Understanding Industrial Liquid Filtration: A Comparison of Three Type Filters
Industrial processes often involve liquid filtration to remove impurities and contaminants. The choice of filter depends on the specific requirements of the application, including the size and type of particles to be removed, flow rate, and pressure drop. In this blog post, we’ll delve into three common polypropylene filters used in industrial liquid filtration: nominal string wound filters, meltblown filters, and pleated absolute filters.
Nominal String Wound Filters
- Construction: These filters consist of a core wrapped with layers of wound polypropylene string (yarn).
- Filtration Mechanism: Particles are captured within the depth of the filter media, making them suitable for removing larger particles.
- Efficiency: Nominal filters are rated by their nominal micron rating, indicating the approximate size of particles they can remove.
- Applications: Ideal for coarse filtration, removing large particles, wide range of particle sizes, effective for jelly/sticky particles and suspended solids.
Meltblown/Spunbonded Filters
- Construction: Meltblown/Spunbonded filters are produced by extruding molten polypropylene fibers, bonded together to create a web of randomly oriented fibers.
- Filtration Mechanism: The dense fiber structure provides a high surface area for capturing smaller particles.
- Efficiency: Meltblown filters offer higher efficiency than nominal filters, capable of removing finer particles.
- Applications: Commonly used for pre-filtration and fine filtration, removing particles in the micron range. Mainly water application
Pleated Absolute Filters
- Construction: Pleated absolute filters consist of multiple layers of pleated polypropylene media.
- Filtration Mechanism: Particles are captured on the surface of the filter media, providing high efficiency and low pressure drop (due to the large filtration area..
- Efficiency: Absolute filters are rated by their absolute micron rating, indicating the smallest size of particles they can reliably remove.
- Applications: Used for final filtration, removing very fine particles and ensuring high-purity liquid. Very effective for removal of similar size particles.
Key Differences Summarized
| Feature | Nominal String Wound | Meltblown/Spunbonded | Pleated Absolute |
| Construction | Wound polypropylene string | Extruded polypropylene fibers | Pleated polypropylene media |
| Filtration Mechanism | Depth filtration | Surface filtration | Surface filtration |
| Efficiency | Nominal micron rating | Higher efficiency than normal | Absolut micron rating |
| Applications | Coarse filtration | Pre-filtration and fine filtration | Final filtration |
Choosing the Right Filter
The selection of the appropriate filter depends on several factors:
- Particle size and type: The size and nature of the particles to be removed will determine the required filter efficiency.
- Flow rate: The desired flow rate will influence the filter’s capacity and pressure drop.
- Pressure drop: The allowable pressure drop across the filter will affect the overall system performance.
- Cost: The initial cost and ongoing maintenance costs of the filter should be considered.
By carefully considering these factors, you can select the most suitable filter for your specific industrial application.
Dutch Filtration manufacturers the different types of cartridges in The Netherlands. Check with our specialists the best suitable elements for your process or replacements for other makes.
