Manufacture nitroglycerine

Worldwide Technology Assessment of Nitroglycerin Manufacture, 4 Vols., (Proprietary Information) Mason and Hanger, Silas Mason, 1985. 

Nitroglycerine can detonate in pipes of diameter down to approximately 5 mm. In nitroglycerine manufacture there is, therefore, an inherent danger of transmission of detonation from one manufacturing house to another in the series. Even a pipe which has been emptied of nitroglycerine can have on it a skin of the product sufficient to enable transmission of detonation from one end of the pipe to the other. To prevent the spread of an accident it is now usual to transfer nitroglycerine as a non-explosive emulsion in an excess of water. Such emulsion transfer is particularly convenient with the NAB process, as the emulsion transfer lines can also carry out the necessary process of washing and purification. 

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. 

Spent acid from nitroglycerine manufacture is not used to prepare nitrating mixture since it contains too much organic matter with which it is undesirable to contaminate the nitration. Decomposition of these substances during nitration could make the process difficult to control and might lead to accidents. 

As already mentioned above, the purity of the glycerine exerts a fundamental influence on the efficiency and safety of nitroglycerine manufacture. The so-called dynamite glycerine, a very pure water-free product, distilled several times under reduced pressure is produced for manufacture of nitroglycerine. 

As compared with the Nobel process for nitroglycerine manufacture certain innovations were introduced in this method, namely ... 

According to British reports from World War I [33], during nitroglycerine manufacture the nitrogen content of the nitric acid (including that recovered by denitration) was consumed as follows ... 

Fig. 36. Flow-sheet of the combined method of nitroglycerine manufacture.

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. 38. Nitrator for continuous nitroglycerine manufacture according to Schmid (original pattern).

A flow-sheet for nitroglycerine manufacture by the continuous Schmid method is shown in Fig. 43. 

A diagram of a plant for nitroglycerine manufacture by the continuous Ra-czynski process, including the separating and washing units, is outlined in Fig. 46. 

Fig. 47. Continuous nitrator for Biazzi nitroglycerine manufacture (according to Kuhn, W. J. Taylor, Groggins [4]).

Fig. 48. Flow-sheet for nitroglycerine manufacture according to Biazzi (Stettbacher [45]).

Fig. 50. Nitroglycerine manufacture — a general view of the nitrator, separator and washing equipment in a remote controlled Biazzi continuous plant (Ardeer Factory, Nobel Division, Imperial Chemical Industries Ltd., Great Britain, photograph of Vista of Glasgow, Glasgow, C 3).

The earliest plants for nitroglycerine manufacture were installed in buildings of very light construction made of planks and sui rounded by a high mound of earth (Fig. 61). 

The Mikolajczak process is usually safer than nitroglycerine manufacture. It is necessary, however, to maintain a low nitrating temperature and to use acid free from oxides of nitrogen which favour oxidation reactions. Local overheating should be carefully avoided, because dilute acid is specially prone to produce oxidation processes. 

The intention of this paper is to describe some of the more unusual safety design requirements. In order to better understand these requirements, a brief history of the type of process utilized in the manufacture of BALL POWDER is presented. Next those safety advantages internal to the process are summarized. Specific requirements in the areas of grain formation, nitroglycerine manufacture and transfer, and continuous drying are discussed. Finally, the basic fire protection system utilized is described. 

Technological principles of nitroglycerine manufacture Mixed acid composition and yield of the process Equipment for production of nitroglycerine Stirring... 

Batch methods of nitroglycerine manufacture Old process Nobel process... 

Safety problems have already been tackled in the general description of processes. Biasutti [15) described over 20 accidents in nitroglycerine manufacture. 

Mixed acids for nitroglycerine manufacture should be as free as possible from suspended matter, such as sulphates of iron or lead, as these may delay the separation. 

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