JPH0368443A - Gas-liquid system catalytic reactor and burnout preventing method for packed layer thereof - Google Patents

Abstract

PURPOSE:To perform extinguishment at an early stage by constituting a packed layer while plurally dividing it and also forming the space parts between the packed layers and providing the closable dampers on the inlets of the space parts. CONSTITUTION:A fixed type packed layer is divided into plural packed layers 15-17. The space parts 19 for interrupting heat transfer are provided on the boundary parts of the respective packed layers. Furthermore the closable dampers 18 for introducing fluid utilized for cooling or extinguishment are provided on the inlet parts of the space parts 19. The dampers 18 are opened or fluid for cooling or extinguishment is made pass by firing predicting information due to an ash reservoir box 24, etc. Thereby firing burnout of the respectively divided packed layers 15-17 or enlargement of burnout range to the other packed layers can be prevented previously and effectively.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a packed bed type gas-solid contact reactor, and in particular, the present invention relates to a packed bed type gas-solid contact reaction apparatus, and in particular, the present invention relates to a packed bed type gas-solid contact reaction apparatus, and in particular, a catalyst or an adsorbent deposited in a packed bed provided in a reaction vessel The present invention relates to a gas-solid catalytic reaction device suitable for preventing burnout of a packed bed due to ignition of ash containing flammable substances or minimizing the area of burnout, and a method for preventing burnout of the packed bed.

[Conventional technology]

An example of the structure of a conventional packed bed type gas-solid catalytic reaction apparatus (for example, Japanese Patent Publication No. 56-32012).

In Fig. 0 shown in Fig. 6, the reaction gas enters the reaction vessel 1 through the gas port 2, passes through the filling M6, 7, and 8, and then is discharged from the gas outlet 3. In this reaction vessel 1, ash containing flammable substances (referred to as flammable ash) 10.1
1 is attached and deposited inside the filling layers 7 and 8 that cannot be easily removed by the soot blower 5, and
Reaction gas inlet condition 2 For example, when the temperature, 02 (oxygen) concentration, etc. become high, combustible substances in the ash 10.11 are oxidized.

There was a problem in that the filled layers 7 and 8 were burned out due to heat generation. In such a reaction vessel 1, the temperature of the exhaust gas is usually measured using an inlet gas thermometer 12 and an outlet gas thermometer 13 in the reaction vessel 1, but the temperature rise inside the packed bed 9 is not measured. Ta. Therefore, ignition in the packed bed can only be discovered when the outlet gas thermometer 13 has risen markedly and a large-scale ignition has progressed, but even if extinguishing is started at that point, most of the packed bed has already been ignited. 7,
There were many cases where it was too late because 8 had been burnt out, and it was extremely difficult to detect the ignition of the packed bed at an early stage.

Even if 1. ignition is detected early and cooling air or inert extinguishing gas is introduced from the gas population 2.2, for example, if ash is deposited at the entrance of the packed bed 7, such as ash 10, Filling/1i (Unable to introduce fire extinguishing or cooling gas into the interior of 9.

Therefore, there was a problem in that the heat caused by the ignition of the ash 11 was transmitted to the adjacent filling M7 and burned out.

That is, in the gas-solid catalytic reaction apparatus according to the prior art, 1
Not only is it difficult to detect fire early.

Even if a small amount of ash accumulates at the inlet of the packed bed and blocks the flow of reaction gas, the downstream part of the packed bed receives heat from other parts that generate heat and is burned out. was there.

[Problem to be solved by the invention]

As mentioned above, in the conventional technology, not only is it extremely difficult to early detect ignition of a packed bed due to the accumulation of combustible ash, but even if ash is not deposited inside the packed bed, it is difficult to detect ignition at the entrance of the packed bed. The ash was deposited in the igniting part of the adjacent packed bed, and the flow of the reaction gas was obstructed.
There was a problem in that the burnout area of the packed bed was expanded.

It is an object of the present invention to solve the problems of the prior art as described above, to detect and quickly extinguish ignition in a packed bed consisting of catalysts, adsorbents, etc. provided in one reaction vessel, and to An object of the present invention is to provide a gas-solid catalytic reaction device having a packed bed having a structure in which the burnout does not spread to other packed beds even if a situation where one part is burnt out occurs, and a method for preventing burnout of the packed bed. .

