Question

The height of the down sprue is 175 mm and its CS area at the base is 200 $m{m}^2$. The CS area of the horizontal runner is also 200 $m{m}^2$. Assuming no losses, indicate the correct choice for the time (second) required to fill a mould cavity of volume ${10}^{6}m{m}^3$. (Use g = 10 $m/s^2$)

• A. 26.7
• B. 8.45
• C. 84.50
• D. 2.67

Answer 1

The correct option is D 2.67

$\text{Velocity of metal at the bottom of sprue,}$

$V_s=\sqrt{2\times 10\times 175\times {10}^{-3}}$

$=1.87m/s=1870mm/s$

$A_s={A_{runner}}_{{}^{\prime }}$

$V_s=V_{runner}$

$\text{Pouring time}=\frac{{10}^{6}m{m}^3}{200m{m}^2\times 1870mm/s}=2.67s$