JP2013190152A - Rotary spiral blade device and smoke-tube type heat exchanger of pellet combustor using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent increase of rotary torque of a spiral blade and damage of the spiral blade and a rotary driving mechanism due to an anchoring layer of fly ash and powder and granular material formed on an inner wall of a cylindrical tube.SOLUTION: A rotary spiral blade device includes a spiral blade 51 rotatably inserted into a cylindrical tube 4, and a driving mechanism 11 rotatably supporting the spiral blade 51, and rotating and driving it. The spiral blade 51 has the shape formed by spirally disposing a band plate 52 around a spiral axis along the longitudinal direction of the band plate, and supported by the driving mechanism 11 rotatably on the spiral axis as a rotating axis O, a blade radius Da of a first piece blade 51a at one side from the rotating axis O to a blade tip, of a blade diameter D at an optional position orthogonal to the rotating axis O of the spiral blade 51, is formed with a set clearance gap with respect to an inner wall of the cylindrical tube 4, and a blade radius Db of a second piece blade 51b at the other side, is formed shorter than the blade radius Da.

Description

  The present invention relates to a rotary spiral blade device, for example, a rotary spiral blade device used in a flue-tube heat exchanger that recovers combustion heat of a wood-based pellet combustor, a screw feeder that transfers powder particles, and the like. The present invention relates to a rotating spiral blade device.

  For example, Patent Document 1 discloses that a dilute solution of an absorption chiller / heater is heated to a concentrated solution by the combustion heat of a pellet combustor using woody biomass fuel (hereinafter referred to as woody pellet fuel) as fuel. Smoke-tube heat exchangers have been proposed for use as heat sources for regenerating high temperature regenerators. Specifically, a smoke tube heat exchanger with a structure in which a plurality of smoke tubes, which are heat transfer tubes that distribute the combustion exhaust gas of the pellet combustor, are arranged horizontally in a high-temperature regenerator where a dilute solution is introduced. Has been. In particular, in order to improve heat exchange with the dilute solution of the absorbent, a baffle plate consisting of spiral blades with twisted strips is inserted in the smoke tube along the gas flow direction, and the combustion exhaust gas is swirled and stirred by the baffle plate. It has been proposed to let

JP 2009-236322 A

  On the other hand, in Patent Document 1, since the flow rate of combustion exhaust gas in the smoke pipe of the smoke tube heat exchanger is low, fly ash composed of ash and dust in the wood pellet fuel exhaust gas accumulates in the smoke pipe and performs heat exchange. In view of the reduction in efficiency, it has been proposed to make the structure in which fly ash is difficult to accumulate in the smoke pipe. However, the technique described in the document may not always be sufficient to avoid a decrease in heat exchange efficiency due to fly ash accumulated in the smoke pipe.

  Therefore, it is conceivable to insert the spiral blade into the smoke tube so that the spiral blade is wound around the rotational axis or the spiral blade is wound around the rotational axis. According to this, since the fly ash accumulated in the smoke pipe by the rotation of the spiral blade can be transferred to one end of the smoke pipe and discharged, a decrease in heat exchange efficiency due to the accumulated fly ash can be avoided.

  However, when the moisture in the smoke tube condenses when the operation of the pellet combustor is stopped, the fly ash adhering to the inner surface of the smoke tube becomes a paste due to the dew condensation water and may harden like cement. When such a hardened fly ash sticky layer is formed on the inner wall of the smoke pipe, the tip of the spiral blade rotates in contact with the sticky layer, so that the friction between them increases and the spiral blade rotates. There is a problem that the load torque of the drive mechanism increases. In addition, if a foreign object is caught between the tip of the spiral blade and the fixed layer, the load torque is suddenly increased and the rotary drive mechanism may be damaged, or the spiral blade itself may be damaged.

