FI117519B - Combustion device for burning gaseous composition containing gases and the method of its use - Google Patents

Description

117519

FIELD OF THE INVENTION The present invention relates to a combustion apparatus for gases containing a flammable gaseous compound having at least one heat transfer, a side formed by a first plurality of flow passageways and a second plurality of flow passageways, at least one flue gas feed line and at least one flue gas outlet line.

10 There are constantly stricter limit values for emissions of various gaseous compounds. For example, industrial solvent emissions, volatile organic compounds (VOCs), have recently been subject to new, substantially stricter emission standards in the EU. Directive 1999/13 defines the permitted industrial solvent concentrations for process waste gases.

There are many ways to achieve these VOC standards. It is possible, for example, to switch to water-soluble paints or varnishes or to modify the process to achieve the desired result. Usually, however, these options do not · *; *; This is not possible, leaving the solution to be cleaned of solvent emissions after processes 20. The most common cleaning methods used are thermal or. for catalytic combustion and solvent concentration. Biological purification methods have also been developed.

• · ·· ·

There are many problems with solvent aftertreatment. Emissions of solvents may contain toxic compounds or may occur during post-treatment. The emissions you receive also contain various solids that must be removed by filtration. Often, however, the problem is the low solvent content of solvent emissions, whereby the pre-*:, 7 sign energy generated by the combustion is not sufficient to maintain combustion, but additional energy is required to raise the gas to the combustion temperature. The combustion temperature is in the thermal: typically 800-900 ° C and in the catalytic combustion typically 300-400 ° C.

30 However, the use of additional energy is expensive, so recuperative and regenerative heat exchangers have been introduced to save it. They are used to transfer energy from the waste gas to the heating of solvent emissions from combustion. In recuperative countercurrent heat exchangers it is possible to achieve an efficiency of about 80% 117519 2. In regenerative heat-based heat exchangers, efficiency of up to 90% can be achieved.

Catalytic combustion is becoming more common due to the lower need for additional energy. Another major advantage of catalytic combustion is that low temperature combustion produces very little or no nitrogen oxides (commonly referred to as NOX in this disclosure) as well as toxins such as dioxins.

The prior art in the field of catalytic combustion is represented, for example, by the catalytic combustion of Haldon Topsoe A / S air-mixed solvents in which the gas to be burned is fed to a heat exchanger where it preheats. The preheated gas is fed to 10 separate burners, from which the burned gas is fed to a reactor, where the gas passes through a solid bed of granular catalyst. The burned and purified gas is then led to a heat exchanger where it preheats the gas to be injected, and the pure gas is led to the outside air as exhaust gas. ϊ

Another prior art catalytic incinerator is a loop-like catalytic oxidation equipment manufactured by M&W 15 Industries Inc. Here, the gas to be incinerated is preheated as in the apparatus described above. The gas is burned in the next step, after which the burned gas is passed through a catalyst -! * V bed as exhaust gas to the outside air. However, these installations are quite space consuming and have several separate components.

In combustion plants using granular catalysts commonly used in current technology, the specific surface area of catalysts is quite low. Catalysts generally include oxides of base metals, which are sensitive to some of the substances known as catalyst poisons. Thus, such agents destroy the activity of the catalyst.

Said grain catalysts typically have a service life of several years.

* »· • · · • # ·. * ··. 25 On the other hand, there are various regenerative heat exchangers known as apparatuses, • · 9, · which have two heat exchangers side by side, one for heat storage and one for * '· “. Regularly changing the direction of gas flow can provide heat or ...! *. The problem with the equipment is, of course, the need for two heat exchangers / • heaters and the fact that • when changing the flow direction, there is always a small amount of treated * * * * 30 waste solvent containing waste gas in the exhaust air. This, in turn, diminishes the purification efficiency by as much as one percent, which in turn makes it more difficult to reach the newest standards.

It is therefore an object of the invention to provide a combustion apparatus capable of achieving the strictest emission standards required so that the apparatus has a good efficiency and 117519 3 so that the need for additional energy is minimized. It is a further object of the invention to provide a combustion apparatus that is as small, light and simple in construction as is easily portable and operable.

