JPH03249922A - Ash accumulation removing equipment - Google Patents

Abstract

PURPOSE:To reduce the size of equipment as well as the amount of jet fluid necessary to remove ash to be smaller than those of the ordinary equipment and to efficiently remove ash accumulation by providing the fluid piping having fluid jet nozzles directed downwards along the supporting members supporting catalyst layers. CONSTITUTION:In the ash accumulation removing device in a catalyst reactor 1 having catalyst layers 2 on the plural stages provided along the direction of gas flow, the accumulated ash is removed by the fluid jetted from the fluid piping which is provided along the supporting members 3, 4 supporting the catalyst layers 2 and has the fluid nozzles 5 directed downwards. As a result, a smaller equipment than the ordinary one is obtained, and the amount of fluid to be jetted necessary to remove ash is reduced, and the ash accumulation is efficiently removed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a catalytic reaction device, and particularly to a device suitable for removing ash deposits in a vertical flow catalytic reactor for exhaust gas denitrification.

[Prior Art] Ash tends to accumulate in an exhaust gas denitrification device that reduces and removes NOx in exhaust gas by bringing exhaust gas into contact with a catalyst in the presence of a reducing agent. In particular, the ash concentration in the exhaust gas from coal-fired boilers is higher than that in the exhaust gas from heavy oil-fired boilers, so ash tends to accumulate in the denitrification reactor.

Figure 7 shows a typical flue system of a coal-fired boiler equipped with a denitrification device.

As shown in FIG. 1, the denitrification reactor 11 is placed in the middle of an exhaust gas duct 12, and a bypass duct 14 is attached to the exhaust gas duct 12 to protect the catalyst block 13.

That is, when the denitrification reactor 11 is operated under normal conditions, the exhaust gas from the boiler 15 passes through the denitrification reactor 11 from the exhaust gas duct 12 to the catalyst block 13 as shown by arrow A in FIG. Denitration is performed by the catalyst block 13.

On the other hand, due to a tube breakage accident in boiler 15, boiler 1
If an abnormal situation occurs that causes the operation of the catalyst block 13 to be stopped, the denitrification reactor 11 is disconnected from the exhaust gas duct 12 in order to protect the catalyst block 13 from steam and water, and the exhaust gas is diverted as indicated by arrow B in Figure 7. As shown, the exhaust gas duct 12 flows into the bypass duct 14, the air preheater 16, and the induced draft fan 1.
7, it is pressurized and released into the atmosphere.

On the other hand, the combustion air in the air duct 18 is
As shown in the figure, the pressure is increased by the forced draft fan 19, and the air is
6 and is supplied as combustion air to the boiler 15.

For the denitrification reactor 11 of a boiler with a large amount of ash in the exhaust gas, a so-called vertical type system, as shown in Figure 7, is adopted in which the exhaust gas flows from the top to the bottom of the catalyst block 13 in order to prevent ash. ing.

As a conventional denitrification device of this type, an ash deposit removal device in a vertical flow reactor as shown in FIGS. 4 and 5 is known.

The example shown in FIG. 4 uses a rake-type soot blower, and the example shown in FIG. 5 uses an oscillating-type soot blower. In either device, the injection nozzle 5 is arranged so that the injection fluid from the injection nozzle 5 hits the entire upper surface of the catalyst block 2.
It is characterized by the placement of

Incidentally, related to this type of device, for example, Utility Model Application Publication No. 58-107131, Utility Model Publication No. 62-21303, etc. can be cited.

[Problems to be Solved by the Invention] Although the above-mentioned conventional technology can remove ash accumulation, it does not take into consideration the point of focusing on areas where ash accumulation is likely to occur, that is, efficiently removing ash accumulation. There wasn't. In other words, in these conventional devices, the injection nozzle was arranged so that the injection fluid hit the entire upper surface of the catalyst block.
There are problems in that the scale of the device is large, and that when the device is used, the injection fluid is injected even onto a portion of the upper surface of the catalyst where most of the ash is not deposited, which is uneconomical.

SUMMARY OF THE INVENTION An object of the present invention is to provide an apparatus that is smaller than conventional apparatuses, can reduce the amount of injection fluid required for ash removal, and can efficiently remove ash deposits.

