JP5848032B2 - Smoke removal equipment - Google Patents

Description

  The present invention relates to a flue gas treatment apparatus.

Some flue gas treatment devices include a mist removal device that removes mist in order to treat mist generated during SO ₂ absorption treatment by wet flue gas desulfurization. And the exhaust gas processing apparatus which removed the mist which cannot be removed with this mist removal apparatus with SGH (steam-gas heater), and sent the waste gas from which the mist was removed to a GGH reheater is known.

  As one of such a flue gas treatment device, a device according to Patent Document 1 (Japanese Patent No. 3852820) is provided. In Patent Document 1, exhaust gas from a combustion plant such as a boiler is introduced into a gas-gas heater heat recovery device (hereinafter also referred to as a GGH heat recovery device) through a denitration device, an air preheater, and the like, and the combustion plant such as a boiler. After heat is recovered by heat exchange with industrial air, most of the dust is removed by the electric dust collector. Thereafter, the exhaust gas is pressurized by a fan, and SOx in the exhaust gas is removed by a flue gas desulfurization apparatus (wet desulfurization apparatus).

  Mist is removed from the exhaust gas cooled to the saturated gas temperature by the flue gas desulfurization apparatus (wet desulfurization apparatus) by the mist removal apparatus. Further, the exhaust gas is heated and collided with a plurality of SGH steam pipes, and mist that has not been removed is removed. The exhaust gas from which the mist has been removed in this way is sent to the GGH exhaust gas reheater and heated by the recovered heat from the GGH heat recovery device.

Japanese Patent No. 3852820

  As described above, in the prior art, the scattered mist in the exhaust gas is removed by heating and collision with SGH. However, when SGH is used for a long time, the function of heating and collision deteriorates due to the scale generated. If this is left unattended, the mist removal function will be reduced. Further, the remaining mist reaches the GGH reheater, a scale is generated by the remaining mist, and it becomes easy to adhere to the GGH reheater. As a result, this scale may block the element of the GGH reheater, which may increase the differential pressure.

In order to avoid such a state, in the conventional apparatus, it was necessary to appropriately stop the operation and clean the constituent devices.
Therefore, in the conventional smoke treatment apparatus, it is inevitable to interrupt the operation in a short cycle, and a countermeasure has been desired.

  In view of the problems of the prior art, the present invention has an object of providing a flue gas treatment apparatus capable of continuous operation over a long period of time while preventing the solid content of the residual mist in the GGH reheater from being scaled. To do.

In order to achieve the above object, the present invention provides an exhaust gas desulfurization device that removes sulfur in exhaust gas from a combustion plant, an exhaust gas reheater that reheats the exhaust gas that has passed through the exhaust gas desulfurization device, and the exhaust gas. In a flue gas treatment apparatus installed on the downstream side of the reheater and equipped with a fan that sucks the exhaust gas on the upstream side, it is possible to heat the exhaust gas upstream of the exhaust gas reheater and remove mist in the exhaust gas. A washing type exhaust gas heating unit is detachably provided. The washable exhaust gas heating unit is provided in a replaceable manner and can be cleaned after the replacement.

  In one embodiment of the smoke treatment apparatus according to the present invention, an opening is provided in the exhaust gas passage wall, and the washable exhaust gas heating unit can be taken in and out through the opening.

Moreover, the flue gas processing apparatus which concerns on this invention is divided into several in the width direction of the said waste gas passage wall , and the said washable exhaust gas heating unit is installed in the embodiment.

  Furthermore, the flue gas treatment apparatus according to the present invention is an embodiment in which the washable exhaust gas heating unit is a heater that indirectly heats exhaust gas with a heat medium, generally steam. it can. In this case, the exhaust gas heating section of the heater can have a corrugated structure.

  ADVANTAGE OF THE INVENTION According to this invention, the flue gas processing apparatus which enabled the continuous operation for a long term is provided, preventing scaling of the solid content of the residual mist in a SGH and GGH reheater.

It is a conceptual diagram explaining the outline | summary about one Embodiment of the flue gas processing apparatus which concerns on this invention. BRIEF DESCRIPTION OF THE DRAWINGS It is a perspective view explaining the embodiment about the washable exhaust gas heating unit employ | adopted with the flue gas processing apparatus which concerns on this invention. It is a perspective view explaining the embodiment about the structure which accommodates a washable type flue gas heating unit about the flue gas processing device concerning the present invention. It is a perspective view explaining the state which accommodated the washable exhaust gas heating unit about the structure of FIG. It is sectional drawing by the AA line of FIG. It is a perspective view explaining the form which draws out a washable exhaust gas heating unit from the upper part about the structure of the form of Drawing 3. It is a perspective view explaining the form which pulls out a washable type exhaust gas heating unit from the lower part about the structure of the form of Drawing 3. It is a conceptual diagram explaining the outline | summary about other embodiment of the flue gas processing apparatus which concerns on this invention.

