JP2012168216A - Heat exchanger and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat exchanger with improved heat exchanging efficiency between a fluid medium and a sheet-like member, and to provide an image forming device.SOLUTION: The heat exchanger includes a heat-exchanging body having a passage formed therein where a fluid medium flows in a direction orthogonal to a sheet-like member conveyance direction, and fluid medium conveying means for conveying the fluid medium into the passage through a piping that connects an inlet and an outlet formed upstream and downstream sides, respectively, in the fluid medium flow direction of the passage. The sheet-like member is brought into contact with a heat-exchange surface of the heat-exchanging body directly or via a heat conductive member to exchange heat between the sheet-like member and the fluid medium. When the width in the sheet-like member conveyance direction of the passage is L and the height of the passage is G, G<L is satisfied.

Description

  The present invention relates to a heat exchange device used in an image forming apparatus such as a printer, a facsimile machine, and a copying machine, and an image forming apparatus provided with the heat exchange device.

  2. Description of the Related Art As an image forming apparatus, an apparatus that forms a toner image on a sheet-like sheet using electrophotographic technology and melts and fuses the toner by passing through a thermal fixing device is known. In general, the temperature of the heat fixing device varies depending on the type of toner and paper, the paper conveyance speed, and the like, but is set and controlled at a temperature of about 180 [° C.] to 200 [° C.] to fuse the toner instantaneously. The surface temperature of the paper immediately after passing through the heat fixing device is a high temperature of about 100 [° C.] to 130 [° C.] although it depends on the heat capacity (specific heat, density, etc.) of the paper. Since the melting temperature of the toner is lower, the toner is slightly soft at the time immediately after passing through the heat fixing device, and remains in a sticky state for a while until the paper cools down. Therefore, when the image output operation is repeated continuously and the paper after passing through the heat fixing device is stacked in the paper discharge container, if the toner on the paper cannot be sufficiently cured and is in a soft state, the toner on the paper A so-called blocking phenomenon that sticks to another sheet may occur, and the image quality may be significantly reduced.

  2. Description of the Related Art Conventionally, in an electrophotographic image forming apparatus for office use, a sheet is brought into contact with a heat exchanger cooled by blowing air with a fan directly or through a heat conducting member, so that the heat exchanger and the sheet are not in contact with each other. Many air-cooling systems that use heat exchange to cool the paper have been adopted.

  In the cooling device described in Patent Document 1, a heat sink that is a heat exchanger is provided on the inner peripheral surface of a conveyance belt that is a heat transfer member and carries and conveys paper. The heat sink is cooled by blowing air with a fan, and the sheet conveyed by the conveying belt is cooled by removing heat from the sheet to the heat sink via the conveying belt when passing through the region facing the heat sink. As described above, by using the heat sink, the contact width between the heat sink and the paper in the paper conveyance direction can be increased, and the cooling time of the paper by the heat sink becomes longer, so that the cooling efficiency of the paper can be increased accordingly. .

  In recent years, there has been an increasing need for light printing such as high-speed printing such as telephone bills and receipts, and printing of color glossy images on cardboard, coated paper, and the like. In such a light printing, a large amount of printing is performed at a high speed, so it is necessary to cool a high-temperature paper more efficiently. In addition, unlike office use, color printing is frequently performed and glossy images are also frequently used. Therefore, high-efficiency cooling has been demanded in order to fix images at a high temperature with a thermal fixing device.

  In the image forming apparatus described in Patent Document 2, a cooling device that includes a cooling roller that is supported by a bracket so as to be rotatable via a bearing and that is a heat exchanger that cools the sheet while contacting the sheet and transporting the sheet, It is provided downstream of the fixing device in the sheet conveyance direction. The paper after passing through the heat fixing device is cooled by the cooling roller of the cooling device, so that the toner on the paper is cooled and hardened, and the occurrence of the blocking phenomenon can be suppressed. Further, the cooling roller has a tubular structure, and a cooling liquid as a fluid medium is flowed into the cooling roller from an inlet provided on one end side in the axial direction of the cooling roller toward a discharge port provided on the other end side. The cooling roller whose temperature has been raised by taking heat away from is cooled by the coolant. Since such a liquid cooling method can be cooled more efficiently than the air cooling method, the cooling efficiency of the paper can be increased.

  However, in the cooling device described in Patent Document 2, since the contact width between the cooling roller and the sheet in the sheet conveyance direction is narrow, the cooling time of the sheet by the cooling roller is shortened. Therefore, it is conceivable to use a hollow block member having a wide contact width with the paper in the paper conveyance direction instead of the cooling roller as a heat exchanger, and to flow the coolant through the hollow inside of the block member as a flow path. .

  However, when the flat area of the flow path is constant, the higher the flow path height, which is the height of the hollow interior of the block member, the more cooling liquid is present in the flow path, and between the paper and the cooling liquid. When the heat exchange is performed, the amount of the coolant that can diffuse heat in the flow path increases, so the amount of heat per unit volume of the coolant decreases. Therefore, when the flow rate of the cooling liquid discharged from the discharge port is the same, the amount of heat per unit volume of the cooling liquid discharged from the inside of the flow path is also reduced, so that heat is generated in the cooling liquid not discharged from the inside of the flow path. It tends to remain. Therefore, the temperature difference between the cooling liquid in the flow path and the paper is reduced, and there is a problem that the heat exchange efficiency between the cooling liquid and the paper is reduced accordingly.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a heat exchange device capable of improving the heat exchange efficiency between the fluid medium and the sheet-like member, and the heat exchange device. An image forming apparatus is provided.

In order to achieve the above object, the invention of claim 1 is directed to a heat exchanger in which a flow path through which a flow medium flows is formed in a direction orthogonal to the sheet-like member conveyance direction, and a flow medium flow direction in the flow path. A fluid medium conveying means for conveying the fluid medium to the flow path through a pipe communicating with an inlet and an outlet provided on the upstream side and the downstream side, respectively, and a sheet-like shape on the heat exchange surface of the heat exchanger In a heat exchanging apparatus for exchanging heat between the sheet-like member and the fluid medium by bringing the member into contact with each other directly or via a heat transfer member, the width of the flow path in the sheet-like member conveying direction is L, and the flow If the road height is G, the relationship G <L is satisfied.
The invention according to claim 2 is the heat exchange device according to claim 1, wherein the heat exchange device has the height from the heat exchange surface to the outer peripheral surface facing the heat exchange surface as H. The flow path is formed at a position closer to the heat exchange surface than the position H / 2 from the heat exchange surface of the body.
Further, in the heat exchange device according to claim 1 or 2, in the heat exchange device according to claim 1 or 2, if D is a smaller diameter of the diameter of the inlet and the diameter of the pipe, L≈D or L> D As well as satisfying the relationship of G≈D or G <D.
According to a fourth aspect of the present invention, in the heat exchange device according to the first, second, or third aspect, A is a cross-sectional area of the flow path in a direction orthogonal to the flow medium flow direction, and the flow medium in the pipe or the inflow port. When the cross-sectional area in the direction orthogonal to the flow direction is B, the relationship of A ≦ B is satisfied.
The invention according to claim 5 is the heat exchange device according to claim 1, 2, 3, or 4, wherein the flow path gradually expands from the inlet to the flow path inside the heat exchanger. A region having a shape is provided.
The invention according to claim 6 is the heat exchange device according to claim 1, 2, 3, 4 or 5, wherein the inlet from the inlet to the flow path inside the heat exchanger is provided from the inlet. The present invention is characterized in that there is provided a fluid medium diffusing means for diffusing the flowing fluid medium upstream or downstream in the sheet-like member conveyance direction.
The invention according to claim 7 is the heat exchange device according to claim 1, 2, 3, 4, 5 or 6, wherein a heat insulating means is provided at least on the outer peripheral surface of the heat exchanger facing the heat exchange surface. It is characterized by.
The invention of claim 8 is a toner image forming means for forming a toner image on a sheet-like member, and a heat fixing means for fixing the toner image formed on the sheet-like member to the sheet-like member at least by heat. And a cooling unit that cools the sheet-like member on which the toner image is fixed by the heat fixing unit, wherein the cooling unit is the claim 1, 2, 3, 4, 5, 6 or 7 as the cooling unit. It is characterized by using the heat exchange apparatus.
According to a ninth aspect of the present invention, there is provided a toner image forming means for forming a toner image on a sheet-like member, and a heat fixing means for fixing the toner image formed on the sheet-like member to the sheet-like member at least by heat. And a heating means for heating the sheet-like member, the heat exchange device according to claim 1, 2, 3, 4, 5, 6 or 7 is used as the heating means. It is characterized by this.

