JPH0611380B2 - How to replace the catalyst block - Google Patents

Description

The present invention relates to a denitration device for removing nitrogen oxides (hereinafter simply referred to as NO _x ) in combustion exhaust gas discharged from a boiler plant, a combined cycle power plant, etc. In particular, the present invention relates to a method for exchanging the catalyst block filled in the denitration reactor of the denitration device.

[Conventional technology]

In recent years, Japan has been converting fuel from conventional heavy oil burning to coal burning and LNG (liquefied natural gas) burning in order to correct the dependence on petroleum due to the tight supply of heavy oil. In the boiler, a large-capacity thermal power plant that burns coal only and LGN is built.

However, since coal fuel has poorer combustibility than petroleum fuel and gas fuel, NO _x and unburned components contained in exhaust gas are likely to be generated, and especially flames are divided and re-exhaust gas is exhausted to reduce NO _x. Circulation, two-stage combustion, in-furnace denitration, etc. are also adopted to perform slow combustion to reduce NO _x .

And in this coal-only burning power, LNG-only burning power,
There are few boiler loads that are always operated at full load, and the load is increased to 75% load, 50% load, 25% load, lowered and operated, or stopped, so-called daily start-stop (Daily Start Stop, hereinafter simply referred to as DSS) Stops driving for 13 hours at night,
Alternatively, the operation is being stopped for 32 hours and 56 hours on weekends by weekend start / stop operation (hereinafter simply referred to as WSS), and a thermal power plant having an intermediate load is being transferred.

On the other hand, for this intermediate load thermal power generation, in addition to this thermal power generation boiler, a so-called combined plant in which a gas turbine with good starting characteristics and an exhaust heat recovery boiler are combined is also used.
During the daytime when there is a large demand for electricity by performing SS operation and WSS operation,
Some are going to be constructed that drive only on weekdays and stop on nights and weekends.

As a feature of recent demand for electric power, the maximum and minimum difference in electric power load has increased along with the growth of nuclear power generation, and there is a tendency to shift the boiler for thermal power generation from base load to load adjustment. By changing the pressure according to the load to perform a variable pressure operation, that is, a so-called variable pressure operation boiler that operates in the supercritical pressure range at full load and in the subcritical pressure range at partial load. Because it can be improved by several percent.

However, it is convenient for the boiler side to perform the DSS operation and the WSS operation in which the start, stop, and load changes are frequently performed on a daily or weekly basis, but it is not preferable for the denitration device.

The denitration catalyst of the denitration device usually shows high activity at 300 ° C or higher, and generally, the denitration device is installed between the economizer and the air preheater of the boiler to perform the denitration reaction at a temperature of about 350 ° C. The exhaust gas temperature changes depending on the fluctuation of the boiler load, and the exhaust gas temperature at the outlet of the economizer is 350 ° C at full load.
This is because the temperature is around 300 degrees Celsius during the 1/2 load operation and about 270 degrees Celsius during the 1/4 load operation, and the denitration performance decreases.

Further, when the exhaust gas temperature is too low, SO ₃ contained in the exhaust gas is adsorbed by the pores of the denitration catalyst and binds with water to cause capillary condensation, and further, SO ₃ and NH ₃ react to cause acid ammonium sulfate. (NH ₄ HSO ₄ ), ammonium sulfate [(NH ₄ ) ₂ S
O ₄ ], ammonium sulfite [(NH ₄ SO ₃ )] and the like are produced, and these adhere to the catalyst surface to reduce the denitration performance.

FIG. 13 is a schematic system diagram for flue gas in a conventional boiler.

In FIG. 13, the combustion-like air in the air duct 1 is boosted by the forced draft fan 2 and the exhaust gas duct 4 by the air preheater 3.
After being heated by the exhaust gas, the gas is supplied from the wind box 5 to the boiler 6.

On the other hand, the exhaust gas burned in the boiler 6 flows to the convection heat transfer section 7, passes through the superheater 8, the reheater 9 and the economizer 10, and then enters the inlet flue 1
Together is by connexion denitration in NH ₃ from NH ₃ injection pipe 12 at 1 promotes denitration in the catalyst 14 in the denitration apparatus 13 disposed downstream, the NO _x in the exhaust gas are removed outlet flue 15, Air preheater 3, dust collector 16, induced draft fan 17
It is pressurized by and released into the atmosphere.