These objects have now been achieved as set forth in the appended claims.

The invention relates to a combustion apparatus for gases containing a flammable gaseous compound having at least one heat transfer section having a primary side and a secondary side formed by a first plurality of flow passages and a second plurality of flow passages, at least one flue gas outlet. The combustion apparatus according to the invention is characterized in that: - the same gas flows on the primary and secondary sides of the heat transfer section, - at least a part of the surface of the heat transfer section which is in contact with the flowing gas is catalytically active the gaseous compounds are combusted on the active surfaces, and - the heat generated by combustion in the first set of flow channels is transferred to the gas flowing in the second set of flow channels of the heat transfer section.

As will be apparent to one skilled in the art, the primary and secondary sides of the heat transfer section mean different sides of the heat transfer section, such as gas and / or liquid flowing in the first direction on the primary side and the same or different gas on the secondary side; / or the fluid flows in a direction opposite to the first direction. The gas and / or liquid can, of course, flow from the primary side to the secondary side or vice versa.

Thus, gases containing flammable gaseous compound are fed into the apparatus through at least one of the feed lines and upon contact with a catalytically active surface, they are flameless. In this way, the hotter gases from the '' · '' gases in the flow passages of the heat transfer part release their heat to the cooler gases that flow. * ··, in the opposite direction.

· · J j:: On virta u u u u u kaas u u u u kaas kaas kaas kaas u u *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***:::::: *** *** ***::::: 30 ***: Prior to the catalytically active surface, the gas contains flammable compounds, whereas thereafter these compounds are no longer present in the gas or are present in very small amounts which are harmless to the environment.

4, 117519

It will be obvious to one skilled in the art that the gas mixture burned during the start-up phase of the apparatus is preheated to the required temperature by means of additional energy. The additional energy source may be any known energy source, such as an electric resistor or a burner.

Thus, the combustion apparatus according to the invention is very simple in construction, with few movable parts such as valves, so that it is easy to adjust and operate. It is also inexpensive to maintain and has the potential to be very compact and easy to move. Further, with the combustion plant according to the invention, it is possible to achieve a very high efficiency, even close to 100%. Likewise, the need for additional energy is limited to the start-up phase of the plant when the hydrocarbon content in the gas exceeds a certain limit, for example about 0.7 g / pm.

It is possible to add an exhaust gas analyzer to the outlet of the apparatus according to the invention, which ensures that no excessive amount of harmful solvents is released into the open air, and which enables the analyzer to monitor the operation of the apparatus. After the analyzer, it is also possible to provide a channel through which incompletely purified gases are returned to combustion.

,. According to one embodiment of the invention, said first flow channels • *% * · '·] is the set of heat transfer of the primary set of flow channels. According to a "tlkf another embodiment, said first set of flow channels have a V .: 20 heat transfer part of the secondary flow channels in a set.

According to another embodiment of the invention, the surface in contact with the flowing gas of the first set of flow channels of the heat transfer section is at least * * catalytically active in its area and the second stream of the heat transfer section. the contact surface of a plurality of background channels with the flowing gas is at least • f * ;; · * 25 catalytically active in its area. Preferably, the surfaces of the flow channels are catalytically active such that in the region where the first surfaces are active. the other surfaces on one side of these are inactive and vice versa.

According to an embodiment of the invention, the surface in contact with the flowing gas, p: *, of a plurality of flow channels, is catalytically active in an area of 10 to 100%, preferably 25 to 100%. It is also clear that the flow channels may be catalytically active in different parts of their area.

In the combustion apparatus according to the invention, it is possible to use any catalyst known per se to a person skilled in the art who is able to burn the desired gases without flame. According to a preferred embodiment, the catalytically active 117519 5 surface contains a noble metal catalyst and / or a catalytically active metal oxide.

Thus, for example, the noble metal catalyst may be selected from the group consisting of metallic platinum, metallic palladium, palladium oxide, metallic gold and alloys thereof. The catalytically active metal oxide may be, for example, iron oxide, cerium, zirconium, nickel, cobalt, copper, chromium, tungsten or vanadium oxide.

