Atomization performance of Tiantaishan tunnel spray dust reduction

Anode for a non-transferred DC plasma spray torch was designed to improve electrothermal efficiency. A theoretical calculation was made for the electrothermal efficiency in a DC plasma torch operating with argon at atmospheric pressure with power level in the range of 5.2–20 kW using energy balance equations. ANOVA for the two level factorial design was done. Plasma gas flow rate, current intensity, nozzle diameter and length were found to influence the efficiency. The efficiency was found to decrease with increase in current intensity and nozzle length and to increase with increase in nozzle diameter and gas flow rate. The overall energy balance calculations showed that the heat transfer to the plasma-forming gas decreases with increase in arc current and the same was more significant at higher flow rates. Plasma jet velocity for different flow rates, input to the torch and nozzle dimensions was calculated from the gas enthalpy. It was found that the velocity increased with increase in the power input to the torch and gas flow rate and decreased with increase in nozzle length and diameter. The current–voltage characteristics of the torch operating with argon gas were studied for different gas flow rates. The Nottingham coefficients were calculated using least – square method.

Experimental study on the atomization characteristics and dust removal efficiency of a fan-shaped nozzle for purifying working environment

This Research aims to obtain appropriate management for Impact sprinklers to overcome the problem of soil damage due to droplets’ kinetic energy. Nozzle pressure and diameter had a major influence on droplet size which highly affects the droplet kinetic energy. Experiments were conducted at the National Irrigation Laboratory of Agricultural Engineering Research Institute (AEnRI), Dokki, Giza, Egypt was chosen to represent the engineering data of the selected impact sprinkler, riser and operating pressure. Two different nozzle diameters 3.2 mm and 3.9 mm were examined in this work at three different pressures range: 175 kPa, 200 k Pa and 225 kPa Then we found the results as follow: - Precipitation rates at pressure 225 kPa are the most regular rates, followed by pressure 200 kPa followed by pressure 175 kPa for the two tested nozzles. - Droplet Kinetic energy at the end of the wet diameter at nozzle diameter 3.2 mm is 26.83 J (10)-3, 23.9 J (10)-3 and 18.3 J (10)-3 at pressure 175 kPa, 200kPa, and 225kPa respectively, and at nozzle diameter 3.9 mm is 37.7 J 10-3, 35.78 J (10)-3 and 27.82 J (10)-3 at pressure 175 kPa, 200kPa, and 225kPa respectively.

Visualization studies of the spray from swirl injectors under elevated ambient pressure

This paper aims to improve the efficiency of uniform flow electrostatic collector. First, the principle of electrostatic dust removal technology, including electrostatic dust removal principle and an overview of uniform flow electrostatic dust collector. Then, methods to improve dust removal efficiency by analyzing the relationship between dust removal efficiency and operating parameters. These include electric field design optimization, dust removal plate optimization, and airflow distribution control. Then, the factors affecting the efficiency of dust removal are analyzed, including the particle characteristics and the gas characteristics. Finally, the electric field optimization design based on numerical simulation and the airflow distribution optimization design based on CFD simulation are presented. Through theoretical simulation and optimization design, the dust removal efficiency of uniform flow electrostatic dust collector can be improved and the dust removal effect can be further optimized.

In order to solve the problem of dust pollution in the comprehensive excavation face, the matching relationship between the long forced ventilation and the short dust removal sucking was grasped, and reasonable control dust removal process parameters were obtained. In this paper, the 3-1 coal return air roadway in Hongliulin Coal Mine is taken as the research object. By establishing the working face physical model and adopting the numerical simulation method, the different axial diameter outward air ratio is compared and analyzed. Combined with the field measurement, it is verified to obtain the optimal range of dust axial diameter outward air ratio. The application results show that a swirl air curtain is formed along the sidewall of the roadway after the adoption of the attached air duct, and a dust control air curtain pointing to the head is gradually formed after entering the section of the roadheader. When the axial diameter outward wind ratio is 1:2∼1:3, the breathing dust at the driver's position can be controlled within 17 mg/m3, and the dust removal efficiency can be increased to more than 93%, which greatly improves the working environment and ensures the occupational health and safety of workers.

