ES2272733T3 - STEEL PIECES MANUFACTURED OF AUSTENITIC OR SEMI-SUBSTANTIAL STEEL IN A PLANT FOR THE PRODUCTION OF SULFURIC ACID AND PROTECTION PROCEDURE AGAINST CORROSION. - Google Patents
STEEL PIECES MANUFACTURED OF AUSTENITIC OR SEMI-SUBSTANTIAL STEEL IN A PLANT FOR THE PRODUCTION OF SULFURIC ACID AND PROTECTION PROCEDURE AGAINST CORROSION. Download PDFInfo
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- ES2272733T3 ES2272733T3 ES02743117T ES02743117T ES2272733T3 ES 2272733 T3 ES2272733 T3 ES 2272733T3 ES 02743117 T ES02743117 T ES 02743117T ES 02743117 T ES02743117 T ES 02743117T ES 2272733 T3 ES2272733 T3 ES 2272733T3
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- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 title claims abstract description 84
- 229910000831 Steel Inorganic materials 0.000 title claims abstract description 54
- 239000010959 steel Substances 0.000 title claims abstract description 54
- 238000005260 corrosion Methods 0.000 title claims abstract description 37
- 230000007797 corrosion Effects 0.000 title claims abstract description 37
- 238000000034 method Methods 0.000 title claims abstract description 20
- 238000004519 manufacturing process Methods 0.000 title abstract description 7
- 229910052729 chemical element Inorganic materials 0.000 claims abstract description 12
- 239000002253 acid Substances 0.000 claims description 7
- 229910052750 molybdenum Inorganic materials 0.000 claims description 7
- 239000011733 molybdenum Substances 0.000 claims description 7
- ZOKXTWBITQBERF-UHFFFAOYSA-N Molybdenum Chemical compound [Mo] ZOKXTWBITQBERF-UHFFFAOYSA-N 0.000 claims description 6
- 238000009835 boiling Methods 0.000 claims description 4
- 238000009434 installation Methods 0.000 claims description 3
- 239000012141 concentrate Substances 0.000 claims 2
- 239000000463 material Substances 0.000 description 11
- PXHVJJICTQNCMI-UHFFFAOYSA-N nickel Substances [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 8
- 239000011651 chromium Substances 0.000 description 7
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 4
- 229910052804 chromium Inorganic materials 0.000 description 4
- 239000002826 coolant Substances 0.000 description 4
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 3
- 229910045601 alloy Inorganic materials 0.000 description 3
- 239000000956 alloy Substances 0.000 description 3
- 239000007789 gas Substances 0.000 description 3
- 229910052759 nickel Inorganic materials 0.000 description 3
- 229910052710 silicon Inorganic materials 0.000 description 3
- 239000010703 silicon Substances 0.000 description 3
- 238000012360 testing method Methods 0.000 description 3
- 238000010521 absorption reaction Methods 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 2
- 239000007769 metal material Substances 0.000 description 2
- 229910001018 Cast iron Inorganic materials 0.000 description 1
- 229910000863 Ferronickel Inorganic materials 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 229910052793 cadmium Inorganic materials 0.000 description 1
- BDOSMKKIYDKNTQ-UHFFFAOYSA-N cadmium atom Chemical compound [Cd] BDOSMKKIYDKNTQ-UHFFFAOYSA-N 0.000 description 1
- 230000003197 catalytic effect Effects 0.000 description 1
- 239000000919 ceramic Substances 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 238000009833 condensation Methods 0.000 description 1
- 230000005494 condensation Effects 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000003628 erosive effect Effects 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- 238000007654 immersion Methods 0.000 description 1
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 229960002523 mercuric chloride Drugs 0.000 description 1
- LWJROJCJINYWOX-UHFFFAOYSA-L mercury dichloride Chemical compound Cl[Hg]Cl LWJROJCJINYWOX-UHFFFAOYSA-L 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 229910044991 metal oxide Inorganic materials 0.000 description 1
- 150000004706 metal oxides Chemical class 0.000 description 1
- 239000004033 plastic Substances 0.000 description 1
- 229920003023 plastic Polymers 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 238000012546 transfer Methods 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23F—NON-MECHANICAL REMOVAL OF METALLIC MATERIAL FROM SURFACE; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL; MULTI-STEP PROCESSES FOR SURFACE TREATMENT OF METALLIC MATERIAL INVOLVING AT LEAST ONE PROCESS PROVIDED FOR IN CLASS C23 AND AT LEAST ONE PROCESS COVERED BY SUBCLASS C21D OR C22F OR CLASS C25
