JPH11351554A - Vent stack safety apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate a fear of igniting a vent stack. SOLUTION: The vent stack safety apparatus 10 comprises a first exhaust cylinder 11 arranged through a sidewall of a vent stack 1 therein to introduce a collected combustible gas 3 thereinto and to discharge it into the stack 1, and an exhaust tube 13 having a plurality of discharge outlets 16 arranged under the cylinder 11 through the sidewall of the stack 1 to inject a non-combustible gas 14 introduced from an exterior to the gas 3 introduced externally from the cylinder 11 to heat the gas 3 and to generate an accelerated flow of the gas 3 upward. Thus, the gas 3 exhausted from the cylinder 11 into the stack 1 decreases in its specific gravity and also decreases in its concentration. Further, the gas can be exhausted at a fast speed into the atmosphere up to a high place to reduce a drop of the gas to the vicinity of a ground of a leeward side and to eliminate a riskiness of its ignition.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to an unnecessary flammable gas generated in a chemical plant and a power plant, for example,
Liquid fuel such as liquefied natural gas stored in tanks is vaporized and released into the atmosphere without burning unnecessary combustible gas that may become gaseous and leak from the tank. Vent stack safety device.

[0002]

2. Description of the Related Art Unnecessary flammable gas generated in power plants and the like, which cannot be used because of its low concentration, is released on the ground and released into the air above a raised exhaust pipe. Then, they are mixed and diluted with the air to dispose of them without fear of burning.

FIG. 4 is a configuration diagram of a vent stack for exhausting unnecessary combustible gas generated in such a chemical plant and a power plant into the atmosphere. As shown in the figure, in order to exhaust unnecessary combustible gas 3 to the atmosphere, a cylindrical exhaust stack 2 is placed inside a cylindrical vent stack 1 erected on the ground with its height raised. Combustible gas leaked from the fuel tank, etc. and collected after being placed and erected
To the top of the exhaust stack 2 projecting slightly upward from the top of the vent stack 1 to discharge the combustible gas 3 to the atmosphere from the top, mix, diffuse, and dilute in the atmosphere. The density is reduced.

When the temperature of the flammable gas 3 is high and the specific gravity is lower than that of the air, the flammable gas rises in the atmosphere, diffuses into the atmosphere by the wind 8, and is diluted by the atmosphere. The vent stack 1 can be disposed of by discharging it to the atmosphere as a harmless substance having a low concentration and no risk of ignition or the like.

However, when the low temperature flammable gas 3 is released into the atmosphere in such a vent stack 1, the specific gravity of the flammable gas 3 at a low temperature is greater than that of air. As shown in FIG. 4, even if it is discharged into the atmosphere from the top of the vent tack 1, it is blown by the wind 8 and diffused into the atmosphere, but it approaches the ground while descending due to gravity. In a certain area on the leeward side of the vent stack 1, the combustible gas 3 released into the atmosphere and once diffused may be concentrated to the flammable limit range where ignition is performed again.

As described above, when the concentration of the flammable gas 3 falls within the flammable limit range, there is a possibility that the flammable gas 3 ignites, and the handling of the fire in the vicinity where the released flammable gas 3 drops a lot is considered. Strict restrictions are required, and in some cases, problems such as the need for evacuation may occur. For this reason, conventionally, in order to prevent a problem caused by the possibility of ignition of the concentrated combustible gas 3 discharged into the atmosphere in this way, a discharge protruding from the top of the vent stack 1 is provided. The flammable gas 3 released from the top of the cylinder 2 is provided with a flame cylinder at the top of the exhaust cylinder 2 as shown in FIG. A method is employed in which the gas 3 is burned and released into the atmosphere.

However, in the case where such a method is used, as shown in the figure, when another flammable gas tank 5 or the like is installed in a facility where the vent stack 1 is provided. When the flammable gas 7 gushes out of the flammable gas tank 5 through the safety valve 6 into the atmosphere, the flammable gas 7 squirting into the atmosphere from the safety valve 6 diffuses while flowing in the wind 8. When the flame 4 approaches the flame 4 at the top of the exhaust stack 6 and the concentration of the flammable gas 7 is within the flammable limit range, the flammable gas 7 is ignited by the flame 4 and further propagates the flammable gas 7. However, there is a risk that even the flammable gas stored in the flammable gas tank 5 may ignite.