  This will be described with reference to FIG. 3, as described in Patent Document 1, a spiral blade 101 formed by twisting a strip in a spiral shape is rotatably inserted into a smoke tube 102 that is a cylindrical tube, and the spiral blade 101 is orthogonal to the rotation axis O. The blade | wing cross section 103 cut | disconnected by the surface to perform is shown. The blade cross section 103 is a rectangular cross section symmetrical to the rotation axis O. The rotational axis O coincides with the spiral axis Os that is the twist axis of the spiral blade 101. The spiral axis Os in the illustrated example is a line along the longitudinal direction of the strip passing through the geometric center of the rectangular cross section in the plate width direction of the strip, that is, the intersection of the diagonal lines of the rectangular cross section. Here, when the spiral blade 101 is rotated in the smoke tube 102 and used, for example, when the operation of the high-temperature regenerator is stopped, the moisture in the smoke tube 102 is condensed, and the fly ash adhering to the inner surface of the smoke tube by the condensed water is generated. It may become a paste and harden. In this case, the hardened fly ash fixed layer 105 is formed on the inner wall surface of the smoke tube 102, and rotates in the direction of the arrow 106, for example, in a state where the tip of the spiral blade 101 is in contact with the fixed layer 105. Therefore, the friction between the tip of the spiral blade 101 and the fixed layer 105 is increased, and the load torque of the rotational drive mechanism of the spiral blade 101 is increased. In addition, if the foreign matter 107 is caught between the tip of the spiral blade 101 and the fixed layer 105, the load torque is suddenly increased, which may damage the rotational drive mechanism or damage the spiral blade 101 itself.

Such a problem is not limited to the rotating spiral blade device applied to the smoke tube heat exchanger, but a rotating spiral blade such as a screw feeder that rotates the spiral blade inserted into the cylindrical tube to transfer the granular material. The same applies to the apparatus. That is, when the granular material is made into a paste by condensed water or the like, a fixed layer of the granular material may be formed on the inner wall of the cylindrical tube in which the spiral blade is inserted, and the friction between the spiral blade and the fixed layer increases. To do. In addition, if a foreign object is caught between the tip of the spiral blade and the fixed layer, the load torque is suddenly increased and the rotary drive mechanism may be damaged, or the spiral blade itself may be damaged.

  The problem to be solved by the present invention is that in a rotating spiral blade device formed by inserting a rotationally driven spiral blade into a cylindrical tube, a fixed layer of fly ash or granular material formed on the inner wall of the cylindrical tube It is to prevent an increase in the rotational torque of the spiral blade, damage to the spiral blade, and damage to the rotary drive mechanism.

  In order to solve the above problems, a rotating spiral blade device of the present invention comprises a spiral blade that is rotatably inserted into a cylindrical tube, and a drive mechanism that rotatably supports and rotates the spiral blade. The spiral blade has a shape in which the strip is spirally wound around a spiral axis along the longitudinal direction of the strip, and the spiral shaft is rotatably supported by the drive mechanism as a rotation axis O. Of the blade diameter D in the cross section orthogonal to the rotation axis O of the spiral blade, the blade radius Da of one first blade from the rotation axis O to the blade tip is between the inner wall of the cylindrical tube. The blade gap radius Db of the other second single blade is formed to be shorter than the blade radius Da of the first single blade.

  According to the rotary spiral blade device of the present invention having such a rotary spiral blade, the dew condensation is caused by the tip of the first single blade in which a set gap (initial clearance) is formed between the inner wall of a cylindrical tube such as a smoke tube. Even if powder fluid such as fly ash that has been made into a paste by water is applied to the inner wall surface of the cylindrical tube and hardened, the blade radius Db of the second single blade is the blade radius Da of the first single blade. Therefore, the second single blade does not come into contact with the fixed layer of the hardened powder fluid. As a result, since the tip of the spiral blade comes into contact with the fixed layer and the frictional force is generated only on the first single blade side, the increase in rotational torque can be halved. Further, even when the fly ash fixing layer is not formed, the spiral blades supported by the drive mechanism in a cantilever manner are always formed on the inner wall of the cylindrical tube by the first single blades having the blade radius Da formed in the axial direction. Rotate in contact. On the other hand, since the second single blade having the blade radius Db rotates without contacting the inner wall of the cylindrical tube, the frictional force between the spiral blade and the cylindrical tube can be reduced, and the load rotational torque can be constantly reduced.

