DE102019215569A1 - Water separation from the flue gas of clinker burning plants - Google Patents

Abstract

Process for separating water from the flue gas of clinker burning plants and appropriately configured clinker burning plants.

Description

The present invention relates to methods and systems for separating water from the flue gas of clinker burning systems.

The operation of clinker burning plants requires the use of process water. This water is usually lost as water vapor in the exhaust gas and cannot be reused. Part of the water can be recovered from the exhaust gas through cooling and condensation. However, this cooling and drying of the flue gas causes the problem that the exhaust gas cools down too far and there is no longer sufficient buoyancy for the exhaust gas. There is also the problem that dissolved acid gases (SO ₂ , HCI etc.) set a low pH value in the condensate, which can lead to corrosion. As state of the art could JP 2012-56794 , U.S. 4,915,914 , WO 02/059043 A2 or WO 2016/030207 A1 to be named. As prior art relating to heat exchangers, for example EP 0 982 427 A1 , EP 1 106 729 A2 , U.S. 4,955,435 or US 7,243,403 B2 to be named. However, even these solutions can still be improved; in particular, these solutions cannot easily be used for water separation in clinker burning plants.

The processes and systems of the prior art still show problems and therefore still have considerable potential for improvement.

The object of the present invention was accordingly to provide systems and methods which avoid the disadvantages of the prior art or further improve the systems and methods of the prior art.

These and other objects that become apparent to the person skilled in the art when considering the present description are achieved by the subject matter of the claims, the subclaims representing preferred embodiments.

Further embodiments according to the invention and preferred subjects emerge from the following description.

• Der Ausdruck „und/oder“ bedeutet im Rahmen der vorliegenden Erfindung, dass sowohl die einzelnen Elemente, die mit diesem Ausdruck verbunden sind, als auch eine Kombination der einzelnen Elemente umfasst ist.

In the context of the present invention, the following terms and expressions are used as follows:

• In the context of the present invention, the term “and / or” means that both the individual elements that are associated with this term and a combination of the individual elements are included.

In the context of the present invention, the exhaust gas from the kiln of the clinker plant and to be subjected to water removal is sometimes also referred to as exhaust air. Since this gas passes through the preheater, it is sometimes also referred to as preheater exhaust or exhaust air. However, it must be distinguished from the clinker cooler exhaust air in each case.

In the context of the present invention, the abbreviation “SNCR” means “selective non-catalytic reduction”, or else selective non-catalytic reduction. The SNCR is a secondary process that is used, for example, for flue gas denitrification. Thermolysis converts gaseous nitrogen oxides (NOx) into water vapor and nitrogen using, for example, ammonia or urea. These terminology and technology are well known to those skilled in the art.

In the context of the present invention, the abbreviation “SCR” means “selective catalytic reduction”, or else selective catalytic reduction. This is a well-known technique for reducing nitrogen oxides in exhaust gases from, for example, combustion plants and industrial plants. In a chemical reaction on the SCR catalytic converter, nitrogen oxides are reduced with the aid of compounds such as ammonia. These terminology and technology are well known to those skilled in the art.

The present invention therefore relates to a method for separating water from the flue gas of clinker burning plants.
The system parts and devices required for this are in a corresponding operative connection with one another or are configured accordingly.
At least the following interrelated components are included within the scope of the present invention: at least one preheater, optionally a calciner, a kiln, which is preferably a rotary kiln, at least one clinker cooler with at least one exhaust air removal device, at least one exhaust gas cleaning device, at least one condensation device for water vapor contained in the exhaust gas and at least one exhaust chimney.

The subject of the present invention is also a clinker burning plant comprising the mentioned components, which are operatively connected to each other, a preheater, optionally a calciner, a kiln, which is preferably a rotary kiln, a clinker cooler with at least one exhaust air device, at least one exhaust gas purification device, at least one condensation device for water vapor contained in the exhaust gas and at least an exhaust chimney.

Various embodiments of the present invention and disclosure are presented below.

It is possible within the scope of the present invention for several condensation devices to be operated for water vapor contained in the exhaust gas.
In the method of the present invention, the exhaust gas stream of an exhaust gas purification system originating from the kiln is designed and passed through at least one cooling device configured for condensation of entrained water vapor. The condensed water is discharged from the system or passed on for further use within the system. This further use can, for example, be the cooling of hotter system parts.

The cooler exhaust air emerging from the clinker cooler is at least partially captured. The cooler exhaust air collected from the clinker cooler and the exhaust gas from the kiln are combined or mixed with one another. This mixing usually takes place after the exhaust gas has been cleaned and the moisture contained in the exhaust gas has condensed out, but before it enters the exhaust air chimney or when it enters the exhaust air chimney or only in the exhaust air chimney.
For this purpose, it is possible to divide the exhaust gas flows and then mix them partly in front of and partly in the exhaust stack.

In embodiments of the present invention, one or more method steps selected from the group consisting of SCR, SNCR, filtration and combinations thereof are carried out for exhaust gas purification.

In embodiments of the present invention, one or more of the following process steps can be carried out: downstream, in relation to the flow direction of the exhaust gas originating from the preheater, an SCR, an SNCR in the calciner, if this is available, regulation and control of the pH value in the condensing device.
In embodiments of the present invention, the control of the pH is achieved by adding a basic liquid or a basic gas. By adding the basic species, acidic components contained in the exhaust gas, in particular SO ₂ and HCl, are neutralized. Depending on the amount of acid components (i.e. depending on the clinker used), continuous readjustment of the metering may be necessary - for this reason, readjustment of the condensation settings may also be necessary.

In preferred embodiments of the present invention, this metering takes place either in the SNCR, preferably in the calciner (if present), in the SCR, preferably in an SCR system (catalyst), or in the condensation device. It is also possible to meter in the basic liquid or the basic gas at several of these three points mentioned or also at all of the three points.