[Means to solve the problem]

The object of the present invention is to divide a fixed packed bed provided in a gas flow path in two reaction vessels into a plurality of packed beds, and to provide a predetermined width at the boundary between each divided packed bed. A space is formed for the purpose of heat insulation, and a damper is provided at the entrance of the space so that it can be opened and closed during normal operation of the gas-solid catalytic reaction apparatus.

The above damper is closed so that all the reaction gas passes through the packed bed, and ash containing flammable substances is deposited in an ash box installed upstream or downstream of the packed bed to predict ignition. This can be detected early by detecting the degree of temperature rise of the ash, and the damper installed in the boundary space between the divided packed beds can be opened, or a fire extinguishing or cooling fluid can be circulated to prevent burnout. This is achieved by thermally insulating the packed bed section where the process started and other normal packed bed sections.

The present invention provides a gas-solid contact reaction apparatus having a fixed packed bed formed by filling a gas flow path in a reaction vessel with a catalyst or an adsorbent, wherein the packed bed is divided into a plurality of packed beds. A space is formed between a plurality of adjacent packed layers and has a structure that blocks heat transfer. established.

By means of opening a damper provided between the plurality of packed beds or introducing a cooling or extinguishing fluid based on ignition prediction information of ash containing flammable substances deposited in the packed bed.

In the present invention, the means for predicting the ignition of ash containing combustible materials deposited in the packed bed is provided with a packed bed having a structure that blocks the influence of heat on the plurality of packed beds that are adjacent to each other.
An ash storage box for storing ash containing combustible substances is provided at a predetermined position on the upstream side or downstream side of the packed bed provided in the gas flow path in the reaction vessel, and the ash storage box is provided with: The structure allows for the replacement of accumulated ash on a regular basis.
The ash storage box is equipped with a temperature detection device that measures the temperature of the accumulated ash and monitors the ignition of the ash. As a means for removing and renewing the ash accumulated in the ash storage box, it is preferable to use a means for removing the ash by scattering it by soot blowing, or a means for removing the ash by turning the ash storage box upside down and letting the ash fall. .

The method for preventing burnout of a packed bed in a gas-solid contact reactor of the present invention is based on two methods: one on the upstream side of a packed bed constituted by a plurality of divided packed beds provided in a gas flow path in a reaction vessel; An ash collection box for storing ash containing flammable substances at least one location is provided at a predetermined position on either or both of the downstream sides, and the temperature of the ash deposited in the ash collection box is detected.

Either monitor and predict the ignition temperature of the ash and open the damper installed in the space between the plurality of divided packed beds.
Alternatively, a cooling or fire extinguishing fluid is introduced to prevent fire damage to the packed bed portion or to suppress expansion of the burnout area.

[Effect] Due to changes in the operating conditions of the gas-solid catalytic reactor.

When conditions are met for the accumulated ash to ignite, the temperature of the ash accumulated in the ash storage box for ignition prediction increases. By detecting this temperature rise, ignition of the accumulated ash can be reliably predicted.

In addition, since gases are poor conductors of heat compared to solids, by flowing air or other cooling gas or fire extinguishing gas into the spaces created by dividing the packed bed into several parts, it is possible to Even if a part of the layer burns out, heat transfer to other parts and fire spread can be prevented.

〔Example〕

An embodiment of the present invention will be described below in more detail based on one drawing.

FIG. 1 shows an example of the structure of the gas-solid contact reaction apparatus of the present invention, and FIG. 3 shows the horizontal cross-sectional shape of the packed bed portion. As shown in FIG. 1 and FIG.
It was divided into nine parts.

A damper 18 having an openable and closable structure is installed above the space 19, and a damper 8° 18a having the structure shown in FIG. That is, one damper 18a of the dampers provided at the intersection of the space portions 19 has only the shaft 35 left and the plate portion of the damper has been deleted, and the other damper 18
is attached to the upper part of the space part 19 so as to be openable and closable, with the same shape as it is. and.