  Further, in the state where the fixed layer is formed on the inner wall surface of the cylindrical tube, according to the conventional spiral blade, there is no gap (clearance) between the blade and the fixed layer. If sandwiched between the tip and the fixing layer, the spiral blade is difficult to rotate. In this regard, according to the first aspect of the present invention, since the first single blade having a large diameter is formed on the upper side and the lower side of the rotating shaft for each axial position where the phase of the twist angle differs by 180 °, for example, the upper side When a foreign object is caught in the gap between one tip of the first single blade located at the position and the fixing layer, the tips of the two first single blades adjacent to each other in the axial direction are in sliding contact with the lower fixing layer. . The two first single blades adjacent to each other serve as fulcrums, and the spiral blade is bent toward the lower second single blade side by the force acting on the first single blade that has bitten the foreign matter. A gap between the tip of one blade and the fixing layer is widened, and the foreign object can be overcome. As a result, it is possible to prevent damage to the spiral blades and damage to the rotary drive mechanism due to the fixed layer of fly ash and powder formed on the inner wall of the cylindrical tube.

  In this case, the spiral axis can be set inside the rectangular cross section orthogonal to the longitudinal direction of the strip, for example, on the center line of the thickness of the strip having the rectangular cross section. Further, the spiral axis is out of the rectangular cross section outside the rectangular cross section orthogonal to the longitudinal direction of the band plate, that is, away from the center line of the plate thickness of the rectangular cross section in the orthogonal direction (eccentric). It can be set parallel to the longitudinal direction of the strip. As in the latter case, the spiral shaft is decentered from the center line of the plate thickness, so that the blade surface at the tip of the first blade of the spiral blade is always obliquely applied to the inner wall surface or the fixed layer surface of the cylindrical tube. Will be in touch. As a result, even when foreign matter is caught between the tip of the first single blade and the fixing layer, the tip of the spiral blade gets over the foreign matter compared to the case where the blade surface is in perpendicular contact with the fixing layer surface. Since a required amount of deformation (angle) of the spiral blade surface is small, an increase in load torque can be further suppressed. It should be noted that the eccentric direction of the spiral shaft (rotating shaft) decentered from the center line of the thickness of the band plate is easily deviated from the region in the direction in which the first blade of the spiral blade travels, thereby easily getting over the foreign matter. .

  The rotating spiral blade device of the present invention can be applied to a smoke pipe of a smoke pipe heat exchanger of a high temperature regenerator of an absorption chiller / heater. In this case, the high-temperature regenerator of the absorption chiller / heater is disposed horizontally in the furnace including a furnace equipped with a combustor for burning wood pellet fuel, a container into which a dilute solution to be regenerated is introduced. It has a plurality of smoke pipes, and can be configured to include a smoke pipe heat exchanger that distributes combustion exhaust gas discharged from the furnace to the smoke pipes and heats the diluted solution to regenerate.

  By constructing the high-temperature regenerator of the absorption chiller / heater in this way, even if the fuel exhaust gas of wood pellets with high fly ash concentration is circulated in the smoke pipe of the flue-tube type heat exchanger, it will fly by the rotating spiral blade device. Since ash is discharged without accumulating in the smoke pipe, it is possible to avoid a decrease in heat exchange efficiency. Moreover, even when the pellet combustor is shut down, the moisture in the smoke tube condenses, the fly ash adhering to the inside of the smoke tube hardens like cement, and a fixed layer is formed on the inner wall of the smoke tube. An increase in load torque of the drive mechanism can be suppressed. In addition, even if a foreign object is caught between the tip of the spiral blade and the fixed layer, a rapid increase in load torque can be suppressed, so that it is possible to avoid damaging the rotary drive mechanism or damaging the spiral blade itself.

  According to the present invention, in a rotating spiral blade device formed by inserting a rotationally driven spiral blade into a cylindrical tube, damage to the spiral blade due to a fixed layer of fly ash or granular material formed on the inner wall of the cylindrical tube In addition, damage to the rotary drive mechanism can be prevented.

