Electrostatic Electrodes Research Articles

Discharge Electrode Degradation in Dry Electrostatic Precipitator Cleaning of Exhaust Gases from Industrial Solid Waste Incinerators

The electrodes of industrial electrostatic precipitators degrade as a result of two phenomena: corrosion and erosion. The first is chemical degradation by highly reactive compounds formed during combustion, in particular, during the incineration of municipal or industrial wastes or high-sulfur coal. The degradation intensity of electrostatic precipitator electrodes depends on the chemical composition of the exhaust gasses. High concentrations of chlorides, fluorides, or sulfur in the exhaust gasses cause strong corrosion of the electrostatic precipitator elements. The second mechanism is the erosion caused by solid particles conveyed by the exhaust gas stream due to their collision with the electrodes. In this study, the analysis of the degradation of electrodes of an electrostatic precipitator downstream of an industrial waste incinerator was carried out. The industrial wastes of unknown sources were subjected to thermal degradation in a rotary kiln. The aim of this study was to provide fundamental knowledge about the mechanisms of electrode degradation located on the surface of discharge electrodes of electrostatic precipitators during the combustion of industrial wastes.

Design and analysis of mode-matched decoupled mass MEMS gyroscope with improved thermal stability

This paper presents an efficient design approach for microelectromechanical systems (MEMS) gyroscope considering the design constraint of MEMSCAP’s Silicon-on-Insulator Multi-User MEMS Processes (SOIMUMPs). A design for a decoupled mass MEMS resonant gyroscope with tuning electrodes is presented to minimize cross-axis coupling and optimize the gyroscope’s performance. The device features a size of 1.8 ×2.772 mm2 . A decoupled mass MEMS gyroscope has been designed using a novel mechanical beam configuration that optimizes the structural design to reduce unwanted interactions between drive and sense axes motions. Mode order has been achieved by obtaining the first two modes as drive and sense modes at 9946.3 Hz and 10 202.7 Hz, respectively. Parallel plate electrostatic tuning electrodes have been added to adjust and match the drive and sense modes at the resonant frequencies of 9946 Hz. This mode matching is crucial for optimizing gyroscope performance, accuracy, and sensitivity. The effects of temperature variation on the performance of the designed decoupled mass MEMS gyroscope have been investigated, particularly in terms of its mode-matched operation achieved using tuning electrodes. Finite element method (FEM) simulations were conducted, demonstrating that thermal stability was achieved, and mode-matched operation was maintained within the temperature range of −40 °C to 80 °C. The gyroscope exhibits enhanced performance compared to existing MEMS gyroscopes under mode-matched conditions, featuring a lower temperature coefficient of frequency (TCF) at 0.0415 Hz °C−1 in the drive mode and 0.0165 Hz °C−1 in the sense mode. FEM analysis for the fabrication process tolerances has been done, where MEMS gyroscope’s resonant frequencies, output capacitance, output displacement, and sense mode quality factor have shown negligible changes to fabrication process tolerances. Transient analysis was conducted using CoventorWare MEMS+ 3D schematic, which was integrated with MATLAB Simulink to measure the MEMS gyroscope’s output response, which corresponded with the varying input angular velocity signal.

Effects of Diameter between Electrodes on Properties of Electrostatic Quadrupole Deflector

Abstract: This study investigates the impact of varying the electrostatic quadrupole deflector diameter (EQDD) on the image when charged particles undergo deflection. A comparison is made between aberration figures, the kinetic energy of the electron beam, and the flight time concerning different EQDD values. The results showed that the most effective image is created at the image plane when the EQDD is double the radius of the electrostatic quadrupole deflector electrode (r). Keywords: Charge particle, Electrostatic quadrupole deflector, SIMION 8.1.

