A dual fluidized beds system essentially comprises of two fluidized bed reactors coupled
together with a provision of gas or materials transfer in between. It may be a combination of
circulating-circulating or bubbling-circulating or bubbling-bubbling type systems. A noble
application is in a gasification process for coal or biomass where nitrogen of air is not
allowed to dilute the product gas.
The final article in this section presents a modification to the Green’s function
approach for modeling acoustic pressure, where the use of conformal mapping is
replaced by a group of bound vortices. The author shows that the approach is readily
extended to three dimensions. The method is discussed in the context of aircraft noise.
The dual fluidized beds experimental set up is made of transparent perspex material. The
system consists of a fast bed riser, a cyclone to separate the solids, a down comer with a L-
valve, a bubbling fluidized bed and a return pipe with another L-valve. The system is
shown schematically in Fig 1. The solids after passing through the fast bed riser gets
separated in the cyclone, descend downwards through the down comer and enter the
bubbling bed reactor through the L-valve. A part of bed materials in the bubbling bed
system are then transferred back into the...
In this section, the hydrodynamics of a dual fluidized beds has been discussed using the
almost similar system as described in (Loffler et al. 2003; Kaiser et al., 2003) except the
mechanism for the solids transfer between the vessels. Loop seal device has been used in the
studies described in (Loffler et al. 2003; Kaiser et al., 2003). In the current study, two L-
valves, in place of loop seals, have been installed between the coupled reactors. The L-valves
absorb a part of pressure that is built up due to static head of solids in the downcomer.
Depending upon the pressure...
The energy demand for the endothermic
gasification reaction is met by the combustion of residual char in the fast bed combustor.
The circulating bed materials act as heat carrier between the two fluidized beds and
maintain the required temperature in gasifier. Therefore, the hydrodynamics of such a dual
fluidized beds system needs to be thoroughly understood for successful design and
operation of the system for industrial application.
With the amazing advances of scientific research, Hydrodynamics - Theory and Application presents the engineering applications of hydrodynamics from many countries around the world. A wide range of topics are covered in this book, including the theoretical, experimental, and numerical investigations on various subjects related to hydrodynamic problems. The book consists of twelve chapters, each of which is edited separately and deals with a specific topic. The book is intended to be a useful reference to the readers who are working in this field....