It is sectional drawing of the high temperature regenerator of the absorption cold / hot water machine provided with the smoke pipe type heat exchanger of one Embodiment with which the rotation spiral blade apparatus of this invention is applied. It is a perspective view which shows the whole high temperature regenerator of the absorption cold / hot water machine of one Embodiment of this invention. It is a figure explaining the problem at the time of rotating the conventional spiral blade | wing in a cylindrical tube. It is a figure which shows the structure of Example 1 of the rotation spiral blade | wing of this invention. It is a figure which clarifies operation | movement of the rotation spiral blade | wing of Example 1. FIG. It is a figure which shows the structure of Example 2 of the rotation spiral blade | wing of this invention. It is a figure which clarifies operation | movement of the rotation spiral blade | wing of Example 2. FIG. It is a figure which clarifies the effect of the rotation spiral blade | wing of Example 2. FIG. It is a figure explaining an example in the case of manufacturing the spiral blade | wing of Example 1, 2 of this invention by press work.

  With reference to FIG.1 and FIG.2, the high temperature regenerator of the absorption cold / hot water machine provided with the smoke pipe type heat exchanger of one Embodiment with which the rotation spiral blade apparatus of this invention is applied is demonstrated. FIG. 1 shows the high-temperature regenerator of the absorption chiller / heater of the present embodiment in half, a horizontal cylindrical furnace 1, a regenerative container 2 disposed above the cylindrical furnace 1, Is provided with a smoke tube heat exchanger 3 provided in The smoke tube heat exchanger 3 includes a plurality of smoke tubes 4 arranged horizontally in the regeneration container 2, and spiral blades 5 rotatably supported in the smoke tube 4 are inserted in the tube axis direction. A combustor for burning wood pellet fuel (not shown) is detachably provided in a cylindrical portion 1a at the left end in the figure of the cylindrical furnace 1. In the figure of the cylindrical furnace 1, the cylindrical portion 1 b at the right end is opened to the rear smoke chamber 6. Further, one end of the smoke pipe 4 of the smoke pipe type heat exchanger 3 is opened in the rear smoke chamber 6. The other end of the smoke tube 4 is opened to the front smoke chamber 7. The bottom of the rear smoke chamber 6 is connected to an ash accumulation box 8 provided below the position of the cylindrical furnace 1. An exhaust cylinder 7a is provided at the bottom of the front smoke chamber 7 below the cylindrical furnace 1, and the exhaust cylinder 7a is connected to an induction blower via a cyclone (not shown). The regeneration container 2 is formed by surrounding the outer peripheral side of the cylindrical furnace 1 and the smoke tube 4, and a dilute solution is introduced therein. The upper and side walls of the rear smoke chamber 6 and the front smoke chamber 7 are doubled, and a dilute solution is circulated inside the double wall to constitute a part of the regeneration container 2. . A heat insulating material 13 is provided on the back wall of the rear smoke chamber 6.

  Here, the detailed structure of the smoke pipe type heat exchanger 3 which is the characteristic structure of this embodiment is demonstrated. Inside the plurality of smoke pipes 4, spiral blades 5 each having a strip plate formed in a spiral shape are inserted. One end of the spiral blade 5 is drawn from the smoke pipe 4 opened in the casing of the front smoke chamber 7 that forms the container wall of the regeneration container 2, and is provided in the casing on the opposite side of the container wall of the front smoke chamber 7. The bearing 9 is connected to a rotating shaft 10 that is rotatably supported by the bearing 9. On the other hand, the other end of the spiral blade 5 is rotatably inserted into the smoke pipe 4 opened in the rear smoke chamber 6. That is, the spiral blade 5 is supported in a cantilever manner so as to be rotatable around the rotation shaft 10. A rotating shaft 10 supported by the bearing 9 is connected to a rotation driving mechanism 11 of the spiral blade 5. The rotational drive mechanism 11 of this embodiment is configured to rotationally drive the spiral blade 5 around the rotary shaft 10 by a motor 12 via a power transmission mechanism such as a gear, a chain, or a sprocket.

  With this configuration, according to the high-temperature regenerator of this embodiment, the combustion exhaust gas of the wood pellet fuel burned by the combustor attached to the cylindrical portion 1a of the cylindrical furnace 1 is the rear smoke chamber 6 It is led to the smoke pipe 4 constituting the smoke pipe type heat exchanger 2 through. The combustion exhaust gas guided to the smoke pipe 4 flows through the smoke pipe 4 and is discharged from the front smoke chamber 7 to the chimney. In the process of flowing through the cylindrical furnace 1 and the plurality of smoke pipes 4, the diluted solution of the absorbing liquid introduced into the regeneration container 2 is heated by the heat of the combustion exhaust gas. The dilute solution in the regeneration vessel 2 is also heated by heat from the furnace wall of the cylindrical furnace 1. As a result, the dilute solution is concentrated and guided to a low-temperature regenerator (not shown), while the vapor generated in the regenerator 2 is also guided to the low-temperature regenerator, and the concentrated solution supplied from the regenerator 2 is heated. Used for playback.

