Collection Efficiency as a Function of Particle Size,Shape and Density: Theory and Experience

The performance features of both industrial and experimental fabric filter systems with respect to the concentration and particle size properties of the collector effluents are examined. From a qualitative viewpoint the factors that should influence significantly the collection characteristics of a fabric filter are dust properties, fabric properties, operating parameters, filter cleaning method, and critical interdependencies. The quantitative prediction of performance and the establishment of design parameters are limited for a generalized approach but data have been reported that provide excellent support for limited applications.     

A Policy of Options

As many of you know, I previously served as Deputy Administrator of the Environmental Protection Agency at a time when the problem of air pollution control was reaching a peak of public awareness. The work of the Air Pollution Control Association in investigating facts and accelerating the development of solutions earned my high respect then and my continued admiration now.     

Air Pollution Control of an Electric Furnace Steelmaking Shop

The body of information presented in this paper is directed to design engineers, operating management and others who may be concerned with the prevention of atmospheric emissions from electric arc steelmaking furnaces. Inland Steel Co. has recently begun operating its first electric furnace shop. Air pollution control equipment for the shop was installed to meet or exceed the legal requirements of applicable air pollution ordinances and regulations. General shop production requirements were established at 100 tons of steel per hour (maximum) to meet sales forecasts and intermediate production facility requirements. Conventional swing roof furnace design was selected for the pair of furnaces in the shop.     

Stack Dust Sampling: in-Stack Filter or E.P.A. Train

The Environmental Protection Agency has recommended or specified methods for the measurement of participate concentrations in flue gases. The EPA Train for this measurement originally comprised two segments: the front half and the impinger train downstream from the filter proper. This review examines the controversial areas implicit in the use of this EPA Train or the revised EPA train which eliminates the impinger train.     

Cyclic Trends in Los Angeles Fine Participates

Noontime visibilities in downtown Los Angeles, averaged over the smog season of June through November, show two cycles of general deterioration and improvement. The improvement since 1962 is confirmed by available high volume filter data and conditions in 1974/75 are at least as good as at anytime since observations were begun in 1933. The decrease in frequency of “rule 57” days suggests that the improvement of the last decade and perhaps the cyclic variation of the past 40 years has been primarily of meteorological origin.     

Interpretation of Meteorological Pollutant Roses in Areas Subject to Nocturnal Drainage Winds

The composition of aerosol particle products formed from the photochemical reaction of terpenes with NO_x and the chemical reaction of terpenes with ozone was determined using direct insertion probe/high resolution mass spectrometry. Samples of the aerosol particles generated from these gas phase reactions were collected on stainless steel disks using a specially-designed impactor. The samples were analyzed using computer-controlled high resolution mass spectrometry. The photochemical reaction of limonene with NO_x produced more than 30 reaction products in the aerosol phase. The major products identified included aldehydes, alcohols, acids, peroxides, and nitrate esters of alcohols, acids, and peroxides. In addition, there was evidence of dimeric and possibly trimeric reaction products. The composition of aerosol particle products formed from the dark reaction of ozone with limonene was determined and found similar to those products generated in the photochemical reaction, excluding the nitrated species. Aerosol concentrations were monitored using nephelometry which indicated a conversion of terpene to aerosol of 50% or greater for both the limonene and terpinolene reaction systems. The results show that direct insertion probe high resolution mass spectrometric technique has the capability for determining the composition of very polar and high molecular weight materials in aerosol particles. The composition of terpene aerosol particle products and the mass spectral data obtained from their analysis can be used in further studies to determine the importance of terpene aerosol particle formation in ambient air.     

An Ozone Event in Indianapolis

There are doubts concerning the sources of the pollutant ozone in an urban location. Current control regulations,¹ for example, are based on local sources. Many studies suggest that plumes of pollutants released by upwind areas are the cause. For example, New York City has been associated with high O₃ in New England,² Chicago with O₃ in Milwaukee,³ and St. Louis with O₃ in rural Illinois.⁴ Others^5,6 have suggested the problem must be treated on a synoptic scale. In an effort to understand the problem at Indianapolis better, a series of experiments involving aircraft flights were conducted in the Indianapolis area and their results are herein reported. Specifically, a cross country flight of over 100 mi both to the northeast and southwest of Indianapolis, a vertical spiral to 28,000 ft, low level data associated with takeoff and landing of the aircraft, and ground data at four sites, are available for the afternoon of June 9,1976.     

Economics and Alternatives for Sulfur Removal from Coke Oven Gas

Two processes are currently being employed in North America for the desulfurization of coke oven gas, the Vacuum Carbonate System, and the Stretford System. A third, the Sulfi-ban Process, which was recently announced, now has several plants scheduled for construction. Overall operating requirements for each of these processes are considered in detail. Emphasis is placed on an identification of power and steam requirements, the types and amounts of solid and/or liquid waste streams produced together with methods for their treatment, and the net desulfurization efficiencies achieved by each process. Detailed estimates of capital and operating costs for desulfurization are considered, and equipment needs for environmental control requirements are discussed.     

The Change of Concentration Standard Deviations with Distance

Calculations of pollutant concentrations at various downwind and crosswind distances from an elevated point source are frequently based on diffusion models and parameter values contained in Turner’s Workbook of Atmospheric Dispersion Estimates.1 These calculations can be made much more speedily on a computer or on a currentgeneration, programmable desk calculator, if the values of the horizontal and vertical standard deviations of plume concentrations distributions are stated explicitly as a mathematical function of downwind distance. The alternative is to read the values from Turner’s Figures 3-2 and 3-3 and input them into the calculation for each individual value of downwind distance.     

A Microprocessor-Based Air Quality Monitoring System

Portable air quality monitoring systems may be required to supplement fixed installations or to provide for quick response to a transient situation, possibly at a remote location. A microprocessor-based monitoring unit has been developed for use with existing sensors. The unit is portable and its operational sequence can be programmed to adapt it to any unique requirements existing at the deployment site. Selectable on-site calculations are performed on raw data, and a hard copy or tape record of results can be produced.