JP6395626B2 - Heat exchanger for heating device and single-end radiant tube burner - Google Patents

Description

  In the present invention, a plurality of heat transfer tube members are used to divide an air supply passage through which combustion air flows and an exhaust passage through which combustion exhaust gas from a combustion region formed at the front end side flows. The present invention relates to a heat exchanger for a heating device and a single-end radiant tube burner formed in a structure.

  2. Description of the Related Art Conventionally, a combustion apparatus (a recuperator) having a heat exchanger for a heating apparatus (a recuperator) that recovers exhaust heat of combustion exhaust gas is known. As such a combustion apparatus, a single end radiant tube burner is used in industrial indirect heating such as carburizing. This single end radiant tube burner performs combustion by mixing the fuel gas ejected from the fuel introduction pipe with the combustion air that is ejected through the heat exchanger for the heating device. And the combustion exhaust gas which has high heat by this combustion passes the inside of the single end radiant tube connected with the said heat exchanger for heating devices, and it heats with the radiant heat from a single end radiant tube. With such a configuration, a compact and energy-saving heating device is realized.

  The combustion air and the combustion exhaust gas exchange heat while flowing inside the heat exchanger for the heating device. Therefore, the region in which the combustion exhaust gas and combustion air can exchange heat is limited to the length range of the heating device heat exchanger. Although it is conceivable to improve the heat exchange efficiency by lengthening the heat exchanger for the heating device itself, there is a problem in that this leads to an increase in the size of the heat exchanger for the heater.

  Then, as described in Patent Document 1, it is considered that the heat exchanger for a heating device has a multiple tube structure partitioned by a heat exchange wall. Specifically, while the combustion air flows through a 1.5 reciprocating stroke in the length direction from the front end side to the rear end side of the heat exchanger for the heating device, it is supplied so as to exchange heat with the exhaust gas that reciprocates once. It is considered to improve the heat exchange efficiency between combustion air and combustion exhaust gas by arranging an air flow path and an exhaust flow path.

JP 2003-262305 A

  However, even with the above-described configuration, the heat exchange efficiency cannot be improved sufficiently compared with the complicated structure of the heat exchanger for a heating device, and further improvement has been demanded.

  Moreover, according to the said structure, after flue gas flows from the front end side to the rear end side, it turns back from the rear end side to the front end side, and is exhausted by one reciprocation. Then, the discharge port of the combustion apparatus is located on the tip side, that is, the side close to the furnace wall. Therefore, in order to avoid interference between the furnace wall and the discharge port, it is necessary to provide the entire heat exchanger for the heating device including the discharge port so as to be separated from the furnace wall. There is a problem that it is attached in a state of being greatly protruded, and it has also been required to form a heating device using a heat exchanger for a heating device in a compact manner.

  Therefore, in view of the above situation, an object of the present invention is to provide a heat exchanger for a heating device having a simple configuration with a small size and good heat exchange efficiency.

[Configuration 1]
In order to achieve the above object, the characteristic configuration of the heat exchanger for a heating device of the present invention is:
Using a plurality of heat transfer tube members, a multi-tube structure is formed by partitioning an air supply passage through which combustion air flows and an exhaust passage through which combustion exhaust gas from a combustion region formed at the front end side flows. A heat exchanger for a heating device,
The rear end side has an air introduction port for receiving the supply of combustion air to the inside, and the rear end side has a combustion exhaust gas discharge port for discharging the combustion exhaust gas generated in the combustion region to the outside,
The air supply channel is
A first air supply passage through which the combustion air supplied from the air inlet flows from the rear end side toward the front end side;
A second air supply passage through which the combustion air that has flowed through the first air supply passage flows from the front end side toward the rear end side;
The combustion air that has flowed through the second air supply channel has a third air supply channel that flows from the rear end side toward the front end side and reaches the combustion region on the front end side;
The exhaust passage is
A first exhaust passage through which the flue gas generated in the combustion region flows from the front end side toward the rear end side;
A second exhaust passage through which the flue gas flowing through the first exhaust passage flows from the rear end side toward the front end side;
The combustion exhaust gas that has flowed through the second exhaust flow path has a third exhaust flow path that flows from the front end side toward the rear end side to reach the combustion exhaust gas discharge port,
The third air supply passage and the first exhaust passage are adjacent to each other with one of the plurality of heat transfer tube members interposed therebetween so that the combustion air and the combustion exhaust gas are counterflowed,
The first exhaust flow path and the second exhaust flow path are adjacent to each other with one of the plurality of heat transfer tube members sandwiched between the combustion exhaust gases so as to face each other.
The second exhaust flow path and the second air supply flow path are adjacent to each other with one of the plurality of heat transfer tube members interposed therebetween so that the combustion exhaust gas and the combustion air are opposed to each other,
The second air supply passage and the third exhaust passage are adjacent to each other with one of the plurality of heat transfer tube members interposed therebetween so that the combustion air and the combustion exhaust gas are in parallel flow,
The third exhaust passage and the first air supply passage are adjacent to each other with one of the plurality of heat transfer tube members interposed therebetween so that the combustion exhaust gas and the combustion air are opposed to each other. It is in.

