scholarly journals Improving the mechanical-mathematical model of grain mass separation in a fluidized bed

2021 ◽  
Vol 3 (1 (111)) ◽  
pp. 79-86
Author(s):  
Vadym Bredykhin ◽  
Petro Gurskyi ◽  
Oleksiy Alfyorov ◽  
Khrystyna Bredykhina ◽  
Andrey Pak
Keyword(s):  
Mathematical Model ◽  
Fluidized Bed ◽  
Raw Materials ◽  
Physical And Mechanical Properties ◽  
Continuous Phase ◽  
Mass Separation ◽  
Base Surface ◽  
Equivalent Radius ◽  
Seed Material ◽  
Working Surface

This paper has substantiated the prospect of modeling the processes of separating grain mass into fractions as one of the tasks in the production of high-quality seed material. It has been determined that this could optimize the parameters of separation processes and design new working surfaces for its implementation. It is noted that modeling should take into consideration the influence of the structural and kinematic parameters of grain cleaning machines, the physical and mechanical properties of raw materials, the intralayer processes and forces. The reported theoretical study has improved the mechanical-mathematical model of grain mass separation in a pseudo-fluidized bed according to its density. The model establishes a relationship between the effective coefficient of dynamic viscosity and the density of particles in the discrete and continuous phases and the volumetric concentration of discrete phase particles. At the same time, the porosity of a fluidized bed has been accounted for, as well as the longitudinal and transverse angles of inclination of the base surface to the horizontal plane, the amplitude and frequency of oscillations of the particles of the continuous phase; the direction angle of oscillations relative to the perpendicular to the base surface. The adequacy of the improved mechanical-mathematical model has been confirmed by comparing the experimental and theoretical results of grain mass fractionation modeling. It was found that the differences in the density values of the separated fractions of GM did not exceed 7...8 %, that is, they were within the margin of error. It has been established that the improved model of grain mass separation in a fluidized bed could be used to determine the rational values for the parameters of a pneumatic sorting table that is used for the fractionation of the corresponding seed material. The initial data, in this case, are the density of the continuous and solid phases of grain mass, the friction coefficient of the seeds, and the equivalent radius of the particle. The result of modeling is the rational values of the amplitude and oscillation frequency of the working surface of the pneumatic sorting table, and the angles of inclination of the working surface

Modeling of Bulk Material Loading Into Sieve of the Scissor-type Separator

2020 ◽  
pp. 59-68
Author(s):  
Іgor Dudarev ◽  
◽  
Vasyl Olkhovskyi ◽  
Keyword(s):  
Mathematical Model ◽  
Raw Materials ◽  
Bulk Material ◽  
Physical And Mechanical Properties ◽  
Raw Material ◽  
Entire Surface ◽  
Feed Production ◽  
Favorable Conditions ◽  
Oscillating Motion ◽  
The Mathematical Model

In agriculture and feed production, seeds and grains of various crops that require cleaning and separation are used as sowing material and raw materials. For seed and grain cleaning and separation the separators of different type are used. During operation, these separators take into account the physical and mechanical properties of the raw material. The article proposes the design of bulk material separator of scissor type, which has small dimensions and is easy to maintain. The efficiency of separator depends on the uniformity of the bulk material loading on the sieve surface. Therefore, substantiation of rational parameters of separator is an extremely important task. So, the aim of the study is to model the loading process of bulk material from the unloading hole of the hopper on an inclined flat sieve of the scissor-type separator, which performs oscillating motion. The proposed mathematical model of the bulk material loading from the hopper to the separator sieve allows us to determine the trajectory of the particle falling and to describe the position of the sieve, which changes due to the rotation of the eccentric. Also, modeling allows us to justify the rational parameters of the separator, taking into account the kinematic mode of its operation. Under these parameters, a layer of material of the same height will be formed on the sieve, which will provide favorable conditions for the separation process. In addition, the mathematical model allows us to determine the rational parameters of the relative position of the hopper and the sieve. In this case the entire surface of the sieve is used effectively.

scholarly journals Optimization of wood fibre refining process in fibreboard production with new refiner disc working surface geometry

