In that experiment, we studied on plate and frame filter press by using mint solution. Filtration is an important unit process which is used in fruit juice, oil, etc. industries. The principles behind filtration are basically very simple. All that is involved is the separation of a solid from the liquid in which it is suspended by passing the liquid through a porous medium with pore sizes too small to allow passage of the solid particles. In the plate and frame filter press method, the solid particles are separated from liquid part by using high pressure. Solid particles are separated with filters which can not pass from filter, so their particle size is so high with respect to filter pores. Pressure is help to separate the particles by increasing flow rate of liquid.
Flow rate is one of the most important effect on filtering. Because in increasing flow rate, the separation of cake increase with increasing time and depending on pressure. Type of filters and pore size of the filters are the other effects. Because of these effects quality of filtration change. Also pore size effect the quality, the small pore size increases the clarification of the liquid.
In filtration the liquid passes through two resistances in series; that of the cake and that of the filter medium. The filter medium resistance, which is the only resistance in clarifying filters, is normally important only during the early stages of cake filtration. The cake resistance is zero at the start and increase with time as filtration proceeds. However, according to our results the cake resistance of mint didn’t increase with time. Time for filtrate collection decreased and this was not expected result.
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