JP2020079700A - Heat recovery device - Google Patents

Abstract

To provide a heat recovery device of a simple structure, capable of recovering and reusing heat from used combustion gas.SOLUTION: The heat recovery device comprises a passage section serving as a combustion gas passage, and a plurality of pipe-shaped members 32 each storing a heat medium in an inner space thereof. Lower parts 32a of the pipe shaped members 32 are disposed inside the passage section to constitute a heat receiving section for receiving heat from combustion gas, and upper parts 32b of the pipe-shaped members 32 are disposed outside the passage section to constitute a heat radiation section for radiating heat received by the heat receiving section to the ambience, whereby heat is recovered from the combustion gas and the ambient air present outside the passage section is heated by the recovered heat.SELECTED DRAWING: Figure 4

Description

  TECHNICAL FIELD The present invention relates to a heat recovery device that can be used in a seaweed producing machine for producing dry seaweed.

  As a laver producing machine for producing thin sheet-shaped dried laver, a laver provided with a drying chamber in addition to a paper making section, a dehydrating section, and a stripping section is widely known. In the dry seaweed production method using such a seaweed making machine, while moving the cage holder holding the cage by the endless chain, the raw seaweed is thinly made on the cage at the papermaking section, and then the cage holder is dehydrated. After moving it to and dehydrating the raw seaweed on the cage by air suction, it is further dehydrated by press. The raw nori after the press dehydration is sent to the drying chamber and is exposed to high temperature air while being conveyed by a conveyor in the drying chamber. As a result, the raw seaweed is dried, and then the dried seaweed (dry seaweed) is stripped from the cage at the stripping portion. The stripped dry seaweed is carried out from the seaweed making machine.

  Air heated by a heating device provided at an adjacent position is fed into the drying chamber. More specifically, the heating device includes a pipe into which high temperature combustion gas generated by burning heavy oil or the like is fed. The air taken in from the outside of the drying chamber is blown onto the tube burned by the fan to be heated and sent to the drying chamber. Further, the combustion gas from which heat has been taken is exhausted from the chimney to the outside of the drying chamber as a used exhaust gas after completion of work, and the exhaust gas is considerably hot. Therefore, a heat recovery device that recovers thermal energy from exhaust gas and reuses it is utilized. For example, in a seaweed production machine, a heat recovery device that warms the outside air taken into a heating device by the heat recovered from the exhaust gas is used (for example, see Patent Document 1).

  Patent Document 1 exemplifies a heat recovery device (heat exchange element) in which a plurality of metal plates are inserted in parallel in a direction along the flow of exhaust gas into a pipe that guides exhaust gas to a chimney. In this heat recovery device, exhaust gas is taken into every other space partitioned by each plate and flows upward, and outside air is taken into every other space to flow in a direction orthogonal to the combustion gas. .. As a result, so-called heat exchange is performed in which heat is taken from the exhaust gas by each plate and the outside air is warmed by the taken heat.

Japanese Utility Model Publication No. 57-189394

  However, in the conventional technique disclosed in Patent Document 1, a heat recovery device is disposed in a vertically extending pipe that discharges exhaust gas, and a duct that allows the outside air to flow through the heat recovery device in a horizontal direction. Since there is a partition wall between the outside air and the exhaust gas, the structure of the peripheral equipment including the heat recovery device and the duct connecting to the heat recovery device becomes complicated, and the heat from the exhaust gas is simple with a simple structure. There was a problem that it could not be collected and reused. Further, in the heat recovery device of Patent Document 1, heat exchange is performed by the partition wall separating the outside air and the exhaust gas, but there is a problem that the heat exchange rate is low.

  Therefore, it is an object of the present invention to provide a heat recovery device having a simple structure and capable of recovering and reusing heat from used combustion gas.

  The heat recovery device of the present invention includes a passage portion that is a passage for combustion gas, and a tubular member in which a heat medium is housed in an internal space, and a lower portion of the tubular member is located inside the passage portion. Then, constituting a heat receiving portion that receives heat from the combustion gas, the upper portion of the tubular member is located outside the passage portion, and constitutes a heat radiating portion that releases the heat received by the heat receiving portion to the surroundings, Heat is recovered from the combustion gas, and the collected heat heats the ambient air outside the passage.

  According to the present invention, heat can be recovered from the used combustion gas and reused with a simple structure.

