Filter device

Abstract

To provide a filter device that is able to perform, with a simple configuration, an air volume control by a volume flow rate.SOLUTION: A filter device includes: a filter; a pipe; a blower that sucks air filtered by the filter via the pipe; a wind speed sensor that measures a mass flow rate of a gas flowing through the pipe; a temperature sensor that measures a temperature; a pressure sensor that measures an atmospheric pressure; and a processor that controls suction of the blower, based on the measured atmospheric pressure, the measured temperature, and the measured mass flow rate.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a filter device. [Background technology]

[0002] In sheet manufacturing equipment that uses a dry process to produce sheets from waste paper and other paper scraps, waste particles such as short fibers unsuitable for sheet production and colorants contained in the paper scraps are collected and disposed of using a waste particle collection unit. To maintain a constant volumetric flow rate into the waste particle collection unit, the rotation speed of the waste particle blower is controlled using an air velocity sensor attached to the rectifier. However, the air velocity detected by the air velocity sensor is a mass flow rate, which can lead to discrepancies with the volumetric flow rate. While air flow meters capable of measuring volumetric flow rates are also known, they are more expensive than mass-flow rate-based air velocity sensors.

[0003] For example, Patent Document 1 discloses a volumetric flowmeter for a cooling fan that is installed in a duct and includes an air receiving plate that receives the flow of air generated by the cooling fan, and a conversion unit that converts the inclination angle of the air receiving plate into a volumetric flow rate. According to this document, it is possible to measure minute volumetric flow rates of a cooling fan. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-38714 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the air flow meter of Patent Document 1 has a wind receiving plate inside the duct, which causes a large pressure loss. [Means for solving the problem]

[0006] A filter device according to one aspect of the present application comprises a filter, a pipe, a blower that sucks in air filtered by the filter through the pipe, a wind speed sensor that measures the mass flow rate of gas flowing through the pipe, a temperature sensor that measures the temperature, a pressure sensor that measures the air pressure, and a processor that controls the suction of the blower based on the air pressure measured by the pressure sensor, the temperature measured by the temperature sensor, and the mass flow rate measured by the wind speed sensor. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a perspective view showing a schematic configuration of a waste powder collecting device according to a first embodiment. [Figure 2] FIG. 2 is a perspective view of the waste powder collecting device as seen from the opposite side of FIG. 1. [Figure 3] FIG. 2 is a perspective view showing a schematic configuration of an air volume regulator. [Figure 4] FIG. 4 is a cross-sectional side view of the rectifier taken along the cross section bb of FIG. 3; [Figure 5] FIG. 4 is a flowchart showing the flow of an air volume adjustment method. [Figure 6] FIG. 10 is a schematic configuration diagram of a sheet manufacturing apparatus according to a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0008] Embodiment 1 ***Outline of waste powder collection device*** Fig. 1 is a perspective view showing a schematic configuration of a waste powder collection device as a filter device according to embodiment 1. Fig. 2 is a perspective view of the waste powder collection device as seen from the opposite side of Fig. 1. In Fig. 2, some components are not shown to make the internal configuration easier to understand. The schematic configuration of the waste particle collection device 100 according to this embodiment will be described with reference to FIGS. 1 and 2. Each figure illustrates three mutually perpendicular axes: an X axis, a Y axis, and a Z axis. In this embodiment, the Z axis is defined as the vertical direction, but this is not limiting. The direction along the X axis is referred to as the "X direction," the direction along the Y axis as the "Y direction," and the direction along the Z axis as the "Z direction." The tip of the arrow in each axis direction is also referred to as the "plus side," and the base of the arrow is also referred to as the "minus side." For example, the Y direction refers to both the positive and negative Y directions. The positive Z direction is also referred to as "up," and the negative Z direction is also referred to as "down." In the following figures, dimensions and scales may differ from those of the actual ones to facilitate understanding.

[0009] The waste powder collection device 100 of this embodiment is a filter-type dust collection device, a so-called bag filter device, that collects dust in the exhaust of industrial equipment, and can be used for collecting powder in the exhaust, recovering crushed products, local dust collection, etc. The waste powder collecting device 100 is composed of a filter section 34, a waste powder box 35, an air volume adjusting device 60 including a rectifier 10, a cover member 30, a back airflow generating section 38, and the like. 1, the waste powder collection device 100 is in the shape of a vertically long rectangular parallelepiped, and is configured by stacking, in this order from the bottom, a waste powder box 35, a filter unit 34, an air volume regulator 60, and a cover member 30. These components are assembled into a housing 99, which mainly consists of the filter unit 34, to form a single device.

[0010] As shown in FIG. 2, the filter unit 34 includes four cylindrical filters 13. The number of filters 13 is not limited to four, and any number may be used. The filters 13 are cylindrical filter bags (filter cloths) that extend vertically. As shown in FIG. 1, two air intakes 34b are provided on one side of the filter unit 34. Pipes (not shown) from an upstream device are connected to the air intakes 34b, and dust-containing gas flows into the filter unit 34 from the pipes.

