|
(11) | EP 1 387 125 A2 |
| (12) | EUROPEAN PATENT APPLICATION |
|
|
|
|
|||||||||||||||||||||||
| (54) | Apparatus and method for thermal neutralization of gaseous mixtures |
| (57) A process gas incinerator (1) for neutralizing chemical non-innocent gaseous mixtures
uses thermally induced neutralization reactions, and does not rely on the use of auxiliary
compounds. In these reactions, chemical non-innocent gaseous mixtures are neutralized
to form benign and environmentally friendly products. A plurality of flame breakers
is disposed inside of the reaction chamber (2) of the process gas incinerator. The
flame breakers introduce variations in gas flow paths and flame patterns, and provide
surfaces of elevated temperature inside the reaction chamber. The process gas incinerator
is constructed in a way as to support neutralization of a wide range of amounts of
non-innocent gaseous mixtures of arbitrary composition. |
Field of the Invention
[0001] The invention generally relates to incinerators. More specifically, the invention relates to incinerators used for neutralizing effluent gaseous mixtures.
Background of the Invention
[0002] During the last decade, the increasing importance of environmental issues gained growing general recognition. The trend to promote and enforce environmental friendliness, in the United States reflected through institutions like the Environmental Protection Agency (EPA), puts a special emphasis on the issue of waste disposal in many industrial processes. This applies especially to chemicals that can be legally released into the environment, such as ammonia (NH3). According to the Toxics Release Inventory (TRI) published by the EPA, the amount of total air emissions of ammonia totaled 151,065,784 pounds in the U.S. in 1999. However, release of gaseous NH3 pollutes the environment to a degree, which in certain cases might damage or even destroy the ozone layer. Ammonia gas is now being increasingly recognized as a pollutant, and emission limits are being currently established by various jurisdictions around the world.
[0003] Many different industries produce effluent gaseous mixtures containing ammonia, as for example foundries, solvent manufacturers, asphalt roof shingle manufactures, charcoal manufacturers, and nitriding and nitrocarburizing plants, among others. Typical methods to dispose of and/or neutralize ammonia containing gaseous mixtures include for example treatment of the effluent gaseous mixture with solutions of an inorganic acid, as described in U.S. Pat. No 4,001,374 to Haese, issued January 4, 1977, and selective oxidation in the presence of a solid catalyst, as described in U.S. Pat. No 5,906,803 to Leppalahti, issued May 24, 1999. However, each of theses processes is afflicted with its own difficulties and drawbacks. The treatment of NH3 containing gaseous mixtures with inorganic acids produces chemical waste, which by itself either has to be disposed of or regenerated. The oxidation process described by Leppalathi typically applies to gaseous mixtures containing only traces of ammonia, for example 0.5 Vol. %. Furthermore, this process utilizes the addition of an oxide of nitrogen (NOx), a class of compounds carrying their own individual environmental risks.
[0004] A promising alternative to the above-described methods is high temperature endothermic dissociation of ammonia in the presence of a metallic catalyst. During this process, NH3 is dissociated into individual dinitrogen (N2) and dihydrogen (H2) molecules, which are both totally benign, and may be safely released to the environment. Also, no NOX compounds are formed. Nevertheless, when this technique is chosen to remove residual ammonia contained in the effluent gases stemming from a nitriding process, it is applicable only to small and medium size nitriding systems. Furthermore, problems generally encountered in the field of catalysis are also an issue for such an endothermic dissociation process.
[0005] It would be advantageous to provide an apparatus for neutralizing ammonia containing gaseous mixtures that is simple and efficient. Preferably, such a device would not utilize any further catalytic or auxiliary components. It would be further advantageous to provide a method, which allows for neutralization of gaseous mixtures containing ammonia on a large range of scales, being applicable to mixtures containing only a small amount of NH3 up to atmospheres of 100 % NH3. It would also be advantageous to provide an environmentally friendly method, in which neutralization of ammonia results substantially in products, which are benign, and which themselves do not provide further environmental hazards. Of further advantage would be a method that is cheap, efficient, and thus competitive with existing technologies.
Object of the Invention
[0006] In an attempt to overcome the limitations of the prior art it is an object of the present invention to provide a process atmosphere incinerator for neutralizing chemical non-innocent gaseous mixtures that uses a thermally induced neutralization reaction, and which does not rely on the use of auxiliary components.
[0007] It is further an object of the present invention to provide a process atmosphere incinerator, in which chemical non-innocent gaseous mixtures are neutralized to form benign and environmentally friendly products.
[0008] It is another object of the present invention to provide a process atmosphere incinerator design, implementations of which support neutralization of a wide range of amounts of non-innocent gaseous mixtures of arbitrary composition.
Summary of the Invention
[0009] In accordance with an aspect of the present invention, there is provided a process atmosphere incinerator having a reaction chamber for thermally reacting gaseous mixtures and a burner connected to said reaction chamber, the process atmosphere incinerator comprising a plurality of flame breakers disposed inside said reaction chamber, the flame breakers providing surfaces of elevated temperatures within gas flow paths.
