JP2001355834A - Smoke discharging and treating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a smoke discharging and treating device, capable of contriving cost down by using a high corrosion resistant material locally but not totally of a chimney, capable of restricting the reduction of the temperature of waste gas desulfurized in a wet type desulfurizing device even when high-temperature low corrosive gas is not introduced into the chimney, capable of preventing the dispersion of mist by restricting the generation of condensed water while retaining the flow speed of gas, discharged out of the chimney, without reducing the same, capable of preventing the generation of down-wash phenomenon, capable of eliminating the necessity of incorporation of a movable device or the like which expands or contracts the sectional area of flow passage into the discharging port of the chimney in accordance with the flow rate of exhaust gas and capable of avoiding the increase of an installation cost as well as an operation charge. SOLUTION: The chimney 4 is constituted of a double structure having an outer tube 4a and an inner tube 4b while high corrosive gas, desulfurized in the wet type desulfurizing device 3 and saturated by moisture, is introduced into the inner tube 4b and high-temperature low corrosive gas from a gas burning boiler 5 is introduced into a space between the outer tube 4a and the inner tube 4b.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flue gas treatment apparatus.

[0002]

2. Description of the Related Art Generally, as shown in FIG. 3, exhaust gas discharged from a coal-fired or oil-fired boiler 1 is subjected to dust removal by an electrostatic precipitator 2 and desulfurization by a wet desulfurization device 3.
Although the exhaust gas is released from the chimney 4 to the atmosphere, the exhaust gas desulfurized by the wet desulfurization device 3 is a moisture-saturated gas, so that mist scattering poses a problem.

For this reason, conventionally, as shown in FIG. 4, when a gas-fired boiler 5 is located near a coal-fired or oil-fired boiler 1, the gas is discharged from the gas-fired boiler 5 and is discharged by an electric precipitator 6. The high-temperature and low-corrosive exhaust gas from which dust has been removed is introduced into the chimney 4 and mixed with the exhaust gas desulfurized by the wet desulfurization device 3 to raise the temperature of the exhaust gas and suppress the generation of condensed water. It was done to prevent the scattering.

[0004]

As described above, the exhaust gas discharged from the gas-fired boiler 5 is introduced into the chimney 4 in order to increase the temperature of the exhaust gas desulfurized by the wet desulfurization device 3 to prevent the mist from scattering. In this case, the flow rate of the exhaust gas introduced into the chimney 4 is increased by that amount, so that the diameter of the chimney 4 is increased. However, the exhaust gas desulfurized by the wet desulfurization device 3 is saturated with water. Not only that, since it is a highly corrosive gas containing chlorine, sulfur oxide, nitrogen oxide, and the like, a high-corrosion-resistant material (for example, stainless steel or acid-resistant lining material) must be used for the entire chimney 4 having a large diameter. This has the disadvantage of disappearing, leading to an increase in cost.

When the gas-fired boiler 5 stops operating and no high-temperature, low-corrosive gas is introduced into the chimney 4, the temperature of the exhaust gas desulfurized by the wet desulfurization unit 3 cannot be increased, and the condensate cannot be condensed. While the generation of water cannot be suppressed and it is difficult to prevent the mist from scattering, the gas flow velocity is reduced by the decrease in the flow rate of the exhaust gas discharged from the chimney 4 having a large diameter, and the exhaust gas is moved downward. Because the so-called downwash phenomenon that hangs down, to prevent this,
The discharge port of the chimney 4 needs to incorporate a movable device or the like that expands / contracts the cross-sectional area of the flow passage in accordance with the flow rate of the exhaust gas, which also has the disadvantage of increasing equipment costs and operating costs.

In view of such circumstances, the present invention may use a high-corrosion-resistant material for a part of the chimney having a large diameter, instead of the entire chimney. Even when not introduced, it is possible to suppress a decrease in the temperature of the exhaust gas desulfurized by the wet desulfurization device, to suppress the generation of condensed water and prevent the mist from scattering, while reducing the gas flow rate discharged from the chimney. Without the need for installing a movable device that expands or contracts the cross-sectional area of the flow channel in accordance with the flow rate of exhaust gas at the outlet of the chimney. It is an object of the present invention to provide a flue gas treatment device that can avoid an increase in the amount of smoke.