[Operation effect 1]
With the above-described configuration, the combustion air supplied to the air introduction port moves from the rear end side to the front end side of the first air supply flow path, is folded back at the front end side, and the second air supply flow path is changed from the front end side to the rear end side. And further folded back on the rear end side so that the third air supply passage moves from the rear end side to the front end side to reach the combustion region.

  On the other hand, the flue gas generated in the combustion region moves the first exhaust passage from the front end side to the rear end side, turns back at the rear end side, moves the second exhaust passage from the rear end side to the front end side, It is configured to be folded at the front end side, move the third exhaust passage from the front end side to the rear end side, and be discharged from the combustion exhaust gas discharge port.

Here, the third air supply passage and the first exhaust passage are adjacent to each other with one of the plurality of heat transfer tube members interposed therebetween so that the combustion air and the combustion exhaust gas are opposed to each other.
The first exhaust passage and the second exhaust passage are adjacent to each other with one of the plurality of heat transfer tube members interposed therebetween so that the combustion exhaust gases are opposed to each other.
The second exhaust flow path and the second air supply flow path are adjacent to each other with one of the plurality of heat transfer tube members interposed therebetween so that the combustion exhaust gas and the combustion air are opposed to each other.
The second air supply passage and the third exhaust passage are adjacent to each other with one of the plurality of heat transfer tube members interposed therebetween so that the combustion air and the combustion exhaust gas are in parallel flow,
The third exhaust flow path and the first air supply flow path are adjacent to each other with one of the plurality of heat transfer tube members so that the combustion exhaust gas and the combustion air are opposed to each other. During the flow of 1.5 reciprocating strokes in the length direction from the front end side to the rear end side, heat exchange is performed with the combustion exhaust gas flowing through the 1.5 reciprocating strokes.

  That is, without forming the heat exchanger for the heating device longer than necessary, the heat exchange between the combustion air and the combustion exhaust gas can be achieved, the combustion air can be preheated, and the combustion exhaust gas can be cooled.

  Moreover, the point which can fully ensure the area | region where the combustion air and combustion exhaust gas heat-exchange by a counterflow contributes to high heat exchange efficiency.

  Further, the combustion exhaust gas reaches the rear end side from the front end side, and further returns to the front end side, and then heat exchange is performed by 1.5 reciprocations reaching the rear end side. Therefore, the exhaust gas exhaust port is provided on the rear end side. Yes. Therefore, when the heat exchanger for a heating device is attached to a furnace wall or the like, the exhaust gas discharge port is provided at a position separated from the furnace wall or the like, and is similar to the air inlet provided away from the furnace wall. Less likely to interfere with furnace walls. Therefore, the heat exchanger for a heating device can be attached in a state of being close to the furnace wall or the like, and can be used as a compact heating device in a state where it does not protrude greatly from the furnace wall or the like.

[Configuration 2]
In order to achieve the above object, the characteristic configuration of the heat exchanger for a heating device of the present invention is:
Using a plurality of heat transfer tube members, a multi-tube structure is formed by partitioning an air supply passage through which combustion air flows and an exhaust passage through which combustion exhaust gas from a combustion region formed at the front end side flows. A heat exchanger for a heating device,
An inner tube, an inner guide tube, and a cylindrical body;
An inner tube flange portion is provided on the outer peripheral surface of the rear end side of the inner tube, and an inner guide tube flange portion is provided on the outer peripheral surface of the distal end side of the inner guide tube. The inner guide tube is inserted through the inner guide tube, and the inner tube flange portion and the inner guide tube flange portion are inserted into the inner surface side of the inner guide tube from the rear end side to the distal end side. Arranged in a posture to sandwich the cylindrical body between,
Between the inner pipe and the inner guide pipe, the combustion exhaust gas generated in the combustion region forms a first exhaust passage that flows from the front end side toward the rear end side,
Between the inner guide pipe and the cylindrical body, the combustion exhaust gas that has flowed through the first exhaust flow path forms a second exhaust flow path that flows from the rear end side toward the front end side,
Within the thickness sandwiched between the inner surface and the outer surface of the cylindrical main body, the flue gas flowing through the second exhaust passage flows from the front end side toward the rear end side and reaches the flue gas exhaust port. Three exhaust passages are formed by partitioning with heat exchange walls,
A first air supply passage through which the combustion air supplied from the air inlet flows from the rear end side toward the tip end side on the outer surface side of the third exhaust passage within the thickness of the cylindrical main body. Is formed by partitioning with a heat exchange wall,
A second supply airflow in which the combustion air that has flowed through the first supply air flow path flows from the front end side toward the rear end side closer to the inner surface side than the third exhaust flow path within the thickness of the cylindrical main body The path is partitioned and formed by heat exchange walls,
Formed inside the inner pipe is a third air supply flow path in which the combustion air flowing through the second air supply flow path flows from the rear end side toward the front end side and reaches the combustion region on the front end side. It is in a certain point.

