Question

The height of the down-sprue is 175mm and it cross-sectional area at the base is 200 mm${}^2$. The cross sectional area of the horizontal runner is also 200 mm${}^2$. Assuming no losses, the time (in seconds) required to fill a mold cavity of volume ${10}^{6}m{m}^3$ is

• A. 84.50
• B. 2.69
• C. 8.45
• D. 26.72

Answer 1

The correct option is B 2.69

The given dimensions of mold box are shown in the figure.


The discharge velocity at the runner exit is determined as

$v=\sqrt{2\times 9.81\times 0.175}=1.8529m/s=1852.9mm/s$

The filling time is given by

$t=\frac{{10}^6}{200\times 1852.9}=2.698s$