Hammer Crusher Research Articles

Identifying the influence of the pitch of hammers with cutting edges on the average length of feed crushed in hammer grinders

The object of the research is to identify the influence of the pitch of the hammers with cutting edges on the determination of the average length of feed, crushed from by-product stem raw materials in hammer crushers. However, a problem was identified such as the lack of an analytical expression for determining the average length of chopped stem feed by a hammer grinder depending on the distance between the edges of adjacent hammers. With a simultaneous change in the angles of the location of the stem with the maximum size in the layer and, using the methods of probability theory for determining the mathematical descriptions of the function of two arguments, in this study an analytical expression was obtained for determining the average length of particles crushed by hammer crushers depending on the distance between the faces of adjacent hammers. Hammers with cutting edges are used to crush feed from by-product stem raw materials. The end working part of the hammer is milled at an angle of 90°, i.e. two cutting edges are processed at the end of the hammer. As a result of the practical calculations, the average length of feed crushed from by-product stem raw materials was determined depending on the parameters of the hammer crusher. From the resulting graph of the influence of the distance between the faces of adjacent hammers on the average length of crushed particles, it is evident that when the distance between the faces of adjacent hammers changes, the average length of crushed particles varies within the range of 36.19...53.39 mm. To verify the reliability of the obtained expression, experiments were carried out on a crusher with a distance between the faces of adjacent hammers of 20 mm. In this case, the average length of the crushed particles was equal to 38.75 mm, and the theoretical value was 40.16 mm. The difference between them was 3.64 %, which proves the reliability of the obtained analytical expression. The conducted theoretical studies with the receipt of an analytical expression, ensuring the determination of the average length of feed, chopped from by-product stem raw materials, is the solution to an important problem in the development of theoretical foundations of chopping machines, significantly affecting the efficiency of mechanization and operation of feed choppers in practice

The Diatomite Grinding Technology Concept for the Protection of Diatomite Shells and the Control of Product Grading.

Diatomite deposits in Poland are located in the Podkarpackie Voivodeship, and the only active deposit is in Jawornik Ruski. Therefore, it is a unique material. Improved rock processing methods are constantly in demand. In the research presented here, we have used research methods such as X-ray diffraction (XRD), scanning electron microscope (SEM), particle shape analysis, and appropriate sets of crushing machines. Diatomite comminution tests were carried out on test stands in different crushers (jaw crusher, hammer crusher, high-pressure roller press, ball mill) using different elementary crushing force actions: crushing, abrasion, and impact, occurring separately or in combination. The machines were tested with selected variable parameters to obtain products with a wide range of grain sizes ranging from 0 to 10 mm. The ball mill (yield 87%, system C3) and the hammer crusher with HPGR (high-pressure grinding roller) (yield 79%, system D2 + D3) have the greatest impact on diatom shell release and accumulation in the finest 0-5 μm and 5-10 μm fractions. For commercial purposes, it is important to obtain very fine fractions while keeping the shells undisturbed.

Analysis of failure characteristics of screen plates of ring hammer crusher used in coal handling applications

The screen plate, a critical component within a ring hammer crusher (also known as a ring granulator or rolling ring crusher), plays a vital role in the secondary crushing of coal. Functioning both as a platform for coal crushing and as a sieve to achieve the desired coal size, it is essential to understand and examine its failure characteristics to enhance its mechanical and wear resistance properties in coal handling applications. This study thoroughly explored the failure modes, mechanisms, and underlying causes of screen plate failures. Microscopic techniques such as optical microscopy (OM), scanning electron microscopy (SEM), Vickers microhardness test and spectrochemical analysis were utilised to identify the failure mechanism. Failure modes identified from the macroscopic analysis were discharged hole widening, hole wall break-off, plate edge crack, plate fracture, one-sided edge slimming, and general surface wear of the screen plate. The fractographic and wear track analysis identified the principal failure mechanisms of three-body abrasive wear, two-body sliding abrasion wear, shear-induced fatigue fracture and brittle shear fracture. The root causes of the failures are the rotor’s direct impact, defects in the parent material, the presence of hard materials in the coal and the use of unsuitable steel grade in the screen plate manufacturing. The service life of the screen plate can be improved through proper material selection, uniform crusher feeding, surface modification of the surface of the “as purchase” screen plate with appropriate wear-resistant materials, and adherence to good maintenance practices.

