JP6880948B2 - Nozzle device - Google Patents

Description

The present invention relates to a nozzle device that diffusely supplies a liquid binder to pulverized coal.

A coke oven for producing coke for metallurgy is widely known by charging coking coal into a carbonization chamber, heating it at a predetermined temperature, and carbonizing it to dry distillation. Non-fine coking coal with inferior cohesiveness may be used as the coking coal charged into the coke oven, and while adding a binder to the pulverized coal produced by crushing the non-fine coking coal. A method is known in which the kneaded product is kneaded and the kneaded product is pressed with a roll to form agglomerated coal or briquette, which is then charged into a carbonization chamber.

As a technique for kneading pulverized coal, a method of spraying a binder while transporting the pulverized coal from one end side to the other end side of the kneading container with a screw is known. As a device for spraying a binder, Patent Document 1 describes a nozzle device for diffusing and supplying a liquid binder to pulverized coal, and a gas having a binder supply nozzle and an extension pipe portion extending into the binder supply nozzle. The binder supply nozzle has a supply pipe, and the binder supply nozzle has a pair of binder guide wall members that sandwich the gas supply pipe from the radial direction of the gas supply pipe, and the gas supply pipe and the binder guide wall member. A passage for allowing the binder to flow down naturally toward the pulverized coal is formed between the spaces, and a plurality of gas outlets are formed in the extension pipe portion, and the gas is ejected from the gas outlet. A nozzle device is disclosed, which comprises diffusing a binder that naturally flows down from the binder supply nozzle with the gas to be produced.

The nozzle device is installed on the upstream side of the kneading container in order to secure the kneading time of the pulverized coal and the binder, but it is installed on the upstream side excessively or the gas injection angle is large and the spray range of the binder is wide. If it becomes too wide, the binder will be sprayed directly under the pulverized coal supply port of the kneading container. If more binder is sprayed directly under the pulverized coal supply port of the kneading container, the pulverized coal is stored only at a level lower than the screw shaft at this position, so that the binder adheres to the screw shaft or becomes. Since the storage level of the pulverized coal is low, the time for acclimatizing with the pulverized coal is insufficient, and the binder flows out to the bottom surface of the kneading container, and the outflowing binder sticks to the bottom surface, which may cause a problem of equipment stoppage. Therefore, in the nozzle device, the installation position and the angle of the gas spray port are determined so that the amount of the binder sprayed directly under the pulverized coal supply port of the kneading container does not become excessively large.

Japanese Patent No. 4869775

In the nozzle device of Patent Document 1, the gas outlets are evenly arranged, and the injection angles of these gas outlets are set to be the same as each other. If the angle of the gas outlet is reduced in order to spray the binder within a predetermined range, the binder is concentrated on a specific position on the pulverized coal charged into the kneading container, and the kneaded product containing a large amount of binder is sprayed. And a kneaded product with a small amount of binder are mixed, and there is a risk that the quality will vary widely. Increasing the angle of the gas injection port reduces the concentration on a specific position, but the spray range of the binder becomes too wide, and it adheres to the shaft of the screw directly under the pulverized coal supply port or sticks to the bottom of the kneading container. There are concerns about problems such as

Therefore, an object of the present invention is to make the spraying of the binder on the pulverized coal more uniform within a predetermined range.

The present inventor has diligently studied the above problems and found that it is important to adjust the arrangement of gas outlets and the ejection angle. That is, the present invention is (1) a nozzle device for diffusing and supplying a liquid binder toward pulverized coal conveyed by a screw in a kneading container, and a binder having a flow path for allowing the binder to flow down naturally. It has a supply nozzle and a gas supply pipe having an extension pipe portion extending into the binder supply nozzle, and the extension pipe portion has a plurality of gases for ejecting gas toward the binder that naturally flows down. The spouts are formed on both sides of the center line extending along the lower end of the extension pipe portion.
The plurality of gas outlets formed on one side of the center line are characterized in that all of the following conditions 1 to 5 are satisfied.
Condition 1: When the ejection angle of each of the gas outlets with respect to the vertical downward direction is θ, the ejection angle θ is 5 ° or more and 40 ° or less.
_{Condition 2: The angle difference θ dif} of the ejection angle θ of the gas outlets adjacent to each other in the pipeline direction of the extending pipe portion is 20 ° or less.
Condition 3: Of the plurality of gas outlets, the gas outlet located at one end in the pipeline direction is the first end gas outlet, and the gas outlet is located at the other end. Moreover, when the gas outlet having an ejection angle θ larger than that of the first end gas outlet is defined as the second end gas outlet, the first and second end gas outlets are defined as the second end gas outlet. The gas outlet located between the gas outlets has a larger ejection angle θ than the gas outlet adjacent to the first end gas outlet side, or has the same ejection angle θ.
Condition 4: When the median value of the ejection angle θ of the first end gas outlet and the ejection angle θ of the second end gas outlet is θ _med , the ejection angle θ is equal to or less than the _{median value θ med.} The number of the gas outlets is 1 times or more and 1.5 times or less the number of the gas outlets whose ejection angle θ exceeds the median value θ _med.
Condition 5: The angle difference between the ejection angle θ of the first end gas outlet and the ejection angle θ of the second end gas outlet is 15 ° or more.

