EP1952063A1

EP1952063A1 - Device and method for cleaning the exhaust gases in heating installations with simultaneous heat recovery and with dust removal

Info

Publication number: EP1952063A1
Application number: EP06818666A
Authority: EP
Inventors: Rupert Merkl
Original assignee: Individual
Current assignee: Individual
Priority date: 2005-11-18
Filing date: 2006-11-20
Publication date: 2008-08-06
Also published as: WO2007057214A1; DE102005055550A1

Abstract

The invention relates to a method for cleaning the exhaust gases in heating installations with simultaneous heat recovery, which can be used for all kinds of liquid and solid fuels. The exhaust gas passes a heat exchanger (3; 103; 203; 403) and is subsequently at least partially sent through a perforated guiding element into a chamber (5; 105; 205; 405) with a spraying system (7; 107; 207; 407) for producing finely dispersed drops of water, where the pollutants contained in the exhaust gas are removed by spraying with the finely dispersed drops of water. The perforated guiding element may be pivotably mounted. With preference, the guiding element is an aperture plate (13; 113; 213; 413) or a perforated plate. The pollutants contained in the exhaust gas are removed initially by sprinkling and then by spraying with the finely distributed drops of water. The spraying direction of the finely distributed drops of water differs here from the direction of flow of the exhaust gas emerging from the perforated guiding element. The method may be additionally used for removing the dust deposits. The invention also relates to the device for carrying out the method.

Description

Apparatus and method for cleaning the exhaust gases in heating systems with simultaneous heat recovery and with dust removal

The invention relates to an apparatus and a method for cleaning the exhaust gases in heating systems with simultaneous heat recovery and with dust removal. The invention also relates to the use of the method and apparatus for heating systems with selected fuels.

The permissible values for pollutant emissions from heating systems have been increasingly tightened by the legislator in recent years, thereby contributing to the reduction of environmental pollution. The pollutants emitted by a heating system primarily include sulfur oxides and nitrogen oxides. In addition, the CO ₂ emissions should also be considered. Although CO ₂ is not a pollutant per se, but increasingly polluted by its increased emission from heating systems and the environment, it is also counted among the pollutants in the context of this invention.

In addition to the problem of complying with the legal requirements and the permissible emission limits for heating systems regulated therein, there is an increasing amount of dust in the heating system due to the increasing use of solid fuels such as wood or renewable raw materials. By WO-A-00/09948 an apparatus and a method for cleaning the exhaust gases of small heating systems with simultaneous heat recovery has already become known, in which the exhaust gas coming from the heater via an inlet pipe and a multi-part guide in a chamber with a spray system for producing finely divided drops of water is passed. The multi-part design of the exhaust gas serves to first divert the exhaust gas several times and then to conduct it via an annular flow channel into the chamber with the spray system. The exhaust gas passes through a heat exchanger and the multiple diversion serves to extend the flow path via the heat exchanger. The flow channel opens in the direction of the chamber with the spray device, where the already significantly cooled exhaust gas abuts a further element of the guide member and an annular gap formed thereby on the mist formed in the chamber of finely divided water droplets and so the pollutants from the exhaust effect be removed. The so purified exhaust gas leaves the device via an outlet disposed above the chamber, while the condensate is guided in the direction of the bottom of the chamber and passed through a dedicated further outlet in a water bath,

Furthermore, by DE-A-36 37 973 an apparatus and a method for purifying exhaust gases with simultaneous heat recovery has become known. The apparatus disclosed therein comprises a chamber having a spray system for producing finely divided drops of water disposed in the upper portion of the chamber and a plurality of step bottoms extending approximately from the bottom of the chamber to the spray unit. A heat exchanger assembly of two concentrically arranged Rippenrohrwenden is arranged laterally in the chamber along its wall. The passing through an inlet into the chamber to be cleaned exhaust gas is now guided from bottom to top through the heat exchanger assembly to the spray system to produce finely divided water droplets and the fine water mist generated by this then pushes the exhaust gas back toward the bottom of the chamber, where , moistened by this mist of water, reaches the individual step bottoms in the chamber. These serve to dry the exhaust gas, which then flows out of the device in the lower region of the chamber via an outlet.

US-A-4,686,940 discloses a device for purifying the exhaust gases in heating systems with simultaneous heat recovery, in which also via a chamber in which finely divided water droplets are, which is also cleaned in this chamber exhaust gas is cleaned. The water mist is not generated in this chamber itself, but in a tubular guide in which water, which feeds from a water bath located below the chamber, is conveyed upwards to a fan and is finely sprayed through it. In the area of the fan, this tubular guide has a multiplicity of small openings through which the spray droplets then enter the chamber together with the exhaust gas. The exhaust gas is directed via a separate inlet in the region of the tubular guide in which the fan is located. A heat exchanger extends over the condensate collected at the bottom of the device up to the chamber. It is designed as a tubular heat exchanger and surrounds the chamber from the outside over its entire length.

Based on this prior art, the present invention seeks to provide an apparatus and a method for cleaning the exhaust gases in heating systems with simultaneous heat recovery and dust removal, said apparatus and methods are particularly, but not exclusively suitable for large systems, and wherein both the Device and the method as simple as possible and are therefore designed very economical and work with high efficiency.