[0010] In accordance with another aspect of the present invention, there is provided a process atmosphere incinerator having a reaction chamber for thermally reacting gaseous mixtures, and a burner connected to the reaction chamber for horizontally introducing a flame into the reaction chamber along a longitudinal direction thereof, the process atmosphere incinerator having an inlet for chemically non-innocent gaseous mixtures disposed on the bottom section of the reaction chamber, an outlet for neutral gaseous mixtures disposed on the top section of the reaction chamber, and at least one partitioning wall inside the reaction chamber for providing a substantially horizontal gas flow path from the inlet to the outlet.
[0011] In accordance with an aspect of the present invention, there is further provided a method for thermally reacting chemically non-innocent gaseous mixtures, comprising the steps of introducing chemically non-innocent gaseous mixtures into a reaction chamber, introducing a horizontal flame into the reaction chamber along a longitudinal direction thereof, providing surfaces of elevated temperatures within gas flow paths inside the reaction chamber, subjecting the chemically non-innocent gaseous mixture to thermally induced chemical reactions while guiding it through the reaction chamber, cooling the neutralized gaseous mixture before releasing it from the reaction chamber, and releasing the neutralized gaseous mixture into the ambient atmosphere.
[0012] In accordance with an aspect of the present invention, there is also provided a method for thermally reacting chemically non-innocent gaseous mixtures, comprising the steps of introducing chemically non-innocent gaseous mixtures into a reaction chamber, providing atmospheric turbulences within gas flow paths inside the reaction chamber, providing surfaces of elevated temperatures within gas flow paths inside the reaction chamber, subjecting the chemically non-innocent gaseous mixture to thermally induced chemical reactions while guiding it through the reaction chamber, cooling the neutralized gaseous mixture before releasing it from the reaction chamber, and releasing the neutralized gaseous mixture into the ambient atmosphere.
Brief Description of the Drawings
[0013] Exemplary embodiments of the present invention will now be described in conjunction with the following drawings, in which similar reference numbers designate similar items:
[0015] Figure 2 presents a side-view of a neutralization chamber of the process atmosphere incinerator according to a first embodiment of the present invention;
[0016] Figure 3 presents a side view of a neutralization chamber of the process atmosphere incinerator according to a second embodiment of the present invention;
[0017] Figure 4 presents a top view of the neutralization chamber of the process atmosphere incinerator according to the second embodiment of the present invention;
[0018] Figure 5 presents a cross section of the neutralization chamber of the process atmosphere incinerator according to the second embodiment of the present invention;
Detailed Description of the Invention
[0021] The following description is presented to enable a person skilled in the art to make and use the invention, and is provided in the context of a particular application thereof. Various modifications to the disclosed embodiments will be readily apparent to those skilled in the art, and the general principles defined herein are easily applied to other embodiments and applications without departing from the spirit and the scope of the invention. Thus, the present invention is not intended to be limited to the embodiments disclosed, but is to be accorded the widest scope consistent with the principles and features disclosed herein.
[0022] In Figure 1, a schematic block diagram of a process atmosphere incinerator 1 is shown. The main chemical reactions take place in a horizontal neutralization chamber 2. In the following, when referring to a neutralization chamber, a horizontal neutralization chamber is implied, unless specified otherwise. The neutralization chamber 2 is equipped with an encasement or lining 3. The material chosen for the lining 3 of the neutralization chamber 2 is selected to be resilient to chemical corrosion from chemicals to be neutralized or formed in the neutralization process and to be resilient to melting at the incinerator operating temperature. Typically a ceramic material is selected, which is chemically inert, and serves as insulating layer as well as heat reservoir.
[0023] The chemical reactions, which take place in the neutralization chamber, are generally referred to herein as neutralization reactions of chemically non-innocent gaseous mixtures. Non-innocent gaseous mixtures contain substances in the gas phase, which do not behave neutral in the sense of any common acid/base-theory, including the HSAB concept of Pearson. Thus, gaseous mixtures, which do not contain ammonia as in the present example, but possibly contain hydrogen sulfide or carbon monoxide, would qualify as non-innocent gaseous mixtures. A neutralization reaction refers to any chemical reaction, in which the non-innocent component of a gaseous mixture is transformed into one or more neutral products. Since the neutralization reaction is thermally initiated, the apparatus described in the present invention is referred to as an incinerator. Since commonly gaseous mixtures to be neutralized often are effluent gases stemming from certain industrial processes, the apparatus described in the present invention is referred to as a process atmosphere incinerator. Of course, the use of such a process atmosphere incinerator is not limited to the common or typical uses thereof. The neutralization chamber 2 of the present embodiment is a specific example of a reaction chamber for chemically reacting gaseous mixtures.
[0024] A burner nozzle 4 is connected to one of the sidewalls of the neutralization chamber 2. The burner nozzle 4 horizontally introduces a flame into the neutralization chamber along a longitudinal direction thereof. The flame adjusts the reaction conditions inside the neutralization chamber to a certain temperature as well as to a certain atmospheric composition. The burner nozzle 4 is connected to an air blower 5, and to a fuel feed line 6. The combination of the burner nozzle 4, the air blower 5, and the fuel feed line 6 is referred to as a burner. Typically, natural gas is used as a fuel source to operate the burner. Furthermore, an additional air feed line 7 is connected to the neutralization chamber 2 for a fine-tuning of the combustion conditions, and for an adjustment of the conditions for the neutralization reaction. The gaseous mixture to be neutralized is introduced through a feed line 8 into the neutralization chamber 2.
