JPH05212228A - High temperature and high pressure dust removal equipment - Google Patents

Abstract

PURPOSE:To contrive to prevent cracks generated at the lower end or a tubular ceramic filter by collecting dust contg. unburnt content in combustion gas in the lower stage of the tubular ceramic filter. CONSTITUTION:A dust collecting means 16 is installed in the inner surface of a part located in the 3rd filter chamber 7c in the lower stage of a tubular ceramic filter 11. In the dust collecting means 16, plural, oblong heat resistant metal plates are vertically installed in the form of a fin in the inner surface of the lower stage of the tubular ceramic filter 4 from the inner surface of the tubular ceramic filter 4 toward its center. And, instead of the dust collecting means 16, a dust separation sleeve body 19 may be installed in the inner surface of the lower stage of the tubular ceramic filter 4. Thereby cracks generated in the lower end of the tubular ceramic filter is prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-temperature and high-pressure dedusting device attached to a coal-fired pressurized fluidized bed boiler combined power generation system, and more particularly to a high-temperature and high-pressure combustion gas generated in a coal-fired pressurized fluidized bed boiler. The present invention relates to a high temperature and high pressure dedusting device for removing minute ash dust.

[0002]

2. Description of the Related Art Conventionally, a coal-fired pressurized fluidized bed boiler combined cycle power generation system includes a high-temperature and high-pressure dedusting device together with a cyclone for removing ash dust in high-temperature and high-pressure combustion gas generated in the coal-fired pressurized fluidized bed boiler. It is attached. This high-temperature and high-pressure dedusting device performs precision dedusting for further removing fine dust in the combustion gas that has not been removed by a cyclone, and generally has a heat-resistant multi-tubular multi-chamber structure.

As shown in FIG. 7, this multi-tubular multi-chamber high-temperature high-pressure dedusting device has a plurality of tubular ceramic filters between upper and lower tube plates b and c provided in a vertical hollow body a. g
Is provided, a combustion gas inlet d is formed at the upper end of the vertical body a, and a dust discharge port e is formed at the lower end.
A plurality of clean gas outlet pipes f are connected to the vertical body a located between the upper and lower tube plates b and c, and gas is exhausted at the tip portions of these clean gas outlet pipes f so as to connect them. A pipe h is provided upright, and a backwash gas pipe i for injecting a high-speed gas for backwash into the clean gas outlet pipe f is provided at each connection port of the gas discharge pipe f so as to face it. It has the configuration provided.

Then, as shown by the arrow in the figure, the high-temperature and high-pressure combustion gas G containing dust D introduced from the combustion gas inlet d into the vertical body a flows to the tubular ceramic filter g side, and the lower tube sheet. While reaching the c side, the dust D is filtered through the tubular ceramic filter g to become the clean gas S, which passes through the respective clean gas outlet pipes f, and is joined and exhausted by the gas discharge pipe h. Will be. Then, when such a filtration state continues for a predetermined time and dust D accumulates on the inner wall surface of the tubular ceramic filter g and the filtration efficiency decreases, the backwashing high-speed gas K is fed from the above-mentioned backwashing gas pipe i. Are injected into the respective clean gas outlet pipes f to generate high-pressure pressure waves utilizing the ejector effect, and the high-pressure pressure waves force the dust layer adhered and deposited on the inner wall surface of the tubular ceramic filter g. It will be peeled off and removed.

Thereafter, the dust removed from the inner wall surface of the tubular high-temperature and high-pressure filter g by the backwashing high-speed gas K from the backwash gas pipe i in this way is moved by its own weight into the vertical body a.
It falls inside and is appropriately discharged from the vertical body a through the lock hopper h provided at the dust discharge port e.

[0006]

By the way, in the conventional high temperature and high pressure dedusting device of the multi-tube multi-chamber structure described above, when the high temperature and high pressure combustion gas G is introduced into the vertical body a, the vertical body is removed. Since the lower space K of the lower tube sheet c in a has a high pressure, a drift of the combustion gas G occurs in the vertical body a, and the high temperature and high pressure introduced into the tubular ceramic filter g from the upper tube sheet b side. The combustion gas G had accumulated in the vicinity of the lower tube sheet c. Therefore, a large amount of floating fly ash containing unburned carbon in the combustion gas G is present in the lower portion inside the tubular ceramic filter g, and is easily accumulated on the surface thereof. When the high-speed gas K for backwashing is injected, the floating fly ash containing unburned carbon re-combusts on its surface and the temperature of its inner surface rises abnormally. A large temperature difference occurs between them, which may cause a large thermal stress on the lower end portion of the tubular ceramic filter g to cause a crack.

