JP2002195544A - Cooling method for waste gas - Google Patents

Cooling method for waste gas

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Publication number
JP2002195544A
JP2002195544A JP2000397909A JP2000397909A JP2002195544A JP 2002195544 A JP2002195544 A JP 2002195544A JP 2000397909 A JP2000397909 A JP 2000397909A JP 2000397909 A JP2000397909 A JP 2000397909A JP 2002195544 A JP2002195544 A JP 2002195544A
Authority
JP
Japan
Prior art keywords
exhaust gas
water
cooling
cooling tower
nozzle
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
JP2000397909A
Other languages
Japanese (ja)
Inventor
Michitake Fujiwara
道丈 藤原
Shinsuke Kishi
伸典 岸
Hiroaki Ishida
博章 石田
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Nippon Steel Corp
Original Assignee
Sumitomo Metal Industries Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Sumitomo Metal Industries Ltd filed Critical Sumitomo Metal Industries Ltd
Priority to JP2000397909A priority Critical patent/JP2002195544A/en
Publication of JP2002195544A publication Critical patent/JP2002195544A/en
Pending legal-status Critical Current

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Abstract

PROBLEM TO BE SOLVED: To provide a cooling method for waste gas in which dioxins can be prevented from being resynthesized and waste water is not produced without increasing the cost of a device and a running cost. SOLUTION: When the flow rate of waste gas from a waste combustion and treatment device is x m3 (normal state)/hr, the length of a waste gas introducing part is x/3 mm or more, the exhaust speed of waste gas in a cooling tower is 0.2 to 2 m/sec, a retention time of waste gas in the cooling tower is 3 to 20 seconds, the diameter of water droplet of water jetted from a water distributing nozzle is 150 μm or smaller and the temperature of a gas exhaust part is 120 to 200 deg.C.

Description

【発明の詳細な説明】DETAILED DESCRIPTION OF THE INVENTION

【0001】[0001]

【発明の属する技術分野】本発明は、ダイオキシン類
(以下、単にダイオキシンという)の再合成が防止可能
であり、しかも排水が発生しない排ガス冷却方法に関す
る。
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exhaust gas cooling method capable of preventing resynthesis of dioxins (hereinafter simply referred to as dioxins) and generating no waste water.

【0002】[0002]

【従来の技術】従来、廃棄物燃焼処理装置からの排ガス
は冷却塔上方から導入し、排ガスを散水により冷却し、
冷却塔の下方から冷却後の排ガスを排出していた。この
冷却塔は、上端部に排ガス導入部が配置されるととも
に、内部には下方に向けて散水する散水ノズルが設けら
れ、下端部には排水捕集部が形成され、この排水捕集部
の上方に、下方に向けて開口するガス排出部が設けられ
ている。このような従来の排ガス冷却装置は、下方に向
かう排ガス中に散水するので、水滴の落下方向と排ガス
流の方向が同じであり、水滴の排ガス中での滞留時間が
短く、水滴が蒸発しきれないため、排水の発生が避けら
れない。さらに、ガスの偏流による冷却装置内の温度ム
ラが生じ易く、散水冷却時の冷却ムラが起きやすくなる
ため蒸発しきれない水滴が生じる可能性が高くなり、排
水が発生しやすくなる。このようにして排水が発生する
と、水処理設備が必要となり、その設備費とランニング
コストの増大につながるため改善が求められていた。
2. Description of the Related Art Conventionally, exhaust gas from a waste combustion treatment apparatus is introduced from above a cooling tower, and the exhaust gas is cooled by spraying water.
The exhaust gas after cooling was discharged from below the cooling tower. In the cooling tower, an exhaust gas introduction part is arranged at an upper end, a water spray nozzle for spraying water downward is provided inside, and a drain collection part is formed at a lower end, and a drain collection part is formed. A gas discharge portion that opens downward is provided above. In such a conventional exhaust gas cooling device, since water is sprayed into the exhaust gas flowing downward, the falling direction of the water droplet and the direction of the exhaust gas flow are the same, the residence time of the water droplet in the exhaust gas is short, and the water droplet evaporates completely. Because of the lack of water, the generation of wastewater is inevitable. Furthermore, temperature unevenness in the cooling device due to gas drift is likely to occur, and cooling unevenness during water spray cooling is likely to occur, so that there is a high possibility that water droplets that cannot be completely evaporated are generated, and drainage is likely to occur. When wastewater is generated in this way, a water treatment facility is required, which leads to an increase in the facility cost and running cost, and improvement has been required.

【0003】[0003]

【発明が解決しようとする課題】例えば、特開2000-111
018号公報には、図1に示すように、冷却塔1の下部
に、排ガスを塔内に導入する排ガス導入部2を設けて、
冷却塔1の上部に冷却後の排出ガスを煙道に排出するガ
ス排出部3を設けることにより、冷却塔内の排ガスの流
れを上向きに形成し、排ガス導入部2とガス排出部3と
の間に上方に向けて水を噴射できる散水ノズル4が設け
られた排ガス冷却装置が開示されている。
For example, Japanese Patent Application Laid-Open No. 2000-111
In the publication No. 018, as shown in FIG. 1, an exhaust gas introduction unit 2 for introducing exhaust gas into the cooling tower 1 is provided below the cooling tower 1,
By providing a gas discharge unit 3 for discharging the cooled exhaust gas to the flue above the cooling tower 1, the flow of exhaust gas in the cooling tower is formed upward, and the exhaust gas introduction unit 2 and the gas discharge unit 3 There is disclosed an exhaust gas cooling device provided with a water spray nozzle 4 between which water can be jetted upward.

