JPS58229A - Packing method for catalyst - Google Patents

Abstract

PURPOSE:To make the flow velocity of the gas flowed into narrow holes of catalysts uniform to prevent the damage of catalysts, by packing multistage catalysts, which treat the waste gas having a high duct concentration, at intervals of specific dimensions or more. CONSTITUTION:In case that cartridge catalysts are packed in a denitrifying reaction vessel for the waste gas having a high dust concentration, cartridges 3A of the second stage and following stages are so fabricated that a length D from the upper end of the cartridge to the surface of a packed catalyst 1 has a value obtained by adding a length >=10 times as long as the diameter of narrow holes of the catalyst to a length which is set considering the conventional production error. When flanges 5 are matched to one another to pile up vertically cartridges 3A, where catalysts 1 are packed in this manner, in the denitrifying reaction vessel, intervals of catalysts are held sufficiently, and therefore, the flow velocity of the gas which is flowed out from catalyst narrow holes in the upper stage is made uniform when this gas is flowed to catalyst narrow holes in the lower stage, and the wear of end faces of catalysts is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for filling a catalyst, and more particularly to a method for filling a catalyst in a denitrification reactor for treating exhaust gas with a high dust concentration.

In denitrification equipment for exhaust gas with high dust concentration such as coal-fired die 2-5 exhaust gas, the denitrification catalyst is normally stored in a cartridge and then
The reactor is filled.

That is, the shape of the conventional denitrification catalyst is the first one.

A cross-sectional view of this catalyst loaded into a cart is shown in the second figure.
As shown in the figure, the catalyst 1 is cubic and has a large number of pores 9 parallel to the gas flow direction 2.

This catalyst is placed on the support par 4 at the bottom of the cartridge 3, as shown in FIG. 2, so that the vertical holes 9 of the catalyst are parallel to the gas flow.

Many are packed in parallel. The t-port par 4 has a grid shape and is fixed to the side wall of the cartridge, and the catalyst 1 is loaded thereon. In order to manufacture such a cartridge 3, conventionally, the length of the cartridge should not be shorter than the length of the catalyst5, and the length of the cartridge should be longer than K11, taking into account some manufacturing errors.
-4$' 0 For example, in Fig. 2, if the catalyst length M is 5o.■, then the length of the cartridge is 600mm, taking into account the thickness B of the napolet members 4 of 50cm above and below the catalyst. Manufactured to a length of 1/2 inch.

Cartridges 3 filled with catalyst 1 are used by stacking them in multiple stages in a reaction vessel, but in the case of high dust concentration such as coal-fired boiler exhaust gas, the exhaust gas passing through the pores s9 of the catalyst is transferred to the next stage. Since the catalyst KA remains in equilibrium at a flow rate of 1, there is a problem in that the end face of the catalyst in the next stage is worn more severely than the end face of the first stage. For example, according to a calculation example, the gas flow rate inside the catalyst pores is 9!, since the porosity of the catalyst is about 0.7! 1/Q of the tower flow rate, 7-143 times,
Furthermore, since wear is approximately proportional to the cube of the flow velocity, the wear on the end faces of the catalysts in the second and subsequent stages is approximately three times that of the first stage catalysts.

In order to avoid wear of the tips of the catalysts in the second and subsequent stages, the pores of the lower stage catalyst should be located directly below the pores of the upper stage catalyst.
It is sufficient to prevent the catalyst end face from directly hitting the gas flow, but
It is practically impossible to fill the catalyst in this way.

An object of the present invention is to provide a catalyst filling method that minimizes wear on the end faces of the catalyst in the second and subsequent stages and avoids damage to the catalyst.

In order to achieve the above object, the present invention provides a method for filling a denitrification reactor for exhaust gas with a high dust concentration with a catalyst at a distance of at least 10 times the pore diameter of the catalyst in the second and subsequent stages relative to the gas flow. In the present invention, when using a cartridge to fill the catalyst, in addition to the clearance due to conventional manufacturing errors, the catalyst pore diameter F (see Figure 1,
The length of each cartridge is determined by taking into consideration a margin of at least 10 times the length (usually 4 to 20 times).

In the present invention, the reason why the spacing between the catalysts is set to 2010 times or more the pore diameter is because if the spacing is smaller than this, abrasion of the end faces of the catalysts in the second and subsequent stages is unavoidable.

Next, FIG. 3 shows a perspective view when the catalyst 1 is filled into the cartridge 3A by the method of the present invention.
The distance from the upper end of the cartridge 3m in the second and subsequent stages to the top surface of the packed catalyst 1 is the same as the distance that takes into account conventional manufacturing errors plus a length that is at least 2010 times the catalyst pore diameter. will be produced in When the cartridges 3A filled with the catalyst Is1 are stacked one above the other in the reaction vessel with the fufunji 5 placed one on top of the other, the gap between the catalysts is maintained sufficiently, so that the gas flowing out of the catalyst pores flows through the catalyst pores in the lower stage. The flow velocity is made uniform before entering the hole, and wear on the catalyst end face is prevented.

In the above embodiment, a margin is mainly provided in the upper part of the cartridge 3, but a similar margin may be provided in the lower portion of the cartridge 3 and the bar 4. Further, the present invention can be similarly applied to catalyst packing without using a cartridge.

As mentioned above, in the present invention, by filling the catalyst in the gas flow direction and maintaining a specific interval or more, the flow velocity distribution at the upper stage catalyst outlet is made uniform and the local high flow velocity is reduced. This can reduce wear on the end faces of the catalysts in the lower and subsequent stages to the same level as in the first stage.

[Brief explanation of the drawing]

Figure 1 is a perspective view of a denitrification catalyst, Figure 12 is a cross-sectional view of a catalyst car showing a conventional catalyst filling method, and Figure 3 is a cross-sectional view of a catalyst car.
FIG. 2 is a perspective view of a catalyst cartridge showing a catalyst filling method of the present invention. 1...Catalyst, 2...Gas flow, 3.3mm...Cartridge, 4...Support par. Representative Patent Attorney Takecho Kawa Figure 1

Claims (2)

[Claims] (1) When filling a denitrification reactor for treating exhaust gas with a high dust concentration, a catalyst characterized in that the catalyst is packed at a distance of at least 10 times the pore diameter of the second-stage catalyst or later with respect to the gas flow. filling method. (2) The scope of the patent terminal described in item 1, wherein the catalyst is loaded in a cartridge, and the cartridge has a length such that a catalyst spacing is at least 10 times the pore diameter of the catalyst. How to fill the catalyst.