However, during operation of the boiler 6, the catalyst 1 of the denitration device 13
The dust adheres to the catalyst 4, but the dust adhered to the catalyst 14 is in a dry state during normal operation and the catalyst 1
It does not affect the deterioration of 4.

However, the gas (atmosphere) is present at the start-up of the operation when performing the DSS operation or the WSS operation, or when the operation is stopped (when the car is stopped)
The temperature may drop below the dew point, and the catalyst deterioration component in the dust may move to the surface of the catalyst 14, causing sudden performance deterioration.

It is a boiler 6 to perform DSS operation and WSS operation.
When the plant having the denitration device 13 such as the above is started, the entire plant is cold, so that moisture in the combustion gas is condensed on the surface of the catalyst 14 or when the operation is stopped for a long time due to a power supply situation, etc. This is because exposure of the passage 11 and the outlet flue 15 to a gas (air) containing a large amount of moisture causes a decrease in catalyst performance.

FIG. 14 is a characteristic curve diagram showing the change over time in catalyst activity with respect to the operating time of the denitration device 13. As the operating time of the denitration reactor 13 elapses, the catalyst activity is deteriorated as shown by the curve A in FIG. 14 due to poisoning of the catalyst 14 due to deterioration components in the exhaust gas, poisoning of the catalyst 14 or sintering due to heat of the exhaust gas. Gradually decreases. Therefore, in order to maintain the denitration performance of the denitration device 13 for a long time, the deteriorated or poisoned catalyst 14 is regenerated by washing with water or the like.
Alternatively, a method of stacking a new catalyst on the deteriorated or poisoned catalyst 14 or replacing it with a new catalyst is used. In general, the large-scale denitration device 13 is economical,
In terms of reliability, a new catalyst is piled up on the deteriorated or poisoned catalyst 14 (catalyst stacking method), or all the deteriorated or poisoned catalyst 14 is replaced with a new catalyst (catalyst exchange method). Has been.

FIG. 15 is a characteristic curve diagram of the denitration performance by the catalyst accumulation method and the catalyst exchange method.

When the operating time of the denitration device 13 elapses, the denitration performance also decreases from point C of curve B to point D as the catalyst activity decreases.
However, this denitration performance is provided with a limit value E for maintaining the denitration performance of the denitration device 13, and when the denitration performance drops to this limit value E (up to point D in FIG. 15), the denitration performance is reduced. The nominal performance must be improved. What is used at this time is the above-mentioned catalyst pick-up method.

This additional loading method is a method in which an additional loading space for the additional loading catalyst is secured in advance in the denitration device 13 and the additional loading catalyst is filled onto the initial filling catalyst.

With this additional catalyst, the denitration performance is restored from point D in FIG. 15 to point G on curve F. Further, if the denitration performance decreases to the limit value E point and reaches the H point due to the change with time, if the catalyst is piled up in the same manner as described above, the denitration performance is restored from the H point to the I point.

When the catalyst addition method is repeated in this manner, the addition space in the denitration device 13 is exhausted, and when the catalyst deteriorates to point J, the catalyst exchange method is used in which the deteriorated and poisoned catalyst is replaced with a new catalyst.

That is, according to the catalyst exchange method, as shown in FIG. 15, the catalyst poisoned and deteriorated to the point J (regulation value E point) (same as the point D) is replaced with a new catalyst, and the curve K reaches the point L. A new catalyst improves the denitration performance.

However, for example, in the denitration reactor 18 in the denitration device 13 of a 400 MW coal-fired boiler, as shown in the plan views and perspective views of FIGS. Are stacked in two stages, and the additional catalyst blocks 20 are stacked in one stage in a stack of 104, and are stacked in three stages in the exhaust gas flow direction.

FIGS. 16 (a) and 16 (b) are perspective views showing how the catalyst blocks stacked in the denitration reactor 18 of the denitration device 13 are carried in and out.

In FIGS. 16 (a) and 16 (b), 19 is an initial packing catalyst block, and 20 is an additional catalyst block.

