US1256935A - Process of producing nitrogen compounds of metals. - Google Patents

Description

PROCESS 0F PRODU APPLI M. SEM.

ROGEN COMPOUNDS 0F METALS.

ILED Nov.2|. 1916.

Patented Feb. 19, 1918.

CING

cATl N l' UNITED STATES A PATENT oEELIoE,

HATHIAS SEM, 0F GHRISTIANIA, NORWAY, A'SSIGNOB. T0 DET NORSKE AKTIESELSKAB FOB ELEKTBOKEMISK INDSTRI, NOBSK INDUSTRI-HYPOTEKBANK, OF CHRIS- '.rnmm, NORWAY.

:PROCESS 0F PBOD'UCING NITROGEN COMPOUNDS OF METALS.

Specification ot Letters Patent. 4Patented Feb. 19, 1918.

Application met! November 21, 1916. Serial No. 132,597.

To all 'whe-mit may concern.'

Be it known that I, MATHIAs SEM, a subject ofthe King of Norway, residing at Christiania, Norway, have in-vented certain new and useful Improvements in the Prooesses of Producing Nitrogen Compounds of Metals; and" I do hereby declare the following to be a full, clear, and exact descriptionof the invention, such as will enable .others skilled in the art to which it appertains to make and use the same.

This invention relates to the manufacture of nitrogen compounds by .the action of -slon or cloud of pulveruleunt'carbld in a cur- 4rent of gaseous nitrogen.,

' The various known processes of contmuously producing cyanamids in electrical furnaces have met with many difficulties mainly on account of the specific consistency lof the Imaterial during the reaction which involves that the material burns on to the walls orl other parts of the furnace and makes it diiicult to convey the material through the furnace. To avoid "these diiiiculties it has been proposed by Tofani (German Patent No. 246077) to produce a shower of carbid dust inra towershaped Yfurnace and to cause Athe nitrogen gas to ascend through this Y Y, shower in counter current to the carbid dust.

By means of producing variations in the vellocity of the gas current he intends to control the timeV of descent of the powder through the furnace.

It isnot possible howeverfin this manner to bring about a complete nitriication of the lcarbid during the short time which it takes the carbid to descend. For this' purpose the' distribution of the powder in the gas is much too uneven and not sufficiently fine.

The present invention has for its object al process of continuously producing cyanamid and other nitrogen compounds, in which the nitrificatio'n to take place under conditions 'where the exothermic, character of the procpartly to bring about a very rapid nitriicatlon.

The process being exothermic and thus taking place under evolution of heat it may be compared with combustion processes. Under certain conditions a combustion process may evolve a very high temperature and then frequently displays aiiame, that is a confined zone is produced within which the temperature is higher than in the rear as well as in the front strata. This zone secures an even supply of combustible and oxygen, an automatic maintenance of the combustion and a most complete combustion.

In a nitrilication process it is also possible to provide conditions allowing of producing suclla zone, a sort of reaction fiame whereby e continuity and completion is secured. In contradiction to ordinary combustion the nitrification is a process in which a large reduction of volume takes place, the nitrogen being absorbed by the carbid. When carbid in the form most suitable for obtaining a powerful reaction-viz. the atomized state .0r in the form of a dust-is brought to ordinary combustion process, but as the gas is absorbed in the solid substance by the reaction, the evolution of heat will be distributed over a so much smaller volume, and to said difficulties yare avoided by causing the an increasing extent in. accordance with the proceedin of the nitrilication process that at a certain distance from the point where the mixture of carbid dust and gas entesl 'furnace chamber there will be formed and automatically maintained a zone representing the maximumJtemperature of the furnace. `T his zone will have a higher temperature than that which is necessary to initiate the nitriication and it is only necessary to provide certain controlling arrangements in order to prevent the lradiation of heat to the brick-work or to the front strata in the furnace from becoming greaterthan the evolved heat (whereby the flame would be extinguished.) From practical reasons oneiwill however make such arrangementsv forl instance byproviding an electric arc which could be easily ignited. or which could be maintained constantly burning that an eX- tinction of the fiame is prevented..I

