When damp fly ash adheres to the inner wall of a rotary drum, production downtime and labour-intensive cleaning operations are only a matter of time. This was the challenge faced by Waste Overall Solutions S.A. Through close development collaboration between the Greek waste management specialist and singold gerätetechnik gmbh, a simple yet highly innovative solution was created: a pneumatic singold QJ 80 Distance Knocker mounted on a movable carriage, enabling it to access virtually the entire length of the rotating drum.
The challenge
What begins as a thin layer gradually builds up with every revolution of the drum. Damp fly ash adheres to the inner wall of a rotary drum specially modified for this application, eventually forming stubborn deposits. These deposits restrict material flow and make regular cleaning essential.
Waste Overall Solutions wanted to address this issue using a pneumatic knocker from singold. However, because the build-up occurred along the entire length of the drum, a conventional arrangement with permanently mounted knockers offered only limited effectiveness. A completely new approach was therefore required.
A singold distance knocker provided an ideal basis for the solution. As it’s not mounted directly onto the vessel, it offered the flexibility to target different areas of the drum as required – a key prerequisite for the overall system design.
Working together to develop the optimum solution
From the earliest planning stages, singold worked closely with Waste Overall Solutions to design the application. Together, the partners identified the optimum operating positions for the dis-tance knocker, coordinated the compressed air supply and provided guidance on the most effective installation method.
In addition, singold recommended determining the most effective impact points through practi-cal testing on the drum itself, as every drum exhibits its own unique vibration characteristics. Throughout the design phase, close technical collaboration continued. singold answered de-tailed engineering questions, advised on installation orientation, supported the mechanical de-sign and assisted the customer right through to commissioning.
An innovative design
With technical support from singold, Waste Overall Solutions developed an exceptional solution. Instead of installing several fixed distance knockers along the drum, the company designed a movable carriage. A pneumatic QJ 80 knocker was mounted on this carriage, which travels along two curved guide rails following the contour of the drum.
An electrically powered cable winch positions the knocker precisely where deposits need to be removed. The result is a cost-effective alternative to installing multiple permanently mounted knockers.
The carriage, weighing approximately 80 kilograms, also absorbs the reaction forces generated by the distance knocker. This enables a single QJ 80 to cover almost the entire length of the drum.
Proven performance
The solution demonstrated its effectiveness during the initial commissioning tests. Waste Overall Solutions described the impact performance of the distance knocker as both powerful and highly precise.
An initial installation error was quickly rectified with the prompt support of singold and its Greek distribution partner, Vraykos, allowing the system to enter reliable operation without delay.
The successful test phase confirmed the effectiveness of the jointly developed concept. Waste Overall Solutions is highly satisfied with the solution and sees considerable potential for further applications using singold knockers.
More than a standard solution
This project demonstrates how standard products can be adapted to highly specialised applications through creative engineering. The key to success was not only the distance knocker itself, but also the close collaboration between Waste Overall Solutions, the Greek distribution partner Vraykos and the engineers at singold.
The result is an application in which a single movable QJ 80 can reach virtually the entire rotary drum, providing an impressive example of the versatility of pneumatic distance knockers well beyond traditional silo applications.