US1686799A

US1686799A - Apparatus for the synthesis of ammonia

Info

Publication number: US1686799A
Application number: US524087A
Authority: US
Inventors: Claude Georges
Original assignee: LAZOTE Inc
Current assignee: LAZOTE Inc
Priority date: 1921-12-22
Filing date: 1921-12-22
Publication date: 1928-10-09
Anticipated expiration: 1945-10-09

Description

Oct. 9, 1928.

Original Filed Dec. 22. 1921 2 Sheets-Sheet INVENToR. @Zw Q v3 ATTORNEY` G. CLAUDE APPARATUS FOR THE SYNTHESIS 0F AMMONIA Original Filed Dec. 22. 1921 I 2 Sheets-Sheet 2l lNVENTOR.

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Patented Octl 9, 1928.

UNITED STATES A ,1,686,799 PATENT OFFICE.

GEORGES CLAUDE, OF PARIS, FRANCE, ASSIGNOR, BY MESNE ASSIGNMENTS, T0 LAZOTE INC., A CORPORATION 0F DELAWARE.

APPARATUS FOR THE SYNTHESIS OF AMMONIA.

Application led December 22, 1921, Serial No. 524,087. Renewed December 17, 1926.

- This invention relates to apparatus for use in the-synthetic production of ammonia.

Inthe synthesis of ammonia, particularly with processes involving the use of hyperpressures, the enormous working activity of the catalyzing material brings about a relat-ively rapid deterioration of this material, especially if, owing to fortuitous circumstances, the purity of the gas leaves anything to be desired or if, in consequence of faulty regulation or faulty internal arrangements, the internal temperature becomes too high.

It is, therefore, of the highest importance to be able with great vfacility to renew the catalyzing material after deterioration of the same. In this connection the extremely reduced dimensions of the reaction tubes for a given output consequent upon the extreme reduction of the volume of the gases and the enormous activity ofthe formation of ammonia, already assist in obtaining this result, but in a manner which is still inadequate.

The present invention contemplates the provision of means which overcome the dificulties hitherto experienced in the replacement of the catalyzing material and which enable this replacement to be carried out quickly and with ease. The particular devices adapted for obtaining the desired results in accordance with this invention are especially applicable to the process which has been described in the c'o-pending patent application of Georges Claude, Serial No.

, 516.045 filed November 18, 1921.

The process described in the above mentioned application takes into account the necessity of practically suppressing the elimination of the heat of reaction through the walls of the pressuresupporting tube, with a view to avoiding explosions through excessive expansion of their internal layers. The characteristic feature of this process consists infact in carrying away a quantity of heat equal to the heat of the reaction in the issuing gases and in abandoning the practice which consisted in bringing the entering gases up to the temperature of reaction at the expense of the heat of the gases which have leftthe catalyzing material. The process according to the patent applications mentioned above consists, therefore, in introducing the gases into the enclosure where the reaction takes place Without having heated them, or but little, Vand in causing them to circulate along an inner tube containing the catalyzing materialA and affording at each point a thermal conductivity such that at the polnt in question the quantity of heat removed from the gases in the inner tube is as exactly as possible equal to that which is produced at this same point by the reaction.

According to the present invention in an apparatus for the synthetic production of ammonia the member constituting the closure of the outer pressure supporting tube carries a conduit which constitutes the exit tube for the gases after reaction, the said conduit being continued beyond said member so as to project into thev nteriorof the pressure supporting tube and carrying on its extended portion the inner tube containing the catalyzing material, With this construction of apparatus the closure member and the inner tube may be easily and quickly removed for effecting the renewal of the catalyzing materiaL In order that the invention may be clearly understood and readily carried into eect the same will now be more fully described with reference to the accompanying drawings in which:

Figure 1 shows in section one form of the improved -apparatus according to the present invention.

Figures 2 and 3 show details of the arrangement in which the closure-member or head is provided with an interrupted screwthread.

In Figure 1 the -pressure-supporting tube H is made of a special metal adapted to resist the action of the gases present, for example of steel containing a high percentage of nickel, such as one of the steels commercially known as A T G or B T G; this tube is insulated externally against the conduction of heat as far as the vicinity of its head D; which is screwed'to the inside of the tube lI-I with an hermetic joint F of the smallest diameter possible so as to. call into play the minimum amount of effort both for closing and for resistance to pressure.

The catalyzing material C is placed in an inner tube T having vanl external heat insulating coating E of decreasing thickness, and the reacting gases which enter through the orice A, which may be located upon the head D or laterally upon the tube H, circulate in the annular space B around the heat insulated tube T-E. The tube T is conhead D to which it is attached and, in order thereupon to replace the catalyzing material, it suffices to remove the plug R.

It Will be seen that this replacing operation is effected easily and Without having to interfere with the external tube H,l which is by far the heaviest part of the apparatus and which may remain permanently in position, together with its elect-ric heating circuits S, in its insulated receptacle, .and can thus be maintained Without difficulty at the reaction temperature.

