SIMULATING PARTICLE FLOW IN THE CYCLONE SEPARATOR BY VARYING DIFFERENT INLET BOUNDARY CONDITIONS ALSO VARYING THE NO OF PARTICLES AT INLET
Ans1) The four Empirical models used for Cyclone seperator efficiency is are as follows:-
1. koch and licht model
2. Lappel model
3. LI AND WANG MODEL
4. Iozia and Leith model
KOCH AND LICHT MODEL.
This theory recognised the inherently turbulent nature of cycloones and the distribution of gas residence times within the cyclone Koch and Licht describes particles motion in the entry and collection regions with the additional Following assumption.
- The tangential velocity of particles is equal to the tangential velocity od the gas flow. Also there is no slip condition in the tangential direction of particles and gasflow.
- The tangential velocity is related to the radius of cyclone by uR^n=constant
Lappel model.
This model is based on the force balance without considering the flow resistance. Lapple assumed that a particle entering the cyclone is evenly distributed across the inlet opening. The particles that travels from inlet Half-width to the wall in the cyclone is collected with 50% effieciency.
LI AND WANG MODEL
This includes particle bounce or re-entairtainment and turbulent diffusion at the cyclone wall. this model developed based on the assumption that ,The radial particle velocity and radial concentration profile are not constant, for uncollected particles within the cyclone.
Iozia and Leith model
This model is developed base on force balance . The model assumes that aparticles carried by the vortex endures the influence of two forces centrifugal force and flow resistance .
Ans2) Performance of simulation based on cyclone seperator geometry. This includes various preprocessing settings in different modules such as, in space clim , meshing and Fluent.
1) model of a cyclone seperator was uploaded on the space claim ,Then Fluid volume was extract by using prepare tool .After the fluid volume extraction the other solid bodies was supressed for physics.
2) In meshing module the fluid volume was meshed (size=10mm) .and three named selection parameters were created (inlet,outlet1,and outlet2)
3) Fluent settings.
- the analysis is set to be steady and gravity was enebled.
- Viscous model was selected as k-epsilon with RNG formulation ,swrill dominated flow was enabled.
- discreet phase modeling setting is mention on the picture.
- then injection setting was incountered ,antharsite particles are inserted within the model setting, Along with type of injection also set ,and the details such as particles diameter and velocity and the entitiy to influenced are mention in the image below.
- boundary conditions (only inlet condition are provided along with DPM ) There are four conditions for DPM at inlet ie, reflect, trap,escape,wall jet ,we have to varry this condition and observe the change in particles tracking and other results.
- standard initialization was done and calculation was ran for considering 600 itteration for each case.
In this way all the preprocessing setting was performed to make an cyclone seperator simualtion.
CASE BY CONSIDERING REFLECT DPM IN BOUNDARY CONDITION.
CASE BY CONSIDERING TRAP DPM IN BOUNDARY CONDITION.
CASE BY CONSIDERING ESCAPE DPM IN BOUNDARY CONDITION.
CASE BY CONSIDERING WALL JET DPM IN BOUNDARY CONDITION.
Ans3) For this we have to varry the no. of particles through the inlet and compare 3 cases.
As the no. of particles depend upon mesh size (no. of cells present on the inlet surface) so we have to varry the mesh size to varry the particles flow inside the fluid region.
Case1. Mesh size=10mm with reflect DPM boundary condition
Case2. Mesh size=9.5mm with reflect DPM boundary condition
Case3. Mesh size=9mm with reflect DPM boundary condition
Comparision of particle data:-
CASES NUMBERS TRACKED ESCAPED INCOMPLETE
1 364 121 243
2 368 125 243
3 382 324 28
SO in this way simulation was performed and all the results are calculated.
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