This object is achieved by a method for cleaning the exhaust gases in heating systems with simultaneous heat recovery, in which the exhaust gas passes through a heat exchanger and then a chamber with a spray system for producing finely divided water droplets, wherein at least a portion of the exhaust gas via a pivotally mounted, perforated Guiding led into the chamber with the spray system and there contained in the exhaust gas Pollutants are removed by spraying with the finely divided water droplets produced by the spray system, and wherein the spray direction of the finely divided water droplets from the sprayer differs from the flow direction of the exiting the perforated guide element exhaust gas.

This provides a considerably simplified and yet very effective method compared with the prior art. Preferably, the exhaust gas is thereby guided completely by means of the pivotally mounted, perforated guide element into the chamber with the spray system. As a result of the perforation of the guide element, the exhaust gas flow is quasi linearized and the area of the chamber in which the exhaust gas then impinges on the finely divided water droplet mist is applied uniformly.

This object is also achieved by a method for purifying the exhaust gases in heating systems with simultaneous heat recovery, in which the exhaust gas passes through a heat exchanger and then a chamber with a spray system for generating finely divided water droplets, wherein at least a portion of the exhaust gas via a perforated guide element into the chamber guided there with the spray system and there the pollutants contained in the exhaust gas are removed by spraying with the finely divided water droplets generated by the spray, the spray direction of the finely divided water droplets from the spray differs from the flow direction of the exiting the perforated guide element exhaust gas, and wherein the perforated guide member cooperates with a non-perforated orifice, which is pivotally mounted in the chamber with the Sprüh- anläge and adjacent to the heat exchanger.

If the perforated guide element, through which the exhaust gas flows from the heat exchanger into the chamber with the spray device, is preferably formed as a pinhole, and particularly preferably as a perforated plate, a simple and economical production of the perforated guide element is made possible in this way. As a material for the perforated guide element in principle stainless steel or other corrosion-resistant and temperature-resistant materials in question. The achieved cleaning effect of the exhaust gas is optimized by the fact that in the flow of the exhaust gas through the perforated guide element, the pollutants contained in the exhaust gas first, in a first step, by drumming kammermer on the guide element and then, in a second step, by spraying be removed with the finely divided water droplets produced by the sprayer.

It has been found that a significantly higher efficiency in the removal of pollutants from the exhaust gas could be achieved by the cleaning of the exhaust gas carried out in these two steps. This increased efficiency is caused by a double heat transfer in the meeting of the exhaust gas with the finely divided water droplets produced in the spray system. First of all, condensate forms on the perforated guide element, on the chamber side, from the fine mist of the water droplets, which the exhaust gas strikes when passing from the heat exchanger to the chamber with the spray system. This condensate dissolves in the despite the passing of the heat exchanger still sufficiently hot exhaust gas on the perforated guide element already a part of the pollutants contained in the exhaust gas. The further purification of the exhaust gas is effected when the exhaust gas, following the guide element, flows into the chamber with the spray system and there impinges on the spray of the finely divided water droplets. Even then, the exhaust is still hot enough so that the shock-like encounter with the finely divided water droplets can be used for a further effective dissolution of the pollutants from the exhaust.

In addition to the purpose of purifying exhaust gases in heating systems and heat recovery, it may be further provided to effectively eliminate dust deposition on the heat exchanger. Basically, the problem of dust separation, in particular in the use of wood and wood products, such as wood pellets and wood chips, or renewable raw materials, as well as their processing, of considerable importance. But it is precisely these fuels are becoming increasingly important due to the high cost of oil and natural gas. Heating systems are z. B. designed so that they optionally suitable for petroleum and natural gas and wood and wood products, wood pellets and wood chips, as well as renewable raw materials for firing. So far, no concept has been known for a heating system, which allows cleaning of the heat exchanger existing for optimal energy use of the dust at selected intervals. As a result, the problem of dust separation on the heat exchanger or leaching for solid fuel firing, as in the use of wood pellets, gains even more importance in firing than the question of saving energy in these heating systems.

According to the invention, the additional removal of the dust on the heat exchanger can be achieved in that the pivotally mounted, perforated guide member for removing the dust deposit pivoted away from the heat exchanger and thereby the finely divided water droplets are passed through the heat exchanger for cleaning.

According to a further embodiment, the additional removal of the dust deposit on the heat exchanger can also be achieved by arranging the pivotally mounted, non-perforated diaphragm adjacent to the heat exchanger and adjacent to the chamber with the spray system, and forming this wall as it flows through the exhaust gas , which limits and closes the heat exchanger with respect to the chamber with the spray unit, and wherein the removal of the dust separation, the aperture swung open and thereby the finely divided water droplets are passed through the heat exchanger for cleaning.

Optionally, the exhaust flow may be interrupted during this cleaning time. However, this is not absolutely necessary, since the cleaning time is relatively short, so that it does not represent a significant environmental impact, if in this time the exhaust gas flows out of the device unpurified or less purified.

In this way, a simple and economical, optionally by a possible brief interruption of the firing, a cleaning of the heat exchanger or, if more than one heat exchanger is used, can be achieved and the system can still be installed compactly and without requiring much space.