  In the present invention, when the flat area of the flow path is constant, the height G of the flow path is smaller than the width L of the flow path in the sheet-like member transport direction, so that the height G is larger than the width L. Also, the flow medium in the flow path can be reduced. As a result, the amount of fluid medium that can diffuse heat in the flow path when heat exchange is performed between the sheet-like member and the fluid medium is smaller than when the gap G is larger than the width L. The amount of heat per unit volume of the fluid medium increases. Therefore, when the flow rate of the fluid medium discharged from the discharge port is constant, the amount of heat per unit volume of the fluid medium discharged from the discharge port increases, and it is difficult for heat to remain in the fluid medium in the flow path. The temperature difference between the fluid medium in the flow path and the sheet-like member can be suppressed, and the heat exchange efficiency between the fluid medium and the sheet-like member can be improved.

  As mentioned above, according to this invention, there exists the outstanding effect that the heat exchange efficiency of a fluid medium and a heat exchange body can be improved.

(A) Sectional view when the liquid cooling type cooling member according to Configuration Example 1 is viewed from a direction orthogonal to the paper conveyance direction, (b) The liquid cooling type cooling member according to Configuration Example 1 is viewed from the paper conveyance direction. (C) Sectional drawing at the time of seeing the cooling member of the liquid cooling system which concerns on the structural example 1 from upper direction. 1 is a schematic configuration diagram of an image forming apparatus according to an embodiment. The schematic block diagram of the cooling device which is a heat exchange apparatus. (A) A cross-sectional view of the liquid-cooling type cooling member according to Configuration Example 2 when viewed from a direction orthogonal to the sheet conveying direction, and (b) a liquid-cooling type cooling member according to Configuration Example 2 when viewed from above. (C) Sectional drawing at the time of seeing the cooling member of the liquid cooling system which concerns on the structural example 2 from a paper conveyance direction. Sectional drawing at the time of seeing the cooling member provided with the cooling fluid spreading | diffusion means in which a cooling fluid spread | diffuses uniformly in the width direction in the area | region from the vicinity of an inflow port to the flow path of a wide narrow gap. Sectional drawing when the cooling member which made the flow path of a wide narrow gap a shape (planar shape) different from a cooling surface shape is seen from the direction orthogonal to a paper conveyance direction. Sectional drawing at the time of seeing the cooling member which covered outer surface other than the cooling surface with the heat insulating material from the direction orthogonal to a paper conveyance direction. The schematic block diagram of the heating apparatus which is a heat exchange apparatus.

  An embodiment in which the heat exchanging device of the present invention is used as a cooling means for a sheet that is a sheet-like member in an image forming apparatus will be described. However, the heat exchanging device of the present invention is limited to that used in an image forming apparatus. It is also possible to adapt as a heating means. That is, the heat exchange device of the present embodiment is a cooling device if the sheet-like member is cooled with a cooled fluid medium, and becomes a heating device if the sheet-like member is heated with a warm fluid medium. Therefore, the heat exchange device of the present invention can be used as long as it is a device that requires cooling or heating of the sheet-like member. It can be installed in food processing equipment. In this embodiment, a liquid is used as the fluid medium, but a gas may be used depending on the application of the heat exchange device.

  FIG. 2 is a schematic configuration diagram of a tandem intermediate transfer belt type color image forming apparatus equipped with a cooling device 12 having a cooling plate 11 of the present embodiment.

  An intermediate transfer belt 51 as an intermediate transfer medium is stretched by a plurality of rollers, and the intermediate transfer belt 51 is configured to rotate by these rollers, and an image forming process means is disposed around the intermediate transfer belt 51. ing.

  When the rotation direction of the intermediate transfer belt 51 is indicated by an arrow a in the drawing, image formation is performed in order from the upstream side in the rotation direction of the intermediate transfer belt 51 above the intermediate transfer belt 51 and between the rollers 52 and 53. As the process means, an image station 54Y, an image station 54C, an image station 54M, and an image station 54Bk are arranged. For example, in the image station 54Y, a charging device 110Y, an optical writing device 112Y, a developing device 113Y, and a cleaning device 114Y are arranged around a drum-shaped photoconductor 111Y, and a position opposite to the photoconductor 111Y with the intermediate transfer belt 51 interposed therebetween. In addition, a primary transfer roller 115 </ b> Y is provided as a transfer unit to the intermediate transfer belt 51. The other three image stations 54C, 54M and 54Bk have the same configuration. The four image stations 54Y, 54C, 54M, and 54Bk are arranged in parallel on the left and right sides so as to have a predetermined pitch interval.

  In this embodiment, the optical writing device 112 is an optical system using an LED as a light source. However, the optical writing device 112 can also be configured by a laser optical system using a semiconductor laser as a light source, and exposes the photoconductor 111 according to image information. Do.

  Below the intermediate transfer belt 51, a sheet storage unit 119 and a sheet feeding roller 23 for the sheet 4, which is a sheet-like member, a registration roller pair 21, and a roller 55 that stretches the intermediate transfer belt 51 are interposed via the intermediate transfer belt 51. The surface of the intermediate transfer belt 51 is opposed to a secondary transfer roller 56 that is provided so as to be opposed to the secondary transfer roller 56 as a transfer unit of the toner image from the intermediate transfer belt 51 to the paper 4 and a roller 58 that is in contact with the back surface of the intermediate transfer belt 51. A cleaning device 59 that is provided in contact with the surface and cleans the front surface of the intermediate transfer belt 51, a thermal fixing device 116, a cooling device 12 that has a cooling plate 11 that cools the paper 4, and discharge of the paper 4 after toner fixing. A paper discharge accommodating portion 117, which is a portion, is disposed. A paper transport path 128 extending from the paper storage unit 119 to the paper discharge storage unit 117 extends. In addition, when forming an image on the back side of the paper 4 during the double-sided image formation, the paper 4 for double-sided image formation that reverses the front and back of the paper 4 that has once passed through the cooling device 12 and transports the paper 4 to the registration roller pair 21 again. A path 29 is also provided.

  The cooling plate 11 of the cooling device 12 is a heat receiving portion that receives the heat of the paper 4, and is connected / connected by a pipe 105 together with a radiator 103 equipped with a fan 104, a pump 100, and a tank 101, and is filled with a cooling liquid. Yes. As shown by the arrow of the piping 105, the cooling liquid circulation path supplies the cooling liquid cooled by the radiator 103 to the cooling plate 11, discharges it after passing through the cooling plate 11, and then the tank 101, pump The cooling liquid is circulated by the rotational pressure of the pump 100 and radiated by the radiator 103 to cool the cooling liquid, that is, the cooling plate 11. The liquid feeding capacity of the pump 100, the size of the radiator 103, and the like are selected based on the flow rate, pressure, cooling efficiency, and the like determined by the thermal design conditions (the amount of heat and temperature conditions that the cooling plate 11 should cool).