The catalytically active surface is obtained by any means known to those skilled in the art, such as dipping or spraying, for example, plasma spraying. Various supports or binders may also be used with the catalysts and, for example, when precious metal catalysts are used, the precious metal typically has a surface area of about 1-3%. Catalysts often have large or very large specific surface areas as well as micropore areas, which are further up to ten times larger than those used in conventional granular catalysts. The high specific surface area improves the efficiency of the catalyst and increases its service life.

The catalysts used are still typically resistant to a wide variety of toxins, such as sulfur, chlorine or phosphorus, and have a very long lifetime, even over ten years. The combustion apparatus according to the invention is thus considerably more durable and more durable than the prior art apparatus. The apparatuses of the invention are generally not regenerated, but the heat transfer section is completely replaced. Need- • ·. However, surface activity can be restored by means of an acid / base wash solution **.

· ** ·· • · / i; : ***: According to a preferred embodiment of the invention, there are two or more heat transfer units: · · ♦: ***: more. In this case, preferably only one (or part) of the heat transfer part has catalytic active surfaces. In the apparatus according to the invention it is possible; . , *. 25 also uses a single heat transfer section divided into two or more phases that are different from one another.

In a combustion apparatus according to this embodiment, a gas containing flammable gas is preferably fed to the first heat transfer section, whereby t ** t 'is the gas flowing from the first flow channel of the second heat transfer section ί · ϊ t 30. contacting surface is at least partially catalytically active with respect to its surface area.

According to one embodiment of the invention, the heat transfer portion or heat transfer portions are plate heat exchangers. It will be appreciated that other types of heat transfer parts may also be used and that if the apparatus has two or more heat transfer parts, these parts may be different from one another. The heat transfer members are preferably made of metal or ceramic material, most preferably stainless steel.

According to the invention, it is also possible to mix oxidizing gas with gases containing a flammable gaseous compound prior to being fed to the incinerator, provided that the composition of the gases is such that they do not burn as such to achieve the desired purification result. Such a situation would be, for example, a production disruption that would create a so-called gas supply to the equipment. by a solvent. It is possible to connect the apparatus to the supply line of the gas 10 containing the flammable gaseous compound, for example an on-line meter, which measures the solvent of the gas to be supplied, or the like. concentrations.

Naturally, the apparatus of the invention is capable of burning and purifying any flammable gaseous and / or liquid compound. Preferably, the flammable gaseous compounds are volatile organic compounds (VOCs). With the apparatus according to the invention, it is possible to burn and purify autothermally, for example, gas mixtures containing 1 g of solvents / m3. In such a combustion, the temperature of the gas mixture rises to about 30 ° C upon combustion.

It is possible to use the apparatus according to the invention in all industrial processes, which generate residual scrubbers which can be burned and cleaned by the apparatus. It is also possible to use the equipment, for example, for land cleaning at old fuel stations or the like.

···:: • • t. ·· *, The invention will be described in more detail with reference to the accompanying drawings, in which ··· * ..

Fig. 1 shows a combustion apparatus according to a first embodiment of the invention: Fig. 2 shows a combustion apparatus according to a second embodiment of the invention, Fig. 3 shows a combustion apparatus according to a third embodiment of the invention; Figure 5 shows a combustion apparatus according to a fifth embodiment of the invention.

Fig. 1 shows an incinerator according to a first embodiment of the invention. The figure shows the gas supply line 1 of the flammable gaseous compound, the heat transfer section 2 which is the first flow channels 3 and the second flow channels 4 of the plate heat exchanger, the heat transfer section 2, the combustion gas outlet 5 and the pre-heater 6 which is the electrical resistance here. In addition, the figure shows the catalytically active surface 7 of the heat transfer 7 · 117519 part 2 and the flowing gas 8 of the second flow channels 4 of part 2. Approximately 30% of the surface of the other flow channels is catalytically active. The catalytically active surface is shown in this and other figures by cross lines.