Optimization of Parameters for Fluidized Bed-Type Tribo-Electrostatic Separation of End-of-Life Vehicle Waste Polymer Particles by Response Surface Methodology

End-of-life vehicles (ELVs) have resulted in huge quantities of waste vehicle polymers, the reuse of which could be effective in mitigating pollution and creating economic value. Based on the developed fluidized bed-type electrostatic separation equipment, this paper investigated the separation of two groups of commonly used mixed vehicle-use polymer particles, namely, acrylonitrile-butadiene-styrene (ABS)-polyamide (PA)-polypropylene (PP) (black) and polyethylene (PE)-PP (white)-polyvinyl chloride (PVC). First, the force of the particle in an electric field was analyzed, and the kinetic model of the particle in a high-voltage electrostatic field was established. Then, individual factor experiments were conducted on the fluidization time (T), the first-stage electrostatic separation chamber electrode voltage (U 1), the second-stage electrostatic separation chamber right field electrode voltage (U 3) and the second-stage electrostatic separation chamber left field electrode voltage (U 5) to investigate the pattern of separation results affected by each of these factors, individually. Finally, based on response surface methodology (RSM) experiments, the effects of the abovementioned three factors and their interactions on the purity of the separation of the three types of particles in each group were analyzed. The optimum separation parameters for ABS-PA-PP (black) particles in the experiments were determined as follows: T of 385 s, U 1(U 3) of −32 kV and U 5 of −37 kV. The optimum separation parameters for PE-PP (white)-PVC particles were found as follows: T of 398 s, U 1(U 3) of −40 kV and U 5 of −38 kV. The experimental validation of the abovementioned parameters obtained the purities of the three set of ABS-PA-PP (black) types of particles being 95.67%, 91.34% and 99.12%, respectively. The purities of the three set of PE-PP (white)-PVC types of particles being 96.21%, 93.20% and 86.74%.

In-plane structure of the electric double layer in the primitive model using classical density functional theory.

The electric double layer (EDL) has a pivotal role in screening charges on surfaces as in supercapacitor electrodes or colloidal and polymer solutions. Its structure is determined by correlations between the finite-sized ionic charge carriers of the underlying electrolyte, and, this way, these correlations affect the properties of the EDL and of applications utilizing EDLs. We study the structure of EDLs within classical density functional theory (DFT) in order to uncover whether a structural transition in the first layer of the EDL that is driven by changes in the surface potential depends on specific particle interactions or has a general footing. This transition has been found in full-atom simulations. Thus far, investigating the in-plane structure of the EDL for the primitive model (PM) using DFT has proved a challenge. We show here that the use of an appropriate functional predicts the in-plane structure of EDLs in excellent agreement with molecular dynamics simulations. This provides the playground to investigate how the structure factor within a layer parallel to a charged surface changes as a function of both the applied surface potential and its separation from the surface. We discuss pitfalls in properly defining an in-plane structure factor and fully map out the structure of the EDL within the PM for a wide range of electrostatic electrode potentials. However, we do not find any signature of a structural crossover and conclude that the previously reported effect is not fundamental but rather occurs due to the specific force field of ions used in the simulations.

Development of a Coal Dust Concentration Sensor Based on the Electrostatic Induction Method.

In order to solve the problems of easy blockage and difficult maintenance of the current coal dust concentration sensor, a coal dust concentration sensor based on the electrostatic induction method was designed. Based on the analysis of the principle of electrostatic induction dust concentration detection, an electrostatic induction dust concentration sensor composed of a electrostatic detection electrode, a dust extraction fan, an induction signal processing circuit, an insulator, a shield, and other parts was designed. The influence of the length and width of the electrostatic detection electrode and the particle flow rate on the standard deviation of the induction signal was analyzed through experiments to optimize them. The induction signals on the electrostatic detection electrode at different dust concentrations were determined in tests, and the mathematical relationship between the standard deviation of the induction signal and the dust concentration was obtained. According to segment multiple-curve height fitting, the maximum deviation between the detected value and actual dust concentration does not exceed 10%.

