Artykuły w czasopismach: „Hammer energy”

1

MARIAN, Ovidiu, Ioan DROCAȘ, Ionel BUDÄ‚CAN, Dumitru POP i Mircea MUNTEAN. "Influence of Sieve Openings Size for Hammer Mills on the Degree of Shredding and Grinding Energy Consumption for Wheat". Bulletin of University of Agricultural Sciences and Veterinary Medicine Cluj-Napoca. Agriculture 70, nr 2 (26.11.2013): 471–72. http://dx.doi.org/10.15835/buasvmcn-agr:9825.

Pełny tekst źródła

Streszczenie:

Hammer mills are machines used in agriculture to obtain concentrated fodder mix. The hammer mills grinding materials is produced upon impact of the hammer material and crushing plate located inside the grinding chamber. Depending on the hammers rotor assembly mode, the following types of mills can be used: hammer mills articulated and fixed hammer mills. The finesse of the flour obtained is directly influenced by the type of hammer and sieve used.

Style APA, Harvard, Vancouver, ISO itp.

2

Liberman, Yako, Konstantin Letnev i Lyubov Gorbunova. "Algorithm of Energy-Saving Control Over Hammers of Active Excavator Buckets". MATEC Web of Conferences 346 (2021): 03033. http://dx.doi.org/10.1051/matecconf/202134603033.

Pełny tekst źródła

Streszczenie:

The article considers the operation of excavators designed to mine hard or frozen soils. To reduce significant energy consumption, which characterizes the process, active buckets equipped with special hammers are used. Minimizing the energy consumption of such buckets can be achieved by optimally controlling their operating modes. Expressions for the energy consumed by a hammer, characteristics of its head, operating modes, soil are derived, with the minimum of the energy estimated. On the basis of those expressions, an algorithm of energy-saving control over hammers of active excavator buckets is formed and described. It determines the corresponding speed of impact of the hammer head on the soil which can be supplied to the hammer control system in the form of a command signal. The combination of all speeds when digging a track will provide the required performance of the excavator, with each speed set to the minimum, from the viewpoint of optimizing the energy consumption, necessary for the work of the hammer.

Style APA, Harvard, Vancouver, ISO itp.

3

Wróblewski, Adam, Pavlo Krot, Radosław Zimroz, Timo Mayer i Jyri Peltola. "Review of Linear Electric Motor Hammers—An Energy-Saving and Eco-Friendly Solution in Industry". Energies 16, nr 2 (14.01.2023): 959. http://dx.doi.org/10.3390/en16020959.

Pełny tekst źródła

Streszczenie:

Standard hydraulic breaking hammers are widely used for crushing oversized blasted materials and concrete structures demolition in industry. These hammers, installed in on-surface working excavators or stationary manipulators at the dumping points of underground conveyors, provide the required limited sizes of bulk materials and enable the safe operation of other equipment (screens, crushers). In parallel, hydraulic hammers have an alternative—fully electric hammers. This paper aims to review existing linear electric motor (LEM) hammers as an energy-saving and eco-friendly solution in industry. Global market analysis is presented with potential branches of LEM hammers. Several aspects for implementation—design optimization, dynamics simulation, machine control, and performance estimation—are considered. Different case studies for LEM-hammer application are given. The preliminary measurements are demonstrated on the electric hammer of Lekatech Company, which is intended for the mining industry and construction demolition. Experiments showed that depending on the impact frequency, type of rock, and shape of the crushing tool, the time to fracture varies significantly. Optimal parameters exist for every case, for which adjusting requires online hammer control.

Style APA, Harvard, Vancouver, ISO itp.

4

Enjeti, Praveen Teja, Gangaiah Gaddam, Venkata Sai Kumar Gali, Sasi Kumar Reddy Gurram, Shashank Isukala, Siva Sankar Reddy Kamasani, Bhuvaneswar Reddy Kunduru i Lokesh Chowdary Jagarlamudi. "Electric Press Machine by Using Stepper Motor". International Journal for Research in Applied Science and Engineering Technology 10, nr 3 (31.03.2022): 1251–59. http://dx.doi.org/10.22214/ijraset.2022.40847.

Pełny tekst źródła

Streszczenie:

Abstract: In ancient times material was shaped manually using hand hammers. Later on, big hammers were used to press large quantities of material at a time or to press a thick metal workpiece. Then after steam power and windmills were utilized to operate the large steam hammers. Prior to the invention of the machine press, workers were required to manually hammer metal by hand to change the shape of materials. After that, it cannot able used to change the shape of large or big size material, and itit’shysically ineffective. The steam hammer was developed around the mid – the 1800s and is also known as a drop hammer, the steam hammer or drop hammer was essentially an early version of the modern-day machine press. The only difference is that the steam hammer was powered by steam, whereas most modern-day machine presses are powered by hydraulics and electricity. Now day world, we are normally using a mechanical press machine and hydraulic press machine. In this paper, we are explaining about electric press machine by using stepper motor. Keywords: Arduino UNO R3, TB6600 4A Stepper Motor Driver, Permanent magnet Stepper Motor, SMPS (switched-mode power supply)

Style APA, Harvard, Vancouver, ISO itp.

5

Paraschiv, Gigel, Georgiana Moiceanu, Gheorghe Voicu, Mihai Chitoiu, Petru Cardei, Mirela Nicoleta Dinca i Paula Tudor. "Optimization Issues of a Hammer Mill Working Process Using Statistical Modelling". Sustainability 13, nr 2 (19.01.2021): 973. http://dx.doi.org/10.3390/su13020973.

Pełny tekst źródła

Streszczenie:

Our paper presents the hammer mill working process optimization problem destined for milling energetic biomass (MiscanthusGiganteus and Salix Viminalis). For the study, functional and constructive parameters of the hammer mill were taken into consideration in order to reduce the specific energy consumption. The energy consumption dependency on the mill rotor spinning frequency and on the sieve orifices in use, as well as on the material feeding flow, in correlation with the vegetal biomass milling degree was the focus of the analysis. For obtaining this the hammer mill was successively equipped with 4 different types of hammers that grind the energetic biomass, which had a certain humidity content and an initial degree of reduction ratio of the material. In order to start the optimization process of hammer mill working process, 12 parameters were defined. The objective functions which minimize hammer mill energy consumption and maximize the milled material percentage with a certain specific granulation were established. The results obtained can serve as the basis for choosing the optimal working, constructive, and functional parameters of hammer mills in this field, and for a better design of future hammer mills.

Style APA, Harvard, Vancouver, ISO itp.

6

Yan, Xiaopeng, i Baijin Chen. "Analysis of a Novel Automatic Control Approach for the Free Forging Hammer". Applied Sciences 10, nr 24 (21.12.2020): 9127. http://dx.doi.org/10.3390/app10249127.

