JP2022142581A - Exhaust system, dryer and image formation system - Google Patents

Abstract

To provide an exhaust system that can suppress excessive heating of a suction fan.SOLUTION: An exhaust system 32 evacuates air containing water content generated around a heating part 31 for heating a sheet S, which is transported inside a housing 20, to the outside of the housing 20. The exhaust system 32 includes: a duct 40 for guiding air to the outside of the housing 20 while absorbing heat of the air; a suction fan 41 for sucking air into the duct 40; and a cooling fin 42 for absorbing heat of the air circulating through the duct 40.SELECTED DRAWING: Figure 5

Description

The present invention relates to an exhaust device for exhausting air from the inside of a housing to the outside, a drying device, and an image forming system.

A cooling structure for cooling a fixing device of an image forming apparatus is known (Patent Document 1). In this cooling structure, a longitudinally extending housing and a cover form a duct, the interior of the duct is partitioned into a cooling duct and a branch duct, and an exhaust fan (suction) is provided at the exhaust port of the duct. there is The cooling duct is composed of a space defined by an electromagnetic induction heating coil and a partition member. The branch duct is positioned outside the partition member and is formed to join the cooling duct near the exhaust port. This structure cools the electromagnetic induction heating coil of the fixing device.

JP 2007-286163 A

However, in the cooling structure described above, there is a risk that the exhaust fan will be excessively heated by the exhaust air (hot air), resulting in failure. In other words, sufficient consideration was not given to the life of the exhaust fan.

SUMMARY OF THE INVENTION In view of the above circumstances, the present invention provides an exhaust device, a drying device, and an image forming system capable of suppressing excessive heating of a suction fan.

The present invention is an exhaust device that exhausts air containing moisture generated around a heating unit that heats a sheet conveyed inside a housing to the outside of the housing, wherein the air is heated while absorbing the heat of the air. A duct for guiding the air to the outside of the housing, a suction fan for sucking the air into the duct, and cooling fins for absorbing heat of the air flowing through the duct.

In this case, a blower fan for sending outside air into the duct may be further provided downstream of the cooling fins in the air circulation direction.

In this case, a water storage part may be provided in the duct for storing water generated by condensation of water contained in the air inside the duct.

In this case, a disposal tank may be provided detachably on the housing, for discarding the water stored in the water reservoir.

A drying apparatus according to the present invention includes a conveying section that conveys a sheet on which ink has landed, a heating section that faces the conveying section and dries the ink, and any one of the exhaust devices described above.

In this case, a plurality of the exhaust devices may be arranged along the conveying direction of the sheet, and the flow rate of the air flowing through the duct may be larger for the exhaust devices provided on the downstream side in the conveying direction. .

In this case, three or more of the exhaust devices may be arranged along the sheet conveying direction, and an interval between the adjacent exhaust devices may narrow toward the downstream side in the conveying direction.

An image forming system of the present invention includes an inkjet recording apparatus that forms an image by ejecting ink onto a sheet, and any one of the drying apparatuses described above.

According to the present invention, excessive heating of the suction fan can be suppressed.

1 is a perspective view showing the appearance of an image forming system according to an embodiment of the invention; FIG. 1 is a front view schematically showing the inside of an image forming system according to an embodiment of the invention; FIG. 1 is a block diagram showing electrical configurations of a printer and a drying device according to one embodiment of the present invention; FIG. It is a top view showing an outline of an inside of a drying device concerning one embodiment of the present invention. It is a side view showing an outline of an exhaust device concerning one embodiment of the present invention. It is a flow chart explaining operation of a drying device concerning one embodiment of the present invention. It is a side view showing an outline of an exhaust system concerning the 1st modification of one embodiment of the present invention. It is a side view which shows the outline of the exhaust apparatus which concerns on the 2nd modification of one Embodiment of this invention. It is a side view which shows the outline of the exhaust device which concerns on the 3rd modification of one Embodiment of this invention. It is a top view which shows the outline of the inside of the drying apparatus which concerns on the 4th modification of one Embodiment of this invention. It is a top view which shows the outline of the inside of the drying apparatus based on the 5th modification of one Embodiment of this invention.