[Operation effect 2]
According to the above configuration, the heat transfer tube member includes an inner tube, an inner guide tube, and a cylindrical main body,
An inner tube flange is provided on the outer peripheral surface of the rear end side of the inner tube, and an inner guide tube flange is provided on the outer peripheral surface of the inner guide tube on the front end side. A posture in which the cylindrical body is sandwiched between the inner tube flange portion and the inner guide tube flange portion while the guide tube is inserted and the inner tube is inserted from the rear end side to the front end side on the inner guide tube inner surface side. Therefore, it is easily assembled and formed from the inner tube, the inner guide tube, and the cylindrical main body.

Further, between the inner pipe and the inner guide pipe, a first exhaust passage in which the combustion exhaust gas generated in the combustion region flows from the front end side toward the rear end side is formed,
Between the inner guide tube and the cylindrical main body, a second exhaust flow path in which the flue gas flowing through the first exhaust flow path flows from the rear end side toward the front end side is formed,
Within the thickness sandwiched between the inner surface and the outer surface of the cylindrical main body, the third exhaust passage that the combustion exhaust gas that has flowed through the second exhaust passage flows from the front end side toward the rear end side and reaches the combustion exhaust gas discharge port. While partitioning with heat exchange walls,
Within the thickness of the cylindrical main body, a first air supply passage through which the combustion air supplied from the air inlet flows from the rear end side toward the front end side is defined by a heat exchange wall on the outer surface side of the third exhaust passage. Formed,
Within the thickness of the cylindrical main body, the second supply air flow path, in which the combustion air that has flowed through the first supply air flow path flows from the front end side toward the rear end side on the inner surface side of the third exhaust flow path, is a heat exchange wall. Partition and form,
Since the combustion air that has flowed through the second air supply passage flows from the rear end side toward the front end side inside the inner pipe and forms a third air supply passage that reaches the combustion region on the front end side, the cylindrical main body Functions as a plurality of heat transfer tube members partitioned by a heat exchange wall, and the third air supply flow path and the first exhaust flow path have a plurality of flows so that the combustion air and the combustion exhaust gas are opposed to each other. Adjacent to the inner pipe of the heat transfer pipe members,
The first exhaust passage and the second exhaust passage are adjacent to each other with the inner guide tube among the plurality of heat transfer tube members so that the combustion exhaust gases are opposed to each other,
The second exhaust flow path and the second air supply flow path are adjacent to each other with the inner wall surface of the cylindrical main body among the plurality of heat transfer tube members so that the combustion exhaust gas and the combustion air are opposed to each other,
The second air supply flow path and the third exhaust flow path are heat that partitions the inside in the thickness direction of the cylindrical body of the plurality of heat transfer tube members so that the combustion air and the combustion exhaust gas are in parallel flow. Adjacent to the exchange wall,
The third exhaust flow path and the first air supply flow path are heat that partitions the inside in the thickness direction of the cylindrical body of the plurality of heat transfer tube members so that the combustion exhaust gas and the combustion air are opposed to each other. Combustion exhaust gas that flows 1.5 reciprocating strokes while the combustion air flows 1.5 reciprocating strokes in the length direction from the front end side to the rear end side because it is adjacent to the exchange wall Heat exchange.

  That is, without forming the heat exchanger for the heating device longer than necessary, the heat exchange between the combustion air and the combustion exhaust gas can be achieved, the combustion air can be preheated, and the combustion exhaust gas can be cooled.

  In addition, it is considered that the fact that a sufficient area for heat exchange between the combustion air and the combustion exhaust gas in the counterflow can be secured contributes to high heat exchange efficiency.