Particularly suitable basic gas or basic liquid are ammonia or an aqueous ammonia solution. Furthermore, wastewater containing ammonia (photo water or wastewater, e.g. from agriculture) is also conceivable.
In particular in the case of metering in with SCR or SNCR, an aqueous urea solution can be metered in instead of the basic liquid. This solution is actually pH-neutral, but ammonia formed from it can then function as a basic species.

The water condensed out in the context of the process of the present invention can, if it is fed to a further use in the system itself, be used, for example, as process water or as cooling water. If the water is discharged from the system, it can be used as drinking or tap water, as water for agriculture, and / or as service water. Depending on the intended use for which it is ultimately used, it is possible within the scope of the present invention to subject the water to further purification after or when it is discharged from the system.

In various embodiments of the present invention, the condensation of the water from the moist exhaust air from the preheater can be carried out in a multi-stage spray condenser. Such components are known to the person skilled in the art and need not be described further here; Instead of the German term “Sprühkondensator”, the term “Scrubber” can also be used.

Furthermore, in embodiments of the present invention, it is possible to carry out the condensation with the hose bundle heat exchanger described further below.

Of course, other condensation devices customary in the art can also be used.

In embodiments of the present invention, the energy obtained from the exhaust air during the condensation of moisture is used again to supply the clinker burning plant. For example, heat exchangers or turbines or the like can be used for this purpose.

In embodiments of the present invention, the mixing of the exhaust gas flows from the kiln and the cooler exhaust air collected from the clinker cooler can take place by means of mixing chambers, valves, turbulence or combinations of these process measures in the exhaust air chimney or before, but after the (last) condensation device.

In the system of the present invention, the at least one exhaust gas cleaning device for cleaning the exhaust gas flow originating from the furnace is configured and arranged in such a way that the exhaust gas flow originating from the furnace is cleaned with it.
The at least one condensation device is configured and arranged in such a way that condensation of the water vapor entrained in this exhaust gas stream is at least partially enabled.

Although rarely necessary or wanted, the system of the present invention can be configured in such a way that not only water is condensed out, but also other substances.

In the context of the present invention, this condensation device can be configured in such a way that either almost all of the water vapor is condensed (within the scope of the technical / atmospheric possibilities) or only part of the water vapor, in which case the system is configured in such a way that this portion to be condensed out of the water vapor can be set to a certain percentage value. In other words, the relative exhaust gas humidity of the resulting, dried exhaust gas stream can be adjusted to a desired target value. This allows the buoyancy in the exhaust air chimney to be controlled in addition to that via the control by the admixed clinker cooler exhaust air.

The system of the present invention comprises a device for discharging the condensation water from the system or for conveying the water within the system for further use within the system. Of course, it is possible to split up the condensate and only discharge part of it and leave the rest in the system.

The at least one exhaust air device for cooler exhaust air exiting the clinker cooler is configured in such a way that the exiting cooler exhaust air is at least partially captured and can be passed on, so that this cooler exhaust air can be mixed with the dehumidified exhaust air from the preheater and can then be introduced into the exhaust air chimney. In preferred embodiments of the present invention, this exhaust air removal device is configured in such a way that the exact amount of the cooler exhaust air conducted for mixing with the dehumidified preheater exhaust gas can be precisely set. This allows the buoyancy in the exhaust chimney to be controlled in a targeted manner.

The system according to the present invention is configured or designed in such a way that the dehumidified exhaust air coming from the kiln (i.e. the exhaust gases coming from the preheater) and the cooler exhaust air coming from the clinker cooler can be mixed with one another.
This mixing of the two waste gas streams takes place either after the single condensation device or, if several condensation devices are used, after the last condensation device.
The mixing of these gas streams can take place with the aid of a mixing device before the exhaust chimney, or with the aid of a mixing device arranged in the outer wall of the exhaust air chimney, or with the aid of a mixing device arranged inside the exhaust air chimney. It is also possible to introduce the gas streams into the exhaust air chimney via a separate feed line and then to mix them with one another, either with an additional mixing device or without a special mixing device, simply by flowing through each other.
In one embodiment of the present invention, the mixture in front of the exhaust chimney is preferred. Mixing device in this sense can in principle be any mixing device known from the prior art, for example also a simple T-connection or Y-connection of two pipes.

According to the method described above, the clinker burning plant of the present invention can comprise an SCR plant, an SNCR plant, a filter plant or several of these plants.

In embodiments of the present invention, the clinker burning plant comprises a device configured for SCR downstream, in relation to the flow direction of the exhaust gas originating from the pre-dryer (preheater).

In embodiments of the present invention, the clinker burning plant comprises an apparatus configured for SNCR in the calciner.
In embodiments of the present invention, the clinker burning plant comprises a device for regulating and controlling the pH value in the condensation device.

In embodiments of the present invention, the clinker burning plant can comprise a multi-stage spray condenser as the condensation device.
In a further embodiment of the present invention, the clinker burning plant can comprise a hose bundle heat exchanger as a condensation device.
In a further embodiment of the present invention, the clinker burning plant can comprise further condensation devices known from the prior art.

In embodiments of the present invention, the clinker burning plant comprises at least one device for obtaining and forwarding the energy obtained during the condensation.

In further embodiments of the present invention, the clinker burning plant comprises mixing chambers and / or valves for mixing the two gas flows mentioned.

In some embodiment of the present invention it is possible that the gas streams provided for emission through the exhaust air chimney are subjected to additional heating (or, more rarely, also cooling), for example by means of heat exchangers.

In embodiments of the present invention, it is possible to pass the moist exhaust gases originating from the preheater as a total flow through the following devices, or to divide them into different partial flows. In this context, it is possible, for example, to design part of the moist exhaust air from the preheater for an SCR in an SCR system (catalytic converter) and to divert another part past this component. It is also possible not to lead part of the moist preheater exhaust air through the condensation device, but rather past the condensation device, so that part of the exhaust air is not dehumidified.
The exact division of the streams into partial streams results from the precise conditions on site and can easily be carried out by a person skilled in the art.