- C23F13/00—Inhibiting corrosion of metals by anodic or cathodic protection
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F28—HEAT EXCHANGE IN GENERAL
- F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
- F28F21/00—Constructions of heat-exchange apparatus characterised by the selection of particular materials
- F28F21/08—Constructions of heat-exchange apparatus characterised by the selection of particular materials of metal
- F28F21/081—Heat exchange elements made from metals or metal alloys
- F28F21/082—Heat exchange elements made from metals or metal alloys from steel or ferrous alloys
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
- C22C38/44—Ferrous alloys, e.g. steel alloys containing chromium with nickel with molybdenum or tungsten
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23F—NON-MECHANICAL REMOVAL OF METALLIC MATERIAL FROM SURFACE; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL; MULTI-STEP PROCESSES FOR SURFACE TREATMENT OF METALLIC MATERIAL INVOLVING AT LEAST ONE PROCESS PROVIDED FOR IN CLASS C23 AND AT LEAST ONE PROCESS COVERED BY SUBCLASS C21D OR C22F OR CLASS C25
- C23F13/00—Inhibiting corrosion of metals by anodic or cathodic protection
- C23F13/005—Anodic protection
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F28—HEAT EXCHANGE IN GENERAL
- F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
- F28F19/00—Preventing the formation of deposits or corrosion, e.g. by using filters or scrapers
- F28F19/004—Preventing the formation of deposits or corrosion, e.g. by using filters or scrapers by using protective electric currents, voltages, cathodes, anodes, electric short-circuits
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Mechanical Engineering (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- General Engineering & Computer Science (AREA)
- Preventing Corrosion Or Incrustation Of Metals (AREA)
- Prevention Of Electric Corrosion (AREA)
- Physical Or Chemical Processes And Apparatus (AREA)
- Spark Plugs (AREA)
Abstract
Description
Piezas de acero fabricadas de acero austenítico o semiaustenítico en una planta para la producción de ácido sulfúrico y procedimiento de protección contra la corrosión.Steel parts made of austenitic steel or semi-synthetic in a plant for the production of acid sulfuric and corrosion protection procedure.
La invención se refiere a un procedimiento para la protección contra la corrosión de piezas de acero hechas de acero austenítico o semiaustenítico durante la producción de ácido sulfúrico y las respectivas piezas de acero.The invention relates to a method for Corrosion protection of steel parts made of austenitic or semi-austenitic steel during acid production sulfuric and the respective pieces of steel.
En general, el ácido sulfúrico se produce
mediante la conversión catalítica del contenido de SO_{2} de
ciertos gases para obtener SO_{3} y -en el caso de gases secos-
mediante la subsecuente absorción del SO_{3} formado en ácido
sulfúrico concentrado o -en caso de gases húmedos- mediante la
subsecuente condensación del ácido sulfúrico formado. Los
componentes técnicos habituales tales como el desecador, el aparato
de absorción, el intercambiador de calor, etc se ponen en contacto
con el ácido sulfúrico concentrado a partir de aproximadamente el
93% en peso y a una temperatura elevada. Este ácido sulfúrico es
extremadamente agresivo y ejerce una fuerte y rápida corrosión
sobre las piezas estructurales a utilizar. Por lo tanto, las piezas
estructurales que se ponen en contacto con ácido sulfúrico deben
hacerse de materiales resistentes a la corrosión. Aleaciones
especiales de acero ferrítico, hierro fundido, plásticos, cerámica,
vidrio u otros materiales con un revestimiento correspondiente han
demostrado ser particularmente resistentes a la corrosión. Para
estas aplicaciones, los materiales no metálicos tienen generalmente
propiedades mecánicas desfavorables y son difíciles de procesar. Los
materiales metálicos tienen buenas mecánicas, pero su resistencia a
la corrosión no es suficiente o los materiales son muy caros. En
particular son necesarios para su uso en los intercambiadores de
calor, componentes provistos de paredes muy finas, que necesitan
una alta transferencia de calor. En estos componentes, la anterior
resistencia a la corrosión ya no es suficiente. Estas instalaciones
funcionan habitualmente con una concentración de ácido sulfúrico
