Industrial filter fabrics for cement and bulk solids conveying

Application

Cement & Bulk Solids

Air slide fabrics, fluidisation textiles, and conveying media for cement plants, alumina refineries, and powder handling. Controlled air permeability for reliable, energy-efficient material transport.

The Challenge

Cement plants and bulk solids operations rely on gravity-assisted pneumatic conveying to transport powders like cement clinker, raw meal, fly ash, and alumina. Air slide systems use a permeable fabric membrane to distribute low-pressure air evenly beneath the material, creating a fluidised layer that flows by gravity along an inclined trough.

The fabric is the critical component: it must provide precisely controlled air permeability, withstand temperatures up to 220°C, resist abrasion from sharp mineral particles, and maintain consistent performance over years of continuous operation. Poor fabric selection leads to uneven fluidisation, material blockages, excessive air consumption, and costly downtime.

Typical Applications

Cement clinker and raw meal conveying

Fly ash transport in power stations

Alumina powder handling (Bayer process)

Soda ash and sodium bicarbonate transport

Calcium carbonate and limestone powder conveying

Flour and food powder fluidisation

Chemical powder and granulate handling

Silo aeration and discharge assistance

Key Fabric Requirements

Air slide and conveying fabrics must meet strict performance parameters to ensure reliable material flow.

Controlled Air Permeability

Precisely engineered airflow rates (typically 3–10 m³/m²/min at 20 mbar) ensure uniform fluidisation across the entire slide length without channelling or dead zones.

Temperature Resistance

Cement and alumina processes involve hot materials up to 220°C. Fabrics must maintain dimensional stability and permeability at elevated temperatures without degradation.

Abrasion Resistance

Cement clinker and mineral particles are highly abrasive. High-tenacity polyester and aramid constructions provide extended service life in demanding environments.

Consistent Permeability

Uniform air distribution requires consistent permeability across the entire fabric. Tight manufacturing tolerances ensure even fluidisation and prevent material flow problems.

Anti-Static Properties

Powder conveying generates electrostatic charge. Antistatic treatments and conductive fibres prevent spark ignition — critical for ATEX zones in cement and chemical plants.

Long Service Life

Air slides run continuously. Premium fabrics maintain their air permeability for 5–10 years, minimising maintenance stops and replacement costs.

How Air Slide Conveying Works

Understanding the principle helps select the right fabric for your application.

Air Supply

Low-pressure air (10–50 mbar) is fed into the lower chamber of the air slide trough beneath the permeable fabric membrane.

Fluidisation

Air passes through the fabric uniformly, aerating the powder above. The material becomes a pseudo-fluid that flows by gravity along the inclined trough.

Gravity Transport

The fluidised material slides smoothly along the trough at 2–5° inclination — no moving parts, low energy, minimal wear. The fabric controls the entire process.