JP2000271422A - Downward stream type temperature reduction column - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a water jet type temp. reduction column capable of reducing the temp. of low temp. waste gas to lower temp. than that in a conventional method, and also capable of stabilizing the waste gas flow introduced from plural waste gas introducing ports and capable of surely preventing deficiencies due to unvaporized waterdrop. SOLUTION: Plural waste gas introducing ports 6 are formed, and a water spray nozzle 4 is arranged at the central part of these waste gas introducing ports 6, and the supply of the waste gas supplied to each waste gas introducing port 6 by a waste gas distributing device 9b is uniformalized, and the flow rate of the waste gas introduced from each waste gas introducing port 6 is uniformalized to stabilize the flow in a drum part, and the water is sprayed into the waste gas stream to be surely vaporized and to prevent the undesirable behavior of the sprayed waterdrop.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a downflow type cooling tower for spraying water into high-temperature exhaust gas discharged from an incinerator of a refuse incineration facility, a combustible waste treatment facility, or the like to cool it to a predetermined temperature. It is about. More specifically, the present invention relates to a downflow type cooling tower provided with a device for uniformly distributing exhaust gas to a plurality of exhaust gas inlets in the above-described cooling tower.

[0002]

2. Description of the Related Art Exhaust gas discharged from an incinerator as described above has a high temperature of 800 ° C. or higher, and this high-temperature exhaust gas is subjected to heat energy recovery means such as a boiler or an economizer or a water injection type gas cooler. Thirty-five
It is cooled to a temperature of about 0 ° C. and sent to a subsequent electric dust collector or the like to be subjected to dust collection processing.

[0003] Recently, it has been found that organic halogen compounds such as dioxin generated in exhaust gas are generated at a temperature near 300 ° C. For this reason, a method of cooling exhaust gas to a low temperature of 200 ° C. or lower and collecting dust at a low temperature by a bag filter is becoming mainstream.

In order to cool the exhaust gas to 200 ° C. or less in this way, for example, the exhaust gas which has been heated to 250 to 350 ° C. by a boiler or the like is further guided to a cooling tower, and water is injected. A method of cooling to a temperature of 200 ° C. or less is used. In this way, the exhaust gas is
By cooling to below C, the formation of the above-mentioned organic halogen compounds such as dioxin can be effectively prevented.

[0005] However, the conventional water spray type cooling tower requires the above-described exhaust gas to be cooled to a lower temperature.
It turns out that it is not always suitable. Hereinafter, the reason will be described.

FIGS. 17 and 18 show a schematic structure of a conventional downflow type cooling tower. Reference numeral 101 in the figure denotes a substantially cylindrical body of the cooling tower. An exhaust gas introduction duct 102 is connected to an upper end of the body 101, and an exhaust gas discharge duct 103 is connected to a lower portion of the body 101. And
Exhaust gas introduced into the body 101 from the exhaust gas introduction duct 102 flows downward in the body 101 and is discharged from the exhaust gas discharge duct 103.
In addition, a dust discharge unit 10 is provided at the lower end of the body 101.
5 are provided.

A plurality of water spray nozzles 104 are provided on the upper peripheral wall of the body 101, for example. Water is sprayed from these water spray nozzles 104 in the form of mist, and the sprayed water droplets come into contact with the exhaust gas in the body 101 to evaporate, thereby cooling the exhaust gas by the latent heat of vaporization.

By the way, as described above, the body 10
If the temperature of the exhaust gas introduced into 1 is low, the evaporation rate of the above-mentioned water droplets becomes slow. For this reason, the non-evaporated water droplets that have not completely evaporated reach the inner surface of the body portion 101 and wet the inner surface, causing problems such as adhesion of dust. In addition, there is a disadvantage that the unevaporated water droplets flow out together with the exhaust gas from the exhaust gas discharge duct and reach a bag filter at a subsequent stage. Further, wet dust is generated by the unevaporated water droplets, which causes problems such as sticking of dust and difficulty in discharging dust.

[0009] The above-mentioned problems are caused by the structure of such a conventional downflow type cooling tower. That is, such a cooling tower is designed so that water droplets completely evaporate in the body 101, but in fact, the exhaust gas introduced into the body is sufficiently and uniformly diffused. Instead, part of the exhaust gas reaches the exhaust gas discharge duct 103 in a short-circuit manner. For this reason, the exhaust gas does not have a predetermined residence time in the body portion 101, and thus does not have a sufficient evaporation time of the sprayed water droplets. To reach.

[0010] Actually, the flow of exhaust gas in the cross section of the body 101 is not completely uniform, but becomes non-uniform. For this reason, supercooling occurs due to partial evaporation of water droplets in the body, the temperature distribution becomes uneven, and the sprayed water droplets reach the inner surface of the body 101 without completely evaporating. Is generated.

