direct crossflow

In direct crossflow, the feedwater is moving tangentially along the membrane. Rather than being completely forced through, only a portion of the feedwater passes through the membrane, while most of it is recirculated. 

Direct crossflow is applicable with tubular membranes, which are widely used in water filtration systems. It can also be used with smaller capillary membranes, as long as a recirculation flow is permanently available to keep the membranes clean. The shear provided by the recirculation flow will maintain a certain level of turbulence at the membrane surface. Any rejected material pushed against the membrane wall will be subject to the turbulence and moved away. 

Typical direct crossflow applications are concentrating yeasts, proteins, starches and algae. In the separation of oily solutions, the same kind of turbulence is needed to keep the oil away from the membrane wall and thus keeping the membrane clean and available for continuous filtration. 

The majority of applications in this field will be set up to be a concentration process in order to create as much clean water as possible by concentrating the retentate to 20 percent, 10 percent or even less of the original feedwater flow. 

If you have any questions, please contact us.

Typical applications

  • Produced water
  • Yeast concentration
  • Oil/water separation
  • Protein concentration

Benefits

  • Improved membrane filtration runs
  • Good membrane separation possibilities
  • Allows for oil separation applications
  • Conditioned process for optimized performance
  • Adjustable power consumption

Featured case

Daqing slider image

Heilongjiang province, China

Produced water