ES2382118T3

ES2382118T3 - Drying and drying system for paper material production plants as a band

Info

Publication number: ES2382118T3
Application number: ES10176140T
Authority: ES
Inventors: Pietro Saccomano Rocchi Burlamacchi; Massimo Giannecchini
Original assignee: Novimpianti Drying Technology SRL
Current assignee: Novimpianti Drying Technology SRL
Priority date: 2009-09-16
Filing date: 2010-09-10
Publication date: 2012-06-05
Anticipated expiration: 2030-09-10
Also published as: PL2298988T3; ITMI20091582A1; ATE544904T1; EP2298988B1; EP2298988A1; IT1395745B1

Abstract

An evaporative drying and desiccating system (10) for a web-like paper material is described. The system (10) comprises at least one first drying device (12), of the pressurised rotating cylinder type fed by steam, on which the web-like paper material to be desiccated is dynamically wound. The cylinder (12) contains a pipe system, for the removal of the condensate, inside it. The system (10) thus comprises at least one second drying device (14), of the hood type, which at least partially covers the cylinder (12) and that comprises at least one first burner (16) capable of producing high temperature dry air. The hood (14) is both capable of blowing the high temperature dry air onto the web-like paper material wound on the cylinder (12), and sucking the moist air released from such a web-like paper material. Positioned along the pipes (26) for releasing the moist air from the hood (14), there are at least one waste heat boiler (34), fed by the moist air released from the web-like paper material and capable of generating high pressure steam for feeding a thermocompressor (36) and a make-up valve (70), which supply steam to the cylinder (12), and at least one auxiliary burner (58), capable of increasing the temperature of the moist air coming from the hood (14). The system (10) is finished off by an exhaust and recirculation fan (32) and by a recirculation and balancing pipe system (72) that, together with the release pipes (26) and through one or more adjustment proportioning valves (64; 38), make it possible to regulate and balance the air flows. It is thus superfluous to use a fuel boiler for feeding the cylinder (12), making it possible moreover, for the thermal conditions of the hood (14) and of the waste heat boiler (34) to be independently regulated, and the amount of energy required by the system (10) is reduced.

Description

Sistema de secado y desecado para plantas de producción de material de papel a modo de banda. Drying and drying system for paper material production plants as a band.

La presente invención se refiere a un sistema de secado y desecado para plantas de producción de un material de papel a modo de banda, en particular pero no exclusivamente, para plantas de producción de rollos de papel higiénico. The present invention relates to a drying and drying system for production plants of a paper-like paper material, in particular but not exclusively, for toilet paper roll production plants.

Tal como resulta conocido, en el procedimiento de producción de papel en general, y en particular en la producción de papel higiénico, resulta necesario realizar una etapa de secado por evaporación del producto que se está procesando, a fin de extraer el exceso de agua. El producto a secar, realizado normalmente a partir de pasta de papel diluida con agua, se prepara y se envía al sistema de secado y desecado tras una etapa preliminar de prensado. En la entrada del sistema de secado y desecado, la hoja de papel que se está procesando presenta un contenido bajo en sólidos, equivalente a aproximadamente entre el 35% y el 40% a una temperatura aproximadamente de 35°C. En otras palabras, tras la etapa de prensado, la hoja de papel que se está procesando puede comprender todavía hasta el 65% de agua. La etapa de prensado, por lo tanto, no permite eliminar toda el agua de las fibras de papel, que se ha de retirar por lo tanto por evaporación. As is known, in the paper production process in general, and in particular in the production of toilet paper, it is necessary to carry out an evaporation drying step of the product being processed, in order to extract the excess water. The product to be dried, usually made from paper pulp diluted with water, is prepared and sent to the drying and drying system after a preliminary pressing stage. At the entrance of the drying and drying system, the sheet of paper being processed has a low solids content, equivalent to approximately between 35% and 40% at a temperature of approximately 35 ° C. In other words, after the pressing stage, the sheet of paper being processed can still comprise up to 65% water. The pressing stage, therefore, does not allow removing all water from the paper fibers, which must therefore be removed by evaporation.

El producto acabado, en el caso específico que comprende el papel higiénico, requiere un contenido en sólidos muy superior a los valores mencionados anteriormente. Por lo tanto, es evidente que en la etapa de secado por evaporación, resulta necesario extraer la mayor parte del contenido de agua residual de la hoja de papel, así como realizar una hoja continua de papel que sea suficientemente seca. Tras la etapa de secado y desecado por evaporación, la hoja de papel se almacena en bobinas para procesarse posteriormente (etapa denominada de "conversión") y, por último, proceder al embalaje para la entrega y la venta final al por menor. The finished product, in the specific case that includes the toilet paper, requires a solids content that is much higher than the values mentioned above. Therefore, it is evident that in the evaporation drying stage, it is necessary to extract most of the residual water content of the paper sheet, as well as to make a continuous sheet of paper that is sufficiently dry. After the drying and drying stage by evaporation, the paper sheet is stored in reels for further processing (called the "conversion" stage) and, finally, proceed to the packaging for delivery and final retail sale.