In order to prevent the above problems, there is a cooling tower in which the flow of exhaust gas passing through the inside of the body is used as a swirling flow, and water is sprayed at the center of the swirling flow. However, in such a case, the problem of uneven flow of the exhaust gas in the trunk is not fundamentally solved, and unevaporated water droplets easily reach the inner surface of the trunk due to centrifugal force. The problem that dust adheres as a wet surface is not solved.

In order to solve the above-mentioned problems, an exhaust gas inlet formed at the upper part of the body of the cooling tower and introducing exhaust gas downward into the body, and a central part of the exhaust gas inlet are provided at the center of the exhaust gas inlet. A downflow type cooling tower equipped with a water spray nozzle for spraying water downward has been developed.

In such a cooling tower, the water droplets sprayed from the water spray nozzle are instantaneously and efficiently mixed in the flow of the exhaust gas having a high enthalpy immediately after being introduced from the exhaust gas inlet, and the water droplets are sprayed. As the contact between the gas and the exhaust gas becomes active, the gas evaporates completely in a short time. Further, the exhaust gas introduced downward from the exhaust gas inlet forms a downward jet-like flow in the body. Then, water is sprayed downward from the water spray nozzle during the flow of the downward exhaust gas, and the gravity acting on the sprayed water droplets is also downward. Therefore, the water droplets move to the lower part of the body together with the downward flow of the exhaust gas, and evaporate before reaching the lower part of the body because the contact between the water droplets and the exhaust gas is active as described above.

In the above-mentioned temperature reducing tower, it is necessary to introduce the exhaust gas at a high speed from the exhaust gas inlet and to surely evaporate the sprayed water droplets in a short time. In addition, the exhaust gas introduced from the exhaust gas inlet needs to flow down in a stable manner together with the sprayed water droplets as a jet-like flow.

For this reason, the exhaust gas inlet cannot have a large diameter, and a plurality of exhaust gas inlets must be provided in order to secure a required amount of exhaust gas treatment. However, simply providing a plurality of exhaust gas introduction ports may cause the water droplet flows injected into each exhaust gas introduction port to interfere with each other, and at this time, the evaporation action in the body may be inhibited.

In order to stabilize the mixed flow of the water droplet flow and the exhaust gas flow from each exhaust gas inlet more reliably, the flow rate of the exhaust gas supplied to each exhaust gas inlet is made uniform, and the flow velocity of each exhaust gas flow is reduced. It is effective to make them equal.

In order to stabilize the flow of the exhaust gas from each exhaust gas inlet, it is effective to make the flow rate of the exhaust gas supplied to each exhaust gas inlet uniform and equalize the flow velocity of each exhaust gas flow.

[0018]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and even when the exhaust gas to be supplied is at a low temperature, the sprayed water droplets evaporate quickly and surely, and the unevaporated water is discharged. While preventing problems caused by water droplets,
An object of the present invention is to provide a downflow type cooling tower capable of uniformly supplying exhaust gas to a plurality of exhaust gas inlets and stabilizing the flow of exhaust gas introduced from these exhaust gas inlets.

[0019]

According to the first aspect of the present invention, there are provided a plurality of exhaust gas inlets for introducing exhaust gas downward into a body of a cooling tower, and a central portion of the exhaust gas inlet. A water spray nozzle for spraying water downward, an exhaust gas introduction duct for supplying exhaust gas to the exhaust gas inlet, and an exhaust gas introduction duct provided between the exhaust gas introduction duct and each of the above exhaust gas introduction ports. An exhaust gas distribution device is provided that uniformly distributes and supplies the exhaust gas supplied through the duct to the exhaust gas introduction ports.

Therefore, water is sprayed directly into the flow of the exhaust gas introduced from these exhaust gas inlets, so that the sprayed water droplets evaporate reliably in a short time. In addition, since the water droplets sprayed downwardly evaporate while flowing downward together with the flow of the exhaust gas introduced downward from the exhaust gas inlet, the behavior of these water droplets is stable and reliable, and the unevaporated water droplets are It is reliably prevented from adhering to the inner surface of the body.

Further, since a plurality of the exhaust gas introduction ports are provided, the flow of the exhaust gas can be more uniformly and stably formed in the body portion, and the evaporation of the water droplets can be further ensured. .

Further, since the exhaust gas is uniformly supplied to the plurality of exhaust gas inlets by the exhaust gas distribution device, the flow velocities of the exhaust gas introduced from the respective exhaust gas inlets become exactly equal to each other, and the plurality of exhaust gas in the body portion are reduced. The plurality of exhaust gas flows can be uniformly and stably formed in the body without causing any adverse effect due to the interference of the exhaust gas flows with each other.

According to a second aspect of the present invention, in the exhaust gas distribution apparatus, the exhaust gas distribution device includes a branch duct branched from the exhaust gas introduction duct and communicating with each of the exhaust gas introduction ports. And a flow rate adjusting damper for adjusting the flow rate of the exhaust gas flowing through these branch ducts.

