Spray Electrification Research Articles

Study on the evaluation method of spray electrification hazards using a small amount of liquid sample

Study on the evaluation method of spray electrification hazards using a small amount of liquid sample

Measurement of Spray Electrification of Acetic Esters and Investigation of Antistatic Method

Measurement of Spray Electrification of Acetic Esters and Investigation of Antistatic Method

SPRAY DEPOSITION ON MAIZE USING AN ELECTROSTATIC SPRAYER

ABSTRACT It is a well-known fact that the application of pesticides can be improved using an electrostatic spray due to the reduction of the application rate and increase in deposition on plant targets. However, little information exists on the use of such technology in maize crops. Thus, this study is aimed to evaluate the spray deposition on maize resulting from spray application using an electrostatic sprayer in combination with low application rates and different spray compositions. A field experiment was conducted in a randomized block having a 2×2×2 factorial design with two application rates (95 and 52 L ha-1), with or without the spray electrification, and with or without the synthetic adjuvant. The droplet electrification ability, interference of the electrical conductivity of the spray solution, losses of spray solution to the soil, and spray deposition on maize plants were evaluated for two cases of insecticide applications. The Faraday cage method was used to determine the spray electrification ability of the equipment. The spray deposition on plants and the losses to the soil were analyzed using a tracer (food coloring dye) added to the spray solution that was subsequently detected by spectrophotometry. It was seen that the electrostatic sprayer improved the spray application efficiency, which responded positively to the increase in the electrical conductivity of the spray solution. The deposition of the electrified spray solution on the upper third canopy of maize was found to be higher; the spray solution electrification also reduced the losses to the soil, regardless of the application rate.

Relationship between spray electrification of ethyl acetate and spraying conditions

Relationship between spray electrification of ethyl acetate and spraying conditions

A-57 水噴霧による空気のイオン化とその応用(その3) : マイナスイオンが中枢および自律神経活動に及ぼす影響

A-57 水噴霧による空気のイオン化とその応用(その3) : マイナスイオンが中枢および自律神経活動に及ぼす影響

Spatial Distribution of Negative Air Ions Produced by an Ultrasonic Mist Maker

of water shear of spray electrification due to ultrasonic vibration. The negative air ion density was high compared with that of ambient air at a long distance near the ground floor. No ozone or nitrogen oxides were generated as by-products, but the density of charged air ions decreased rapidly with increasing of height from the floor. Within a distance of 10 m, we could produce a high density of negative air ions, which could be absorbed into our body through skin contact and aspiration.

Effect of particle loading on the collection performance of an electret cabin air filter for submicron aerosols

Electret filters are composed of permanently charged electret fibers and are widely used in applications requiring high collection efficiency and low-pressure drop. We tested electret filter media used in manufacturing cabin air filters by applying two different charging states to the test particles. These charging states were achieved by spray electrification through the atomization process and by bipolar ionization with an aerosol neutralizer, respectively. Polydisperse solid NaCl particles with 0.1%, and 1% solutions or liquid dicotyl sebacate (DOS) particles were generated from an atomizer, and they were loaded on the filter media. The amount of charge, the mean particle size, and the particle material significantly affected the collection performance of the electret filter media for submicron particles. The collection efficiency of the electret filter media degraded as more particles were loaded, and showed minimum efficiency at steady state. The electret filter media captured the highly charged particles more efficiently during the transient state. At steady state, the filter media loaded with smaller NaCl particles showed lower collection efficiency. The filter media loaded with liquid DOS particles showed collection efficiency much lower than those loaded with solid NaCl particles.

입자 퇴적이 승용차용 정전 필터의 미세 입자 포집 특성에 미치는 영향

An electret filter is composed of permanently charged electret fibers and is widely used in applications requiring high collection efficiency and low-pressure drop. In this work, the collection efficiency of the filter media used in manufacturing cabin air filters was investigated by using poly-disperse particles when submicron particles were loaded. Long-term experiments were conducted by applying two different charging states, which were spray electrification and charge equilibrium by bipolar ionization. In order to investigate the effect of particle loading in filter media, NaCl particles were generated from 0.1 % and 1% solutions by an atomizer. Liquid DOS particles were used to evaluate the effect of liquid particles on the collection efficiency of an electret filter. The results show significant effect of charge amount and size distribution of loading particles on the collection performance of a filter media in submicron region. Smaller particles loaded in electret fibers cause a more rapid degradation in collection efficiency and have lower minimum efficiency with time. The pressure drop of a tilter media do rarely increase when the collection efficiency decreases to the minimum value. For the larger particles charged by spray electrification, which have charge amounts more than that of Boltzmann equilibrium charge distribution, the pressure drop of a filter media slowly increases in comparison with that of equilibrium charged particles. For DOS particles it is shown that the charging level of an electret filter severely decreases and the collection efficiency is below 10% in some particle size range.

