A7 五、發明説明（1 ) 發明t景 發明範圍 本發明有關於一種電熔爐之操作方法，其中戴奥辛 (dioxin)及其他有毒物質可避免自安裝於一製鋼廠或廢物熔 解場之一電熔爐，例如一電弧爐等，與廢氣一同排出。 先前技術 在裝設有一電弧爐之製鋼廠，設有兩種排氣系統：一種 是直接排氣系統，直接將電弧爐内熔解廢金屬所產生之廢 氣直接自爐體抽送排氣到一袋濾器以利用袋濾器收集灰 塵；另一種是建造一排氣系統，將設有電弧爐之建築物之 電弧爐於將廢金屬倒入電弧爐或自電弧爐放出熔解金屬時 所釋出之排氣，從安裝電弧爐上之天花板套管（hood)抽到袋 濾器内。這些排氣系統為一收集塵垢裝置。 在上述直接排氣系統之排氣溫度高，因為是直接從爐體 抽氣，卻要透過冷卻塔將之冷卻。然後通過冷卻氣體透過 一袋濾器收集塵垢。 經濟部中央樣準局負工消費合作社印製 (請先閲讀背面之注意事項再填寫本頁)A7 V. Description of the invention (1) The scope of the invention The invention relates to a method of operating an electric furnace, in which dioxin and other toxic substances can be avoided from being installed in an electric furnace in a steel plant or a waste melting site, For example, an electric arc furnace is discharged together with the exhaust gas. In the prior art, in a steel plant equipped with an electric arc furnace, there are two types of exhaust systems: one is a direct exhaust system, which directly exhausts the exhaust gas generated by melting scrap metal in the electric arc furnace from the furnace body to a bag filter. Bag filters are used to collect dust; the other is to construct an exhaust system that discharges the waste metal into the arc furnace or discharges the molten metal from the arc furnace. Pump from the ceiling hood on the electric arc furnace into the bag filter. These exhaust systems are dust collection devices. The exhaust temperature of the above direct exhaust system is high, because it is directly drawn from the furnace body, but it is cooled by a cooling tower. Dirt is then collected by the cooling gas through a bag of filters. Printed by the Central Consumer Procurement Bureau, Ministry of Economic Affairs, Consumer Cooperatives (Please read the notes on the back before filling this page)
然而，在上述傳統式集座裝置含於排氣之有毒氯化物， 戴奥辛（dioxin)(多氯聯笨及其同分異構物），重金屬及其他 有毒物質並不能充分收集。因此，遂需研發一種能改良去 除有毒物質效率之方法。 同時，傳統式做法是以吸收物，例如活性碳等，來吸收 含於排氣中之有毒物。為保持高吸收效率，則需大量之吸 收物，致成本增加。同時，另一問題為，如何處理使用後 之吸收物，處理不當會進而二度污染破壞環境。 本紙張尺度適用中國國家標準（CNS ) A4規格（210X297公釐） A7 B7 五、發明説明（2 ) 發明之概要 本發明的目的為藉吸收物有效去除由電熔爐產生之排氣 中的有毒物質，及處理使用過之吸收物又不致污染環境。 為達成上述目的，根據本發明之操作方法，自電熔爐内 含於排氣之戴奥辛（dioxin)及其他有毒物是以活性碳吸收， 該吸收物能吸收傳送到電溶爐做為初破或破射物之有毒物 質。 根據本發明，含於來自電熔爐之排氣的戴奥辛（dioxin)及 其他有毒物質可以高度效率去除，並且提供能吸收有毒物 質之碳吸收物到電熔爐，該吸收物能有效利用並不會造成 二度環境污染。 圖式簡單說明 第1圖為說明根據本發明一第一實施例之電熔爐操作之 概略圖。 第2圖為第1圖所示實施例中修改之吸收塔的垂直剖面 圖。 第3圖為說明根據本發明一第二實施例之電熔爐操作之 概略圖。 經濟部中央標率而貨工消費合作社印製 (讀先閱讀背面'5'注意事項再填寫本頁)However, in the above-mentioned conventional block device, the toxic chlorides contained in the exhaust gas, dioxin (polychlorinated biphenyls and its isomers), heavy metals and other toxic substances cannot be collected sufficiently. Therefore, it is necessary to develop a method that can improve the efficiency of removing toxic substances. At the same time, the traditional method is to use absorbents, such as activated carbon, to absorb the toxic substances contained in the exhaust gas. In order to maintain high absorption efficiency, a large amount of absorbent is required, resulting in increased cost. At the same time, another issue is how to dispose of the absorbents after use. Improper treatment will further pollute and damage the environment. This paper size applies the Chinese National Standard (CNS) A4 specification (210X297 mm) A7 B7 V. Description of the invention (2) Summary of the invention The purpose of the invention is to effectively remove the toxic substances in the exhaust gas generated by the electric furnace by means of absorbents , And disposal