Therefore, by adjusting each of the flow rate adjusting dampers, the amount of exhaust gas supplied to each exhaust gas inlet can be accurately and reliably adjusted, and the flow velocity of exhaust gas introduced from each exhaust gas inlet is made uniform. These flows can be stabilized.

According to a third aspect of the present invention, there is provided the exhaust gas distribution device, wherein the exhaust gas distribution duct is branched from the exhaust gas introduction duct and communicates with each of the exhaust gas introduction ports. And a guide vane provided in the exhaust gas introduction duct on the upstream side for deflecting the exhaust gas flowing and uniformly flowing the exhaust gas to the branch duct.

Therefore, by the above-mentioned guide vane,
The flow rate of exhaust gas supplied to each branch duct is adjusted uniformly, the amount of exhaust gas supplied to each exhaust gas inlet can be adjusted accurately and reliably, and the flow rate of exhaust gas introduced from each exhaust gas inlet to the body is uniform. And these flows can be stabilized. Further, in this apparatus, since the flow of the exhaust gas is adjusted by deflecting the flow of the exhaust gas by the guide vanes, the pressure loss is small.

According to a fourth aspect of the present invention, there is provided the exhaust gas distribution device, wherein the exhaust gas distribution device is arranged so as to surround the plurality of exhaust gas introduction ports, and a part of the annular circulation flow passage communicates with the exhaust gas introduction duct. And one end portion is provided to correspond to each of the exhaust gas introduction ports, and one end portion is branched and connected to the above-described circulation flow path, and a middle portion communicates with each of the exhaust gas introduction ports, and the other end portion communicates with each other at a central portion. And a plurality of branched flow paths.

Therefore, the exhaust gas supplied from the exhaust gas introduction duct flows while circulating or circulating in the above-mentioned annular orifice, and a part of this flow flows into each of the above-mentioned branch flow paths, and each of the exhaust gas is introduced. Supplied to the mouth. Therefore, the exhaust gas flows into each distribution channel under the same conditions, and the flow rate of the exhaust gas supplied to each exhaust gas inlet becomes accurately uniform.

Further, since the other end of each branch flow path is communicated with each other at the central portion, even if a difference in pressure or the like in these branch flow paths occurs, the branch flow path can be connected through this communication part. These pressure differences and the like are immediately eliminated, and the conditions such as the pressure in each branch flow path become equal, so that the flow rate of the exhaust gas can be distributed very accurately. In addition, the exhaust gas branches and flows into each branch flow path while turning or circulating in the circulation flow path, so that pressure loss is small.

According to a fifth aspect of the present invention, the cross-sectional area of the branch flow path is set so that the flow rate of the exhaust gas in the branch flow path is faster than the flow rate of the exhaust gas in the circulation flow path. Is set to be smaller than the cross-sectional area of the above-mentioned circulation channel.

Generally, when exhaust gas containing dust flows in a flow path having such a branch flow path, dust tends to accumulate in the branch flow path. However, in this case, since the cross-sectional area of the branch flow path is set to be small and the flow velocity inside the branch flow path is increased, it is possible to prevent dust from accumulating in these branch flow paths.

According to a sixth aspect of the present invention, a flow rate adjusting damper for adjusting a flow rate of exhaust gas flowing into the branch flow path from the circulation flow path is provided at one end of the branch flow path. It is characterized by being provided.

Therefore, by adjusting these flow rate adjusting dampers, the flow rate of the exhaust gas flowing into each branch flow path is forcibly adjusted, and the flow rate of the exhaust gas supplied to each exhaust gas inlet is reliably and accurately uniform. It can be.

[0034]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIGS. 1 and 2 show a cooling tower according to a first embodiment of the present invention. The cooling tower cools the exhaust gas from the incinerator by 250 to 350 ° using a waste heat recovery boiler or the like.
After cooling to C, the low temperature exhaust gas is further
It cools to below C.

Reference numeral 1 in the figure denotes a main body, that is, a body of the cooling tower, and the body 1 has a substantially cylindrical shape. A plurality of, for example, three exhaust gas inlets 6 are formed in the upper wall of the upper end.

Exhaust gas of 200 ° C. or higher after being discharged from the incinerator and recovered by a boiler or the like is discharged to an exhaust gas introduction duct 2 by an unillustrated induction fan or the like.
Through the exhaust gas inlet 6 and the body 1
It is configured to be introduced downward into the inside.

An exhaust gas discharge duct 3 is provided on the lower peripheral wall of the body 1.
Is connected to a dust collector such as a bag filter (not shown). The exhaust gas introduced from the exhaust gas inlet 6 flows downward in the body 1, is discharged from the exhaust gas discharge duct 3, and is sent to the dust collector. The bottom of the body 1 is provided with a dust discharge section 5 for discharging dust.
Is provided.