  On the other hand, the combustion exhaust gas flowing through the smoke pipe 4 has a relatively low flow rate and a high fly ash concentration. However, since the combustion exhaust gas is swirled by the spiral blade 5, the diluted solution in the regeneration container 2 is removed from the pipe wall of the smoke pipe 4. Since the amount of heat transferred can be increased, the heat exchange efficiency can be improved. However, on the other hand, since fly ash tends to settle and accumulate in the smoke pipe 4, thermal conduction is inhibited by the fly ash accumulation layer. In this respect, according to the present embodiment, the spiral blade 5 is rotated by the rotation drive mechanism 11, so that the fly ash accumulated in the smoke pipe 4 is transferred to the lower smoke chamber 6 by the rotating spiral blade 5, for example. Discharged into the ash collection box. Further, the fly ash floating in the smoke pipe 4 and the powdered ash shaved by the spiral blade 5 as will be described later are blown to the front smoke chamber 7 side along with the combustion exhaust gas, and passed through the exhaust pipe 7a. Will be collected by the cyclone. As a result, it is possible to suppress heat transfer from being inhibited by the fly ash accumulation layer in the smoke pipe 4.

Hereinafter, the Example of the rotation spiral blade | wing of this invention is described using figures.
Example 1
In FIG. 4, the structure of Example 1 of the rotation spiral blade | wing of this invention is shown. FIG. 4A is a view of the spiral blade 51 according to the first embodiment as viewed from the rotation axis direction, FIG. 4B is a perspective view of the spiral blade 51, and FIG. . However, FIG. 6C exaggerates the features of the present embodiment, and the scale is different from FIGS. The spiral blade 51 of the present embodiment is formed in a shape in which the band plate 52 is twisted in a spiral shape. Of the blade diameter D in an arbitrary cross section orthogonal to the rotation axis O of the spiral blade 51, the blade radius Da of one first single blade 51 a from the rotation axis O to the blade tip is set between the inner wall of the smoke tube 4. The gap (initial clearance) is formed to a dimension that is formed. The blade radius Db of the other second single blade 51b is shorter than the blade radius Da of the first single blade 51a. The spiral blade 51 passes through a point where the strip 52 having a width corresponding to the blade diameter D is prorated by the blade radius Da and the blade radius Db, and a line extending in the longitudinal direction of the strip 52 is twisted (spiral). The shaft has a spiral shape. Therefore, as shown in FIG. 5C, the positions of the first single blade 51a and the second single blade 51b in the blade circumferential direction change at a period of every twist angle of 180 °. Further, the spiral axis of the spiral blade 51 is Os shown in FIG. 4A, but as is clear from the drawing, it is made coincident with the rotational axis O of the spiral blade 51. In other words, the spiral blade 51 of the present embodiment passes through a point that is biased to one side of the center of the band width direction of the rectangular cross section orthogonal to the longitudinal direction of the band plate 52 and extends in the longitudinal direction of the band plate 52. The belt plate 52 is twisted around the (spiral axis Os), and is supported by the rotational drive mechanism 11 so as to be rotatable about the spiral axis Os as the rotation axis O.

  According to Example 1 formed in this way, as shown in FIG. 5, even if the fixed layer 20 of fly ash is formed on the inner wall of the smoke tube 4, an increase in load torque of the rotary drive mechanism 11 can be suppressed, Moreover, even if the foreign matter 21 is caught between the tip of the spiral blade 51 and the fixed layer 20, it is possible to avoid damaging the rotary drive mechanism 11 or damaging the spiral blade 51 itself. That is, FIG. 5A shows a cross section 53 orthogonal to the rotation axis O at an arbitrary position of the spiral blade 51. As shown in the figure, the blade radius Da of the first single blade 51 a from the rotation axis O is positioned so as to hold an initial clearance Dc, which is a set gap, with the inner wall of the smoke tube 4. On the other hand, the gap between the tip of the second single blade 51b formed at the blade radius Db and the inner wall of the smoke pipe 4 is maintained at a clearance obtained by adding the difference in blade radius (Da−Db) to the initial clearance Dc.

