THE FILTRATION OF THE JUICE. 



In some factories the partially clarified liquor is also filtered en masse 

 in filters known as ' mechanical filters ' ; in others the juice is cleaned hy 

 boiling, and by skimming off the floating impurities; the vessels in which thi& 

 process is carried on are known as 'eliminators' and in Java as 'Fletcher pans.' 



Taylor Bag Filters. The Taylor bag filter consists of stockings 

 of stout cloth, generally about six feet long and four inches in diameter; these 

 stockings are suspended in groups of from twenty to fifty in a horizontal 

 frame ; the frame is perforated with holes in rows a short distance apart ; into- 

 the holes are fitted gun metal sockets furnished with screw threads for the 

 reception of the gun metal cones to which the bags are tied. The whole 

 system of frame and bags is enclosed in an upright iron box, access to which 

 is afforded by means of close-fitting doors; the sides of this box project a 

 height of about two feet above the frame ; the scums being allowed to flow 

 over the frame, the clear juice passes through, the dirt being retained in the 

 stockings. A steam connection is usually fitted up in the interior of the box 

 so that the high temperature necessary to rapid filtration may be maintained, 

 A view partly in section and partly in elevation is shown in Fig. 151. 



Frame Filter Press. In Fig. 152 is shown a view partly in 

 section and partly in elevation of a central feed frame filter press ; it consists of 

 a heavy cast-iron frame 3, on which are supported a number of plates c ; on 

 the sides of the plates are cast lugs from which the plates depend. The latter 

 are made either square or circular, generally the former. On their surface 

 are formed a number of corrugations about one quarter of an inch deep ; in 

 the centre of each is an opening so that when all the plates are fixed in position 

 there is a circular conduit running through the press. Near a lower angle of 

 each plate is an aperture which communicates by a channel with a cock placed 

 at the bottom of one of the sides of the plate, and through which the filtered 

 juice is drawn off. Filtration is made through strong twill cloth as a general 

 rule, but in the absence of other material ordinary gunny bags form an 

 efficient substitute. Cloths, with circular holes cut to correspond with the 

 holes in the plates, are hung over each plate. The edge ef the cloth is securer! 

 in the hole in the plate by means of a hollow screw with a deep rim. In 

 working the press after all the cloths have been placed in position, the whole 

 is screwed tight by means of levers acting on the wheel e, which works the 

 screw thread /, and by means of suitable piping juice is pumped or forced by 

 a montjus through the press along the conduit g ; the clean juice passes 

 through the cloth and the suspended dirt is caught between the cloths. At the 

 upper corners of the plates are openings communicating with another set of 

 piping by means of which water or steam may be forced through the scum 

 after the press is filled. This type of press is not very convenient ; the bags 

 have a great tendency to tear away at the centre, and washing to remove 



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