Extruder, cylinder for extruder, monitoring device, monitoring method, and program

Abstract

In an extruder (10), in a cylinder (100), the end surfaces of a plurality of unit blocks (101) each having a hole into which a screw can be inserted are connected to each other via a connection portion (130). The extruder (10) has a closed space (133) surrounded by a first gasket (131) and a second gasket (132) surrounding the hole in the connection portion (130). The extruder (10) also has a pressure adjustment unit (160) that is a mechanism capable of adjusting the pressure of the closed space (133), when supplied with a predetermined fluid, to a designated preset pressure higher than the internal pressure of the hole when the extruder (10) is in operation, and a leakage monitoring unit (170) including a sensor capable of detecting the leakage of the fluid in the closed space (133).

Description

Extruder, extruder cylinder, monitoring device, monitoring method and program

[0001] The present invention relates to an extruder, an extruder cylinder, a monitoring device, a monitoring method, and a program.

[0002] Various techniques have been disclosed for the cylinders that constitute the extruder.

[0003] For example, in a twin-screw extruder in which cylinder units are connected to form a long cylinder, a technology has been disclosed in which the sealing device is made up of a hollow metal ring body, part of which has a through hole, the ring bodies are connected by a gas chamber, and the gas chamber is filled with an inert gas (Patent Document 1).

[0004] In addition, a technology has been disclosed in which pressurized raw material passes through the gap between the annular protrusion and the annular recess to reach the packing, the raw material enters the annular groove, and presses the packing against the outer surface of the annular protrusion and the inner surface of the annular recess, thereby achieving sealing by utilizing the pressure of the raw material (Patent Document 2).

[0005] JP-A No. 10-235712 JP-A No. 11-156919

[0006] However, the above-mentioned configuration may lose its sealing effectiveness due to fluctuations in the clamping force caused by repeated heating and cooling, or due to seal damage, etc. In such a case, if the pressure inside the cylinder is higher than atmospheric pressure, there is a possibility that gas generated inside the extruder may leak to the outside, which is undesirable.

[0007] The present disclosure has been made to solve such problems, and aims to provide an extruder or the like that suppresses leakage of gas inside a cylinder to the outside.

[0008] The extruder according to the present disclosure has a cylinder, an inlet, an outlet, and a screw. The cylinder has end faces of a plurality of unit blocks, each having a hole into which the screw can be inserted, connected via a connecting portion. The inlet receives the object to be processed at one end of the cylinder. The outlet discharges the processed object downstream at the other end of the cylinder. The screw is rotatably housed in the cylinder and transports the object to be processed from the inlet to the outlet. This extruder has a closed space surrounded by a first gasket that surrounds the hole at the connecting portion and a second gasket that further surrounds the first gasket. The extruder also has a pressure adjustment unit, which is a mechanism that can adjust the pressure in the closed space when a predetermined fluid is supplied to a predetermined set pressure that is higher than the internal pressure of the hole when the extruder is operating, and a leak monitoring unit that includes a sensor that can detect fluid leaks in the closed space.

[0009] The extruder cylinder according to the present disclosure comprises a plurality of unit blocks connected together to house a screw and form an extruder. The extruder cylinder includes unit blocks, a first gasket, a second gasket, a pressure adjusting unit, and a leak monitoring unit. The unit blocks are cylindrical members each having a hole through which the screw can be inserted. The first gasket is sandwiched between a pair of opposing end faces at the connection between the connected unit blocks to surround the hole. The second gasket is sandwiched between the pair of end faces to further surround the first gasket, thereby forming a closed space around the hole. The pressure adjusting unit is a mechanism capable of adjusting the pressure in the closed space to a predetermined set pressure higher than the internal pressure of the hole when the extruder is operating. The leak monitoring unit includes a sensor capable of detecting the flow of fluid in the closed space.

[0010] The monitoring device according to the present disclosure is a monitoring device for an extruder cylinder. The extruder cylinder is configured by connecting a plurality of unit blocks, each having a hole through which a screw can be inserted, via a double annular gasket, to form a closed space surrounding the hole at the connecting portion. The monitoring device has a cylinder data receiving unit, a pressure setting unit, a leak data receiving unit, and a notification unit. The cylinder data receiving unit receives data related to the internal pressure at a predetermined position in the cylinder of an operating extruder. The pressure setting unit sets the pressure of the fluid to be supplied to the closed space so that the pressure in the closed space is higher than the internal pressure. The leak data receiving unit receives data related to the leak from a leak monitoring unit that detects fluid leaks in the closed space. If a leak is detected, the notification unit notifies the user of the detection information.

[0011] The present disclosure provides a monitoring method for an extruder cylinder, which includes a cylinder consisting of multiple unit blocks, each having a hole through which a screw can be inserted, connected via a double annular gasket to form a closed space surrounding the hole at the connecting portion. The monitoring method includes a process of receiving data on the internal pressure at a predetermined position in the cylinder of an operating extruder, and a process of setting a set pressure for the closed space so that the pressure in the closed space is higher than the internal pressure. The monitoring method also includes a process of detecting fluid leaks in the closed space and, if a leak is detected, a process of notifying a user of the detection information.

[0012] The program according to the present disclosure is a monitoring method program executed by a monitoring device for an extruder cylinder. The extruder cylinder is configured by connecting multiple unit blocks, each having a hole through which a screw can be inserted, via a double annular gasket, to form a closed space surrounding the hole at the connecting portion. The monitoring method includes a process of receiving data regarding the internal pressure at a predetermined position in the cylinder of an operating extruder, and a process of setting the pressure of a fluid supplied to the closed space so that the pressure in the closed space is higher than the internal pressure. The monitoring method also includes a process of receiving data regarding a leak from a leak monitoring unit that detects a fluid leak in the closed space, and a process of notifying a user of the detection information if a leak is detected.