As shown in FIG. 1, ash storage boxes 24 were installed at three locations upstream of the soot blower 5. The ash storage box 24 is formed by a stainless steel outer wall plate 27 having the structure shown in FIG. 2, and the inside thereof is divided into three by partition plates 28 made of the same material as the filling layer. The upper part of the ash storage box 24 has an open structure, and the bottom plate 29 is provided with ventilation holes 30 having a diameter of 1 square inch at intervals of 3 mm. Blow air pipe 33. A thermocouple 34 was installed along the blow tube 32 so that the tip of the thermocouple 34 for measuring the temperature of the ash was located in the center. Also.

Blow air pipe 33. The blow tube 32 had an outer diameter of 1011 m so that it could serve as a support member when the ash storage box 24 was installed in the gas flow path inside the reaction vessel 1. By blowing compressed air through the blow pipe 32, the ash accumulated in the ash storage box 24 can be scattered and renewed.

Changes in the operating conditions of the gas-solid catalytic reactor 2, for example, changes in the type of fuel used in the upstream combustion device, may result in combustible substances being entrained in the flue gas stream entering the reaction vessel 1. When the properties of the ash change, the air from the blow tube 32 shown in FIG. 2 removes the previously deposited ash and deposits new ash. And blow air pipe 33
also serves as a support device for the ash storage box 24.

This ash storage box 24 was attached to the inlet of one reaction vessel 1 at three positions, and its temperature behavior was observed. Since the temperature behavior was almost the same at all three locations, the temperature behavior of the ash storage box 24 placed in the center is shown in FIG. 5(a) as a representative example.

When using a fuel that produces highly flammable ash (H), the fuel in the upstream combustion device is throttled and the 02 concentration in the exhaust gas flowing into the second reaction vessel l is determined as shown in Figure 5 (b). ), when the temperature increases from 4 to 5% to 15 to 16%, the temperature of the ash accumulated in the ash storage box 24 starts to rise,
After about 10 minutes, the ash (H) ignited and burned, and the temperature rose rapidly.
Normally, when operating with fuel that produces ash (L) with low flammability, the concentration of 02 in the inflowing exhaust gas is 15.
As shown in FIG. 5(a), even when the temperature was increased to ~16%, the temperature increase of the accumulated ash remained at about 20° C., and no sudden rise in temperature was observed as in the case of ash (H).

Note that when the boiler is started up or in operation, the combustion exhaust gas is flowing inside the reaction vessel, so normally the O1 concentration is low and ignition of ash is unlikely to occur.However, when the boiler is stopped, combustion Since the exhaust gas does not flow, the 02 concentration in the reaction vessel may rise to about 15 to 16%, and ignition of ash may occur.

When the temperature of the ash (H) rises rapidly as shown in FIG. At the same time, the damper 18.18a is opened and cold air is introduced into the space 19 of the packed bed at a flow rate of about 4 to 5 m/s for about 16 hours to cool the temperature of the packed bed to below 100°C. When the packed bed was opened and inspected, it was found that only the packed bed 41 was burnt out, and the remaining 8 packed beds were completely healthy among the 9 filled parts M36 to 44 shown in Fig. 3. like.

In the gas-solid contact reaction apparatus of the present invention provided with a plurality of divided packed beds, burnout of the packed bed could be suppressed to a minimum.

Note that as another means for early detection of ignition of the accumulated ash containing combustible substances, it is also possible to install a plurality of thermometers inside the packed bed to detect a temperature rise. However, there is a limit to the number of monitoring thermometers that can be installed in large packed beds, and ash does not necessarily ignite in the areas where thermometers are installed.

Detection of the ignition site may be delayed due to ash.

〔Effect of the invention〕

As described above in detail, the fixed packed bed constituted by the catalyst or adsorbent of the gas-solid contact reaction apparatus of the present invention is divided into a plurality of packed beds.

In addition, a space is provided at the boundary between each packed bed to block heat transfer, and an openable and closable damper is provided at the entrance of the space to introduce cooling or extinguishing fluid. Should the damper be opened based on ignition prediction information from the ash container, etc.?

Alternatively, by circulating a cooling or extinguishing fluid, it is possible to effectively prevent each of the two divided packed beds from igniting and burning out, or to prevent the spread of the burnt area to other packed beds. Also.

