ISESP XVI
Budapest, Hungary, 2022

26 October 2022 (Day 1)
ESP School
Options for Precipitator Upgrades Introduction to ESP Systems 101 Extended operation by selection of negative or positive corona ESP for hygroscopic & clogging dust The use of ESP to reduce mercury emissions and the cooperation of electrostatic precipitators with existing air pollution control systems Understanding the Deutsch Equation Safety & Risk Management of Electrostatic Precipitators
27 October 2022 (Day 2)
Technical Sessions
TS1 - ESP fundamentals
Collection of Carbon Particles in Diesel Exhaust Gas Using Intermittent Dielectric Barrier Discharge This study investigated the performance of a novel electrostatic precipi- tator. This system consists of a charging section and collection section with glass plates that have discharge electrodes on them. Biased alternating current (AC) with high voltage was intermittently applied to the discharge electrodes to build up charges with polarity similar to the bias on the dielectric surface to create a strong electric field between the electrodes and the surface. This electric field attracts the soot charged in the charging section to the glass surface, where plasma can cause the oxidative decomposition of the collected soot. In this system, the intermittent mode of voltage application plays a key role in the collection of particulates. The collection efficiency of the reactor was estimated with an OFF duration in the range of 0–1990 ms and an ON duration of 10 ms. The surface potential distributions of the dielectric substrates used in the reactor were measured with respect to the time duration after the voltage application had been completed. Thus, it was found that the collection efficiency was influenced by the OFF duration, because the surface charges on the glass plates had a certain lifetime. DIFFERENT TYPES OF DUST RESISTIVITY It is generally accepted that dust resistivity in excess of 1011 Ω𝑐𝑚 leads to the formation of back corona and to a deterioration of ESP performance. Besides dust conditioning, the most popular approach for reducing problems with back corona is the application of pulsed corona systems. The idea behind pulsing is very simply to reduce the E-field within the dust layer by reducing the time-averaged current density. However, experience shows that other high resistivity cases are resolved successfully with an opposing approach, using especially smooth HV from three- phase rectifiers in combination with high current densities. A detailed investigation into this discrepancy has revealed that high values of dust resistivity can be traced back to at least two different mechanisms. “Standard” high resistivity dusts show the behaviour which is typical for dielectrics. High potential drop across the dust layer is produced by the injection and immobilization of charge carriers into the material. Resistivity is strongly dependent on time and corona polarity and inversely proportional to the root of current density. The dust layers reach a high level of space charge density. In a sample of an “untypical” high resistivity dust we found that resistivity is independent of layer thickness and of corona polarity and does not show time effects. The dust layer does not accumulate any significant amount of space charge. The potential drop across the dust layer is nearly independent from current density, resulting in a resistivity which is inversely proportional to current density. With very high E-fields, the dust layer shows a progressive increase of current uptake with time, ending in a breakthrough. All these are the typical characteristics of a varistor material. Our results show that different mechanisms of high dust resistivity do exist. Therefore an appropriate choice of the high voltage supply and its control should be based on a thorough analysis of the electrical properties of the dust. A clearly better separation efficiency will be achieved. Study on High Temperature Ultra-clean Electrostatic-fabric Integrated Precipitator Technology and Its Application Prospect in Cement Industry The gas denitrification has always been the most difficult environmental problem in cement industry. High Temperature Ultra-Clean Electrostatic-Fabric Integrated Precipitator (EFIP for short) adopts the alloy fiber filter media, the service temperature can reach above 400°C, and the dust removal before denitrification can be realized by working with SCR. A pilot-scale test bench integrated technology of High Temperature Ultra-Clean EFIP and denitration has been built in a power plant, achieving the outlet dust concentration of less than 10mg/m3 and the outlet NOx concentration of less than 50mg/m3. Since the application of the High Temperature Ultra-Clean EFIP in the 1750t/d baking furnace of an aluminum plant, the dust concentration and the operating pressure drop has been kept below 5mg/m3 and 500Pa respectively for a long term. This technology is very suitable for cement industry, which can realize the integration process of "high temperature dust removal + low dust denitration", and solve the difficulties of denitration in cement industry.TS2 - Advancements in power supply
The effect of Micro-Pulse Technologies power Supply on Electrostatic Precipitator performance Performance Comparison of 1-Phase and 3-Phase HV Linear Power supplies for ESP in Recovery Boiler applications Technical Analysis and Extended Application of Variable Frequency Power Supply
This paper introduces the principle and circuit topology of a new-type variable frequency power supply. The variable frequency power supply changes the output impedance of the transformer through amplitude modulation and frequency modulation control to suppress the back corona phenomenon, which provides a new technical means for back corona control of ESP. The output ripple coefficient of the variable frequency power supply is small and the spark is turned off in real time, which can effectively avoid the continuous flashover of the superimposed pulse power supply. Meanwhile, it has a high reliability structure for an ideal basic DC high-voltage unit of pulse power supply. Additionally, the variable frequency power supply can also be used as the supporting power supply of ozone generator for low-temperature flue gas denitration. The power consumption of the ozone generator is less than 7.5kw/kgO3 at high ozone concentration, and the index is better than the Chinese industry standard.