The flammable gaseous compound containing gas 8 is fed to the combustion apparatus via a feed-in unit 1. The gas 8 flows in the first flow channels 3 of the plate heat exchanger. At the junction of the first flow channels 3 and the second flow channels 4 is an electric resistor 6 for preheating the gas 8 during the start-up phase of the apparatus. The gas 8 is then introduced into other flow channels 4, about 30% of whose surface area is catalytically active, and the catalytically active surface is located at the bottom of the plates with respect to the inlet 1. On this catalytic surface, the flammable compounds are flameless. In the upper portions of the second flow passages 4, the heat contained in the hot gas 8 is transferred to the colder gas 8 flowing in the first flow passages, whereby the electric resistor 6 is no longer needed for preheating. The burned gas 8 is then passed through an outlet 5 to the open air.

The heat transfer section shown is a plate heat exchanger having, for example, about 100 plates having a thickness of about 1.5 to 1.5 mm and spaced from 1 to 3 mm. The temperature of the incoming gas can be up to 300 ° C and the temperature change in the equipment: *; * · can be up to 200 ° C. Typically, the temperature of the incoming gas varies • · ... ϊ between room temperature and 300 ° C.

Fig. 2 shows a combustion apparatus according to a second embodiment of the invention.

The apparatus according to this embodiment has two heat transfer sections 9 and 10,

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:, .. J which are plate heat exchangers here. The gas s *** s 8 containing the flammable gaseous compound is supplied to the apparatus through an inlet 1 from which the gas 8 flows in the first flow passages 11 of the first plate heat exchanger 9. In the first plate heat exchanger 9, the gas 8 typically has a temperature of about room temperature. ··. To 300 ° C. Thereafter, the gas 8 enters first-to-primary flow channels 12 of the second plate heat exchanger 10, which in this embodiment are catalytically active over their entire area: **. The burned gas 8 then flows to the second flow channels 13 of the second plate heat exchanger 10 and to the first plate heat exchanger 9:. *. 30 to other flow channels 14 where it preheats the gas to be injected 8. Lo- • · ψ ·. ···. the burned gas 8 is discharged from the system. The temperature of the gas 8 in the second plate heat exchanger 10 is typically about 300-500 ° C, but preferably below; 600 ° C.

According to a preferred embodiment of the invention, the heat transfer portion having 35 catalytically active surfaces is about 1/3 of the total heat transfer portion.

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It will be apparent to one of ordinary skill in the art that the locations of the preheater 6 shown in the figures are freely selectable for optimum cleaning results.

Figure 3 shows a combustion apparatus according to a third embodiment of the invention. The apparatus is otherwise similar in structure to that shown in Figure 2 except for the positioning of the catalytically active surface. In a third embodiment, the catalytic active surface is formed by about 40% of the upper portions 12 of the first flow channels 12 of the second plate heat exchanger 10 with respect to the gas 8 inlet 1.

Figure 4 shows an incinerator assembly according to a fourth embodiment of the invention. The apparatus is otherwise similar in structure to that shown in Figure 2 except for the positioning of the catalytically active surface. In the fourth embodiment, the second flow channels 13 of the second plate heat exchanger 10 are all catalytically active.

Figure 5 shows a combustion apparatus 15 according to a fifth embodiment of the invention. The apparatus is otherwise similar in structure to that shown in Figure 2 except for the positioning of the catalytically active surface. In the fifth embodiment shown, the first flow channels 12 of the second plate heat exchanger 10 are catalytically active from about 60% of their surface area as viewed from the top of the flow channels and the second flow channels 13 are catalytically active from below the bottom portions of the flow channels.

*. *. It will be apparent to a person skilled in the art that the embodiments shown in the figures are examples of the combustion apparatus according to the invention and are therefore not limited to the invention. . as claimed.

»· * * · · • ·· ** • · '• * * • · • * ···:' ·· * * • · ···.

• · · * • * ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** «« «* * * * * *. · · · · * '.