[0013] According to the present disclosure, it is possible to provide an extruder, a cylinder for an extruder, a monitoring device, a monitoring method, and a program that suppress leakage of gas inside the cylinder to the outside.

[0014] FIG. 1 is an overall configuration diagram of an extruder according to a first embodiment. FIG. 2 is a block diagram of a monitoring device according to the first embodiment. FIG. 3 is a flowchart of a monitoring method executed by the monitoring device according to the first embodiment. FIG. 4 is an overall configuration diagram of an extruder according to a second embodiment. FIG. 5 is an overall configuration diagram of an extruder according to a third embodiment. FIG. 6 is a block diagram of a monitoring device according to the third embodiment. FIG. 7 is a flowchart of a monitoring method executed by the monitoring device according to the third embodiment. FIG. 8 is an overall configuration diagram of an extruder. FIG. 9 is a perspective view of a unit block. FIG. 10 is a partial cross-sectional view of a cylinder.

[0015] The present invention will be described below through embodiments of the invention, but the invention according to the claims is not limited to the following embodiments. Furthermore, not all of the configurations described in the embodiments are necessarily essential means for solving the problems. For clarity of explanation, the following description and drawings have been omitted and simplified as appropriate. In each drawing, the same elements are assigned the same reference numerals, and duplicate explanations are omitted as necessary.

[0016] <Embodiment 1> Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Fig. 1 is an overall configuration diagram of an extruder 11 according to embodiment 1. The extruder 11 shown in Fig. 1 is a schematic diagram showing each component for ease of understanding.

[0017] For convenience in explaining the positional relationships of the components, FIG. 1 is illustrated using a right-handed Cartesian coordinate system. The positive Z-axis direction corresponds to the vertically upward direction. The XY plane corresponds to the horizontal plane. Furthermore, in FIG. 2 and subsequent figures, when a Cartesian coordinate system is used, the X-axis, Y-axis, and Z-axis directions of FIG. 1 correspond to the X-axis, Y-axis, and Z-axis directions of these Cartesian coordinate systems, respectively.

[0018] The extruder 11 according to the present disclosure mainly comprises a cylinder 100, an inlet 111, a discharge port 112, and a screw 110. The extruder 11 also comprises a monitoring device 20, a driving device 120, a connecting unit 130, a fluid supply unit 150, a pressure adjusting unit 160, a leak monitoring unit 170, and a cylinder data measuring unit 180.

[0019] In the cylinder 100, end faces of a plurality of unit blocks 101, each having a hole into which the screw 110 can be inserted, are connected to each other via a connecting portion 130. The cylinder 100 shown in FIG. 1 is configured by connecting a unit block 101A and a unit block 101B via the connecting portion 130.

[0020] In the following description, when multiple unit blocks 101 are indicated, an alphabetical letter is added after a numerical symbol, such as "unit block 101A," indicating an individual configuration. When unit blocks are collectively referred to, an alphabetical letter is not added after a numerical symbol, such as "unit block 101."

[0021] The receiving port 111 receives the object to be processed at one end side of the cylinder 100 (the minus side of the X axis in FIG. 1).

[0022] The discharge port 112 discharges the processed object downstream at the other end of the cylinder 100 (the positive side of the X axis in FIG. 1 ). The extruder 11 discharges the processed object from the discharge port 112 and supplies it to a post-processing unit 200. The post-processing unit 200 further processes the processed object received from the discharge port 112.

[0023] The screw 110 is rotatably housed in the cylinder 100 and transports the material to be treated from the receiving port 111 to the discharge port 112. The screw 110 is driven by a driving device 120. The driving device 120 includes a motor and a reducer, and rotates the screw 110 at a desired rotational speed.

[0024] The connecting portion 130 is a portion where the unit block 101 A and the unit block 101 B are connected to each other, and includes a first gasket 131 , a second gasket 132 , and a closed space 133 .

[0025] The first gasket 131 is an annular gasket fixed so as to surround the hole in the unit block 101 into which the screw 110 is inserted. The first gasket 131 is sandwiched between the unit block 101A and the unit block 101B. With this configuration, the first gasket 131 separates the atmosphere inside the first gasket 131 from the atmosphere outside the first gasket 131.

[0026] The second gasket 132 is an annular gasket fixed so as to surround the periphery of the first gasket 131. The second gasket 132 is sandwiched between the unit block 101A and the unit block 101B, similar to the first gasket 131. With this configuration, the second gasket 132 separates the atmosphere inside the second gasket 132 from the atmosphere outside the second gasket 132.

[0027] The closed space 133 is a space surrounded by the unit block 101A, the unit block 101B, the first gasket 131, and the second gasket 132. That is, the closed space 133 is between the unit block 101A and the unit block 101B, and is a space outside the first gasket 131 and inside the second gasket 132. The closed space 133 is separated from the space inside the cylinder 100 by the first gasket 131. In addition, the closed space 133 is separated from the space outside the cylinder 100 by the second gasket 132.

[0028] The closed space 133 is filled with a predetermined fluid supplied from the fluid supply unit 150. The predetermined fluid is, for example, an inert gas such as nitrogen or argon. The predetermined fluid may be any other gas or liquid as long as it is a fluid that is unlikely to affect the reaction inside the cylinder 100. In addition, at this time, the pressure of the closed space 133 filled with the fluid is set higher than the internal pressure of the cylinder 100 in the extruder 11 that is processing the object to be processed. As a result, in the extruder 11, if the sealing function of the first gasket 131 deteriorates, the fluid filled in the closed space 133 will flow into the inside of the cylinder 100.

[0029] For example, the fluid supply unit 150 supplies compressed gas to the closed space 133 via the pressure adjustment unit 160. Alternatively, the fluid supply unit 150 pressure-feeds a fluid stored in a tank to the closed space 133 via the pressure adjustment unit 160. In this case, the fluid supply unit 150 may include a tank that stores the fluid and a pump that pressure-feeds the stored fluid.

