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7. PRESS FILTERS. 



The press filter is an assemblage of trays form -Hi 

 of an exterior circle of cast iron and an interior 

 disk of sheet iron pierced with holes ; they are 

 provided at the top with a hole corresponding to 

 a service pipe. Of the two exterior trays which are 

 full, one is fixed on a frame of cast iron, and the 

 other is movable and works as also the pierced 

 plates, upon two ears on two horizontal supporting 

 arms. Each interior tray is furnished with a tap 

 on its lower side, and a cloth is applied to the upper 

 surface of each. These trays are tightened by means 

 of a screw, so that there is a circular compartment 

 on the interior between them communicating by 

 the upper hole, with the service pipe and they are 

 so adjusted by means of rubber washers that the 

 apparatus is perfectly tight and all the compart- 

 ments form filters. The deposit rendered muddy 

 by the carbonatation is forcily sent up by the juice 

 lifter, through the service pi, e and fills all the 

 compartments. Pressure compels the clear liquid to 

 run out by the lower taps, whilst the carbonate of 

 lime with all the impurities remains in the compart- 

 ments nearly dry. 



AYhen the operation is finished, the trays are 

 loosened, the cake that remains is let fall and the 

 apparatus is fixed again for another operation. The 

 cakes from the press-filters are a very fine manure 

 which is carefully gathered. When the cloths are 

 worn out they are replaced by others. 