(2) The binder supply nozzle has a pair of binder guide wall members that sandwich the gas supply pipe from the radial direction, and the binder is naturally placed between the gas supply pipe and the binder guide wall member. The nozzle device according to (1) above, wherein a passage for flowing down is formed.

(3) The nozzle device according to (1) or (2) above, wherein the plurality of gas outlets are formed at substantially equal intervals in the pipeline direction.

According to the nozzle device satisfying the above-mentioned conditions 1 to 5, the binder can be sprayed more evenly within a predetermined range.

It is a schematic block diagram of the agglomerate coal production apparatus provided with a nozzle apparatus. It is a front view of the nozzle device. It is a bottom view of the nozzle device. It is the schematic of the extension pipe part seen from the direction which the center line L1 extends. It is a figure corresponding to FIG. 4, and is a figure for demonstrating the influence which the magnitude of the ejection angle θ has on the spraying of a binder. It is a bottom view of the nozzle device. It is the schematic of the extension pipe part seen from the radial direction. It is the schematic of the extension pipe part which shows the arrangement of a gas outlet (comparative example 1). It is a bar graph which shows the water amount distribution (comparative example 1). It is the schematic of the extension pipe part which shows the arrangement of a gas outlet (comparative example 2). It is a bar graph which shows the water amount distribution (comparative example 2). It is the schematic of the extension pipe part which shows the arrangement of a gas outlet (comparative example 3). It is a bar graph which shows the water amount distribution (comparative example 3). It is the schematic of the extension pipe part which shows the arrangement of a gas outlet (Example 1). It is a bar graph which shows the water amount distribution (Example 1). It is the schematic of the extension pipe part which shows the arrangement of a gas outlet (Example 2). It is a bar graph which shows the water amount distribution (Example 2).

FIG. 1 is a schematic configuration diagram of a kneaded charcoal manufacturing apparatus provided with a nozzle apparatus according to an embodiment of the present invention. The kneading charcoal manufacturing apparatus includes a nozzle apparatus 1, a kneading vessel 2, and a screw 3 rotatably housed in the kneading vessel 2. The kneading container 2 extends in the axial direction of the screw 3, and a pulverized coal injection chute 2a is provided on the upper wall portion on one end side, and a discharge chute 2b is provided on the lower wall portion on the other end side. .. The nozzle device 1 sprays the binder onto the pulverized coal charged in the kneading container 2. Details of the nozzle device 1 will be described later.

A drive motor 4 is connected to the screw 3, and by driving the drive motor 4, the screw 3 can be rotated in the direction of the arrow X. The screw 3 can be functionally divided into a transport portion and a kneading portion. The transport section has a function of transporting the pulverized coal charged from the charging chute 2a toward the kneading section in the arrow Y direction, and the kneading section has a function of transporting the pulverized coal and the binder in the arrow Y direction while kneading. Have. The arrow Y direction is parallel to the axial direction of the screw 3.

On the outer peripheral surface of the screw 3 in the kneading portion, a feed blade 3a shown by white and a return blade 3b shown by hatching are formed. The feed blade 3a has a function of feeding the pulverized coal and the binder in the direction of the arrow Y, and the return blade 3b has a function of stagnating the pulverized coal and the binder fed in the direction of the arrow Y. By cooperating with these feed blades 3a and return blades 3b, the pulverized coal and the binder can be conveyed while being kneaded.

The kneaded product of pulverized coal and binder is discharged from the discharge chute 2b, agglomerated or molded by a roll compactor, transported to a coal tower, charged into a carbonization chamber, and then carbonized in a coke oven.

