Manufacture continuous method

Relatively little can be added to the description of the methods of l ETN manufacture. Continuous methods are mostly used in modern plants (see also Fig. 74, Vol. II. p. 188). 

Factors affecting the rate of nitration of DNT TNT will be discussed in Section VIII Urbanski (Ref 74) lists several processes for die batchwise manufacture of TNT (eg, the French , British , USSR etc). All of them are essentially similar with only minor differences in MA comp ns and methods of separating the crude TNT from its spent acid. These processes hav been largely replaced by continuous nitration techniques. The Biazzi and Bofors continuous processes for the manuf of TNT are described briefly under Continuous Methods of Manufacturing Explosives in Vol 3, CS01-L. 

Tetryl. In the manufacture of Tetryl, it is usual not to nitrate dime thy laniline directly, but to dissolve it first in coned sulfuric acid and then to nitrate the dimethylaniline sulfate so obtained. Direct nitration of dimethylaniline proceeds so violently that it can be carried out only under specialized conditions. Many years experience of Tetryl manufacture has shown that the ratio of sulfuric acid to dimethylaniline should not be lower than 3 1, since a smaller amount of sulfuric acid may be detrimental to the nitration process. However, the ratio of sulfuric acid to dimethylaniline must not be too high, otherwise Tetryl yield is decreased. Temp must be maintained between 20-45° to avoid sulfonation of the benzene ring. Care must be exercised not to leave any unreacted dimethylaniline prior to introduction of nitric acid, because of the potential violence of the dimethyl-aniline-nitric acid reaction. Consequently, continuous methods of prepn are to be preferred as they inherently minimize accumulation of unreacted dimethylaniline... 

The main advantage of the proposal is that it needs no change of the national regulations and the manufacturer continues to evaluate his material performance by a test method he knows and understands. 

Continuous Methods of Manufacture of Explosives. The first successful method was invented by Schmid of Austria, but some attempts were made as early as 1864. Description, with flow sheets is given in Vol 3 of Encycl, pp C501 to C510 for the methods of Schmid, Biazzi, German and Bofors... 

MF can also be manufd by Biazzi Process. Since it is not described in Vol 3 of this Encycl, pp C50lff, under "Continuous Methods for Manufacturing Explosives it is suggested that info be obtained directly from Dr Mario Biazzi, Ing, Vevey, Switzerland... 

Continuous Manufacture, See Continuous. Method d for Manufacturing Explosives, /ol 3, pp C501-L to C504-R... 

THE CONTINUOUS METHOD OF LEAD AZIDE MANUFACTURE (ACCORDING TO MEISSNER [110, 111])... 

The continuous method for the manufacture of lead styphnate (according to Meissner [58, 59])... 

Herz succeeded in preparing RDX by direct nitration of hexamine, but the yields were low and the process was expensive and unattractive for large scale production. Hale, at Picatinny Arsenal in 1925, developed a process for manufacturing RDX which produced yields of 68%. However, no further substantial improvements were made in the manufacture of RDX until 1940 when Meissner developed a continuous method for the manufacture of RDX, and Ross and Schiessler from Canada developed a process which did not require the use of hexamine as a starting material. At the same time, Bachmann developed a manufacturing process for RDX (1.5) from hexamine which gave the greatest yield. 

Continuous methods for manufacturing expls 3C501-C510... 

From experience gained over many years, special equipment and methods of nitration and purification of nitroglycerine have been developed and certain traditions established. Recently, however, changes have occurred in this field. Continuous methods of nitroglycerine manufacture have been introduced. In many cases they have revolutionized traditional techniques and led to new manufacturing processes. 

In the recently introduced continuous methods of nitroglycerine manufacture nitrators made from acid resistant steel are used since the art of welding stainless steel had progressed remarkably by the 1930 s. The design and construction of nitrators for nitrating glycerine are included in the descriptions of individual methods of nitration. 

All this makes the manufacture of nitroglycerine particularly dangerous and all that has been said previously with regard to the danger of TNT manufacture and the advisability of producing it by continuous methods applies with much greater emphasis to nitroglycerine. 

The continuous method of nitroglycerine manufacture invented by A. Schmid [38] involves not only continuous nitration, but also continuous separation and washing of the product. A novel idea introduced by Schmid was the nitrator made of acid-resistant steel with mechanical stirring (Fig. 38). 

Fig. 46. Flow-sheet of continuous method of manufacture of nitroglycerine according...

Process. Commercial processes manufacturing lalex can he div ided into batch, semibatch, and continuous methods... 

Continuous methods have also been developed for manuf of expls other than NG. As examples may be cited nitration plants for benzene (Refs 5 6a) aromatic hydrocarbons other than benz (Refs 7, 13 16) PE (Refs 17, 19, 21, 21b 22) DEG (Refs 21, 22 28) various org compds (Ref 36) cellulose, starch, sugar, etc (Ref 21) methyl nitrate (Ref 23a), etc. A continuous method for manufg propellants is described in Ref 46. A continuous method for manuf of TNT by the method of Bofors was installed in 1955 at the Fabrica Naval de Explosivos, Azul, Argentina (Ref 34a) Description of Some Continuous Methods for Manufacturing Explosives. 

B1AZZI CONTINUOUS METHOD FOR MANUFACTURING TNT BELGIAN INSTALLATION... 

Continuous Methods for Manufacturing Nitrocellulose. Several methods are known, of which the Dietzsch process developed during WWII in Germany is briefly described here under Combustible and Consumable Cartridge Cases. This method combines vapor-phase and liquid-phase nitration processes. The Japanese used during WWII a continuous liquid-phase method of nitration of paper pulp, which was in the form of a sheet... 

Raczynski Process. A continuous process for manufg NG, invented by Raczynski in 1935 (Ref 1), the distinctive feature of which is exact metering of mixed acid and glycerine by means of automatic mechanical devices (also see under Continuous Methods for Manufacturing Explosives in Vol 3, C501-L to C504-R)... 

---