[0011] The gas filtered by the four filters 13 is sucked up into the cover member 30 (Fig. 1), passes through the rectifier 10 of the air volume regulator 60, and is then discharged from the exhaust port 10b. The cover member 30 functions as an exhaust flow path that guides the exhaust gas filtered by the filter section 34 to the rectifier 10. The rectifier 10 is an exhaust guide pipe, and a blower 40 (Fig. 3) is provided downstream of the exhaust port 10b to suck in the gas inside the filter section 34. In other words, the waste powder collecting device 100 includes a filter section 34, a rectifier 10 that discharges the exhaust gas filtered by the filter section 34 from an exhaust port 10b, and a blower 40 as a blower section that sucks in the exhaust gas.

[0012] As shown in Fig. 2, a reverse airflow generating unit 38 is provided next to the rectifier 10. Fig. 2 shows a state in which the cover member 30 is removed, and the reverse airflow generating unit 38 has four injection heads 18. The injection heads 18 are arranged corresponding to positions above the filter 13. Pipes are connected to the injection heads 18 from a compressor (not shown), and compressed air is supplied to them. When the waste powder collection device 100 is in operation, dust such as powder adheres to the outer surface of the filter 13. The spray head 18 periodically injects pulses of air into the filter bag to knock off dust from the exterior surfaces of the filters 13. In a preferred embodiment, the spray head 18 sprays air sequentially onto each of the four filters 13. The dust that is knocked off falls into the waste dust box 35 by gravity.

[0013] ***Air flow regulator and rectifier configuration*** Fig. 3 is a perspective view showing a schematic configuration of an air volume regulator, and corresponds to Fig. 1. Fig. 4 is a side cross-sectional view of the rectifier taken along the line bb in Fig. 3. The air volume adjusting device 60 is composed of a rectifier 10, a blower 40, a control unit 20, a memory unit 21, and the like.

[0014] As shown in FIG. 4, the rectifier 10 is composed of a first pipe 1, a second pipe 2, a wind speed sensor 3, a temperature sensor 4, and the like. The first pipe 1 is a cylindrical exhaust pipe whose upstream base end is connected to the cover member 30. It extends in the Y direction and then tapers toward the downstream side, gradually decreasing in diameter. This tapered shape is also referred to as a constriction. The second pipe 2 is a slightly smaller version of the first pipe 1 and is concentrically arranged within the first pipe 1. Gas within the cover member 30 is drawn in from the two base ends of the first pipe 1 and the second pipe 2, as shown by the arrows in FIG. 4. The gas drawn into the second pipe 2 passes through the second pipe and exits through the exhaust port 2b. The gas then merges with the gas flowing through the first pipe 1 at the tapered portion of the first pipe, travels downstream, and is discharged from the exhaust port 10b of the first pipe 1. The area where the two airflows converge is also referred to as a confluence.

[0015] As described above, the rectifier 10 employs a double-ring structure in which the second pipe 2 is concentrically arranged within the first pipe 1. Furthermore, by providing downstream throttle sections in both the first pipe 1 and the second pipe 2, turbulence is suppressed, allowing the gas to flow downstream in a stable manner without significant disruption. An air velocity sensor 3 is attached downstream midway within the second pipe 2 as a mass flow detector. In a preferred embodiment, the air velocity sensor 3 is a thermal flow sensor. A thermal flow sensor includes, for example, a heater constructed using MEMS (microelectromechanical systems), a thermopile upstream of the heater, and another thermopile downstream of the heater. The thermal flow sensor detects the temperature difference associated with the gas flow as an electromotive force difference, thereby detecting the air velocity in terms of mass flow rate. This principle allows for extremely small pressure loss due to the thermal flow sensor. The air velocity sensor 3 is electrically connected to the control unit 20 via an interface circuit (not shown). Note that the air velocity sensor 3 is not limited to a thermal flow sensor.

[0016] A temperature sensor 4 serving as a temperature detection unit is attached downstream of the junction in the first pipe 1. In a preferred embodiment, a thermistor is used as the temperature sensor 4. The temperature sensor 4 is electrically connected to the control unit 20 via an interface circuit (not shown). The temperature sensor 4 measures the exhaust temperature of the rectifier 10. Note that the temperature sensor 4 is not limited to a thermistor, and may be a contact temperature sensor or a non-contact temperature sensor. The blower 40 is an exhaust fan, and in a preferred embodiment, a centrifugal blower is used. However, it is not limited to a centrifugal blower, and any blower with sufficient exhaust capacity will suffice. The tip of the blower is the internal space of the air volume control device, and is also connected to the outside of the device.

