Grinding Intensity Research Articles

SPECIFIC ENERGY CAPACITY OF PROCESSING AND ENERGY EFFICIENCY FOR PROCESS OF GRINDING WITH WHEELS FROM SUPERHARD MATERIALS

The analysis of modern research shows that when evaluating the specific energy intensity of the abrasive processing process, one should pay attention not only to the indicators of grinding power and material removal rate, but also to the indicator of the wear of the abrasive tool, which we will show below for the grinding tool made of superhard materials. It is shown that the traditional method of estimating the specific energy capacity based on the ratio of the grinding power to the processing productivity does not provide an adequate solution, since with it the specific heat capacity of processing exceeds the specific heat capacity of melting of the processing material by almost an order of magnitude. Therefore, it is the application of a new approach to the assessment of the specific energy intensity of diamond grinding, taking into account the wear of the working layer of the diamond wheel, and makes it possible to estimate the indicators of the specific energy intensity of grinding and the energy efficiency coefficient. It has been proven that when estimating the specific energy capacity of grinding metal-ceramic composite materials consisting of a low-melting and refractory component, the latent heat capacity of melting of the low-melting component should be taken as the basis. It is shown that the plastic mode of grinding occurs precisely when the specific energy capacity of grinding, taking into account the wear of the wheel, becomes close to the specific heat capacity of melting of a brittle material.

COMPUTER SIMULATION OF PRELIMINARY HEAT TREATMENT AND RADIAL-SHEAR ROLLING OF BRASS

This paper presents the results of computer modeling of preliminary heat treatment and radial-shear rolling of L63 brass in the Deform program by cellular automata method. Quenching and annealing were simulated as pre-heat treatment modes. Radial-shear rolling consisted of three passes with a compression of 3 mm per pass. The variable parameters were the roll rotation speed (40 rpm, 70 rpm and 100 rpm) and the workpiece heating temperature before rolling (500°C and 700°C). It was found that the most effective mode of preliminary heat treatment of L63 brass is annealing at a temperature of 500°C. The most rational value of the heating temperature of the workpiece before rolling is 500°C, since in this case, at all selected speeds the recrystallization process does not start, which contributes to intensive grain grinding. An increase of roll rotation speed causes additional deformation heating, which contributes to recrystallization and a decrease of grain grinding intensity.

Influence of the Degree of Loading of a Ball Drum Mill with Grinding Balls on the Intensity of Coal Grinding

There is a direct relationship between the degree of loading of a ball drum mill with grinding balls and the intensity of coal grinding. With an increase in the degree of loading of the ball mill, the intensity of coal grinding also increases. This is due to the fact that with an increase in the number of grinding balls inside the mill, coal is exposed to more intense friction forces and impacts, which leads to more efficient grinding of the material. However, it should be borne in mind that if the mill is loaded too much, there may be a problem with insufficient circulation of the material, which can lead to a decrease in the efficiency of the mill. Thus, the optimal degree of loading of the ball drum mill with grinding balls should be selected depending on the characteristics of the material and the operating conditions of the mill to achieve maximum efficiency of grinding coal

Comparative corrosion performance of YSZ-coated Ti-13Zr-13Nb alloy and commercially pure titanium in orthopedic implants

