US1037061A - Process of manufacturing nitrogen compounds. - Google Patents

Description

A. SCHWEITZER & P. HAUPF. PROCESS OF MANUFACTURING NITROGEN COMPOUNDS.

APPLICATION FILED MARJZ, 1912.

1,037,061 Patented Aug. 27, 1912.

- Fig.1. T

UNITED STATES PATENT OFFICE.

ALEXANDER sonwnrrznn AND rnrrz HAUFF, or sTU'rTeARr, GERMANY.

PROCESS OF MANUFACTURING- NI TROGEN .COMPOUNDS.

s ecification of Letters Patent.

Patented Aug. 27, 1912.

Application filed March 12, 1912. Serial No. 683,198.

To all whom it may concern:

Be it known that We, ALEXANDER SCHWEITZER and FRITZ HAUFF, citizens of the German. Empire; residing at Stuttgart, Germany, have invented-certain new and useful Improvements in Processes of Manufacturing Nitrogen Compounds, of which the following is a specification.

Our invention relates to the manufacture .of nitrogen compounds by electrically heat-- ing quantities of such substances as compounds of the alkalis or alkali earths in the presence of carbon and in an atmosphere of nitrogen.

Many processes of the above kind for the fixation of nitrogen, utilizing the hydrates, oxids, or carbonates of the alkali or alkali earth metals are known and patented, but when carried out on an industrial scale these previous processes have been attended with great drawbacks. It has been found ditficult and costly to attain the high temperature required for the reaction and the retorts in which the reaction is carried out are seriously attacked owing to thebasic character of the charge.

The object of the present invention is to overcome the drawbacks hitherto experienced and to secure a continuous operation.

The invention consists substantially in that the reaction charge, 2'. e. a mixture containing alkali or alkali earth metal compounds and carbon, is continuously guided through an electrically heated zone in a form allowing conductance of electric current and permeable to gas when heated, in a direction opposing a current of nitrogen containing gas, the charge constituting'an v number of the lnsulating partitions 0 being electrical resistance in the heating zone.

To bring the charge to a form in which it can be used as a resistance for conducting the electric current'the alkali or earth alkali compounds along with fluxes when required and coal are finely powdered and mixed and subjected t 0 a coking process, preferably after the mixture has been formed into briquets. The mixture is thus in the form of lumpsand' incomparison with the uncoked mixture possesses increased electrical conductivity and a porous gas permeable structure which offers a large surface very desirable in the treatment in a current of gas, which porous condition is not lost when the briquets are subjected to the heat. Utilizing for instance a mixture containing equal proportions of barium carbonate and coal there is obtained a coke which is ext-remely'suitable for forming the nitrogen compounds in an electric heating zone, and of which the composition corresponds with a mixture of about of barium carbonate and 40% of coke.

The continuous heating of any desired amount of the material formed in'the above described manner, forthe purpose of fixation of nitrogen, may be preferably carried out in a cupola furnace of the type illus trated in the accompanying drawings. ,At about half the height of'the shaft e of the furnace electrodes 6 pass transversely through the walls a of the shaft and project into the charge space. To insure that substantially only that part of the charge lying between the electrodes participates in the conduction of the current, the shaft is divided by partitions terial arranged both above and below the electrodes and extending close to the zone between the same. The electrodes may be of carbon, graphite or the like but are preferably of chilled metal. The removal of the material takes place on the hearth of the furnace and fresh material is fed in to a corresponding extent at the top. The nitrogen or gas containing nitrogen is blown in at the hearth throughpipes d and passes over the charge which is falling down through the shaft. The waste gases leave the furnace at f.

The furnace illustrated in the drawing is provided with two electrodes 6 but there is no reason why a larger number should not be employed. With polyphase currents for example three electrodes may be used, the

then preferably such that there is one partition in the shaft at right angles to the main direction of each current flowing through the charge.

What we claim is:

1. The process of manufacturing nitrogen compounds consisting in continually guiding a mixture containing carbon and a compound of an alkali or alkali earth metal through" an electrically heated zone, said mixture being permeable to gas and possessing electrical conductivity, and itself serving as a resistance for the generation of heat,

preserving the permeability of the mixture during the heating operation, and passing a current of nitrogen containing gas through the material while in the heated zone.

2. The process of manufacturing nitrogen compounds consisting in continually guiding a mixture containing carbon and an-unfused compound of an alkali or alkali earth metal through an electrically heated zone,

said mixture possessing electrical conductivity and itself serving as a resistance for the generation of heat, controlling such heat so as to keep the temperature below the fusing point, and passing a current of nitrogen containing gas through the material while in such electrically heated zone. i

3. The process of manufacturing nitrogen compounds which consists in forming a porous mixture of carbon and a compound of an alkali or alkali earth metal, coking such mixture without fusion, guiding such coked mixture through an electrically heated zone, the mixture itself serving as an-electrical conductor and resistance for the generation of heat, controlling such heat to prevent fusion, thereby preserving the permeability of thematerial, and passing a current of nitrogen containing gas through the mixture.

4. Process of manufacturing, nitrogen compounds consisting in continually guiding a coked mixture containing alkali or alkali earth metal compounds andcarbon through an electrically heated zone guiding a current of nitrogen containing gas through said mixture in said electrically heated zone and using said mixture as an electrical re sistance in said heating zone and preventing the heating current from materially affect ing' the bulk of mixture outside the heating zone.

5. Process of manufacturing nitrogen compounds consisting in continually guiding a mixture containing alkali or alkali earth metal compounds and carbon through a shaft provided with electrodes projecting thereinto, using the mixture within the shaft between the electrodes as heating resistance in an electric current limiting the active zone of current transmission to that portion of the mixture lying substantially in the plane of the electrodes and transmitting a current of nitrogen containing gas through said shaft .and mixture therein positioned between the electrodes.

6. Process of manufacturing nitrogen compounds consisting in continually guiding a coked mixture. containing alkali or alkali earth metal compounds and carbon through a shaft provided with electrodes projecting thereinto, using the mixture within the shaft between the electrodes as heating resistance in an electric current limiting the active zone of current transmission to that portion of the mixture lying substantially in" the plane of the electrodes and transmitting a current of nitrogen containing gas through said shaft and mixture therein in a direction opposite the direction of movement of the mixture through the shaft.

In testimony whereof, we aflix our signatures in presence of two witnesses.

MLEXANDER SQHWEITZER. FRITZ HAUFF.

Witnesses:

Farm KLAIBER, PAULINE KLAIBER.

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