[0017] The control unit 20 and memory unit 21 are composed of multiple integrated circuits and electronic components mounted on a control board 45. The control board 45 is a control board incorporated into the control device of the waste powder collection device 100 and the control unit of a higher-level device, and is located in an environment outside the waste powder collection device 100. The control unit 20 is configured with one or more processors, and controls each part of the air volume adjustment device 60 in accordance with a control program stored in the memory unit 21. The storage unit 21 is configured with a RAM (Random Access Memory) and a ROM (Read Only Memory). The RAM is used for temporary storage of various data, and the ROM stores a control program for controlling the operation of the air volume adjustment device 60 and associated data. The control program stores a startup program that indicates the order and content of processing when starting up the air volume adjustment device 60, and an air volume adjustment program that controls the rotation speed of the blower 40 so that the volumetric flow rate through the filter unit 34 is constant.

[0018] A pressure sensor 5 serving as a pressure detection unit is electrically connected to the control unit 20 via an interface circuit (not shown). In a preferred example, the pressure sensor 5 is a piezo-resistive air pressure sensor, and is mounted on the control board 45. The pressure sensor 5 measures the air pressure in the space in which the control board 45 is located. This space is the space beyond the exhaust air of the blower and is also the intake source for the air that flows into the filter unit 34. Therefore, the pressure detected by the pressure sensor 5 is related to the pressure at the position of the wind speed sensor 3, and by correcting it through calculation, the pressure at the position of the wind speed sensor 3 can be estimated. Note that the pressure sensor 5 is not limited to a piezo-resistive type, and any sensor that can detect air pressure will suffice. In this embodiment, the rectifier 10 has a first pipe 1, a second pipe 2 arranged inside the first pipe 1, a wind speed sensor 3 arranged inside the second pipe 2 as a wind speed detection unit that measures the mass flow rate of gas flowing through the second pipe 2, a temperature sensor 4 arranged inside the first pipe 1 as a temperature detection unit that measures the temperature of the exhaust gas, and a pressure sensor 5 arranged outside the rectifier 10 as a pressure detection unit that measures the pressure of the outside air.

[0019] ***Air volume adjustment method*** FIG. 5 is a flowchart showing the flow of the air volume adjustment method. Here, the method for adjusting the volumetric flow rate will be explained mainly with reference to Fig. 5, and with reference to other figures as appropriate. The following steps are performed by the control unit 20 executing the air volume adjustment program in the memory unit 21 to control each unit including the blower 40.

[0020] In step S10, the mass flow rate value M is acquired by the wind speed sensor 3, the temperature value T(K) is acquired by the temperature sensor 4, and the air pressure value P is acquired by the pressure sensor 5, and the detected data are sent to the control unit 20. The current rotation speed of the blower 40 is set to I. The target volumetric flow rate value is set to q. It is preferable to measure the air pressure at the position where the wind speed sensor 3 is installed as the air pressure value P. However, in this embodiment, the atmospheric pressure detected by the pressure sensor 5 in the environment where the waste powder collection device 100 is installed is used instead.

[0021] In step S11, the corrected rotation speed i of the blower 40 is derived. The value acquired in step S10 is substituted into equation (1) to calculate the corrected rotation speed, where α is a constant prepared in advance. i = IαqP / TM ………Equation (1)

[0022] The formula (1) was derived as follows. From the gas equation, P / RT = n / V …………Equation (2) The relationship between the mass flow rate value M and the volume flow rate value Q measured by the anemometer 3 is expressed as follows, using the density ρ of the fluid: ρ=M / Q ………Formula (3) is.

[0023] In addition, since the amount of substance and mass of a gas are proportional, using the proportionality constant β, ρ = nβ / V …………Equation (4) and From equations (2), (3) and (4), P / RT = M / βQ ......Equation (5) It can be expressed as:

[0024] Replacing β / R with the constant α and rewriting the equation for Q, we get Q=TM / αP ………Equation (6) Since the rotation speed of the blower 40 and the volumetric flow rate are almost proportional, if we divide the target value by the current value, i / I = αqP / TM …………Equation (7) This can be expressed as follows, which can be rewritten as equation (1).

[0025] While it is desirable for T, P, and M to be values ​​at the same location in the pipe, in this embodiment they are values ​​at different locations, and furthermore, they contain measurement errors dependent on the performance of the sensor. Since α also depends on the components in the air, strictly speaking, it is not a value that can be prepared in advance as a constant, and will contain errors from a value prepared in advance as a constant. Therefore, i calculated using equation (1) also contains errors. However, if the error in i calculated using equation (1) is smaller than the error in the volumetric flow rate required for blower 40, the calculation in step S11 is sufficient.

[0026] In fact, in a prototype developed by the inventors, an air velocity sensor 3 with an error of ±2% was used, and temperature and pressure sensors 4 and 5 with an error of ±0.5% were used. Furthermore, deviations due to differences in the positions of the air velocity sensor 3 and the temperature and pressure sensors 4 and 5 were corrected using pre-measured correction values, so that the deviations due to differences in position were kept to an error of approximately ±0.5%. Furthermore, although α depends on the components in the air, it has a deviation of approximately ±1%. Furthermore, the volumetric flow rate accuracy required of the blower 40 is ±5%. In other words, the blower 40 can be controlled with sufficient accuracy.