[0030] The pressure adjustment unit 160 is a mechanism that can adjust the pressure in the closed space 133 when a predetermined fluid is supplied from the fluid supply unit 150 to a predetermined set pressure that is higher than the internal pressure of the hole when the extruder 11 is operating. The pressure adjustment unit 160 is, for example, a pressure adjustment valve or a pressure regulator. The pressure adjustment unit 160 has a function of adjusting the pressure in the closed space 133 to the predetermined set pressure.

[0031] The set pressure can be set to be approximately 0.1 MPa to 1 MPa higher than the internal pressure in the vicinity of the connecting portion 130 of the cylinder 100. The pressure adjusting unit 160 adjusts the set pressure manually or automatically. If the pressure adjusting unit 160 is configured to automatically adjust the set pressure, the pressure adjusting unit 160 is communicatively connected to the monitoring device 20 and receives data related to the set pressure calculated by the monitoring device 20.

[0032] The leakage monitoring unit 170 includes a sensor capable of detecting leakage of fluid in the closed space 133. A situation in which leakage of fluid occurs occurs when the sealing function of the first gasket 131 or the second gasket 132 is deteriorated.

[0033] The set pressure of the closed space 133 is higher than atmospheric pressure and higher than the internal pressure of the cylinder 100. Therefore, if the sealing function of the first gasket 131 or the second gasket 132 deteriorates, the fluid remaining in the closed space 133 leaks out of the closed space 133. This causes the pressure inside the closed space 133 (the set pressure) to decrease at least temporarily. In this case, after the pressure in the closed space 133 temporarily decreases, the pressure adjustment unit 160 pumps the fluid into the closed space 133 to maintain the set pressure. In this case, even if the pressure in the closed space 133 stabilizes, the fluid continues to leak. In this case, the greater the amount of fluid leakage, the greater the flow rate of the fluid in the closed space 133. Therefore, by monitoring changes in the fluid flow or pressure in the closed space 133, the extruder 11 can detect a deterioration in the sealing function of the first gasket 131 or the second gasket 132.

[0034] The leak monitoring unit 170 is, for example, a flow meter capable of detecting the flow of fluid in the closed space 133. When no leak occurs in the closed space 133, the flow meter does not detect a fluid flow. That is, in this case, the flow rate indicated by the flow meter is zero. On the other hand, when a leak occurs in the closed space 133, the flow meter detects a fluid flow corresponding to the degree of leakage. That is, the larger the flow rate value detected by the flow meter, the greater the amount of fluid leaking from the closed space 133. The leak monitoring unit 170 may be a pressure meter capable of detecting fluctuations in pressure in the closed space 133. By including the leak monitoring unit 170, the extruder 11 can detect a deterioration in the sealing function of the first gasket 131 or the second gasket 132 of the cylinder 100. That is, the leak monitoring unit 170 may be a flow sensor capable of detecting the flow of fluid caused by a leak in the closed space. Alternatively, the leak monitoring unit 170 may be a pressure sensor capable of detecting a change in fluid pressure caused by a leak in the closed space.

[0035] The leak monitoring unit 170 is communicatively connected to the monitoring device 20 and supplies information regarding fluid leakage in the closed space 133 to the monitoring device 20. This allows the extruder 11 to suitably provide monitoring information about the cylinder 100 to a user who uses the monitoring device 20.

[0036] The cylinder data measurement unit 180 measures cylinder data. The cylinder data is, for example, data related to the internal pressure of the cylinder 100. In this case, the cylinder data measurement unit 180 is a pressure gauge that measures the internal pressure of the cylinder 100.

[0037] The cylinder data measurement unit 180 is used to set the pressure inside the closed space 133. That is, the user knows the internal pressure of the cylinder 100 at the connecting portion 130 from the pressure inside the cylinder 100 measured by the cylinder data measurement unit 180. Furthermore, the user sets the pressure of the closed space 133 to be higher than the internal pressure of the cylinder 100 at the connecting portion 130. That is, the extruder 11 can suitably set the set pressure of the fluid to be filled into the closed space 133 by having the cylinder data measurement unit 180 measure the internal pressure of the cylinder 100.

[0038] The cylinder data measurement unit 180 is preferably installed near the connecting part 130, but is not limited to being installed near the connecting part 130 as long as the pressure distribution inside the cylinder 100 is known. The cylinder data measurement unit 180 may acquire cylinder data relating to the internal pressure near the discharge port 112, for example.

[0039] The cylinder data measurement unit 180 may be a pressure gauge that measures the internal pressure at a plurality of different measurement positions along the extension direction of the cylinder. In this case, the pressure adjustment unit 160 can set the pressure of the fluid to be filled into the closed space 133 to a set pressure that is higher than the pressure in the vicinity of the closed space 133 estimated from the internal pressures measured at the plurality of different measurement positions.

[0040] If the relationship between the temperature and the internal pressure in the cylinder 100 is known in advance, the cylinder data measurement unit 180 may be a thermometer instead of a pressure gauge. In this case, the cylinder data is data related to the temperature inside the cylinder 100.

[0041] It should be noted that if the internal pressure of the cylinder 100 can be ascertained without using the cylinder data measurement unit 180 , the extruder 11 does not need to have the cylinder data measurement unit 180 .

[0042] The post-processing unit 200 receives the object to be processed discharged by the extruder 11 and processes the received object. For example, the post-processing unit 200 may be connected to the cylinder 100 downstream of the discharge port 112 and have a function of storing the object received from the discharge port 112. The post-processing unit 200 may further have a function of sending the gas received from the discharge port 112 to another device.

