SCIENTIFIC AND PRACTICAL SUBSTANTIATION OF THE EFFECT OF OPERATING PARAMETERS ON HYDRAULIC RESISTANCE IN A ROTOR-TYPE DYNAMIC DUST COLLECTION APPARATUS

УДК 66.01

ABSTRACT

This study investigates the effect of key operating parameters on the hydraulic resistance of a rotor-type dynamic dust collection apparatus. Experiments were conducted at gas velocities of 10–20 m/s, rotor speeds of 400–600 rpm, and water flow rates of 0.075–0.175 m³/h under both dry and wet conditions. The results show that hydraulic resistance increases significantly with rising gas velocity. Higher rotor speeds intensify turbulence and contribute to additional local resistance within the apparatus. Increasing water flow rate enhances the gas–liquid contact surface, improving interaction efficiency but also leading to higher pressure losses. Empirical relationships describing the dependence of total hydraulic resistance on these parameters were established. The findings provide a basis for optimizing design parameters and operating conditions, improving the efficiency and performance of rotor-type dynamic dust collection systems.

АННОТАЦИЯ

В данном исследовании изучается влияние ключевых рабочих параметров на гидравлическое сопротивление роторного динамического пылеулавливающего аппарата. Эксперименты проводились при скоростях газа 10–20 м/с, частоте вращения ротора 400–600 об/мин и расходе воды 0,075–0,175 м³/ч как в сухих, так и во влажных условиях. Результаты показывают, что гидравлическое сопротивление значительно возрастает с увеличением скорости газа. Более высокие частоты вращения ротора усиливают турбулентность и способствуют дополнительному локальному сопротивлению внутри аппарата. Увеличение расхода воды увеличивает площадь контакта газа и жидкости, повышая эффективность взаимодействия, но также приводя к увеличению потерь давления. Были установлены эмпирические зависимости, описывающие зависимость общего гидравлического сопротивления от этих параметров. Полученные результаты служат основой для оптимизации параметров конструкции и условий эксплуатации, повышения эффективности и производительности роторных динамических пылеулавливающих систем.

Keywords: rotor-type dynamic apparatus, dust-laden gas, hydraulic resistance, gas velocity, rotor rotational speed, water flow rate, MATLAB, systems analysis, spray device, pressure loss.

Ключевые слова: роторный динамический аппарат, запыленный газ, гидравлическое сопротивление, скорость газа, частота вращения ротора, расход воды, MATLAB, системный анализ, распылительное устройство, потери давления.

Introduction. Industrial enterprises within the chemical, construction-materials, mineral-processing, and asphalt-concrete sectors generate considerable amounts of dust-laden gases. If such emissions are discharged directly into the atmosphere, they worsen environmental conditions, pollute the air of working areas, and create health risks for personnel and nearby populations. For this reason, the development of efficient and scientifically grounded gas-cleaning technologies with acceptable energy consumption remains an urgent engineering task. As a result of technological processes carried out in industrial enterprises, large amounts of dust-laden gases are released into the atmosphere. Such emissions are widely encountered in the construction materials industry, chemical industry, mineral fertilizer production, asphalt–concrete mixture preparation, and other sectors. The direct discharge of dust-laden gases into the atmosphere leads to environmental degradation, contamination of the working area air, and the formation of conditions hazardous to human health. Therefore, the development of highly efficient, scientifically grounded, and energy-efficient methods for dust gas purification remains an urgent task.

Rotor-type dynamic dust collection apparatuses represent one of the promising methods for cleaning dust-laden gases, in which mechanical, aerodynamic, and hydrodynamic effects are simultaneously exerted on the gas flow. In such devices, the dust-laden gas is intensively set into motion by a rotating working element, forms strong contact with the working liquid, and dispersed particles are absorbed into the liquid phase. However, the efficiency of this process is evaluated not only by the degree of purification but also by the hydraulic resistance generated within the apparatus. This is because an increase in pressure loss directly affects fan power, energy consumption, and overall operational costs.

