(September  6, 2018) —Contributed by Christopher F. Hastings, Market Specialist – Petroleum

Just say you had a blend tank with 100,000 bpd and it was off-specification [Octane] and it has to be downgraded from 95 octane to 93 octane. It could easily cost $96,500 in lost revenue per batch!

Successful blending is a function of the performance of the propeller mounted to the side-entry tank mixer. There are many vendors who claim their propeller is the best, however only Philadelphia Mixing Solutions has tested them all.

In the summer of 2017 we tested the leading propellers in identical conditions in our laboratory in Palmyra, PA. The results were recently published in the article BLENDING IN ABOVE GROUND STORAGE TANKS WITH SIDE-ENTERING AGITATORS in the September 2018 issue of Chemical Engineering Research and Design.

The key to successful blending is the breakdown of the gravity boundary layers that exist in a stratified tank which is the worst case for mixing. Blending of multi-layers of product that might settle out at their respective gravities is a gradual process. Each boundary layer must be broken down and the flow is upwards through each layer, gradually moving upwards to the surface. The complete tank only gets into motion towards the end of the mixing process.

When failure to achieve a blend occurs it is because the propeller being used does not have the velocity and volumetric displacement to break through one or more of the boundary layers.

Poor mixing has been the result of lost revenue for years, but those days are over. With over 200 years of collective mixing knowledge, your first contact should be Philadelphia Mixing Solutions.
The globally proven in-tank mixing solutions company. Contact us for additional information.

Additional Information:
Recommended Orientations: BSER Fixed-Angle Side Entry Mixers
Blending in above ground storage tanks with side-entering agitators