Dalmia DSP Success Story
TECHNICAL PREPARATION 19
- Maximum grinding pressure to be designed:
Having higher margins on grinding pressure enables
mill to have sufficient margins for future potentials
- Lesser pressure drop across nozzle ring and mill
casing: As pressure drop is directly proportional to fan
power consumption, we had observed that FLSmidth
offered maximum pressure drop across mill. Thereby,
we had a detailed discussion with FLSmidth and their
principals to modify their mill internals and casing
design so that their pressure drop across mill was
reduced. FLSmidth R&D changed the design of mill
casing to reduce the pressure drop across mill from
880 mmwg to 800 mmwg resulting in reduction of
specific power consumption of mill fan by 0.49 kWh/t
on material of Atox mill
- Maximum nozzle ring area: The nozzle ring area
plays an important role in mill internal design as
it drives the lifting of material inside the mill with
certain velocity and pressure. If the nozzle ring area
is increased, it provides better potential for the mill.
During evaluation of offers we noticed that Pfeiffer
had offered minimum nozzle ring area and after
several discussions with their principals we convinced
them and accordingly they increased their nozzle ring
area from 4.9 m^2 to 7.3 m^2
- One size bigger classifier than standard size for
the offered mill: We have observed in recent past
that for any upgradation in VRM, suppliers offer a
bigger size classifier saying that it shall enhance the