La etapa de secado y desecado por evaporación del papel higiénico se realiza actualmente mediante un sistema que presenta dos dispositivos independientes, que simultáneamente, sin embargo, en la hoja de papel durante dicha etapa de secado y desecado. The drying and drying stage by evaporation of the toilet paper is currently carried out by a system that has two independent devices, which simultaneously, however, on the paper sheet during said drying and drying stage.

Un primer dispositivo de secado comprende una campana de alto rendimiento, que proporciona para inyectar aire caliente, a una temperatura de hasta aproximadamente 650°C en la campanas de última generación, sobre la hoja de papel que se está procesando. El aire caliente se produce normalmente con un quemador de fuego directo. A first drying device comprises a high performance hood, which provides for injecting hot air, at a temperature of up to about 650 ° C in the latest generation hoods, onto the sheet of paper being processed. Hot air is normally produced with a direct fire burner.

Las campanas de alto rendimiento requieren asimismo descargar el vapor de agua extraída de la hoja de papel que se está procesando en la atmósfera. El flujo que comprende el vapor de agua y el aire que transporta el mismo se denomina "niebla" en el lenguaje técnico. Dicha "niebla" presenta una temperatura elevada, aproximadamente de 400°C a 550°C en las plantas de última generación. Por consiguiente, la dispersión en la atmósfera de la "niebla" reduce sustancialmente la eficiencia térmica de las campanas de alto rendimiento. High-performance hoods also require the discharge of water vapor extracted from the sheet of paper being processed in the atmosphere. The flow that comprises water vapor and the air that carries it is called "fog" in the technical language. This "fog" has a high temperature, approximately 400 ° C to 550 ° C in the latest generation plants. Consequently, the dispersion in the atmosphere of the "fog" substantially reduces the thermal efficiency of the high performance hoods.

Al mismo tiempo que se realiza la inyección de aire, la hoja de papel que se está procesando entra en contacto con un cilindro calentado con vapor de agua que presenta un diámetro comprendido entre aproximadamente 1,5 m y aproximadamente 6 m. El cilindro comprende un recipiente a presión que aloja el vapor del procedimiento hasta aproximadamente 10 bar G y superior, dentro del mismo. El vapor se produce normalmente en calderas convencionales, tubos de humos, tubos de agua o tecnologías similares, provistas a su vez con quemadores de combustible (metano, GLP, gasóleo, etc.) que presentan una eficiencia de combustión máxima equivalente aproximadamente a 90%. At the same time that the air injection is performed, the sheet of paper being processed comes into contact with a cylinder heated with steam that has a diameter between about 1.5 m and about 6 m. The cylinder comprises a pressure vessel that houses the process steam up to approximately 10 bar G and above, within it. Steam is normally produced in conventional boilers, smoke pipes, water pipes or similar technologies, which are in turn provided with fuel burners (methane, LPG, diesel, etc.) that have a maximum combustion efficiency equivalent to approximately 90% .

En los sistemas actuales de secado y desecado, toda la "niebla", o una parte de la misma, producida por la campana de alto rendimiento se puede utilizar para precalentar el aire del procedimiento y el aire comburente con el que se alimentan los quemadores de la propia campana. En algunos sistemas de secado y desecado, tales como por ejemplo el descrito en la solicitud de patente nº IT2007LU000003A, a nombre del presente solicitante, la "niebla" producida por la campana de alto rendimiento se puede utilizar asimismo para producir vapor a baja temperatura y baja presión (aproximadamente 3 bar G), que se puede utilizar para alimentar una caja de vapor apta para corregir la sección transversal de la humedad. En otras soluciones, tales como por ejemplo la descrita en la solicitud de patente nº IT2009MI000364A, a nombre del presente solicitante, la "niebla" producida por la campana de alto rendimiento, por último se puede utilizar para producir vapor a alta presión (hasta 20 bar G), que puede ser reutilizar directamente en el procedimiento de secado gracias a la presencia de una caldera que funciona colaborando con la principal. In current drying and drying systems, all "fog", or a part thereof, produced by the high-performance hood can be used to preheat the process air and the oxidizing air with which the burners are fed. The bell itself. In some drying and drying systems, such as the one described in patent application No. IT2007LU000003A, in the name of the present applicant, the "fog" produced by the high performance hood can also be used to produce low temperature steam and low pressure (approximately 3 bar G), which can be used to feed a steam box suitable for correcting the cross section of moisture. In other solutions, such as the one described in patent application No. IT2009MI000364A, in the name of the present applicant, the "fog" produced by the high performance hood, can finally be used to produce high pressure steam (up to 20 bar G), which can be reused directly in the drying process thanks to the presence of a boiler that works in collaboration with the main one.