[0025] In the example of neutralizing NH3 under oxidative conditions, three reactions are of major importance. The neutralization reaction begins with the oxidation of ammonia to form nitrogen oxides, for example nitrogen monoxide NO, as shown in equation 1:
Nitrogen monoxide further reacts with additional ammonia to produce dinitrogen and water, equation 2, both of which are benign and natural occurring components in earth's atmosphere:
Also, ammonia partly dissociates following an endothermic decomposition reaction, as shown in equation 3:
[0026] As can be seen from the reaction equations, reactions 1 and 2 are exothermic, and produce heat, whereas reaction 3 is endothermic, and consumes heat. For the overall reaction to proceed, well-defined reaction conditions are desirable, in which a fine balance between the three reactions is achieved. A certain amount of heat and thus a certain temperature is preferable to initiate the chemical reactions. On the other hand, if the temperature is too high, reactions, in which heat is produced, will be hampered. This effect will be most pronounced for the reaction, in which the largest amount of heat is produced, namely reaction 2 (+1816 kJ/mol). As a consequence, not all the nitrogen monoxide formed in reaction 1 will be consumed, which in turn leads to an increased NOx level in the neutralized gaseous mixture released to the atmosphere. It has been found that the neutralization of ammonia using the apparatus and method of the present embodiment is preferably carried out in a temperature range of 800-1100 °C. In this case, the average amount of NOx in the emission gas released through a flue 9 to the ambient atmosphere is less than 40 mg/m3. It has also been found that the process according to the present invention almost quantitatively neutralizes all ammonia present in an effluent gas. The average amount of NH3 in the emission gas is less than 6 mg/m3.
[0027] A process control unit automatically adjusts the conditions in the neutralization chamber 2. The process control unit comprises a processor 10, which is connected to a sensor 11 for sensing the conditions inside the neutralization chamber 2, to a control valve 12 for adjusting the amount of fuel fed to the burner, and to a control valve 13, for adjusting the amount of additional air introduced into the neutralization chamber 2. Thus, the process control unit automatically maintains the optimum temperature necessary to neutralize a known gaseous mixture. Depending on the composition of the gaseous mixture to be neutralized, the overall reaction might be either endothermic or exothermic. The amount of oxygen, and therefore the amount of air supplied to the neutralization chamber is adjusted to ensure that it is sufficient to react with all the gases present. This includes not only the gases to be neutralized, but also gaseous fuel and other reactants if any as well. When the amount of exothermically reacting gases in the gaseous mixture to be neutralized is low, more natural gas is used to help to maintain an adequate reaction temperature. This is typically the case in nitriding atmospheres diluted by N2. In the case of the gaseous mixture to be neutralized containing a higher amount of exothermically reacting gases, such as H2, a vigorous reaction releasing large amounts of heat is generated and the temperature of combustion rises. However, as illustrated above, excessively high temperature is conducive to the generation of an increased amount of NOx in the gases released by the process atmosphere incinerator 1. To compensate for this effect, the process control unit automatically adjusts the amounts of air and natural gases. The processor 10 receives data from the sensor 11, and accordingly adjusts the flow of air and fuel through an automated setting of the control valves 12 and 13. The addition of air not only serves to provide the adequate amount of oxygen, but also helps to adjust the temperature of the reaction mixture.
[0028] In Figure 2, a side-view down the latitudinal direction of the neutralization chamber 2 according to a first embodiment of the present invention is shown. The burner nozzle 4 is positioned in a sidewall of the neutralization chamber as to introduce a flame into the neutralization chamber along a longitudinal direction thereof. A baffle 21, which extends horizontally along the longitudinal direction of the neutralization chamber, and which is positioned right above the burner nozzle 4, further helps to guide the flame along the desired direction. An inlet 22 for the gaseous mixture to be neutralized is positioned in the floor section of the neutralization chamber, and right below the burner nozzle. Alternatively, the gas inlet 22 for the gaseous mixture to be neutralized is disposed in the same wall of the neutralization chamber 2 as the burner nozzle 4. It is advantageous to place the inlet 22 for the gaseous mixture to be neutralized below the burner nozzle 4, so that the incoming gaseous mixture is directly conducted to the hot zone of the neutralization chamber 2. An outlet 23 connects the neutralization chamber 2 to the flue 9, through which the neutralized gaseous mixture is released to the atmosphere. The outlet 23 is disposed on the top section of the neutralization chamber, and on the opposite site of the baffle 21, with respect to the gas inlet 22. The baffle 21 not only serves to direct the flame of the burner along a desired direction, but also assists in guiding the gaseous mixture through the neutralization chamber 2.