entre el 93% en peso y el 100% en peso y una temperatura de hasta
140ºC. Un procedimiento conocido de protección contra la corrosión
es la protección anódica contra la corrosión. En este procedimiento,
los materiales a proteger se revisten con una capa de óxido
metálico que evita el ataque de la
corrosión.In general, sulfuric acid is produced by catalytic conversion of the SO 2 content of certain gases to obtain SO 3 and - in the case of dry gases - by subsequent absorption of SO 3 formed in sulfuric acid. concentrated or - in the case of wet gases - by the subsequent condensation of the sulfuric acid formed. The usual technical components such as the desiccator, the absorption apparatus, the heat exchanger, etc. are contacted with the concentrated sulfuric acid from about 93% by weight and at an elevated temperature. This sulfuric acid is extremely aggressive and exerts a strong and rapid corrosion on the structural parts to be used. Therefore, structural parts that come into contact with sulfuric acid must be made of corrosion resistant materials. Special alloys of ferritic steel, cast iron, plastics, ceramics, glass or other materials with a corresponding coating have proven to be particularly resistant to corrosion. For these applications, non-metallic materials generally have unfavorable mechanical properties and are difficult to process. Metal materials have good mechanics, but their corrosion resistance is not enough or the materials are very expensive. In particular, components provided with very thin walls, which require high heat transfer, are necessary for use in heat exchangers. In these components, the previous corrosion resistance is no longer sufficient. These installations usually operate with a sulfuric acid concentration between 93% by weight and 100% by weight and a temperature of up to 140ºC. A known corrosion protection procedure is anodic corrosion protection. In this procedure, the materials to be protected are coated with a layer of metal oxide that prevents the attack of the
corrosion.
El uso de aceros austeníticos durante la producción de ácido sulfúrico se conoce desde el documento EP 0 130 967. Las clases de aceros indicadas en este documento se dirigen en particular a su uso en intercambiadores de calor. Los materiales aquí utilizados no satisfacen los requisitos que deben ahora ser cumplimentados por los materiales resistentes a la corrosión. Para las instalaciones técnicas actualmente en uso se requieren en particular menores tasas de corrosión. Para mejorar la resistencia a la corrosión, el documento US 5.028.396 propone aceros inoxidables austeníticos con un contenido de silicio relativamente alto que constan esencialmente de un 17,5% de Cr, un 17,5% de Ni, entre un 4,6 y un 5,8% de Si, siendo el resto Fe.The use of austenitic steels during Sulfuric acid production is known from EP 0 130 967. The classes of steels indicated in this document are addressed at Particular to its use in heat exchangers. The materials used here do not meet the requirements that should now be filled in by corrosion resistant materials. For the technical installations currently in use are required in particularly lower corrosion rates. To improve resistance to corrosion, US 5,028,396 proposes stainless steels austenitic with a relatively high silicon content that they consist essentially of 17.5% Cr, 17.5% Ni, between 4.6 and 5.8% of Si, the rest being Fe.
Además, el documento US 5.695.716 presenta aleaciones austeníticas resistentes a la corrosión de cromo, ferroníquel que incluyen al menos un 32% en peso de cromo.In addition, US 5,695,716 presents chrome corrosion resistant austenitic alloys, ferronickel including at least 32% by weight of chromium.
El documento DE 38 30 365 describe el uso de aceros ferríticos de cromo - molibdeno que son resistentes al ácido sulfúrico con una concentración desde el 94% en peso en adelante y con una temperatura por debajo del punto de ebullición. Estos aceros ferríticos son muy caros y más difíciles de procesar que los aceros austeníticos. La resistencia a la corrosión tampoco se considera suficiente.Document DE 38 30 365 describes the use of chrome-molybdenum ferritic steels that are acid resistant sulfuric acid with a concentration from 94% by weight onwards and with a temperature below the boiling point. These ferritic steels are very expensive and more difficult to process than austenitic steels. The corrosion resistance is also not considered enough.
