Mill Line Research Articles

PECULIARITIES OF BREEDING TO CREATE LINES OF AN ODORIFEROUS HERB-PARSLEY

Purpose. To elucidate peculiarities of breeding to create parsley lines, to identify lines with increased values of valuable economic traits, to create and to reproduce new combining-able genotypes. Methods. Field, measuring and weighing, laboratory, computing, and analytical. Results. The results of the evaluation of garden parsley Petroselinum crispum Mill (Nym) lines are presented. The lines that combine high yields of leaves and roots, marketability, compact leaf rosettes, high content of vitamin C in leaves, shortened roots, and good combining ability have been selected. Line 'Korotkoplidna' has a compact rosette of leaves (20.3 cm long, 24.8 cm wide); its root is 26% shorter (18.2 cm long) than in the check accession, Kharkivianka; it yields 32.5% of roots more (22.8 t/ha); its marketability is 21.5% better (94.8%); the vitamin C content is 36.95 mg/100 g higher (210.15 mg/100 g); and its leaves accumulate low levels of nitrates (1,164 mg/kg). Line 'Perspektyvna' has a shortened root (by 29% or 17.4 cm long), yields 21% of leaves more (6.9 t/ha) and 22.1% of roots more (21.0 t/ha) the check accession; its marketability is 14.7% better (88.0%); the vitamin C content is 43.92 mg/100 g higher (217.12 mg/100 g); and its leaves accumulate low levels of nitrates (1,020 mg/kg). Line 'Vitaminka' was distinguished due to a compact rosette of leaves (18.3 cm long, 27.0 cm wide) and a shortened root (by 29% or 17.4 cm long); it yields 40.3% of leaves more (8.0 t/ ha) and 13.4% of roots more (19.5 t/ha); its marketability is 18.7% better (92.0%); and its leaves accumulate low levels of nitrates (977 mg/kg). Conclusions. Thus, the breeding studies allowed for identification of the promising garden parsley lines to use in breeding programs. One leaf parsley line and 3 turnip-rooted parsley lines have been selected; two of them ('Korotkoplidna' and 'Perspektyvna') have been transferred to the National Center for Plant Genetic Resources of Ukraine.

Improving the design of the lining of the ball mill used to improve the quality of grinding

This article discusses the traditional ball mill lining used and the improved ball mill lining. Experimental data of the proposed and previous linings are presented. The economic effect of using a new improved ball mill lining design is shown. Also, based on the dimensions of the ores, their mechanical properties, the material and construction of the detail were selected first. It is recommended to use high-manganese steel alloy, if corrosion occurs due to friction, and chromium – molybdenum steel alloy as the material of the detail. As a result of changing the design of the part in the proposed technology, it can be seen that the ore crushing process has improved. As a result of the good ore grinding process, it became easier to extract metals and alloys from the crushed ore. In order to obtain research results, several studies were conducted using traditional and improved technology. Thanks to this technology, the economic efficiency of the production enterprise has increased due to the improvement of ore crushing, the increase of the service life of the part, the saving of resource energy, and the reduction of the time required for technical repairs.

Terminal sliding mode control based on recursive stochastic configuration network for ball mill lining replacement process

The precise control of multi-joint manipulators presents significant challenges in the context of replacing internal liners of large grinding machines. These challenges arise due to the uncertainty of system parameters and external disturbance. A terminal sliding mode control based on a recursive stochastic configuration network is proposed to ensure that the system is stable, and it reduces system oscillations in this article. In addition, a disturbance observer based on recursive stochastic configuration network is designed to estimate and compensate for the uncertainties in the system, thereby improving the robustness of the system. To enhance the realism of the simulations, the simulation modeling process incorporated uncertainty parameters and external disturbance information. The simulation results demonstrated the effectiveness of the proposed terminal sliding mode control approach in meeting the practical control requirements. This accomplishment presents a valuable new method for controlling mechanical arms. The method is applicable under conditions of system uncertainty and external disturbance.

