JPH0952011A - Dust collector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a dust collector using a filter member group composed of an air permeable porous solid, preventing the mixing of dust with purified gas even when a partial crack or damage is generated in filter members and capable of detecting the leak generating place or degree of dust. SOLUTION: A filter members 22 each composed of a porous solid are housed in a container 21 having a dust-containing gas inlet 24 and a purified gas outlet duct 26 so that dust-containing gas is supplied into the filter members 22 from the dust-containing gas inlet 24 and purified gas is taken out of the filter members 22 to be guided to the outlet duct 26. Filter members 11b, the pressure detector 13 detecting the pressure difference between them and a flow velocity detector 14 are arranged to the gathering discharge duct 27 of a purified gas outlet and a part of the group of the filter members 22 is set to a filter member 15 having air permeability and reduced in pressure loss and both ends of the opening of the filter member 15 are closed by porous solids 15a, 15b and a level detector 16 is further provided therein.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dust collecting apparatus used for high temperature and high pressure gas generated in a pressurized fluidized bed boiler, a gasification furnace or the like.

[0002]

2. Description of the Related Art A combined cycle power plant that drives a gas turbine by supplying high temperature and high pressure combustion exhaust gas generated in a pressurized fluidized bed boiler to a gas turbine can obtain high efficiency power generation.
In order to prevent wear of the gas turbine, it is essential to send clean exhaust gas from which dusts have been removed to the gas turbine.
Therefore, usually, a dust collector is installed to remove dust (combustion ash, dust) and the like of combustion exhaust gas in advance.

In this type of combined cycle power plant, as shown in FIG. 3, combustion exhaust gas 32 generated in a pressurized fluidized bed boiler 31 is guided through a duct 33 to a cyclone dust collector 34 utilizing centrifugal force. In the dust collector 34, most dust in the combustion exhaust gas is collected and removed.

However, the gas turbine 36 side is required to be a clean gas, and is made to pass through a high-temperature and pressure-resistant precision dust collector 35 called a ceramic filter, which is made of a porous solid having air permeability. After being made into clean gas, it is sent to the gas turbine 36.

The dust collected by the cyclone dust collector 34 and the precision dust collector 35 is collected by the dust collector 34a.
And 35a, and then discharged outside the system.
Further, after driving the gas turbine 36, the combustion exhaust gas 37
Is recovered by various heat exchangers (not shown) and released to the atmosphere.

FIG. 2 shows an example of a conventional precision dust collecting apparatus, which will be described below. A group of filter bodies 22 made of a gas permeable porous solid is housed in a container 21 having a fireproof and heat insulating material on its inner surface, and is fixed in the container 21 by a sealing tube sheet 23a and a reinforcing tube sheet 23b. .

The dust-containing combustion gas 32 enters the filter body 22 through the gas inlet hole 24, and when passing through the filter body 22 from its inner surface to its outer surface, dust 25 in the gas adheres to and drops off on the inner surface of the filter body 22. Then, the dust 25 is collected in the lower part of the container 21 and then discharged to the outside of the system. On the other hand, the exhaust gas that has passed through the filter body 22 from the inner surface to the outer surface and is cleaned is sent to the gas turbine through a plurality of outlet ducts 26 that open to the side wall of the container 21 and a collective discharge duct 27 that serves as a gas outlet. .

A backwash nozzle 11 for introducing a backwash airflow is installed in the outlet duct 26, and the backwash airflow sent from the compressor 12 is passed from the backwash nozzle 11 to the container 21 through the common pipe 12a and the valve 12b. After a certain amount of airflow is blown into the inside of the filter body 22 at a constant time (backwash cycle time) to remove the dust adhering to the inner surface of the filter body 22 into the filter body 22, the dust collecting action described above is performed. Repeat.

[0009]

The container 21 of the dust collecting apparatus.
In the group of the filter bodies 22 housed inside, the exhaust gas containing dust and the clean gas are separated and separated at the sealing tube sheet 23a and the inner and outer wall portions of the filter body 22. It is predicted that deterioration of the sealing portion due to deterioration over time or unexpected trouble, or partial cracking or damage of the filter body 22, that is, the ceramic filter body, will deteriorate the dust collection performance. When this occurs, the exhaust gas containing dust is mixed in the clean gas, in other words, the clean gas containing dust is directly sent to the gas turbine, causing wear of the gas turbine, and shutting down the entire plant.

