Chernii O.A. Some peculiarities of experimental studies of the dynamics of vibro feeders for release and delivery of uranium ores

Details
Parent Category: Geo-Technical Mechanics, 2019
Category: Geo-Technical Mechanics, 2019, № 144

Geoteh. meh. 2019, 144, 209-217

https://doi.org/10.15407/geotm2019.144.209

Some peculiarities of experimental studies of the dynamics of vibro feeders for release and delivery of uranium ores

1Chernii O.A.

1Institute of Geotechnical Mechanics named by N. Poljakov NAS of Ukraine

UDC 678.4.06:621.81

Language: Russian

Abstract.

The paper discusses the dynamics of vibratory feeders with rubber elastic connections; a method for determining the parameters of the feeder and determining the dependence of its own oscillation frequency and amplitude on the stiffness parameters of the suspension, which change as a result of the elastic properties of rubber and their temperature of self-heating during cyclic deformation, is presented. The use of vibrating feeders (including sectional ones) and schemes for vibrating production, delivery and loading of ore in underground conditions allowed to mechanize one of the most labor-intensive and dangerous processes of mining mineral raw materials and to solve the following tasks: to increase the productivity of production and loading of lumpy rock in 2.5-3 times; to increase the intensity of mining and reduce the life of the treatment units and horizons; reduce labor intensity and reduce the cost of the process of production and loading of ore; to increase the uniformity of the outflow of the rock mass from the outlet orifices and to reduce by 3-5 times the frequency of hanging up the lumpy material; the use of partitioned feeders reduces the number of freezes in 25-60 times; increase the size of the conditional excavation piece; practically exclude cases of injuries in the processes of release and loading, occupying 30-60 % of all cases in underground works; to mechanize the process of release and loading and create conditions for the implementation of low-waste cyclical and continuous production technology. The Volterra principle is introduced into the method for determining the vibration parameters of the vibrator feeder with rubber shock absorbers to account for the elastic-hereditary properties of rubber. A transcendental characteristic equation was obtained for determining the amplitude of oscillations of the feeder’s working body. The amplitude-frequency characteristic of the feeder calculated by this equation is shown. Also in this paper it is assumed that the rheological characteristics of rubber depend on the heating temperature of the elastic bonds. The external thermal conductivity coefficient h of rubber shock absorbers was calculated for a temperature range of 288 K < T < 310 K. The dependences of the energy absorption coefficient y on the strain frequency at various heating temperatures were found experimentally. The amplitude-frequency characteristics of the considered oscillatory system showed that with an increase in the heating temperature of the elastic connections, the amplitude of the working body oscillations decreases, which can lead to a loss of performance and operational reliability of the feeder. All these factors should be taken into account when designing vibration machines equipped with rubber shock absorbers.

Keywords:

uranium ore, mining machines, elastomeric elements, methods for calculating the elastic-hereditary media

References:

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About the authors:

Chernii Oleksandr Anatoliiovych, Ph. D. Student in Department of Elastomeric Component Mechanics in Mining Machines, Institute of Geotechnical Mechanics named by N. Polyakov of National Academy of Science of Ukraine (IGTM NASU), Dnipro, Ukraine, This email address is being protected from spambots. You need JavaScript enabled to view it.