The nozzle device 1 is preferably installed on the upstream side in the transport direction of the kneaded product (arrow Y direction). When the installation position is on the downstream side, the equipment must be increased in size because the transport distance of the kneaded material must be increased in order to secure the kneading time of the pulverized coal and the binder. However, as described above, the nozzle device 1 is arranged so that the amount of the binder sprayed directly under the pulverized coal charging chute 2a of the kneading container 2 does not become excessively large.

The configuration of the nozzle device will be described in detail with reference to FIGS. 2 and 3. FIG. 2 is a front view of the nozzle device, and the paper surface normal direction corresponds to the arrow Y direction (that is, the transport direction of the kneaded product). FIG. 3 is a bottom view of the nozzle device, and the definition of the arrow Y direction is the same as that of FIG.

The nozzle device 1 includes a gas supply pipe 11 and a binder supply unit 12. The gas supply pipe 11 extends in the vertical direction, and an extension pipe portion 110 extending toward the binder supply unit 12 extends in the horizontal direction at the lower end portion thereof. The alternate long and short dash line L1 in FIG. 3 is a center line in which the central axis of the extension pipe portion 110 is traced to the outer surface of the extension pipe portion 110 (hereinafter referred to as the center line L1), in other words, the lower end of the extension pipe portion 110. Indicates the position of the part. A plurality of gas outlets 110a are formed in the extension pipe portion 110. In FIG. 3, when the angle of one gas outlet 110a arranged in the arrow Y direction is θ1 and the angle of the other gas outlet 110a is θ2, a plurality of gases are the same so that θ1 + θ2 are the same at any position. The spout 110a is formed. For convenience of explanation, a plurality of gas outlets 110a formed in one region of the center line L1 are defined as S1 to S7, respectively. However, when it is not necessary to distinguish the gas outlets S1 to S7, they are collectively referred to as the gas outlet 110a.

The binder supply unit 12 includes a main binder supply pipe 121 and a pair of guide wall members 122 welded and fixed to the lower end side of the main binder supply pipe 121. The pair of guide wall members 122 sandwich the extension pipe portion 110 of the gas supply pipe 11 from the outside in the radial direction, and each end portion of each guide wall member 122 faces the center side of the extension pipe portion 110. A bent portion 122a is formed. The bent portion 122a is welded and fixed to the outer peripheral surface of the extension pipe portion 110.

The element shown by hatching in FIG. 3 is a binder, and the binder naturally flows down in the passage formed between the extension pipe portion 110 and the guide wall member 122. As a result, the gas ejected from the gas outlet 110a can collide with the binder that naturally flows down inside the binder supply unit 12.

The lower end of the guide wall member 122 is formed above the lower end of the extension pipe portion 110. As a result, the gas ejected from each gas outlet 110a is prevented from colliding with the guide wall member 122, and the binder can be sprayed over a wider range.

Here, the binder naturally flows down inside the main binder supply pipe 121, and a driving device for forcibly supplying the binder becomes unnecessary, so that the cost can be reduced. Further, in the present invention, the gas and the binder are not discharged from the nozzle device in a mixed state, but the gas is ejected from the gas outlet 110a toward the binder that naturally flows down, so that the gas is generated by the sludge contained in the binder. It is possible to prevent the spout 110a from being clogged.

FIG. 4 is a schematic view of the extension pipe portion 110 viewed from the direction in which the center line L1 extends, and L2 indicated by the alternate long and short dash line indicates a reference line extending in the vertical direction through the center line L1 and is indicated by an arrow. L3 indicates the ejection direction of the gas, and θ indicates the angle formed by the reference line L2 and the ejection direction L3 (hereinafter, referred to as an ejection angle).

With reference to FIGS. 2 to 4, the gas outlets S1 to S7 are arranged in this order in the direction of the center line L1 of the extension pipe portion 110, and the gas outlets S1 to S3 have the same ejection angle θ. The gas outlets S5 to S7 are set to the same ejection angle θ, and the gas outlet S4 is set to an ejection angle θ different from these. In order to spray the binder more uniformly, the gas outlet 110a must satisfy the following conditions 1 to 5.

