Ebullating Assembly?

So here I am sitting in the middle of a 6 billion dollar construction site building a heavy oil plant trying to clear out our warehouse to make room to remove a couple of ebullating assemblies....

The ebullating pump is a centrifugal pump that sits below a reactor tower filled with catalyst. Catalysts tend to be solids (ie: don't float well) and cooler than the surrounding liquid as the chemical reaction they are helping usually absorbs heat. Both effects cause them to settle to the bottom of a reactor over time. The ebullating pump recirculates the cool and catalyst-rich production fluid from the bottom of the reactor back to the top of the reactor. The fluid is usually sent through a re-heater to warm the catalyst and fluid back to the reactor operating temperature before re-injecting it back into the reactor. The situation mimics the recirculation of fluid in a boiling pot, hence the term ebullating, from the French verb "embouillir". "em" + bouillir" = "to place + boiling".

There are usually numerous suction feed pipes from the reactor to the ebullant pump and they can be quite complex. The numerous pipes are needed to ensure uniform draw from all around the bottom of the reactor. Otherwise hot or cold spots form, causing carbon deposits to form ("coking" when heavy oil is concerned) and plug the suction lines or pump.

Since the pump and suction pipes are subject to frequent plugging caused by coking and catalyst deposition, the pipes and pump are removable. They are installed on a common structural steel skid as a complete assembly called - now wait for it - the ebullating assembly. The skid suction and discharge piping is attached to the reactor with high pressure-temperature clamps (Securemax). The whole assembly can be removed and another quickly installed to keep the reactor in operation. The removed assembly can be sent to a maintenance shop for flushing with high pressure water chisels, as the coke is like concrete once it bakes on to the pipe walls or pump casing.

Hope this helps!

Cheers,

Steamer Stan