[0043] Next, the monitoring device 20 will be described with reference to FIG. 2. FIG. 2 is a block diagram of the monitoring device 20 according to the first embodiment. The monitoring device 20 is a device that monitors gas leakage from the cylinder 100 in the extruder 11. The monitoring device 20 is, for example, a server, a personal computer, or a tablet terminal. The monitoring device 20 may be a dedicated device including a calculation device such as a CPU (Central Processing Unit). The monitoring device 20 mainly includes a cylinder data receiving unit 22, a pressure setting unit 23, a leakage data receiving unit 24, a notification unit 25, and a memory unit 29.

[0044] Although not shown, the monitoring device 20 may have an interface for inputting and outputting predetermined information. In this case, the information input means may be, for example, a button, a switch, a keyboard, etc. In this case, the information output means may be, for example, a display, a speaker, a lamp, etc.

[0045] The cylinder data receiving unit 22 receives cylinder data related to the internal pressure at a predetermined position in the cylinder 100 of the operating extruder 11. The cylinder data receiving unit 22 may receive the cylinder data through an information input operation performed by a user. Furthermore, if the cylinder data receiving unit 22 is connected to the cylinder data measuring unit 180 so as to be able to communicate with the cylinder data measuring unit 180, the cylinder data receiving unit 22 may receive the cylinder data directly from the cylinder data measuring unit 180.

[0046] The pressure setting unit 23 calculates a set pressure based on the cylinder data. The pressure setting unit 23 sets the pressure of the fluid to be supplied to the closed space 133 so that the pressure in the closed space 133 is higher than the internal pressure of the cylinder 100. That is, the pressure setting unit 23 determines the internal pressure of the cylinder 100 from the received cylinder data, and sets a value higher than the internal pressure of the cylinder 100 as the pressure inside the closed space 133 using a predetermined algorithm.

[0047] Furthermore, the pressure setting unit 23 controls the pressure adjusting unit 160 so that the closed space 133 has a set pressure. That is, the pressure setting unit 23 controls the adjustment of the adjustment valve of the pressure adjusting unit 160 based on the calculated set pressure.

[0048] The pressure setting unit 23 may present to the user the pressure or the set pressure adjusted by the pressure adjusting unit 160. In this case, the pressure setting unit 23 presents to the user a pressure value for manually adjusting the pressure adjusting unit 160.

[0049] The pressure setting unit 23 may set the set pressure based on internal pressure data at multiple points in time during a predetermined period. More specifically, the pressure setting unit 23 may calculate the maximum value of the internal pressure data at multiple points in time during a predetermined period and set a value higher than the maximum value by a predetermined value as the pressure in the closed space 133. The pressure setting unit 23 may also calculate a moving average of the internal pressure data at multiple points in time during a predetermined period and set a value higher than the calculated moving average by a predetermined value as the pressure in the closed space 133. With this configuration, the extruder 11 can more appropriately calculate the pressure in the closed space 133. In this case, the extruder 11 can dynamically set the pressure in the closed space 133. Therefore, for example, in a case where the post-treatment unit 200 intermittently or dynamically vents the internal gas, the extruder 11 can set the set pressure according to the pressure in the post-treatment unit 200.

[0050] Furthermore, if the cylinder data measurement unit 180 is a pressure gauge that measures the internal pressure at a plurality of different measurement positions along the extension direction of the cylinder 100, the pressure setting unit 23 calculates the pressure in the closed space 133 based on the internal pressure measured at the plurality of different measurement positions. In this case, the pressure setting unit 23 estimates the internal pressure near the connecting portion 130 from the internal pressures at the plurality of different measurement positions, and sets a pressure higher than the estimated internal pressure as the pressure in the closed space 133.

[0051] The leak data receiving unit 24 receives data related to leaks from the leak monitoring unit 170 that detects fluid leaks in the closed space 133. The leak data is data indicating that the fluid sealed in the closed space 133 is leaking. The leak data is data related to the flow of fluid in the closed space 133. The leak data may also indicate changes in pressure in the closed space 133.

[0052] The notification unit 25 determines whether or not there is a fluid leak in the closed space 133 based on the data related to the leak. Furthermore, when the notification unit 25 detects a fluid leak, it notifies the user that a fluid leak has been detected (detection information). The means for notifying the user of the detection information is, for example, the information output means described above. Alternatively, the means for notifying the user of the detection information may be a communication means. In this case, the notification unit 25 notifies the detection information to a communication terminal carried by the user.

[0053] The storage unit 29 includes a non-volatile memory such as a flash memory, etc. The storage unit 29 stores a program for realizing the functions according to the present disclosure.

[0054] The above has described the monitoring device 20. With the above-described configuration, the monitoring device 20 can prevent gas inside the cylinder 100 from leaking to the outside.

[0055] Next, a method executed by the monitoring device 20 will be described with reference to Fig. 3. Fig. 3 is a flowchart of the monitoring method executed by the monitoring device 20 according to the first embodiment. The monitoring method according to Fig. 3 is a method for monitoring an extruder cylinder in which a plurality of unit blocks, each having a hole into which a screw can be inserted, are connected via a double annular gasket to form a cylinder that forms a closed space surrounding the hole at the connecting portion.

[0056] First, the cylinder data receiving unit 22 of the monitoring device 20 receives data (cylinder data) relating to the internal pressure at a predetermined position in the cylinder 100 of the operating extruder 11 (step S11). The cylinder data receiving unit 22 supplies the received cylinder data to the pressure setting unit 23.

[0057] Next, the pressure setting unit 23 sets the pressure of the closed space 133 so that the pressure in the closed space 133 is higher than the internal pressure (step S12). After the pressure setting unit 23 sets the pressure in the closed space 133, the pressure adjusting unit 160 adjusts the pressure of the fluid supplied from the fluid supply unit 150.

[0058] Next, the leakage data receiving unit 24 starts monitoring for fluid leakage in the closed space 133 (step S13).