This study delves into the corrosion performance and wear behavior of orthopedic implant alloys, particularly the Ti-13Zr-13Nb alloy and commercially pure titanium (cp-Ti), both coated with Yttria-Stabilized Zirconia (YSZ) nanoceramic. The research utilizes the Taguchi design of experiments (DOE) approach and employs electrophoretic deposition (EPD) techniques to create thin, well-adhering YSZ layers on these alloys. Employing an orthogonal Taguchi L9 array, the study investigates how various EPD parameters, including electrical voltages, YSZ concentration, deposition duration, and grinding intensity, influence the deposition yield on both Ti alloys. To optimize the EPD parameters for these Ti alloys, the coated substrates underwent thickness and adhesion tests. The optimal conditions established are as follows: for commercially pure Ti, YSZ coating thickness and adhesion were achieved using 60 Vs, 7 min of deposition, 15 % concentration, and 400° of grinding. Meanwhile, for Ti-13Zr-13Nb, the ideal parameters were 60 Vs, 7 min of deposition, 20 % concentration, and 400° of grinding. Comprehensive characterization techniques were employed, including high-resolution scanning electron microscopy (FE-SEM) for alloy analysis, optical microscopy and atomic force microscopy (AFM) for surface microstructure and thickness evaluation, energy-dispersive X-ray spectroscopy (EDAX) for composition analysis, and X-ray diffraction (XRD) for phase analysis.The research goes on to assess corrosion resistance by subjecting the optimal coated Ti alloys to simulated body fluid (SBF) using electrochemical methods such as polarization (Tafel) and cyclic polarization. Additionally, adhesion force was measured using a tip tester. Notably, both cp-Ti and Ti-13Zr-13Nb coatings showcased enhanced corrosion resistance in Ringer's solution at 37 °C. Importantly, the corrosion rate of the coated Ti-13Zr-13Nb alloy (1.888 × 10–3) was found to be lower than that of the coated cp-Ti alloy (3.013 × 10–3)..

EFFECT OF MECHANICAL ACTIVATION OF REAGENTS ON SYNTHESIS OF Li-Sm FERRITE

The effect of the energy intensity of mechanical grinding of Sm2O3(14.7 wt.%)//Fe2O3(77.5 wt.%)/Li2CO2(7.8 wt.%) powder reagents on synthesis of Li-Sm ferrite was investigated by X-ray diffraction analysis, thermogravimetry, and differential scanning calorimetry. The study used a Retsch E-max ball mill, which provides different energy intensity of mechanical grinding at different rotational speed of 300, 1000, and 1500 rpm. The interaction between the initial reagents was analyzed through heating the powder mixture to 900 °C in air in the furnace of the Netzsch STA 449C Jupiter thermal analyzer. A complete cycle of ferrite synthesis, including high temperature isothermal holding, was performed in the laboratory furnace at 900 °C for 240 min. It was found that at increased energy intensity of powder grinding, the temperature range of interaction between Sm2O3/Fe2O3/Li2CO3 shifts to lower temperatures by 200 °С, which indicates an increased reactivity of powder reagents. In this case, a two-phase composite material is formed during synthesis, which consists of unsubstituted lithium ferrite α-Li0.5Fe2.5O4 (81.0–81.8 wt.%) and SmFeO3 (18.2–19 wt.%). Within the limits of the experimental error, the concentration ratio of the synthesized phases does not depend on the energy intensity of grinding the initial reagents. Synthesis of unsubstituted lithium ferrite was confirmed by X-ray diffraction data (lattice parameter of ~0.833 nm), an endothermic peak in the differential scanning curve indicating the α-Li0.5Fe2.5O4 →β-Li0.5Fe2.5O4 transition, and by the Curie temperature (~630 °C) determined by thermogravimetry in a magnetic field. The result obtained may generate interest in the technology of ferrites of new compositions substituted with rare earth elements, which possess unique properties.

Determining the effect of the direction of installing the cutting edges of shredder roller blades on process parameters

This paper reports a study aimed at increasing the intensity of grinding of the stems of coarse-stemmed crops by establishing the influence of the orientation of the cutting edge of the cutter-shredder knives on the quality of the technological grinding operations. Analytical dependences of the planar movement of the roller-shredder were established and it was determined that for rollers with knives, the cutting edge of which is directed in the direction opposite to the direction of rotation: – exceeding the value of the vertical components of the total forces of resistance of the knives, which made it possible to increase the values of forces, and, as a result, more intensive destruction of the layer of plant remains; – exceeding the values of the driving force of the knives based on the dependence of the driving force on structural and kinematic parameters (roller weight, drum radius, blade height, blade inclination angle, acceleration). Experimental studies have established an excess of up to 20 % of the quality indicators of milling sunflower and corn stems with roller knives, the cutting edge of which is directed in the direction opposite to the direction of rotation. The average number of crushed pieces of corn stalks in the range of less than 50 mm is 13.6 % higher in the combined unit, the cutter blades of which are directed with the cutting edge in the direction opposite to the direction of rotation. It was established that with zero and 3.92 kN (400 kg) additional loading, an increase in speed from 7.45 km/h to 13.6 km/h leads to a decrease in the values of the average traction resistance. The highest value of traction resistance was set at a speed of 13.6 km/h and an additional load of 7.84 kN (800 kg). The lowest value of traction resistance was established at zero additional load and a speed of 22.0 km/h, which is 21.5 % less than at a speed of 7.45 km/h and 14.1 % less than at a speed of 13.6 km/h.

