JP5774431B2 - Wall surface radiant burner unit - Google Patents

Description

  The present invention relates to a wall surface radiant burner unit capable of heating a treatment material more uniformly.

  As a heating furnace for heating a treatment material, for example, the treatment material and the atmosphere in the furnace are heated by a burner that generates a flame substantially parallel to the treatment material from a furnace wall located on the side of the treatment material toward the treatment material. What to do is known. In the burner of such a heating furnace, the fuel is ejected radially to form a conical flame. That is, since the cross-sectional shape of the flame is substantially circular, the heating condition is different between the portion near the flame and the portion away from the flame in the treatment material, and it is difficult to heat the treatment material uniformly.

  With respect to such a problem, Patent Documents 1 and 2 disclose an apparatus that spreads a flame in order to form a flat flame with a thin thickness and heat the treatment material. Patent Document 1 “A device for expanding a frame and a furnace using this device” has a main nozzle for guiding a main jet flow composed of one of combustion gas and combustion support gas, and flows around the main jet flow, and is substantially constant. Secondary nozzle that guides the secondary jet flow consisting of the other of combustion gas and combustion support gas, and deflects the secondary jet flow by sucking the secondary jet flow into the main jet flow by the Coanda effect And a curved surface arranged tangentially to the secondary jet stream so as to mix the secondary jet stream and the main jet stream to form a frame.

  Patent Document 2 “Walking Beam Type Metal Heating Furnace with Slit Nozzle Type Burner or Slit Nozzle Type Regeneration Burner” has a slit type burner or a slit nozzle type regenerative burner having a flat burner flame on the side wall of the furnace. Attach and build a new walking beam type metal heating furnace with a total height of about 2,500 mm and a low profile, low construction costs and energy saving.

JP-A-8-178230 Japanese Patent Laid-Open No. 10-183235

  However, it is difficult to form a thin flat flame. Moreover, it is difficult to heat the treatment material so that the heat distribution becomes uniform simply by forming a flat and flat flame and heating the treatment material.

  The present invention was devised in view of the above-described conventional problems, and provides a wall surface radiant burner unit capable of heating a treatment material more uniformly and miniaturizing a furnace body. The purpose is to do.

A wall surface radiation type burner unit according to the present invention includes a furnace element that forms a radiation wall surface facing a treatment material, and a burner that forms a flat flame along the radiation wall surface of the furnace body element to heat the radiation wall surface. The treatment material is heated by radiant heat from the radiant wall surface, and the burner is formed in the furnace body element, and is formed in the furnace body element, and is formed in the furnace body element and connected to the opening. An air passage through which combustion air is circulated, and the air passage and the radiation wall surface are connected by a continuous curved surface through the opening, and the air passage of the burner The curved path is formed so as to be located in the back of the curved surface and to be turned back with respect to the curved surface .

  The flat flame is characterized in that it is along the radiation wall surface by an air flow of combustion air that produces a Coanda effect.

  The burner includes a fuel injection unit that injects fuel into the air flow path along the curved path.

  The air flow path of the burner is downstream of the joining portion where the fuel from the fuel injection portion and combustion air join, and around the reversal portion where the curved surface is folded back toward the curved path. A baffle portion for stirring and mixing fuel and combustion air is formed.

  The burner has a heat storage section that warms combustion air by exhaust, and is configured by arranging a pair of regenerative burner devices that alternately perform a combustion operation and an exhaust operation with the radiation wall surface interposed therebetween, The flat flame caused by the combustion operation of the other regenerative burner device is caused to flow along the radiation wall surface by the air flow along the radiation wall surface generated along with the exhaust suction operation of the regenerative burner device. .

  In the wall surface radiation type burner unit according to the present invention, the treatment material can be heated more uniformly and the furnace body can be miniaturized.

It is a partially broken perspective view of the heating furnace provided with the said burner unit which shows suitable one Embodiment of the wall surface radiation type burner unit which concerns on this invention. It is a principal part longitudinal cross-sectional view of the wall surface radiation type burner unit shown in FIG. It is the A section enlarged view in FIG. It is a top view of the wall surface radiation type burner unit shown in FIG. It is explanatory drawing explaining the effect | action of the baffle part with which the wall surface radiation type burner unit shown in FIG. 1 is equipped.

  Hereinafter, a preferred embodiment of a wall surface radiation type burner unit according to the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a partially broken perspective view illustrating a configuration of a heating furnace 1 including a wall surface radiation type burner unit according to the present embodiment. The heating furnace 1 according to the present embodiment constitutes, for example, a part of a continuous heating furnace in which the processing material 2 being conveyed passes through a preheating zone, a heating zone, and a soaking zone.