Embodiments of the present invention will be described below with reference to the accompanying drawings. Note that U, Lo, L, R, Fr, and Rr shown in the drawings indicate up, down, left, right, front, and rear. Terms indicating direction and position are used in this specification, but these terms are used for convenience of description and are not intended to limit the technical scope of the present invention.

[Image forming system]
An image forming system 100 will be described with reference to FIGS. 1 and 2. FIG. FIG. 1 is a perspective view showing the appearance of the image forming system 100. As shown in FIG. FIG. 2 is a front view showing the outline of the inside of the image forming system 100. As shown in FIG.

The image forming system 100 includes a paper feeding device 110 , a printer 1 , a drying device 120 and a post-processing device 130 . The sheet feeding device 110 includes a large-capacity storage unit capable of storing thousands of sheets S, and supplies the sheets S to the printer 1 as needed. The printer 1 is an inkjet recording apparatus that ejects ink onto a sheet S to form an image. The drying device 120 heats and dries the ink ejected onto the sheet S. As shown in FIG. The post-processing device 130 performs post-processing on the sheet S such as punching, stapling, and folding.

[printer]
The printer 1 will be described with reference to FIGS. 2 and 3. FIG. FIG. 3 is a block diagram showing the electrical configuration of the printer 1 and the drying device 120. As shown in FIG.

The printer 1 has a rectangular parallelepiped housing 3 . A paper feed cassette 4 for storing sheets S such as plain paper and coated paper is detachably provided in the lower part of the inside of the housing 3 . A paper feed roller 5 for feeding the sheet S is provided near the paper feed cassette 4 . Above the paper feeding cassette 4, a conveying unit 7 is provided that attracts the sheet S and conveys it in the Y direction (leftward direction). An image forming unit 6 having a plurality of inkjet heads (not shown) is provided above the transport unit 7 . A discharge port 9 is provided on the left side of the housing 3, and a pair of discharge rollers 8 for discharging the image-formed sheet S from the discharge port 9 toward the drying device 120 is provided on the left side of the conveying unit 7. there is An ink container 13 for supplying ink to the image forming unit 6 is provided on the left side of the paper feed cassette 4 .

Inside the housing 3 , a transport path 10 is provided from the paper feed cassette 4 to the discharge port 9 via the transport unit 7 . A plurality of transport roller pairs 11 that transport the sheet S are provided in the transport path 10 . A registration roller pair 12 is provided upstream of the image forming unit 6 in the transport direction.

Each unit of the printer 1 is controlled by the control unit 2 . As shown in FIG. 3 , the control unit 2 has a storage unit 14 , an arithmetic processing unit 15 and a communication unit 16 . The storage unit 14 is a storage medium such as a semiconductor memory, and stores programs, data, and the like. The arithmetic processing unit 15 executes arithmetic processing according to a program or the like. The communication unit 16 is electrically connected to the control unit 33 of the drying device 120 to be described later, and communicates with the control unit 33 . Note that the control unit 2 may be implemented by an integrated circuit that does not use software.

[Image formation processing]
Here, a basic image forming operation of the printer 1 will be described. For example, when a print job is input to the printer 1 from an external terminal or the like, the paper feed roller 5 feeds the sheet S taken out from the paper feed cassette 4 to the transport path 10 . The registration roller pair 12 temporarily blocks the sheet S to correct the skew, and feeds the sheet S onto the belt of the conveying unit 7 at a predetermined timing. The conveying unit 7 conveys the sheet S in the Y direction while sucking it onto the belt. The image forming unit 6 (inkjet head) ejects ink droplets onto the sheet S on the belt to form (print) a full-color image. The discharge roller pair 8 discharges the image-formed sheet S from the discharge port 9 .

[Drying device]
Next, the drying device 120 will be described with reference to FIGS. 2 to 5. FIG. FIG. 4 is a plan view showing the outline of the inside of the drying device 120. As shown in FIG. FIG. 5 is a side view showing an outline of the exhaust device 32. As shown in FIG.