A Complex Reaction Network Model for Spontaneous Mirror Symmetry Breaking in Viedma Deracemizations.

Attrition-enhanced chiral symmetry breaking in crystals, known as Viedma deracemization, is a promising method for converting racemic solid phases into enantiomerically pure ones under non equilibrium conditions. However, many aspects of this process remain unclear. In this study, we present a new investigation into Viedma deracemization using a comprehensive kinetic rate equation continuous model based on classical primary nucleation theory, crystal growth, and Ostwald ripening. Our approach employs a fully micro-reversible kinetic scheme with a size-dependent solubility following the Gibbs-Thomson rule. To validate our model, we use data from a real NaClO3deracemization experiment. After parametrization, the model shows spontaneous mirror symmetry breaking (SMSB) under grinding. Additionally, we identify a bifurcation scenario with a lower and upper limit of the grinding intensity that leads to deracemization, including a minimum deracemization time within this window. Furthermore, this model uncovers that SMSB is caused by multiple instances of concealed high-order autocatalysis. Our findings provide new insights into attrition-enhanced deracemization and its potential applications in chiral molecule synthesis and understanding biological homochirality.

TRANSITION FROM THE PLASTIC MODE OF DIAMOND GRINDING OF CERAMICS TO MELTING AND FEATURES OF THE MELTING OF INSTRUMENTAL CERAMICS

It is shown that the traditional method of estimating the specific energy capacity based on the ratio of grinding power to processing productivity does not provide an adequate solution, since with it the specific heat capacity of processing exceeds the specific heat capacity of melting ceramics by almost an order of magnitude, and therefore, any diamond processing of ceramics should immediately enter the plasticity regime, which is not really the case. Therefore, it is the application of a new approach to the assessment of the specific energy intensity of diamond grinding, taking into account the wear of the working layer of the diamond wheel, that makes it possible to assess the possibility of achieving the energy conditions for the transition of ceramic processing to the plastic mode.
 It is shown that the plastic mode occurs precisely when the specific energy capacity of grinding becomes close to the specific heat capacity of melting ceramics.
 It was found that similar to the processes during the thermal melting of ceramics, melting crusts are also formed in the discharge hole during electroerosion grinding. Quantitative analysis of melting products shows that a structure close to the fracture of the sample is formed in the discharge holes after melting, in which there is no oxygen.

Improving flotation decarbonization efficiency of coal gasification fly ash by mechanically breaking pore: An experimental and molecular dynamics simulation study

The high unburned carbon content of solid waste coal gasification fly ash is the main reason that it cannot be used in the construction material industry, which leads to serious waste of resources and environmental pollution. Currently, decarburization flotation has been a dominating method for coal gasification fly ash resource utilization. However, the flotation process has low efficiency and high reagent consumption because of the rich surface porosity of unburned carbon. Herein, we innovatively developed a mechanical grinding strategy to break the pore distribution on the surface of unburned carbon, significantly reducing the pore size, increasing hydrophobic functional groups and improving the flotation efficiency. The removal rate of unburned carbon is more than 95% in flotation tailings with a mechanical grinding intensity of 120 rpm and grinding time of 30 min. Furthermore, the adsorption of water on porous unburned carbon surface was studied by molecular dynamics simulation for the first time, and the results show that decreasing the particle surface porosity of unburned carbon can accelerate the diffusion rate of water molecules on the unburned carbon surface, improve the wettability of the particle surface and increase the adhesion probability between the unburned carbon particles and bubbles and remarkably improve the its floatability. This work is the first application of mechanically breaking pore to the flotation separation of unburned carbon and ash from coal gasification fly ash and provides valuable inspiration for the design of porous particles flotation, not limited to the separation of gasification fly ash.