The present invention solves such a problem found in the conventional dust collecting apparatus using a filter body made of an air-permeable porous solid, and the filter body is partially cracked or damaged. Even if the dust is prevented from being mixed into the clean gas, it is an object to provide a dust collecting apparatus capable of detecting the location and degree of dust leakage.

[0011]

According to the present invention, a filter body made of a gas permeable porous solid is contained in a container having a dust-containing gas inlet and a clean gas outlet, and the dust-containing gas is filtered from the dust-containing gas inlet. In order to solve the above problems, the following means are taken in the dust collecting apparatus in which the clean gas is supplied to the inside of the filter body, the clean gas is taken out from the outside of the filter body, and is guided to the clean gas outlet.

(1) Clean gas outlet at the dust collector outlet,
For example, a filter made of a porous solid is installed in each clean gas outlet duct at each outlet or at a collecting portion, and a pressure detecting device and a flow velocity detecting device for detecting a pressure difference before and after the filter are provided.

(2) A part of the filter body made of a porous solid contained in the container is used as a filter body which is more permeable to dust and has a smaller pressure loss, and the opening of the filter body. Both ends should be covered with, for example, a conventional porous solid that does not allow dust to pass therethrough, and a level detection device such as an electrostatic capacitance method should be provided inside thereof.

It should be noted that a part of the above-mentioned porous filter body may be a single substance or a plurality thereof, and its position in the container is not limited, but it is usually made of the porous substance. It is assumed that a plurality of conventional filter body groups are divided into groups around a part of the filter body group and a required number of them are arranged.
Further, the filter body may be separately arranged in the space portion of the conventional filter body portion.

(1) In the dust collecting apparatus according to the present invention, as described in (1) above, since the filter body made of porous solid is arranged at the clean gas outlet or the like, clean gas to be fed to the gas turbine. When dust is contained due to the occurrence of the above-mentioned unexpected phenomenon, dust adheres to the inlet surface of the filter body made of this porous solid, and clean gas is sent to the gas turbine as in the conventional case. It

On the other hand, the pressure loss before and after the filter made of the porous solid increases in proportion to the amount of dust adhering to the inlet surface of the filter made of the porous solid. The following equation holds for the pressure loss.

[0017]

[Equation 1]

Therefore, since the dust collector according to the present invention is equipped with the pressure loss and flow velocity detectors before and after the filter made of the porous solid, the increase in the amount of dust-containing dust in the clean gas due to the change with time can be considered. It can be estimated, and it is possible to predict an emergency stop or an operation stop of the entire plant from the deterioration status of the dust collecting performance of the dust collecting apparatus.

(2) Further, as described in the above item (2), a filter body having a level detecting device therein is arranged in a part of the filter body group, and the unexpected phenomenon occurs in the dust collecting device. When the gas is generated, the gas containing dust flows into a part of the filter body group at the time of the internal pressure of the container at the time of backwashing, and the dust is accumulated inside. By detecting the amount of dust accumulated by the level detection device, the situation of deterioration of the dust collection performance and the location of the unexpected phenomenon can be specified.

(3) Therefore, since it is possible to obtain information on the degree of deterioration of the dust removal performance of the dust collector and the situation obtained from the above items (1) and (2), it is easy to determine whether the subsequent operation is possible. Alternatively, since the location of the unexpected phenomenon is specified, the dust collecting apparatus can be easily repaired and maintained.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION A dust collecting apparatus according to the present invention will be specifically described below based on the embodiment shown in FIG.
In FIG. 1, the same parts as those of the conventional device shown in FIGS. 2 and 3 are denoted by the same reference numerals for simplification of description.

The dust collecting apparatus according to this embodiment has the structure shown in FIG. That is, the outlet duct 26 shown in FIG.
Filter bodies 11a and 11b made of a porous solid are attached to the rear part and the collecting and discharging duct 27, for example, the filter body 11b.
A differential pressure detection device 13 for measuring the pressure difference between the front and rear and a flow velocity detection device 14 for measuring the flow velocity are provided.

Further, instead of a part of the filter body group 22 made of a porous solid housed in the container 21, a filter body 15 which is more breathable and has a small pressure loss is arranged, and the openings at both ends thereof are the same as those in the conventional case. Breathable porous solids 15a, 15b
Closed with a level detector 1 such as a capacitance type
6 are provided. The porous solids 15a, 15b
Is desired to be removable, but a fixed type is also acceptable.