[0029] A plurality of flame breakers 24 is mounted inside the neutralization chamber 2. A shape of a flame breaker 24 is preferably that of an elongated parallelepiped, the flame breaker 24 being mounted vertically to the floor section of the neutralization chamber 2. The direction of longitudinal extension of the flame breaker 24 is perpendicular to the direction of longitudinal extension of the flame introduced by the burner nozzle 4 into the neutralization chamber 2. Thus, the flame produced by the burner strikes the plurality of flame breakers 24, and is therefore disturbed. Breaking of the flame inside the neutralization chamber 2 then introduces atmospheric disturbances in the reactive region of the neutralization chamber 2. Here, the reactive region is essentially the area where the flame breakers 24 are located. The plurality of flame breakers 24 fulfills a variety of functions. The atmospheric turbulences introduced by the flame breakers 24 result in a thorough mixing of the gases present in the neutralization chamber 2, and avoid the build-up of either temperature or concentration gradients. This promotes uniform reaction conditions throughout the reactive region, and further promotes an even distribution of the gaseous mixture inside the neutralization chamber 2. Since the flame breakers 24 present an obstacle in the path the gas travels from the inlet 22 through the neutralization chamber to the outlet 23, the flame breakers 24 enhance the duration of stay of a single gas molecule in the reactive region of the neutralization chamber 2. This causes an increase of time available for a chemical reaction, and consequently an increase in conversion rate. Also, the flame breakers 24 provide a reactive surface, which possibly adsorbs certain gases. It is believed that adsorption is in many cases an essential step for activation of molecules to be neutralized, and for initial predissociation. Gas molecules, like NH3, hit the surface of the flame breaker 24, and undergo homolytic or heterolytic bond cleavage, creating reactive radicals or ions. These reactive species then undergo further reactions, eventually leading to the formation of the final products. The presence of the flame breakers 24 is therefore important in the conversion of chemically non-innocent gaseous mixtures.
[0030] Alternatively, the flame breaker 24 is provided in the form of a perforated brick. The perforation of the flame breaker 24 serves several purposes. Amongst other advantages, it increases the amount of atmospheric turbulences in the neutralization chamber 2, thus enhancing the beneficial effects resulting from atmospheric disturbances as described above. The perforation also provides an increased surface area of the flame breaker 24, thus allowing a larger amount of gases to be adsorbed at the flame breaker 24.
[0031] According to the present embodiment, the flame breakers 24 are manufactured from a ceramic material. This material has a high specific heat capacity, and serves as a heat reservoir. In operation, the flame breakers 24 help to provide a certain base temperature, which can be fine-tuned by admixture of ambient air, and by adjusting the ratio of oxygen and fuel. The ceramic material is chemically inert, and resistant to many of the reactive species present in the gaseous mixture or adsorbed to the surface of the flame breakers 24, even including nitride ions N3-. Thus, the ceramic material not only ensures a high life span of the flame breakers 24, but also reproducible reaction conditions. Further, the flame breakers act to absorb heat from exothermic reactions thereby mitigating the effects of rapidly progressing exothermic reactions by reducing the rapid temperature rise within the chamber caused thereby.
[0032] An inlet 25 for additional air is disposed in close proximity to the outlet 23 for the neutralized gaseous mixture. The additional air fed into the neutralization chamber 2 is usually at ambient temperature, and therefore at a substantially lower temperature than the inside of the neutralization chamber. Part of the additional air coming from the inlet 25 will travel to the reactive region of the neutralization chamber, thus providing the adequate amount of oxygen to maintain chemical reactions. While traveling inside the neutralization chamber 2, the additional air will get into contact with the lining 3 and the flame breakers 24, causing a certain degree of cooling of these components, and thus adjusting the reaction conditions inside the neutralization chamber 2. Since the inlet 25 is disposed in vicinity to the outlet 23, part of the additional air also mixes with the neutralized gaseous mixture. This will rapidly cool down and dilute the effluent. This way, it is safer to release the effluent from the neutralization chamber. Components like the flue 9 or any other components, which are in contact with the effluent from the process atmosphere incinerator 1, do not have to withstand excessive thermal stress. Also, the concentration of chemically non-innocent components in the effluent, which is already very low due to the efficiency of the apparatus described in the embodiment of the present invention, is further reduced.
[0033] In Figure 3, a side-view down the latitudinal direction of the neutralization chamber 2 according to a second embodiment of the present invention is shown. The baffle 21, the outlet 23, the flame breaker 24, as well as the inlet 25 for additional air fulfill the same functions as described above. Under a ceramic base plate 26 covering the floor section of the neutralization chamber 2, there is running along the longitudinal direction thereof at least one gas activation channel 27. The gas activation channel 27 comprises a supply pipe 28 and a gas inlet 29, the supply pipe 28 and the gas inlet 29 being positioned at opposite sites of the gas activation channel 27. The gas inlet 29 is positioned in close proximity to and below the burner nozzle 4. In operation of the process atmosphere incinerator, the gas activation channel 27,which extends through substantially the whole length of the neutralization chamber 2, is heated to elevated temperatures. A non-innocent gas mixture to be neutralized enters the neutralization chamber through the supply pipe 28, passes through the gas activation channel 27, and enters the reactive zone of the neutralization chamber through the gas inlet 29. While passing through the gas activation channel 27, the non-innocent gas mixture to be neutralized is preheated. Preheating the non-innocent gas mixture supports and aids the neutralization process. For example, at elevated temperatures, the chemical equilibrium between ammonia and H2 and N2, is shifted towards the side of the benign dissociation products dihydrogen and dinitrogen, compare reaction 3. Thus, a certain amount of ammonia in the gas mixture to be neutralized dissociates into H2 and N2, even before reaching the combustion zone.