  Further, the combustion exhaust gas reaches the rear end side from the front end side, and further returns to the front end side, and then heat exchange is performed by 1.5 reciprocations reaching the rear end side. Therefore, the exhaust gas exhaust port is provided on the rear end side. Yes. Therefore, when the heat exchanger for a heating device is attached to a furnace wall or the like, the exhaust gas discharge port is provided at a position separated from the furnace wall or the like, and hardly interferes with the furnace wall or the like. Therefore, the heat exchanger for a heating device can be attached in a state of being close to the furnace wall or the like, and can be used as a compact heating device in a state where it does not protrude greatly from the furnace wall or the like.

[Configuration 3]
The characteristic configuration of the single-ended radiant tube burner of the present invention is as follows:
A heat exchanger for the heating device, surrounding the combustion region and projecting to the front end side, provided with an outer pipe for guiding the combustion exhaust gas from the combustion region to the first exhaust passage, and the combustion region A fuel introduction pipe for supplying fuel gas is provided.

[Operation effect 3]
According to the above configuration, when the fuel gas is combusted in the combustion region, the sufficiently preheated combustion air discharged from the heat exchanger for the heating device can be supplied to the combustion in the combustion region, and the outer tube Since the combustion heat can be radiated to the outside, a single end radiant tube burner capable of performing efficient combustion can be configured. Further, the outer pipe guides the combustion exhaust gas to the first exhaust passage, so that the combustion exhaust gas can be sufficiently cooled by heat exchange with the combustion air, and an energy efficient operation can be realized.

Schematic of single-ended radiant tube burner

  Below, the heat exchanger for heating devices and the single end radiant tube burner concerning the embodiment of the present invention are explained. In addition, although suitable examples are described below, these examples are described in order to more specifically illustrate the present invention, and various modifications can be made without departing from the spirit of the present invention. The present invention is not limited to the following description.

  In addition, in this application, when calling the front-end | tip and rear end of the heat exchanger for heating apparatuses, the side to which the outer tube | pipe 1 of the heat-exchange body for heating apparatuses is connected is set as a front end, and the side away from the front end is described as a rear end. Also, the direction connecting the front end side and the rear end side of the multi-tube structure is the axial direction (direction indicated by X in the figure), and the axial center side in the corresponding radial direction (direction indicated by Y in the figure) is the inner surface and outer circumference The surface side is referred to as the outer surface. These notations indicate relative positional relationships that do not depend on the arrangement posture or the like of the heat exchanger for the heating device.

[Single End Radiant Tube Burner]
Single-end radiant tube burner, as shown in Figure 1,
A fuel introduction pipe comprising an outer pipe 1 whose front end is blocked, an inner pipe 2 that is inserted into the outer pipe 1 and supplies combustion air, and a fuel introduction pipe 3 that introduces fuel gas into the inner pipe 2. 3 is formed with a combustion region 31 that emits a flame at the tip end side, and a tip exhaust passage La is formed between the outer tube 1 and the inner tube 2;
A cylindrical main body 4 sandwiched between an outer tube flange portion 11 provided on the outer peripheral surface side of the rear end side of the outer tube 1 and an inner tube flange portion 21 provided on the outer peripheral surface side of the rear end side portion of the inner tube 2. With
An inner guide tube 5 extending from the rear end side of the outer tube 1 to the inside of the cylindrical body 4;
An outer box 6 that covers the inner pipe flange portion 21 on the rear end side of the cylindrical main body 4 is provided.