Mathematical model for multivariate nonlinear prediction of SMD of X-type swirl pressure nozzles

To address the issue of excessive soil content in straw feed after harvesting by a straw feed harvester, this study designed a dust removal apparatus. Its optimal operating parameters were determined through a combination of numerical simulations and field experiments. Using dust removal efficiency as the evaluation criterion, the Box-Behnken experiment and variance analysis revealed that the factors influencing the dust removal efficiency of the apparatus, in order of significance, were the number of dust removal drums, the aperture of the dust sieve, and the rotational speed of the dust removal drums. The optimal parameter combination consisted of 5 dust removal drums, a dust sieve aperture of 5 mm, and a drum rotational speed of 370 r/min. The dust removal efficiency obtained from numerical simulation using these optimal parameters was 94.1%, while the field verification test yielded an efficiency of 93.5%, with a relative error of 0.64% between the two results, confirming the accuracy of the numerical simulation parameters. The optimized dust removal apparatus significantly improves the quality of straw fodder by reducing dust content, which not only enhances the efficiency of straw recycling but also supports sustainable agricultural practices, promoting both mechanization and green development in the industry.

The mathematical and physical model of the liquid propellant spray in straight nozzle was proposed for studying the performance characteristics of the small-scale liquid rocket engine. With the Fluent software, the numerical simulation was carried out. Sauter mean diameter (SMD) of the HAN-based liquid propellant (LP1846) in the engine combustor changing with spray pressure, nozzle diameter and the liquid surface tension were analyzed. The results indicate that: in the spray pressure region of 1.8MPa~3.0MPa, at a fixed spray pressure, the smaller is the nozzle diameter, the smaller is the droplets’ SMD and the relationship between the SMD and the nozzle diameter is approximately linearity; for the same nozzle diameter and spray pressure, the larger is the surface tension, the larger is the liquid droplets’ SMD.

Pulsed high-velocity water jets are of interest for breaking rocks and other materials. This paper describes a straightforward way of generating single water pulse with a hammer impacting a piston that rests on top of a chamber filled with water. This impacting action pressurises the water, expelling it at high velocity through a nozzle. A theoretical investigation is outlined aimed at gaining a better understanding of this system for generating water pulses. A computational model is developed to simulate the pressure dynamics in the chamber based on continuity and momentum equations for a compressible viscous flow. This model is used to optimise the relative sizes of the hammer and piston as well as the height of the water column to produce the highest velocity water pulse. The model was validated by building an experimental apparatus. In these experiments maximum pressures of about 200 MPa were measured inside the chamber over a time period of about 560 μs. This produced a water pulse with maximum velocity of 600 m/s. Experiments were conducted with nozzle diameters between about 1 mm and 4 mm to study the effect of discharge volume on the pressure history. The results illustrate that although the peak attainable pressure decreases with an increase in nozzle diameter, the duration of the elevated pressure remains similar for all nozzles.

The mining and its transportation processes generate a substantial quantity of dust, which harms miners' health. The extended inhalation of dust particles could result in pneumoconiosis. There are numerous studies on coal mine dust removal, but only a handful of articles critically comment on it. A systematic coal mine dedusting literature review has been conducted to attempt a comprehensive and reproducible analysis. This article reviews dust suppression methods by experiment in coal mines from three aspects: chemical modification of dust removers, structural improvement of dust removers, and other factors. The review showed that independent experimental research suits dust remover's structural improvement and chemical modification. Compared to non-phytochemical modifications, phytochemical modifications are more efficient and environmentally friendly. The development of dust remover structures concentrates primarily on the nozzle structure, nozzle diameter, the number of holes, and the distance, with the nozzle diameter being of particular significance. Sometimes, tweaking the nozzle structure does not yield significant efficiency improvements. However, supersonic nozzles demonstrate high efficiency and are likely to be a key area of future research. Experiments also investigated other factors' effects on coal mines' dust removal efficacy, including ventilation system, metamorphic degree of coal, and particle diameter. This review provides the latest dust removal technology information for coal mines. Intelligent technology provides the basis for experimental research on dust removal in coal mines. The future trends of experimental research in the coal mine dust control field include intelligent and automated dust control systems, comprehensive control of multiple pollutants, application of new materials and technologies, and interdisciplinary collaboration and cross-disciplinary research.

