RWE Generation's Eemshaven power plant is the largest coal and biomass power plant in the Netherlands. Covered conveyor belts ensure dust-free transport of the coal from ships to the power plant or the storage yard. This process was always accompanied by jerks and jolts due to frequent belt mis-tracking. The constant downtime of the conveyor belts caused delays in supply and additional costs. RWE consulted TBK Group, after which it was decided to install our CenTrax tracker rollers for a trial period. Within a month, it was already clear that CenTrax was the solution to their mis-tracking problem.
Gert-Jan Arkema, Maintenance Engineer Bulk Handling at RWE Generation Eemshaven, explains “We use several conveyor belts at our power plant. We use a hopper to transfer the coal from one conveyor to another, but coal from the US and Russia is often damp, which means it sticks to the walls of the hopper. As a result, the load is then skewed when it reaches the conveyor belt, resulting in mis-tracking.
Solid and robust
Alex Budding, our account manager at TBK Spillage Control adds: “It soon became clear that RWE were looking for a solid and robust system. The previous system used by RWE did not meet this requirement. In September last year, we installed a CenTrax type SO-1200 under the RWE ROECA11 conveyor. The swivel bearing of the CenTrax tracking system is robust and rotates extremely smoothly. Furthermore, the swivel bearing is fitted with ball bearings and an angular contact bearing, in order to properly absorb the axial and radial forces. Arkema is extremely satisfied with this, “TBK has shown that they were able to help with enthusiasm and professionalism. The trial tracker rollers were installed free of charge. The trials were positive, the tracker rollers simply proved their worth. Our response was ‘This is exactly what we need!’.”
Optimal contact between roller and conveyor
The CenTrax system is a multi roller tracker system, consisting of a central roller and a tapered tracker roller on both sides. The robust rollers are lined with 8 mm of extremely wear-resistant rubber. The rubber vulcanisation process is carried out in an autoclave. This creates a permanent and seamless bond between the rubber and the steel roller shell. The rubber has a diamond profile, to ensures optimal contact between roller and conveyor. Even when the conveyor belt is wet, as in the case of RWE, where a wet conveyor belt is the result of damp coal.
51 CenTrax tracking systems
The combination of roller lining and swivel bearing, means the CenTrax belt tracker system has no equal. “This became clear within a month of the trials, and so I was allowed to immediately arrange the installation of 51 CenTrax tracker systems”, Budding says proudly. “As standard, we always perform a strength calculation for the CenTrax construction, a ‘finite element method’, which is what we did on the tracker rollers for RWE.”Arkema confirms that “Coal is a heavy load for conveyor belts, but in the case of the residual gypsum and bottom ash products, a smaller and lighter version is sufficient. We have had CenTrax installed on almost all our conveyors!”
Arkema: “Previously, we had to stop the conveyors several times a day. We would stop everything to carry out a thorough clean. Sometimes that would cost us a total of a half day in delays and costs. Now, a stop only occurs when a ship is empty or when the belt has run for a certain time and requires cleaning. Our downtime frequency is currently many times lower, resulting in huge cost savings. Reports of mistracking have dropped from 250 times per month to only 3 times per month. The investment soon pays for itself.”
“Complete shut-down of the power plant was not an option, so several sessions were planned to install everything. The entire project took about 3 working weeks, including installation”, Budding explains. Arkema is very satisfied with the collaboration “Agreements were always kept, and if any hiccups occurred, TBK would not think in terms of problems, but in terms of solutions. My experience of the collaboration with TBK is extremely positive.”
About Eemshaven power plant
In 2015, RWE commissioned a new 1,560 megawatt capacity state-of-the-art coal-fired power plant in Eemshaven, Groningen. In the coming years, this new power plant will play an important role in Netherland's energy supply. This is why the Dutch government, over ten years ago, designated the Maasvlakte and the area around Eemshaven as locations for new power plants. This was partly because of the proximity of a port for the supply of fuel, and the availability of sufficient cooling water. As from the second half of 2019, 15% of coal at the Eemshaven power plant will be replaced by sustainable biomass in the form of wood pellets. The replacement of coal by sustainable biomass is an important mainstay in achieving the national target of 14% renewable energy generation in the Netherlands by 2020, as stipulated in the 2013 Energy Agreement (Energieakkoord).