  When the image forming process is focused on the image station 54Y, the image forming process is in accordance with a general electrostatic recording method, and exposure is performed by the optical writing device 112Y on the photoreceptor 111Y uniformly charged by the charging device 110Y in the dark. Then, an electrostatic latent image is formed, and this electrostatic latent image is visualized as a toner image by the developing device 113Y. The toner image is transferred from the photoreceptor 111Y to the intermediate transfer belt 51 by the primary transfer roller 115Y. The surface of the photoreceptor 111Y after the transfer is cleaned by the cleaning device 114Y. The other image stations 54 have the same configuration as the image station 54Y, and the same image forming process is performed.

  The developing devices 113Y, 113C, 113M, and 113Bk in the image stations 54Y, 54C, 54M, and 54Bk each have a visible image forming function using different four color toners, and each of the image stations 54Y, 54C, 54M, and 54Bk. If yellow, cyan, magenta and black are shared, a full-color image can be formed. Therefore, while the same image forming area of the intermediate transfer belt 51 sequentially passes through the four image stations 54Y, 54C, 54M, and 54Bk, the primary provided so as to face the respective photoreceptors 111 with the intermediate transfer belt 51 interposed therebetween. If the toner image is overlaid and transferred onto the intermediate transfer belt 51 by the transfer bias given by the transfer roller 115, the same image forming area will be assigned to each of the image stations 54Y, 54C, 54M and 54Bk. At the time of passing, the full color toner image can be obtained by overlapping transfer on the same image area.

  Then, the full color toner image formed on the intermediate transfer belt 51 is transferred to the paper 4. The intermediate transfer belt 51 after the transfer is cleaned by a cleaning device 59. When transferring to the paper 4, a transfer bias is applied to the secondary transfer roller 56 at the time of transfer, and a transfer electric field is formed between the secondary transfer roller 56 and the roller 55 via the intermediate transfer belt 51. This is done by passing the paper 4 through the nip portion between the roller 56 and the intermediate transfer belt 51. After the transfer of the full-color toner image from the intermediate transfer belt 51 to the paper 4, the full-color toner image carried on the paper 4 is fixed on the paper 4 by the heat fixing device 116, so that a full-color final image is formed on the paper 4. After that, the paper 4 is stacked on the paper discharge accommodating portion 117.

  In the image forming apparatus of the present embodiment, the paper 4 passes through the cooling device 12 disposed immediately after the heat fixing device 116 before the paper 4 is stacked in the paper discharge accommodating portion 117. When passing, the sheet 4 heated by the heat fixing device 116 comes into contact with the cooling plate 11 serving as the heat receiving portion via the cooling belt 15 and passes through the heat exchange, so that the sheet passes through the cooling surface of the cooling plate 11. Heat is absorbed from 4, and this heat is transmitted to the cooling liquid inside the cooling plate 11. The coolant that has reached a high temperature due to the transfer of heat is then discharged from the cooling plate 11 and sent to the radiator 103 equipped with the fan 104 via the tank 101 and the pump 100, where the heat is exhausted outside the image forming apparatus. It is. The coolant whose heat is removed by the radiator 103 and lowered to near room temperature is then sent to the cooling plate 11 again. By such an exhaust heat cycle with high cooling performance by the coolant, the sheet 4 heated to a high temperature by the heat fixing device 116 is efficiently cooled.

  In the present embodiment, as will be described later, the cooling liquid flow path formed close to the cooling surface of the cooling plate 11 has a wide and narrow gap, so that the cooling performance is improved. Accordingly, when the paper 4 is discharged and stacked in the paper discharge storage portion 117, the temperature of the paper 4 can be lowered and the toner on the paper 4 can be surely cured. In particular, it is possible to avoid the blocking phenomenon that has been a serious problem in the double-sided image formation output.

  In this embodiment, the cooling plate 11 that is a heat exchanger is used to cool the paper 4 via the cooling belt 15 that is a heat transfer member, but this is caused by deterioration (cooling) of an image formed on the paper surface. If the paper 4 touches and slides on the plate 11, the image surface is scratched and scratches are generated. If such a problem does not occur or does not matter, the paper 4 is directly contacted with the cooling plate 11. It does n’t matter.

  FIG. 3 is a schematic configuration diagram of the sheet cooling device 12 that is a heat exchange device, and includes a liquid cooling type cooling plate 11 that lowers the temperature of the high-temperature sheet 4. The cooling device 12 mainly includes a cooling belt unit 13 located above the cooling device 12 and a transport belt unit 14 located below. The upper cooling belt unit 13 is in contact with the surface of the hot paper 4 and cools the cooling belt 15. The lower conveying belt unit 14 conveys the paper 4 together with the cooling belt 15. Each of the conveyor belts 16 is provided with a role to perform the above function. The cooling belt 15 and the conveyance belt 16 are stretched by a plurality of rollers, and are rotated by driving means such as a motor (not shown). In the present embodiment, the cooling belt 15 rotates to the left, and the conveyance belt 16 rotates to the right, so that the paper 4 is conveyed from the left side to the right side. For example, the driving roller 17 of the cooling belt 15 is connected to a motor, the driving roller 17 is rotationally driven by the motor, and the driving force of the driving roller 17 is transmitted to the roller 18 of the conveying belt 16 by a gear or the like. And the linear velocity of the conveying belt 16 are matched, and the paper 4 is nipped and conveyed. The cooling belt 15 and the conveying belt 16 are provided so that the outer peripheral surfaces facing each other are in close contact with each other with an appropriate tension and are in close contact with each other in a wide region, and the high temperature paper 4 is fed into the contact region and sandwiched. Transport. The sheet 4 is cooled during the nipping and conveying.

  The cooling plate 11, which is a heat exchanger, is provided in a stationary state on the cooling belt unit 13 side, is disposed inside the cooling belt 15, and cools the paper 4 via the cooling belt 15. At this time, since the cooling belt 15 becomes a heat transfer medium interposed between the cooling plate 11 and the paper 4, a material having as high a thermal conductivity as possible or a thin film shape is desirable (for example, a thin stainless belt or a polyimide film). . The arrangement position / state of the cooling plate 11 in the cooling belt 15 is provided so as to be in close contact with the inner peripheral surface of the cooling belt 15 in the region where the outer peripheral surfaces of the cooling belt 15 and the conveying belt 16 contact each other. It has been. By doing so, the surface area of the cooling plate 11 with which the inner peripheral surface of the cooling belt 15 is in close contact is a heat exchange surface, which is a so-called cooling surface 19. And in order to improve adhesiveness with the cooling belt 15, the cooling surface 19 of the cooling plate 11 is made into the curved shape, and the cooling belt 15 is made to apply substantially equal force to the whole region of the cooling surface 19. FIG.

  When the cooling belt 15 rotates in the above state, the inner peripheral surface of the cooling belt 15 slides in contact with the cooling surface 19 of the cooling plate 11 while maintaining a close contact state. In other words, since the cooling surface 19 also serves as a sliding surface, the cooling surface 19 is preferably curved in terms of enabling smooth sliding, and the curved surface has a high surface finish without unevenness. Surface treatment with low accuracy and coefficient of friction is required. In the present embodiment, in order to further improve the contact state between the sheet 4 and the outer peripheral surface of the cooling belt 15 and the contact state between the inner peripheral surface of the cooling belt 15 and the cooling surface 19, and increase the nipping and conveying force of the sheet 4, A pressing roller 26 is provided at an appropriate position to apply a force from the inside of the conveyor belt 16 toward the cooling surface 19.

