Filtration is a widely recognized technique for removing contamination from hydrocarbon condensate streams For such challenging applications, backflush filtration, or so-called gas-assisted backwash filtration, is the technology of choice to achieve very low utility consumption and long cycle times.
When solids concentrations are high and continuous operation for an extended period is required, static filters with disposable filter elements are not suitable. In this respect, an automatically regenerated filter is required, which can operate continuously, even during its cleaning sequences. By back-washing in-situ, downtime and related maintenance costs are reduced. Operator exposure to hazardous products and waste disposal is minimized.
Conventional automatic backwash filter systems typically only use the available process pressure as driving force for backwashing. For challenging applications, these filter designs are not sufficient to meet the modern refiner’s demands. Heavier crudes require higher performance of existing, or newly installed processing units. As such, many of the conventional backwash systems suffer from a variety of operational problems:
- short cycle times
- high pressure drops
- continuous backwashing
- plugging of filter media
- clogging of filters
These issues cause unnecessary operator head-aches and high operational costs. Problems can be avoided by using improved filter element cleaning technology, based on more powerful backwashing that keeps the pressure drop just after backwash at a constant level (baseline dp).
For that reason Dahlman has developed gas-assisted backwash technology that removes solids from filter media much more effectively compared to conventional technologies, even in challenging applications such as slurry oil, amine or heavy coker gasoil product filtration.