxygen are provided to incinerate the waste solids.

What is claimed is: 
     
         1 . A method for incinerating waste solids comprising:
 providing a fluidized bed of solid particles at an elevated temperature in a reactor;   passing the waste stream, comprising the waste solids and water, onto the fluidized bed of solid particles, wherein the fluidized bed of solid particles has a sufficiently elevated temperature to vaporize substantially all of the water into an offgas stream;   mixing the waste solids among the fluidized bed of solid particles; and   providing sufficient heat and oxygen to incinerate the waste solids.   
     
     
         2 . The invention of  claim 1 , wherein more than 50 wt % of the water in the waste stream is vaporized. 
     
     
         3 . The invention of  claim 1 , wherein fuel is added to the waste stream to assist in incineration of the waste solids. 
     
     
         4 . The invention of  claim 1 , wherein mixing the waste solids among the fluidized bed of solid particles provides sufficient fluidizing pressure to prevent downflow of any liquid content remaining entrained with the waste solids. 
     
     
         5 . The invention of  claim 1 , wherein incinerating the waste solids produces particulates that entrain in the offgas stream. 
     
     
         6 . The invention of  claim 5 , wherein the offgas stream and the particulates are passed through a particulate filter, the particulate filter trapping the entrained particulates. 
     
     
         7 . The invention of  claim 6 , further comprising incinerating the particulates on the particulate filter. 
     
     
         8 . The invention of  claim 1 , wherein the fluidized bed of solid particles are selected from the group consisting of ceramic balls, steel balls, stainless-steel balls, rocks, and combinations thereof. 
     
     
         9 . The invention of  claim 1 , further comprising preheating the waste stream before the waste stream is passed onto the fluidized bed of solid particles such that the waste stream is at a boiling point of the water. 
     
     
         10 . The invention of  claim 1 , further comprising sizing the waste solids to fines before the waste stream is passed onto the fluidized bed such that the waste stream is passed onto the bed of solid particles through a spray nozzle. 
     
     
         11 . The invention of  claim 1 , wherein the waste stream further comprises urea. 
     
     
         12 . The invention of  claim 1 , wherein the waste solids are selected from the group consisting of fecal matter, paper products, hygiene products, and combinations thereof. 
     
     
         13 . A system for incinerating waste solids comprising:
 a fluidized bed reactor comprising a fluidized bed of solid particles at an elevated temperature;   an inlet configured to pass the waste stream, comprising the waste solids and water, onto the bed of solid particles, wherein the fluidized bed of solid particles has a sufficiently elevated temperature to vaporize substantially all of the water into an offgas stream;   the fluidized bed reactor further configured to mix the waste solids among the fluidized bed of solid particles and to provide heat and oxygen to incinerate the blackwater solids.   
     
     
         14 . The invention of  claim 13 , wherein more than 50 wt % of the water in the waste stream is vaporized. 
     
     
         15 . The invention of  claim 13 , wherein the fluidized bed reactor is further configured to mix the waste solids and the fluidized bed of solid particles with sufficient fluidizing pressure to prevent downflow of any liquid content remaining entrained with the waste solids. 
     
     
         16 . The invention of  claim 13 , wherein incinerating the waste solids produces particulates that entrain in the offgas stream. 
     
     
         17 . The invention of  claim 16 , further comprising a particulate filter configured to have the offgas stream and the particulates pass through and trap the entrained particulates. 
     
     
         18 . The invention of  claim 13 , further comprising a preheater configured to preheat the waste stream before the waste stream is passed onto the fluidized bed such that the waste stream is at a boiling point of the water. 
     
     
         19 . The invention of  claim 18 , wherein the preheater is further configured to receive heat from the offgas stream for part of preheating the waste stream. 
     
     
         20 . A waste treatment system for a recreational vehicle, comprising the system of  claim 13 .