The side view which shows typically the seaweed maker in Embodiment 1 of this invention. Sectional drawing which showed typically the inside of the hut in which the seaweed maker in Embodiment 1 of this invention was installed. Partial plan view of a cage and a cage holder that retains the cage used in the laver making machine according to Embodiment 1 of the present invention. Structure explanatory drawing of the air heating device with which the seaweed maker in Embodiment 1 of this invention is equipped. The side view which shows typically the pipe which comprises the air heating device with which the seaweed maker in Embodiment 1 of this invention is equipped. (A) Side view (b) Front view (c) Plan sectional view of the heat recovery device according to Embodiment 1 of the present invention (A) The front view of the outside air intake surface on which the current plate provided in the heat recovery device according to Embodiment 1 of the present invention is arranged, (b) The partial sectional view along the outside air flow (A) Plan view of the plate-shaped member with which the heat recovery apparatus in Embodiment 1 of the present invention is provided (b) Partial enlarged view of plane (c) Partial enlarged view of modification Structure explanatory drawing of the air heating device with which the seaweed maker in Embodiment 2 of this invention is equipped.

(Embodiment 1)
First, with reference to FIGS. 1 and 2, a seaweed maker according to Embodiment 1 of the present invention will be described. The seaweed maker 1 is for manufacturing a thin sheet of dry seaweed, and includes a front stage 2 and a drying chamber 3 arranged behind the front stage 2 (on the right side of the paper in FIG. 1). The seaweed making machine 1 is installed in a hut 4 shown in FIG. The front part 2 includes an endless chain 5, and a papermaking part 6, a dehydrating part 7, a stripping part 8 and a cleaning part 9 arranged along the endless chain 5.

  The endless chain 5 functions as a conveying unit that conveys the frame-shaped cage holder 11 holding a plurality of cages 10 shown in FIG. 3 to the paper making section 6, the dehydrating section 7, the stripping section 8, and the cleaning section 9. The transporting means may have various structures. Hereinafter, the direction in which the endless chain 5 conveys the cage holder 11 from the papermaking section 6 to the dehydration section 7 (the left-right direction on the paper surface of FIG. 1) is the X direction, and the direction orthogonal to the X direction in the horizontal plane (FIG. 2). The horizontal direction of the paper surface is defined as the Y direction, and the height direction orthogonal to the XY plane (the vertical direction of the paper surface of FIG. 1) is defined as the Z direction.

  The paper making unit 6 makes raw seaweed w (see FIGS. 2 and 3) on the cage 10. In this specification, the operation of making raw seaweed w into paper is referred to as "papermaking". The dehydrating unit 7 dehydrates the raw seaweed w produced on the cage 10 by air suction and then further press dehydrates. As a result, the raw seaweed w on the cage 10 is formed into a sheet.

  The cage holder 11 holding the dehydrated raw seaweed w is moved from the front part 2 to the drying chamber 3. In the drying chamber 3, a plurality of (in this case, two) endless chains 12 are arranged at predetermined intervals in the vertical direction. Transfer to the endless chain 12 of. At this time, the cage holder 11 is carried in between a plurality of skeletons 12a erected on the endless chain 12 (arrow a1), and in this state, inside the drying chamber 3, the upper endless chain 12 and the lower endless chain 12 are separated. They are conveyed in order (arrows a2 to a5). During this time, the raw seaweed w on the cage 10 is exposed to high-temperature air to be dried. The cage holder 11 holding the dried seaweed (dry seaweed) is transferred from the lower endless chain 12 to the endless chain 5 of the front part 2 (arrow a6) and conveyed to the stripping part 8. The stripping section 8 strips the sheet-shaped dry seaweed from the cage 10. The cleaning unit 9 cleans the cage 10 from which the dry seaweed has been stripped off. The cage holder 11 holding the washed cage 10 is conveyed to the paper making section 6 again (arrow a7).

  In FIG. 2, a first opening 13 is formed along the longitudinal direction of the endless chain 12 at a position below the side wall 3a of the drying chamber 3 and below the lower endless chain 12. There is. Air heated by a heating device 17 described below (hereinafter, referred to as “heated air”) is fed to the drying chamber 3 through the first opening 13. The raw seaweed w is gradually dried while being conveyed by the endless chain 12 while being exposed to the heated air.

  In this way, the seaweed making machine 1 includes the papermaking section 6 for making raw seaweed w on the cage 10 of the cage holder 11 holding a plurality of cages 10, and the raw seaweed produced by the papermaking section 6. Dewatering unit 7 for dehydrating w, drying unit (drying chamber 3) for drying raw seaweed w dehydrated by the dehydrating unit 7, and air heating unit (heating device for generating heated air and supplying it to the drying unit). 17) and a stripping section 8 for stripping dried dry seaweed from the cage 10.

