Application and Considerations of Submerged Slurry Pumps in Power Plants

Submerged slurry pumps are specifically designed to handle slurries containing solid particles and are highly abrasive. They are widely used in scenarios requiring the lifting and transportation of slurry from pits, pools, and tanks.

1.Applications in Power PlantsSubmerged slurry pumps are critical components in thermal power plants, primarily handling abrasive and corrosive slurries generated during combustion processes. Key applications include:

1)Bottom Ash Handling:Used to pump bottom ash (coarse ash collected at the boiler’s bottom) mixed with water into slurry form. The pump transports this abrasive mixture to disposal sites or dewatering systems.

2)Fly Ash Slurry Systems:Fly ash (fine particulate captured from flue gases) is mixed with water to suppress dust. Submerged pumps transfer this slurry to storage ponds or recycling facilities.

3)Ash Pond Management:deployed in ash ponds to recirculate, mix, or transfer slurry to prevent settling and maintain pond stability.

4)Flue Gas Desulfurization (FGD) Systems:Used in some wet FGD systems to handle limestone slurry or gypsum mixtures, though materials must be compatible with corrosive chemistries.

2.Key Advantages for Power Plant Use

1)Leak-Free Operation:Eliminates seal failures and fluid leakage, crucial for handling environmentally regulated waste materials.

2)High Abrasion Resistance:Constructed with materials like high-chrome iron (27% Cr) to withstand prolonged exposure to abrasive ash particles.

3)Minimal Maintenance:No external sealing systems reduce maintenance complexity and costs.

4)Self-Priming Capability:Operates effectively in submerged conditions without manual priming.

3.Critical Considerations and Precautions

1)Material Selection:Abrasion Resistance: Use hardened alloys (e.g., high-chrome white iron) for components like impellers and liners.

Corrosion Resistance: For acidic slurries (e.g., fly ash with leached heavy metals), opt for duplex stainless steel or rubber-lined components.

2)Adequate Submergence:Ensure the pump remains fully submerged during operation to prevent vortex formation, air ingress, and cavitation. Insufficient submergence can lead to dry running and damage.

3)Clog Prevention:

Install intake screens or grates to block large debris (e.g., unburned coal chunks, solidified slag).

Use recessed impeller or vortex designs to handle solids without clogging.

4)Abrosion Management:

Design systems with easy access for component replacement (e.g., modular designs).

Monitor wear patterns regularly and maintain inventory of wear parts like impellers and liners.

5)Chemical Compatibility:

Test slurry pH and chemistry. Fly ash slurry can become corrosive due to leaching agents (e.g., sulfates, chlorides).

Avoid material mismatches (e.g., standard stainless steel may fail in chloride-rich environments).

6)Installation and Maintenance:

Ensure overhead crane access for pump extraction during maintenance.

For shaft-driven models, protect external seals with clean flush water to prevent grit ingress.

Automate monitoring of pump performance (e.g., flow rate, motor current) to detect blockages or wear early.