Dry-Type Primary Off-Gas Cleaning for LD Converter Off-Gas
As the steel industry strives for cleaner production processes, the Dry Dedusting System (DDS) offers a state-of-the-art approach to manage LD converter (BOF) primary off-gas. This system ensures highly efficient gas cleaning, significantly reduces energy consumption, and maximizes plant availability, setting a new standard in environmental compliance and operational efficiency.
The Dry Dedusting System (DDS) for LD converters (BOF) is designed to reduce dust concentration in LD converter (BOF) off-gas before it is either recovered and sent to a gas holder for temporary storage or released in a controlled manner via the flare stack. The system includes a first-stage gas cooling process using either a hot water cooling stack or a steam cooling stack.
The cooling stack extracts heat from the LD converter (BOF) off-gas by transferring it to water or steam. This process lowers the gas temperature before it enters the evaporation cooler.
In the evaporation cooler, a contact cooling system, the LD converter (BOF) off-gas is further cooled to the required operating temperature through the injection of steam and water via specially designed dual-flow nozzles. Coarse dust is separated at the bottom of the evaporation cooler and collected in the evaporation cooler hopper. From there, it is transported to a storage silo via a mechanical or pneumatic coarse dust transport system.
The pre-treated gas is conveyed to the electrostatic precipitator, where fine dust is removed with high precision. The collected fine dust is stored in the electrostatic precipitator hoppers and transported to a storage silo via a mechanical fine dust transport system.
Downstream the electrostatic precipitator, the axial ID fan provides the necessary suction power and is essential for overall process control. Then, the gas is directed to the cup valve type switch-over station, where it can be sent either to the flare stack or the gas holder.
Benefits of Primary Dry Dedusting System (DDS) for LD Converters (BOF)
- Achieve superior dust emission control with minimal dust levels
- Recover thermal energy efficiently
- Eliminate water treatment compared to wet dedusting systems, reducing system complexity and costs
- Increase operational efficiency
- Future-proof operations with best-available techniques (BAT) compliance, meeting stringent environmental standards