[0059] Next, the notification unit 25 determines whether or not a fluid leak has been detected (step S14). If it is determined that a fluid leak has not been detected (step S14: NO), the notification unit 25 repeats step S14. If it is determined that a fluid leak has been detected (step S14: YES), the notification unit 25 notifies the user of information regarding the fluid leak (step S15). When the notification unit 25 notifies the user of information regarding the fluid leak, the monitoring device 20 ends the series of processes.

[0060] Although the first embodiment has been described above, the extruder 11 according to the first embodiment is not limited to the above-described configuration. For example, the extruder 11 may have a heater that heats the cylinder 100.

[0061] The cylinder data received by the cylinder data receiving unit 22 may be a predicted value calculated by simulation. In this case, the predicted value may be calculated using, for example, the type and temperature of gas generated inside the extruder 11 as input.

[0062] The fluid filled in the closed space 133 is preferably nitrogen, but may also be carbon dioxide, steam, an inert gas such as argon, or a liquid such as oil. The leak monitoring unit 170 may monitor the pressure difference between multiple distant locations in the closed space 133.

[0063] As described above, according to the present embodiment, it is possible to provide an extruder, an extruder cylinder, a monitoring device, a monitoring method, and a program that suppress leakage of gas inside the cylinder to the outside.

[0064] <Embodiment 2> Fig. 4 is an overall configuration diagram of an extruder 12 according to embodiment 2. The extruder 12 shown in Fig. 4 has unit blocks 101A to 101D as unit blocks 101 that constitute a cylinder 100. Accordingly, the extruder 12 has three connecting sections 130. Furthermore, the closed spaces 133 of the three connecting sections 130 that the extruder 12 has are connected by relay sections 134. In other words, the unit block 101 has closed spaces 133 that span a plurality of connecting sections 130.

[0065] With the above-described configuration, the pressure adjusting unit 160 supplies fluid to the closed space 133 spanning the three connecting units 130. Furthermore, the leak monitoring unit 170 detects fluid leakage in the closed space 133 spanning the three connecting units 130.

[0066] With this configuration, the extruder 12 can detect a decrease in the sealing function of the first gasket 131 and the second gasket 132 in the closed space 133 spanning multiple unit blocks 101 .

[0067] As described above, according to this embodiment, it is possible to provide an extruder, an extruder cylinder, a monitoring device, a monitoring method, and a program that suppress leakage of gas from inside the cylinder. <Embodiment 3> Next, embodiment 3 will be described. Figure 5 is an overall configuration diagram of extruder 13 according to embodiment 3. Extruder 13 has unit blocks 101A to 101D as unit blocks 101 that constitute cylinder 100. Accordingly, extruder 13 has connecting portions 130A, 130B, and 130C.

[0068] The connecting portion 130A exists between the unit block 101A and the unit block 101B. The connecting portion 130B exists between the unit block 101B and the unit block 101C. The connecting portion 130C exists between the unit block 101C and the unit block 101D. The connecting portion 130A has a closed space 133A. The connecting portion 130B has a closed space 133B. The connecting portion 130C has a closed space 133C. The closed space 133A, the closed space 133B, and the closed space 133C are each independent spaces.

[0069] The closed space 133A is connected to a pressure adjusting unit 160A and a leak monitoring unit 170A. Similarly, the closed space 133B is connected to a pressure adjusting unit 160B and a leak monitoring unit 170B. The closed space 133C is connected to a pressure adjusting unit 160C and a leak monitoring unit 170C. The fluid supply unit 150 supplies fluid to each of the pressure adjusting units 160A, 160B, and 160C.

[0070] The monitoring device 20B according to this embodiment is connected to the pressure adjustment units 160A, 160B, and 160C so that they can be controlled separately. The monitoring device 20B also receives data related to leaks from the leak monitoring units 170A, 170B, and 170C, respectively. That is, the monitoring device 20B receives data related to leaks in the closed space 133A from the leak monitoring unit 170A, data related to leaks in the closed space 133B from the leak monitoring unit 170B, and data related to leaks in the closed space 133C from the leak monitoring unit 170C.

[0071] That is, the cylinder 100 of the extruder 13 includes a closed space 133 in each of a plurality of connecting portions 130 along the stretching direction. Each of the plurality of closed spaces 133 also has a pressure adjusting portion 160 and a leak monitoring portion 170.

[0072] The monitoring device 20B according to this embodiment is communicably connected to the cylinder data measurement unit 180 and acquires cylinder data directly from the cylinder data measurement unit 180. The monitoring device 20B according to this embodiment is also communicably connected to the fluid supply unit 150. This allows the monitoring device 20B to control the operation of the fluid supply unit 150.

[0073] 6 is a block diagram of a monitoring device 20B according to the third embodiment. The monitoring device 20B differs from the monitoring device 20 in that it includes a fluid control unit 21 and a state management unit 26.

[0074] The fluid control unit 21 controls the fluid supply unit 150. This allows the fluid control unit 21 to start supplying the fluid from the fluid supply unit 150 after the extruder 13 starts operating, for example.

[0075] The pressure setting unit 23 according to this embodiment can set independent pressures for the plurality of pressure adjusting units 160 .

[0076] The status management unit 26 manages the status of each of the multiple leak monitoring units 170. That is, the status management unit 26 can identify, for example, in which closed space 133 of the multiple connecting units 130 a pressure drop has been detected. More specifically, the status management unit 26 may receive data related to leaks accompanied by identifiers from the leak monitoring units 170. Alternatively, the status management unit 26 may have separate interfaces for receiving data related to leaks from the leak monitoring units 170A, 170B, and 170C.

[0077] When a fluid leak is detected in any of the leak monitoring units 170, the notification unit 25 notifies the user in an identifiable manner which connection unit 130 the leak was detected in. This facilitates maintenance of the sealing function of the extruder 13. The extruder 10 can also provide the user of the monitoring device 20B with the monitoring data of the cylinder 100 in a unified manner.