  The material of the cooling plate 11 itself is related to the heat exchange with the cooling belt 15 and the heat exchange with the cooling liquid 5, so that the material having good thermal conductivity, for example, aluminum or copper is preferable.

  By the cooling device 12, the cooling belt 15 receives the heat of the paper 4 during nipping and conveying, and the heat is transferred to the cooling plate 11 to exchange heat with the coolant 5 of the cooling plate 11. Then, the cooling plate 11 and the cooling belt 15 are cooled by the heat exchange, whereby the paper 4 is cooled and the temperature of the paper 4 is lowered.

  In the present embodiment, the cooling liquid 5 is used as a fluid medium that receives heat from the paper 4 via the cooling plate 11 and exchanges heat. The cooling liquid 5 is a cooling plate 11 as shown in FIG. It is made to circulate by the closed loop circulation system comprised by the flow path 27 and the coolant circulation means 20 which were formed in the inside. The cooling liquid 5 cooled in the circulation process flows through the flow path 27 of the cooling plate 11, whereby the cooling plate 11 (cooling surface 19) is cooled. The heat received by the cooling surface 19 is transmitted to the flow path 27 of the cooling plate 11 to warm the coolant 5, and the warmed coolant 5 is discharged from the discharge port of the cooling plate 11 (not shown). The discharged coolant 5 is sent to a radiator 103 equipped with a tank 101, a pump 100, and a fan 104. The heated coolant 5 is exhausted by the radiator 103, and the temperature is lowered to approximately room temperature. Thereafter, the cooled coolant 5 is supplied again from the inlet 25 of the cooling plate 11 to the flow path 27. The high-temperature paper 4 is efficiently cooled by such an exhaust heat cycle of the coolant circulation.

[Configuration example 1]
1A is a cross-sectional view when the cooling plate 11 is viewed from a direction orthogonal to the paper transport direction, and FIG. 1B is a cross-sectional view when the cooling plate 11 is viewed from the paper transport direction. FIG.1 (c) is sectional drawing at the time of seeing the cooling plate 11 from upper direction.

  FIG. 1A shows an example of a liquid-cooling type cooling plate 11. The cooling plate 11 has a hollow block shape, and the cooling liquid 5 flows through the hollow portion as a flow path 6. The figure is a schematic sectional view around the cooling plate 11.

  The sheet 4 is sandwiched between a cooling belt 15 and a conveying belt 16 that are rotationally driven from the left side to the right side of the sheet, and is conveyed in the same direction as the cooling belt 15 and the conveying belt 16. The cooling plate 11 is provided so as to be in contact with the inner peripheral surface of the cooling belt 15. When the paper 4 is nipped and conveyed between the cooling belt 15 and the conveyance belt 16, the paper 4 is cooled by the cooling plate 11 via the cooling belt 15. The coolant 5 flows into the flow path 6 from the inlet 25 on the back side of the paper, and flows toward the discharge port 28 on the front side of the paper (not shown).

  In the present configuration example, when the plane area of the flow path 6 is constant, the height G of the flow path 6 is smaller than the width L of the flow path 6 in the paper transport direction, so the height G is greater than the width L. The coolant 5 in the flow path 6 can be reduced as compared with the case. As a result, the amount of the coolant 5 in which heat can be diffused in the flow path 6 when heat exchange is performed between the coolant 5 and the paper 4 than when the gap G is larger than the width L. The amount of heat per unit volume of the coolant 5 increases. Therefore, when the flow rate of the cooling liquid 5 discharged from the discharge port 28 is the same, the amount of heat per unit volume of the cooling liquid 5 discharged from the discharge port 28 increases, and heat is generated in the cooling liquid 5 in the flow path 6. Since it is difficult to remain, the temperature difference between the coolant 5 and the paper 4 in the flow path 6 can be suppressed, and the heat exchange efficiency between the coolant 5 and the paper 4 can be improved. Accordingly, the hot paper 4 can be efficiently cooled.

[Configuration example 2]
In order to efficiently lower the temperature of the paper 4, it is necessary to increase the heat flux from the paper 4 to the coolant 5 across the wall of the cooling plate 11. Here, the heat flux between the wall of the cooling plate 11 and the coolant 5 is convective heat transfer from "JP Hallman Heat Transfer Engineering <Top> (Brain Book Publishing), P11-12". It is expressed as the following equation (1).

However,
W [W]: Heat flux h [W / m ² · ° C.]: Heat transfer coefficient of cooling plate inner wall surface X [m ² ]: Cooling plate inner wall area Tr [° C.] Cooling plate inner wall surface temperature Tw [° C.]: Liquid temperature (position sufficiently away from the inner wall of the cooling plate)

  From Equation 1, in order to increase the heat flux W, it is necessary to decrease the liquid temperature Tw, increase the cooling plate inner wall area X, or improve the heat transfer coefficient h of the cooling plate inner wall surface.

  Here, as shown in FIG. 1B and FIG. 1C, when the coolant 5 flows into the inlet 25 and is discharged from the outlet 28 through the flow path 6, The flow velocity distribution of the coolant 5 in the flow path 6 forms a flow field like a flow velocity profile 7 shown in the figure.

  As can be seen from FIGS. 1B and 1C, the flow around the center line CL connecting the inflow port 25 and the discharge port 28 is fast, but the flow is slower as the distance from the center line CL increases. The slow flow of the coolant 5 not only causes a decrease in the heat transfer rate (heat exchange rate) between the coolant 5 and the cooling plate 11, but also receives the heat from the paper 4 and warms the coolant 5; The replacement with the cooled new coolant 5 flowing into the flow path 6, that is, the flow of the coolant 5 in the flow path 6 does not go smoothly. The worst state of the flow in the flow path 6 is the retention of the coolant 5, and such a retention may occur. If the cooling liquid 5 stays in the flow path 6, the cooling liquid 5 in the cooling plate 11 enters a heat retaining state at a high temperature, and the paper 4 cannot be cooled.

  The flow velocity profile 7 in the flow path 6 in the cooling plate 11 in a cross section when the cooling plate 11 shown in FIG. 1B is viewed from the sheet conveying direction is divided into the vicinity of the center and the vicinity of the end in the sheet conveying direction. The flow velocity profile near the center is denoted by reference numeral 7a, and the flow velocity profile near the end is denoted by reference numeral 7b. Note that the vicinity of the center and the vicinity of the edge in the paper conveyance direction are the positions near the center as shown in FIG. 1C, and the positions near the center line CL, and the positions near the edge are the positions near the inner side surface 11c. .

  As can be seen from the flow velocity profile 7 shown in FIG. 1B, the flow velocity near the edge is slower than that near the center in the paper conveyance direction. This is because the width of the flow path 6 in the paper conveyance direction is wide. In other words, the contact area (contact width) between the cooling plate 11 and the paper 4 to be brought into contact with each other via the cooling belt 15 is inevitably larger than a certain size in order to improve the cooling performance. It is a phenomenon that occurs.

  Further, in common in the vicinity of the center and the end in the sheet conveyance direction, as shown in FIG. 1C, the coolant 5 is closer to the inner upper surface 11b and the inner bottom surface 11a than the vicinity of the center line CL. However, this is caused by the height of the flow path 6 (the distance from the inner upper surface 11b to the inner bottom surface 11a), and is a phenomenon that always occurs when the height of the flow path 6 is increased. The slow flow of the coolant 5 in the vicinity of the inner bottom surface 11 a close to the paper 4 is a fatal problem for the cooling performance of cooling the paper 4.