Pełny tekst źródła

Streszczenie:

This paper proposes an electro-hydraulic servo control method and realizes the automatic control and remote control of free forging hammers for the first time. A configuration and control strategy for the program-control free forging hammer are constructed. Based on the configuration, a single-acting differential servo cylinder system is proposed to drive the follow-up spool valve and then control the motion state of the hammerhead. Furthermore, a non-contact measurement method is adopted to detect the real-time position of the hammerhead, and the installation position of the measuring sensor is isolated from the hammer body and foundation, thereby reducing the influence of vibration and impact on the accuracy of the feedback signal and ensuring the successive forming process of the forging hammer. In addition, a blow energy model of the forging hammer processing system is established, and a fuzzy-PID control scheme for the forging hammer is then adopted. Based on the control strategy, the striking accuracy of the proposed automatic forging hammer is significantly improved compared with the traditional forging hammer. Finally, the method is applied to an 8 MN forging hammer, and the results show its better processing performance than traditional hammers in terms of all indices.

Style APA, Harvard, Vancouver, ISO itp.

7

Borosnyói, Adorján. "NDT ASSESSMENT OF EXISTING CONCRETE STRUCTURES: SPATIAL ANALYSIS OF REBOUND HAMMER RESULTS RECORDED IN-SITU". Engineering Structures and Technologies 7, nr 1 (15.12.2015): 1–12. http://dx.doi.org/10.3846/2029882x.2015.1085331.

Pełny tekst źródła

Streszczenie:

A comparative spatial analysis of surface hardness of structural concrete is introduced. Main objective of the paper is to make a repeatability comparison of three types of the still most popular non-destructive testing devices for concrete: L-type original Schmidt rebound hammer, N-type original Schmidt rebound hammer and N-type Silver Schmidt rebound hammer. Results indicate that the surface hardness measurement uncertainty is related to the weight of the hammer mass and is apparently not related to the impact energy of the rebound hammer devices. It is observed that the measure of surface hardness for the Silver Schmidt rebound hammer (Q-value) does not have positive correlation to the original rebound index (R). Results indicate the best performance of the N-type original Schmidt rebound hammer in terms of stability and normality of data. Geostatistical analysis of the measured data (in terms of empirical semivariograms) highlights different statistical behaviour for the mechanical recording rebound hammers and for the electro-optical recording rebound hammer.

Style APA, Harvard, Vancouver, ISO itp.

8

Bo, Kun, Siyuan Sun, Yong Hu i Maosen Wang. "Design Optimization and Performance Analysis of the Pneumatic DTH Hammer with Self-Propelled Round Bit". Shock and Vibration 2021 (6.07.2021): 1–13. http://dx.doi.org/10.1155/2021/6653390.

Pełny tekst źródła

Streszczenie:

Although pneumatic down-the-hole (DTH) hammers have good performance of high penetration rate and minimal deviation tendency in the vertical section of oil and gas wells, they have not been successfully used in directional drilling due to drill tool wear and wellbore disturbance. Herein, we developed a novel type of pneumatic DTH hammer with a self-propelled round bit to overcome the technical difficulties of directional drilling. Nonlinear dynamic modeling developed by the authors was used to analyze the working principle and performance of the novel DTH hammer. The kinematics and dynamics simulation of this hammer were carried out using MATLAB language, and the motion law of the piston was revealed. The performance of the novel hammer was numerically simulated and evaluated by considering fluctuations of the front and rear chamber pressure, impact energy, acceleration, and frequency. The results show that our novel DTH hammer’s working principle is feasible and has an adequate structural design. The simulation results demonstrate reasonable design parameters. Compared to the numerical results for conventional DTH hammers, the velocity and acceleration of the piston of the novel hammer changed smoothly. The frequency was slightly higher than that of conventional hammers, while other parameters were nearly equal. The novel DTH hammer can be used in directional drilling, trenchless drilling, and seabed sampling drilling.

Style APA, Harvard, Vancouver, ISO itp.

9

Soldatenko, L., A. Shipko i I. Shipko. "DIRECTION OF IMPROVEMENT OF THE WORKING BODIES OF HAMMER". Grain Products and Mixed Fodder’s 20, nr 2 (15.07.2020): 41–47. http://dx.doi.org/10.15673/gpmf.v20i2.1766.

Pełny tekst źródła

Streszczenie:

Among the many types of grinding machines used in enterprises of grain processing, food and other industries, an important place belongs to hammer crushers. This is explained by the possibility of their use for grinding materials of various origins (plant, animal, mineral, as well as various wastes of food production), various particle size distribution (lumpy, briquetted, granular, fibrous), having different strength properties (hard, medium hard, soft, brittle, viscous), capable of being crushed once or requiring double sequential crushing. In addition, hammer crushers are characterized by relative simplicity of design, and most importantly - they destroy materials in the most rational way - by impact loading as a result of two successive strokes: a hammer on a particle and particles on the surface of the deck. The execution of these attacks at right angles creates the conditions for the intensification of the destruction process. However, the wear of the hammers leads to a rounding of their impact faces, which makes the angles of attack in the active zone of the hammers significantly different from the direct one. Under the influence of shock-frictional loads, their working surfaces quickly wear out, which leads to a decrease in productivity and crushing efficiency, to an increase in energy consumption, a disturbance in the balance of hammer rotors, an increase in the vibroacoustic activity of crushers, and other negative consequences The invention of the “Hammer of the crusher” provides for the use of ring-shaped multi-toothed hammers, the durability of which, when using traditional materials and conventional heat treatment, is increased by 4...5 times, eliminates the need for periodic rearrangement of hammers, stabilizes the operation of crushers. The possibility of self-sharpening ring-shaped multi-toothed hammers after reversing the hammer rotor simplifies the maintenance of crushers, eliminates personnel errors when replacing worn hammers. If multi-toothed hammers are subjected to liquid non-electrolysis boration and heat treatment using an optical quantum generator, then their durability can increase by more than ten times.

Style APA, Harvard, Vancouver, ISO itp.

10

Yang, Un Hyok, Tok Hyong Han, Un Chol Han, Il Gwang Tae, Ryo Myong Hong i Song Chol Kim. "Numerical Analysis of a Small Pneumatic Hammer Performance Based on Evaluation Method of Friction Force". Shock and Vibration 2022 (12.04.2022): 1–10. http://dx.doi.org/10.1155/2022/3839896.

Pełny tekst źródła

Streszczenie:

Mechanical power loss in pneumatic hammers comes from the friction between parts in relative motion, and wear is among the failure mechanisms of the top hammer. Therefore, it is important for high performance and a longer service life of pneumatic hammers to reduce the friction force between parts in relative motion. This study presented a novel approach to quantitatively determine the friction force and consider it in the simulation model of pneumatic hammer. First, the friction force between piston and cylinder in a small pneumatic hammer was measured using an experimental setup at different inlet pressures. We could find from the experimental result that the friction force was about 0.8 N under the horizontal installation when there was no pressure supply, but it increased significantly, was 20 times greater than that without pressure supply, due to aerodynamic action by compressed air leaked from the annular gaps between the cylindrical matching surfaces of the components. In addition, it increased from 10.27 to 16.7 N due to an increase in inlet pressure and mechanical power loss in the pneumatic hammer that was about 10% of impact energy. Then, numerical analysis for a small pneumatic hammer performance was performed by a model considered the friction force using AMESim software. Finally, it can be seen from the simulation results that the proposed approach could significantly reduce the error between the simulated and the measured values for the impact energy because of ignoring the friction force. This approach will be used to predict service life of piston and find a low friction piston of pneumatic hammer in practical engineering.

