Patent Application
20240360624
The present application is based on, and claims priority from JP Application Serial Number 2023-072371, filed Apr. 26, 2023, the disclosure of which is hereby incorporated by reference herein in its entirety.
The present disclosure relates to a sheet manufacturing device and a water vapor recovery mechanism.
Hitherto, mechanisms that suppress an influence of dew condensation that occurs inside a device have been known. Dew condensation forms water droplets and falls onto members or products, which may cause various problems. For example, JP-A-2020-21009 discloses an image forming device that restricts dew condensation to occur only at a specific location and reduces the occurrence of dew condensation at locations other than the specific location.
However, the device described in JP-A-2020-21009 has a problem in that a duct, a water vapor moving section, or the like tends to have a complicated configuration. Specifically, for example, a cross-sectional shape of the water vapor moving section is a lattice shape. Therefore, the members have complicated configurations, which may cause an increase in manufacturing costs. In other words, there is a need for a device that has a simple configuration and can suppress water droplets formed by dew condensation from falling onto critical parts.
According to an aspect of the present disclosure, a sheet manufacturing device includes: a heating section that heats a web containing fibers; and a hood section that is arranged above the heating section and collects water vapor generated from the web, in which the hood section includes a collection section that holds water droplets generated on an inner surface of the hood section.
According to an aspect of the present disclosure, a water vapor recovery mechanism includes: a hood section that collects water vapor generated from below; and an exhaust section that communicates with an inside of the hood section, in which the hood section includes a collection section that holds water droplets generated on an inner surface of the hood section, and the exhaust section sucks air inside the hood section and collects the water vapor.
In the following embodiment, a sheet manufacturing device 1 that recycles a paper piece such as waste paper in a dry manner will be exemplified and described with reference to the drawings. The sheet manufacturing device according to the present disclosure is not limited to a dry type, and may be a wet type. In the present specification, the dry type means that the recycling is not performed in a liquid, but is performed in air such as the atmosphere.
In the following drawings, an X axis, a Y axis, and a Z axis are used as coordinate axes orthogonal to one another, a direction pointed by each arrow is a + direction, and a direction opposite to the + direction is a − direction. The Z axis is a virtual axis along a vertical direction, a +Z direction is an upward direction, and a −Z direction is a downward direction. The −Z direction is a direction in which gravity acts. In the sheet manufacturing device 1, a side ahead of a transport direction of a raw material, a web, a sheet, or the like may be referred to as downstream, and a side opposite to the transport direction may be referred to as upstream. For convenience of illustration, the size of each member is different from the actual size.
As illustrated in
The sheet manufacturing device 1 manufactures the sheet P3 from the waste paper C. In the sheet manufacturing device 1, the first unit group 101, the third unit group 103, and the second unit group 102 are arranged from a −Y direction toward a +Y direction when viewed from a side in a −X direction.
The waste paper C is transported from the first unit group 101 to the second unit group 102 via a pipe 21 that traverses the third unit group 103. Then, the waste paper C is subjected to defibration or the like in the second unit group 102 to become fibers, and is then made into a mixture containing a binding material or the like. The mixture is transported to the third unit group 103 via a pipe 24. The mixture is formed into a web W in the third unit group 103, and then formed into a strip-shaped sheet P1. The strip-shaped sheet P1 is formed into the sheet P3 by being cut in the first unit group 101.
The first unit group 101 includes a buffer tank 13, a quantitative supply section 15, a joining section 17, and the pipe 21. In the first unit group 101, these components are arranged in the above-described order from upstream to downstream. The first unit group 101 also includes a first cutting section 81, a second cutting section 82, a tray 91, and a shredding section 95. The first cutting section 81 and the second cutting section 82 cut the strip-shaped sheet P1 into the sheet P3 having a predetermined shape. The first unit group 101 further includes a water supply section 67. The water supply section 67 is a water storage tank. The water supply section 67 supplies water for humidification to each of a first humidification section 65 and a second humidification section 66 to be described later through a water supply pipe (not illustrated).
The waste paper C is input into the buffer tank 13 from a raw material input port 11. The waste paper C is, for example, a shredded waste paper piece containing fibers such as cellulose. Humidified air is supplied into the buffer tank 13 from the second humidification section 66 included in the third unit group 103.