Further, in this embodiment, the following exhaust gas distribution device is provided in order to evenly distribute and supply the exhaust gas supplied from the exhaust gas introduction duct 2 to each of the exhaust gas introduction ports 6 described above. ing.

That is, the end of the exhaust gas introduction duct 2 has a number corresponding to the number of the exhaust gas introduction ports 6, and in this embodiment, three branch ducts 2a, 2b, 2c.
Are branched and connected, and these branch ducts 2a, 2a
b and 2c are respectively connected to the exhaust gas inlets 6 described above.
It is connected to the.

The above branch ducts 2a, 2b,
In the middle of 2c, flow control dampers 9a, 9b,
9c is provided. Then, these flow rate adjusting dampers 9a, 9b, 9c are respectively adjusted to adjust the respective branch ducts 2.
The flow rate of the exhaust gas flowing through the insides a, 2b, and 2c is adjusted, and the flow rate of the exhaust gas supplied to each exhaust gas inlet 6 is evenly distributed.

Note that the exhaust gas distribution device is not limited to the above-described one. For example, a branch duct or the like may be arranged so that the exhaust gas is evenly distributed by the duct itself. Further, the flow rate adjusting damper may be adjusted in opening when the cooling tower is started up, or may be adapted to cope with a large change in operating conditions.

Each of the exhaust gas inlets 6 is provided with a water spray nozzle 4.
Sprays water, and cools the exhaust gas by evaporation of the sprayed water droplets. Hereinafter, the configuration and operation of the exhaust gas inlet 6 and the water spray nozzle 4 will be described.

First, each of the exhaust gas inlets 6 has a circular shape, and opens downward in the body 1 to introduce exhaust gas downward. A substantially cylindrical rectifying guide member 7 is provided to protrude downward so as to surround each of the exhaust gas inlets 6. In the case of this embodiment, these rectifying guide members 7 are formed in a cone shape whose diameter decreases toward the tip.

The flow velocity of the exhaust gas introduced from the exhaust gas inlet 6 through the flow regulating guide member 7 is set to a high speed of, for example, 10 to 25 m per second. The sum of the opening areas of the exhaust gas introduction port 6 and the rectifying guide member 7 is equal to the sectional area of the body 1 described above.
/ 2 to 1/25.

The water spray nozzle 4 is arranged at the center of the exhaust gas inlet 6 and the rectifying guide member 7 and is configured to spray water downward. The tip of the water spray nozzle 4 is located at the tip of the cone-shaped rectifying guide member 7, that is, the portion where the exhaust gas flow velocity is the fastest, and is configured to spray water at this position.

It is preferable that the water spray nozzle 4 can spray fine water particles, such as a two-fluid nozzle and a pressurized one-fluid nozzle. Also, as spray water,
An alkaline absorbing liquid such as slaked lime slurry may be used to remove acidic components in the exhaust gas. Water is supplied to these water injection nozzles 4 from a water supply mechanism (not shown), and the spray amount of water is controlled by a control device (not shown) together with the control of the entire cooling tower.

Next, the operation of the exhaust gas inlet 6 and the water spray nozzle 4 as described above will be described. Exhaust gas is introduced into the body 1 downward from the exhaust gas introduction port 6 and the rectifying guide member 7, and the exhaust gas flows in a jet-like flow downward in the body 1. Then, water is sprayed downward from the water spray nozzle 4 to the center of the flow of the jet-shaped exhaust gas.

Therefore, the water spray nozzle 4 is provided at the center of the flow of the jet-like exhaust gas introduced from the exhaust gas inlet 6.
The water droplets are sprayed from the water, and the sprayed water droplets are instantaneously and efficiently mixed into the flow of the high-enthalpy exhaust gas at a high speed immediately after being introduced from the above-mentioned exhaust gas inlet, and the contact between the water droplets and the exhaust gas becomes active. Therefore, it evaporates completely in a short time.

The exhaust gas introduced downward from the exhaust gas inlet 6 forms a downward jet flow in the body 1. Then, water is sprayed downward from the water spray nozzle 4 during the flow of such downward exhaust gas,
And the gravity acting on the sprayed water droplet is also downward. Therefore, the water droplets move downward with the flow of the exhaust gas downward, and evaporate before reaching the lower part of the body 1 because the contact between the water droplets and the exhaust gas is active as described above.

Therefore, the sprayed water droplets evaporate in the flow of the exhaust gas in the form of a jet, and the unevaporated water droplets unnecessarily diffuse out of the flow of the exhaust gas to reach the inner wall of the body. Thus, it is possible to reliably prevent the exhaust gas from being exhausted from the exhaust gas exhaust duct and reaching the subsequent bag filter. Therefore, the cooling tower according to the present invention can surely prevent the problem caused by lowering the temperature of the introduced exhaust gas, and can cool the exhaust gas to a lower temperature.