of used absorbents will not pollute the environment. In order to achieve the above object, according to the operating method of the present invention, dioxin and other toxic substances contained in the exhaust gas from the electric furnace are absorbed by activated carbon, and the absorbent can be absorbed and transmitted to the electric melting furnace as a preliminary break or Toxic substances of projectiles. According to the present invention, dioxin and other toxic substances contained in the exhaust gas from the electric furnace can be removed with high efficiency, and a carbon absorber capable of absorbing the toxic substance is provided to the electric furnace. The absorbent can be effectively used without causing Second degree environmental pollution. Brief Description of the Drawings Fig. 1 is a schematic diagram illustrating the operation of an electric furnace according to a first embodiment of the present invention. Fig. 2 is a vertical sectional view of a modified absorption tower in the embodiment shown in Fig. 1; Fig. 3 is a schematic diagram illustrating the operation of an electric furnace according to a second embodiment of the present invention. Printed by the Central Ministry of Economic Affairs and printed by the Consumer Goods Cooperative (read the "5" notice on the back before filling in this page)
第4圖為第3圖所示實施例中修改之吸收塔的垂直剖面 圖。 第5圖為顯示第3圖之導管水平剖面圖。 第6圖為顯示第3圖之袋濾器之部分放大圖。 較佳實施例之說明 現參考第1圖說明第一實施例。在一電弧爐1，如第1 5 本紙張尺度適用中國國家標準（CNS ) A4規格（210X 297公釐） 經濟部中央標準趵员工消費合作社印繁 A7 B7_ _ 五、發明説明（3 ) 圖所示，電極3垂直插入爐體。電爐1之排氣口 2迷接到 一直接排氣系統A之入口以直接抽氣及排氣。在建築物天 花板設有一天花板套管4位於電爐1上方，ϋ做為建築物 排氣系統Β之入口，以間接抽氣及排氣。 在直接排氣系統A’設有外界空氣進氣板5可調整排氣 口 2之開/關，在下游設有連續之燃燒塔6，冷卻塔7，袋房 8，填料單元(charging unit)21，一袋房9及一強升壓送風機 10。再者，一送風機12及一袋房13，設於建築排氣系統之 天花板套管4的下游。 燃燒塔6内設有燃燒器Π於内以燃燒及分解一氧化碳 氣體及其他自電爐1排氣包含於排氣氣體中未燃燒的成分。 冷卻塔7内設有散熱器，供冷卻水循環，以將排氣冷卻 至袋濾器可耐熱之攝氏250度或更低溫度。 8與9分別具有複數個袋濾器Η及16，以收集在排氣 之塵埃。集於袋濾器14及袋濾器16之塵埃分別定期清除， 然後透過輸送器31及32棄置。 填料單元21由一斗(h〇pper)22構成以儲存粉狀之活性 碳，一透風器23及一填料喉24 ’其尖端連接袋房8及9之 間的排氣導管17。儲存於22之活性碳以壓力經由送風写23 傳送到填料喉，然後自填料喉24之尖點吹送到排氣管17。 活性碳的供應量最好是排氣每Nm3 1〇〇到5〇〇mg(毫克）。 在袋房9下游設有一升壓送風器1〇,及一氣流通道切 換風門（damper) 30設於送風器之下游。在風門3〇之下 游，一導管分支成兩方向：一導管連接建築排氣系統B之 本紙張尺度適用中國國家榡準（CNS ) Μ规格（210Χ：297公釐） β 'IT {請先閱讀背面之注意事項再填寫本頁} 經濟部中央標隼局W工消費合作社印繁 ~一 — A7 r ,—〜〜----------- B7 五、發明説明（4 ) " 送風写 _ ° Z之上游侧，使流經直接排氣.系統A之排氣可與流 、星建築拆氣系統B之排氣會合；另一導管設於排氣管35， 連接到煃_(未顯示)。 ± 袋厚13具有複數袋濾器36。在排氣流經袋濾器36 τ Y即自Η月13之上部排氣到大氣成為淨化氣體。集於袋 滅器36之塵埃定期清理，透過輸送器清除。 、、/ _ 巧風器10運作時，自電爐1抽送攝氏800度到1200 度之排氣即通過燃燒塔，未燃燒之氣體，例如一氧化碳(c〇) 等即被機繞。然後氣體在通路冷卻塔7時冷卻到攝氏25〇 或 '下。細的微塵，包括戴奥辛（di〇xin)，重金屬等即在 氣體通過袋房8時收集。此時，在袋房8下游之排氣，其 溫度變成攝氏15G度或以下。 在本實施例，將活性碳透過填料單元21吹到排氣，戴 奥辛（di〇Xin)，重金屬，及其他有毒物質即為活性碳吸收。 吸收有毒物質之活性碳即收集於袋房9内。若活性碳是在 袋房8之下游供應，則比在袋房8之上游供應量要少。再 者’因活性碳是供應到排氣，其溫度在通過袋房8時已降 低’可燃性塵埃則集於袋房8，因而由活性碳產生塵爆或火 災之風險即可減低。 活性碳及熟石灰的混合物可放置於斗22内以吹到排氣 内。如此，在排氣内酸性氣體，例如鹽酸(HC1)，硫酸(H2S〇4) 等可以中和，而減少排到外面的酸性氣體的量。 自袋房9内清除活性碳之排氣以一升壓送風器透過 一排氣管35排到大氣。然而，亦可以風門30切換而與建 7 本紙張尺度適用中國國家操準（CNS ) A4規格（210X297公釐） (請先閱讀背面t注意事項再填寫本頁)Figure 4 is a vertical sectional view of a modified absorption tower in the embodiment shown in Figure 3. Fig. 5 is a horizontal sectional view showing the catheter of Fig. 3. Fig. 6 is an enlarged view showing a part of the bag filter of Fig. 3. Description of the Preferred Embodiment The first embodiment will now be described with reference to FIG. In an electric arc furnace 1, such as the 15th paper size applicable to the Chinese National Standard (CNS) A4 specifications (210X 297 