  Further, when viewing the flow velocity profile 7 in a cross section when the cooling plate 11 shown in FIG. 1C is viewed from above, it is in the vicinity of the center of the flow path 6 in the sheet conveyance direction, as in FIG. It can be seen that the flow of the coolant 5 in the vicinity of the inner surface 11c near the end of the flow path 6 in the sheet conveyance direction is significantly slower than in the vicinity of the center line CL. This is because the width of the flow path 6 is widened in the paper conveyance direction, but the cooling performance is improved in the contact area (contact width) between the cooling plate 11 and the paper 4 that are contacted via the cooling belt 15. This is a phenomenon that must happen because you have to earn money to make it happen.

  As a result, in the cross-sectional direction when the cooling plate 11 shown in FIG. 1C is viewed from above, the sheet 4 can be loaded only in a narrow range near the center line CL, which is near the center of the cooling plate 11 in the sheet conveyance direction. It turns out that it cannot cool efficiently.

  As described above, when FIG. 1B and FIG. 1C are combined and the flow velocity profile 7 is viewed three-dimensionally, even in the vicinity of the center of the flow path 6 in FIG. As shown by 1 (b), the flow is slow in the vicinity of the inner upper surface 11b and the inner bottom surface 11a of the flow path 6. Further, in the vicinity of the inner upper surface 11b and the inner bottom surface 11a as shown in FIG. 1B, and in the vicinity of the inner side surface 11c, which is near the end of the flow path 6 in the sheet conveyance direction, as shown in FIG. In both cases, the flow of the coolant 5 is slow. For this reason, in a region where the flow of the coolant 5 is slow and in the vicinity of the inner upper surface 11b or the inner bottom surface 11a of the flow path 6 and the inner surface 11c, the coolant does not stay or stay in the coolant. It is predicted that only the flow of fear is generated.

  Therefore, when the cooling plate 11 having the configuration as in the configuration example 1 is used, even if the liquid cooling method is used, it is difficult to efficiently cool the paper 4 and an increase in size is inevitable.

  In the present configuration example, the flow path formed in the cooling plate 11 that is a heat exchanger is formed in a wide and narrow gap so that the paper 4 can be cooled efficiently, and FIG. 1B and FIG. ), The coolant 5 flows over the entire flow path in the cooling plate 11 so that the flow of the coolant does not slow down or stagnate in the vicinity of the inner upper surface 11b, the inner bottom surface 11a, and the inner side surface 11c. So that it flows smoothly

  4A is a cross-sectional view of the cooling plate 11 according to the present configuration example when viewed from a direction orthogonal to the paper transport direction, and FIG. 4B is a view of the cooling plate 11 according to the present configuration example from above. 4C is a cross-sectional view of the cooling plate 11 according to this configuration example when viewed from the paper transport direction.

  The cooling liquid 5 flows into the flow path 27 in the cooling plate 11 from the inflow port 25, flows into the flow path 27, and is discharged from the discharge port 28 on the opposite side. As shown in FIG. 4B, the flow path 27 is formed so that the flow direction of the coolant 5 intersects the paper transport direction. This is to prevent variations in the cooling of the paper 4 due to the temperature gradient of the cooling plate 11 caused by the flow of the coolant 5.

  Further, as shown in FIGS. 4A and 4C, the flow path 27 formed in the cooling plate 11 is a region on the outer bottom surface of the cooling plate 11 that contacts the inner peripheral surface of the cooling belt 15, that is, cooling. While having the same area as the surface 19, the height of the flow path 27 in the area of the cooling surface 19 (interval from the inner upper surface 11 b to the inner bottom surface 11 a) is made low and narrow. This is because the flow rate of the flow medium flowing through the flow path increases when the flow medium flows through the narrow gap flow path, and the flow rate does not increase by increasing the power of the pump 100. This is because the flow velocity in the entire area of the flow path 27 is increased.

  That is, the slowness of the flow near the inner top surface 11b and the inner bottom surface 11a of the cooling plate 11 and the inner side surface 11c, which are problems in the flow path 6 of the cooling plate 11 described with reference to FIG. In the flow path 27 of the cooling plate 11 configured as shown in FIG. 4C or the like, all of the slow flow in the vicinity can be eliminated by the narrow flow path effect. That is, the flow velocity can be increased in the entire area of the flow path 27 by lowering the height of the flow path 27 and making it narrow.

  Further, the distance from the center in the sheet conveyance direction (near the center line CL), which has been a problem in the flow path 6 of the cooling plate 11 described with reference to FIG. The slower the flow of the coolant 5 is, the larger the flow path 27 is like the flow path 6 but the lower the height of the flow path 27 (the distance from the inner upper surface 11b to the inner bottom surface 11a). If the gap is narrow, the cooling liquid 5 inevitably spreads and flows to the upstream side and the downstream side in the sheet conveying direction without increasing the power of the pump 100 and increasing the flow rate, and thus it is eliminated. Therefore, as shown in FIG. 4B, even if the flow path 27 has a wide shape in the sheet conveyance direction, if the height of the flow path 27 is reduced to a narrow gap, the cooling liquid is spread throughout the flow path 27. 5 flows smoothly without stagnation, and the replacement of the coolant 5 in the cooling plate 11 is performed smoothly. As a result, the heat exchange efficiency (heat transfer efficiency) between the paper 4 and the cooling plate 11 is improved. .

  Here, the flow path 27 having a wide and narrow gap provided in the cooling plate 11 of this configuration example will be described a little more.

  In this configuration example, as shown in FIG. 4A, when the width of the flow path 27 in the sheet conveyance direction is L and the height of the flow path 27 in the width L is G, G < The shape of the flow path 27 is set so as to satisfy the relationship of L. Thereby, the flow velocity of the entire flow path 27 including the vicinity of the inner bottom surface 11a close to the cooling surface 19 is increased, and the heat exchange efficiency (heat transfer efficiency) between the cooling liquid 5 and the cooling plate 11 is increased.

  Further, as shown in FIG. 4C, the thickness of the cooling plate 11 from the cooling surface 19 to the outer upper surface 11d in the direction orthogonal to the flow direction of the cooling liquid 5 (the height direction of the cooling plate 11) is H. At this time, the position where the flow path 27 is provided in the cooling plate 11 is a position closer to the cooling surface 19 than the position H / 2 from the cooling surface 19, and if possible, as shown in FIG. It is desirable to provide the flow path 27 at a position close to. Thus, by providing the flow path 27 at a position close to the cooling surface 19, the heat exchange efficiency (heat transfer efficiency) between the cooling surface 19 (cooling belt 15) and the coolant 5 is increased. High heat exchange responsiveness and highly efficient cooling of the paper 4 by the cooling plate 11 are possible. Further, by moving the flow path 27 away from the wide outer upper surface 11d on the opposite side of the cooling surface 19 of the cooling plate 11, the coolant 5 flowing in the flow path 27 is also affected by the external air heat from the outer upper surface 11d side. It becomes difficult.

  Therefore, by adopting the above-described configuration as the flow path 27 provided in the cooling plate 11, the cooling performance of the cooling plate 11 is improved, and a high cooling effect of the paper 4 is obtained. When cooling simulation was actually performed under the same conditions and confirmed, a cooling surface (contact area) of 1/3 to 1/4 compared with the heat sink shape described in Japanese Patent Application Laid-Open No. 2010-002644 (Patent Document 1). I was able to.

  Since the flow path 27 provided in the cooling plate 11 of the present configuration example has a curved shape (a curved shape slightly concentric with the cooling surface 19) like the cooling surface 19, the width L of the flow path 27 is set to an arc. However, the width L of the flow path 27 may be the length of the string. In addition, if the distance from the cooling surface 19 to the flow path 27, that is, the thickness of the cooling surface 19, is not extremely different depending on the location in the paper conveyance direction, the heat exchange efficiency does not change so much. As shown in FIG. 6, the flow path 27 may have a shape different from the curved cooling surface 19 (planar shape in FIG. 6). In this case, the horizontal length of the flow path 27 is the width. L.

