CRJ Trommel Screen and Picking Station team up for compost processing.

Our customer is a leading provider of waste management and resource recovery solutions. They operate facilities across the UK and Ireland and manage a wide range of hazardous and non-hazardous waste streams. With sustainability at the forefront of their operation, they aim to reduce the impact of waste on the environment by turning waste into valuable products for manufacturing or energy conversion.

Their state-of-the-art facility is one of the UK’s largest organic waste recovery sites. They process both combined garden and food waste and pure green waste to produce high-grade compost certified to British Standard PAS100.

To produce PAS100 compost, our customer uses an in-vessel composting system. This 12-week process includes the screening of the organic waste to remove the fine particles. The remaining material is then processed through a picking station to remove contaminants that are non-compostable, such as plastic bags, plastic bottles, and food wrappers.

CRJ Services has been supporting this customer with the hire of a Doppstadt SM518 trommel screen and Kiverco PS122 picking station to complete this stage of their composting process. The SM518 is fitted with a 40mm drum to remove the fine fraction. The oversize material is then fed directly onto the picking station, where operators pick out the impurities and separate them into various 40-yard skips located below the station.

All CRJ’s picking stations are enclosed and come with lighting, heating, and electrical sockets for operators’ comfort. They also come equipped with a variable speed belt that can be adjusted to suit the application and assist with optimal separation. In addition, an emergency stop cord runs along the length of the station to ensure operators can stop the equipment in case of an emergency.

As the remaining material leaves the picking station, it passes under an overband magnet which removes any ferrous metals, leaving a clean organic material that is sent to a high-speed shredder to be shred down to a 40mm product, ready for loading into a vessel.

The IVC (in-vessel composting) speeds up the natural composting process by introducing airflow through the bottom of the vessel and extracting it through pipes in the roof. Heat is generated naturally, killing harmful bacteria and allowing the material to break down to produce compost. Then, at timed intervals, the compost is moved to another vessel, and the process is repeated.

Once complete, the compost is moved to the maturation area and placed into ‘windrows’. The ‘windrows’ are turned regularly to aerate the compost and ensure the heat is evenly spread through the material. Once this 6-8 week process is complete, the material is ready to be screened into 20mm and 10mm compost.