JPH07332647A - Multiple-tube and-chamber dedusting device - Google Patents

Abstract

PURPOSE:To reduce cost and enhance maintenance by integrating a cyclone for the removal of coarse dust with an ash treatment device of a ceramic tube filter for fine dedusting. CONSTITUTION:The inside of a vertical type hollow vessel 1 is vertically segmented, thereby forming filter chambers 16a, 16b and 16c and a lower part chamber 18 where a plurality of ceramic tube filters 2 are installed, which penetrate the filter chambers and whose both ends are opened to the upper chamber and the lower chamber 18. A dirty gas flow inlet 10 is installed to the upper chamber of the hollow vessel 1 while a dust outlet 19 is installed to the bottom of the lower chamber 18 and a clean gas outlet 12 is installed for every filter chamber, thereby forming a multiple-tube and-chamber dedusting device. In this dedusting device, a cyclone 8 is installed in the hollow vessel 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dust removing device for removing dust such as fly ash contained in high-temperature and high-pressure combustion gas, and in particular, simplifies a device for treating ash removed from the gas, and The present invention relates to a filter that prevents damage to a filter due to reburning of unburned components.

[0002]

2. Description of the Related Art In a coal-fired pressurized fluidized bed boiler combined cycle power generation system, a large amount of dust is contained in the combustion gas,
From the viewpoint of gas turbine protection and environmental protection, it is necessary to remove these dusts. A multi-tube multi-chamber dust removing device as shown in FIG. 2 is often used for removing dust.
The multi-tube multi-chamber dust remover has a structure in which a plurality of ceramic tube filters 2 are arranged in a vertical hollow container 1.
The inside of the hollow container 1 is divided into a plurality of filtration chambers 16 by the partition plate 3.
a, 16b, 16c, an upper chamber 17 and a lower chamber 18, and a clean gas outlet 12 is provided in each chamber. The clean gas outlet 12 is connected to the ejector 4, and is integrated by a gas discharge pipe 13. A backwash gas pipe 14 is connected to the base of the ejector 4.

The dust-containing gas G discharged from the boiler (not shown) is a gas inlet 15 provided in the upper part of the hollow container 1.
Since the ceramic tube filter 2 flowing from the inside into the ceramic tube filter 2 and descending inside the tube has a porous structure, gas exudes to the surface of the tube, and dust is filtered during this period. Clean gas is clean gas outlet 1
It is taken out of the vertical hollow container from 2, is merged by the gas discharge pipe 13 through the ejector 4, and is sent to a gas turbine (not shown). In addition, the backwash gas is sent to the ejector 4 through the backwash gas pipe 14 at regular intervals, and the high-pressure pressure wave obtained by the ejector effect is sent into the hollow container 1 and the inner surface of the ceramic tube filter 2 is It is designed to peel off and remove the dust attached to. The separated dust falls inside the ceramic tube filter 2 and is sent from the bottom surface of the lower chamber 18 to an ash processing device (not shown).

In order to reduce the frequency of the above-mentioned backwash,
It is general that the cyclone 6 is provided outside the multi-tube multi-chamber dust remover, and the gas roughly dedusted in advance by the cyclone 6 is fed into the multi-tube multi-chamber dust remover.

[0005]

By the way, the above dust removing apparatus has two problems.

First, the first problem will be described. When the cyclone is installed outside the multi-tube multi-chamber dust remover as described above, the dust collected by the cyclone and the dust collected by the multi-tube multi-chamber dust remover are treated separately. There is a need to. Therefore, a plurality of ash treatment devices are required, which causes problems such as increased cost and deteriorated maintainability.

Next, the second problem will be described. When low oxygen operation is performed due to an increase in the load of the boiler, dust containing a large amount of unburned matter adheres to the inner wall of the ceramic tube filter. In such a state, when the load of the boiler is lowered and the oxygen concentration is increased, the dust adhering to the tube is recombusted, and a large temperature difference occurs between the inner surface and the outer surface of the ceramic tube filter. As a result, the thermal stress may damage the ceramic tube filter. Such damage often occurs in the lower part of the ceramic tube filter where the gas descending speed is extremely low and dust is likely to stay or adhere.

An object of the present invention is to solve the above two problems.

[0009]

In order to solve the above-mentioned first problem, in the present invention, a multi-tube multi-chamber dust removing device is provided with
Install a cyclone. The dust outlet of this cyclone is positioned vertically above the dust outlet of the multi-tube multi-chamber dust remover. Further, the gas roughly dedusted by the cyclone is allowed to flow into the ceramic tube filter in the vertical container.