As shown in FIG. 2 , the drying device 120 has a rectangular parallelepiped housing 20 . A carry-in port 21 is provided on the right side of the housing 20 , and a carry-out port 22 is provided on the left side of the housing 20 . Inside the housing 20, a transport path 23 is provided that extends from the carry-in port 21 to the carry-out port 22. As shown in FIG. A transport roller pair 24 is provided on the downstream side of the transport path 23 in the transport direction.

As shown in FIGS. 2 and 4 , the drying device 120 includes a conveying section 30 , a heating section 31 , a plurality of exhaust devices 32 and a control section 33 . The transport unit 30 transports the sheet S on which ink has landed (on which an image has been formed). The heating section 31 faces the upper portion of the conveying section 30 and dries the ink on the sheet S. As shown in FIG. Each exhaust device 32 exhausts air containing moisture generated around the heating unit 31 to the outside of the housing 20 . The controller 33 controls each part of the drying device 120 . A right end portion of the transport section 30 protrudes from the carry-in port 21 to the outside of the housing 20 and is inserted into the discharge port 9 of the printer 1 . Thus, the transport path 10 of the printer 1 and the transport path 23 of the drying device 120 are connected.

<Conveyor>
As shown in FIG. 2, the transport section 30 is provided near the center of the interior of the housing 20 (the intermediate portion of the transport path 23). The transport unit 30 has a transport belt 34 , a transport plate 35 and a suction unit 36 . The transport belt 34 is formed in an endless shape and is wound around a drive roller 34A and a driven roller 34B. The conveying plate 35 has its upper surface in contact with the inner surface of the conveying belt 34 . The conveying belt 34 and the conveying plate 35 are formed with a large number of ventilation holes (not shown). The suction unit 36 applies a suction force to the sheet S on the conveying belt 34 through the ventilation holes. The drive roller 34A, the driven roller 34B, the transport plate 35, the suction unit 36, and the like are supported by a pair of front and rear transport frames 30F (see FIG. 4). When the driving roller 34A is rotationally driven by a motor (not shown), the conveying belt 34 rotates counterclockwise and conveys the sheet S in the Y direction while attracting it.

<Heating unit>
The heating section 31 has a drying housing 37 and a plurality of light sources 38 . The drying housing 37 is formed in a rectangular parallelepiped shape with an open bottom surface. Each light source 38 is composed of a halogen heater, a carbon heater, an infrared light emitting diode, or the like, and housed inside the drying housing 37 . Each light source 38 is formed in a rod-like or belt-like shape with its longitudinal direction extending in the front-rear direction. A plurality of (for example, 12) light sources 38 are arranged at regular intervals in the transport direction (horizontal direction). When the heating unit 31 heats the sheet S conveyed inside the housing 20, the ink on the sheet S is also heated, and water in the ink evaporates. As a result, the pigment of the ink is fixed on the sheet S. As shown in FIG. The heating unit 31 is provided with a measuring unit (not shown) for measuring the temperature inside the drying housing 37 and the temperature of each light source 38 .

<Exhaust device>
As shown in FIG. 4 , a plurality of (for example, three) exhaust devices 32 are arranged behind the transfer section 30 and the heating section 31 . The plurality of exhaust devices 32 are arranged at regular intervals along the sheet S conveying direction (horizontal direction). The exhaust device 32 reduces the temperature and humidity around the transport section 30 and the heating section 31 by discharging air containing moisture evaporated from the ink to the outside of the housing 20 .

Each exhaust device 32 includes a duct 40, a suction fan 41, cooling fins 42, a blower fan 43, and a waste tank 44 (see FIG. 5). Since the plurality of exhaust devices 32 have the same structure, one exhaust device 32 will be described below.