【0004】しかし、この装置では、排ガスを一旦下方
に向けて塔内に導入しているので、水冷却前の対流部に
おける温度低下が約100℃以上となり、このように排ガ
スが先ず緩冷却されると、ダイオキシンの再合成がおこ
り易くなる。従って、この構造では、後段のプロセスで
触媒等によるダイオキシン除去が必須となり、設備費の
増大およびランニングコストの増大を招くという問題が
ある。
However, in this apparatus, since the exhaust gas is once introduced downward into the tower, the temperature drop in the convection section before water cooling is about 100 ° C. or more, and thus the exhaust gas is first cooled slowly. Then, the resynthesis of dioxin easily occurs. Therefore, in this structure, there is a problem that dioxin removal by a catalyst or the like is indispensable in a subsequent process, which leads to an increase in equipment cost and an increase in running cost.

【0005】また、特開平11-141856号公報には、図2
に示すように、冷却塔1本体を仕切板5で仕切られた内
塔6を有し、この仕切板5に衝突するように排ガスを導
入する排ガス導入部2を有し、排ガス導入部2とガス排
出部3との間にある散水ノズル4を有する排ガス冷却装
置が開示されている。この冷却方法は、この仕切板5に
衝突するように排ガスを導入し、この排ガスに旋回流を
与えながら、排ガスを冷却塔1の下方に導入し、冷却塔
1上方へ誘導し、排ガス導入部2とガス排出部3との間
にある散水ノズル4から下方に向けて水を噴射して排ガ
スを冷却するものである。
Japanese Patent Application Laid-Open No. 11-141856 discloses that FIG.
As shown in the figure, the cooling tower 1 has an inner tower 6 partitioned by a partition plate 5, and has an exhaust gas introduction unit 2 for introducing exhaust gas so as to collide with the partition plate 5. An exhaust gas cooling device having a water spray nozzle 4 between the gas discharge unit 3 is disclosed. In this cooling method, exhaust gas is introduced so as to collide with the partition plate 5, and while giving a swirling flow to the exhaust gas, the exhaust gas is introduced below the cooling tower 1 and guided upward of the cooling tower 1; Water is sprayed downward from a sprinkling nozzle 4 between the gas discharge section 2 and the gas discharge section 3 to cool the exhaust gas.

【0006】しかし、この冷却方法でも、冷却塔1で
は、排ガスを一旦下方に向けて塔内に導入しているの
で、水冷却前の対流部にける温度低下が約100℃以上と
なり、このように排ガスが先ず緩冷却されると、ダイオ
キシンの再合成がおこり易くなる。従って、この構造で
は、後段のプロセスで触媒等によるダイオキシン除去が
必須となり、設備費の増大およびランニングコストの増
大を招くという問題がある。また、冷却塔1の構造が複
雑になるため設備費が高くなり、内塔6内にダストの付
着が起こり易く、ダスト除去のメンテナンスに手間がか
かるという問題もある。
However, even in this cooling method, in the cooling tower 1, since the exhaust gas is once introduced downward into the tower, the temperature drop in the convection section before water cooling becomes about 100 ° C. or more. When the exhaust gas is first slowly cooled, re-synthesis of dioxin easily occurs. Therefore, in this structure, there is a problem that dioxin removal by a catalyst or the like is indispensable in a subsequent process, which leads to an increase in equipment cost and an increase in running cost. Further, since the structure of the cooling tower 1 becomes complicated, equipment costs are increased, and dust tends to adhere to the inner tower 6, so that there is a problem that maintenance for dust removal takes time.

【0007】本発明の目的は、設備費の増大およびラン
ニングコストの増大を招くことなく、ダイオキシンの再
合成が防止可能であり、しかも排水が発生しない排ガス
の冷却方法を提供することにある。
An object of the present invention is to provide a method for cooling exhaust gas which can prevent re-synthesis of dioxin and does not generate wastewater without increasing equipment costs and running costs.

【0008】[0008]

【課題を解決するための手段】本発明者は、排ガスの偏
流を極力減少できる方法等について排ガス冷却ミニプラ
ント装置を使用して試験を行い検討した。
Means for Solving the Problems The present inventor conducted a test using a flue gas cooling mini-plant apparatus and examined a method for minimizing the drift of flue gas as much as possible.

