Molding and drying system and method for controlling the molding and drying system

Abstract

To provide a molding / drying system capable of obtaining a molded / dried article that generates less dust, and a method of controlling the molding / drying system.SOLUTION: A molding / drying system 1 according to the present invention, comprises: a first feeder 2 that feeds a treated object; a second feeder 3 that feeds a treated object of a lower water content relative to the treated object to be fed from the first feeder 2; a molder / dryer 6 that allows a treated object fed from the first feeder 2 and a treated object fed from the second feeder 3 to pass between a pair of heated rollers 62 to carry out the molding / drying of the treated objects and obtain a molded / dried article; a dust meter 71 that measures the concentration of dust generated from the molded / dried article; and a controller 8 that controls at least one of a ratio of an amount of the treated object fed to the molder / dryer 6 from the first feeder 2 and an amount of the treated object fed to the molder / dryer 6 from the second feeder 3, and at least one of the number of rotations of the pair of rollers 62, on the basis of a measurement result of the dust meter 71.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a molding and drying system for processing objects and a control method thereof.

Background Art

[0002] Organic and inorganic sludges such as sewage sludge, night soil sludge, and industrial wastewater sludge are recycled by being formed into dried granules and then used as fuel or civil engineering materials. In addition, general waste such as food waste and food processing residues may also be recycled. Hereinafter, sludge and general waste are collectively referred to as processing objects.

[0003] When forming a processing object, it is difficult to form a so-called powder-like dried product with a low water content of the processing object. Therefore, generally, after adding water to the dried product and using a granulating device to form it in a state where the water content of the processing object is high, for example, it is dried using a band-type ventilation dryer in which stirring and pulverizing actions are unlikely to occur. The water content of the processing object required for forming in the granulating device is said to be 20% W.B. or more. Note that "% W.B." is a unit notation for indicating the water content on a wet basis, which shows how much water there is with respect to the total weight.

[0004] In such a molding and drying system in which the molding and drying of the processing object are performed by separate devices, the number of devices for processing the processing object increases, resulting in an increase in equipment investment costs and an increase in the installation area of the devices. In addition, when the number of devices is large, there is also a problem that maintenance costs and maintenance management costs increase.

[0005] On the other hand, the applicant of the present application has proposed a molding and drying machine that can perform molding and drying in the same device (see, for example, Patent Document 1, etc.). In this molding and drying machine, the processing object is passed between a pair of rollers having circumferential grooves formed on the outer periphery and supplied with steam for heating inside, thereby molding and drying the processing object. By using the molding and drying machine described in Patent Document 1, the number of devices in the molding and drying system can be reduced.

Prior Art Documents

[0006] [Patent Document 1] Japanese Patent Publication No. 2006-038339 [Overview of the project] [Problems that the invention aims to solve]

[0007] Incidentally, when molded and dried products are loaded onto transport vehicles such as trucks or placed into containers, dust can be generated from the molded and dried products, and it is desirable to suppress this dust. By using the molded and dried machine described in Patent Document 1, dust generation can be reduced compared to when using a band-type aeration drying device. However, since the properties of the sludge and general waste to be processed vary from day to day, depending on the properties of the material processed by the molded and dried machine, a large amount of dust may be generated from the resulting molded and dried product. There are also systems that produce dense and hard molded and dried products that do not generate dust, or long molded and dried products that are less likely to break, but the capital investment costs tend to be high. Furthermore, if the molded and dried products are used as fuel for incineration, for example, if they are dense and hard, they are not necessarily easy to burn. Also, if they are long, problems are likely to occur in the conveying system of the molded and dried products, and in bagging, packability is reduced, so it becomes necessary to include a process to adjust them to the appropriate length.

[0008] In view of the above circumstances, the present invention aims to provide a molding and drying system and a control method for the molding and drying system that can obtain a molded and dried product with appropriate properties that does not generate dust easily. [Means for solving the problem]

[0009] The molding and drying system of the present invention, which solves the above problems, A first supply device for supplying the material to be processed, A second supply device that supplies a workpiece with a lower moisture content than the workpiece supplied from the first supply device, A molding dryer that obtains a molded and dried product by passing a workpiece supplied from the first supply device and a workpiece supplied from the second supply device between a pair of heated rollers, A dust meter for measuring the concentration of dust generated from the molded and dried product, The system is characterized by comprising a control device that controls, based on the measurement results of the dust meter, the ratio of the amount of material to be processed supplied from the first supply device to the molding dryer to the amount of material to be processed supplied from the second supply device to the molding dryer, and at least one of the rotation speeds of the pair of rollers.

[0010] According to the molding and drying system of the present invention, the control device performs control based on the measurement results of the dust meter, thereby enabling the production of a molded and dried product with appropriate properties in which the amount of dust generated from the workpiece is controlled.

[0011] Here, the pair of rollers may have circumferential grooves formed on their outer surfaces.

[0012] In the molding and drying system of the present invention, The molded and dried product is equipped with a measuring device for measuring the moisture content or temperature, The control device may control, based on the measurement results of the measuring device, at least one of the following: the ratio of the amount of material to be processed supplied from the first supply device to the molding dryer to the amount of material to be processed supplied from the second supply device to the molding dryer, the rotation speed of the pair of rollers, and the amount of heating of the pair of rollers, other than those controlled based on the measurement results of the dust meter.

[0013] By doing so, the processed material can be molded and dried to the desired moisture content.

[0014] Here, the control device may control the pressure of the heating steam supplied to the pair of rollers when controlling the amount of heating of the pair of rollers.

[0015] Furthermore, in the molding and drying system of the present invention, The system includes a mixer that mixes the material to be processed supplied from the first supply device and the material to be processed supplied from the second supply device and supplies the mixture to the molding dryer. The control device may control the mixing time in the mixer based on the measurement results of the dust meter and the measurement results of the measuring device.