TEGA Industries Ltd: Journey of an Indian MNC (Part B)

Madan Mohanka set up Tega Industries Ltd. in 1976 to manufacture abrasion-resistant rubber mill lining products used in the mining and mineral processing industries. In 2011, as part of its inorganic expansion strategy, Tega bought a company in Chile. However, post-acquisition, several managerial, legal and commercial problems crept up in its manufacturing facilities in Chile, leading to financial downturn in Tega's fortunes in 2016 and compelling it to planning a revival between 2016-19. However, political unrest and Covid 19 uncertainty has caused a dilemma related to further investments worth INR 1.25 billion. Management is contemplating the next steps.

ВЫБОР ЖИДКОСТНОКОЛЬЦЕВОГО ВАКУУМНОГО НАСОСА ДЛЯ ШАРОВОЙ МЕЛЬНИЦЫ С ВАКУУМНЫМ ОТВОДОМ

The use of powders is of interest in many industries. At the same time, the degree of grinding of materials depends on the intended purpose; in particular, in the production of paints, it is necessary to ensure a certain fineness of grinding of the pigment. The smaller the particles, the higher its hiding power. However, excessively high grinding fineness may reduce the hiding power of the pigment. It is proposed to grind the pigment in a two-section cylindrical-conical ball mill with vacuum removal of particles of a given degree of grinding. The article describes the design of the mill and shows a diagram of the line for vacuum transportation of the crushed pigment. The purpose of the work is to determine the main parameters of the vacuum line of pneumatic transport when grinding solid organic materials using a ball mill with a vacuum outlet. A method for calculating the geometric, kinematic and dynamic parameters of the developed mill and pneumatic transport line is presented. A significant reduction in energy costs for excess grinding is achieved through timely vacuum removal of crushed particles. The vacuum in the system is created and maintained by a liquid ring vacuum pump. Various options for the operation of the developed installation are described: direct grinding; additional grinding and recirculation of additional liquid generated during the operation of the liquid ring vacuum pump, which further reduces energy costs during grinding

Online Grain Size Measurement by Laser Ultrasonics in a Hot Rolling Mill

Laser ultrasonics (LUS) has shown through numerous studies and in-situ laboratory experiments, its suitability to track microstructural features evolution as well as metallurgical transformation in steels during thermal cycles with temperatures reaching 1250°C. This prior work has motivated the use of this technology to be in applied in an industrial hot strip mill (HSM) in Eisenhüttenstadt, Germany. For this purpose, a transportable trolley which embedded LUS components (Generation and Detection Lasers, Two-Wave Mixing Interferometer, Dedicated Fibered Optical Head) was designed. The industrial investigation was carried on moving strips during normal production at several locations of the HSM, resulting in signals for high-strength lowalloy (HSLA) and advanced high-strength steel (AHSS) grades. The development of a specific data processing tool allowed calculating the grain size from the analysis of the online recorded signals. Such results were then compared to predictions from metallurgical models, finding reasonably close values. LUS appears as a suitable solution to monitor microstructural features and metallurgical transformations occurring in steel in a Hot Strip Mill (HSM) line. This approach could enable in the future the development of more reliable models and control loop of the process. This action was supported by the European commission and led by a consortium composed by ArcelorMittal, Imagine Optic and IMI-NRC.

Обеспечение качественной обработки внутренней поверхности электросварных труб на операции удаления грата в линии стана

The paper presents results of reviewing literary and patent sources on design and technological solutions in grinding (notching) the internal burr in the electric welded pipes production. Based on the review data, optimal designs were determined of the internal deburring stabbing tool located on the deburring machine rod. Studies were carried out on stabbing the internal burr in the production of pipes with the diameter of 60.3...73.0 mm in the pipe electric welding unit line using various methods and design solutions. Quantitative indicators were analyzed of designs of the internal deburring machine rods with the deburring function. Based on results of the practical studies of various methods for dividing the internal burr into parts in the mill line, the optimal option for designing the internal deburring machine rod was determined. This design makes it possible to reduce the number of emergency stops at clogging with long segments of the remote burr by the mill transport line, increase coefficient of the equipment (mill) effective operation and the yield of the useful products, as well as ensure the high-quality washing out of small segments of the removed internal burr inside the pipe with a high-pressure water jet at the flushing operations.