BioResources ◽  
2021 ◽  
Vol 16 (4) ◽  
pp. 7751-7766
Author(s):  
Aleksandr Vititnev ◽  
Natalia Chistova ◽  
Yuri Alashkevich ◽  
Venera Matygulina ◽  
Roman Marchenko
Keyword(s):  
Mechanical Properties ◽  
Raw Materials ◽  
Experimental Studies ◽  
Reducing Power ◽  
Physical And Mechanical Properties ◽  
Refining Process ◽  
Wood Fibre ◽  
Surface Geometry ◽  
Working Surface ◽  
Qualitative Characteristics

Refining of fibrous semi-finished products is an important stage in fibreboard production because the efficiency of this stage affects the resulting fibres’ dimensional and qualitative characteristics. These, in turn, determine the physical and mechanical properties of the finished products, as well as the energy intensity of the process. The efficiency of this process depends on the raw materials used and the geometry of the refiner disc working surface and its operational modes. This article presents the results of the optimisation of wood fibre refining at a low concentration (2 to 4%), using fundamentally new refiner discs in high-density fibreboard production. Based on numerous theoretical and experimental studies, and on the results of processing, the problem of optimising the refining process was solved, taking into account the use of new refiner disc geometry. As a result, the optimal values of refiner process parameters and operation modes making it possible to prepare wood-fibre semi-finished products efficiently while reducing power consumption in refining were established. After optimising the refining process, the new geometry of refiner disc working surfaces provides optimal dimensional and qualitative characteristics of wood fibres, which results in finished products with high physical and mechanical properties in accordance with GOST 4598 (2018) without using bonding resins.

The effect of pressure on the compressibility of aluminum alloys

2020 ◽  
pp. 102-107
Keyword(s):  
Mechanical Properties ◽  
Mathematical Model ◽  
Liquid Metal ◽  
Control Systems ◽  
Physical And Mechanical Properties ◽  
Reliable Data ◽  
Output Process ◽  
Automated Control ◽  
Input And Output ◽  
Crystallization Under Pressure

To obtain reliable data on the properties of liquid metal and create automated control systems, the technological process of molding with crystallization under pressure is studied. A mathematical model of the input and output process parameters is developed. It is established that the compressibility of the melt can represent the main controlled parameter influencing on the physical-mechanical properties of the final products. The obtained castings using this technology are not inferior in their physical and mechanical properties to those produced by forging or stamping.

Mathematical model for combined extrusion of bar stock into cylindrical die by fl at working surface punch

2020 ◽  
pp. 309-312
Author(s):  
S.N. Larin S.N. ◽  
V.I. Tregubov ◽  
A.N. Isaeva
Keyword(s):  
Mathematical Model ◽  
Extrusion Force ◽  
Technological Parameters ◽  
Thin Walls ◽  
Working Surface ◽  
Industrial Implementation ◽  
Pressure Estimation

Combined extrusion processes can be in demand in the production of body products with jumper in the central part and thin walls. Often, their industrial implementation requires theoretical justifi cation of power regimes. Mathematical model of combined extrusion created on the basis of the upper estimates method is presented. The effect of technological parameters on extrusion force is established based on the obtained expressions for pressure estimation.

scholarly journals Alkali-Activated Zeolite 4A Granules—Characterization and Suitability Assessment for the Application of Adsorption

Crystals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 360
Author(s):  
Pauls P. Argalis ◽  
Laura Vitola ◽  
Diana Bajare ◽  
Kristine Vegere
Keyword(s):  
Compressive Strength ◽  
Raw Materials ◽  
Physical And Mechanical Properties ◽  
Morphological Properties ◽  
Solid Ratio ◽  
Suitability Assessment ◽  
Bet Analysis ◽  
Zeolite 4A ◽  
Compressive Strength Test ◽  
Alkali Activated