To facilitate the dis-assembly, the end of the tube H is provided, for example, With tWo small Hat parts J which fit into a recess made in a very thick lxed metal plate K. This metal plate thus plays the part of a counter-k spanner When acting with a Spanner upon the head D. v v

The invention includes, furthermore, the facilitation of the renewal of the catalyzing material to the point of rendering such renevvals almost as simple asthe replacing of a projectile in a gun of large calibre.

In this connection it will be remarked that one of the consequences of the method of circulation of the gases hereinbefore referred to is that the temperature of the pressure-supporting tube H decreases progressively along its length, from the end Where the hot gases penetrate into the catalyzing material and Where this temperature is equal to the reaction temperature up to the other end which carries the head D Where this temperature but slightly exceeds the surrounding temperature. Were the head also at a temperature only slightly raised then the conditions as re` gards tightness of the joint F, vand of nongripping of the screw threads in case of frequent dismountings, could be satisfactorily complied with by maintaining good lubrication of the srcew threads. In order to obtain this result it suiiices to arrange as far as possible for the intimate contact with the head of the cold or slightly heated entering gases and to prevent as far as possible contact With the f issuing hot gases. With this object the gases may be made to pass out through a central tube L separated from the head by an asbestos lining M and hermetically sealed by means of a stuffing box M packed with asbestos or by means of a countersunk joint.

The cold gases on the contrary enter in direct contact with the metal, through the oriice A and the annular conduit O Which distributes them symmetrically in such manner as to prevent any inequalities of temperature which Would deleteriously affect the tightness of the joint. The tube L through which the gases issue must be made of metal which is capable of supporting their high temperature. The connection With the tube or steel coil for conducting these gases to the ammonia liquelier is effected by means of a connection N immersed -in Water. The head D may be made of a metal Which fits as Well as possible from the point of viewof gripping of the screw threads, the metal of special type of which the pressure-supporting tube is formed; it may, for example, be made of mild or semi-hard steel in the case Where the special steels mentioned above are used for the tube H.

In order to quickly replace the catalyzing material, it Would hardly be practical, after vhaving unscrevved the connected parts T D, to remove the used up material, refill the tube T with fresh non-formed material (i.e.notre duced by hydrogen), again screw up the connected parts T D in the tube H and 4then form the catalyzing material. The present invention provides that, after exhaustion of the catalyzing material, the connected parts T D are replaced by another identical' part already formed in another supplementary external tube by means of hydrogen or preferably by the small hyper-compressed gaseous residue still containing hydrogen issuing from the last catalyzer tube of the plant dur-- ing normal Working.

In this latter case the ammoniacal gases produced may be sent on issuing from this supplementary tube into a sulphuric acid absorber and the final residue can be returned tothe hydrogen-making plant. As the output of gas in this supplementary tube is very low, and as the effect of the internal heat insulating lining E is less than that under conditions of normal output, it may happen that when the reduction is very advanced the tube rises in temperature despite all the heating circuits being cut oli'. It Will suffice to reduce the pressure of the gaseous residue feeding this tube by means of a regulating cock in order to successfully control this tendency.

Under the conditions thus depicted even the unscrevving of the head D becomes a lengthy operation in consequence of the compulsory length ofthe screwed portion, espe- .cially if the operation has to be simultanethat, on forcing in the tube T so that the head D goes home, a rotation of one fourth or one Sixth of a revolution isfsuticient to effect engagement of the male and femalethreads,

the rotation being effected for example byA the aid of a handle controlling through a tangent screw a toothed crown made in the head D; in this way'there can be crushed a veryv A and mounted in bearings X1, X2, X? and X4 on the plate K. These two screws V are controlled, for example, byahandle P through gearing P which permits of a considerable reduction of the effort necessary for crushing the packing ring at F and for obtaining the tightness.. More simply, by means of a handle a toothed lwheel mounted upon the axis of one of the twoscrews and engagng with a second similar toothed wheel mounted upon the axis of the other screw may be caused to rotate direct. These same figures show that the head D and the tube H are provided respectively with male and female interrupted screw threads.

lVhen the head is in place it suffices to screw lthe gas inlet and outlet tubes thereto by means of the connections A. and N, the latter being then immersed in cold water as has been explained.

Various changes may be made in the details of arrangements of the parts as hereinbefore described without departing from the invention or sacrificing any of the advantages thereof.

I claim:

l. An apparatus for the synthetic production of ammonia in which a member constituting a closure of the outer pressure supporting tube carries a conduit for the gases, the said conduit being continued beyond said member so as to proj ectstraightforward into the interior of the pressure-supporting tube and carrying on its extended portion an inner tube containing the catalyzing material.

2. An apparatus for the synthetic production of ammonia in which a member constituting a closure of the outer pressure-supporting tube carries a conduit for the gases, the said conduit being continued beyond said member so as to project straight-forward into the interior of the pressure-supporting tube and carrying on its extended portion an inner tube containing the catalyzing material, and means whereby the gases that are to undergo reaction are admitted into the space between the outer pressure-supporting tube and the inner tube at that end of the apparatus where the closure member is located.