Style APA, Harvard, Vancouver, ISO itp.

11

Chervov, Vladimir V. "EXPERIENCE OF STEEL PILE DRIVING BY PNEUMATIC HAMMERS IN UNDERGROUND CONSTRUCTION BY THE CUT-AND-COVER METHOD". Interexpo GEO-Siberia 2, nr 4 (21.05.2021): 173–80. http://dx.doi.org/10.33764/2618-981x-2021-2-4-173-180.

Pełny tekst źródła

Streszczenie:

The timeliness of application of pneumatic hammers in the deep bore tunneling in underground construction is justified. The penetration resistance forces in steel pipe driving in soil are determined. The analysis of long-term operation of adjustable capacity pneumatic hammers shows the conformity of the blow energy and the driven pipe diameter. The relationship between the unit blow energy and the open-ended pipe diameter is proposed. The main pneumatic hammer parameter to govern the machine performance is substantiated. The standard pneumatic hammers of adjustable capacity are characterized. The cases of vertical pipe driving at construction sites in Russia are described. The technological capability of construction of retention wall in soil using rolled steel, namely, I-beams, U-sections, piling bars, etc. is illustrated. The production tooling arrangements to ensure secure mounting of the hammer on the axial element driven in soil are described.

Style APA, Harvard, Vancouver, ISO itp.

12

Mangalam, Madhur, Matheus Maia Pacheco, Patrícia Izar, Elisabetta Visalberghi i Dorothy Munkenbeck Fragaszy. "Unique perceptuomotor control of stone hammers in wild monkeys". Biology Letters 14, nr 1 (styczeń 2018): 20170587. http://dx.doi.org/10.1098/rsbl.2017.0587.

Pełny tekst źródła

Streszczenie:

We analysed the patterns of coordination of striking movement and perceptuomotor control of stone hammers in wild bearded capuchin monkeys, Sapajus libidinosus as they cracked open palm nut using hammers of different mass, a habitual behaviour in our study population. We aimed to determine why these monkeys cannot produce conchoidally fractured flakes as do contemporary human knappers or as did prehistoric hominin knappers. We found that the monkeys altered their patterns of coordination of movement to accommodate changes in hammer mass. By altering their patterns of coordination, the monkeys kept the strike's amplitude and the hammer's velocity at impact constant with respect to hammer mass. In doing so, the hammer's kinetic energy at impact—which determines the propagation of a fracture/crack in a nut—varied across hammers of different mass. The monkeys did not control the hammer's kinetic energy at impact, the key parameter a perceiver-actor should control while knapping stones. These findings support the hypothesis that the perceptuomotor control of stone hammers in wild bearded capuchin monkeys is inadequate to produce conchoidally fractured flakes by knapping stones, as do humans.

Style APA, Harvard, Vancouver, ISO itp.

13

Khudher, Assad Y., Salim A. Almaliki i Majed S. Himoud. "Effect of Hammer Shape and Impact Area on Hammer Mill Performance under Different Feed Rates". Basrah Journal of Agricultural Sciences 34, nr 2 (2.11.2021): 88–99. http://dx.doi.org/10.37077/25200860.2021.34.2.07.

Pełny tekst źródła

Streszczenie:

The research aims to compare the performance (PC) and specific energy consumption (Spc.) of the hammer mill when using the T-hammer against the (traditional) rectangular hammer. A homemade mill with four hammers was used in experiment. 36 treatments: 2 hammer shape x 3 impact area (840, 720 and 960 mm2) x 2 feeding rates (1500 and 3000 g min-1) x 3 replicates, with completely random design. The results showed that there was no significant effect of hammer shape on PC at the feed rate of 3000 g min-1, while there was an effect at the rate of 1500 g min-1. An effect was also found for the impact area on the PC at both feeding rates and on Spc., as an inverse relationship appeared between the impact area and mill productivity at the feed rate 1500 g min-1. The area of 720 mm2 surpassed the area 480 and 960 mm2 at the rate of feeding 3000 g min-1, as it recorded 1215.65 g min-1 compared to 950.65 and 882.65 g min-1, respectively. There is effect of feeding rate on PC and Spc. The traditional hammer is recommended for simplicity of design, manufacture and performance at high feed rates compared to the T-shaped hammer.

Style APA, Harvard, Vancouver, ISO itp.

14

Tambovtsev, Pavel N. "EXPERIMENTAL VALIDATION OF PARAMETERS OF HEAVY GRAVITY PNEUMATIC HAMMERS FOR CASING PIPE RAMMING IN SOIL". Interexpo GEO-Siberia 2, nr 4 (21.05.2021): 130–40. http://dx.doi.org/10.33764/2618-981x-2021-2-4-130-140.

Pełny tekst źródła

Streszczenie:

Vertical penetration of steel pipes with a diameter of 530-1420 mm and to 100-150 m long in soil requires high blow energy (10-100 kJ). Design of the percussion machines using the available pneumatic hammers is constrained due to the high flow rate of an energy source required. It is of the current concern to design an air-driven percussive tool capable to ensure high blow energy at low flow rate of compressed air. This study describes the testing data of a breadboard model of a new gravity pneumatic hammer. The operating mode of the model hammer is studied, and the blow energies, blow frequencies and compressed air flow rates are evaluated as functions of air pressure in the main line. The tests proved stability of cycling operation of the model tool at the high blow energy and low flow rate of the energy source at the main line pressure of 0.36-0.77 MPa. Using the dynamic similarity criteria, the standard sizes of heavy pneumatic hammers are developed, their blow energy and air flow rate are determined, and the efficiency is evaluated.

Style APA, Harvard, Vancouver, ISO itp.

15

Chernienkov, EM, A. Yu Primychkin i L. Yu Belozertseva. "Energy efficiency evaluation of high-pressure DTH hammers". IOP Conference Series: Earth and Environmental Science 991, nr 1 (1.02.2022): 012030. http://dx.doi.org/10.1088/1755-1315/991/1/012030.

Pełny tekst źródła

Streszczenie:

Abstract The design of a domestically produced DTH hammer for drilling holes in rocks of medium and high strength is presented. Using the mathematical modeling method, the serviceability of the hammer at an energy source pressure of 2.4 MPa is proved. The results of DTH hammer prototype testing at lab and full scale are presented.

Style APA, Harvard, Vancouver, ISO itp.

16

Li, Ying, Jinghui Li, Wei Shi, Xin Li i Bin Wang. "Analysis of the Dynamic Characteristics of the Top Flange Pile Driving Process of a Novel Monopile Foundation without a Transition Section". Sustainability 14, nr 10 (13.05.2022): 5950. http://dx.doi.org/10.3390/su14105950.

