Page 294 - Biomass Gasification, Pyrolysis And Torrefaction Practical Design and Theory
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270                          Biomass Gasification, Pyrolysis and Torrefaction


                                 Fuel             Gas to pilot burner
                                                  Oxygen
                             Burner


                      Pressure
                     water outlet


                      Cooling screen




                         Pressure
                        water inlet
                        Quench
                        water
                                                        Cooling jacket


                                                         Gas outlet


                                                         Water
                                                        overflow






                                             Granulated slag

            FIGURE 8.16 A schematic of a top-fed downflow entrained-flow gasifier.

            Figure 8.16, and (ii) the side-fed upflow (used by Koppers-Totzek, the
            Shell gasification process, Prenflo, and the Lurgi multipurpose), shown in
            Figure 8.17.


            8.4.1 Top-Fed Gasifier

            Top-fed gasifiers use a vertically cylindrical reactor vessel into which pul-
            verized fuel (biomass or coal) and gasifying agent(s) are conveyed by oxy-
            gen and injected from the top. This vessel resembles a vertical furnace with
            a downward burner (Figure 8.16). The fuel and the gasifying agent(s) are
            injected into the reactor through a jet that generally sits at the reactor’s mid-
            dle section.
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