Aalborg Portland in Aalborg, Denmark, has been using solid recovered fuel (SRF) for many years. The SRF is burnt in the pre-calciner on a grey cement kiln line. Substitution rates have grown over the years and are currently at approximately 45%. Around 65,000t/yr of its alternative fuel is baled and wrapped SRF, which mostly arrives via sea directly into the plant. To overcome some operational issues, Aalborg Portland recently purchased a new bale-opener from fellow Danish firm ReTec Miljø ApS.
Aalborg Portland, part of the Cementir group, had been experiencing challenges with opening SRF bales that had been leading to problems further down the fuel preparation process. The earlier method used a ‘robotic machine’ to cut up the bale and remove the wrapping by way of an arm. However, for various reasons, this solution was not optimal and the operator frequently had to open bales individually using a front-end loader. This was leading to knock-on effects later in the fuel preparation process.
In the autumn of 2016, Aalborg Portland contacted ReTec, which demonstrated its bale-opener to the company. The result was an immediate improvement over the previous arrangement. The bales are now ripped open by the bale-opener’s ripperdrum, a simple and reliable mechanical operation. The SRF produced is very loose and emerges in a consistent, continuous flow. This has enabled significant improvement downstream, for example in screening steps. The bale-opener can handle any shape or size of bale. The capacity of the plant to handle baled SRF has almost doubled to 40t/hr and, to date, there have been no issues with reliability. Good fuel quality and reliable operation has resulted in satisfaction from plant employees and a good return on investment.