(duct)
As shown in FIG. 5 , the duct 40 is provided between the vicinity of the heating section 31 and the rear surface of the housing 20 . The duct 40 communicates the vicinity of the heating unit 31 and the outside of the housing 20 . The duct 40 is, for example, an aluminum alloy pipeline having a circular cross section. Since the duct 40 is made of aluminum alloy, which has a higher thermal conductivity than synthetic resin or the like, it guides the air to the outside of the housing 20 while absorbing the heat of the circulating air. In the following description, "flow direction" refers to the direction of air flowing inside the duct 40, and "upstream/downstream" refers to upstream/downstream in the flow direction.

One end of the duct 40 has an intake port 40A for taking in air into the duct 40, and the other end of the duct 40 has an exhaust port 40B for discharging the air to the outside of the housing 20. there is The intake port 40</b>A opens toward the gap between the conveying section 30 and the heating section 31 . Therefore, the air heated by the heating unit 31 on the conveying belt 34 (hereinafter also referred to as "high-temperature air") is taken into the duct 40 through the intake port 40A. The exhaust port 40B opens to the rear surface of the housing 20 . A middle portion of the duct 40 is curved so as to protrude downward. That is, the duct 40 is formed in a U-shape, and the bottom of the U-shaped portion serves as a water reservoir 45 . Although the details will be described later, the water storage part 45 has a function of storing water W generated by condensation of moisture contained in the air inside the duct 40 .

(suction fan)
The suction fan 41 is, for example, an electric axial flow fan that rotates a propeller fan around its axis. The suction fan 41 is fixed near the exhaust port 40B of the duct 40 . The suction fan 41 draws high temperature air into the duct 40 .

(cooling fin)
The cooling fins 42 are heat absorption/radiation parts having a plurality of plate members 50 made of, for example, an aluminum alloy. The cooling fins 42 are provided inside the duct 40 on the upstream side of the water reservoir 45, specifically near the intake port 40A. Each plate member 50 extends along the air circulation direction so as not to block the air circulation in the duct 40 . The plurality of plate members 50 are arranged at intervals in the radial direction of the duct 40 and fixed to a column member 51 penetrating the duct 40 in the radial direction. The cooling fins 42 absorb heat from the hot air flowing through the duct 40 .

(Blower fan)
The blower fan 43 is similar to the suction fan 41 and is an electric axial flow fan. The blower fan 43 is fixed to the blower port 52 opening in the duct 40 on the upstream side of the water reservoir 45 and on the downstream side of the cooling fins 42 . The air outlet 52 communicates with the outside (rear surface) of the housing 20 via an air supply duct 53 . The air supply duct 53 is, for example, an aluminum alloy pipe having a circular cross section. The blower fan 43 blows outside air into the duct 40 on the downstream side of the cooling fins 42 .

(waste tank)
The waste tank 44 is detachably attached to the housing 20 . Waste tank 44 is connected via tube 48 to reservoir 45 of duct 40 . Although the details will be described later, the water W stored in the water storage portion 45 is discarded in the disposal tank 44 .

<Control unit>
As shown in FIG. 3 , the control section 33 is similar to the control section 2 of the printer 1 and has a storage section 54 , an arithmetic processing section 55 and a communication section 56 . The communication unit 56 is electrically connected to the communication unit 16 of the control unit 2, and the control unit 2 and the control unit 33 communicate information with each other. The suction fan 41 and the blower fan 43 are each electrically connected to the controller 33 via a drive circuit (not shown) and driven and controlled by the controller 33 . Note that the control unit 33 may be realized by an integrated circuit that does not use software.

[Action of drying device]
Now, with reference to FIG. 6, the basic operation of the drying device 120 will be described. FIG. 6 is a flow chart for explaining the operation of the drying device 120. As shown in FIG.

The control unit 33 determines whether or not a print job has been input to the printer 1 (step S1). Specifically, when a print job is input to the printer 1 , the controller 2 of the printer 1 transmits a notification that the print job has been input to the controller 33 of the drying device 120 . When the control unit 33 receives the notification (step S1: YES), the control unit 33 starts warm-up operation (step S2). On the other hand, if the control unit 33 does not receive the notification (step S1: NO), the control unit 33 repeats determination of whether or not a print job has been input. Note that the control unit 33 does not operate the exhaust device 32 during the warm-up operation.

