- Low-pressure economizer
Each heating surface has a hammering dust removal device and dust will be collected
in two hoppers. Collected dust will be conveyed through drag chain conveyor to
existing raw mill silo.
1.10 Basic Plant Design Concept - Layout
- Vertical type boiler to accommodate in the available space
- PH Boiler in line with down comer duct to minimize the duct length and pressure
drop. - PH Boiler civil design to be integrated with Cement Pre-Heater Building Design.
- PH Fan shall be designed with PH Boiler and its ducting pressure drop.
- PH Boiler dust conveying philosophy shall be finalized along with cement
engineering. - PH Boiler MCC shall be accommodated with cement PH MCC.
- Sufficient space for maintenance.
1.11 Basic Plant Design Concept – Process & Mechanical Design/ Energy Savings
- PH Boiler shall be designed to utilize maximum heat available from PH down comer
gases after due consideration of Raw mill / Coal mill drying heat requirement. - Configuration depends on number of PH fans/strings, in case of common boiler
for 2 PH fans, Booster fan will be required to cater the additional pressure drop
across the PH Boiler. - Ensure minimum temperature drop /false air ingressment in upstream &
downstream of PH Boiler duct thus increasing the net heat availability across
boiler. - LP steam system design envisaged to extract maximum lower grade heat
available. - Adequate thickness selection for casing & duct with stiffeners citing higher
negative pressure system. - High sealing efficiency Inclined / Oval Multilouver Damper in PH Bypass duct to
avoid dust accumulation and ease of operation. - Lower approach and pinch temperature design to maximize steam generation
with higher heat transfer area provision - All modules are of bare and seamless tube selection with hammering system for
effective dust dislodging and reliable steam generation. - Pressure drop across (tapping to tapping) the system is limited to 100 mmwc
- Double RAV in conveying system to avoid false air ingressment.
- Lower flue gas velocity design envisaged in Ducting (12 m/sec) and in Boiler
(6m/sec) for lower pressure drop and better reliability.