Electrostatic spray catalytic particle coating on carbon electrode for enhancing electrochemical reaction

The uniform coating of catalytic materials on the electrode surface is essential for improving the performance of electrochemical reactions. In this study, the electrostatic spray coating technique is used to deposit Molybdenum disulfide (MoS2) particles on carbon electrodes and examine the electrochemical hydrogen evolution reaction (HER) performance in a 0.1 M H2SO4 electrolyte. The experimental results reveal that the electrostatic spray coating method achieves a more uniform coating MoS2 catalyst particles on the carbon fiber substrate. It provides good adhesion for electrocatalyst binding on the carbon paper electrodes. During HER analysis, a 25% higher current density is obtained from the electrostatic spray-coated electrodes compared to the manual spray-coated electrode at a potential of 0.95 V. Electrochemical impedance spectroscopy, and electrochemical surface area measurements indicate the superior electrochemical characteristics of the electrostatic spray-coated electrode. The faradaic efficiency of the electrostatic spray-coated electrode is close to 100% at a high applied potential of −1.6 V with a 0.0059 L volume of hydrogen generation. Moreover, chronoamperometric measurements demonstrate the excellent durability of the electrostatic spray-coated carbon electrodes. This study suggests that the facile electrostatic spray method is efficient for coating electrodes with high uniformity and good adhesion for various electrochemical applications.

Design of a high-voltage electrostatic ultrasonic atomization nozzle and its droplet adhesion effects on aeroponically cultivated plant roots

In the process of aeroponics cultivation, the atomizer is one of the most important influencing factors on the cultivation process. This paper presented the design of an ultrasonic atomization nozzle using contact charging and a root droplet adhesion test rig. The purpose of this study was to reveal the relationship between the main operating parameters of the high-voltage electrostatic ultrasonic atomization nozzle and the atomization effect using droplet adhesion measurements. In this study, the ultrasonic effect of nozzle was achieved by using Laval tube, and the design of the key parameters for the high-voltage electrostatic ultrasonic atomization nozzle were inlet pressure, electrostatic voltage root core electrode material and spray distance; the droplet size variation and root adhesion patterns were obtained through experiments. The best operating parameters were analyzed by using the orthogonal test method, and the droplet deposition distribution of the root system at different scales was investigated in the atomization chamber. The test results revealed that when the root core electrode material was coppe and the nozzle working parameters were at 0.4 MPa of inlet pressure, at 1.75 m the spray distance, at 12 kV of the electrostatic voltage, the root system has the highest droplet adhesion. Keywords: ultrasonic nozzle, high pressure electrostatic system, droplet size measurement, root adhesion test, droplet deposition effect DOI: 10.25165/j.ijabe.20231602.7222 Citation: Gao J M, Guo Y N, Tunio M H, Chen X C, Chen Z J. Design of a high-voltage electrostatic ultrasonic atomization nozzle and its droplet adhesion effect on aeroponically cultivated plant roots. Int J Agric & Biol Eng, 2023; 16(2): 30–37.

Electrostatically Induced Voltage Generated in Two Ungrounded Metal Cases When Charged Object Moves Away from the Cases

Static electricity is used in numerous practical applications, such as copy machines and dust collectors. When a person gets up from a chair or walks in a room using an air conditioner, the person's body becomes charged. When a charged body approaches or moves away from the metal case of an electronic device, the electronic device suffurs a malfunction or failure due to the electrostatically induced voltage. The electrostatically induced voltage of a charged body moving away from a metal case is higher than the voltage induced when the charged body approaches the metal case. We conducted an experimental study on the electrostatically induced voltage generated in two ungrounded metal cases when a charged body moves away from the metal cases. The results showed that electrostatically induced voltages of 0.4 to 0.5 times was generated in the two ungrounded metal cases against the voltage of the charged body when each electrostatic induction electrode with a spark gap and each electromagnetic wave sensor is used of a noncontact electrostatic measuring device. We believe that these results will aid in the prevention of malfunction or failure of electronic devices.