In the dust collecting apparatus according to the present embodiment, since the filter body 11b made of porous solid is arranged in the collecting and discharging duct 27 at the clean gas outlet, as described above, the clean gas to be fed to the gas turbine is Even if dust is included due to the occurrence of an unexpected phenomenon, dust adheres to the inlet surface of the filter 11b made of this porous solid, and clean gas is sent to the gas turbine as in the conventional case.

Further, since the dust collecting apparatus according to the present embodiment is provided with the differential pressure detecting device 13 and the flow velocity detecting device 14 for detecting the pressure loss before and after the filter body 11b made of the porous solid, the dust collecting device cleans with time. The increase in the amount of dust-containing dust in the gas can be estimated, and it is possible to predict an emergency stop or operation stop of the entire plant from the deterioration status of the dust collecting performance of the dust collector.

Further, in the present dust collecting apparatus, the filter body 15 having the level detecting device 16 inside is disposed in a part of the filter body 22 group, and when a situation such as damage of the filter body 22 occurs, it is reversed. The gas containing dust flows into the part 15 of the filter body group at the time of the pressure inside the container during washing, and the dust accumulates inside. By detecting the accumulated amount of dust with the level detection device 16, the deterioration state of the dust collection performance and the place where an unexpected phenomenon occurs can be known.

As described above, according to the dust collecting apparatus of the present embodiment, it is possible to know the degree of deterioration of the dust removal performance and the situation thereof. Therefore, it is easy to determine whether or not the driving operation is possible thereafter, and the dust collecting apparatus is repaired. The maintenance can be facilitated.

[0028]

As described above, in the dust collecting apparatus according to the present invention, the dust collecting performance of the dust collecting apparatus is obtained by disposing the filter at the clean gas outlet and detecting the pressure differential pressure and the flow velocity before and after the filter. It is possible to detect the occurrence of an unexpected phenomenon that deteriorates. In addition, even if such a phenomenon occurs, clean gas can be sent to the gas turbine by installing the filter body as in the past, so information on the increase in dust content over time without stopping the gas turbine can be obtained. It is possible to make a judgment as to whether or not the vehicle can be operated.

Further, in the dust collecting apparatus according to the present invention, a filter body which is more permeable and has a smaller pressure loss is arranged in a part of the filter body made of a porous solid, and both ends of the opening of the filter body are made porous. Since it is blocked with a solid and further has a level detecting device inside thereof, when the above-mentioned unexpected phenomenon occurs, dust-containing dust is accumulated in this filter body due to a pressure increase in the container during backwashing.

Since the amount of the dust accumulated in the filter body can be detected by the level detecting device, information can be obtained to identify the location of the unexpected phenomenon and to determine the magnitude of the trouble, and determine whether the operation can be stopped or not. This has the effect of facilitating the repair and maintenance of the dust collector.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a dust collector according to an embodiment of the present invention, (a) is a vertical cross-sectional view, and (b) is a horizontal cross-sectional view.

FIG. 2 is a sectional view of a dust collecting apparatus according to a conventional example.

FIG. 3 is a system diagram of a combined power generation system including a conventional dust collector.

[Explanation of symbols]

 11 Backwash Nozzle 11a Filter 11b Filter 12 Compressor 12a Common Pipe 12b Valve 13 Differential Pressure Detector 14 Flow Rate Detector 15 Filter 15a Porous Solid 15b Porous Solid 16 Level Detector 21 Container 22 Filter 23a For Sealing Tube sheet 23b Reinforcing tube sheet 24 Gas inlet hole 26 Outlet duct 27 Collective discharge duct

Claims (1)

[Claims] 1. A group of filter bodies made of an air-permeable porous solid is housed in a container having a dust-containing gas inlet and a clean gas outlet, and the dust-containing gas is supplied from the dust-containing gas inlet to the inside of the filter body. Then, in the dust collector configured to take out the clean gas from the outside of the filter body and guide it to the clean gas outlet, the filter body at the clean gas outlet portion, and a pressure detection device for detecting a pressure difference therebetween. A flow velocity detecting device is arranged, and a part of the group of the filter bodies is made a filter body having a higher air permeability and a smaller pressure loss, and both ends of the openings of the filter body are closed with a porous solid, and a level is further provided inside the filter body. A dust collecting apparatus comprising a detection device.