Pełny tekst źródła

Streszczenie:

As the most widely used foundation type, the pile-driving capacity of large-diameter monopile foundations and the hammer force of pile top flanges is increasing, as are the stress and strain of traditional flange structures under the resistance to the cyclic impact load of pile hammers. This paper conducts an empirical study on the Rudong 150 MW offshore wind farm project in Longyuan, Jiangsu Province. The numerical simulation and calculation method of large-diameter pile fatigue damage is mastered and proposed, and a simulation analysis and comparison is conducted, as is an analysis of the sensitivity and feedback of the key software parameters. Based on the results of the above analysis, a pile simulation analysis of the offshore wind power projects under construction and those that are about to be started is performed. The pile hammer stroke energy and pile top hammer stroke process curve are extracted. According to the time range curve of limit and hammer stroke forces, the flange limit stress and distribution of the pile roof are simulated. Combined with the process characteristics of large-diameter pile sinking and analysis in the case of high hammer energy and high acceleration, the effect of the impact on the sensor is discussed. The results show that the instantaneous loading analysis could load at the flange of the pile, the maximum instantaneous stress was above 500 MPa, and the final maximum stress was approximately 307 MPa. Different loading methods vary greatly in the calculation results of the structure, so choosing the appropriate loading simulation method is key to pile sinking analysis.

Style APA, Harvard, Vancouver, ISO itp.

17

Yarovoy, Mikhail, Roman Druzhinin i Andrey Kornev. "Theoretical foundations for determining the energy of movement of the annular layer in a hammer crusher". АгроЭкоИнфо 2, nr 50 (14.04.2022): 22. http://dx.doi.org/10.51419/202122222.

Pełny tekst źródła

Streszczenie:

In the course of a comprehensive analysis of the theory of the working process of hammer crushers, the insufficiency of theoretical studies of the processes occurring in the crushing chamber was revealed. One of the areas of theoretical research considered in this article is the determination of the displacement energy of the annular layer in a hammer crusher. Keywords: HAMMER CRUSHERS, ANNULAR LAYER, PASSABLE PARTICLES, ENERGY, SPEED, HAMMER, ROTOR, WORK OF DEFORMATION, POWER

Style APA, Harvard, Vancouver, ISO itp.

18

Ambriško, Ľubomír, Daniela Marasová i Peter Klapko. "Energy Balance of the Dynamic Impact Stressing of Conveyor Belts". Applied Sciences 13, nr 7 (23.03.2023): 4104. http://dx.doi.org/10.3390/app13074104.

Pełny tekst źródła

Streszczenie:

This paper presents research into the energy balance of stressing conveyor belts by impact processes. Research is described in the areas of measuring the resistance of conveyor belts to puncture, the impact process, and the effect of changes to the impact height on the tensile and impact forces. Measurements were performed on a rubber–textile belt with a polyamide carcass. Hammers with pyramidal and spherical impactors were used to compare the resistance of the examined conveyor. Values were obtained for the maximum energies for the selected impact heights and the residual positional energies for the measured bounce heights. The difference between these energies represents the impact energy. The results confirmed that the impact energy of a hammer with a pyramidal impactor is greater than the impact energy of a hammer with a spherical impactor, while this difference increases with increasing impact height. The shape of the pyramidal impactor simulates sharp-edged materials, which is the cause of greater damage in the tribological interaction with the conveyor belt. This paper provides information for determining the limit conditions for setting appropriate impact heights depending on the weight of the material transported using a given belt conveyor.

Style APA, Harvard, Vancouver, ISO itp.

19

Hong, Sokgun, Un Chol Han, Gum Chol Kim, Kwang Myong Ri i Song Ri. "Numerical Simulation of the Collision Breakage Process between the Agglomerate and Hammer in a Hammer Crusher Using DEM". Shock and Vibration 2023 (25.07.2023): 1–14. http://dx.doi.org/10.1155/2023/2838179.

Pełny tekst źródła

Streszczenie:

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.

Style APA, Harvard, Vancouver, ISO itp.

20

Vukmirovic, Djuro, Jovanka Levic, Aleksandar Fistes, Radmilo Colovic, Tea Brlek, Dusica Colovic i Olivera Djuragic. "Influence of grinding method and grinding intensity of corn on mill energy consumption and pellet quality". Chemical Industry 70, nr 1 (2016): 67–72. http://dx.doi.org/10.2298/hemind141114012v.

Pełny tekst źródła

Streszczenie:

In recent years there is an emerging trend of coarse grinding of cereals in production of poultry feed due to positive influence of coarse particles on poultry digestive system. Influence of grinding method (hammer mill vs. roller mill) and grinding intensity of corn (coarseness of grinding) on mill specific energy consumption and pellet quality was investigated. By decreasing grinding intensity of corn (coarser grinding), specific energy consumption of both hammer mill and roller mill was significantly decreased (p < 0.05). When comparing similar grinding intensities on hammer mill and roller mill (similar geometric mean diameter or similar particle size distribution), specific energy consumption was higher for the hammer mill. Pellet quality decreased with coarser grinding on hammer mill but, however, this effect was not observed for the roller mill. Generally, pellet quality was better when roller mill was used. It can be concluded that significant energy savings could be achieved by coarser grinding of corn before pelleting and by using roller mill instead of hammer mill. From the aspect of pellet quality, if coarser grinding is applied it is better to use roller mill, concerning that more uniform particle size distribution of corn ground on roller mill probably results in more uniform particle size distribution in pellets and this provides better pellet quality.

Style APA, Harvard, Vancouver, ISO itp.

21

Youd, T. Leslie, Hannah W. Bartholomew i Jamison H. Steidl. "SPT Hammer Energy Ratio versus Drop Height". Journal of Geotechnical and Geoenvironmental Engineering 134, nr 3 (marzec 2008): 397–400. http://dx.doi.org/10.1061/(asce)1090-0241(2008)134:3(397).

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

22

Skalozubov, V., N. Bilous, D. Pirkovskiy, I. Kozlov, Yu Komarov i O. Chulkin. "Water Hammers in Transonic Modes of Steam-Liquid Flows in NPP Equipment". Nuclear and Radiation Safety, nr 2(82) (6.06.2019): 43–46. http://dx.doi.org/10.32918/nrs.2019.2(82).08.

Pełny tekst źródła

Streszczenie:

The analysis of well-known studies in modelling conditions for water hammers in equipment and components of pipeline systems has revealed that definition of conditions and parameters of water hammers in the transonic modes of single- and two-phase flows (at a speed of propagation of acoustic disturbances) is the least studied problem. The original method is proposed for determining the conditions and parameters of water hammers in transonic flow modes subject to the transition of the kinetic energy of the flow stagnation into the energy of the water hammer pulse. It was found that the simulated hydrodynamic loads in transonic modes can significantly exceed the corresponding known recommendations of N. Zhukovsky. The proposed method of equations computer modelling served to determine the criteria range for water hammers due to aperiodic thermohydrodynamic instability in transonic flow modes.