  Next, the structure of the hut 4 will be described with reference to FIG. A plurality of (two in this case) exhaust fans 14 as first fans are installed on the ceiling of the hut 4. The exhaust fan 14 discharges the heated air blown up from the drying chamber 3 to the outside. The discharged heated air has high humidity because it contains the moisture taken from the raw seaweed w. An outside air introduction port 15 is provided on one side wall 4a of the hut 4, and in winter, outside air having a low temperature and low humidity is introduced into the hut 4 through the outside air introduction port 15 (arrow b).

  2 and 4, inside the cabin 4, at a position adjacent to the drying chamber 3 with the side wall 3a of the drying chamber 3 interposed therebetween, a space 16 for heating air to be fed to the drying chamber 3 is provided. It is provided. The space 16 is partially surrounded by a plurality of walls including a side wall 3a of the drying chamber 3 and an inner wall 4b provided in the cabin 4 at a predetermined distance from the side wall 3a. A main part of the heating device 17 is arranged in this space 16. FIG. 4 schematically shows the KK cross section shown in FIG. 2 and 4, the heating device 17 has a function of supplying heated air to the drying chamber 3, and includes a burner 18, a first pipe 19A bent in a U shape in a side view, and a first pipe 19A. The second pipe 19B is connected to the first pipe 19A through the connecting portion 20 and is bent at a plurality of locations, and a plurality of (here, three) intake fans 21 as a second fan are configured. It

  The burner 18 constitutes a combustion gas generation unit that combusts heavy oil, kerosene, gas fuel or the like to generate high temperature combustion gas, and has a discharge port 18a for discharging the combustion gas. The discharge port 18a communicates with the first pipe 19A. The first tube 19A is formed of a metal having a high thermal conductivity, and forms a passage (flow passage) for the combustion gas generated by the burner 18. The first pipe 19A is configured by connecting a plurality of pipes that are parallel in the vertical direction. As shown in FIG. 5, the flow path of the combustion gas in the first pipe 19A has a first section A extending in the X direction below the space 16 and a second section extending upward from the end of the first section A. It is divided into a section B and a plurality of (here, two) third sections C branched from the end of the second section B into a plurality (here, two hands) and folded back along the first section A. It should be noted that the number of pipes arranged above the first section A may be one, and in this case, there is only one third section C. The end of the first pipe 19A corresponding to the third section C extends from one side of the side wall 3a (that is, the space 16) to an outer position (FIG. 4), and at that position, the first end of the first pipe 19A is connected via the connecting portion 20. It is connected to the second pipe 19B. The surface of the first tube 19A becomes hot due to the combustion gas supplied therein.

  The second pipe 19B guides the combustion gas that has passed through the first pipe 19A and the connecting portion 20 to the chimney 22. As shown in FIG. 5, the flow path of the combustion gas in the second pipe 19B is a fourth section D that extends upward from the connecting portion 20, and a fifth section E that extends substantially horizontally from the end of the fourth section D. Then, the fifth section E is divided into a sixth section F reaching the chimney 22. The dashed-dotted line Q shown in FIGS. 4 and 5 illustrates the boundary between the second tube 19B and the chimney 22. The combustion gas discharged from the discharge port 18a of the burner 18 passes through the first section A to the sixth section F in this order (see a plurality of arrows shown in FIG. 5). The chimney 22 has a discharge port 22a arranged outside the hut 4, and the combustion gas guided to the chimney 22 from the second pipe 19B goes out of the hut 4 (that is, the drying chamber 3) through the discharge port 22a. Discharge. As described above, the pipe including the first pipe 19A and the second pipe 19B guides the combustion gas generated by the combustion gas generation means to the discharge port for discharging the combustion chamber 3 to the outside. Note that the combustion gas may be guided to the chimney 22 not by a plurality of tubes but by a single tube.

  In FIG. 4, the plurality of intake fans 21 are arranged in parallel in the X direction above the first tube 19A, and suck the air in the cabin 4 to arrange the first tube 19A in the arrangement direction ( Here, it is sprayed downward (arrow c). The air blown to the first tube 19A draws heat from the combustion gas existing inside the first tube 19A to become a high temperature. As a result, heated air is generated, and thereafter, the heated air is fed to the lower part of the drying chamber 3 through the first opening 13 by the intake fan 21 (arrow d). Further, the combustion gas deprived of heat is discharged from the chimney 22 to the outside of the hut 4 as used exhaust gas.

  As shown in FIG. 2, the heated air sent to the drying chamber 3 from the space 16 in which the heating device 17 is arranged is blown up (arrow e), and removes water from the raw seaweed w spread on the cage 10. A part of the heated air that has blown up is discharged to the outside of the hut 4 by the exhaust fan 14 (arrow f). A second opening 23 for connecting the drying chamber 3 and the space 16 is formed above the side wall 3a of the drying chamber 3. A part of the heated air blown up in the drying chamber 3 is returned to the space 16 through the second opening 23 (arrow g).