Therefore, when the safety valve 6 of the flammable gas tank 5 installed near the vent stack 1 is activated, the flammable gas 7 is discharged into the atmosphere when an accident occurs. At the top of the vent stack 1, a valve 9 provided in the exhaust stack 2 for delivering the flammable gas 3 for generating a flame 4 is closed to forcibly shut off the release of the flammable gas 3 from the exhaust stack 2. Then, a method is employed in which the flame 4 burning at the top of the exhaust stack 2 is extinguished to prevent ignition of the combustible gas 7.

[0009] However, it takes several seconds to shut off the fuel using the valve 4 provided in the exhaust pipe 2 for discharging the flammable gas 3.
Since it takes several tens of seconds for the top flame 4 to extinguish, the flammable gas 7 ejected from the flammable gas tank 5 during this time reaches the flame 4 and ignites, causing the flammable gas tank 5 to ignite. There is a problem that the fuel in the interior may ignite, leading to the occurrence of a major accident.

In addition, even if the flame 4 can be extinguished, when the operation returns to the normal operation, the flame 4 is again fired.
There is a problem that it is necessary to ignite, and a lot of time and labor are required for the work for that.

In order to solve such a problem, the present applicant has proposed Japanese Patent Application No. 8-173462, entitled "Safety Device for Flare Stack". In the flare stack safety device of the present proposal, a plurality of discharge pipes for discharging non-combustible gas are arranged around a flame tube that burns unnecessary combustible gas in the flare stack and generates a flame 4. It is like that.

As described above, the non-flammable gas is discharged from the plurality of discharge pipes arranged around the flame tube at the top of the flare stack, so that the flammable gas 7 is released from the other flammable gas tanks 5 and the like. Even if there is a leak due to the operation of the flammable gas, the flammable gas 7 approaching the flame 4 is agitated by the nonflammable gas released from the discharge pipe before being ignited by the flame 4, and its concentration is reduced. The concentration is out of the range, and it is possible to prevent the flammable gas from igniting even if it reaches the flame burning at the top of the flare stack. Further, if a sufficient space is provided between the discharge tube and the flame tube, the above-described approach of the combustible gas 7 to the flame 4 can be reliably prevented, and the flame of the flare stack can be prevented by the non-combustible gas released from the discharge tube. However, there is an advantage that the fire is not extinguished.

However, in the flare stack safety device proposed above, since the flame 4 is still generated at the top of the flare stack, an unexpected accident or an operation error from the surrounding flammable gas tank 5 causes the flame 4. When a large amount of unnecessary flammable gas 7 leaks, there is a possibility that these flammable gases 7 are blown by the wind and ignite in proximity to the flame 4, and due to this ignition, The problem that the flammable gas in the flammable gas tank 5 is ignited still cannot be completely prevented. Further, in the event of an accident or the like, if the flame 9 at the top of the flare stack is extinguished by closing the valve 9 provided for the safety of the exhaust stack 2 for safety, after the restoration work is completed to the normal state, It is necessary to re-ignite the flame 4, and there is a problem that an operation for the re-ignition is required.

[0014]

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned problems caused when a combustible gas is released from the vent stack to the atmosphere without burning it, or to solve such problems. In particular, in order to eliminate a problem that occurs in a vent stack (flare stack) in which combustible gas released from the vent stack into the atmosphere is forcibly burned at the top of the exhaust stack 2 and released into the atmosphere, power generation is performed. Unnecessary flammable gas generated in places is released to the atmosphere without burning at the top of the vent stack, and flammable Heating the gas to a high temperature, reducing its specific gravity and accelerating the upward flow of combustible gas, which is released into the atmosphere from the vent stack Unishi Te, the possibility of released flammable gas approaches the vicinity of the ground and lowered small comb also,
The concentration of flammable gas released into the atmosphere can also be reduced to a concentration outside the flammable range, and even if the flammable gas falls to near the ground, it will not ignite It is an object to provide a vent stack safety device capable of achieving a safe concentration.

[0015]

Therefore, the first vent stack safety device of the present invention has the following means.

