In a paper mill drying process, a sheet of paper slurry (water-fiber mixture) has a linear velocity of 5 m1s as it is rolled. Radiant heaters maintain a sheet temperature of T_s = 330 K, as evaporation occurs to dry, ambient air at 300 K above and below the sheet.

(a) What is the evaporative flux at a distance of x = 1 m from the leading edge of the roll? What is the corresponding value of the radiant flux (irradiation, G) that must be supplied to the sheet to maintain its temperature at 330 K? The sheet has an absorptivity of a = 1.

(b) To accelerate the drying and paper production processes, the velocity and temperature of the strip are increased to 10 m/s and 340 K, respectively.

To maintain a uniform strip temperature, the irradiation G must be varied with x along the strip. For 0 < x < 1 m, compute and plot the variations h_m,x(x), N"_A(x), and G(x).

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T, Paper slurry