Even if the properties of ash containing flammable substances change due to the type of fuel, etc., it can be easily replaced by blowing the ash accumulated in the ash storage box, making it extremely reliable. This has the effect that ignition prediction information can be obtained and the packed bed can be reliably protected.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing the structure of a reaction vessel of a gas-solid contact reaction apparatus exemplified in an example of the present invention. Fig. 2 is a perspective view showing an example of the structure of the ash collection box shown in Fig. 1, Fig. 3 is a sectional view showing an example of the arrangement of the packed layer part shown in Fig. FIGS. 5(a) and 5(b) are perspective views showing an example of the structure of a damper provided in the cavity of the packed bed shown in FIG. FIG. 6 is a graph showing the change over time in 02WA degrees contained in the exhaust gas when the exhaust gas is throttled, and FIG. 6 is a schematic diagram showing the structure of a reaction vessel of a conventional gas-solid contact reactor. 1...Reaction vessel 3...Gas outlet 5...Soot blower 10, 11...Ash 13...Outlet gas thermometer 15, 16.17...Filled bed 2...Gas inlet 4... ... Ash discharge port 6.7, 8.9 ... Filled bed 12 ... Inlet gas thermometer 14 ... Temperature indicator 18, 18a ... Damper 19 ... Space 20.21 ...・Ash 23
... Ash thermometer of ash collection box 24 ... Ash collection box 25 ... Ash blowing air pipe 26 ... Temperature indicator 27 ... Outer wall board 28
...Partition plate 29...Bottom opening 30...Vent hole 31...Blow nozzle 32...Blow pipe 33...Blow air pipe 34...
Thermocouple (temperature detector) 35...shaft

Claims (1)

[Claims] 1. A gas-solid contact reaction apparatus having a fixed packed bed formed by filling a gas flow path in a reaction vessel with a catalyst or an adsorbent, the packed bed comprising a plurality of Between a plurality of filling layers that are divided into packed layers and adjacent to each other,
forming a space having a structure that blocks heat transfer; and providing a damper having an openable and closable structure on the upstream side that is the entrance of the space;
By means of opening a damper provided between the plurality of packed beds or introducing a cooling or extinguishing fluid based on ignition prediction information of ash containing flammable substances deposited in the packed bed, A gas-solid catalytic reaction apparatus characterized by having a packed bed structured to block thermal influence on the plurality of mutually adjacent packed beds. 2. In the gas-solid contact reaction apparatus according to claim 1, at a predetermined position on either or both of the upstream side and downstream side of the packed bed provided in the gas flow path in the reaction vessel, An ash collection box for storing ash containing combustible substances in at least one location is provided, the ash collection box has a structure that allows the accumulated ash to be periodically replaced, and the temperature of the ash deposited in the ash collection box is 1. A gas-solid catalytic reaction device characterized by being provided with a temperature detection device for detecting ignition of ash and monitoring ignition of ash. 3. In the gas-solid contact reaction apparatus according to claim 2, the means for removing and renewing the ash accumulated in the ash box is a means for removing the ash by scattering it by soot blowing, or a means for removing the ash by scattering it by soot blowing, or a means for removing the ash by scattering it by soot blowing, or A gas-solid contact reaction device characterized by being a means for removing ash by rotating it in reverse. 4. A method for preventing burnout of a packed bed in a gas-solid contact reaction apparatus according to claim 1, which comprises a plurality of divided packed beds provided in a gas flow path in a reaction vessel. An ash box is provided at a predetermined position on either or both of the upstream side and downstream side of the configured packed bed to collect ash containing at least one combustible substance, and the ash containing flammable substances is deposited in the ash box. The temperature of the ash is detected, the ignition temperature of the ash is monitored, and this is used as ignition prediction information for the ash deposited in the packed bed, and is placed in the space between the plurality of divided packed beds constituting the packed bed. Filling of a gas-solid catalytic reaction device characterized by opening a provided damper or introducing a fluid consisting of a coolant or a fire extinguisher to prevent or suppress ignition damage to the packed bed portion. How to prevent layer burnout.