Analysis of the blast furnace operations with a volume of 5000 m3 on tuyeres of different diameters from the positions of full mechanical energies of flows of combined blow and hearth gas

In the commissioning period of the development of pulverized coal injection technology (PCI) on a blast furnace No. 9 with a volume of 5000 m3 of PJSC “ArcelorMittal Kryvyi Rih”, frequent cases of burnout of refrigerators of the cooling system of the shoulders and air tyueres appeared due to the highly developed peripheral gas flow. An attempt to limit the gas flow at the periphery by controlling the distribution of charge materials on the top produced a short-term result. Based on the prevailing ideas, that to reduce the intensity of the peripheral gas flow, it is necessary to increase the speed of the blast and, accordingly, the kinetic energy of the blast flow, flowing out of the air tuyeres of a blast furnace, it was decided to reduce their diameter. As a result of analysis of the operation of the specified blast furnace using the technology of PCI on tuyeres with a diameter of 150 and 140 mm, increased peripheral gas flow with a smaller diameter was established. Based on the results of the analysis, conclusions were made by many researchers and it was shown that with constant kinetic energy of the blast, flowing from the tuyeres of different diameters, the dimensions of the combustion zone are always larger before the tuyeres of a larger diameter. This is explained by the fact that the kinetic energy of the gas flow is only a part of their total mechanical energy. It was shown that to analyze the change in the size of the combustion zones and the depth of penetration of the hearth gas, it is necessary to use the full mechanical energy of the flows of the combined blast on the cut of the tuyere and hearth gas. It was established that the transition to PCI in a blast furnace instead of natural gas, it always causes an increase in the peripheral gas flow. The main reason for this phenomenon is associated with a decrease in the total mechanical energy of blast and hearth gas. It was recommended on a blast furnace with a volume of 5000 m3 with a hearth diameter of 14.7 m and the PCI technology to maintain the total mechanical energy of the blast flow at least 2100–2600 kJ/s, and the full mechanical energy of the hearth gas flow at least 5100–5300 kJ/s.

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Влияние качества агломерата и кокса на технико-экономические показатели доменной плавки

Metallurgicheskaya i gornorudnaya promyshlennost ◽

10.33101/s004-0244074 ◽

2018 ◽

pp. 17-24

Author(s):

D.A. Kassim ◽

A.K. Tarakanov ◽

V.P. Lyalyuk ◽

P.I. Otorvin ◽

A.A. Gusev

Keyword(s):

Blast Furnace ◽

Gas Flow ◽

Gas Permeability ◽

Raw Materials ◽

Mechanical Energy ◽

Blast Furnaces ◽

Depth Of Penetration ◽

Total Mechanical Energy ◽

Blowing Regime

Purpose: Compare the results of blast furnace smelting efficiency, when chang-ing the qualitative characteristics of the sinter and coke, and the calculated param-eters of the blowing regime of melting. Methodology: Analysis of technical and economic performance of blast furnaces during periods of work on the agglomerate with different metallurgical characteris-tics and different diameter of the tuyeres. Findings: The experience of blast furnaces with a volume of 2,700 and 2,000 m3 confirmed a known fact of the dependence of furnace efficiency and coke consump-tion not only through the quality of charge materials, but also through the distribu-tion of the gas flow along the furnace section. Originality: The technological analysis of the results of the operation of blast furnaces with the volume of 2700 and 2000 m3 with a change of the quality of the sinter and pellets in combination with the change of the blowing regime parame-ters was performed. On the basis of the performed analysis, it was confirmed the expediency of increasing the gas permeability of the charge by improving the quali-ty of the raw materials while increasing the total mechanical energy of the com-bined gas-blast and hearth-gas, which are responsible for the length of the com-bustion zone and the depth of penetration of the gas flow to the center of the blast furnace. Practical value: Alternation of tuyeres of different diameters along with the im-provement of the quality characteristics of charge materials, additionally contrib-utes to the enhancement of the positive effect due to the expansion of the combus-tion zones in the furnace hearth. And if in this case the total mechanical energy of the mountain gas rises and the depth of penetration of the furnace gas to the fur-nace axis increases, the effect of using high-quality raw materials can be maxim-ized. Keywords: agglomerate, coke, blowing, tuyeres, gas permeability, quality, total energy.

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Three-dimensional kinematics and limb kinetic energy of running cockroaches.

