KR101334528B1 - Selective catalytic reuction system for using filter belt - Google Patents

Abstract

The embodiment of the present invention relates to a selective catalyst reduction system comprising a filter belt. The selective catalyst reduction system comprises: an exhaust passage through which exhaust gas containing nitrogen oxides and sulfur oxides moves; a selective catalyst reduction reactor having a catalyst for reducing the nitrogen oxides in the exhaust gas by being connected to the exhaust passage; a reductant supplying unit spraying a reductant containing ammonia to the exhaust gas which will be induced to the selective catalyst reduction reactor by being installed on the exhaust passage; a poisoning material removal chamber connected to the exhaust passage through an opening part, and installed closely to the exhaust passage between the selective catalyst reduction reactor and reductant supplying unit; a filter belt installed to be circulated between the poisoning material removal chamber and exhaust passage through the opening part, and filtering catalyst poisoning materials generated by the reaction between the ammonia from the reductant and the sulfur oxides from the exhaust gas; multiple rollers circulating the filter belt; and a filter heater removing the catalyst poisoning materials, filtered by the filter belt, by heating a part of the filter belt being circulated in the poisoning material removal chamber.

Description

Selective Catalytic Reduction System with Filter Belt {SELECTIVE CATALYTIC REUCTION SYSTEM FOR USING FILTER BELT}

Embodiments of the present invention relate to a selective catalytic reduction system for reducing nitrogen oxides, and more particularly, to a selective catalytic reduction system including a filter belt.

In general, a selective catalytic reduction (SCR) system is a system for reducing nitrogen oxides by purifying exhaust gas generated from a diesel engine.

The selective catalytic reduction system reacts the nitrogen oxides contained in the exhaust gas with the reducing agent while passing the exhaust gas and the reducing agent together in the reactor equipped with the catalyst, thereby reducing the nitrogen and the water vapor.

The selective catalytic reduction system uses ammonia (NH ₃ ) directly or a hydrolysis of urea (urea) as a reducing agent for reducing nitrogen oxides.

Selective catalytic reduction systems also utilize high temperature catalysts, which generally have an active temperature range from 250 degrees Celsius to 400 degrees Celsius. However, when the temperature of the exhaust gas purified by the selective catalytic reduction system is lowered to 250 degrees Celsius or less, the catalyst is poisoned by the sulfur component contained in the fuel of the diesel engine, so that the activity of the catalyst is continuously decreased.

However, the material poisoning the catalyst can be decomposed or removed by an external heat source. Accordingly, a method of regenerating the poisoned catalyst by raising the entire exhaust gas by using a separate external heating device has been used.

However, since a large amount of energy is required to raise the total temperature of the exhaust gas to the extent that the poisoned catalyst can be regenerated, there is a problem in that air consumption is excessive due to excessive consumption of fuel and fuel combustion.

Embodiments of the present invention provide a selective catalytic reduction system comprising a filter belt capable of stably maintaining the activity of the catalyst by removing catalyst poisoning material in advance.

According to an embodiment of the present invention, the selective catalytic reduction system includes an exhaust flow path through which an exhaust gas containing nitrogen oxides (NOx) and sulfur oxides (SOx) move, and a nitrogen oxide (NOx) of the exhaust gas connected to the exhaust flow path. A selective catalytic reduction reactor including a catalyst for reducing a), a reducing agent supply unit installed on the exhaust passage and injecting a reducing agent containing ammonia (NH ₃ ) into the exhaust gas to be introduced into the selective catalytic reduction reactor; It is installed adjacent to the exhaust passage between the reducing agent supply unit and the selective catalytic reduction reactor and can be circulated between the exhaust passage and the poisoning substance removal chamber through the opening, and through the opening And a catalyst formed by the reaction of sulfur oxides in the exhaust gas with ammonia in the reducing agent. A filter belt for filtering every poisoning material, a plurality of rollers for circulating the filter belt, and a portion of the filter belt circulating in the poisoning material removal chamber to filter the filter belt And a filter heater for removing the catalyst poisoning substance.

In addition, the selective catalytic reduction system may further include an ash blower installed in the poisoning material removal chamber to inject fluid into the filter belt heated by the filter heating unit.

