Ϊ378213 六、發明說明： 【發明所屬之技術領域】 本發明係關於使用直接噴射燃料至爐内使其緩慢燃燒之 燃燒方式的蓄熱式交替燃燒器之連續加熱爐。 【先前技術】 使用直接喷射燃料至爐内使其緩慢燃燒之燃燒方式的蓄 熱式父替燃燒器之連續加熱爐’係使燃燒器的空氣供給口與 燃料供給口相隔間隔而開口，且平行地配置空氣供給路與燃 料供給路，如此之連續加熱爐已為人所知。此種連續加熱 爐，係各別供給空氣與燃料至爐内而藉由在爐内使空氣與燃 料混合並燃燒，以抑制因燃燒所發生之Ν〇χ (例如，參照 專利文獻1)。 又，此種連續加熱爐，係自鋼材的進料侧並列設置預熱 區、加熱區、均熱區’而藉使在加熱區被加熱的爐内蒙豕 (furnace atmosphere)朝預熱區亦即進料側流動以有效率地 利用所發生的熱。因此，在連續加熱爐内進料側附近設有町 使在加熱區被加熱的爐内蒙氣朝進料侧流動之煙道。 [專利文獻1]日本專利第2683545號說明書 【發明内容】 (發明所欲解決之問題） 上述之連續加熱爐，由於爐内蒙氣朝煙道，亦即，自抽出 側朝向進料侧在爐内流動，因此，在燃燒器中藉由空氣供給 098129658 4 D而來自配置於煙道側之燃料供給口所供給的屋料被爐内 冬氣吹動而不和自空氣供給口所供給的空氣混合而有於未 燃燒之狀態下在煙道内流動之虞。因此，其有排出未燃燒的 氣體之危險’又，其有無端浪費燃料且有發生黑煙等之課題。 • 本發明係鏗於上述先前的課題所完成 ，其目的為提供一種 Τ面抑制NOx之發生一面可有效率地使燃料燃壤之連續 加熱爐。 _ (解決問題之手段） 本發明之連續加熱爐，其具備有：在自進iftili朝向抽出側 搬送鋼材的搬送方向並列設置複數個熱處理區之爐體；被設 在搬送方向之最上游側，可流入在上述爐體内和搬送方向相 反方向流動之爐内蒙氣的煙道；及，在上述爐體之側壁，沿 搬送方向所配設之複數個燃燒器；其特徵為，上述燃燒器具 有使供給空氣至上述爐體内的空氣供給口作為終端之空氣 ♦供給路；及’在上述空氣供給口的周圍與該空氣供給口相隔 間隔所配置使燃料供給至上述爐體内的燃料供給口作為終 端之燃料供給路；在上述燃燒器中，位於搬送方向最上游側 .的上述燃燒器’相對於上述空氣供給口使配置於搬送方向上 -游側之上述燃料供給口作為終端的上述燃料供給路，朝向該 燃料供給路的上述終端而在上述空氣供給口侧傾斜。 上述燃燒器中，包含位於搬送方向之最上游侧的上述燃燒 器，在位於搬送方向最上游側的上述熱處理區自最上游側於 098129658 5 搬送方向並列之複數個上述燃燒器，相對於上述空氣供給口 使配置於搬送方向上游側之上述燃料供給口作為終端的上 述燃料供給路，朝向該燃料供給路的上述終端而在上述空氣 供給口側傾斜，如此為其特徵。 上述燃燒器中’包含位於搬送方向之最上游側的上述燃燒 器’在位於搬送方向之最上游側的上述熱處理區之全部上述 燃燒器，相對於上述空氣供給口使配置於搬送方向上游侧之 上述燃料供給口作為終端的上述燃料供給路，朝向該燃料供 給路的上述終端在上述空氣供給口側傾斜，如此為其特徵。 自傾斜之上述燃料供給口所供給的燃料，在自上述空氣供 給口所供給的空氣之周邊部，合流於該所供給之空氣流而被 供給，如此為其特徵。 又’本發明之連續加熱爐，其具備有：在自進料侧朝向柚 出側搬送鋼材的搬送方向並列設置複數個熱處理區之爐 體；被設在上述搬送方向之最上游側，可流入在上述爐體内 和上述搬送方向相反方向流動之爐内蒙氣的煙道；及，在上 述爐體之侧壁，沿著搬送方向所配設之複數個燃燒器；其特 徵為，上述燃燒器具有：使供給空氣至上述爐體内的空氣供 給口作為終端之空氣供給路；及，在上述空氣供給口的周圍 與該空氣供給口隔開間隔所配置而供給燃料至上述爐體内 的燃料供給口作為終端之燃料供給路；而在上述燃燒器中， 相對於上述空氣供給口使配置於搬送方向上游侧之上述燃 098129658 6 1378213 料供給口作為終端的上述燃料供給路，其燃料在自上述空氣 供給口所供給的空氣之周邊部，和該供給的空氣流合流，而 朝向該燃料供給路的上述終端於上述空氣供給口側傾斜。 (發明效果） 本發明之連續加熱爐，其可一面抑制Ν〇χ之發生另一面 安全且有效率地使燃料燃燒。 【實施方式】 以下參照附圖詳細說明本發明之連續加熱爐的較適當之 一實施形態。 圖1表示本發明之連續加熱爐的適當之一實施形態的縱 剖面圖，圖2係圖1之平面剖面圖。 如圖1及圖2所示，本實施形態之連續加熱爐丨，在大致 直方體狀之爐體10的長邊方向中之一邊端自使鋼材F進料 的進料侧10a朝向另一邊端鋼材f抽出之抽出側i〇b，並列 設有作為熱處理區之預熱區X、加熱區γ及均熱區Z。在各 熱處理區之境界，設有鋼材F可通過而區隔鄰接的區間之間 隔壁18。 鋼材F在爐體1 〇内自進料側1 〇a朝向抽出側1 〇b，由於 在爐體10之上下方向中大致中央水平地被搬送，因此，自 進料側10a朝向抽出侧l〇b方向為鋼材ρ之搬送方向。 在爐體10内之搬送方向的最上游側，設有可流入和鋼材 F的搬送方向相反方向流動的填_内蒙氣之煙道2〇。在此煙道 098129658 7 1378213 2〇的前方設有煙囪（未圖示）而連通至爐體ίο的外部。 又，在預熱區X、加熱區γ及均熱區z之寬度方向的相 對面之侧壁12，設有複數個各相對向之燃燒器30。在圖1 之例中’在各區X、Y、Z之各側壁12各設有6個燃燒器 3〇’而在自鋼材F被搬送位置之上侧與下侧各大致以等間隔 設置各3個’上侧3個燃燒器30與下側3個燃燒器30各個 沿搬送方向大致水平地並排配置。此等燃燒器3〇係對向之 呈對的燃燒器30彼此間交互反覆燃燒和蓄熱之蓄熱式燃燒 器。 各燃燒器30係由：供給空氣至爐體1〇内而以空氣供給口 31作為終端之空氣供給路32 ;及，以供給燃料至配置於空 氣供給口 31周圍的爐體1〇内之2個燃料供給口 33作為終 h的2個燃料供給路34 ;如此所構成。各燃燒器3〇具有之 空氣供給口 31與2個燃料供給口 33’被配置成沿鋼材F之 搬送方向呈大致水平的位置，而2個燃料供給口 33在鋼材 F之搬送方向中各別在空氣供給口 31之上游側與下游側和 空亂供給口 31隔開間隔而被配置。又，空氣供給路32係自 空氣供給口 31大致水平地，而燃料供給路34則自燃料供給 口 33大致水平地被形成於側壁12内。以下的說明中，在鋼 材F之搬送方向中位於空氣供給口 31的上游側之燃料供給 口 33及燃料供給路34被稱為上游侧燃料供給口 33a及上游 侧燃料供給路34a，而位於下游側之燃料供給口 33及燃料 098129658 8 1378213 33b及下游側燃料供給 供給路34被稱為下游側燃料供給口 路34b 圖3係說明位於搬送方向最上游侧之燃燒器30的平面剖 面圖。 有關空氣供給路32、上__供給路⑽及下游_ =供給路34b，除了位於最上游側對向之上下二對上游_ 羞4供給路m卜’對於㈣12之壁面m係被設成大致 厂口垂直方向。又’位於最上游侧對向之上下二對上游側燃 /、⑺路34a係朝向作為終端之上游側燃料供給口 亦即’被設成㈣爐體1G的时而在接近空氣供給口 3i 侧的方向傾斜。㈣，上游健料供給路34a之傾斜角度， 破設定成，被供給的燃料在自空氣供給口 31所供給的空氣 之周邊和被供给的空氣合流而混合流動狀地傾斜。 在本實施形態之連續加熱爐丨中，自爐體1〇之進料側1〇a 破進料的鋼材F，—面自設在爐體10内之預熱區X、加熱 區Y、均熱區z而順序地被搬送，—面以設在各區内的燃燒 器30被熱處理而朝抽出側l〇b搬送。 但疋，此一連續加熱爐1在加熱區γ及均熱區z發生的 燃燒排氣會朝煙道20流動。