From fine powder to coarse wood chips: Vyncke converts all kinds of waste into green energy. No two plants are alike, but they all have one component in common: the feed bunker that stores the material just before it enters the fire source. Control & automation engineer Stijn Denoulet: “Controlling the level in the feed bunker is crucial for uniform incineration, but we did not yet have a solution that worked with all types of fuel. With the SITRANS LR580 radar meter, we found one.”
Turning waste into energy
South West Flanders, 1920s. Blacksmith Louis Vyncke repairs boilers that provide steam for energy-intensive flax processing. Why not burn flax waste to make steam, instead of expensive coal, he wonders. In this way, we do not have to dispose of waste and we will need less, if any, coal. A century later, Vyncke is a thriving multinational with the same core business: making green energy from production waste.
“From small pellets to large pieces of bulky waste: we have mastered the art of incineration,” explains Stijn. “That does involve some expertise. You want the material to be fully burned out, emissions to meet local standards and, most importantly, the plant to remain available. An incinerator gets a hard time. We design them to require as little intervention as possible.”
“Every machine is bespoke. We can supply just the incineration plant, but also build them turnkey: from fuel preparation to turbine.”
Bunker ensures uniform incineration
“One component is the same everywhere: the feed bunker. This is a buffer between the silo where the fuel is stored and the fire source. It captures differences in flow rate so that the flow remains even. In high silos, gravity causes the material to be more compact at the bottom than at the top.
“We like to keep the bunker about half full. It should obviously not overflow, but neither should it empty out completely, as the material seals the air between the silo and the fire source. Measuring the level of the bunker is a challenge because we incinerate so many different materials. Dust makes light measurement difficult. Sticky or coarse material rules out capacitive gauges and vibrating forks, as something can get stuck there. And most radars fail because the bunker is very small: between one and three metres wide and high, and only half a metre deep. That creates ‘noise’ due to reflections that we could not filter out until now.”
“Finding a separate solution for each material is prohibitive. That takes too much engineering time. Until now, we worked with microwave barriers in 90% of cases. This usually goes well, but does not give much information. We placed three under each other, leaving us with only three information points: empty, exactly half-full and full. Ideally, you should have an analogue signal for more precise information. For the remaining 10% - sticky substances, which can stick to the eye of the barrier - we still had to look for an alternative.”
One solution for all circumstances
“For our Danish customer AAK, we did a retrofit with the new radar meter SITRANS LR580. AAK makes SHEA oil, with the residual product being a fine powder. Again, we had used three microwave barriers, supplemented by a laser meter. But that laser often failed because of the large amount of dust. The machine continued to work, but we had no control over the level and operators had to intervene daily because the laser was giving error messages. Not ideal for a basically unmanned plant. The retrofit went smoothly: the LR580 worked immediately on factory settings, we did tweaks via the Bluetooth connection.”
About Vyncke
Vyncke (Harelbeke) builds biomass plants that convert production waste into green energy on site. From simple incineration plants to complete factories, every project is tailor-made. The group employs some 500 people in ten locations worldwide.
