COAL-TAB, 307 



Fig. 103 which shows an end view and a plan of the stills, 

 heaters, condensers, etc. The plant shown has a capacity of 10 

 tons per day. It is only necessary to add that the gas required 

 for heating is derived from a gas producer not shown in the plan, 

 or from coke ovens. 



REFERENCES TO THE DIAGRAM 



A. Crude Tar Inlet. 



B. Tar Regulating Tank. 



C. No. 1 Still. 



D. No. 2 Still. 



E. No. 3 Still. 



F. Pitch-Cooler. 



G. Heater-Coolers. 



H. Water Coil Condensers. 



J. Sight Boxes. 



K. Water and Naphtha Outlet. 



L. Light Oil Outlet. 



M. Creosote Oil Outlet. 



N. Anthracene Oil Outlet. 



O. Pitch Outlet. 



P. Bunsen Burners. 



Q. Gas Main. 



K. Thermometers. 



S. Safety Valves. 



T. Flue. 



U. Chimney. 



V. Steam Pipes. 



W. Water Pipes. 



The picture Fig. 104 provides a view of this continuous plant 

 in operation. 



We may now proceed to consider the next step, which con- 

 sists in dealing with the several products of the distillation in 

 the tar stills. The ammoniacal liquor goes to a different depart- 

 ment where it yields sulphate of ammonia. The crude naphtha 

 and light oils are usually redistilled for the separation of ben- 

 zene 1 and its homologues. But as it contains small quantities 

 of basic substances, including aniline, it is first shaken up with 

 sulphuric acid which removes these compounds, and subse- 



1 These hydrocarbons are called commercially, benzol, toluol, etc., but the 

 pure hydrocarbons are in chemical language distinguished as benzene, tolueiie, etc. 