21 is a beam, 22 is an auxiliary monorail, 23 is a main monorail, 24 is a carry-in / out port of the denitration reactor 18, 25 is a carrying frame, and 26 is a new catalyst block. In the denitration reactor 18, additional catalyst blocks 20 are stacked on top of the initially packed catalyst blocks 19 and 19, and the deteriorated initially packed catalyst and blocks 19 and 19 shown in FIG.
The procedure for exchanging the new catalyst block 26 shown in FIG. 19 and FIG. 16 (b) is performed as follows.

Step 1. All the stacked catalyst blocks 20 located at the top of FIG.
It is moved laterally from left to right in Fig. 6 (a), and the main monorail 23 moves from the depth of the denitration reactor 18 to the carry-in / out port 24.
(a) is moved in the vertical direction and is carried out of the denitration reactor 18 from the carry-in / out port 24. (Only the initial packing catalyst block 19 is arranged in the denitration reactor 18.) Step 2. The initial packed catalyst block 19 is also carried out of the denitration reactor 18 as in Step 1. (Denitration reactor 18
All the catalyst blocks 19 and 20 inside are discharged and become empty. ) Step 3. In the reverse order of Step 2, the new catalyst block 26 shown in FIG. (Only the new catalyst block 26 is placed in the denitration reactor 18.) Step 4. Additional catalyst block 20 carried out in Step 1
In the reverse order of Step 1, the main monorail 23 and the auxiliary monorail 22 are carried into the denitration reactor 18, and the new catalyst block 26 carried in Step 3 is piled up to stack the catalyst blocks 20. (In the denitration reactor 18, a new catalyst block 26 and an additional catalyst block 20 are shown in FIG.
It is arranged as in (a). Even if the initially loaded catalyst block 19 is replaced with the new catalyst block 26 as described above, the reason why the additional catalyst 20 is still stacked on the new catalyst block 26 is that the additional catalyst block 20 is larger than the new catalyst block 26. When it deteriorates first and is replaced next time, the additional catalyst block 20 is stacked on the new catalyst block 26 in order to replace the additional catalyst block 20 on the new catalyst block 26 with a new catalyst block 26.

In this way, not only the exchange of the catalyst block group 36 and the catalyst block group 37 to be exchanged this time, but also the exchange of the catalyst block on the assumption of the exchange of the next catalyst block, the exchange work of the catalyst block becomes more and more complicated. .

[Problems to be solved by the invention]

As described above, according to the method of exchanging the catalyst block according to the conventional technique, all the initially filled catalyst block and the additional catalyst block that have already been filled are carried out of the denitration reactor, and then the new catalyst block and the additional catalyst block are carried in this order. In order to do so, the following problems were encountered.

(1) Since the additional catalyst block used for exhaust gas treatment is left outside the denitration reactor for a long time, the temperature in the atmosphere,
Due to rain or the like, dust adhering to the accumulated catalyst block may cause a decrease in catalytic activity.

(2) When the additional catalyst block is repeatedly carried in and out, the additional catalyst block is damaged or a minute crack is generated due to a collision at the time of carrying in and out, and the strength is reduced.

(3) It is necessary to have a storage space for temporarily storing the additional catalyst blocks and initial-loaded catalyst blocks that have been carried out.

(4) Since the initial filling catalyst block 19 and the additional catalyst block 20 are all carried out, it takes a lot of time to carry in and out, resulting in a high cost.

The present invention is intended to eliminate such conventional drawbacks,
It is an object of the invention to provide an efficient and inexpensive method for exchanging a catalyst block.

[Means for solving problems]

In order to achieve the above-mentioned object, the present invention is to carry out a new catalyst block loading / unloading line after all the catalyst blocks in the packing line and loading / unloading line closest to the loading / unloading port of the denitration reactor are carried out of the denitration reactor. The catalyst block group that is closest to the carry-in / out row of the exchange row is moved to the position where the exchange row and the carry-in / out row intersect, and the additional catalyst block in the catalyst block group is added to the loading row. It is characterized by repeating the operation of stacking on the catalyst block and filling it from the back of the packing row, and carrying out the initially filled catalyst block, and finally loading the catalyst block group sequentially from the back of the packing row to the entrance of the loading / unloading row. To do.