[0016] Depending on the mixing of the material to be processed supplied to the molding dryer, the material may become highly viscous, potentially causing it to stick to the walls or scraper of the molding dryer or to clog. On the other hand, it may also result in insufficient molding, leading to a brittle and easily broken product. By controlling the mixing time in the mixer, variations in the moisture content of the molded and dried product can be suppressed, while reducing the risk of the material clogging the molding dryer and preventing excessive breakage of the molded and dried product's shape.

[0017] Here, the control device may control the mixing time by changing the supply position of at least one of the materials to be processed supplied from the first supply device and the materials to be processed supplied from the second supply device in the mixer, based on the measurement results of the dust meter and the measurement results of the measuring device. Alternatively, the mixer may change the mixing distance, which is the distance over which the materials to be processed supplied from the first supply device and the materials to be processed supplied from the second supply device are transported while being mixed, by changing the supply position of at least one of the materials to be processed.

[0018] Furthermore, in the molding and drying system of the present invention, It is equipped with a receiving section for receiving the molded and dried product that falls from the molding dryer, The dust meter may measure the dust generated when the molded and dried product falls into the receiving section.

[0019] This configuration can also be said to reflect the situation when the formed and dried product is loaded onto a transportation means such as a truck or placed in a container. By measuring the concentration of dust generated from the formed and dried product with a dust meter when the formed and dried product falls, it is possible to obtain a formed and dried product with an appropriate property in which the amount of dust generated in those situations is controlled.

[0020] Moreover, the forming and drying system of the present invention for solving the above problems is a first supply device for supplying a workpiece, a second supply device for supplying a workpiece having a lower water content than the workpiece supplied from the first supply device, a forming and drying machine that forms and dries the workpiece by passing the workpiece supplied from the first supply device and the workpiece supplied from the second supply device between a pair of heated rollers to obtain a formed and dried product, a dust meter for measuring the concentration of dust generated from the formed and dried product, a measuring device for measuring the water content or temperature of the formed and dried product, Based on the measurement result of the dust meter, controlling the ratio of the amount of the workpiece supplied from the first supply device to the forming and drying machine and the amount of the workpiece supplied from the second supply device to the forming and drying machine, and based on the measurement result of the measuring device, controlling at least one of the rotational speed of the pair of rollers and the heating amount of the pair of rollers. It is characterized by comprising a control device.

[0021] According to this forming and drying system, it is possible to make the workpiece into a formed and dried product having a desired water content and an appropriate property in which the amount of dust generation is controlled.

[0022] Moreover, the forming and drying system of the present invention for solving the above problems is a first supply device for supplying a workpiece, a second supply device for supplying a workpiece having a lower water content than the workpiece supplied from the first supply device, A molding dryer that obtains a molded and dried product by passing a workpiece supplied from the first supply device and a workpiece supplied from the second supply device between a pair of heated rollers, A dust meter for measuring the concentration of dust generated from the molded and dried product, A measuring device for measuring the moisture content or temperature of the molded and dried product, The system is characterized by comprising a control device that controls, based on the measurement results of the dust meter and the measurement results of the measuring device, the ratio of the amount of material to be processed supplied from the first supply device to the molding dryer and the amount of material to be processed supplied from the second supply device, and at least one of the rotation speeds of the pair of rollers.

[0023] This molding and drying system makes it possible to produce molded and dried products with the desired moisture content and controlled amount of dust generation, resulting in products with appropriate properties.

[0024] Furthermore, the control method for the molding and drying system of the present invention that solves the above problems is: A control method for a molding and drying system comprising: a first supply device for supplying a material to be processed; a second supply device for supplying a material to be processed having a lower moisture content than the material supplied from the first supply device; and a molding and drying machine for molding and drying the material supplied from the first supply device and the material supplied from the second supply device to obtain a molded and dried product, wherein A dust concentration measurement step for measuring the concentration of dust generated from the molded and dried product, The present invention is characterized by comprising a ratio control step that controls the ratio between the amount of material to be processed supplied from the first supply device to the molding dryer and the amount of material to be processed supplied from the second supply device to the molding dryer, based on the dust concentration measured by the dust concentration measurement step.

[0025] This control method for the molding and drying system allows the processed material to be molded and dried to an appropriate quality with controlled dust generation. [Effects of the Invention]

[0026] According to the molding and drying system and control method of the present invention, it is possible to obtain a molded and dried product with appropriate properties while controlling the amount of dust generated. [Brief explanation of the drawing]

[0027] [Figure 1] This is a diagram illustrating a molding and drying system corresponding to one embodiment of the present invention. [Figure 2] Figure 1 is a block diagram showing the hardware configuration for controlling the molding and drying system. [Figure 3] Figure 1 shows the control operation of the molding and drying system. [Figure 4] This diagram is similar to Figure 1, showing the first supply device, dryer, and mixer in the first modified molding and drying system. [Figure 5] Figure 4 is a control diagram illustrating the control of the mixing time in the molding and drying system. [Figure 6] This flowchart shows the control operation of the molding and drying system in the second modified example. [Figure 7] This flowchart shows the control operation of the molding and drying system in the third modified example. [Modes for carrying out the invention]

[0028] Embodiments of the present invention will be described below with reference to the drawings. In this description of the embodiment, a molding and drying system will be used as an example to obtain a molded and dried product by molding and drying sludge such as organic sludge or inorganic sludge as the material to be processed. The molding and drying system of this embodiment can also process muddy general waste, or a mixture of muddy general waste and sludge, to obtain a molded and dried product.

[0029] Figure 1 is a schematic diagram showing a molding and drying system corresponding to one embodiment of the present invention.

[0030] As shown in Figure 1, the molding and drying system 1 comprises a first supply device 2, a second supply device 3, a mixer 4, a molding and drying machine 6, a cushion hopper 7, and a control device 8 (see Figure 2) that controls these components.