  Note that the flow rate flowing from the inlet 25 to the flow channel 27 per unit time is equal to the flow rate discharged from the flow channel 27 through the discharge port 28 so that the coolant 5 flows smoothly in the flow channel 27. It is desirable to be In this configuration example, the inlet 25 and the outlet 28 have the same shape and size. However, if the sectional area of the inlet 25 and the outlet 28 is the same, the shapes of the inlet 25 and the outlet 28 are the same. Need not be the same.

  In this configuration example, as shown in FIG. 4A, the cooling liquid 5 is provided in the cooling plate 11 into which the cooling liquid 5 flows into the flow path 27 in a cross section when the cooling plate 11 is viewed from a direction orthogonal to the paper conveyance direction. The diameter of the inlet 25 is D (however, the smaller diameter is D compared to the inner diameter of the pipe 105 of the coolant circulating means 20 connected to the inlet 25), and the width of the flow path 27 in the sheet conveying direction. Is L, and the height of the flow path 27 within the width L (the distance from the inner top surface 11b to the inner bottom surface 11a) is G, L> G and L≈D or L> D, and G A flow path 27 having a wide and narrow gap was formed so as to satisfy the relationship of ≈D or G <D. That is, the flow path 27 is made a narrow gap so that any of the following conditions (1), (2), (3), and (4) is satisfied and the flow velocity is increased even with the wide flow path 27.

(1) When L> G and L is substantially the same size as D, G is shorter than D (if G ≧ D, the flow path 27 is unlikely to become a narrow gap).

(2) When L> G and L is longer than D, G is approximately the same size as D, or G is shorter than D (if G> D, the flow path 27 is unlikely to be a narrow gap).

(3) When L> G and G is approximately the same size as D, L is longer than D (if L ≦ D, the flow path 27 is unlikely to become a narrow gap).

(4) When L> G and G is shorter than D, L is approximately the same size as D, or L is longer than D (if L <D, the flow path 27 is unlikely to become a narrow gap).

  Even if the flow path 27 is wide and narrow, when the flow path 27 and the inlet 25 are compared in cross-sectional area, the flow velocity in the flow path 27 may become slow depending on the relationship.

  Usually, even if the shape of the flow path is different between the upstream side and the downstream side, if the cross-sectional area is the same and the flow rate flowing therethrough is the same, the flow velocity is the same. When the flow rate is constant between the upstream side and the downstream side and the cross-sectional areas are different, for example, when the cross-sectional area of the flow path is larger on the downstream side than on the upstream side, the flow velocity on the downstream side becomes slower than on the upstream side. Conversely, when the cross-sectional area of the flow path is smaller on the downstream side than on the upstream side, the flow velocity on the downstream side becomes faster than on the upstream side. That is, if the cross-sectional area of the flow path 27 is made larger than the cross-sectional area of the inlet 25, the flow velocity in the flow path 27 becomes slower than the inlet 25, and even if the flow path 27 is a narrow gap, For example, the flow in the vicinity of the inner surface 11c of the cooling plate 11 shown in FIG. In order to avoid this possibility, it is necessary to increase the flow velocity in the flow path 27, and the flow velocity is increased by making the cross-sectional area of the flow path 27 smaller than that of the inlet 25. Specifically, as shown in FIG. 4A, in the cross section when the cooling plate 11 is viewed from the direction orthogonal to the paper transport direction, the cross-sectional area of the flow path 27 is A, and the inlet of the cooling plate 11 25 is B (or B is the inner cross-sectional area of the pipe 105 of the coolant circulation means 20 connected to the inlet 25), the flow path 27 and the inlet so as to satisfy the relationship of A ≦ B. The shape of 25 (or the pipe 105) is set.

  At this time, the flow rate flowing into the flow channel 27 from the inlet 25 per unit time and the flow rate discharged from the flow channel 27 through the discharge port 28 so that the coolant 5 flows smoothly in the flow channel 27. It is desirable to make the cross-sectional areas of the inlet 25 and the outlet 28 equal so that they are equivalent.

  In the present configuration example, the coolant 5 flows immediately after the inlet 25 so that the coolant 5 that has flowed into the channel 27 from the inlet 25 flows smoothly throughout the paper conveyance direction of the channel 27. A flow path shape is provided in the path 27 to be diffused upstream and downstream in the paper conveyance direction.

  When the shape of the flow path 27 is expanded to the two-dot chain line shown in FIG. 4B, the flow path 27 extends to the four corners of the cooling plate 11, and the surface area of the flow path 27 and the cooling surface 19 can be expanded. However, when the cooling liquid 5 flows into the expanded flow path 27 from the inlet 25, the cooling liquid 5 diffuses and spreads to some extent upstream and downstream in the paper conveyance direction, and flows to the entire flow path 27. In the triangular area 29 at the four corners immediately expanded, no flow is generated, and the coolant 5 stays at that location. Such retention of the cooling liquid 5 causes the cooling performance of the cooling plate 11 to deteriorate, and thus the area where the flow of the cooling liquid 5 does not occur is a meaningless area and should be deleted. .

  Therefore, in this configuration example, the triangular areas 29 at the four corners are filled as shown in FIG. Further, in the present configuration example, by using the filled triangular area 29, the coolant 5 immediately after flowing into the flow path 27 from the inflow port 25 passes through the flow path 27 toward the upstream side or the downstream side in the sheet conveyance direction. The filled triangular area 29 was used as a flow guide for the coolant 5 so as to serve as a guide plate that diffuses smoothly. Specifically, as shown in FIG. 4B, one side 27b of the filled triangular area 29 is an area from the vicinity of the inflow port 25 to the flow path 27 having a wide narrow gap, and on the upstream side in the sheet conveying direction. The fan has a fan shape that gradually spreads toward the downstream side.

  Further, as shown in FIG. 4B, the discharge port 28 side is similarly filled with the triangular region 29 so that the coolant 5 flows smoothly in the flow channel 27 and flows from the flow channel 27 toward the discharge port 28. It is desirable that the fan is shaped so that the path gradually narrows so that the coolant 5 in the channel 27 is guided to the discharge port 28.

[Configuration example 3]
In this configuration example, as shown in FIG. 5, the cooling liquid 5 is diffused and spreads in the paper conveyance direction immediately after the inlet 25 so that a smooth flow of the cooling liquid 5 occurs in the entire area of the flow path 27 in the paper conveyance direction. A liquid diffusing means 30 is provided in the flow path 27.

  In FIG. 4B, the shape immediately after the inflow port 25 is a fan shape on one side of the triangular region 29, and the cooling liquid 5 flows smoothly to the upstream or downstream side in the sheet conveyance direction using the fan as a guide. In the present configuration example, the cooling liquid 5 diffuses and spreads more evenly upstream and downstream in the paper transport direction, and is sufficient even in the vicinity of the inner surface 11c that is near the end of the flow path 27 in the cooling plate 11 in the paper transport direction. So that a smooth flow occurs.

  Specifically, a cooling liquid diffusing unit 30 for uniformly diffusing the cooling liquid 5 upstream or downstream in the sheet conveying direction is provided in the region from the vicinity of the inlet 25 to the wide and narrow gap flow path 27. . For example, as shown in FIG. 5, the coolant diffusing unit 30 has a large triangular shape having a point facing the inlet 25 as a vertex when viewed as a whole, and the coolant 5 is a vertex of the large triangle. The flow path 27 is divided into two directions toward both ends of the flow path 27 in the paper conveyance direction.