With such a configuration, the outer tube 1, the inner tube 2, the cylindrical main body 4, and the inner guide tube 5 as heat transfer tube members are used, and an air supply passage A 0 through which combustion air flows and a tip end side are formed. A heat exchanger for a heating device that is formed in a multi-pipe structure by dividing an exhaust passage L0 through which combustion exhaust gas from a combustion region to be flowed flows,
On the rear end side, it has an air introduction port 41 that receives supply of combustion air to the inside, and a combustion exhaust gas discharge port 42 that discharges combustion exhaust gas generated in the combustion region 31 to the outside,
The air supply channel A0 is
A first air supply passage A1 in which combustion air supplied from the air inlet 41 flows in the axial direction from the rear end side to the front end side;
A second air supply passage A2 in which the combustion air flowing through the first air supply passage A1 flows in the axial direction from the front end side to the rear end side;
The combustion air that has flowed through the second air supply passage A2 has a third air supply passage A3 that flows in the axial direction from the rear end side to the front end side and reaches the combustion region 31 on the front end side,
The exhaust passage L0 is
A first exhaust passage L1 in which the combustion exhaust gas generated in the combustion region 31 flows in the axial direction from the front end side to the rear end side;
A second exhaust passage L2 in which the flue gas flowing through the first exhaust passage L1 flows in the axial direction from the rear end side to the front end side;
A combustion exhaust gas flowing through the second exhaust flow path L2 flows in the axial direction from the front end side to the rear end side and has a third exhaust flow path L3 reaching the combustion exhaust gas discharge port 42;
The third air supply passage A3 and the first exhaust passage L1 are adjacent to each other with the inner tube 2 serving as a heat transfer tube member interposed therebetween so that the combustion air and the combustion exhaust gas are opposed to each other. A cylindrical first exhaust flow path L <b> 1 is formed between the guide pipe 5.
The first exhaust flow path L1 and the second exhaust flow path L2 are adjacent to each other with the inner guide pipe 5 serving as a heat transfer pipe member interposed therebetween so that the combustion exhaust gases are opposed to each other. A cylindrical second exhaust flow path L <b> 2 is formed between the wall 45.
The second exhaust flow path L2 and the second air supply flow path A2 are adjacent to each other with the inner surface heat exchange wall 45 of the tubular body 4 serving as the heat transfer tube member so that the combustion exhaust gas and the combustion air are opposed to each other. Then, a cylindrical second air supply channel A2 surrounded by the inner surface heat exchange wall 45 and the first heat exchange wall 46 is formed.
The second air supply passage A2 and the third exhaust passage L3 are adjacent to each other with the first heat exchange wall 46 serving as a heat transfer tube member interposed therebetween so that the combustion air and the combustion exhaust gas flow in parallel. A cylindrical third exhaust flow path L3 surrounded by the heat exchange wall 46 and the second heat exchange wall 47 is formed.
The third exhaust flow path L3 and the first air supply flow path A1 are adjacent to each other with the second heat exchange wall 47 serving as a heat transfer tube member interposed therebetween so that the combustion exhaust gas and the combustion air are opposed to each other. A cylindrical first air supply passage A1 surrounded by the heat exchange wall 47 and the outer heat exchange wall 48 is formed.

Specifically, the inner tube 2, the inner guide tube 5, and the cylindrical body 4 are provided,
The inner pipe 2 is provided with an inner pipe flange portion 21 on the outer peripheral surface of the rear end side of the inner tube 2, and an inner guide tube flange portion 51 is provided on the outer peripheral surface of the inner guide tube 5. In addition, the inner guide tube 5 is inserted from the front end side to the rear end side, and the inner tube flange 21 and the inner tube flange 21 are inserted into the inner surface side of the inner guide tube 5 from the rear end side to the front end side. Arranged in a posture to sandwich the tubular body 4 between the guide tube flange portion 51,
Between the inner tube 2 and the inner guide tube 5, the combustion exhaust gas generated in the combustion region 31 flows between the inner tube 2 and the inner guide tube 5 in the axial direction from the front end side toward the rear end side. Forming a first exhaust flow path L1 of
Between the inner guide tube 5 and the cylindrical main body 4, the combustion exhaust gas flowing through the first exhaust passage L <b> 1 flows in the axial direction from the rear end side toward the front end side and the inner guide tube 5 and the inner surface heat exchange wall 45. A cylindrical second exhaust flow path L2 is formed between the
Within the thickness sandwiched between the inner surface heat exchange wall 45 and the outer surface heat exchange wall 48, the flue gas flowing through the second exhaust passage L2 flows in the axial direction from the front end side to the rear end side to the flue gas exhaust port 42. Forming a cylindrical third exhaust flow path L3 surrounded by the first heat exchange wall 46 and the second heat exchange wall 47,
The second heat exchange wall 47 in which the combustion air supplied from the air inlet 41 flows in the axial direction from the rear end side to the front end side on the outer surface side of the third exhaust flow path L3 within the thickness of the cylindrical main body 4. And a cylindrical first air supply passage A1 surrounded by the outer surface heat exchange wall 48,
Within the thickness of the cylindrical body 4, the inner surface heat exchange wall 45 in which the combustion air that has flowed through the first air supply passage A1 flows in the axial direction from the front end side to the rear end side, closer to the inner surface side than the third exhaust passage L3. And a cylindrical second air supply passage A2 surrounded by the first heat exchange wall 46,
The combustion air that has flowed through the second air supply passage A2 inside the inner pipe 2 flows in the axial direction from the rear end side to the front end side to form a third air supply passage A3 that reaches the combustion region 31 on the front end side. is there.

  Hereinafter, the configuration of each member will be described in detail.

[Outer tube]
The outer tube 1 has a cylindrical shape with the distal end closed, and accommodates the distal end portion of the inner tube 2 therein, and the distal exhaust passage in the space between the inner tube 2 and the outer tube 1 in the axial direction and the radial direction. La is formed. An outer tube flange portion 11 is provided on the outer peripheral surface side of the rear end portion of the outer tube 1, and the outer tube flange portion 11 is provided on the inner guide tube flange portion 51 and the distal end side of the tubular body 4 in the heat exchanger for the heating device. The flange part provided is comprised so that connection is possible.