(1) The unnecessary combustible gas introduced is disposed inside through the side wall of the vent stack which is released to the atmosphere without burning, and the collected combustible gas is supplied from outside. A first exhaust pipe was introduced, which was introduced into the vent stack and discharged into the vent stack through an opening provided in the vent stack. It is preferable that the opening of the first exhaust pipe is arranged substantially at the center in the vent stack.

(2) The combustible which is disposed below the first exhaust stack through the side wall of the vent stack, is introduced from outside with the first exhaust stack, and is discharged into the vent stack through the opening of the first exhaust stack. A non-flammable gas such as high-temperature air or steam introduced from the outside is injected into the flammable gas and mixed with the flammable gas to reduce the concentration while heating the flammable gas and accelerating the flammable gas upward. And a discharge tube provided with a plurality of discharge ports for generating the gas.

Note that the discharge port is disposed not only below the opening of the first exhaust stack but also substantially uniformly throughout the vent stack, and above the combustible gas due to the noncombustible gas discharged from the discharge port. Vents are provided to ensure that the accelerated flow into the vent stack occurs evenly throughout the vent stack and that sufficient mixing of the non-flammable and flammable gases occurs. It is preferable that the discharge tube provided in the stack is formed of a plate-like member and is disposed substantially over the entire surface of the vent stack.

Since the vent stack safety device of the present invention employs the above-mentioned means (1) and (2), (a) the combustible gas discharged from the first exhaust stack into the vent stack is introduced into the vent stack. The non-combustible gas ejected from the discharge port is heated by the high-temperature non-combustible gas discharged from the discharge port of the discharge pipe, which is disposed below the disposed first exhaust pipe, and has a low specific gravity. The force accelerates the ascending flow that occurs in the vent stack, and is released from the top of the vent stack into the atmosphere at a high velocity and can be released to a high position, reducing the descent to the leeward side near the ground. Can be.

Further, the combustible gas discharged from the first exhaust stack into the vent stack is mixed and diluted by the noncombustible gas ejected from below, resulting in a low concentration of a large amount of the noncombustible gas mixed. Even if the flammable gas released into the atmosphere from the top of the vent stack drops to a predetermined area on the lee side and becomes concentrated, the concentration should be low outside the flammable range where ignition does not occur. The danger of ignition near the ground can be completely prevented in combination with the decrease in the descent to the ground near the leeward side.

Further, the flammable gas released into the atmosphere from the top of the vent stack is released without being ignited. Therefore, a separate flammable gas is installed in a facility where the vent stack is installed upright on the ground. Even when a large amount of flammable gas is discharged into the atmosphere due to the operation of a safety valve provided in the flammable gas tank or an operational error, the flammable gas tank is ignited and the flammable gas tank is ignited. It is possible to completely prevent the occurrence of a large accident in which fuel in the fuel ignites.

A second vent stack safety device according to the present invention employs the following means. (3) A connection portion connected to an end of a portion penetrating the side wall of the vent stack, which releases the introduced unnecessary combustible gas to the atmosphere without burning, substantially vents the inside of the vent stack. A second exhaust pipe was provided, which was erected in parallel with the stack, introduced the combustible gas collected from the outside into a connection portion in the vent stack, and discharged to the atmosphere from the top of the vent stack. . In addition, it is preferable that the connection part of the 2nd exhaust pipe which stood inside the vent stack and discharges combustible gas into the atmosphere is arranged substantially at the center of the vent stack and stood up.

(4) The connection part connected to the end of the portion penetrating the side wall of the vent stack surrounds the connection part of the second exhaust pipe erected inside the vent stack, and At the top of the vent stack,
That is, an ejection pipe for ejecting a high-temperature non-combustible gas introduced from the outside is provided on the outer peripheral side of the combustible gas discharged into the atmosphere from the top of the connection portion of the second exhaust pipe. In addition, it is preferable that the interval between the adjacent ejection pipes is about 5 to 10 times the diameter of the ejection pipe, and the plurality of ejection pipes installed upright inside the vent stack are provided. It is preferable to provide a gap between the cylinder and each ejection pipe.