Preferably, the pivotally mounted, perforated guide element or the pivotally mounted, non-perforated diaphragm is pivoted up to 180 °, more preferably up to about 90 ° or less. Depending on the type of installation, it may also be possible that the guide element or the aperture can be swung even at a greater angle than 180 ° to bring the finely divided water droplets in contact with the heat exchanger. It is crucial that the finely divided water droplets can be brought into sufficient contact with the heat exchanger.

The above object is also achieved by a device for cleaning the exhaust gases in heating systems with simultaneous heat recovery, with an inlet for the exhaust gas, a heat exchanger, a chamber with a spray system for producing finely divided water droplets, each having an outlet for the at least partially cleaned Exhaust gas and the contaminant receiving condensate, and arranged in the chamber, a perforated guide element, the Sprühaniage is arranged to produce finely divided drops of water relative to the guide member so that the spray direction of finely divided drops of water from the spray system from the flow direction of the guide element diffusing exhaust gas.

According to a preferred embodiment, the perforated guide element is formed as a pinhole, preferably as a perforated plate.

By the use of such a perforated guide element, the z. B. may be a perforated plate and which may be located where the exhaust passes from the heat exchanger into the chamber with the spray, the exhaust gas is at least partially forced to first pass through the perforated plate, and on the cam side on the surface of the pinhole already separated condensate causes a trickling of the exhaust gas passing through the pinhole and thus a first He-washing out of the pollutants from the exhaust gas. On the way the exhaust gas in the chamber, the exhaust gas comes into contact with the spray from the finely divided water droplets and is now further purified. The formation of condensate occurs when the exhaust gas hits the cool water droplets or the cool water droplet spray because the temperature suddenly drops below the so-called dew point. In principle, it exploits the same phenomenon that is responsible in the atmosphere for causing acid rain.

A further advantage of the device according to the invention is the possibility that it can also be used for removing the dust deposit on the heat exchanger (s) if, according to another embodiment, adjacent to the heat exchanger and adjacent to the chamber with the spray system not perforated panel arranged and is pivotally mounted. This aperture can be swung open and the finely distributed spray mist from the water drops can thus be conducted directly via the at least one heat exchanger. As a result, the cleaning of the heat exchanger is effected there by removal of the dust separation. For this purpose, the exhaust gas flow does not have, but can be interrupted, as has already been described above with regard to an embodiment of the method according to the invention.

The perforated guide member may also be disposed only adjacent to the heat exchanger, wherein adjacent within the meaning of the present invention within the chamber not only includes the immediate vicinity of the heat exchanger, but also means adjacent to the chamber further away.

The perforated guide member may be pivotally mounted depending on the task releasing embodiment when the transition of the exhaust gas from the heat exchanger into the chamber, only in the broadest sense adjacent to the heat exchanger, pivotally or non-pivotably.

The posing task is also solved by the use of the above-described fiction, contemporary method and apparatus, each in one of the embodiments, for in itself any fuels, such as petroleum, gas, Wood and wood products, wood pellets and wood chips, renewable raw materials and preparations thereof.

In the following the invention will be explained in more detail with reference to selected embodiments and the accompanying drawings.

Show it:

1a is a sectional view of the device according to the invention with a pivotally mounted perforated plate,

FIG. 1b shows a plan view of the device according to FIG. 1a rotated by 90 °, FIG.

2a is a sectional view of the device according to the invention with pivoting perforated plate and a bypass flap,

2b shows a plan view of the device according to FIG. 2a rotated through 90 °, FIG.

3 a shows a sectional view of the device according to the invention with perforated plate and further diaphragm,

3b is a sectional view of Fig. 3a, integrated in a boiler area,

3c shows a view according to FIG. 3a, integrated in a complete heating system with water bath, FIG.

4a shows a sectional view of a further embodiment of the device according to the invention,

Fig. 4b: a sectional view of Fig. 3a, integrated in a boiler area, and

4c shows a sectional view according to FIG. 3a, integrated into a heating boiler area for the use of wood chips as

Fuel. embodiments

The exemplary embodiments described below relate in each case to a device for purifying the exhaust gases in heating systems, which has a perforated guide element which is designed continuously as a perforated plate in the form of a perforated plate. They therefore do not relate to the simplest form in which the method according to the invention is exercised and the device according to the invention can be embodied, which merely provides a non-perforated, pivotable guide element. However, it will be readily apparent to one of ordinary skill in the art that all subsequent embodiments are fully applicable to the non-perforated form of the guide member, provided that it does not cause the pollutants to be twice released from the exhaust by, on the one hand, dribbling and, on the other hand, dissolving in the waterdrop spray affect. For the simple embodiment of the non-perforated guide element, the exhaust gas cleaning by dissolving in the water droplet spray comes into consideration.

In this way, the simple embodiment should also be shown in each case in the exemplary embodiments described below in order to avoid unnecessary repetitions.

