In a drying process, $4$ tons of sorghum is reduced from an $18\%(db)$ moisture content to $13\%$

$($db$)$ in one hour. Determine the required heat for drying $($in kca$\frac{l}{s})$ and the necessary airflow rate

$($in $k\frac{g}{s})$ for the drying system. The given parameters are: Drying efficiency $50\%,$ Latent heat of

evaporation $575$kca$\frac{l}{k}g,$ Specific heat of air $0\mathrm{.}24$kca$\frac{l}{k}gC,$ Drying air temperature $44C,$ and

Ambient air conditions $25C$ and $20C$ for dry and wet bulb temperatures, respectively.

a$.2\mathrm{.}6-2\mathrm{.}8,10\mathrm{.}8-10\mathrm{.}9$

b$.2\mathrm{.}6-2\mathrm{.}8,11\mathrm{.}8-11\mathrm{.}9$

c$.26-28$;$10\mathrm{.}8-10\mathrm{.}9$

d$.26-28$;$11\mathrm{.}8-11\mathrm{.}9$