116 PURIFIERS. 



just mentioned may be varied if there be not a plentiful supply of water. The 

 gas, as it leaves the condensers, may pass first through the " breeze separa- 

 tors," then through the dry-lime purifiers, and finally through the wash- vessel. 



PLATE XIV. 



LIME-WATER PURIFIER. 



I will now proceed to the subject of purification by lime-water. 



Fig. 1 is an elevational section of a lime-machine, and Fig. 2 a plan through 



a 6 in Fig. 1. 



A is the inlet pipe through which the gas passes into the chamber B, which 

 is four feet diameter, jointed to the lid of the purifier, and supported upon 

 two cast-iron beams C. On to the bottom flanch of this chamber a 

 circular ring of thin wrought-iron plate is riveted, of such a diameter 

 that its outside rim will be within five inches of the tank of the purifier. 



D is a hoop supported from the tank by bolts d d, etc., having its upper 

 edge level with the before-named plate, and its lower edge four or five 

 inches below it. The space left between this hoop and the ring is three- 

 eighths of an inch, through which the gas (after having overcome the 

 pressure of the column of water contained in the tank, plus the pressure 

 in the gasometers) will pass, and bubble up through the lime-water. 



E is an arm made to revolve on the spindle S : the parts e e of this arm 

 continue through the aperture and over the ring, serving to keep the 

 lime from settling or obstructing the passage of the gas. 



F is the outlet for the purified gas. 



G is a stuffing-box, through which the spindle S passes. 



H a miter-wheel, connected to a water-wheel or steam-engine for turning the 

 spindle. 



I is a pipe, through which the lime-water is drawn off when it has become 

 saturated with the impurities of the gas. It will be observed, that by this 

 contrivance the water can be completely drained off, by opening a slide- 

 valve bolted to the flanch of the pipe K, without suffering the gas to 

 escape along with it, because a column of water will remain in the tube I 

 equal to the height of the bottom of the tank, measured from the inner 

 radius of the curve of the tube, viz. twelve inches, which is always more 



