JP2527514Y2 - High-temperature acid gas quenching device - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-temperature acid gas quenching apparatus for rapidly cooling a high-temperature acid gas such as a coal combustion gas containing corrosive components such as sulfur oxides.

[0002]

2. Description of the Related Art For example, when coal is burned in various combustion furnaces such as a boiler of a thermal power plant, a chemical plant, and a metal smelter, harmful sulfur oxidation such as sulfur dioxide and sulfur trioxide is emitted from this combustion device as exhaust gas. Since high-temperature acid gas containing waste is discharged, it is necessary to remove sulfur oxides in these high-temperature acid gases from the viewpoint of pollution prevention and the like. A quenching device for quenching is provided. In these quenching devices, when a cooling medium such as water is sprayed from a spray nozzle onto a high-temperature acid gas passing through the casing to cool the sulfuric acid, the sulfur oxide is cooled by the cooling medium to reach a dew point, and is turned into sulfuric acid droplets (condensation) ), Which causes corrosion of the casing. To prevent this, high-grade acid-resistant, corrosion-resistant metal or acid-resistant, corrosion-resistant bricks made of expensive materials such as Hastelloy (trade name) containing a large amount of nickel, chromium, etc. in the quenched part. And so on to prevent corrosion.

On the other hand, in order to avoid the use of such expensive materials, Japanese Utility Model No. 1-1 previously filed by the present applicant has been proposed.
There is known a quenching device in which special consideration is given to the structure and material as disclosed in Japanese Patent Publication No. 3235 and Japanese Utility Model Publication No. 1-40991. That is, such a quenching device is made of a heat-resistant and corrosion-resistant resin reinforced with a reinforcing fiber such as carbon fiber at a predetermined interval in the radial direction with respect to the inner circumferential surface of the casing on the inner circumferential surface of the casing through which the high-temperature acid gas passes. A protective plate is provided, and a gas heat insulating layer is provided between the protective plate and the inner peripheral surface of the casing, and a cooling medium supply spray nozzle for high-temperature acidic gas is supplied to the gas passage inside the protective plate where the protective plate is located. It is provided so as to oppose the acid gas flow, and a corrosion-resistant lining material is provided on the inner peripheral surface of the casing in the gas heat insulating layer, and water is used as a cooling medium for the high-temperature acid gas in the casing surrounded by the protective plate. Spraying prevents corrosion of the casing, such as by preventing water and high-temperature acidic gas from contacting on the inner wall surface of the casing and causing sulfur oxides to form dew points and form dew. It has to so that.

[0004]

However, as described above, a corrosion prevention device using a material such as a high-grade acid-resistant or corrosion-resistant metal containing a large amount of nickel, chromium, etc. has an extremely expensive structure and is economically disadvantageous. is there. In order to avoid this phenomenon, a quenching device in which a protective plate made of a special material is provided in the casing as described above and the cooling water is injected from a spray nozzle through a gas passage inside the quenching device is provided. Is performed inside the protective plate, the surface of the protective plate comes into contact with high-temperature acidic gas and water, and the protective plate is made of a special material such as a heat-resistant and corrosion-resistant resin reinforced with reinforcing fibers such as carbon fibers as described above. Therefore, there is a problem in that general carbon steel cannot be used similarly to the casing, and manufacture is difficult.

[0005] On the other hand, in the above configuration, a falling layer of cooling water of the spray nozzle is formed on the surface of the protection plate to block the surface of the protection plate from high-temperature acid gas, and even if it is intended to protect the surface, it is necessary to spray by spraying. Because of this, the falling layer inevitably tends to be interrupted, so that the surface of the protective plate cannot be reliably protected from an acidic atmosphere. Further, in the above-described configuration, since the upper end of the gas heat-insulating layer is opened to the gas passage, the high-temperature acid gas flows into the gas heat-insulating layer, and water is jetted upward. As a result, spray water easily enters the gas heat insulating layer. For this reason, the inner wall (iron shell) of the casing, which is one of the components of the gas heat insulating layer, is exposed to the high-temperature acid gas and water, and sulfuric acid is condensed on the inner wall, and is likely to corrode. For this purpose, it is necessary to provide a corrosion-resistant lining on the inner wall surface of the casing. In this case, it is necessary to use a lining material having a high heat-resistant temperature.