因此，在各燃燒器30中，其有 於空氣供給口 31之搬送方向上游側，亦即，向煙道20方向 而位於氣流下游侧之燃料供給口 33所供給的燃料，其藉由 燃燒排氣而和自空氣供給口 31所供給空氣相離之方向流 098129658 9 1378213 動’其不和空氣混合而與燃燒排氣一起朝向煙道20流出， 有此種情形。 當未燃燒之燃料從煙道20排出時，被排出之未燃燒氣體 具有危險性’除了浪費燃料外亦有發生黑煙之虞。此時，例 如燃料即使不和設在單一燃燒器30之空氣供給口 31所供給 的空氣混合而與燃燒排氣一起朝煙道20流出時，假如在流 動之前方，亦即在朝向煙道20氣流的下游側存在有其他燃 燒器30時，則有藉由該燃燒器30而燃燒該燃料之情形。但 是，在最靠近煙道20侧，亦即，位於搬送方向最上游侧的 燃燒1§ 30 ’由於在其上游侧，亦即在朝向煙道2〇之氣流的 下游側不存在有燃燒器30，因此，燃料有不被燃燒而被排 出之可能性比其他的燃燒器3〇更高。 因此’在本實施形態之連續加熱爐1中，位於搬送方向的 最上游側對向之上下二對燃燒器30之上游侧燃料供給路 34a ’被設成朝向爐體1〇内方接近空氣供給口 31側方向傾 斜(在以下之說明中，為了區別傾斜之上游側燃料供給路34a 與未傾斜之上游側燃料供給路34a，而以最上游燃料供給路 36來說月）。因此’例如即使通墁最上游權料供給路％所 供的燃料因為燃燒排氣之氣流而流動，則由於最上游燃料 供給路36事先於搬送方向下游側傾斜，因此，其容易和自 空氣供給"31所供給的空氣混合，而可抑制未燃燒之燃料 朝向煙道20流動之發生。又，此時，最上游燃料供給路％ 098129658 Ϊ378213 之傾斜度被設定成，被供給的燃料在自空氣供給口 31所供 給的空氣之周邊合流時一面順沿空氣一面混合流動，如此之 傾斜度為佳。 例如，通過事先在搬送方向下游側傾斜之最上游燃料供給 路36所供給之燃料如被設定成進入自空氣供給口 31所供給 的空氣之中心時，則有因為氧濃度高而燃燒火焰溫度必然變 高而NOx發生位準亦變高之可能。因此，如本實施形態之 最上游燃料供給路36般，如設定成所供給的燃料在自空氣 供給口 31所供給的空氣周邊一面順沿空氣一面混合流動之 傾斜狀時，則可實現在氧濃度低的部位之擴散緩慢燃燒，而 抑制NOx的發生位準。 圖4係說明第i變形例的連續加熱爐之平面剖面圖，圖5 係說明第2變形例的連續加熱爐之平面剖面圖。 在上述實施形態中’雖然已說明使位於搬送方向最上游側 對向之上下二對燃燒器3〇之上游側燃料供給路34& (36)， 朝向爐體10的内方，亦即朝向作為終端之上游側燃料供給 口 33a設成接近空氣供給口 3H則之方向傾斜的例但如圖 4所示，如對設在㈣方向之最均_區域（此處為預熱 區）X之全部職器3G中位於最上游侧並列在搬送方向具 有複數對燃燒H 30的上游侧燃料供給路34a(36)，使其朝 向爐體ίο的内方在接近空氣供給口 3H則之方向傾斜，如此 亦可特別疋蓄熱式交替燃燒器之情形，如圖6所示，雖然 098129658 11 1378213 以於爐寬度方向對向之右侧壁12與左側壁12的燃燒器30 為一組而實施燃燒和排氣，但為了使溫度左右均等，且燃燒 為以左右鋸齒狀地實施，因此自最上游起第2個以後的燃燒 器30可成為燃燒中最上游的燃燒器30，因此上述「複數對 燃燒器30」，使其為自最上游的燃燒器3〇在搬送方向並列2 個’或者可為燃燒狀態最上游的燃燒器30之2個以上之燃 燒器30即可。又，如圖5所示，如使在搬送方向中設在最 上游側的預熱區X具有全部燃燒器30之上游側燃料供給路 34a(36)’使其朝向爐體10的内方在接近空氣供給口 31 侧之方向傾斜，如此亦可。 又’在本實施形態中，係說明各燃燒器30具有空氣供給 口 31與2個燃料供給口 33，此等係沿著鋼材F之搬送方向 位在大致水平之位置，且2個燃料供給口 33a、33b係各被 配置於空氣供給口 31的上游侧與下游侧之例。因此’朝向 爐體10的内方接近於空氣供給口 31侧方向傾斜的燃料供給 口 33，雖然僅設成在搬送方向中位於空氣供給口 31上游側 之一邊的燃料供給口 33，但其並不受限於此。例如’ 3個以 上的燃料供給口 33被設成圍繞空氣供給口 31時，亦可使位 於空氣供給口 31上游側之數個燃料供給口 33，或在位於空 氟供給口 31上游侧之全部燃料供給口 33作為终端之上游側 燃料供給路34a，使其於空氣供給口 31側傾斜，如此亦可。 此時’空氣供給口 31之上游侧的燃料供給口 33是指，例如， 098129658 12 1378213 比空氣供給口 31之搬送方向下游側的緣部31a，燃料供給 口 33之搬送方向下游侧的緣部33c則係位於上游側的燃料 供給口 33(參照圖7)。又，相對於空氣供給口 31之下游側 的緣部31a，在上游側其一部分係所配置之燃料供給口 33， ' 在實驗或經驗上而言，使利用燃燒排氣不和自空氣供給口 31所供給的空氣混合而有未燃燒可能的燃料供給口 33作為 終端之燃料供給路34，使其全部於空氣供給口 31側傾斜， _ 如此亦可。 _【圖式簡單說明】 圖1表示適合本發明之連續加熱爐之一實施形態的縱剖 面圖。 圖2係圖1之平面剖面圖。 圖3係說明在搬送方向中位於最上游側之燃燒器的平面 剖面圖。 • 圖4係說明第1變形例之連續加熱爐的平面剖面圖。 圖5係說明第2變形例之連續加熱爐的平面剖面圖。 圖6係說明蓄熱式交替燃燒器之燃燒態樣的說明圖。 圖7表示適用於本發明之連續加熱爐的燃燒器之空氣供 - 給口與燃料供給口的位置關係之概略圖。 【主要元件符號說明】 1 連續加熱爐 10 爐體 098129658 13 1378213 i〇a 進料侧 1 Ob 抽出侧 12 側壁 12a 壁面 18 間隔壁 20 煙道 30 燃燒器 31 空氣供給口 31a 空氣供給口之搬送方向下游側的緣部 32 空氣供給路 33 燃料供給口 33a 上游侧燃料供給口 33b 下游侧燃料供給口 33c 上游侧燃料供給口之搬送方向下游側的緣部 34 燃料供給路 34a 上游侧燃料供給路 34b 下游侧燃料供給路 36 最上游燃料供給路 F 鋼材 X 預熱區 Y 加熱區 z 均熱區 098129658 14Ϊ378213 VI. Description of the Invention: [Technical Field of the Invention] The present invention relates to a continuous heating furnace of a regenerative alternating burner using a combustion mode in which a fuel is directly injected into a furnace to be slowly combusted. [Prior Art] A continuous heating furnace of a regenerative parent burner using a combustion method in which a fuel is directly injected into a furnace to be slowly combusted is opened such that the air supply port of the burner is spaced apart from the fuel supply port, and is parallel Such an air supply path and a fuel supply path are known, and such a continuous heating furnace is known. In