【0009】図3は、試験に使用した排ガス冷却ミニプ
ラント装置の概念図である。同図に示すように、冷却塔
1を備え、該冷却塔1の上部に該冷却塔1と同一軸を有
する排ガス導入部2、冷却塔1内の上部に散水ノズル
4、冷却塔1の下部にガス排出部3を有する排ガス冷却
ミニプラント装置(廃棄物処理量:2質量t/dまたは20質
量t/d規模)を使用して、排ガス導入部の長さ(湾曲部
分を除く冷却塔と同一軸の配管長さ:以下、単に排ガス
導入部長さともいう)と排ガス偏流指数との関係等を調
査した。
FIG. 3 is a conceptual diagram of an exhaust gas cooling mini-plant apparatus used for the test. As shown in the drawing, an exhaust gas introducing section 2 having a cooling tower 1 and having the same axis as the cooling tower 1 is provided at an upper part of the cooling tower 1, a water spray nozzle 4 is provided at an upper part of the cooling tower 1, and a lower part of the cooling tower 1 is provided. Using a flue gas cooling mini-plant apparatus (waste treatment amount: 2 mass t / d or 20 mass t / d scale) having a gas discharge section 3, the length of the exhaust gas introduction section (with the cooling tower excluding the curved section) The relationship between the length of the pipe on the same axis: hereinafter simply referred to as the length of the exhaust gas introduction section) and the exhaust gas drift index was investigated.

【0010】以下に、この試験の前提条件について述べ
る。図4(a)、(b)は、排ガス偏流指数を求めたと
きの冷却塔における温度計の位置を示す概念図であり、
図4(a)は側面図を、図4(b)は平面図をそれぞれ
示す。
The prerequisites for this test are described below. FIGS. 4A and 4B are conceptual diagrams showing the position of the thermometer in the cooling tower when the exhaust gas drift index is obtained.
FIG. 4A is a side view, and FIG. 4B is a plan view.

【0011】同図(a)に示すように、温度計を冷却塔
1の散水ノズル4直上位置()、散水ノズル4直上と
ガス排出部3直上とのほぼ中間点位置()、ガス排出
部3直上位置()の3位置において、同図(b)に示
すように、それぞれ周方向に60度間隔で、6ヶ所(A〜F)
の温度計を冷却塔1の内側に約50mm出して挿入し、それ
ぞれの計測値をTA,TB,…,TE,TFと表し、排
ガス偏流指数を求めた。
As shown in FIG. 1A, the thermometer is located at a position () immediately above the water spray nozzle 4 of the cooling tower 1, at a substantially intermediate point position () just above the water spray nozzle 4 and immediately above the gas discharge part 3, and at a gas discharge part. At three positions immediately above (3), six positions (A to F) at circumferentially 60-degree intervals as shown in FIG.
Of about 50 mm was inserted into the inside of the cooling tower 1 and the measured values were expressed as TA, TB,..., TE, TF, and the exhaust gas drift index was obtained.

【0012】すなわち、排ガス偏流Pは下記式から求め
られ、ガス導入部長さがχ/3のときのP値を1として
指数化したものを便宜的に排ガス偏流指数とした。 P=(TA〜TFの最大値) /(TA〜TFの最小
値)×(TA〜TFの最大値) /(TA〜TFの最小
値)×(TA〜TFの最大値) /(TA〜TFの最小
値) また、図5は排ガスの空塔速度の定義位置を示す概念図
である。
That is, the flue gas drift P is obtained from the following equation, and the value obtained by indexing the P value when the length of the gas introduction portion is 1/3 as 1 is defined as the flue gas drift index for convenience. P = (maximum value of TA to TF) / (minimum value of TA to TF) × (maximum value of TA to TF) / (minimum value of TA to TF) × (maximum value of TA to TF) / (TA to (Minimum value of TF) FIG. 5 is a conceptual diagram showing the definition position of the superficial velocity of the exhaust gas.

【0013】すなわち、同図に示す最大直径部の断面積
を基に、下記式から排ガスの空塔速度V(m/sec)が求め
られる。 V=G/3600×(273+T1)/273/(πD2/4) ただし、G:冷却塔入り側の排ガス流量 (m3(標準状
態)/h)、 T1:冷却塔入り側の排ガス温度 (℃)、 D:冷却塔の最大直径 (m)。
That is, the superficial velocity V (m / sec) of the exhaust gas is obtained from the following equation based on the cross-sectional area of the maximum diameter portion shown in FIG. V = G / 3600 × (273 + T1) / 273 / (πD 2/4) However, G: exhaust gas flow rate of the cooling tower entry side (m 3 (standard state) / h), T1: cooling tower entry side exhaust gas Temperature (° C.), D: Maximum diameter of cooling tower (m).

【0014】以上の前提条件を基に、排ガス導入部長さ
と排ガス偏流指数との関係等を求める試験を実施した。
以下に得られた知見について述べる (A)図6は、排ガス導入部長さと排ガス偏流指数との
関係を示すグラフである。なお、このときの試験条件
は、冷却塔内の排ガスの空塔速度が1m/secであり、冷
却塔内の前記排ガスの滞留時間が10秒であり、散水ノズ
ルから噴出する水の水滴径が約100μmであり、冷却塔の
出側温度が180℃である。
Based on the above prerequisites, tests were conducted to determine the relationship between the length of the exhaust gas introduction section and the exhaust gas drift index.
(A) FIG. 6 is a graph showing the relationship between the exhaust gas introduction section length and the exhaust gas drift index. The test conditions at this time were as follows: the superficial velocity of the exhaust gas in the cooling tower was 1 m / sec, the residence time of the exhaust gas in the cooling tower was 10 seconds, and the water droplet diameter of the water jetted from the water spray nozzle was It is about 100 μm, and the outlet temperature of the cooling tower is 180 ° C.