Style APA, Harvard, Vancouver, ISO itp.

23

Chen, Dong Hua, i Li Quan Wang. "Dynamic Response of Hammer Impacting Pile under Gravity Field". Applied Mechanics and Materials 610 (sierpień 2014): 65–69. http://dx.doi.org/10.4028/www.scientific.net/amm.610.65.

Pełny tekst źródła

Streszczenie:

Pile hammer impact system is composed of hammer, pile cap and pile. Gravity field will produce uneven stress in the pile which is placed on a fixed rigid plane, and gravitational potential energy will increase the impact energy which is inputted to the pile during the impact process. These will influence dynamic response of collision process between pile hammer and pile. In this paper, a gravity field factor was added in the Simth difference equations which are based on One-dimensional Wave Equation. The numerical model of pile hammer impact system was established. A program was written to implement the numerical model. Simulation results indicated that the duration of collision, the peak and stable value of impact force and the effective impact energy would be affected by the gravity field.

Style APA, Harvard, Vancouver, ISO itp.

24

Jiang, Yang, Yue Xin She, Wen Bin Sun, Bao Hai Chen i Hua Rong Shen. "Consolidation Effect and Influencing Factors of Dynamic Compaction for Filling Subgrade". Applied Mechanics and Materials 204-208 (październik 2012): 1617–21. http://dx.doi.org/10.4028/www.scientific.net/amm.204-208.1617.

Pełny tekst źródła

Streszczenie:

The parameters of dynamic compaction impacting on consolidation effect such as fall-height of hammer, impact mode, impact space, etc. are analysed by dynamic FEM method. The method of choosing parameters of dynamic compaction and consolidation effect of dynamic compaction on filling subgrade are illuminated by field test. Conclusions are drawn: with the increase of impact energy, the range of plastic deformation zone will extend to a certain depth in subgrade, which will certainly expand the effective reinforcement range of subgrade; optimal impact times of a subgrade is available; the consolidate depth and influencing area by light hammer with heavy impact is less than that by heavy hammer with light impact when impact energy is equal; with the increase of hammer diameter, both deformation and strain of subgrade reduce under the same impact energy.

Style APA, Harvard, Vancouver, ISO itp.

25

Santana, Christian M., Fernando A. B. Danziger i Bernadete R. Danziger. "Energy Measurement in the Brazilian SPT System". Soils and Rocks 37, nr 3 (1.09.2014): 243–55. http://dx.doi.org/10.28927/sr.373243.

Pełny tekst źródła

Streszczenie:

This paper presents results of the instrumentation of 373 blows from two SPT deployments performed in the Sarapuí II Test Site, located in Duque de Caxias, Rio de Janeiro. In these blows the hammer drop height, its velocity at impact, the rate of blows and also the energy transferred to the rod stem have been measured. It is therefore possible to know the loss of energy for the SPT process (and the corresponding efficiency factors), since the hammer is delivered at zero velocity up to the time the transmitted energy reaches the rod stem.

Style APA, Harvard, Vancouver, ISO itp.

26

Barreto, Gilmar W., José C. A. Cintra i Nelson Aoki. "Proposal of an Energy Comparison System in the SPT". Soils and Rocks 37, nr 1 (1.01.2014): 61–71. http://dx.doi.org/10.28927/sr.371061.

Pełny tekst źródła

Streszczenie:

This paper describes a mechanical device to compare the energy transference from the blow of a hammer to the stem referring to standardized and non-standardized equipment in Brazil. The device allows to measure the vertical displacement of a sleeve due to one or more blows of a hammer falling freely. Tests were carried out using three pieces of equipment for the SPT measurements, but only one was mounted on a tripod standardized by the NB 6484:2001 norm. Based on the displacement values, a comparative analysis of the available energies of the equipment was conducted. The efficiency of the standard tripod for the test performed without a strict control of the fall of the hammer relative to the transfer efficiency of the test performed with a strict control of the fall height was 82.5%, showing a significant influence of human factor on the results. The lowest coefficient of variation of the displacements (5.05%) was obtained for the test using mechanized equipment with an automatic hammer. From the standpoint of the available energy of the system, it is possible to use non-standard equipment by applying the correction factor (Cf) to SPT results. Finally, static tests were performed on the sleeve and the energy transferred to the system was calculated.

Style APA, Harvard, Vancouver, ISO itp.

27

Kharisov, Timur. "Assessing serpentinite compressive strength using regression analysis". Izvestiya vysshikh uchebnykh zavedenii. Gornyi zhurnal, nr 1 (17.02.2021): 45–53. http://dx.doi.org/10.21440/0536-1028-2021-1-45-53.

Pełny tekst źródła

Streszczenie:

Introduction. Today, the express method for assessing rock compressive strength using the Schmidt hammer is becoming more and more relevant and demanded. Compared to laboratory methods, measurements by this non-destructive express method result in the height of striker rebounding. The device has to be calibrated for further transition from the rebound height Hr to compressive strength in the UCS sample of the rock type under study. Research methodology included selection of hand specimen on the slopes of the Kiembai chrysotile asbestos open pit for laboratory tests. The height of striker rebounding was measured of Proceq RockShmidt Type N Schmidt hammer according to the ASTM method in local areas of exposed massif. Compressive strength of rock samples was tested in the laboratory using Wille Geotechnik servo hydraulic testing system. Research results. Based on the obtained data, an empirical formula has been established describing the dependence between compression strength of serpentinite in the UCS sample and striker height of rebounding of a Schmidt Type N hammer. The author’s results were compared to the ones obtained by the predecessors using a Schmidt Type L hammer when studying physical and mechanical properties of serpentinite in another field. The difference in the empirical formulas is due to the difference in physical and mechanical properties of serpentinite building up the deposits under consideration, as well as the difference in impact energy of the working Schmidt hammers

Style APA, Harvard, Vancouver, ISO itp.

28

Sy, Alex, i R. G. (Dick) Campanella. "Dynamic performance of the Becker hammer drill and penetration test". Canadian Geotechnical Journal 30, nr 4 (1.08.1993): 607–19. http://dx.doi.org/10.1139/t93-053.

Pełny tekst źródła

Streszczenie:

The Becker penetration test (BPT) blow counts are commonly correlated to the standard penetration test (SPT) N-values for foundation design and liquefaction potential assessment in coarse-grained soils. Most of the existing correlations, however, do not adequately account for the variable energy output of the ICE 180 diesel hammer used in the Becker system, and the shaft resistance acting on the Becker pipe is often ignored. To obtain reliable BPT–SPT correlations, an extensive study of the BPT has been conducted at several sites in British Columbia. Dynamic measurements of Becker drill rigs and penetration tests were conducted that included hammer combustion and bounce chamber pressures, as well as force and acceleration near the top of the drill pipe. The dynamic field data are presented, including the maximum energy transferred to the top of the Becker pipe (ENTHRU). An energy approach for correcting Becker blow counts to a reference ENTHRU level of 30% of the hammer-rated energy is proposed. Different combustion conditions, drill rigs, and pipe sizes are investigated in the study. The test results show that ENTHRU is a fundamental and useful parameter for normalizing the BPT blow counts to account for the variable energy transfer from the diesel hammer. Key words : penetration test, dynamic measurement, energy, pile driving, diesel hammer, stress-wave propagation.