the continuous heating furnace, air and fuel are separately supplied to the furnace, and air and fuel are mixed and burned in the furnace to suppress the occurrence of defects due to combustion (for example, refer to Patent Document 1). Further, in such a continuous heating furnace, a preheating zone, a heating zone, and a soaking zone are disposed side by side from the feed side of the steel material, and the furnace atmosphere in the heating zone is heated toward the preheating zone. The feed side flows to efficiently utilize the heat that occurs. Therefore, a flue which flows in the furnace heated in the heating zone toward the feed side is provided in the vicinity of the feed side in the continuous heating furnace. [Patent Document 1] Japanese Patent No. 2683545 (Invention) The above-mentioned continuous heating furnace has a gas in the furnace toward the flue, that is, from the extraction side toward the feed side in the furnace. Flow, therefore, the stock supplied from the fuel supply port disposed on the flue side in the burner by the air supply 098129658 4 D is blown by the winter air in the furnace without mixing with the air supplied from the air supply port. And there is a ripple in the flue in an unburned state. Therefore, there is a risk of discharging unburned gas. In addition, there is a problem that fuel is inevitably wasted and black smoke is generated. The present invention has been made in view of the above-mentioned prior problems, and an object thereof is to provide a continuous heating furnace capable of efficiently fueling a fuel while suppressing the occurrence of NOx. _ (Means for Solving the Problem) The continuous heating furnace of the present invention is provided with a furnace body in which a plurality of heat treatment zones are arranged in parallel in a conveyance direction in which the steel material is conveyed toward the extraction side, and is disposed on the most upstream side in the conveyance direction. a flue that can flow into the furnace in the furnace body and in the opposite direction of the conveying direction; and a plurality of burners disposed along the conveying direction on the side wall of the furnace body; wherein the burner has An air supply port that supplies air to the furnace body is used as a terminal air supply path; and a fuel supply port that supplies fuel to the furnace body at a distance from the air supply port around the air supply port In the above-described burner, the burner "located on the most upstream side in the transport direction" is the fuel supply port that is disposed in the transport direction and the fuel supply port in the transport direction as the terminal fuel. The supply path is inclined toward the air supply port side toward the terminal end of the fuel supply path. In the burner, the burner is disposed on the most upstream side in the transport direction, and the plurality of burners are arranged in the transport direction from the most upstream side in the transport direction of the 098129658 5 in the heat treatment zone on the most upstream side in the transport direction, with respect to the air. The supply port is characterized in that the fuel supply path that is disposed at the fuel supply port on the