  As a result, according to the first embodiment, as shown in FIG. 5B, when the spiral blade 51 rotates in the direction of the illustrated arrow 22, the tip of the first single blade 51 a rubs the surface of the fixing layer 20. Rotate. On the other hand, the rotation trajectory 23 at the tip of the second single blade 51b has a dashed line in the figure, so that there is a sufficient gap 55 between the surface of the fixed layer 20. As a result, the tip of the second single blade 51b rotates without rubbing the surface of the fixed layer 20. That is, the tip of the spiral blade 51 comes into contact with the fixed layer 20 and the frictional force is generated only on one side of the first single blade 51a. Therefore, the load on the rotary drive mechanism 11 due to the formation of the fixed layer 20 The increase in torque can be halved. Further, even when the fly ash fixing layer 20 is not formed, the spiral blades 51 supported in a cantilever manner by the rotation drive mechanism 11 are always provided by the first single blades 51a having a plurality of blade radii Da in the axial direction. It rotates in contact with the inner wall of the smoke tube 4. On the other hand, since the second single blade 51b having the blade radius Db rotates without contacting the inner wall of the smoke tube 4, the frictional force between the spiral blade 51 and the smoke tube 4 can be reduced, and the load rotation torque can be constantly reduced.

  Further, as shown in FIG. 5C, in the state where the fixing layer 20 is formed on the inner wall surface of the smoke tube 4, even if the foreign matter 21 is sandwiched between the tip of the first single blade 51a and the fixing layer 20, There is a sufficient gap 55 between the tip of the second single blade 51 b and the fixing layer 20. As a result, when the tip of the first single blade 51a bites the foreign material 21, the spiral blade 51 is displaced in the direction of the arrow 56 by the gap 55 by the biting force. The tip can get over the foreign material 21. That is, as shown in FIG. 4 (c), large-diameter first single blades 51a are formed on the upper and lower sides of the rotating shaft for each axial position where the twist angle phase is 180 ° different. Therefore, for example, when the foreign matter 21 is caught in a gap between one tip of the first single blade 51a located on the upper side in the drawing and the fixing layer 20, the tips of the two first single blades 51a adjacent to each other in the axial direction. Is in sliding contact with the lower fixing layer 20. Then, the two first single blades 51a adjacent to each other serve as fulcrums, and the spiral blade 51 is bent to the lower second single blade side 51b side by the force acting on the first single blade 51a biting the foreign material 21. Therefore, the gap between the tip of the first single blade 51a and the fixing layer 20 is widened, and the foreign material 21 can be overcome. Thereby, the damage of the spiral blade | wing 51 by the fixed layer 20 of the fly ash formed in the inner wall of the smoke pipe 4 and the damage of the rotation drive mechanism 11 can be prevented.

(Example 2)
In FIG. 6, the structure of Example 2 of the rotation spiral blade | wing of this invention is shown. FIG. 4A is a view of the spiral blade 61 of the second embodiment viewed from the direction of the rotation axis, and FIG. 4B is a perspective view of the rotation spiral blade 61. As illustrated, the spiral blade 61 of the second embodiment is different from the spiral blade 51 of the first embodiment in that the spiral axis Os of the strip plate 52 forming the spiral blade 61 is set in the longitudinal direction of the strip plate 52. It is characterized in that it is set not on the inside of the orthogonal rectangular cross section 63 but on the outside. That is, the spiral axis Os is separated from the center line of the plate thickness of the rectangular cross section 63 of the strip plate 52 in the orthogonal direction, that is, decentered in the thickness direction of the strip plate 52, and the longitudinal direction of the strip plate 52 deviated from the cross section 63. It is set parallel to the direction. Other configurations are the same as those of the first embodiment. That is, the first single blade and the second single blade having the same configuration as in the first embodiment are provided, and the spiral axis Os and the rotation axis O of the spiral blade 61 are configured to coincide with each other.