In order to solve the second problem, a gas for connecting the center of rotation of the cyclone provided in the multi-tube multi-chamber dust remover and the lower chamber of the multi-tube multi-chamber dust remover Provide a flow path.

[0011]

The dust-containing gas first flows into the cyclone provided inside the multi-tube multi-chamber dust removing device, and the dust is roughly removed there. The dust outlet of the cyclone is located vertically above the dust outlet of the multi-tube multi-chamber dust remover.
The dust collected by the cyclone falls from the dust discharge port of the cyclone to the dust discharge port of the multi-tube multi-chamber dust remover, and is treated together with the dust collected by the multi-tube multi-chamber dust remover. As a result, the cyclone and the multi-tube multi-chamber dust removing apparatus can be integrated into a single dust processing system, and the first problem can be solved.

Further, when the swirl center of the cyclone in the multi-tube multi-chamber dust remover and the lower part of the multi-tube multi-chamber dust remover are connected by a gas flow path, gas is generated in the swirl center of the cyclone by the action of centrifugal force. Due to the low pressure, a gas flow from the lower part of the multi-tube multi-chamber dust remover toward the center of the cyclone occurs. As a result, a downward flow is generated in the lower portion of the ceramic tube filter, and this downward flow can forcibly guide the dust attached to the surface of the ceramic tube filter to the dust discharge port. As a result, it is possible to prevent re-combustion of dust containing unburned components on the surface of the ceramic tube filter, and the second problem is solved.

[0013]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a view showing a cross section of a multi-tube multi-chamber dust removing apparatus for solving the first problem. In FIG. 1, reference numeral 1 is a vertical hollow container formed of a heat-resistant and pressure-resistant material, and the inside thereof is divided into three filtration chambers 1 by four partition plates 3.
It is divided into 6a, 16b, 16c and an upper chamber 17 and a lower chamber 18. Then, the two ceramic tube filters 2 are arranged in parallel so as to penetrate the partition plate 3.

The ceramic tube filter 2 is made by sintering fine ceramic powder and solidifying it, and has a porous structure having a large number of pores of about several μm.

The filter chambers 16a, 16b and 16c are provided with independent clean gas outlets 12 and ejectors 4, respectively. Each ejector 4 is a clean gas exhaust pipe 13
Are connected by.

A dust outlet 19 is provided on the bottom surface of the lower chamber 18.
Is provided, and the dust accumulated at the bottom of the lower chamber 18 is sent to an ash processing device (not shown).

A tangential inflow type cyclone 8 is provided in the upper part of the hollow container 1, and a dust-containing gas inflow pipe 10 is horizontally attached to the side surface of the cyclone 8 at a position offset to the outside of the cyclone center axis. Has been. The vortex finder 9 of the cyclone 8 has a structure in which the tip is bifurcated and a U-turn is made downward in the upper chamber 17. A dust discharge pipe 20 extending vertically to the lower chamber 18 is provided at the tip of the conical portion of the cyclone 8.
The cyclone 8 and the dust discharge pipe 20 are fixed to the hollow container 1 by the partition plate 3.

Next, the operation principle of the dust removing device shown in FIG. 1 described above will be described.

The dust-containing gas G discharged from the boiler (not shown) flows horizontally from the dust-containing gas inflow pipe 10 into the cyclone 8 provided inside the hollow container 1. Since the dust-containing gas inflow pipe 10 is attached to the cyclone 8 with a center offset to the outside, the dust-containing gas entering the cyclone 8 is given a swirling velocity component. The dust-containing gas descends while swirling in the cyclone 8, then reverses and rises along the central axis of swirling. Then, it flows downward through the vortex finder 9 in the upper chamber 17.

Inside the cyclone 8, due to the swirling of the dust-containing gas, a centrifugal force acts on the dust contained in the gas, and the dust with a large particle size collides with the wall surface of the cyclone 8. The dust that collides with the wall in this way loses kinetic energy and cannot follow the gas flow.
Gravity slides down the inner wall of the cyclone 8 and drops through the dust discharge pipe 20 into the lower chamber 18.

The gas roughly dedusted by the cyclone 8 flows into the ceramic tube filter 2 from above the ceramic tube filter 2. Since the ceramic tube filter 2 has a porous structure having pores of several μm, gas gradually exudes to the outside of the ceramic tube filter 2 while flowing downward in the ceramic tube filter 2. During this time, dust contained in the gas is filtered, and the gas becomes a clean gas containing almost no dust.