Further, in the cooling tower of the present invention, water is directly sprayed on the exhaust gas immediately after being introduced, and the temperature of the exhaust gas is cooled to a low temperature of 200 ° C. or less in a short time. Therefore, this exhaust gas passes through a temperature range in which an organic halogen compound such as dioxin is easily generated as described above in a short time,
Since the entire exhaust gas is uniformly cooled without unevenness, the effect of suppressing organic halogen compounds such as dioxin can be further enhanced.

The dust generated in the incinerator and conveyed into the body 1 together with the exhaust gas is partially dropped in the body 1 due to inertial force or the like. In this case, as described above, since the sprayed water droplets are completely evaporated in the body 1, no wet dust is generated by the unevaporated water droplets. It is discharged outside.

The exhaust gas cooled to a predetermined temperature by the water spray as described above is sent to a dust collector or the like at the subsequent stage through the exhaust gas discharge duct 3 and is subjected to dust collection processing and detoxification processing. From the atmosphere.

In this embodiment, a rectification guide member 7 for rectifying the flow of the exhaust gas introduced into the body 1 is provided at the exhaust gas inlet 6. The exhaust gas inlet 6 is naturally formed in the upper wall portion of the body portion 1. If there is a wall near the exhaust gas inlet 6, the flow of the introduced exhaust gas collides with the wall, and the exhaust gas inlet 6 The flow of the exhaust gas introduced from 6 into the body 1 does not flow vertically downward, and water droplets sprayed into the exhaust gas flow may undesirably reach the wall surface and form a wet surface. .

However, by providing the rectifying guide member 7, the flow of the exhaust gas introduced from the exhaust gas inlet 6 is accurately rectified downward, and does not flow in an undesired direction. Can be reliably eliminated. Further, when a plurality of the exhaust gas inlets 6 are provided, the flows of the plurality of exhaust gas from the exhaust gas inlets 6 do not actively collide with each other, and the vaporizing actions of the water droplets interfere with each other. There is no.

The exhaust gas inlet 6 has a circular shape, and the rectifying guide member 7 has a circular shape.
Is a cylindrical member protruding downward from the surrounding area. Since the circular exhaust gas inlet 6 and the rectifying guide member 7 are symmetrical with respect to the center point, the exhaust gas to be cooled is uniformly introduced from around the flow of the sprayed water droplets. The streams are more uniformly mixed when mixed.

Further, a plurality of the above-mentioned exhaust gas inlets 6 are provided in the upper part of the body 1. Therefore, the evaporation load in the body section can be dispersed, and a more uniform flow of exhaust gas can be formed in the body 1.

Further, by appropriately setting the number of the exhaust gas inlets 6 with respect to the exhaust gas throughput, the cross-sectional area of one exhaust gas inlet 6 and the flow rate of the introduced exhaust gas can be arbitrarily set. It becomes possible. Therefore, it is easy to set the state of mixing and contact between the exhaust gas introduced from the exhaust gas inlet 6 and the sprayed water droplets to be optimal, and the degree of freedom in design is increased.

Further, three or more exhaust gas inlets 6 are provided at equal intervals on the same circumference in the upper part of the body. Accordingly, the flows of the plurality of exhaust gases introduced from the exhaust gas inlet 6 have a symmetrical positional relationship in the cross section of the body, so that the flows of the plurality of exhaust gases are stable and the evaporation in the cross section of the body. The load can be distributed in an even area distribution.

The flow rate of the exhaust gas introduced from the exhaust gas inlet 6 into the body 1 is set to 10 m / sec or more. Normally, in a cooling tower that cools the exhaust gas by water spraying, the average flow velocity of the exhaust gas in the body is relatively low, about 1 to 5 m / s, in order to secure the evaporation time of the sprayed water droplets. As described above, the flow of the exhaust gas is not uniform in the evaporation region in the body unless the rectifying means is used.

To introduce the exhaust gas to be cooled into the exhaust gas inlet at such a low flow rate means that the total area of the exhaust gas inlet needs to be equal to the cross-sectional area of the body. Even though there is a finite number, one exhaust gas inlet is a relatively large opening, and even if water spray is performed at such an opening, the unevenness of the gas flow due to the large opening is reduced by the conventional method. It is not desirable to make the average flow velocity of the exhaust gas at the exhaust gas inlet extremely small, since it may occur as in the case of the hot tower and cause problems.

According to the investigation by the present inventors, if the average flow rate of the exhaust gas when introducing the exhaust gas from the exhaust gas inlet into the body is approximately 10 m / sec or more, the water spray cooling target per one point of the exhaust gas inlet is required. The sensible heat density of the exhaust gas is 2 to 10 times or more, and the high-speed flow of 10 m / s or more is sprayed with the exhaust gas to be cooled while effectively increasing the evaporation effect of the spray water droplet by the spray type water spray nozzle. It becomes possible to promote the evaporation by contacting the water droplets efficiently while colliding with each other. Here, the value of 2 to 10 times means that the average body velocity of the above-mentioned ordinary cooling tower is 1 to 5 times per second.
m.