Next, the control unit 33 determines whether or not the warm-up has been completed (whether or not the measurement unit has detected a predetermined value) (step S3). If the warm-up is completed (step S3: YES), the control unit 33 transmits a notification of the completion of the warm-up (warm-up completion notification) to the control unit 2 (step S4). Upon receiving the warm-up completion notification, the control unit 2 executes the print job, and the sheet S on which the image is formed is delivered to the drying device 120 . On the other hand, if the warm-up has not been completed (step S3: NO), the determination as to whether or not the warm-up has been completed is repeated.

Next, the control unit 33 activates the transport unit 30, the heating unit 31 and the exhaust device 32 to start the drying process and the exhaust process (step S5). Specifically, the controller 33 drives the driving roller 34A to rotate the conveying belt 34, turn on the light source 38, and drive the suction fan 41 and the blower fan 43 to rotate. The heating unit 31 heats the sheet S and the ink conveyed while being attracted to the conveying belt 34, and dries the ink. This heat also heats the air in the gap between the conveying belt 34 and the heating unit 31 to become high-temperature air. Also, since the water in the heated ink evaporates, the amount of water vapor in the hot air increases.

The control unit 33 transmits an inquiry to the control unit 2 as to whether or not the print job has ended (step S6). If the control unit 33 receives a reply indicating that the print job has not ended from the control unit 2 (step S6: NO), it continues the drying process and the like. On the other hand, when the control unit 33 receives a reply indicating that the print job has ended from the control unit 2 (step S6: YES), it stops the heating unit 31 and the exhaust device 32, and ends the drying process and the exhaust process (step S6: YES). S7).

[Action of exhaust device]
Next, the action (exhaust processing) of the exhaust device 32 will be described with reference to FIG.

As described above, the high-temperature air exhausting process by the exhaust device 32 is performed at the same time as the drying process. When the control unit 33 drives the suction fan 41 and the like, an air current is generated inside the duct 40 from the intake port 40A toward the exhaust port 40B (see the arrow shown in FIG. 5). The high-temperature air is sucked into the duct 40 from the intake port 40A, and flows downstream while being deprived of heat by contacting the inner surface of the duct 40 and the cooling fins 42 (plate material 50). That is, the duct 40 and the cooling fins 42 absorb heat from the hot air and lower the temperature of the hot air. Here, as the cooling of the high-temperature air progresses, the water vapor contained in the high-temperature air begins to exceed the saturated water vapor amount, and excess water vapor exceeding the saturated water vapor amount begins to turn into water W (water droplets WD). That is, condensation begins to occur.

Further, when the control unit 33 drives the blower fan 43, outside air is taken into the duct 40 through the air supply duct 53 (see the arrow shown in FIG. 5). The high-temperature air that has passed through the cooling fins 42 is rapidly cooled by being joined with the outside air sent by the blower fan 43, promoting dew condensation.

Mainly, the U-shaped portion of the duct 40 is a range where dew condensation is likely to occur, and the water W (water droplets WD) generated by the dew condensation falls mainly along the inner surface of the duct 40 and reaches the water storage portion 45 (U-shaped portion). bottom). The water W accumulated in the water storage part 45 is recovered to the waste tank 44 through the tube 48 . According to this configuration, when the waste tank 44 is full, the user can remove the waste tank 44 from the housing 20 and easily discard the collected water W.

The air that has passed through the water reservoir 45 has a lower temperature and lower humidity than the air before passing through the water reservoir 45 . The low-temperature air passes through the downstream side of the duct 40 by the airflow generated by the suction fan 41 and is discharged to the outside of the housing 20 from the exhaust port 40B.

