Fouling causes

Cooling System Corrosion Corrosion can be defined as the destmction of a metal by chemical or electrochemical reaction with its environment. In cooling systems, corrosion causes two basic problems. The first and most obvious is the failure of equipment with the resultant cost of replacement and plant downtime. The second is decreased plant efficiency to loss of heat transfer, the result of heat exchanger fouling caused by the accumulation of corrosion products. 

Butadiene is also known to form mbbery polymers caused by polymerization initiators like free radicals or oxygen. Addition of antioxidants like TBC and the use of lower storage temperatures can substantially reduce fouling caused by these polymers. Butadiene and other olefins, such as isoprene, styrene, and chloroprene, also form so-called popcorn polymers (250). These popcorn polymers are hard, opaque, and porous. They have been reported to... 

Fouling (caused by precipitation, lodgment of loose material and debris damaged packing)... 

Rapid fouling caused by water outlet temperature above 125T... 

Fouling caused by increasing perfusion rates can be partially compensated by increasing the spin-filter rotation speed. However, according to Yabaimavar... 

The function of seal strips is to interfere with, and hence reduce, the fluid flow through the bypass area. Often, one pair of seal strips is used for every 18 in of shell ID (inner diameter). These seal strips encourage good shell-side cross-flow velocity and also help reduce localized fouling, caused by low velocity. 

In principle, pollution control should be a major application for reverse osmosis. In practice, membrane fouling, causing low plant reliability, has inhibited its widespread use in this area. The most common applications are special situations... 

A common problem of this technique is the gradual decrease in permeate flux associated with membrane clogging or fouling, caused by adsorption or physical deposition of particles and/or macromolecules on membrane pores. Fouling can be minimized by prior clarification (particulate removal) of the feed solution, by the selection of operational conditions that minimize interactions between membranes and macromolecules, by the use of tangential flow, or by performing intermittent back-flushing operations. 

Membranes are very finely porous structures and like all such porous structures used in an industrial context are susceptible to fouling caused by adhesion of components of the materials being processed. This fouling can be minimised or avoided if suitable polymers are used in membrane manufacture. However, the selection of membrane polymers suited to particular separations has until now been a matter of experience (and failure) rather than science. However, an AFM used with the colloid probe technique [23] can provide a rapid means of assessing the adhesion of solutes to membrane materials and is hence a powerful tool for the membrane technologist. 

Silica fouling causes high pressure drop and low productivity. Silica scaling causes low rejection of silica and perhaps other ions as well. 

Mineral fouling caused by the deposit of insoluble carbonates, sulfates, or hydroxides can be removed by preparing the following cleaning solution ... 

Membrane fouling A phenomenon characteristic of all membrane-based filtration processes in which the membrane adsorbs or interacts with feed components. Membrane fouling causes a flux decrease and may also increase the retention of certain components in the feed. Membrane fouling is typically a time-dependent phenomenon and often independent of concentration. In some situations a partial dependence on concentration may be observed. 

Resin consumption and cost. Resin deteriorates in use. Volume changes during adsorption and elution and mechanical wear cause breakage and attrition. Chemical poisoning and fouling cause gradual loss of adsorptive capacity. In three South African plants, useful resin life was estimated ([M3], p. 143) at from 19,000 to 27,000 volumes of solution treated per volume of resin. This represents about 3 years usage in normal service. 

Fouling caused by corrosion products, dirt, and migrating pieces of packings can be retarded by installing a suction screen at the reboiler... 

During the degumming, the authors reported a sharp decline in the permeate flux at the beginning of the process of permeation and attributed this behavior to the concentration polarization and to membrane fouling, and this initial sharp drop in the flow was more intense in PES and PS membranes. The decline in the permeate flux was much less pronounced in the long term, 250 min, that initially, 50 min this trend implies that a system of consolidation of fouling caused by the cake may have affected the membrane after the initial filtration. Additionally, PVDF membranes achieved the highest retention of phospholipids, up to 98%. 

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