THE DISPOSAL AND UTILIZATION OF RESIDUALS. I2Q 



gravity. Very often an old and disused holder tank is 

 utilized for the store well, and it is worth while, not only to 

 ascertain that it is perfectly sound and tight in the first 

 place, but to test it every few years. In the early days of 

 gas lighting, when the liquid products were regarded as of 

 little or no value, no particular trouble was taken to make 

 a perfectly sound tank. And not unfrequently it will be 

 found that the low returns for liquid products suggest the 

 existence of serious leakage. Apart from the waste of 

 material, the penalties for fouling wells and water courses 

 are onerous. 



Difficulties often arise from want of efficient separa- 

 tion of water and tar. If there is only one well, and 

 the contents are periodically disturbed by flushing the 

 scrubber, the chances are that there will occasionally be 

 claims, if the tar is sold to distillers, for reduction in respect 

 of water in the tar. And if the ammoniacal liquor is utilized 

 on the works, trouble may arise from tarry matter in the liquor. 

 To avoid agitation of the liquid, all inlet pipes should be 

 carried well down below the surface. It is evident that a 

 flow of liquid falling into the well from a height perhaps 

 6 feet above the surface of the contents will agitate them 

 to an extent sufficient to interfere with the proper settling 

 down of the tar. And there is no advantage in keeping tar 

 in stock. It should be disposed of, or sent away as soon 

 as a quantity sufficient to make up a cargo accumulates. 



The utilization of ammoniacal liquor has, in my experience, 

 been confined to the manufacture of sulphate. In some 

 parts of the world, a concentration process for the produc- 

 tion of liquor ammonia is used, but I never heard of its 

 application in England. In Germany, the use of a port- 

 able sulphate apparatus, mounted on trucks, that can be 

 hauled about the country by a road traction engine, has 



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