  As shown in FIG. 1, the heating furnace 1 is provided with a transport unit 3 such as a walking beam for transporting the processing material 2 to be heated. The wall surface radiation type burner unit 4 includes a furnace body element 5 and a pair of alternating combustion type regenerative burner devices 7 constituting the burner. As is well known, the alternating combustion type regenerative burner device 7 has a heat storage section 11 that warms the combustion air C by the exhaust E (see FIG. 2), and performs the combustion operation and the exhaust operation alternately. It has become. The treatment material 2 conveyed by the conveyance unit 3 faces the treatment material 2 and is heated by radiant heat from the radiant wall surface Z that is baked by the burner device 7 and heated to a bright state. In the present embodiment, the radiation wall surface Z on the inner surface of the heating furnace 1 that generates radiant heat for heating the treatment material 2 is the inner surface located above the treatment material 2, that is, the ceiling surface 6 of the heating furnace 1 (see FIG. 2). The case where the ceiling surface 6 is formed by the furnace body element 5 of the wall surface radiation type burner unit 4 will be described as an example. That is, in the illustrated example, the furnace body element 5 forms a furnace ceiling part of the furnace body 1a, and constitutes the furnace body 1a together with a pair of left and right furnace wall parts and a hearth part. The furnace body element 5 may form a furnace wall part or a hearth part. Even in such a case, the furnace body element 5 constitutes the furnace body 1a together with other furnace ceiling parts.

  2 is a longitudinal sectional view of a main part of the wall surface radiant burner unit 4 according to the present embodiment, FIG. 3 is an enlarged view of a portion A in FIG. 2, and FIG. 4 is an upper surface of the wall surface radiant burner unit 4. FIG. In FIG. 4, a fuel injection unit 10 to be described later is omitted, and the air flow path 8 and the like are shown. As shown in FIG. 2, the wall surface radiant burner unit 4 forms a furnace element 5 having a ceiling surface 6 as an inner surface of the heating furnace 1 and made of a heat-resistant material, and a flat flame f along the ceiling surface 6. And a pair of regenerative alternating combustion burner devices 7 for heating the ceiling surface 6.

  The furnace body element 5 has a rectangular parallelepiped shape having a substantially rectangular ceiling surface 6 whose longitudinal direction is perpendicular to the transport direction of the treatment material 2 transported into the heating furnace 1, and constitutes an air flow path 8. One flow path 8a protrudes upward.

  Openings 9 are formed in the ceiling surface 6 of the furnace body element 5 in the form of slits along the conveying direction on both ends in the longitudinal direction. The pair of regenerative burner devices 7 blows out the flat flame f from the opening 9 during one combustion operation, sucks the exhaust E from the opening 9 during the other exhaust operation, and is sandwiched between these two openings 9 The region to be heated becomes a radiation wall surface Z that is heated by the flat flame f and generates solid radiation.

  In the furnace element 5, a part of an air flow path 8 that blows out a flame f during combustion through the opening 9 and sucks exhaust E during exhaust, and a fuel injection section that injects fuel into the air flow path 8. 10 and a pilot burner (not shown) for ignition, and a burner device 7 is constituted by these. The air flow path 8 includes the first flow path 8 a and a second flow path 8 b provided on the upper side of the furnace body element 5 and connected to the heat storage unit 11. A communication pipe 12 for intake and exhaust is connected to the heat storage unit 11.

  As described above, the regenerative alternating combustion burner device 7 is composed of a set of two units. When the air flow path 8 of one burner device 7 is used as a combustion gas supply path for supplying the fuel F and the combustion air C, the exhaust E is discharged from the air flow path 8 of the other burner device 7. It is used as an exhaust discharge path, and is switched by a switching operation and alternately burned. In the heat storage part 11 provided between each air flow path 8 and the communication pipe 12, the exhaust heat when exhausting the exhaust E is stored during the exhaust operation, and when the combustion air C flows during the combustion operation. This is heated. These burner devices 7 are arranged on the furnace body element 5 in a symmetrical shape / structure.

  The air flow path 8 and the radiation wall surface Z are formed so as to be separated by a continuous curved surface S through the opening 9. A curved path Y is formed in the air flow path 8 so as to be located in the back of the curved surface S and to be turned back with respect to the curved surface S. In the illustrated example, the first flow path 8 a of the air flow path 8 extends from the radiation wall surface Z to the opposite side in the longitudinal direction of the furnace body element 5 along the downward straight path D and the opening 9 side. And a curved path Y that curves so as to protrude. That is, the first flow path 8a goes straight downward in the upper part, and in the lower part on the ceiling surface 6 side, the first flow path 8a is curved so as to protrude from the direction orthogonal to the ceiling surface 6 to the opposite side to the radiation wall surface Z. . More specifically, as shown in FIG. 3, the curved path Y is curved toward the ceiling surface 6 side away from the radiation wall surface Z on the straight path D side, and approaches the radiation wall surface Z on the opening 9 side. However, it curves so that it may go to the ceiling surface 6 side. Thus, during the combustion operation, the combustion air C and the fuel F are blown out obliquely along the radiation wall surface Z from the opening 9.