Even if the average flow velocity of the exhaust gas at the exhaust gas inlet is less than 10 m / s, the effect is effective as long as it is close to this value. As a result of extensive surveys and investigations at the tower, it was found from engineering that if the speed was 10 m / s or more, it was effective enough under various conditions and could be applied.
0 m or more. Although the upper limit is not particularly set, for example, in order to prevent the pressure loss from becoming extremely large by using a high-speed flow, the upper limit is set to 25 m / s.
It should be about the degree.

The opening area or the total opening area of the exhaust gas inlet 6 is の to 1/25 of the sectional area of the body 1. As described above, the total cross-sectional area of the plurality of exhaust gas inlets 6 may be set to 1/25 to 1/2 in order to set the average exhaust gas flow rate to 10 m or more and 25 m or less per second. Then, the area of each exhaust gas inlet 6 can be calculated. Conversely, if the area of the exhaust gas inlet 6 is designated in this manner, the average flow velocity in the exhaust gas introduction section becomes 10 m or more and 25 m or less per second as described above, and the above-described effect of the present invention can be more reliably obtained. Can be

The present invention is not limited to the above embodiment. For example, FIGS. 3 and 4 show the second embodiment of the present invention.
An embodiment will be described. This differs from the first embodiment in the configuration of the exhaust gas distribution device described above, and other configurations are the same as those in the first embodiment.

In this embodiment, a bifurcated branch duct 2a, 2c is formed at the tip of the exhaust gas introduction duct 2, and these branch ducts 2a, 2c communicate with the two exhaust gas inlets 6 on both sides, respectively. The exhaust gas introduction port 6 at the center communicates with the center of the end of the exhaust gas introduction duct 2.

The exhaust gas introduction duct 2 includes:
Guide vanes 10c and 10d are provided to deflect the flow of the exhaust gas so as to uniformly send the exhaust gas to the above-described bifurcated branch ducts 2a and 2b, and to uniformly send the exhaust gas also to the central portion between these branch ducts. It is configured. Further, since the supply amount of the exhaust gas tends to increase at the central exhaust gas inlet 6, guide vanes 10a and 10b are provided on both sides of the central exhaust gas inlet, and a part of the exhaust gas is branched into two branch ducts. The exhaust gas is deflected to 2a and 2b, and the exhaust gas is uniformly supplied to these three exhaust gas inlets 6.

In this embodiment, the guide vanes 10
Since the flow of the exhaust gas is deflected by a, 10b, 10c, and 10d and uniformly supplied to each exhaust gas inlet 6, the advantage that the pressure loss is smaller than that using the flow rate adjusting damper of the first embodiment described above. There is. In this embodiment, the above-mentioned guide vanes are fixed, but movable guide vanes may be provided.

FIGS. 5 and 6 show the third embodiment of the present invention.
An embodiment will be described. This differs from the first embodiment in the configuration of the exhaust gas distribution device described above, and other configurations are the same as those in the first embodiment.

The exhaust gas distribution device of this embodiment is arranged around the exhaust gas inlets 6 arranged at equal intervals on the same circumference as described above, and has an annular orifice 12 substantially concentric with the center of the exhaust gas inlets 6.
The exhaust gas introduction duct 2 communicates with a part of the circulation channel 12.

In the center of the orbiting channel 12, three radial branch channels 14 are formed by a fan-shaped guide block 15, and one end thereof is connected to the orbiting channel 12.
The other ends of the branch flow paths 14 communicate with each other at the center. Exhaust gas inlets 6 are respectively connected to the middle of these branch flow paths 14.

In this embodiment, each of the branch passages 14 is formed to have a lower height than that of the circulation passage 12, and the sectional area thereof is set to be smaller than that of the circulation passage 12. .

In the exhaust gas distribution device as described above, the exhaust gas swirls in the orbiting flow path 12, and a part of the swirling exhaust gas flows into the branch flow path 14, and the exhaust gas introduction ports 6.
Supplied to Therefore, the exhaust gas is uniformly supplied to these exhaust gas inlets 6 and the pressure loss is small.

Further, since the branch passages 14 communicate with each other at the center, even if a difference in flow rate or pressure occurs between the branch passages 14, the branch passages 14 pass through the central communication portion. As a result, a part of the exhaust gas flows, and the difference in the flow rate and the pressure as described above is immediately eliminated. Therefore, the exhaust gas can be more accurately distributed to each exhaust gas inlet 6.

In this embodiment, the branch flow path 14 is formed to have a lower height, and has a smaller cross-sectional area than the circulating flow path 12. Therefore, these branch flow paths 14
The flow velocity of the exhaust gas flowing into the circulation flow path 12 is higher than the flow velocity in the circulation flow path 12, thereby preventing the accumulation of dust in the branch flow paths 14.