According to the present invention the nitrification is effected in thel manner that -carbid in the form of dust is blown into a furnace chamber together with the nitrogen or part of. the nitrogen, which is to be com'- bined with the carbid. The nitrogen as well as the carbid should be preheated for instance to about 700-800- C. and before the process is started the brickwork of thefurnace should preferably be brought up to the',

. same temperature as that which by experience has been found to--be mostv suitable for the process. This may for instance beeffected b v means of one or more electric furnaces. By means of altering the quantity of carbid dust supplied', the degree of preheating and the quantity of nitrogen introduced into the furnace it is in ones )ower to regue latev the temperature of .the urnace as desired. .As mentioned the nitrogen gas may be wholly or only partly introduced into the furnace together with the carbid (for instance through an atomizer nozzle.) That portion ofthe nitrogen which may as an al- .tei-native be mtroducedseparately may however be`introduced with a somuch higher temperature, that losses of heat by radiation etc., is compensated for. Highly heated nit-regen gas may also be used to start the working of the furnace and the ignition of the same (incase of the reactionv flame being extinguished), 1

The preheating of the nitrogen gas may be effected by means Vof anI arrangement of l channels or gas passages in the parts of the furnacewhere a reduction of the furnace,

temperature is desirable.

The process A'may be carried out in a shaft furnace of suitable shape and'dimensions so that the products which are in the form of dust are allowed to fall freely through the various zones ofthe furnace.

An apparatus, which may be employed for l carrying the process into effect is diagrammatically illustrated in the accompanying 'drawing which shows a lvertical sectional view of the apparatus.. e In the drawing 1 designates the shaft of the furnace, 2 a pipe for the supply of carbid and nitrogen, 3 electrodes, 4 a gas outlet, and 5 the funnel-shaped bottom of the furnace.

6 and 8 designates an injector device, and 7 a chamber into which carbid is introduced by means of a feeding device 9.

By carrying the nitrilication into eii'ect the carbid dust'may' be supplied with the usual 'of introducing a carbid in the form of dust vtogether with nitrogen into a. reaction chamber, and heating the reaction components so introduced Ato the reaction temperature by meansv of the heat evolved by the reaction .between carbid and nitrogen .previously introduced a reaction zone being hereby produced which effects the ignition of further quantities 'of reaction components introduced.

3. The process of producing nitrogen compounds' comprising the step of atomizing carbid by means of nitrogen gas, blowing the atomized carbid into a reaction lcompartment by means of gaseous nltrogen, the said lnitrogen and carbid being blown into the said reaction chamber inl a reaction zone in which a sufficiently high temperature is vmaintained by the reaction between carbid and nitrogen. 1

` 4. The process of producing nitrogen compounds comprising the step of blowing' carbid together with heated nitrogen gas into a reaction zone in which a hightem- 4perature is maintained by means of the heat evolvedby the reaction between carbid and nitrogen.

5. The process of producing nitrogen compounds of metalscomprising the step of introducing a carbid -in the form Aof dust together with nitrogen into a reaction chamber, and heating the reaction components so introduced to `the reaction temperature by.

means of the heat evolved by the reaction between carbid and nitrogen previously introduced, theignition of the reaction components being effected by lmeans 02E a source of heat provided for this purpose.

. 6. The process of producing nitrogen compounds of metals comprising the step ofintroducin a carbid in the form of dust toether w1th nitrogeninto a reaction chamer, and heating the reaction'components so introduced to the reaction temperature by means of the heat evolved by the reaction In testimony that I claim the foregoing between carbid and nitrogen previously inas my invention, I have signed my name in trod-need the ignition of the, reaction compresence of two subscribn witnesses.

ponents being efected by means of a source MA HIAS SEM. 5 of heat provided for this purpose, the said Witnesses:

source o heat comprising an electric are ar- C. NORMAN,

' ranged within the reaction compartment. C. F. HANSEN.-

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