JP3547465B2 - Reactor for denitration equipment for ships - Google Patents

Description

[0001]
[Industrial applications]
TECHNICAL FIELD The present invention relates to a reactor for a marine vessel denitration apparatus which is provided in a ship equipped with a diesel engine and reduces and removes nitrogen oxides (NO _x ) in exhaust gas.
[0002]
[Prior art]
A ship equipped with a diesel engine is equipped with an exhaust gas denitration device when reducing and removing nitrogen oxides in exhaust gas. In this exhaust gas denitration apparatus, NO _x by mixing ammonia into the exhaust gas containing, by passing the reactor with catalyst by reducing NO _x nitrogen and selective catalytic reduction method for changing the water (SCR method) Is widely used.
[0003]
As the catalyst of the reactor, for example, a so-called honeycomb-shaped ceramic catalyst having a large number of minute openings formed at both end surfaces in a longitudinal direction formed into a prism having a side of 140 mm to 160 mm is used. The reactor has a configuration in which a large number of catalysts are accumulated in a case.
[0004]
FIG. 7 shows an example of a conventional reactor 100. Inside the case 101, a plurality of prism-shaped honeycomb catalysts 1 (hereinafter, simply referred to as catalysts 1) are stacked in a vertical posture. These catalysts 1 are supported by a grid-like support member 102. FIG. 7 shows a case where the upper and lower layers are separated at a predetermined interval. Exhaust gas introduced from below the case 101 passes through the catalysts 1, 1 of both layers and escapes upward.
[0005]
FIG. 8 shows another example of the conventional reactor 200. Inside the case 201, a plurality of catalysts 1 are stacked with both ends aligned in a horizontal position. These catalysts 1 are divided into upper and lower layers, and a partition 202 that partitions the inside of the case is provided between the lower layer inlet side and the upper layer outlet side. Exhaust gas introduced from below the case 201 passes through the lower catalyst 1 as shown by an arrow in the drawing, and then passes through the upper catalyst 1 and is discharged above the case 201.
[0006]
[Problems to be solved by the invention]
It is necessary to make the reactor of the exhaust gas denitration device of a ship compact so that it can be accommodated in a narrow space inside the ship. In particular, in small vessels, since there is usually no space on the ship's hull or on the deck where a new denitration reactor can be installed, the vertical reactor shown in FIG. It will be installed inside.
[0007]
However, the ceramic honeycomb catalyst contained in the reactor of the denitration apparatus is brittle in terms of strength and tends to chip. Further, when it comes into direct contact with the members of the reactor, it is scraped off by friction due to vibration and is easily worn away.
[0008]
For this reason, in the reactor 100 in which the catalyst is vertically arranged as shown in FIG. 7, an accident in which the load of the catalyst 1 is concentrated on a portion in contact with the support member 102 and damages the catalyst is likely to occur. This type of reactor is therefore unsuitable for marine applications and has been practically used almost exclusively on land.
[0009]
That is, equipment mounted on a ship is susceptible to shock vibrations caused by waves and vibrations transmitted from a mounted engine, and therefore needs to have excellent vibration resistance. Then, in order to improve the vertical vibration resistance of the catalyst, the load may be dispersed by arranging the catalysts 1 horizontally as in the reactor 200 shown in FIG.
[0010]
However, the reactor 200 according to the conventional design concept shown in FIG. 8 has a problem that the space required for installation is too large. The width dimension is the sum (a + b + b) of the dimension a in the longitudinal direction of the catalyst 1 and the dimensions b and b of the space in the case 201 provided at both ends in the longitudinal direction of the catalyst 1 for guiding the exhaust gas. This large size was difficult to secure in ships without wasted space. This has been an obstacle to the practical use of a horizontal reactor in which the longitudinal direction of the catalyst is aligned with the lateral direction.
[0011]
An object of the present invention is to provide a compact reactor having excellent vibration resistance of a catalyst.
[0012]
[Means for Solving the Problems]
The reactor for a marine denitration apparatus according to claim 1 is a reactor for a marine denitration apparatus provided with a plurality of catalysts having both ends opened in a longitudinal direction in a case, wherein the positions of the catalysts in the longitudinal direction are the same. It is characterized in that each catalyst is arranged so as to be sequentially shifted in the direction.
[0013]
