Computational simulation of centrifugal washer

using discrete element method (DEM).

Edy Merendino

Nicolas Spogis

José Roberto Nunhez

L-CFD- FEQ - Unicamp

TOPICS

• Aseptic carton packages;

• Recycling process;

• Model parameters set-up ;

• Simulation and e Results;

• Conclusions.

Aseptic carton packages

Recycling process

Recycling process

PE/Al composite

Recycling process of PE/Al Composite

Pellets productionRoof tiles production Thermal separation

Centrifugal washer

Static body

Rotor

Centrifugal washer

Starting centrifugal washer simulation

Starting centrifugal washer simulation

Starting centrifugal washer simulation

Starting centrifugal washer simulation

Starting centrifugal washer simulation

• Finding materials properties

• Finding static friction coefficient.

• Finding rolling friction coefficient

• Setting-up radius and density

Setting-up parameters: Simulation vs. Real

Fitted Surface; Variable: Torque

2**(2-0) design

55 50 45 40

-1,2 -0,8 -0,4 0,0 0,4 0,8 1,2

Massa específica

-1,2

-0,8

-0,4

0,0

0,4

0,8

1,2

Ra

io

Fitted Surface; Variable: Potência

2**(2-0) design

7200 6800 6400 6000 5600 5200 4800

-1,2 -0,8 -0,4 0,0 0,4 0,8 1,2

Massa específica

-1,2

-0,8

-0,4

0,0

0,4

0,8

1,2

Ra

io

Real parameters

Dissipated power = 5800 W

Applied torque = 60 N.m

Simulated parameters

Model parameters : Resume

Physical

propertyMaterial Value Unit

Shear Modulus Steel 10000 MPa

Poison Ratio Steel 0,3 -

Density Steel 7850 kg/m3

Shear ModulusPE/Al

Composite271 MPa

Poison RatioPE/Al

Composite0,3 -

DensityPE/Al

Composite500 kg/m3

Particle geometry Value Unit

Radius 0,1 [m]

Interaction Material Material Value

Coefficient of

restitutionSteel PE/Al Composite 0,45

Coefficient of

restitutionPE/Al Composite PE/Al Composite 0,45

Static friction

coefficientSteel PE/Al Composite 0,3

Static friction

coefficientPE/Al Composite PE/Al Composite 0,6

Rolling friction

coefficientSteel PE/Al Composite 0,3

Rolling friction

coefficientPE/Al Composite PE/Al Composite 0,3

Operational parameter Value Unit

Material per batch 6 [Kg]

Rotation frequency 927 [rpm]

Rotor extreme velocity 33 [m/s]

Simulation: 4 rotors

Simulation: 2 geometries

Results :

Results :

Results: Dissipated power by collisions

Potência dissipada por colisões

0

2000

4000

6000

8000

10000

12000

Rotor 01 Rotor 02 Rotor 03 Rotor 04

Po

tên

cia

[W

]

Sem chicanas Com chicanaswithout baffles with baffles

Results: Average torque applied in rotor

Torque Médio no rotor

0,0

20,0

40,0

60,0

80,0

100,0

120,0

Rotor 01 Rotor 02 Rotor 03 Rotor 04

To

rqu

e [

N.m

]

Sem chicanas Com chicanas without baffles with baffles

Results: Average particles velocity

Velocidade média das partículas

0,0

0,5

1,0

1,5

2,0

2,5

3,0

Rotor 01 Rotor 02 Rotor 03 Rotor 04

Velo

cid

ad

e [

m/s

]

Sem chicanas Com chicanas without baffles with baffles

Results: Average relative velocity of collision between

particles and static body

Velocidade relativa média de colisão das

partículas com a parte estática

0,000,200,400,600,801,001,201,401,601,80

Rotor 01 Rotor 02 Rotor 03 Rotor 04

Ve

loc

ida

de

[m

/s]

Sem chicanas Com chicanaswithout baffles with baffles

Results: Number of collision during 60 seconds

Número de colisões em 60 segundos

0

250000

500000

750000

1000000

1250000

1500000

Rotor 01 Rotor 02 Rotor 03 Rotor 04

Nú

me

ro d

e c

olisõ

es

Sem chicanas Com chicanas

without baffles with baffles

Tipo de Colisão Rotor 01 Rotor 02 Rotor 03 Rotor 04

Partícula/

Partícula64,2% 64,8% 66,3% 64,7%

Partícula/

Parte Estática35,6% 35,0% 33,6% 35,0%

Partícula/

Rotor0,2% 0,1% 0,2% 0,2%

Tipo de Colisão Rotor 01 Rotor 02 Rotor 03 Rotor 04

Partícula/

Partícula74,8% 74,5% 73,7% 75,5%

Partícula/

Parte Estática21,4% 21,1% 22,5% 21,0%

Partícula/

Chicana3,3% 3,9% 3,4% 3,1%

Partícula/

Rotor0,5% 0,5% 0,4% 0,4%

Results: Types of collision

Results: Distribution of collisions by particles

0

100

200

300

400

0 4000 8000 12000 16000

Número de colisões

Nú

me

ro d

e p

artí

cula

s

Rotor 01

Rotor 02

Rotor 03

Rotor 04

0

400

800

1200

1600

2000

0 4000 8000 12000 16000Número de colisões

Nú

me

ro d

e p

artí

cula

s

Rotor 01

Rotor 02

Rotor 03

Rotor 04

Without Baffles With Baffles

Conclusions

• Baffles improve particles mixing but increase power

consumption and torque needed.

• Baffles decrease collision relative velocity and number of

collisions.

• No big difference between rotors will notice.

Next steps

• Implement changes at static body and rotor in order to

validate simulation.

• Measure of new parameters in the real equipment and

compare with the simulations

• Improve setting-up parameters

Thanks !

Thanks !

EDY MERENDINO

edy.merendino@tetrapak.com

+ 55 (19) 3345 2832