A Filter Press for Sludge Dewatering is an essential piece of equipment used in wastewater treatment, industrial applications, and environmental engineering to separate solids from liquids in sludge. Below is a detailed guide of the specifications and considerations for a filter press, including the equipment’s performance, design, materials, and features.
Material: Typically Polypropylene or Stainless Steel for corrosion resistance, especially for aggressive or chemically polluted sludges.
Plate Size: Common sizes range from 470 mm to 2000 mm. Typical sizes include:
800 x 800 mm
1000 x 1000 mm
1200 x 1200 mm
Larger plates generally have higher throughput.
Number of Plates: Can range from 10 to 120 plates depending on the size of the filter press and required capacity.
Small capacity: 10-30 plates.
Large capacity: 50-120 plates.
Filter Cloth: Usually polyester or polypropylene woven or non-woven fabric with a pore size from 5 microns to 100 microns.
Pressing System
Hydraulic or Mechanical Closure:
Hydraulic presses are the most common and can generate pressures between 6 to 16 bar (87 to 232 psi). Some models may operate up to 25 bar for high-pressure filtration.
Mechanical presses can also be used for lower pressure applications.
Hydraulic Pressure: The hydraulic press applies uniform pressure across all the filter plates, ensuring a better separation of solids from the liquid.
Typically 5 tons to 40 tons of pressure, depending on the system size.
Filter Plate Shifting Mechanism: Automatic or manual systems to separate the plates after each cycle, facilitating the removal of the solid cake.
Cake Thickness: Generally between 25 mm to 50 mm, but this can be adjusted based on the material and process requirements.
Sludge Flow and Capacity
Flow Rate: The flow rate of the sludge slurry entering the filter press, measured in m³/hr, is an important specification to determine the press size and number of plates.
Small capacity filter press: Around 1 to 5 m³/hr.
Medium capacity filter press: Around 5 to 30 m³/hr.
High capacity filter press: Can process up to 200 m³/hr or more.
Sludge Characteristics: The characteristics of the sludge (e.g., solid content, viscosity) significantly affect dewatering efficiency. Typical sludge solids concentration ranges from 1% to 5% before dewatering.
Filter Cake Moisture Content
The moisture content of the filter cake typically ranges from 20% to 40%, depending on the type of sludge, filter press settings, and operational parameters.
Higher moisture content can be reduced by adjusting cycle time, pressure, and adding chemical conditioning agents (e.g., flocculants or coagulants).
Feed System and Sludge Conditioning
Feed Pumps: High-pressure diaphragm pumps, screw pumps, or centrifugal pumps are used to introduce the sludge into the filter press.
Pump capacity varies based on the sludge flow and pressure required.
Typical pump pressures range from 2 bar to 6 bar.
Sludge Conditioning: A chemical dosing unit is used to add flocculants or coagulants to the sludge to improve flocculation and enhance dewatering efficiency. This is often essential for oily, sticky, or highly viscous sludge