According to the exhaust device 32 according to the present embodiment described above, the duct 40 and the cooling fins 42 are made of aluminum alloy (made of metal), which has a higher thermal conductivity than, for example, synthetic resin. It can efficiently absorb the heat of high temperature air. As a result, the temperature of the air flowing through the duct 40 can be lowered, so excessive heating of the suction fan 41 can be suppressed. As a result, the suction fan 41 will not be damaged by excessive heating, and the life of the suction fan 41 can be extended.

Further, according to the exhaust device 32 according to the present embodiment, since the outside air sent by the blower fan 43 joins the high-temperature air in the duct 40 downstream of the cooling fins 42, the air that has passed through the cooling fins 42 The temperature can be lowered further. Further, since the high-temperature air flowing through the duct 40 is cooled by the outside air sent by the blower fan 43, excess moisture in the air can be forcibly condensed inside the duct 40. - 特許庁As a result, the air from which excess water has been removed comes into contact with the suction fan 41, so that it is possible to prevent the suction fan 41 from malfunctioning due to adhesion of water in the air.

Further, according to the exhaust device 32 of the present embodiment, the duct 40 is provided with the water storage portion 45 , so that the water droplets WD condensed in the duct 40 can be stored in the water storage portion 45 . As a result, it is possible to prevent the water droplets WD from flowing back to the heating unit 31 or adhering to the suction fan 41 .

By the way, since the sheet S and the conveying belt 34 move while being heated by the heating unit 31, the heating time is accumulated from the upstream side to the downstream side in the conveying direction. Therefore, focusing on one sheet S, the sheet S located at the upstream end in the transport direction has the lowest temperature, and the sheet S moved to the downstream end in the transport direction has the highest temperature. Considering the radiant heat from the sheet S, the conveying belt 34, etc., the air in the gap between the conveying belt 34 and the heating unit 31 also reaches the highest temperature on the downstream side in the conveying direction.

Therefore, in the drying device 120, the flow rate of the air flowing through the duct 40 is set so that the exhaust device 32 provided on the downstream side in the conveying direction has a greater flow rate. Specifically, the rotational speed of the suction fan 41 is set higher for the exhaust device 32 provided on the downstream side in the transport direction. More specifically, the suction fan 41 of the exhaust device 32 arranged most upstream in the transport direction is set to rotate at low speed, and the suction fan 41 of the exhaust device 32 arranged most downstream in the transport direction is set to rotate at high speed. The suction fan 41 of the exhaust device 32 disposed between the two exhaust devices 32 is set to rotate at medium speed (intermediate between low speed rotation and high speed rotation). In addition, the rotational speed of the blower fan 43 may be set higher for the exhaust device 32 provided on the downstream side in the transport direction so as to be proportional to the rotational speed of the suction fan 41 .

According to the drying device 120 according to the present embodiment described above, since the discharge amount of the plurality of exhaust devices 32 (the flow rate of the air flowing through the duct 40) increases toward the downstream side in the conveying direction, the heating unit 31 The ambient temperature can be made generally uniform from upstream to downstream in the conveying direction. As a result, it is possible to prevent excessive heating of only a portion of the conveying section 30, the heating section 31, and the like. In addition, in the drying device 120 according to the present embodiment, the rotation speeds of the plurality of suction fans 41 (blowing fans 43) are changed depending on the arrangement, but this is not the only option, and the rotation speeds of the plurality of suction fans 41 and the like are all changed. They may be the same.

In addition, in the exhaust device 32 according to the present embodiment, the duct 40 and the air supply duct 53 are made of an aluminum alloy having a circular cross section, but the present invention is not limited to this. The cross-sectional shapes of the duct 40 and the air supply duct 53 may be elliptical or polygonal such as quadrangular (not shown). Further, the material of the duct 40 and the air supply duct 53 may be galvanized iron plate, steel plate, stainless steel plate, or the like. The material of the duct 40 may be any material as long as it has a high thermal conductivity compared to a material such as a synthetic resin which has a low thermal conductivity. On the other hand, the material of the air supply duct 53 may be synthetic resin or the like. Moreover, it is preferable that the material of the duct 40 and the like be a material that is difficult to corrode. Furthermore, in order to prevent corrosion and improve the flow of water droplets WD, the inner peripheral surface of the duct 40 and the like may be coated with fluorine or the like.