[Means to solve the problem] The above object of the present invention is achieved by the following configuration.

In other words, in an ash deposition removal device for a catalytic reactor that has catalyst layers provided in multiple stages along the gas flow direction and removes deposited ash using fluid injected from a fluid pipe, the ash deposit removal device has a catalyst layer provided in multiple stages along the gas flow direction, and removes deposited ash using fluid injected from a fluid pipe. an ash deposit removal device for a catalytic reactor equipped with a fluid pipe having a fluid jet nozzle facing downward; The above-mentioned ash deposit removal device for a catalytic reactor uses the member as a support member for fluid piping, or the diameter of the fluid jet nozzle of the fluid piping at the location where the support members intersect with each other is larger than the diameter of the fluid jet nozzle at other locations. The above-mentioned ash accumulation removal device for a catalytic reactor, or the above-mentioned ash accumulation removal device for a catalytic reactor, wherein the density of the fluid jetting nozzles of the fluid pipes at the locations where the supporting members intersect with each other is greater than the density of the fluid jetting nozzles at other locations; It is.

[Operation] Ash accumulation on the upper surface of the catalyst layer in the catalytic reactor is caused by turbulence in the gas flow caused by a catalyst layer support member placed in the gas flow above the catalyst layer.

FIG. 6 shows that the horizontal catalyst layer support member in the reactor allows
This indicates that gas flow turbulence occurs downstream of this, resulting in ash accumulation on the catalyst layer directly below the catalyst layer support member.

The ash deposit removal device according to the present invention can remove the deposited ash by using fluid ejected from a fluid jet nozzle having a downward jet direction and disposed along the catalyst layer support member. Therefore, even if ash is deposited directly under the horizontal catalyst layer support member,
It is possible to remove it efficiently.

Furthermore, space can be saved by using the catalyst layer support member as a fluid pipe.

Furthermore, by increasing the diameter or density of the fluid ejecting nozzles of the fluid piping at the locations where the support members intersect with each other, it is possible to remove the ash below the intersections where a large amount of ash tends to accumulate.

[Example] An embodiment of the present invention is shown in FIG.

The denitrification reactor 1 is a vertical flow type reactor, and the combustion exhaust gas flows from top to bottom. A block-shaped catalyst block 2 is filled in the denitrification reactor 1 over the entire cross section of the exhaust gas flow path. This catalyst block 2 is installed on a catalyst support beam 3, and the catalyst support beam 3 is further supported by a horizontal girder 4. The catalyst block 2, the support beams 3, and the horizontal girders 4 form a catalyst block unit, which is installed in multiple stages in the direction of the exhaust gas flow path. In this example,
The insides of the catalyst support beams 3 and the horizontal girders 4 serve as flow paths for ash removal fluid. Along these support beams, a large number of injection nozzles 5 are installed directly below them.The combustion exhaust gas contains ash, and when the gas flows through the reactor, the ash flows through the support beams. Due to the turbulence in the gas flow caused by the horizontal beams 4 and 3, it is easy to deposit on the upper surface of the catalyst block 2 directly under the turbulence of the gas flow, that is, directly under the horizontal beams 4.

In the present invention, since the injection nozzle 5 is arranged along the horizontal beam 4 and the support beam 3 and directly below them, even if ash accumulation occurs directly under the horizontal beam 4, it can be efficiently removed. Also,
As in this embodiment, if the support beams 3 and horizontal girders 4 are used as fluid piping through which the pressure medium for ash removal flows, the equipment becomes small-scale.

In addition, by arranging the injection nozzle 5 on the downstream side of the support beam 3 and the horizontal girder 4, the support beam 3 and the horizontal girder 4 can be
This changes the formation of vortices in the gas flow downstream of the gas flow, which also helps prevent dust accumulation.

Another embodiment of the invention is shown in FIG. In this example, the first
Instead of using the inside of the support beam 3 and the horizontal girder 4 (hereinafter also referred to as beam 3.4) in the embodiment shown in the figure for the fluid flow path, as shown in FIG. An example in which a part of the beam is used as the fluid flow path 6, and a beam 3.4 as shown in Fig. 2(b).
This is an example in which the fluid pipe 6 is used as a support member for the fluid piping 6. These embodiments also provide the same effects as the embodiment shown in FIG.