Avanzando desde esta técnica anterior, el objeto esencial de la invención es mejorar la protección contra la corrosión de al menos una pieza de acero de un dispositivo hecho de acero austenítico o semiaustenítico durante la producción de ácido sulfúrico, en dicho dispositivo la pieza de acero se pone en contacto con el ácido sulfúrico.Moving forward from this prior art, the object essential of the invention is to improve protection against corrosion of at least one piece of steel from a device made of austenitic or semi-austenitic steel during acid production sulfuric, in said device the steel part is put in contact with sulfuric acid.
De acuerdo con la invención, se suministra un procedimiento que comprende las características de la reivindicación 1.In accordance with the invention, a method comprising the features of the claim one.
De las reivindicaciones independientes se hacen evidentes realizaciones ventajosas de la invención.The independent claims are made Obvious advantageous embodiments of the invention.
Los experimentos han mostrado que los tipos de acero con un contenido de Cr de entre un 15% en peso y un 26,2% en peso, un contenido de Ni de entre un 9% en peso y un 25,2% en peso y un contenido mínimo de Si de un 0,75% en peso, son particularmente resistentes a la corrosión.Experiments have shown that the types of steel with a Cr content of between 15% by weight and 26.2% in weight, a Ni content of between 9% by weight and 25.2% by weight and a minimum Si content of 0.75% by weight, are particularly corrosion resistant.
En términos de resistencia a la corrosión, se sabe que especialmente el silicio y el cromo de entre los elementos químicos de las aleaciones, forman una capa pasiva, mientras que el níquel y el molibdeno debilitan la formación de la capa pasiva.In terms of corrosion resistance, it knows that especially silicon and chromium between the elements chemical alloys, form a passive layer, while the Nickel and molybdenum weaken the formation of the passive layer.
La relación de elementos químicos (Cr + Si)/(Ni + Mo) en la banda de entre 1,01 y 1,34 ha demostrado ser particularmente ventajosa.The ratio of chemical elements (Cr + Si) / (Ni + Mo) in the band between 1.01 and 1.34 has proven to be particularly advantageous.
De forma similar, para aquellos tipos de acero que solamente tienen un contenido menor de silicio se obtuvo una relación ventajosa de los elementos químicos Cr/(Ni + Mo) en la banda de entre 0,8 y 1,1.Similarly, for those types of steel that only have a lower silicon content, a advantageous ratio of the chemical elements Cr / (Ni + Mo) in the band between 0.8 and 1.1.
La relación es particularmente favorable cuando el molibdeno está presente en una cantidad no demasiado grande de entre el 0% en peso y el 2,5% en peso. Dependiendo de la disponibilidad de los tipos de acero a suministrar para los materiales en bruto tales como tubos o planchas, pueden utilizarse piezas de acero austenítico o semiaustenítico con un contenido de molibdeno de entre un 2% en peso y un 2,5% en peso.The relationship is particularly favorable when molybdenum is present in a not too large amount of between 0% by weight and 2.5% by weight. Depending on the availability of the types of steel to be supplied for raw materials such as tubes or plates, can be used pieces of austenitic or semi-austenitic steel with a content of molybdenum between 2% by weight and 2.5% by weight.
Particularmente críticas para la corrosión son aquellas bandas en las cuales la concentración de ácido sulfúrico es de aproximadamente entre el 97% en peso y el 99% en peso o la temperatura del ácido sulfúrico es de aproximadamente entre 160ºC y 230ºC.Particularly critical for corrosion are those bands in which the concentration of sulfuric acid it is approximately between 97% by weight and 99% by weight or the sulfuric acid temperature is approximately 160 ° C and 230 ° C.
Durante la producción del ácido sulfúrico, los componentes particularmente sensibles a la corrosión son los intercambiadores de calor, tales como, por ejemplo, los intercambiadores de calor de placas o los intercambiadores de calor de carcasas y tubos, así como el sistema completo de tuberías.During the production of sulfuric acid, the Particularly corrosion sensitive components are the heat exchangers, such as, for example, plate heat exchangers or heat exchangers of housings and tubes, as well as the complete system of pipes.
