$5000lb$ oil is being heated in a stirred tank by saturated steam which is condensing in the steam coils immersed in the tank. The tank is well mixed.

Temperature of the saturated steam is $267F$ and the heat transfer rate is given by

hat$(Q)=\frac{dQ}{dt}=hT$

where Q is the heat transferred in BTU and $h$ is the heat transfer coefficient. Oil initially at $60F$ enters to the tank at a rate of $1018l\frac{b}{h}$ and leaves at the same rate. If the energy introduced by the motor is $3$ hp with $75\%$ efficiency, how long does it take for the discharged oil from the tank to rise from $60F$ to $90F?$ and Hint: Reference temperature is $($:$T_{\text{r}\text{e}\text{f}}=60F$