Specification for Particulates

Specification for Particulates Feed, recycle, and product from size reduction operations are defined in terms of the sizes involved. It is also important to have an understanding of the degree of aggregation or agglomeration that exists in the measured distribution. 

EUROVENT has always led the field in measuring and characterizing air filters. Since 1979 EUROVENT 4/5 has set the standard in Europe and provided the basis for European Standard EN 779 1993, Specifications for Particulate Air Filters for General Ventilation. 

Specification for Particulates Feed, recycle, and product from... 

To examine a sample by inductively coupled plasma mass spectrometry (ICP/MS) or inductively coupled plasma atomic-emission spectroscopy (ICP/AES) the sample must be transported into the flame of a plasma torch. Once in the flame, sample molecules are literally ripped apart to form ions of their constituent elements. These fragmentation and ionization processes are described in Chapters 6 and 14. To introduce samples into the center of the (plasma) flame, they must be transported there as gases, as finely dispersed droplets of a solution, or as fine particulate matter. The various methods of sample introduction are described here in three parts — A, B, and C Chapters 15, 16, and 17 — to cover gases, solutions (liquids), and solids. Some types of sample inlets are multipurpose and can be used with gases and liquids or with liquids and solids, but others have been designed specifically for only one kind of analysis. However, the principles governing the operation of inlet systems fall into a small number of categories. This chapter discusses specifically substances that are normally liquids at ambient temperatures. This sort of inlet is the commonest in analytical work. 

Pollutants. The problems posed by ak pollutants are very serious. Within a museum, measures can be taken to remove harmful substances as efficiently as possible by means of the installation of appropriate filter systems in the ventilation equipment. Proposed specification values for museum climate-control systems requke filtering systems having an efficiency for particulate removal in the dioctyl phthalate test of 60—80%. Systems must be able to limit both sulfur dioxide and nitrogen dioxide concentrations <10 /ig/m, and ozone to <2 /ig/m. ... 

Twelve oxygen grades are defined by the Gas Specification Committee of the Compressed Gas Association (CGA) (24), 10 of which are given in Table 4. The contaminants identified relate to possible residues from the atmosphere as well as particulates or fibers that may have been contributed by the manufacturing process or the distribution system. In addition, government agencies and certain commercial users have developed specifications for individual needs (25). In most cases, these specifications closely parallel the CGA grades. 

Specifications for gas turbine fuels prescribe test limits that must be met by the refiner who manufactures fuel however, it is customary for fuel users to define quality control limits for fuel at the point of delivery or of custody transfer. These limits must be met by third parties who distribute and handle fuels on or near the airport. Tests on receipt at airport depots include appearance, distfllation, flash point (or vapor pressure), density, freezing point, smoke point, corrosion, existing gum, water reaction, and water separation. Tests on delivery to the aircraft include appearance, particulates, membrane color, free water, and electrical conductivity. 

If an ESP is 90% efficient for particulate removal, what overall efficiency would you expect for two of the ESPs in series Would the cost of the two in series be double the cost of the single ESP List two specific cases in which you might use two ESPs in series The gaseous effluent from a process is 30 m min at 65°C. How much natural gas at 8900 kg cal m would have to be burned per hour to raise the effluent temperature to 820 "C Natural gas requires 10 m of air for every cubic meter of gas at a theoretical air fuel ratio. Assume the air temperature is 20°C and the radiation and convection Iosm s are 10%. 

Wet scrubbers have found widespread use in cleaning contaminated gas streams because of their ability to effeetively remove both particulate and gaseous pollutants. Specifically, wet scrubbing describes the technique of bringing a contaminated gas stream into intimate contact with a liquid. The types most widely used for particulate control are spray towers, packed-bed units, ionizing wet scrubbers, and venturi scrubbers. 

Wolcoff, N., and Bruetsch, R. Size Specific Total Particulate Emission Factors for Nobile Sources. US EPA Publication EPA-460/3-85-00, Ann Arbor, Nichlgan, 1985. 

The various venturi-scrubber models embody a variety of assumptions and approximations. The solutions of the equations for particulate collection must in general be determined numerically, although Calvert et al. [J. Air Pottut. Control Assoc., 22, 529 (1972)] obtained an explicit equation by making some simplifying assumptions and incorporating an empirical constant that must be evaluated experimentally the constant may absorb some of the deficiencies in the model. Although other models avoid direct incorporation of empirical constants, use of empirical relationships is necessary to obtain specific estimates of scrubber collection efficiency. One of the areas of greatest uncertainty is the estimation of droplet size. 