  Hereinafter, a flue gas treatment apparatus according to the present invention will be described with reference to embodiments shown in the accompanying drawings.

FIG. 1 conceptually shows an embodiment of the smoke treatment apparatus according to the present invention.
In the embodiment of FIG. 1, the combustion plant 1 is a combustion plant such as a coal-fired power plant. In a coal-fired power plant, exhaust gas from a boiler is a target for treatment.

In FIG. 1, exhaust gas (not shown) discharged from the combustion plant 1 is introduced into a GGH heat recovery device (gas-gas heater heat recovery device) 2 through an exhaust gas passage 11 and a heat recovery heat medium (water) ) To recover heat. That is,
In the GGH heat recovery device 2, a low-temperature heat medium is introduced through a low-temperature heat medium pipe 15 from a GGH reheater 6 described later, and the low-temperature heat medium and the exhaust gas are heat-exchanged to cool the exhaust gas.
The exhaust gas cooled by the GGH heat recovery device 2 enters the flue gas desulfurization device (wet desulfurization device) 3.

In the flue gas desulfurization apparatus 3, limestone (CaCO ₃ ) is suspended in water to form a limestone slurry, and this limestone slurry is brought into contact with exhaust gas in an absorption tower to absorb and remove sulfurous acid gas (SO ₂ ) in the exhaust gas. Then, gypsum (CaSO ₄ -2H ₂ O) is formed by oxygen in the exhaust gas and oxygen in the air introduced into the liquid chamber of the absorption tower.

In the flue gas desulfurization apparatus 3, the exhaust gas is cooled to the saturated gas temperature, and mist containing solids is generated by the reaction in the absorption tower.
The exhaust gas containing mist enters the mist removing device 4, and the mist collected by the collision is removed by washing with water.
However, gas containing mist that is not collected by the mist removing device 4 is introduced into the washable exhaust gas heating unit 50. This washable exhaust gas heating unit 50 constitutes a characteristic part of the present invention. Details of the structure of the washable exhaust gas heating unit 50 will be described later.

  In the washable exhaust gas heating unit 50, the exhaust gas is heated by exchanging heat with the exhaust gas by the steam from the steam pipe 16 branched from the steam main pipe 12, and the mist in the exhaust gas is collided and removed.

  Further, the exhaust gas exiting the washable exhaust gas heating unit 50 enters the SGH (steam gas heater) 5 where the exhaust gas is heated by heat exchange with the steam from the steam pipe 13 branched from the steam main pipe 12, and the SGH 5 The mist is further removed by the collision with the tube group constituting the.

  With such a configuration, the mist in the exhaust gas remaining through the flue gas desulfurization device 3 and the mist removal device 4 is almost completely obtained by the two-stage steam heating and collision of the washable exhaust gas heating unit 50 and the SGH 5. Can be removed.

  The exhaust gas from which the mist has been removed enters the GGH reheater (gas-gas heater reheater) 6. The GGH reheater 6 is fed with a high-temperature heat medium from the GGH heat recovery device 2 through the high-temperature heat medium pipe 14 to reheat the exhaust gas.

  The low-temperature heat medium from the GGH reheater 6 is returned to the GGH heat recovery device 2 through the low-temperature heat medium pipe 15. Further, the exhaust gas from the GGH reheater 6 is sucked by the fan 8 and discharged from the chimney 9.

  The fan 8 sucks the devices from the flue gas desulfurization device 3 to the washable exhaust gas heating unit 50, SGH 5, and GGH reheater 6 through the exhaust gas passage 11. Accordingly, the exhaust gas desulfurization system including the exhaust gas passage 11 has a negative pressure.

  Here, FIG. 2 shows an embodiment of the washable exhaust gas heating unit 50. It is preferable to install a plurality of washable exhaust gas heating units 50 in the width direction of the exhaust gas passage 11. FIG. 2 shows one of the plurality of washable exhaust gas heating units 50.

