JPH0116525B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a dry exhaust gas denitrification device, and particularly to a parallel flow denitrification catalyst device located in a vertical duct.

<Conventional technology and its problems> Dry exhaust gas denitrification catalyst devices form a catalyst layer in the high-temperature boiler exhaust gas flow path, and inject ammonia as a reducing agent upstream to reduce nitrogen in the exhaust gas as it passes through the catalyst layer. It decomposes oxides (NOx) into water and nitrogen. Among these, parallel flow denitrification equipment forms a catalyst layer using a plate catalyst, honeycomb catalyst, etc., and the pressure loss when gas passes through the catalyst layer can be covered by the fan allowance when planning the boiler. There are certain characteristics. Figure 1 shows a system diagram of a boiler using this parallel flow type denitration equipment. The flow of exhaust gas G generated in boiler 1 is turned from horizontal to vertical between the economizer outlet and air heater 2, After being denitrified in the catalyst layer 5 formed upstream of the nitrogen gas 2, the nitrogen gas is discharged into the atmosphere from the chimney 4 through the air heater 2 and the dust collector 3.
However, there is a lot of soot and dust in the exhaust gas of a coal (pulverized coal)-fired thermal power generation boiler, so it is recommended that the exhaust gas be installed in a position where the exhaust gas flows from the top to the bottom, as shown in Figures 1 and 3, to prevent it from accumulating on the catalyst layer. good. This catalyst layer 5 consists of a catalyst 1 formed into a plate shape as shown in FIG.
The catalyst element 6 is formed by stacking a large number of catalyst elements 6 arranged at intervals. For this reason, it takes a lot of time and effort to carry in, take out, and refill the catalyst elements 6, and because the individual catalyst elements 6 are stacked one by one, the catalyst elements 6
It was difficult to arrange the exhaust gas G in an orderly manner, resulting in poor passage of the exhaust gas G. Therefore, the catalyst layer 5 must be constantly managed, which is inconvenient and uneconomical.

Furthermore, as an apparatus in which a denitrification catalyst layer is formed in a vertical gas passage, there is an invention disclosed in Japanese Patent Application Laid-Open No. 141480/1983. This also applies to the structure shown in FIG. 8, in which packaged plate catalysts are stacked one by one on a three-tiered bed, and corresponds to stacking the catalyst elements 6 in FIG. 2 of the present invention. Furthermore, a crane 12' is required for each floor, and a large number of cranes are required, and a catalyst storage area 14'' is provided for each floor, which poses a problem of requiring a gas passage floor area and a large space.

<Objective of the Invention> An object of the present invention is to eliminate the above-mentioned drawbacks of the prior art, and to provide a denitrification catalyst device that is easy to work with and has a formed catalyst layer of good quality.

<Summary of the Means> In short, the present invention provides a method in which exhaust gas is turned from the horizontal direction to the vertical direction along the guide plate and flows vertically in the flue, on the vertical wall side downstream in the horizontal gas flow direction.
The denitrification catalyst apparatus is characterized in that it is provided with a hatch for carrying in a catalyst block that opens into the space above the guide plate, and a truck that runs on a beam on which the carried-in catalyst block is placed.

<Example> An example of the present invention will be described below with reference to the drawings.

First, as shown in FIG. 4, a plurality of catalyst elements 6 are assembled and fixed to form a block to form a catalyst block 7. The periphery of this catalyst block 7 is surrounded by a plate material 18, and the bottom of the block is further covered with a lattice-shaped crosspiece 1.
9 to reinforce the catalyst block 7 and to allow exhaust gas G to pass from the top to the bottom of the block. When the block is arranged in the exhaust gas duct D to form a catalyst layer, the height h of the block is set to be the same as the thickness of the catalyst layer. Next, a catalyst layer is formed using this catalyst block 7, but since the catalyst block 7 has a large volume and is a heavy object, in order to facilitate the movement and installation of this catalyst block 7, it is shown in FIG. A catalyst block transfer apparatus shown in FIG. 7 is used. That is, 8 is a cart for transporting the catalyst block 7, and a table 9 for placing the catalyst block is provided on its upper surface. The table 9 is moved up and down by hydraulic pressure or other appropriate means, and when it has risen to the highest position 9', the mounting surface of the table 9 is the upper end surface 1 of the catalyst support beam 14 shown in FIG.
4', and in the case of the lowest position, it is lower than the upper end surface 14' of the support beam 14. Reference numeral 11 denotes a rope for moving the cart provided at the front and rear of the cart 8 in the moving direction.
Next, the method of installing the catalyst block 7 will be explained. First, in FIG. 3, the catalyst block 7 is carried into the duct D through the hatch 13 which opens into the space above the rectifying plate 20 by the block carrying device 17. At this time, a cart 8 with a table 9 at the highest position is placed directly below the catalyst block 7. Next, when the catalyst block is completely placed, the operator pulls the rope and moves the trolley 8. In this case, the lower surface of the catalyst block 7 is connected to the upper end surface 14' of the catalyst support beam 14, as shown in FIG. It's taller so you can move around more freely. Next, when the catalyst block 7 comes to a predetermined position, the table 9 is gradually lowered. As a result, the catalyst block 7 is placed on the catalyst support beam 14 as shown in FIG. 7, and a space is created between the placement surface of the table 9 and the lower surface of the catalyst block 7. The now free carriage 8 is returned to the suspended position of the block by means of the rope 11 on the opposite side. Note that 10 is a rail for moving the cart 8. A catalyst layer is formed in the exhaust gas duct D by repeating the above operations.

Note that there are multiple rows of rails 10 for moving the catalyst block in parallel in a direction perpendicular to the longitudinal direction of the rails.
When the truck 8 is made movable on rails provided in a direction perpendicular to the longitudinal direction of the rails shown in the figure, the catalyst layer can be quickly formed by simply carrying in the catalyst block from one hatch.

<Effects of the Invention> By carrying out this invention, a catalyst layer formed by a heavy catalyst block can be formed by using a hatch that opens into a space on a guide plate that changes the gas flow direction from a horizontal direction to a vertical direction, and in combination with a truck. A denitrification catalyst device is formed, and only one block carrying device such as a crane is required. In addition, no floor space is required for the carrying means, and the operation is easy.

[Brief explanation of drawings]

Fig. 1 is a system diagram of a boiler having a parallel flow type denitrification device, Fig. 2 is a perspective view of a catalyst element, and Fig. 3 is a sectional view of an exhaust gas duct having a denitrification catalyst device according to an embodiment of the present invention. , Fig. 4 is a perspective view of the catalyst block, Fig. 5 is a side view of the cart for transporting the catalyst block, Fig. 6 is a front view of the cart with the table in the highest position, and Fig. 7 is with the table in the lowest position. FIG. 8 is a front view of a conventional denitrification catalyst device. 5... Catalyst layer, 6... Catalyst element, 7...
Catalyst block, 8... Cart, 9... Table, 1
0...Rail, 11...Rope, 13...Hatch, 14...Catalyst support beam, 17...Block carrying device, 20...Guide plate.

Claims (1)

[Claims] 1. Into the flue in which exhaust gas flows vertically from the horizontal direction along the guide plate, there is a catalyst block loading pipe that opens on the vertical wall side downstream in the horizontal gas flow direction and into the space above the guide plate. A denitrification catalyst device comprising a hatch and a cart that runs on a beam on which a catalyst block is placed.