Ahora se explicarán realizaciones del proceso a modo de ejemplo con referencia a los dibujos, en los cuales:Now process realizations will be explained to example mode with reference to the drawings, in which:
La figura 1 muestra una curva de densidad/potencial de corriente de un material austenítico.Figure 1 shows a curve of density / current potential of an austenitic material.
La figura 2 es una representación esquemática de la protección anódica de un intercambiador de calor.Figure 2 is a schematic representation of Anodic protection of a heat exchanger.
La figura 1 muestra la curva de
densidad/potencial de corriente de un material austenítico típico
que contiene entre un 16,5% y un 18,5% en peso de cromo, entre un
11% y un 14% en peso de níquel y entre un 2% y un 2,5% en peso de
molibdeno. En esta medición, se utilizó como medio ácido sulfúrico
con una concentración del 98% en peso y a una temperatura de 200ºC.
Como cátodo, se utilizó un cátodo de acero hecho de 1,4404. En la
abscisa, el potencial se representa en milivoltios (mV) contra un
electrodo de referencia de Hg/HgSo_{4} y en la ordenada la
densidad de la corriente se representa en miliamperios por
centímetro cuadrado (mA/cm^{2}). También pueden utilizarse otros
electrodos de referencia, tal como, por ejemplo, un electrodo de
dicloruro de mercurio o una barra de
cadmio.Figure 1 shows the current density / potential curve of a typical austenitic material containing between 16.5% and 18.5% by weight of chromium, between 11% and 14% by weight of nickel and between 2% and 2.5% by weight of molybdenum. In this measurement, sulfuric acid with a concentration of 98% by weight and at a temperature of 200 ° C was used as the medium. As a cathode, a steel cathode made of 1.4404 was used. In the abscissa, the potential is represented in millivolts (mV) against a reference electrode of Hg / HgSo4 and in the ordinate the density of the current is represented in milliamps per square centimeter (mA / cm2) . Other reference electrodes may also be used, such as, for example, a mercury dichloride electrode or a bar of
cadmium.
La primera parte del diagrama en la banda entre 0 y 600 mV muestra un pico que es denominado potencial activo. En la banda entre 600 mV y 1800 mV la curva muestra un valle, el denominado potencial pasivo. La elevación subsecuente desde 1800 mV se denomina potencial transpasivo. Para conseguir una protección contra la corrosión tan efectiva como sea posible en la protección anódica contra la corrosión, la densidad de la corriente debe recaer dentro de la banda del potencial pasivo. Los valores aquí representados son ejemplares, ya que son dependientes del material y de la temperatura.The first part of the diagram in the band between 0 and 600 mV shows a peak that is called active potential. In the band between 600 mV and 1800 mV the curve shows a valley, the called passive potential. The subsequent elevation from 1800 mV It is called transpassive potential. To get protection against corrosion as effective as possible in protection anodic against corrosion, the density of the current must fall within the band of passive potential. Values here represented are exemplary, since they are dependent on the material and of the temperature.
La figura 2 muestra la disposición de la protección anódica contra la corrosión en un intercambiador (1) de calor de carcasas y tubos para ácido sulfúrico. A través de una conexión (2), se introduce el medio refrigerante dentro de una primera cámara (3) del intercambiador (1) de calor de cascasas y tubos. Desde ahí, el medio refrigerante se distribuye y fluye a través de tubos individuales (4) al interior de una segunda cámara (5) desde la cual el medio refrigerante se descarga de nuevo. A modo de ejemplo, aquí sólo se representan dos tubos (4).Figure 2 shows the layout of the anodic corrosion protection in an exchanger (1) of shell and tube heat for sulfuric acid. Through a connection (2), the cooling medium is introduced into a first chamber (3) of the casing heat exchanger (1) and tubes From there, the cooling medium is distributed and flows to through individual tubes (4) inside a second chamber (5) from which the cooling medium is discharged again. TO As an example, only two tubes (4) are shown here.