[0027] The measurement accuracy and placement positions required for the air velocity sensor 3, temperature sensor 4, and pressure sensor 5 should be such that the error in i calculated by equation (1) is smaller than the volumetric flow rate accuracy required for the blower 40, and the types and placement positions of the air velocity sensor 3, temperature sensor 4, and pressure sensor 5 can be selected within a range that satisfies this condition. Therefore, the air velocity sensor 3, temperature sensor 4, and pressure sensor 5 do not necessarily have to be installed inside the first pipe 1 or the second pipe 2.

[0028] In step S13, an instruction is issued to set the corrected rotation speed i obtained in step S11 as the rotation speed of the blower 40. In other words, the control unit 20 corrects the flow rates of the gas flowing through the first pipe 1 and the second pipe 2.

[0029] In step S14, it is determined whether or not an end command for the operation has been issued. If an end command has been issued, the operation of the air volume regulator 60 is terminated. If an end command has not been issued, the process proceeds to step S15.

[0030] In step S15, it is determined whether a predetermined time has elapsed. If the predetermined time has elapsed, the process returns to step S10 and the sensor value is acquired again. If the predetermined time has not elapsed, the process waits until the predetermined time has elapsed. The predetermined time is the cycle time of the feedback control and is set appropriately within the range of, for example, several seconds to several tens of minutes.

[0031] As described above, the waste particle collecting device 100 of this embodiment can provide the following effects. The waste powder collection device 100 includes a filter unit 34, a rectifier 10 that discharges the exhaust gas filtered by the filter unit 34 from an exhaust port 10b, and a blower 40 that serves as a blower unit for sucking in the exhaust gas. The rectifier 10 includes a first pipe 1, a second pipe 2 that is arranged inside the first pipe 1, an air velocity sensor 3 that is arranged in the second pipe 2 and serves as an air velocity detection unit for measuring the mass flow rate of the gas flowing through the second pipe 2, and a temperature sensor 4 that is arranged in the first pipe 1 and serves as a temperature detection unit for measuring the temperature of the exhaust gas. Outside the rectifier 10, there is a pressure sensor 5 that serves as a pressure detection unit for measuring the pressure of the outside air. The waste powder collection device 100 corrects the rotation speed of the blower 40 based on the detection values ​​of the group of sensors, the air velocity sensor 3, the temperature sensor 4, and the pressure sensor 5.

[0032] According to this, by correcting the rotation speed of the blower 40 from the detected atmospheric pressure value, temperature detected value, and mass flow rate, it is possible to control the air volume based on the volumetric flow rate, taking into account changes in air density. Therefore, unlike conventional devices in which the volumetric flow rate changes depending on changes in atmospheric pressure and temperature because the air volume is controlled by the mass flow rate, the waste powder collection device 100 equipped with the air volume regulator 60 controls the air volume based on the volumetric flow rate, thereby controlling the rotation speed of the blower 40 so that the volumetric flow rate through the filter section 34 is constant. Furthermore, the temperature sensor 4 and the pressure sensor 5 can be publicly known small general-purpose sensors, and the air velocity sensor 3 can be a small general-purpose mass flow rate sensor. Therefore, it is possible to provide a waste powder collecting device 100 that can control the air volume based on the volume flow rate with a simple configuration.

[0033] The temperature sensor 4 is a thermistor, the pressure sensor 5 is a piezo-resistive pressure sensor, and the air velocity sensor 3 is a thermal flow sensor. This allows the temperature detection unit, pressure detection unit, and wind speed detection unit to be constructed using general-purpose small sensors, making it possible to construct a waste powder collection device 100 that controls wind volume based on volumetric flow rate in a simple and inexpensive manner.

[0034] Furthermore, the rectifier 10 is not limited to a double ring structure in which the second pipe 2 is arranged concentrically within the first pipe 1, but may be a single-structure pipe, and the shape of the cross section perpendicular to the flow is not limited to a circle but may be other shapes such as a rectangle. Furthermore, as can be seen from equation (1), it can also be interpreted that the control unit 20 increases the blower rotation speed as the measured pressure increases, decreases the blower rotation speed as the measured temperature increases, and decreases the blower rotation speed as the measured mass flow rate increases.

[0035] Embodiment 2 ***Application to sheet manufacturing equipment*** FIG. 6 is a schematic diagram of a sheet manufacturing apparatus. The waste powder collecting device 100 can be suitably applied to the sheet manufacturing apparatus 200.

[0036] The sheet manufacturing apparatus 200 manufactures sheets from paper scraps such as waste paper in a dry process. The sheet manufacturing apparatus 200 is not limited to a dry process and may be a wet process. In this embodiment, the dry process means that the process is carried out in air such as the atmosphere, rather than in a liquid.

[0037] 6, the sheet manufacturing apparatus 200 has a first unit group 111, a second unit group 112, and a third unit group 113. The first unit group 111, the second unit group 112, and the third unit group 113 are supported by a frame (not shown).