In addition, the selective catalytic reduction system may further include a bypass passage for bypassing the selective catalytic reduction reactor to connect the poisoning material removal chamber and the exhaust passage.

The filter heating unit may be a burner or a heater.

The catalyst poisoning substance may include one or more of ammonium sulfate (NH ₄ ) ₂ SO ₄ ) and ammonium bisulfate (NH ₄ HSO ₄ ).

The filter belt may be made of metal fiber.

The filter belt may include stainless steel (SUS).

The selective catalytic reduction system may further include an ash collecting unit collecting the ash remaining after the catalyst poisoning material is burned by the filter heating unit.

According to embodiments of the present invention, the selective catalytic reduction system including a filter belt can stably remove the catalyst poisoning material to keep the activity of the catalyst stable.

1 is a block diagram showing a selective catalytic reduction system including a filter belt according to a first embodiment of the present invention.
2 is a block diagram showing a selective catalytic reduction system including a filter belt according to a second embodiment of the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings, which will be readily apparent to those skilled in the art to which the present invention pertains. The present invention may be embodied in many different forms and is not limited to the embodiments described herein.

In addition, in the various embodiments, elements having the same configuration are represented by the same reference symbols in the first embodiment, and in the other second embodiment, only the configurations different from those of the first embodiment are described .

The drawings are schematic and illustrate that they are not drawn to scale. The relative dimensions and ratios of the parts in the figures are shown exaggerated or reduced in size for clarity and convenience in the figures, and any dimensions are merely illustrative and not restrictive. And to the same structure, element or component appearing in more than one drawing, the same reference numerals are used to denote similar features.

The embodiments of the present invention specifically illustrate ideal embodiments of the present invention. As a result, various variations of the illustration are expected. Thus, the embodiment is not limited to any particular form of the depicted area, but includes modifications of the form, for example, by manufacture.

Hereinafter, a selective catalytic reduction (SCR) system 101 according to a first embodiment of the present invention will be described with reference to FIG. 1.

As shown in FIG. 1, the selective catalytic reduction system 101 according to the first embodiment of the present invention includes a selective catalytic reduction (SCR) reactor 30, an exhaust passage 51, and a reducing agent supply unit 37. ), A poisoning material removal chamber 45, a filter belt 41, a roller 48, and a filter heating portion 46.

In addition, the selective catalytic reduction system 101 according to the first embodiment of the present invention may further include an ash blower 47 and a bypass flow path 58.

The exhaust passage 51 moves the exhaust gas containing nitrogen oxides NOx and sulfur oxides SOx, and is connected to the selective catalytic reduction reactor 30 to supply the exhaust gas to the selective catalytic reduction reactor 30.

The selective catalytic reduction reactor 30 purifies the exhaust gas of the diesel engine to reduce the nitrogen oxide (NOx) contained in the exhaust gas. In one example, the selective catalytic reduction system 101 according to the first embodiment of the present invention can reduce the nitrogen oxides (NOx) of the exhaust gas discharged from the diesel engine.

The selective catalytic reduction reactor 30 reacts the nitrogen oxide (NOx) contained in the exhaust gas with a reducing agent to reduce the nitrogen and water vapor. And the selective catalytic reduction reactor 30 includes a catalyst 35. Specifically, a catalyst 35 known to those skilled in the art, such as zeolite, vanadium, and platinum, is installed in the interior of the selective catalytic reduction reactor 30 through a catalyst carrier. In the first embodiment of the present invention, the catalytic reaction is performed when the internal temperature of the selective catalytic reduction reactor 30 is within the range of 300 degrees Celsius to 350 degrees Celsius with the catalyst 35 mounted inside the selective catalytic reduction reactor 30. Good catalyst 35 can be used.

In addition, the housing of the selective catalytic reduction reactor 30 may be made of, for example, stainless steel (stainless used steel, SUS).

The reducing agent supply unit 37 is installed on the exhaust passage 51 to inject a reducing agent containing ammonia (NH ₃ ) into the exhaust gas before flowing into the selective catalytic reduction reactor 30. The injected reducing agent is mixed with the exhaust gas and introduced into the selective catalytic reduction reactor 30. In a first embodiment of the present invention, ammonia (NH ₃ ) can be used directly as a reducing agent or hydrolyzed urea.