A major problem in the field of adsorbents is that binders (kaolin clay, bentonite) introduced to bind zeolites and ensure the needed mechanical strength, are not able to sorb gases like CO2 and N2, and decrease the overall adsorption capacity. To solve this problem, one of the pathways is to introduce a binder able to sorb such gases. Thus, in this study, the physical and mechanical properties of a novel binder based on metakaolin and its composite with zeolite 4A in the granular form were studied. Metakaolin was used as a precursor for alkali-activated binder, which was synthesized using an 8M NaOH activation solution. Raw materials were characterized using granulometry, X-ray diffraction (XRD), and differential thermal analysis (DTA); and final products were characterized using density measurements, a compressive strength test, XRD, Brunauer–Emmett–Teller (BET) analysis, and scanning electron microscopy (SEM). Alkali-activated metakaolin was found to be efficient as a binding material when data for morphological properties were analyzed. A relationship was observed—by increasing the liquid-to-solid ratio (L/S), compressive strength decreased. Zeolite granule attrition was higher than expected: 2.42% and 4.55% for ZG-0.8, 3.64% and 5.76% for ZG-1.0, and 2.73% and 4.85% for ZG-1.2, measured at 4 and 5 atmospheres, respectively.

scholarly journals Study of the Incorporation of Biomass Bottom Ash as a Filler for Discontinuous Grading Bituminous Mixtures with Bitumen Emulsion

2021 ◽  
Vol 11 (8) ◽  
pp. 3334
Author(s):  
Jorge Suárez-Macías ◽  
Juan María Terrones-Saeta ◽  
Francisco Javier Iglesias-Godino ◽  
Francisco Antonio Corpas-Iglesias
Keyword(s):  
Raw Materials ◽  
Bottom Ash ◽  
Chemical Properties ◽  
Physical And Mechanical Properties ◽  
Waste Biomass ◽  
Bituminous Mixtures ◽  
Bitumen Emulsion ◽  
Main Disadvantage ◽  
Physical And Chemical ◽  
And Chemical Properties

Energy consumption, because of population development, is progressively increasing. For this reason, new sources of energy are being developed, such as that produced from the combustion of biomass. However, this type of renewable energy has one main disadvantage, the production of waste. Biomass bottom ash is a residue of this industry that currently has not much use. For this reason, this research evaluates its use as a filler in bituminous mixtures, since this sector also has a significant impact on the environment, as it requires large quantities of raw materials. With this objective, first, the physical and chemical properties of biomass bottom ashes were evaluated, verifying their characteristics for their use as filler. Subsequently, bituminous mixtures were conformed with biomass bottom ash as filler, and their physical and mechanical properties were analyzed through particle loss and Marshall tests. The results of these tests were compared with those obtained with the same type of mixture but with conventional and ophite aggregates. This study confirmed that biomass bottom ash was viable for use as a filler, creating mixtures with a higher percentage of bitumen, better mechanical behavior, and similar physical properties. In short, more sustainable material for roads was obtained with waste currently condemned to landfill.

AUTOMATED OPERATIONAL SCHEDULING SYSTEM FOR MULTI-STAGE PRODUCTION: MATHEMATICAL MODEL AND SOFTWARE IMPLEMENTATION

2021 ◽  
Vol 3 (102) ◽  
pp. 18-37
Author(s):  
OXANA S. LOGUNOVA ◽  
MIKHAIL B. ARKULIS
Keyword(s):  
Mathematical Model ◽  
Raw Materials ◽  
Software Implementation ◽  
Scheduling System ◽  
Operation Conditions ◽  
Multi Stage ◽  
Complete Set ◽  
Wip Inventory ◽  
Production Areas ◽  
Strip Production

The purpose of the study is to improve the efficiency of production areas of multi-stage production with the possibility of rational use of equipment capacity and stocks of WIP inventory in the operation conditions of the automated operational scheduling system. Features of the considered problem regarding operative calendar planning are: necessity of processing raw materials at several stages according to the flow chart; an array of the equipment which demands division of work into three periods for each party; availability of planned and unscheduled equipment downtime; necessity to complete set of orders from several suborders; availability of incomplete production in a warehouse; restrictions in order and timing of orders. In the work, the authors construct a mathematical model with the use of multidimensional matroids with structured elements in the construction of free time scale for equipment loading. The research was carried out for a metallurgical plant at the cold strip production site...

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