[0034] In Figure 4, a top-view of the neutralization chamber 2 according to the second embodiment of the present invention is shown. The neutralization chamber 2 comprises three gas activation channels 27, each gas activation channel having a supply pipe 28 and a gas inlet 29. Alternatively, the neutralization chamber comprises any other number of gas activation channels 27. The gas activation channels 27 are welded from a shaped strip of a metallic material. Preferably, the gas activation channels 27 are made from Inconel® , a nickel-chromium alloy consisting of about 70% Ni, 20% Cr, and additional metals, for example iron, Fe. Such alloys are resistant to oxidation, reducing environments, corrosive environments and high temperature environments, and posses good mechanical properties. Therefore, Inconel® is well suited for the use in furnace mufflers and heat-treating equipment. Alternatively, the gas activation channels 27 are made from any other material possessing a suitable amount of chemical inertness to the conditions applied by the heated non-innocent gas mixtures, and appropriate thermal conductivity.
[0035] In Figure 5, a cross section of the neutralization chamber 2 according to the second embodiment of the present invention is shown. Three gas activation channels 27 are shown disposed beneath the ceramic base plate 26. The gas activation channels 27 posses a rectangular cross-section. Alternatively, the gas activation are made in a way as to possess any other type of suitable cross-section, such as a round cross-section, a square cross-section, or the like. Also, other ways of guiding the gas activation channels 27 through the neutralization chamber are easily envisioned. For example, the gas activation channels 27 are positioned at the sidewalls of the neutralization chamber 2, or the gas activation channels run through the neutralization chamber 2. Preferably, the gas activation channels are provided as straight tubular constructions. Alternatively, bent and winding tubular constructions are provided as gas activation channels 27. When the process atmosphere incinerator serves a plurality of different processes at the same time, the effluent gaseous mixtures stemming form each process are directed to different gas activation channels 27. If the process atmosphere incinerator serves only one process, the effluent gaseous mixture is distributed among the plurality of gas activation channels 27.
[0036] The neutralization chamber 2 according to the embodiments of the present invention is preferably a horizontal neutralization chamber. Alternatively, the neutralization chamber 2 is a vertical neutralization chamber. Referring now to Figure 6, a top-view of a horizontal neutralization chamber 30 is shown. The sensor 11 is mounted to a sidewall of the horizontal neutralization chamber 30, and senses the atmospheric conditions in the reactive region of the horizontal neutralization chamber 30. A longitudinal direction of an oblong base of the flame breaker 24 forms an angle ξ with the longitudinal direction of the horizontal neutralization chamber 30. The angle ξ can be adjusted as to provide the best conditions for flame breaking, leading to the highest conversion rates and the lowest production of undesirable side products. In the apparatus described in present invention, the angle ξ amounts approximately to 20º. Alternative arrangements of flame breakers include for example an asymmetric distribution of flame breakers inside the neutralization chamber.
[0037] The horizontal design of the neutralization chamber 2 is significant to the present invention for a variety of reasons. It allows for a compact arrangement of the components comprising the neutralization chamber 2, and it also allows for a facile extension of the capacity of the process atmosphere incinerator. Given a predefined spacing between two flame breakers 24, increasing the number of flame breakers 24 increases the size of the reactive zone of the neutralization chamber. This in turn increases the maximum process gas flow. Process atmosphere incinerators 1 according to the present invention with a process gas flow in the range from 65 l/min up to 1000 l/min have been demonstrated. Depending on the size of the neutralization chamber 2, the capacity of the burner 4, and the number of flame breakers 24 disposed inside the neutralization chamber 2, among other characteristics of the process atmosphere incinerator 1, some flame breakers of the plurality of flame breakers 24 are not within the path of the flame created by the burner 4. However, all of the flame breakers 24 fulfill the important functions of introducing atmospheric turbulences inside the neutralization chamber 2, and prolonging the duration of stay of molecules to be neutralized in the reactive region. Optionally, two flames are introduced into the neutralization chamber from two burner nozzles disposed on opposing sides of the neutralization chamber. The horizontal design further allows for a vertical arrangement of the flame breakers. This enables one to build the flame breakers using commercially available ceramic building blocks. On the other hand, a vertical design of the neutralization chamber would lend itself to a construction, in which the flame breakers are to be horizontally mounted. The thermal stress then is likely to cause the flame breakers to fail under gravitational strain. In order to avoid this, tailor-made flame breakers are to be used, dramatically increasing the production cost of a process atmosphere incinerator. Even though the use of horizontal flame breakers is believed to be less preferred, horizontally disposed flame breakers still benefit substantially from the inventive features of the invention, and their use is not intended to be excluded.