The waste paper C to be defibrated is temporarily stored in the buffer tank 13 and then transported to the quantitative supply section 15 when the sheet manufacturing device 1 operates. The sheet manufacturing device 1 may include a shredder provided upstream of the buffer tank 13 to shred waste paper or the like.
The quantitative supply section 15 includes a measuring instrument 15a and a supply mechanism (not illustrated). The measuring instrument 15a measures a mass of the waste paper C. The supply mechanism supplies the waste paper C measured by the measuring instrument 15a to the joining section 17 positioned downstream thereof. That is, the quantitative supply section 15 measures a predetermined mass of waste paper C by using the measuring instrument 15a, and supplies the waste paper C to the joining section 17 positioned downstream through the supply mechanism.
Both digital and analog measuring mechanisms can be applied as the measuring instrument 15a. Specifically, examples of the measuring instrument 15a include physical sensors such as a load cell, a spring scale, and a balance. In the present embodiment, a load cell is used as the measuring instrument 15a. The predetermined mass of the waste paper C measured by the measuring instrument 15a is, for example, about several grams to several tens of grams.
A known technology such as a vibrating feeder can be applied as the supply mechanism. The supply mechanism may be included in the measuring instrument 15a.
The measurement and supply of the waste paper C in the quantitative supply section 15 is batch processing. That is, the supply of the waste paper C from the quantitative supply section 15 to the joining section 17 is performed intermittently. The quantitative supply section 15 may include a plurality of measuring instruments 15a, and may operate the plurality of measuring instruments 15a at different timings to improve the efficiency of the measurement.
In the joining section 17, the waste paper C supplied from the quantitative supply section 15 is mixed with shredded pieces of the slit piece S supplied from the shredding section 95. The slit piece S and the shredding section 95 will be described later. The waste paper C mixed with the shredded pieces flows into the pipe 21 from the joining section 17.
The pipe 21 transports the waste paper C from the first unit group 101 to the second unit group 102 by an airflow generated by a blower (not illustrated).
The second unit group 102 includes a defibrating section 31 which is a dry-defibrating machine, a separating section 32, a pipe 23, a mixing section 33, and the pipe 24. In the second unit group 102, these components are arranged in the above-described order from upstream to downstream. The second unit group 102 further includes a pipe 25 coupled to the separating section 32, a recovery section 35, a compressor 38, and a power supply section 39.
The waste paper C transported through the pipe 21 flows into the defibrating section 31. The defibrating section 31 performs dry defibration of the waste paper C supplied from the quantitative supply section 15, so that the waste paper C becomes fibers. A known defibrating mechanism can be applied as the defibrating section 31.
The defibrating section 31 may have the following configuration, for example. The defibrating section 31 includes a stator and a rotor. The stator has a substantially cylindrical inner surface. The rotor is installed inside the stator and rotates along the inner surface of the stator. The shreds of the waste paper C are caught between the inner surface of the stator and the rotor and are defibrated by a shearing force generated between the stator and the rotor. As a result, the tangled fibers contained in the shreds of the waste paper C are untangled. The waste paper C is made into fibers and transported to the separating section 32.
The separating section 32 separates the defibrated fibers. Specifically, the separating section 32 removes components contained in the fibers that are unnecessary for manufacturing the sheet P3. Specifically, the separating section 32 separates relatively long fibers and relatively short fibers from each other. The relatively short fibers may cause a decrease in strength of the sheet P3 and are thus separated in the separating section 32. The separating section 32 also separates and removes a coloring material, an additive, and the like contained in the waste paper C. A known technology such as a disk mesh method can be applied to the separating section 32.
Humidified air is supplied into the separating section 32 from the second humidification section 66 of the third unit group 103.
The defibrated fibers are transported to the mixing section 33 via the pipe 23 after the relatively short fibers are removed. Unnecessary components such as the relatively short fibers and the coloring material are discharged to the recovery section 35 via the pipe 25.
The mixing section 33 mixes the fibers with the binding material or the like in the air to form the mixture. Although not illustrated, the mixing section 33 includes a flow path through which the fibers are transported, a fan, a hopper, a supply pipe, and a valve.