The present invention solves the drawbacks of the conventional quenching device, and prevents the quenching device from contacting the inner wall of the casing with a high-temperature acid gas and a cooling medium such as water, thereby reducing the acid dew point or the like. An object of the present invention is to provide a quenching device for high-temperature acidic gas which can be prevented from corrosion and can be constituted by using ordinary carbon steel.

[0007]

In order to achieve the above object, the high-temperature acidic gas quenching device of the present invention is provided as follows: (1) A high-temperature acidic gas flowing in a casing is rapidly cooled by a cooling medium in the casing. In the quenching device for high-temperature acid gas that has been provided, an air insulation layer is provided on the inner peripheral surface of the upstream casing so that the periphery is sealed and the high-temperature acid gas passes through the inner peripheral surface. A downstream casing extending downstream with a gap provided with the air heat insulating layer over the circumference, and an inflow portion of a cooling medium communicating with the gap provided on the entire circumference of the downstream casing at an upper position of the air heat insulating layer; A cooling medium jacket is provided on the outer peripheral portion of the downstream casing in communication with the inflow portion. (2) In the configuration of the above (1), the inflow portion of the cooling medium communicating with the gap is formed by forming a saw-shaped triangular weir over the entire periphery of the upper end of the downstream casing. (3) In the configuration of the above (1) or (2), a corrosion-resistant lining is attached to an inner wall surface of the downstream casing in the gap portion and a downstream portion thereof.

[0008]

(1) The high-temperature acidic gas is sent into the upstream casing of the quenching device, passes through the inner peripheral surface of the air insulation layer, and is sent into the downstream casing. On the other hand, in the gap formed around the entire periphery between the outer casing of the air insulating layer and the downstream casing, a cooling medium is provided from the cooling medium jacket to the entire periphery of the downstream casing at the upper position of the air insulating layer. Inflow from the inflow section. Therefore, a wet wall descending along the inner wall surface on the entire inner wall surface of the downstream casing, that is,
A curtain of cooling medium is formed. The hot acid gas is quenched by the wet wall. At this time, first, since the air heat insulating layer is located in the upstream casing in a portion where the cooling medium is taken into the quenching device, The action does not quench the hot acid gas,
At the quenching start portion (boundary portion), the inner wall of the casing inner wall and the air heat insulating layer is prevented from reaching the acid dew point, and dew condensation of sulfuric acid is avoided.

When the high-temperature acid gas passes through the air heat insulating portion, it is rapidly cooled by the wet wall. However, at this time, since the wetted wall is formed on the entire inner wall surface of the downstream casing, the inner wall surface of the downstream casing is shielded from the high-temperature acidic gas and the contact with the high-temperature acidic gas is prevented.
Thereby, dew condensation on the inner wall surface is prevented. This protects the hot acid gas quenching device from corrosion.
Therefore, the quenching device can be formed using carbon steel. (2) The cooling medium in the cooling medium jacket overflows from the triangular weir by making the inflow portion of the cooling medium communicating with the gap a saw-tooth triangular weir formed over the entire periphery of the upper end of the downstream casing. As a result, the coolant flows more evenly from the entire circumference into the gap, and the cooling medium flows more uniformly on the entire inner wall surface of the downstream casing. Then, even if the supply amount of the cooling medium fluctuates or the downstream casing has a slight inclination, the entire inner surface of the downstream casing can be made a wet wall. Therefore, the inner wall surface of the downstream casing is more reliably shut off from the high-temperature acidic gas.

(3) When a corrosion-resistant lining is attached to the gap portion and the inner wall surface of the downstream portion, if the cooling medium curtain is interrupted due to an unexpected situation, or the cooling medium supplied into the cooling medium jacket is rapidly cooled. After passing through the device, it may be circulated and used to become a liquid containing an acidic component, or it may become acidic, such as dilute sulfuric acid, on the way down the inner surface of the downstream casing as a wet wall. Even in this case, corrosion of the inner surface of the downstream casing can be prevented by the corrosion-resistant lining. Further, in the corrosion-resistant lining used in this case, since the inner surface of the downstream casing is cooled by the wet wall, a lining material having a low heat-resistant temperature can be used.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail with reference to the embodiments shown in the drawings. FIG. 1 is a longitudinal sectional view showing an embodiment of the high-temperature acid gas quenching device of the present invention. Reference numeral 10 denotes a casing to which a high-temperature acidic gas containing a corrosive gas such as sulfur dioxide is sent. An upstream casing 20 of the high-temperature acid gas quenching device is located downstream of the gas flow of the casing 10. An air insulating layer having a predetermined length in the gas flow direction is provided on an inner peripheral surface of the upstream casing 20. 21 are formed. This air insulation layer 21 is
A vertical inner circumferential member 21a, an upper inverted conical member 21b, and a lower horizontal member 21c, which are located at a predetermined distance from the inner wall of the casing 20 on the inner peripheral surface of the casing 20, are filled with air inside. Is formed as a closed annular space. High-temperature acidic gas passes through the inside of the inner peripheral surface 22 of the inner peripheral member 21 a of the air heat insulating layer 21.