By only partially dehumidifying the exhaust air streams, a sufficiently high level of buoyancy can be set in the exhaust air chimney in the event that the moisture content of the preheater exhaust gas is otherwise unsuitable for various reasons.

In other embodiments of the present invention, it is possible to regulate the buoyancy of the exhaust gases in the exhaust chimney via the exact proportion of the metered amount of the clinker cooler exhaust air coming from the clinker cooler.

In the context of the present invention, it was surprisingly found that by adding the cooler exhaust air to the cooled and dried exhaust gas, both the density of the exhaust gas and the temperature of the exhaust gas can be increased. This measure ensures that the exhaust gas is lifted sufficiently at the emission point.
The corrosion problem is solved within the scope of the present invention in that the pH value in the condensate is suitably adjusted by adding one or more basic gases or liquids, in particular ammonia. For galvanized steel e.g. B.> pH 5.5.

In embodiments of the present invention, no fan or blower is arranged between the condensation device and the exhaust air chimney; the dehumidified exhaust gases have sufficient buoyancy of their own within the scope of the present invention, so that additional fans or blowers between the condensation device and the exhaust chimney are not necessary.

In embodiments of the present invention, the addition of the basic gases or liquids can take place either directly in or upstream of a condenser.
In embodiments of the present invention, an SNCR or. SCR system can be adapted to the acid gas content with regard to the reducing agent conversion in such a way that the desired pH value is reached in the condenser.

In embodiments of the present invention, apart from the mixing of dehumidified exhaust gas and clinker cooler exhaust air, no further process steps are carried out between the condensation step and introduction into the exhaust air chimney (possibly apart from the passage through pipes to the exhaust air chimney).
Accordingly, in embodiments of the present invention, apart from the mixing device for the dehumidified exhaust gas and the clinker cooler exhaust air, there are no further devices between the condensation device and the exhaust air chimney (possibly apart from pipes for guiding through to the exhaust air chimney).

In the context of the present invention, an essential aspect is that exhaust gas and clinker cooler exhaust air are only mixed shortly before entry, when entering or in the exhaust chimney, i.e. after the condensation step.

In embodiments of the present invention, the various gas streams ( Exhaust gas and clinker cooler exhaust air) can also be divided independently of one another and then mixed, for example, partly in front of and partly in the chimney.

In embodiments of the present invention, the condensation step or device is the last step / device before the exhaust gases are introduced into the exhaust stack.

The present invention also relates to special heat exchangers.

From the exhaust gas from industrial plants, e.g. B. clinker burning plants, part of the water is to be separated and condensed in the context of the present disclosure. A solution was found which, based on the amount of separated water, causes the lowest possible investment and operating costs and is insensitive to corrosion. The amount of water actually separated can vary depending on the weather and climatic conditions.

In the context of the present invention, therefore, a heat exchanger made of film webs is used in preferred variants for cooling and condensation. For this purpose, two film webs in each case are glued or welded in the longitudinal direction in such a way that when the films are inflated they take the form of a tube bundle or several tube bundles running in parallel. Such film webs can then be introduced into a housing which contains a gas distributor in the upper area and a gas collector and a condensate discharge at the bottom. The hot, humid gas then flows from top to bottom through the hose bundle and is cooled from the outside by the ambient air. The orientation of the hose webs is vertical in the context of the present disclosure in order to ensure optimal condensate drainage. The small thickness of the films between 25 μm and 200 μm allows a sufficiently high heat transfer despite the poor thermal conductivity of the film material, which is usually in the range from 0.1 W m ⁻¹ K ⁻¹ to 0.9 W m ⁻¹ K ⁻¹ , at the same time the specific costs for the heat exchanger surface remain very low. In this way, large areas and overall cross-sections can be realized inexpensively. The exhaust gas flowing through hardly causes any pressure loss. Since the exhaust gas is dedusted in preferred embodiments, there is no significant wear of the heat exchanger surfaces and the special heat exchangers of the present disclosure therefore have lifetimes of one year or more.

Suitable materials are available up to at least 120 ° C, in some cases also for temperatures above 150 ° C. In a variant of the present invention, suitable plastics have glass transition temperatures of at least 120.degree. C., in particular of at least 150.degree. The films preferably have sufficient strength to hold their own weight and, in addition, the weight of the condensate. If the exhaust gas coming out of the process is too hot, a corresponding pre-cooling, e.g. B. can be used by water injection.
The materials used for the foils have sufficient thermal resistance for the temperatures prevailing in the process and sufficient resistance to water (vapor) for the atmospheric humidities prevailing in the process.
In a variant of the present invention, the materials used for the films are resistant to acid gas components such as SO ₂ and HCl that may be contained in the exhaust gas to be dried. If the pH value is regulated before the condensation, as described, materials with lower acid resistance can be used.

Although the present invention mostly refers to films made of plastic, the films do not necessarily have to be made of plastic. Metal foils and composite foils can also be used in the context of the present invention. The particular advantage of plastic films is that they can be obtained inexpensively.

In variants of the present invention, preferred plastics for the film webs of the heat exchangers are polyimides and polyester films, in particular polyimides. When choosing them, make sure that they have sufficient thermal resistance. This thermal resistance can be associated with glass transition temperatures of at least 120 °, preferably at least 150 ° C.
Suitable polyimides are available for example under the trade names Kapton ^® or Vespel (without a defined glass transition temperature) of DuPont.

The heat exchangers of the present invention are based on foils, preferably thermoplastic polymer foils, which are partially welded to one another in pairs (or a greater number) so that they correspond to the structure of a hose bundle.
The preferred flexible thermoplastic polymer films can be polyimide films, polyester films (for example polyethylene terephthalate films), polyamide films, ethylene polymer films or elastomer films. Polyimide films and polyethylene terephthalate films are preferred. The polymer film preferably has a thickness of 10 to 125 micrometers and a glass transition temperature (or a Melting point or a softening point) of 190 to 300 ° C. In some variants, the polymer film can contain an inorganic filler or other additives to increase the thermal conductivity of the polymer film.
The thermoplastic polyimide film can be produced in some variants by polymerization and imidation from aromatic tetracarboxylic acid compounds, including 2,3,3 ', 4'-biphenyltetracarboxylic acid dianhydride (a-BPDA) and 4,4'-oxydiphthalic acid dianhydride, and diamine compounds such as 1,3- bis (4-aminophenoxybenzene) (TPE-R) or 1,3-bis (3-aminophenoxybenzene).

