New learnings and strategies for meeting future recovery boiler particulate emission limits with existing electrostatic precipitators

It is foreseeable that recovery boiler particulate emission limits in the United States and Canada will continue to get more stringent with time. Because of this, continued improvement of emission control equipment, as well as a better understanding of how operating parameters affect performance, are necessary. Although electrostatic precipitators (ESPs) are often viewed as a mature technology, many improvements in ESP technology continue to be developed. In recent years, academic efforts have improved the understanding of recovery boiler operating conditions on ESP performance. Additionally, advancements in materials, power supplies, and design continue to improve the efficiency and reliability of ESPs. This paper discusses how recovery boiler and electrostatic precipitator (ESP) operating factors affect ESP performance based on process simulations and practical experience, and how these learnings can be implemented to improve future operation of existing ESPs.

Electrotechnological complex for dedusting ventilation exhausts heat recovery units in production facilities and units

Currently, to create a microclimate in the production facilities of agro-industrial production are widely used utilizers of waste heat of ventilation emissions. But the air of such premises is clogged with dust impurities and has a high moisture content, as a result of which condensate falls on the heat-transfer surfaces, and dust sticks to the moistened surface. As a result, the efficiency of heat exchangers is significantly reduced, and the hydraulic resistance increases, which can cause a decrease in air supply. Therefore, there is a need to combat dust in the air supplied to heat recovery units. The most common method of purification of gas streams from solid dust impurities is the deposition of the latter in electrostatic precipitators, to increase the efficiency of which use gravitational moving water film. Currently, there are no mathematical descriptions and calculated dependences for horizontal electrostatic precipitators and electrohydrocyclones. The aim of the study is to formulate a mathematical description of the processes of movement of solid particles in the chambers of the horizontal electrostatic precipitator and electrohydrocyclone. The analysis of the existing systems of heat utilization of exhaust air and influence of dustiness on efficiency of their use is resulted. The possibility of using various systems for dust cleaning of exhaust air in agro-industrial facilities is considered. The technological and constructive scheme of the electrotechnological complex of utilization of heat of ventilating emissions which includes the electrohydrocyclone for clearing of dust of exhaust air is offered. The effect of determining forces, including electric, on the motion of a dust particle in the rotating flow of an electrohydrocyclone is analyzed. Equations describing the motion of a particle in an air rotating flow under the action of an electric field are determined, and mathematical models are compiled to calculate the trajectory of the dust particle. Simplified analytical expressions for particle motion trajectories are presented. Keywords: dust, separation, electric field, cyclone, airflow