1. Combination of exhaust gas purification, heat recovery and cleaning of the heat exchanger according to VARIANT 1

In Fig. 1 a. is the cleaning of the exhaust gas, the heat recovery and cleaning of the heat exchanger causing area of a heating system as shown here device according to the invention. The exhaust gas is passed through inlet 1 into the apparatus and passes first a heat exchanger 3, which is formed in this and in the following embodiments as a tubular heat exchanger, with or without oberflächenvergrößernden fins, stainless steel or other, resistant to aggressive substances and media materials. Equivalent to this embodiment can also be provided to drive the exhaust gas through more than one heat exchanger. At the area of the device according to the invention, which receives the heat exchanger 3, is followed by a chamber 5, which has a spray unit 7 for generating finely divided water droplets. This spray unit 7 can consist of a water nozzle or have a plurality of nozzle sticks, as is the case in FIG. 1a, and is illustrated once more in detail via FIG. To the chamber 5 with the spray unit 7, the outlet 9 closes for the purified exhaust gas, and 11, the pressure line for the spray unit 7 to be supplied water is called. At a later point in time, it will be discussed what this water feeds from. In the transition from the region in which the heat exchanger 3 is arranged, in the chamber 5, a pinhole 13 is pivotally mounted. This pinhole 13 is formed in the present embodiment as a perforated plate and rotatably supported by approximately 90 °. Depending on the design, the angle by which the aperture plate 13 is rotatably mounted, even up to, for example, 95 ° or 100 °. It is basically also a rotatable storage by 180 ° possible, if the construction of the device allows.

The exhaust gas flowing into the device via the inlet 1 is purified in the following way:

First, it passes through the heat exchanger 3 with a common initial temperature of about 180 ° C to 150 ° C and is about 100 ° C or even significantly lower, namely about 50-60 ° C, cooled when it hits the pinhole 13. This perforated plate 13 is initially folded into the device and the largest portion of the exhaust gas now flows through the pinhole 13, or is passed through it, wherein it is on the chamber side ready on the pinhole 13 deposited condensate from the spray unit 7 to produce finely divided Falls drops of water and takes place on the pinhole 13, a first heat transfer between the condensate and the exhaust gas. At the pinhole 13, the exhaust gas that passes through this pinhole 13, quasi sprinkled with the now become a condensate of water droplets fine spray of the spray 7, which causes a first transition of pollutants in the water condensate. After passing through the pinhole 13, the exhaust gas strikes the fine spray of water droplets from the spray unit 7 itself and is further cleaned by this spraying. When exiting the nozzle or nozzles of the spray unit 7, the finely divided water drops have a temperature of about 20 ° C to 40 ° C, a maximum of 50 ° C. The finely divided water droplet mist provides a very large surface area, which makes it possible in this shock-like encounter of despite the heat exchanger 3 and the first contact of the exhaust gas with the water condensate at the pinhole 13 still sufficiently hot exhaust gas with the relatively cold water droplet mist another very effective Dissolving the pollutant components of the exhaust gas, which can be referred to as heating or flue gas as well, to effect in the water droplets.

In this way, the water droplets of the mist are loaded from the finely divided water droplets with the pollutants of the exhaust gas and passed through a manifold 15 from the device in a further down to be explained in more detail reservoir. In this case, this manifold 15 is arranged in the device that the water condensate is guided solely by the action of gravity to the manifold and there is derived from the chamber 5. Therefore, the manifold 15 is located at the bottom of the device. The so exempt from the pollutants at least to a large extent exhaust gas is then discharged through the outlet 9 to the atmosphere. An in the figure not shown dropper is additionally provided here to effect the complete separation of the finely divided water droplets.

Especially when the heating system with which the device according to the invention is to be combined is used for firing with solid fuels, such as wood, wood pellets or renewable raw materials, the problem of dust separation or leaching is very problematic and the cleaning of the heat exchanger more important the energy savings that can be made by the device. The dust removal causes a significant reduction in the efficiency of the heating system, if no efficient cleaning can be made. According to the invention this cleaning is effected in a very simple manner by the pinhole 13, which is pivotally mounted, away from the heat exchanger by about 90 ° or a depending on the design thereof different degrees in the direction of the inner wall of the chamber 5 is folded. The effluent stream is interrupted and the mist emerging from the spray unit 7 from the finely divided water droplets now passes directly to the heat exchanger 3 in order to clean it.

In the embodiment of the device shown in Figures Ia and Ib several nozzle sticks of the spray unit 7 are provided and also still different nozzles are used, so that any dust from the area of the heat exchanger 3 is washed out.

2. Combination of exhaust gas purification, heat recovery and cleaning of the heat exchanger after VARIANT 2

A modification of the previously described device is shown in Figures 2a and 2b, wherein like components of the device with the same, only by 100 extended reference numerals are designated. This modified according to the first embodiment device additionally has a bypass 117, which is arranged adjacent to the inlet 101 of the exhaust gas or heating or flue gas and opened or closed by a pivotable flap 119. This pivotable flap 119 is pivotally connected to the pointing in the direction of the inlet part 1 of the heat exchanger 102, which is either closed by a 90 ° - rotation of the bypass 117 or opened by a 90 ° rotation in the opposite direction of the bypass 117. Ie. the pivotable flap 119 passes the exhaust gas flowing into the device via inlet 101 either via the heat exchanger 103, and thus leads the exhaust gas to a purification, or via the bypass 117 directly to the outlet 109. With this variant of the device according to the invention, it is not at all necessary to interrupt the exhaust gas flow to clean the heat exchanger 103. As the cleaning of the Heat exchanger 103 usually takes only a short time, for this short period of time the exhaust gas can be passed without the cleaning step to the outlet 109, without presenting an environmental risk.