[0007]

SUMMARY OF THE INVENTION The present invention relates to a flue gas treatment apparatus for discharging a moisture-saturated and highly corrosive gas desulfurized by a wet desulfurization apparatus from a chimney to the atmosphere, wherein the chimney has an outer cylinder and an inner cylinder. It has a double-pipe structure and introduces moisture-saturated and highly corrosive gas into the inner cylinder, and introduces high-temperature and low-corrosive gas into the space between the outer and inner cylinders. The present invention relates to a flue gas treatment device.

[0008] The smoke exhaust treatment device may be configured to use the exhaust gas of a gas-fired boiler as the high-temperature low-corrosive gas.

According to the above means, the following effects can be obtained.

[0010] The moisture-saturated and highly corrosive gas desulfurized by the wet desulfurization device is introduced into the inner tube of the stack having a double-pipe structure, and is introduced into the space between the outer tube and the inner tube of the chimney. A high-temperature, low-corrosive gas is introduced, and the temperature of the moisture-saturated, high-corrosive gas introduced into the inner cylinder is raised by the high-temperature, low-corrosive gas, and the generation of condensed water is suppressed, and the mist is dispersed. Is prevented.

As a result, it is possible to use a lightweight and high corrosion-resistant material such as FRP only for the inner cylinder of the chimney, and to use a high-strength and low-cost material such as rolled steel for general structures in the outer cylinder of the chimney. Therefore, it is not necessary to use a high corrosion-resistant material such as a stainless steel material or an acid-resistant lining material for the entire chimney having a large diameter, which leads to cost reduction.

Further, even when the high-temperature and low-corrosive gas is not introduced into the space between the outer cylinder and the inner cylinder of the chimney, a layer of air covered with the outer cylinder is formed around the inner cylinder of the chimney. The temperature of the exhaust gas that rises in the inner cylinder is less likely to decrease, and the generation of condensed water is suppressed, and the mist can be prevented from scattering. The diameter of the exhaust gas is matched with the flow rate of the exhaust gas desulfurized by the wet desulfurization device, so the gas flow rate discharged from the inner cylinder of the chimney is maintained without decreasing, the downwash phenomenon does not occur, and the It is not necessary to incorporate a movable device or the like for expanding / contracting the cross-sectional area of the flow passage in accordance with the flow rate of the exhaust gas at the discharge port, and it is possible to avoid an increase in equipment costs and operation costs.

[0013]

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

FIGS. 1 and 2 show an example of an embodiment of the present invention. In the drawings, the portions denoted by the same reference numerals as those in FIG. 4 represent the same components, and the basic configuration is shown in FIG. It is the same as the conventional one shown here, but the feature of this illustrated example is that
As shown in FIGS. 1 and 2, the chimney 4 is connected to an outer cylinder 4a and an inner cylinder 4b.
A water-saturated and highly corrosive gas desulfurized by the wet desulfurization device 3 is introduced into the inner cylinder 4b, and the gas is introduced into the space between the outer cylinder 4a and the inner cylinder 4b. The point is that high-temperature and low-corrosive gas discharged from the boiler 5 and from which dust has been removed by the electric dust collector 6 is introduced.

In the drawing, reference numeral 7 denotes a support member, and the support member 7 arranges the inner cylinder 4b at the center of the outer cylinder 4a.

Next, the operation of the illustrated example will be described.

The moisture-saturated and highly corrosive gas desulfurized by the wet desulfurization device 3 is introduced into the inner tube 4b of the stack 4 having a double pipe structure, and the gas between the outer tube 4a and the inner tube 4b of the stack 4 is formed. A high-temperature, low-corrosive gas is introduced into the space between them, and the temperature of the water-saturated, high-corrosive gas introduced into the inner cylinder 4b is increased by the high-temperature, low-corrosive gas, thereby generating condensed water. Restrained,
Mist scattering is prevented.