  When the coolant diffusion means 30 having a large triangular shape is viewed microscopically, it is composed of a collection of a plurality of small triangular shapes having different opening widths and opening angles. The amount and direction of the cooling liquid 5 passing therethrough are adjusted according to the opening width and opening angle of each, so that a uniform flow is generated in the entire area of the flow path 27 in the sheet conveyance direction. In addition, the arrow in FIG. 5 shows the diffusion and spreading state of the coolant 5 by the coolant diffusion means 30.

  The diffusion method and shape of the cooling liquid diffusing means 30 provided in the flow path 27 are not limited. Even if the cooling liquid diffusing means 30 is directly formed in the flow path 27, the cooling liquid is separately supplied to the flow path 27 as a separate member. You may make it attach the spreading | diffusion means 30. FIG. Further, for example, a member having a hole, a net-like or fiber-like member may be used as the coolant diffusing means 30.

[Configuration Example 4]
In the present configuration example, the outside air heat is prevented from flowing into the coolant 5 in the flow path 27 from other than the cooling surface 19 of the cooling plate 11, and the temperature of the coolant 5 in the flow path 27 rises due to the outside air heat. To suppress.

  As described with reference to FIG. 4A and the like, the cooling performance of the cooling plate 11 is improved by setting a narrow gap even in the wide flow path 27, and only the dimension of the cooling plate 11 in the paper conveyance direction is obtained. In addition, as shown in FIG. 4C, the thickness of the cooling plate 11 from the cooling surface 19 to the outer upper surface 11d can be reduced, and the cooling plate 11 can be downsized.

  However, when the thickness of the cooling plate 11 is reduced, the distance from the outer upper surface 11d of the cooling plate 11 to the flow path 27 is reduced, and the outside air heat flows into the cooling liquid 5 in the flow path 27 from the outer upper surface 11d in a wide surface area. Resulting in. If the outside air heat flows into the cooling liquid 5 in the flow path 27 in this way, the cooling liquid 5 in the flow path 27 is warmed by the outside air heat and the cooling performance of the cooling plate 11 is lowered.

  Therefore, in this configuration example, for example, the heat insulating material 31 as a heat insulating means as shown in FIG. 7 covers the outer surface of the cooling plate 11 including at least the outer upper surface 11d other than the cooling surface 19, and the outside air heat is generated from the outer upper surface 11d and the like. Inflow to the cooling liquid in the flow path 27 is suppressed, temperature fluctuation of the cooling liquid 5 due to outside air heat is suppressed, and the temperature of the cooling liquid 5 is not increased. In addition, the heat insulation method by the said heat insulation means, the material of the heat insulation means, the arrangement | positioning method, etc. are not limited to what was mentioned above.

  In the present embodiment, the heat exchanging device has been applied to the cooling device 12 that is a cooling means for cooling the paper after fixing, but similarly, the curling of the paper 4 after fixing is corrected as the cooling means for the paper 4. It can also be applied as a high quality device for output image quality and paper state quality, such as a curl correction device or a gloss control device for controlling the glossiness of a toner image formed on the paper 4.

  In addition, the heat exchange device of the present embodiment can be used not only as a cooling unit but also as a heating unit if the fluidized medium is warmed before flowing into the heat exchanger. For example, it can be used in a warming device that warms the paper 4 before image transfer. The reason why the paper 4 is warmed before the image transfer is to improve transferability with an intermediate belt or the like during the transfer, and to control the moisture content of the paper 4.

  When adapting to a heating apparatus, the cooling apparatus 12 of FIG. 3 can be utilized as it is as the apparatus configuration. When the part name of the cooling device 12 is changed and viewed as the heating device 212 as shown in FIG. 8, the cooled paper 4 is heated by the heating belt 215 during nipping conveyance. Heating heat is conducted by the heating plate 211 that exchanges heat with the heating liquid 205. The heating plate 211 and the heating belt 215 are heated by heat exchange, whereby the paper 4 is heated and the temperature of the paper 4 is increased.

  Further, the circulation of the warming liquid 205 is also circulated by a closed loop circulation system constituted by the flow path 227 formed in the warming plate 211 and the warming liquid circulation means 220 as in FIG. The warming liquid 205 warmed in the circulation process flows through the flow path of the warming plate 211, so that the warming surface 219 of the warming plate 211 is warmed.

  The temperature that has been sucked and cooled by the heating surface 219 is transmitted to the flow path 227 of the heating plate 211 to cool the heating liquid 205, and the cooled heating liquid 205 is discharged from the heating plate 211. Then, the discharged warming liquid 205 is sent to the radiator 103 equipped with the tank 101, the pump 100, and the fan 104. At this time, for example, heat exhausted from the heat fixing device 116 is blown to the radiator 103 by the fan 104, and the cooled warming liquid 205 is warmed by the radiator 103 and raised to a high temperature. Thereafter, the warmed warming liquid 205 is supplied again from the inlet 225 of the warming plate 211 to the flow path 227. The low-temperature paper 4 is efficiently warmed by such a heating liquid circulation heating cycle.

