Problem: Understanding how to effectively inject wash water in most efficient placement to dilute acid that has formed in the liquid phase and dissolve salt deposits.

Best practice: Invest in a CFD study to validate performance before beginning injector design. Using flow rate and pressure drop to determine injection points is not enough. Using quills instead of spray injectors will likely create excess free water that will not properly interact with the vapor stream and may cause erosion and other corrosion issues. 

Problem: Injection system that is ineffective that can lead to wasted chemical and possible corrosion on overhead piping due to neutralizer that is not volatilized

Best practice: Using a spray injector designed specifically for atomization with steam is the optimal solution – Steam Atomized Retractable Injector. This solution is preferable to feeding the neutralizer through a quill along with steam. Use of the Steam Atomized Retractable Injector ensures none of the neutralizer remains in a liquid state and is then more effective at neutralizing the HCl. 

Problem: Poor wash water distribution and pooling on the floor of the header box

Best practice: Position the spray nozzles inside the header box itself or by using the clean-out plugs, if available, to install individual spray nozzles at pre-determined locations. Invest in a CFD study to validate performance before beginning injector design. The process gas flow rate and velocity greatly affect the performance of the spray injector, and CFD can assist in optimal spray nozzle placement.