Ensuring Continuity with a Temporary Bypass
Because the plant operates continuously, sludge handling could not be interrupted during construction. Jansen&Heuning therefore designed a temporary facility that became operational in April 2024. Two shaftless screw conveyors, directly connected to the filter presses via new collection hoppers, ensured reliable transfer of the sludge cake. This setup enabled two trailers to be loaded simultaneously while the old installation was dismantled. The bypass allowed a safe transition to the new situation without loss of capacity and will remain available as an emergency backup system.
The Permanent Installation
In the second phase, carried out between May and September 2024, the permanent transfer station was built. Four filter presses discharge into collection hoppers from which several screw conveyors transport the material to silos and a belt conveyor. The silos are elevated to save ground space and to enable direct loading of trailers from above. Beneath the silos, a completely new weighbridge has been integrated into a weighbridge hall with stair tower and platforms. This setup not only accelerates the logistics process but also ensures highly accurate truck loading.
An important part of the installation is the extraction system with filters. It reduces emissions and prevents odour nuisances in the surrounding area. Combined with the closed conveying lines, this system contributes to a safe and hygienic working environment.
Technical Focus: Mechanical Conveying
The choice for shaftless screw conveyors is decisive for the performance of the installation. Sludge cake is difficult to transport with conventional systems because of its variable, viscous texture. Shaftless conveyors eliminate the risk of clogging around a central shaft and therefore guarantee a continuous, reliable flow with less maintenance.
In addition, a conveyor belt is used for horizontal transfer inside the weighbridge hall. Where screw conveyors handle vertical or inclined conveying, the belt conveyor ensures reliable horizontal transport. Together these systems form an integrated conveying chain in which each component fulfils its specific function.
The silos are the core of the transfer facility. By using vertical storage and discharging directly into trailers, the flow of logistics is streamlined. The weighbridge underneath allows trucks to be both loaded and weighed in one operation, which reduces the number of transport movements and increases efficiency.
Efficiency, Sustainability and Safety
The installation achieves an energy saving of around 30 % compared to the previous system. This is the result of optimized bulk flows, gravity-assisted conveying and the closed transport lines. The vertical arrangement with silos also yields significant space savings, allowing a more compact and efficient site layout.
Safety and environmental protection have also been improved. The closed conveying systems minimize direct exposure of operators to sludge cake, while the extraction unit with filters reduces emissions and controls odours. In addition, modular design made it possible to reuse parts of the old installation, supporting circularity and resource efficiency.
Collaboration and the Role of Jansen&Heuning
In this project, Jansen&Heuning acted as main contractor and integrator. We were responsible for the design, engineering, supply and installation of the complete system, working closely with Utibo (steel construction) and Batenburg (automation). Based on our long-standing expertise in bulk handling, we supplied the key components: the shaftless screw conveyors, the belt conveyor, the collection hoppers and the elevated silos with integrated weighbridge. By combining these into one seamless system, we delivered a technically advanced solution that fully meets the requirements of the waterboard.
Conclusion
The Garmerwolde project demonstrates how mechanical conveying solutions perform in practice under demanding conditions. By combining different conveying principles in one integrated facility, a robust and sustainable system has been created that provides both operational and ecological benefits. The sludge cake transfer station is a clear example of how Jansen&Heuning applies its bulk handling expertise to make complex material flows manageable and efficient.
