Introduction and simulation of a small electro cyclone for collecting indoor pollen particles

Mitigation approaches and techniques for combustion power plants flue gas emissions: A comprehensive review

Population growth and urbanization are driving energy demand. Despite the development of renewable energy technologies, most of this demand is still met by fossil fuels. Flue gases are the main air pollutants from combustion power plants. These pollutants include particulate matter (PM), sulfur oxides (SOx), nitrogen oxides (NOx), and carbon oxides (COx). The release of these pollutants has adverse effects on human health and the environment, including serious damage to the human respiratory system, acid rain, climate change, and global warming. In this review, a wide range of conventional and new technologies that have the potential to be used in the combustion power plant sector to manage and reduce flue gas pollutants have been examined. Nowadays, conventional approaches to emissions control and management, which focus primarily on post-combustion techniques, face several challenges despite their widespread use and commendable effectiveness. Therefore, studies that have proposed alternative approaches to achieve improved and more efficient methods are reviewed. The results show that new advances such as novel PM collectors, attaining an efficiency of nearly 100 % for submicron particles, microwave systems, boasting an efficiency of nearly 90 % for NO and over 95 % for SO2, electrochemical systems achieving above 90 % efficiency for NOx reduction, non-thermal plasma processes demonstrating an efficiency close to 90 % for NOx, microalgae-based methods with efficiency ranging from 80 % to 99 % for CO2, and wet scrubbing, exhibit considerable potential in addressing the shortcomings of conventional systems. Furthermore, the integration of hybrid methods, particularly in regions prioritizing environmental concerns over economic considerations, holds promise for enhanced control and removal of flue gas pollutants with superior efficiency.

CFD Investigations of Cyclone Separators with Different Cone Heights and Shapes

Due to the great achievements in the field of optimization of the design of cyclone separators, non-standard solutions are sought to increase their performance. Therefore, in this study, we consider the impact of different cone and cylinder height variants on the performance of cyclone separators. Additionally, we propose non-standard shapes for these sections. Three different heights: H/D = 0.5, 1.0, and 1.5, with D (the main cyclone body diameter), are analyzed. Since the cone is one of the most important geometrical entities, three different shapes viz. a straight (conventional) profile, a concave profile as well as a convex profile are also taken into account. Cyclone performance is rated at three different inlet velocities viz. Uin = 10 m/s, 15 m/s, and 20 m/s. Hence, a total of 27 simulations have been performed using the Reynolds stress model. It becomes apparent from the present study that the pressure loss is lowest in the convex variant, whereas the separation efficiency is better in the conventional design. Furthermore, an increase in the length of the cylindrical section reduces pressure drop with a mild decrease in the collection efficiency in all variants.