Assessment of effect of lining material on energy efficiency of starting up ball mills

The article presents the possibility of increasing the service life of mill lining. Special attention is paid to the use of rubber linings for mills. A mathematical model of the asynchronous motor of ore grinding mills has been developed, i.e., the moment of resistance is shock. A system of equations for a synchronous motor of a mill plant for the d and q axes is described. Based on mathematical modeling of mill plant operating modes, it was determined that the corrosion coating prolongs the mill's service life, and the transition time is reduced to 10%.

Using machine learning regression models to predict the pellet quality of pelleted feeds

Pelleted feeds are widely used in monogastric animal production systems because they not only improve animal performance (increasing digestibility and feed consumption) but are convenient to store and handle. However, pellet quality can be affected by many factors. While previous studies have reported the effect of a single or several factors on pellet quality, no studies have investigated how pellet quality can be affected by the large number of factors that vary during feed manufacturing. Therefore, the current study reports using machine learning regression models to predict pellet quality using commercial feed mill data. A dataset consisting of 2471 observations describing the pellet manufacturing process, the feed formulation, and environmental conditions (e.g. outdoor temperature) were collected from two feed mill lines for 8 months. Sixteen features (13 continuous, 3 categorical) were used for building the regression models, and the output was the pellet durability index (PDI) of the pelleted feeds. Twelve regression algorithms including Linear Regression (LR), Least Absolute Shrinkage and Selection Operator (LASSO) regression, Ridge Regression (RR), Support Vector Regression (SVR), Linear Support Vector Regression (LSVR), Random Forest (RF), Decision Tree (DT), Gradient Boosting Regression (GBR), Adaptive Boosting Regression (ABR), Multi-Layer Perceptron (MLP) neural network, K-Nearest Neighbor (KNN), and Stacking Regression (SR) were examined in this study. Feature importance analysis using permutation importance was performed to identify what features were most relevant for each model. Average outdoor temperature, bakery byproduct and wheat inclusion levels, as well as production line all had high permutation importance values, while the fat added into the mixer (with controls at the mill already in place to limit it) was less important than most features. The cleaned dataset was preprocessed and then split into a training (80 % of total samples, n = 1147) and a testing (20 % of total samples, n = 287) set. A 5-fold cross-validation process was applied and learning curves were used to verify the presence of overfitting for each algorithm before and after tuning the hyperparameters on the training set. The models that exhibited overfitting were excluded from the final results and only models with tuned hyperparameters were evaluated on the testing set. The SVR algorithm was selected as the best overall model for predicting PDI, as it had the lowest mean absolute and mean squared prediction errors (MAE = 3.280, MSPE = 16.192), and the second highest concordance correlation coefficient (CCC = 0.636). In conclusion, this study shows that feed mill features describing manufacturing parameters, feed formulation, and environmental data can be successfully used to build machine learning regression models for pellet quality prediction.

REACHING THE HIGH LEVEL OF MECHANICAL PROPERTIES IN THIN-WALLED TUBULAR PRODUCTS AND SHAPES OF HIGH STRENGTH STEELS

To produce thin-walled tubular products and profiles with high level of mechanical properties, it is advisable to use two-phase (DP) steel, which has a ferritic-martensitic microstructure. The main technological element in the production of such products, which provides a combination of high strength and ductility is a special heat treatment in the temperature range from A1 to A3. This heat treatment provides a microstructure consisting of a soft ferrite matrix containing martensite inclusions located at the grain boundaries. Tubular products and profiles made of high-strength steels are obtained in continuous units, in which the areas of heating, deformation and cooling are separated. In this case a water-air sprayer must be integrated into the mill line for controlled cooling of the outgoing product. In the case where the deformation process takes place at temperatures below A1, it is rational to carry out the heat treatment directly in the line with heating by means of a through-inductor followed by cooling.