Analisis Pembebanan Statis Komponen Crossbar Clinker Cooler dengan Variasi Beban Horizontal terhadap Lubang Pasak

A clinker cooler is a very important piece of equipment in the cement industry because it functions to cool the slag or clinker that comes out of the kiln. In the cement industry, the processed clinker is first heated in a rotary kiln at °C and then lowered to temperature again. Next, the crossbar hammer crusher driven by the drive plate crushes the clinker. Clinker is transferred from the cooler inlet to the cooler outlet by this device. The performance of the main clinker cooler due to small errors can cause the kiln to stop working or disrupt other operations, such as in the mile finish area. In certain cases, cement production was disrupted due to a break in the crossbar component in the clinker cooler using the tested software Ansys Workbench 2020. It is hoped that the data from this simulation can be used as a benchmark between the results of the simulation, it can be used as a benchmark between the results of the best modified design for increasing crossbar durability through statistical loading tests with the FEA method.

Analysis of the influence of wear of working parts on the efficiency of crushing process in a hammer crusher

Analysis of the influence of wear of working parts on the efficiency of crushing process in a hammer crusher

Substantiation of the main parameters of a hammer crusher for grinding municipal solid waste

The scientific novelty of the research lies in the determination and substantiation of the rational values of the main parameters of a hammer crusher designed for grinding organic components of municipal solid waste. A method has been developed for calculating the speed and effort, as well as the maximum elastic-plastic deformation of the components of the waste due to the collision of the waste against each other, against the wall of the working chamber of the crusher, as well as against knives welded on the walls of the working chamber at different heights at an angle of 120 degrees with each other. The aim of the study is to develop a hammer crusher design with low energy and material consumption with increased technical and operational performance. As a result of the experimental studies, the dependences of the crusher performance on the number of revolutions of the rotor shaft, on the light area of the grates, and on the diameter of the rotor were obtained. The processing of the obtained experimental data made it possible to obtain a mathematical model that adequately describes the process of crushing the organic components of the waste in a hammer crusher. Design and production of hammer crushers with rational parameters will reduce energy and material consumption by approximately 1.5-2.0 times compared to traditional designs.

Selection of an optimal set of machines for sorting and crushing municipal solid waste

The article is dedicated to the selection of the optimal set of machines for sorting and crushing municipal solid waste based on its properties and accumulation rates. Considering the properties of waste and technologies for its collection, a new technological scheme for processing municipal solid waste was developed and, based on this scheme, the optimal set of machines was selected. In addition, the research conducted to determine the fractional composition of the waste made it possible to substantiate the diameter of holes in the drum screen mesh. Based on the analysis of the morphological composition of the waste at the end of the technological chain, the type of crusher design was determined and the main parameters of the hammer crusher were substantiated in connection with the technological processing. The optimal set of machines will make it possible to process the components of municipal solid waste for use in the form of secondary raw materials with the least material and time costs.

Mechanical and physical aspects of the theory of interaction between a crusher hammer and an air-grain layer

When crushing various raw materials of mineral, vegetable and animal origin hammer crushers of various designs are widely used, in which the rotor with hammers attached to it can be located both horizontally and vertically. During the operation of a hammer crusher with a vertical axis, a stable air-grain layer is formed near its deck, upon contact with which the crusher hammers wear out, and the wear itself depends on the contact stresses acting in the layer and the path (stay time) of the hammers in it. The problem posed is similar to the well-known problem of applied physics about a rotating disk, with the difference that tensile stresses act on the disk, and compressive stresses act on the air-grain one. The article obtained a theoretical expression for the linear wear of the crusher hammer, which depends on the characteristics of the layer, the properties of the crushed material and the grinding time, and in a complex way - from the distance from the edge of the hammer to the axis of its suspension. A comparison of the theoretical wear curves with the real outlines of worn hammers shows their identity.

Numerical Simulation of the Collision Breakage Process between the Agglomerate and Hammer in a Hammer Crusher Using DEM

This paper focuses on simulating the collision breakage process between the agglomerate and hammer in a hammer crusher by the discrete element method (DEM) as the interaction between particles. This enables us to consider the energy change in the collision breakage process of the hammer. The agglomerate model is built by using the EDEM 2.7 software according to the principle of closest packing in crystallography, while the hammer model is modeled into an assembly of different sizes of spherical particles to make the collision breakage process between the agglomerate and hammer as the one of interrelation of particles. With these models, we mainly investigated collision force, collision impulse, energy breaking agglomerate, and the relationship between the specific breakage energy and agglomerate damage ratio. The collision force is represented as Gaussian function, the collision impulse is represented by the function of the mass ratio of agglomerate to hammer and the product of agglomerate mass and collision velocity, and the relationship between the specific breakage energy and agglomerate damage ratio is represented by exponential function. Finally, it can be seen from this study that, when crushing the agglomerate by hammer impact, it is necessary to increase the specific breakage energy by 1.75 times in order to increase the agglomerate damage ratio from 85% to 90% but 2.13 times in order to increase 95%. The proposed method can be used for the further development and design of the various types of crusher.