From this perspective, the present study comprehensively investigates the influence of the design and operating parameters of a rotor-type dynamic dust collection apparatus on hydraulic resistance. The objective of the research is to determine the effects of gas velocity, rotor rotational speed, and water flow rate on total hydraulic resistance, to evaluate their variation patterns, and to substantiate the optimal operating conditions of the apparatus [1,2,3,4].

Methods. The experiments were carried out under laboratory conditions using a model of a rotor-type dynamic dust collection apparatus. The general view of the laboratory model of the device is shown in Fig. 1.

The apparatus design was developed based on a six-stage systems analysis performed in the MATLAB environment, after which a laboratory-scale model was constructed. The following stages were consistently modeled: inlet section, motion of the dust-laden gas, kinematics of rotor and disk rotation, internal flow distribution, introduction of the working liquid, formation of the gas–liquid contact zone, and discharge of the cleaned gas and generated sludge. As a result, a functional and конструктив solution for a highly efficient rotor spray-type apparatus was obtained [5].

Figure 1. General view of the laboratory model of the apparatus

According to the operating principle, the dust-laden air stream is introduced into a cylindrical корпус through an inlet nozzle. Inside the cylindrical корпус, radially arranged branch pipes are installed along the direction of rotation; their ends are positioned close to disks rigidly mounted on a shaft. The disks are driven into rotational motion by a drive shaft and are perforated to allow air passage. Under the influence of rotation, the dust-laden gas intensively circulates within the active volume of the apparatus and is directed toward the корпус wall. The working liquid is supplied through a nozzle and forms a liquid film on the apparatus wall and within the internal volume. As a result, intensive gas–liquid contact is established, and dispersed particles present in the gas are absorbed into the liquid phase. The cleaned gas is discharged through an outlet nozzle located in the upper part of the apparatus, while the generated sludge is removed through a sludge pipe.

During the experiments, the gas velocity was set to υ_in = 10, 12, 14, 16, 18, and 20 m/s. The rotor rotational speed was varied as n = 400, 500, and 600 rpm, and the water flow rate was investigated at Q_water = 0.075, 0.125, and 0.175 m³/h. Under dry conditions (without water supply), the aerodynamic characteristics of the apparatus were evaluated, whereas under wet conditions (with water supply), the hydrodynamic characteristics were analyzed. The gas flow rate corresponding to these velocities varied from 0.0785 m³/s to 0.1571 m³/s, or from 282.7 m³/h to 565.5 m³/h. During the experiments, the total hydraulic resistance ΔP total and the overall resistance coefficient ζ total were determined. The obtained results were processed in the form of tables and graphs and subjected to comparative analysis with respect to the influence of individual parameters.

 Results. The experimental results clearly demonstrated that gas velocity, rotor rotational speed, and water flow rate significantly influence the formation of hydraulic resistance in a rotor-type dynamic dust collection apparatus. Initially, the effect of gas velocity on hydraulic resistance was analyzed under dry operating conditions (without water supply). Figure 2 illustrates the variation of hydraulic resistance with increasing gas velocity at rotor speeds of 400, 500, and 600 rpm [6].

The graphical analysis shows that hydraulic resistance increases consistently with increasing gas velocity across all operating modes. In particular, at a rotor speed of 400 rpm, the experimental hydraulic resistance increased from 107 Pa to 487 Pa; at 500 rpm, from 126 Pa to 561 Pa; and at 600 rpm, from 145 Pa to 637 Pa.

Figure 2. Effect of gas velocity and rotor rotational speed on hydraulic resistance under dry conditions

This behavior can be explained by the increase in flow kinetic energy, dynamic pressure, and local resistances within the apparatus as gas velocity rises. Furthermore, at the same gas velocity, higher rotor rotational speeds correspond to higher hydraulic resistance values.

In the next stage, the influence of rotor rotational speed was analyzed separately. Figure 3 presents the variation of hydraulic resistance with increasing rotor speed from 400 to 600 rpm for different gas velocities.