【0015】図6に示すように、排ガス導入部長さをχ
/3mm未満にした場合には、排ガス偏流指数が急激に大き
くなるが、χ/3mm以上であれば、試験規模によらず排ガ
ス偏流指数がほぼ一定となる。
[0015] As shown in FIG.
When it is less than / 3 mm, the exhaust gas drift index increases rapidly, but when it is χ / 3 mm or more, the exhaust gas drift index becomes almost constant regardless of the test scale.

【0016】(B)廃棄物処理量が20質量t/d規模の排
ガス冷却ミニプラント装置を使用して、空塔速度と排水
発生量との関係を調査した。図7は、冷却塔内の空塔速
度と排水発生量との関係を示すグラフである。なお、こ
のときの試験条件は、排ガス導入部長さがχ/2mm一定
で、冷却塔内の排ガスの滞留時間が7秒であり、散水ノ
ズルから噴出する水の水滴径が約85μmであり、冷却塔
の出側温度が180℃である。
(B) The relationship between the superficial velocity and the amount of waste water generated was investigated using an exhaust gas cooling mini-plant apparatus having a waste treatment amount of 20 mass t / d. FIG. 7 is a graph showing the relationship between the superficial velocity in the cooling tower and the amount of generated wastewater. The test conditions at this time were as follows: the length of the exhaust gas introduction section was constant at χ / 2 mm, the residence time of the exhaust gas in the cooling tower was 7 seconds, the water droplet diameter of the water ejected from the water spray nozzle was about 85 μm, The outlet temperature of the tower is 180 ° C.

【0017】同図に示すように、空塔速度は0.2〜2m/se
cの範囲で排水発生量がゼロとなる。この空塔速度の範
囲外で排水が発生する理由は、空塔速度が0.2m/sec未満
となると、ガスの流れが一方向ではなくなり、ガス流れ
に乱れが生じ易くなるので、散水された水滴が冷却塔の
内壁に接触し、蒸発しないでそのまま排水となるからで
あると推定され、空塔速度が2m/sec超となると、同様に
ガス流れに乱れが生じ易くなるので、散水された水滴が
冷却塔の内壁に接触し、蒸発しないでそのまま排水とな
るからであると推定される。
As shown in FIG. 1, the superficial velocity is 0.2 to 2 m / se.
The amount of generated wastewater becomes zero in the range of c. The reason why drainage is generated outside this range of superficial superficial velocity is that if the superficial superficial velocity is less than 0.2 m / sec, the gas flow will not be unidirectional and the gas flow will be easily disturbed, It is presumed that the water comes into contact with the inner wall of the cooling tower and becomes wastewater without evaporating.If the superficial tower speed exceeds 2 m / sec, the gas flow is likely to be disturbed as well, This is presumed to be due to contact with the inner wall of the cooling tower, which is discharged without being evaporated.

【0018】(C)廃棄物処理量が20質量t/d規模の排
ガス冷却ミニプラント装置を使用して、排ガス滞留時間
と排水発生量との関係を調査した。図8は、排ガスの滞
留時間と排水発生量との関係を示すグラフである。な
お、このときの試験条件は、排ガス導入部長さがχ/2mm
一定で、冷却塔内の排ガスの空塔速度が1.2m/secであ
り、散水ノズルから噴出する水の水滴径が約85μmであ
り、冷却塔出側温度が180℃である。
(C) The relationship between the residence time of the exhaust gas and the amount of waste water generated was investigated using an exhaust gas cooling mini-plant apparatus having a waste treatment amount of 20 mass t / d scale. FIG. 8 is a graph showing the relationship between the residence time of exhaust gas and the amount of generated wastewater. The test conditions at this time were that the length of the exhaust gas introduction section was χ / 2 mm.
It is constant, the superficial velocity of the exhaust gas in the cooling tower is 1.2 m / sec, the water droplet diameter of the water jetted from the water spray nozzle is about 85 μm, and the cooling tower outlet temperature is 180 ° C.

【0019】同図に示すように、排ガス滞留時間は、3
〜20秒の範囲で排水発生量がゼロとなる。なお、排ガス
滞留時間が3秒未満または20秒超となると、散水量の制
御が不安定になるため排水が発生するもと推定される。
As shown in FIG.
The amount of drainage generated becomes zero in the range of ~ 20 seconds. If the residence time of the exhaust gas is less than 3 seconds or more than 20 seconds, it is estimated that drainage is generated because the control of the watering amount becomes unstable.