[0038] In Figure 7, a side-view down the latitudinal direction of a vertical neutralization chamber 40 is shown. Like the horizontal neutralization chamber 30, the vertical neutralization chamber 40 comprises an inlet 22 for the gaseous mixture to be neutralized, an outlet 23 for the neutralized gaseous mixtures, and a plurality of flame breakers 24. Further, a burner nozzle 4 is disposed in one of the walls of the vertical neutralization chamber 40. Advantageously, the burner nozzle 4 is disposed in the lower section of the vertical neutralization chamber 40. Further advantageously, the burner nozzle 4 is disposed in the floor section of said vertical neutralization chamber 40. In this example, the flame breakers 24 are horizontally mounted. Nevertheless, the flame breakers 24 fulfill the basic functions of introducing atmospheric turbulences inside the vertical neutralization chamber 40, and providing surfaces at elevated temperatures, which help to control the reaction temperature inside the vertical neutralization chamber 40, prolong the duration of stay of molecules to be neutralized in the reactive region of the vertical neutralization chamber 40, and support possible activation through predissociation of molecules to be neutralized. Of course, various other designs of neutralization chambers are envisaged, in which flamebreakers serve the same purpose as described above.
[0039] As previously mentioned, the shape of the flame breaker 24 is preferably that of an elongated parallelepiped. However, the shape of the flame breaker 24 is optionally varied as to provide the most efficient atmospheric turbulences for a certain construction of the neutralization chamber. The most effective shape of the flame breaker 24 depends on whether the flame breakers 24 are used in vertically or horizontally operating process atmosphere incinerators. For example, the shape of the flame breaker is optionally chosen as an elongated triangular prism. Further optionally, the sidewalls of the flamebreakers constitute curved surfaces, rather than plane surfaces. It is possible to envisage flame breakers 24 having concave surfaces, convex surfaces, or any combination of all of the above-mentioned surface types. Alternatively, the shape of the flame breaker 24 is that of a plate having perforations or holes for passage through of the flame and the gases inside the neutralization chamber 2. These openings in the flame breakers 24 cause a vigorous mixing of the gases inside the neutralization chamber 2. Various other shapes and forms of the flame breakers 24 are easily envisioned.
[0040] The process atmosphere incinerator 1 of the present invention also lends itself to catalytic applications. Optionally, the flame breakers 24 are coated with catalytically active material. Such a treatment then extends the scope of the apparatus described in the present invention to include a whole variety of neutralization reactions carried out in the gas phase.
[0041] It is further possible to incorporate heat-exchanging elements (not shown) inside the neutralization chamber 2. Since in many cases the neutralization reactions are exothermic reactions, a certain amount of excess heat is produced during the neutralization of chemical non-innocent gaseous mixtures. The heat-exchanging elements are not only used to dispose of the excess heat, but also to introduce the energy gained from the neutralization reaction into other processes. The excess heat is for example used to preheat the chemically non-innocent gaseous mixtures to be neutralized. This way, the portion of the time the gaseous mixture stays in the reactive region, which is spend to thermally activate the molecules to be neutralized, is significantly reduced. Therefore, the amount of time available for the neutralization reaction is increased, and the efficiency of the process atmosphere incinerator 1 is enhanced.
[0042] Although the present invention has been described with respect to specific embodiments thereof, various changes and modifications can be carried out by those skilled in the art without departing from the scope of the invention. Therefore, it is intended that the present invention encompass such changes and modifications as fall within the scope of the appended claims.
1. A process atmosphere incinerator having a reaction chamber for thermally reacting
gaseous mixtures and a burner connected to said reaction chamber, said process atmosphere
incinerator comprising a plurality of flame breakers disposed inside said reaction
chamber, said flame breakers providing surfaces of elevated temperatures within gas
flow paths.
2. A process atmosphere incinerator defined in claim 1, wherein the flame breakers introduce
variations in gas flow paths and flame patterns inside said reaction chamber.
3. A process atmosphere incinerator defined in claim 1, wherein at least one flame breaker
is vertically mounted to the inside of the reaction chamber, being supported by the
floor section of the reaction chamber.
4. A process atmosphere incinerator defined in claim 3, wherein a shape of the at least
one flame breaker is substantially that of an elongated parallelepiped, a longitudinal
direction of an oblong base of the flame breaker forming an acute angle with a longitudinal
direction of the reaction chamber.
5. A process atmosphere incinerator defined in claim 4, wherein the longitudinal direction
of the oblong base of the flame breaker forms an angle of approximately 20° with the
longitudinal direction of the reaction chamber.
6. A process atmosphere incinerator defined in claim 3, wherein the flame breaker is
formed of a ceramic material.
7. A process atmosphere incinerator defined in claim 1, wherein the burner horizontally
introduces a flame into the reaction chamber along a longitudinal direction thereof.
8. A process atmosphere incinerator defined in claim 1, comprising a reaction chamber
having a baffle disposed above the inlet for the flame produced by the burner, said
baffle horizontally extending along the longitudinal direction of the reaction chamber.
9. A process atmosphere incinerator defined in claim 8, comprising a reaction chamber
having an inlet for chemically non-innocent gaseous mixtures and an outlet for neutral
gaseous mixtures, said inlet and set outlet disposed on opposite sides with respect
to the baffle.
10. A process atmosphere incinerator defined in claim 1, further comprising a process
control unit for regulating the conditions of the chemical reactions inside the reaction
chamber, said process control unit including a sensor disposed for sensing the reaction
conditions inside the reaction chamber, a first valve to regulate an amount of air
fed to the reaction chamber, a second valve to regulate an amount of fuel fed to the
burner, and a controller to control the amount of air to be fed to the neutralization
chamber and the amount of fuel to be fed to the burner in dependence on the reaction
conditions sensed by sensor.