A través de otra conexión (6), se introduce el ácido sulfúrico caliente. El ácido sulfúrico fluye alrededor de los tubos (4) llenos de medio refrigerante y se descarga de nuevo a través de la conexión (7). Cuando fluye alrededor de los conjuntos de tubos (4), el ácido sulfúrico se enfría.Through another connection (6), the hot sulfuric acid. Sulfuric acid flows around the tubes (4) filled with cooling medium and discharged back to through the connection (7). When it flows around the sets of tubes (4), the sulfuric acid is cooled.
Se monta una pluralidad de cátodos (8) de metal entre los tubos (4) y el intercambiador de calor de cascasas y tubos. La representación muestra un cátodo (8) a modo de ejemplo. El número de cátodos (8) utilizados depende del tamaño del intercambiador de calor y también de la temperatura y concentración del ácido sulfúrico. El cátodo (8) está hecho del material 1,4404 y está en contacto permanente con el ácido sulfúrico. El cátodo (8) se conecta con el polo negativo de un potencioestato (9) mediante una línea eléctrica. El potencioestato (9) es una fuente de tensión de corriente continua cuyo polo positivo (10) está conectado través de una línea eléctrica con las piezas del intercambiador (1) de calor de carcasas y tubos a proteger.A plurality of metal cathodes (8) are mounted between the tubes (4) and the casing heat exchanger and tubes The representation shows an cathode (8) by way of example. He number of cathodes (8) used depends on the size of the heat exchanger and also the temperature and concentration of sulfuric acid. The cathode (8) is made of material 1,4404 and It is in permanent contact with sulfuric acid. The cathode (8) it is connected to the negative pole of a potentiostat (9) by a power line Potentiostat (9) is a voltage source of direct current whose positive pole (10) is connected through of an electric line with the parts of the exchanger (1) of heat of housings and tubes to protect.
Se inserta un segundo electrodo (11) de referencia en el intercambiador de calor de carcasas y tubos a través de una junta y se conecta con el potencioestato (9) a través de una línea eléctrica. Este electrodo (11) de referencia está igualmente rodeado de forma permanente por el ácido sulfúrico y suministra una base de medición para el potencioestato (9). Por medio de la tensión eléctrica entre el electrodo (11) de referencia y el cátodo (8), se determina y se ajusta el potencial necesario para la protección contra la corrosión en el potencioestato (9).A second electrode (11) of reference in the shell and tube heat exchanger a through a joint and connects to the potentiostate (9) through of a power line. This reference electrode (11) is also permanently surrounded by sulfuric acid and supplies a measuring base for the potentiostat (9). By means of the electrical voltage between the reference electrode (11) and the cathode (8), the necessary potential is determined and adjusted for corrosion protection in the potentiostat (9).
En la siguiente tabla, se muestra el comportamiento frente a la corrosión de los materiales de acuerdo con al invención a diferentes temperaturas y una concentración de ácido sulfúrico del 98% en peso. El caudal de ácido sulfúrico fue de un m/s. El comportamiento frente a la corrosión se determinó mediante ensayos de inmersión. En todos los casos, el período de ensayo fue de 7 días. Se determinó la velocidad de erosión midiendo el flujo de corrosión y mediante la conversión a mm/a. El medio de ensayo se renovó después de cada ciclo de ensayo.In the following table, the Corrosion behavior of materials according with the invention at different temperatures and a concentration of 98% sulfuric acid by weight. The sulfuric acid flow rate was of an m / s. Corrosion behavior was determined by immersion tests. In all cases, the period of trial was 7 days. The erosion rate was determined by measuring the corrosion flow and by conversion to mm / a. The middle of test was renewed after each test cycle.
\newpage\ newpage
Así, las tasas de corrosión son directamente inferiores a las de la técnica anterior.Thus, the corrosion rates are directly inferior to those of the prior art.