3. Combination of exhaust gas purification, heat recovery and cleaning of the heat exchanger according to VARIANT 3

While with the previous embodiments, a device for purifying the exhaust gases with heat recovery and removal of dust deposition has been shown on the heat exchanger, which is a quasi-linearizing unit with respect to the exhaust gas flow between the region of the heat exchanger 3, 103 and the chamber 5, 105, This linear transition of the exhaust gas from the heat exchanger 3, 103 into the chamber 5, 105 in the present third embodiment is no longer provided, as a result of which a more compact construction becomes possible. Again, to describe the embodiment, the same components with respect to the previous embodiments with the same but by 200 extended reference numeral.

In this arrangement, which has a more compact construction of heat exchanger 203 and chamber 205, the exhaust gas first flows into the heat exchanger 203 via the inlet 201, as also described so far. The heat exchanger 203 is followed by the passage of the exhaust gas into the chamber 205 with the spray unit 207, a pinhole 213, via which a first cleaning of the exhaust gas is effected, as also explained above. The nozzles of the spray unit 207 are in this embodiment, however, not in a quasi-linear arrangement to the heat exchanger 203, based on the exhaust stream, but the exhaust gas is deflected and the nozzle of the spray nozzle 207 are in this embodiment above the heat exchanger 203. Thus, the Heat exchanger 203 virtually integrated into the region of the chamber 205 with the spray unit 207, but still forms an independent unit. The nozzles of the spray unit 207 are arranged above the heat exchanger 203 to prevent the mist from falling out of the finely divided drops of water To reach and exploit the 207 gravity spray unit with gravity. The outlet 209 is arranged in this embodiment on the same side as the inlet 201 and adjacent thereto.

A cleaning of the heat exchanger is achieved in this arrangement, characterized in that a further aperture 221 is provided, which adjoins the chamber 205 with the spray unit 207 and opposite the chamber 205 forms a wall which limits the heat exchanger relative to the chamber 205 and closes. This further panel 221 is also pivotally mounted on the joint 223 and is folded in this embodiment in the cleaning operation by about 90 ° - or depending on the design again at a different angle - upwards. The cleaning of the heat exchanger 203 can then be done automatically via the mist from the finely divided water droplets of the spray unit 207 or alternatively by hand.

The inventive device in its embodiment shown here by way of example with three embodiments can be retrofitted due to their compact design both in existing old heating systems, as are of course also used for any type of newly developed heating systems. In Fig. 3b is shown by way of example and schematically in block diagram, as the inventive device can be integrated into a boiler area of a heating system. In this case, A is the burner for the use of petroleum or (natural gas), or the firebox shown using solid fuels, with a combination of both is possible, and with an arrow the transition to the area B with internal heat exchanger surfaces illustrated.

From the region B, the exhaust gas is further led to the inlet 201 for the exhaust gas in the device according to the invention. In FIG. 3b, the device according to the invention is shown according to VARIANT 3, because here the compact construction according to this variant is well suited for installation. In the same way but also the devices according to the embodiments 1 and 2, ie the VARIANTS 1 and 2, can be used. The invention proper device itself is constructed, as has been explained with regard to VARIANT 3.

In Fig. 3c, a complete heating system is shown schematically, will now be described with reference to the further use of the dissolved water from the exhaust pollutants water condensate. In Fig. 3c A again denotes the burner or combustion chamber, B, the internal heat exchanger surfaces, of which the exhaust gas in the device according to the invention, for example, again with reference to the VARIANT 3, is passed.

The pollutant-laden water droplets of the mist from the finely divided water droplets according to the embodiments of the VARIANTEN 1 and 2 are collected so that they flow together in the lower part of the chamber following gravity, and also according to the embodiment of VARIANT 3, it is provided that the water condensate collects in the lower region of the chamber 205 and is conducted via the outflow 225 to a reservoir in the form of a water bath 227. In order to neutralize the possibly more or less acidic precipitate of the water condensate from the water droplet mist from the chamber 205, the Wassεrbad 227 is selected depending on the type of fuel or firing, ie tuned to the fuel neutralizing agent such. For example, MgO in the case of petroleum as a fuel is added to a vessel 229 which passes through the water condensate before entering the water bath 227. The water condensate from the water droplet mist of the chamber 205, which has been heated by the hot exhaust gas, now still has a temperature of about 30-50 ° C. An additional heat exchanger 231 disposed in the water bath serves to cool the water bath 227 so that a temperature is reached which makes it suitable for reuse for feeding the spray unit 207 and thus reusing it as finely divided water droplet mist in the chamber 205. The heat exchanger 231 serves to supply the cold water to the boiler feed in the hot water heating. This is shown in Fig. 3c via the line 233, which opens into the boiler 235 for the service water. The temperature of the water bath 227 is approximately between 15-25 ° C. Investigations have shown that the water condensate from the chamber 205, which is used again via the drain 225 and after passing through the container 229 with MgO and the water bath 227 for the water feed into the spray unit 207, a pH of about 7, 0 has.

