Combustion material process and related apparatus

Abstract

The present invention relates to a process ( 1 ) for the combustion of materials (X), comprising the steps of: (a) inserting the preferably compacted materials (X) in a reaction chamber ( 3 ) and closing the chamber ( 3 ); (b) injecting a flow of combustible gas and a corresponding flow of a comburent gas, which are in the correct stoichiometric ratio to each other, into the reaction chamber ( 3 ), so as to activate combustion of the materials (X); (c) continuing the thermochemical reaction of the oxidizable elements, for example carbon, with the oxygen present, without introducing any more gases; (d) injecting comburent gas to feed the thermochemical reactions of the oxidizable elements present in the materials (X), until the increase in temperature stops; (e) opening a throttle valve ( 5 ) to expel the gases, while continuing to introduce comburent gas at a substantially constant pressure until all remaining carbon has been oxidized, the strongly bound oxides have been subjected to pyrolysis and the metals present have been oxidized.

1 . A process for the combustion of materials (X), comprising at least the steps of:
 inserting the materials (X) in a reaction chamber ( 3 ) and closing the chamber ( 3 );   injecting into the chamber ( 3 ) a flow of a combustible gas and a corresponding flow of a comburent gas in the relative stoichiometric ratio, until the combustion of the materials is activated;   the process ( 1 ) being characterised in that it comprises at least the step of:   continuing the thermochemical reaction of the oxidizable elements present in the materials (X) with the oxygen contained in the materials (X), at least until the increase in temperature stops.   
     
     
         2 . The process according to  claim 1 , characterised in that the continuation of the thermochemical reaction occurs without the introduction of gases from the outside. 
     
     
         3 . The process according to  claim 1  or  2 , characterised in that it comprises the further step of:
 again injecting a comburent gas to feed the thermochemical reaction of the oxidizable elements present in the materials (X), at least until the increase in temperature stops. 
 
     
     
         4 . The process according to  claim 3 , characterised in that it comprises the further step of:
 opening a throttle valve ( 5 ) to expel the gases from the chamber ( 3 ), while continuing to inject comburent gas to complete the thermochemical reaction of the oxidizable elements.   
     
     
         5 . The process according to  claim 4 , characterised in that opening the throttle valve ( 5 ) and continuing injection of the comburent gas take place at a substantially constant pressure. 
     
     
         6 . The process according to  claim 4 , characterised in that the step of opening the throttle valve ( 5 ) continues until the pressure inside the reaction chamber ( 3 ) is equal to the atmospheric pressure. 
     
     
         7 . The process according to  claim 4 , characterised in that it comprises the further step of:
 expelling the gases into the outside environment.   
     
     
         8 . The process according to  claim 7 , characterised in that the gases are expelled into the outside environment through a first stage of storage in a container ( 6 ) and a second stage of passing through a fume scrubbing device ( 22 ). 
     
     
         9 . The process according to  claim 8 , characterised in that the fume scrubbing device ( 22 ) comprises a copper-based catalyst ( 23 ), designed to interact with the fumes, so as to avoid the introduction of hydrogen and carbon monoxide molecules into the environment. 
     
     
         10 . The process according to  claim 9 , characterised in that carbon dioxide without halogenated compounds comes out of the fume scrubbing device ( 22 ). 
     
     
         11 . The process according to  claim 8 , characterised in that, from storage in the container ( 6 ), gradual cooling causes the fractional deposition of oxidized metals in powdery form at corresponding collection compartments ( 7 ). 
     
     
         12 . An apparatus for the combustion of materials (X), comprising a reaction chamber ( 3 ), having an inlet ( 8 ) for the insertion of materials (X), an outlet ( 4 ) through which the gases can flow out and circuits ( 9 ) for introducing reagent gases, the apparatus ( 2 ) being characterised in that the comburent gas oxygen enrichment fraction (F), expressed as a percentage, the apparatus ( 2 ) maximum operating pressure (P), expressed in bars, the reaction chamber ( 3 ) free internal volume (V), expressed in cubic metres, the mass (M) of materials (X) inserted in the reaction chamber ( 3 ), expressed in tons, and the maximum temperature (T) reached in at least one portion of the reaction chamber ( 3 ), expressed in Kelvins, are linked according to the formula
     FPV/M≧ 5.24×10 −2 ×( T   2 −314.73 ×T )
   
     
     
         13 . The apparatus according to  claim 11 , characterised in that it comprises a sealed, hollow outer shell ( 10 ) and an inner casing ( 11 ), matching the shell ( 10 ) cavity, made of refractory material, there being a space ( 12 ) interposed between the shell ( 10 ) and the casing ( 11 ). 
     
     
         14 . The apparatus according to  claim 13 , characterised in that the space ( 12 ) comprises an inlet channel ( 13 ) and an outlet channel ( 14 ) for the passage of coolant fluid. 
     
     
         15 . The apparatus according to  claim 14 , characterised in that it comprises sensors ( 15 ) and respective valve units, housed in the outlet channel ( 14 ), designed to check the pressure of the coolant fluid in the space ( 12 ), for keeping it at values substantially equal to those of the pressure (P) inside the reaction chamber ( 3 ). 
     
     
         16 . The apparatus according to  claim 12 , characterised in that the circuits ( 9 ) for introducing reagent gases comprise nozzles ( 16 ,  17 ) respectively intended to introduce combustible fluid and comburent fluid into the reaction chamber ( 3 ), according to suitable stoichiometric ratios for adjusting and controlling combustion in the reaction chamber ( 3 ). 
     
     
         17 . The apparatus according to  claim 12  or  13 , characterised in that the outlet ( 4 ) through which the gases can flow out is intercepted by a throttle valve ( 5 ) substantially consisting of a plug ( 18 ) shaped to match a respective hole ( 19 ) in the inner casing ( 11 ) made of refractory material, the hole ( 19 ) communicating with the reaction chamber ( 3 ), the plug ( 18 ) being forced to block the hole ( 19 ) by means of a pusher ( 20 ) with controlled and adjustable action. 
     
     
         18 . The apparatus according to  claim 13 , characterised in that the shell ( 10 ) consists of a plurality of shell portions which can be connected to each other, the disassembly of the shell portions allowing extraction of the inner casing ( 11 ) made of refractory material for its substitution and maintenance. 
     
     
         19 . The apparatus according to  claim 12 , characterised in that the inlet ( 8 ) for inserting the materials (X) houses a lid ( 21 ) made of refractory material having a shape and dimensions matching those of the inlet ( 8 ). 
     
     
         20 . The process and apparatus according to  claim 1  or  12 , characterised in that the combustible fluid is methane or another gaseous fuel. 
     
     
         21 . The process and apparatus according to  claim 1  or  12 , characterised in that the comburent fluid comprises gaseous oxygen.