Returning now to Fig. [28], at the bottom of the column is a manifold E, with pipes F and G whereby either exhaust or live steam may be admitted. H designates the discharge or slop valve, controlled by a float I whereby a constant level of slop or spent wash is kept in the bottom chamber.
To the right of the column is seen the slop tester J and hydrometer L, whereby the spent wash may be tested to see if the spirit is being properly extracted. The steam pressure is indicated by means of a float N contained within a vessel M, a tally weight moving against a scale K, showing the pressure of steam entering through pipe O and acting against water contained in vessel M. Each chamber is provided with a manhole plate P, and a try-cock Q, whereby the operation of each chamber may be tested. R is a gage glass to show the level of the slop in the bottom chamber.
At the top of the column are three rectifying chambers fitted with boiling pipes and traps T, which distribute the ascending vapor and boil out the low wines returned from the wash-heater or fore-warmer.
The heater consists of a shell enclosing a series of tubes extending into an upper and lower chamber. The wash or “beer,” is pumped into the lower chamber of the heater, and passes upward through the tubes to the upper chamber from which is it carried by a pipe to the plate A next below the rectifying plates.
Fig. 30.—Detail of Perforated Plate A.
The vapor from the column passes into the middle compartment of the heater and surrounds the beer tubes. The vapors give their heat to the beer and are thus cooled, the low wines being condensed and flowing back onto the uppermost rectifying plate, while the highly vaporized portions pass out to the condenser. This is of the same general construction as the heater, the vapor being cooled and condensed to liquid by the tubes through which a constant current of cool water is passed. This enters at U and passes out at V. These tubular condensers are particularly good as they may be easily cleaned. From the condenser the spirit passes to a discharge box W. A portion of the flow passes into a test tube X, provided with a hydrometer. A trap Y and an air pipe Z provide means for the escape of gas.