4. Combination of exhaust gas purification, heat recovery and cleaning of the heat exchanger after VARIANT 4

A further modification of the inventive device for purifying exhaust gases, heat recovery and cleaning of the heat exchanger used is shown in Figures 4a to 4c, wherein like components of the device with the same, only by 400 extended reference numerals are designated.

As shown in Fig. 4a, the exhaust gas is passed according to this embodiment via inlet 401 into the device and initially passes again a heat exchanger 403 in the form of a tubular heat exchanger with or without oberflächenvergrößernden lamellae, made of stainless steel or other, against aggressive substances and substances resistant materials is formed. It can also be provided more than one heat exchanger. The heat exchanger 403 is connected via an outlet opening 404 to a chamber 405, in which the cleaning of the exhaust gas takes place, as also described in the previous exemplary embodiments, and in which there is a spray unit 407 for producing finely divided water droplets. This spray unit 407 may consist of a water nozzle or a plurality of nozzle sticks 407 'have. The spray cone formed by the actuation of the spray unit 407 for the purification of the exhaust gas is schematically illustrated in FIG. 4a with reference numeral 408. The pressure line for the water to be supplied to the spray unit 407 is denoted by 411 and shown in Figs. 4b, 4c.

In the exemplary embodiment, a plurality of nozzle rods 407 'of the spray system 7 are provided, and different nozzles can also be used. det to improve the cleaning result of the device according to the invention.

The chamber 405 with the spray unit 407 also has an outlet 409 for the purified exhaust gas and two, each designated 410 condensate discharge nozzle for connection to corresponding condensate drain lines. At a later time, it will be discussed why more than one drain is provided for the condensate. Adjacent to the outlet opening 404 of the heat exchanger 403, in the chamber 405, a perforated guide element in the form of a perforated plate 413 or a perforated plate is arranged pivotably as a cleaning flap provided with guide plates. The pinhole 413 is rotatably mounted in the exemplary embodiment by about 90 °. The angle by which the pinhole 413 is rotatably mounted, can also be more than 90 °.

To purify the exhaust gas this first passes through the heat exchanger 403 with an installation-dependent initial temperature in the range of about 160 ° C to 22O ⁰ C and is in the heat exchanger 403 to about 100 ° C or even significantly lower, namely about 50-60 ⁰ C, cooled before it leaves the heat exchanger 403 via the outlet opening 404 in the direction of the chamber 405. There it meets the cleaning flap in the form of the perforated plate 413, which is folded into this embodiment for the purification of the exhaust gas into the chamber 405, so that the exhaust gas flows substantially through the pinhole 413, or is passed therethrough. Upon exiting the aperture 413, it encounters condensate already deposited on the aperture 413 from the spray unit 407 to produce finely divided drops of water, and via the aperture 413 a first heat transfer between the condensate and the waste gas already takes place. At the pinhole 413, the exhaust gas that passes through this pinhole 413 is quasi sprinkled with the fine mist of the spray unit 407 which has now become a condensate of water droplets, thereby causing a first transition of the pollutants into the water condensate. After passing through the cleaning flap formed as a perforated plate 413, the exhaust gas impinges on the spray cone 408 from the fine water droplet spray from the spray system 407 and is further cleaned by this spraying. When exiting the nozzle or nozzles of the spray unit 407, the finely divided water droplets of the spray cone 408 have a temperature of approximately 20 ° C. to 40 ° C. and a maximum of 50 ° C. The spray of finely divided water droplets provides a very large surface, which makes it possible, in this shock-like coincidence of the exhaust gas still sufficiently hot despite the heat exchanger 403 and the first contact of the exhaust gas with the water condensate at the pinhole 413, with the relatively cold water droplet. Spray to cause a further, very effective dissolution of the pollutant components of the exhaust gas in the water droplets.

In this way, the water droplets of the spray are loaded with the pollutants of the exhaust gas and passed through the two condensate drain stub 410 via corresponding condensate drain lines from the chamber 405 in a reservoir which corresponds to the described with reference to the previous embodiments in Fig. 3c reservoir or condensate tank ,

In this case, the water condensate is also guided according to this embodiment so that it flows solely through the action of gravity to the condensate outlet stub 410 and out of the chamber 405. Therefore, the condensate discharge nozzles 410 are arranged in the lower region of the device. The exhaust gas thus at least largely freed from the pollutants is then released via the outlet 409 to the atmosphere. A droplet separator (not shown in detail in FIG. 4 a) may additionally be provided here in order to effect the complete separation of the finely distributed water droplets.

To clean the heat exchanger after this VARIANT 4, the pivotally mounted pinhole 413 counterclockwise, ie away from the heat exchanger 403, by pivoting about 90 °, in the embodiment, slightly less than 90 °, in the direction of the wall of the chamber 405th brought into their cleaning position. In this way, the fine water droplet- Spray no longer intercepted at the aperture 413, but flows in the direction of the ceiling of the chamber 405 and drips from there down. In this way, the mist emerging from the spray system 407 from the finely distributed water drops now reaches the heat exchanger 403 via the deflection through the ceiling of the chamber 405 in order to clean it. In this cleaning phase, the second, in Fig. 4a left, approximately below the heat exchanger 403 shown condensate drain neck 410 is required. The reference numeral 414 correspondingly designates two heating connections in FIG. 4a.