upstream side in the transport direction is inclined toward the air supply port side toward the terminal end of the fuel supply path. In the burner, the burners including the burners located on the most upstream side in the transport direction are disposed on the upstream side of the transport direction with respect to the air supply port in the heat treatment zone on the most upstream side in the transport direction. The fuel supply port is a fuel supply passage of the terminal, and the terminal toward the fuel supply passage is inclined at the air supply port side. The fuel supplied from the inclined fuel supply port is supplied to the peripheral portion of the air supplied from the air supply port, and is supplied to the supplied air flow. Further, the continuous heating furnace of the present invention includes a furnace body in which a plurality of heat treatment zones are arranged in parallel in a conveyance direction in which the steel material is conveyed from the feed side to the pomelo discharge side, and is provided in the upstream side of the conveyance direction to flow in a flue that is ventilated in a furnace that flows in a direction opposite to the transport direction in the furnace body; and a plurality of burners disposed along a side of the furnace body along a transport direction; characterized in that the burner An air supply passage that supplies air to the furnace body as a terminal, and a fuel that is disposed at a distance from the air supply port and that supplies fuel to the furnace body The fuel supply port is a fuel supply passage of the terminal, and the fuel supply port is disposed at the fuel supply port of the fuel supply port on the upstream side of the conveyance direction with the fuel supply port 098129658 6 1378213 as the terminal. a peripheral portion of the air supplied from the air supply port merges with the supplied air flow, and the terminal is directed toward the fuel supply path Air supply port side is inclined. (Effect of the Invention) The continuous heating furnace of the present invention can safely and efficiently burn the fuel while suppressing the occurrence of enthalpy. [Embodiment] Hereinafter, a more appropriate embodiment of the continuous heating furnace of the present invention will be described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a longitudinal sectional view showing an embodiment of a continuous heating furnace of the present invention, and Fig. 2 is a plan sectional view of Fig. 1. As shown in Fig. 1 and Fig. 2, in the continuous heating furnace of the present embodiment, the feeding side 10a of the material F is fed toward the other side at one of the longitudinal directions of the substantially rectangular body 10 The extraction side i〇b of the steel f is drawn, and the preheating zone X, the heating zone γ, and the soaking zone Z as heat treatment zones are arranged in parallel. At the boundary of each heat treatment zone, a steel material F is passed through to partition the partition 18 between adjacent sections. The steel material F is conveyed from the feed side 1 〇a toward the extraction side 1 〇b in the furnace body 1 ,, and is conveyed substantially horizontally in the lower direction of the furnace