Sin embargo, la energía de la "niebla" no permite generar todo el vapor necesario para el procedimiento de secado, sino únicamente entre el 60% y el 70% de dicho vapor y, por lo tanto, resulta inevitablemente necesario que exista un generador de vapor exterior que proporcione la cantidad restante. Además, dicho generador de vapor exterior resulta necesario en las etapas intermedias del procedimiento de secado, tales como la etapa de puesta en funcionamiento de toda la planta para producir el rollo de papel (la denominada etapa de "calentamiento") y/o el caso en que el propio rollo de papel está roto. However, the "fog" energy does not allow generating all the steam necessary for the drying process, but only between 60% and 70% of said steam and, therefore, it is inevitably necessary that there is a generator of outside steam that provides the remaining amount. In addition, said external steam generator is necessary in the intermediate stages of the drying process, such as the commissioning stage of the entire plant to produce the paper roll (the so-called "heating" stage) and / or the case in which the paper roll itself is broken.

En la patente US nº 4.615.122, se describe un procedimiento para alimentar vapor y aire caliente al cilindro de desecado de un sistema de secado y desecado, en el que se proporciona una caldera de recuperación, eliminando potencialmente una caldera exterior dispuesta a distancia. Dicha solución presenta una configuración en serie entre la caldera y la campana, con el problema de que no puede realizar una regulación independiente entre las condiciones térmicas de la campana y las de la caldera, ya que la campana y la caldera presentan unos flujos de aire en serie y están regulados por un único quemador. Por lo tanto, resulta posible eliminar la planta de caldera exterior, a expensas, sin embargo, de la flexibilidad en la regulación de las condiciones térmicas de todo el sistema de secado y desecado y, por consiguiente, a expensas de la flexibilidad de la producción del papel deshidratado. In US Patent No. 4,615,122, a process for feeding steam and hot air to the drying cylinder of a drying and drying system is described, in which a recovery boiler is provided, potentially eliminating an external boiler arranged at a distance. This solution has a series configuration between the boiler and the hood, with the problem that it cannot perform independent regulation between the thermal conditions of the hood and those of the boiler, since the hood and boiler have air flows in series and are regulated by a single burner. Therefore, it is possible to eliminate the external boiler plant, at the expense, however, of the flexibility in regulating the thermal conditions of the entire drying and drying system and, consequently, at the expense of production flexibility of dehydrated paper.

Por lo tanto, el propósito general de la presente invención es realizar un sistema de secado y desecado para plantas de producción de un material de papel a modo de banda, en particular pero no exclusivamente, para plantas de producción de rollos de papel higiénico, que permita superar los problemas mencionados anteriormente de los sistemas realizados según la técnica anterior. Therefore, the general purpose of the present invention is to perform a drying and drying system for production plants of a paper-like paper material, in particular but not exclusively, for toilet paper roll production plants, which allow to overcome the problems mentioned above of the systems made according to the prior art.

En particular, un objetivo de la presente invención es realizar un sistema de secado y desecado para plantas de producción de un material de papel a modo de banda que no presente generador de vapor exterior alguno, de tal modo que sea completamente independiente tanto durante la etapa de secado normal del papel como durante las etapas intermedias. In particular, an objective of the present invention is to carry out a drying and drying system for production plants of a paper material in the form of a band that does not have any external steam generator, so that it is completely independent both during the stage of normal drying of the paper as during the intermediate stages.

Un propósito adicional de la presente invención realizar asimismo un sistema de secado y desecado para plantas de producción de un material de papel a modo de banda, en el que tanto las condiciones térmicas de la campana como las de la caldera se puedan regular de un modo completamente independiente, lo que permita regular la temperatura, la presión de funcionamiento y las masas de aire circulante que son completamente distintas para los dos dispositivos de secado independientes (campana y caldera). A further purpose of the present invention is also to carry out a drying and drying system for production plants of a paper-like paper material, in which both the thermal conditions of the hood and the boiler can be regulated in a manner completely independent, which allows to regulate the temperature, the operating pressure and the circulating air masses that are completely different for the two independent drying devices (hood and boiler).

