As part of their work in the company that works their group must design a packing tower to treat a water contaminated by means of dragging. The contaminated stream contains trichloroethene (TCE), 1,1,1-trichloroethane (TCA) and 1,1-dichloroethene (DCE). The concentrations of the three contaminants, and some other properties of those chemicals, are shown in the table below. Suppose a temperature of 20 C Compound Conc. in Concentration Aqueous Diffusivity Henry's waste stream, required, CE diffusivity in air constant CO (mg/L) mg/L m/s m/s TCE 16.3 0.005 0.89x109 0.99x10 0.35 TCA 0.56 0.20 0.85x10-9 0.98x10-5 0.61 DCE 0.27 0.006 1.04x10-9 1.15x10-5 0.91 data: Volumetric flow, Q = 100 gallons per minute (gpm) Packing type = 2-inch plastic saddles = Tip Use an Excel spreadsheet to keep track of your calculations. This will be particularly helpful when answering (6) and (9). Solve from to 9 1 Determine an airflow rate, Qa, in m3/s that gives a bubbling factor of at least 3 for all compounds that require removal. Based on that at that flow rate, what is the bubbling factor for each of the three compounds? (ie you must determine a flow rate, which will give a different bubbling factor for each contaminant). 2) Based on the given Q and the calculated Qa, determine the mass flow rate, GM, that will result in a pressure drop of AP/L = 50 Pa/m. Hint: Use the Eckert relation figure. Report your answer in kg/(m2-s). 3) Using the GM, calculate the area of the tower and the diameter of the tower given AP/L = 50 Pa/m. 4) Is the diameter of the tower at least 12 times the diameter of the packing material? If not, then choose a larger diameter (hint use a diameter that is equal to 15 times the diameter of the fill material). Now what is the cross-sectional area of the tower? Why is it important to satisfy this? criterion?+ As part of their work in the company that works their group must design a packing tower to treat a water contaminated by means of dragging. The contaminated stream contains trichloroethene (TCE), 1,1,1-trichloroethane (TCA) and 1,1-dichloroethene (DCE). The concentrations of the three contaminants, and some other properties of those chemicals, are shown in the table below. Suppose a temperature of 20 C Compound Conc. in Concentration Aqueous Diffusivity Henry's waste stream, required, CE diffusivity in air constant CO (mg/L) mg/L m/s m/s TCE 16.3 0.005 0.89x109 0.99x10 0.35 TCA 0.56 0.20 0.85x10-9 0.98x10-5 0.61 DCE 0.27 0.006 1.04x10-9 1.15x10-5 0.91 data: Volumetric flow, Q = 100 gallons per minute (gpm) Packing type = 2-inch plastic saddles = Tip Use an Excel spreadsheet to keep track of your calculations. This will be particularly helpful when answering (6) and (9). Solve from to 9 1 Determine an airflow rate, Qa, in m3/s that gives a bubbling factor of at least 3 for all compounds that require removal. Based on that at that flow rate, what is the bubbling factor for each of the three compounds? (ie you must determine a flow rate, which will give a different bubbling factor for each contaminant). 2) Based on the given Q and the calculated Qa, determine the mass flow rate, GM, that will result in a pressure drop of AP/L = 50 Pa/m. Hint: Use the Eckert relation figure. Report your answer in kg/(m2-s). 3) Using the GM, calculate the area of the tower and the diameter of the tower given AP/L = 50 Pa/m. 4) Is the diameter of the tower at least 12 times the diameter of the packing material? If not, then choose a larger diameter (hint use a diameter that is equal to 15 times the diameter of the fill material). Now what is the cross-sectional area of the tower? Why is it important to satisfy this? criterion?+