Since the vent stack safety device of the present invention employs the above-mentioned means (3) and (4), (b) a second erected fuel gas is discharged from the top of the vent stack to the atmosphere. The outer periphery of the exhaust stack is provided with a plurality of erupting pipes that are erected so as to eject high-temperature non-combustible gas outside the flammable gas released into the atmosphere from the top of the vent stack. The flammable gas flowing in the second exhaust stack is heated by the non-flammable gas flowing in the adjacent ejection pipe, and has a lower specific gravity. It is released into the lee, and the descent to the leeward side near the ground is reduced.

At the top of the vent stack, the flammable gas released from the second exhaust stack into the atmosphere mixes and dilutes the outer periphery of the flammable gas from the ejection pipe with the non-flammable gas released into the atmosphere. As a result, a large amount of non-combustible gas is mixed and the concentration becomes low, and the combustible gas released into the atmosphere from the top of the vent stack drops to a predetermined area on the leeward side and is concentrated. However, the low concentration outside the flammable range that does not ignite can be released into the high atmosphere at a speed higher than the top of the vent stack, and the descent to the ground near the leeward side can be reduced, so that The danger of ignition in the can be completely prevented.

Further, as in the above (a), the flammable gas released into the atmosphere from the top of the vent stack is released without being ignited, so that the flammable gas is released to another flammable gas tank installed on the ground. Even if the flammable gas in the flammable gas tank is discharged into the atmosphere due to the operation of the provided safety valve or an erroneous operation, the flammable gas is ignited and the fuel in the flammable gas tank is ignited. It is possible to prevent the occurrence of a major accident in which a fire occurs.

The third vent stack safety device of the present invention employs the following means. (5) A connecting portion connected to the end of the portion penetrating the side wall of the vent stack, which releases the introduced unnecessary combustible gas to the atmosphere without burning, is substantially vented inside the vent stack. A flue was provided that was erected in parallel with the stack, and emitted flue gas, which was incombustible gas generated by a boiler or the like, to the atmosphere.

(6) Unnecessary flammable gas collected through the vent stack and the side wall of the flue is introduced into the flue from the outside, and is discharged from an opening provided in the flue. Was introduced into the flue, and a third exhaust stack was provided so as to be discharged into the atmosphere from the top of the flue. The flammable gas introduced into the flue from the third exhaust stack is such that smoke discharged from a boiler or the like is about 90 degrees, and it is preferable to introduce the combustible gas into the flue from above the flue. .

Since the vent stack safety device of the present invention employs the above-mentioned means (5) and (6), (c) is erected substantially parallel to the vent stack inside the vent stack,
Unnecessary combustible gas collected from the third exhaust stack was introduced into the flue, which emitted the non-combustible gas emitted from the boiler, etc., into the atmosphere. The combustible gas is mixed with the high-temperature flue gas flowing in the flue, heated and reduced in specific gravity, and diluted by mixing with the flue gas. It will be low. As a result, it is released from the top of the vent stack to the high atmosphere at a high speed, and the descent to the leeward side near the ground is reduced, and the concentration of flammable gas is reduced, and the descent near the ground is reduced. However, even if the concentration of the flammable gas is concentrated, the danger of ignition can be completely prevented.

Further, as in the case of the above (a), the flammable gas released into the atmosphere from the top of the vent stack is released into the atmosphere together with the smoke without ignition.
Even if a safety valve provided on another flammable gas tank standing on the ground is activated, or if a large amount of flammable gas in the flammable gas tank is discharged into the atmosphere due to an operation error, etc. It is possible to prevent the occurrence of a major accident in which the combustible gas is ignited and the fuel in the combustible gas tank is ignited.

[0031]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of a vent stack safety device according to the present invention will be described below with reference to the drawings. In the drawings showing the following embodiments, members that are the same as or similar to those shown in FIGS. 4 and 5 are given the same reference numerals, and descriptions thereof are omitted. FIG. 1 is a view showing a first embodiment of a vent stack safety device according to the present invention, and FIG.
Is a longitudinal sectional view, and FIG. 1B is a view taken along the line AA shown in FIG.
FIG.