FIGS. 7 and 8 show the fourth embodiment of the present invention.
An embodiment will be described. This differs from the first embodiment in the configuration of the exhaust gas distribution device described above, and other configurations are the same as those in the first embodiment.

In this embodiment, the height of the circulation channel 12 and each of the branch channels 14 in the third embodiment are the same. The operation of this embodiment is substantially the same as that of the third embodiment, but has a simple structure and is easy to manufacture.

FIGS. 7 and 8 show the fourth embodiment of the present invention.
An embodiment will be described. This differs from the first embodiment in the configuration of the exhaust gas distribution device described above, and other configurations are the same as those in the first embodiment.

In this embodiment, a small flow rate adjusting damper 16 is provided at the inlet of the branch passage 14 in the fourth embodiment. Since the flow rate of the exhaust gas flowing into each branch flow path 14 can be directly adjusted by these flow rate adjusting dampers 16, the supply amount of the exhaust gas to each exhaust gas inlet 6 can be accurately adjusted. In addition, only a small auxiliary flow adjustment damper 16 needs to be provided, and the pressure loss is small.

In each of the above embodiments, three exhaust gas inlets are arranged at equal intervals on the same circumference, but the number and arrangement of these exhaust gas inlets 6 are as described above. It is not limited to one.

For example, as in the sixth embodiment shown in FIG. 11, four exhaust gas inlets 6 may be arranged at equal intervals on the same circumferential line concentric with the body 1. Further, as in the seventh embodiment shown in FIG. 12, three exhaust gas inlets 6 may be arranged at equal intervals on the diameter line of the body 1. The arrangement and number of the exhaust gas inlets 6 can be arbitrarily set to an arbitrary number according to the design of the cooling tower and other conditions.

Various types of rectifying guide members can also be used. For example, FIG. 13 shows an eighth embodiment of the present invention. In this embodiment, for example, an exhaust gas inlet 6 is formed in the upper wall 20 of the body 1, and a cylindrical rectifying guide member 21 is provided around the exhaust gas inlet 6. This has substantially the same function as the above-described rectifying guide member 7, but has a simple structure and is easy to manufacture.

FIG. 14 shows a rectifying guide member according to a ninth embodiment of the present invention. In this embodiment, an exhaust gas inlet 6 is formed in an upper wall 20 of a body 1 and a cone-shaped rectifying guide member 22 is provided around the exhaust gas inlet 6. This embodiment has the same configuration as the rectifying guide member 7 of the above-described embodiment.

FIG. 15 shows a straightening guide member according to a tenth embodiment of the present invention. In this embodiment, a cylindrical rectifying guide member 23 is provided so as to project around the exhaust gas inlet 6 formed in the upper wall 20 of the body 1. The joint is formed on the curved surface portion 24. In this case, the flow of the exhaust gas is smooth and the pressure loss is small.

Further, it is not always necessary to provide the rectifying guide member as described above. For example, as in the eleventh embodiment of the present invention shown in FIG. 16, the exhaust gas inlet 6 may be simply formed in the upper wall 20 of the body 1. In this case, if the tip of the water spray nozzle 4 is made to protrude inside the exhaust gas inlet 6, that is, on the downstream side of the flow of the exhaust gas, the flow of the exhaust gas introduced from the exhaust gas inlet 6 will be increased. Even if it is disturbed in the vicinity of the upper wall 20, the sprayed water droplets do not get caught in the disturbance and adhere to the inner surface of the upper wall 20 or the like.

Note that the present invention is not limited to the above embodiment, and various changes and modifications can be made. For example, the cross-sectional shapes of the exhaust gas inlet and the rectifying guide member are not necessarily limited to a circle, but may be other shapes.

[0087]

As described above, according to the present invention, water is sprayed directly into the flow of the exhaust gas introduced from the exhaust gas inlet, so that the sprayed water droplets evaporate reliably in a short time. In addition, since the water droplets sprayed downward evaporate while flowing downward together with the flow of the exhaust gas introduced downward, the behavior of these water droplets is stable and reliable, and the unevaporated water droplets are deposited on the inner surface of the body. Adhesion is reliably prevented.

Further, since a plurality of the exhaust gas inlets are provided, the flow of the exhaust gas can be more uniformly and stably formed in the body portion. The exhaust gas is supplied uniformly by the device. Therefore, the flow rates of the exhaust gas introduced from the respective exhaust gas introduction ports become exactly equal to each other, and the flows of the plurality of exhaust gases in the body do not interfere with each other and adversely affect each other. The effect is great, for example, a plurality of exhaust gas flows can be formed, and the water droplets can be completely evaporated more reliably.

[Brief description of the drawings]

FIG. 1 is a schematic longitudinal sectional view of a cooling tower according to a first embodiment of the present invention.

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

FIG. 3 is a schematic longitudinal sectional view of a cooling tower according to a second embodiment of the present invention.