[0031] The first supply device 2 consists of a first hopper 20. The first hopper 20 has a first screw conveyor 21. The first hopper 20 receives dewatered sludge (material to be processed) whose moisture content has been reduced to approximately 70% WB, and transfers the received material to be processed by the first screw conveyor 21 to supply it to the mixer 4. The first screw conveyor 21 is a screw conveyor rotated by a first motor (not shown) whose rotational speed can be changed by a first inverter 22. Increasing the frequency of the first inverter 22 increases the rotational speed of the first motor, and decreasing the frequency of the first inverter 22 decreases the rotational speed of the first motor. Changing the rotational speed of the first motor increases or decreases the amount of material to be processed supplied from the first supply device 2 to the mixer 4. The material to be processed supplied from the first supply device 2 to the mixer 4 has a moisture content of approximately 70% WB, the same as when it was received. Hereinafter, the material to be processed supplied from the first supply device 2 may be referred to as high-moisture material to be processed.

[0032] The second supply device 3 consists of a second hopper 31 and a dryer 32. The second hopper 31 has a second screw conveyor 311. Similar to the first hopper 20, the second hopper 31 receives dewatered sludge (material to be processed) with a moisture content of approximately 70% WB, and transfers the received material to be processed by the second screw conveyor 311 to supply it to the dryer 32. The second screw conveyor 311 is a screw conveyor rotated by a second motor (not shown) that rotates at a constant rotational speed. However, the rotational speed of the second motor may be made changeable, and control may be performed to increase or decrease the amount of material to be processed supplied from the second hopper 31 to the dryer 32.

[0033] The dryer 32 has a drying chamber 320 and a multi-tube heating tube 321 located inside the drying chamber 320. This dryer 32 is a continuous conduction heat transfer dryer capable of continuously processing materials. Materials supplied to the dryer 32 from the second hopper 31 are dried by contact with the multi-tube heating tube 321 rotating inside the drying chamber 320, becoming materials with a low moisture content of about 10% WB, and are sequentially supplied to the mixer 4. The degree to which the materials are dried by the dryer 32 is adjustable. The moisture content of the materials obtained by this dryer 32 is preferably 5% WB to 40%, more preferably 5% WB to 20%, and even more preferably 10% WB to 20%. By drying in the dryer 32, the materials supplied to the mixer 4 from the second supply device 3 have a lower moisture content than when they were received. Hereinafter, the materials supplied from the second supply device 3 may be referred to as dried materials.

[0034] Mixer 4 receives and mixes the high-moisture material to be treated supplied from the first supply device 2 and the dried material to be treated supplied from the second supply device 3. Inside mixer 4, intermittent spiral blades are arranged to transfer the high-moisture material and the dried material while mixing them by rotating. Mixer 4 is provided with a first receiving port for receiving the high-moisture material supplied from the first supply device 2 and a second receiving port for receiving the dried material supplied from the second supply device 3, with the first receiving port located downstream of the second receiving port in the transfer direction of the materials to be treated. Therefore, only the dried material is transferred in the transfer path between the second receiving port and the first receiving port, and the high-moisture material and the dried material are transferred while being mixed in the transfer path downstream from the first receiving port in the transfer direction. However, the high-moisture material and the dried material may be received at a single receiving port.

[0035] The high-moisture treated material and the dried treated material supplied to the mixer 4 become a treated material with a moisture content intermediate between the moisture content of the high-moisture treated material and the moisture content of the dried treated material, and are then supplied to the molding dryer 6. Here, the moisture content of the treated material supplied from the mixer 4 to the molding dryer 6 can be changed by changing the ratio of the amount of high-moisture treated material to the amount of dried treated material. Specifically, increasing the amount of high-moisture treated material relative to the amount of dried treated material will supply a treated material with a high moisture content to the molding dryer 6. Conversely, decreasing the amount of high-moisture treated material relative to the amount of dried treated material will supply a treated material with a low moisture content to the molding dryer 6. The moisture content of the treated material supplied from the mixer 4 to the molding dryer 6 generally varies between 20% WB and 50% WB, controlled based on the measurement results of the dust meter 71 described later.

[0036] The molding dryer 6 includes a hopper section 61, a pair of rollers 62, a pair of scrapers 64, a second inverter 66, and a steam pressure regulating valve 68. Of these, the hopper section 61, the pair of rollers 62, and the pair of scrapers 64 have the same configuration as those disclosed in Japanese Patent Application Publication No. 2006-038339.

[0037] The hopper section 61 is positioned above the pair of rollers 62. The hopper section 61 has openings at the top and bottom. The material to be processed, mixed by the mixer 4, is fed into the hopper section 61 through the top opening and stored inside the hopper section 61. The stored material to be processed is supplied from the bottom opening of the hopper section 61 to the upper part between the pair of rollers 62.

[0038] The pair of rollers 62 consists of a drive roller 62A, which receives driving force from a roller motor (not shown), and a driven roller 62B, which rotates by receiving driving force from the drive roller 62A. In Figure 1, the rotation directions of the drive roller 62A and the driven roller 62B are indicated by white arrows. The drive roller 62A and the driven roller 62B are hollow cylindrical shapes with the same inner and outer diameters. The drive roller 62A and the driven roller 62B are arranged so that their axes are parallel to each other. Furthermore, the drive roller 62A and the driven roller 62B are supported so as to be rotatable about their respective axes, and one point in the circumferential direction on their outer circumference is close to each other.