In the figure, a first exhaust cylinder 11 is installed inside the outer cylinder by penetrating an outer cylinder which is a side wall of the vent stack 1, and is provided at an end of the first exhaust cylinder 11 at the center of the outer cylinder. The opening 12 is arranged. On the other hand, a discharge pipe 13 is disposed below the first exhaust pipe 11 so as to penetrate an outer cylinder facing the outer cylinder through which the first exhaust pipe 11 penetrates. The discharge pipe 13 is provided with a valve 15 capable of discharging a high-temperature non-combustible gas 14 such as air or water vapor into the vent stack 1 in a short time. 14 is supplied into the vent stack 1. Non-combustible gas 14 supplied into vent stack 1
From a number of outlets provided on the upper surface of the discharge tube 13,
The air is discharged so as to generate an upward uniform flow throughout the inside of the vent stack 1.

A drain pipe 17 and a drain pump 18 are connected to the bottom of the vent stack 1 so as to discharge the water 19 remaining at the bottom of the vent stack 1.

The vent stack safety device 1 of the present embodiment
At 0, the flammable gas 3 discharged into the vent stack 1 from the opening 12 of the first exhaust stack 11 has a large specific gravity due to low temperature, and immediately descends by gravity immediately after being discharged from the opening 12. On the inner circumference of the vent stack 1 and on the upper surface of a discharge tube 13 formed in a cylindrical shape having a substantially cylindrical diameter, upward from a discharge port 16 formed so as to be evenly distributed inside the vent stack 1. Agitated and mixed by the non-flammable gas 14 such as high-temperature steam and air released by the process, the non-flammable gas 14 having a specific gravity smaller than that of air is obtained.
In addition, the mixed gas 20 in which the concentration of the flammable gas 3 is reduced to the outside of the flammable range is also obtained.

As a result, the mixture gas 20 whose temperature has risen and the specific gravity has decreased and the concentration of the flammable gas 3 has been reduced to a flammable range in which the flammable gas 3 is not ignited by mixing with the non-flammable gas 14 is ejected from the discharge port 16. Due to the jetting power of the non-combustible gas 14 to be produced, the ascending speed increases, and the gas is discharged at a higher speed than the upper part of the vent stack 1 and can be discharged into a high atmosphere.

Further, after the mixed gas 20 is released from the vent stack 1, it is possible to reduce the possibility that the mixed gas 20 descends to reach the ground. 3 is sufficiently diluted by mixing the non-flammable gas 14 to become a mixed gas 20 having a small amount of three components of the combustible gas. Since the concentration component of the gas 3 is out of the flammable range, there is no ignition.

Further, by contacting the low temperature flammable gas 3 introduced into the vent stack 1 from the opening 12, the moisture in the non-combustible gas 14 released into the vent stack from the discharge port 16 is liquefied. Although there is a possibility, the liquefied water 19 is stored at the bottom of the vent stack 1 and is discharged to the outside of the vent stack by the water distribution pipe 17 and the drain pump 18 without any particular problem.

Further, the flammable gas 3 released into the atmosphere
Is discharged from the top of the vent stack 1 without ignition, and is provided in another flammable gas tank installed in a facility where the vent stack 1 erected on the ground is disposed. The safety valve is activated,
Even when a large amount of combustible gas is discharged into the atmosphere due to an operation error or the like, the combustible gas is no longer ignited, and the fuel in another combustible gas tank is ignited. Such an accident can be reliably prevented from occurring.

FIG. 2 is a longitudinal sectional view showing a second embodiment of the vent stack safety device according to the present invention. In the figure, an outer cylinder which is a side wall of the vent stack 1 is penetrated, and a connecting portion 22a is connected to an end arranged at the center of the outer cylinder, and this connecting portion 22a is made parallel to the vent stack 1,
Around the second exhaust pipe 22 erected at the center, the second exhaust pipe 22 is spaced apart from the second exhaust pipe 22 and has substantially the same height as the second exhaust pipe 22. A plurality of ejection pipes 23 are provided to discharge the non-combustible gas into the atmosphere.

The plurality of ejection pipes 9 have the same diameter, and the second
The connecting portion 23a is connected to the end portion of the vent stack 1 through which the outer tube penetrates in the same manner as the exhaust tube 22.
Are arranged at equal intervals on the circumference concentric with the second exhaust pipe 22.

