CH141303A

CH141303A - Apparatus for the catalysis of gases.

Info

Publication number: CH141303A
Authority: CH
Inventors: D Ougree-Marihaye Soci Anonyme
Original assignee: D Ougree Marihaye Sa
Priority date: 1928-04-07
Filing date: 1929-03-04
Publication date: 1930-07-31

Description

  

  Appareil pour la catalyse des gaz.    La présente invention est relative à un  appareil destiné à la catalyse des gaz, par  exemple à l'oxydation de l'ammoniaque en       oxydes    d'azote, et comportant un     préchauf-          feur    de gaz avant catalyse.  



  Des préchauffeurs utilisés jusqu'ici dans  les appareils de combustion de l'ammoniaque  ne permettaient pas d'éviter complètement  les effets des condensations et des dilatations  qui détruisent rapidement les -appareils.  



  En outre, la perte du catalyseur était  dans certains cas appréciable.  



  La présente invention remédie à ces di  vers     inconvénients.     



  L'objet de l'invention est un appareil  pour la catalyse des gaz, caractérisé par un       préchauffeur    des gaz à. traiter permettant  une libre dilatation de ses parties, par une  chambre de catalyse des gaz disposée à la  suite du     préchauffeur,    par un récupérateur  des particules entraînées par les gaz sortant  de la chambre de catalyse, et par des condui-    tes reliant le récupérateur, d'une part au       préchauffeur    et, d'autre part, à des tubu  lures d'évacuation des gaz.  



  Le dessin annexé représente une forme  d'exécution de l'appareil. selon l'invention,  donnée à. titre d'exemple.  



  La     fig.    1 est une coupe verticale d'un ap  pareil destiné à la catalyse de l'ammoniaque  en oxyde d'azote;  La     fig.    2 est une vue en perspective de  sa toile de catalyse.  



  Le gaz ammoniaque, en mélange par exem  ple avec de l'air, entre par un tuyau 2 dans  un faisceau tubulaire 3; ce tuyau présente  des boîtes à bourrages 4 permettant les di  latations du faisceau et d'une enveloppe  chauffante 5 qui forment le préchauffeur.  Le gaz ammoniaque se réchauffe par échange  1     hermique    avec les gaz circulant à l'exté  rieur du faisceau 3. Celui-ci est     maintenu     par des plaques 6 formant chicanes dans  l'enveloppe 5. A la sortie du préchauffeur,      les gaz chauds sont dirigés avec une incidence  convenable sur une toile 8 de catalyse par  une embouchure 7 de forme appropriée.  



  La toile de catalyse a une forme en sac  représentée, à titre d'exemple, par la     fig.    2.  Cette forme correspond à une surface de ré  volution engendrée par un arc de chaînette  tournant autour d'un axe sensiblement paral  lèle à. la direction d'amenée des gaz au cata  lyseur. Cette disposition offre l'avantage  d'améliorer la résistance mécanique et le ren  dement de chaque élément de surface de cata  lyseur en régularisant ses conditions de fonc  tionnement. La toile de catalyse peut être     cons-          tituéeparplusieurs    épaisseurs de treillis métal  lique réunies par soudure, par couture ou au  trement.

   Le gaz catalysé est évacué par des  orifices percés au travers de la paroi 5a d'une  chambre de catalyse dont la paroi entoure la  toile de catalyse et en épouse la forme. Ils  sont. ensuite conduits dans un récipient 9 ser  vant de récupérateur des particules du     cat.a.--          lyseur    entraînées. Ce récipient est pourvu à  cet effet d'une chicane constituée par un  manchon 10 déterminant un espace annulaire  dans lequel les gaz pénètrent     radialement,     tandis qu'ils sont évacués     axialement    à tra  vers ledit manchon. puis, de bas en haut par  un tube vertical il. Ces gaz déposent dans  le récupérateur 9 les corpuscules solides qu'ils  Tiennent éventuellement en suspension.

   Une  partie des gaz nécessaires aux échanges ther  miques peut ensuite être envoyée par la,     ma-          nceuvre    de registres lia et     111?    à travers le  préchauffeur, de manière que des gaz chauds  évoluent autour du faisceau tubulaire et à  travers les chicanes à l'intérieur du     préchauf-          feur    en réchauffant l'ammoniaque amené  dans le faisceau tubulaire 3. Ces gaz ayant  servi au préchauffage sont ensuite amenés  par un conduit 13 dans une conduite 12 où  ils retrouvent l'autre partie des gaz traités  qui a traversé le registre     11b.  



  Apparatus for the catalysis of gases. The present invention relates to an apparatus intended for the catalysis of gases, for example for the oxidation of ammonia to nitrogen oxides, and comprising a gas preheater before catalysis.



  Preheaters hitherto used in ammonia combustion apparatus did not completely avoid the effects of condensations and expansions which rapidly destroy the apparatus.



  In addition, the loss of the catalyst was in some cases appreciable.



  The present invention overcomes these various drawbacks.



