1. Type of Application
▪ Water & Wastewater Treatment:
Typical slot size: 0.25 mm-1.0 mm.
Prevents sand, grit, and suspended solids while maintaining high flow.
▪ Ion Exchange & Resin Systems:
Typical slot size: 0.2 mm-0.5 mm.
Prevents resin beads from escaping into downstream piping.
▪ Food & Beverage Processing:
Slot size depends on the product (juice clarification may require 0.1 mm-0.3 mm).
▪ Mining & Industrial Dewatering:
Coarse slot sizes, 1.5 mm-3.0 mm, for fast drainage of slurry and solids.
2. Particle Size Distribution
Always analyze the particle size distribution of your process stream.
The general rule: Select a slot size slightly smaller than the minimum particle size you want to retain.
Example: If particles below 0.5 mm must be removed, choose a 0.3 mm-0.4 mm slot size.
3. Flow Rate and Open Area
▪ Smaller slots = better filtration, but lower flow capacity.
▪ Larger slots = higher flow, but risk of media loss.
Engineers often balance slot size vs open area depending on pump capacity and system requirements.
4. Material and Corrosion Resistance
▪ SS304: General water treatment applications.
▪ SS316L: Corrosive or seawater environments.
▪ Special alloys (Hastelloy, Duplex): High-temperature or chemical processing.
Different alloys may allow finer slot sizes without risk of deformation.
5. Industry Standards and Customization
Many industries follow ASTM or ISO filtration standards.
Manufacturers can also customize slot sizes based on:
▪ Pressure drop requirements
▪ Filtration efficiency targets
▪ Cleaning or backwash methods