The highly heat-resistant polyimide substrate film can in variants have no glass transition temperature or a glass transition temperature (Tg) of approx. 340 ° C. or higher. It can be produced in variants from aromatic tetracarboxylic acid compounds such as 3,3'4,4'-biphenyltetracarboxylic acid dianhydride (s-BPDA) or pyromellitic acid dianhydride and diamine compounds such as p-phenylenediamine (PPD) or a combination of PPD and 4,4'-diaminophenyl ether, through polymerization and imidation can be produced.
In some variants, the above-mentioned multilayer polyimide film has a coefficient of linear expansion (machine direction - MD), traverse direction (TD) and their average, at 50-200 ° C.) of 10 × 10 ^-6 to 35 × 10 ^-6 cm / cm / ° C on.

The flexible heat exchanger of the invention can in principle be produced by a process which comprises the following steps: applying a flexible thermoplastic polymer film to the surface of a further flexible thermoplastic polymer film and partially fusing both polymer films to combine both polymer films to form the tubular pattern between the polymer films to train.
The heat exchanger is manufactured in a variant with a process that includes the steps of arranging a flexible thermoplastic polymer film on another flexible thermoplastic polymer film over an intermediate thermoplastic polymer film from which a line pattern (hose structure) has already been cut, and fusing the two polymer films on the intermediate one flexible thermoplastic polymer film to form the tubular structure.

The manufacture can be done by a method comprising the steps of placing a polymer film on another polymer film, heating both polymer films in a tube-like pattern by applying heat to both polymer films via a heat insulating material in the conduction pattern and fusing both polymer films to combine both polymer films with one another and to form the conductive pattern between the polymer films.

The production can also take place via a method comprising the steps of arranging one polymer film on another polymer film, and applying heat to both polymer films by means of a thermal head in a pattern that is reversed to the line pattern (tube structure), and fusing the two polymer films, if necessary on an intermediate one Polymer film, to combine both.

Exemplary heat exchangers that correspond to this description are in the 2 to 5 shown.

These particular heat exchangers are used in preferred embodiments of the present invention.

• Ausführungsform I. Verfahren zum Abtrennen von Wasser aus dem Rauchgas von Klinkerbrennanlagen, wobei die Klinkerbrennanlage mindestens die miteinander in Wirkverbindung stehenden folgenden Bestandteile
  1. a) einen Vorwärmer,
  2. b) optional einen Calcinator,
  3. c) einen Brennofen, bevorzugt einen Drehrohrofen,
  4. d) einen Klinkerkühler mit mindestens einer Abluftabführvorrichtung,
  5. e) mindestens eine Abgasreinigungsvorrichtung,
  6. f) mindestens eine Kondensationsvorrichtung für im Abgas enthaltenen Wasserdampf,
  7. g) mindestens einen Abluftkamin
  umfasst, und wobei
  • A) der aus dem Brennofen stammende Abgasstrom einer Abgasreinigung unterworfen und durch eine zur Kondensation mitgeführten Wasserdampfs konfigurierte Kühlvorrichtung geleitet wird,
  • B) das kondensierte Wasser aus der Anlage abgeführt oder einer weiteren Verwendung in der Anlage zugeführt wird,
  • C) die aus dem Klinkerkühler austretende Kühlerabluft zumindest teilweise aufgefangen wird,
  dadurch gekennzeichnet, dass die aus A) und C) resultierenden Gasströme nach Abgasreinigung und Kondensationsschritt
  • I) aber vor dem Abluftkamin,
  • II) bei Eintritt in den Abluftkamin, oder
  • III) im Abluftkamin,
  vermischt werden.
• Ausführungsform II. Verfahren nach Ausführungsform I, dadurch gekennzeichnet, dass einer oder mehrere der folgenden Verfahrensschritte zur Abgasreinigung SCR, SNCR, Filtrierung, durchgeführt wird.
• Ausführungsform III. Verfahren nach Ausführungsform I oder II, dadurch gekennzeichnet, dass einer oder mehrere der folgenden Verfahrensschritte eine SCR des aus dem Vortrockner stammenden Abgases stromabwärts, in Bezug auf die Flussrichtung des Abgases, eine SNCR im Calcinator, Regulierung und Kontrolle des pH-Wertes in der Kondensationsvorrichtung, durchgeführt wird bzw. werden.
• Ausführungsform IV. Verfahren nach einer der vorhergehenden Ausführungsformen, dadurch gekennzeichnet, dass das auskondensierte Wasser bei Zuführung einer weiteren Verwendung in der Anlage als Prozesswasser oder als Kühlwasser, oder nach dem Abführen aus der Anlage, gegebenenfalls nach weiterer Aufreinigung, als Trink- oder Leitungswasser, als Wasser für die Landwirtschaft, und/oder als Brauchwasser verwendet wird.
• Ausführungsform V. Verfahren nach einer der vorhergehenden Ausführungsformen, dadurch gekennzeichnet, dass die Kondensation in einem Mehrstufen-Sprühkondensator durchgeführt wird.
• Ausführungsform VI. Verfahren nach einer der vorhergehenden Ausführungsformen, dadurch gekennzeichnet, dass die bei der Kondensation gewonnene Energie zur Versorgung der Klinkerbrennanlage herangezogen wird.
• Ausführungsform VII. Verfahren nach einer der vorhergehenden Ausführungsformen, dadurch gekennzeichnet, dass die Vermischung der aus A) und C) resultierenden Gasströme mittels Mischkammern, Ventilen, Verwirbelung oder Kombinationen davon im Abluftkamin erfolgt.
• Ausführungsform VIII. Klinkerbrennanlage umfassend mindestens die miteinander in Wirkverbindung stehenden folgenden Bestandteile
  • a) einen Vorwärmer,
  • b) optional einen Calcinator,
  • c) einen Brennofen, bevorzugt einen Drehrohrofen,
  • d) einen Klinkerkühler mit mindestens einer Abluftabführvorrichtung,
  • e) mindestens eine Abgasreinigungsvorrichtung,
  • f) mindestens eine Kondensationsvorrichtung für im Abgas enthaltenen Wasserdampf,
  • g) mindestens einen Abluftkamin,
  wobei
  • A) die mindestens eine Abgasreinigungsvorrichtung zur Reinigung des aus dem Brennofen stammenden Abgasstrom konfiguriert und angeordnet ist, die mindestens eine Kondensationsvorrichtung zur Kondensation des im Abgasstrom mitgeführten Wasserdampfs konfiguriert und angeordnet ist,
  • B) eine Vorrichtung zur Abführung aus oder Weiterleitung innerhalb der Anlage des kondensierten Wassers umfasst ist,
  • C) die mindestens eine Abluftabführvorrichtung aus dem Klinkerkühler derart konfiguriert ist, dass austretende Kühlerabluft zumindest teilweise aufgefangen wird,

