Question

The flow rate of liquid metal into the downsprue of a mold = 1 liter/sec. the cross-sectional area at the top of the sprue = 800 mm2 and its length = 275 mm. what area should be used at the base of the sprue to avoid aspiration of the molten metal? 430.74 cm2 540 mm2 430.74 mm2 540 cm2

Answer 1

According to question

Flow rate  = 1 lt / sec

Also area of cross section = 800 m^2

So   pi r^2 = 800
Thus    r^2 = 800 * 7/22
              r = 16

Thus radius   r  = 16 mm
Given length   H = 175 mm

Thus   for height 175  radius can be calculated as
 1000 = pi R^2 H
Thus

R^2 = 1000  * 7/22 * 175
R = 236

Thus area needed = pi R^2 = 22/ 7 * 236^2 = 175044