On the other hand, when the exhaust gas having a relatively low temperature of 150 degrees Celsius or more and less than 250 degrees Celsius is introduced into the selective catalytic reduction reactor 30, sulfur oxides (SOx) of the exhaust gas and ammonia (NH ₃ ) of the reducing agent react. Catalyst poisoning material is produced. The catalyst poisoning substance may include one or more of ammonium sulfate (NH ₄ ) ₂ SO ₄ ) and ammonium bisulfate (NH ₄ HSO ₄ ).

The catalyst poisoning substance is adsorbed onto the catalyst 35 to lower the activity of the catalyst 35. Such catalytic poisoning material may be decomposed or removed by an external heat source.

The poisoning material removal chamber 45 is installed adjacent to a part of the exhaust flow path 51 between the reducing agent supply 37 and the selective catalytic reduction reactor 30. The poisoning substance removal chamber 45 and the exhaust flow path 51 are connected to each other through the opening.

The filter belt 41 is installed such that one side is located inside the exhaust passage 51 and the other side is located inside the poisonous substance removal chamber 45. The filter belt 41 circulates between the exhaust passage 51 and the poisoning substance removal chamber 45. The plurality of rollers 48 circulates the filter belt 41.

The filter belt 41 filters the catalyst poisoning substance generated by the reaction of sulfur oxides SOx of the exhaust gas traveling along the exhaust passage 51 with ammonia NH ₃ of the reducing agent. Accordingly, the catalyst poisoning material may be minimized from flowing into the selective catalytic reduction reactor 30, and the catalyst 35 may be effectively suppressed from poisoning.

Further, in the first embodiment of the present invention, the filter belt 41 may be formed of metal fiber. In one example, the filter belt 41 may be made into a mesh shape using metal fibers. The filter belt 41 may be formed of a metal such as stainless used steel (SUS). However, the first embodiment of the present invention is not limited thereto, and the metal fiber forming the filter belt 41 may be variously modified within a range of shapes and materials known to those skilled in the art.

The filter heating unit 46 heats a part of the filter belt 41 circulating in the poisoning material removal chamber 45 so that the filter poisoning is filtered out of the exhaust gas from which the filter belt 41 moves along the exhaust flow path 51. The material is removed from the filter belt 41.

Therefore, the filter belt 41 can filter out the catalyst poisoning substance from the exhaust gas which continuously moves along the exhaust flow path 51, without degrading performance.

Specifically, the filter heating unit 46 may be a burner or a heater, and various heating methods known to those skilled in the art may be used.

An ash blower 47 is installed in the poisoning material removal chamber 45 to inject fluid into the filter belt 41 heated by the filter heating part 46. That is, the ash blower 47 causes the catalyst poisoning material filtered by the filter belt 41 to be burned by the filter heating section 46 and blows away the ash ASH remaining from the filter belt 41.

Bypass flow path 58 is a selective catalytic reduction reactor (ASH) blown from the filter belt 41 by the ash blower 47 and a portion of the exhaust gas introduced into the poisoning material removal chamber 45 through the opening ( Bypass 30) and discharge it. That is, the ash ASH is prevented from flowing back into the selective catalytic reduction reactor 30 by the bypass flow path 58.

By such a configuration, the selective catalytic reduction system 101 including the filter belt 41 according to the first embodiment of the present invention removes the catalyst poisoning material in advance, thereby providing a catalyst 35 installed in the selective catalytic reduction reactor 30. ) Can be stably maintained.

Specifically, in the first embodiment of the present invention, the filter belt 41 opens the exhaust flow path 51 while circulating between the exhaust flow path 51 and the poisonous substance removal chamber 45 by the plurality of rollers 48. The catalyst poisoning material of the exhaust gas moving along can be filtered and then removed from the poisoning material removal chamber 45.

In addition, in the first embodiment of the present invention, the catalyst poisoning material filtered by the filter belt 41 may be immediately removed through the filter heating unit 46.

Therefore, according to the first embodiment of the present invention, it is possible to filter out the catalyst poisoning substance from the exhaust gas continuously moving along the exhaust flow passage 51 without degrading the filtering performance of the filter belt 41.