[0078] FIG. 7 is a flowchart of a monitoring method executed by the monitoring device 20B according to the third embodiment.

[0079] First, the cylinder data receiving unit 22 of the monitoring device 20B receives cylinder data relating to the internal pressure at a predetermined position in the cylinder 100 of the operating extruder 11 from the cylinder data measuring unit 180 (step S21). The cylinder data receiving unit 22 supplies the received cylinder data to the pressure setting unit 23.

[0080] Next, the pressure setting unit 23 sets the pressure of the closed spaces 133A, 133B, and 133C so that the pressure in each closed space 133 is higher than the internal pressure near the corresponding connecting portion 130 (step S22). Once the pressure setting unit 23 has set the pressure, the fluid control unit 21 starts supplying fluid from the fluid supply unit 150. Furthermore, the pressure adjustment unit 160 adjusts the pressure in each closed space 133.

[0081] Next, the leakage data receiving unit 24 starts monitoring the leakage of fluid in each closed space 133 (step S23).

[0082] Next, the notification unit 25 determines whether or not a fluid leak has been detected (step S24). If it is not determined that a fluid leak has been detected (step S24: NO), the notification unit 25 repeats step S24. If it is determined that a leak has been detected (step S24: YES), the notification unit 25 notifies the user of information regarding the connection unit in which the fluid leak was detected (step S25). Here, the notification unit 25 also notifies the user of information regarding the connection unit 130 in which the fluid leak occurred, as information regarding the fluid leak. Once the notification unit 25 has notified the user of information regarding the connection unit in which the fluid leak was detected, the monitoring device 20 ends the series of processes.

[0083] The above has described the third embodiment. According to this embodiment, it is possible to provide an extruder, an extruder cylinder, a monitoring device, a monitoring method, and a program that can suppress leakage of gas from inside the cylinder and facilitate maintenance of the sealing function of the cylinder.

[0084] (Configuration of Extruder) Next, an embodiment of an extruder to which the present disclosure can be applied will be described. FIG. 8 is an overall configuration diagram of an extruder 10. The extruder 10 shown in FIG. 8 is partially shown in cross section for ease of understanding. The extruder 10 is a device that performs chemical recycling by depolymerizing waste plastics in order to reuse them. The extruder 10 mainly includes a cylinder 100, a screw 110, an inlet 111, an outlet 112, a motor 121, a reducer 122, a temperature adjustment unit 190, and a storage unit 210.

[0085] The cylinder 100 is configured by connecting a plurality of unit blocks 101 in the extension direction. The cylinder 100 is configured from unit blocks 101A to 101H. An inlet 111 is provided on the upstream side of the cylinder 100. Above the inlet 111, a raw material feeder 300 is shown. The raw material feeder 300 supplies raw material M10 to the inlet 111 in predetermined amounts.

[0086] The cylinder 100 accommodates a screw 110. The screw 110 is rotationally driven by a motor 121 and a reducer 122. The screw 110 conveys the raw material M10 received through an inlet 111 downstream. The screw 110 basically has a spiral groove, but in the region where depolymerization is promoted, the screw 110 may have an uneven shape or the like for kneading the raw material M10 and applying a shear force thereto.

[0087] A temperature adjustment unit 190 is installed around the cylinder 100. The temperature adjustment unit 190 is a heater that heats the cylinder 100 from the outer periphery thereof. The extruder 10 depolymerizes the raw material M10 by heating and stirring it while transporting it downstream. A discharge port 112 is provided downstream of the cylinder 100. The discharge port 112 is connected to a storage unit 210.

[0088] A plurality of types of substances, such as gas, liquid, and slurried residue, generated as a result of depolymerization are supplied to reservoir 210 through outlet 112. By opening exhaust valve 211, reservoir 210 supplies gas to recovery device 230 through pipe 220. Recovery device 230 liquefies the recovered gas using a condenser or the like. The liquid and residue accumulated in reservoir 210 are periodically recovered.

[0089] With the above-described configuration, the extruder 10 effectively thermally decomposes or depolymerizes the raw material M10 to be processed. The extruder 10 discharges gas, liquid, and residue generated by depolymerization during transport into the storage section 210. During this process, the internal pressure of the cylinder 100 is higher than atmospheric pressure. The unit blocks 101 constituting the cylinder 100 are sealed with gaskets. However, with long-term use of the extruder 10, metal fatigue and other problems may occur in the fastening portions between the unit blocks 101 due to repeated heating and cooling. This may also cause a deterioration or loss of the gasket's sealing function. Therefore, by adopting the above-described configuration for the extruder 10, the cylinder 100 of the extruder 10 can prevent gas generated inside from leaking to the outside of the cylinder 100.

[0090] (Configuration of unit block) Next, the unit block will be described. Fig. 9 is a perspective view of a unit block 101. The unit block 101 is a cylindrical block having a hole 102, which is a through hole extending parallel to the X axis. The hole of the unit block 101 shown in Fig. 9 has a shape in which two cylinders partially overlap each other. This is because the unit block 101 constitutes the cylinder 100 of the twin-screw extruder. The unit block 101 has a flange portion 108 that is perpendicular to the hole 102 at a position where it is connected to another adjacent unit block 101.

[0091] Flange portion 108 is provided with a plurality of connecting holes 106 into which fastening members are inserted. Flange portion 108 also has recess 103, fluid inlet 104, and fluid supply port 105. Recess 103 is a space for forming closed space 133, and first gasket 131 and second gasket 132 are installed therein.

[0092] The fluid inlet 104 is an opening of a hole that passes through the flange portion 108. The fluid supply port 105 is the other opening of the hole that is connected to the fluid inlet 104 and is provided in the recess 103. The fluid inlet 104 is a fluid inlet for receiving a supply of fluid from the pressure adjustment unit 160. The fluid supply port 105 is an opening for filling the closed space 133 with the fluid supplied from the pressure adjustment unit 160.