  The object of the invention is an apparatus for the catalysis of gases, characterized by a gas preheater. treat allowing free expansion of its parts, by a gas catalysis chamber arranged after the preheater, by a recuperator of the particles entrained by the gases leaving the catalysis chamber, and by conduits connecting the recuperator, d 'on the one hand to the preheater and, on the other hand, to the gas discharge pipes.



  The accompanying drawing shows an embodiment of the apparatus. according to the invention, given to. as an example.



  Fig. 1 is a vertical section of an apparatus intended for the catalysis of ammonia into nitrogen oxide; Fig. 2 is a perspective view of its catalysis fabric.



  The ammonia gas, mixed for example with air, enters through a pipe 2 into a tube bundle 3; this pipe has stuffing boxes 4 allowing the beam to expand and a heating jacket 5 which form the preheater. The ammonia gas is heated by hermetic exchange 1 with the gases circulating outside the bundle 3. The latter is held by plates 6 forming baffles in the casing 5. At the outlet of the preheater, the hot gases are directed with a suitable incidence on a fabric 8 of catalysis by a mouth 7 of suitable shape.



  The catalysis fabric has a bag shape shown, by way of example, in FIG. 2. This shape corresponds to a surface of revolution generated by a chain arc rotating around an axis substantially parallel to. the direction of gas supply to the catalytic converter. This arrangement offers the advantage of improving the mechanical strength and the yield of each catalytic converter surface element by regularizing its operating conditions. The catalysis fabric can be made up of several layers of metallic mesh joined together by welding, sewing or trement.

   The catalyzed gas is discharged through orifices pierced through the wall 5a of a catalysis chamber, the wall of which surrounds the catalysis fabric and conforms to its shape. They are. then conducted into a receptacle 9 serving as a recuperator of the entrained cat.a - lyser particles. This receptacle is provided for this purpose with a baffle formed by a sleeve 10 determining an annular space into which the gases enter radially, while they are axially discharged through said sleeve. then, from bottom to top through a vertical tube there. These gases deposit in the recuperator 9 the solid particles which they possibly hold in suspension.

   A part of the gases necessary for thermal exchanges can then be sent by the register operation 11a and 111? through the preheater, so that hot gases move around the tube bundle and through the baffles inside the preheater by heating the ammonia brought into the tube bundle 3. These gases having been used for preheating are then brought via a conduit 13 in a conduit 12 where they find the other part of the treated gases which has passed through the register 11b.

Claims

CLAIM Apparatus for the catalysis of gases, characterized by a gas preheater. process established so as to allow free expansion of its parts, by a gas catalysis chamber placed after the preheater, by a recuperator of the particles entrained by the gases leaving the catalysis chamber, and by pipes connecting the recuperator, on the one hand to the preheater and, on the other hand, to gas discharge pipes.

SUB-CLAIMS 1 Apparatus according to claim, characterized in that the particle recuperator is a container provided with a plug formed by a sleeve defining in said container an annular space in which the gases penetrate radially while they are are discharged axially through said sleeve. 2 Apparatus according to claim and sub-claim 1, characterized in that the aforesaid sleeve is extended by a vertical tube through which the gases travel from bottom to top.

3 Apparatus according to claim, charac terized in that the preheater comprises a tube bundle traversed by the gases to be treated and arranged at. inside a chamber in which circulates at least part of the hot fluid exiting the receptacle, the gas supply pipe to. treat a tubular bundle passing through one of the walls of this chamber through stuffing boxes allowing relative movement of these two elements.

q Apparatus according to claim and sub-claim 3, characterized in that the preheater comprises normal plates. direction of the tube bundle and forming baffles inside the chamber, while increasing the rigidity of the tube bundle. Apparatus according to claim, characterized in that the catalyst has a bag-shaped surface inside the catalysis chamber. Apparatus according to claim and sub-claim 5, characterized in that the aforesaid surface is a surface of revolution generated by a chain arc rotating about an axis parallel to the direction of the gases to be treated.

7 Apparatus according to claim and sub-claims 5 and 6, characterized in that the wall of the catalysis chamber matches the shape of the surface of the catalytic converter and comprises a series of channels allowing the flow of the treated gases. 8 Apparatus according to claim and sub-claims 5, 6 and 7, characterized in that the gases are introduced inside said surface by means of a sleeve forming a mouth which directs the gas mixture to be treated on the catalyst and standardizes the distribution of the gas stream.

9 Apparatus according to claim, characterized in that the elements are arranged in two columns, one comprising the supply channel for the gases to be treated, the preheater of these gases opening into the catalysis chamber and the 'Another component includes the catalytic converter particles recuperator entrained by the treated gases, as well as a vertical tube extending this recuperator, these two columns being connected by conduits fitted with registers, one of which is used to bring into the recuperator the gases which have undergone catalysis, one another.

diverting out of the vertical tube towards the preheater, a part of the treated gases and a third conduit serving to bring back into the evacuation channel of the treated gases, the part of these gases which has been diverted through to the preheater.