Particle size distribution in commercial pig compound feeds in Switzerland: survey and methodological considerations.

The grinding intensity of pig feed is considered one potential predisposing factor for gastric ulcers, and a variety of particle size recommendations have been published for pig feeds. We subjected 51 different commercial compound feeds for pigs (38 meals, 13 pellets/granulates) to dry and/or wet sieve analysis. The amount of particles passing the finest sieve (or being soluble) was estimated by the difference to the total dry matter weighed prior to sieving. Mean particle size was calculated based on the weighted average of the material retained on the sieves (MPSsieves), and additionally with accounting for this lost material (MPStotal). Dry sieve analysis of the meals yielded MPSsieves of 0,58-2,90 mm and MPStotal of 0,58-2,89 mm; only 0,02 to 2,71 % of the dry matter passed all sieves. Wet sieve analysis of all meals and pellets yielded similar MPSsieves of 0,63-1,66 mm, but dramatically lower MPStotal of 0,26-1,04 mm; between 35 and 66 % of the dry matter was not retained on the sieves. Pellets had smaller MPS, and a higher proportion of particles passing all sieves than meals. Depending on the reference used, a maximum of 26 % of meals conformed to recommendations for pig feed particle size. None of the pelleted feeds met these criteria, irrespective of the source consulted for the recommendation. Wet sieving should be considered the standard analysis, because in dry sieving, very fine particles adhering to larger particles may not be registered separately but contribute erroneously to larger particle weight. In addition, the MPS calculation should account for material lost through the finest sieve. Reasons why Swiss pig feed does not meet particle size recommendations should be further investigated.

THE REGIME CHOICE WITH EFFECTIVE GRINDING BY THE WAY CONTROL INTER-AXIS DISTANCE MACHINE TOOLS

The problem of effective grinding of rotating surfaces is to improve the quality and increase productivity, while reducing costs. The problem can be solved by controlling the distance H between of the rotation tool axes with the part on CNC machines and rational choosing of a shape tool. The purpose of the article is to increase the grinding efficiency of the rotation surfaces with the end face of the conical abrasive tool by rational choice of mode parameters when controlling the inter-axis distance machine tools. To achieve this goal, the following research objectives should be solved. Determine the modes of grinding by limiting the kinematic factors. To find the influence of the dependence of the angular spatial orientation of the contact line of the tool and the part on the angle of small taper of its formed fragment by choosing the dimensions of the machine adjustment. To analyze the influence of the relative position and size of the contact area depending on the kinematics and technical requirements for processing. For the first time, the kinematic constraints of the limit value of the projection of the speed of relative motion in the normal direction, which is used as the grinding intensity, taking into account the rotational and translational motions of the feed. The spatial angular position of the contact line of the tool with the part is determined taking into account the dimensions of the machine adjustment, namely, the wheelbase and the angle of the circle profile. The algorithm of definition of modes of deep grinding is established. The graphical dependences of the angles of orientation of the contact line on the angle of editing of the circle and the wheelbase of the machine are obtained. The dependences of the reduction of the radial dimensions of the conical surface of the part during grinding in the direction opposite to the axial feed of the wheel are described. The dimensions of the contact area determine the quality: the length along the axis of the part, the number of passes, and the width - the conditions of heat release and cooling

Ancient Maya Embedded Economies and Changing Ground Stone Densities in Households at Actuncan, Belize

In embedded economies where multiple modes of production and exchange exist, artifact distributions in households alone do not reflect the strength of specific modes. We use a diachronic perspective tied to changes in political economies and artifact class densities standardized by excavation volume at the Maya site of Actuncan, Belize, to elucidate changes in the strength of individual production and exchange modes in the Preclassic and Classic periods. We focus on ground stone densities as a measure of grinding intensity across elite and common households. Data indicate that common households always ground more maize than elites, but intensity peaked in the Late Classic when tax and tribute demands and market exchanges were greatest. In the Terminal Classic, common household grinding intensity decreased by half as tribute burdens diminished, illustrating the impact of political hierarchies on household economies.

