The accumulation of bottom sludge and water (BS&W) is a problem that the crude oil industry constantly faces when storing crude oil. BS&W reduces available storage space and corrodes tank floors and lower shell plates. If the sludge breaks free during pump-down (discharge), serious damage can be caused to transfer pumps, potentially disrupting refinery operations.
Among the best ways way to control and remove BS&W is to keep the contents of the storage tank in a constant state of contact motion. Swivel angle side entry mixers, like those provided by SPX’s Plenty® Mixers, provide an effective solution.
Plenty Mixers Clean Up at the Tank Farm
For a petroleum company based in India, swivel angle side entry mixers from SPX’s Plenty® Mixers, have proven successful in keeping any tank sludge suspended so it can be evenly fed to the tank discharge outlet.
The petroleum company purchased 45 of the mixers for its tank farm project on the East coast of India. The project features 15 tanks, each equipped with three Plenty mixers for controlling and preventing the accumulation of BS&W deposits.
Previously, the company had to carry out periodic tank cleaning that was both hazardous and expensive, and caused storage capacity downtime.In addition, the use the Plenty side entry swivel angle mixers enables Indian Oil to recover valuable hydrocarbons from BS&W, which contributes to the plant’s profitability. Savings are also generated because the need for tank cleaning is reduced.
Constant Flow, Less Shear
The Plenty side entry mixers work by generating a fluid regime in a given time in large tanks, where the application demands that a high percentage of the installed power is used to promote flow with little or no shear.
More Proof
Plenty side angle swivel mixers also proved beneficial in a project where a 376,000bbls (59870 cu.m) capacity tank holding Light Arabian Crude had an average BSW depth of 622 mm.
Laboratory tests estimated a total sludge content of 10,000bbls (1600 cu.m.) of which 40% was water, 30% sediment and 30% oil. After installing two 37kW Plenty swivel angle mixers, running them for 48 hours and sweeping progressively at timed increments, the average sludge level was down to 25mm.