  The outer tube 1 is inserted into the through hole W1 of the furnace wall W in a state where the combustion region 31 formed inside is positioned in the furnace, the outer tube flange portion 11 is the inner guide tube flange portion 51, and the cylindrical main body 4 At the same time, it is used in a state of being fixedly attached to the furnace wall W from the outer surface side. The fuel gas supplied from the fuel introduction pipe 3 is ignited and combusted in the combustion region 31 by a pilot burner (not shown) or the like by the combustion air supplied from the third air supply passage A3, and supplies heat into the furnace. At the same time, the combustion exhaust gas is circulated to the first exhaust passage L1 through the tip exhaust passage La.

[Inner pipe]
The inner tube 2 is formed in a tubular shape whose front end is inserted into the outer tube 1 and the heat exchanger for a heating device, and includes an inner tube flange portion 21 on the outer peripheral surface side of the rear end side of the inner tube 2. The distal end portion on the distal end side of the inner tube 2 is inserted into the outer tube 1. A third air supply passage A3 through which combustion air can be circulated is formed so as to form a combustion region 31 that emits a flame in an inner region of the inner tube 2 inserted through the outer tube 1, and fuel gas is supplied. The fuel introduction pipe 3 to be introduced is inserted.

  The fuel introduction pipe 3 is inserted into the inner pipe 2 and is fixed to the axial center of the inner pipe 2 so that the nozzle portion 32 at the tip is located in the outer pipe 1 and is supplied from within the fuel introduction pipe 3. A fuel gas typified by LNG is ejected from the nozzle portion 32. The combustion air supplied from a third air supply passage A3 formed between the fuel introduction pipe 3 and the inner pipe 2 is used for combustion. A fuel mixing section 33 is provided on the base end side of the fuel introduction pipe 3 located on the rear end side of the heat exchanger for the heating device, and a plurality of fuel gases and primary combustion air are mixed so that the amount of heat can be adjusted. is there. In addition, the nozzle portion 32 of the fuel introduction pipe 3 is formed in a divergent shape, so that the generated flame can be stably held in a wide area in the inner pipe, and combustion heat can be supplied uniformly in the outer pipe 1. It is.

(Cylindrical body)
The cylindrical main body 4 has a multiple tube structure in which a plurality of steel plates serving as heat exchange walls are formed and welded to form a heat transfer tube member in a concentric cylindrical shape. The cylindrical main body 4 has a first air supply passage A1 that guides the combustion air supplied to the tip side in the thickness direction from the outer surface side to the inner surface side in the radial direction, and the combustion exhaust gas supplied to the tip side. A third exhaust flow path L3 that leads to the end side and discharges, and a second air supply flow path A2 that guides the combustion air supplied from the front end side from the first air supply path A1 to the rear end side and supplies it to the inside of the outer box 6 Are stacked in this order across the heat exchange walls. Further, the cylindrical main body 4 is provided with an air introduction port 41 connected to the first air supply flow path A1 and a combustion exhaust gas discharge port 42 connected to the third exhaust flow path L3 in the rear end side wall portion. Further, a discharge port 43 for discharging combustion air from the second air supply flow path A2 is formed on the rear end side end face side, and an introduction port 44 for introducing exhaust gas into the third exhaust flow path L3 is formed at the front end side end. It is. The tubular body 4 is sandwiched between the outer tube flange portion 11 and the inner tube flange portion 21, and between the outer tube flange portion 11 and the flange portion on the distal end side of the tubular body 4, Further, the bolts are connected and fixed in such a manner as to sandwich an inner guide pipe flange portion 51 described later.

[Inner guide tube]
The inner guide tube 5 is provided with an inner guide tube flange portion 51 on the outer peripheral surface on the front end side, and is joined to the outer tube flange portion 11. The rear end side inserts the inner tube, and the front end side of the inner tube flange portion 21. It is formed in a tubular shape opening in the vicinity. Thus, the first exhaust flow that is formed inside the tubular body 4 and outside the inner tube 2 between the inner tube 2 and the inner guide tube 5 and directly receives the combustion exhaust gas from the tip exhaust passage La. Divided into a path L1 and a second exhaust flow path L2 formed between the inner guide pipe 5 and the cylindrical main body 4 and leading to the third exhaust flow path L3 by folding the combustion exhaust gas flowing in the first exhaust flow path L1 It is arranged to form.