  A horizontal portion of the second flow path 8b of the air flow path 8 connected to the heat storage unit 11 has a circular cross section. On the other hand, the vertical portion of the second flow path 8b connected to the first flow path 8a is directed downward so as to match the shape of the first flow path 8a in accordance with the shape of the opening 9, as shown in FIG. It is gradually formed into a wide rectangular shape. As a result, the flame f blown out from the opening 9 has a thin flat shape. The opening area of the opening 9 is set slightly smaller than the cross-sectional area of the first flow path 8a, and the flow velocity at the opening 9 is increased.

  A pair of fuel injection portions 10 of each burner device 7 is provided on both ends in the longitudinal direction of each opening 9 and injects fuel F into the air flow path 8 along the curved path Y. The fuel injection unit 10 is provided on the radiation wall surface Z side of the first flow path 8a, and the fuel F is injected toward the curved outer surface Y1 that is curved and protrudes. The fuel injection port 10a of the fuel injection unit 10 is located in the lower part of the straight path D, whereby the combustion air C and the fuel F are merged with the upstream side of the curved path Y as the junction X.

  As shown in FIG. 5, the air flow path 8 is downstream of the joining portion X where the fuel F from the fuel injection portion 10 and the combustion air C join, and the curved surface S faces the curved path Y. A baffle portion 13 for agitating and mixing the fuel F and the combustion air C is formed around the reversal portion T turned back. In the illustrated example, a baffle 13 a as a protrusion protruding from the inner curved surface Y <b> 2 facing the outer curved surface Y <b> 1 is provided at an appropriate interval in the longitudinal direction of the opening 9 on the straight path D side with respect to the curved path Y. Combustion air C and fuel F are agitated by baffle 13a to facilitate mixing. The combustion air C that smoothly flows while avoiding the baffle 13a is blown out vigorously from the opening 9, accompanied by the combustion air C and the fuel F that are agitated and mixed. By both of these actions, both the fuel / air mixture and the flow velocity can be maintained even in the flat flame f. The fuel injection units 10 are not limited to a pair (two units), and may be one unit or three units or more.

  The flame f blown out from the opening 9 is a flat flame f that travels along the radiation wall surface Z of the ceiling surface 6 due to the Coanda effect that acts on the air flow of the combustion air C by the curved surface S that extends to the radiation wall surface Z. Become. Furthermore, in the present embodiment, the flat flame f generated by the combustion operation of the other burner device 7 is surely along the radiation wall surface Z by the air flow along the radiation wall surface Z generated by the exhaust suction operation of the one burner device 7. The entire ceiling surface 6 is in a brilliant state. Thus, the entire surface of the radiation wall Z can be efficiently heated to generate solid radiation, and the treatment material 2 can be heated uniformly.

  According to the wall surface radiation type burner unit 4 according to the present embodiment, the radiation wall surface Z of the furnace body element 5 is heated by the flat flame f generated by the pair of heat storage alternating combustion type burner devices 7, and the heated radiation is obtained. Since the treatment material 2 is heated by the radiant heat from the entire surface of the wall surface Z, the treatment material 2 can be heated more uniformly than in the case of heating by directly applying a flame of a burner.

  Since the flat flame f is caused to follow the radiation wall surface Z by the air flow of the combustion air C that causes the Coanda effect, the radiation wall surface Z can be efficiently heated. Further, the flat flame f generated by the combustion operation of the other burner device 7 can be caused to follow the radiation wall surface Z by the air flow along the radiation wall surface Z generated by the exhaust suction operation of the one burner device 7. Thus, the radiant wall surface Z can be efficiently heated by the flat flame f.

  Specifically, the burner device 7 is formed with an opening in the furnace body element 5 and blows out a flat flame f. The burner device 7 is formed in the furnace body element 5 and is connected to the opening 9 to circulate combustion air C. Since the air flow path 8 and the radiation wall surface Z are connected by the continuous curved surface S via the opening 9, the flame f blown from the opening 9 is radiated by the Coanda effect. It can be along the wall Z. A pair of heat storage alternating combustion type burner devices 7 generate a series of airflows in which the flat flame f is blown out from one opening 9 and sucked into the other opening 9 along the radiation wall Z. Since the flat flame f extends along the radiation wall surface Z along with the air flow, the radiation wall surface Z can be reliably and efficiently heated.

