Dewatering Reject from Food Waste With RUNI Screw Compactor

When household food waste is refined into biopulp for anaerobic digestion, the remaining plastic and other non-organic reject can contain a large amount of water. This makes the reject heavy and costly to transport, dispose of, or send to incineration.

A RUNI screw compactor efficiently dewaters the reject, reducing its weight while recovering additional organic material for biopulp production. Depending on the material mix, the RUNI can typically achieve 50–65% dry matter, sometimes even higher.

Recover More Biopulp and Reduce Reject Weight

During the refining of food waste, water is often added to separate organic material from plastic, packaging, and other non-organic materials. The resulting reject can therefore contain significant amounts of liquid and valuable organic material.

The RUNI screw compactor presses liquid and remaining organic material out of the reject. This returns additional biopulp to the process while leaving a considerably drier reject for disposal or incineration.

The result is:

Up to 55% reduction in reject weight
50–65% dry matter, depending on the material mix
More organic material recovered for biopulp production
Lower costs for transportation and disposal
Efficient dewatering with low energy consumption

Reliable Dewatering for Anaerobic Digestion Plants

Anaerobic digestion plants operate around the clock, and reject from food waste can contain abrasive materials such as sand, small pieces of metal, and other contaminants. This places high demands on the equipment handling the reject stream.

The RUNI SK370 is designed for continuous 24/7 operation and has proven to be a strong and reliable solution for dewatering reject from food waste and other organic waste processing.

The SK370 can process approximately 2,000–5,000 kg of reject per hour, depending on the material and setup, and is suitable for plants with a continuous need for dewatering.

For plants with a lower or more occasional need for dewatering, the RUNI SK240 offers a smaller alternative.

A Food Waste Compactor Designed for Your Process

We know that every food waste processing line is different. With our modular design we can customize the screw compactor and associated equipment to match the required capacity, material composition, feeding system, and available space.

For reject containing a high proportion of organic food waste, we can supply a specially developed screw designed to improve dewatering and recover more organic material.

The machines can also be integrated with different conveyor and feeding solutions.

We also offer solutions for handling Tetra Pak, cans, PET bottles, and other food containers directly, allowing these materials to bypass the de-packer where appropriate.

Efficient Food Waste Recycling

By removing water from the reject and recovering additional organic material, a RUNI food waste compactor can help optimize the overall food waste recycling process.

The dewatered reject is significantly lighter and contains less liquid, reducing the amount of material that needs to be transported and disposed of. At the same time, the recovered organic material can be returned to the biopulp stream and used for anaerobic digestion.

This means that the RUNI solution can help reduce reject costs while maximizing the recovery of biomass from food waste.