Introduction

Vacuum distillation columns in refineries can suffer from reliability issues due to premature coking of wash bed packing.  A spray distributor is generally used to keep this packing wet, but the liquid sprayed does not reach the packing as intended.  Reliability of this distillation column is critical to a refinery’s operation and premature shutdowns due to fouling are extremely costly.

Challenges and Opportunities

A spray distributor is generally used to keep wash bed packing wet.  Traditional maximum free passage style nozzles are generally used in this service due to their fouling resistance, but they tend to atomize liquid too effectively.  In turn, a large volume percentage of liquid being sprayed from the nozzle is easily entrained in vapor counter flow orientation and no longer participating in wetting of the wash bed packing.  Dry packing leads to premature coking and fouling in the distillation column.

Solution

Lechler gathered voice of customer from key stakeholders in the industry to design a spray nozzle specifically for use in entrainment sensitive applications, namely the SMDmax™.  This nozzle is also more clog resistant than traditional maximum free passage style nozzles.  This new nozzle reduces entrainment from a spray nozzle by up to 300%.  

Outcomes and Evaluation

Lechler conducted extensive spray testing , and the nozzles we have in service are showing evidence of increased liquid flow rates beneath the packing. This illustrates that the spray nozzle is able to get more liquid to the packing as intended.  This increases the reliability of the wash bed section in vacuum distillation columns, which has a positive impact on a refinery’s uptime, distillation efficiency, and heavy metals removal.

Make the switch to the SMDmax™ today!

Contact us today to learn how we can provide you with a quality spray solution