Scrubber design is not a simple matter of selecting whatever demisting technology you want and applying a K-factor. First the required separation performance must be determined based on the service. Then scrubber design starts upstream with the inlet piping sizing, components (valves, etc.) and routing. Proper inlet design ensures a stable flow regime, low entrainment of liquid into the gas due to shearing, and prevents swirling flow from entering the scrubber. A low shear inlet distributor is necessary to minimize shearing of large droplets into smaller harder to separate droplets and to provide adequate distribution into the vessel. The scrubber design should also account for proper disengaging space for bulk liquid separation (gravity separation) and flow distribution between internal elements. The demisting technology selection must account for drop size, the liquid load expected to be carried by the gas to the demisting device, the gas flow rate (velocity), the surface tension and viscosity of the liquid, the expected density driving force for separation, the operating temperature/pressure of the system, fouling potential, and the required separation efficiency. Even the gas and liquid outlet designs can impact the separation. All of these elements must be integrated to provide sustained efficiency of the scrubber across its operating range.
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Sr. Process Advisor and the Separations Lead, Chevron Energy Technology Company
Jimmie Riesenberg is a Sr. Process Advisor and the Separations Lead for the Chevron Energy Technology Company supporting the design and troubleshooting of separations world-wide. He is also the Chevron Compact Modular Processing Systems Engineering Manager, responsible for the development and qualification of subsea processing technology. Jimmie has been with Chevron including time with Texaco for over 24 years and has worked in all aspects of process engineering from upstream to downstream as well as Gas Plants, LNG and Gas to Liquids. He earned an M.S and B.S. in Chemical Engineering from Drexel University in Philadelphia. He is the Program Chair for the SPE Separations Technology Technical Section, was a member of the industry committee that revised the GPSA Engineering Data Book Separations Section, and is on the Steering Committee and Technical Advisory Committee for the Separations Technology Research Program (STAR) JIP.