Steam side boil outs of carbon fouled evaporators.
Evaporator cleanliness is crucial to the efficient operation of a sugar factory. Fouled evaporators can impact everything from beet end heat balance, pan boiling, byproduct drying, ect. Fouling of the juice sides of evaporators has been happening since sugar beets have been being processed. The composition of the scale on the juice side is commonly a form of calcium scale. The process for removing calcium scale is well established and proven, while the steam side is not something that is routinely done. Analysis of the steam side fouling showed >95% organics. This would require a different boil out chemistry than the proven solution for the metal scales. For this we decided to apply Hydri-Maize® CIP 3421, a peroxide-based solution, with caustic. When working with a peroxide solution safety needs to be well thought out. Peroxide will expand over 10x when applied to organic material and will be very exothermic. Having a place to go with the expanded material along with all the material that will be removed is very important. Hydri-Maize® CIP 3421 with caustic showed to be a very effective combination with evaporator efficiencies returning to design the following campaign.