A single-effect evaporator with a heat transfer area of $70\:m^{2}$ concentrates a salt solution using steam. The salt solution feed rate and temperature are $10000\:kg\:h^{-1}$ and $40^{\circ}C$, respectively. The saturated steam feed rate and temperature are $7500\:k\: h^{-1}$ and $150^{\circ}C$, respectively. The boiling temperature of the solution in the evaporator is $80^{\circ}C$. The average specific heat of the solution is $0.8 \text{ kcal } kg^{-1}\:K^{-1}$. The latent heat of vaporization is $500\text{ kcal } kg^{-1}$. If the steam-economy is $0.8$, the overall heat transfer coefficient is _____________  $\text{kcal } h^{-1}\:m^{-2}\:K^{-1}$ (rounded off to the nearest integer).