Figure 3. Effect of rotor rotational speed on hydraulic resistance

This behavior can be explained by the fact that higher Rotor rotational speed intensifies the internal swirl, promotes more complex circulation trajectories, and strengthens turbulence generation. As the rotating elements accelerate, the gas flow experiences repeated redirection and stronger local interactions with the rotor-disks assembly. These mechanisms increase local hydrodynamic losses and contribute to a larger total pressure drop.

From a practical standpoint, the result is significant because Rotor rotational speed is often treated as a convenient control parameter for intensifying contact processes. However, the current experiments show that the advantage of improved mixing is accompanied by additional energy losses. Therefore, increasing Rotor rotational speed should be justified not only by its potential effect on dust capture, but also by the corresponding increase in hydraulic resistance.

Influence of liquid flow rate in wet operation.

In wet operation, the influence of water flow rate was studied additionally at a Rotor rotational speed of 600 rpm. The results demonstrated that, at all investigated gas velocities, increasing the water flow rate caused an increase in hydraulic resistance. At a gas velocity of 20 m/s, the pressure drop rose from 1132 Pa at a water flow rate of 0.075 m3/h to 1182 Pa at 0.125 m3/h and to 1231 Pa at 0.175 m3/h. At a gas velocity of 14 m/s, the hydraulic resistance increased from 526 to 551 and 575 Pa over the same liquid-flow range.

Figure 4. Effect of water flow rate on hydraulic resistance

As seen from the graph, hydraulic resistance increases with increasing water flow rate at all gas velocities. In particular, at a gas velocity of 20 m/s, hydraulic resistance increased from 1132 Pa to 1182 Pa and 1231 Pa, while at a gas velocity of 14 m/s, it increased from 526 Pa to 551 Pa and 575 Pa. This trend is explained by the formation of a liquid film and an increased number of fine droplets within the apparatus, which create additional hydrodynamic resistance to the gas flow. At the same time, an increase in water flow rate enhances the gas–liquid contact surface area [7].

Thus, the results indicate that the formation of hydraulic resistance in a rotor-type dynamic dust collection apparatus occurs in a sequential and interrelated manner. Initially, gas velocity determines the overall energetic state of the flow; subsequently, rotor rotation complicates the internal flow structure; and under wet conditions, water flow rate acts as an additional hydrodynamic factor influencing the system.

Discussion. The obtained results confirm that the formation of hydraulic resistance in a rotor-type dynamic dust collection apparatus is a multifactorial process. First, an increase in gas velocity leads to a rise in the kinetic energy of the flow, resulting in a sharp increase in pressure losses. Second, an increase in rotor rotational speed generates additional turbulence and swirling flows within the apparatus, thereby intensifying local resistances. Third, an increase in water flow rate under wet operating conditions expands the gas–liquid contact surface, creating favorable conditions for particle capture; however, it simultaneously contributes to an increase in hydraulic resistance [6,7].

This situation gives rise to an important practical trade-off. On the one hand, increasing gas velocity, rotor speed, and water flow rate can enhance the dust collection efficiency. On the other hand, these increases are accompanied by higher energy consumption and pressure losses. Therefore, the operating conditions of the apparatus should be selected not only based on maximum purification efficiency but also considering hydraulic resistance and energy consumption.

Conclusion

As a result of the conducted study, the influence of operating parameters on hydraulic resistance in a rotor-type dynamic dust collection apparatus was established.

It was found that hydraulic resistance increases significantly with increasing gas velocity in all operating modes, making it the primary factor determining pressure losses. An increase in rotor rotational speed enhances turbulence and swirling motion within the apparatus, leading to an additional rise in hydraulic resistance. An increase in water flow rate under wet conditions expands the gas–liquid contact surface but also results in higher hydraulic resistance values. The maximum hydraulic resistance observed under the highest operating conditions reached 1231 Pa.

The obtained results are of practical importance for the design of rotor-type dynamic dust collection apparatuses, the scientific justification of their конструктив parameters, and the achievement of an optimal balance between efficiency and energy consumption.

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