US2579474A - Apparatus for preparing explosives - Google Patents

Description

. Dec. 25, 1951 F. A. F. CRAWFORD APPARATUS FOR PREPARING EXPLOSIVES 2 SHEETS-SHEET 1 Filed Dec. 6, 1946 3 wvmvkw, FREDERICK flLEXflN ER FERRIER cmwronb 1951 v F. A. F. CRAWFORD 2,579,474

APPARATUS FOR PREPARING EXPLOSIVES I Filec l De0..6, 1946 2 SHEETS-l-IEET 2 FICiTZ FRDERI6K mum DER FfinRmR RAWFOR vture of nitroglycerine and the like.

Patented Dec. 25 1951 APPARATUS FOR PREPARING EXPLOSIV ES Frederick A. F. CrawfonLWest Kilbride, Scotland, assignor to Imperial Chemical Industries Limited, a corporation of Great Britain Application December 6, 1946, Serial No. 714,626 In Great-Britain December 7, 1945 4 Claims. 1

The present invention relates to an improved process and apparatus for the continuous manufacture of explosive liquid nitric esters from rapidly esterifiable liquid polyhydric alcohols and more especially to the continuous manufac- More particularly the invention relates to a new and improved circulatory process for the manufacture of the aforesaid explosive liquid nitric esters, wherein the esterifiable organic liquid compound is continuously nitrated with a nitrating acid medium and the resulting liquid nitric ester is separated from the refuse nitrated acid.

The object of the present invention is to provide a process which can be used with relative safety for the continuous production of liquid explosive nitric esters'which includes the step of quickly and continuously removing by centrifugal separation the liquid. explosive nitric ester from a continuous succession of relatively small quantities of a mixture of said liquid explosive nitric ester and refuse nitrating acid resulting from the interaction of aliquid polyhydric alcohol and nitrating acid.

According to the present invention the process for the continuous manufacture of explosive liquid nitric esters from rapidly esterifiable liquid polyhydric alcohols comprises continuously introducing the alcohol and nitrating acid into a mixing space, subjecting the incipiently reacted mixture to continuous circulation by impelling it at a rate sumcient to maintain turbulence throughout the circulation out of the lower part of said space through a narrow externally cooled tubular conduit external to said space to a horizontally remote locus at which the reaction is complete and back'into the upper part of said space, bleeding oil a portion of the substantially completely reacted mixture at said remote locus, and separating by continuous centrifugal action the liquid explosive nitric ester from the bled ofi portion while the latter is still in emulsion form.

Preferably the resulting continuously separated liquid explosive nitric ester is immediately emulsified with an .aqueous Washing medium.

So long as the liquid explosive nitric ester remains emulsified in the refuse nitrating acid in its passage between the nitrating vessel and the centrifugal separator there is no danger of any detonation arising in the centrifugal separator being carried back through the column of liquid to the nitrator. The proviso according to the present invention that the incipiently reacted mixture is to be impelled at a rate sufficient to maintain turbulence throughout the circulation 1 of the reaction mixture past a horizontally re- ..mote locus makes it possible for the nitrating vessel and the centrifuge to be sufficiently distanced that no explosion debris from either is likely to reach theother.

Apparatus suitable for the process according to the invention, comprises a mixing vessel having a lower portion of larger diameter accommodating a rotary impeller and an upper neck portion. of smaller diameter open at the top accommodating the shaft of the said impeller, inlets for the liquid reagents, an external circulation pipe jacketed over substantially its whole length and leading from the vessel at the level of said impeller to a horizontally remote locus and returning into the neck of said vessel, if desired the impeller shaft may have stirrer blades, a continuous centrifugal separator in the vicinity of said locus at a lower hydrostatic level than said vessel and a branch communication from a portion of said external circulation pipe at said locus entering said centrifugal separator;

said separator having an outlet for the refuse acid and anoutlet for the separated liquid explosive nitric ester leading to re-emulsifying apparatus in which said ester is emulsified in an aqueous washing liquid in close proximity to said separator. The centrifugal separator and the reemulsifying apparatus are preferably shielded by a surrounding baflie structure, and a bafile structure through which the external circulating pipe passes is preferably interposed between the mixing vessel and the remote part of the circulating pipe.

The invention has the advantage that no matter how far distant is the locus from which the stream is bled off to the separator, the whole stream circulating from the mixing vessel to said locus and back again is maintained in emulsion by its turbulent flow. As the distance the emulsion has to travel from said locus to the separator, over which it is not maintained in turbulent flow by the impelling means, may be made very short, it follows that the horizontal distance between the separator and the mixing vessel may be made very considerable without any separation of the emulsion travelling between the two vessels taking place, and hence without the possibility of a detonation in one of the vessels being communicated through the liquid 7 1 is a bleed-off pipe and 6 is a centrifugal separa-.

tor, I is a pipe in which the separated liquid 6X.-

plosive nitric ester delivered through an outflow pipe I5 in water by means of a water jet IS, the pipe I leading to a washing tank not shown in the drawing. 8 is a refuse acid outflow pipe, 9 is an emergency runaway cock, I0 is a concrete lined trench, l I is a concrete explosion bafiie run ning transversely across the trench. I8 is an overflow gutter and I2 is a concrete shielding structure for the centrifugal separator 6.

