Dusseldorf headquartered GEA is helping food manufacturers improve productivity and reduce maintenance costs by retrofitting the ring dryers used in vital wheat gluten production. It is upgrading the ring dryers with GEA Certex – ATEX-certified explosion vent doors and newly designed casing sections for the disintegrators made from highly wear-resistant material. The doors provide safe venting if there is an explosion within the dryer. They are also resistant to deformation caused by heat, pressure fluctuations, or vibration, which avoids the costly and time-consuming process of replacing safety panels following an incident. The upgrade is suitable for operators of starch flash dryers working with wheat, corn, potato, tapioca, and other starch sources, as well as operators producing vital wheat gluten as a by-product.
GEA recently upgraded the ring dryers at BioWanze, Belgium’s largest producer of bioethanol, which it manufactures from wheat. The plant produces around 350 liters of renewable fuel and 75 kg of vital gluten per ton of wheat. The valuable co-products from this process are primarily used to make high-quality animal feeds and fertilizer.
When the plant opened in 2008, GEA supplied two very large ring dryers for drying the wheat gluten – a plant-based protein – extracted from the process. Ring dryers are a special type of pneumatic/flash dryer with the addition of a centrifugal classifier (manifold) and a fixed beater hammer mill (disintegrator) to provide selective recycling and screen-less grinding of material. These lower drying temperatures as well as improving both efficiency and product quality.
Retrofitted GEA Certex explosion vent doors
The original dryers were protected by safety bursting panels to provide a fail-safe release in the event of an explosion within the dryer. At the time, this was the only type of explosion protection that had been given ATEX type approval. However, this type of safety panel is inherently susceptible to failure caused by heat and pressure distortion or vibration, resulting in the dryer needing to be shut down for repairs. When BioWanze upgraded the dryers by increasing airflow and capacity in 2017, failure frequency increased.
During a planned two-week maintenance shutdown in March 2020, GEA replaced the panels with new GEA Certex explosion vent doors. These are not vulnerable to deformation caused by heat or pressure fluctuations or to vibration. If a door is activated, it does not need to be replaced but can be reset using a relatively simple sacrificial tab. Since fitting the Certex explosion vent doors, BioWanze has had no further incidents of vent failure, allowing production to continue unhindered. This has significantly reduced downtime and maintenance costs. The new doors are now fitted as standard on all GEA ring dryers.
Disintegrator casing upgrade
BioWanze faced another challenge. Wheat gluten is very abrasive, especially when wet. This was causing extreme wear on the casing of the disintegrator used to mill the wheat gluten at the inlets of the BioWanze dryers. The casing is made from very thick mild steel which, after only a few years’ use, had worn very thin and had to be patched by the plant engineers. This wear was reducing efficiency.
To solve the problem, GEA worked closely with plant engineers at BioWanze to redesign the casing sections for the disintegrators using highly wear-resistant material and, where the casing is in contact with moisture, duplex stainless steel that is both abrasion- and corrosion-resistant. The casings were also replaced with the new design during the maintenance shutdown in March 2020. The reduction in wear means that the critical tolerance between the tip of the blades and the casing can be maintained. This ensures that the product is ground correctly. The upgrade has also reduced maintenance costs and unplanned stoppages.
Now available for all GEA ring dryers that operate with highly abrasive products, this simple upgrade is today fitted as standard on all new GEA wheat gluten disintegrators. In addition to installing the latest technologies into new plants, GEA is also keen to further modernize existing plants in order to generate maximum efficiency and sustainability for customers.