dadurch gekennzeichnet, dass die Anlage weiterhin

• I) eine nach den Abgasreinigungs- und Kondensationsvorrichtungen aber vor dem Abluftkamin angeordnete Mischvorrichtung für die aus A) und C) resultierenden Gasströme,
• II) eine in der äußeren Wandung des Abluftkamins angeordnete Mischvorrichtung für die aus A) und C) resultierenden Gasströme,
• III) im Inneren des Abluftkamins angeordnete Mischvorrichtung für die aus A) und C) resultierenden Gasströme, oder
• IV) getrennte Zuleitungen für die aus A) und C) resultierenden Gasströme in den Abluftkamin umfasst.
• Ausführungsform IX. Klinkerbrennanlage nach Ausführungsform VIII, dadurch gekennzeichnet, dass sie eine oder mehrere Vorrichtungen konfiguriert zur Abgasreinigung mittels SCR, SNCR, Filtrierung, umfasst.
• Ausführungsform X. Klinkerbrennanlage nach Ausführungsform VIII oder IX, dadurch gekennzeichnet, dass sie eine oder mehrere Vorrichtungen konfiguriert zur SCR des aus dem Vortrockner stammenden Abgases stromabwärts, in Bezug auf die Flussrichtung des Abgases, SNCR im Calcinator, Regulierung und Kontrolle des pH-Wertes in der Kondensationsvorrichtung, umfasst.
• Ausführungsform XI. Klinkerbrennanlage nach einer der Ausführungsformen VIII bis X, dadurch gekennzeichnet, dass sie einen Mehrstufen-Sprühkondensator umfasst.
• Ausführungsform XII. Klinkerbrennanlage nach einer der Ausführungsformen VIII bis XI, dadurch gekennzeichnet, dass sie mindestens eine Vorrichtung zur Gewinnung und Weiterleitung der bei der Kondensation gewonnenen Energie umfasst.
• Ausführungsform XIII. Klinkerbrennanlage nach einer der Ausführungsformen VIII bis XII, dadurch gekennzeichnet, dass sie zur Vermischung der aus A) und C) resultierenden Gasströme konfigurierte Mischkammern und/oder Ventile umfasst.
• Ausführungsform XIV. Wärmetauscher umfassend ein Gehäuse, in dem in Längsrichtung verklebte oder verschweißte Folienbahnen, die beim Aufblasen die Form eines Schlauchbündels oder mehrerer parallel verlaufender Schlauchbündel einnehmen, angeordnet sind, welches im oberen Bereich einen Gasverteiler, und am Boden einen Gassammler und eine Kondensatabfuhr enthält, wobei die Folienbahnen in dem Gehäuse derart ausgerichtet sind, dass die Schlauchbündel im Wesentlichen senkrecht ausgerichtet sind. Im Wesentlichen senkrecht bedeutet dabei eine lotrechte Ausrichtung bzw. eine Ausrichtung, die von der Lotrechten bis zu 45° abweicht.
• Ausführungsform XV. Verfahren nach einer der Ausführungsformen I bis VII, dadurch gekennzeichnet, dass zur Kondensation in Schritt f) ein Wärmetauscher gemäß Ausführungsform XIV eingesetzt wird.
• Ausführungsform XVI. Klinkerbrennanlage nach einer der Ausführungsformen VIII bis XIII, dadurch gekennzeichnet, dass die Kondensationsvorrichtung f) ein Wärmetauscher gemäß Ausführungsform XIV ist.

The subject of the present invention or disclosure are, inter alia, the following embodiments denoted by Roman numerals:

• Embodiment I. A method for separating water from the flue gas of clinker burning plants, wherein the clinker burning plant has at least the following components that are operatively connected to one another
  1. a) a preheater,
  2. b) optionally a calciner,
  3. c) a kiln, preferably a rotary kiln,
  4. d) a clinker cooler with at least one exhaust air removal device,
  5. e) at least one exhaust gas cleaning device,
  6. f) at least one condensation device for water vapor contained in the exhaust gas,
  7. g) at least one exhaust chimney
  includes, and where
  • A) the exhaust gas stream coming from the kiln is subjected to exhaust gas cleaning and passed through a cooling device configured for condensation,
  • B) the condensed water is discharged from the system or fed to a further use in the system,
  • C) the cooler exhaust air exiting the clinker cooler is at least partially captured,
  characterized in that the gas streams resulting from A) and C) after exhaust gas cleaning and condensation step
  • I) but in front of the exhaust chimney,
  • II) when entering the exhaust chimney, or
  • III) in the exhaust chimney,
  be mixed.
• Embodiment II. The method according to embodiment I, characterized in that one or more of the following method steps for exhaust gas purification SCR, SNCR, filtration is carried out.
• Embodiment III. Process according to embodiment I or II, characterized in that one or more of the following process steps include an SCR of the exhaust gas originating from the pre-dryer downstream, with regard to the flow direction of the exhaust gas, an SNCR in the calciner, regulation and control of the pH value in the condensation device is or are carried out.
• Embodiment IV. The method according to one of the preceding embodiments, characterized in that the condensed water, when fed for further use in the plant as process water or as cooling water, or after being discharged from the plant, optionally after further purification, as drinking or tap water, is used as water for agriculture, and / or as service water.
• Embodiment V. Method according to one of the preceding embodiments, characterized in that the condensation is carried out in a multi-stage spray condenser.
• Embodiment VI. Method according to one of the preceding embodiments, characterized in that the energy obtained during the condensation is used to supply the clinker burning plant.
• Embodiment VII. The method according to one of the preceding embodiments, characterized in that the mixing of the gas streams resulting from A) and C) takes place by means of mixing chambers, valves, turbulence or combinations thereof in the exhaust air chimney.
• Embodiment VIII. Clinker burning plant comprising at least the following components which are operatively connected to one another
  • a) a preheater,
  • b) optionally a calciner,
  • c) a kiln, preferably a rotary kiln,
  • d) a clinker cooler with at least one exhaust air removal device,
  • e) at least one exhaust gas cleaning device,
  • f) at least one condensation device for water vapor contained in the exhaust gas,
  • g) at least one exhaust chimney,
  in which
  • A) the at least one exhaust gas purification device is configured and arranged for cleaning the exhaust gas flow originating from the kiln, the at least one condensation device is configured and arranged for the condensation of the water vapor entrained in the exhaust gas flow,
  • B) a device for the discharge from or forwarding within the system of the condensed water is included,
  • C) the at least one exhaust air removal device from the clinker cooler is configured in such a way that exiting cooler exhaust air is at least partially captured,

characterized in that the plant continues

• I) a mixing device for the gas flows resulting from A) and C), which is arranged after the exhaust gas cleaning and condensation devices but in front of the exhaust air chimney,
• II) a mixing device arranged in the outer wall of the exhaust chimney for the gas flows resulting from A) and C),
• III) a mixing device for the gas streams resulting from A) and C) arranged in the interior of the exhaust chimney, or
• IV) comprises separate feed lines for the gas flows resulting from A) and C) in the exhaust air chimney.
• Embodiment IX. Clinker burning plant according to embodiment VIII, characterized in that it comprises one or more devices configured for exhaust gas purification by means of SCR, SNCR, filtration.
• Embodiment X. Clinker burning plant according to embodiment VIII or IX, characterized in that it configures one or more devices for SCR of the exhaust gas originating from the pre-dryer downstream, in relation to the flow direction of the exhaust gas, SNCR in the calciner, regulation and control of the pH value in the condensation device.
• Embodiment XI. Clinker burning plant according to one of the embodiments VIII to X, characterized in that it comprises a multi-stage spray condenser.
• Embodiment XII. Clinker burning plant according to one of the embodiments VIII to XI, characterized in that it comprises at least one device for obtaining and forwarding the energy obtained during the condensation.
• Embodiment XIII. Clinker burning plant according to one of the embodiments VIII to XII, characterized in that it comprises mixing chambers and / or valves configured for mixing the gas flows resulting from A) and C).
• Embodiment XIV.Heat exchanger comprising a housing in which longitudinally glued or welded film webs, which when inflated take the form of a hose bundle or several parallel hose bundles, are arranged, which contains a gas distributor in the upper area and a gas collector and a condensate discharge at the bottom , wherein the film webs are aligned in the housing in such a way that the tube bundles are aligned essentially perpendicularly. Essentially perpendicular here means a perpendicular alignment or an alignment that deviates from the perpendicular by up to 45 °.
• Embodiment XV. Process according to one of the embodiments I to VII, characterized in that a heat exchanger according to embodiment XIV is used for the condensation in step f).
• Embodiment XVI. Clinker burning plant according to one of the embodiments VIII to XIII, characterized in that the condensation device f) is a heat exchanger according to embodiment XIV.

One advantage of the present invention is that the condensed water can be reused. With very low levels of SO ₂ in the exhaust gas, it could be used as drinking water; with higher SO ₂ levels and a corresponding ammonia input, the water would still be well suited for irrigation of agricultural areas, since the ammonium sulfate content has a positive effect on the growth of the Affects plants.

All preferred embodiments which are described above in connection with the method also apply analogously to the system.

The components of the systems according to the invention are in operative connection with one another, i.e. are connected to one another by suitable pipelines, etc. in a way that ensures the general functionality of the device. The measures required for this are known to a person skilled in the art.

The present invention is explained in more detail below with reference to the drawings. The drawings are not to be interpreted in a limiting manner and are not true to scale. Furthermore, the drawings do not contain all the features that conventional systems have, but are reduced to the features essential for the present invention and its understanding. The same reference symbols in the various figures each have the same meaning as listed in the list of reference symbols.

1 shows a cement clinker burning plant comprising the concept according to the invention in a general representation. In this drawing, gas flows are represented by dashed arrows / lines (including those gas flows which entrain fine particles or moisture). The right part is a standard cement clinker burning plant, including preheaters 5 , preferably designed as several cyclones, a calciner 6th , an oven 4th , which is preferably a rotary kiln, clinker cooler 3 , from which the cooled clinker is discharged (shown below right) and fed to its further use. It is shown how exhaust gas is derived from the preheater above and then optionally through an SCR system (catalytic converter) 9 or bypassing it (the option being represented by the dashed lines by means of the slashes).