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Claims (13)

117519 9 An apparatus for combustion of gases containing a flammable gaseous compound having at least one heat transfer section (2, 9, 10) having a primary side and a secondary side formed by a first plurality of flow channels (3, 11, 12) and a second 5 plurality of flow channels (4). , 13, 14), at least one supply line (1) for gases (8) containing flammable gaseous compound and at least one outlet line (5) for combustion gas, characterized in that - the same gas (8) flows through the heat transfer section (2,9, 10). ) primary and secondary - gas (8) flows through the primary flow channels (3, 11, 12) of the secondary flow 10 channels (4, 13, 14) or vice versa, - a heat transfer portion (2, 9, 10) in at least a first flow channels the surfaces (3, 11, 12) of the set (3, 11, 12) which come into contact with the flowing gas (8) are X at least a part of their surface area catalytically active in which the gaseous compounds burning on the catalytically active surfaces burn; - in the first set of flow channels (3, 11, 12) the heat generated by combustion is transferred to the gas (8) flowing in the second flow channel set (4, 13, 14) of the heat transfer section (2, 9, 10). 2. Förbränningsapparatur enligt patent krav 1, the tongue and groove of such a för-15 is played on a strömningskanaler (3, 11, 12) and a primer is applied to the fluffing xlingsdelens (2, 9, 10). 2. claimed in claim 1 combustion apparatus, characterized in that said first set of flow channels (3, 11, 12) of the heat transfer portion (2, 9; 10) of the primary side en-20 set of flow channels. • · 3. Förbränningsapparatur enligt patentkrav 1, the tongue and groove such as the strömningskanaler (3, 11, 12) and the second strömningskanaler (2,9,10). 4. Förbränningsapparatur enligt patentkrav 1, kännetecknad av att den yta som commercial contact with med den gas (8) som strömmar i coloringxlingsdelens (2, 9, 10) första mängd strömningskanaler (3, 11, 12) ätminstone account en del av a n d e n t h e c o m p o n t h e activit och att den yta som commerce contact med den gas (8) som strömmar i • a IV. ' colorfulxlingsdelens (2, 9, 10) andra playd strömningskanaler (4, 13, 14) ätmins- * · * · * 25 tone account en del av sin yta är catalytiskt Activ. r 5. Förbränningsapparatur enligt nägot av patentkraven 1-4, kännetecknad av att den yta som kommer i contact med den gas (8) som strömmar i mängden ström- y. ningskanaler (3,4, 11, 12, 13, 14) account 10-100% Avail Catalyst Activated. • · · • 3. claimed in claim 1 combustion apparatus, characterized in that said first set of flow channels (3,11, 12) is in heat transfer section (2, 9, 10), • · the primary side a number of flow channels. • · * · · + Combustion apparatus according to claim 1, characterized in that the contact surface of the heat transfer part (2, 9, 10) with the flowing gas (8) of the first set of flow channels (3, 11, 12) is at least for their surface area: ***. 2, 9, 10), and the surface in contact with the flowing gas (8) of the second set of flow channels * · · (4, 13, 14) is catalytically active in at least part of its surface area. * * i «• * · Combustion apparatus according to one of Claims 1 to 4, characterized in that the surface in contact with the flowing gas (8) of the plurality of flow channels (3, 4, 11, 12, 13, 14). is 10 to 100% catalytically active in its area. 117519 ίο 6. Förbränningsapparatur enligt patentkrav 5, teleknäs av att den yta som 30 commercial contact med den gas (8) som strömmar i playing stömningskanaler (3, 4. 11, 12, 13, 14) account 25-100% av sin yta business catalytic converter Activ. • · · * · Combustion apparatus according to Claim 5, characterized in that the surface in contact with the flowing gas (8) of the plurality of flow channels (3, 4, 11, 12, 13, 14) is catalytically active in an area of 25-100% of its surface area. 7. Förbränningsapparatur enligt face av patent kraven 1-6, kangnetecknad av att den catalytically activated submerged alpha metal catalysts and / or catalytic catalysts Activated metal oxides. 