The hopper communicates with the flow path for the fibers via the supply pipe. The valve is provided in the supply pipe between the hopper and the flow path. The hopper supplies the binding material such as starch into the flow path. The valve adjusts a mass of the binding material supplied from the hopper to the flow path. Thereby, a mixing ratio of the fibers and the binding material is adjusted.
The mixing section 33 may have a similar configuration for supplying the coloring material, the additive, and the like in addition to the above configuration for supplying the binding material.
The fan of the mixing section 33 transports the fibers downstream with the generated airflow and mixes the binding material or the like in the air to form the mixture. The mixture flows from the mixing section 33 into the pipe 24.
The recovery section 35 includes a filter (not illustrated). The filter filters out unnecessary components such as the relatively short fibers transported through the pipe 25 by the airflow.
The compressor 38 generates compressed air. The filter may be clogged due to fine particles among the unnecessary components. The compressed air generated by the compressor 38 can be blown onto the filter to blow away adhering particles and clean the filter.
The power supply section 39 includes a control section (not illustrated) and a power supply device that supplies power to the sheet manufacturing device 1. The power supply section 39 distributes power supplied from the outside to each component of the sheet manufacturing device 1. The control section is electrically coupled to components of the sheet manufacturing device 1 and integrally controls operation of the components.
The third unit group 103 accumulates and compresses the mixture containing the fibers to form the strip-shaped sheet P1 which is recycled paper. The third unit group 103 includes an accumulation section 50, a first transport section 61, a second transport section 62, the first humidification section 65, the second humidification section 66, a drainage section 68, a heating section 70, and a water vapor recovery mechanism 40. The water vapor recovery mechanism 40 includes a hood section 41, a pipe 48, and an exhaust section 49. In
In the third unit group 103, the accumulation section 50, the first transport section 61, the second transport section 62, the first humidification section 65, and the heating section 70 are arranged in the above-described order from upstream to downstream. The second humidification section 66 is arranged below the first humidification section 65. The hood section 41 is arranged above the heating section 70 in the water vapor recovery mechanism 40.
The accumulation section 50 generates the web W by accumulating the mixture containing the separated fibers in the air. The accumulation section 50 includes a drum member 53, a blade member 55 installed in the drum member 53, a housing 51 that houses the drum member 53, and a suction section 59. The mixture is taken into the drum member 53 from the pipe 24.
The first transport section 61 is arranged below the accumulation section 50. The first transport section 61 includes a mesh belt 61a and five tension rollers (not illustrated) that stretch the mesh belt 61a. The suction section 59 faces the drum member 53 with the mesh belt 61a interposed therebetween in a direction along the Z axis.
The blade member 55 is positioned inside the drum member 53 and is rotationally driven by a motor (not illustrated). The drum member 53 is a semi-cylindrical sieve. A net functioning as a sieve is provided at a side surface of the drum member 53 that faces downward. The drum member 53 allows particles of the fibers, the mixture, or the like smaller than an opening size of the net serving as a sieve to pass from the inside to the outside.
The mixture is discharged to the outside of the drum member 53 while being stirred by the rotating blade member 55 within the drum member 53. The humidified air is supplied into the drum member 53 from the second humidification section 66.
The suction section 59 is arranged below the drum member 53. The suction section 59 sucks air inside the housing 51 through a plurality of holes of the mesh belt 61a. The plurality of holes of the mesh belt 61a allow air to pass through but impede the passage of the fibers, the binding material, and the like contained in the mixture. As a result, the mixture discharged to the outside of the drum member 53 is sucked downward together with the air. The suction section 59 is a known suction device such as a blower.
The mixture is dispersed in the air within the housing 51 and accumulated on an upper surface of the mesh belt 61a by gravity and suction by the suction section 59 to form the web W.
The mesh belt 61a is an endless belt and is stretched by five tension rollers. The mesh belt 61a rotates counterclockwise in
The second transport section 62 transports the web W downstream of the first transport section 61 in place of the first transport section 61. The second transport section 62 peels the web W from the upper surface of the mesh belt 61a and transports the web W toward the heating section 70. The second transport section 62 is positioned above a transport path of the web W and is arranged slightly upstream of a starting point on a return side of the mesh belt 61a. A+Y-direction-side portion of the second transport section 62 and a −Y-direction-side portion of the mesh belt 61a partially overlap each other in the vertical direction.