  2 and 4, a duct 24 extending in the X direction is provided above the intake fan 21. In FIG. 4, above one end of the duct 24 and above the second pipe 19B corresponding to the fifth section E, an opening 24a for taking in air that has entered the hut 4 through the outside air inlet 15. Are formed. A plurality of openings 24b are formed on the lower surface of the duct 24 that faces the intake fan 21. The air in the hut 4 is sent to the duct 24 from the opening 24a (arrow h shown in FIG. 4), and is further sent to the space 16 (above the intake fan 21) via the opening 24b (see FIG. 4). Indicated arrow i). Therefore, the intake fan 21 blows the air sent to the space 16 through the duct 24 and a part of the heated air sent from the drying chamber 3 toward the first tube 19A. As described above, a part of the second pipe 19B which is a passage for combustion gas (exhaust gas) and a part of the duct 24 which is a passage for air to be heated by the heating device 17 are arranged in the vertical direction (horizontal direction). May be) adjacent to each other.

  In FIG. 4, a heat recovery device 30 is provided at a position apart from the space 16 in the hut 4. The heat recovery device 30 has a function of removing heat from the combustion gas (exhaust gas) in the second pipe 19B and recovering it, and heating the air sent to the duct 24 by the recovered heat. That is, the seaweed making machine 1 includes an air heating unit (heating device 17) that generates heated air and supplies the heated air to the drying unit. Then, the air heating unit (heating device 17) discharges the combustion gas generating means (burner 18) for generating combustion gas and the combustion gas generated by the combustion gas generating means to the outside of the drying unit (drying chamber 3). Heat for recovering heat from the pipes (first pipe 19A and second pipe 19B) leading to the exhaust port 22a and the combustion gas supplied to the pipes, and warming the air taken in from outside the drying unit by the recovered heat The recovery device 30 and a heating air supply means (a fan for intake air) that blows air warmed by the heat recovery device 30 onto a pipe (first pipe 19A) and supplies the heating air generated thereby to the drying unit. 21) and are provided.

  Next, the detailed structure of the heat recovery device 30 will be described with reference to FIGS. 6(a), 6(b) and 6(c). It should be noted that FIG. 6C shows a cross section taken along line S-S shown in FIG. The heat recovery device 30 has a housing 31 as a main body, and a plurality of tubular members 32 extending in the vertical direction (Z direction) are erected therein in a staggered arrangement. The tubular member 32 has a closed space extending in the longitudinal direction inside thereof (so-called hollow), and the heat medium is stored in the space inside the tubular member 32. The tubular member 32 is formed of a metal having a high thermal conductivity. The plurality of tubular members 32 may be provided so as to extend in a direction other than the direction perpendicular to the horizontal plane, and may be an array other than the staggered array.

  4, in the heat recovery device 30 according to the first embodiment, the upper part of the housing 31 covers the entire surface of the opening 24a of the duct 24, and the lower part of the housing 31 corresponds to the fifth section E. It is attached so as to cover a space provided by removing a part of the tube 19B. The housing 31 is provided with a partition plate 33 for partitioning a flow path of air sent to the duct 24 and a flow path of combustion gas sent to the second pipe 19B, and the tubular member 32 is a partition plate 33. Is vertically penetrated. This prevents the air sent to the duct 24 from entering the second pipe 19B or the exhaust gas (combustion gas) in the second pipe 19B from entering the duct 24. In the present embodiment, the partition plate 33 is arranged horizontally. Hereinafter, a portion of the housing 31 below the partition plate 33 will be referred to as a “lower portion 31a of the housing 31”, and a portion of the housing 31 above the partition plate 33 will be referred to as an “upper portion 31b of the housing 31”. The lower part 31a and the upper part 31b of the housing 31 may be prepared as separate bodies, and the upper part of the lower part 31a and the lower part of the upper part 31b may be joined together to form one housing 31.