Requirements for graphite-containing lubricants and equipment for applying to a controlled-moving mandrel in the manufacture of pipes from stainless steel grades in a continuous mill line

In order to reduce the negative impact of temperature-deformation conditions on a working surface of a controlled-movable mandrel and improve the quality of resulting pipes, graphite-containing lubricants are used in modern pipe rolling mills in the line of a continuous rolling mill in the production of pipes, which is applied in the form of an aqueous suspension. Thus, the resulting continuous separating graphite coating makes it possible to reduce the coefficient of friction when the mandrel contacts the deformable metal. This, in turn, ensures the stable operation of the rolling equipment, increasing the durability of the mandrels and the quality of finished pipes. A lubricant is made up of several components, the most important of which is graphite. It is its properties that largely determine the quality and effectiveness of the resulting lubricating coating. The paper presents the results of studies of various properties of graphite, on the basis of which the requirements for its use as a lubricant were developed. The requirements for a suspension of graphite-containing lubricant and equipment for its application to the surface of a controlled-movable mandrel are also indicated, which together make it possible to obtain a high-quality graphite coating. The non-compliance of the properties of the graphite-containing lubricant with the requirements, as well as its poor application to the working surface of the mandrel, leads to incomplete separation of contact surfaces during the hot deformation of the metal. This can cause mandrels to rolling lap, reduce the quality of the inner surface of finished pipes, primarily from stainless steel grades, due to the formation of various defects in the form of deep scratches, cavities, and flaw, as well as a source of reducing the durability of continuous mill mandrels.

Calculation and experimental technique for evaluating the parameters of the contact interaction of a strip billet with a roll tool in the ERW mill lines

A technique for determining the areas of contact surfaces for the lower and upper roll tools is presented. The study of contact surfaces was carried out on contact prints obtained as a result of the experiment. The drawbacks of the existing method of fixing the imprints of contact surfaces, in which the contact of the strip (tubular billet) with the rolls was determined through the paper, were analyzed and taken into account. A technique for fixing contact prints is proposed, in which there is a direct contact of the strip with the rolls. Parameters of the obtained contact prints of the strip with the lower and upper rolls for all forming stands electric of ERW mill 30–50 were measured. As a result of measurements of contact prints, additional parameters of the boundaries of contact surfaces are introduced. For the bottom and top rolls, the length of the contact was taken along the bottom and the flange of the roll, respectively. It was found that, in the first approximation, the contact surfaces can be rather exactly approximated by a power function. The internal contact surfaces of the strip with the upper rolls were approximated using a decreasing power function, while the external ones with the lower rolls — using an increasing power function. On the basis of experimental data and analysis of indentation parameters, a technique has been developed for determining the contact surfaces of a strip with lower and upper rolls of various configurations. The input boundary of the contact surface was determined by the shape index m. Comparison of the input boundaries of the contact surfaces obtained in the experiment and by the technique shows a high convergence.

Rubber linings for ball mills: New designs and production technologies

The current-level technologies of ore ball milling require novel understanding of the fill flow inside a mill, as well as the structure–lining material–process variables interaction. It is necessary to know: which physical phenomena cause wear of mill lining to evaluate the wear rate; which surface ensure milling; whether the flow is constant in time as the loading due to flow can both increase and decrease in the course of the mill rotation. The paper presents a new concept of the destruction mechanism of lining in drum mills, and on this basis, a wavy design of rubber lining is proposed. For the first time, the laboratory tests were carried out to determine the relative wear resistance of rubbers in the hydroabrasive environment. To select the parameters of rubber linings, the influence of the impact energy on the fracture resistance of the lining surface is investigated, and the mathematical relations to calculate coefficient of energy transfer to the metal structure of the machine are presented. The increased capacity of mills in terms of feed and finished size output with the Polymet wavy rubber linings is substantiated to be the result of the forced change in flow layers inside the mill over the work surface composed of elastic component (rubber) and rigid component (metal). The results of industrial tests of mills with the wavy structure of rubber linings with their work surface pregnant with balls or vulcanized metal inserts (Polymet) are presented. A promising technology with the use of screw extruders (syringes) for manufacturing of linings, dividing and discharge grids, sieves and other structurally complex products based on wear-resistant rubbers by filling molds under pressure has been proposed. This ensures high quality products without the need for increased material consumption per half-way product with direct molding technology.