Un propósito adicional de la presente invención es, por último, realizar un sistema de secado y desecado para plantas de producción de un material de papel a modo de banda, que permita reducir tanto el consumo energético de la planta en general y las emisiones contaminantes que dispersa en la atmósfera la propia planta, ya que, tal como se ha indicado anteriormente, la regulación independiente de la campana y de la caldera permite configurar las condiciones térmicas del modo más apropiado para el tipo de papel que se está procesando. A further purpose of the present invention is, finally, to carry out a drying and drying system for production plants of a paper material as a band, which allows reducing both the energy consumption of the plant in general and the pollutant emissions that The plant itself is dispersed in the atmosphere, as, as indicated above, the independent regulation of the hood and the boiler allows the thermal conditions to be configured in the most appropriate way for the type of paper being processed.

Dichos propósitos según la presente invención se alcanzan realizando un sistema de secado y desecado para plantas de producción de material de papel a modo de banda, en particular pero no exclusivamente, para plantas para producir rollos de papel higiénico, tal como se indica en la reivindicación 1. Said purposes according to the present invention are achieved by performing a drying and drying system for production plants of paper-like paper, in particular but not exclusively, for plants for producing rolls of toilet paper, as indicated in the claim. one.

Las características adicionales de la presente invención se ponen de manifiesto en las reivindicaciones subordinadas, que forman parte integrante de la presente descripción. Additional features of the present invention are revealed in the dependent claims, which form an integral part of the present description.

Las características y las ventajas de un sistema de secado y desecado para plantas destinado a producir un material de papel a modo de banda según la presente invención se pondrá más claramente de manifiesto a partir de la siguiente descripción, proporcionada a título de ejemplo y no con fines limitativos, haciendo referencia a los dibujos esquemáticos adjuntos, en los que la única figura es una vista esquemática de una forma de realización preferida de dicho sistema. The characteristics and advantages of a drying and drying system for plants intended to produce a paper-like paper material according to the present invention will become more clear from the following description, provided by way of example and not with limiting purposes, referring to the accompanying schematic drawings, in which the only figure is a schematic view of a preferred embodiment of said system.

Cabe señalar que, en la figura adjunta, unas referencias numéricas idénticas indican elementos que son iguales o equivalentes. It should be noted that, in the attached figure, identical numerical references indicate elements that are equal or equivalent.

Haciendo referencia a la figura 1, se representa un sistema de secado y desecado por evaporación, que se puede utilizar en una planta destinado a producir un material de papel a modo de banda, realizado según la presente invención. El sistema se indica en su totalidad con la referencia numérica 10. Referring to Figure 1, an evaporation drying and drying system is depicted, which can be used in a plant intended to produce a paper-like paper material, made according to the present invention. The system is indicated in its entirety with numerical reference 10.

El sistema de secado y desecado 10 comprende en primer lugar un primer dispositivo de secado 12, del tipo cilindro giratorio calentado, denominado asimismo "cilindro Yankee", en el que el material de papel a modo de banda que se va a desecar (no representado) se enrolla dinámicamente, constituido por una hoja de papel que presenta un contenido elevado en agua. La hoja de papel alcanza el cilindro Yankee 12 de la estación de procesamiento anterior, habitualmente una estación de prensado, que resulta muy conocida en el estado de la técnica y, por lo tanto, no se describirá en detalle en la presente descripción. Sin embargo, en función de cómo se realiza la etapa de prensado de la hoja de papel, la cantidad de agua presente en la propia hoja, puede variar hasta más de un 60% en peso. The drying and drying system 10 first comprises a first drying device 12, of the heated rotating cylinder type, also called "Yankee cylinder", in which the web-like paper material to be dried (not shown) ) is dynamically rolled up, consisting of a sheet of paper that has a high water content. The sheet of paper reaches the Yankee cylinder 12 of the previous processing station, usually a pressing station, which is well known in the state of the art and, therefore, will not be described in detail in the present description. However, depending on how the pressing stage of the paper sheet is performed, the amount of water present in the sheet itself can vary up to more than 60% by weight.

El cilindro Yankee 12 presenta habitualmente un diámetro comprendido entre aproximadamente 1,5 m y aproximadamente 6 m, mientras que su anchura equivale a la anchura de los formatos estándar más comunes de las bobinas utilizadas en las plantas de procesamiento de papel. El cilindro Yankee 12 se realiza en forma de un recipiente de vapor a presión, que contiene un sistema de tuberías (no representado) dentro del mismo, destinado a la eliminación del condensado. The Yankee 12 cylinder usually has a diameter between approximately 1.5 m and approximately 6 m, while its width equals the width of the most common standard formats of the reels used in paper processing plants. The Yankee 12 cylinder is made in the form of a pressure steam vessel, which contains a piping system (not shown) within it, intended for the removal of condensate.