[Action]

The catalyst block exchange method of the present invention replaces most of the catalyst blocks by movement within the denitration reactor, reduces the catalyst blocks carried out of the denitration reactor, and replaces the catalyst blocks in a short time. It was made possible.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings. Fig. 1
(a), (b) is a perspective view for explaining the method of replacing the catalyst block according to the embodiment of the present invention, FIG. 2 is an enlarged perspective view of the catalyst block of FIG. 1, and FIG. 3 is an M of FIG. Detailed view of enlarged section,
FIG. 4 is an enlarged detailed view of the portion N of FIG. 2, FIG. 5 (a),
(b) is a plan view and a perspective view of the catalyst block in the denitration reactor, FIGS. 6 and 7 are plan views for explaining the method of replacing the catalyst block, and FIGS. 8 to 10 are storage spaces for the catalyst block. FIG. 11 is a side view showing an arrangement state of the catalyst block on the beam, and FIG. 12 is a perspective view explaining another carrying-in / out method.

In FIGS. 1 to 5, reference numerals 19 to 26 are the same as the conventional ones.

27 is a connecting jig, 28 is a support, 29 is a connecting jig 27
Concave portion, 30 is a convex portion of the support 28, 31 is a support 2
8 is a screw portion, 32 is a handle, 33, 34 and 35 are catalyst block packing lines, carry-in / carry-out lines, and exchange lines, and 36 and 37 are catalyst blocks 2 which are piled up on the initial packed catalyst block 19.
0 is a stack of catalyst blocks, a new catalyst block 26 is a stack of catalyst blocks 20, and a stack of catalyst blocks 20 is a stack of catalyst blocks, 38 is a gap, and 39 is a dust accumulation prevention plate.

Before explaining the method of exchanging the catalyst block in such a structure, a jig for carrying out and carrying in the catalyst block will be described with reference to FIGS. 2 to 4.

The catalyst blocks are carried out as a catalyst block group 36 by stacking one stage of the additional catalyst blocks 20 on top of the two-stage initially packed catalyst blocks 19 and integrating the three stages of catalyst blocks. As shown in FIG. 4, the means for integrally fixing the three-stage catalyst block is a transportation frame having a connecting jig 27 for the third-stage initially filled catalyst block 19 and a support 28 engaging with it. It is composed of 25.

FIG. 4 shows an example of a carrying jig used for replacing the catalyst block of the present invention. Connection jigs 27 having recesses 29 are attached to both upper ends of the short sides of the lower stage initially filled catalyst block 19. Then, the convex portion 30 of the support 28 that engages with the concave portion 29 of the connecting jig 27 can be fixed to the transportation frame 25 assembled in a truss shape. Support 28
As shown in FIG. 3, the screw portion 31 provided on the upper end of the support 28 is tightened by rotating the handle 32 to fix the truss-shaped carrying frame 25 and the lower-stage initially-filled catalyst block 19 to the fixing. 3 by tightening together
The catalyst blocks of the stage are integrated and carried out as a catalyst block group 36. On the other hand, by loosening the screw portion 31, the support 28 is lowered, whereby the convex portion 30 of the support 28 and the concave portion 29 of the connecting jig 27 are disengaged, and the catalyst block group 36 is integrated. Is eliminated. (The same applies to the catalyst block group 37 in which the new catalyst block 26 and the additional catalyst block 20 are integrated.) Hereinafter, the replacement method of the catalyst block will be described with reference to FIGS. 1 and 5 (a) and (b). .

Step 1. The initial charging catalyst block 19 and the additional catalyst block 20 are integrated, and the catalyst block group 36 is entirely denitrified by the auxiliary monorail 22 and the main monorail 23.
It is carried out from the carry-in / out entrance 24. Therefore, there is no catalyst block group 36 located in the shaded area in FIGS. 5 (a) and 5 (b).
Is a filling row, 34 is a loading / unloading row, and 35 is an exchange row.

Step 2. As shown in FIG. 6, the new catalyst block 26 is loaded by the main monorail 23 into the packing line 3 closest to the carry-in / out port 24.
3 and carry in to the point O where the loading / unloading line 34 intersects and set
Next, the exchange row 3 closest to the new catalyst block 26 at point O
The catalyst block group 36 of No. 5 is moved by the auxiliary monorail 22 to the point P where the exchange row 35 and the loading / unloading row 34 intersect, and O
On top of the new catalyst block 26 located at the point, the additional P point catalyst block 20 is stacked by the main monorail 23. Then, the new catalyst block 26 and the additional catalyst block 20 are combined to form a catalyst block group 37, which is moved to the deepest point Q of the packing row 33 closest to the carry-in / out port 24 by the auxiliary monorail 22 and set. The initially packed catalyst block 19 remaining at the point P is carried out of the denitration reactor 18 by the main monorail 23 as it is.