[0039] Multiple grooves are formed along the circumferential direction on the outer circumferential surfaces of both the drive roller 62A and the driven roller 62B. The grooves of the drive roller 62A and the grooves of the driven roller 62B are positioned alternately in the axial direction, and in the close proximity of the drive roller 62A and the driven roller 62B, the opening of the groove forms a rectangle with the outer circumferential surface of the other roller. These grooves are formed in a dovetail shape, becoming wider towards the bottom. Side plates and a rotating support shaft are provided at both axial ends of the drive roller 62A and the driven roller 62B. The rotating support shafts of the drive roller 62A and the driven roller 62B are equipped with gears, and the rotation of the drive roller 62A is transmitted to the driven roller 62B by the meshing of the gears, so that both the drive roller 62A and the driven roller 62B rotate at the same rotational speed and the same peripheral speed.

[0040] The rotary support shaft is hollow and connected to a rotary joint. Steam is supplied to the rotary joint at one end. This steam is saturated steam, but it may also be superheated steam. This steam is supplied to the drive roller 62A and driven roller 62B via the hollow portion of the rotary support shaft at one end, heating the drive roller 62A and driven roller 62B from the inside. After heating the drive roller 62A and driven roller 62B, the steam becomes condensate and is discharged to the outside of the molding dryer 6 via the rotary support shaft and rotary joint at the other end.

[0041] A pair of scrapers 64 are biased toward the drive roller 62A and the driven roller 62B. Each scraper 64 has a comb-like shape with multiple claws. The number of claws is the same as the number of grooves in the drive roller 62A and the driven roller 62B, and each claw engages with its respective groove.

[0042] The second inverter 66 is used to change the rotational speed of the roller motor that rotates the drive roller 62A. Increasing the frequency of the second inverter 66 increases the rotational speed of the roller motor, and decreasing the frequency of the second inverter 66 decreases the rotational speed of the roller motor. This second inverter 66 allows the rotational speed of the drive roller 62A and the driven roller 62B that moves with the drive roller 62A to be adjusted to any desired rotational speed.

[0043] The steam pressure regulating valve 68 is an automatic valve for adjusting the steam pressure supplied to the drive roller 62A and the driven roller 62B via the rotary joint and rotating support shaft described above. In Figure 1, the pipe downstream of the steam pressure regulating valve 68 is depicted as being connected only to the drive roller 62A, but the pipe supplying the steam branches off and is also connected to the driven roller 62B. Therefore, the steam that has passed through the steam pressure regulating valve 68 is supplied to both the drive roller 62A and the driven roller 62B. By increasing the opening of the steam pressure regulating valve 68, the steam pressure supplied to the drive roller 62A and the driven roller 62B increases, and as a result, the amount of heating of the drive roller 62A and the driven roller 62B increases.

[0044] As the drive roller 62A and driven roller 62B rotate in the direction of the white arrows shown in Figure 1, the material to be processed stored in the hopper section 61 is sequentially pressed into the grooves of the drive roller 62A and driven roller 62B. The pressed-in material is then shaped by these grooves and dried by the heated drive roller 62A and heated driven roller 62B to become a shaped dried product. The shaped dried product has a trapezoidal cross-sectional shape with a bottom base of approximately 9 mm, a top base of approximately 7 mm, and a height of approximately 7 mm. This cross-sectional shape can be changed to any shape by changing the bottom width of the groove, the depth of the groove, and the opening width of the groove. As the drive roller 62A and driven roller 62B rotate, the shaped dried product that reaches the scraper 64 breaks into pieces of a certain length and falls down due to the scraping action of the scraper 64. If the material to be processed is sludge, the length will be approximately 10 mm. When the molded and dried product breaks, or when the scraper 64 comes into close proximity to or contacts the molded and dried product in the groove, dust is generated. This dust is sucked up along with the air inside the molded and dried machine 6 and sent outside the molded and dried machine 6, where it is collected by the bag filter 75, which will be described later.

[0045] The cushion hopper 7 includes a receiving section 70, a dust meter 71, a discharge section 73, a moisture meter 74, and a bag filter 75. The receiving section 70 receives the molded and dried products that fall from the molding dryer 6. Dust is generated from the molded and dried products that fall to the bottom of the receiving section 70 due to the impact of the fall. Dust is especially likely to be generated from areas with low moisture content in the molding dryer 6. Dust is also likely to be generated from molded and dried products if they crack when they fall. This dust is sucked up along with the air inside the receiving section 70 and sent to the outside of the receiving section 70, where it is collected by the bag filter 75.

[0046] The dust meter 71 measures the concentration of dust generated from the molded and dried product. Hereinafter, the dust concentration may be abbreviated as dust concentration. As mentioned above, dust is likely to be generated in the receiving section 70 when the molded and dried product falls. The detection unit of the dust meter 71 is located inside the receiving section 70. Therefore, the dust meter 71 measures the dust concentration generated in the receiving section 70 when the molded and dried product falls. However, as shown by the dashed line in Figure 1, the detection unit of the dust meter 71 may also be placed in the exhaust path connecting the receiving section 70 to the bag filter 75. Since air and dust from inside the receiving section 70 are drawn into and circulate in the exhaust path, the dust concentration generated in the receiving section 70 by the molded and dried product can also be measured by placing it in the exhaust path. If the exhaust path is connected to an exhaust path connected to the molding dryer 6, it is preferable to place the detection unit of the dust meter 71 on the receiving section 70 side of the connection point so as not to mix with dust generated in the molding dryer 6.

[0047] The discharge section 73 discharges the molded and dried product from the receiving section 70. A discharge path is formed within the discharge section 73 to transport the molded and dried product to the discharge outlet.

[0048] The moisture meter 74 measures the moisture content of the molded and dried product. The detection unit of the moisture meter 74 is located in the discharge path formed by the discharge unit 73. By placing the detection unit of the moisture meter 74 in the discharge path, the moisture content can always be measured at a constant position close to the molded and dried product. This moisture meter 74 is an example of a measuring device. Alternatively, a thermometer may be provided to measure the temperature instead of the moisture meter 74. In this case, the thermometer would be an example of a measuring device. However, since there is a correlation between the temperature and moisture content of the molded and dried product, it can be said that the moisture content is also being measured in effect when a thermometer is provided.

