Electrostatic purification

In electrostatic purification, the wet chlorine gas is passed between wire electrodes in vertical tubes. The electrodes are maintained at a d.c. potential of 50 kV with a current density of 0.2 mA/m. The particles and droplets in the chlorine become charged and collect on the tube walls. The resultant liquid is fed back into the brine system or chemically treated before disposal. 

The carbon black (soot) produced in the partial combustion and electrical discharge processes is of rather small particle si2e and contains substantial amounts of higher (mostly aromatic) hydrocarbons which may render it hydrophobic, sticky, and difficult to remove by filtration. Electrostatic units, combined with water scmbbers, moving coke beds, and bag filters, are used for the removal of soot. The recovery is illustrated by the BASF separation and purification system (23). The bulk of the carbon in the reactor effluent is removed by a water scmbber (quencher). Residual carbon clean-up is by electrostatic filtering in the case of methane feedstock, and by coke particles if the feed is naphtha. Carbon in the quench water is concentrated by flotation, then burned. 

N2, and traces of PH, CO2, E, and S large furnaces generate off-gas at a rate of about 120—180 m /min. In most installations the off-gas is passed through a series of Cottrell electrostatic precipitators which remove 80—95% of the dust particles. The precipitators ate operated at temperatures above the 180°C dew point of the phosphoms. The collected dust is either handled as a water slurry or treated dry. Einal disposal is to a landfill or the dust is partially recycled back to the process. The phosphoms is typically condensed in closed spray towers that maintain spray water temperatures between 20 and 60°C. The condensed product along with the accompanying spray water is processed in sumps where the water is separated and recycled to the spray condenser, and the phosphoms and impurities ate settled for subsequent purification. 

In general, plants using SO2 gas derived from metallic sulfides, spent acids, or gypsum anhydrite purify the gas stream before drying it by cold, ie, wet, gas purification. Various equipment combinations including humidification towers, reverse jet scmbbers, packed gas cooling towers, impingement tray columns and electrostatic precipitators are used to clean the gas. 

Jury, E., Safety aspects and measures in electrostatic gas purification, DECHEMA Monogr. 107, 1987, 383 -388... 

Electrorefining purification of a metal using electrolysis Electrostatic charge at rest Element see Chemical Element Elementary Particle collectively the smallest units of matter, electrons, protons, quarks, and so on. 

Clearly, proteins can adhere to surfaces by electrostatic mechanisms, particularly at low ionic strength where the electrostatic field of the surface and the protein is much more extended. Indeed, this is the basis of ion exchange chromatography, so widely used for the separation, purification, and characterization of proteins. However, by the time one reaches the 0.15 M salt concentration of the physiologic environment, general electrostatic processes are no longer dominant. 

Previously reported [2] as a non-melting solid exploding on attempted purification, this proved a very shock sensitive (40 kg/cm) solid of m.p. 150°C. Less sensitive to electrostatic discharge and friction. Methods of explosibility testing for very small quantities of very sensitive materials are described [1]. 

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