Reliable ejector system performance is essential for on-specification oilseeds processing

Abstract: Ejector systems are extensively used within oleochemical processing. Deodorizing, bleaching, degumming, evaporation, distillation, pretreatment and hydrotreatment are critical processes where ejector systems create and maintain low pressure conditions imperative for product quality and throughput objectives. Ejector systems are robust, reliable static equipment with long useful lives. Oilseeds processors and related industries have used these systems for decades.

Performance shortcoming can manifest in ejector systems that cause operating pressure of the aforementioned processes to increase to undesirable levels. Ejector system troubleshooting and identifying root cause(s) for performance shortfall can be difficult. Ejector system operating principles are not often understood by plant operating and maintenance engineers. Variables that affect performance along with the interplay between ejector and condenser can be challenging to interpret.

This paper draws from real-world case studies within oleochemicals and renewable fuels industry to review common performance shortcomings for ejector systems. A review of each situation, what the operations team observed, observations by the ejector system OEM performance improvement engineer, comparison of design and observed key performance measures and deducing root cause are covered. The common drivers of performance shortfall will be addressed in detail, including;

1. Ice formation within 1^st stage ejector
   
2. Elevated cooling water temperature
3. Fouling
4. Excessive air ingress
5. Mechanical failure
6. Poor medium pressure motive steam supply
   

Significant economic penalty occurs when ejector systems underperform. Defining root cause of performance shortfall is critical to getting back to on-specification product quality and plant throughput. This paper gathers actual performance issues with ejector systems, working through root cause to get back to design performance. Also provided is recommended best practice for maintaining good health and operation of ejector systems. The reader will have a deeper understanding of ejector system troubleshooting.