mm) Central Standards of the Ministry of Economy 趵 Employee Consumer Cooperatives Printing Fan A7 B7_ _ V. Description of the invention (3) It is shown that the electrode 3 is vertically inserted into the furnace body. The exhaust port 2 of the electric furnace 1 is connected to an inlet of a direct exhaust system A for direct extraction and exhaust. A ceiling sleeve 4 is provided on the ceiling of the building, which is located above the electric furnace 1 and serves as the entrance of the building exhaust system B for indirect extraction and exhaust. The direct exhaust system A 'is provided with an external air inlet plate 5 to adjust the opening / closing of the exhaust port 2. A downstream continuous combustion tower 6, a cooling tower 7, a bag house 8, and a charging unit are provided. 21. A bag house 9 and a strong booster blower 10. Furthermore, a blower 12 and a bag house 13 are provided downstream of the ceiling sleeve 4 of the building exhaust system. The burner 6 is provided in the combustion tower 6 to burn and decompose carbon monoxide gas and other unburned components contained in the exhaust gas from the electric furnace 1 exhaust gas. The cooling tower 7 is provided with a radiator for circulating cooling water to cool the exhaust gas to a temperature of 250 degrees Celsius or lower that the bag filter can withstand heat. 8 and 9 have a plurality of bag filters Η and 16, respectively, to collect the dust in the exhaust gas. The dust collected in the bag filter 14 and the bag filter 16 are periodically removed respectively, and then discarded through the conveyors 31 and 32. The packing unit 21 is composed of a bucket 22 to store powdered activated carbon, a ventilator 23 and a packing throat 24 'whose tips are connected to the exhaust duct 17 between the bag houses 8 and 9. The activated carbon stored in 22 is conveyed to the stuffing throat through the supply air writing 23 under pressure, and then blown from the tip of the stuffing throat 24 to the exhaust pipe 17. The supply of activated carbon is preferably 100 to 500 mg (mg) per Nm3 of exhaust gas. A booster blower 10 is provided downstream of the bag house 9, and an airflow channel switching damper 30 is provided downstream of the blower. Downstream of the damper 30, a duct is branched into two directions: a duct connected to the building exhaust system B. The paper size is applicable to China National Standards (CNS) M specifications (210 ×: 297 mm) β 'IT {Please read first Note on the back, please fill out this page again}} Industrial and Commercial Cooperatives of the Central Bureau of Standards of the Ministry of Economic Affairs and Industrial Printing Co., Ltd. ~ 1 — A7 r, — ~~ ----------- B7 5. Description of Invention (4) & quot Supply air write _ ° on the upstream side of Z, so that the direct exhaust flows through. The exhaust of system A can meet the exhaust of stream and star building degassing system B; the other duct is located in exhaust pipe 35 and connected to 煃_ (Not shown). The bag thickness 13 has a plurality of bag filters 36. The exhaust gas passes through the bag filter 36 τ Y, that is, exhausted from the upper part of the leap month 13 to the atmosphere and becomes a purified gas. The dust collected in the bag extinguisher 36 is regularly cleaned and removed through the conveyor. 