Short overview on the jetting-fountain fluidized bed (JFFB) combustor

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• 作者：Farouk M. Okasha ; ^{faroukok@gmail.com" class="auth_mail" title="E-mail the corresponding author} ; ^{faroukok@mans.edu.eg" class="auth_mail" title="E-mail the corresponding author}
• 关键词：Fluidized bed ; Co-combustion ; Jet ; Gaseous fuels ; Biomass
• 刊名：Renewable and Sustainable Energy Reviews
• 出版年：2016
• 出版时间：March 2016
• 年：2016
• 卷：55
• 期：Complete
• 页码：674-686
• 全文大小：2040 K

文摘

The jetting-fountain fluidized bed (JFFB) is a novel configuration for fluidized bed. It is basically a bubbling fluidized bed equipped with a spouted jet in the upper part of the bed. A part of gases is fed through the distributor to fluidize bed solids while the remaining part is fed through a vertical pipe creating a jet-fountain zone. A distinct feature of JFFB different from previous spouted bed configurations is that the jet spout height is independent of the bed height. This feature makes the design more flexible and the flow regimes more extendable. The JFFB is characterized by excellent gas–solids contact that is expected to result in high heat and mass transfer both in bed and freeboard zones.

The experiments carried out using the JFFB furnish promising results. The power consumption in delivering gases into the combustor was found much lower. It confirms a rapid reliable method for initial heating of fluidized bed combustor. The JFFB enables gaseous fuels to burn smoothly like a normal premixed flame avoiding acoustic effects and explosions due to volume combustion in the bubble phase. Applying the JFFB dampens greatly the overheating in the freeboard, in particular, at lower bed temperatures. A useful feature of the jetting-fountain fluidized bed configuration is the option to apply staged-air technique in combustion processes. Staged-air combustion has been applied for gaseous and biomass fuels. The performance of the combustor has been found much better when compared with conventional operation.