Journal of Experimental Biology ◽

10.1242/jeb.200.13.1919 ◽

1997 ◽

Vol 200 (13) ◽

pp. 1919-1929 ◽

Cited By ~ 11

Author(s):

R Kram ◽

B Wong ◽

R J Full

Keyword(s):

Kinetic Energy ◽

High Speed ◽

Mechanical Energy ◽

Center Of Mass ◽

Three Dimensional ◽

The Body ◽

Morphological Data ◽

Fast Running ◽

Total Mechanical Energy ◽

Reaction Forces

We tested the hypothesis that fast-running hexapeds must generate high levels of kinetic energy to cycle their limbs rapidly compared with bipeds and quadrupeds. We used high-speed video analysis to determine the three-dimensional movements of the limbs and bodies of cockroaches (Blaberus discoidalis) running on a motorized treadmill at 21 cm s-1 using an alternating tripod gait. We combined these kinematic data with morphological data to calculate the mechanical energy produced to move the limbs relative to the overall center of mass and the mechanical energy generated to rotate the body (head + thorax + abdomen) about the overall center of mass. The kinetic energy involved in moving the limbs was 8 microJ stride-1 (a power output of 21 mW kg-1, which was only approximately 13% of the external mechanical energy generated to lift and accelerate the overall center of mass at this speed. Pitch, yaw and roll rotational movements of the body were modest (less than +/- 7 degrees), and the mechanical energy required for these rotations was surprisingly small (1.7 microJ stride-1 for pitch, 0.5 microJ stride-1 for yaw and 0.4 microJ stride-1 for roll) as was the power (4.2, 1.2 and 1.1 mW kg-1, respectively). Compared at the same absolute forward speed, the mass-specific kinetic energy generated by the trotting hexaped to swing its limbs was approximately half of that predicted from data on much larger two- and four-legged animals. Compared at an equivalent speed (mid-trotting speed), limb kinetic energy was a smaller fraction of total mechanical energy for cockroaches than for large bipedal runners and hoppers and for quadrupedal trotters. Cockroaches operate at relatively high stride frequencies, but distribute ground reaction forces over a greater number of relatively small legs. The relatively small leg mass and inertia of hexapeds may allow relatively high leg cycling frequencies without exceptionally high internal mechanical energy generation.

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Available Energy in Cars’ Exhaust System for IoT Remote Exhaust Gas Sensor and Piezoelectric Harvesting

Energies ◽

10.3390/en13164169 ◽

2020 ◽

Vol 13 (16) ◽

pp. 4169

Author(s):

Francesco Madaro ◽

Iman Mehdipour ◽

Antonio Caricato ◽

Francesco Guido ◽

Francesco Rizzi ◽

...

Keyword(s):

Kinetic Energy ◽

Gas Flow ◽

Mechanical Energy ◽

Exhaust System ◽

Electrical Energy ◽

Exhaust Gas ◽

Available Energy ◽

Remote Sensor ◽

Exhaust Energy ◽

Sensor Temperature

The exhaust system of the light-duty diesel engine has been evaluated as a potential environment for a mechanical energy recovery system for powering an IoT (Internet of Things) remote sensor. Temperature, pressure, gas speed, mass flow rate have been measured in order to characterize the exhaust gas. At any engine point explored, thermal energy is by far the most dominant portion of the exhaust energy, followed by the pressure energy and lastly kinetic energy is the smallest fraction of the exhaust energy. A piezoelectric flexible device has been tested as a possible candidate as an energy harvester converting the kinetic energy of the exhaust gas flow, with a promising amount of electrical energy generated in the order of microjoules for an urban or extra-urban circuit.

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Development and implementation of the new approaches to diagnostics and management of the blast furnace smelting

Fundamental and applied problems of ferrous metallurgy ◽

10.52150/2522-9117-2019-33-61-77 ◽

2019 ◽

pp. 61-77

Author(s):

Yu.S. Semenov ◽

Е.І. Shumelchik ◽

V.V Horupakha

Keyword(s):

