13. Technical Comparison of Latest Generation Clinker Coolers
13.1 Function of Clinker Cooler
Clinker to be quenched i.e. rapid cooling by strong and efficient aeration of air so
that clinker temperature can be reduced from 1400 Deg C to around 600 Deg C in
recuperation zone only i.e. immediate after kiln discharge clinker in cooler.
Following are the benefits by rapid cooling (Quenching)
- To recuperate the useful heat, contain by hot clinker and take back as secondary
air and tertiary air temperature for efficient and complete fuel combustion in
kiln and PC. - Reducing the snowman and red river formation tendency.
- The clinker quality is improved for phase arresting.
- Reduction in heat losses by clinker and vent gases.
- Clinker coming out of the kiln had to be cooled to temperature at
which it could be handled economically by available conveying equipment like
pan, drag chain conveyors.
In order to achieve above cooling of clinker the combination of right air flow &
pressure, air velocity and air flow pattern is very important, there are two type
of air flow patterns used in latest generation coolers:
13.2 Horizontal Aeration
Horizontal air movement (Coanda effect) by around 40 m/sec velocity cools the
clinker bed co currently, which provides higher retention time for efficient heat
transfer, this not only recuperate the heat effectively but also avoid snowman and
red river problems. Coanda effect helps to segregate the fine and coarse clinker,
coarse at bottom and fines at top of the clinker bed, leads to extract more heat and
reduce pressure drop across the bed thus reducing the power. This principle is used
in IKN Coolers by IKN.
13.3 Vertical Aeration
Vertical air movement is used to cool the clinker bed, which provides comparatively
less retention time because air escapes rapidly from least resistance path, resulting
in lesser efficient cooling of clinker may create snowman and red river issues. This
principle is used in FLS cross bar coolers, Polytrack cooler by TKIL and Sino walk
cooler offered by M/s LNVT.
13.4 Specific Requirement for Cooler Sizing & Designing - Cooler Area - Cooler loading to be maximum 50 tpd/M2 at potential capacity
of 9500 TPD - Recuperation Efficiency - To be maximum for lower sp. Fuel consumption
- Zero Vent Gas Losses - After required recuperation air, mid tap 1 & 2 gases
as per WHR design whatever balance gases are remaining shall be taken
back into cooler by Hot air recirculation duct. So practically no vent gases are