[0038] 6, the direction in which the pieces of paper C, sheet P3, slit pieces S, and unnecessary scraps move is indicated by white arrows. In the sheet manufacturing apparatus 200, the side ahead in the conveying direction of the pieces of paper C, web W, sheet P3, etc. is sometimes referred to as downstream, and the side going upstream in the conveying direction is sometimes referred to as upstream. In the following description, a collection of pieces of paper C made up of multiple pieces of paper C is also simply referred to as piece of paper C.

[0039] The sheet manufacturing apparatus 200 manufactures a sheet P3 from a piece of paper C. In the sheet manufacturing apparatus 200, a first unit group 111, a second unit group 112, and a third unit group 113 are arranged from the X-minus direction to the X-plus direction. The third unit group 113 houses the waste powder collection device 100. The pieces of paper C are stored in the storage section 32 of the first unit group 111, and are supplied from the storage section 32 through the discharge section 39 to the junction section 17, and then transported to the third unit group 113 via the piping 92. The pieces of paper C are then defibrated in the third unit group 113 to become fibers, and then made into a mixture containing a binder and the like. The mixture is transported via the piping 94 to the second unit group 112. The mixture is made into a web W in the second unit group 112, and then formed into a belt-shaped sheet P1. The belt-shaped sheet P1 is cut in the first unit group 111 to become a sheet P3.

[0040] The first unit group 111 includes a storage section 32, a measuring section 15, a confluence section 17, and a pipe 92. In the first unit group 111, these components are arranged in the above order from upstream to downstream. The first unit group 111 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 sheets P3 of a predetermined shape. The first unit group 111 also includes a water supply section 87. The water supply section 87 is a water storage tank. The water supply section 87 supplies water for humidification to each of a first humidifier section 85 and a second humidifier section 86 (described later) via a water supply pipe (not shown).

[0041] The storage unit 32 stores paper pieces C, which are the raw material for the sheet P3, and supplies them downstream via the discharge unit 39. The paper pieces C contain fibers such as cellulose and are, for example, shredded waste paper. Humidified air is supplied into the storage unit 32 from the second humidifier 86 provided in the second unit group 112. The pieces of paper C are temporarily stored in the storage unit 32, and then transported to the measuring unit 15 via the discharge unit 39. The sheet manufacturing apparatus 200 may be provided with a shredder upstream of the storage unit 32 that shreds the pieces of paper C and the like.

[0042] The measuring unit 15 has a sensor unit 15a and a supply mechanism (not shown). The sensor unit 15a measures the mass of the pieces of paper C. The supply mechanism supplies the pieces of paper C weighed by the sensor unit 15a to the downstream junction 17. That is, the measuring unit 15 weighs the pieces of paper C by a predetermined mass using the sensor unit 15a, and supplies them to the downstream junction 17 using the supply mechanism. The sensor unit 15a can be either a digital or analog weighing mechanism. Specifically, the sensor unit 15a can be a physical sensor such as a load cell, a spring balance, or a balance. In this embodiment, a load cell is used as the sensor unit 15a. The predetermined mass at which the sensor unit 15a weighs the piece of paper C is, for example, several grams to several tens of grams.

[0043] The measuring unit 15 measures and supplies the pieces of paper C in batches. That is, the supply of the pieces of paper C from the measuring unit 15 to the junction 17 is performed intermittently. The measuring unit 15 may have multiple combinations of sensor units 15a and supply mechanisms, and the multiple sensor units 15a may be operated at staggered times to improve the efficiency of measuring and supply. The sheet manufacturing apparatus 200 has two sensor units 15a and a supply mechanism attached to each. As a result, the pieces of paper C are transported alternately to the junction 17 from the two sets of sensor units 15a and supply mechanisms.

[0044] At the confluence 17, the pieces of paper C supplied from the measuring unit 15 are combined with the fine fragments of the slit pieces S supplied from the shredding unit 95 and mixed together. The slit pieces S and the shredding unit 95 will be described later. The pieces of paper C mixed with the fine fragments flow from the confluence 17 into the pipe 92. The piping 92 transports the pieces of paper C from the first unit group 111 to the third unit group 113 via the second unit group 112 by means of the suction airflow generated by the downstream defibrating unit 33.

[0045] The third unit group 113 has a defibrating unit 33 which is a dry type defibrator, a separating unit 42, a pipe 93, a mixing unit 36, and a pipe 94. Furthermore, the third unit group 113 also has a pipe 96 branching off from the separating unit 42, and a waste powder collector 100 and a power supply unit 69 to which the pipe 96 is connected.

[0046] The pieces of paper C transported through the piping 92 flow into the defibrating unit 33. The defibrating unit 33 dry-defibrates the pieces of paper C supplied from the measuring unit 15 into fibers. A known defibrating mechanism can be applied to the defibrating unit 33. The defibrating unit 33 may have the following configuration, for example. The defibrating unit 33 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 small pieces of paper C are sandwiched between the inner surface of the stator and the rotor and are defibrated by the shear force generated between them. This causes the tangled fibers contained in the paper pieces C to be untangled. The paper pieces C are made into fibers and transported to the separation unit 42.