[0093] (Configuration of Closed Space) Next, the closed space configured in the connecting portion will be described with reference to Fig. 10. Fig. 10 is a partial cross-sectional view of the cylinder. Fig. 10 shows the connecting portion 130A where the unit block 101A and the unit block 101B are connected, but the other connecting portions have the same configuration.

[0094] In the connecting portion 130A, the adjacent unit blocks 101A and 101B are connected by a flange portion. The unit blocks 101A and 101B are fixed together by a plurality of bolts and nuts which are connecting members 107.

[0095] A first gasket 131 and a second gasket 132 are sandwiched between the unit block 101A and the unit block 101B. The first gasket 131 is sandwiched between a pair of opposing end faces at the connecting portion 130 of the connected unit blocks 101, and surrounds the periphery of the hole 102. The second gasket 132 is sandwiched between the pair of end faces, and further surrounds the periphery of the first gasket 131, thereby forming a closed space 133 around the hole 102. In other words, the space surrounded by the first gasket 131 and the second gasket 132 is the closed space 133. The closed space 133 is connected to the fluid inlet 104 via the fluid supply port 105.

[0096] The first gasket 131 and the second gasket 132 are, for example, hollow metal O-rings. Alternatively, the first gasket 131 and the second gasket 132 may be O-rings with holes. The first gasket 131 and the second gasket 132 may be sealing members other than hollow metal O-rings.

[0097] With this configuration, the closed space 133 is filled with fluid from the fluid inlet 104. The closed space 133 filled with fluid is separated from the hole 102 by the first gasket 131. The closed space 133 is also separated from the outside of the unit block 101 by the second gasket 132.

[0098] As described above, the cylinder 100 is configured such that a plurality of unit blocks 101, each having a hole 102 into which the screw 110 can be inserted, are connected via a double annular gasket, that is, a first gasket 131 and a second gasket 132. As a result, the cylinder 100 forms a closed space 133 surrounding the hole 102 at the connecting portion 130. If the sealing function of the first gasket 131 deteriorates, fluid will flow from the closed space 133 into the hole 102. If the sealing function of the second gasket 132 deteriorates, fluid will flow from the closed space 133 to the outside of the cylinder 100.

[0099] The above has described the configuration of the connecting unit 130. Although not shown, the leak monitoring unit 170 and the pressure adjusting unit 160 may be installed so as to be in contact with the fluid inlet 104. Furthermore, the leak monitoring unit 170 may be provided inside the unit block 101A along the hole that forms the closed space 133 of the unit block 101A.

[0100] With the above-described configuration, the cylinder 100 can prevent gas from leaking from the cylinder to the outside. The cylinder 100 also allows the user to easily recognize any deterioration in the sealing function of the gasket that constitutes the cylinder. Furthermore, the cylinder 100 is configured to facilitate maintenance of the gasket that constitutes the cylinder.

[0101] The program for executing the above-described monitoring method includes a set of instructions (or software code) that, when loaded into a computer, causes the computer to perform one or more functions described in the embodiments. The program may be stored in a non-transitory computer-readable medium or a tangible storage medium. By way of example and not limitation, computer-readable media or tangible storage media include random-access memory (RAM), read-only memory (ROM), flash memory, solid-state drive (SSD) or other memory technologies, CD-ROM, digital versatile disc (DVD), Blu-ray (registered trademark) disc or other optical disk storage, magnetic cassette, magnetic tape, magnetic disk storage or other magnetic storage device. The program may also be transmitted on a transitory computer-readable medium or communication medium. By way of example and not limitation, transitory computer-readable media or communication media include electrical, optical, acoustic, or other forms of propagated signals.

[0102] The present invention has been described above with reference to the embodiments, but the present invention is not limited to the above. Various modifications that can be understood by those skilled in the art can be made to the configuration and details of the present invention within the scope of the invention. For example, the extruder and cylinder according to the present disclosure are not limited to twin-screw extruders. The extruder and cylinder according to the present disclosure may also be single-screw.

[0103] This application claims priority based on Japanese Patent Application No. 2023-137865, filed on August 28, 2023, the disclosure of which is incorporated herein in its entirety.

[0104] The present disclosure can be used, for example, as an extruder that extrudes and discharges received raw materials while kneading them.

[0105] REFERENCE SIGNS LIST 10 Extruder 11 Extruder 12 Extruder 13 Extruder 20 Monitoring device 21 Fluid control unit 22 Cylinder data receiving unit 23 Pressure setting unit 24 Leakage data receiving unit 25 Notification unit 26 Status management unit 29 Memory unit 100 Cylinder 101 Unit block 102 Hole 103 Recess 104 Fluid inlet 105 Fluid supply port 106 Connecting hole 107 Connecting member 108 Flange portion 110 Screw 111 Receiving port 112 Discharge port 120 Driving device 121 Motor 122 Reducer 130 Connecting portion 131 First gasket 132 Second gasket 133 Closed space 134 Relay portion 150 Fluid supply unit 160 Pressure adjustment unit 170 Leakage monitoring unit 180 Cylinder data measurement unit 190 Temperature adjustment unit 200 Post-treatment unit 210 Storage unit 211 Exhaust valve 220 Pipe 230 Recovery device 300 Raw material feeder M10 Raw material M11 Processing object

Claims

1. An extruder comprising: a cylinder in which the end faces of a number of unit blocks, each having a hole through which a screw can be inserted, are connected via a connecting section; an inlet at one end of the cylinder for receiving an object to be treated before processing; a discharge outlet at the other end of the cylinder for discharging the object to be treated downstream after processing; and a screw rotatably housed in the cylinder for transporting the object to be treated from the inlet to the discharge outlet, wherein the extruder has a closed space surrounded by a first gasket at the connecting section which surrounds the hole and a second gasket which further surrounds the first gasket, a pressure adjustment section which is a mechanism which can adjust the pressure of the closed space when a predetermined fluid is supplied to a predetermined set pressure which is higher than the internal pressure of the hole when the extruder is operating, and a leakage monitoring section which includes a sensor which can detect leakage of the fluid in the closed space.