El sistema de secado y desecado 10, por lo tanto, comprende un segundo dispositivo de secado 14, del tipo campana, que cubre por lo menos parcialmente el cilindro Yankee 12 y que puede tanto inyectar aire seco a una temperatura elevada sobre la hoja de papel enrollada en dicho cilindro Yankee 12 como aspirar el aire húmedo, asimismo a una temperatura elevada, denominado "niebla" en el lenguaje técnico, liberado de la propia hoja de papel durante la etapa de desecado. El aire seco inyectado por la campana 14 presenta habitualmente una temperatura que puede alcanzar aproximadamente los 700°C y valores superiores, mientras que el aire húmedo extraído de la hoja de papel puede presentar una temperatura de hasta 450°C y valores superiores. The drying and drying system 10, therefore, comprises a second drying device 14, of the bell type, which covers at least partially the Yankee cylinder 12 and which can both inject dry air at an elevated temperature onto the paper sheet rolled into said Yankee 12 cylinder as sucking moist air, also at an elevated temperature, called "fog" in the technical language, released from the paper sheet itself during the drying stage. The dry air injected by the hood 14 usually has a temperature that can reach approximately 700 ° C and higher values, while the humid air extracted from the paper sheet can have a temperature of up to 450 ° C and higher values.

El aire seco a una temperatura elevada, inyectado por la campana 14, se produce mediante un quemador 16 que utiliza un combustible (por ejemplo metano, GLP o gasóleo) alimentado a través de una tubería de alimentación apta Dry air at an elevated temperature, injected by the hood 14, is produced by a burner 16 that uses a fuel (for example methane, LPG or diesel) fed through a suitable feed pipe

18. El aire, extraído de la atmósfera y transportado, a través de una tubería de entrada apta 20 y mediante un ventilador 22, hacia el propio quemador 16, se utiliza como comburente. El flujo de gas de combustión y de aire en la salida del quemador 16 constituye el aire seco para el secado y desecado, que se envía a presión hacia la campana 14 a través de una o más tuberías de entrada 24. 18. The air, extracted from the atmosphere and transported, through a suitable inlet pipe 20 and by means of a fan 22, towards the burner 16 itself, is used as a oxidizer. The flow of combustion gas and air at the outlet of the burner 16 constitutes dry air for drying and drying, which is sent under pressure to the hood 14 through one or more inlet pipes 24.

Por otro lado, el aire húmedo a temperatura elevada, extraído desde la campana 14 de la hoja de papel que se está procesando, se transmite a través de una o más tuberías de liberación 26 y se envía por lo menos parcialmente, mediante un ventilador de recirculación 28, hacia el quemador 16 para que se pueda calentar y reutilizar por la propia campana 14 a fin de secar la hoja de papel. La parte restante de aire húmedo a temperatura elevada extraído de la campana 14 se envía por último, a través de las tuberías de liberación 26, hacia un intercambiador térmico aire On the other hand, the humid air at high temperature, extracted from the hood 14 of the sheet of paper being processed, is transmitted through one or more release pipes 26 and is sent at least partially, by a fan of recirculation 28, towards the burner 16 so that it can be heated and reused by the hood 14 itself in order to dry the paper sheet. The remaining part of high temperature humid air extracted from the hood 14 is finally sent, through the release pipes 26, to an air heat exchanger

--: aire 30 (no siempre presente), donde se cede una parte de su calor al aire exterior, para que se envíe al quemador 16, y al aire reintegración, a través de la tubería de entrada 20 y, por lo tanto, se expulsa del sistema 10 mediante un ventilador de escape y recirculación 32. air 30 (not always present), where a part of its heat is transferred to the outside air, so that it is sent to the burner 16, and to the reintegration air, through the inlet pipe 20 and, therefore, is expelled from the system 10 by means of an exhaust and recirculation fan 32.

A lo largo de las tuberías 26 destinadas a liberar el aire húmedo de la campana 14, se dispone por lo menos una caldera de recuperación 34, alimentada por dicho aire húmedo o "niebla" y que puede generar vapor a alta presión (entre aproximadamente 10 bar G y aproximadamente 20 bar G) de tal modo que a su vez alimenta un termocompresor 36 y una válvula de reintegración o "de aporte" 70, a través de una tubería de suministro 40, que alimenta el vapor hacia el cilindro Yankee 12. Por lo tanto, el vapor producido por la caldera de recuperación 34 minimiza, en el sistema 10, la utilización de una caldera de combustible convencional para alimentar el cilindro Yankee 12. Along the pipes 26 intended to release the humid air from the hood 14, at least one recovery boiler 34 is provided, fed by said moist air or "fog" and which can generate high pressure steam (between approximately 10 bar G and approximately 20 bar G) in such a way that it in turn feeds a thermocompressor 36 and a reintegration or "supply" valve 70, through a supply pipe 40, which feeds the steam into the Yankee cylinder 12. Therefore, the steam produced by the recovery boiler 34 minimizes, in system 10, the use of a conventional fuel boiler to feed the Yankee cylinder 12.