Further, in the exhaust device 32 according to the present embodiment, the water reservoir 45 is formed by curving the duct 40 into a U-shape, but the present invention is not limited to this. For example, the water reservoir 45 may be formed by bending the duct 40 into a V shape (not shown). Alternatively, as shown in FIG. 7, the water reservoir 46 may be a recess formed in the bottom surface of the duct 40 (first modification). In addition, although the water storage part 45 is formed as a part of the duct 40, the water storage part 47 is formed of a member different from the duct 40 as shown in FIG. (second modification). In this case, it is preferable that a hole is made in the bottom surface of the duct 40 and the water reservoir 47 is attached so as to cover the hole. Also, in this case, the waste tank 44 and the tube 48 may be omitted. In addition, in the case of the first and second modifications, it is preferable that the duct 40 be provided so as to slope downward toward the water reservoirs 46 and 47 (not shown).

Further, in the exhaust device 32 according to the present embodiment, the exhaust port 40B of the duct 40 is open to the rear surface of the housing 20, but this is not a limitation, and for example, the exhaust port 40B may be opened to the upper surface of the housing 20 or the like. good (not shown). Further, although the outside air intake port of the air supply duct 53 is opened in the rear surface of the housing 20, it is not limited to this, and may be opened in the upper surface of the housing 20 or the like (not shown). .

Further, in the exhaust device 32 according to the present embodiment, the blower fan 43 is arranged upstream of the water reservoir 45 and downstream of the cooling fins 42, but the invention is not limited to this. Since the blower fan 43 only needs to be able to send outside air into the duct 40 on the downstream side of the cooling fins 42, for example, as shown in FIG. It may be provided downstream of the water reservoir 45 (third modification). Further, for example, two or more blower fans 43 and the like may be provided on the upstream side and the downstream side with the water reservoir 45 interposed therebetween (not shown).

Further, in the exhaust device 32 according to the present embodiment, the suction fan 41 and the blower fan 43 are axial blowers, but they are not limited to this, and may be, for example, centrifugal blowers such as sirocco fans (not shown). ).

Further, in the exhaust device 32 according to the present embodiment, the high-temperature air taken in from the intake port 40A is forcibly cooled by joining the outside air taken in from the blower fan 43 (air blower port 52). , the invention is not limited thereto. For example, the blower fan 43, the blower port 52, and the air supply duct 53 may be omitted, and the high-temperature air taken in from the air intake port 40A may be naturally cooled and condensed while passing through the duct 40 (not shown). ).

Further, in the exhaust device 32 according to this embodiment, the cooling fins 42 are made of aluminum alloy, but the present invention is not limited to this. The material of the cooling fins 42 is the same as that of the duct 40 and the like, and may be any material as long as it has a high thermal conductivity compared to a material such as a synthetic resin, which is considered to have a low thermal conductivity. The cooling fins 42 may be made of a material that is resistant to corrosion, or may be coated with fluorine or the like to prevent corrosion and improve the flow of water droplets WD. Furthermore, the cooling fin 42 has a plurality of plate members 50, but is not limited to this and may have a plurality of rod-shaped members (not shown). Even in this case, it is preferable that the rod-shaped member is extended in the air circulation direction.

Moreover, although the waste tank 44 is provided in the exhaust device 32 according to the present embodiment, the present invention is not limited to this. For example, the waste tank 44 may be omitted when there is little need to collect the water W in the water storage part 45, such as when the water W stored in the water storage part 45 is small.

Although the drying device 120 according to this embodiment is provided with the three exhaust devices 32, the present invention is not limited to this. At least one exhaust device 32 should be provided, and the number of exhaust devices 32 can be freely changed according to the length of the conveying unit 30 and the heating unit 31 in the conveying direction.