The second transport section 62 includes a transport belt, a plurality of rollers, and a suction mechanism (not illustrated). The transport belt has a plurality of holes through which air passes. The transport belt is stretched by a plurality of rollers, and rotates as the rollers rotate.
The second transport section 62 makes an upper surface of the web W adhere to a lower surface of the transport belt by a negative pressure generated by the suction mechanism. As the transport belt rotates in this state, the web W adheres to the transport belt and transported downstream.
The first humidification section 65 humidifies the web W containing the fibers accumulated in the accumulation section 50 of the third unit group 103. Specifically, the first humidification section 65 is, for example, a mist type humidifier, and supplies mist M from below to the web W transported by the second transport section 62 to humidify the web W. The first humidification section 65 is arranged below the second transport section 62 and faces the web W transported by the second transport section 62 in the direction along the Z axis. A known humidification device such as an ultrasonic type humidification device can be applied as the first humidification section 65.
As the web W is humidified with the mist M, the function of the starch as the binding material is promoted, and the strength of the sheet P3 is improved. Furthermore, since the web W is humidified from below, droplets formed by the mist are prevented from falling onto the web W. Furthermore, since humidification is performed from a side opposite to a contact surface between the transport belt and the web W, sticking of the web W to the transport belt is reduced. The second transport section 62 transports the web W to the heating section 70.
The heating section 70 heats and presses the web W to form the strip-shaped sheet P1. The heating section 70 includes a pair of heating rollers 71 and 72. Each of the pair of heating rollers 71 and 72 has a built-in electric heater and has a function of heating the surface of the roller.
By continuously passing the web W between the pair of heating rollers 71 and 72, the web W is pressed while being heated. As a result, the air in the web W which is soft and contains a relatively large amount of air is reduced, and the fibers are bound together by the binding material, so that the strip-shaped sheet P1 is formed. The strip-shaped sheet P1 is transported to the first unit group 101 by a transport roller (not illustrated).
As the heating section 70 heats the web W, water contained in the web W evaporates as water vapor V. Generally, when water vapor is cooled, dew condensation occurs. Hitherto, when dew condensation becomes significant, water droplets may fall downward, deteriorating the quality of a finished product or the like. Therefore, the water vapor recovery mechanism 40 recovers the water vapor V generated from the web W and prevents water droplets formed by the dew condensation of the water vapor V from falling onto critical parts such as the heating section 70 and the sheet P1.
The hood section 41 is opened downward and has a shape in which an internal space thereof is tapered from the bottom to the top. Thereby, the hood section 41 has a function of collecting the water vapor V generated from below, that is, the water vapor V generated from the web W. Note that details of the hood section 41 will be described later.
The pipe 48 is coupled to a top portion of the hood section 41. The pipe 48 is routed downward and coupled to the inside of the first humidification section 65. The exhaust section 49 is provided along a path of the pipe 48 from the hood section 41 to the first humidification section 65. The exhaust section 49 communicates with the inside of the hood section 41.
The exhaust section 49 is, for example, an electric suction fan, which sucks air inside the hood section 41, collects the water vapor V generated from the web W and humid air, and sends the water vapor V and the humid air to the first humidification section 65. As the exhaust section 49 performs the suction, the water vapor V is more easily collected into the hood section 41. Therefore, the occurrence of dew condensation on an outer side of the hood section 41 can be further suppressed.
As a result, the water vapor V generated from the web W in the heating section 70 is collected inside the hood section 41 positioned above. A part of the water vapor V condenses on an inner surface of the hood section 41. The remaining part of the water vapor V is returned to the first humidification section 65 via the pipe 48, and humidifies the web W together with the mist M generated by the first humidification section 65.
The second humidification section 66 is arranged below the first humidification section 65. A known evaporative humidification device can be applied as the second humidification section 66. Examples of the evaporative humidification device include those that evaporate water by applying wind to a wet nonwoven fabric to generate humidified air.