Step 3. In the same manner as in Step 2, the next new catalyst block 26 is loaded from the loading / unloading port 24 by the main monorail 23, and set at the point O where the filling row 33 and the loading / unloading row 34 intersect. Then, the catalyst block group 36 located at the R point of the exchange column 35 is moved to the P point, the additional block 20 at the P point is set to the new catalyst block 26 at the O point, and the catalyst block group 37 of the packing column 33 is set as the catalyst block group 37. It is conveyed in the direction of point Q by the auxiliary monorail 23. Then, the initially packed catalyst block 19 at point P is carried out as it is from the denitration reactor 18 by the main monorail 23.

Thus, in the example of FIG. 6, by repeating Step 2 and Step 3 seven times, a new catalyst block 26 is provided in the lower two stages in the packing row 33 of FIG. 6, and a replacement row 35 of FIG. It will be appreciated that the stack of additional catalyst blocks 20 (right column of packing row 33) are stacked and the initial packing catalyst block 19 and new catalyst block 26 of packing row 33 are replaced.

Then, the new catalyst block 26 and the additional catalyst block 20 are filled in the packing row 33 of FIG. 6 as the catalyst block group 37, so that the right row (exchange example 35) of the packing row 33 is emptied. This column is now the filling column 33
And the column on the right side becomes the exchange column 35.

By repeating such an operation, in the example of FIG. 6, when the filling row 33 becomes one row as shown in FIG. 7 at the 12th time, Step n. Finally, the packing line 3 farthest from the carry-in / out port 24
3 and the loading / unloading line 34 are all empty. In this case, from the back of the packing line 33 (point S), the new catalyst block 26 stacked outside the denitration reactor 18 and the additional catalyst block 20 once carried out are transferred as shown in FIG. 1 (b). The frame 25 is integrated into a catalyst block group 37, and the main monorail 22 and the auxiliary monorail 23 pass through the loading / unloading line 34 and the filling line 33.
Fill with. In this way, the filling row 33 and the loading / unloading row 34 are the first
When the catalyst block group 37 is stacked in three layers as shown in FIG. (B), the initial catalyst block 19 and the new catalyst block 26 are filled.
Replacement work is completed.

By exchanging the catalyst block in this order,
A storage space for storing the catalyst block outside the denitration reactor 18 and a replacement time can be reduced.

For example, in the example of FIGS. 5 (a) and 5 (b), 312 catalyst blocks are stacked in one stage.

However, 60 catalyst blocks (about 2
0%) is carried out of the denitration reactor 18 through the carry-in / out port 24, but the remaining 252 catalyst blocks (about 80%) are still arranged inside the denitration reactor 18, and the additional catalyst block 84 is added. Only the transfer from the exchange row 35 to the packing row 33 within the denitration reactor 18 is performed.

Therefore, all the catalyst block groups 36 in the denitration reactor 18 are
After carrying out all 312 catalysts, this time, as compared with the case where 312 catalyst block groups 37 are carried in, the denitration reactor 18
Since the number of catalyst blocks to be carried out is small and the catalyst block group 37 to be carried in is also small, carry-in,
It takes less time to carry out and less storage space for storing the catalyst block.

As described above, the feature of the present invention is that the denitration reactor 1 does not carry out the catalyst block unnecessary to be carried out to the outside of the denitration reactor 18 as much as possible.
Relocate within 8 to improve efficiency and secure storage space for carry-out and carry-in. The present invention is more effective as the number of catalyst blocks in the denitration reactor 18 increases.

FIG. 8 shows the arrangement of the catalyst blocks before the replacement, but the additional catalyst blocks 20 in the shaded portions in FIG. 8 cannot be carried out of the denitration reactor 18 and the denitration reaction is not carried out. It is shown to be rearranged in the container 18. If the catalyst blocks in the denitration reactor 18 are arranged in m columns and n columns, and the size of one catalyst block is a and b is horizontal, the area T of the shaded area in FIG. 8 is T = a * b (m-1) (n-1), and theoretically a catalyst storage space can be secured outside the denitration reactor 18 corresponding to this.

