Mixing in Chemical Industry

Parent Category: Industries

Mixing is an important part in chemical industry and appears in processes such as dispersion of two or more liquid, powdery or gaseous ingredients, deagglomeration to avoid lumps and homogenization of mixtures. Flow modeling can help to understand the flow in an agitator, to quickly suggest improvements to construction and operation parameters and to reduce production and maintenance expenses.

NOGRID offers a wide range of rheology models including those found in chemical industry. NOGRID's unique abilities to handle moving parts in the fluid domain allow the simulation of any conceivable agitator geometries and operation modes such as

  • rotating and counterwise rotating agitator blades, possibly moving up and down periodically at the same time
  • overlapping operation ranges of moving parts as found in twin-screw agitators
  • free surfaces at inlets or for different fluid levels or for fast rotating agitators with high centrifugal forces

The particular strengths of NOGRID's meshless CFD simulation software are the rapid preprocessing (no grids need to be generated) and the outstanding short computation time even for complicated moving parts commonly found in agitators.

 

Frustrum shaped mixing vessel

This example shows a frustrum shaped mixing vessel with a simple rotating blade. The inlet and outlet are omitted. The challenge is the fast and exact computation of the free surface. In particular the agitator blade can partly surface as it is close to the free surface.

CFD meshless Flow Simulation chemical mixing CFD meshless Flow Simulation chemical mixing

Figure 1: Velocity field and free surface flow in a simple mixing chamber

 

Twin-screw agitator in a double cylinder

Twin-screw agitators exhibit more complicated fluid mechanical phenomena than found in single-screw agitators. Mesh based simulation methods usually fail to efficiently deal with the overlapping operating ranges of the rotating blades. In NOGRID software there is no difference in modeling and computation efficiency compared to a single-screw agitators.

CFD meshless flow simulation mixing chemical industry

Figure 2: Velocity field and free surface flow in a twin-screw agitator