Methods and apparatus for use in cooling an injector tip

A gasification system comprising:

• a reactor vessel;
• and
• at least one feed injector extending generally longitudinally through said reactor vessel, said at least one feed injector comprises:
• an inlet;
• a tip end;
• a flow passage extending longitudinally through said feed injector from said inlet to said tip end, said flow passage defined by an outer wall and an inner wall, wherein said flow passage includes a flow change feature, and said inlet is proximate said flow change feature;
• an annular cooling channel substantially circumscribing said flow passage and including a first end and an opposing second end, wherein said first end is adjacent said inlet and proximate said flow change feature, and said second end is proximate said tip end, wherein said cooling channel is defined by at least one cooling channel wall;
• and
• a buffer region extending radially directly from said cooling channel wall to said outer wall of said flow passage such that said buffer region separates said annular cooling channel from said flow passage, said buffer region is substantially solid and extends axially between first and second ends of said cooling channel, said buffer region having a first width at said first end, said buffer region having a second width at said second end, said first width is wider than said second width.