【0020】(D)廃棄物処理量が20質量t/d規模の排
ガス冷却ミニプラント装置を使用して、散水ノズルから
噴出する水の水滴径と排水発生量との関係を調査した。
図9は、水滴径と排水発生量との関係を示すグラフであ
る。なお、このときの試験条件は、排ガス導入部長さが
χ/2mm一定で、冷却塔内の排ガスの空塔速度が1.2m/sec
であり、排ガス滞留時間が7秒であり、冷却塔の出側温
度が180℃である。
(D) Using a flue gas cooling mini-plant apparatus with a waste treatment amount of 20 mass t / d, the relationship between the water droplet diameter of water spouted from the watering nozzle and the amount of drainage was investigated.
FIG. 9 is a graph showing the relationship between the water droplet diameter and the amount of generated wastewater. The test conditions at this time were as follows: the exhaust gas introduction section length was constant at χ / 2 mm, and the superficial velocity of the exhaust gas in the cooling tower was 1.2 m / sec.
The exhaust gas residence time is 7 seconds, and the outlet temperature of the cooling tower is 180 ° C.

【0021】同図に示すように、水滴径は、150μm以下
で排水発生量がゼロとなる。本発明は、以上の知見に基
づいてなされたもので、その要旨は、下記のとおりであ
る。
As shown in the figure, when the water droplet diameter is 150 μm or less, the amount of drainage generated becomes zero. The present invention has been made based on the above findings, and the gist is as follows.

【0022】(1)冷却塔を備え、該冷却塔の上部に該
冷却塔と同一軸を有する排ガス導入部、冷却塔内の上部
に散水ノズル、そして冷却塔の下部にガス排出部を有す
る冷却装置を使用して排ガス導入部から冷却塔に送られ
る廃棄物燃焼処理装置からの排ガスを散水ノズルから噴
出する水により冷却し、次いでガス排出部を経由して冷
却塔から排出させる排ガスの冷却方法において、前記廃
棄物燃焼処理装置からの排ガスの流量がχm3(標準状
態)/hrであるとき、排ガス導入部の長さがχ/3mm以上
であり、冷却塔内の排ガスの空塔速度が0.2〜2m/secで
あり、冷却塔内の排ガスの滞留時間が3〜20秒であり、
散水ノズルから噴出する水の水滴径が150μm以下であ
り、ガス排出部の温度が120〜200℃であることを特徴と
する排ガスの冷却方法。
(1) A cooling system having a cooling tower, an exhaust gas introduction part having the same axis as the cooling tower at the upper part of the cooling tower, a water spray nozzle at the upper part in the cooling tower, and a gas discharge part at the lower part of the cooling tower. A method of cooling exhaust gas from a waste combustion treatment device sent from an exhaust gas introduction unit to a cooling tower using an apparatus, cooled by water jetted from a water spray nozzle, and then discharged from the cooling tower via a gas discharge unit In the above, when the flow rate of the exhaust gas from the waste combustion treatment device is χm 3 (standard state) / hr, the length of the exhaust gas introduction part is χ / 3 mm or more, and the superficial velocity of the exhaust gas in the cooling tower is 0.2 to 2 m / sec, the residence time of the exhaust gas in the cooling tower is 3 to 20 seconds,
A method for cooling exhaust gas, wherein a water droplet diameter of water spouted from a water spray nozzle is 150 μm or less, and a temperature of a gas discharge part is 120 to 200 ° C.

【0023】(2)前記散水ノズルの1孔あたりの水量
を750L/hr以下とすることを特徴とする上記(1)に記
載の排ガスの冷却方法。 (3)前記散水ノズルの孔数と入側水圧とが、下記
(1)式を満足することを特徴とする上記(1)に記載
の排ガスの冷却方法。
(2) The exhaust gas cooling method according to the above (1), wherein the water amount per hole of the water spray nozzle is 750 L / hr or less. (3) The exhaust gas cooling method according to the above (1), wherein the number of holes and the inlet water pressure of the water spray nozzle satisfy the following expression (1).

【0024】 (ノズルの孔数)×(ノズル入側水圧(MPa))≧2.5MPa (1) (4)前記散水ノズルとして、水および窒素、または、
水および空気を噴射する2流体ノズルを使用することを
特徴とする上記(1)に記載の排ガスの冷却方法。
(Number of nozzle holes) × (Nozzle inlet water pressure (MPa)) ≧ 2.5 MPa (1) (4) Water and nitrogen, or
The exhaust gas cooling method according to the above (1), wherein a two-fluid nozzle for injecting water and air is used.

【0025】[0025]

【発明の実施の形態】水滴径を150μm以下にする方法に
ついて以下に述べる。先ず、ノズル1孔当たりの散水量
と水滴径との関係を廃棄物処理量が20質量t/d規模の排
ガス冷却ミニプラント装置を使用して調査した。
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A method for reducing a water droplet diameter to 150 μm or less will be described below. First, the relationship between the amount of water sprayed per nozzle hole and the water droplet diameter was investigated using an exhaust gas cooling mini-plant apparatus having a waste treatment amount of 20 mass t / d.

