Separators electrical precipitators

Electrical precipitation a process using an electrical field to improve the separation of hydrocarbon reagent dispersions. May be used in chemical treating processes on a wide variety of refinery stocks. 

Instead of filtration or centrifuging as a means of separating the crystallized wax from oil, an electrical precipitation method has been proposed, similar to that employed in desalting of crude or removal of entrained solids from gases. 

Solutions are separated from precipitates by centrifuging. Semimicro centrifuges (Section II.4.5), either hand-operated or electrically-driven, can be used. Adapters are provided inside the buckets (baskets) in order to accommodate micro centrifuge tubes with narrow pen ends. 

From a practical standpoint catalyst loss due to carryover with the gas stream from the reactor and regenerator may be an important problem. Attrition of particles decreases their size to a point where they are no longer fluidized, but move with the gas stream. It has been customary to recover most 6f these catalyst fines by cyclone separators and electrical precipitation equipment placed in the effluent lines from reactor and regenerator. 

In general, material enrichment is conducted by physical separation processes such as density separation, magnetic separation, electrical assortment, and flotation. With complex or poorer ores where physical separation is neither possible nor economically feasible, a wet-chemical process such as leaching, precipitation or extraction is often used. Generally, the wet-chemical processing of the ore preparation is also a substantial part of the hydrometallurgical... 

Electrostatic Precipitators The principles and operation of electrical precipitators are discussed in Sec. 17 under Gas-Sohds Separations. Precipitators are admirably suited to the collection of fine mists and mixtures of mists and solid particulates. Tube-type precipitators have been used for many years for the collection of acid mists and the removal of tar from coke-oven gas. The first practical installation of a precipitator by Cottrell was made on sulfuric acid mist in 1907. Most older installations of precipitators were tube-type rather than plate-type. However, recently two plate-type wet precipitators employing water sprays or overflowing weirs have been introduced by Mikropul Corporation [Bakke,/. Air Pollut. Control Assoc., 25, 163 (1975)] and by Fluid Ionics. Such precipitators operate on the principle of making all particles conductive wnen possible, which increases the particle migration velocity and collection efficiency. Under these conditions, particle dielectric strength becomes a much more impor-... 

Radius distance from centerline of cyclone separator distance from centerUne of concentric-cyUnder electrical precipitator Time... 

Filtration Centrifugation Sedimentation Cyclone separator Electrostatic precipitator Demister Magnetic separator Screening Liquid-solid Liquid-solid or liquid-liquid Liquid-solid Gas-solid or Gas-liquid Gas-solid Gas-solid or gas-liquid Solid-solid Solid-liquid Solid-solid Pressure reduction Centrifugal force Gravity Flow Electric field Pressure reduction Magnetic field Size of particles... 

There are numerous variations of the wet process, but all involve an initial step in which the ore is solubilized in sulfuric acid, or, in a few special instances, in some other acid. Because of this requirement for sulfuric acid, it is obvious that sulfur is a raw material of considerable importance to the fertilizer industry. The acid—rock reaction results in formation of phosphoric acid and the precipitation of calcium sulfate. The second principal step in the wet processes is filtration to separate the phosphoric acid from the precipitated calcium sulfate. Wet-process phosphoric acid (WPA) is much less pure than electric furnace acid, but for most fertilizer production the impurities, such as iron, aluminum, and magnesium, are not objectionable and actually contribute to improved physical condition of the finished fertilizer (35). Impurities also furnish some micronutrient fertilizer elements. 

In some circumstances, separation of solid from a liquid is better achieved by use of a centrifuge than by filtration, and a small, electrically driven centrifuge is a useful piece of equipment for an analytical laboratory. It may be employed for removing the mother liquor from recrystallised salts, for collecting difficultly filterable precipitates, and for the washing of certain precipitates by decantation. It is particularly useful when small quantities of solids are involved centrifuging, followed by decantation and re-centrifuging, avoids transference losses and yields the solid phase in a compact form. Another valuable application is for the separation of two immiscible phases. 

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