US1326442A - Cyanamid-oven. - Google Patents

Description

G. E. COX.

CYANAMID OVEN.

APPLICATION FILED JULY 24. ms.

Patented Dec. 30, 1919.

UNITED STATES PATENT OFFICE.

GEORGE E. COX, N IAGABAIAIJLS, NEW YORK, ASEIGNOR T0 AMERICAN CYANAMID COMPANY, OF NEW YORK, N. Y., A CORPORATION OF MAINE.

GYANAMID-OVEN.

To all whom it may concern:

Be it known that I, Gnonun E. Cox, a citizen of the United States residing at Niagara. Falls, in the county of- Nia are and State of New York, have invents certain new and'useful Improvements in Cyanamid- Ovens;and I do hereby declare the followingrto be a. full, clear, and exact descri tion of the invention, such as will enab e others skilled in the art to which it appertains to make and use the same. This invention relates to cyanalnid ovens and has for its object to improve the linings of the'same in a manner less costly than has been heretofore proposed.

With this object in view the invention consists in the novel parts and combinations of parts all as will .bemore fully hereinafter described and particularly pointed out in the claims.

Referring to the accompanying drawings forming a art of this specification in which like numerals designate like parts in all the ,views:

Figu oven lined according to this invention;

Fig. 2 is. a detail view taken on the line 2-2 of Fig. 1;

Fig. 3 is a view similar to Fig. 1 showing 8. =Sr(1JmeWh8.t modified form of the invention; an a 'Fig. 4 is a detail view taken on the line H of Fig. 3.

In order that the recise invention may be the more clearly un erstood, it is said:

[In the manufacture ofcyanamid it has been heretofore the practice to take a finely ground carbid and insert the same into a container. This container filled with its charge of carbid is placed in. an oven lined with suitable refractory and insulated material- A suitable electric resistor is inserted axially through the container in a space provided therefor.

The lid is placed on the oven, nitrogen admitted and the current turned on to the resistor. At a temperature upward of 800-1000 G. the hot carbid adjacent to the resistortakes' up nitrogen and is convented into cyanamid. This reaction progreases outwardly throughout the massuntil the whole more or less completely converted to 'eyanamid, when the said mass is p. p p cool. The container with its content t .Wof c H left" thenremoved anll the oven re 1 is a sectional view of a cyanamid specification of Letters Patent. Patented Dec. 30, 1919.

llpplication filed July 21, 1919. Serial No. 312,183.

and expense, and it becomes dented and bat- B0 tered through handling which makes it ditliculs to distribute its content of solid cyanam1 In order to obviate this difficulty and especially because of the excessive cost of metal containers, a substitute for the same was found, consisting .in a paper sleeve which was inserted into the oven and then filled with carbid, after which nitrificationwas started in the usual manner. This paper sleeve must be manufactured from stout paper and of definite dimensions and even with the greatest care it, would frecpliently tear or spit from the pressure of t e contained powdered carbid. An annular space had to be left between the paper container and the oven for inserting the proper equipment for placing the paper and holding it in place during the fillin with carbid as well asto assist in the distribution of the nitrogen. This annular space re- A containers it was found that the ordinary cyanamid oven, cylindrical in form and provided with the usual refractory lining, could be lined with a single sheet of paper or preferably corrugated strawboard; the usual paper cylinder; 'forformin a space for the resistor could be inserte and then the whole oven could be filled with carbid. all as will be clear from the prior U. S. Patent #1315678, dated Sept. 9, 1919, to W. II. Middleton, assigned to the American Cyanamid Company, and entitled Process of manufacturin cyanamid. In this manner the strawboar or paper could he merely laid around the inside wall of the oven with'a suitable lap without special formi Operating according to this latter proc fiure a given oven would hold say 35 per cent. more carbid than where the said prior paper sleeve was used and nearly 50 per cent. more than where the a metal container was used, and this without any change whatever in the structure of the that a heavy cox-rug oven itself. In such cases the nitrogen was led through a. hole at the side and bottom of the oven which was covered with broken stri s of corrufited strawboards extending tot e center to and also tothe top of the com ated lining and in this way nitrogen was istributed through the broken up strawboard both to the center and to the to of the oven.

This latter method gave very excellent results, because it produced a high fixation and a large capacity per oven, but it is necesspgg ated strawboardbe u for in case of using-a light lain per where the oven walls are smoot i it w1'l not allow for a free passage of nitrogen aroun the carbid, and'in the case .of an' uneven projection from the oven walls, with this lighter paper there is e. perienced a com siderable loss in the tearing of the paper. Also, one cannot rely on an absolutely even distribution of nitrogen 'in and around the mass in this said procedure, for while the fixation is high it is not as uniform as might be desired in all cases.

In this invention, on the other hand, I have found it desirable to line the inside wall of the oven with a piece of wire screening, or netting, and place the plain paper against this said wire screenin or netting. I'also insert the usual paper cy inder in the center for forming a s iace for the resistor and I fill up the whoie oven with oarbid. In place of using a wire screen, the bricks of the oven lining itself may be molded or out with projections, the span from ti to tip of which are not so great as the pa 1' lining to tear. Plain paper is then p aoed inside of the oven against the brick work with a suitable la and the operations carried on as describe above.