RESEARCH ON WORKING BODIES OF HAMMER CRUSHERS EMPLOYING THE FINITE ELEMENT METHOD

The present paper studies the issues of improving the reliability of the working bodies of hammer crushers. This machine is widely used for grinding grain material in animal husbandry and the processing industry. The main wear element of such crushers is the hammers and disks to which they are attached. To study the strength characteristics of these parts, a technique and algorithm for studying the stress-strain state of the hammer crusher disc employing the finite element method (FEM) using computer simulation software products were developed. The mathematical apparatus of finite element method simplifies the model construction where the stress-strain state must be explored. Finite element method provides solutions in the form of stress and deformation fields in almost any cross-section of structural parts. The express analysis module of the APM FEM COMPASS system was used as the software for this work. The implementation of finite element methodwill reduce the metal intensity of the equipment, increase the reliability of its operation and reduce the cost, improve the quality of the feed produced. The results of the study showed that the maximum stresses occur on the surface creating the internal holes in the place of attachment of the disc to the shaft, but the stresses that occur there remain within the normal range.

Modelling the Rheology of Olive Paste for Oil Extraction Plant Automation: Effects of the Crushing Process on the Rheology of Olive Pastes.

In extra virgin olive oil production, it is essential to obtain a well-prepared olive paste which allows not only the extraction of the oil drops from the olives, but also the achievement of a high-quality oil while maintaining high yields. This work addresses the problem of determining the effect of three crushing machines on the viscosity of the olive paste: a hammer crusher, a disk crusher and a de-stoner were tested. The tests were repeated on both the paste leaving each machine and the paste to which water was added; this was done with the main aim of considering the different dilutions of the paste while entering the decanter. A power law and the Zhang and Evans model were used to analyse the rheological behaviour of the paste. The experimental results allow validation of the two models with a high (more than 0.9) coefficient of determination between experimental and numerical data. The results also show that the pastes obtained with the two classic crushing methods (hammers and disks) are almost identical, with a packing factor of about 17.9% and 18.6%, respectively. Conversely, the paste obtained with the de-stoner entails higher viscosity values and a smaller solid packing factor, of about 2.8%. At 30% dilution with water, the volume of the solid concentration dropped to about 11.6% for the hammer and disc crushers, while for the de-stoner it only reached 1.8%. This behaviour is also reflected in the evaluation of yields, which were 6% lower with the de-stoner. No significant differences regarding the legal parameters of oil quality were found using the three different crushing systems. Finally, this paper establishes some fundamental pillars in the research for an optimal model for identifying the rheological behaviour of the paste as a function of the crusher used. Indeed, since there is an increasing need for automation in the oil extraction process, these models can be of great help in optimizing this process.

Development of a two-stage cyclone

The process of separating the transported material from the carrying gas flow in cyclones at grain-processing enterprises is studied. Feed production is accompanied by the formation of fine flour dust which is a valuable component of fermented feed. Aspiration systems of mini-fodder plants do not provide its full capture, which leads to contamination of the premises, as well as the loss of some of the product. During the analysis of designs and ways to improve centrifugal apparatuses, it was determined that installation of additional swirling devices in the cyclone exhaust pipe is promising for cleaning the air flow from fine dust. The design of cyclone with an additional stage of cleaning the air flow from fine flour dust in the outlet nozzle, used in the pneumatic conveying system of mini-fodder plant, is proposed. The diameter of the axial pipe socket is enlarged to accommodate the baffle cone and vortex funnel inside it. The diameter of the outlet nozzle should be smaller than the diameter of the upper base of the vortex funnel to reduce the fine fraction escape from the cyclone. An experimental unit was developed including a charging hopper, pneumatic receptor-diverter, material pipeline, cyclone, filter, and a suction fan. The material used was wheat grain with a moisture content of 16%, crushed on a hammer crusher with a hole diameter of 3 mm in the sieve. Comparative tests of the proposed cyclone with cyclones of the DC and SNT types were carried out, the results of which prove the effectiveness of the proposed design. In the investigated range (from 0.026 to 0.33 kg/s) the efficiency of the two-stage cyclone in feeding the transported material was higher than that of the commercially available discharger cyclones DC.