、, / _ When the smart air blower 10 is in operation, the exhaust gas of 800 to 1200 degrees Celsius drawn from the electric furnace 1 passes through the combustion tower, and unburned gas such as carbon monoxide (c0) is wound by the machine. The gas is then cooled to 25 ° C or lower in the passage cooling tower 7. Fine dust, including dioxin, heavy metals, etc. is collected as the gas passes through the bag house 8. At this time, the temperature of the exhaust gas downstream of the bag house 8 becomes 15G or lower. In this embodiment, activated carbon is blown through the filler unit 21 to the exhaust gas, and dioxin, heavy metals, and other toxic substances are absorbed by the activated carbon. Activated carbon that absorbs toxic substances is collected in the bag house 9. If the activated carbon is supplied downstream of the bag house 8, the amount of activated carbon is less than that supplied upstream of the bag house 8. Furthermore, since activated carbon is supplied to the exhaust gas, and its temperature has decreased when passing through the bag house 8, the flammable dust is collected in the bag house 8, so the risk of dust explosion or fire from the activated carbon can be reduced. A mixture of activated carbon and slaked lime can be placed in the bucket 22 for blowing into the exhaust. In this way, acid gases such as hydrochloric acid (HC1), sulfuric acid (H2S04), etc. in the exhaust gas can be neutralized, and the amount of acid gases discharged to the outside can be reduced. The exhaust gas from which the activated carbon is removed from the bag house 9 is discharged to the atmosphere through an exhaust pipe 35 by a booster blower. However, it is also possible to switch the damper 30 and build it 7 This paper size is applicable to China National Standard (CNS) A4 (210X297 mm) (Please read the precautions on the back before filling this page)
A7 B7 五、發明説明（5 ) '〜' ---- 築排氣系統B之排翁n 外， 匕見會合。如此，排氣可以大量稀釋。此 其仙士氣之'皿度降到約攝氏60度，因此，戴奥辛(dioxin)及 其他:毒物質漸固化，而可安全地在6竹13收集。 虎妗由-衣房9收集到塵埃輸送器32之活性碳，如第1圖 風線所示，以空H备、、，^ 44_ Μ 〃勒适並供應到電溶爐1做為初碳或碳_射 材質。 i為初碳或碳射物之活性碳，其燃燒熱度為將一金屬加 您化°再者’活性碳本身可有效做為一還原劑及熔解 金屬之成份調整物質。 8由/舌性碳所吸收之戴奥辛（dioxin)在爐子内加熱至攝氏 度或以上尚溫而熱分解。如此，則不會造成二度污染環 境，例如產生碳渣。 不僅收集於袋房9内之活性碳，而且收集於袋房13之 活性碳均可供應到電熔爐1。 根據第1圖之實施例’活性碳吹到導管而由袋濾器收集。 如第2圖所示，在直接排氣系統a亦可設一儲存送風器之 吸收塔40。 如第2圖所示之吸收塔4〇内，在侧壁之下部及上部分 別δχ有一排氣入口 41及排氣出口 42。在吸收塔，雙雙 设有漏斗形壁板44，因此產生一通風空隙43以供應含排氣 之活性碳。自斗45流出之活性碳儲存在漏斗形壁板及吸收 塔40側壁所界定之範圍。 排氣從排氣入口 41流入吸收塔4〇，然後以第2圖箭頭 所示之方向流動。排氣通過通風空隙43流到活性碳儲存部 本紙張尺度適用中國國家標隼（CNS ) Α4規格（210Χ297公釐） i J _________>______丁______&ΡΊ (請先閲讀背面之注意事項再填寫本頁) 經漭部中央樣率而負工消費合作私印紫 經濟部中夾樣導而只工消费合作社印製 A7 B7 五、發明説明（6 ) 分，然後上升到排氣出口 42，有毒物質遂由活性碳所吸收。 吸收有毒物質之活性碳由開啟一設於吸收塔40底部之 閘控閥排出。排出之活性碳即供應到電熔爐1做為初碳或 碳射物。 採用吸收塔40則袋濾器無法完全收集含鉻，錳等，有 機氧化物如戴奥辛（dioxin)，硫化物及氮化物之微塵均可吸 收。 除活性碳外，木炭或其他碳酸吸收物均可使用於吸收塔 40 ° 現參考第3-6圖說明第二實施例。 第二實施例與第一實施例不同在於使用混合塔20而不 是袋房9。第二實施例的其他構造則與第一實施例的類似， 並用相同的參考數字標示，但不再詳細說明。 在混合塔20中，在錐形塔體28内設有一螺旋導引葉片 29。如第4圖所示，一進氣口 18設於混合塔20之上方部 分，以使導管17以切線方向連接到混合塔20。另有兩個 活性碳送風口 21a與21b，設置與進氣口 18之設置相同， 亦即，與混合塔20之周圍壁板成切線關係。在混合塔20 之下邊部分設有一排氣出口 22，及一排氣口 25以在塔體28 之底部排出積澱於其内之灰塵。活性碳送風口 21a及21b 分別設有斗22a及22b以儲存活性碳及送風器23a及23b。 在該實施例，如第5圖所示之填料單元21以向導管17 之周圍的切線方向連接導管17，第一實施例相同，排氣時 活性碳之供應量為每Nm3 100到500毫克。 