2. The extruder according to claim 1, further comprising a cylinder data measurement unit that acquires cylinder data relating to the internal pressure at a specified position of the cylinder, and the pressure adjustment unit is capable of adjusting the set pressure to a pressure higher than the internal pressure based on the received cylinder data when the extruder is operating.

3. The extruder according to claim 2, further comprising: a fluid supply unit that supplies the fluid to the closed space via the pressure adjustment unit; and a pressure setting unit that calculates the set pressure based on the cylinder data and controls the pressure adjustment unit so that the closed space becomes at the set pressure.

4. The extruder according to claim 3, wherein the pressure adjusting section has an adjusting valve capable of adjusting the pressure in the closed space, and the pressure setting section controls the adjustment of the adjusting valve based on the set pressure.

5. The extruder according to claim 4, further comprising a storage section connected to the cylinder downstream of the discharge port and discharging gas received from the discharge port to the outside, the cylinder or the storage section having a cylinder data measurement section that acquires the cylinder data relating to the internal pressure in the vicinity of the discharge port.

6. The extruder according to claim 5, wherein the cylinder data measuring unit is a pressure gauge that measures the internal pressure, and the pressure setting unit receives data on the internal pressure measured by the pressure gauge and sets the set pressure based on the data on the internal pressure at multiple points in time during a specified period.

7. The extruder described in claim 5, wherein the cylinder data measuring unit is a pressure gauge that measures the internal pressure at a plurality of different measurement positions along the extension direction of the cylinder, and the pressure setting unit controls the pressure adjusting unit using the set pressure based on the pressure in the vicinity of the closed space which is estimated based on the internal pressures measured at the plurality of different measurement positions.

8. The extruder according to claim 1, further comprising a notification unit that, when the leakage monitoring unit detects a leakage of the fluid, notifies a user that a leakage of the fluid has been detected.

9. The extruder according to claim 1, wherein the cylinder includes the closed space in each of a plurality of connecting portions along the stretching direction, and each of the plurality of closed spaces has the pressure adjusting portion and the leak monitoring portion.

10. The extruder described in claim 9, further comprising: a status management unit that manages the status of each of the multiple leak monitoring units; and a notification unit that, when a fluid leak is detected in any of the multiple leak monitoring units, notifies a user in an identifiable manner as to which connection unit the fluid leak has been detected in.

11. The extruder according to claim 1, wherein the leakage monitoring unit includes a flow rate sensor capable of detecting a flow of fluid caused by leakage of the fluid in the closed space.

12. The extruder according to claim 1, wherein the leakage monitoring unit includes a pressure sensor capable of detecting a change in pressure of the fluid caused by leakage of the fluid in the closed space.

13. An extruder as claimed in any one of claims 1 to 10, further comprising a temperature adjustment unit for heating the periphery of the cylinder, wherein the receiving port receives the object to be treated including a predetermined plastic, the screw transports the object to be thermally decomposed, and the discharge port discharges downstream multiple types of substances produced by thermal decomposition.

14. An extruder cylinder comprising a plurality of unit blocks connected together to house a screw and form an extruder, the unit blocks being cylindrical members each having a hole through which the screw can be inserted; a first gasket sandwiched between a pair of opposing end faces at the connection of the connected unit blocks and surrounding the hole; a second gasket sandwiched between the pair of end faces and further surrounding the first gasket to form a closed space around the hole; a pressure adjustment unit which is a mechanism capable of adjusting the pressure in the closed space to a predetermined set pressure higher than the internal pressure of the hole when the extruder is operating; and a leakage monitoring unit including a sensor capable of detecting fluid leakage in the closed space.

15. A monitoring device for an extruder cylinder in which a cylinder is formed by connecting a plurality of unit blocks, each having a hole through which a screw can be inserted, via a double annular gasket, to form a closed space surrounding the hole at the connecting portion, the monitoring device comprising: a cylinder data receiving unit that receives data regarding the internal pressure at a predetermined position in the cylinder of an operating extruder; a pressure setting unit that sets the pressure of a fluid to be supplied to the closed space so that the pressure of the closed space becomes higher than the internal pressure; a leakage data receiving unit that receives data regarding leakage from a leakage monitoring unit that detects leakage of the fluid in the closed space; and a notification unit that, when a fluid leak is detected, notifies a user of the detection information.

16. A method for monitoring an extruder cylinder in which a plurality of unit blocks, each having a hole through which a screw can be inserted, are connected via a double annular gasket to form a cylinder that forms a closed space surrounding the hole at the connecting portion, the method comprising: receiving data regarding the internal pressure at a predetermined position in the cylinder of an operating extruder; supplying a fluid to the closed space so that the closed space has a pressure higher than the internal pressure; monitoring for a leak of the fluid in the closed space so as to be detectable; and notifying a user of the detection information if a fluid leak is detected.

17. A program for a monitoring method executed by a monitoring device for an extruder cylinder, in which a cylinder is formed by connecting a plurality of unit blocks, each having a hole through which a screw can be inserted, via a double annular gasket, to form a closed space surrounding the hole at the connecting portion, said monitoring method comprising: receiving data regarding the internal pressure at a predetermined position in the cylinder of an operating extruder; setting the pressure of the fluid to be supplied to the closed space so that the closed space has a pressure higher than the internal pressure; receiving data regarding leakage from a leakage monitoring unit which detects leakage of the fluid in the closed space; and, if a fluid leak is detected, notifying a user of the detection information, said program.

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