The second humidification section 66 humidifies a predetermined region of the sheet manufacturing device 1. The predetermined region is one or more of the buffer tank 13, the separating section 32, and the inside of the drum member 53 of the accumulation section 50. Specifically, the humidified air is supplied from the second humidification section 66 to the above-described region via a plurality of pipes (not illustrated). In each of the above-described components, the humidified air suppresses charging of the waste paper C, the fibers, or the like, and suppresses adhesion to the members due to static electricity.
The drainage section 68 is a drainage tank. The drainage section 68 is used in the first humidification section 65, the second humidification section 66, and the like, and collects and stores old water. The drainage section 68 can be removed from the sheet manufacturing device 1 as necessary to discard accumulated water.
The strip-shaped sheet P1 transported to the first unit group 101 reaches the first cutting section 81. The first cutting section 81 cuts the strip-shaped sheet P1 in a direction intersecting the transport direction, for example, in a direction along the X axis. The strip-shaped sheet P1 is cut into cut sheet P2 by the first cutting section 81. The cut sheet P2 is transported from the first cutting section 81 to the second cutting section 82.
The second cutting section 82 cuts the cut sheet P2 in the transport direction, for example, in a direction along the Y axis. Specifically, the second cutting section 82 cuts peripheries of both sides of the cut sheet P2 in the direction along the X axis. As a result, the cut sheet P2 is formed into the sheet P3 having a predetermined shape such as an A4 sheet or A3 sheet. The sheet P3 is transported diagonally upward and stacked on the tray 91. The sheet P3 can be used as a substitute for copy paper, for example.
When the second cutting section 82 cuts the cut sheet P2 into the sheet P3, the slit piece S, which is a scrap, is generated. The slit piece S is transported approximately in the −Y direction and reaches the shredding section 95 which is a shredder. The shredding section 95 shreds the slit piece S and supplies the shredded pieces to the joining section 17. A mechanism may be installed between the shredding section 95 and the joining section 17 to measure and supply the shredded pieces of the slit piece S to the joining section 17.
As illustrated in
As illustrated in
The pipe 48 is coupled to the top portion of the hood section 41. In
As illustrated in
The support sections 43 are fixed to four corners of the hood section 41 in plan view. Therefore, it is difficult for vibrations or the like during the operation of the sheet manufacturing device 1 to propagate to the hood section 41. As a result, the water droplets generated on the inner surface of the hood section 41 are less likely to fall. For example, screw fastening is applied to fix the hood section 41 and the support sections 43.
The support sections 43 are supported by the frame of the sheet manufacturing device 1 described above. That is, the hood section 41 is supported by the frame via the support sections 43.
The support section 43 is produced using, for example, a metal plate by sheet metal processing. In the present embodiment, the support sections 43 suspend the hood section 41 at four points, but the number of points at which the support sections 43 suspend the hood section 41 is not limited thereto. It is sufficient that the support sections 43 suspend the hood section 41 at one or more points.
As illustrated in
The collection section 410 has a first surface 411 and a second surface 412. The first surface 411 is a surface positioned at a lower end portion of the collection section 410 and intersecting the vertical direction. In the present embodiment, the first surface 411 is along an XY plane. The first surface 411 makes it easier for the water droplets D to be held in the collection section 410. Therefore, it is possible to further suppress the water droplets from falling downward.
The second surface 412 is a surface intersecting the first surface 411. In the present embodiment, the second surface 412 is along a YZ plane. As the second surface 412 is provided, the amount of water droplets D that can be held in the collection section 410 is increased. Therefore, it is possible to further suppress the water droplets from falling downward.
The water droplets D collected in the collection section 410 may be made to flow into the water supply section 67 or the drainage section 68 via a tube or the like.
According to the present embodiment, the following effects can be obtained.
It is possible to suppress the water droplets D formed by dew condensation of the water vapor V from falling onto the critical parts and the sheet P1 with a simple configuration. Specifically, the hood section 41 and the collection section 410 suppress the water droplets D from falling downward, without relying on a configuration in which dew condensation is caused only in a specific location as in the related art. As a result, the occurrence of rust in the device due to the falling water droplets D and the deterioration in quality of the sheet P3 manufactured from the web W are suppressed. In other words, it is possible to provide the sheet manufacturing device 1 and the water vapor recovery mechanism 40 that suppress falling of the water droplets D formed by dew condensation with a simple configuration.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2023-072371 | Apr 2023 | JP | national |