9 本紙張尺度適用中國國家標準（CNS ) A4規格（210 X 297公釐） (讀先鬩讀背面〔之注意事項再填寫本頁)A7 B7 5. Description of the invention (5) '~' ---- Outside the row n of the exhaust system B, see the meeting. In this way, the exhaust gas can be greatly diluted. As a result, its morale's degree dropped to about 60 degrees Celsius, so dioxin and other: poisons gradually solidify, and can be safely collected at 6 bamboo 13. The activated carbon collected from the dust conveyor 32 was collected from the clothing room 9 by the tiger. As shown in the wind line in Figure 1, the empty carbon was prepared and supplied to the electrolysis furnace 1 as the primary carbon. Or carbon_radio material. i is the activated carbon of primary carbon or carbon projectile, and its combustion heat is to add a metal to it. Furthermore, the activated carbon itself can be effectively used as a reducing agent and a component adjusting substance for melting metals. 8 Dioxin absorbed by / tongue carbon is thermally decomposed in the furnace by heating to a temperature of Celsius or above. This will not cause secondary pollution to the environment, such as carbon slag. Not only the activated carbon collected in the bag house 9 but also the activated carbon collected in the bag house 13 can be supplied to the electric furnace 1. According to the embodiment of Fig. 1, activated carbon is blown to a duct and collected by a bag filter. As shown in Fig. 2, the direct exhaust system a may be provided with an absorption tower 40 for storing a blower. In the absorption tower 40 shown in Fig. 2, there is an exhaust inlet 41 and an exhaust outlet 42 at the lower part and the upper part of the side wall δχ. In the absorption tower, funnel-shaped wall panels 44 are both provided, so that a ventilation space 43 is created to supply activated carbon containing exhaust gas. The activated carbon flowing from the bucket 45 is stored in a range defined by a funnel-shaped wall plate and a side wall of the absorption tower 40. The exhaust gas flows from the exhaust inlet 41 into the absorption tower 40, and then flows in the direction indicated by the arrow in FIG. The exhaust gas flows to the activated carbon storage department through the ventilation gap 43. The paper size is applicable to the Chinese National Standard (CNS) A4 specification (210 × 297 mm) i J _________ > ______ 丁 ______ & ΡΊ (Please read the precautions on the back before (Fill in this page) The central sample rate of the Ministry of Economic Affairs and the Consumers ’Cooperative Private Printing Department of the Ministry of Economic Affairs printed a sample guide and only the Consumer ’s Cooperative printed A7 and B7. 5. The invention description (6) points, and then rose to the exhaust outlet 42, Toxic substances are then absorbed by activated carbon. Activated carbon that absorbs toxic substances is discharged by opening a gate control valve provided at the bottom of the absorption tower 40. The discharged activated carbon is supplied to the electric furnace 1 as primary carbon or carbon projectile. With the absorption tower 40, the bag filter cannot completely collect chromium, manganese, etc. Organic oxides such as dioxin, fine particles of sulfide and nitride can be absorbed. In addition to activated carbon, charcoal or other carbonic acid absorbers can be used in the absorption tower 40 °. The second embodiment will be described with reference to Figures 3-6. The second embodiment differs from the first embodiment in that a mixing tower 20 is used instead of the bag house 9. The other structures of the second embodiment are similar to those of the first embodiment and are denoted by the same reference numerals, but will not be described in detail. In the mixing tower 20, a spiral guide vane 29 is provided