body 10, so that the feed side 10a faces the extraction side l〇 The b direction is the direction in which the steel material ρ is transported. On the most upstream side in the conveying direction of the furnace body 10, there is provided a flue 2 填 which is filled with the inner Mongolian gas flowing in the opposite direction to the conveying direction of the steel material F. A chimney (not shown) is provided in front of the flue 098129658 7 1378213 2 而 to communicate with the outside of the furnace body ίο. Further, a plurality of opposed burners 30 are provided in the opposite side walls 12 of the preheating zone X, the heating zone γ, and the soaking zone z in the width direction. In the example of Fig. 1, each of the side walls 12 of each of the zones X, Y, and Z is provided with six burners 3', and the upper side and the lower side of the steel material F are disposed at substantially equal intervals. The three 'top three burners 30 and the lower three burners 30 are arranged side by side substantially horizontally in the conveying direction. These burners 3 are opposite to each other, and the opposite burners 30 interact with each other to recombine combustion and heat storage. Each of the burners 30 includes an air supply path 32 that supplies air to the inside of the furnace body 1 and an air supply port 31 as a terminal, and supplies fuel to the furnace body 1 disposed around the air supply port 31. The fuel supply ports 33 are the two fuel supply paths 34 of the final h; The air supply port 31 and the two fuel supply ports 33' of each of the burners 3 are disposed so as to be substantially horizontal in the conveying direction of the steel material F, and the two fuel supply ports 33 are respectively in the conveying direction of the steel material F. The upstream side of the air supply port 31 is disposed at a distance from the downstream side and the air supply port 31. Further, the air supply path 32 is substantially horizontal from the air supply port 31, and the fuel supply path 34 is formed substantially horizontally from the fuel supply port 33 in the side wall 12. In the following description, the fuel supply port 33 and the fuel supply path 34 located on the upstream side of the air supply port 31 in the conveyance direction of the steel material F are referred to as the upstream side fuel supply port 33a and the upstream side fuel supply path 34a, and are located downstream. The side fuel supply port 33, the fuel 098129658 8 1378213 33b, and the downstream side fuel supply supply path 34 are referred to as a downstream side fuel supply port 34b. FIG. 3 is a plan cross-sectional view showing the burner 30 located on the most upstream side in the transport direction. Regarding the air supply path 32, the upper __ supply path (10), and the downstream _= supply path 34b, the wall surface m of the (four) 12 is set to be substantially the same as the upper side and the lower side of the upstream side. The factory mouth is in the vertical direction. Further, the uppermost side of the upstream side is located on the most upstream side, and the (7) way 34a is directed toward the upstream side fuel supply port as the terminal, that is, when it is set to the (four) furnace body 1G, it