117519 12 Combustion apparatus according to one of Claims 1 to 6, characterized in that the catalytically active surface contains a noble metal catalyst and / or a catalytically active metal oxide. 8. Förbränningsapparatur enligt patent krav 7, the metal sheath of palladium oxide, palladium oxide, metal sheath samt blandningar av de ovan. Combustion apparatus according to claim 7, characterized in that the noble metal catalyst is selected from the group consisting of metallic platinum, metallic palladium, palladium oxide, metallic gold and alloys thereof. 9. Förbränningsapparatur enligt face av patent kraven 1-8, kangnetecknad av att 5 det upvisvl eller flera colorfulxlingsdelar (2, 9, 10). Combustion apparatus according to one of Claims 1 to 8, characterized in that there are two or more heat transfer portions (2,9,10). 10. Förbränningsapparatur enligt patentkrav 9, kennettecknad av att den gas (8) som innehäller en brinnande gasformad förening purse account den första Värmeväx-lingsdelen (2, 9, 10) och att den yta som kommer i contact med den gas (8) som strömmar i den första mängden strömningskanaler (3, 11, 12) i den andra Värmeväx- 10 lingsdelen (2, 9, 10) estminstone account en del av yta är cataltaiskt Activ. Combustion apparatus according to claim 9, characterized in that the gas (8) containing the combustible gaseous compound is supplied to the first heat transfer section (2, 9, 10) and that the first flow channels 15 of the second heat transfer section (2, 9, 10) the surface in contact with the flowing gas (8) of the plurality (3, 11,12) is at least a part of its surface area catalytically active. 11. Förbränningsapparatur enligt face av patent kraven 1-10, turnthroat av att fluffy xlingsdelen / fluffy xlingsdelarna (2, 9, 10) and fluffy fluff. Combustion apparatus according to one of claims 1 to 10, characterized in that the heat transfer section (s) (2, 9, 10) is a plate heat exchanger. ·····. · 12. The method of attorney förbränningsapparaturen enligt face av patentkraven 1-11, kännetecknad av att account de gaser (8) som innehäller en gasformad förening 15 blandas en oxiderande gas innan gaserna rotten account förbränningsapparaturen. Method for operating the combustion apparatus according to claims 1-11, characterized in that the gases (8) containing the combustible gaseous compound are mixed with a oxidizing gas before being fed to the combustion apparatus. Process for operating the combustion apparatus according to claims 1-12, characterized in that the flammable gaseous compounds are volatile organic compounds (VOCs). ♦ ··· • · * 25 • · · • * ·. * · *. Patent patent • # • · * *: **: 1. Förbränningsapparatur för gaser som innehäller en brinnande gasformad fore- r Ning, I am wearing apparatur uppvisar ätminstone en colorfulxlingsdel (2, 9, 10) med en • * · Primary and Secondary, Lively har bildas av en första games strömnings-30 canal (3, 11, 12) och en andra games strömningskanaler (4, 13, 14), ätminstone en matningsförbindning (1) för gaser (8) som innehäller den brinnande gasformade fö- 117519 π reningen, och ätminstone en avlägsningsförbindning (5) för den förbrända gasen, kännetecknad av att samma gas (8) strömmar kä coloringxlingsdelens (2, 9, 10) primär- och sekun-därsida, 5. gasen (8) strömmar frän strömningskan , 11, 12) end primary account strömningskanalerna (4, 13, 14) end secondary side eller tvärtom, de ytor vid ätminstone den första gamden strömningskanaler (3, 11, 12) vid Värmeväxlingsdelen (2, 9, 10), lively commercial contact med den strömmande Gase n (8), and last minute account en del av yta catalytiskt active, vid lively catalytiskt> 10 active ytor de brinnande gasformade föreningarna brinner, och den color som uppstär vid förbränningen i den första mängden strömningskanaler (3, 11, 12) överförs account den gas (8) som strömmar i den andra mängden strömningskanaler (4, 13, 14) av Värmeväxlingsdelen (2, 9, 10). 13. A method for för att använda förbränningsapparatur enligt face av patentkraven 1-12, kangnetecknad av att de brinnande gasformade föreningarna or fly-orga- * · * · * neck föreningar (VOC). ····· • e ··· ··· .. ·· • · · * * · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · ··· · ··· ·· »· * * * • · * · * · · · · · · · · · · · · · · · · ···. • · * ··