[0049] Figure 2 is a block diagram showing the hardware configuration for controlling the molding and drying system shown in Figure 1.

[0050] The control device 8 is a PLC (Programmable Logic Controller) equipped with storage means such as a storage device, display means such as a display, and input means for storing data in the storage means and rewriting stored data. The storage means stores various thresholds and setting values, such as upper and lower limits for dust concentration and upper and lower limits for the moisture content of molded and dried products. The storage means also stores programs that perform various calculations and PID control.

[0051] The control device 8 has a mixing ratio control means 81 and a molding dryer control means 82 as functional configurations formed by a storage means and a program. The measurement results of the dust meter 71 and the moisture meter 74 are transmitted to the control device 8. The mixing ratio control means 81 controls the frequency of the first inverter 22 based on the measurement results of the dust meter 71. The molding dryer control means 82 controls the frequency of the second inverter 66 and the opening degree of the steam pressure regulating valve 68 based on the measurement results of the moisture meter 74.

[0052] Figure 3 is a flowchart showing the control operation of the molding and drying system shown in Figure 1. This flowchart shows the control operation performed by the control device 8 controlling each component of the molding and drying system 1 using various thresholds, various setting values, and programs stored in the storage means of the control device 8.

[0053] When the molding and drying system 1 is started, the initial operation involves opening the steam pressure regulating valve 68 and starting the rotation of a pair of rollers 62 to heat the pair of rollers 62 to a predetermined temperature. Once the pair of rollers 62 have reached the predetermined temperature, the mixer 4, the second supply device 3, and the first supply device 2 are started in that order to begin supplying the material to be processed to the molding and drying machine 6. If the amount of material to be dried supplied from the dryer 32 to the mixer 4 is insufficient, the second supply device 3 is started first to ensure that a sufficient amount of material to be dried is supplied from the dryer 32 to the mixer 4 at the time the mixer 4 is driven. At startup, the frequency of the first inverter 22, the frequency of the second inverter 66, and the opening degree of the steam pressure regulating valve 68 are set to design values ​​or values ​​determined during actual operation (hereinafter sometimes referred to as reference values). Once the above initial operations are completed, the molded and dried material begins to fall from the molding and drying machine 6 to the receiving section 70.

[0054] Once the initial operation is complete and a predetermined time has elapsed, the control operation shown in Figure 3 is started. In this embodiment, the predetermined time is 2 minutes, but this predetermined time can be arbitrarily set by rewriting it using the input means of the control device 8. The dust meter 71 and moisture meter 74 start measuring simultaneously with the startup of the molding and drying system 1 and continuously transmit the measurement results to the control device 8. The process measured by the dust meter 71 corresponds to an example of a dust concentration measurement process. Similarly, the process measured by the moisture meter 74 corresponds to an example of a moisture content measurement process. The control device 8 continuously acquires the dust concentration from the molded and dried product, which is the measurement result of the dust meter 71, and the moisture content of the molded and dried product, which is the measurement result of the moisture meter 74. The control operation shown in Figure 3 is performed continuously after the predetermined time has elapsed, but it may be repeated at predetermined intervals, such as every 2 minutes. When performed at predetermined intervals, the interval can be arbitrarily set by rewriting it using the input means of the control device 8.

[0055] The control device 8 determines whether the average value of the dust concentration over the past two minutes is higher than the upper limit of the concentration stored in the storage means (step S12). Hereinafter, the average value of the dust concentration over the past two minutes measured by the dust meter 71 will be referred to as the concentration measurement value. If the concentration measurement value is higher than the upper limit of the concentration (YES in step S12), the mixing ratio control means 81 increases the frequency of the first inverter 22 according to the deviation between the target value of the dust concentration and the concentration measurement value, thereby increasing the amount of high-moisture material to be processed supplied from the first supply device 2 to the mixer 4 (step S13). The target value of the dust concentration is stored in the storage means, for example, as the median between the upper limit of the concentration and the lower limit of the concentration, which will be described later. While the amount of dry material to be processed supplied from the second supply device 3 to the mixer 4 remains constant, the amount of high-moisture material to be processed increases in step S13. As a result, the ratio of the amount of high-moisture material supplied from the first supply device 2 to the molding dryer 6 via the mixer 4 to the amount of dried material supplied from the second supply device 3 to the molding dryer 6 via the mixer 4 changes so that the former increases. Consequently, the moisture content of the material supplied to the molding dryer 6 increases. The memory means of the control device 8 also stores the upper frequency limit of the first inverter 22, and the control operation in step S13 does not raise the frequency of the first inverter 22 beyond that upper frequency limit.

[0056] If the concentration is not higher than the upper limit (NO in step S12), the control device 8 determines whether the measured concentration is lower than the lower limit of the concentration stored in the storage means (step S14). If it is lower than the lower limit of the concentration (YES in step S14), the mixing ratio control means 81 reduces the frequency of the first inverter 22 according to the deviation between the target value of dust concentration and the measured concentration, thereby reducing the amount of high-moisture material to be treated (step S15). Step S15 reduces the amount of high-moisture material supplied from the first supply device 2 to the molding dryer 6 via the mixer 4. As a result, the ratio of the amount of high-moisture material supplied from the first supply device 2 to the molding dryer 6 via the mixer 4 to the amount of dried material supplied from the second supply device 3 to the molding dryer 6 via the mixer 4 changes so that the latter becomes higher. Consequently, the moisture content of the material supplied to the molding dryer 6 decreases. Furthermore, the memory means of the control device 8 also stores the lower frequency limit of the first inverter 22, and in the control operation in step S15, the frequency of the first inverter 22 is not lowered below that lower frequency limit. If the concentration measurement value is not lower than the lower concentration limit (NO in step S14), the amount of high-moisture material supplied from the first supply device 2 to the mixer 4 is not changed, and the frequency of the first inverter 22 is not changed. Steps S12 to S15 described above correspond to an example of a ratio control process.