Según la presente invención, a lo largo de las tuberías 26 para liberar el aire húmedo de la campana 14, corriente arriba de la caldera de recuperación 34, existe por lo menos un quemador auxiliar 58, que utiliza un combustible extraído a través de una primera tubería de alimentación 60 que extrae el aire, utilizado como comburente, directamente de la atmósfera. El aire comburente se transporta al quemador auxiliar 58 a través de una segunda tubería de alimentación 62, conectada directamente con la tubería de entrada 20 que transporta el aire seco extraído de la atmósfera hacia el quemador 16 de la campana 14 y un ventilador 66 para el aire comburente. According to the present invention, along the pipes 26 to release the humid air from the hood 14, upstream of the recovery boiler 34, there is at least one auxiliary burner 58, which uses a fuel extracted through a first feed pipe 60 that extracts the air, used as a oxidizer, directly from the atmosphere. The combustion air is transported to the auxiliary burner 58 through a second supply line 62, connected directly with the inlet pipe 20 that conveys the dry air extracted from the atmosphere to the burner 16 of the bell 14 and a fan 66 for the oxidizing air

El quemador auxiliar 58 permite obtener un aumento de la temperatura del aire húmedo, procedente de la campana 14 y de un sistema de tuberías de recirculación y equilibrado 72 y que se enviará a la caldera de recuperación 34, desde un valor comprendido aproximadamente entre 400°C y 420°C hasta aproximadamente 600°C y superior. Por lo tanto, al introducir el quemador auxiliar 58 antes del grupo de tuberías de la caldera de recuperación 34, resulta posible que el sistema de secado y desecado 10 según la presente invención no presente la caldera exterior convencional. The auxiliary burner 58 allows to obtain an increase in the temperature of the humid air, coming from the hood 14 and a recirculation and balancing pipe system 72 and which will be sent to the recovery boiler 34, from a value between approximately 400 ° C and 420 ° C up to approximately 600 ° C and higher. Therefore, when the auxiliary burner 58 is introduced before the pipe group of the recovery boiler 34, it is possible that the drying and drying system 10 according to the present invention does not present the conventional outer boiler.

Además, mediante las tuberías 72 y una o más válvulas dosificadoras de ajuste 38 se constituye un segundo circuito de recirculación y equilibrado, además del constituido por las tuberías de liberación 26, asimismo para el flujo de aire de la caldera de recuperación 34. La regulación del flujo de dicho aire recirculado se produce mediante las válvulas dosificadoras de ajuste 64 y 38 dispuestas en las tuberías de liberación 26 y en las tuberías de recirculación y equilibrado 72, respectivamente, a fin de aumentar la masa de aire que circula a través de la caldera de recuperación 34 en una cantidad necesaria para alcanzar la cantidad necesaria de vapor sin modificar las condiciones del procedimiento de la campana 14 y del quemador principal 16. Por consiguiente, el sistema 10 presenta dos grupos separados para alimentar la campana 14 en serie en la caldera de recuperación 34. Al utilizar dos quemadores separados 16 y 58, dos circuitos de recirculación separados 26 y 72 y una serie de válvulas dosificadoras de ajuste 64 y 38, resulta posible, en tiempo real, obtener el equilibrio y la regulación continua e independiente de los flujos de aire de la campana 14 y de la caldera de recuperación 34 y, por lo tanto, del calor relativo y la condiciones energéticas. Furthermore, by means of the pipes 72 and one or more adjusting metering valves 38 a second recirculation and balancing circuit is constituted, in addition to the one constituted by the release pipes 26, also for the air flow of the recovery boiler 34. The regulation of the flow of said recirculated air is produced by the adjusting metering valves 64 and 38 arranged in the release pipes 26 and in the recirculation and balancing pipes 72, respectively, in order to increase the mass of air circulating through the recovery boiler 34 in an amount necessary to reach the necessary amount of steam without modifying the conditions of the procedure of the hood 14 and the main burner 16. Accordingly, the system 10 has two separate groups for feeding the hood 14 in series into the recovery boiler 34. When using two separate burners 16 and 58, two separate recirculation circuits 26 and 72 and a series of adjusting metering valves 64 and 38, it is possible, in real time, to obtain the balance and the continuous and independent regulation of the air flows of the hood 14 and of the recovery boiler 34 and, therefore, of relative heat and energy conditions.

A lo largo de los tubos 26 destinados a liberar el aire húmedo de la campana 14, corriente arriba del quemador auxiliar 58 y de la caldera de recuperación 34, se pueden disponer una o más válvulas de compuerta, no representadas en la figura, que permiten eludir la caldera de recuperación 34 y/o el quemador auxiliar 58, por motivos de seguridad. Along the tubes 26 intended to release the moist air from the hood 14, upstream of the auxiliary burner 58 and the recovery boiler 34, one or more gate valves, not shown in the figure, can be arranged, which allow bypass the recovery boiler 34 and / or the auxiliary burner 58, for safety reasons.

