A saturated steam at $4\mathrm{.}0$ bar is used as a heating media to vaporize fresh water from a brackish water source containing $2\%$ salt. The steam flow rate is $100$ kg$/$min$.$ The flow rate of brackish water is $250$ kg$/$min and its pressure is $2$ bar. Assume that the quality of the steam is $100\%$

a$)$ draw the heat exchange system

b$)$ determine the flow rate of freashwater that is evaporated