Question from Noel de, Nevers Air Pollution Control Engineering, Problens 7.9

In Example 7.1, what are the values of a, b, and c in Eq. (7.1)? If we wish to rewrite that equation in terms of the volumetric flow rate instead of the filter area, and if the flow velocity through the filter is 2ft/min, what would the values of a, b, and c be?

[Eq. (7.1)

[Example 7.1]

Purchasepriceofequipmentwithoutauxiliaries=a+b( size c Example 7.1. (This example is a simplification of the example on p. 111 of [8]). We wish to purchase and install a fabric filter to collect fine particles. Using the methods shown in Chapter 9 , we conclude that we will need 13400ft2 of filter area. What will the complete purchased filter cost? What will the whole installation cost? From [8] we have that the purchase price of the filter, bags included, is Purchasepriceofequipmentinthissizerange=$41000+ft2$8.75(filterarea)1.00=$41000+$8.7513400=$158250 In 111p, mentioned about [8] METEOROLOGY FOR AIR POLLUTION CONTROL ENGINEERS 111 TABLE 5.3 Wind speed and direction for some U.S. cities 3. The prevailing wind direction is the direction from which the wind blows most frequently, not necessarily the direction from which the strongest wind comes. These wind directions are mostly governed by local topography, e.g., onshore or offshore winds, or local mountains and valleys. 4. These values are averages for a year. The source used data from different years at different sites, so some are from 1975, some 1976, and some 1977. 5. Chicago is unjustly called "The Windy City;" others have more wind [8]. 5.5 TEMPERATURE INVERSIONS Temperature inversions play a significant role in air pollution meteorology. Within an inversion the air is stable against buoyant vertical motion. That stability also lessens the exchange of wind energy between the air layer near the ground and high altitude winds, so that both horizontal and vertical dispersions of pollutants are hindered. There are four ways to produce an inversion: Cool a layer of air from below, heat a layer of air from above, flow a layer of warm air over a layer of cold air, or flow a layer of cold air under a layer of warm air [9]. All of these occur. The first, cooling from below, is the very common radiation inversion discussed in Section 5.3.4 and Fig. 5.7; the other three are discussed here. Heating an air layer from above can occur if a cloud layer absorbs incoming solar energy, but it most often occurs when there is a high-pressure region (common