(Condition 1)
The ejection angle θ must be 5 ° or more and 40 ° or less. When the ejection angle θ is less than 5 °, the ejection direction of the gas becomes excessively downward, so that the binder cannot be widely sprayed in the transport direction of the kneaded product (arrow Y direction). When the ejection angle θ exceeds 40 °, the ejection direction of the gas becomes excessively lateral, so that the binder may excessively adhere to the inner wall of the kneading container 2.

(Condition 2)
_{The angle difference θ dif} of the ejection angle θ of the adjacent gas outlets 110a in the center line L1 direction must be 20 ° or less. The reason for limiting the angle difference θ _dif will be described in detail with reference to FIG. FIG. 5 is a diagram corresponding to FIG. 4, and the binder that naturally flows down is shown by hatching. L3 ₁ and L3 ₂ indicate the ejection directions of the gas outlets 110a adjacent to each other in the center line L1 direction, and the _{ejection angle θ of L3 2} is set to be larger than that of L3 _1. The gas of _{L3 2 having} a larger ejection angle θ hits the binder flowing down from the binder supply pipe 121 first, and the binder located in the direction of _{L3 2 is sprayed in the gas ejection direction.} The binder located in the _{L3 1 direction is pulled by the binder located in the L3 2} direction, and flows down the route separated from the extension pipe portion 110. If the angle difference theta _dif is 20 ° greater than the binder which is located L3 ₁ direction flows down a more spaced route extending extraction tube 110, long distance from the gas outlet 110a for injecting the gas into the L3 ₁ direction Therefore, at the time of contact with the binder, the ejection energy is reduced and the spraying power is insufficient, so that the gas is dropped without being sprayed.

(Condition 3)
Of the plurality of gas outlets 110a, the gas outlet 110a located at one end in the center line L1 direction is defined as the first end gas outlet, and is the gas outlet 110a located at the other end. When the gas outlet 110a having an ejection angle θ larger than that of the first end gas outlet 110a is defined as the second end gas outlet, the first and second end gas outlets of these gas outlets The gas outlet 110a located between them must have a larger ejection angle θ or the same ejection angle θ than the gas outlet 110a adjacent to the first end gas outlet 110a side. By satisfying the condition 3, the binder can be sprayed more uniformly.

In the present embodiment, the first end gas outlet corresponds to the gas outlet S7, and the second end gas outlet corresponds to the gas outlet S1. Further, the gas outlet S2 has the same ejection angle θ as the gas outlet S1, the gas outlet S3 has the same ejection angle θ as the gas outlet S2, and the gas outlet S4 has a larger ejection angle than the gas outlet S3. The ejection angle θ is small, the gas outlet S5 has a smaller ejection angle θ than the gas outlet S4, the gas outlet S6 has the same ejection angle θ as the gas outlet S5, and the gas outlet S7 has the gas outlet S6. And the ejection angle θ are the same, so that the condition 3 is satisfied. Needless to say, the condition 3 is satisfied even if the arrangement directions of the gas outlets S1 to S7 are opposite to each other.

Here, FIG. 6 is a bottom view of the nozzle device, and the position where the gas outlet 110a is formed is different from the configuration of FIG. For convenience of explanation, a plurality of gas outlets 110a formed in one region of the center line L1 are defined as S1'to S7', respectively. In the configuration shown in FIG. 6, the gas outlets S1'to S7' are arranged in a so-called V shape, and the condition 3 is not satisfied.

FIG. 7 is a layout diagram of the ejection ports S1 ′ to S7 ′ of FIG. 6 viewed from the radial direction, and the triangular region indicated by the hatching is the influence of the gas ejected from the gas ejection ports S1 ′, S4 ′ and S7 ′. The range covered by the force (spraying force) is schematically shown. When the gas outlets S1'to S7' are arranged in a V shape, the spraying force of the gas outlet S1'and the gas outlet S7', which are located at the ends and have the largest ejection angle θ, becomes dominant and naturally flows down. Since the binder to be sprayed is pulled in the ejection direction of the gas outlet S1'and the gas outlet S7'as a whole, the binder to be sprayed by the gas outlet S4'with the smallest ejection angle θ is dropped without being sprayed. It ends up. Therefore, in the configuration of FIG. 6 which does not satisfy the condition 3, the binder cannot be sprayed uniformly.