Mechanochemical preparation of NiCuSn nanoparticles and composites in presence of cetyltrimethylammonium bromide (CTAB) and the catalytic application of the products in homocoupling and hydration of terminal alkynes

We report the synthesis of the NiCuSn nanoparticles and nanocomposites in mechanochemical route using CTAB as milling additive. The study of grinding intensity (frequency) and time interval drew up the importance of the well-chosen operation parameters. The mild milling resulted in formation of NiSn intermetallics, while the intense ones aided the evolution of bronze and copper(I) oxide phases. The utilization of CTAB proved to be the key factor to prevent or slow down the process of mechanical alloying and to fritter the metal grains into the nanodimensions. The dynamic light scattering data demonstrated positively charged particles with average solvodynamic diameters of around 70 nm applying intense or long-term millings. Without CTAB or with relatively short or weak grindings, these values remained between 230 and 550 nm, as in the case of the surface areas getting around 20 m2/g with and 1 m2/g without CTAB. The catalytic transformation of p-methoxyphenylacetylene in dimethyl sulfoxide showed that the copper, copper(I) oxide and bronze particles managed the reaction toward the evolution of 1,3-diyne in Glaser-Hay homocoupling without base addition, while the Sn and SnO2 phases assisted to the Markovnikov-type hydration of alkyne groups. The formation of α-diketone signed that the anti-Markovnikov route was also occurred. The use of CTAB was found to exert a profound effect on the quality of catalytic end-products through the controlled generation of bronze and tin oxide phases and the solid solution of nickel atoms.

Х-ray Study and Computer Simulation of the Structure of Amorphous-Crystalline Titanite

The structure of amorphous-crystalline titanite obtained by mechanical activation was studied by X-ray diffraction and simulation methods. The short-range order characteristics were calculated using Finbak-Warren's method. It was found that the coordination numbers of metal atoms decreased as the result of titanite grinding. The atomic configurations of short-range order of ground titanite were constructed by translation of titanite unit cell. The theoretical X-ray patterns were calculated using Debye's method and were compared with the experimental curves. The structure of ground titanite in the mill with centrifugal factor 40 g was described satisfactorily by the model of mechanical mixture of clusters containing 2016 atoms, disordered during the molecular dynamics with clusters containing 12096 atoms. The increase of grinding intensity led to the sharp decrease of sizes of small cluster.

X-ray Study and Computer Simulation of the Structure of Amorphous-Crystalline Titanite

The structure of amorphous-crystalline titanite obtained by mechanical activation was studied by X-ray diffraction and simulation methods. The short-range order characteristics were calculated using Finbak-Warren's method. It was found that the coordination numbers of metal atoms decreased as the result of titanite grinding. The atomic configurations of short-range order of ground titanite were constructed by translation of titanite unit cell. The theoretical X-ray patterns were calculated using Debye's method and were compared with the experimental curves. The structure of ground titanite in the mill with centrifugal factor 40 g was described satisfactorily by the model of mechanical mixture of clusters containing 2016 atoms, disordered during the molecular dynamics with clusters containing 12096 atoms. The increase of grinding intensity led to the sharp decrease of sizes of small cluster. Keywords: amorphous-crystalline titanite, X-ray diffraction, computer simulation, mechanical activation, Debye's method.