[0057] Furthermore, as the amount of high-moisture material to be processed from the first supply device 2 increases or decreases, the amount of material stored in the hopper section 61 also increases or decreases. However, the amount of material stored in the hopper section 61 is controlled by a level meter (not shown) to maintain an appropriate storage level. If the storage level exceeds the upper limit of the level meter, control is performed to shut down the equipment upstream of the hopper section 61. If the storage level falls below the lower limit of the level meter, the control device 8 increases the supply amount of material to be processed from the equipment upstream of the hopper section 61, while maintaining the ratio of the amount of dried material to be processed and the amount of high-moisture material to be processed at that time, by increasing the supply amounts from the dryer 32 and the first supply device 2.

[0058] Next, we will describe a control operation that is performed in parallel with the control operations in steps S12 to S15, based on the measurement of the moisture content of the molded and dried product. The control device 8 determines whether the average moisture content of the molded and dried product over the past two minutes is higher than the upper limit of moisture content stored in the storage means (step S17). Hereinafter, the average moisture content over the past two minutes measured by the moisture meter 74 will be referred to as the measured moisture content. The upper limit of moisture content used here is, for example, 20% WB. If the measured moisture content is higher than the upper limit of moisture content (YES in step S17), the molded and dried machine control means 82 increases the opening of the steam pressure regulating valve 68 according to the deviation between the measured moisture content and the target moisture content, thereby increasing the steam pressure supplied to the drive roller 62A and the driven roller 62B (step S18). That is, it increases the amount of heating of the pair of rollers 62. The target moisture content is stored in the storage means as, for example, the median between the upper limit of moisture content and the lower limit of moisture content, which will be described later. Furthermore, if the moisture content measurement value significantly exceeds the upper limit of the moisture content, the molding dryer control means 82 increases the opening of the steam pressure regulating valve 68 to its maximum and simultaneously reduces the frequency of the second inverter 66 according to the deviation between the moisture content measurement value and the moisture content target value, thereby reducing the rotational speed of the drive roller 62A and the driven roller 62B (step S18). Significantly exceeding the upper limit of the moisture content is, for example, when it exceeds 30% WB. As a result, the amount of heat applied to the workpiece in the molding dryer 6 increases, and the moisture content of the molded dry product can be reduced. In other words, in step S18, the molding dryer 6 is controlled so that a dried molded product that does not exceed the upper limit of the moisture content is obtained. The storage means of the control device 8 also stores the lower limit of the frequency of the second inverter 66, and in the control operation in step S18, the frequency of the second inverter 66 is not lowered below that lower limit.

[0059] In step S18, if the moisture content measurement value does not significantly exceed the moisture content upper limit, the molding dryer control means 82 may, instead of increasing the opening of the steam pressure regulating valve 68, lower the frequency of the second inverter 66 according to the deviation between the moisture content measurement value and the moisture content target value. If the moisture content measurement value significantly exceeds the moisture content upper limit, the molding dryer control means 82 may reduce the frequency of the second inverter 66 to the lower frequency limit and simultaneously increase the opening of the steam pressure regulating valve 68 according to the deviation between the moisture content measurement value and the moisture content target value. However, since lowering the frequency of the second inverter 66 reduces the processing capacity of the workpiece in the molding dryer 6, it is preferable in step S18 to prioritize the control of the steam pressure regulating valve 68 over the frequency of the second inverter 66 and change the frequency of the second inverter 66 only when the moisture content significantly exceeds the moisture content upper limit.

[0060] If the moisture content measurement is not higher than the upper moisture content limit (NO in step S17), the control device 8 determines whether the moisture content measurement is lower than the lower moisture content limit stored in the storage means (step S19). The lower moisture content limit used here is, for example, 10% WB.

[0061] If the moisture content measurement is lower than the lower limit of moisture content (YES in step S19), the molding dryer control means 82 determines whether the rotation speed of the drive roller 62A or the driven roller 62B is above or below a reference value (step S20). In other words, in step S20, the determination is made based on the reference value of the frequency of the second inverter 66 stored in the storage means of the control device 8. If the frequency of the second inverter 66 is above the reference value (i.e., the rotation speed of the drive roller 62A or the driven roller 62B is above the reference value) (YES in step S20), the opening of the steam pressure regulating valve 68 and the frequency of the second inverter 66 are not changed in the molding dryer control means 82.

[0062] If the frequency of the second inverter 66 is below a reference value (NO in step S20), the molding dryer control means 82 reduces the opening of the steam pressure regulating valve 68 according to the deviation between the measured moisture content and the target moisture content, and at the same time increases the frequency of the second inverter 66 according to the deviation between the measured moisture content and the target moisture content (step S21).

[0063] In step S21, the molding dryer control means 82 may increase the frequency of the second inverter 66 in accordance with the deviation between the measured moisture content and the target moisture content, thereby preferentially increasing the rotational speed of the drive roller 62A and the driven roller 62B. The upper frequency limit of the second inverter 66 is also stored in the storage means of the control device 8. If the measured moisture content is significantly below the lower moisture content limit, the molding dryer control means 82 may increase the frequency of the second inverter 66 to the upper frequency limit and simultaneously decrease the opening of the steam pressure regulating valve 68 in proportion to the moisture content. Significantly below the lower moisture content limit is, for example, a value lower than 5% WB. By decreasing the opening of the steam pressure regulating valve 68, the amount of heating of the pair of rollers 62 is reduced.

[0064] As a result, the amount of heat applied to the workpiece in the molding dryer 6 is reduced, and the moisture content of the molded and dried product can be increased. In other words, in step S21, the molding dryer 6 is controlled to reduce the degree of drying so that a molded and dried product with increased moisture content is obtained.

