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Our customer is a pioneer in Air Pollution Control Technology offering a full spectrum of products and services for power, cement, sugar, chemical and metal industries. To a cement clinker mill, they were supplying pulse jet type fabric filter containing 6 bag nests of 558 bags each. Since, the fabric filter was of non-compartmentalized design, it was essential to ascertain uniform distribution of dust laden gas based on CFD analysis.

To ascertain uniformity of flow between bag nests, Zeus Numerix simulated flow through the inlet ducting comprising of inlet plenum, plenum cut-outs, baffle plates and guide vanes. The regions comprising of filter bags were modelled as porous zones. An unstructured tetrahedral mesh was generated in the domain and simulation was done using our proprietary incompressible flow solver. The simulation generated data on pressure drop, flow distribution and peak velocity regions. Finally, a Lagrange model for prediction of dust settlement regions was employed. The particle size distribution followed Rosin-Rammler distribution.

Left: Velocity distribution in bag nest region, Right: Dust particle trace and settlement in bag filter.

Zeus Numerix observed non-optimal flow distribution in the original design and accordingly recommended guide-vanes and damper cut-out sizes to meet desired uniformity. Simulations were conducted on the modified inlet plenum and results confirmed improvement in flow. The final report was submitted to the end client based on which approval was obtained to go ahead with commissioning at site.