Therefore, the present invention has been devised in order to effectively solve these problems, and its purpose is to prevent damage due to cracks generated at the lower end of the tubular ceramic filter at a high temperature. A high pressure dedusting device is provided.

[0008]

To achieve the above object, the first invention is to provide a plurality of tubular ceramic filters between upper and lower tube plates in a vertical body and to divide the upper and lower tube plates into upper and lower multi-stages. To form a plurality of filtration chambers, on the other hand, a combustion gas inlet for introducing high temperature and high pressure combustion gas is formed at the upper end of the vertical body, and a dust discharge port is formed at the lower end, and the vertical body of each of the filtration chambers is formed. In a high-temperature high-pressure dedusting device each having a clean gas outlet formed in, in the lower stage of the tubular ceramic filter, a dust collecting means for collecting dust containing unburned components in the combustion gas is provided. The second aspect of the present invention is the inner wall surface of the lower stage of the tubular ceramic filter,
The tubular ceramic filter is provided with a dust separating sleeve body for guiding the dust layer falling from the inner wall surface of the upper stage and dropping the dust layer from the lower end portion of the tubular ceramic filter.

[0009]

As described above, according to the first aspect of the invention, the dust collecting means is provided inside the lower stage of the tubular ceramic filter to collect the dust containing the unburned matter, and the surface of the dust collects the unburned dust. By actively re-burning the components, the unburned components that were previously generated directly on the inner surface of the tubular ceramic filter are re-combusted at a position away from the inner surface of the tubular ceramic filter. This makes it possible to reduce the temperature difference between the inner surface and the outer surface of the tubular ceramic filter due to an abnormal temperature rise on the inner surface, and prevent damage to the tubular ceramic filter due to thermal stress. Further, in the second invention, by providing the dust separating sleeve body inside the lower stage of the tubular ceramic filter, downflow occurs in the dust separating sleeve body and the lower stage inner surface of the tubular ceramic filter, and the floating of fine dust can be prevented. As a result, the dust load on the lower inner surface of the tubular ceramic filter is reduced and the accumulation of unburned components is reduced, and like the first invention, it is possible to prevent the tubular ceramic filters from being damaged due to reburning of unburned components. ..

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 shows an embodiment of a high temperature and high pressure dedusting device having a multi-tube multi-chamber structure of the present invention. As shown in the figure, in this multi-tube multi-chamber high-temperature high-pressure dedusting device, upper and lower tube plates 2 and 3 are provided in an internal hollow vertical body 1 formed of a heat-resistant material such as a steel plate. Between the upper and lower tube plates 2 and 3, there are provided two tube type ceramic filters 4 connected so as to penetrate them. In addition, between these upper and lower tube plates 2 and 3, two intermediate tube plates 5a and 5b are formed in the middle portion of the tube type ceramic filter 4 to support the tube type ceramic filter 4 more stably. In addition, the upper and lower tube sheets 2 and 3 are divided into three sections. That is, the inside of the vertical body 1 is defined by the space between the upper and lower tube sheets 2 and 3.
First, the upper chamber 6, the filtration chamber 7, and the lower chamber 8 are partitioned from the top, and the filtration chamber 7 is further divided by the two intermediate tube plates 5a and 5b from the top to the first filtration chamber 7a, the second filtration chamber 7b, and the second filtration chamber 7b. It is divided into three filtration chambers 7c.

The tubular ceramic filter 4 is, for example, S
It is formed by sintering fine ceramic powder such as io ₂ into a tubular shape with upper and lower openings, and has a large number of holes of about several μm, and when a high-temperature and high-pressure combustion gas G is passed through, a high temperature is obtained. The combustion gas G is cleaned by collecting minute dust D of several μm to several tens μm in the high pressure combustion gas G.

At the upper end of the vertical body 1, a cyclone (not shown) is used to roughly remove dust from 600 to 800 ° C.
A combustion gas inlet 9 for introducing a certain amount of combustion gas G is formed, and a dust discharge port 10 having a lock hopper 15 for discharging dust D in the combustion gas G is formed at the lower end thereof. Has been done. Furthermore, this vertical body 1
Of the first filtration chamber 7a, the second filtration chamber 7b, and the third filtration chamber 7c of the filtration chamber 7 are three clean gases for discharging the clean gas S from which the dust D has been removed. Outlet pipe 1
1a, 11b, 11c are formed horizontally in parallel.