METHOD ACHIEVING COOLING UNIFORMITY AND OPTIMAL PLATE-CURVATURE DURING ULTRA-FAST COOLING IN A HSM

The flow field in the top and bottom surface of the hot rolled strip is different during cooling process with effect of gravity. Then it can affect the strip cooling uniformity of the top and bottom surface, and the plate curvature problems may be appeared. The finite element method was taken to study the plate curvature affecting law and a conclusion was obtained: the uniformity of the heat transfer coefficient in the top and bottom surface was the key to keep plate curvature well after rolling. The finite volume method was taken to calculate the heat transfer coefficient during run-out table laminar cooling (LC) and ultra-fast cooling (UFC) with different top nozzle fluxes and water flux ratios. The heat transfer coefficient and its distribution with different cooling methods and process parameters were obtained, and some conclusions were obtained by analysis: the bottom and top surface heat transfer coefficient can be kept nearly the same by adjusting water flux ratio between the bottom nozzle and top nozzle. The optimal water flux ratios of laminar cooling were 1.20 and 1.15 when top nozzle fluxes were 100m3/h and 120m3/h respectively. The optimal water flux ratios of ultra fast cooling were 1.08, 1.10, 1.15, 1.20 and 1.20 when top nozzle fluxes were 80m3/h, 100m3/h, 120m3/h, 140m3/h and 160m3/h respectively. The obtained results and water flux ratio calculating model were used in several strip cooling lines of the hot strip mill lines and obtained favorable effect.

Comparative analysis of methods for improving the quality of hardened pipe and bar stock for agricultural machinery parts

The problem of obtaining a high-quality surface is acute in thermal, chemical-thermal and thermomechanical processing of products of rolling production. But, due to the fact that many metallurgical plants are insufficiently equipped with cleaning tools for these types of processing, the required surface quality of metal products is not ensured. Operations related to the removal of defects in the surface of rolled products employ from 30 to 60% of the workers in rolling shops. The need for cleaning leads to a rupture of the production flow, since the metal must be pre-cooled for inspection and cleaning of defects. As a result, the total cost of cleaning is 2 - 3 times higher than the cost of performing the main technological operations - heating and deformation of the metal. In this regard, the combined methods of hot rolling with simultaneous hardening and elimination of surface defects are of particular interest, which gives significant energy savings and excludes etching operations in solutions of sulfuric and hydrochloric acids. The paper considers new methods for stripping rolled stock before deformation in the high-temperature thermomechanical treatment (HTMT) mode of cylindrical hot-rolled solid and hollow billets with screw compression (SC) deformation, combining, along with a high-performance method of shaping and strengthening of rolled products, environmentally friendly (acid-free) methods of surface cleaning, as well as methods of removing surface layer defects combined with mechanical processing. At the same time, simultaneously with cleaning the surface and increasing the accuracy of rolled products, the structure of the surface layer is formed by the mechanism of phase transformations during thermomechanical processing. The type of fracture changes at low-temperature destruction from brittle to ductile. It should also be noted, that there is the need for further development of such well-proven cleaning methods as blade and waterjet processing, which allow, when cleaning rolled products from any steel grades from scale, to implement the most reliable cleaning system, ensure effective removal of surface and deeper defects, increase yield, reduce energy consumption and fit well into the continuous rolling mill line. According to recent studies, waterjet treatment increases the fatigue life of hollow cylindrical parts by up to 15%.