On the other hand, the ratio U of the number of catalyst blocks in the shaded area in FIG. 8 to the total number of catalyst blocks is Becomes As the number of columns m and rows n increases, the numerator (m-1) (n-1) and the denominators m and n come closer to the same value, and thus the occupied ratio U approaches 1. That is, the ratio of the number of catalyst blocks rearranged in the denitration reactor 18 to the total catalyst blocks becomes large. In other words, as the number of catalyst blocks increases, the number of catalyst blocks rearranged in the denitration reactor 18 also increases, and the exchange method of the present invention becomes more and more advantageous.

Next, since the moving distance of each catalyst block accompanying the loading / unloading of the catalyst block becomes a factor of the loading / unloading time and the damage status of the catalyst block, this loading / unloading time is the replacement method of the present invention and the conventional example. The following is compared with the replacement method of.

FIG. 9 schematically shows the movement of the catalyst block at the innermost portion of the packing row 33. The distance ma to the outside of the denitration reactor 18 is m × a, and the distance to the outside of the denitration reactor 18 from the carry-in / out port 24 and to the carry-in again via the ground or another storage place is 1. . Also the first
In FIG. 0, the moving distance of the additional catalyst block 20 rearranged in the denitration reactor 18 is {b + a + b (n-
1)}. Thus, m in the present invention ×
Calculation of the total transfer amount W ₁ of n catalyst blocks is as follows.

_{W 1 = m (m + 2n} -1) a + mn (n-1) b + as follows to calculate all of the movement amount _{W 2} of the prior art catalyst block with (m + n-1) V similar to the following methods.

W ₂ = {n (n + 1) + (n-1) m (m + 1)} a + mn (n-1) b + mnV Therefore, when the exchange method of the present invention is carried out, the shortened distance ΔW of the push-up catalyst block input is ΔW _{= W 2 -W 1 = {n} (n + 1) + m (mn -2n)} a + (mn-mn + 1) is represented by V, m, n since a sufficiently large integer mn-2m-n> 0, Since mn-m-n + 1> 0 and ΔW> 0, it can be seen that the movement amount of the catalyst block by the exchange method of the present invention is shortened as compared with the exchange method of the prior art.

In the denitration equipment in a 400 MW coal-fired boiler,
Eight catalyst blocks in a column (packing row 35), 13 catalyst blocks in a row (loading / unloading row 34), depth of catalyst block 1 m, width 2.5 m, moving distance outside the denitration reactor 18 When calculated assuming 100 m, the shortened distance ΔW is 9,382 m, and the exchange method of the present invention is more advantageous than the conventional exchange method.

Since the distance V >> a is normally satisfied, the value of the shortened distance ΔW is
Depending on (mn-m-n + 1), the effect can be expected irrespective of the values of m and n, but if the distance V is small, the shorter the distance m becomes, the shorter the distance m becomes from the formula of the shortening distance ΔW. Since ΔW becomes large, a larger effect can be expected in the denitration reactor 18 having the long packing line 33 and long loading / unloading line 34.

Note that FIG. 1 (a) is a perspective view of the catalyst block viewed from the filling method, and the cause of the gap 38 between the catalyst blocks will be described. Normally, the I-type steel is used for the beam 21 for catalyst block which supports the catalyst blocks 19 and 20. This is because when the flow direction of the exhaust gas flows from the top to the bottom of FIG. 1 (a), the area blocked by the beam 21 is small and the strength is excellent. The size of the I-beam 21 is generally 200 to 300 mm in height and 150 to 200 in width.
It is about mm. When the catalyst blocks 19, 20 are placed on the I-shaped steel beam 21, it is assumed that the catalyst blocks 19, 1 are
If 9 or 20 and 20 are closely contacted with each other, a portion where exhaust gas does not pass through the catalyst blocks 19 and 20, that is, a dead space becomes large, and the catalyst blocks 19 and 20 do not work effectively, which is not economical. In other words, even if the gap 38 is removed and there is close contact, there is a manufacturing tolerance, and the gap 38 does not always become zero. Therefore, gas containing a large amount of dust in the exhaust gas, such as coal-burned exhaust gas, will not enter the gap 38. It may enter and cause stress resistance and corrosion.