  In FIG. 6A, in the front-rear direction of the lower portion 31a of the housing 31 (the left-right direction of the paper surface in FIGS. 4 and 6), a combustion gas introduction pipe 34A having both ends opened and a combustion gas discharge pipe 34A are formed. 34B are provided respectively. One end 34Aa of the pipe 34A for introducing the combustion gas is connected to the end of the cut second pipe 19B on the upstream side (the left side of the paper in FIGS. 4 and 6). Further, one end 34Ba of the combustion gas discharge pipe 34B is connected to the cut end portion of the second pipe 19B on the downstream side (on the right side of the paper in FIGS. 4 and 6). Further, the front-rear surface of the lower portion 31a of the housing 31 is open in a region facing the other end 34Ab of the combustion gas introduction pipe 34A and the other end 34Bb of the combustion gas discharge pipe 34B. The region from the partition plate 33 to the other end 34Ab of the combustion gas introduction pipe 34A and the region from the partition plate 33 to the other end 34Bb of the combustion gas discharge pipe 34B are closed. Exist). That is, the pipe 34A for introducing the combustion gas, the pipe 34B for exhausting the combustion gas, and the lower portion 31a of the housing 31 are replaced by the removed second pipe 19B, and are left behind without being removed. A flow path for combustion gas connected to the pipe 19B is formed. Thereby, the combustion gas can be guided to the chimney 22 without leaking to the hut 4.

  As shown in FIG. 6A, in the upper portion 31b of the housing 31, one surface G1 that faces the opening 24a of the duct 24 and the other surface G2 that is the opposite side thereof are open. There is. Therefore, the air in the hut 4 is taken into the upper portion 31b of the housing 31 from the other surface G2 side and further sent into the duct 24. That is, the other surface G2 is an air intake surface. In the upper portion 31b of the housing 31, a feeding fan 37 as a third fan, which rotates around a rotation boss 36 whose axis 35 is horizontal, is located inside the duct 24 on one surface G1 side. It is provided in the state. The fan 37 for sending in forcibly sends the air in the hut 4 into the duct 24. The feeding fan 37 is not limited to the above-described configuration, and may be, for example, a sirocco fan, or may be provided on the other surface G2 side of the upper portion 31b of the casing 31 or the casing 31. It may be provided in the duct 24 apart from the upper portion 31b.

  In FIG. 6A, a portion of the tubular member 32 extending downward from the partition plate 33 (hereinafter, referred to as a “lower portion 32a of the tubular member 32”) reaches the inside of the flow path of the combustion gas. That is, from the front surface of the lower portion 31a of the casing 31 facing the other end 34Ab of the combustion gas introduction pipe 34A, to the lower portion 31a of the casing 31 facing the other end 34Bb of the combustion gas discharge pipe 34B. Between the rear surfaces is a passage portion which is a passage for the combustion gas through which the combustion gas flows, and the lower portion 32a of the tubular member 32 is located inside the passage portion. Therefore, the lower portion 32a of the tubular member 32 is exposed to the combustion gas (exhaust gas) and directly receives heat from the combustion gas. That is, the lower portion 32a of the tubular member 32 is provided on the passage through which the combustion gas supplied to the pipes (the first pipe 19A and the second pipe 19B) is directed to the discharge port 22a (of the chimney 22), It constitutes a heat receiving part that receives heat from. When the lower portion 32a of the tubular member 32 receives heat from the combustion gas, the heat medium contained in the tubular member 32 boils and changes from liquid to gas. In the first embodiment, the boiling point of the heat medium is lowered by depressurizing the inside of the tubular member 32, whereby the heat medium is efficiently vaporized.

  A portion of the tubular member 32 extending upward from the partition plate 33 (hereinafter, referred to as “upper portion 32b of the tubular member 32”) reaches a height position facing the opening 24a of the duct 24. Therefore, the upper portion 32b of the tubular member 32 is exposed to the air in the hut 4. The heat medium that has become a gas by receiving heat from the combustion gas in the lower portion 32a of the tubular member 32 moves to the upper portion 32b of the tubular member 32, releases the heat to the surrounding air, and then condenses into a liquid. Change. That is, the upper portion 32b of the tubular member 32 constitutes a heat radiation portion that releases the heat received by the heat receiving portion (lower portion 32a of the tubular member 32) to the air taken in from the outside of the drying portion (drying chamber 3). The heat medium that has returned to the liquid flows back from the upper portion 32b of the tubular member 32 to the lower portion 32a of the tubular member 32. That is, the heat medium is housed in a sealed tubular member that extends between the heat receiving portion and the heat radiating portion, and the heat recovery device 30 is received by the heat receiving portion by the movable heat medium between the heat receiving portion and the heat radiating portion. Transfers heat to the heat sink. In this way, by transmitting heat by the heat medium, heat can be efficiently transmitted from the heat receiving portion to the heat radiating portion.

