Tubular Membrane for High Viscosity & High Solid Content Feed Treatment

Many industrial production lines generate raw materials containing suspended particles, mycelium, fiber residues or viscous colloids. Conventional hollow fiber and spiral wound membranes have narrow flow channels, which are prone to rapid blockage when processing such feeds, leading to frequent shutdown and short service life. Centrifuges can achieve solid-liquid separation, yet they cannot remove dissolved macromolecular impurities and consume high energy.

Tubular membrane modules are specially developed for difficult-to-filter materials. The feed flows inside the membrane tubes under cross-flow mode. The unique open channel design minimizes particle deposition, making tubular membrane widely accepted in bio-fermentation, animal extract, pigment purification and high-concentration slurry clarification.

Structure & Working Principle

A tubular membrane system consists of pressure vessels, multiple membrane tubes, feed pump, circulation tank and control cabinet. The membrane layer is coated on the inner wall of supporting tubes. Under cross-flow pressure, clear permeate passes radially through the membrane wall, while concentrated retentate carrying solids circulates back to the feed tank.

Cross-flow creates high shear force along the inner membrane surface. This continuous scouring prevents solid cake from building up. Unlike dead-end filtration where solids stack quickly on the filter surface, cross-flow tubular filtration maintains stable flux even at high solid concentration. Membrane materials include ceramic and polymeric options, matching different temperature and chemical resistance requirements.

Comparison with Other Membrane Types

• Hollow fiber membrane: Small lumen, easy clogging; suitable for low-solid, low-turbidity liquid.

• Spiral wound membrane: Narrow spacer channel; not recommended for feed with large particles.

• Tubular membrane: Large inner channel, strong anti-blocking capacity; suitable for high solids, viscous, particle-rich feed.

Key Advantages of Tubular Membrane System

1. Excellent tolerance to high solids and viscous feed. Large diameter channels avoid particle blockage and reduce unplanned downtime.

2. Flexible material selection. Ceramic tubular membranes resist high temperature, strong acid and alkali; polymeric tubular membranes provide cost-effective solutions.

3. Simple cleaning operation. Surface cake layer can be removed efficiently by CIP cleaning. Severe fouling can be recovered through chemical soaking.

4. Modular design. Users can expand the processing capacity by adding membrane tubes according to production demand.

5. Easy observation and maintenance. Individual damaged tubes can be replaced separately instead of changing the whole module, lowering replacement cost.

Operation & Fouling Mitigation

Transmembrane pressure, cross-flow velocity and feed temperature are three critical parameters. Higher cross-flow velocity enhances surface shear and reduces fouling, but increases energy consumption. Operators need to balance flux and power cost.

Regular CIP cleaning schedule is required. Alkali cleaning removes organic pollutants and protein residues, while acid cleaning eliminates inorganic scaling. Real-time monitoring of TMP and permeate flux helps operators judge membrane condition and trigger cleaning before irreversible fouling occurs.

Typical Industrial Applications

• Fermentation broth clarification: Separate mycelium from antibiotics, enzyme and amino acid fermentation liquid.

• Animal & plant extract purification: Remove suspended residues from bone peptide, fish protein and botanical extracts.

• Natural pigment separation: Clarify pigment stock solution with particles and colloids.

• Wastewater containing heavy sludge: Pre-treatment of high-solids industrial wastewater before subsequent membrane processes.

Conclusion

Tubular membrane fills the market gap for tough high-solid separation scenarios. Its outstanding anti-clogging performance and flexible material options make it a reliable choice when other membrane types fail. Combined with standardized CIP protocols, tubular membrane systems deliver stable continuous production and reduce overall operational expenditure for manufacturers dealing with complex raw liquids.