In this manner I am able to secure a very uniform flow of nitrogen gas around and about the carbid which gives-in practice an exceedingly uniform fixation of the carbid for the formation of cyanamid. It also gives as high a fixation as is obtained by the previous methods. This method also has the advantage 'of allowing me to usea cheaper form of lining than is' possible by the previous process and with less trouble and diiliculty in handlin the same. I re fer to have the oven s ightly tapere as shown, it being somewhat largcr in diameter at the top than at the bottom, because when the carbid fixes the nitrogen with the formation of cyanan'lid, the latter shrinks away from the oven lining somewhat, and by the use of a tapered oven the charge may be more easily withdrawn. "I v 7 Referring to the accompanying drawings, 1 indicates any suitable outer shell, 2 any suitable refractory lining, preferably tapered as shown, 3 a cover having a refractory lining 4, and the depending rim 5, dipping Y near the bottom I provide the nitrogen in nitroge to slowinto a sand seal 6, held by the annular member 7 as shown.

On the inside surface of the refractory lining "Z, I preferably la wire cloth, or a and msi e the netting 8 1' wire netting lay-prefera ly smooth paper sheets 9. the center of the oven place the paper or other combustible tube 10 for the accommoside let 12. Between the inlet 12 and the tube 11 I ma place a tube of crumpled up, or corrugated paper 13 as shown, in or er to lead dation of the resistor 11, and at the 13, I may lay wire cloth 14 as shown in F1g. 1, or it may be omitted as shown-1n Fig. 3, if the tube 13 is made sufiiciently strong to keep open a passage for. the nitrogen.

'rtion' 15 of the paper 9 may also extend above the wire cloth 14 as shown in Fig. 1. The modifiedconstruction illustrated in Figs. 3 and 4'is substantially the same as except the inside surface of the refractory lining is roughened as indicated at 18. The prowetions 19 are suitably molded in the ricks, but may be otherwise roduced, are spaced sufficiently c use to each oth prevent the tearing of the paper lining 20. 21 represents books that areplaced in the carbid charge 22 to fa 'ilitate the with-P. drau'al of the formed cyanamidfrom the the resistor, and above this tube oven.

It will thus be seen that I have discovered that the space left'by the meshes of wire cloth, or a wire screen, will not be filled up after the combustible paper stroyed, and that it will be suliieient to furnish a passage for the feeding of the nitro n in the process. In other words, it will now be clear that I have dismvered, it is not necessary to even 0 to the expense an trouble that are inc dent to the highl ellicient process disclosed in the said Mid leton application above mentioned; for I may even avoid a corrugated lining for theoven, and

employ plain paper, provided there are present supporting pro ections for said paper spaced so close that it will not tear.

Of course, u on nitrification the paper around the insi e of the oven chars and the ingot of cyanamid shrinks away from the walls and screening sufficiently, so that if a roper taper is given to the oven lining 2 it is a simple matter to withdraw the in ot. A crane picks up the ingot of cyanamid attaching hooks to the rings the iron rods 21, and

oven.

A great advantage in this improved process lies in the fact that a very chea grade of plain paper 9 can be used. T e wire screening 8 may be used over and over again and when the brick in the walls of the oven lmmg are molded or cut in grooves 18 on the ends of carries itout of the lining 9 is deas by no appreciable replacements am -necessary. Also, a perfectly-uniform passage of nitrogen is thus provided inand around the mass 22, and there is combined with the previous advantages claimed for the full oven, a better reflection ofhe'at to the-mass from the lining 2, resulting in more perfect fixation 'at the outside of the ingot 22. As a result the last mentioned previous. process. It is stantially as evident that thoseskilledin the art can vary. this procedure without essentially changing its principle-and 'I, therefore, do not wish to be. restricted to the above disclosure, except as may be required bythe claims.

What I claim is 1. In a cyanam'ui oven rovided with a re fractory lining, the com ination of a combustible, substantially smooth, paper lining and a plurality of supporting means-separated by interstices, located between said refractory linin and said paper lining, subescl'ibed.

2. In a cyanamid oven provided with a refractory lining and a resistor the combination of a combustible tube surrounding'said resistor; a plurality of supporting non-combustible surfaces separated y interstices and in closeproximity to said refractory lining; a substantially smooth combustible sheet material resting against said supporting surfaces; means to introduce nitrogen into said oven; and means to convey the introduced nitrogen to said tube, substantially as described.

3. In acyanarnid oven, having a tapered inside refractory lining; non-combustible supporting surfaces separated by interstices associated with said lining; and a paper lining resting on said surfaces, substantially as described.

4. The process of producing commercial cyanamid, which consists in providing a cyanamid oven with an upwardly flaring refractory lining; associating with said lining non-combustible supporting surfaces separated by nitrogen conveying'spaces; resting on said surfaces acombustible lining; providin spaces for an igniting resistor and for t e admission of nitrogen to said resistor; substantially filling the interior of said last named lining with calcium cal-bid except for said last named spaces; implanting a lifting means in the carbid charge to facilitate the removal of the ingot from the tapering oven; admitting nitrogen to said carbid; and igniting the charge, substantially as described.

In testimony whereof I affix my signature, in presence of two witnesses.

GEORGE E. 00X

Witnesses 2 MARGARET Fmi'rr, Louisa WILLS.

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