[0065] Furthermore, in step S21, if the measured moisture content is not significantly below the lower limit of moisture content, the molding dryer control means 82 may preferentially reduce the opening of the steam pressure regulating valve 68 in proportion to the moisture content. Also, if the moisture content is significantly below the lower limit of moisture content, the molding dryer control means 82 may minimize the opening of the steam pressure regulating valve 68 or close the steam pressure regulating valve 68 while simultaneously increasing the frequency of the second inverter 66 according to the deviation between the measured moisture content and the target moisture content. However, since increasing the frequency of the second inverter 66 can increase the processing capacity of the workpiece in the molding dryer 6, it is preferable in step S21 to prioritize controlling the frequency of the second inverter 66 over the steam pressure regulating valve 68, and to change the opening of the steam pressure regulating valve 68 only when the moisture content is significantly below the lower limit.

[0066] If the moisture content measurement is not lower than the lower limit of moisture content (NO in step S19), the opening degree of the steam pressure regulating valve 68 and the frequency of the second inverter 66 are not changed. As mentioned above, if the frequency of the second inverter 66 is above the reference value (YES in step S20), the opening degree of the steam pressure regulating valve 68 and the frequency of the second inverter 66 are also not changed.

[0067] Steps S17 to S21 described above correspond to an example of a molding heating control process, which controls at least one of the rotation speed of the pair of rollers 62 and the amount of heating of the pair of rollers 62 based on the measurement results of the moisture meter 74. In addition, the amount of heating of the pair of rollers 62 is controlled by adjusting the opening degree of the steam pressure regulating valve 68 in steps S18 and S21. Therefore, this opening degree adjustment control corresponds to an example of controlling the amount of heating of the pair of rollers 62.

[0068] If the control operation in step S18 is completed, if the result is NO in step S19, if the result is YES in step S20, or if the control operation in step S21 is completed, it is determined whether the molding and drying system 1 has processed the specified amount of material to be processed (step S22). If the control device 8 has processed the specified amount of material to be processed (YES in step S22), the control operation of the molding and drying system 1 is terminated, the steam pressure regulating valve 68 is closed, and each component of the molding and drying system 1 shown in Figure 1 is stopped. If the specified amount of material to be processed has not been processed (NO in step S22), the process returns to steps S12 and S17 and continues the control operation of the molding and drying system 1 based on the moisture content measurement value. The control operation based on the dust concentration measurement value described above is similar; if the control operation in step S13 is completed, if the result is NO in step S14, or if the control operation in step S15 is completed, the determination in step S22 is made, and if NO, the control operation based on the dust concentration measurement value is continued, and if YES, the molding and drying system 1 is stopped. Furthermore, when the flow shown in Figure 3 is repeated at predetermined intervals, if the result in step S22 is NO, the control device 8 determines whether a time equivalent to the predetermined interval has elapsed since the previous processing. If it is determined that the time has elapsed, the processing in steps S12 and S17 is resumed.

[0069] According to the molding and drying system 1 described above, the control device 8 controls the amount of high-moisture material supplied from the first supply device 2 based on the measurement results of the dust meter 71, thereby adjusting the ratio of the amount of high-moisture material supplied to the molding and drying machine 6 to the amount of dried material. As a result, the molding and drying machine 6 can produce molded and dried products with appropriate properties and controlled dust generation. This is achieved by adjusting the ratio of the amount of high-moisture material supplied to the molding and drying machine 6 to the amount of dried material according to the dust concentration. This prevents the molded and dried products from becoming excessively dry, brittle, and prone to generating dust, while simultaneously allowing them to break when scraped by the scraper 64 or when dropped to the bottom of the receiving section 70, resulting in molded and dried products of appropriate length. In this way, even if the properties of the material change, the material supplied to the molding and drying machine 6 is automatically adjusted to a moisture content that allows for the production of molded and dried products with appropriate properties and controlled dust generation.

[0070] Furthermore, since the rotation speed of the pair of rollers 62 or at least one of the vapor pressure supplied to the pair of rollers 62 is controlled based on the measurement results of the moisture meter 74, the workpiece can be molded and dried to the desired moisture content. As a result, the entire molding and drying system 1 has a balanced control system that ensures the processing volume of the workpiece, produces molded and dried products of the appropriate length, and produces molded and dried products with the desired moisture content.

[0071] Furthermore, since the dust meter 71 primarily measures dust generated when the molded and dried product falls into the receiving section 70, this configuration can be said to reflect situations such as when the molded and dried product is loaded onto a transport vehicle such as a truck or placed into a container. By using the dust concentration at this time as the measurement result, it becomes possible to control the amount of dust generated at the transportation site of the molded and dried product while obtaining molded and dried product with appropriate properties.

[0072] The following inventive concepts can also be extracted from the molding and drying system 1 described above.

[0073] A first supply device for supplying the material to be processed, A second supply device that supplies a workpiece with a lower moisture content than the workpiece supplied from the first supply device, A molding dryer that molds and dries a workpiece supplied from the first supply device and a workpiece supplied from the second supply device to obtain a molded and dried product, A dust meter for measuring the concentration of dust generated from the molded and dried product, A molding and drying system characterized by comprising a control device that controls the ratio of the amount of material to be processed supplied from the first supply device to the molding and drying machine and the amount of material to be processed supplied from the second supply device to the molding and drying machine, based on the measurement results of the dust meter.

[0074] Next, a modified example of this embodiment will be described. In the following description, the same reference numerals used previously may be used for the names of components that have been described so far, and redundant explanations may be omitted.

[0075] Figure 4 is a schematic diagram similar to Figure 1, showing the first supply device, dryer, and mixer in the first modified molding and drying system.