  In addition, although such a multi-pipe structure has a complicated structure and seems to be difficult to manufacture, in reality, the first and second air supply channels are disposed in the thickness direction of the cylindrical body 4. Since only A1 and A2 and the third exhaust flow path L3 are formed, a pair of bottomed double cylinders can be manufactured by a simple process such as integration by welding or the like, and the inner guide pipe 5 is attached thereto. Since it was configured to realize a further multilayer by providing separately, the heat exchange efficiency could be further increased by adding a simple configuration.

〔Outer case〕
The outer box 6 surrounds the inner pipe flange portion 21 and the discharge port 43, and forms an outer box inner space 61 for introducing the combustion air discharged from the second air supply passage A2 into the third air supply passage A3. In this way, it is connected to the flange portion on the rear end side of the cylindrical main body 4.

[Flow passage of combustion air and combustion exhaust gas]
With the configuration described above, the combustion exhaust gas generated in the combustion region 31 flows through the clearance formed at the distal end side of the outer tube 1 and the inner tube 2 through the distal exhaust passage L0 from the distal end side to the rear end side, Guided from the first exhaust flow path L1 formed between the guide tube 5 and the inner tube 2 to the rear end side of the cylindrical main body 4, reaches the vicinity of the inner tube flange portion 21, and reaches the inner guide tube 5 and the cylindrical main body 4 Is circulated so as to circulate in the second exhaust flow path L2 formed between the two. The combustion exhaust gas flowing in the second exhaust flow path L2 in this way flows through the second exhaust flow path L2 from the rear end side toward the front end side and reaches the front end side of the inner guide pipe 5. The combustion exhaust gas flowing in the second exhaust flow path L2 flows into the third exhaust flow path L3 and flows from the front end side to the rear end side of the cylindrical main body 4 and is provided on the rear end side on the outer surface of the cylindrical main body 4 42 is discharged.

  On the other hand, the combustion air supplied from the air inlet 41 to the first air supply passage A1 is preheated by receiving heat from the combustion exhaust gas flowing through the third exhaust passage L3, while being on the rear end side of the cylindrical body 4 Flows from the tip to the tip. Further, the combustion air that has reached the distal end side of the cylindrical main body 4 flows into the second air supply passage A2 and is preheated by receiving heat from both the third exhaust passage L3 and the second exhaust passage L2. The combustion air thus preheated is discharged from the discharge port 43 on the rear end side of the cylindrical main body 4.

  Combustion air discharged from the rear end side of the cylindrical main body 4 passes through the outer casing 6 and flows into the third air supply passage A3 in the inner pipe 2. Here, since the third air supply passage A3 is adjacent to the tip exhaust passage La and the first exhaust passage L1 through the inner pipe 2, the cylindrical body 4 is further preheated while receiving heat from the combustion exhaust gas. It flows from the rear end side toward the front end side and further toward the inside of the outer tube 1. A fuel introduction pipe 3 is provided in the inner pipe 2, and reaches a combustion region 31 in which a flame is emitted on the tip side of the fuel introduction pipe 3 inside the extended inner pipe 2 in the outer pipe 1. In the combustion region 31, the fuel gas is burned by the combustion air to generate heat, and the combustion exhaust gas having heat is again cylindrical from the tip exhaust passage La formed between the outer tube 1 and the inner tube 2. It flows into the main body 4. The combustion exhaust gas is then heat-exchanged, and after preheating the combustion air from the above-described tip exhaust passage La through the first exhaust passage L1, the second exhaust passage L2, and the third exhaust passage L3, the cylindrical body 4 It is discharged outside.

  Therefore, the combustion air can exchange heat with the combustion exhaust gas in a stroke (one reciprocal half) of the length from the front end side to the rear end side of the cylindrical main body 4, so that the heat exchange efficiency is increased. The heat exchange efficiency could be further increased by adding a simple configuration.

  In the above-described embodiment, the heat exchanger for a heating device used for the radiant tube burner has been described as an example.

  The heat exchanger for a heating device of the present invention can be used as, for example, a single end radiant tube burner used in industrial indirect heating such as carburizing.