Claims (14)
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE10128032A DE10128032A1 (en) | 2001-06-08 | 2001-06-08 | Process for protecting steel part of apparatus against corrosion comprises using anodic protection, in which an anode, cathode and reference electrode are connected together |
| DE10128032 | 2001-06-08 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| ES2272733T3 true ES2272733T3 (en) | 2007-05-01 |
Family
ID=7687749
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| ES02743117T Expired - Lifetime ES2272733T3 (en) | 2001-06-08 | 2002-05-28 | STEEL PIECES MANUFACTURED OF AUSTENITIC OR SEMI-SUBSTANTIAL STEEL IN A PLANT FOR THE PRODUCTION OF SULFURIC ACID AND PROTECTION PROCEDURE AGAINST CORROSION. |
Country Status (11)
| Country | Link |
|---|---|
| US (1) | US20040238375A1 (en) |
| EP (1) | EP1409756B1 (en) |
| JP (1) | JP2004529274A (en) |
| KR (1) | KR20040023612A (en) |
| AT (1) | ATE340274T1 (en) |
| DE (2) | DE10128032A1 (en) |
| EA (1) | EA006778B1 (en) |
| ES (1) | ES2272733T3 (en) |
| MX (1) | MXPA03011234A (en) |
| PE (1) | PE20030023A1 (en) |
| WO (1) | WO2002101106A1 (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20110041515A1 (en) * | 2007-10-18 | 2011-02-24 | Michael Lee Fraim | High Efficiency, Corrosion Resistant Heat Exchanger and Method of Use Thereof |
| DE102010006541B4 (en) * | 2010-02-01 | 2016-03-17 | Outotec Oyj | Method and apparatus for cooling acid |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0018124A1 (en) * | 1979-04-02 | 1980-10-29 | Monsanto Company | Anodically passivated vessel and method of passivating it |
| CA1199305A (en) * | 1982-01-21 | 1986-01-14 | C-I-L Inc. | Anodic protection system and method |
| US5028396A (en) * | 1982-06-11 | 1991-07-02 | Chemetics International Company, Ltd. | Apparatus formed of high silicon chromium/nickel in steel in the manufacture of sulpheric acid |
| US4576813A (en) * | 1983-07-05 | 1986-03-18 | Monsanto Company | Heat recovery from concentrated sulfuric acid |
| DE4342188C2 (en) * | 1993-12-10 | 1998-06-04 | Bayer Ag | Austenitic alloys and their uses |
| DE19807632A1 (en) * | 1998-02-23 | 1999-09-02 | Bayer Ag | Device for concentrating and purifying sulfuric acid |
-
2001
- 2001-06-08 DE DE10128032A patent/DE10128032A1/en not_active Withdrawn
-
2002
- 2002-05-28 JP JP2003503852A patent/JP2004529274A/en active Pending
- 2002-05-28 EP EP02743117A patent/EP1409756B1/en not_active Expired - Lifetime
- 2002-05-28 KR KR10-2003-7016039A patent/KR20040023612A/en not_active Application Discontinuation
- 2002-05-28 DE DE60214859T patent/DE60214859T2/en not_active Expired - Lifetime
- 2002-05-28 AT AT02743117T patent/ATE340274T1/en not_active IP Right Cessation
- 2002-05-28 MX MXPA03011234A patent/MXPA03011234A/en active IP Right Grant
- 2002-05-28 ES ES02743117T patent/ES2272733T3/en not_active Expired - Lifetime
- 2002-05-28 WO PCT/EP2002/005842 patent/WO2002101106A1/en active IP Right Grant
- 2002-05-28 US US10/479,304 patent/US20040238375A1/en not_active Abandoned
- 2002-05-28 EA EA200400008A patent/EA006778B1/en not_active IP Right Cessation
- 2002-06-07 PE PE2002000475A patent/PE20030023A1/en not_active Application Discontinuation
Also Published As
| Publication number | Publication date |
|---|---|
| PE20030023A1 (en) | 2003-02-03 |
| US20040238375A1 (en) | 2004-12-02 |
| EP1409756B1 (en) | 2006-09-20 |
| MXPA03011234A (en) | 2004-02-26 |
| EP1409756A1 (en) | 2004-04-21 |
| WO2002101106A1 (en) | 2002-12-19 |
| EA006778B1 (en) | 2006-04-28 |
| ATE340274T1 (en) | 2006-10-15 |
| KR20040023612A (en) | 2004-03-18 |
| EA200400008A1 (en) | 2004-04-29 |
| JP2004529274A (en) | 2004-09-24 |
| DE10128032A1 (en) | 2002-12-12 |
| DE60214859D1 (en) | 2006-11-02 |
| DE60214859T2 (en) | 2007-04-12 |
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