is closer to the air supply port 3i side. Tilt in direction. (4) The inclination angle of the upstream feed material supply path 34a is set to be such that the supplied fuel is mixed and fluidized in the vicinity of the air supplied from the air supply port 31 and the supplied air. In the continuous heating furnace of the present embodiment, the steel material F which has been blown from the feed side 1〇a of the furnace body 1 is surface-prepared from the preheating zone X and the heating zone Y in the furnace body 10, both of which are The hot zone z is sequentially conveyed, and the burners 30 provided in the respective zones are heat-treated and conveyed toward the drawing side l〇b. However, the combustion exhaust gas generated by the continuous heating furnace 1 in the heating zone γ and the soaking zone z will flow toward the flue 20 . Therefore, each of the burners 30 is provided on the upstream side in the conveying direction of the air supply port 31, that is, the fuel supplied from the fuel supply port 33 located on the downstream side of the airflow in the direction of the flue 20, by the combustion row The flow in the direction of the air supplied from the air supply port 31 is 098129658 9 1378213. It is not mixed with air and flows out together with the combustion exhaust gas toward the flue 20, which is the case. When unburned fuel is discharged from the flue 20, the unburned gas that is discharged is dangerous. In addition to wasting fuel, there is also a black smoke. At this time, for example, even if the fuel is not mixed with the air supplied from the air supply port 31 provided in the single burner 30 and flows out toward the flue 20 together with the combustion exhaust gas, if it is before the flow, that is, toward the flue 20 When there are other burners 30 on the downstream side of the airflow, there is a case where the fuel is burned by the burners 30. However, on the side closest to the flue 20, that is, the combustion 1 § 30 ' on the most upstream side in the transport direction, there is no burner 30 on the upstream side thereof, that is, on the downstream side of the airflow toward the flue 2 Therefore, the possibility that the fuel is discharged without being burned is higher than that of the other burners. Therefore, in the continuous heating furnace 1 of the present embodiment, the upstream side fuel supply path 34a' of the upper and lower pairs of burners 30 in the upstream direction of the transport direction is disposed so as to approach the air supply toward the inside of the furnace body 1 The port 31 side is inclined (in the following description, in order to distinguish the inclined upstream side fuel supply path 34a from the unslanted upstream side fuel supply path 34a, the most upstream fuel supply path 36 is used for the month). Therefore, for example, even if the fuel supplied by the most upstream material supply path % flows due to the flow of the exhaust gas, the most upstream fuel supply path 36 is inclined in the downstream direction of the conveyance direction, so that it is easy to supply from the air. The air supplied by the 31 is mixed to suppress the flow of unburned fuel toward the flue 20. Further, at this time, the inclination of the