【0026】図10は、ノズル1孔当たりの散水量と水
滴径との関係を示すグラフである。なお、このときの試
験条件は、排ガス導入部長さχ/2mm一定で、冷却塔内の
排ガスの空塔速度が1.2m/secであり、排ガス滞留時間が
7秒であり、冷却塔出側温度が180℃である。また、(ノ
ズルの孔数)×(ノズル入側水圧(MPa))の値を2MPa一定
で試験を行った。
FIG. 10 is a graph showing the relationship between the amount of water spray per nozzle hole and the diameter of water droplets. The test conditions at this time were as follows: the exhaust gas introduction section length was constant at χ / 2 mm, the superficial velocity of the exhaust gas in the cooling tower was 1.2 m / sec, the exhaust gas residence time was 7 seconds, and the cooling tower outlet temperature Is 180 ° C. Further, the test was performed with the value of (number of nozzle holes) × (nozzle inlet water pressure (MPa)) kept constant at 2 MPa.

【0027】同図に示すように、ノズル1孔当たりの散
水量が750L/hr以下で、150μm以下の水滴径が得られ
る。次に、(ノズルの孔数)×(ノズル入側水圧(MPa))と
水滴径との関係を廃棄物処理量が20質量t/d規模の排ガ
ス冷却ミニプラント装置を使用して調査した。
As shown in the figure, a water droplet size of 150 μm or less can be obtained when the amount of water sprayed per nozzle hole is 750 L / hr or less. Next, the relationship between (number of nozzle holes) × (nozzle inlet water pressure (MPa)) and water droplet diameter was investigated using an exhaust gas cooling mini-plant apparatus having a waste treatment amount of 20 mass t / d.

【0028】図11は、(ノズルの孔数)×(ノズル入側
水圧(MPa))と水滴径との関係を示すグラフである。な
お、このときの試験条件は、排ガス導入部長さχ/2mm一
定で、冷却塔内の排ガスの空塔速度が1.2m/secであり、
排ガス滞留時間が7秒であり、冷却塔出側温度が180℃
である。また、ノズル1孔当たりの散水量が750L/hr一
定で試験を行った。
FIG. 11 is a graph showing the relationship between (number of nozzle holes) × (nozzle inlet water pressure (MPa)) and water droplet diameter. Incidentally, the test conditions at this time, the exhaust gas introduction section length χ / 2mm constant, the superficial velocity of the exhaust gas in the cooling tower is 1.2m / sec,
Exhaust gas residence time is 7 seconds, cooling tower outlet temperature is 180 ° C
It is. In addition, the test was performed with a constant water spray amount of 750 L / hr per nozzle hole.

【0029】同図に示すように、(ノズルの孔数)×(ノ
ズル入側水圧(MPa))が2.5 MPa以上で、150μm以下の水
滴径が得られる。散水ノズルとしては、水のみを使用し
ても、上記の条件を満たせば、冷却塔からの排水は発生
しないが、水と窒素(又は空気)の2流体ノズルを使用
すれば、水滴径はより小さくなるので、散水量の急激な
変動があっても、排水は発生しない。
As shown in the figure, when (number of nozzle holes) × (nozzle inlet water pressure (MPa)) is 2.5 MPa or more, a water droplet diameter of 150 μm or less is obtained. Even if only water is used as the watering nozzle, if the above conditions are satisfied, no drainage from the cooling tower is generated. However, if a two-fluid nozzle of water and nitrogen (or air) is used, the water droplet diameter becomes larger. Because of the small size, no drainage occurs even if there is a sudden change in the amount of watering.

【0030】散水量の制御は所定の排出ガス温度となる
ようにフィードバック制御やその他の制御方法を用いて
制御すれば良く、本発明の冷却塔の運転方法と併用して
用いられる。
The amount of water spray may be controlled using feedback control or other control methods so as to reach a predetermined exhaust gas temperature, and is used in combination with the cooling tower operation method of the present invention.

【0031】[0031]

【実施例】廃棄物処理量:20質量t/d規模のシャフト炉
型のガス化溶融試験炉で発生した排ガスを試験冷却装置
(廃棄物処理量:20質量t/d)で冷却した試験結果につ
いて以下に述べる。
[Example] Waste treatment amount: Test result of cooling exhaust gas generated in a gasification and melting test furnace of a shaft furnace type of 20 mass t / d scale with a test cooling device (waste disposal amount: 20 mass t / d) Is described below.

【0032】試験は、全て試験冷却装置の出側排出ガス
温度を120〜200℃になるように散水量を制御しておこな
った。それぞれの場合について、3日ずつ試験した。表
1に試験条件とその結果を示す。
All tests were conducted by controlling the amount of water sprayed so that the outlet exhaust gas temperature of the test cooling device was 120 to 200 ° C. In each case, three days were tested. Table 1 shows the test conditions and the results.

