xiii. A, 3 Ycasiano and Valencia: Producer-gas Plant 107 



Gas outlet. — The gas outlet E (fig. 2) is a rectangular opening, 

 14.4 centimeters by 34.4 centimeters, controlled by the three-way 

 cock D (fig. 4), which opens either to the chimney E or to the 

 gas pipe F. 



Cleaning machinery. — The vertical gas delivery pipe / (fig. 3) , 

 the inside diameter of which is 17.5 centimeters, is water-sealed 

 at the lower end. The gas is forced through the pipe downward, 

 and large quantities of dust, small particles of coal, and flaky 

 ashes are removed. The direction of flow of the gas is changed 

 abruptly by the short horizontal pipe J, 17.5 centimeters inside 

 diameter, and by the vertical scrubber K, 30 centimeters in dia- 

 meter. This scrubber, as is shown in the cross section (fig. 6), 

 is provided with two spray nozzles of the umbrella type and 

 with a water seal at the bottom. The water box is provided 

 with an overflow to the sewer. The water spray from the nozzles 

 meets the upward-going gas and removes most of any remaining 

 dust or other residual solid matter in suspension. The water 

 spray also serves the purposes of cooling the gas and of con- 

 densing the tar. 



The gas, mixed with a certain amount of water that is fed and 

 kept in circulation by a small pump, is next passed through the 

 first centrifugal machine, revolving at a rate of about 2,800 per 

 minute, where the heavy matter, consisting mostly of tar, is 

 largely removed. In the machine the water is mixed intimately 

 with the gas, and they are discharged together. The gas is 

 separated by being collected in a vertical holder, and the water 

 and impurities go into the separating tank. The tar floats on 

 the water and runs through an opening in one side of the tank. 



The holder, into which the gas is delivered by the first centrifuge, 

 consists of a cylinder 65 centimeters in diameter by 110 centimeters in 

 height, provided with an opening in one side to fit the discharge pipe. 

 The center of this opening is located 17.5 centimeters above the bottom of 

 the gas holder. A vertical pipe, open at both ends, passes through the 

 bottom of the gas holder. The upper end of this pipe reaches slightly 

 above the discharge pipe, while the lower is water-sealed. Another opening 

 is in the cover of the gas holder and connects with the intake pipe of the 

 second centrifuge. 



On leaving the gas holder, the gas passes to the second cen- 

 trifuge, where again it is mixed intimately with water, introduced 

 as in the first centrifuge. This operation causes the further 

 separation of residual tar in the gas. 



The gas is then delivered under pressure to the condenser or 

 moisture separator (fig. 7). This consists of seven perforated 

 plates of equal dimensions, placed vertically on top of packed 