That from the SCR system (catalytic converter) 9 Coming exhaust gas and / or the exhaust gas bypassed is then passed on (optionally, as shown here, by means of a fan) to a filter or deduster. These filters or dust extractors are optional. Whether these filters or dust extractors are used depends on how much dust is entrained in the exhaust gas flow.

Coming from the filter or dust extractor, the exhaust gas is then passed on (shown here by means of a fan) and wholly or partially into the condensation device 1 initiated. The possibility of partially passing the condensation device 1 is represented here by means of the slashes through the dashed lines. A partial bypass takes place in particular, when the moisture content of the exhaust air is relatively low. In the condensation device 1 the moisture contained in the exhaust air (essentially water) is then separated out. The degree of separation depends on the desired degree of drying or the degree of mixing with the clinker cooler exhaust air; it only has to be ensured that the subsequent mixing will result in sufficient buoyancy in the exhaust air chimney 8th is achieved. The setting of the degree of condensation can take place in a regulated manner, which is not explicitly shown in this figure. Starting from the condensation device 1 the condensed liquid (essentially water) is then discharged. In 1 The illustration shows the discharge of water (H ₂ O) or an aqueous solution of, in particular, ammonium sulfate.

In 1 are also three positions 2a , 2 B and 2c shown where a basic substance can be introduced as a gas or liquid. In particular, this liquid is ammonia. 2a illustrates the entry into the calciner, where an SNCR can take place. 2b illustrates the entry in component 9 where an SCR can expire. 2c illustrates the entry of the basic compound into the condensation device. The entry of the basic compound in the form of gas or liquid serves on the one hand to neutralize acidic (or acidic reacting) compounds in the exhaust air (in particular sulfur dioxide and hydrogen chloride); In the context of the SCR or SNCR, however, this connection can also be used to run the corresponding SCR, SNCR, so that the pollutant content of the exhaust air (in particular NO _x ) can be reduced. Furthermore, in 1 illustrates how exhaust air coming from the clinker cooler after the condensation device 1 and in front of the exhaust chimney 8th with those from the condensation device 1 coming, dried exhaust gases can be mixed, optionally additionally with the condensation device 1 bypassed part of the preheater exhaust gases. Although in 1 illustrates that the two or possibly three gas flows between the condensation device 1 and the exhaust chimney 1 be mixed, but it is also possible to use these gas streams on entry into the exhaust chimney 8th to mix, or if necessary only in the exhaust chimney 8th self.
In 1 is also shown as coming from the clinker cooler 3 Exhaust air coming from the preheater for reheating 5 originating exhaust gas can be used. For this purpose, part of the cooler exhaust air is diverted and, for example, that from the preheater 5 originating exhaust gas flow mixed, as shown in the left part of the drawing under the exhaust chimney 8th is illustrated.

2 shows a heat exchanger based on hose bundles which is preferably used according to the invention in the condensation devices 10 . In 2 is illustrated how this hose bundle 10 can be arranged in a condensation device. The damp exhaust gas 40 is in 2 from the top left through the flue gas distributor 20th in and then against gravity through the hose bundle 10 headed down. In these hose bundles 10 the exhaust gases are cooled down 40 , whereby the moisture contained in the exhaust gases at least partially condenses.

The condensate 50 runs down the inside of the walls of the hose bundle, following the force of gravity, and then drips (or flows) into the condensate collector digit 30th who is in 2 as a recess at the bottom of the device, from where the condensate 51 can then be derived, is represented. The dried exhaust gases 41 are derived from the condensation device in FIG. 2 at the bottom left.

3 shows the hose bundle in the two parts a) and b) 10 out 2 . The hose bundle 10 are made up of two film webs arranged on top of one another 101 and 102 which are glued or welded to one another at certain points in such a way that the film webs create structures that correspond to a bundle of tubes.
In figure 3a) it is shown how these film webs 101 and 102 lie loosely on top of one another and are connected to one another at the contact points. This is the state of the hose bundle heat exchanger in the non-operational state.
In 3b) the operational status of the hose heat exchanger is shown. It can be seen again that the tube bundle consists of two sheets of film 101 and 102 are constructed. In contrast to 3a) is in 3b) shown as the moist exhaust gas 40 is passed through the hose structures of the heat exchanger. Through this passage, the tube webs lying loosely on top of one another (or loosely attached to one another) in the non-operative state are inflated and thereby assume a tube-like shape.

In 4th is shown as an example on a hose element, such as the hose bundle heat exchanger of 2 and 3 function. The damp exhaust gas 40 is introduced from above into the inner cavity of a hose element. The moist exhaust gas flows accordingly 40 down through the hose element. On the outside of the individual hose elements, cold ambient air comes in from below 60 headed along upwards. The cold ambient air 60 takes heat from the humid exhaust gas 40 and consequently heats up along the hose element and then becomes heated air 61 that can be discharged from the top of the heat exchanger element. Simultaneously the humid exhaust gas alternates with it 40 cooled, which means that the same amount of moisture can no longer remain in the gaseous state and condenses out accordingly. The condensed liquid is in 4th in the form of droplets 50 shown inside the individual hose element. The arrows pointing from bottom to top outside of the hose element in 4th show the direction of flow of the cooling air (initially cold ambient air 60 then heated ambient air 61 ) on. The dried exhaust gas (dried by condensation of liquid) can then be drawn off in the lower part of the heat exchanger, as shown in FIG 2 is already illustrated. After all, in 4th in the lower part it is still shown that there is the condensate 51 collect and then can be diverted downwards.

5 illustrates a condensation device in which a number of hose bundles 10 in a weather protection (protection from solar radiation, precipitation and wind) comprehensive housing 100 are hung. The case 100 is in 5 Although shown as a cube, it can also take other forms depending on the respective requirements. In this 5 is illustrated how the moist exhaust gas 40 in the top left of the housing 100 is initiated. The dehumidified, dried exhaust gas is then out of the housing at the bottom right 100 derived.
It is shown schematically in this figure that cold ambient air 60 from below into the housing 100 is introduced and then as heated ambient air 61 emerges from the top of the housing. On the one hand, this passage can take place automatically, for example supported by the chimney effect, or the cooling medium, in particular ambient air, can pass through the housing by means of blowers and / or fans 100 be directed. In addition, in 5 still indicated that the condensate 51 from the bottom of the case 100 can be derived.

