1. St. Petersburg State Polytechnical University TU Kaiserslautern Obtaining and investigation of the mechanical properties of pellets Kim Vitaliy Yashin Aleksey 1

2. About our internship 2

3. Introduction Agglomeration of extrusion and spheronization is one of the most known methods of production of the pellets. The process consists of four process stages: Granulation Extrusion Spheronisation Drying 3

4. Granulation 4 The first step of an extrusion - spheronisation cycle consists of the preparation of the plastic mass. Different types of granulators are used to perform the mixing of the powder blend and the granulation liquid. During the granulation step the evaporation of the fluid phase should be restricted to a minimum. This could especially be a problem with the high shear mixers as they introduce a large amount of energy into the mass which is partly transformed into heat.

5. Extrusion 5 A.B. Fig. 1. Schematic view of a screw extruder. (A) Axial type, (B) radial type.

6. Spheronisation 6 Fig. 6. Pellet-forming mechanism: I - cylinder; II - rope; III - dumb bell; IV - sphere with a cavity outside; V, sphere.

7. Drying 7 The fourth and final step of the process is the drying of the pellets. The pellets can be dried at room temperature or at elevated temperature in a fluidized bed or in an oven. Bataille in 1993 reported the use of a microwave oven as the final phase in the production process of pellets.

8. Experiment 8 Texture analysisLaboratory of powder materials

9. Experiment 9 Pellet Table Cylindrical probe of stainless steel

10. Experiment 10 A.B. A. – Pellet before test; B. – Pellet after test. Whole batch after uniaxial compression experiments

11. 11 Experiment N p D, mm D, mM, gM, kgV, m3ρ, kg/m3 W1, N*mm W1, J Wm1, J/kg W2, N*mm W2, JWm2, J/kg 13,20,00320,0262,64E-051,716E-081538,7050,5650,000565321,413481,9360,001935673,317317 23,3970,00340,0262,59E-052,053E-081261,86970,7970,000797230,779811,1150,001114843,041719 32,9440,002940,0212,12E-051,336E-081586,8060,4770,000477322,512821,4030,001403166,182352 42,8370,002840,0161,64E-051,196E-081371,72550,4430,000442927,006361,4570,001457588,871046 Plot built by Exponent software A data table obtained by analyzing the plot

12. 12 Experiment Energy divided by mass distribution Function describing this distribution

13. Work plan: Simulation of spheronization process in EDEM Software Deformation of one pellet simulation by finite element method 13