Ponchel, G., and Irache, J.M., Specific and non-specific bioadhesive particulate systems for oral delivery to the gastrointestinal tract, Adv. Drug Del Rev., 34 191-219 (1998). 

Pollution control devices for particulates do not depend upon new technology whereas SO2 control does. Since the first decade of this century, as a result of Cottrell s original work (9j, the electrostatic precipitator had been used to collect fly ash particulates. These devices were used on many of the older coal burning plants which had converted to oil. On the reconversion to coal, they were put back in operation or else new ESP units were put in the place occupied by the older ones. The performance of these systems, when designed for a specific coal, was... 

Modified filter sampling methods that are available will measure ambient levels of strong acid in ambient aerosol samples, and these methods do so with acceptable precision and accuracy [as indicated by the balance between measured anions and cations (56, 57)] in the absence of significant levels of particulate weak acids. Additional intercomparisons involving intrinsically different techniques for particulate strong acidity [e.g., IR spectroscopy (48), thermal speciation (38, 45), and filter methods (28)] are needed. Further information on the occurrence of various weak acids in airborne particles is needed, along with further studies of techniques for their specific determination in atmospheric aerosol samples. 

Once the inhalation exposure questions have been identified, the specifications for each personal monitor must be determined and the monitor must be validated for the contaminant being measured. Table I, updated from Samet et al. (14), identifies currently available personal monitors, and Table II, taken from an Environmental Protection Agency (EPA) report (15), shows the projected needs in the 1990s. There are a number of opportunities for research on personal monitors Table II indicates that relatively few commercial units are currently available for either particulate or gas-phase species. For compounds such as polycyclic aromatic hydrocarbons (PAHs), a two-stage sampler is required because some PAHs exist simultaneously in the gaseous and particulate phase (16). Consequently, research must be ranked with respect to the significance of the air pollution problem, and the technological developments required to provide reliable samplers must be defined. 

For smokers, the personal mean values for particulate matter, in this instance respirable particle concentrations, were driven by the indoor air passive smoke (23). The studies summarized in Table III show similar information for other pollutants, and for many the outdoor levels are much lower than the indoor levels that result from the presence of specific indoor sources or activities (40). 

AMP aminohydrolase, an enzyme relatively specific for AMP, has been observed in reptiles (44), erythrocytes (38), snail (45), unfertilized fish eggs (46), invertebrates (47), a variety of mammalian tissues (20), and a particulate fraction of pea seeds (48). Evidence suggests that the frog muscle AMP aminohydrolase is located within or just beneath the sarcolemma (49). The rabbit skeletal and heart muscle enzymes were found in the cytoplasm and mitochondria (20, Jfi, 50, 51), while the enzyme of kidneys and gills of freshwater fish was located in the cytoplasmic fraction (52). The enzyme occurs in most areas of the rat (53) and rabbit brain (54). The nonspecific enzyme from several microbial sources deaminates adenosine triphosphate (ATP) and adenosine diphosphate (ADP) as well as AMP (see Section V). 

Air emissions testing data from five facilities were evaluated for this report. The results are summarized here, by pollutant. The most extensive testing was performed by WP L, who tested criteria pollutants, heavy metals, dioxins and furans, and other organic compounds. Table 6-2 summarizes test data for all criteria pollutants at WP L.18 Ohio Edison tested particulate, S02, NOx, and lead emissions results from this whole tire test are provided in Table 6-3.12 Illinois Power tested PM, metals, and S02 their emissions data are summarized in Table 6-4.4 In 1979, United Power Association performed two TDF tests at their Minnesota facility, and conducted air emissions tests during the first test burn for particulate, NOx, SOz, sulfuric acid, and chloride.17 These emission results are summarized in Table 6-5.17 Northern States Power tested TDF in their wood-fired utility boiler in 1982, without much success.9 Their emissions data are summarized in Table 6-6.9 Comparisons of the data from these plants are provided in the pollutant specific discussions that follow the Northern States Power data are not included with graphical summaries of the other four facilities, because its boiler is wood fired, while the other four co-fire the TDF with coal. 

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