Gasifier feed system

Abstract

The present invention has been designed to provide a solution to problems with conventional gasifiers which operate by having fuel introduced at one end of a gasification retort and gas and residues removed from the other end. This frequently results in powdered char residues being ejected with the gas, causing increased gas clean-up requirements. The present invention provides a solution to this problem by removing the gas from the retort at the fuel inlet end via the fuel feed apparatus which is preferably a combined ram and scroll feed providing a supply of fuel under anaerobic conditions.

1 - 13 . (canceled) 
   
   
       14 . An apparatus in which gases produced anaerobically in a gasifier retort are extracted at the fuel inlet end of the retort in which char and residue extraction is effected at the opposite end of the retort from the fuel input end by a scroll and rotary valve mechanism to avoid egress of gas and ingress of air. 
   
   
       15 . An apparatus claimed in  claim 14  in which the gases produced in the gasifier retort are extracted via the fuel feeder. 
   
   
       16 . An apparatus as claimed in  claim 14  or  claim 15  in which the fuel feed or feeds are cooled before discharge into the gasifier retort by means of one or more water jackets. 
   
   
       17 . An apparatus as claimed in  claim 16  in which the gaseous products of the gasification process are cooled at discharge from the gasifier retort by means of one or more water jackets. 
   
   
       18 . An apparatus as claimed in  claim 16  or  claim 17  with provision for oils and/or tars to be fed into the gasifier retort via one or more tubes extending into the retort. 
   
   
       19 . An apparatus as claimed in  claim 18  in which oils and/or tars are fed into the gasifier retort via a tube or tubes forming the core of a fuel feed scroll. 
   
   
       20 . An apparatus as claimed in  claim 18  or  claim 19  in which the oils and tars are produced in the gasification process.