As described above, according to the present embodiment, the cooling that is the heat exchanger in which the flow paths 6 and 27 through which the cooling liquid 5 that is the fluid medium flows in the direction perpendicular to the sheet conveyance direction that is the sheet-like member conveyance direction is formed. The cooling liquid 5 is conveyed to the flow paths 6 and 27 through the plate 11 and the pipes 105 communicated with the inlet 25 and the outlet 28 provided on the upstream side and the downstream side in the cooling liquid flow direction of the flow paths 6 and 27, respectively. And a pump 100 as a fluid medium conveying means, and a sheet 4 as a sheet-like member is brought into contact with a cooling surface 19 as a heat exchange surface of the cooling plate 11 directly or via a cooling belt 15 as a heat transfer member. In the cooling device 12, which is a heat exchange device that exchanges heat between the paper 4 and the coolant 5, when the width of the flow paths 6 and 27 in the paper conveyance direction is L and the height of the flow paths 6 and 27 is G. It satisfies the relationship of G <L Since the height G of the flow paths 6 and 27 is smaller than the width L of the flow paths 6 and 27 in the paper conveyance direction, the coolant 5 in the flow paths 6 and 27 is larger than when the height G is larger than the width L. Can be reduced. Accordingly, the coolant 5 in which heat can be diffused in the flow paths 6 and 27 when heat exchange is performed between the sheet 4 and the coolant 5 than when the gap G is larger than the width L. And the amount of heat per unit volume of the coolant 5 is increased. Therefore, the amount of heat per unit volume of the cooling liquid 5 discharged from the discharge port 28 increases, and heat hardly remains in the cooling liquid 5 in the flow paths 6, 27. It is possible to suppress the temperature difference between the liquid 5 and the paper 4 from being reduced, and to improve the heat exchange efficiency between the cooling liquid 5 and the paper 4. Further, since the flow path formed in the cooling plate 11 has a wide and narrow gap shape that satisfies the relationship of G <L, the cooling liquid 5 flows smoothly over the entire flow path, and the heat exchange efficiency is improved. As a result, the paper 4 can be efficiently cooled.
Further, according to the present embodiment, when the height from the cooling surface 19 of the cooling plate 11 to the outer upper surface 11d that is the outer peripheral surface facing the cooling surface 19 is H, H / Since the flow path 27 is formed at a position closer to the cooling surface 19 than the position 2, high heat exchange response with the cooling surface 19, highly efficient cooling, or heating is possible.
Further, according to the present embodiment, if the smaller diameter of the diameter of the inlet 25 and the diameter of the pipe 105 is D, L≈D or L> D and G≈D or G <D. By satisfying the relationship, the shape of the flow path in which the coolant 5 flows smoothly and smoothly in the entire flow path is further improved, so that the heat exchange efficiency (heat transfer efficiency) is further improved and the paper 4 can be cooled more efficiently.
Further, according to the present embodiment, when the cross-sectional area in the direction orthogonal to the coolant flow direction of the flow path 27 is A, and the cross-sectional area of the pipe 105 or the inlet 25 in the direction orthogonal to the coolant flow direction is B. By satisfying the relationship of A ≦ B, the flow path shape in which the coolant 5 flows smoothly and smoothly in the entire flow path 27 is further improved, so that the heat exchange efficiency (heat transfer efficiency) is further improved, and the paper 4 is further increased. It can be cooled efficiently.
Further, according to the present embodiment, the fan-shaped region in which the flow path 27 gradually spreads from the inlet 25 to the flow path 27 in the cooling plate is provided, so that the cooling is performed immediately after the inlet 25. Since the fan-shaped region in which the liquid 5 is diffused and spreads upstream and downstream in the paper conveyance direction is formed in the flow path 27, the cooling liquid 5 flows smoothly in the entire flow path 27 and is exchanged over the entire flow path 27. The efficiency is improved, and the cooling efficiency of the paper 4 is greatly improved.
Further, according to the present embodiment, the flow for diffusing the cooling liquid 5 flowing in from the inlet 25 to the upstream side or the downstream side in the sheet conveying direction from the inlet 25 inside the cooling plate to the flow path 27. By providing the cooling liquid diffusing means 30 as the medium diffusing means, the cooling liquid 5 flowing in from the inlet 25 diffuses and spreads in the paper transport direction, so that the cooling liquid 5 flows smoothly over the entire area of the flow path 27. The exchange efficiency is improved over the entire area of the flow path 27, and the cooling efficiency of the paper 4 is greatly improved.
Further, according to the present embodiment, by providing the heat insulating material 31 that is a heat insulating means on at least the outer upper surface 11d facing the cooling surface 19 of the cooling plate 11, the outside air heat flows from the outer upper surface 11d and the like into the flow path 27. It is possible to maintain the temperature of the cooling liquid 5 in the cooling plate 11 by suppressing the flow into the cooling liquid 5, suppressing the temperature fluctuation of the cooling liquid 5 due to outside air heat, and preventing the temperature of the cooling liquid 5 from rising. And stable cooling performance can be maintained.
Further, according to the present embodiment, the thermal fixing device is a toner image forming unit that forms a toner image on the paper 4 and a thermal fixing unit that fixes the toner image formed on the paper 4 to the paper 4 at least by heat. 116, and a cooling unit that cools the sheet 4 on which the toner image is fixed by the thermal fixing device 116, a cooling device that is a heat exchange device having the cooling plate 11 of the present invention as the cooling unit. 12, the cooling device 12 having the cooling plate 11 having high cooling performance is mounted on the image forming apparatus, so that the output image quality and paper state quality can be improved.
Further, according to the present embodiment, a toner image forming unit that forms a toner image on the paper 4, a heat fixing unit that fixes the toner image formed on the paper 4 to the paper 4 at least by heat, and In the image forming apparatus provided with a heating unit for heating the paper 4, a high heating is achieved by using a heating device 212 which is a heat exchange device having the heating plate 211 of the present invention as the heating unit. Since the heating device 212 having the heating plate 211 having performance is mounted on the image forming apparatus, it is possible to improve the quality of the output image quality and paper state quality.

4 Paper 5 Coolant 6 Flow path 7 Flow rate profile 7a Flow rate profile 7b Flow rate profile 11 Cooling plate 11a Inner bottom surface 11b Inner upper surface 11c Inner side surface 11d Outer upper surface 12 Cooling device 13 Cooling belt unit 14 Conveying belt unit 15 Cooling belt 16 Conveying belt 17 Drive roller 18 Roller 19 Cooling surface 20 Coolant circulation means 21 Registration roller pair 23 Paper feed roller 25 Inlet 26 Press roller 27 Channel 27b One side 28 Discharge port 29 Triangle area 29 Paper transport path 30 Coolant diffusion means 31 Heat insulating material 51 Intermediate transfer belt 52 Roller 53 Roller 54 Image station 55 Roller 56 Secondary transfer roller 58 Roller 59 Cleaning device 100 Pump 101 Tank 103 Radiator 104 Fan 105 Piping 110 Charging Device 111 Photoconductor 112 Optical writing device 113 Developing device 114 Cleaning device 115 Primary transfer roller 116 Thermal fixing device 117 Paper discharge storage portion 119 Paper storage portion 128 Paper transport path 205 Heating liquid 211 Heating plate 212 Heating device 215 Heating device Warm belt 219 Heating surface 220 Warming liquid circulation means 225 Inflow port 227 Flow path

JP 2010-002644 A JP 2006-003819 A

Claims (9)

A heat exchanger in which a flow path through which a fluid medium flows in a direction orthogonal to the sheet-like member conveyance direction;
A fluid medium transporting means for transporting the fluid medium to the channel through piping connected to an inlet and an outlet provided on the upstream and downstream sides of the fluid medium in the fluid medium flow direction,
In the heat exchanging apparatus that performs heat exchange between the sheet-like member and the fluid medium by bringing the sheet-like member into contact with the heat exchange surface of the heat exchange body directly or via a heat transfer member,
A heat exchanging apparatus characterized in that a relationship of G <L is satisfied, where L is a width of the flow path in the sheet-like member conveyance direction and G is a height of the flow path. The heat exchange device of claim 1,
When the height from the heat exchanging surface of the heat exchanging body to the outer peripheral surface facing the heat exchanging surface is H, the heat exchanging surface is located at a position H / 2 from the heat exchanging surface of the heat exchanger. A heat exchange device, characterized in that the flow path is formed at a position close to. In the heat exchange apparatus of Claim 1 or 2,
Heat having a relationship of L≈D or L> D and G≈D or G <D, where D is the smaller diameter of the diameter of the inlet and the diameter of the pipe. Exchange equipment. In the heat exchange apparatus of Claim 1, 2, or 3,
The relationship of A ≦ B is satisfied, where A is the cross-sectional area in the direction perpendicular to the fluid medium flow direction of the flow path, and B is the cross-sectional area of the pipe or the inlet in the direction perpendicular to the fluid medium flow direction. A heat exchange device characterized by. The heat exchange device according to claim 1, 2, 3 or 4,
A heat exchanging device, wherein a fan-shaped region in which the flow path gradually extends is provided between the inlet and the flow path inside the heat exchange element. The heat exchange device according to claim 1, 2, 3, 4 or 5,
Provided with a fluid medium diffusion means for diffusing the fluid medium flowing in from the inlet to the upstream side or the downstream side in the sheet-like member conveying direction between the inlet and the flow path inside the heat exchanger. A heat exchange device characterized by that. The heat exchange device according to claim 1, 2, 3, 4, 5 or 6,
A heat exchanging device, characterized in that a heat insulating means is provided at least on an outer peripheral surface of the heat exchanging body facing the heat exchanging surface. Toner image forming means for forming a toner image on a sheet-like member;
Heat fixing means for fixing the toner image formed on the sheet-like member to the sheet-like member by at least heat;
An image forming apparatus comprising: a cooling unit that cools the sheet-like member on which the toner image is fixed by the heat fixing unit;
An image forming apparatus using the heat exchanging device according to claim 1, as the cooling unit. Toner image forming means for forming a toner image on a sheet-like member;
Heat fixing means for fixing the toner image formed on the sheet-like member to the sheet-like member by at least heat;
In an image forming apparatus provided with a heating means for heating the sheet-like member,
An image forming apparatus using the heat exchange device according to claim 1, 2, 3, 4, 5, 6, or 7 as the heating means.

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