Further, according to the first embodiment of the present invention, it is not necessary to raise the exhaust gas as a whole for the regeneration or the poisoning suppression of the catalyst 35, and the catalyst poisoning material is removed only by local heating to a part of the filter belt 41. Can be removed. Thus, in suppressing the poisoning of the catalyst 35, it is possible to minimize the generation of additional energy consumed and air pollutants.

Hereinafter, a selective catalytic reduction (SCR) system 102 including a filter belt 41 according to a second embodiment of the present invention will be described with reference to FIG.

As shown in FIG. 2, in the selective catalytic reduction system 102 according to the second embodiment of the present invention, the ash trapping unit collecting the ashes remaining after the catalyst poisoning material is burned by the filter heating unit 46 is collected. And 80. In addition, the ash collecting unit 80 may be installed on the bypass flow path 58.

In addition, the structure of the ash collecting unit 80 is not limited to that shown in Figure 2, it may include a structure that can be easily changed by those skilled in the art.

By such a configuration, the selective catalytic reduction system 102 according to the second embodiment of the present invention can stably maintain the activity of the catalyst 35 installed in the selective catalytic reduction reactor 30 by removing catalyst poisoning material in advance. In addition, the ash trapping unit 80 may separate and discard the ash ASH remaining on the catalyst poisoning material. Therefore, it is possible to further minimize the air pollutants contained in the exhaust gas finally discharged to the outside.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art. will be.

It is therefore to be understood that the embodiments described above are to be considered in all respects only as illustrative and not restrictive, the scope of the invention being indicated by the appended claims, It is intended that all changes and modifications derived from the equivalent concept be included within the scope of the present invention.

30: Selective Catalytic Reduction Reactor 35: Catalyst
37: reducing agent supply portion 41: filter belt
45: poisoning material removal chamber 46: filter heating portion
47: ash blower 48: roller
51: exhaust flow path 58: bypass flow path
80: ash collector
101, 102: selective catalytic reduction system

Claims (8)

An exhaust passage 51 through which the exhaust gas containing nitrogen oxides NOx and sulfur oxides SOx moves;
A selective catalytic reduction reactor 30 connected to the exhaust passage 51 and including a catalyst 35 for reducing nitrogen oxides (NOx) of the exhaust gas;
A reducing agent supply unit 37 installed on the exhaust passage 51 to inject a reducing agent containing ammonia (NH ₃ ) into the exhaust gas to be introduced into the selective catalytic reduction reactor (30);
A poisoning material removal chamber 45 installed adjacent to the exhaust flow passage 51 between the reducing agent supply portion 37 and the selective catalytic reduction reactor 30 and connected to the exhaust flow passage 51 through an opening;
A filter belt is installed to circulate between the exhaust passage 51 and the poisoning material removal chamber 45 through the opening, and filters the catalyst poisoning material generated by the reaction between sulfur oxides of the exhaust gas and ammonia of the reducing agent. (filter belt) 41;
A plurality of rollers 48 for circulating the filter belt 41; And
A filter heating part 46 for heating a part of the filter belt 41 in circulation in the poisoning material removal chamber 45 to remove the catalyst poisoning material filtered by the filter belt 41.
Selective catalytic reduction system comprising a. In claim 1,
Selective catalytic reduction system further comprises an ash blower (47) installed in the poisoning material removal chamber (45) to inject fluid into the filter belt (41) heated by the filter heating section (46). . In claim 1,
And a bypass flow passage (58) for bypassing said selective catalytic reduction reactor (30) to connect said poisoning material removal chamber (45) and said exhaust flow passage (51). In claim 1,
The filter heating unit 46 is a selective catalytic reduction system is a burner or a heater. In claim 1,
The catalytic poisoning material is a selective catalytic reduction system comprising at least one of ammonium sulfate (NH ₄ ) ₂ SO ₄ ) and ammonium bisulfate (NH ₄ HSO ₄ ). In claim 1,
The filter belt 41 is a selective catalytic reduction system made of metal fiber (metal fiber). In claim 1,
The filter belt 41 is a selective catalytic reduction system comprising stainless steel (Stainless used steel, SUS). 8. The method according to any one of claims 1 to 7,
Selective catalytic reduction system further comprises an ash collecting unit (80) for collecting the ash remaining after the catalyst poisoning material is burned by the filter heating unit (46).

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