A valve capable of discharging a non-combustible gas 14 such as high-temperature air or water vapor into the vent stack 1 in a short time in each of the jet pipes 23 penetrating the outer cylinder of the vent stack 1. The connection pipe 22 a through which the nonflammable gas 14 flows the combustible gas 3, that is, the second exhaust pipe 22 is provided with an interval therebetween through the valve 15. Connection pipe 23a,
That is, the combustible gas 3 which is supplied into the ejection pipe 23 and discharges the non-combustible gas 14 at high pressure from the connection portion 22a to the atmosphere from the top which is almost the same height as the vent stack 1 and the second exhaust pipe 22 It is released to the outside. The interval between adjacent ones of the connection portions 23a of the ejection pipes 23 arranged at equal intervals on the circumference is the same as that of the ejection pipe 2.
3 is about 5 to 10 times the diameter.

The vent stack safety device 2 of the present embodiment
In 1, the combustible gas 3 is exhausted into the atmosphere at the top of the second exhaust pipe 22, and the high-temperature, high-pressure incombustible gas 14 is discharged from a plurality of ejection pipes 23 provided outside the second exhaust pipe 22. As a result, the combustible gas 3 exhausted from the second exhaust pipe 22 to the atmosphere becomes a non-combustible gas 14 of high pressure and high temperature.
By mixing with, the specific gravity becomes smaller than air,
In addition, the mixed gas 20 in which the concentration of the flammable gas 3 is reduced to the outside of the flammable range is also obtained.

In particular, even when the combustible gas 3 passes through the connecting portion 22a inside the vent stack 1 which is set up in parallel, the jet pipe 2 which is set up so as to surround the connecting portion 22a.
3 is heated by the non-flammable gas 14 passing through the connecting portion 23a, the temperature becomes high, the density becomes lower, and the contact between the low-temperature non-flammable gas 3 and the non-flammable gas 14 Since it only happens at the top of stack 1,
The moisture in the non-combustible gas 14 that heats the combustible gas 3 has no possibility of liquefaction in the vent stack 1 and is liquefied stored at the bottom of the vent stack 1 provided in the first embodiment. There is no need to provide a water distribution pipe 17 and a drain pump 18 for discharging water to the outside.

As a result, the temperature rises, the specific gravity decreases, and the combustible gas 3
Mixed gas 2 whose concentration has decreased to a flammable range where ignition does not occur
0 is also due to the suction force of the non-combustible gas 14 ejected into the atmosphere from the top of the connection portion 23a, and the ascending speed is increased,
It is released at a higher rate than the top of the vent stack 1 and can be released into high atmosphere. For this reason, after the mixed gas 20 is released from the vent stack 1, it is less likely that the mixed gas 20 descends and reaches the ground. Is sufficiently diluted by mixing with the non-combustible gas 14 at the top of the vent stack 1 to be released as a mixed gas 20 containing three components of the combustible gas.
Even if the flammable gas 3 is concentrated near the ground on the leeward side, the concentration of the flammable gas 3 is out of the flammable range, so that it does not ignite.

Further, as in the first embodiment, the flammable gas 3 released into the atmosphere is released from the top of the vent stack 1 without being ignited. Even if the safety valve of another flammable gas tank is operated or a large amount of flammable gas in the flammable gas tank is discharged into the atmosphere due to an operation error or the like, it is not possible to ignite this flammable gas. In addition, it is possible to prevent the occurrence of an accident due to the ignition of the combustible gas 3.

Next, FIG. 3 is a longitudinal sectional view showing a third embodiment of the vent stack safety device according to the present invention.

As shown in the figure, an outer cylinder which is a side wall of the vent stack 1 is penetrated, and is erected substantially in parallel with the vent stack 1 from an end located at the center portion of the outer cylinder, such as a power plant. A flue 26 is provided which discharges flue gas 27 generated in the boiler to the atmosphere. In addition, flue 26
An outer cylinder provided on the side opposite to the outer cylinder of the vent stack 1 penetrating therethrough and a flue 2 erected inside the vent stack 1
6 is provided with an opening 29 in the flue 26 so as to provide an opening 29 inside the flue 26, and unnecessary low-temperature flammable gas 3 generated in a power plant or the like is discharged to the third exhaust pipe. The gas is introduced into the upper part of the flue 26 through the cylinder 28.

The vent stack safety device 2 of the present embodiment
In 5, the low temperature combustible gas 3 discharged into the flue 26 from the third stack 28 is mixed with the flue gas 27 rising in the flue 26 immediately after being released. Normally, the temperature of the flue gas 27 generated in a power plant or the like is as high as 90 ° C. or higher and has a large capacity, so that the low-temperature combustible gas 3 is heated by mixing to become lighter than air, Also decrease.

