Enhancement of Cathode Dust Collection and its Application in Improving the Efficiency of Dry Electrostatic Precipitator

As the main equipment of flue gas dedusting in coal fired boiler, electrostatic precipitator (ESP) can meet the requirements of emission standard for air pollutants from coal-fired power plants through improving the efficiency of ESP and combining with desulfurization system while not installing wet ESP (WESP). This paper introduces the modifications of ESP cathode structure to improve the efficiency of dust collection by reducing the secondary dust loss at cathode. The application of cathode dust collection provides a reference for the improvement of ESP dust collection efficiency.

Prediction of Particle-Collection Efficiency for Vacuum-Blowing Cleaning System Based on Operational Conditions

The dust-collection system, as the core of a sweeper vehicle, directly inhales dust particles on the pavement. The influence of variable operational conditions on particle-separation performance was investigated using computational fluid dynamics (CFD) Euler–Lagrange multiphase model. The particle-separation performance efficiency and retention time were used to evaluate the dust-collection efficiency. The uniform design (UD) and multiple regression analysis (MRA) methods were employed to predict and optimize the effects of reverse-blowing flow rate, pressure drop, and traveling speed on separation efficiency. The results indicated that the dust-collection performance initially increased and then decreased with increasing reverse-blowing flow rate. As the pressure drop increased, there was an increase in total dust-collection efficiency. However, the efficiency decreased with increasing traveling speed. The regression model showed that the proposed approach was able to predict the particle collection efficiency accurately. In addition, the optimum operational conditions were obtained, namely a reverse-blowing flow rate of 2100 m3/h, a traveling speed of 5 km/h, and a pressure drop of 2400 Pa. The maximum particle-separation efficiency was 99.10%, which showed good agreement with the experimental results.

Enhancement of particle collection efficiency considering the structural interplay: particle motion characteristics analysis

The vacuum-blowing cleaning system, utilizing positive and negative pressure mixed-delivery theory, has been adopted for the road sweeper vehicle. To enhance the solid particle separation performance and to evaluate the motion characteristics of inhaled particles under different structural parameters, the gas-solid flow in the vacuum-blowing cleaning system was investigated by using computational fluid dynamics (CFD) technology. The influence of the main structural parameters on the grade dust collection efficiency and average detention time of the inhaled particles was determined, such as suction-inlet diameter, suction-inlet inclination angle, and front baffle inclination angle. And the interplay between them was also investigated. In addition, a dust collection efficiency model was built, based on uniform design (UD) and multiple regression analysis (MRA), and subsequently verified via experiments. The results revealed that the structural parameters have significant influence on the dust collection performance. The suction-inlet diameter, front baffle inclination angle, and suction-inlet inclination angle exerted the highest, second-highest, and lowest influence, respectively. Furthermore, the interaction among structural parameters also influenced the collection performance. The highest, second-highest, and lowest levels of influence were determined for the inlet diameter/baffle inclination angle, inlet inclination angle/baffle inclination angle, and inlet diameter/inlet inclination interactions, respectively. The highest dust collection efficiency (i.e., 96.10%) and a short average detention time of particles in the chamber were realized under the following conditions: suction-inlet diameter and inclination angle: 200 mm and 110°, respectively, and front baffle inclination angle: 105°.

Dust emissions’ reduction into the atmosphere by environmental-engineering systems of smallsize devices with counter-swirling flows (CSF)

The article discusses the features of using environmentalengineering systems of small-size devices with counter-swirling flows (CSF) to reduce dust emissions into the atmosphere. The reasons for the decrease of the dust collection efficiency by CSF systems are analyzed. The layout diagram of the dust collection system with CSF devices and the organization of suction from the dust collector hopper are given.

Dust Collection Performance of Bag Filters in Rice Processing Facilities

HighlightsThe rice dust collection performance of bag filters was investigated.The pressure drop and rice dust collection efficiency were measured with various parameters.Correlation equations are suggested for the pressure drop across a clean filter medium and across the dust cake.Abstract. Because rice dust constitutes a form of air pollution, bag filters are widely used in rice processing facilities. Rice dust has various particle sizes, and the dust concentration in air is low with rice dust. Research on the rice dust collection performance of bag filters is necessary for effective dust collection in rice processing facilities. The objective of this study was to investigate the rice dust collection performance of bag filters. The pressure drop and rice dust collection efficiency were measured with various face velocities, dust concentrations, and fabric filter media. The dust collection efficiency decreased slightly with increases in the face velocity and in the maximum pressure drop in normal conditions. In addition, correlation equations of the pressure drop across a clean filter medium and across the dust cake are suggested to predict the pressure drop in overloaded conditions in rice processing facilities. The average error was 20.2%, and it decreased with increasing pressure drop. Using the correlation equations, bag filters can be managed to remove the deposited dust before the pressure drop significantly increases or reaches its maximum value. Keywords: Bag filter, Dust collection efficiency, Pressure drop, Rice dust.