Did you ever wonder how that deep brown crust is created on pretzels and bagels? There’s just a little more to it than toasting them under a burner.
A process engineer from a well-known bagel company contacted me about a problem in their operation. They were having issues containing the lye solution in a dip tank that the bagels are run through. Lye, also known as sodium hydroxide, is a very corrosive, alkali substance. When handling this liquid solution, personnel protection equipment (PPE) is required to protect skin and eyes. The engineer found evidence of the lye solution dripping from the conveyor onto other components in the process. For safety, maintenance and cleanliness, he needed to find a way to contain the lye in the dip tank area.
The conveying system used a gear-driven sprocket to move the conveyor. The conveyor was a 30” wide open-mesh belt with chain links attached to the outside for the sprocket. It was used to move the bagel dough into a dipping station which contained the lye solution. As you can imagine, there are plenty of areas for the solution to collect into these voids of the belt and drip downstream. The dough would soak up the solution and then travel into the oven for baking. As the dough is heated, the lye will start to react with the steam and bagel proteins, turning it into something safe to eat. This Maillard reaction creates the browning of the dough and that yummy crust on the outside.
To keep the process safe and clean, they had to keep the lye solution in the dipping area. Because the concentration of the lye was very low, we recommended a stainless steel Super Air Knife. (EXAIR offers a variety of materials for different types of chemicals) The engineer ordered model 110030SS Super Air Knife, mounted it above the conveyor, and aimed it in a counter-flow direction to the conveyor travel. As the belt exited the solution, the Super Air Knife would blow the excess from the mesh and the links back into the dip tank. This kept the area clean and safe from the caustic solution.
If you have similar processes with caustic or corrosive chemicals that need to be contained, we would be glad to discuss your application and determine which of our products would be helpful to keep your processes, personnel and facility safe.