Flotation of copper smelter slags intensified by impact crushing

This paper examines the mineral and chemical composition of converter slags generated by Balkhash Copper Smelter, as well as the forms in which copper ispresent in them. The paper describes the results of flotation of the above product, which was prior subjected to fine crushing in jaw and hammer crushers. The paper features a comparative analysis that looks at the size distribution and the distribution of the key valuable components by grain size of the slag pre-crushed in jaw and hammer crushers. It is shown that the different breaking techniques realized by these crushers influence the size distribution of the crushed product, the share of particles smaller than 0.071 mm and the distribution of copper by fraction. The authors looked at the grinding kinetics of the copper smelter slags pre-crushed in the above specified crushers and compared the share of –0.071 mm particles, as well as that of –0.045 mm particles (which are the finest fraction). It was established that the optimum hammer crushing duration is 45 min. A longer duration leads to overgrinding. At the same time for the jaw crusher, the overgrinding effect and the accumulation of the –0.045 mm particles become expressed if the crushing cycle lasts for 60 min. Flotation of the pre-crushed converter slags resulted in a quality concentrate containing 27.5 to 39.0 wt % copper (depending on the slag crushing duration). In all cases, the recovery of copper was every time higher (by 5% on average) for slags pre-crushed in the hammer crusher. It is pointed out that impact crushing of copper smelter slags significantly intensifies the flotation process. This should be taken into consideration when optimizing the processing schemes.This research was funded by the Russian Science Foundation; Agreement No. 22-27-00526.

Spindle optimization and reliability analysis of ring hammer crusher

In this paper, ANSYS Workbench is used to carry out static analysis on the main shaft of ring hammer crusher, and the equivalent stress nephogram and displacement nephogram of the main shaft are obtained, and the strength and stiffness of it are checked. Taking total mass of the main shaft as the objective function, with the maximum strain and equivalent stress, the central composite experimental design method and MOGA algorithm are used to optimize the size structure of the main shaft, so that the optimized size can not only meet the strength requirements, but also reduce the material. Finally, according to the optimization analysis results, the reliability of the optimized spindle is analyzed by six sigma analysis. The results show that the quality of the optimized spindle is reduced by 18.0% under the condition of satisfying the strength and stiffness, and the reliability of it also meets the requirements.

Определение оптимальных конструктивно-технологических параметров молотковой дробилки с решетами в торцевых поверхностях

When preparing compound feeds, the main machines used for grain crushing are hammer crushers. To obtain a better-quality finished product with lower energy costs, it is necessary to determine the optimal design and technological parameters of a hammer crusher. To this end, the laboratory of livestock production mechanization has designed a hammer crusher with sieves in the end surfaces. The hammer crusher has adjustable cross-sections of the sieve holes, so there is no need to replace the sieves. Experimental studies have been carried out at the production facilities of the North-East Federal Agency of Scientific Institutions to determine the impact of changes in structural and technological parameters of the crusher on its main performance indicators. According to the results of experimental studies, mathematical models of the working process of the hammer crusher have been obtained. As a result, the optimal design and technological parameters of the hammer crusher have been determined: the area of the sieve openings 58.6 мм2 ; the height of the material separation ring 40 mm and the size of the air filter area 6 m2 , while the throughput capacity of the crusher is 1.23 t/h, specific energy consumption is 3.44 kWh/(t×units of fineness degree), the average size of crushed particles is 1.45 mm, the share of whole grains in the finished product is 0.17%.

Vibration processes resulting from uneven rotation of the hammer crusher drive pulleys

Livestock farming, as one of the main sectors of the agro-industrial cluster, cannot do without good quality forage. For the best absorption of feed, all the nutrients that make up its composition should be given to the animals in a milled form. Hammer mills are among the most compact machines for milling. The grinding of grain forages is a rather energy-intensive process. One of the variants for solving the power intensiveness problem can be the application of a a hammer crusher with periodic fluctuations in the angular speed in the rotation of the the working body. That is accompanied by the appearance of additional external stimulating force - vibration on the elements of a hammer crusher. In the article the question of vibration occurrence at non-uniform rotation of a crusher working body drive pulleys is considered. And such parameters as vibration acceleration, vibration displacement, and vibration velocity in three different axes are considered. In order to optimise the vibration parameters, experiments were carried out on units of different designs with different centre of rotation offset (2 mm). At this uneven rotation speed of 1800 min-1, the vibration velocity on the X-axis increased by 546% and 200%, depending on the machine design. The vibration displacement on the same axis, even at 450 min−1, increased by 442%. Based on these results, we examined the prerequisites for the investigated hammer crusher drive design, which is expected to improve the separation and evacuation process of the crushed product from the crushing chamber, and have an overall positive impact on the crushing process.