Por lo tanto, el sistema de secado y desecado 10 comprende un primer depósito separador 42 que puede recoger el "vapor de expansión instantánea" y el "vapor de purga", así como los condensados calientes, procedentes del cilindro Yankee 12 a través de una tubería 44. Desde el primer tanque separador 42, el vapor de expansión instantánea y el vapor de purga se reintroducen en el termocompresor 36 a través de una tubería 46, mientras que los condensados calientes se envían, a través de una tubería de retorno 48 y mediante una primera bomba de circulación 50 destinada alimentar la caldera de recuperación 34, hacia un segundo depósito acumulador y Therefore, the drying and drying system 10 comprises a first separator tank 42 which can collect the "instant expansion steam" and the "purge steam", as well as the hot condensates, coming from the Yankee cylinder 12 through a pipe 44. From the first separator tank 42, the instant expansion steam and the purge steam are reintroduced into the thermocompressor 36 through a pipe 46, while the hot condensates are sent, through a return pipe 48 and by means of a first circulation pump 50 intended to feed the recovery boiler 34, towards a second accumulator tank and

5 separador 52. 5 separator 52.

Una segunda bomba de circulación 54 impulsa los condensados que se encuentran en el segundo depósito acumulador y separador 52, a través de una tubería apta 56, en el grupo de tubos de la caldera de recuperación 34, que puede, por lo tanto, generar un fluido bifásico. Dicho líquido bifásico se envía a un cuerpo de cilindro superior 68 A second circulation pump 54 drives the condensates found in the second accumulator and separator tank 52, through a suitable pipe 56, in the tube group of the recovery boiler 34, which can, therefore, generate a biphasic fluid Said biphasic liquid is sent to an upper cylinder body 68

10 de la caldera de recuperación 34, que de este modo funciona como caldera de la tubería de agua: la parte líquida del líquido bifásico se reintroduce en el depósito acumulador y separador 52, que funciona como cuerpo de cilindro inferior de la caldera de recuperación 34, mientras que la parte de vapor del propio líquido bifásico, a través de la tubería de suministro 40, alimenta el termocompresor 36 y la válvula de reintroducción o "de aporte" 70. 10 of the recovery boiler 34, which thus functions as a boiler of the water pipe: the liquid part of the biphasic liquid is reintroduced into the accumulator and separator tank 52, which functions as the lower cylinder body of the recovery boiler 34 , while the steam part of the biphasic liquid itself, through the supply pipe 40, feeds the thermocompressor 36 and the "inlet" or "inlet" valve 70.

15 Además de los elementos descritos hasta el momento y representados en la figura, el sistema de secado y desecado 10 puede presentar todos los dispositivos para controlar el nivel, la temperatura y la presión (no representados) que resulten necesarios para que el mismo pueda funcionar correctamente, así como un posible sistema electrónico de control lógico programable (PLC). 15 In addition to the elements described so far and represented in the figure, the drying and drying system 10 can have all the devices to control the level, temperature and pressure (not shown) that are necessary for it to function. correctly, as well as a possible electronic programmable logic control system (PLC).

20 La caldera de recuperación 34 presenta asimismo todo el equipo de seguridad previsto (válvula de seguridad, termostato de reinicio manual, etc.) que permiten la autorización de la misma según la Directiva PED 97/23/EC relativa a la seguridad de dichos dispositivos. 20 The recovery boiler 34 also has all the safety equipment provided (safety valve, manual reset thermostat, etc.) that allow its authorization according to PED Directive 97/23 / EC regarding the safety of such devices .

Por lo tanto, se ha observado que el sistema de secado y desecado para plantas de producción de un material de Therefore, it has been observed that the drying and drying system for production plants of a material of

25 papel a modo de banda, según la presente invención, alcanza los propósitos indicados anteriormente. Gracias a la presencia de la caldera de recuperación, que utiliza la energía de la "niebla" de escape de los dispositivos de secado, y del quemador auxiliar, que a su vez aumenta la energía de dicha "niebla", resulta de hecho posible utilizar el vapor producido en el procedimiento de producción de secado y desecado, lo que permite una reducción sustancial de la incidencia de la energía específica por unidad de masa del producto acabado. Además, se produce 25 paper as a band, according to the present invention, achieves the purposes indicated above. Thanks to the presence of the recovery boiler, which uses the energy of the "fog" exhaust of the drying devices, and the auxiliary burner, which in turn increases the energy of said "fog", it is in fact possible to use the steam produced in the drying and drying process, which allows a substantial reduction in the incidence of specific energy per unit mass of the finished product. In addition, it occurs

30 asimismo una reducción de las emisiones de CO2 en el procedimiento de producción global del rollo de papel, ya que el quemador auxiliar, que utiliza "nieblas" a una temperatura elevada como el aire en la entrada a la cámara de combustión, optimiza el procedimiento de combustión. 30 also a reduction in CO2 emissions in the overall paper roll production process, since the auxiliary burner, which uses "mists" at an elevated temperature such as air at the entrance to the combustion chamber, optimizes the procedure of combustion

El alcance de la protección de la presente invención se define según las reivindicaciones adjuntas. The scope of protection of the present invention is defined according to the appended claims.

