Costs particulate

The addition of inorganic compounds to polyethylene is carried out for a variety of reasons. Fillers are sometimes only low-cost particulate materials used to extend the polyethylene and, therefore, lower the cost of the fabricated item. However, fillers usually affect some other aspect of the finished product such as the stiffness (modulus) or the processability of the polyethylene to increase rates of fabrication. Fillers may also reduce mold shrinkage and the thermal expansion coefficient Filler such as mica may increase heat resistance. Some examples of these compounds are discussed below. 

Module type Channel Packing spacing(cm) density (m Energy " ) costs Particulate plugging Ease of cleaning... 

Plastics. In the plastics industry, the term filler refers to particulate materials that are added to plastic resins in relatively large, ie, over 5%, volume loadings. Except in certain specialty or engineering plastics appHcations, plastics compounders tend to formulate with the objective of optimizing properties at minimum cost rather than maximizing properties at optimum cost. Table 2 fists typical plastic fillers and their uses. 

The solubiHty of phosphoms in water is about 3 ppm. However, process water used in phosphoms manufacture or handling often catties larger amounts of phosphoms as particulates or small droplets, depending on the water temperature. Phosphoms-contaminated water is commonly called phossy water. Phosphoms has low solubiHty in most common solvents, but is quite soluble in carbon disulfide and some other special solvents. The solubiHty in CS2 and benzene was formerly used in phosphoms analyses, but toxicity and increasing waste disposal costs have led to mote use of toluene and xylene, and mote tecentiy to the use of nonchemical turbidity measurements. 

The cost of an electric-drive rotaiy-cutter sample of the smallest size manufactured—suitable for gravity sampling of fine particulate solids or shiny flow—including timer and control unit was approximately 5,000 in 1996. 

Relatively low capital cost Relatively small space requirements Ability to collect particulates as well as gases Collected substances may be recovered by distillation... 

The electrostatic effect can be incorporated into wet scrubbing by charging the particulates and/or the scrubbing-liquor droplets. Electrostatic scrubbers may be capable of achieving the same efficiency for fine-particulate removal as is achieved by high-energy scrubbers, but at substantially lower power input. The major drawbacks are increased maintenance of electrical equipment and higher capital cost. 

Three of the disadvantages of ESPs are as follows (1) the initial cost is the highest of any particulate collection system, (2) a large amount of space is required for the installation, and (3) ESPs are not suitable for combustible particles such as grain or wood dust. 

When selecting a system to remove particulate from a gas stream, many choices concerning equipment can be made. The selection could be made on the basis of cost, gas pressure drop, efficiency, temperature, resistance, etc. Table 29-3 summarizes these factors for comparative purposes. The tabular values must not be considered absolute because great variations occur between types and manufacturers. No table is a substitute for a qualified consulting engineer or a reputable manufacturer s catalog. 

List the advantages and disadvantages of using a baghouse, wet scrubber, or LSI tor particulate collection from an asphalt plant drying kiln. The gases are at 250 X and contain 450 mg m of rock dust in the 0.1-10 /rm size range. Gas flow is 2000 min. Consider initial and operation cost, space requirement, ultimate disposal, etc,... 

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