As shown in FIG. 2, the washable exhaust gas heating unit 50 includes a heat transfer tube group 53 including a plurality of heat transfer tubes that extend vertically to the exhaust gas flow 101. Here, the term “perpendicular” includes substantially orthogonal forms such as substantially orthogonal within the scope of common knowledge of those skilled in the art.
The heat transfer tube group 53 is provided between the upper supply tube 51 and the lower discharge tube 52. The internal space of the heat transfer tube group 53 is in fluid communication with the tubes 51 and 52 at the upper and lower ends thereof.
Depending on the installation conditions, this up-down direction can be rotated 90 degrees and set to the left-right direction with respect to the flow direction.

  Furthermore, partition plates 56 are provided on the left and right sides of the washable exhaust gas heating unit 50. A plurality of partition plates 56 a are also provided in the middle in the longitudinal direction of the heat transfer tube group 53 of the washable exhaust gas heating unit 50.

  A steam inlet flange 54 is welded to the upper supply pipe 51 of the washable exhaust gas heating unit 50, and a steam outlet flange 55 is welded to the lower discharge pipe 52.

  The steam flows from the steam inlet flange 54 through the supply pipe 51, the plurality of heat transfer pipe groups 53, the lower discharge pipe 52, and the steam outlet flange 55. At this time, the exhaust gas stream 101 and the steam exchange heat. ing.

FIG. 3 shows an embodiment of a structure for installing the washable exhaust gas heating unit 50.
As illustrated, a rectangular support hole 57a is provided in the upper wall 11a of the exhaust gas passage 11, and a support hole 57b is provided in the lower wall 11b corresponding to the support hole 57a. A virtually rectangular parallelepiped space is formed from the four sides of the support hole 57a to the four sides of the support hole 57b. A washable exhaust gas heating unit 50 is installed in this space.
The places where the washable exhaust gas heating unit 50 is installed are four places in the width direction of the exhaust gas passage 11 perpendicular to the exhaust gas flow direction 101 in the illustrated form. The number of installed washable exhaust gas heating units 50 and the like are appropriately set according to various conditions.

Further, an upper flange 58 is fixed to the support hole 57a, and a lower flange 59 is fixed to the support hole 57b. The upper flange 58 and the lower flange 59 include flange portions 58a and 59a and base portions 58b and 59b, respectively.
The upper flange 58 and the lower flange 59 are respectively fixed to the upper wall 11a and the lower wall 11b by fixing means such as welding at the base portions 58b and 59b, respectively.

A line connecting the center of the rectangular support hole 57a, that is, the center of the inner periphery of the base portion 58b of the upper flange 58, and the center of the rectangular support hole 57b, that is, the center of the inner periphery of the base portion 59b of the lower flange 59, It coincides with the axis of the rectangular parallelepiped space.
Note that the upper flange 58 and the lower flange 59 are normally covered with a lid as will be described later when the flue gas desulfurization apparatus 3 is operated.

  Further, as shown in FIG. 3, a hoist 60 is installed on the upper wall 11 a of the exhaust gas passage 11. The hoist 60 is installed on the hoist support frame 64 so as to be movable in the width direction of the exhaust gas passage 11. The hoist 60 includes a hanging chain 65 and a hook 61, and is configured to support the washable exhaust gas heating unit 50 so as to be movable up and down from the support hole 57a toward the support hole 57b. .

FIG. 4 shows a state in which the washable exhaust gas heating unit 50 is installed in FIG.
Moreover, the state which installed the washable exhaust gas heating unit 50 in FIG. 5 is shown with the cross section. As shown in the figure, the exhaust gas stream 101 is introduced into the SGH 5 in the downstream of the washable exhaust gas heating unit 50.

  Referring to FIGS. 4 and 5, the widths B and C of the washable exhaust gas heating unit 50 are the inner peripheral widths B 1 and C 1 and the rectangular lower flange 59 in the base 58 b of the rectangular upper flange 58. It is understood that the base portion 59b is formed smaller than the inner peripheral widths B1 and C1.

  Next, in order to extract the washable exhaust gas heating unit 50 upward, as shown in FIG. 6, the lid 63 (see FIG. 5) of the upper flange 58 is removed. Next, the hook 61 at the tip of the suspension chain 65 of the hoist 60 is hooked on the wire rope 62 stretched between the two attachment portions provided in the supply pipe 51 at the top of the washable exhaust gas heating unit 50. Then, the suspension chain 65 is lifted up while being wound up, and the washable exhaust gas heating unit 50 is pulled out from the upper flange 58.

