Designing a 30 Ton-Per-Hour (TPH) Municipal Solid Waste (MSW) pretreatment line requires precise machinery sequencing. Incorrect equipment placement leads to severe screen blinding, material wrapping, and lost recovery of high-value recyclables.

A common question among EPC contractors and facility designers is: Should the bag opener be placed before or after the primary trommel screen?

Why Bag Openers Are Often Installed Before Trommel Screening

For many MSW sorting lines that receive bagged household waste, the bag opener is typically installed upstream of the trommel screen. Opening the bags first allows the contents to become more accessible for subsequent size classification.

However, the final equipment sequence should be confirmed according to incoming waste characteristics, process objectives and the selected machinery configuration.

Engineering Reasons for Placing Bag Opener First:

1. Screen Blinding Prevention: Unopened plastic bags roll along the interior of a trommel screen drum without discharging their contents. This causes “trampolining,” where unbagged organic waste passes straight through the drum without being screened.
2. Particle Size Liberation: Ripping bags open at Stage 1 liberates these items so the trommel screen can fractionate them by size.
3. Optimized Trommel Loading: Opening bags homogenizes the material bed depth entering the trommel drum, maintaining uniform rotation balance.

Recommended Equipment Sequence for a 30 TPH Line

For equipment models and technical specifications, explore our Industrial Waste Bag Opener Machine and Bag Breaker.

To examine full plant spatial layouts and 3D line configurations, explore our complete waste sorting machine production line engineering solutions.