[0047] The separation unit 42 separates the defibrated fibers. More specifically, the separation unit 42 removes components contained in the fibers that are unnecessary for manufacturing the sheet P3. Specifically, the separation unit 42 separates relatively long fibers from relatively short fibers. Relatively short fibers are separated in the separation unit 42 because they may reduce the strength of the sheet P3. The separation unit 42 also separates and removes coloring materials and additives contained in the pieces of paper C. Known technologies such as a disk mesh method can be applied to the separation unit 42. Humidified air is supplied to the interior of the separation unit 42 from the second humidifier 86 of the second unit group 112. The separated raw fiber material is transported to the mixing section 36 via a pipe 93 by an air current generated by a blower (not shown) disposed at the tip of the air current pipe 43 .

[0048] The gas containing the waste powder then flows into the filter section 34 from the intake port 34b of the waste powder collector 100 via the piping 96. As explained in FIG. 2, the waste powder is removed from the flow-in gas by the filter 13, and then the gas is discharged from the exhaust port 10b of the rectifier 10. The waste powder is collected in the waste powder box 35. As explained above, the waste powder collector 100 is a bag filter, and is equipped with the blower 40 that generates an exhaust flow and the compressor 44 that generates compressed air for cleaning the filter.

[0049] The mixing unit 36 ​​mixes powder additives such as binders with the fibers in the air to form a mixture. The mixing unit 36 ​​includes a powder supply mechanism 49. The powder supply mechanism 49 has a built-in hopper. The powder supply container 29 is attached to the powder supply mechanism 49. Although not shown, the mixing unit 36 ​​also includes a flow path for transporting the fibers, a valve, and a fan in addition to the powder supply mechanism 49. The hopper sends binder powder supplied from the powder supply container 29 into the flow path. The sheet manufacturing apparatus 200 uses starch as a binder for the fibers. A valve (not shown) adjusts the flow rate, i.e., the mass, of the binder supplied from the hopper to the flow path. This adjusts the mixture ratio of the fibers and binder. In addition to the powder supply container 29 and powder supply mechanism 49 that supply the binder, the mixing section 36 may also include a similar configuration for supplying colorants, additives, etc. The fan in the mixing section 36 generates an airflow that transports the fibers downstream while mixing the binder, etc. into the air to form a mixture. The mixture flows from the mixing section 36 into the pipe 94.

[0050] The power supply unit 69 has a power supply device (not shown) that supplies power to the control board 45 and the sheet manufacturing apparatus 200. The power supply unit 69 distributes power supplied from an external source to each component of the sheet manufacturing apparatus 200. The control board 45 is mounted with the control unit 20, the memory unit 21, and the pressure sensor 5, and is configured to be able to measure the atmospheric pressure in the environment in which the waste powder collection device 100 is installed. In a preferred example, the control unit 20 and the memory unit 21 also have a function of overall control of the sheet manufacturing apparatus 200. The control board 45 may be connected to a computer 76. The computer 76 is, for example, a notebook computer, and stores a control program for the entire sheet manufacturing apparatus 200 including the waste powder collecting device 100.

[0051] The second unit group 112 deposits and compresses the mixture containing fibers to form a belt-shaped sheet P1, which is recycled paper. The second unit group 112 includes a depositing unit 48, a first conveying unit 83, a second conveying unit 84, a first humidifying unit 85, a second humidifying unit 86, a drainage unit 88, and a forming unit 70. In the second unit group 112, the deposition section 48, the first conveyance section 83, the second conveyance section 84, the first humidification section 85, and the forming section 70 are arranged in the above order from upstream to downstream. The second humidification section 86 is arranged below the first humidification section 85.

[0052] The deposition unit 48 deposits the mixture containing the separated fibers in the air to generate a web W. The deposition unit 48 has a drum member 53, blade members 55 installed inside the drum member 53, a housing 51 that houses the drum member 53, and a suction unit 59. The mixture is taken into the drum member 53 through a pipe 94. A first conveying unit 83 is disposed below the accumulation unit 48. The first conveying unit 83 has a mesh belt 83a and five tension rollers (not shown) that tension the mesh belt 83a. The suction unit 59 faces the drum member 53 in the direction along the Z axis, with the mesh belt 83a sandwiched between them.

[0053] The blade member 55 is located inside the drum member 53 and is driven to rotate by a motor (not shown). The drum member 53 is a semi-cylindrical sieve. A mesh that functions as a sieve is provided on the downward-facing side of the drum member 53. The drum member 53 allows particles such as fibers and mixtures that are smaller than the size of the mesh openings of the sieve to pass from the inside to the outside. The mixture is agitated by rotating blade members 55 inside drum member 53 and then discharged to the outside of drum member 53. Humidified air is supplied to the inside of drum member 53 from second humidifying section 86.

