TECHNICAL PREPARATION 9
Pre-heater Cyclones
For pre-heater cyclone sizing and design, the specific
requirement given to all suppliers were:
- 350 mmwg pressure at fan inlet on guaranteed
output: To reduce the PH fan specific power
consumption as low as possible, 350 mmwg was
the minimum PH fan inlet guaranteed draft as yet.
There was a lot of reluctance on this parameter as,
due to this, suppliers had to increase their cyclone
size and they had doubts on material dropping due
to lower velocity profile in PH cyclones and risers.
We discussed and convinced all suppliers along with
their principals that, normally plants were operated
with lower pressure drop and velocity during start
up, and no material drop was observed. Finally,
they agreed and offered the required parameter and
sizing accordingly. - Pre-heater cyclone efficiencies: To get the benefit
of reduction in dust loss and reduction in PH exit
temperature due to better heat transfer.
We have given the requirement of 95% cyclone
efficiency for all cyclones however KHD and LNVT
have offered increment in their cyclone efficiencies
whereas FLSmidth and TKIL have offered us their
standard efficiency cyclones but also assured that
their principals are working on it and in the R&D
stage.