  In the upper portion 32b of the tubular member 32, a plurality of flat plate-shaped radiating fins 38 that spread in the horizontal direction are arranged at predetermined intervals in the vertical direction. An opening (not shown) corresponding to the cross-sectional shape of the tubular member 32 is formed in each radiating fin 38, and the upper portion 32b of the tubular member 32 is inserted into the radiating fin 38. As a result, the tubular member 32 and the radiation fin 38 are joined together without any gap so that heat is conducted from the upper portion 32b of the tubular member 32 to the radiation fin 38. That is, the heat radiating portion (upper portion 32b of the tubular member 32) has a fin for heat radiation (radiating fin 38). As a result, the effective area in which the heat radiating portion contacts the air can be increased, and the heat can be efficiently radiated from the heat radiating portion to the surrounding air. In addition, the shape and the attachment mode of the heat radiation fin 38 may be arbitrary.

  In FIG. 6 and FIG. 7, a plurality of (in this case, four) straightening vanes 39 are provided on the air intake surface side of the upper portion 31 b of the housing 31. FIG. 7B shows a TT cross section (FIG. 7A) when the air intake surface is viewed from the front. Further, in FIG. 7A, the tubular member 32 and the radiation fins 38 are not shown for convenience. In FIG. 7A, the plurality of straightening vanes 39 are arranged in a substantially X shape when the air intake surface is viewed from the front. In the air intake surface, the center 40 of the area surrounded by the plurality of flow regulating plates 39 is located substantially on the same straight line as the axis 35 of the rotary boss 36. In FIG. 7B, the current plate 39 includes a standing portion 39a standing upright to the air intake surface, and a bent portion 39b bent from an end of the standing portion 39a opposite to the outside air intake surface. Composed. The bent portions 39b are provided so as to face the same circumferential direction with respect to the center 40.

  The air blown into the air intake surface by the blow-in fan 37 is rectified by the plurality of rectifying plates 39 so as to be dispersed and flow evenly over the entire air intake surface. That is, the seaweed making machine 1 is equipped with an air feeding means (a fan 37 for feeding as a third fan) that feeds air to the heat radiating portion (the upper portion 32b of the tubular member 32), and a plurality of rectifiers are provided. The plate 39 serves as a rectifying unit that regulates the flow of air sent to the heat radiating unit by the air sending unit. As a result, the air sent to the upper portion 32b of the tubular member 32 is not biased to the air intake surface, and evenly hits the upper portion 32b of the tubular member 32 and all the radiating fins 38. The efficiency of releasing heat to is improved. The rectifying means is not limited to the above-described configuration using the rectifying plate 39, and may be any one as long as it regulates the flow of the air sent to the heat radiating portion by the sending fan 37. It may be installed on the fan 37 side.

  Next, a specific operation of the heat recovery device 30 will be described. While the combustion gas (exhaust gas) passes through the second pipe 19B, the lower portion 32a (heat receiving portion) of the tubular member 32 receives heat from the combustion gas. Due to the received heat, the heat medium stored inside the tubular member 32 rises in temperature and is vaporized (evaporated) when it reaches the boiling point.

  The vaporized heat medium moves (raises) to the upper portion 32b (heat dissipation portion) of the tubular member 32. The upper portion 32b of the tubular member 32 and the heat radiation fin 38 receive heat from the heat medium and radiate the heat to the surrounding air. As a result, the air passing through the upper portion 31b of the housing 31 is heated by the upper portion 32b of the tubular member 32 and the heat radiation fins 38 and sent into the duct 24. The heat medium that has transferred the heat condenses and returns to liquid, and falls to the lower portion 32 a of the tubular member 32. By adopting such a structure, heat can be recovered from the used combustion gas (exhaust gas) and reused with a simple structure.

  As described above, the heat recovery device 30 includes a passage portion that is a passage for the combustion gas, a heat receiving portion (a lower portion 32a of the tubular member 32) that receives heat from the combustion gas, the passage portion being provided inside the passage portion. A heat dissipating portion (an upper portion 32b of the tubular member 32) that is provided outside and releases the heat received by the heat receiving portion to the surroundings, recovers the heat from the combustion gas in the passage portion, and collects the heat from the outside of the passage portion. Warm the ambient air at. Since the heat recovery device 30 has a structure in which the heat receiving portion and the heat radiating portion are integrally arranged in the housing 31, it can be easily attached to the flow path of the combustion gas. For example, in the case of the laver making machine 1 shown in FIG. 4, an opening for accommodating the housing 31 is provided in the upper part of the second tube 19B, and the heat recovery device 30 can be easily installed by inserting the opening from above. it can.

  Further, the heat recovery device 30 provided with the fan 37 (air supply means) for sending in serves as a warm air generator that recovers heat from the combustion gas in the passage portion and warms the air by the recovered heat to supply the air. .. The gas from which heat is recovered in the heat recovery device 30 and the warm air generator is not limited to the combustion gas obtained by burning the fuel, but may be the gas heated by the electric heater.