Blast Furnace ◽

Gas Flow ◽

Cooling System ◽

Flame Temperature ◽

Peripheral Zone ◽

Pulverized Coal ◽

Quantitative Composition ◽

Blast Furnace Smelting ◽

New Approaches ◽

Steel Works

The article presents a brief description of the results of blast furnace production research carried out at the Yenakiieve Iron & Steel Works and the Dneprovsky Iron & Steel Integrated Works in 2011–2019. For the conditions of transition modes of blast furnace to ensure its stability in changing the qualitative and quantitative composition of the components of the charge materials, as well as in the change of fuel additives in the blast, the complex use of information of modern means of automated control is proved: stationary thermosets and thermocouples to the lining. New approaches to the choice of rational charging programs using the principle of variable maximum ore loading along the radius of the furnace within the charging cycle for working conditions on a charge of low quality have been developed. The implementation of such a charging program over the next three years has allowed to ensure a stable and economical course of melting, and its adaptation to the technology of using pulverized coal has allowed to reduce the gas flow temperature of the peripheral zone throughout the height of the blast furnace, as well as to preserve the cooling system during the development of lining-free. Expert module of adjustment of the program of charging using the established rational ranges of change of temperature indices of gas flow distribution along the radius of the furnace under different technological conditions of blast furnace has been developed and implemented on three blast furnaces. The method of reasonable choice of location of closed air tuyeres or air tuyeres of different diameter was developed and tested using information on change of lining temperatures on height and circumference of blast furnace. The method of equalizing the raceway adiabatic flame temperature around the blast furnace circumference by creating a non-uniform flow rate of pulverized coal in the air tuyeres has been improved and implemented. The basic technological requirements for blast furnace blasting after its long stop without release of "gantry" cast iron and scraping of materials from the furnace, the use of which before and in the blast furnace blasting of the Yenakiieve Iron & Steel Works and the Dneprovsky Iron & Steel Integrated Works after a long-lasting set-up were developed economic indicators, while ensuring the preservation of refractory lining, structures and equipment.

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Energetics and mechanics of terrestrial locomotion. IV. Total mechanical energy changes as a function of speed and body size in birds and mammals

Journal of Experimental Biology ◽

10.1242/jeb.97.1.57 ◽

1982 ◽

Vol 97 (1) ◽

pp. 57-66 ◽

Cited By ~ 1

Author(s):

N. C. Heglund ◽

M. A. Fedak ◽

C. R. Taylor ◽

G. A. Cavagna

Keyword(s):

Body Size ◽

Kinetic Energy ◽

Elastic Energy ◽

Mechanical Energy ◽

Motor Units ◽

Metabolic Energy ◽

Small Animals ◽

Centre Of Mass ◽

Terrestrial Locomotion ◽

Total Mechanical Energy

This is the final paper in or series examining the link between the energetics and mechanics of terrestrial locomotion. In this paper the kinetic energy of the limbs and body relative to the centre of mass (EKE, tot of paper two) is combined with the potential plus kinetic energy of the centre of mass (ECM, tot of paper three) to obtain the total mechanical energy (excluding elastic energy) of an animal during constant average-speed locomotion. The minimum mass-specific power required of the muscles and tendons to maintain the observed oscillations in total energy, Etot/Mb, can be described by one equation: Etot/Mb = 0.478. vg 1.53 + 0.685. vg + 0.072 where Etot/Mb is in W kg-1 and vg is in m s-1. This equation is independent of body size, applying equally as well to a chipmunk or a quail as to a horse or an ostrich. In marked contrast, the metabolic energy consumed by each gram of an animal as it moves along the ground at a constant speed increases linearly with speed and is proportional to Mb-0.3. Thus, we have found that each gram of tissue of a 30 g quail or chipmunk running at 3 m s-1 consumes metabolic energy at a rate about 15 times that of a 100 kg ostrich, horse or human running at the same speed while their muscles are performing work at the same rate. Our measurements demonstrate the importance of storage and recovery of elastic energy in larger animals, but they cannot confirm or exclude the possibility of elastic storage of energy in small animals. It seems clear that the rate at which animals consume energy during locomotion cannot be explained by assuming a constant efficiency between the energy consumed and the mechanical work performed by the muscles. It is suggested that the intrinsic velocity of shortening of the active muscle motor units (which is related to the rate of cycling of the cross bridges between actin and myosin) and the rate at which the muscles are turned on and off are the most important factors in determining the metabolic cost of constant-speed locomotion. Faster motor units are recruited as animals increase speed, and equivalent muscles of small animals have faster fibres than those of larger animals. Also, the muscles are turned on and off more quickly as an animal increases speed, and at the same speed a small animal will be turning muscles on and off at a much higher rate. These suggestions are testable, and future studies should determine if they are correct.