most upstream fuel supply path % 098129658 Ϊ 378213 is set such that the supplied fuel mixes and flows along the air while merging from the air supplied from the air supply port 31, and thus the inclination It is better. For example, when the fuel supplied from the most upstream fuel supply path 36 inclined in the downstream direction of the conveyance direction is set to enter the center of the air supplied from the air supply port 31, the combustion flame temperature is inevitable because of the high oxygen concentration. It becomes higher and the NOx occurrence level becomes higher. Therefore, as in the case of the most upstream fuel supply path 36 of the present embodiment, it is possible to realize oxygen in the case where the supplied fuel is mixed and flows along the air supplied from the air supply port 31 while flowing along the air. The diffusion of the low concentration portion is slowly burned, and the occurrence level of NOx is suppressed. Fig. 4 is a plan sectional view showing a continuous heating furnace in an i-th modification, and Fig. 5 is a plan sectional view showing a continuous heating furnace in a second modification. In the above-described embodiment, it has been described that the upstream side fuel supply paths 34 & (36) facing the upper and lower pairs of the burners 3 in the upstream direction of the transport direction are directed toward the inside of the furnace body 10, that is, the orientation The upstream side fuel supply port 33a of the terminal is provided so as to be inclined in the direction close to the air supply port 3H, but as shown in FIG. 4, for example, the most uniform region (here, the preheating zone) X provided in the (four) direction. The upstream side fuel supply path 34a (36) having a plurality of pairs of combustion H 30 in the transport direction and located in the most upstream side of the server 3G is inclined toward the inside of the furnace body λ in the direction approaching the air supply port 3H, In particular, in the case of a regenerative alternating burner, as shown in Fig. 6, although 098129658 11 1378213 is a group of burners 30 opposite to the right side wall 12 and the left side wall 12 in the furnace width direction, combustion and arranging are carried out. In order to make the temperature uniform, and the combustion is performed in a zigzag manner, the second and subsequent burners 30 from the most upstream can become the most upstream burner 30 in the combustion, so the above-mentioned "complex burners" 30", making it Since most burner upstream in the conveyance direction in parallel 3〇 2 'can be the most upstream or the combustion state of the combustor 30 to 30 of the two burners. Further, as shown in FIG. 5, the preheating zone X provided on the most upstream side in the conveying direction has the upstream side fuel supply path 34a (36)' of all the burners 30 so as to face the inside of the furnace body 10. It is also possible to incline in the direction close to the side of the air supply port 31. Further, in the present embodiment, each of the burners 30 has an air supply port 31 and two fuel supply ports 33, and these are located at substantially horizontal positions along the conveying direction of the steel