Claims

1. Drying and drying system (10) for a paper-like paper material, the system comprising (10):

5 at least a first drying device (12), of the steam-pressurized pressurized rotating cylinder type, on which the paper-like paper material to be dried is dynamically wound, said cylinder (12) being internally provided with a piping system intended to extract condensate;

at least a second drying device (14), of the bell type, which covers at least partially

10 said cylinder (12) and comprising at least a first burner (16) capable of producing dry air at elevated temperature, said bell (14) being able to blow said dry air at high temperature on the paper material as a band wound on said cylinder (12) and for aspirating the moist air released by said paper material as a band, and

15 at least one recovery boiler (34), fed by moist air released by the paper material as a strip and arranged along pipes (26) to release said moist air from said bell (14), being said recovery boiler (34) capable of generating high pressure steam to feed a thermocompressor (36) and a supply valve (70) that supply steam to said cylinder (12),

20 in which along the pipes (26) intended to release said moist air from said hood (14), upstream of said recovery boiler (34), at least one auxiliary burner (58) is also provided, suitable for increasing the temperature of said moist air from said bell (14) and for sending it to said recovery boiler (34).

2. System (10) according to claim 1, characterized in that said auxiliary burner (58) uses a fuel extracted through a first feed pipe (60) and extracts the air, used as a oxidizer, directly from the atmosphere through of a second supply pipe (62), directly connected to an inlet pipe (20) that brings dry air extracted from the atmosphere to said bell (14) and through a fan (66) for the oxidizing air.

3. System (10) according to claim 1 or 2, characterized in that said auxiliary burner (58) is capable of increasing the temperature of said moist air from said bell (14) from a value between approximately 400 ° C and 420 ° C to a value of approximately 600 ° C and higher.

System (10) according to any one of claims 1 to 3, characterized in that said recovery boiler

(34) is capable of generating steam at a pressure between about 10 bar G and about 20 bar G.

5. System (10) according to any of the preceding claims, which also comprises at least one

40 exhaust and recirculation fan (32) and a system of recirculation and balancing pipes (72) suitable for forming a second recirculation and balancing circuit, in addition to a first formed by the pipes (26) intended to release moist air from said bell (14), for the air flows of said recovery boiler

(34) and said auxiliary burner (58).

System (10) according to claim 5, characterized in that along the pipes (26) intended to release moist air from said bell (14), upstream of said auxiliary burner (58) and said boiler of recovery (34), and along said recirculation and balancing pipe system (72) one or more adjustment metering valves (64; 38) are provided that are capable of sending certain amounts of moist air released by the paper material as a band, both to the atmosphere and to said auxiliary burner (58), being suitable

50 also to reintroduce it into the circuits of said bell (14) even after having passed through said recovery boiler (34), said one or more adjusting metering valves (64; 38) continuously regulating the flows and allowing balancing the system (10) in real time.

7. System (10) according to any of the preceding claims, which also comprises at least one

First separating tank (42) suitable for receiving steam and hot condensates from said cylinder (12), the steam from said cylinder (12) being reintroduced into said thermocompressor (36) through a pipe (46).

System (10) according to claim 7, which also comprises at least a second accumulator tank and

60 separator (52), said second accumulator and separator tank (52) receiving hot condensates from said first separator tank (42) through a return pipe (48) and by at least a first circulation pump (50 ) to feed said recovery boiler (34).

9. System (10) according to claim 8, which also comprises at least a second circulation pump 65 (54) capable of sending to said recovery boiler (34) the hot condensates contained in said second accumulator and separator tank (52 ), thus being able to generate said recovery boiler (34) a biphasic fluid.

System (10) according to claim 9, characterized in that said biphasic fluid is sent to an upper cylinder body (68) of said recovery boiler (34), the liquid part of said biphasic fluid being reintroduced into said second accumulator tank and separator (52), which functions as a lower cylinder body of said recovery boiler (34), and the vapor part of said fluid being sent to a supply pipe

(40) connecting said recovery boiler (34) with said thermocompressor (36) and said supply valve (70).