【0033】[0033]

【表1】 [Table 1]

【0034】同表に示すように、前記図3の試験装置を
使用して、排ガス流量がχm3(標準状態)/hr であると
き、排ガス導入部長さがχ/3mm以上であり、排ガスの空
塔速度が0.2〜2m/secであり、排ガスの滞留時間が3〜20
秒であり、散水ノズルから噴出する水の水滴径が150μm
以下である本発明例は排水発生が無く、しかも排出ガス
中のダイオキシン濃度が0.03ng-TEQ/m3(標準状態)
以下であった。
As shown in the table, when the exhaust gas flow rate was χm 3 (standard state) / hr, the length of the exhaust gas introduction section was 排 ガ ス / 3 mm or more using the test apparatus shown in FIG. Superficial superficial velocity is 0.2-2m / sec, residence time of exhaust gas is 3-20
Seconds, and the diameter of the water jetting from the watering nozzle is 150 μm
In the following examples of the present invention, no wastewater is generated, and the dioxin concentration in the exhaust gas is 0.03 ng-TEQ / m 3 (standard state).
It was below.

【0035】また、前記図3の試験装置を使用しても、
比較例1〜7に示すように、排ガス導入部長さ、排ガス
の空塔速度、排ガスの滞留時間および散水ノズルから噴
出する水の水滴径が適正な範囲を外れたため、排水発生
が発生した。
Further, even if the test apparatus shown in FIG. 3 is used,
As shown in Comparative Examples 1 to 7, wastewater was generated because the length of the exhaust gas introduction portion, the superficial velocity of the exhaust gas, the residence time of the exhaust gas, and the diameter of the water droplet jetted from the water spray nozzle were out of appropriate ranges.

【0036】一方、図1および2の試験装置(廃棄物処
理量:2質量t/d)を使用した従来例1および2は、排水
の発生が無かったが、排出ガス中のダイオキシン濃度が
0.2ng-TEQ/m3(標準状態)以上と本発明例に比べて高
くなった。
On the other hand, in the conventional examples 1 and 2 using the test apparatus (waste disposal amount: 2 mass t / d) shown in FIGS. 1 and 2, no wastewater was generated, but the dioxin concentration in the exhaust gas was low.
0.2 ng-TEQ / m 3 (standard state) or more, which was higher than that of the present invention.

【0037】[0037]

【発明の効果】本発明の排ガスの冷却方法により、排水
が発生しないばかりか、冷却塔出側の排出ガス中のダイ
オキシン濃度が極めて低くなり、後段で触媒や吸着剤等
を用いるダイオキシン除去設備等が不要となる。
According to the method for cooling exhaust gas of the present invention, not only no waste water is generated but also the dioxin concentration in the exhaust gas at the outlet of the cooling tower becomes extremely low, and dioxin removal equipment using a catalyst, an adsorbent, etc. in the subsequent stage. Becomes unnecessary.

【図面の簡単な説明】[Brief description of the drawings]

【図1】特開2000-111018号公報に記載の発明構成を示
す概念図である。
FIG. 1 is a conceptual diagram showing the configuration of the invention described in JP-A-2000-111018.

【図2】特開平11-141856号公報に記載の発明構成を示
す概念図である。
FIG. 2 is a conceptual diagram showing the configuration of the invention described in JP-A-11-141856.

【図3】試験に使用した排ガス冷却ミニプラント装置の
概念図である。
FIG. 3 is a conceptual diagram of an exhaust gas cooling mini-plant apparatus used for a test.

【図4】排ガス偏流指数を求めたときの冷却塔における
温度計の位置を示す概念図であり、図4(a)は側面図
を、図4(b)は平面図をそれぞれ示す。
FIG. 4 is a conceptual diagram showing the position of a thermometer in a cooling tower when an exhaust gas drift index is obtained. FIG. 4 (a) is a side view, and FIG. 4 (b) is a plan view.

【図5】排ガスの空塔速度の定義位置を示す概念図であ
FIG. 5 is a conceptual diagram showing a definition position of a superficial velocity of exhaust gas.

【図6】排ガス導入部長さと排ガス偏流指数との関係を
示すグラフである。
FIG. 6 is a graph showing a relationship between an exhaust gas introduction section length and an exhaust gas drift index.

【図7】冷却塔内の空塔速度と排水発生量との関係を示
すグラフである。
FIG. 7 is a graph showing a relationship between a superficial velocity in a cooling tower and an amount of generated wastewater.

【図8】排ガスの滞留時間と排水発生量との関係を示す
グラフである。
FIG. 8 is a graph showing the relationship between the residence time of exhaust gas and the amount of generated waste water.

【図9】水滴径と排水発生量との関係を示すグラフであ
る。
FIG. 9 is a graph showing a relationship between a water droplet diameter and an amount of generated wastewater.

【図10】ノズル1孔当たりの散水量と水滴径との関係
を示すグラフである。
FIG. 10 is a graph showing the relationship between the amount of water spray per nozzle hole and the diameter of a water droplet.

【図11】(ノズルの孔数)×(ノズル入側水圧(MPa))と
水滴径との関係を示すグラフである。
FIG. 11 is a graph showing the relationship between (number of nozzle holes) × (nozzle inlet water pressure (MPa)) and water droplet diameter.

【符号の説明】[Explanation of symbols]

1:冷却塔、 2:排ガス導入部、 3:ガス排出部、 4:散水ノズル、 5:仕切板、 6:内塔。 1: cooling tower, 2: exhaust gas introduction part, 3: gas discharge part, 4: water spray nozzle, 5: partition plate, 6: inner tower.

