Tube-bundle heat exchangers are commonly used to quench reacting fluids to drop the temperature of the reacting fluid below a specific temperature which cuts off undesirable chemical reactions in a minimal time as practical. A common commercial application is production of olefins. Shell and tube type and bundles of tube in tube exchanges are used in this application, the method is applicable to both. Significant variations in reacting fluid mass flow rates in the tubes of the tube-bundle can cause sub-optimal performance of the process. By placement of precise partial obstruction to flow of the reacting fluids at the tube exits to an outlet plenum chamber, these flow variations can be controlled. By adding remotely readable temperature measurement, and making the obstructions adjustable, the operator of the production facility can minimize production losses due to the variations in flow between tubes in the tube-bundle.