As best seen inFigs. 2, 3a and 4a are the outer walls of the jackets of the pipes 3 and 4, and I3 and I4 are the inlet pipes respectively for the liquid polyhydric alcohol and for the nitrating acid. I! is a bottom closure for the mixing vessel I which can be destroyed by means'not shown if an emergency should arise for cleaning purposes.

I claim: 1. An apparatus for carrying out the continu- :ous manufacture of explosive liquid nitric esters from rapidly esterifiable liquid polyhydric alcohols comprising in combination a mixing vessel having the lower portion thereof of larger diameter than the upper portion, 'a rotary impeller in said lower portion and substantially occupying the entire space within the same, the shaft of said impeller passing through the said upper portion, two inlets for liquid reagents leading into said upper portion, an external circulation pipe jacketed over substantially its entire length leading from the said lower portion at the level of said impeller to a horizontally remote locus and returning horizontally to the said upper portion for flow of liquid from said larger diameter portion of said mixing vessel to'said smaller diameter portion, and a continuous centrifugal separator having its inlet connected to said chculation pipe by a bleed-off pipe connecting at said remote locus.

2. Apparatus for carrying out the continuous manufacture of explosive liquid nitric esters from rapidly esterifiable liquid polyhydric alcohols comprising in combination a mixing vessel having the lower portion thereof of larger diameter than the upper portion, a rotary impeller in said lower portion and substantially occupying the entire space within the same, two inlets for liquid reagents leading into said upper portion, an external circulation pipe jacketed over substantially its entire length leading from the said lower portion at the level of said impeller to a horizontally remote locus and returning horizontally to the said upper portion for flow of liquid from said larger diameter portion of said mixing vessel to said smaller diameter portion and a continuous centrifugal separator having its inlet connected to said circulation pipe by a bleed-off pipe connecting at said remote locus.

3. Apparatus as set forth in claim 2 wherein said separator has an outlet forrefuse acid and an outlet for the liquid explosive nitric ester, said explosive nitric ester outlet leading to apparatus forre-emulsifying in an aqueous washing liquid in close proximity to said separator.

4. Apparatus as set forth in claim 2 wherein an explosive baflie structure is placed between said mixing space and said remote locus.

FREDERICK A; F. CRAWFORD.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,312,119 Hough Aug. 5, 1919 1,893,447 Schmid Jan. 3, 1933 2,332,527 Pyzel Y Oct. 26, 1943 2,363,834 Crater Nov. 28, 1944 2,436,767 Gerlicher Feb. 24, 1948 FOREIGN PATENTS Number Country Date 38,821 Sweden Apr. 22, 1913

Claims (1)

1. AN APPARATUS FOR CARRYING OUT THE CONTINUOUS MANUFACTURE OF EXPLOSIVE LIQUID NITIRC ESTERS FROM RAPIDLY ESTERIFABLE LIQUID POLYHYDRIC ALCOHOLS CONPRISING IN COMBINATION OF AMIXING VESSEL HAVING THE LOWER PORTION THEREOF OF LARGER DIAMETER THAN THE UPPER PORTION, A ROTARY IMPELLER IN SAID LOWER PORTION AND SUBSTANTIALLY OCCUPYING THE ENTIRE SPACE WITHIN THE SAME, THE SHAFT OF SAID IMPELLER PASSING THROUGH THE SAID UPPER PORTION, TWO INTLETS FOR LIQUID REAGENTS LEADING TION SAID UPPER PORTION, AN EXTERNAL CIRCULATION PIPE JACKETED OVER SUBSTANTIALLY ITS ENTIRE LENGTH LEADING FROM THE SAID LOWER PORTION AT THE LEVEL OF SAID IMPELLER TO A HORIZONTALLY TO THE SAID UPPER AND RETURNING HORIZONTALLY TO THE SAID UPPER PORTION FOR FLOW OF LIQUID FROM SAID LARGER DIAMETER PORTION OF SAID MIXING VESSEL TO SAID SMALLER DIAMETER PORTION, AND A CONTINUOUS CENTRIFUGAL SEPARATOR HAVING ITS INLET CONNECTED TO SAID CIRCULATION PIPE BY A BLEED-OFF PIPE CONNECTING AT SAID REMOTE LOCUS.

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