A case study of high-temperature polyetherimide film capacitor fabrication

Capacitors, as the basic building block of power electronics and electrical systems, are the major constraint of the increasingly integrated power systems that require new capable polymer dielectric films operating at higher temperatures >125 °C. Despite tremendous research efforts on the lab scale, there remains a considerable barrier and knowledge basis for converting polymeric films to functioning capacitors desired in actual applications. The authors tackled the polyetherimide (PEI) film scale up issues and developed various engineering processes for film de-wrinkling, optimal metallization, static elimination, and capacitor fabrication improvement. The authors discovered various fabrication challenges such as the electrostatic charge, metallization scheme, winding tension, and end electrode disconnects. To fabricate a high yield of PEI capacitor bobbins, it is necessary to utilize static eliminators (radioactive ionizers), moderately thick aluminum metallization (15–30 Ω/sq), and winding tension (60–100 g). It is also effective to evaluate capacitance, dielectric loss, equivalent series resistance, and thermal cycling stability of capacitors. This work sheds some light on converting PEI films and other polymeric films to capacitors on a scale up fabrication effort. The practical learning from film handling to capacitor fabrication in this work provided the necessary knowledge for manufacturing high-temperature polar film capacitors.

Reduced breakdown voltage for in-liquid plasma discharges using moveable electrodes

Minimizing the breakdown voltage and discharge current required to initiate direct in-liquid discharges, thus lowering power-source requirements and avoiding electrode ablation, is crucial for industrial applications of in-liquid plasmas. Here we demonstrate such considerable reductions by employing movable electrodes, without changing the electrode configuration or increasing the system complexity. The new mechanism is based on electrostatic electrode attraction resulting in a reduction in the discharge spacing by up to 6 times and facilitating a plasma initiation at lower breakdown voltages. The accumulated charges consumed by the discharge revert the electrodes to the initial positions, forming a gliding arc between the enlarged gaps and thus inhibiting current increases and electrode ablation.

A Low-g MEMS Accelerometer with High Sensitivity, Low Nonlinearity and Large Dynamic Range Based on Mode-Localization of 3-DoF Weakly Coupled Resonators.

This paper presents a new design of microelectromechanical systems (MEMS) based low-g accelerometer utilizing mode-localization effect in the three degree-of-freedom (3-DoF) weakly coupled MEMS resonators. Two sets of the 3-DoF mechanically coupled resonators are used on either side of the single proof mass and difference in the amplitude ratio of two resonator sets is considered as an output metric for the input acceleration measurement. The proof mass is electrostatically coupled to the perturbation resonators and for the sensitivity and input dynamic range tuning of MEMS accelerometer, electrostatic electrodes are used with each resonator in two sets of 3-DoF coupled resonators. The MEMS accelerometer is designed considering the foundry process constraints of silicon-on-insulator multi-user MEMS processes (SOIMUMPs). The performance of the MEMS accelerometer is analyzed through finite-element-method (FEM) based simulations. The sensitivity of the MEMS accelerometer in terms of amplitude ratio difference is obtained as 10.61/g for an input acceleration range of ±2 g with thermomechanical noise based resolution of 0.22 and nonlinearity less than 0.5%.

Implementation of the Biological Muscle Mechanism in HASEL Actuators to Leverage Electrohydraulic Principles and Create New Geometries

Biomimicry is a field of research that uses the functional and structural components of nature, at macroscopic and microscopic scales, to inspire solutions to problems in our industrial world. Soft robotics is an area of research that uses biomimicry, in this case, mimicking skeletal muscles (referred to in this field as “muscle-mimicking actuators”, to perform task of high difficulty, that can be operated in a harmlessly in different environments. One of the most recent advancements to develop from this field is the “Hydraulically amplified self-healing electrostatics (HASEL) actuator”. However, this method also brings many of the issues associated with the geometry of its design, especially with respect to the efficiency of the system. Though this system mimics the functionality of the skeletal muscle, there is room to adjust the existing electrostatic mechanisms, that distribute the locally produced force, to mimic the structure of the mechanism that distributes the force to the skeletal muscular, which is also locally produced. In this paper, we show that the current electrostatic parallel electrodes, as well as the zipping mechanisms, can be replaced with the sliding mechanism. This eliminates issues associated with compartmentalizing of the primary electrostatic force and the secondary hydraulic forces leading to a more efficient and controlled transmission electrostatic and hydrostatic forces to the load compared to current iterations and their geometric components.