PROSES CRUSHING MATERIAL LIMESTONE UNTUK BAHAN BAKU DALAM PROSES PRODUKSI SEMEN DI PT SEMEN BATURAJA (PERSERO) TBK

Cement is the main raw material in infrastructure development. Good infrastructure is supported by a good cement production process, so competent engineers are needed in the cement production process. This activity aims to understand the workings of the limestone crusher used in the cement manufacturing process at PT Semen Baturaja (Persero) Tbk. The data collection methodology in this activity, namely taking references from journals and books about the cement production process (secondary data), as well as interviews and direct observation with field supervisors and equipment operators in the cement production process (primary data). The data that has been obtained is then showed so that it is known that in the process of crushing the limestone material at PT Semen Baturaja (Persero) Tbk, the crusher used is a hammer crusher type hydraulic unit with 2 hammers flanking each other to crush the material. Limestone is the most important raw material in the process of making cement.

DEVELOPMENT AND RESEARCH OF A VIBRATING DRYER FOR PROCESSING OF WET DISPERSED WASTE OF FOOD INDUSTRIES

One of the most urgent problems of Ukrainian food industry enterprises (in particular, sugar, alcohol, brewery, coffee), as well as enterprises producing fruit and berry juices, is the processing of wet dispersed waste with an initial moisture content of 90-95%. As practice has shown, these wastes after dehydration to a moisture content of 20-25% can be effectively used as valuable additives to agricultural fodder or as fuel. At the same time, the specified final humidity can be ensured by the sequential implementation of mechanical methods of dewatering the processed material on a vibrating screen, in a screw press and vibrating impact load in a closed press-form, which allows to significantly reduce energy costs compared to thermal dehydration. But for longer storage of the specified waste, a moisture content of no higher than 8% is required, which can be achieved only after their additional heat treatment. The article proposes a scheme of a combined dryer in which processed waste sequentially passes through the stages of mechanical dehydration in screw feeders, grinding in a hammer crusher, processing on vibrating screens with spatial dynamic loading and final thermal dehydration in a fluidized state in jets of hot air or steam, which are secondary products of this enterprise. At the same time, the offered dryer provides a closed working process, which allows, if it necessary, to dehydrate the same portion of waste several times until the optimal final moisture is reached. The article also presents equations and dependencies for determining the duration of waste dehydration at each stage of the dryer's work process, its productivity in terms of dehydrated waste and the total power of the electric motors of the proposed equipment. All this allows you to evaluate the effectiveness of the considered dryer in comparison with other machines of a similar purpose.

Research on the high-efficiency crushing, sorting and recycling process of column-shaped waste lithium batteries

The efficient and environmentally friendly recycling technology of waste lithium batteries has become a research hotspot, in which mechanical crushing is an important part of the recycling process. Through experimental methods, the compressive and impact properties of columnar lithium batteries were studied, and the crushing product characteristics and crushing efficiency of the single tear crushing method, single hammer crushing method, and two-step crushing method were investigated. The study shows that the two-step crushing method could achieve 100 % dissociation of all battery components, and the crushed products can be recycled according to their particle size distribution characteristics. The power consumption of the two-step crushing method was only 23.59 % of that of a single hammer crusher, and the reduction of carbon dust emission in the crushing process was as high as 76.29 %. The high crushing efficiency and environmentally friendly of the two-step crushing method are of great practical significance for the subsequent industrial promotion of waste battery recycling.

Modernization of drive of vertical hammer crusher VMD-105 at Orenburg Minerals

The authors inform briefly about the Russian mining company—JSC Orenburg Minerals, which produces chrysotile asbestos and chrysotile fiber. With an increase in production volume, it became necessary to increase productivity of crushing process on vertical hammer crushers (24 pcs.) installed at the stages of fine crushing. For this purpose, modernization of the drive of vertical hammer crusher VM -105 was proposed, which allowed to increase its productivity by 10% owing to changed gear ratio of the V-belt transmission from 1.64 to 1.4 after replacement of pulleys (the diameter of the drive pulley was increased from 335 mm to 355 mm, and the diameter of the driven pulley was reduced from 550 mm to 500 mm). At the same time, the existing design of the basic parts was used and, in particular, the axial distance of the V-belt transmission was preserved. Thus, the proposed modernization avoids structural changes to the body parts and, thereby, provides a fairly simple and efficient replacement of the drive. The calculations show that the implementation of the design solutions enables a reduction in the cost of one ton of mined ore by 0.94%, tan increase in the profitability of products by 5.19% and an increase in the labor productivity by 2.95%. Additional capital costs for the modernization of all 24 vertical hammer crushers installed at the stages of fine crushing amount to about 8 million rubles and pay off in less than 6.5 months. The project is effective, pays off quickly and is recommended for the implementation at JSC Orenburg Minerals and other mining companies.