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Mechanical Energy Expenditures and Movement Efficiency in Full Body Reaching Movements

Journal of Applied Biomechanics ◽

10.1123/jab.26.1.32 ◽

2010 ◽

Vol 26 (1) ◽

pp. 32-44 ◽

Cited By ~ 2

Author(s):

Daohang Sha ◽

Christopher R. France ◽

James S. Thomas

Keyword(s):

Kinetic Energy ◽

Potential Energy ◽

Target Location ◽

Mechanical Energy ◽

The Body ◽

Reaching Movements ◽

Whole Body ◽

Joint Power ◽

Total Mechanical Energy ◽

Full Body

The effect of target location, speed, and handedness on the average total mechanical energy and movement efficiency is studied in 15 healthy subjects (7 males and 8 females with age 22.9 ± 1.79 years old) performing full body reaching movements. The average total mechanical energy is measured as the time average of integration of joint power, potential energy, and kinetic energy respectively. Movement efficiency is calculated as the ratio of total kinetic energy to the total joint power and potential energy. Results show that speed and target location have significant effects on total mechanical energy and movement efficiency, but reaching hand only effects kinetic energy. From our findings we conclude that (1) efficiency in whole body reaching is dependent on whether the height of the body center of mass is raised or lowered during the task; (2) efficiency is increased as movement speed is increased, in part because of greater changes in potential energy; and (3) the CNS does not appear to use movement efficiency as a primary planning variable in full body reaching. It may be dependent on a combination of other factors or constraints.

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A downscaling cold model for solid flow behaviour in a top gas recycling-oxygen blast furnace

High Temperature Materials and Processes ◽

10.1515/htmp-2020-0083 ◽

2020 ◽

Vol 39 (1) ◽

pp. 447-456

Author(s):

Zhenlong An ◽

Jingbin Wang ◽

Yanjun Liu ◽

Yingli Liu ◽

Xuefeng She ◽

...

Keyword(s):

Blast Furnace ◽

Gas Flow ◽

Stagnant Zone ◽

Flow Zone ◽

Cold Model ◽

Solid Flow ◽

Oxygen Blast ◽

Top Gas Recycling ◽

Batch Weight ◽

Gas Recycling

AbstractThe top gas recycling-oxygen blast furnace (TGR-OBF) is a reasonable method used to reduce both coke rate and energy consumption in the steel industry. An important feature of this process is shaft gas injection. This article presents an experimental study on the gas–solid flow characteristics in a TGR-OBF using a two-dimensional cold model. The experimental conditions and parameters were determined using a series of similarity criteria. The results showed that the whole flow area in the TGR-OBF can be divided into four distinct flow zones, namely, the stagnant zone, the plug flow zone in the upper part of the shaft, the converging flow zone and the quasi-stagnant flow zone, which is similar to that in a traditional blast furnace. Then the effects of batch weight and the ratio (X) of the shaft injected gas flow rate to the total gas flow rate on solid flow behaviour were investigated in detail. With the increase in batch weight, the shape of the stagnant zone tends to be shorter and thicker. Furthermore, with the increase in X value from 0 to 1, the stagnant zone gradually becomes thinner and higher. The results obtained from the experiments provide fundamental data and a validation for the discrete element method–computational fluid dynamics-coupled mathematical model for TGR-OBFs for future studies.

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Hydrodynamic constraints on the energy efficiency of droplet electricity generators

Microsystems & Nanoengineering ◽

10.1038/s41378-021-00269-8 ◽

2021 ◽

Vol 7 (1) ◽

Author(s):

Antoine Riaud ◽

Cui Wang ◽

Jia Zhou ◽

Wanghuai Xu ◽

Zuankai Wang

Keyword(s):

Energy Efficiency ◽

Kinetic Energy ◽

Total Energy ◽

Viscous Dissipation ◽

Shear Force ◽

Mechanical Energy ◽

Electric Energy ◽

The Past ◽

Viscous Shear ◽

Impingement Velocity

AbstractElectric energy generation from falling droplets has seen a hundred-fold rise in efficiency over the past few years. However, even these newest devices can only extract a small portion of the droplet energy. In this paper, we theoretically investigate the contributions of hydrodynamic and electric losses in limiting the efficiency of droplet electricity generators (DEG). We restrict our analysis to cases where the droplet contacts the electrode at maximum spread, which was observed to maximize the DEG efficiency. Herein, the electro-mechanical energy conversion occurs during the recoil that immediately follows droplet impact. We then identify three limits on existing droplet electric generators: (i) the impingement velocity is limited in order to maintain the droplet integrity; (ii) much of droplet mechanical energy is squandered in overcoming viscous shear force with the substrate; (iii) insufficient electrical charge of the substrate. Of all these effects, we found that up to 83% of the total energy available was lost by viscous dissipation during spreading. Minimizing this loss by using cascaded DEG devices to reduce the droplet kinetic energy may increase future devices efficiency beyond 10%.

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