FIG. 4 is a schematic cross-sectional view taken along line 4-4 in FIG. 3;

FIG. 5 is a schematic longitudinal sectional view of a cooling tower according to a third embodiment of the present invention.

FIG. 6 is a schematic cross-sectional view taken along line 6-6 of FIG.

FIG. 7 is a schematic longitudinal sectional view of a cooling tower according to a fourth embodiment of the present invention.

FIG. 8 is a schematic cross-sectional view taken along the line 8-8 in FIG. 7;

FIG. 9 is a schematic longitudinal sectional view of a cooling tower according to a fifth embodiment of the present invention.

FIG. 10 is a schematic cross-sectional view taken along the line 10-10 in FIG. 9;

FIG. 11 is a plan view showing an arrangement of an exhaust gas inlet according to a sixth embodiment of the present invention.

FIG. 12 is a plan view showing an arrangement of an exhaust gas inlet according to a seventh embodiment of the present invention.

FIG. 13 is a longitudinal sectional view of a rectifying guide member according to an eighth embodiment of the present invention.

FIG. 14 is a vertical sectional view of a rectifying guide member according to a ninth embodiment of the present invention.

FIG. 15 is a longitudinal sectional view of a rectifying guide member according to a tenth embodiment of the present invention.

FIG. 16 is a longitudinal sectional view of an exhaust gas inlet according to an eleventh embodiment of the present invention.

FIG. 17 is a schematic longitudinal sectional view of a conventional cooling tower.

FIG. 18 is a schematic cross-sectional view taken along line 18-18 of FIG. 17;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Body of cooling tower 2 Exhaust gas introduction duct 2a, 2b, 2c Branch duct 3 Exhaust gas exhaust duct 4 Water spray nozzle 6 Exhaust gas inlet 9a, 9b, 9c Flow control damper 10a, 10b, 10c, 10d Guide vane 12 circulating flow Road 14 Branch flow path 16 Flow adjustment damper

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Junichiro Ueda 1-2-1, Marunouchi, Chiyoda-ku, Tokyo, Japan Inside Nihon Kokan Co., Ltd. (72) Inventor Takehiko Inada 1-1-2, Marunouchi, Chiyoda-ku, Tokyo, Japan (72) Inventor Takehiko Aoki 1-2-1, Marunouchi, Chiyoda-ku, Tokyo, Japan In-tube (72) Inventor Masato Kato 1-2-1, Marunouchi, Chiyoda-ku, Tokyo, Japan F term in the company (reference) 3K070 DA05 DA09 DA37 DA73 DA74

Claims (6)

[Claims] 1. A plurality of exhaust gas inlets for introducing exhaust gas downward into a body of a cooling tower, a water spray nozzle provided at a center of the exhaust gas inlet and spraying water downward.
An exhaust gas introduction duct that supplies exhaust gas to the exhaust gas introduction port, and an exhaust gas that is provided between the exhaust gas introduction duct and each of the exhaust gas introduction ports and that is supplied through the exhaust gas introduction duct described above, An exhaust gas distribution device for uniformly distributing and supplying the exhaust gas to the inlet; 2. The exhaust gas distribution device includes: a branch duct branched from the exhaust gas introduction duct and communicated with each of the exhaust gas introduction ports; and a branch duct provided in the middle of each of the branch ducts. The downflow type cooling tower according to claim 1, further comprising a flow rate adjusting damper for adjusting a flow rate of the flowing exhaust gas. 3. The exhaust gas distribution device is provided in a branch duct branched from the exhaust gas introduction duct and communicating with each of the exhaust gas introduction ports, and at least in the exhaust gas introduction duct upstream of these branch ducts. The downflow type cooling tower according to claim 1, further comprising: a guide vane for deflecting the exhaust gas flowing and flowing uniformly in the branch duct. 4. The exhaust gas distribution device according to claim 1, wherein the exhaust gas distribution device includes a plurality of exhaust gas introduction ports, the plurality of exhaust gas introduction ports being disposed around the annular circulation flow path partially communicating with the exhaust gas introduction duct, and each of the exhaust gas introduction ports. A plurality of branch flow paths are provided correspondingly, one end of which is branched and connected to the above-mentioned circulation flow path, and a middle part thereof communicates with each of the exhaust gas introduction ports, and the other end thereof communicates with each other at a central part. The downflow type cooling tower according to claim 1, wherein: 5. The cross-sectional area of the branch flow path is smaller than the cross-sectional area of the circular flow path so that the flow rate of exhaust gas in the branch flow path is faster than the flow rate of exhaust gas in the circular flow path. 5. The downflow type cooling tower according to claim 4, wherein the cooling tower is set small. 6. A flow control damper for adjusting a flow rate of exhaust gas flowing into the branch flow path from the circulation flow path at one end of the branch flow path. Item 4. A downflow type cooling tower according to Item 4.