[0054] The suction unit 59 is disposed below the drum member 53. The suction unit 59 sucks air from inside the housing 51 through multiple holes in the mesh belt 83a. The multiple holes in the mesh belt 83a allow air to pass through but prevent fibers and binders contained in the mixture from passing through. As a result, the mixture discharged to the outside of the drum member 53 is sucked downward together with the air. The suction unit 59 is a known suction device such as a blower. The mixture is dispersed in the air within the housing 51 and is deposited on the upper surface of the mesh belt 83a by gravity and the suction of the suction section 59 to form the web W.

[0055] The mesh belt 83a is an endless belt stretched over five tension rollers. The mesh belt 83a rotates counterclockwise in FIG. 6 due to the rotation of the tension rollers. As a result, the mixture is continuously deposited on the mesh belt 83a, forming a web W. The web W contains a relatively large amount of air and is soft and inflated. The first conveying section 83 conveys the formed web W downstream by the rotation of the mesh belt 83a.

[0056] The second conveying section 84 is located downstream of the first conveying section 83 and conveys the web W in place of the first conveying section 83. The second conveying section 84 peels the web W from the upper surface of the mesh belt 83a and conveys it toward the forming section 70. The second conveying section 84 is located above the conveying path of the web W and slightly upstream of the starting point of the return side of the mesh belt 83a. The positive X side of the second conveying section 84 and the negative X side of the mesh belt 83a partially overlap in the vertical direction. The second conveying section 84 has a transport belt, multiple rollers, and a suction mechanism (not shown). The transport belt has multiple holes to allow air to pass through. The transport belt is stretched over multiple rollers and rotates with the rotation of the rollers. The second conveying section 84 adsorbs the upper surface of the web W to the lower surface of the transport belt by using negative pressure generated by the suction mechanism. When the transport belt rotates in this state, the web W is adsorbed to the transport belt and transported downstream.

[0057] The first humidifying section 85 humidifies the web W containing fibers deposited in the depositing section 48 of the second unit group 112. More specifically, the first humidifying section 85 is, for example, a mist-type humidifier, and humidifies the web W transported by the second conveying section 84 by supplying mist M from below. The first humidifying section 85 is disposed below the second conveying section 84 and faces the web W transported by the second conveying section 84 in the direction along the Z axis. A known humidifying device, for example, an ultrasonic type, can be used for the first humidifying section 85. By humidifying the web W with the mist M, the function of the starch as a binder is promoted, and the strength of the sheet P3 is improved. In addition, since the web W is humidified from below, droplets from the mist are prevented from falling onto the web W. Furthermore, since the web W is humidified from the side opposite the 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 84 transports the web W to the forming section 70.

[0058] The forming unit 70 has processing rollers 71 and 72. The processing rollers 71 and 72 compress the web W containing fibers and form it into a strip-shaped sheet P1. The processing rollers 71 and 72 form a pair, and each has an electric heater built in to increase the temperature of the roller surface. The processing rollers 71 and 72 are each a substantially cylindrical member. The rotation axis of the processing roller 71 and the rotation axis of the processing roller 72 are arranged along the Y axis. With respect to the transport path of the web W, the processing roller 71 is arranged substantially above, and the processing roller 72 is arranged substantially below. A gap is provided between the side surface of the processing roller 71 and the side surface of the processing roller 72 according to the thickness of the sheet P3 to be manufactured.

[0059] The processing rollers 71 and 72 are driven to rotate by a stepping motor (not shown). The web W is sandwiched between the processing rollers 71 and 72 and sent downstream while being heated and pressurized. That is, the web W continuously passes through the forming unit 70 and is press-formed while being heated. By using the processing rollers 71 and 72 as a pair of forming members, the web W can be efficiently heated and pressurized.

[0060] By passing through the forming section 70, the web W, which is soft and contains a relatively large amount of air, has the air contained therein reduced and the fibers are bound together by the binder, so that the web W is formed into a belt-shaped sheet P1. The belt-shaped sheet P1 is transported to the first unit group 111 by transport rollers (not shown).

[0061] Second humidifier 86 is disposed below first humidifier 85. A known evaporative humidifier can be used for second humidifier 86. An example of an evaporative humidifier is one that blows air onto a moistened nonwoven fabric or the like to evaporate the moisture and generate humidified air.

[0062] The second humidifying section 86 humidifies a predetermined area of ​​the sheet manufacturing apparatus 200. The predetermined area is one or more of the storage section 32, the separation section 42, and the inside of the drum member 53 of the accumulation section 48. Specifically, humidified air is supplied to the above-mentioned area from the second humidifying section 86 via multiple pipes (not shown). In each of the above-mentioned configurations, the humidified air suppresses the electrostatic charge on the paper pieces C, fibers, etc., and prevents them from adhering to the members due to static electricity.

[0063] The drainage unit 88 is a drainage tank. The drainage unit 88 is used in the first humidifying unit 85, the second humidifying unit 86, etc., and collects and stores old water. The drainage unit 88 can be removed from the sheet manufacturing apparatus 200 as needed, allowing the accumulated water to be discarded.