On the other hand, a downstream casing 30 is arranged around the outer side of the air heat insulating layer 21 with a required gap 31 formed between the outer casing of the upstream casing 20 and the upper end 30a of the downstream casing 30. A predetermined distance H at a position above the heat insulating layer 21 and from the upper end of the air heat insulating layer 21
It is located in the lower position. The upper end 30a of the downstream casing 30 is formed as an inflow portion of cooling water as a cooling medium. In this inflow portion, a saw-tooth triangular weir 34 is provided on the entire periphery of the upper end 30a of the downstream casing 30. Is formed. A water jacket 40 whose outer wall extends upward beyond the cooling water inflow portion at the upper end 30 a of the downstream casing 30 is attached to the upper outer peripheral portion of the downstream casing 30. Reference numeral 41 denotes a cooling water supply port provided appropriately around the lower portion of the water jacket 40. A corrosion-resistant lining 32 is attached to the gap 31 of the downstream casing 30 and the inner wall surface of the downstream portion thereof.

In such a configuration, the high-temperature acid gas is sent through the casing 10 and reaches the air heat insulating layer 21 of the upstream casing 20 of the quenching device, and passes through the inner peripheral surface 22 here. It flows downstream. On the other hand, the cooling water in the water jacket 40 overflows from the triangular weir 34, which is a cooling water inflow portion formed on the entire periphery of the upper end 30a of the downstream casing 30, and flows into the gap 31, and The surface of the corrosion-resistant lining 32 on the inner surface of the side casing 30 is lowered, and a wet wall (water curtain) 33 is formed on this surface.
Thus, at the inlet of the cooling water into the gap 31 which is the quenching start portion of the quenching device, the air heat insulating layer 21 is formed on the inner peripheral surface of the upstream casing 20 inside the gap 31. The inner peripheral surface 22 of the air insulating layer 21 is not quenched, and the high-temperature acid gas is quenched in this portion to prevent condensation of sulfuric acid, and the cooling water is located a predetermined distance H below the upper end of the air insulating layer 21. The cooling water flows into the space 31 near the inflow portion of the high-temperature acidic gas into the air heat insulating layer 21, that is, the inner surface of the inverted conical member 21 b and the inner wall surface of the upstream casing 20 on the upper portion thereof. The inner wall portion around the inflow portion is not rapidly cooled, so that dew condensation of the portion is prevented and corrosion due to an acid dew point is also prevented.

The high-temperature acid gas passes through the air insulating layer 21 and flows downstream of the downstream casing 30.
The quenching effect is caused by the wet wall 33 by the water curtain. At this time, since the wet wall 33 is formed in the downstream casing 30, the inner wall surface itself as well as the corrosion-resistant lining 32 of the inner wall surface is shielded from high-temperature acidic gas, and corrosion of the portion is prevented. You. At this time, the cooling water overflows from the saw-tooth triangular weir 34 and the gap 31
Since it is formed by flowing into the inside, it is formed as a continuous flow in a state where interruption is prevented as much as possible, and not only the quenching effect but also the corrosion preventing effect is surely performed. The high-temperature acid gas quenched here flows further downstream and is introduced into a gas treatment device such as a desulfurization device to be subjected to exhaust gas treatment. Further, the cooling water provided for cooling is collected on the downstream side (not shown) of the downstream casing 30, cooled to a predetermined temperature by a separately provided cooler or the like, and then again into the water jacket 40 from the cooling water supply port 41. Introduced and used.

