Franchuk V.P., Svietkina О.Yu., Antsiferov A.V. On the issue of calculation of temperature at the ball shock action in vertical vibration mill

Details
Parent Category: Geo-Technical Mechanics, 2018
Category: Collection of scientific papers «Geotekhnicheskaya Mekhanika» Issue 140

Geoteh. meh. 2018, 140, 81-90

DOI: https://doi.org/10.15407/geotm2018.03.081

ON THE ISSUE OF CALCULATION OF TEMPERATURE AT THE BALL SHOCK ACTION IN VERTICAL VIBRATION MILL

1FranchukV.P., 1Svietkina О.Yu., 1AntsiferovA.V.

1National Technical University «Dnipro Polytechnic»

UDC621.926.22.001 : 622.732

Language: Russian

Abstract.

The article presents a method for determining temperature developed in zone of ball impact during the grinding operations. This method of loading is implemented in vertical vibratory mills and is called vibratory impact. Simultaneously with the grinding, there are also other effects that are called mechanical activation. These processes were investigated by the authors for a long period of time during which a great amount of theoretical and experimental results was obtained. In this paper, the constructive scheme of vertical vibration mill is considered. Grinding bodies have a shape of balls. Main parameters of this mechanical system, which effect disintegration of material particles under the impact action, are determined. Theoretical analysis shows that disintegration in the impact zone provides not only the material surface activation, but also a destruction of the particle internal structure. As a result of vibratory-impact loading, volume ionization of crystals of the material being ground occurs. As an example is consideration of equation for the increment of potential energy of atoms in the nodes of the crystal lattice, which is deformed upon impact. Its analysis allows concluding that activation processes are associated with a certain critical temperature. Results of experiments with vertical vibratory mills also indicate a significant effect of temperature in the impact zone between the balls. A method is proposed for temperature calculation. Mode of grinding chamber operation and the ball size and properties are used as initial data. Diagrams of dependence between temperature in contact zone and amplitude and frequency of the mill vibration are presented. Effect of the ball diameter was also studied. It is shown that with more intensive mode of the mill operation and greater diameter of the balls, temperature is also increased. Additional factors taken into account reduce temperature in the impact zone. However, even in this case, effect of temperature cannot be ignored. The conducted experiments showed the possibility of mechanical activation of many materials: metals, minerals, titanium and silicon carbides, coal. Therefore, further development of the proposed technology should assume taking into account changes in the ground material properties.

Keywords: vertical vibration mill, vibration impact loading, grinding, mechanical activation, collision of balls, impact zone, temperature.

References:

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About the authors:

Franchuk Vsevolod Petrovich, Doctor of Technical Sciences (D.Sc), Professor, Professor in the Department of Mining Machines and Engineering, National Technical University «Dnipro Polytechnic» (NTU «Dnipro Polytechnic»), Dnepr, Ukraine, This email address is being protected from spambots. You need JavaScript enabled to view it.

Svietkina Olena Yuriivna, Doctor of Technical Sciences (D.Sc), Associate Professor, Head of Department of Chemistry, National Technical University «Dnipro Polytechnic» (NTU «Dnipro Polytechnic»), Dnepr, Ukraine, This email address is being protected from spambots. You need JavaScript enabled to view it.

Antsyferov Alexandr Vladimirovich, Candidate of Technical Sciences (Ph.D), Associate Professor in the Department of Mining Machines and Engineering,, National Technical University «Dnipro Polytechnic» (NTU «Dnipro Polytechnic»), Dnepr, Ukraine, This email address is being protected from spambots. You need JavaScript enabled to view it.