11. A process atmosphere incinerator defined in claim 1, wherein the controller comprises
a processor.
12. A process atmosphere incinerator having a reaction chamber for thermally reacting
gaseous mixtures, and a burner connected to said reaction chamber for horizontally
introducing a flame into said reaction chamber along a longitudinal direction thereof,
said process atmosphere incinerator comprising:
an inlet for chemically non-innocent gaseous mixtures disposed on the bottom section of the reaction chamber;
an outlet for neutral gaseous mixtures disposed on the top section of the reaction chamber; and
at least one partitioning wall inside the reaction chamber for providing a substantially horizontal gas flow path from the inlet to the outlet.
13. A process atmosphere incinerator defined in claim 12, wherein the burner is disposed
to horizontally introduce a flame into the reaction chamber along a longitudinal direction
thereof.
14. A process atmosphere incinerator defined in claim 12, further comprising at least
one flame breaker, said at least one flame breaker being mounted to the inside of
the reaction chamber.
15. A process atmosphere incinerator defined in claim 14, wherein the at least one flame
breaker is vertically mounted to the inside of the reaction chamber, and supported
by the floor section of the reaction chamber.
16. A process atmosphere incinerator defined in claim 15, wherein a shape of the at least
one flame breaker is substantially that of an elongated parallelepiped, a longitudinal
direction of an oblong base of the flame breaker forming an acute angle with a longitudinal
direction of the reaction chamber.
17. A process atmosphere incinerator defined in claim 16, wherein the longitudinal direction
of the oblong base of the flame breaker forms an angle of approximately 20º with the
longitudinal direction of the reaction chamber.
18. A process atmosphere incinerator defined in claim 14, wherein the flame breaker is
formed of a ceramic material.
19. A process atmosphere incinerator defined in claim 12, further comprising a process
control unit for regulating the conditions of the chemical reactions inside the reaction
chamber, said process control unit including a sensor, disposed for sensing the reaction
conditions inside the reaction chamber, a first valve to regulate an amount of air
fed to the reaction chamber, a second valve to regulate an amount of fuel fed to the
burner, and a controller to control the amount of air to be fed to the neutralization
chamber and the amount of fuel to be fed to the burner in dependence on the reaction
conditions sensed by sensor.
20. A process atmosphere incinerator defined in claim 19, wherein the controller comprises
a processor.
21. A process atmosphere incinerator having a reaction chamber for thermally reacting
gaseous mixtures, a burner connected to said reaction chamber for horizontally introducing
a flame into said reaction chamber along a longitudinal direction thereof, an outlet
for neutral gaseous mixtures, and at least one gas activation channel running in a
direction through the reaction chamber for thermally activating gaseous mixtures,
said at least one gas activation channel comprising:
a supply pipe for receiving chemically non-innocent gaseous mixtures; and
an outlet for releasing chemically non-innocent gaseous mixtures into the reaction chamber.
22. A process atmosphere incinerator defined in claim 21, wherein the burner is disposed
to horizontally introduce a flame into the reaction chamber along a longitudinal direction
thereof.
23. A process atmosphere incinerator defined in claim 21, wherein the outlet for releasing
non-innocent gaseous mixtures of the gas activation channel is positioned in close
proximity to a nozzle of the burner.
24. A process atmosphere incinerator defined in claim 21, further comprising at least
one flame breaker, said at least one flame breaker being mounted to the inside of
the reaction chamber.
25. A process atmosphere incinerator defined in claim 24, wherein the at least one flame
breaker is vertically mounted to the inside of the reaction chamber, and supported
by the floor section of the reaction chamber.
26. A process atmosphere incinerator defined in claim 25, wherein a shape of the at least
one flame breaker is substantially that of an elongated parallelepiped, a longitudinal
direction of an oblong base of the flame breaker forming an acute angle with a longitudinal
direction of the reaction chamber.
27. A process atmosphere incinerator defined in claim 26, wherein the longitudinal direction
of the oblong base of the flame breaker forms an angle of approximately 20º with the
longitudinal direction of the reaction chamber.
28. A process atmosphere incinerator defined in claim 24, wherein the flame breaker is
formed of a ceramic material.
29. A process atmosphere incinerator defined in claim 21, further comprising a process
control unit for regulating the conditions of the chemical reactions inside the reaction
chamber, said process control unit including a sensor, disposed for sensing the reaction
conditions inside the reaction chamber, a first valve to regulate an amount of air
fed to the reaction chamber, a second valve to regulate an amount of fuel fed to the
burner, and a controller to control the amount of air to be fed to the neutralization
chamber and the amount of fuel to be fed to the burner in dependence on the reaction
conditions sensed by sensor.
30. A process atmosphere incinerator defined in claim 29, wherein the controller comprises
a processor.
31. A method for thermally reacting chemically non-innocent gaseous mixtures, comprising
the steps of:
introducing chemically non-innocent gaseous mixtures into a reaction chamber;
guiding the chemically non-innocent gaseous mixture along a gas flow path from an inlet to an outlet of the reaction chamber;
providing surfaces of elevated temperatures inside the reaction chamber within gas flow path and between two guiding walls of the reaction chamber, the surfaces of elevated temperature for providing atmospheric turbulences thereabouts within gas flow paths inside the reaction chamber, the turbulences other than those relating to guiding the gas flow within the gas flow path;
subjecting the chemically non-innocent gaseous mixture to thermally induced chemical reactions while guiding it through the reaction chamber;
cooling the neutralized gaseous mixture after releasing it from the reaction chamber. and before releasing it into the ambient atmosphere; and
releasing the neutralized gaseous mixture into the ambient atmosphere.