Further, each of these clean gas outlet pipes 11a, 1
A gas discharge pipe 12 is erected at the tips of the 1b and 11c so as to connect them, and the clean gas S flowing from each of the clean gas outlet pipes 11a, 11b and 11c is joined and exhausted. ing. Further, backwash gas pipes 14a, 14b, 14c are provided at the connection ports 13a, 13b, 13c of the gas discharge pipe 12 and the clean gas outlet pipes 11a, 11b, 11c, respectively, in opposition thereto. Cage,
The high-speed gas K for backwashing is injected into each clean gas outlet pipe 11a, 11b, 11c.

A dust collecting means 16 is provided on the inner surface of the lower portion of the tubular ceramic filter 4 located in the third filtration chamber 7c. The dust collecting means 16 is, as shown in FIG.
A plurality of heat-resistant metal plates 17 formed vertically long are erected in a fin shape from the inner wall surface of the tubular ceramic filter 4 toward the center thereof on the inner surface of the lower portion of the tubular ceramic. The floating dust D containing a large amount of unburned components floating on the inner surface of the lower stage of the filter 4 is attached to the surface thereof and collected.

Next, the operation of this embodiment will be described.

As shown in FIG. 1, first, the combustion gas G roughly dedusted by a cyclone (not shown) is introduced into the upper space 6 from the combustion gas inlet 9 at the upper end of the vertical body 1, and the pipe From the upper end of the mold filter 4 flows to the filtration space 7 side. Then, as shown in FIG. 3, first, a part of the combustion gas G passes through the upper wall surface of the tubular ceramic filter 4 to remove the dust D contained therein when flowing to the first filtration chamber 7a side, whereby the clean gas is obtained. After being converted to S, it passes through the clean gas outlet pipe 11a and flows into the gas discharge pipe 12. Next, a part of the combustion gas G flowing further downward in the tubular ceramic filter 4 is removed of the dust D contained therein when flowing from the middle stage of the tubular ceramic filter 4 to the second filtration chamber 7b in the same manner as above. After being converted into the clean gas S, it passes through the clean gas outlet pipe 11b and flows into the gas discharge pipe 12. Then, the remaining combustion gas G that finally flowed to the lower part of the tubular ceramic filter 4
Here, the flow velocity is rapidly reduced, and when it is in a state of substantially staying in the lower inner surface of the tubular ceramic filter 4 and slowly flows toward the third filtration chamber 7c, the dust D contained therein is removed and the clean gas S is removed. After being converted, it passes through the clean gas outlet pipe 11c and flows into the gas discharge pipe 12. At this time, the floating dust D containing unburned matter, which is almost in a state of staying on the lower inner surface of the tubular ceramic filter 4, adheres to and accumulates on the metal plate 17 of the dust collecting means 16.

Next, the combustion gas G is continuously filtered for a predetermined time, and the dust D in the combustion gas G adheres to and deposits on the inner wall surface of the tubular ceramic filter 4 to form a dust layer D.
_{When 1} is formed, the filtration efficiency decreases, so that each backwash gas pipe 14a, 14b, 14c is connected to each clean gas outlet pipe 1
The dust layer D ₁ is removed by injecting a high-speed backwashing high-speed gas onto 1a, 11b, and 11c. That is, when the high-speed gas for backwashing is injected, the high-speed gas for backwashing entrains the air in the gas discharge pipe 12 by the ejector effect, and the first filtration chamber 7a, the second filtration chamber 7b, and the third filtration chamber of the filtration chamber 7 are ejected. 7
A high pressure wave is generated in c. Then, the dust layer D ₁ adhered and deposited on the inner wall surface of the tubular ceramic filter 4 is peeled off and blown off by the high-pressure pressure wave, and then falls in the tubular ceramic filter 4 by its own weight, and a part thereof is dust. The remaining dust layer D ₁ collected by the collecting means 16 is discharged to the outside of the vertical body 1 from the dust discharge port 10 provided with the lock hopper 15.

At this time, on the lower inner surface of the tubular ceramic filter 4 equipped with the dust collecting means 16, the floating dust D floating in or near the dust layer D ₁ collected by the dust collecting means 16. The unburned components therein may reburn, but the burning will be performed on the surface of the metal plate 17. That is, in the present invention, the dust collecting means 16 is provided inside the lower stage of the tubular ceramic filter 4 to collect the dust D in the combustion gas G, and the unburned components in the dust D are positively recovered on the surface thereof. By causing the combustion, re-combustion of the unburned component that has been directly generated on the inner surface of the tubular ceramic filter 4 in the past can be performed at a position away from the inner surface of the tubular ceramic filter 4. It was done. Therefore, the temperature difference between the inner surface and the outer surface of the tubular ceramic filter 4 due to an abnormal temperature rise on the inner surface is reduced, and the tubular ceramic filter 4 can be prevented from being damaged by thermal stress.