As a result, FRP is applied only to the inner cylinder 4b of the chimney 4.
It is possible to use a high-strength, low-cost material such as rolled steel for general structure (SS material) for the outer cylinder 4a of the chimney 4 using a lightweight and high corrosion-resistant material such as There is no need to use a high corrosion-resistant material such as a stainless steel material or an acid-resistant lining material for the entire chimney 4, which leads to cost reduction.

Also, when the gas-fired boiler 5 stops operating and no high-temperature, low-corrosive gas is introduced into the space between the outer cylinder 4a and the inner cylinder 4b of the chimney 4, the inner cylinder A layer of air covered with the outer cylinder 4a is formed around the outer cylinder 4b, and a certain heat retaining effect is generated. Therefore, the temperature of the exhaust gas rising in the inner cylinder 4b is hardly reduced, and the generation of condensed water is suppressed. And mist can be prevented from scattering.
Since the diameter of the inner cylinder 4b is equal to the flow rate of the exhaust gas desulfurized by the wet desulfurization device 3, the flow velocity of the gas discharged from the inner cylinder 4b of the chimney 4 is maintained without decreasing, and the downwash phenomenon Does not occur, and it is not necessary to incorporate a movable device or the like for expanding / contracting the cross-sectional area of the flow channel in accordance with the flow rate of the exhaust gas at the discharge port of the chimney 4, and it is possible to avoid an increase in equipment costs and operation costs.

As described above, it is sufficient to use a high-corrosion-resistant material partially instead of the entire chimney 4 having a large diameter, so that the cost can be reduced, and even when the high-temperature and low-corrosive gas is not introduced into the chimney 4, The temperature of the exhaust gas desulfurized by the wet desulfurization device 3 can be suppressed from lowering, and the generation of condensed water can be suppressed to prevent the mist from scattering. On the other hand, the gas flow discharged from the chimney 4 can be kept without decreasing. In addition, it is possible to prevent the occurrence of the downwash phenomenon and eliminate the need for incorporating a movable device or the like that expands and contracts the cross-sectional area of the flow passage in accordance with the flow rate of the exhaust gas at the discharge port of the chimney 4, thereby increasing equipment costs and operating costs. Can also be avoided.

The flue gas treatment apparatus of the present invention is not limited to the above illustrated example, but may use a gas other than the exhaust gas of a gas-fired boiler as a high-temperature, low-corrosion gas. Of course, various changes can be made without departing from the spirit of the present invention.

[0022]

As described above, according to the flue gas treatment apparatus of the present invention, it is only necessary to use a high-corrosion-resistant material for a part of the chimney having a large diameter instead of the whole, and to reduce the cost. Even when high-temperature, low-corrosive gas is not introduced into the chimney, the temperature of the exhaust gas desulfurized by the wet desulfurization device can be prevented from lowering, and the generation of condensed water can be suppressed to prevent mist from scattering. A movable device that expands and contracts the cross-sectional area of the flow channel according to the flow rate of exhaust gas can be incorporated at the discharge port of the chimney. Eliminate the need
An excellent effect that an increase in equipment cost and operation cost can be avoided can be achieved.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an example of an embodiment of the present invention.

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is a schematic configuration diagram of a conventional example.

FIG. 4 is a schematic configuration diagram of another conventional example.

[Explanation of symbols]

 3 Wet desulfurizer 4 Chimney 4a Outer cylinder 4b Inner cylinder 5 Gas fired boiler

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3K061 VA01 VA04 VA13 4D002 AA02 AC01 BA02 BA16 EA05

Claims (2)

[Claims] 1. A flue gas treatment apparatus for releasing moisture-saturated and highly corrosive gas desulfurized by a wet desulfurization apparatus from a chimney to the atmosphere, wherein the chimney has a double pipe structure having an outer cylinder and an inner cylinder, A flue gas treatment apparatus characterized in that a moisture-saturated and highly corrosive gas is introduced into the inside and a high-temperature and low-corrosive gas is introduced into the space between the outer cylinder and the inner cylinder. 2. The flue gas treatment apparatus according to claim 1, wherein exhaust gas from a gas-fired boiler is used as the high-temperature, low-corrosion gas.