comes as a powder or in an aqueous solution, and is generally the most economical chemical used for oxygen scavenging. The sulfite is very effective and reacts with the dissolved oxygen in the water according to the reaction shown in Equation (3), removing the oxygen from the system. With this chemical reaction, the sulfite attacks the oxygen at a ratio (dosage) of approximately 7.5 parts sulfite to 1 part oxygen. 2Na2SO3 + O2 → 2Na2SO4 (3) In this reaction, the sulfite and oxygen form a solid sodium sulfate product, which is carried through in the feedwater. The solid must be removed from the boiler water via the blowdown that is discharged from the boiler system as wastewater (Figure 4). Depending on the specific requirements of an application, this can be one of the drawbacks to using sodium sulfite - this end product adds to the overall solids concentration in the boiler water. With higher-pressure boilers, or boilers that Call the Solids Mixing Ribbon & Cone Blenders Fluidizing Mixers Sigma Blade Mixers (also for high-viscosity mixing) Size Reduction Wet & Dry Size Reduction Steel & Ceramic Lined Mills Jars & Jar Rolling Mills Vacuum Drying Dryers & Complete Systems are generating steam to drive turbines, maintaining a low solids content in the steam is more critical, and the use of a sulfite scavenger would not be recommended in those cases. Another factor to note is that the sulfor all your solids processing Experts Applications: APIs ∙ Ag-Chemicals Biologics ∙ Catalysts Ceramics ∙ Chemicals Food Ingredients Herbicides ∙ Minerals Nutraceuticals ∙ Pesticides Pharmaceuticals ∙ Pigments Polymers ∙ Powdered Metals Proteins ∙ Resins ∙ Vitamins FIGURE 4. The diagram shows a typical boiler blowdown configuration Innovation www.pauloabbe.com 855-789-9827 sales@pauloabbe.com For details visit adlinks.chemengonline.com/70310-28 CHEMICAL ENGINEERING WWW.CHEMENGONLINE.COM For details visit adlinks.chemengonline.com/70310-31 SEPTEMBER 2018 35 Q ual 191 ity & Since 1http://www.pauloabbe.com http://adlinks.chemengonline.com/70310-28 http://adlinks.chemengonline.com/70310-31 http://WWW.CHEMENGONLINE.COM