374 SORGHUM. 



where the hot gases are distributed into the pipes of the drier, and 

 through them iuto the chimney, at a temperature of 380° F., with a 

 great saving of fuel. 



After remaining in the retort a sufficient length of time to be raised 

 to a cherry-red heat, the organic substances which have been taken up 

 from the juice are here expelled. 



At intervals, the cliar-slide at the bottom of cooler is opened, and 

 a quantity of char drawn off and tested, which test, proving correct, 

 soon enables the chai'-burner to tell how much char should be drawn at 

 certain intervals : for if too much is drawn, the char will be improp- 

 erly burned, and will be unsuited for use in the filters. This can be 

 learned by practice and by test. The cooler is a sheet iron tube, con- 

 nected with the bottom of the retort, where the char is reduced in 

 temperature to 120° F., and is then received in barrows, or, in large 

 houses, upon an endless carrier apron, which delivers it to an elevator, 

 raising it t ) a dust box and blower, where the fine dust char is taken 

 away, and the clean char is received in a carrier with inclined shoots, 

 so as to fill the filters quickly and uniformly. 



The filters are iron cylinders and usually designed so that the height 

 is six times the diameter, until within a few years, when filters have 

 been made ten feet in diameter and eighteen feet high. The style of 

 filter somewhat depends upon the size of char used, and the manner 

 of working the house, whether very fine grain or coarse char — each 

 size having its partisans, claiming superiority for each. The filter is 

 filled with animal charcoal, and the liquor is let in upon it expelling 

 the air. Great care is necessary that the whole filter should be full, 

 and the juice not allowed to run down on one side only. After the 

 liquor has completely filled the filter, the cock is turned on at the bot- 

 tom, and the liquor is conducted to the top of another filter, and also 

 to a third, if needed, so the juice passes over a set of two or more, 

 discharging the juice clear and colorless; this gees on until the color 

 grows dark, or is not satisfactory, and they arc stopped, the foul filters 

 washed out by letting th.e water flow in at the top, pressing the liquor 

 out beiore it, until it does not show a trace of sweetness. The filter is 

 then allowed to drain. Sometimes steam is used, or an exhaust is ap- 

 plied to the bottom to draw off the water — air following to fill the 

 vacuum. The lower man hole is now opened, and the exhausted char 

 conveyed directly to the drier over the kilns by means of a suspended 

 rail car or elevator. 



The plate represents the sectional view of filter and kiln house ; the 

 car to convey it to the elevator, the elevatjr to raise it up into the top 