Establishing the effect of a simultaneous reduction in the filling load inside a chamber and in the content of the crushed material on the energy intensity of self-oscillatory grinding in a tumbling mill

The effect of a simultaneous change in the degree of filling a chamber with load κbr and in the content of the crushed material κmbgr on the efficiency of the self-oscillatory grinding process has been estimated.
 Using a method of numerical modeling based on the results of experimental visualization of the flow has helped establish an emergent dynamic effect of the sharp increase in the self-oscillatory action of two-faction loading at a joint reduction in κbr and κmbgr. A significant decrease in the passive quasi-solid loading motion zone has been detected, as well as an increase in the active pulsation zone and a growth of dilatancy. The manifestation of the effect is enhanced by the simultaneous interaction of increasing the scope of self-oscillations and weakening the coherent properties of particles in a loose large fraction under the influence of the particles of fine fraction. A significant decrease in the values of the inertial loading parameters has been established: maximum dilatancy υmax, the relative scale of self-oscillations ψRυ, the maximum share of the active part of κfammax, and the generalized complex degree of dynamic activation Ka. A 2.65-time growth of υmax was detected, ψRυ increased by 5 times, κfammax ‒ by 4.36 times, Ka ‒ by 18.4 times, at a joint decrease in κbr from 0.45 to 0.25, in κmbgr ‒ from 1 to 0.
 The synergistic technological effect of a sharp decrease in the specific energy intensity Еo/Еs has been established, as well as an increase in the relative performance Co/Cs in the self-oscillatory grinding, due to a significant increase in the dynamic action of loading, which is exacerbated by the joint interaction of reduced κbr and κmbgr.
 The process of the self-oscillatory grinding of cement clinker has been investigated. A 62 % reduction in Еo/Еs and a 125 % increase in Co/Cs were detected at a joint decrease in κbr from 0.45 to 0.25, in κmbgr ‒ from 1 to 0.125.
 The established effects make it possible to substantiate the parameters for the energy-efficient self-oscillatory process of grinding in tumbling mills with a conventional structure

CURRENT STATE AND PROSPECTS FOR IMPROVING THE PROCESS OF MILLING FIBROUS SEMI-FINISHED HIGH CONCENTRATION PROCESSES (REVIEW)

There is presented a review of scientific literature characterizing the main directions of modern research of the process of grinding of fibrous semi-finished products of high consistence. Theoretical approaches are described in the study of qualitative parameters of pulp during its processing in knife grinding machines. Researchers note an increase in the paper-forming properties of the pulp and the physical and mechanical characteristics of the finished product. This paper provides an overview of experimental studies of the high consistence pulp milling process. The effect of high consistence mass grinding intensity on the quality of the finished product is considered, the nature of fiber development when grinding high and low consistence mass is compared. Experimental studies show that an increase in the intensity of exposure when grinding a high consistence mass leads to a decrease in the tensile energy absorption index, and a decrease in the deformation of the paper sheet is also observed with an increase in the grinding intensity. With an increase in the pulp c consistence, a change in the degree of delamination, internal and external fibrillation of the fiber wall is observed. The high-consistence pulp milling process is accompanied by higher specific energy consumption compared to low- consistence pulp milling, but observations at the fiber wall level show a more developed external specific surface area. This review of the scientific literature will serve as a basis for further research on the grinding of high consistence fibrous materials.

СОВЕРШЕНСТВОВАНИЕ РАБОЧИХ ОРГАНОВ ДЛЯ ПОЛОСОВОЙ ОБРАБОТКИ ПОЧВЫ ПО ТЕХНОЛОГИИ STRIP-TILL

When cultivating agricultural crops in the system of soil-protective ecologically safe farming, the Strip-Till technology is effective, which allows you to cultivate the soil in strips in the zone of rows and thereby limit the area of the field subject to loosening. The required indicators for loosening the strips in one pass are achieved by the milling tools. Their disadvantage is increased energy consumption. The purpose of the research is to improve the working units of soil-cultivating cutters for strip tillage in the direction of reducing energy consumption. An innovative milling cutter with different-sized knives has been created, which allows, while maintaining a given quality of soil crumbling, reducing the intensity of excessive grinding of the lower part of the milled layer to small erosive hazardous particles. On soil with a moisture content of 21% and a hardness of 1.6 MPa, comparative tests of the innovative and basic cutters were carried out. In the tests, the factors were changed - the depth of processing was in the range of 8-12 cm and the forward speed was from 0.61 to 1.09 m/s. The test results were presented in the form of mathematical models of the relationship of variable factors with the energy intensity of soil milling with innovative and basic structures. In accordance with the method of optimal planning of a multifactorial experiment, a central orthogonal compositional plan was used. An experiment-planning matrix was drawn up for each of the tested structures. With two factors, it contains a core for 2 × 2 = 4 experiments, four star points and one central experiment. By comparing the models, an average reduction of 15.8% in the energy intensity of strip milling of the soil with the use of innovations with the same quality of soil crumbling was established. This allows us to recommend the innovation for use as part of a complex of soil cultivation and seeding machines for cultivation of crops using Strip-Till technology

