Crude potassium nitrate $($KNO$3)$ containing $78\%$ w$/$w KNO$3,5\%$ w$/$w impurities and the rest water, is purified through crystallisation from aqueous solution. The crude KNO$3$ is dissolved in a recycled KNO$3$ solution. A continuous cooling crystalliser$-$filter is used to produce KNO$3$ crystals containing $70\%$ of the KNO$3$ in the fresh feed to the process.

There are two outlet streams from the crystalliser$-$filter: solution $($mother liquor$)$ and crystal cake. The latter consists of the KNO$3$ crystals produced in the crystalliser $(90\%$ w$/$w$)$ and occluded between crystals solution containing dissolved KNO$3,$ water and impurities. The crystal cake is washed with pure water in a washer$-$filter to remove the majority of the occluded solution. The rate of water is $1/5$th of the rate of the crude KNO$3.$ The mother liquor leaving the crystalliser joins the filtrate $($the liquid leaving the filter$)$ to form a new stream, $25\%$ of which is purged and the rest is recycled to the dissolver.

The crystal product is the filter cake after the washing with pure water. It consists of $97\%$ w$/$w pure KNO$3$ crystals and the rest is occluded solution

$($i$)$ Draw the flow diagram showing all streams with their notation and known information

Using a basis of $1000$ kg of raw DMT per hour calculate the rate of the:

$(1)$ crystal product crystals and occluded solution$)$

$(2)$ purge

$(3)$ recycleand the rest water, is purified through crystallisation from aqueous solution. The

crude $KN{O}_3$ is dissolved in a recycled $KN{O}_3$ solution. A continuous cooling

crystalliser$-$filter is used to produce $KN{O}_3$ crystals containing $70\%$ of the $KN{O}_3$ in

the fresh feed to the process.

There are two outlet streams from the crystalliser$-$filter: solution $($mother liquor$)$

and crystal cake. The latter consists of the $KN{O}_3$ crystals produced in the

crystalliser $(90\%\frac{w}{w})$ and occluded between crystals solution containing

dissolved $KN{O}_3,$ water and impurities. The crystal cake is washed with pure water

in a washer$-$filter to remove the majority of the occluded solution. The rate of water

is $\frac{1}{5^{th}}$ of the rate of the crude $KN{O}_3.$ The mother liquor leaving the crystalliser

joins the filtrate $($the liquid leaving the filter$)$ to form a new stream, $25\%$ of which is

purged and the rest is recycled to the dissolver.

The crystal product is the filter cake after the washing with pure water. It consists

of $97\%\frac{w}{w}$ pure $KN{O}_3$ crystals and the rest is occluded solution.

$($i$)$ Draw the flow diagram showing all streams with their notation and known

information.

$($ii$)$ Using a basis of $1000kg$ of raw DMT per hour calculate the rate of the:

$(1)$ crystal product $($crystals and occluded solution$)$

$(2)$ purge

$(3)$ recycle

$(4)$ rate of the stream leaving the crystallizer and entering the filter