The wet electrostatic precipitator (WESP) overcomes the shortcomings of traditional electrostatic precipitators, such as dust re-entrainment and back corona. It can effectively remove high-specific-resistivity dust, with a good removal effect on PM2.5. It is proposed to adopt chemical agglomeration and humidification agglomeration technology in the wet electrostatic precipitators to achieve ultra-low dust emissions from coal-fired power plants. The results show that the addition of chemical agglomerates, surfactants, and water vapor all affect the dust diameter of coal-fired power plants. After adding sesbania gum (SG), the D50 of dust particles increases from 28.29 μm to 48.22 μm. And the D50 of dust particles is 36.46 μm when spraying 3.6 kg/h water vapor only. With the cooperation of chemical agglomeration agents and water vapor, the dust agglomeration effect and removal efficiency can be further improved. When 10 mg/L SG is synergistically combined with 2.9 kg/h water vapor, the D50 is 64.75 μm, and the dust removal efficiency reaches 97.88%. On this basis, by adding 5 mg/L of Hexadecyltrimethylammonium bromide (CTAB), the D50 is 83.06 μm, and the dust removal efficiency increases to 98.62%. The synergistic effect of chemical agglomeration and humidification agglomeration promotes the aggregation of dust from coal-fired power plants. It can improve the removal efficiency of WESP for fine particulate matter but has little impact on the operation of existing equipment. The synergistic effects of multiple agglomeration technologies are also the direction for future research on the removal efficiency of fine particulate matter.

Low interfacial tension liquid–liquid extraction with impinging-jets contacting method: Influencing parameters and relationship

Experimental and theoretical investigation of the influence of liquid droplet size on effectiveness of online compressor cleaning for industrial gas turbines

Hydraulic spraying is the main method for applying entomopathogenic fungi (EPF). Negative effects of nozzle and spray pressure on conidial viability have been reported, and appropriate droplet size ranges have been proposed to mitigate them. However, information integrating nozzle-pressure interactions with both physical and biological parameters to identify configurations that maximize pest-control efficacy remains limited. Conventional flat-fan XR110 nozzles and hollow-cone nozzles, including conventional ATR80 and air-induction TVI80, covering a range of orifice sizes, were initially evaluated for clogging at a spray pressure of 1.0 MPa. Only small-orifice flat-fan nozzles showed clogging. Droplet size distribution of non-clogging nozzles with ISO 01 and 02 orifice sizes was assessed at spray pressures between 1.0 and 2 MPa, together with their effects on conidial spray efficiency (conidia μL-1), conidial viability (%), and conidial infectivity (%) during application of a Beauveria bassiana-based product for the control of Ceratitis capitata. Nozzles showed different relationships between spray pressure and both conidial spray efficiency and viability loss. Small-droplet nozzles (XR110 and ATR80) achieved the highest efficiency. The XR110 nozzle showed the greatest viability loss across all pressures. Despite this, the ISO 02 XR110 nozzle resulted in the highest pest-control efficacy and EPF-confirmed mortality, comparable to those obtained with conventional and air-induction ISO 02 hollow-cone nozzles. The new parameter 'spray effectiveness' normalizes the biological outcome by the actual viable dose and provides insight into resource use efficiency, cost savings, and environmental impact. Optimizing B. bassiana applications requires balancing clogging risk, droplet and deposition characteristics, conidial viability, and biological efficacy. © 2026 Society of Chemical Industry.