  According to the second embodiment formed in this way, even if the fly ash fixing layer 20 is formed on the inner wall of the smoke pipe 4, an increase in load torque of the rotary drive mechanism 11 can be suppressed, and the tip of the spiral blade 61 and Even if the foreign matter 21 is caught between the fixed layer 20, the risk of damaging the rotary drive mechanism 11 or damaging the spiral blade 61 itself can be avoided. This will be described with reference to FIG. FIG. 7A shows a cross section 63 in a direction orthogonal to the rotation axis O at an arbitrary position of the spiral blade 61. In other words, a cross section 63 of the spiral blade 61 passing through the rotation axis O (Os) at an arbitrary position of the spiral blade 61 is shown. Thus, the spiral blade 61 of this embodiment is formed in a spiral shape by decentering the rectangular cross section 63 of the strip 52 in the direction orthogonal to the spiral axis Os, that is, in the thickness direction of the strip 52. The axis Os is used as the rotation axis O.

  According to the second embodiment, since the blade surface 64 of the spiral blade 61 is shifted in the orthogonal direction from the rotation axis O, the blade surface 64 at the tip of the spiral blade 61 is the inner wall surface of the smoke tube 4 or the fixed layer 20. It always abuts diagonally against the surface. By the way, for example, when the blade surface 64 vertically contacts the surface of the fixed layer 20 (FIG. 8A), when the foreign matter 21 is caught between the tip of the spiral blade 61 and the fixed layer 20, Even when the angle θ of the spiral blade 61 is deformed, only a foreign object having a height H1 can be overcome. In contrast, in the second embodiment, if the tip of the spiral blade 61 is deformed by the angle θ, the foreign object 21 having a height H2> H1 can be overcome. In other words, the deformation angle θ of the blade surface 64 required to get over the foreign object 21 having the same height is small (FIG. 8B). As a result, an increase in load torque can be further suppressed as compared with the first embodiment. In other words, in the second embodiment, the spiral axis (Os = O) decentered from the center line of the plate thickness of the strip plate forming the spiral blade 61 has the blade surface 64 of the spiral blade 61 away from the spiral axis Os. In other words, the blade surface 64 is shifted from the spiral axis Os to the region on the arrow 22 side (region in which the first one blade 61a advances), or the spiral shaft Os of the spiral blade 61 is moved away from the surface 64 in the orthogonal direction. By decentering to the opposite side of the arrow 22 side, it becomes easy to get over the foreign matter 21.

  In each of the first and second embodiments described above, an example in which a member that constitutes the rotation axis O of the spiral blades 51 and 61 is not provided. However, the present invention is not limited to this, and the spiral blades 51 and 61 can be fixed to a member constituting the rotary shaft O, and the spiral blade around the member constituting the rotary shaft O can be formed. 51 and 61 can also be wound and formed. Furthermore, although the spiral blades 51 and 61 of the first and second embodiments can be formed by twisting the band plate, other known manufacturing methods can be applied instead. For example, when the spiral blades 51 and 61 are manufactured by pressing, the upper die 71 and the lower die 71 are sequentially moved in the direction indicated by the arrow 73 by a press device including the upper die 71 and the lower die 72 shown in FIG. The spiral blades 51 and 61 can be processed by opening and closing the mold 72. When processing the spiral blade 51, the boundary between the first single blade 51a and the second single blade 51b is positioned at the center of the upper mold 71 and the lower mold 72 in the direction orthogonal to the illustrated arrow 73, and the arrow 73 illustrated in FIG. Send the strip in the direction and process it. On the other hand, the processing method of the spiral blade 61 is the same as the processing method of the spiral blade 51. The difference is that the spiral blade 51 is set so that the boundary between the first blade 51a and the second blade 51b is set at the center position of the upper mold 71 and the lower mold 72, and the elongation of the boundary portion becomes zero. is there. The spiral blade 61 has a shape in which the balance of the elongation of the first single blade 61a and the second single blade 62b is lost, and displacement occurs over the entire length of the plate width.