Style APA, Harvard, Vancouver, ISO itp.

29

Cong, T. C. "Study the Coefficient of Energy Transfer from Hammer to Pile Driven in Two Layers Foundation Base, Pile Bearing Side Friction q₁#q₂ Pile Bottom Encounters Constant Resistance". Applied Mechanics and Materials 427-429 (wrzesień 2013): 195–99. http://dx.doi.org/10.4028/www.scientific.net/amm.427-429.195.

Pełny tekst źródła

Streszczenie:

This paper consider the collision of hammer to pile driven into two layers foundation base, piles bearing side friction q1 ≠ q2, applies the theoretical basis of longitudinal collision of elastic bars and method of wave propaganda DAlember, determine the velocity of pile heads in the time interval, compress work of elastic buffering on pile head, from the calculation of coefficient of energy transfer from hammer to pile, choosing pile head buffering and hammer heads according to the coefficient of energy transfer calculated.

Style APA, Harvard, Vancouver, ISO itp.

30

Anbazhagan, P., M. E. Yadhunandan i Ayush Kumar. "Effects of Hammer Energy on Borehole Termination and SBC Calculation Through Site-Specific Hammer Energy Measurement Using SPT HEMA". Indian Geotechnical Journal 52, nr 2 (4.01.2022): 381–99. http://dx.doi.org/10.1007/s40098-021-00582-z.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

31

Zhou, Fangrong, Gang Wen, Guochao Qian, Yutang Ma, Hao Pan, Jing Liu i Jiaying Li. "A High-Efficiency Deep-Learning-Based Antivibration Hammer Defect Detection Model for Energy-Efficient Transmission Line Inspection Systems". International Journal of Antennas and Propagation 2022 (28.09.2022): 1–12. http://dx.doi.org/10.1155/2022/3867581.

Pełny tekst źródła

Streszczenie:

Automated inspection using unmanned aerial vehicles (UAVs) is an essential means to ensure safe operations of the power grid. Defect detection for antivibration hammers on transmission lines in inspection imagery is one of the critical tasks for automated UAV inspection. It needs a machine interpretation system to automatically detect numerous inspection images. In this paper, a high-efficiency model based on Cascade RCNN (region-convolutional neural network) is proposed to detect antivibration hammer defects with reduced costs and speedier response, which applies in energy-efficient transmission line inspection systems. Firstly, to reduce computational costs, this study modifies the Cascade RCNN with a probabilistic interpretation to achieve the best trade-off between the inference time and average precision. Secondly, an antivibration hammer defect detector (AVHDD) model is proposed that uses a deep layer aggregation-based feature extraction network and a highly effective weighted bidirectional feature fusion network to replace the original ResNet and FPN on the modified Cascade RCNN to further enhance the model performance. Finally, a fine classification (FC) scheme for the types of antivibration hammer defects is proposed based on defect features to rationalize the model. The AVHDD reached an experimental mAP of 97.24% when IoU = 0.75, which is 2.93% higher than the original Cascade RCNN, and the defect recall was 98.9% while also significantly improving the inference speed. Moreover, the experimental results indicate that the overall performance of the proposed model is superior to typical models, confirming its suitability for energy-efficient transmission line inspection systems.

Style APA, Harvard, Vancouver, ISO itp.

32

Ämmälä, Ari. "Comparison of Pin Mill and Hammer Mill in the Fine Grinding of Sphagnum Moss". Energies 16, nr 5 (3.03.2023): 2437. http://dx.doi.org/10.3390/en16052437.

Pełny tekst źródła

Streszczenie:

Dried sphagnum moss was ground using a pin mill and a hammer mill under various operating conditions, i.e., changes in the rotor frequency and feed rate. The specific energy consumption of the size reduction was recorded. The ground powder was characterized by median particle size, width of size distribution (span), loose and tapped bulk densities, and the Hausner ratio. Pin milling used less energy for size reduction than hammer milling, especially when the target size was below 100 μm. In both milling methods, the specific energy consumption was mainly caused by the rotor frequency used. However, in pin milling, the specific energy consumption was also dependent on the production rate: the higher the rate, the higher the energy consumption. No such dependence was observed with the hammer mill. The span was wider in pin milling than hammer milling in the intermediate product size range although the difference decreased at the fine and coarse ends. A similar pattern was found for bulk densities. However, the flowability of powder, as characterized by the Hausner ratio, was comparable between the grinding methods.

Style APA, Harvard, Vancouver, ISO itp.

33

Ji, Peng, Jiling Yang, Nan Zhang, Qian Zhai, Minjie Li, Yueyi Wang, Tianlun Shen i Alfrendo Satyanaga. "Energy Measurement in Standard Penetration Tests". Sustainability 15, nr 6 (7.03.2023): 4763. http://dx.doi.org/10.3390/su15064763.

Pełny tekst źródła

Streszczenie:

The standard penetration test (SPT) is a widely used in situ test method worldwide that can evaluate soil properties based on the blow counts (N-value). The N-value depends on soil properties, and the energy transferred to the drill pipe during hammering. Currently, European and American scholars generally believe that variation in the amount of hammer energy transmitted to the drill pipe due to different types of drop hammer systems is the primary factor that leads to variations in N-value. In China, there is a lack of research on the quantitative energy transfer efficiency of the drop hammer system based on test data from a penetration test instrument. In this study, an in-situ test in Jiangsu Province was performed at a test site using standard penetration test instruments that are commonly used in China. Corresponding time history curves and strain, acceleration, force, velocity, energy and penetration degree data were obtained through the stress wave test. The propagation law of the stress wave and energy in a drill pipe was analyzed, and the energy transfer efficiency of the domestic SPT system was measured. In the stress wave test, most of the measured hammer energy efficiency was between 74.5 and 84.5%, and the measured average energy was 0.3723 kJ; the average energy efficiency was 78.7%; the standard deviation (SD) of the energy efficiency was 3.82, and the coefficient of variation (CV) of energy transfer efficiency(ER) was 4.9%. The average energy efficiency of 78.7% can be considered to be the energy efficiency of the domestic SPT system. The calculated results reported in this article can be used to improve the quantitative level of domestic investigation. Based on the calculated Er, the results obtained from different SPT systems at home and abroad can be corrected.

Style APA, Harvard, Vancouver, ISO itp.

34

Dudlik, A., S. B. H. Schönfeld, O. Hagemann i H. Fahlenkamp. "Water hammer and cavitational hammer in process plant pipe systems". Kerntechnik 68, nr 3 (1.06.2003): 91–96. http://dx.doi.org/10.1515/kern-2003-0047.

