Snížení emisí tuhých znečišťujících látek elektrostatickou metodou

Abstract

The presented dissertation deals with the research of electrostatic separation of solid pollutants from the flue gases of small power boilers. The main result of the research is the development of the principles of designing such electrostatic precipitators in a content acceptable for further use in engineering practice. Theoretical and experimenta results of research of this work increase the effectiveness of further research in this field. The solution of the set tasks in work made it possible to clarify the idea of the process of electrostatic precipitation for studied particles. The specific results of this work can be summarised as follows. Since solid pollutants emitted from low power boilers are formed by particles of the submicron spectrum, charges of these particles must be evaluated using the mutual action of the field charging mechanism and the diffuse charging mechanism, not using them separately or by summing them. To correctly predict the efficiency of electrostatic precipitators, such field-diffusion charge evaluation methods are discussed in this work, and a simplified method is proposed, the validity of which is experimentally verified. This newly proposed method demonstrates satisfactory convergence in the range of particles from 50 to 1000 nm with a charging time over 0.1 seconds under the conditions of a conventional electrostatic precipitator, while the prediction of the separation efficiency has an accuracy acceptable for practical technical calculations. The proposed method also requires fewer inputs and is less laborious, making engineering much easier. This work describes an optimization technique for evaluating the use of electrostatic precipitators capacity for flue gas cleaning. Thus, the required efficiency is first presented as a balance between the electrical and design parameters of the electrostatic precipitator and makes it possible to determine the most suitable way to prove the required separation efficiency. The proposed technique is based on the principles of electrostatic separation and is independent of the source and characteristics of emissions. The labour intensity of the proposed technique is low, which, together with its universality, is the main advantage. The presented optimization technique can be used for any boiler, heat output level and fuel type. Furthermore, when designing the design of electrostatic precipitator for cleaning flue gases from these boilers, predicting the value of the required voltage, and evaluating the capacity utilization of already installed precipitators to control emissions and evaluate the possibility of reducing energy consumption. Based on the above, the construction of an electrostatic precipitator is developed and subsequently tested, which ensures compliance with the requirements of ECODESIGN in the part of PM emissions. Preparations are currently underway for the mass production of boilers with a heat output of 250 kW equipped with electrostatic precipitators as their inseparable parts of the boilers.