In order to prevent this, a dust accumulation prevention plate 39 having a triangular shape with a sharp upper end is provided on the catalyst block 19, 19 or 20, 2.
The catalyst blocks 19 and 19 are provided in the space 38 between the two.
Alternatively, if the gap 38 between the 20 and 20 is small, it becomes difficult to install the deposition prevention plate 39. Further, in arranging the catalyst blocks 19, 19, 20, 20, the catalyst blocks 19, 19 or 20, always in the packing row 33 direction,
A gap 38 is required between 20 so that the catalyst blocks do not collide with each other when moving.

As described above, there is always a gap 38 in the packing column 33 direction of the catalyst block arranged in the denitration device, and the connecting jig 27 and the support 28 in the embodiment of the present invention utilize this gap 38. is there.

Usually, the gap 38 is about 50 to 100 mm, and the connecting jig 27 provided on the catalyst block 19, 19 or 20, 20 and the support 28 for receiving it work within the range of the gap 38.

FIG. 12 is a perspective view when the catalyst block groups 36 and 37 are carried in and out by the carrying frame 25. 2 blocks of the catalyst 19 piled up in the transport frame 25 and an initial packing catalyst block 20
If a total of 6 blocks of (new catalyst block 26), 4 blocks in total, are loaded and loaded at the same time, the work time for loading and unloading will be about half.

〔The invention's effect〕

According to the present invention, most of the additional catalyst blocks move only in the denitration reactor and are not discharged, so that the storage space for the catalyst blocks is small and the operation time for exchanging the catalyst blocks is short.

[Brief description of drawings]

FIGS. 1 to 12 explain the method of replacing the catalyst block according to the present invention. FIGS. 1 (a) and 1 (b) are perspective views showing the method of replacing the catalyst block, and FIG. Fig. 3 is an enlarged perspective view of the catalyst block of Fig. 3, Fig. 3 and Fig. 4 are enlarged detail views of the M part and N part of Fig. 2, and Fig. 5 (a) and (b) are the catalyst blocks in the denitration reactor. 6 and 7 are plan views for explaining the method of replacing the catalyst block, and FIGS. 8 to 10 are diagrams for explaining the storage space and transport distance of the catalyst block, and FIG. Is a side view showing the arrangement state of the catalyst block on the beam, FIG. 12 is a perspective view illustrating another loading / unloading method, FIG. 13 is a schematic system diagram of a flue air duct in a conventional boiler, and FIG. 14 is denitration. Fig. 15 is a characteristic curve diagram showing the change over time in the catalytic activity with respect to the operating time of the equipment. Fig. 15 shows the catalyst addition method and the catalyst exchange method. Characteristic curve diagram of a denitration performance that, first
6 (a) and 6 (b) are perspective views for explaining the conventional method of replacing the catalyst block, and FIGS. 17 (a) and 17 (b) are a plan view and a perspective view of the catalyst block in the denitration reactor. 13 ... Denitration device, 18 ... Denitration reactor, 19 ... Initially packed catalyst block, 20 ... Stacked catalyst block, 2
4 ... Carry-in / out port, 26 ... New catalyst block, 33 ...
Filling line, 34 ... Loading / unloading line, 35 ... Exchange line, 36, 3
7 ... Catalyst block group.

Claims (1)

[Claims] 1. A catalyst block group, which is obtained by stacking catalyst blocks on top of an initial packing catalyst block, is carried out of the denitration reactor to the outside of the denitration reactor to replace the initial packing catalyst block and the new catalyst block. After all the catalyst blocks in the packing line and the loading / unloading line closest to the loading / unloading port of the denitration reactor are carried out of the denitration reactor, the new catalyst block is loaded into the position where the loading / unloading line and the packing line intersect. At the same time, the catalyst block group closest to the carry-in / out port of the exchange row is moved to the position where the exchange row and the carry-in / out row intersect, and the additional catalyst block of the catalyst block group is stacked on the new catalyst block in the packing row to It is characterized in that the operation of loading from the back and carrying out the initially loaded catalyst block is repeated in sequence, and finally the catalyst block group is carried in from the back of the packing row to the entrance of the loading / unloading row. How to replace the catalyst block to be.