Pełny tekst źródła

Streszczenie:

Abstract Fast acting valves are often applied for quick safety shut-down of pipelines for liquids and gases in the chemical and petrochemical industry as well as in power plants and state water supplies. The fast deceleration of the liquid leads to water hammer upstream the valve and to cavitational hammer downstream the fast closing valve. The valve characteristics given by manufacturers are usually measured at steady state flow conditions of the liquid. In comparison, the dynamic characteristics depend on the initial liquid velocity, valve closing velocity, the absolute pipe pressure and the pipe geometry. Fraunhofer UMSICHT conducts various test series examining valve dynamic characteristics in order of the dynamic analysis of pressure surges in fast closing processes. Therefore a test rig is used which consists of two pipelines of DN 50 and DN 100 with an approximate length of 230 m each. In this paper the results of performed pressure surge experiments with fast closing and opening valves will be compared to calculations of commercial software programs such as MONA, FLOWMASTER 2. Thus the calculation software for water supply, power plants, oil and gas and chemical industry can be permanently improved.

Style APA, Harvard, Vancouver, ISO itp.

35

Wang, Shao Hua, Li Hui Lang i Li Jing Lin. "Investigation on the Energy Efficiency of Innovative Hybrid Impact Hydroforming". Advanced Materials Research 989-994 (lipiec 2014): 1282–85. http://dx.doi.org/10.4028/www.scientific.net/amr.989-994.1282.

Pełny tekst źródła

Streszczenie:

The innovative hybrid impact hydroforming (IHF) technology use high energy forming complex parts in very short time which can improving forming quality of hardforming materials like Aluminum alloy widely used in automotive and aircraft industries. The impact hydroforming technology means the most features are formed by hydroforming and the small features are rapidly reshaped by high intensity impact energy in a very short time after the traditional hydroforming. Thus, the impact energy is the most important parameter of Innovative Hybrid Impact Hydroforming. Using numerical simulation software MSC.PATRAN/DYTRAN, the whole system of hybrid impact hydroforming apparatus was analyzed. The initial gas pressure and the mass of hammer directly affect the energy efficiency. The results show greater initial gas pressure will linear increase the energy output. Moreover, the bigger mass of hammer will reduce the velocity of hammer, but it still increase the energy output. Therefore, the research is very useful for improving energy efficiency of IHFand widing its application.

Style APA, Harvard, Vancouver, ISO itp.

36

Birch, R. S., N. Jones i W. S. Jouri. "Performance Assessment of an Impact Rig". Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 202, nr 4 (lipiec 1988): 275–85. http://dx.doi.org/10.1243/pime_proc_1988_202_120_02.

Pełny tekst źródła

Streszczenie:

A recent upgrading of a drop hammer rig was carried out and a series of calibration tests established the energy losses in the existing anvil. Both the test results and the mathematical modelling showed that significant energy losses would occur at high impact loads. An alternative anvil design considerably reduced the energy losses and improved the performance of the drop hammer rig.

Style APA, Harvard, Vancouver, ISO itp.

37

Wang, Gang, i Yu Wan Cen. "Simulation on the Regulating Characteristics of the Pulse Modulation Hydraulic Hammer". Advanced Materials Research 422 (grudzień 2011): 176–83. http://dx.doi.org/10.4028/www.scientific.net/amr.422.176.

Pełny tekst źródła

Streszczenie:

To improve the regulating characteristics of impact energy, simplify structure of hydraulic hammer, a new pulse modulation hydraulic hammer is presented in the paper which can help regulate its impact frequency easily. The motion equations of the hydraulic hammer are established, its simulation model is obtained and the dynamic simulation is carried out on AMESim. The dynamics of high-speed ON/OFF valve is taken into account in the simulation model. The tendency of simulation results conforms to experimental results; it shows that the pulse modulation hydraulic hammer is feasible, and the hydraulic hammer model is reasonable. The time delay in high working frequency is also analyzed.

Style APA, Harvard, Vancouver, ISO itp.

38

Shi, Fengnian, Toni Kojovic, Joan S. Esterle i Dean David. "An energy-based model for swing hammer mills". International Journal of Mineral Processing 71, nr 1-4 (wrzesień 2003): 147–66. http://dx.doi.org/10.1016/s0301-7516(03)00035-8.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

39

Batilas, A. V., P. C. Pelekis, P. G. Roussos i G. A. Athanasopoulos. "SPT Energy Measurements: Manual vs. Automatic Hammer Release". Geotechnical and Geological Engineering 35, nr 2 (19.12.2016): 879–88. http://dx.doi.org/10.1007/s10706-016-0138-z.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

40

Płachta, Adam, Jacek Pawlicki i Kinga Rodak. "Strength–Energy and Structural Effects of Dynamic Deformation of Aluminum Alloy". Solid State Phenomena 226 (styczeń 2015): 49–52. http://dx.doi.org/10.4028/www.scientific.net/ssp.226.49.

Pełny tekst źródła

Streszczenie:

This paper presents the results of dynamic deformation tests performed on aluminum alloy PA4. The studiem was carried out by using rotary hammer, in the range of high rate of deformation: 400 – 2000 s-1. The test were carried using a rotary hammer of RSO type owned by Silesian Technical University in Institute of Technology Metals. Before the dynamic deformation, the heating treatment was carried out allowed for eliminating structural effects resulting from the previous technological treatments and for obtaining the homogenous grain structure. The tests were carried out with linear velocity in the range of 5 – 30 m/s. After deformation the following mechanical characteristics were determined: deformation limit εg, strain rate , tensile strength UTS, impact strength U. Independently of the dynamic deformation tests were carried out tensile test under static conditions. Moreover bending test were performed on Charpy type hammer with initial impact energy equal 300 J. The analysis of the microstructure was carried out using scanning electron microscopy Hitachi S–3400 N.

Style APA, Harvard, Vancouver, ISO itp.

41

Fu, Jianhong, Yu Su, Wei Jiang, Shuanggui Li i Yingjie Chen. "Wellbore annulus water hammer pressure prediction based on transient multi-phase flow characteristics". Oil & Gas Science and Technology – Revue d’IFP Energies nouvelles 74 (2019): 84. http://dx.doi.org/10.2516/ogst/2019058.

Pełny tekst źródła

Streszczenie:

Water hammer pressure has been known to cause formation fracture and well-control problems. Accurate prediction of water hammer pressure is crucially important to determine the selection of shut-in methods. In this study, the mathematic model of wellbore annulus transient water hammer has been established with the consideration of transient multi-phase flow characteristics, and it has been solved by the Method Of Characteristic (MOC). Finally, this paper focused on the effects of gas cutting, shut-in time and friction on water hammer pressure, and gas kick time were also regarded to study on the influence of water hammer pressure. The results show that both the gas cutting and gas kick time have few influences on the maximum water hammer pressure, but intensified the attenuation of water hammer pressure. Additionally, the peak value of water hammer pressure declines with the increase of the shut-in time, and the effect of friction loss on water hammer pressure became significant with the increase of well depth. More importantly, both the additional water hammer pressure and Shut-In Casing Pressure (SICP) generated by the closure of BlowOut Preventer (BOP) are likely to cause formation at the shallow casing shoe damage.