[0064] The strip-shaped sheet P1 transported to the first unit group 111 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, along the Y axis. The strip-shaped sheet P1 is cut into single sheets P2 at the first cutting section 81. The single sheets P2 are transported from the first cutting section 81 to the second cutting section 82. The second cutting section 82 cuts the single sheet P2 in the conveyance direction. Specifically, the second cutting section 82 cuts the single sheet P2 near both sides in the direction along the X axis. As a result, the single sheet P2 becomes a sheet P3 of a predetermined shape, such as A4 size or A3 size.

[0065] When the second cutting section 82 cuts the single sheets P2 into sheets P3, slit pieces S, which are scraps, are generated. The slit pieces S are transported downward to the shredding section 95, which is a shredder. The shredding section 95 shreds the slit pieces S into small pieces and supplies them to the junction 17. A mechanism may be installed between the shredding section 95 and the junction 17 to weigh the small pieces of the slit pieces S and supply them to the junction 17. The sheet P3 is conveyed substantially upward and accumulated on the tray 91. In this manner, the sheet P3 is manufactured by the sheet manufacturing apparatus 200. The sheet P3 can be used as a substitute for, for example, copy paper.

[0066] In other words, the sheet manufacturing apparatus 200 includes a waste powder collection device 100, a defibrating section 33 that defibrates the raw material, a deposition section 48 that deposits the material to form a web W, and a forming section 70 that compresses the web W to form a sheet, and the waste powder collection device 100 collects waste powder from the raw material defibrated by the defibrating section 33.

[0067] As described above, the sheet manufacturing apparatus 200 of this embodiment can provide the following effects. The sheet manufacturing apparatus 200 includes a waste powder collection device 100, a defibrating section 33 that defibrates the raw material, a deposition section 48 that deposits the material to form a web W, and a forming section 70 that compresses the web W to form a sheet, and the waste powder collection device 100 collects waste powder from the raw material defibrated by the defibrating section 33.

[0068] According to this, the sheet manufacturing apparatus 200 has a simple configuration and is equipped with the waste powder collecting device 100 that controls the air volume based on the volume flow rate. Therefore, even if the temperature or air pressure in the operating environment changes, by controlling the air volume based on the volume flow rate, the rotation speed of the blower 40 can be controlled so that the volume flow rate flowing through the filter unit 34 remains constant. Therefore, it is possible to provide a sheet manufacturing apparatus 200 that can control the air volume based on the volume flow rate with a simple configuration. The sheet manufacturing apparatus 200 can also be regarded as a filter apparatus. Furthermore, even an apparatus used for a purpose other than sheet manufacturing can be regarded as a filter apparatus. [Explanation of symbols]

[0069] 1...first pipe, 2...second pipe, 2b...exhaust port, 3...wind speed sensor, 4...temperature sensor, 5...pressure sensor, 10...rectifier, 10b...exhaust port, 13...filter, 15...measuring unit, 15a...sensor unit, 17...junction unit, 18...spray head, 20...control unit, 21...memory unit, 29...powder supply container, 30...cover member, 32...storage unit, 33...fibrillation unit, 34...filter unit, 34b...air intake port, 35...waste powder box, 36...mixing unit, 38...back airflow generating unit, 39...discharge unit, 40...blower, 42...separation unit, 43...air flow pipe, 44...compressor, 45...control board, 48...accumulation unit, 49...powder supply mechanism, 51...house jigs, 53...drum member, 55...blade member, 59...suction section, 60...air volume adjustment device, 69...power supply section, 70...forming section, 71...treatment roller, 72...treatment roller, 76...computer, 81...first cutting section, 82...second cutting section, 83...first conveying section, 83a...mesh belt, 84...second conveying section, 85...first humidifying section, 86...second humidifying section, 87...water supply section, 88...drainage section, 91...tray, 92...piping, 93...piping, 94...piping, 95...shredding section, 96...piping, 99...casing, 100...waste powder collection device, 111...first unit group, 112...second unit group, 113...third unit group, 200...sheet manufacturing apparatus.

Claims

1. Filters and Piping and a blower that sucks the air filtered by the filter through the piping; a wind speed sensor for measuring the mass flow rate of the gas flowing through the pipe; a temperature sensor for measuring a temperature; a pressure sensor for measuring atmospheric pressure; a processor that controls the suction of the blower based on the air pressure measured by the pressure sensor, the temperature measured by the temperature sensor, and the mass flow rate measured by the air velocity sensor; A filter device comprising:

2. The processor causes the blower to perform suction more strongly as the air pressure measured by the pressure sensor increases.

10. The filter device of claim 1.

3. The processor causes the blower to perform suction less as the temperature measured by the temperature sensor increases.

10. The filter device of claim 1.

4. the temperature sensor is a thermistor; the pressure sensor is a piezoresistive pressure sensor, The air velocity sensor is a thermal flow sensor.

10. The filter device of claim 1.

5. a defibrating unit that defibrates the raw material; a deposition section for depositing material to form a web; a forming section that compresses the web to form a sheet; a waste powder pipe that sends waste powder generated from the raw material defibrated by the defibrating unit to the filter; The filter device according to any one of claims 1 to 4, further comprising:

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