AI-Based Electrode Optimisation for Small Satellite Ion Thrusters

Computing capacities for numerical modelling are available to an unprecedented extent today. The spread of various artificial intelligence (AI) -based solutions (which in many cases are also resource-intensive operations) is also facilitated by this increase in capacity, which offers several new opportunities in this area. On the one hand, optimization tasks can be done quickly, on the other hand, it is also possible to solve (estimate) problems where we cannot (for some reason) create a model for the initial problem. In our article, we investigate how to apply artificial intelligence-based solutions to electromagnetic field computing tasks as efficiently as possible. The required theoretical summary presents an implemented application: optimization of electrostatic ion engine accelerator electrodes for orbit correction operations. To solve each problem, we used methods from the supervised machine learning toolkit, usually along with LMS (least mean square method) update steps. All inputs required for AI were solved by numerical space calculation (primarily using the finite element method). The data input required to optimize the electrodes of an ion thruster can come from two sources: measurement data or simulation results. Given that the operating environment of a satellite can be modelled in a vacuum chamber, it is a particularly difficult issue to perform the measurement, but even more difficult in the case of optimisation. Therefore, an effective solution to the problem can only be achieved by simulation. The primary goal of this research is to optimise the fuel (in this case, the number of ions) during operation, with the stated aim of maximising the time of operation of the spacecraft.

A specially-designed electrostatic sensor for the condition monitoring of rolling bearings

The electrostatic method is a rapidly growing research field in the monitoring of rotating equipment. This article reports how a specially-designed integrated electrostatic sensor was utilized to monitor the working conditions of rolling bearings. We firstly analyzed the principle and mathematic modeling of inner current noise generated by cable vibration and deformation. To ensure the electrostatic monitoring avoided being affected by cable vibration and deformation, we designed a ring-shaped printed circuit board to integrate the electrostatic electrode and condition unit together, which can be mounted tightly beside the rolling bearings; in this way, the cable connecting the electrode with the condition unit is removed and the distance between the electrode and rollers is shortened. Experiments using this integrated sensor board were conducted to obtain the electrostatic signals of working bearings. Time features were analyzed in detail to show the differences of four working bearings across the whole process. Experimental results show that the proposed integrated electrostatic sensor has a good performance in the electrostatic monitoring of rolling bearings.

An 8-Bit Digitally Operated Micromachined Accelerometer

This work presents successful implementation and characterization of an 8-bit digitally operated micromachined accelerometer. Such device is comprised of an electrostatically tunable acceleration switch with 8 sets of electrostatic tuning electrodes. Similar to bits in a binary number, the tuning force of each electrode set increases by a factor of 2 with respect to the adjacent electrode set. A fabricated device has been interfaced with a micro-controller performing a binary search by controlling state of different tuning electrodes (ON or OFF) to interpret the acceleration with 8 bits of resolution. Measurement results show good agreement between the applied acceleration and the binary acceleration output of the sensor reported by the controller. The tested 8-bit prototype has full-scale acceleration of 2.7g with resolution 10.5 mg s (1/28 of full scale). Requiring only a bias voltage for operation (zero static current) and readout of the switch output (a digital high or low voltage) that can be performed directly by a digital controller, such devices can lead to ultra-low power accelerometers by eliminating the need for an analog-front-end. [2020-0201]

A Method for Measuring the Height of Hand Movements Based on a Planar Array of Electrostatic Induction Electrodes.

This paper proposes a method based on a planar array of electrostatic induction electrodes, which uses human body electrostatics to measure the height of hand movements. The human body is electrostatically charged for a variety of reasons. In the process of a hand movement, the change of a human body’s electric field is captured through the electrostatic sensors connected to the electrode array. A measurement algorithm for the height of hand movements is used to measure the height of hand movements after the direction of it has been obtained. Compared with the tridimensional array, the planar array has the advantages of less space and easy deployment; therefore, it is more widely used. In this paper, a human hand movement sensing system based on human body electrostatics was established to perform verification experiments. The results show that this method can measure the height of hand movements with good accuracy to meet the requirements of non-contact human-computer interactions.

A Novel Micromachined Z-axis Torsional Accelerometer Based on the Tunneling Magnetoresistive Effect.