The reactor for a denitration apparatus for a marine vessel according to claim 2 is a reactor for a denitration apparatus for a marine vessel provided with a plurality of catalysts having open ends at both ends in the longitudinal direction, wherein the positions of the catalysts in the longitudinal direction are the same. The catalysts are stacked so as to be sequentially shifted in the direction, and the catalysts are arranged such that the longitudinal direction of the catalyst and the traveling direction of the ship are at right angles.
[0014]
[Action]
The catalyst has sufficient vibration resistance especially against vertical vibration acceleration received when the hull is pitching. Further, since the catalysts are stacked with their positions gradually shifted in the longitudinal direction, the exhaust gas can be easily guided to each catalyst evenly, and the space provided at both ends in the reactor can be saved.
[0015]
【Example】
First, a reactor 2 of a first embodiment used in a ship will be described with reference to FIGS. The catalyst 1 used in the first embodiment of the present invention is the same as that conventionally used.
As shown in FIGS. 1 and 2, the case 3 of the reactor 2 includes a lower part 4 having an exhaust gas inlet 6 on the lower side and an upper part 5 having the same outlet 7 on the upper side.
[0016]
In the lower part 4 and the upper part 5 of the case 3, a plurality of (five in the figure) catalysts 1 are stacked in a plurality of stages (five in the figure), respectively. In each stage, the catalysts 1 are arranged with their end faces aligned with the traveling direction A so that the longitudinal direction is orthogonal to the traveling direction A of the ship. In other words, each catalyst 1 is arranged so that its longitudinal direction coincides with the lateral direction B (the direction of rolling) of the ship.
[0017]
Here, the number of stacking stages can be selected from 4 stages to a maximum of 9 stages, but it is usually preferable to set 5 to 7 stages. Therefore, the catalyst stacking height h at this time is 150 mm × 5 steps = 750 mm to 150 mm × 7 when the size of one side of the prismatic catalyst is 150 mm, omitting the ceramic felt 12 shown in FIGS. 4 and 5. Step = 1050 mm.
[0018]
The catalysts 1 in the lower part 4 of the case 3 are stacked while shifting the position by a predetermined dimension for each stage so that the uppermost stage catalyst 1 is retracted to the right in the lateral direction. The position of the lowermost catalyst 1 in the upper part 5 is the same as the position of the uppermost catalyst 1 in the lower part 4. The catalysts 1 in the upper part 5 are stacked while shifting the position by a predetermined dimension for each stage so that the uppermost catalyst 1 is located at the same position as the lowermost catalyst 1.
[0019]
In the case 3, the catalysts 1 stacked in a stepwise manner are held at both ends by a support grid 8 shown in FIG. The support grid 8 is formed by integrating a plurality of holding plates 9 having dimensions matching the end surface of the catalyst 1 with the substrate 10 and the connecting rods 11. Hold.
[0020]
As shown in FIG. 4, assuming that the thickness of the holding plate 9 of the support grid 8 is t, the distance between the adjacent catalysts 1 and 1 in the same stage is smaller than this, and each catalyst 1 in the same stage is It is supported by the end face.
[0021]
As shown in FIGS. 4 and 5, a ceramic felt 12 having a thickness of about several mm is attached to the outer peripheral surface of each catalyst 1. The function of the ceramic felt 12 is to cushion the aggregate of the adjacent or stacked catalysts 1 when an impact is applied. In addition, there is also a function of sealing the space between the adjacent catalysts 1 and 1 to ensure that the exhaust gas introduced into the case 3 passes through the catalyst 1. Further, it prevents the adjacent catalysts 1 and 1 from breaking due to direct contact. In this embodiment, since the upper and lower catalysts 1 and 1 are slightly shifted in the longitudinal direction, the position where the ceramic felt 12 is attached is appropriately shifted accordingly.
[0022]
When the catalyst 1 configured as described above is housed in the case 3, the case 3 is divided into a space S1 connected to the inlet 6, a space S2 connecting the upper part 5 and the lower part 4, and a space S3 connected to the outlet 7. Split. The spaces S1 and S3 are sealed, thereby forming a flow path of exhaust gas indicated by an arrow in FIG.
[0023]
If the dimension of the space S1 of the inlet 6 in the reactor 2 of the present embodiment is b, which is the same as the conventional one, and the dimension of the space S2 connecting the upper and lower portions is c, the length of the catalyst 1 is the same, a. The width of the reactor 2 is a + b + c. Here, in the reactor 2 of this embodiment, since the catalysts 1 are stacked while being shifted stepwise, the dimension c can be considerably smaller than the dimension b. As for the dimension C, since one side of the prismatic catalyst is 140 mm to 160 mm, it is sufficient that C = 180 mm to 240 mm. The width dimension a + b + c of the present reactor 2 <the conventional width dimension a + 2b, and the reactor 2 of the present embodiment can be installed in a smaller space than the conventional one.
[0024]