Дослідження мобільного комбінованого кормоприготувального агрегату

The issues of implementation of the technological process of preparation of feed components for feeding for cattle are considered. The main factors of complete feeding are: a complete set of essential nutrients, timely and affordable and optimally coordinated in quantitative terms of their entry into the bodies of animals. The process of grinding feed components, to a large extent, depends on their physical and mechanical properties. One of the conditions for preparing the feed mixture is the minimum use of additional machines that perform the operations of grinding, mixing and distribution of the finished feed mixture, because it leads to higher energy and labor costs. These costs are associated with additional loading and unloading operations of feed components. In the study of the processes of grinding feed materials, according to the technology of preparation of feed for feeding, using mobile combined feed preparation units, provided their grinding, loading feed components was carried out in the following sequence: first loaded roughage, then root crops, for storage stands out. However, experiments have shown that roughage, in the process of grinding, act as a shock absorber, mitigating the impact loads on the roots of tubers from the knives, cuttings and walls of the hopper. At the first loading of root tubers the process of crushing was more intensive. Experiments with long-fiber materials and roots, showed that the presence of crushed roots in the hopper, when loading roughage, the duration of grinding of the latter does not affect. To intensify the process of grinding long-fiber materials (straw), experiments were conducted with the addition of feed with a larger bulk density (silage), which was introduced after the destruction of the roll. The results of research have shown that the addition of silage can increase the intensity and degree of grinding of straw, this is due to the compaction of the mass in the active cutting zone. This solution allows you to reduce the technological time of the unit and increase its productivity.

Establishing the effect of decreased power intensity of self-oscillatory grinding in a tumbling mill when the crushed material content in the intra-chamber fill is reduced

The influence of the content of crushed material in the intra-chamber grinding fill on the efficiency of the self-oscillatory grinding process in the tumbling mill was assessed. A dynamic effect of a significant decrease in self-oscillatory action of the two-fraction fill of the rotary chamber with an increase in the content of fine fraction was revealed by the method of visual analysis of motion patterns. A decrease in values of the following inertial fill parameters was established: maximum dilatancy υ max , the relative amplitude of self-oscillations ψ Rυ and a maximum share of the active part κ fam max with an increase in the degree of filling the gaps between particles of the coarse fraction κ mbgr . A decrease in the generalized complex degree of dynamic activation K a was also established. The effect is due to the strengthening of the cohesive properties of the incoherent coarse fraction under the influence of the fine fraction. There was a decrease in by 29 % for υ max, by 7 % for ψ Rυ , 2.9 times for κ fam max and 4.2 times for K a with an increase in κ mbgr from 0 to 1 at the degree of filling the chamber with the fill κ br =0.45. Technological effect of a significant decrease in specific energy intensity and an increase in productivity of the innovative self-oscillatory grinding process in comparison with characteristics of the conventional steady-state process at a decrease in the content of crushed material in the fill was established. A process of milling cement clinker with grinding bodies at relative size of 0.026 and κ br =0.45 was considered. A decrease in specific energy intensity by 27 % at κ mbgr =1, by 38 % at κ mbgr =0.5625 and by 44 % at κ mbgr =0 was found. An increase in relative productivity by 7 % at κ mbgr =1, by 26 % at κ mbgr =0.5625 and by 39 % at κ mbgr =0.125 was established. The established effects will make it possible to forecast rational parameters of the self-oscillatory grinding process in a tumbling mill at the variation of the content of the crushed material in the fill