Further, in order to extract the washable exhaust gas heating unit 50 downward, as shown in FIG. 6, the lid 63 of the upper flange 58 and the lid 63 (see FIG. 5) of the lower flange 59 are taken. Next, the hook 61 at the tip of the suspension chain 65 of the hoist 60 is hooked on the wire rope 62 stretched between the two attachment portions provided in the supply pipe 51 at the top of the washable exhaust gas heating unit 50. Then, the suspension chain 65 is suspended while being rewound, and the washable exhaust gas heating unit 50 is pulled out from the lower flange 59 downward.
Whether to pull out from above or from below depends on the environment in which the device is set.

When the washable exhaust gas heating unit 50 is withdrawn upward (FIG. 6) and withdrawn downward (FIG. 7), the washable exhaust gas heating unit 50 is removed from the flue gas desulfurization device 3 by the fan 8. Since the exhaust gas flow 101 of the SGH 5 and GGH reheater 6 is sucked, the exhaust gas passage 11 has a negative pressure.
Therefore, when the washable exhaust gas heating unit 50 is extracted and cleaned, the load on the fan does not become excessive and there is no problem.

  Thus, as described above, since the washable exhaust gas heating unit 50 can be easily replaced and can be cleaned even during the operation of the flue gas desulfurization apparatus 3, the GGH can be cleaned. It is possible to prevent the remaining mist of the reheater 6 from being scaled and prevent the element from being blocked and the differential pressure from being increased due to the scaling.

  Further, during the operation of the flue gas desulfurization apparatus 3, the clogging of the washable exhaust gas heating unit 50 can be measured by a separate measuring means, and the necessity of cleaning of the washable exhaust gas heating unit 50 can be detected.

Other Embodiments FIG. 8 shows another embodiment of the smoke treatment apparatus according to the present invention.
In this embodiment, the washable exhaust gas heating unit 50 configured as described above is arranged between the mist removing device 4 and the GGH reheater 6, and the arrangement of the SGH 5 is omitted. Such a configuration is possible depending on the properties of the exhaust gas to be treated.

The washable exhaust gas heating unit 50 is arranged in a normal wave-shaped structural element tube arrangement extending in a direction perpendicular to the exhaust gas flow 101, that is, a plurality of fin-shaped wave structure elements arranged in a direction perpendicular to the exhaust gas flow 101. You can also
In this way, the washable exhaust gas heating unit 50 is configured with a number of corrugated structural elements with fins, so that the heating efficiency is good.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various changes and modifications can be made based on the technical idea of the present invention.

1 Combustion plant 2 GGH heat recovery unit
3 Flue gas desulfurization equipment (wet desulfurization equipment)
4 Mist removal device 5 SGH (steam-gas heater)
6 GGH reheater 8 Fan 9 Chimney 11 Exhaust gas passage 11a Upper wall 11b Lower wall 11c, 11d Left and right side walls 12 Steam main pipe 50 Washable exhaust gas heating unit 51 Supply pipe 52 Exhaust pipe 53 Heat transfer pipe 54 Steam inlet flange 55 Steam outlet Flange 56 Partition plate 58 Upper flange 59 Lower flange 60 Hoist 61 Hook 63 Cover part 64 Hoist support frame 101 Exhaust gas

Claims (5)

A flue gas desulfurization device that removes sulfur in the exhaust gas from the combustion plant, an exhaust gas reheater that reheats the exhaust gas that has passed through the flue gas desulfurization device, and an upstream side that is installed downstream of the exhaust gas reheater In a flue gas treatment device equipped with a fan that sucks in exhaust gas,
Upstream of the exhaust gas reheater , a washable exhaust gas heating unit that heats the exhaust gas and removes mist in the exhaust gas is detachably provided,
The washable exhaust gas heating unit is provided so as to be replaceable and can be cleaned after replacement.   The exhaust gas treatment apparatus according to claim 1, wherein an opening is provided in the exhaust gas passage wall, and the washable exhaust gas heating unit can be taken in and out through the opening. The flue gas treatment apparatus according to claim 2 , wherein the washable exhaust gas heating unit is divided into a plurality of parts in the width direction of the exhaust gas passage wall .   The flue gas treatment apparatus according to any one of claims 1 to 3, wherein the washable exhaust gas heating unit includes a heater that indirectly heats the exhaust gas with a heating medium. The flue gas treatment device according to claim 4 , wherein the exhaust gas heating section of the heater has a wave structure.

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