Another embodiment of the present invention is shown in FIG. In this embodiment, as shown in FIG. 3(a), the nozzle 5 at the intersection is placed directly under the beam 3.4, where ash accumulation is particularly likely to occur.
An example of increasing the diameter of the 3rd e? I(b) is an example in which the number of injection nozzles 5 at the intersection is increased, and by increasing the amount of injection fluid at the intersection, in addition to the same effect as the embodiment shown in FIG. , the ash removal effect at the intersection of the beams 3.4 can be further improved.

[Effects of the Invention] According to the present invention, ash removal is performed by intensively injecting the ash removal fluid directly under the catalyst layer support member where ash accumulation tends to occur, which is different from conventional ash removal in which fluid is injected over the entire upper surface of the catalyst. Compared to other devices, ash can be removed efficiently with a small-scale device, and the amount of injection fluid can be reduced.

Further, by using the catalyst layer support member as a fluid pipe, space can be saved.

Further, by increasing the amount of fluid ejected particularly at the locations where the support members intersect with each other where ash accumulation is likely to occur, ash can be effectively removed.

[Brief explanation of drawings]

FIG. 1 is a diagram showing an embodiment of the ash removal apparatus according to the present invention, and FIG. 1(a) is a side sectional view of a denitrification reactor,
b) is a sectional view taken along the line I-1 in Figure 1 (a), and Figure 2 is a diagram showing how to attach the fluid flow path to the beam and the injection nozzle.
Figures (a> is a cross-sectional view of an example in which a part of the beam is used as a fluid flow path, Figure 2 (b) is a cross-sectional view of the case where the beam is used as a support for fluid piping, and Figure 3 is a cross-sectional view of the beam and the injection These are explanatory diagrams showing nozzle piping. Figure 3 (a) is a plan view when the diameter of the injection nozzle at the beam length difference section is increased, and Figure 3 (b) is a plan view when the number of injection nozzles at the intersection is increased. The plan view and Fig. 4 are diagrams showing an ash removal device using a conventional rake-type soot blower.
a> is a side sectional view of the denitrification reactor, FIG. 4(b) is a sectional view taken along the line ■-■ in FIG. 4(a), and FIG. 5 is a diagram showing an ash removal device using a conventional oscillating soot blower. , Figure 5(a) is a side cross-sectional view of the denitrification reactor, Figure 5(b) is a cross-sectional view taken along the line ■-■ of Figure 5<a), and Figure 6 is a horizontal cross-sectional view of the FIG. 7 is an explanatory diagram showing that ash is deposited on the catalyst directly below the catalyst, and FIG. 7 is a flue duct system diagram of a boiler in which a denitrification reactor is installed. 1...Denitration reactor, 2...Catalyst block, 3.
...Catalyst support beam, 4.Horizontal beam, 5.Injection nozzle, 6.Fluid flow path

Claims (5)

[Claims] (1) In an ash accumulation removal device for a catalytic reactor that has catalyst layers arranged in multiple stages along the gas flow direction and removes accumulated ash using fluid injected from a fluid pipe, a support member that supports the catalyst layer An apparatus for removing ash deposits in a catalytic reactor, characterized in that a fluid pipe having a fluid jet nozzle facing downward is provided along the pipe. (2) The ash deposit removal device for a catalytic reactor according to claim 1, wherein the support member is a fluid pipe. (3) The ash deposit removal device for a catalytic reactor according to claim 1, wherein the support member is used as a support member for a fluid pipe. (4) Ash accumulation in a catalytic reactor according to any one of claims 1 to 3, characterized in that the diameter of the fluid jetting nozzle of the fluid piping at a location where the supporting members intersect with each other is made larger than the diameter of the fluid jetting nozzle at other locations. removal device. (5) Removal of ash deposits in a catalytic reactor according to any one of claims 1 to 3, characterized in that the density of the fluid jetting nozzles of the fluid piping at the locations where the supporting members intersect with each other is made higher than the density of the fluid jetting nozzles at other locations. Device.