(Condition 4)
When the median value of the ejection angle θ of the first end gas outlet and the ejection angle θ of the second end gas outlet is θ _med , the ejection angle θ of the gas outlet 110a _{having the median value θ med or less} The number must be 1 times or more and 1.5 times or less the number of gas outlets 110a whose ejection angle θ exceeds the median value θ _med. When the number of gas outlets 110a whose ejection angle θ exceeds the median θ _med increases, as described in Condition 2, the gas having a large ejection angle θ becomes dominant, and the binder at the position where the ejection angle θ is small is sprayed. It will drip without being done. On the other hand, if the number of gas outlets 110a having an ejection angle θ of the median θ _med or less becomes too large, the number of binders sprayed to a specific position increases, and uniform spraying cannot be performed.

(Condition 5)
The angle difference between the ejection angle θ of the first end gas outlet and the ejection angle θ of the second end gas outlet defined in Condition 3 must be 15 ° or more. When the angle difference is less than 15 °, the range of the spray angle is narrowed, and the spray of the binder is biased.

From condition 5, it is possible to derive the condition that "the plurality of gas outlets 110a must include gas outlets 110a having different ejection angles θ". If the ejection angles θ of the gas outlet 110a are all set to be the same, the binder is sprayed in a specific direction, and the binder cannot be widely sprayed in the transport direction (Y direction) of the kneaded product. For example, when the ejection angles θ of the gas outlet 110a are all set to 40 °, the proportion of the binder sprayed directly under and in the vicinity of the nozzle device 1 becomes excessively small, so that the kneaded product and the binder having a low binder proportion A high proportion of kneaded material is produced. In addition, there is a concern that the sprayed binder may adhere to the shaft of the screw 3. In the present embodiment, the ejection angles θ of the gas outlets S1 to S3, the gas outlets S4, and the gas outlets S5 to S7 are different from each other.

Next, the present invention will be described in more detail with reference to Examples. Using a nozzle device of a size equivalent to that of an actual machine, the uniform spraying property was evaluated while variously changing the angle and arrangement method of the gas outlet 110a. N ₂ gas was used as the gas. The pressure and flow rate of N ₂ gas were appropriately selected within the range corresponding to the actual machine. Since the binder added to the kneading apparatus is heated and its viscosity is equivalent to that of water at room temperature, water at room temperature was used instead of the binder. The flow rate of water was appropriately selected within the range equivalent to the actual machine. The water amount distribution of the water ejected from the nozzle device was measured with a water amount distribution measuring machine to evaluate the uniform sprayability. Specifically, the water amount distribution in the range of -640 mm to +640 mm is measured from directly under the nozzle device, and the ratio within the range of -240 mm to +240 mm (hereinafter referred to as the distribution evaluation range) and each position within the distribution evaluation range. The uniform sprayability was evaluated based on the variation in the water volume distribution.

FIG. 8A is a schematic view of an extension pipe portion showing the arrangement of the gas outlet 110a of Comparative Example 1. However, in order to simplify the drawing, only the gas outlet 110a formed on one side of the center line L1 is shown, and the gas outlet 110a formed on the other side is omitted (FIG. 9A). The same applies to FIG. 11A). FIG. 8B is a bar graph showing the water volume distribution of Comparative Example 1, and the double-headed arrow indicates the distribution evaluation range. The definition of the double-headed arrow is the same in FIGS. 9B to 11B. In Comparative Example 1, since the ejection angles θ were all 45 °, the water was diffused in the lateral direction, and the amount of water sprayed in the distribution evaluation range was only 26.0%.

FIG. 9A is a schematic view of an extension pipe portion showing the arrangement of the gas outlet 110a of Comparative Example 2. FIG. 9B is a bar graph showing the water volume distribution of Comparative Example 2. In Comparative Example 2, the ejection angles θ were all set to 25 °. Since the ejection angle θ became smaller than that of Comparative Example 1, the proportion of water sprayed in the distribution evaluation range increased to 89.8%. However, the proportion of the water amount distribution at the end of the distribution evaluation range became larger than 10%, and the variation in the water amount distribution became large.

FIG. 10A is a schematic view of an extension pipe portion showing the arrangement of the gas outlet 110a of Comparative Example 3. FIG. 10B is a bar graph showing the water volume distribution of Comparative Example 3. In Comparative Example 3, the arrangement of the gas outlets 110a was set in the same manner as in FIG. 6, and the ejection angles θ were set to 0 °, 5 °, 15 °, and 25 ° in order from the top of the V-shape. The proportion of water sprayed in the distribution evaluation range increased to 90.7%, but the proportion of water volume distribution at 120 mm to 160 mm from the center of the distribution evaluation range increased by more than 10%. In addition, water that was dropped without being sprayed was observed in the vicinity of the position of 0 mm in the transport direction, so that the sprayed state deteriorated.