A novel micromachined z-axis torsional accelerometer based on the tunneling magnetoresistive effect is presented in this paper. The plane main structure bonded with permanent magnetic film is driven to twist under the action of inertial acceleration, which results in the opposite variation of the magnetic field intensity. The variation of the magnetic field is measured by two differential tunneling magnetoresistive sensors arranged on the top substrate respectively. Electrostatic feedback electrodes plated on the bottom substrate are used to revert the plane main structure to an equilibrium state and realize the closed-loop detection of acceleration. A modal simulation of the micromachined z-axis tunneling magnetoresistive accelerometer was implemented to verify the theoretical formula and the structural optimization. Simultaneously, the characteristics of the magnetic field were analyzed to optimize the layout of the tunneling magnetoresistance accelerometer by finite element simulation. The plane main structure, fabricated with the process of standard deep dry silicon on glass (DDSOG), had dimensions of 8000 μm (length) × 8000 μm (width) × 120μm (height). A prototype of the micromachined z-axis tunneling magnetoresistive accelerometer was produced by micro-assembly of the plane main structure with the tunneling magnetoresistive sensors. The experiment results demonstrate that the prototype has a maximal sensitivity of 1.7 mV/g and an acceleration resolution of 128 μg/Hz0.5 along the z-axis sensitive direction.

A high voltage electrostatic filter for particulate matter PM2.5 capture applied in motor vehicle exhaust system

Increasingly strict air pollution regulations along with global warming issue have peeked the interest in cleaner emission emitted by motor vehicle. In line with this, this study was aimed to develop a particulate filtering system based on an electrostatic principle for particulate matter with the diameter less than 2.5 μm, as known as a fine particle, and to test the performance of the filter. The filter consists of aluminum anodes and cathodes as the electrostatic electrodes. These electrodes were placed into the filter frame and installed on a motor vehicle muffler. The test was conducted to estimate the filter performance by measuring particle concentrations before and after using the filters. The filter was tested under four different electrostatic voltages: V1 100 Volt, V2 200 Volt, V3 300 Volt, and V4 400 Volt. The results show that the filter can reduce fine particle concentrations with the best efficiency of 50%, 60%, 62%, and 68%, respectively for V1, V2, V3, and V4. Filter performance was directly influenced by the applied voltage and the time of the test.

Characteristics of dust-collection efficiency and ozone emission by high-voltage electrode shape of electrostatic precipitator for subway tunnel environment

The air pollution level of particulate matters in subway tunnel environments is severe. The present study conducted experimental measurements and analyses on dust-collection efficiencies and ozone emission rates in a lab-scale wind tunnel to determine a high-voltage electrode shape suitable for an electrostatic precipitator to remove airborne particles in subway tunnels. Six high-voltage electrode shapes (saw-type, few-saw-type, short-saw-type, tree-type, wave-type, and spike-type) were tested. The results indicate that while breakdown voltage of the spike-type high-voltage electrode was 66 % of other electrode shapes, its dust-collection efficiency per unit voltage was similar to that of other electrode shapes. However, the dust-collection efficiency per unit of power in the spike-type high-voltage electrode was significantly low. Moreover, the wave-type high-voltage electrode shape had 20 % lower dust-collection efficiency than the saw-type and tree-type high-voltage electrode shapes under conditions of low voltage and high flow velocities. Ozone emission rates for all shapes increased proportionally to the electric current. However, ozone emission rates for each high-voltage electrode shape are varied as 12–23 μg/s per mA. The saw-type and tree-type high-voltage electrode shapes were superior in terms of dust collection, 90 % collection efficiency was shown at about 1.5 W/(m/s)2. The saw-type had a lower ozone emission rate (16.4 μg/s per mA) than the tree-type (19.6 μg/s per mA). Thus, the saw-type shape was the most suitable as a high-voltage electrode in the electrostatic precipitator for removing airborne particles in a subway. The results also indicate that both dust-collection efficiencies and ozone emission rates should be evaluated concurrently when evaluating electrostatic precipitator high-voltage electrodes.