Filters are used in a variety of industrial applications to remove contaminants from liquids and gases. Two common types of filter media are filter cloths and filter plates. Meanwhile, filter cloths and plates are two commonly used filter media for removing particles from liquids and gases. They differ in material – cloths being made of woven or non-woven fibers while plates are perforated metal sheets. Both offer advantages depending on the filtration application and operating conditions. Let’s explore how they work and their uses.
What Are Filter Cloths?
Filter cloths are permeable woven or non-woven textile media used in various filter elements. They come in endless rolls or pre-cut sheets and are made from synthetic or natural fibers.
Woven filter cloths are made by interlacing warp and weft threads on a loom. They offer:
- Higher strength
- Better dirt holding capacity
- Longer service life
Non-woven filter cloths are made by bonding fibers together using mechanical, chemical or thermal methods. They offer:
- Excellent filtration efficiency
- Higher porosity
- Lower cost
Some common filter cloth materials are:
- Polypropylene – Offers good chemical resistance and strength.
- Nylon – Has high mechanical strength and abrasion resistance.
- Polyester – Provides good balance of properties at moderate cost.
- Glass – Provides excellent chemical resistance but is more brittle.
- Cotton – Offers good particle retention, porosity and moisture absorption.
Filter cloths are used in:
- Bag filters – They form the filtering element of dust collection bags.
- Panel filters – Multiple sheets are pleated and supported in metal frames.
- Frame filters – Single sheets are clamped in a sealing frame.
- Cartridge filters – Wound around a perforated core or support tube.
- Gravity leaf filters – Laid horizontally in tanks for liquid filtration.
What Are Filter Plates?
Filter plates are perforated metal sheets that serve as the filtering element in various types of pressure filters. The perforations or holes in the plates retain particles over a certain size while allowing the filtrate to pass.
Filter plates from filter plate manufacturer are commonly made of:
- Stainless steel – Offers corrosion resistance and high temperature compatibility.
- Monel – Provides chemical resistance and strength at high temperatures.
- Fabric-reinforced rubber – Combination of rubber and fabric layers on metal sheets.
- Plastic – Allows single-use disposable filters for sensitive applications.
Filter plates are used in:
- Plate and frame filters – Multiple metal plates sealed between frames.
- Leaf filters – Single sheets laid horizontally in tanks.
- Shell and tube filters – Perforated cylindrical sleeves within a pressure vessel.
- Disk filters – Stack of circular metal disks sandwiched between end caps.