In this case, the cooling water is supplied to the downstream casing 30.
Even if the inner wall surface is acidified with dilute sulfuric acid or the like by an acid gas or the like when the inner wall surface is lowered, the corrosion-resistant lining 32 prevents the inner wall surface of the downstream casing 30 from being corroded.
Further, since the corrosion-resistant lining 32 is cooled, a material having a low heat resistance can be used. As described above, the members constituting the quenching device are prevented from contacting the hot acid gas and water at the same time, and the quenching of the gas near the gas upstream side of the portion where the quenching is started can be avoided. Therefore, the upstream casing 20 of the component, the air heat insulating layer 22 therein, and the downstream casing 30 can be made of carbon steel. Further, in the present invention, the high-temperature acid gas does not enter the internal space of the air heat insulating layer 21 and there is no concern about corrosion due to the acid dew point inside the heat insulating layer unlike the conventional gas heat insulating layer.

In the above embodiment, the case where the cooling water inflow into the gap 31 is formed with the saw-tooth triangular weir 34 is shown. However, the present invention is not limited to this. The upper end 30a may be cut horizontally and opened. Further, in order to reliably prevent the high-temperature acidic gas from rising in the gap 31 and leaking from the inflow portion of the cooling water at the upper end opening, a space between the upper end 30a of the downstream casing 30 and the upstream casing 20 side is provided. For example, a conical cover extending upward from the upper end 30a is formed over the entire circumference, and a slit-shaped cooling water inflow section is formed on the entire circumference so that the cooling water inflow section is always immersed in the cooling water. Is also good. In this case, the slit-shaped cooling water inflow portion may be a saw-tooth triangular weir as described above. further,
The corrosion-resistant lining 32 on the inner surface is not always essential. For example, the corrosion of the casing formed of carbon steel is prevented by using a new cooling water containing no acidic component at a larger water supply amount. Can be.

[0017]

As is apparent from the above description, according to the present invention, by adopting the structure of the first aspect, the portion which comes into contact with the high-temperature acid gas reaches the acid dew point by cooling,
Alternatively, it is possible to prevent oxidation corrosion due to direct contact between the high-temperature acid gas and the cooling medium, so that members constituting the quenching device for the high-temperature acid gas include high-grade members such as heat resistance, acid resistance, and corrosion resistance. There is no need to use it, and for example, a quenching device can be constructed using carbon steel equivalent to the casing constituting the exhaust gas duct, facilitating manufacture, and obtaining a quenching device that is economical in terms of cost and structure. Can be.
According to the configuration of claim 2, it is possible to more reliably prevent contact with the acidic gas on the inner wall surface of the downstream casing of the quenching device, and it is possible to more reliably prevent corrosion of the inner wall. The reliability of the use of the steel member can be further enhanced. According to the configuration of claim 3, since the inner wall surface that is stronger against the acidic atmosphere is formed, the life of the downstream casing made of carbon steel can be kept long, and the lining material itself is cooled. Therefore, for example, a rubber lining material having a low heat resistance temperature can be used.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of a high-temperature acid gas quenching device of the present invention.

[Explanation of symbols]

REFERENCE SIGNS LIST 20 upstream casing 21 air insulating layer 22 inner peripheral surface of air insulating layer 30 downstream casing 30 a upper end of downstream casing (cooling water inflow portion) 31 gap 32 corrosion resistant lining 33 wet wall (water curtain) 34 saw-tooth triangular weir 40 water Jacket

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References Japanese Utility Model Hei 2-85232 (JP, U)

Claims (3)

(57) [Scope of request for utility model registration] 1. A high-temperature acidic gas quenching device in which a high-temperature acidic gas flowing through a casing is rapidly cooled by a cooling medium in the casing. An air insulation layer through which an acid gas passes is provided, and a downstream casing extending downstream with a gap between the air insulation layer and the entire circumference is arranged around the outside of the air insulation layer. A high-temperature acid gas, wherein a cooling medium inflow portion communicating with the gap is provided on the entire periphery of the downstream casing, and a cooling medium jacket is provided on the outer periphery of the downstream casing in communication with the cooling medium inflow portion. Quenching device. 2. The high-temperature acidity according to claim 1, wherein the cooling medium inflow portion communicating with the gap is formed by forming a saw-tooth triangular weir over the entire periphery of the upper end of the downstream casing. Gas quenching device. 3. The high-temperature acid gas quenching device according to claim 1, wherein a corrosion-resistant lining is attached to an inner wall surface of the downstream casing in the gap portion and a downstream portion thereof.