1: Outer pipe 2: Inner pipe 3: Fuel introduction pipe 4: Cylindrical body 5: Inner guide pipe 6: Outer box 11: Outer pipe flange part 21: Inner pipe flange part 31: Combustion region 32: Nozzle part 33: Fuel Mixing part 41: Air inlet 42: Combustion exhaust gas outlet 43: Release port 44: Inlet 45: Cylindrical main body inner wall 46: First heat exchange wall 47: Second heat exchange wall 51: Inner guide pipe flange part 61: Outer box inner space A0: Air supply flow path A1: First air supply flow path A2: Second air supply flow path A3: Third air supply flow path L0: Exhaust flow path L1: First exhaust flow path L2: Second exhaust flow path L3 : Third exhaust flow path W: Furnace wall W1: Through hole

Claims (3)

Using a plurality of heat transfer tube members, a multi-tube structure is formed by partitioning an air supply passage through which combustion air flows and an exhaust passage through which combustion exhaust gas from a combustion region formed at the front end side flows. A heat exchanger for a heating device,
The rear end side has an air introduction port for receiving the supply of combustion air to the inside, and the rear end side has a combustion exhaust gas discharge port for discharging the combustion exhaust gas generated in the combustion region to the outside,
The air supply channel is
A first air supply passage through which the combustion air supplied from the air inlet flows from the rear end side toward the front end side;
A second air supply passage through which the combustion air that has flowed through the first air supply passage flows from the front end side toward the rear end side;
The combustion air that has flowed through the second air supply channel has a third air supply channel that flows from the rear end side toward the front end side and reaches the combustion region on the front end side;
The exhaust passage is
A first exhaust passage through which the flue gas generated in the combustion region flows from the front end side toward the rear end side;
A second exhaust passage through which the flue gas flowing through the first exhaust passage flows from the rear end side toward the front end side;
The combustion exhaust gas that has flowed through the second exhaust flow path has a third exhaust flow path that flows from the front end side toward the rear end side to reach the combustion exhaust gas discharge port,
The third air supply passage and the first exhaust passage are adjacent to each other with one of the plurality of heat transfer tube members interposed therebetween so that the combustion air and the combustion exhaust gas are counterflowed,
The first exhaust flow path and the second exhaust flow path are adjacent to each other with one of the plurality of heat transfer tube members sandwiched between the combustion exhaust gases so as to face each other.
The second exhaust flow path and the second air supply flow path are adjacent to each other with one of the plurality of heat transfer tube members interposed therebetween so that the combustion exhaust gas and the combustion air are opposed to each other,
The second air supply passage and the third exhaust passage are adjacent to each other with one of the plurality of heat transfer tube members interposed therebetween so that the combustion air and the combustion exhaust gas are in parallel flow,
The third exhaust passage and the first air supply passage are adjacent to each other with one of the plurality of heat transfer tube members sandwiched so that the combustion exhaust gas and the combustion air are opposed to each other. Heat exchanger for equipment. Using a plurality of heat transfer tube members, a multi-tube structure is formed by partitioning an air supply passage through which combustion air flows and an exhaust passage through which combustion exhaust gas from a combustion region formed at the front end side flows. A heat exchanger for a heating device,
An inner tube, an inner guide tube, and a cylindrical body;
An inner tube flange portion is provided on the outer peripheral surface of the rear end side of the inner tube, and an inner guide tube flange portion is provided on the outer peripheral surface of the distal end side of the inner guide tube. The inner guide tube is inserted through the inner guide tube, and the inner tube flange portion and the inner guide tube flange portion are inserted into the inner surface side of the inner guide tube from the rear end side to the distal end side. Arranged in a posture to sandwich the cylindrical body between,
Between the inner pipe and the inner guide pipe, the combustion exhaust gas generated in the combustion region forms a first exhaust passage that flows from the front end side toward the rear end side,
Between the inner guide pipe and the cylindrical body, the combustion exhaust gas that has flowed through the first exhaust flow path forms a second exhaust flow path that flows from the rear end side toward the front end side,
Within the thickness sandwiched between the inner surface and the outer surface of the cylindrical main body, the flue gas flowing through the second exhaust passage flows from the front end side toward the rear end side and reaches the flue gas exhaust port. Three exhaust passages are formed by partitioning with heat exchange walls,
A first air supply passage through which the combustion air supplied from the air inlet flows from the rear end side toward the tip end side on the outer surface side of the third exhaust passage within the thickness of the cylindrical main body. Is formed by partitioning with a heat exchange wall,
A second supply airflow in which the combustion air that has flowed through the first supply air flow path flows from the front end side toward the rear end side closer to the inner surface side than the third exhaust flow path within the thickness of the cylindrical main body The path is partitioned and formed by heat exchange walls,
Formed inside the inner pipe is a third air supply flow path in which the combustion air flowing through the second air supply flow path flows from the rear end side toward the front end side and reaches the combustion region on the front end side. Heat exchanger for heating device.   A heat exchanger for a heating device according to claim 1 or 2, comprising an outer pipe that surrounds the combustion region and projects toward the front end side and guides the combustion exhaust gas from the combustion region to the first exhaust passage. And a single-end radiant tube burner provided with a fuel introduction pipe for supplying fuel gas to the combustion region.

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