A Multi-Step Anomaly Detection Strategy Based on Robust Distances for the Steel Industry

Steel making industries exhibit extreme working conditions characterized by high temperature, pressure, and production speed as well as intense throughput. Due to high economic and energy investments of the overall production process, an intense and expensive preventive maintenance program is adopted to avoid breakdowns. Steel making process would greatly benefit from a predictive maintenance module able to detect incoming faults from data process analysis. However, due to intense preventive maintenance, available data recording process operations enclose only a few samples of fault events, avoiding the efficient application of classical data driven anomaly detection models. In an attempt to overcome the above mentioned limits, we report the outcome of an industrial research project on data-driven anomaly detection in a steel making production process. The study assesses a fault detection strategy for rotating machines in the hot rolling mill line: we developed an automatic two-step strategy, which combines two statistical methods over the available data set: more precisely, the combination of Re-weighted Minimum Covariance Determinant estimator and Hidden Markov Models helped identify working conditions in a drive reducer of a hot steel rolling mill line and automatically isolate signs of decreasing performance or upcoming failures. The proposed strategy has been validated on real data collected in a steel making plant placed in the South of Italy.

Study of energy-intensive mill lining during the grinding of silicon powder

Dynamics of silicon lining an energy-intensive planetary mill was studied using experimental methods and a developed mathematical model. The transformation of the silicon powder microstructure during its mechanical treatment was investigated. It was found that this changes the granulometric composition of the mixture, resulting in a constant reformation of silicon particles formed from the agglomerates, which are crushed and agglomerated into new particles. It is shown that with increasing mechanical treatment time there is an increase in the amount of material in the lining layer. The lining speed constant was determined from the solution of the inverse problem. The theoretical calculations were in good agreement with the experimental data.

Mathematical Model of Temperature Conditions of Sheet Mills with Furnace Coilers

Determining the temperature of the strip at certain points in the technological line of the mill is very important problem in the development of new and optimization of existing technologies of the sheet rolling process. This article proposes a mathematical model of the temperature conditions of strip rolling on a mill with furnace coilers. The model takes into account the temperature change in the deformation zone during rolling, during transportation of the strip in the mill line, as well as in heating devices, in particular, in the furnaces of coilers of the Steckel mill. It is possible to calculate the change in temperature of the strip on coils and the surface of strip wind up in roll when the coiler furnaces. The mathematical model can be used for engineering calculations, as well as a tool for the scientific analysis of technological processes of sheet rolling.

Development of a method for effective strengthening rolled rebar with diameter of 8 mm of ordinary quality steel in terms of mill 320 SPC-1 at OJSC «BSW – Management Company of the Holding «BMC»

The global competition, unstable situation in the world market of rolled metal products, as well as increasing with each day the requirements of consumers of products pose complex tasks for the manufacturer, which must be solved in the shortest possible time. One of these tasks is to expand the range of rebar rolled products in the conditions of the variety rolling shop no. 1 on the continuous small-grade rolling mill 320. Until recently, rolling of reinforcing profiles with a diameter from 10 mm to 40 mm was carried out at the 320 rolling mill. In order to expand the range of rebar products, work was carried out to develop a production technology for profile no. 8 rod fittings with thermal hardening in the mill line for class 500.

Reducing defects in Mile line Of Rolling Plate Departement Using Six Sigma Method

PT. Krakatau Posco is steel company that produces steel and distributes its products both for national and international market. PT. Krakatau Posco produces slabs and plates steel. In meeting the requirements of the markets, the high-quality products are a necessary, thus the company should improve their product quality by reducing defects. The purpose of this study is to identify product defects and to determine the factors that cause during the production process, to propose corrective actions to reduce the number of defects. This research was conducted at Mill Line on Plate Rolling Department PT. Krakatau Posco. The research uses the Six Sigma method. Following the Six Sigma method, the result of DPMO is 568 with δ value is 4.87 which is still under the world target which is 6δ (3.4 DPMO). Proposals steps for improving the quality of plate products are doing routine maintenance and repairing of the machine, checking engine calibration conditions, improving the quality of slab material, heating slab time > 180 minutes, setting parameters (thickness, width, and length) as specified, and checking the straightness of the product plate during the rolling process (camber correction). A post-publication change was made to this article on 20 Apr 2020 as an incorrect version was published.