A hot air at a wet$-$bulb temperature of $34$oC and $5\%$ RH is introduced to a tray dryer at a

flow rate of $720$ m$3/$hr for drying fresh soybean cakes $(1,800$ kg$)$ with $400\%$ MCdb$.$ At the

end of the constant$-$rate period, the moisture content of the soybean cakes reaches $60\%$ wet

basis.

$($a$)$ Determine the amount of water removed by the critical moisture content.

$($b$)$ Determine the mass $($in kg$)$ of dry air introduced into the dryer per hour