FIG. 11A is a schematic view of an extension pipe portion showing the arrangement of the gas outlet 110a of the first embodiment. FIG. 11B is a bar graph showing the water volume distribution of Example 1. In Example 1, the arrangement of the gas outlets 110a and the ejection angle θ were set in the same manner as in FIG. The proportion of water sprayed in the distribution evaluation range increased to 72.5%, and the amount of water in the distribution evaluation range was 10% or less at any position, and the variation in water volume distribution became small.

FIG. 12A is a schematic view of an extension pipe portion showing the arrangement of the gas outlet 110a of the second embodiment. FIG. 12B is a bar graph showing the water volume distribution of Example 2. In Example 2, the gas outlets 110a were arranged substantially diagonally with respect to the center line L1 direction. The minimum value of the gas outlet 110a was set to 5 °, and the maximum value was set to 30 °. The proportion of water sprayed in the distribution evaluation range increased to 73.5%, and the amount of water in the distribution evaluation range was 10% or less at any position, and the variation in water volume distribution became small.

(Modification example 1)
In the present embodiment, the number of gas outlets 110a formed on one side of the center line L1 is set to 7, but the present invention is not limited to this, and any number of 3 or more can be used. it can.

(Modification 2)
In the present embodiment, when the angle of one gas outlet 110a is θ1 and the angle of the other gas outlet 110a is θ2 with the center line L1 in between, θ1 + θ2 are the same at any position. The present invention is not limited to this, and it is sufficient that a plurality of gas outlets 110a formed on one side of the center line L1 satisfy the conditions 1 to 5, respectively. For example, one gas outlet 110a may be arranged as shown in 11A and the other gas outlet 110a may be arranged as shown in FIG. 12A.

1 Nozzle device 2 Kneading container 3 Screw 4 Drive motor 11 Gas supply pipe 12 Binder supply unit 110 Extension pipe 110a S1 to S7 S1'to S7' Gas outlet

Claims (2)

A nozzle device that diffuses and supplies a liquid binder toward pulverized coal that is conveyed by a screw in a kneading container.
It has a binder supply nozzle in which a flow path for spontaneously flowing down the binder is formed, and a gas supply pipe having an extension pipe portion extending into the binder supply nozzle.
The binder supply nozzle has a pair of binder guide wall members that sandwich the gas supply pipe from the radial direction.
A passage for allowing the binder to flow down naturally is formed between the gas supply pipe and the binder guide wall member.
In the extension pipe portion, a plurality of gas outlets for ejecting gas toward the binder that naturally flows down are formed on both sides of a center line extending along the lower end portion of the extension pipe portion.
A nozzle device characterized in that a plurality of gas outlets formed on one side of the center line satisfy all of the following conditions 1 to 5.
Condition 1: When the ejection angle of each of the gas outlets with respect to the vertical downward direction is θ, the ejection angle θ is 5 ° or more and 40 ° or less.
Condition 2: The angle difference θdif of the ejection angle θ of the gas outlets adjacent to each other in the pipeline direction of the extending pipe portion is 20 ° or less.
Condition 3: Of the plurality of gas outlets, the gas outlet located at one end in the pipeline direction is the first end gas outlet, and the gas outlet is located at the other end. When the gas outlet having a larger ejection angle θ than the first end gas outlet is defined as the second end gas outlet, the first and second end gas outlets of these gas outlets are defined as the second end gas outlet. The gas outlet located between the gas outlets has a larger ejection angle θ than the gas outlet adjacent to the first end gas outlet side, or has the same ejection angle θ.
Condition 4: The gas whose ejection angle θ is equal to or less than the median value θmed, where the median value of the ejection angle θ of the first end gas outlet and the ejection angle θ of the second end gas outlet is θmed. The number of spouts is 1 times or more and 1.5 times or less the number of the gas spouts whose ejection angle θ exceeds the median value θmed.
Condition 5: The angle difference between the ejection angle θ of the first end gas outlet and the ejection angle θ of the second end gas outlet is 15 ° or more. The nozzle device according to claim 1, wherein the plurality of gas outlets are formed at substantially equal intervals in the pipeline direction.

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