The clean gas exuded from the ceramic tube filter 2 is filtered into the filtration chambers 16a, 16b, 1 respectively.
The clean gas outlet 12 provided in 6c flows out of the hollow container 1, passes through the ejector 4, and the clean gas discharge pipe 1
3 and sent to a gas turbine (not shown).

At a fixed time interval, the valve 15 is opened and the high-pressure cleaning gas is injected from the backwashing gas pipe 14 into the throttle portion of the ejector 4 for a short time. The pressure wave generated by the ejector effect propagates from the clean gas outlet 12 into the hollow container 1. Due to this pressure wave, the pressure on the outside of the ceramic tube filter 2 instantaneously becomes higher than the pressure on the inside, and due to this pressure difference, the dust adhering to the inside of the ceramic tube filter 2 is forcibly removed. The separated dust falls into the lower chamber 18 by the action of gravity and the gas flowing downward in the ceramic tube filter 2.

The dust stored in the lower chamber 18 is taken out of the hollow container 1 through a dust discharge port 19 provided at the bottom and treated by an ash treatment device (not shown).

With the operation described above, in this embodiment, the dust collected by the cyclone and the ceramic tube filter can be processed by the ash processing apparatus of one system. Next, an embodiment for solving the second problem will be described with reference to FIG. The dust remover shown in FIG. 3 is obtained by adding a gas return pipe 11 to the embodiment shown in FIG. The gas return pipe 11 extends from the lower chamber 18 through the partition plate 3 and the side wall surface of the conical portion of the cyclone 8 to the central axis of the cyclone 8.

The gas pressure in the vicinity of the central axis of the cyclone 8 becomes lower than the gas pressure in the lower chamber 18 due to the action of centrifugal force due to the swirling flow. As a result, the gas in the lower chamber 18 is
It flows through 1 into the center of cyclone 8. When such an upflow occurs, a downflow occurs under the ceramic tube filter 2 in order to balance the mass. The dust peeled off from the inner surface of the ceramic tube filter 2 by backwashing is promptly discharged to the lower chamber 18 by this downward flow.

By the operation described above, in this embodiment, the ash treatment system can be integrated, and the dust in the lower portion of the ceramic tube filter, which was difficult to discharge because the downflow is extremely small, can be reliably discharged. It will be possible.

[0029]

According to the present invention, the cyclone and the ash treatment device of the multi-tube multi-chamber dust removing device, which are conventionally installed separately, can be integrated. As a result, effects such as reduction of the device cost, improvement of maintainability, and reduction of the installation area of the device can be expected.

Further, by improving the performance of discharging the dust in the ceramic tube filter, it is possible to prevent the accident that the unburned portion of the dust is reburned inside the ceramic tube filter and the ceramic tube filter is damaged.

[Brief description of drawings]

FIG. 1 is a diagram showing a method of integrating a cyclone and an ash treatment system of a multi-tube multi-chamber dust remover, which is an embodiment of the present invention.

FIG. 2 is a diagram showing a conventional example.

FIG. 3 is a diagram showing a method of preventing damage to a ceramic tube filter due to re-combustion of dust, which is an embodiment of the present invention.

[Explanation of symbols]

1 ... Hollow container, 2 ... Ceramic tube filter, 8 ...
Cyclone, 10 ... Dust-containing gas inflow pipe, 12 ... Clean gas outlet, 16a, 16b, 16c ... Filtration chamber, 17 ... Upper chamber, 18 ... Lower chamber, 19 ... Dust outlet.

Claims (3)

[Claims] 1. A plurality of filtration chambers, an upper chamber and a lower chamber that are formed by vertically partitioning the interior of a vertical hollow container, penetrate the filtration chamber, and are open at both ends to the upper chamber and the lower chamber. , An annular ceramic filter, a dust-containing gas inlet in the upper chamber of the vertical hollow container, and a dust outlet in the bottom of the lower chamber,
A multi-tube multi-chamber dust remover in which a clean gas outlet is provided for each of the plurality of filtration chambers, wherein a cyclone is provided in the vertical hollow container. 2. The multi-tube multi-chamber dedusting system according to claim 1, wherein the dust outlet of the cyclone is arranged vertically above the dust outlet provided on the bottom surface of the lower chamber. apparatus. 3. A multi-tube multi-chamber dust eliminator according to claim 1, wherein one or more gas passages extending from the lower chamber to the inside of the cyclone are provided.