material F, and two fuel supply ports. Each of 33a and 33b is disposed on the upstream side and the downstream side of the air supply port 31. Therefore, the fuel supply port 33 that is inclined toward the air supply port 31 side toward the inside of the furnace body 10 is provided only in the fuel supply port 33 located on the upstream side of the air supply port 31 in the transport direction. Not limited to this. For example, when three or more fuel supply ports 33 are provided to surround the air supply port 31, a plurality of fuel supply ports 33 located on the upstream side of the air supply port 31 or all of the upstream side of the empty fluorine supply port 31 may be provided. The fuel supply port 33 serves as the upstream side fuel supply path 34a of the terminal, and is inclined at the air supply port 31 side. In this case, the fuel supply port 33 on the upstream side of the air supply port 31 is, for example, the edge portion 31a on the downstream side in the conveyance direction of the air supply port 31, and the edge on the downstream side in the conveyance direction of the fuel supply port 33. 33c is a fuel supply port 33 located on the upstream side (see Fig. 7). Further, with respect to the edge portion 31a on the downstream side of the air supply port 31, a part of the fuel supply port 33 disposed on the upstream side is 'experimentally or empirically, the combustion exhaust gas is not supplied to the air supply port. The air supplied to the 31 is mixed, and the fuel supply port 33 which is not combustible is used as the terminal fuel supply path 34, and all of them are inclined on the air supply port 31 side, which is also possible. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a longitudinal cross-sectional view showing an embodiment of a continuous heating furnace suitable for the present invention. Figure 2 is a plan sectional view of Figure 1. Fig. 3 is a plan sectional view showing the burner located on the most upstream side in the conveying direction. Fig. 4 is a plan sectional view showing a continuous heating furnace according to a first modification. Fig. 5 is a plan sectional view showing a continuous heating furnace according to a second modification. Fig. 6 is an explanatory view showing a combustion state of a regenerative alternating burner. Fig. 7 is a schematic view showing the positional relationship between the air supply port and the fuel supply port of the burner applicable to the continuous heating furnace of the present invention. [Main component symbol description] 1 Continuous heating furnace 10 Furnace body 098129658 13 1378213 i〇a Feeding side 1 Ob Extraction side 12 Side wall 12a Wall 18 Partition wall 20 Flue 30 Burner 31 Air supply port 31a Air supply port conveying direction The downstream side edge portion 32, the air supply path 33, the fuel supply port 33a, the upstream side fuel supply port 33b, the downstream side fuel supply port 33c, the upstream side fuel supply port, the upstream side of the transport direction, the edge portion 34, the fuel supply path 34a, the upstream side fuel supply path 34b. Downstream side fuel supply path 36 Most upstream fuel supply path F Steel X Preheating zone Y Heating zone z Soaking zone 098129658 14