  By the way, when heavy oil is burned by the burner 18, the combustion gas produced contains impurities such as soot and sulfur which are fine particles of carbon. When the combustion gas containing impurities is continuously supplied from the burner 18 to the pipes (the first pipe 19A and the second pipe 19B), the impurities are accumulated on the outer peripheral surface of the lower portion 32a of the tubular member 32 and the like. The accumulated impurities hinder the flow of the combustion gas and reduce the efficiency of heat transfer to the tubular member 32, and therefore need to be removed regularly.

  Therefore, as shown in FIG. 6A, a plate-shaped member 41 formed of metal or the like is mounted in a lower portion 32a (heat receiving portion) of the plurality of tubular members 32 so as to be vertically movable (arrow j). In FIGS. 8A and 8B, the plate member 41 has through holes 41 a formed at positions corresponding to the arrangement of the plurality of tubular members 32. The inner diameter of the through hole 41a is set to be slightly larger than the outer diameter of the tubular member 32, so that the plate member 41 can move up and down with respect to the lower portion 32a of the tubular member 32. The plate member 41 is connected to an elevating body (not shown) screwed to a ball screw (not shown) extending in the ascending/descending direction (here, the vertical direction) of the plate member 41. The plate-shaped member 41 moves up and down by the rotation of a ball screw driven by a drive motor (not shown).

  By moving the plate member 41 up and down, the impurities that have slid on the outer periphery of the tubular member 32 and accumulated in the lower portion 32a of the tubular member 32 are removed by the inner peripheral surface of the through hole 41a. That is, the plate member 41 becomes a sliding member that slides on the outer periphery of the tubular member 32. Further, as in the modified example shown in FIG. 8C, by implanting the fibrous brush 42 on the inner peripheral surface of the through hole 41a and sliding the brush 42 on the outer peripheral surface of the lower portion 32a of the tubular member 32. The impurities may be removed. Thereby, the impurities can be removed more reliably. That is, the brush 42 becomes a sliding member that slides on the outer periphery of the tubular member 32. Further, one side plate that constitutes the lower portion 31a of the housing 31 is made slidable, and the plate-like member 41 is connected to this side plate. During maintenance work, the worker slides the side plate to move the plate-like member 41 up and down. By doing so, the impurities may be removed. In this case, a lifting mechanism such as a ball screw or a drive motor is unnecessary. As described above, the plate-shaped member 41 serves as an impurity removing unit that removes impurities attached to the lower portion 32a (heat receiving portion) of the tubular member 32, and the impurity removing unit slides on the outer periphery of the tubular member 32. It has a sliding member. Thereby, the impurities accumulated in the lower portion 32a of the tubular member 32 can be easily removed. The impurity removing means is not limited to the above configuration. That is, it is only necessary to remove impurities adhering to the heat receiving portion, and for example, high pressure air may be blown to remove impurities.

  As described above, the seaweed maker 1 of the present embodiment includes the heating device 17 that generates heated air and supplies the heated air to the drying chamber 3. Then, the heating device 17 is a pipe (first pipe 19A) for guiding combustion gas generating means (burner 18) for generating combustion gas and a discharge port (chimney 22) for discharging the generated combustion gas to the outside of the drying chamber 3. And a second pipe 19B), a heat recovery device 30 for recovering heat from the combustion gas supplied to the pipe and warming the air taken in from the outside of the drying chamber 3 by the recovered heat, and the heated air for the pipe. The heating air supply means (the intake fan 21 as the second fan) for supplying the heating air generated by spraying to the drying chamber 3 to the drying chamber 3.

  Then, the heat recovery device 30 of the present embodiment is provided on a path through which the combustion gas supplied to the pipe is directed to the chimney 22, and a heat receiving portion (a lower portion 32a of the tubular member 32) that receives heat from the combustion gas, The heat receiving portion includes a heat radiating portion (upper portion 32b of the tubular member 32) that releases the heat received by the heat receiving portion to the air taken in from the outside of the drying chamber 3. As a result, heat can be recovered from the used combustion gas and reused with a simple structure.

(Embodiment 2)
Second Embodiment Next, a second embodiment of the present invention will be described with reference to FIG. The same components as those described in the first embodiment are designated by the same reference numerals and the description thereof will be omitted. The second embodiment and the first embodiment are different from each other in the structure of the pipe forming the passage (flow passage) of the combustion gas.