For example, assuming that the sum of the shifted dimensions of each stage is d, it is effective to set d to 20 to 40% of the catalyst length a. If it is 20% or less, the effect of reducing the space is small, and if it is 40% or more, the catalyst in the lower product is easily broken due to the influence of local load concentration.
[0025]
The arrangement of the catalysts is such that the positions of the catalysts in the longitudinal direction are sequentially shifted in the same direction, so that it is possible to prevent the catalysts from being scraped due to friction between them. Further, since the traveling direction of the ship and the longitudinal direction of the catalyst are arranged so as to be perpendicular to each other, the load applied to each catalyst 1 is dispersed. The reactor 2 of this embodiment has sufficient vibration resistance. Further, the displacement of the catalyst in the longitudinal direction due to the rolling of the ship can be suppressed by the support lattices 8 at the left and right ends.
[0026]
Further, when the denitration apparatus is operated, the position of the end face of the catalyst 1 through which the exhaust gas enters and exits is shifted for each stage, so that the flow of the exhaust gas is entirely smooth. That is, the inflow of the exhaust gas to each of the catalysts 1 in the lower portion 4 is equalized, the inflow from the catalyst in the lower portion 4 to the catalyst 1 in the upper portion 5 is equalized, and the outflow from the catalyst 1 in the upper portion 5 is also equalized.
[0027]
Therefore, the entire catalyst is effectively used, and the denitration performance is improved. Further, since the inflow of the exhaust gas into each catalyst 1 is equalized, there is no portion that flows at a low speed, dust can be prevented from adhering, and the durability is improved.
[0028]
FIG. 6 shows a reactor 22 of the second embodiment. In the present embodiment, a catalyst 21 having a shape in which both ends of a prism are cut by parallel slopes is used. These catalysts 21 are stacked in one or more stages (five in the figure) and vertically in a plurality of stages (five in the diagram) such that the end faces are substantially in the same plane as in the first embodiment. ing.
[0029]
Here, the end faces of the catalysts 21 which are respectively accumulated in the upper part 5 and the lower part 4 of the case 3 in five steps are aligned substantially in the same plane. Therefore, the holding plate 9 of the support grid 28 for holding the catalyst 21 does not have a stepped shape as in the first embodiment, but has an end face inclined along the end face of the catalyst 21. The other components similar to those of the first embodiment are denoted by the same reference numerals as in FIG. 2 and the description thereof is omitted. According to this embodiment, the same operation and effect as those of the first embodiment can be obtained.
[0030]
【The invention's effect】
According to the reactor for the denitration apparatus for a ship according to the present invention, the longitudinal direction of the catalyst provided in the case is perpendicular to the traveling direction of the ship, and the respective catalysts are stacked while being slightly shifted in the longitudinal direction. Therefore, it is possible to reduce the width of the entire reactor without sacrificing the smooth flow of the exhaust gas in the case. Therefore, it can be easily installed in the makeup chimney of the ship.
[Brief description of the drawings]
FIG. 1 is a partially cutaway perspective view of a first embodiment of the present invention.
FIG. 2 is a sectional view of the first embodiment of the present invention.
FIG. 3 is a perspective view of a support grid according to the first embodiment of the present invention.
FIG. 4 is a diagram showing a positional relationship between an end face of a catalyst and a support grid in the first embodiment of the present invention.
FIG. 5 is a perspective view of a catalyst used in the first embodiment of the present invention.
FIG. 6 is a sectional view of a second embodiment of the present invention.
FIG. 7 is a sectional view of a conventional vertical reactor.
FIG. 8 is a cross-sectional view of a conventional horizontal reactor.
[Explanation of symbols]
1 Catalyst 2 Reactor 3 Case A Ship's direction of travel

Claims (2)

In a reactor of a marine denitration apparatus having a plurality of catalysts having both ends opened in a longitudinal direction in a case,
A reactor for a denitration apparatus for ships, wherein each catalyst is arranged such that the position of the catalyst in the longitudinal direction is sequentially shifted in the same direction. In a reactor of a marine denitration apparatus provided with a plurality of catalysts in the case having both ends opened in the longitudinal direction,
Each ship is stacked so that the position of the catalyst in the longitudinal direction is sequentially shifted in the same direction, and each catalyst is arranged such that the longitudinal direction of the catalyst and the traveling direction of the ship are perpendicular to each other. Reactor of denitration equipment.

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