32. A method for reacting chemically non-innocent gaseous mixtures defined in claim 31,
wherein the surfaces at elevated temperatures are provided by at least one flame breaker.
33. A method for thermally reacting chemically non-innocent gaseous mixtures defined in
claim 31, further comprising the step of providing a predefined temperature inside
the reaction chamber by controlling the amount of heat produced in a combustion of
fuel and air, and by mixing gases inside the reaction chamber with additional gases
at a different temperature.
34. A method for thermally reacting chemically non-innocent gaseous mixtures defined in
claim 33, further comprising the step of adjusting the predefined temperature to fall
within a range from 800 ºC to 1100 ºC.
35. A method for thermally reacting chemically non-innocent gaseous mixtures defined in
claim 31, further comprising the step of cooling the neutralized gaseous mixture after
releasing it from the reaction chamber and before releasing it into the atmosphere
by mixing the neutralized gas mixture with gases at lower temperature than the neutralized
gas mixture.
36. A method for thermally reacting chemically non-innocent gaseous mixtures, comprising
the steps of:
introducing chemically non-innocent gaseous mixtures into a reaction chamber;
introducing a horizontal flame into the reaction chamber along a longitudinal direction thereof;
guiding the chemically non-innocent gaseous mixture along a gas flow path from an inlet to an outlet of the reaction chamber;
providing surfaces of elevated temperatures inside the reaction chamber within gas flow path and between two guiding walls of the reaction chamber, the surfaces of elevated temperature for providing atmospheric turbulences thereabouts within gas flow paths inside the reaction chamber, the turbulences other than those relating to guiding the gas flow within the gas flow path;
subjecting the chemically non-innocent gaseous mixture to thermally induced chemical reactions while guiding it through the reaction chamber;
cooling the neutralized gaseous mixture after releasing it from the reaction chamber, and before releasing it into the ambient atmosphere; and
releasing the neutralized gaseous mixture into the ambient atmosphere.
37. A method for reacting chemically non-innocent gaseous mixtures defined in claim 36,
wherein the surfaces at elevated temperatures are provided by at least one flame breaker.
38. A method for thermally reacting chemically non-innocent gaseous mixtures defined in
claim 36, further comprising the step of providing a predefined temperature inside
the reaction chamber by controlling the amount of heat produced in a combustion of
fuel and air, and by mixing gases inside the reaction chamber with additional gases
at a different temperature.
39. A method for thermally reacting chemically non-innocent gaseous mixtures defined in
claim 38, further comprising the step of adjusting the predefined temperature to fall
within a range from 800 ºC to 1100 ºC.
40. A method for thermally reacting chemically non-innocent gaseous mixtures defined in
claim 36, further comprising the step of cooling the neutralized gaseous mixture after
releasing it from the reaction chamber and before releasing it into the atmosphere
by mixing the neutralized gaseous mixture with gases at lower temperature than the
neutralized gas mixture.
41. A method for thermally reacting chemically non-innocent gaseous mixtures, comprising
the steps of:
thermally activating chemically non-innocent gaseous mixtures;
introducing the thermally activated chemically non-innocent gaseous mixtures into a reaction chamber;
guiding the chemically non-innocent gaseous mixture along a gas flow path from an inlet to an outlet of the reaction chamber;
providing surfaces of elevated temperatures inside the reaction chamber within gas flow path and between two guiding walls of the reaction chamber, the surfaces of elevated temperature for providing atmospheric turbulences thereabouts within gas flow paths inside the reaction chamber, the turbulences other than those relating to guiding the gas flow within the gas flow path;
subjecting the chemically non-innocent gaseous mixture to thermally induced chemical reactions while guiding it through the reaction chamber;
cooling the neutralized gaseous mixture after releasing it from the reaction chamber and before releasing it into the ambient atmosphere; and
releasing the neutralized gaseous mixture into the ambient atmosphere.
42. A method for reacting chemically non-innocent gaseous mixtures defined in claim 41,
wherein the surfaces at elevated temperatures are provided by at least one flame breaker.
43. A method for thermally reacting chemically non-innocent gaseous mixtures defined in
claim 41, further comprising the step of providing a predefined temperature inside
the reaction chamber by controlling the amount of heat produced in a combustion of
fuel and air, and by mixing gases inside the reaction chamber with additional gases
at a different temperature.
44. A method for thermally reacting chemically non-innocent gaseous mixtures defined in
claim 43, further comprising the step of adjusting the predefined temperature to fall
within a range from 800 ºC to 1100 ºC.
45. A method for thermally reacting chemically non-innocent gaseous mixtures defined in
claim 41, further comprising the step of cooling the neutralized gaseous mixture after
releasing it from the reaction chamber and before releasing it into the ambient atmosphere
by mixing the neutralized gas mixture with gases at lower temperature than the neutralized
gas mixture.