In addition, in the drying device 120 according to the present embodiment, by changing the rotation speed of the suction fan 41, the flow rate of the air flowing through the duct 40 increases as the exhaust device 32 is provided downstream in the conveying direction. , the present invention is not limited to this. For example, as shown in FIG. 10, by setting the rotational speeds of the suction fans 41 of the plurality of exhaust devices 32 to be the same and changing the inner diameter (or cross-sectional area) of the duct 40, the flow rate of the air flowing through the duct 40 can be changed. You may (4th modification). That is, the inner diameter and the like of the duct 40 may be set larger for the exhaust device 32 provided on the downstream side in the transport direction. In this case, the outer diameter of the propeller fan of the suction fan 41 may be changed so as to be proportional to the inner diameter of the duct 40 (not shown).

Further, in the drying device 120 according to this embodiment, the plurality of exhaust devices 32 are arranged at equal intervals in the transport direction, but the present invention is not limited to this. For example, as shown in FIG. 11, three or more (for example, four in FIG. 10) exhaust devices 32 having the same exhaust flow rate are arranged along the transport direction, and the distance between the adjacent exhaust devices 32 is the transport. It may be set so that it becomes narrower toward the downstream side in the direction (fifth modification). This configuration can also increase the exhaust amount on the downstream side in the transport direction. Note that in the drying device 120 according to the fourth and fifth modifications, the rotation speed of the suction fan 41 may be set higher for the exhaust device 32 provided further downstream in the transport direction.

In addition, in the drying device 120 according to the present embodiment, the conveying unit 30 is of a belt conveying type, but is not limited to this, and for example, a plurality of roller pairs may be provided along the conveying path 23 (not shown). figure).

In addition, in the description of the present embodiment, as an example, the case where the exhaust device 32 is applied to the drying device 120 that dries the ink on the sheet S is shown. image forming apparatus (not shown). In this case, the exhaust device 32 can appropriately exhaust the air around the fixing device that thermally fixes the toner image on the sheet S to the outside.

It should be noted that the description of the above embodiment shows one aspect of the exhaust device, the drying device, and the image forming system according to the present invention, and the technical scope of the present invention is not limited to the above embodiment. The present invention may be changed, replaced, and modified in various ways without departing from the spirit of the technical idea, and the claims include all embodiments that can be included within the scope of the technical idea.

1 Printer (inkjet recording device)
20 Housing 30 Conveying Unit 31 Heating Unit 32 Exhaust Device 40 Duct 41 Suction Fan 42 Cooling Fin 43 Blowing Fan 44 Waste Tank 45, 46, 47 Water Storage Unit 100 Image Forming System 120 Drying Device S Sheet

Claims (8)

An exhaust device for exhausting air containing moisture generated around a heating unit that heats a sheet conveyed inside a housing to the outside of the housing,
a duct that guides the air to the outside of the housing while absorbing the heat of the air;
a suction fan for sucking the air into the duct;
and cooling fins for absorbing heat of the air flowing through the duct. 2. The exhaust system according to claim 1, further comprising a blower fan for blowing outside air into the duct downstream of the cooling fins in the air circulation direction. 3. The exhaust system according to claim 1, further comprising a water storage part provided in said duct for storing water produced by condensation of water contained in said air inside said duct. 4. The exhaust system according to claim 3, further comprising a waste tank that is detachably provided on the housing and that wastes the water stored in the water reservoir. a conveying unit that conveys a sheet on which ink has landed;
a heating unit that faces the transport unit and dries the ink;
A drying apparatus comprising the exhaust apparatus according to any one of claims 1 to 4. A plurality of the exhaust devices are arranged along the conveying direction of the sheet,
6. The drying device according to claim 5, wherein the flow rate of the air flowing through the duct is greater in the downstream side of the conveying direction of the exhaust device. three or more of the exhaust devices are arranged along the conveying direction of the sheet;
7. The drying apparatus according to claim 5 or 6, wherein the distance between adjacent exhaust devices becomes narrower toward the downstream side in the conveying direction. an inkjet recording device that forms an image by ejecting ink onto a sheet;
An image forming system comprising the drying device according to any one of claims 5 to 7.

Images