Style APA, Harvard, Vancouver, ISO itp.

42

Duan, Jiehao, Changjun Li i Jin Jin. "Establishment and Solution of Four Variable Water Hammer Mathematical Model for Conveying Pipe". Energies 15, nr 4 (14.02.2022): 1387. http://dx.doi.org/10.3390/en15041387.

Pełny tekst źródła

Streszczenie:

Transient flow in pipe is a much debated topic in the field of hydrodynamics. The water hammer effect caused by instantaneous valve closing is an important branch of transient flow. At present, the fluid density is regarded as a constant in the study of the water hammer effect in pipe. When there is gas in the pipe, the variation range of density is large, and the pressure-wave velocity should also change continuously along the pipe. This study considers the interaction between pipeline fluid motion and water hammer wave propagation based on the essence of water hammer, with the pressure, velocity, density and overflow area set as variables. A new set of water hammer calculation equations was deduced and solved numerically. The effects of different valve closing time, flow rate and gas content on pressure distribution and the water hammer effect were studied. It was found that with the increase in valve closing time, the maximum fluctuating pressure at the pipe end decreased, and the time of peak value also lagged behind. When the valve closing time increased from 5 s to 25 s, the difference in water hammer pressure was 0.72 MPa, and the difference in velocity fluctuation amplitude was 0.076 m/s. The findings confirm: the greater the flow, the greater the pressure change at the pipe end; the faster the speed change, the more obvious the water hammer effect. High-volume flows were greatly disturbed by instantaneous obstacles such as valve closing. With the increase of time, the pressure fluctuation gradually attenuated along the pipe length. The place with the greatest water hammer effect was near the valve. Under the coupling effect of time and tube length, the shorter the time and the shorter the tube length, the more obvious the pressure fluctuation. Findings also confirm: the larger the gas content, the smaller the fluctuation peak of pipe end pressure; the longer the water hammer cycle, the smaller the pressure-wave velocity. The actual pressure fluctuation value was obviously lower than that without gas, and the size of the pressure wave mainly depended on the gas content. When the gas content increased from 1% to 9%, the difference of water hammer pressure was 0.41 MPa.

Style APA, Harvard, Vancouver, ISO itp.

43

Zhang, Yin Juan. "Research of All-Hydraulic Die Forging Hammer Control System". Advanced Materials Research 785-786 (wrzesień 2013): 1286–89. http://dx.doi.org/10.4028/www.scientific.net/amr.785-786.1286.

Pełny tekst źródła

Streszczenie:

This paper presents the structure and work principle of hydraulic die forging hammer. The mathematic model is established based on momentum theorem which is used to confirm the forging energy and blow number of times. At the same time,it offered the theories reference for the precision control of the run process. The speed, displacement and kinetic energy variety of hammer head were simulated. This research provided the foundation of further controllable and flexible for the forging energy and times.

Style APA, Harvard, Vancouver, ISO itp.

44

Gao, Zheng Guo, Yu Long Du, Xiao Bo Huang i Xin Huang. "Mechanical Behavior of Broken Stone Fills under Dynamic Consolidation". Advanced Materials Research 446-449 (styczeń 2012): 1696–702. http://dx.doi.org/10.4028/www.scientific.net/amr.446-449.1696.

Pełny tekst źródła

Streszczenie:

This paper studies the dynamic response characteristics of broken stone fills. Numerical simulation and in-situ test of the acceleration and settlement of a high fill under dynamic consolidation are carried out. The result shows that increasing compact energy and the compact numbers can improve the reinforcement effect. There is no significant relationship between the dynamic compaction number reaching the stable settlement and compact energy. When the compact energy is the same, compaction with a heavier hammer is better than compaction with a lighter hammer.

Style APA, Harvard, Vancouver, ISO itp.

45

Cárdenas, Daniel, Isao Parra-Tsunekawa, Francisco Leiva i Javier Ruiz-del-Solar. "Automatic Determination of Rock-Breaking Target Poses for Impact Hammers". Energies 15, nr 17 (1.09.2022): 6380. http://dx.doi.org/10.3390/en15176380.

Pełny tekst źródła

Streszczenie:

This paper describes a system for the automatic determination of rock-breaking target poses for impact hammers used in underground mines. The rock-breaking target pose is defined as the position and angle at which the impact hammer must strike a rock in order to break it. The automatic determination of this pose is essential for the autonomous operation of an impact hammer. The proposed system takes as input sensor data composed of point clouds and images, and automatically determines a rock-breaking target pose. The system consists of a rock segmentation subsystem that receives the sensor data and identifies and individualizes the rocks/boulders present above the grizzly, and a rock-breaking target pose generation and evaluation subsystem that receives the rock information produced by the rock segmentation subsystem, and generates a list of rock-breaking target pose candidates, it evaluates them, and it selects the best candidate as the rock-breaking target pose. The system is evaluated using real data. The reported experiments show the system’s capability to generate appropriate target poses.

Style APA, Harvard, Vancouver, ISO itp.

46

Lei, Bufang. "Research on the energy economization of electro-hydraulic hammer". Chinese Journal of Mechanical Engineering (English Edition) 13, nr 01 (2000): 64. http://dx.doi.org/10.3901/cjme.2000.01.064.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

47

OHTA, Ken, Koji UMEGAKI, Koji MUROFUSHI i Yuji OHGI. "J2310102 Energy Transfer through Internal force during Hammer Throw". Proceedings of Mechanical Engineering Congress, Japan 2014 (2014): _J2310102——_J2310102—. http://dx.doi.org/10.1299/jsmemecj.2014._j2310102-.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

48

Ghidaoui, Mohamed S., Bryan W. Karney i Duncan A. McInnis. "Energy Estimates for Discretization Errors in Water Hammer Problems". Journal of Hydraulic Engineering 124, nr 4 (kwiecień 1998): 384–93. http://dx.doi.org/10.1061/(asce)0733-9429(1998)124:4(384).

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

49

Changming, Wu. "Percussive energy transfer in pneumatic top hammer rock drills". International Journal of Surface Mining, Reclamation and Environment 5, nr 1 (styczeń 1991): 33–38. http://dx.doi.org/10.1080/09208119108944284.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

50

Chervov, V. V., I. V. Tishchenko, A. V. Chervov i Yu V. Vanag. "DESIGN OF AN ENERGY-INTENSIVE PNEUMATIC HAMMER BASED ON THE PHYSICAL SIMULATION OF THE HAMMER–SOIL INTERACTION". Journal of Mining Science 57, nr 1 (styczeń 2021): 86–95. http://dx.doi.org/10.1134/s1062739121010105.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

Artykuły w czasopismach na temat „Hammer energy”

Utwórz poprawne odniesienie w stylach APA, MLA, Chicago, Harvard i wielu innych