- ESP Fan shall be designed with AQC Boiler and its ducting pressure drop.
- AQC Boiler dust conveying philosophy shall be finalized along with cement
engineering. - AQC Boiler MCC shall be accommodated with cement Cooler MCC.
- Hot Air Recirculation system shall be designed with 100% Recirculation air and the
cooler connected fans shall be selected with 150 Dec.C Mechanical temperature. - Cooler shall be designed for minimum Clinker temperature with HAR as per
Clinker conveying system. - Sufficient space for erection machinery movement.
1.7 Basic Plant Design Concept – Process & Mechanical Design:
- AQC Boiler shall be designed to utilize maximum heat available from Cooler hot
air gases after due consideration of secondary & tertiary heat requirement and
Cement mill drying heat requirement. - Dual tapping designed for AQC Boiler inlet heat and their key advantages are:
- Segregation of higher-grade heat by suitable tapping in cooler body to generate
higher steam temperature - Higher HP steam generation with respect LP generation helps to enhance the
Power Generation. - Lowering the LP steam generation, reduced loading on condenser
- Bare final Super heater tubes and lesser fins density (2 FPI) in Primary SH modules
for better reliability. - Inbuilt de-duster arrangement to avoid dust carry over into Boiler system.
- Lower flue gas velocity design envisaged in ducting (12 m/sec) and in Boiler (6
m/sec) for lower pressure drop and better reliability. - Pressure drop across (tapping to tapping) the system is limited to 100 mmwc.
- Lesser steam temperature & pressure drop design from Boiler outlet to Turbine
inlet. - LP steam system design envisaged to extract maximum lower grade heat
available. - MOC: -T 11 & P11 grade tubes & pipes for steam temperature more than 420 Deg C
- High sealing efficiency & superior grade MOC (99.9% for GD with SS 310/SA 516)
- Calcium silicate insulation of steam piping (Amb+15 Deg C skin temperature)
- Refractory in AQC inlet duct, Deduster & hopper without external insulation
(Amb+20 Deg C) for lesser temperature drop and better reliability.
1.8 Basic Plant Design Concept – Reliability
- Sacrificing Tubes and angles considered in AQC De-duster, to increase Pressure
Part life.