Also this VARIANT 4 of the device according to the invention can be retrofitted due to their compact design in existing old heating systems or used for any type of newly developed heating systems. In Fig. 4b is shown by way of example and schematically in block diagram with reference to a complete heating system, as the device according to the invention can be integrated into the boiler area of a heating system. In this case, A 'denotes the boiler of the heating system, from which the approximately 160-220 ⁰ C hot exhaust gas to that in the chamber 405 integrated, but of this by a wall, such. B. the partition plate 437, separated heat exchanger 403 passes. An arrow shows the flow direction during this transition.

After cleaning the exhaust gas this is discharged through outlet 409, wherein it has a temperature of about 25-40 ° C. The water droplets of the mist loaded with the pollutants from the finely divided water droplets are collected in such a way that, following gravity, they flow into the lower region of the chamber 405. FIG. 4b shows a condensate drain line 410 in the form of the outflow 425 for the condensate flowing downwards during the exhaust gas purification, via which it is conducted to the reservoir or condensate tank in the form of a water bath 427. In order to neutralize the possibly more or less acidic precipitate of the water condensate from the water droplet mist from the chamber 405, the water bath 427 is also selected depending on the type of fuel or firing, ie tuned to the fuel neutralizing agent such. For example, MgO in the case of petroleum as a fuel is added in a vessel 429 which passes through the water condensate before it gets into the water bath 427. The water condensate from the water droplet mist of the chamber 405, which has been heated by the hot exhaust gas, now still has a temperature of about 30-50 ⁰ C. An additional heat exchanger 431 arranged in the water bath serves to cool the water bath 427, so that a temperature is reached which makes it suitable for reuse for feeding the spray system 407 and thus reusing it as finely divided water droplet mist in the chamber 405.

The heat exchanger 431 serves to supply the cold water to the boiler feed in the hot water heating. This is shown in Fig. 4b via line 433, which opens into the boiler 435 for the service water a temperature of about 12-30 ⁰ C.

The temperature of the water bath 427 is then about 15-25 ° C. Investigations in this embodiment have confirmed the already mentioned with respect to FIG. 3c result that the water condensate from the chamber 405, the overflow 425 and after passing the container 429 with MgO and the water bath 427 again for the water feed in the spray unit 407 is used, has a pH of about 7.0.

The embodiment of the device according to the invention shown as VARIANT 4 is again shown schematically in block diagram in FIG. 4c with reference to a complete heating system which is operated with a wood product. In this type of operation of the heating system with a wood product is particularly the problem of dust deposition on the heat exchanger. Due to the possibility of being able to combine the exhaust gas purification and heat recovery with the purification of the heat exchanger according to the invention, VARIANT 4 is and, in addition, the VARIANTS 1 to 3 shown so far are also very well suited for a heating system operated with wood products.

In Fig. 4c, A 'again denotes the boiler of the heating system, from which the approximately 160-220 ⁰ C hot exhaust gas to that in the chamber 405 integrated, but of this through a wall, such. B. the partition plate 437, separated heat exchanger 403 passes. The arrow shows the flow direction.

After cleaning the exhaust gas this is discharged via outlet 409, wherein it has a temperature of about 10-40 ° C. The water droplets of the mist loaded with the pollutants from the finely distributed water droplets flow into the lower region of the chamber 405 following gravity. To neutralize the possibly more or less acidic precipitate of the water condensate, the water bath 427 also has a neutralizing agent tuned to the fuel added to the container 429, which passes through the water condensate before it enters the water bath 427. Investigations in this embodiment have confirmed the result already stated with regard to FIG. 3c that the water condensate is reused from the chamber 405, which is reused via the drain 425 and after passing the tank 429 with the neutralizing agent and the water bath 427, has a pH of about 7.0.

The temperature of this water condensate is now still in about 30-50 ° C. An additional heat exchanger 431 arranged in the water bath serves to further cool the water bath 427.

Thereafter, the temperature of the water bath 427 is about 1-25 ° C. This cooling effect of the condensate to near ^{0 0} C is achieved by taking advantage of the cold outside air, as will be explained below. The advantage is that very low exhaust gas temperatures can be achieved thereby. The cold outside air can be exploited in that the heat exchanger 431 of the water bath 427 is connected via a pump 439 with another heat exchanger 441, in the area dry fresh air at a temperature of about -20 to 25 ° C flows into the system, as in Fig. 4c made clear with the arrows 443. A fan 445, after passing the heat exchanger 441, transports the air into the bin or bunker 447 for the wood product, which in the exemplary embodiment is wood chips 449, and distributes the air there. This wood is used to dry wood chips 449. The hack Schnitzelbunker 447 then escapes air of a high to very high moisture content and a temperature of about 1-20 ⁰ C. It has been shown that the calorific value of the fuel wood in this way, ie by the drying, substantially until about the 2 times could be increased. The disadvantage of rapid dust separation of the wood products, here the wood chips 449, on the heat exchanger 403, which is connected downstream of the boiler A, by the fast and easy, without much effort and without significant disruption to the operation of the heating system as often feasible cleaning steps be weighed.