───────────────────────────────────────────────────── フロントページの続き (72)発明者 石田 博章 茨城県鹿嶋市大字光3番地 住友金属工業 株式会社鹿島製鉄所内 Fターム(参考) 3K070 DA05 DA37 DA83  ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hiroaki Ishida 3, Oaza Hikari, Kashima City, Ibaraki Prefecture Sumitomo Metal Industries Kajima Works F-term (reference) 3K070 DA05 DA37 DA83

Claims (4)

【特許請求の範囲】[Claims] 【請求項1】 冷却塔を備え、該冷却塔の上部に該冷却
塔と同一軸を有する排ガス導入部、冷却塔内の上部に散
水ノズル、そして冷却塔の下部にガス排出部を有する冷
却装置を使用して排ガス導入部から冷却塔に送られる廃
棄物燃焼処理装置からの排ガスを散水ノズルから噴出す
る水により冷却し、次いでガス排出部を経由して冷却塔
から排出させる排ガスの冷却方法において、前記廃棄物
燃焼処理装置からの排ガスの流量がχm3(標準状態)/h
rであるとき、排ガス導入部の長さがχ/3mm以上であ
り、冷却塔内の排ガスの空塔速度が0.2〜2m/secであ
り、冷却塔内の排ガスの滞留時間が3〜20秒であり、散
水ノズルから噴出する水の水滴径が150μm以下であり、
ガス排出部の温度が120〜200℃であることを特徴とする
排ガスの冷却方法。
1. A cooling device comprising a cooling tower, an exhaust gas introduction part having the same axis as the cooling tower at the upper part of the cooling tower, a water spray nozzle at an upper part in the cooling tower, and a gas discharge part at a lower part of the cooling tower. In the cooling method of the exhaust gas, the exhaust gas from the waste combustion treatment device sent from the exhaust gas introduction unit to the cooling tower is cooled by water jetted from the water spray nozzle, and then discharged from the cooling tower via the gas discharge unit. , The flow rate of exhaust gas from the waste combustion treatment equipment is χm 3 (standard condition) / h
When r, the length of the exhaust gas introduction section is χ / 3 mm or more, the superficial velocity of the exhaust gas in the cooling tower is 0.2 to 2 m / sec, and the residence time of the exhaust gas in the cooling tower is 3 to 20 seconds. The water droplet diameter of the water spouting from the watering nozzle is 150 μm or less,
A method for cooling exhaust gas, wherein the temperature of the gas discharge section is 120 to 200 ° C.
【請求項2】 前記散水ノズルの1孔あたりの水量を75
0L/hr以下とすることを特徴とする請求項1に記載の排
ガスの冷却方法。
2. The water amount per hole of said watering nozzle is 75
2. The method for cooling exhaust gas according to claim 1, wherein the cooling rate is 0 L / hr or less.
【請求項3】 前記散水ノズルの孔数と入側水圧とが、
下記(1)式を満足することを特徴とする請求項1に記
載の排ガスの冷却方法。 (ノズルの孔数)×(ノズル入側水圧(MPa))≧2.5MPa (1)
3. The number of holes of the watering nozzle and the inlet-side water pressure are:
The exhaust gas cooling method according to claim 1, wherein the following expression (1) is satisfied. (Number of nozzle holes) x (Nozzle inlet water pressure (MPa)) ≥ 2.5MPa (1)
【請求項4】 前記散水ノズルとして、水および窒素、
または、水および空気を噴射する2流体ノズルを使用す
ることを特徴とする請求項1に記載の排ガスの冷却方
法。
4. Water and nitrogen as the watering nozzle,
The method for cooling exhaust gas according to claim 1, wherein a two-fluid nozzle for injecting water and air is used.
JP2000397909A 2000-12-27 2000-12-27 Cooling method for waste gas Pending JP2002195544A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
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Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2000397909A JP2002195544A (en) 2000-12-27 2000-12-27 Cooling method for waste gas

Publications (1)

Publication Number Publication Date
JP2002195544A true JP2002195544A (en) 2002-07-10

Family

ID=18862973

Family Applications (1)

Application Number Title Priority Date Filing Date
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Country Status (1)

Country Link
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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2011021810A (en) * 2009-07-15 2011-02-03 Ohkawara Kakohki Co Ltd Straightening device for cooling tower for cooling high temperature gas
CN102954475A (en) * 2011-08-24 2013-03-06 苏州仕净环保设备有限公司 Silane tail gas purifying device
JP2013228166A (en) * 2012-04-26 2013-11-07 Sumitomo Heavy Ind Ltd Drift detection system

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2011021810A (en) * 2009-07-15 2011-02-03 Ohkawara Kakohki Co Ltd Straightening device for cooling tower for cooling high temperature gas
CN102954475A (en) * 2011-08-24 2013-03-06 苏州仕净环保设备有限公司 Silane tail gas purifying device
JP2013228166A (en) * 2012-04-26 2013-11-07 Sumitomo Heavy Ind Ltd Drift detection system

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