In a gas conditioning tower hot flue gas with relatively high dust
loads is cooled by injecting water spray near the top. For
satisfactory operation wet particles should be kept off walls and
all water should have evaporated to yield a uniformly cooled flow
before it reaches the bottom of the tower. For practical reasons
and space limitations the gas often enters through an inlet pipe
making a 150-180° bend shortly before a short diffuser expanding
to full tower diameter (Fig. 1). A swirl generator is placed
immediately before the inlet to the diffuser to prevent
recirculation near walls of the diffuser where cooling water is
introduced and improve pressure recovery.Previous experimental
studies [1] with a short, axial inlet pipe have shown that the
distribution of axial flow could be improved considerably by
inserting a swirl generator at the inlet to the diffuser. This
gives strong back flow only in the central part of the diffuser.
But actual designs involve a number of different designs of the
inlet pipe, usually having a 150-180° sharp bend. The present
experimental study is aimed at determining the influence of the
inlet pipe design on the resulting flow in the upper part of the
tower. The study is carried out using LDA-measurements and flow
visualization in a 1:16 scale laboratory model. In addition, the
degree of mixing on injected water spray is simulated by
visualization studies to find the optimal position of injection
nozzles.
Number of pages | 23 |
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Publication status | Published - 1999 |
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