  As described above, according to the high-temperature regenerator of the absorption chiller / heater equipped with the smoke pipe heat exchanger according to one embodiment of the present invention, the flue gas flowing through the smoke pipe 4 has a relatively low flow rate and fly ash. Although the concentration is high, since the spiral blades 51 or 61 of Example 1 or 2 are inserted into the smoke pipe 4, the combustion exhaust gas is swirled by these spiral blades. As a result, the amount of heat transferred from the pipe wall of the smoke pipe 4 to the dilute solution in the regeneration container 2 can be increased, so that the heat exchange efficiency can be improved.

  Further, since fly ash is liable to settle and accumulate in the smoke pipe 4, heat conduction is hindered by the fly ash accumulation layer, but the spiral blade 51 or 61 of Example 1 or 2 is placed in the smoke pipe 4 of this embodiment. The fly ash accumulated in the smoke pipe 4 is transferred to the front smoke chamber 7 by the rotating spiral blade 51 or 61 and is transferred from the ash discharge port 7a to the ash accumulation box. Discharged. Therefore, it is possible to suppress the heat conduction from being hindered by the fly ash accumulation layer in the smoke pipe 4 and to further improve the heat exchange efficiency.

  Furthermore, even when the operation of the high-temperature regenerator is stopped, even if the moisture in the smoke tube 4 is condensed and the fly ash adhering to the inner surface of the smoke tube 4 is cured by the dew condensation water, the fixed layer 20 is formed. It is possible to halve the length of the spiral blade 51 or 61 whose tip 61 rotates in contact with the fixed layer 20. As a result, the increase in load torque of the rotary drive mechanism 11 of the spiral blade 51 or 61 can be halved. Further, even if the foreign matter 21 is caught between the tip of the spiral blade 51 or 61 and the fixing layer 20, the spiral blade 51 or 61 is shifted or deformed to get over the foreign matter 21, so that the load torque is suddenly increased and rotated. The drive mechanism 11 can be damaged, or damage to the spiral blades 51 or 61 themselves can be avoided. Further, even when the fly ash fixing layer 20 is not formed, the spiral blades 51 or 61 supported in a cantilever manner by the rotational drive mechanism 11 are the second single blades formed in the axial direction on the inner wall of the smoke tube 4. Therefore, the rotational force can be constantly reduced by reducing the frictional force between the spiral blade 51 or 61 and the smoke pipe 4.

  As mentioned above, although the rotating spiral blade apparatus of this invention was demonstrated based on embodiment applied to the smoke pipe type heat exchanger with which the high temperature regenerator of an absorption-type water heater is equipped, it is not restricted to this, The rotating spiral of this invention The blade device can be applied to a powder fluid transfer device such as a screw feeder.

5 Spiral blade 51 Spiral blade 51a First single blade 51b Second single blade 52 Strip 61 Spiral blade O Rotating shaft Os Spiral shaft

Claims (4)

A spiral blade that is rotatably inserted into the cylindrical tube, and a drive mechanism that rotatably supports and rotates the spiral blade;
The spiral blade has a shape in which a band plate is helically twisted around a spiral axis Os along the longitudinal direction of the band plate, and is supported rotatably by the drive mechanism with the spiral axis as a rotation axis O. Of the blade diameter D in the cross section orthogonal to the rotation axis O of the spiral blade, the blade radius Da of one first single blade from the rotation axis O to the blade tip is set between the inner wall of the cylindrical tube. The rotary spiral blade device is characterized in that the blade radius Db of the other second single blade is shorter than the blade radius Da of the first single blade.   The rotary spiral blade device according to claim 1, wherein the spiral axis is set inside a rectangular cross section orthogonal to the longitudinal direction of the strip.   The rotating spiral blade device according to claim 1, wherein the spiral shaft is set outside a rectangular cross section orthogonal to the longitudinal direction of the strip. A furnace equipped with a combustor for burning wood pellet fuel, a container into which a dilute solution to be regenerated is introduced, and a plurality of smoke pipes each comprising a cylindrical pipe disposed horizontally in the container, In a high-temperature regenerator of an absorption chiller / heater comprising a flue gas heat exchanger that circulates flue gas discharged from a furnace through the smoke pipe and regenerates the diluted solution by heating,
A high-temperature regenerator for an absorption chiller / heater comprising the rotary spiral blade device according to any one of claims 1 to 3 in the smoke pipe.

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