STORING OF SUPERPHOSPHATE. 



125- 



of dryness. But this condition, being incapable of being realized in 

 the manner indicated, the inventors remedy it by injecting a- 

 current of hot air to meet the superphosphate as it falls from the- 

 machine into the pit. This process does not appear to have been 

 adopted in practice. 



Dr. Lorenz' Process (Dr. Lutjens' successor). — Dr. Lutjens- 

 has endeavoured to impart great rapidity to all the stages of super- 

 phosphate manufacture. With him it is a case of terminating the 

 whole series of operations in twenty-four hours, so that the product 

 may be warehoused or dispatched. The process which he uses is- 

 kept secret, and Dr. Lutjens has refused to give the author any^ 



Fig. 33. — Lutjens' Superphosphate Dryer. A. Entrance of superphosphate- 

 from "den". B. Entrance for hot air under pressure. C. Diying 

 trough. D. Entrance of cold air under pressure. E. Cooling trough.. 

 F. Sieve. G. Fine superphosphate. H. Core. 



information. Although his process more particularly interests- 

 German manufacturers, who are obliged to make high strength- 

 superphosphates, sold according to their content of phosphoric acid 

 soluble in water, the author thinks it his duty to give the description 

 for the edification of his readers. The superphosphate, whilst at. 

 100° C. (212° F.) in the "den," is taken by a conveyor on to a plat^ 

 form, under which a scraping machine works, and run into the top 

 part of the latter, through a hopper. The scraping machine, and 

 its application, are the object of German patents 95,756 and 96,046^ 

 the author's translation of which from the original German follow, 

 the translations at the end of the brevet being almost unintelligible. 

 German Patent No. 95,756 of 16 March, 1897, Delivered to the- 

 Chem. Fabrik Aktien GeseUschaft Vorm Carl Scharffet Co., Breslau^ 