3. An apparatus for the synthetic production of ammonia in which a member constituting a closure of the outer pressure-supporting tube carries a conduit thermally insulated therefrom, which conduit constitutes the exit tube for the gases after reaction, said conduit being continued beyond said member so as to project straight-forward into the interior of the:pressure-supporting tube and 'the gases after reaction,

carrying on its extended portion an inner tube containing the catalyzing material, and means whereby the gases that are to undergo reaction are admitted into the space between the outer pressure-supporting tube and the inner tube at that end of the apparatus where the said closuremember is located.

4. An apparatus for the synthetic production of ammonia in which the member constituting the closure of the outer pressuresupporting tube has an inlet conduit passing therethrough and through which conduit the gases that are to undergo reaction are introduced into the apparatus so as to cool the aforesaid member, and said member also carrying a conduit which constitutes the exit tube for the gases after reaction, said conduit being continued beyond said member so as to project straight-forward into the interior of the pressure-supporting tube and carrying on its extended portion the inner tube containing the catalyzing material, and means whereby the gases that are to undergo reaction are admitted into the space between the outer4 pressure-supporting tube and the inner tube at that end of the apparatus where the closure member is located.

5. An apparat-us for the synthetic production of ammonia in which a member constituting a closure of t-he outer pressure-supporting tube has an inlet conduit passing r therethrough and through which conduit the gases that are to undergo reaction are introduced into the apparatus so as to cool the aforesaid member, and said member also carrying a conduit thermally insulated therethrough which constitutes the exit tube for said conduit being continued beyond said member so as to project straight-forward into the interior of the pressure-supporting tube and carrying on its extended portion the inner tube containing the catalyzing material, and means whereby the gases that are to undergo reaction are admitted into the space between the outer pressure-supporting tube and the inner tube at that end of the apparatus where the closure member is located.

6. An apparatus for the synthetic pro-l duction of ammonia, comprising an 4outer pressure-supporting tube, an inner tube containing theI catalyzing material contained within the said outer tube, a member constitut-ing a closure of t-he said outer tube, said member and the portion of the outer tube with which it engages being constructed with male and female screw threads of interrupted formation and means being provided for rotating t-he closure member into and out of engagement, and a. conduit which constitutes the exit tube for the gases after reaction carried by the aforesaid member, the said conduit being continued beyond said member so as to project into the interior of the pressuresupporting tube and carrying on its extended portion the aforesaid inner tube containing the catalyzing material.

7 An apparatus for the synthetic production of ammonia, comprising an outer pressure-supporting tube, an inner tube containing the catalyzing material contained within the said outer tube, a member constituting the closure of the said outer tube, said memj ber and the portion ofthe outertube' with which it engages being constructed with male and female screw threads of interrupted formation, and means being provided for rotating the closure member into and out of engagement, an inlet conduit passing through the said member and through which conduit the gases that are to undergo reaction are introduced into the apparatus so as to cool the aforesaid member, and a conduit which consaid inner tube containing the catalyzing ma.-

terial.

8. An apparatus for the synthetic production of ammonia, comprising an outer pressure-supporting tube and an inner tube containing the catalyzing material contained Within the Said outer tube and attached by means such as lag-bolts to a member constituting the closure of the said outer tube, said member carrying a conduit which constitutes the exit tube for the gases after reaction, and said conduit being continued beyond said member so as to project into the interior of the pressure-supporting tube and carrying on its extended portion the aforesaid inner tube containing the catalyzing material.

9. An-apparatus for the synthetic production of ammonia, comprising an outer pressure-supportingtube, an inner tube cont-aining the catalyzing material contained wit-hin the said outer tube, a member constituting the closureof the said outer tube, said member,

and the portion of the outer tube with which it engages being constructedwith male and female screw threads of interrupted formation, and means being provided for rotating the closure member into and out of engagetuting the exit tube being continued beyond said member so as to project into the interior of the pressure-supporting tube and 'carry- .ing on its extended portion the aforesaid inner tube containing the catalyzing material, and additional means such as lag-bolts yfor attaching the aforesaid innner tube to the closure-forming member. y

l0. An apparatus for the synthetic production of ammonia, comprising an outer pressure-supporting tube provided with an external heat-insulating covering and an elec-trical heatingcircuit within the said covering,

lsaid outer tubel being constructed and arranged so as to resist .the physical and chem- -ical conditions to which it is subjected, an

inner tube containing the catalyzing material and constructed with Walls having a variable thermal conductivity along the length of said tube, a member constituting the closure of the said outer tube, said member and the portion of the outer tube with which it engages being constructed with male and female screw threads of interrupted format-ion, and means being provided for rotating the closure member into and out of engagement, an ,inlet conduit passing through the said member and through which conduit the gases that are 'to undergo reaction are introduced into the apparatus so as to cool theaforesaid member, and a conduit which constitutes the exit tube for thegases after reactionvcarried by but thermally insulated from the aforesaid member, the said conduit constituting the exit tube being continued beyond said member so as to project into the interior of the pressure-supporting tube and carrying on its extended portion t-he aforesaid inner tube containing the catalyzing material.

ln testimony whereof l amr my signature.

GEORGES CLAUDE.