Claims

claims

Anspruch [en] A process for purifying exhaust gases in heating installations with simultaneous heat recovery, in which the exhaust gas has a heat exchanger (3, 103, 203, 403) and then a chamber (5, 105, 205, 405) with a spray system (7, 107, 207 407) for producing finely distributed water droplets, wherein at least a portion of the exhaust gas via a pivotally mounted, perforated guide element in the chamber (5; 105; 205; 405) with the spray system (7; 107; 207; 407) out and there the pollutants contained in the exhaust gas are removed by spraying with the finely divided water droplets produced by the spraying unit (7; 107; 207; 407), and the spraying direction of the finely divided droplets of water from the spraying unit is different from the flow direction of the exhaust gas leaving the perforated guide element.

2. A method for purifying the exhaust gases in heating systems with simultaneous heat recovery, wherein the exhaust gas is a heat exchanger (3, 103, 203, 403) and then a chamber (5, 105, 205, 405) with a spray system (7, 107, 207 407) for producing finely divided water droplets, wherein at least a portion of the exhaust gas flows via a perforated guide element into the chamber (5; 105; 205; 4035) with the spray unit

(7; 107; 207; 407) and there removing the pollutants contained in the exhaust gas by spraying with the finely divided water droplets produced by the spray unit (7; 107; 207; 407), the spray direction of the finely divided water drops from the spray unit differs from the flow direction of the exhaust gas exiting the perforated guide element, and wherein the perforated guide element cooperates with a non-perforated orifice (221) located in the chamber (5; 105; 205; 405) is pivotally mounted with the spray device (7; 107; 207; 407) and adjacent to the heat exchanger.

3. The method according to claim 1 or 2, characterized in that the perforated guide element is preferably formed as a perforated plate (13; 113; 213; 413) through which at least a portion of the exhaust gas flows, and the pollutants contained in the exhaust gas first by dribbling and then by spraying with the finely divided drops of water produced by the sprayer (7; 107; 207; 407).

4. The method according to claim 3, characterized in that the pinhole (13; 113; 213; 413) is formed as a perforated plate.

5. The method according to any one of claims 1, 3 and 4, characterized by the additional removal of dust deposition on the heat exchanger

(3; 103; 203; 403), wherein the pivotally mounted, perforated guide member for removing the dust deposit from the heat exchanger pivoted away and thereby the finely divided water droplets for cleaning over the heat exchanger (3; 103; 203; 403) are passed.

A method according to any one of claims 2 to 4, characterized by additionally removing the dust deposit on the heat exchanger (3; 103; 203; 403), the pivotally mounted non-perforated orifice (221) being adjacent to the heat exchanger (3; 103; 203; 403) and adjacent to the chamber (5; 105; 205; 405) is arranged with the spray device (7; 107; 207; 407), and this orifice (221) forms a wall, which flows through the exhaust gas, forming the heat exchanger (3; 103; 203; 403) is delimited and closed with respect to the chamber (5; 105; 205; 405) with the spray device (7; 107; 207; 407), and wherein the cover (221) is removed to remove the dust. swung open and thereby the finely distributed water drops to

Purification over the heat exchanger (3; 103; 203; 403) are passed.

7. The method according to any one of claims 1 to 6, characterized in that the pivotally mounted, perforated guide element or the pivotally mounted, non-perforated diaphragm (221) by up to 180 °, preferably up to about 90 ° or less is pivoted.

8. A device for purifying exhaust gases in heating installations with simultaneous heat recovery and with dust removal, with an inlet (1; 101; 201; 401) for the exhaust gas, a heat exchanger (3; 103; 203; 403), a chamber (5; ; 205; 405) with a spray unit (7; 107; 207; 407) for producing finely divided drops of water, each having an outlet

(9; 109; 209; 409) for the at least partially purified waste gas and the pollutant-receiving condensate, and having a perforated guide element disposed in the chamber (5; 105; 205; 405), the spray device (7; 107; 207, 407) for producing finely distributed water droplets relative to the guide element is arranged so that the spraying direction of the finely divided water droplets differs from the spray system from the flow direction of the exiting the guide element exhaust gas.

9. Apparatus according to claim 8, characterized in that the perforated guide element as a pinhole (13; 113; 213; 413), preferably formed as a perforated plate.

10. Apparatus according to claim 8 or 9, characterized in that the perforated guide element in the transition of the exhaust gas from the heat exchanger (3; 103; 203; 403) in the chamber (5; 105; 205; 405) is arranged.

11. Device according to one of claims 8 to 10, characterized by a non-perforated diaphragm (221), which in addition in the chamber (205) with the spray system (207) and adjacent to the heat exchanger (3; i03; 203; 403) pivotally mounted is arranged.

12. Device according to claim 8 or 9, characterized in that the perforated guide element is arranged adjacent to the heat exchanger (3; 103; 203; 403).

13. Device according to one of claims 8 to 12, characterized in that the perforated guide element is arranged pivotably mounted.

14. Use of the method according to any one of claims 1 to 7 and the device according to one of claims 8 to 13 for heating systems whose fuels are selected from petroleum, gas, wood and wood products, wood pellets and wood chips, renewable raw materials and preparations thereof.