  Since the flame f from the opening 9 has a flat shape, the radiation wall surface Z can be heated more widely and uniformly. Since the flame f formed between the furnace body element 5 and the treatment material 2 is flat, the distance between the treatment material 2 and the inner surface of the furnace body 1a such as the ceiling surface 6 is narrow (in the figure, the height of the heating furnace 1). The heating furnace 1 can be reduced in size.

  Since the curved path Y is formed in the air flow path 8 of the burner device 7 so as to be located at the back of the curved surface S and to be turned back with respect to the curved surface S, when the flame f blows out from the opening 9. The swirling action can be generated in the flame f so as to approach the radiation wall surface Z, and the heating action of the radiation wall surface Z by the flame f can be further improved.

  Since the burner device 7 has the fuel injection part 10 that injects the fuel F into the air flow path 8 along the curved path Y, the fuel F and the combustion are ensured while ensuring a smooth flow of the combustion air C. The merging with the working air C can be smoothed, and the flame f having a high flow velocity can be blown out from the opening 9.

  In the air flow path 8 of the burner device 7, the curved surface S is turned back toward the curved path Y on the downstream side of the merging portion X where the fuel F from the fuel injection unit 10 and the combustion air C merge. Since the baffle portion 13 for stirring and mixing the fuel F and the combustion air C is formed around the inversion portion T, the mixing of the fuel F and the combustion air C can be increased, and high-efficiency combustion is ensured. can do.

  Combustion air C and fuel F that flowed smoothly through the baffle portion 13 maintain the momentum of the airflow, and can sufficiently exert the Coanda effect. With sufficient radiant heat, the radiant wall surface Z is appropriately heated. The processing material 2 can be processed.

  Further, as in the above embodiment, the furnace body element 5 (furnace ceiling part in the figure) and the wall surface radiation type burner unit 4 including the burner device 7 are unitized, and these are connected in series to form the furnace ceiling part and the like. By forming the furnace body 1a, the heating furnace 1 can be easily configured. In the said embodiment, although the furnace element 5 shall comprise a furnace ceiling part, of course, it may comprise a hearth part and a furnace wall part.

DESCRIPTION OF SYMBOLS 1 Heating furnace 1a Furnace body 2 Processing material 3 Conveying part 4 Wall surface radiation type burner unit 5 Furnace element 6 Ceiling surface 7 Regenerative burner device 8 Air flow path 8a 1st flow path 8b 2nd flow path 9 Opening part 10 Fuel Injection unit 10a Fuel injection port 11 Thermal storage unit 12 Communication pipe 13 Baffle unit 13a Baffle C Combustion air D Straight path E Exhaust F Fuel f Flat flame S Curved surface T Reversal part X Merge part Y Curved path Y1 Outer curved surface Y2 Inner curved surface Z radiation wall

Claims (5)

A furnace element that forms a radiant wall facing the treatment material, and a burner that forms a flat flame along the radiant wall of the furnace element and heats the radiant wall, and is treated by radiant heat from the radiant wall. Heating the material ,
The burner includes an opening that is formed in the furnace body element and blows out a flat flame, and an air passage that is formed in the furnace body element and is connected to the opening and through which combustion air flows. The air flow path and the radiation wall surface are connected by a continuous curved surface through the opening,
A wall surface radiant burner unit characterized in that a curved path is formed in the air flow path of the burner so as to be located at the back of the curved surface and to be turned back with respect to the curved surface.   2. The wall surface radiant burner unit according to claim 1, wherein the flat flame is along the radiant wall surface by an air flow of combustion air that produces a Coanda effect. 3. The wall surface radiant burner unit according to claim 1 , wherein the burner has a fuel injection unit that injects fuel into the air flow path along the curved path. The air flow path of the burner is downstream of the joining portion where the fuel from the fuel injection portion and combustion air join, and around the reversal portion where the curved surface is folded back toward the curved path. The wall surface radiant burner unit according to claim 3, wherein a baffle portion for stirring and mixing the fuel and the combustion air is formed. The burner has a heat storage section that warms combustion air with exhaust, and is configured by arranging a pair of regenerative burner devices that alternately perform combustion operation and exhaust operation with the radiation wall surface interposed therebetween,
The flat flame caused by the combustion operation of the other regenerative burner device is caused to flow along the radiation wall surface by the air flow along the radiation wall surface generated by the exhaust suction operation of the one regenerative burner device. The wall surface radiation type burner unit according to any one of claims 1 to 4, wherein

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