Roy Niekerk - Kelvion
Plate & Frame heat exchangers (P&FHE) have been the preferred technology in Lean/Rich amine service for the last decades. The reason is that they are compact, have high thermal efficiency and offer a close temperature approach. Nevertheless, some sites have had issues with gasket leakage or underperformance. Do these bad experiences disqualify this technology? What would be an alternative technology?
The last couple of years, more and more end-users and contractors are selecting Welded Plate-Bloc Heat Exchangers (WPBHE) for the Lean / Rich Amine Exchangers. Overall experience with WPBHE has been good in this service. This technology combines the high efficiency of corrugated plates with the robustness of a welded concept. Dangerous leakages of H2S containing solvents can now be avoided. Now experience is building up; also guidelines for design and engineering are being developed. What is a realistic heat transfer coefficient to calculate with in the initial plant design? And in what sizes and models is this technology available?
WPBHE is a proprietary technology and end-users and contractors must rely on the designs of vendors. Nevertheless, guidelines can be given to review vendor’s designs as well as requirements in engineering specifications for pressure drops, flow distribution and shear stress. International standards such as API 662 for P&FHE do not yet exist for WPBHE. However, these are being developed as we speak.
During plant design choices are made in sparing philosophy and the operational reality is often quite different. Plants with P&FHEs often have a spare unit installed. However, instead of using the spare unit for timely cleaning, they often are put online to keep overall plant performance. This only helps for a short while: lining up the spare unit decreases shear stress and increases fouling rate.
Now there is a growing installed base of WPBHEs in Amine Systems and Sour water strippers, best practices are developed on cleaning and maintenance. This certainly helps in the confidence of end-users in this technology.
WPBHE has also proved to perform outstanding as Stripper Condenser and as Regenerator Reboiler with very small plotspace compared to bulky Shell & Tube Heat Exchangers. An extra advantage of WPBHE reboilers cause significant lower solvent degradation than S&THE. Because of the higher film coefficients, the skin temperatures are lower.
Considering the above, it is no surprise that reference lists for WPBHE in Amine Systems and Sour Water strippers is growing rapidly.
Since his graduation as Chemical Engineer (B.Sc) in The Netherlands in 2001, Roy Niekerk has been working in the field of Heat Transfer Engineering. First for Alfa Laval’s sales office in The Netherlands. After having worked for a brief time in filtration (from 2009 to 2011) he joined Alfa Laval again, this time leading the Southeast Asia Regional Competence Centre for Oil & Gas and Refinery business in Kuala Lumpur, Malaysia. In November 2013, he joined Shell Projects & Technology in Rijswijk, The Netherlands in the Heat Transfer Team supporting various refineries and LNG projects in heat transfer topics as well as leading various Innovation activities. Since August 2017, Roy Niekerk has joined Kelvion in Bochum, Germany in his role as Director Global Market Segment Oil & Gas.