  The second pipe 190B guides the combustion gas that has passed through the first pipe 19A and the connecting portion 20 to the third pipe 190C. That is, one end of the second pipe 190B is connected to the connecting portion 20, and the other end is connected to one end of the third pipe 190C. The alternate long and short dash line R1 shown in FIG. 9 illustrates the boundary between the second tube 190B and the third tube 190C. The third pipe 190C is arranged between the intake fan 21 and the duct 24, and the other end thereof is connected to one end of a combustion gas introduction pipe 34A included in the heat recovery device 30. .. The dashed-dotted line R2 shown in FIG. 9 illustrates the boundary between the third tube 190C and the chimney 220. On the surface of the third tube 190C, a plurality of fins 200 are provided at a predetermined pitch in the horizontal direction.

  The other end of the combustion gas introduction pipe 34A communicates with one end of a combustion gas discharge pipe 34B through the lower portion 31a of the housing 31. The other end of the combustion gas discharge pipe 34B is connected to a chimney 220 having a discharge port 220a located outside the hut 4. The dashed-dotted line R3 shown in FIG. 9 illustrates the boundary between the pipe 34B for discharging the combustion gas and the chimney 220.

  The air sent to the duct 24 (arrow k) is warmed to a predetermined temperature by the heat recovery device 30 as in the first embodiment, and the warmed air goes from the opening 24b of the duct 24 to the intake fan 21. (Arrow l). The warm air toward the intake fan 21 is further heated to a predetermined temperature via the third pipe 190C and the fins 200 heated by the combustion gas, and then sucked into the intake fan 21. As described above, according to the second embodiment, the heat of the combustion gas can be used more effectively to warm the air in the cabin 4. Further, by providing the plurality of fins 200 on the third tube 190C, it is possible to increase the heat transfer area and further improve the efficiency of heat exchange.

  The seaweed making machine 1 and the heat recovery device 30 of the present invention are not limited to the embodiments described so far, and can be appropriately changed without departing from the spirit of the invention. In particular, the use of the heat recovery device 30 is not limited to the seaweed producing machine 1, and may be any application for recovering heat from a high temperature gas such as combustion gas to generate warm air. For example, it is also possible to collect heat from combustion gas that warms a greenhouse that cultivates vegetables and flowers and to cultivate fish to generate hot air separately, and use it to heat a house attached to the vinyl house.

  INDUSTRIAL APPLICABILITY The seaweed maker and the heat recovery device of the present invention can recover heat from used combustion gas and reuse it with a simple structure, and are useful in the field of seaweed production and the so-called environmental technology field of reusing heat energy.

1 Nori making machine 3 Drying room (drying section)
5 Endless chain (transportation means)
6 Papermaking part 7 Dehydration part 8 Stripping part 10 Chest 11 Chest holder 12 Endless chain 17 Heating device (air heating part)
18 burners (combustion gas generation means)
19A First tube (tube)
19B, 190B Second tube (tube)
21 Intake fan (heated air feeding means)
22a, 220a Discharge port 30 Heat recovery device 32 Tubular member 32a Lower part of tubular member (heat receiving part)
32b Upper part of tubular member (heat dissipation part)
37 Fan for feeding (air feeding means)
38 Radiating fins
39 Rectifier plate (rectifier means)
41 Plate-shaped member (impurity removing means, sliding member)
42 Brush (sliding member)
w Raw seaweed

Claims (7)

A passage portion which is a passage for combustion gas,
A tubular member in which a heat medium is housed in an internal space,
The lower portion of the tubular member is located inside the passage portion and constitutes a heat receiving portion that receives heat from the combustion gas,
The upper portion of the tubular member is located outside the passage portion, and constitutes a heat dissipation portion that releases the heat received by the heat receiving portion to the surroundings,
A heat recovery device, wherein heat is recovered from the combustion gas, and ambient air outside the passage is warmed by the recovered heat. The heat recovery device further includes a housing in which the tubular member is provided,
The casing is provided with a partition plate for partitioning a flow path of air sent into a duct into which the air heated by the heat dissipation section is sent and a flow path of the combustion gas sent to the passage section. The heat recovery device according to claim 1, wherein the heat recovery device is provided.   The heat recovery device according to claim 1 or 2, further comprising an air supply unit that supplies air to the heat dissipation unit.   The heat recovery device according to claim 3, further comprising: a rectifying unit that regulates a flow of the air supplied to the heat radiating unit by the air supplying unit. The combustion gas contains impurities,
The heat recovery device according to claim 1, further comprising an impurity removing unit that removes the impurities attached to the heat receiving portion.   6. The heat according to claim 1, wherein the heat medium movable between the heat receiving unit and the heat radiating unit transfers the heat received by the heat receiving unit to the heat radiating unit. Recovery device.   The heat recovery device according to claim 5 or 6, wherein the impurity removing means includes a sliding member that slides on the outer periphery of the tubular member.

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