As a result, after the mixed gas 14 is discharged from the top of the vent stack 1 to the outside air, it does not descend and reach the ground. Further, since the concentration becomes lower than the flammable range, even if the concentration is lowered and concentrated near the ground, no ignition occurs. Further, in the present embodiment, it is not necessary to provide the discharge pipe 13 or the ejection pipe 23 required for introducing the non-combustible gas into the best tack 1 or the valve 15 interposed therebetween, and the cost is reduced. it can. Furthermore, as in the first and second embodiments, the flammable gas 3 is released into the atmosphere without ignition, so that a large amount of flammable gas leaks from another flammable gas tank. Even if it does, there is no concern about accidents.

[0050]

As described above, the first vent stack safety device of the present invention is provided inside the vent stack through the side wall of the vent stack, and collects the combustible gas from the outside into the vent stack. And a first exhaust pipe, which is introduced into the vent stack, and is disposed below the first exhaust pipe through a side wall of the vent stack. The first exhaust pipe introduces flammable gas from outside. In addition, a non-combustible gas introduced from the outside can be blown out to reduce the concentration of the combustible gas, reduce the specific gravity by heating, and generate a flow that accelerates the combustible gas upward. A discharge pipe having a plurality of discharge ports is provided.

As a result, the combustible gas discharged from the first exhaust stack into the vent stack is heated by the high-temperature non-flammable gas discharged from the discharge port of the discharge pipe, the specific gravity decreases, and the combustible gas decreases from the discharge port. The non-combustible gas that is expelled accelerates the upward flow in the vent stack, releases it to the atmosphere at a high speed, releases it to a high position, and reduces the descent to the leeward side near the ground. it can.

Further, the flammable gas is mixed and diluted with the non-flammable gas to have a low concentration, and even if the flammable gas released into the atmosphere falls to a predetermined area on the leeward side and is concentrated. In addition, the concentration outside the flammable range where ignition does not occur is low, and the descent to the leeward side near the ground is reduced, so that the danger of ignition near the ground can be completely prevented.

Further, since the flammable gas released into the atmosphere is released without igniting, a safety valve provided in another flammable gas tank installed in the facility where the vent stack is disposed operates. Even if a large amount of flammable gas is discharged into the atmosphere due to an operation error or the like, this flammable gas can be ignited to completely prevent the occurrence of a major accident that ignites the fuel in the flammable gas tank. Can be prevented.

Further, in the second vent stack safety device of the present invention, the connecting portion connected to the end of the portion penetrating the side wall of the vent stack is erected inside the vent stack, and the collected combustible combustible. Second exhaust pipe that discharges a reactive gas from the top of the vent stack to the atmosphere, and a connection part connected to the end of a portion penetrating the side wall of the vent stack is connected to the second exhaust pipe that is erected. A plurality of erection tubes are provided inside the vent stack so as to surround the part and are provided with an ejection pipe on the outer peripheral side of the flammable gas released into the atmosphere so as to eject a high-temperature non-combustible gas introduced from the outside. And

As a result, the combustible gas flowing through the second exhaust stack in the vent stack is heated by the non-combustible gas flowing through the adjacent ejection pipe, the specific gravity decreases, and the velocity is higher than the top of the second exhaust stack. Released into higher atmospheres, less descent downwind and near the ground.

At the top of the vent stack, the flammable gas released into the atmosphere from the second exhaust stack is mixed and diluted by the non-flammable gas released from the ejection pipe to the atmosphere around the flammable gas. As a result, a large amount of non-flammable gas is mixed and the concentration becomes low, and the combustible gas discharged into the atmosphere from the vent stack part falls to a predetermined area on the leeward side and is concentrated. However, it is possible to reduce the concentration outside the flammable range where it does not ignite, release it into the atmosphere at a high speed, and reduce the descent to the ground near the leeward side. Property can be completely prevented.

Further, as in the case of the above (a), it is possible to prevent occurrence of a large accident in which fuel in another flammable gas tank is ignited.