As a second embodiment of the dust collecting means 16, as shown in FIG. 4, instead of the above-mentioned metal plate 17, a heat-resistant wire mesh 18 is provided on the lower inner surface of the tubular ceramic filter 4. Even if it is formed so as to stretch around the periphery while being slightly separated from the inner surface, the above-mentioned action,
You can expect an effect.

Next, according to the present invention, which will be described as the second invention, as shown in FIG. 5, on the lower inner surface of the tubular ceramic filter 4 provided with the above-mentioned dust collecting means 16,
A dust separating sleeve body 19 is provided instead of the dust collecting means 16. That is, as shown in FIG. 6, the dust separating sleeve body 19 is located on the inner surface of the lower stage of the tubular ceramic filter 4 and has a tubular sleeve body 22 at the lower end of the funnel-shaped dust collecting portion 20 which is opened upward. A plurality of slits 21 are formed on the side surface of the dust collecting portion 20 for allowing the combustion gas G to pass therethrough, and as shown in FIG. The dust D containing unburned matter is prevented from adhering and the separated dust layer D ₁ falling from the inner surfaces of the upper and middle stages of the tubular ceramic filter 4 is separated and passed through the lower chamber 8 to discharge the dust. It is configured to lead to the exit 10.

Therefore, according to the present invention, by providing the dust separating sleeve body 19 inside the lower stage of the tubular ceramic filter 4, downflow occurs in the sleeve body 22 of the dust separating sleeve body 19 and the inner surface of the lower stage of the tubular ceramic filter 4. Since the floating of the fine dust D can be prevented, the load of the dust D on the lower inner surface of the tubular ceramic filter 4 is reduced, and the unburned components in the collected dust layer D ₁ are less accumulated. It is possible to prevent re-combustion of unburned components during backwashing of the intervals and prevent damage to the tubular ceramic filter 4.

[0023]

In summary, according to the present invention, it is possible to prevent cracks that have conventionally occurred at the lower end of a tubular high temperature and high pressure filter, and the durability and reliability of the device are greatly improved. It has an excellent effect of

[Brief description of drawings]

FIG. 1 is an overall schematic view showing an embodiment of a high temperature and high pressure dust remover of the present invention.

FIG. 2 is a partially cutaway perspective view showing an embodiment of dust collecting means.

FIG. 3 is a partially enlarged view showing the operation of the first invention.

FIG. 4 is a partially cutaway perspective view showing a second embodiment of the dust collecting means.

FIG. 5 is a partially enlarged view showing the operation of the second invention.

FIG. 6 is a partially cutaway perspective view showing an embodiment of a dust separation sleeve body.

FIG. 7 is an overall schematic view showing an embodiment of a conventional high temperature and high pressure dust remover.

[Explanation of symbols]

1 Vertical Body 2 Upper Tube Plate 3 Lower Tube Plate 4 Tube Ceramic Filter 7 Filtration Chamber 9 Combustion Gas Inlet 10 Dust Outlet 11 Clean Gas Outlet 16 Dust Collecting Means 19 Dust Separation Sleeve Body D Dust D ₁ Dust Layer G Combustion Gas S Clean gas

Claims (2)

[Claims] 1. A plurality of tubular ceramic filters are provided between upper and lower tube plates in a vertical body, and the upper and lower tube plates are divided into a plurality of upper and lower stages to form a plurality of filtration chambers. On the other hand, the vertical body is provided. Combustion gas inlet for introducing high-temperature high-pressure combustion gas at the upper end of the, forming a dust discharge port at the lower end, further, in the high-temperature high-pressure dedusting device connected to the vertical body of each filtration chamber clean gas outlet pipe, respectively, A high-temperature high-pressure dedusting device, characterized in that a dust collecting means for collecting dust containing unburned components floating in the combustion gas is provided inside a lower stage of the tubular ceramic filter. 2. A dust separation sleeve body for guiding a dust layer falling from the upper inner wall surface of the tubular ceramic filter to the lower inner wall surface of the tubular ceramic filter and dropping it from the lower end portion of the tubular ceramic filter. The high temperature and high pressure dedusting device according to claim 1.