Spray Charging of Droplets in a Wet Scrubber

The experimental setup was designed to study the effect of natural charging of droplets during spraying (called spray electrification or spray charging) in a wet scrubber. The influence of nozzle material, liquid feed rate, and liquid composition on the specific charge (charge per unit volume of liquid) formed in spraying was measured. It was found that the nozzle material has no measurable effect on this specific charge. Increasing the liquid feed rate increases the specific charge significantly. Increasing solute (NaCl or NaOH) concentration increases the conductivity that decreases the formed specific charge. The same correlation between the specific charge and conductivity was also observed with real scrubbing liquids. It is proposed that the specific charge depends only on the value of liquid conductivity, not on liquid composition. The conductivity of the tested scrubbing liquids was high enough to suppress the formation of a high specific charge during spraying.

Charge Distribution of Submicron Particles Charged by Spray Electrification or Corona Discharge

This paper reports on the charge distribution measurements of submicron particles for three different charging mechanisms, which are spray electrification, bipolar ionization and corona discharge process, respectively. The number of elementary charges per particle was investigated by classifying and counting of a discrete mobility class. Charge distribution measurements were performed with NaCl particles generated from a collision atomizer for 0.01, 0.1, 1% NaCl solutions. Experimental results show than charge level of atomized NaCl particles is high and decreases with increasing the dissolved ion concentration. The charge level of the atomized NaCl particles can be reduced to that o Boltzmann equilibrium conditions by the bipolar ionization(Po(sup)210 bipolar ionizer). The charge level on NaCl particles passing through the corona discharge reactor is much higher than those of atomized or bipolar ionized NaCl particles. The evaluation of these measurements results in charge distribution of the submicron particles.

Lightning induced by thermonuclear detonations

The lightning flashes induced by a thermonuclear detonation at Eniwetok Atoll in the Pacific in 1952 are described. The five discharges were upward-propagating and were apparently initiated from instrumentation stations slightly above sea level. The likely mechanism for the necessary charge and electric-field generation (Compton electrons produced by gamma rays from the detonation) is explored quantitatively. The electric-field intensity calculated 3 × 104 v/m is near the value needed to initiate lightning from surface projections. The charge estimated to be available, however, appears to be insufficient to account for the observed lightning. Scattered trade-wind cumulus clouds and spray electrification from the salt water are considered and rejected as charge sources.

The separation of charge at the gas-liquid interface by dispersion of various electrolyte solutions

The electrostatic charge separation associated with the pneumatic dispersion of various electrolyte solutions was investigated by measuring the current flow between the bulk phase reservoir and ground. By varying ionic concentrations, pH, types of ions, solvent, and hydrodynamic conditions, current profiles were generated to determine the influence of these parameters on the mechanism of the spray electrification process. Previous explanations for charge separation based on a shearing of the electrical double layer are discarded in favor of an approach which takes into account the liquid phase ion-pair separation arising from an imbalance of force fields responding to a bulk phase attraction for ions at a suddenly created surface.

Influence of dipolar organic compounds on the electrokinetic potential of glass in KCl solutions

The electrokinetic potential at the glass-solution interface has been measured for several concentrations of potassium chloride and varying concentrations (up to 0.1 M of five dipolar organic compounds. The streaming potential method was used, with a borosilicate glass capillary. The relevance of the results to spray electrification is discussed.

Volume Chargeによる尖端からのCorona放電現象

Corona discharges from pointed bodies are sometimes experienced in the atmosphere. These dischares in the atmosphere are not exactly the same as experienced in laboratories between metal electrodes as shown is Fig. 1, but are caused by volume charges of electrufied water-drops or sands or other similar matter. Therefore, the present experiments were made by using volume charged water-droplets produced by spray electrification as shown if Figs 2 and 3. The results of the measurements of discharge currents and electric waves accompanied by corona are shown in Figs. 5 and 6. The remarkable polarity in the nature of corona may be due to the difference of mobility of electrons and positive ions which are produced in the avalanche of electrons near the point of discharge where the electric field is strong.