This standard specifies the requirements for rotary drum vacuum filtration equipment used for de-watering sludge in water and wastewater treatment plants. It covers materials of construction, design and constructional features, performance requirements, and methods for testing the equipment.
Requirements for sludge de-watering equipment, Part 2: Vacuum filtration equipment
Quick Reference Values
Maximum bed width6 m
Typical bed length10 to 30 m
Total depth of sand layers200 to 300 mm
Total depth of gravel layers300 to 450 mm
Slope for underdrain pipes1 in 100 to 1 in 200
Freeboard above sand level400 to 500 mm
Key Formulas
Filter Yield (kg/m²/h) = (Weight of dry solids in cake per cycle in kg) / (Filter area in m² × Cycle time in hours)
Practical Notes
Proper grading and sourcing of sand and gravel as per the tables is crucial to prevent clogging and ensure long-term performance.
The 6m maximum width is a practical limit for manual removal of dried sludge; for mechanical removal, this can be adjusted.
Consider providing a roof over the beds in areas with high rainfall to improve drying efficiency and prevent washout.