Investigations on Backflush Cleaning of Spent Grain-Contaminated Filter Cloths Using Continuous and Pulsed Jets

Area of Science:

• Food and Beverage Processing
• Filtration Technology
• Industrial Cleaning

Background:

• Woven fabrics are crucial filter media in the food and beverage industry, particularly in breweries for separating wort from spent grains.
• Incomplete removal of filter cake residues leads to reduced filter performance and increased cross-contamination risk.
• Developing efficient cleaning methods for these filter media is essential for maintaining product safety and operational efficiency.

Purpose of the Study:

• To investigate and compare the effectiveness of continuous and pulsed backflush cleaning for woven filter media used in mash filters.
• To develop a reproducible contamination method and residue analysis technique for assessing cleaning efficiency.
• To evaluate the fluid dynamical, procedural, and economic differences between pulsed and continuous backflushing.

Main Methods:

• A reproducible contamination method simulating mash filter use was developed.
• Microscopical image processing was employed for residue analysis to quantify cleaning efficiency.
• Two backflushing procedures (continuous and pulsed) were experimentally compared.

Main Results:

• Pulsed backflushing demonstrated higher cleaning efficiency, achieving cleanliness faster with reduced cleaning agents and time.
• Fluid flow conditions during backflushing were highly dependent on cloth geometry and mesh size.
• Larger mesh sizes significantly improved cleanability by allowing greater backflush volume penetration.

Conclusions:

• Pulsed backflush cleaning offers a more efficient and economical solution for mash filters compared to continuous methods.
• Optimizing cloth geometry and mesh size can enhance the cleanability of filter media.
• These findings enable the development of demand-oriented cleaning strategies for industrial filters.