in the conical tower body 28. As shown in Fig. 4, an air inlet 18 is provided above the mixing tower 20 so that the duct 17 is connected to the mixing tower 20 in a tangential direction. The other two activated carbon air outlets 21a and 21b are provided in the same manner as the air inlet 18, that is, in a tangential relationship with the surrounding wall plates of the mixing tower 20. An exhaust outlet 22 and an exhaust outlet 25 are provided at the lower part of the mixing tower 20 to discharge the dust accumulated therein at the bottom of the tower body 28. The activated carbon air outlets 21a and 21b are respectively provided with buckets 22a and 22b to store activated carbon and air blowers 23a and 23b. In this embodiment, as shown in FIG. 5, the filler unit 21 is connected to the duct 17 in a tangential direction around the duct 17. The same as in the first embodiment, the supply amount of activated carbon during exhaust is 100 to 500 mg per Nm3. 9 This paper size is applicable to Chinese National Standard (CNS) A4 specification (210 X 297 mm) (read first, read the back [Notes before filling in this page]
經濟部中央樣準而负工消贽合作扣印製 A7 B7 五、發明説明（7 ) 在該實施例，導管17内自送風口 24吹走之活性碳與排 氣一起被捲走，如第5圖之箭頭所示。活性碳與排氣及沿 混合塔20内之導引葉片29自送風口 21a及21b吹走到混 合塔20，旋轉及往下。因此，活性碳可有效地與排氣接觸， 而有效吸收包含於排氣内之戴奥辛（dioxin)，重金屬，及其 他有毒物質。 根據第二實施例，如第3圖之虛線所示，收集之活性碳， 經過袋房13到灰塵輸送器33，由空氣傳送並供應到電熔爐 1做為初碳或一碳_射物。 供應之活性碳其燃燒熱度即用以將金屬融化，並與第一 實施例一樣，活性碳本身可有效做為已熔化金屬之還原劑 及結構調整物。 在電熔爐1操作前，是必要預先將活性碳透過填料單元 21吹送以一活性碳形成一過濾層於建築排氣系統B内之袋 房13的過濾器36表面，如第6圖所示。如此，則含於排 氣内之戴奥辛（dioxin)，流經建築排氣系統B也可有效地被 吸收，因此增加收集戴奥辛（dioxin)之效率以及減少營運成 本。 本紙張尺度適用中國國家標準（CNS ) A4規格（210X297公釐） (請先閱讀背面之注意事項再填寫本頁)The central government of the Ministry of Economic Affairs and the Ministry of Economic Affairs cooperated to print A7 and B7. V. Description of the invention (7) In this embodiment, the activated carbon blown away from the air supply port 24 in the duct 17 is swept away together with the exhaust gas. Figure 5 shows the arrow. Activated carbon and exhaust gas are blown away from the air supply openings 21a and 21b to the mixing tower 20 along the guide vanes 29 in the mixing tower 20, and rotate and go down. Therefore, activated carbon can effectively contact the exhaust gas, and effectively absorb dioxin, heavy metals, and other toxic substances contained in the exhaust gas. According to the second embodiment, as shown by the dashed line in FIG. 3, the collected activated carbon passes through the bag house 13 to the dust conveyor 33, is transported by air, and is supplied to the electric furnace 1 as primary carbon or a carbon projectile. The supply of activated carbon is used to melt the metal, and like the first embodiment, the activated carbon itself can be effectively used as a reducing agent and a structural regulator for the molten metal. Before the electric furnace 1 is operated, it is necessary to blow activated carbon through the filler unit 21 in advance to form an activated carbon to form a filter layer on the surface of the filter 36 of the bag house 13 in the building exhaust system B, as shown in FIG. 6. In this way, the dioxin contained in the exhaust gas can be effectively absorbed through the building exhaust system B, so the efficiency of dioxin collection is increased and the operating cost is reduced. This paper size applies to China National Standard (CNS) A4 (210X297 mm) (Please read the precautions on the back before filling this page)