In a third aspect of the vent stack safety device of the present invention, the connecting portion connected to the end of the portion penetrating the side wall of the vent stack is erected in parallel with the vent stack, and a boiler or the like is provided. The flue, the vent stack, and the flue that discharges the incombustible gas generated in the air into the atmosphere are provided through the flue, and the collected unnecessary combustible gas is introduced into the flue from outside, and the smoke A third exhaust pipe is provided which discharges the gas from an opening provided in the road, introduces combustible gas into the flue, and discharges the combustible gas into the atmosphere from the top of the flue.

As a result, the combustible gas introduced into the flue is heated by the high-temperature non-flammable gas flowing through the flue, and its specific gravity is lowered. Flammable gas concentration is low, released at high speed into high atmosphere,
Combined with a decrease in the leeward side near the ground and a decrease in the concentration of flammable gas, a descent near the ground and the concentration of flammable gas may be concentrated, Danger can be completely prevented.

Further, as in the case of the above (a), it is possible to prevent occurrence of a large accident such as ignition of fuel in another flammable gas tank.

[Brief description of the drawings]

FIG. 1 shows the first embodiment of the vent stack safety device of the present invention.
1 (a) is a longitudinal sectional view, FIG. 1 (b) is a plan view taken along the line AA shown in FIG. 1 (a),

FIG. 2 shows a second embodiment of the vent stack safety device of the present invention.
2 (a) is a longitudinal sectional view, FIG. 2 (b) is a plan view taken along the line BB shown in FIG. 2 (a),

FIG. 3 shows a third embodiment of the vent stack safety device of the present invention.
Longitudinal sectional view showing the form,

FIG. 4 is a longitudinal sectional view showing a conventional vent stack,

FIG. 5 is a vertical cross-sectional view showing a conventional flare stack in which a flame tube is provided at the top of an exhaust tube so that flammable gas is forcibly ignited and combustible gas is burned and released into the atmosphere. FIG.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 vent stack 2 exhaust stack 3 flammable gas 4 flame 5 flammable gas tank 6 safety valve 7 flammable gas 8 wind 9 valve 10 vent stack safety device 11 first exhaust stack 12 opening 13 discharge pipe 14 nonflammable gas 15 valve 16 discharge port 17 drain pipe 18 drain pump 19 moisture 20 mixed gas 21 vent stack safety device 22 second exhaust pipe 22a (second exhaust pipe) connection part 23 ejection pipe 23a (ejection pipe) connection part 25 vent stack safety device 26 flue 27 exhaust Smoke 28 third exhaust stack 29 opening

Claims (3)

[Claims] 1. A flammable gas introduced into a vent stack set up on the ground is released into the atmosphere without burning, and even after the release to the atmosphere, the concentration of the flammable gas is out of a flammable range in which ignition does not occur. In the vent stack safety device, a first exhaust pipe that is disposed inside the side wall of the vent stack and introduces the combustible gas into the vent stack, and a side wall of the vent stack A discharge pipe disposed below the first exhaust pipe and having a plurality of discharge ports for discharging a high-temperature non-combustible gas to the combustible gas introduced into the vent stack. A vent stack safety device, characterized in that: 2. A flammable gas introduced into a vent stack set up on the ground is released into the atmosphere without burning, and the concentration of the flammable gas is out of a flammable range in which the concentration of the flammable gas does not ignite even after being released to the atmosphere. In the vent stack safety device, a connection portion penetrating through the side wall of the vent stack and disposed inside is provided upright, and the combustible gas is discharged to the atmosphere from the top of the vent stack. (2) an exhaust pipe, and a connecting portion penetrating through the side wall of the vent stack and disposed inside and surrounding the second exhaust pipe,
A vent stack safety device, comprising: an ejection pipe for ejecting a high-temperature non-combustible gas outside the combustible gas discharged from the top into the atmosphere. 3. A flammable gas introduced into a vent stack erected on the ground is released into the atmosphere without burning, and the concentration of the flammable gas is out of a flammable range in which the concentration of the flammable gas does not ignite even after being released to the atmosphere. In the vent stack safety device, a connection portion is provided standing through the side wall of the vent stack and disposed inside, and a flue for discharging smoke exhaust to the atmosphere; the vent stack and the vent stack; A vent stack safety device provided with a third exhaust pipe provided through a side wall of the flue and introducing the combustible gas into the flue.