List of reference symbols

1

Condensation device

2a, b, c

Adding basic gas or basic liquid, especially ammonia)

2a

to an SNCR in the calciner

2 B

to an SCR system (catalytic converter)

2c

to the condenser

3

Clinker cooler

4th

(Rotary kiln) furnace

5

Pre-heater (cyclone)

6th

Calciner

7th

Filter / dust extractor (optional)

8th

Exhaust chimney

9

SCR system (catalytic converter)

10

Hose bundles made from film webs 101 and 102

20th

Flue gas distributor (if necessary with pre-cooler)

30th

Exhaust pipe with condensate collector

40

Exhaust gas, damp

41

Exhaust gas, dried

50

condensing water in the hose bundle

51

condensate

60

cold ambient air

61

heated ambient air

100

Housing with weather protection and hose bundles suspended in it

101

first (here top) slide

102

second (here lower) slide

It should be pointed out that the features of the present invention and / or disclosure, in particular of the various claims, can be combined with one another as desired without departing from the concept of the present invention.

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• JP 2012056794 [0002]
• US 4915914 [0002]
• WO 02/059043 A2 [0002]
• WO 2016/030207 A1 [0002]
• EP 0982427 a1 [0002]
• EP 1106729 A2 [0002]
• US 4955435 [0002]
• US 7243403 B2 [0002]

Claims (14)

Process for separating water from the flue gas of clinker burning plants, wherein the clinker burning plant has at least the following components, which are operatively connected to one another, a) a preheater, b) optionally a calciner, c) a kiln, preferably a rotary kiln, d) a clinker cooler with at least one exhaust air discharge device , e) at least one exhaust gas purification device, f) at least one condensation device for water vapor contained in the exhaust gas, g) comprises at least one exhaust air chimney, and wherein A) the exhaust gas flow coming from the furnace is subjected to exhaust gas purification and passed through a cooling device configured for condensation, B) the condensed water is discharged from the system or fed to a further use in the system, C) the cooler exhaust air emerging from the clinker cooler is at least partially captured, characterized in that the gas flows resulting from A) and C) according to Ab gas cleaning and condensation step I) but before the exhaust chimney, II) when entering the exhaust air chimney, or III) in the exhaust air chimney. Procedure according to Claim 1 , characterized in that one or more of the following process steps for exhaust gas purification - SCR, - SNCR, - filtration, is carried out. Procedure according to Claim 1 or 2 , characterized in that one or more of the following process steps - an SCR of the exhaust gas originating from the pre-dryer downstream, in relation to the flow direction of the exhaust gas, - an SNCR in the calciner, - regulation and control of the pH value in the condensation device is carried out or become. The method according to any one of the preceding claims, characterized in that the condensed water when fed to a further use in the system as process water or as cooling water, or after being discharged from the system, if necessary after further purification, - as drinking or tap water, - as Water for agriculture, and / or - is used as service water. Method according to one of the preceding claims, characterized in that the condensation is carried out in a multi-stage spray condenser. Method according to one of the preceding claims, characterized in that the energy obtained during the condensation is used to supply the clinker burning plant. Method according to one of the preceding claims, characterized in that the gas flows resulting from A) and C) are mixed by means of mixing chambers, valves, turbulence or combinations thereof in the exhaust air chimney. Clinker burning plant comprising at least the following components, which are operatively connected to one another, a) a preheater, b) optionally a calciner, c) a kiln, preferably a rotary kiln, d) a clinker cooler with at least one exhaust air discharge device, e) at least one exhaust gas cleaning device, f) at least one condensation device for water vapor contained in the exhaust gas, g) at least one exhaust air chimney, where A) the at least one exhaust gas purification device is configured and arranged for cleaning the exhaust gas flow originating from the kiln, the at least one condensation device is configured and arranged for condensing the water vapor entrained in the exhaust gas flow, B) a device for removing the condensed water from or forwarding it within the system is included, C) the at least one exhaust air removal device from the clinker cooler is configured in such a way that exiting cooler exhaust air is at least partially collected d, characterized in that the system also includes I) a mixing device for the gas flows resulting from A) and C), which is arranged after the exhaust gas purification and condensation devices but in front of the exhaust chimney, II) a mixing device arranged in the outer wall of the exhaust chimney for the from A ) and C) resulting gas streams, III) inside the exhaust chimney arranged mixing device for the gas streams resulting from A) and C), or IV) separate feed lines for the gas streams resulting from A) and C) in the exhaust air chimney. Clinker burning plant after Claim 8 , characterized in that it configures one or more devices for exhaust gas purification by means of - SCR, - SNCR, - Filtration, includes. Clinker burning plant after Claim 8 or 9 , characterized in that it comprises one or more devices configured for - SCR of the exhaust gas coming from the preheater downstream, in relation to the flow direction of the exhaust gas, - SNCR in the calciner, - regulation and control of the pH value in the condensation device. Clinker burning plant according to one of the Claims 8 to 10 , characterized in that it comprises a multi-stage spray condenser. Clinker burning plant according to one of the Claims 8 to 11 , characterized in that it comprises at least one device for the recovery and transmission of the energy obtained during the condensation. Clinker burning plant according to one of the Claims 8 to 12th , characterized in that it comprises mixing chambers and / or valves configured for mixing the gas flows resulting from A) and C). Comprehensive heat exchanger - a housing, - in the longitudinally glued or welded film webs which, when inflated, take the form of a hose bundle or several parallel hose bundles, - which has a gas distributor in the upper area, and contains a gas collector and a condensate discharge at the bottom, the film webs in the housing being oriented in such a way that the tube bundles are oriented essentially vertically.

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