[0076] This first modified form of the molding and drying system 1 differs from the previous embodiment in the configuration of the first supply device 2 and the mixer 4. The mixer 4 has an open top, and this open portion serves as a receiving port for the material to be processed. The material to be dried is supplied to the mixer 4 from a specific position near the upstream end in the material transfer direction of the mixer 4. In other words, the supply position of the material to be dried to the mixer 4 is a specific position that does not change.

[0077] The first supply device 2 includes an air cylinder 23 and a flexible nozzle 24. The air cylinder 23 has a piston rod that extends and retracts along the transfer direction of the material to be processed in the mixer 4. The operation of the air cylinder 23 is controlled by a control device 8 (see Figure 2), and the extension and retraction length of the piston rod can be set to any length. The tip of the piston rod is connected to the flexible nozzle 24. The base of the flexible nozzle 24 is attached to the discharge port of the first screw conveyor 21. A supply port 24a for supplying high-moisture material to be processed to the mixer 4 is formed at the tip of the flexible nozzle 24. Due to the operation of the air cylinder 23, the flexible nozzle 24 deforms and the supply port 24a moves along the transfer direction in the mixer 4. Therefore, the supply position of the high-moisture material supplied from the supply port 24a to the mixer 4 changes in the transfer direction in the mixer 4 according to the protruding length of the histone rod of the air cylinder 23.

[0078] When a high-moisture material to be treated is supplied to the upstream side in the transfer direction of the mixer 4, the distance over which the high-moisture material and the dry material are transferred while being mixed increases, and the mixing time also increases. Conversely, when a high-moisture material to be treated is supplied to the downstream side in the transfer direction of the material to be treated, the distance over which the high-moisture material and the dry material are transferred while being mixed in the mixer 4 decreases, and the mixing time also decreases.

[0079] Figure 5 is a control diagram illustrating the control of the mixing time in the molding and drying system shown in Figure 4.

[0080] As described above, the control device 8 constantly acquires the moisture content, which is the measurement result of the moisture meter 74, and can calculate the variation in moisture content over a predetermined time. In this embodiment, the predetermined time is 2 minutes, but this predetermined time can be arbitrarily set by rewriting it using the input means of the control device 8. The variation in moisture content is determined from the difference between the maximum and minimum values ​​of moisture content over the predetermined time, but it may also be determined from the standard deviation or variance. Furthermore, the thresholds for high and low moisture content, the thresholds for the magnitude of variation in moisture content, and the thresholds for high and low dust concentration are stored in the storage means of the control device 8, but these thresholds can also be arbitrarily changed by rewriting them using the input means of the control device 8. Also, in Figure 5, the moisture content of the molded dried product is distinguished as "high," "normal," and "low," and the dust concentration is distinguished as "high," "normal," and "low," and the boundary values ​​for these are set as set values ​​in the control device 8, but it is not necessarily required to adopt the same values ​​as the upper and lower limits of dust concentration and upper and lower limits of moisture content set in the mixing ratio control means 81. The control device 8 controls the mixing time of the moist material and the dry material in the mixer 4 by controlling the air cylinder 23 according to the moisture content, variation, and dust concentration of the molded and dried material. This control is performed at predetermined intervals, such as every two minutes.

[0081] As shown in Figure 5, the control device 8, for example, when the moisture content of the molded dried product is high and the variation in moisture content is large and the dust concentration is high or normal, when the moisture content of the molded dried product is high and the variation in moisture content is normal and the dust concentration is high, and when the moisture content of the molded dried product is normal and the variation in moisture content is large or normal and the dust concentration is high, positions the supply port 24a on the upstream side in the transfer direction of the mixer 4 to lengthen the mixing time. On the other hand, regardless of the high or low moisture content of the molded dried product or the variation in moisture content, if the dust concentration is low, the mixing time is shortened. Separately from the control described above, when the mixing time is long, the load on the blades provided in the mixer 4 and the motor that rotates those blades increases. Therefore, the control device 8 monitors the load current of the motor and, if the load current exceeds a set value, forcibly shortens the mixing time.

[0082] Alternatively, instead of the air cylinder 23 and flexible nozzle 24, multiple first receiving ports for receiving high-moisture material may be installed in the direction of transport in the mixer 4, the base of the branch pipe may be attached to the discharge port of the first screw conveyor 21, and each branched end connected to the first receiving ports, with an automatic on / off valve provided in each branched path. In the case of Figure 5, since it is possible to change the mixing time in three different ways, the branch pipes that branch from the base are arranged in the direction of transport in the mixer 4, and each is equipped with an automatic on / off valve. In this case, the control device 8 controls the automatic on / off valves to change the supply position of the high-moisture material supplied to the mixer 4, thereby changing the mixing time in the same way as in the first modified example.

[0083] This first modified molding and drying system 1 also achieves the same effects as the previous embodiment, but by using the mixing ratio control means 81 and the molding and drying machine control means 82 in combination with the mixing time control described above in this first modified example, it is possible to obtain a molded and dried product in which the material to be dried converges to a more suitable state. In addition, depending on the degree of mixing of the material to be processed supplied to the molding and drying machine 6 or the properties of the high-moisture material to be processed, the material to be processed may become highly viscous, causing it to adhere to the walls or scraper inside the molding and drying machine 6, or causing the material to clog inside the molding and drying machine 6. In this first modified example, by changing the mixing time of the high-moisture material to be processed and the material to be dried, the degree of mixing can be adjusted, thereby obtaining a molded and dried product in which the amount of dust generated is controlled, and the increased viscousness of the material to be processed can be suppressed, reducing the risk of the material to clog inside the molding and drying machine 6.

[0084] Next, a second modified example of the molding and drying system 1 will be described.

[0085] Figure 6 is a flowchart showing the control operation of the molding and drying system in the second modified example.

[0086] The second modified molding and drying system 1 differs from the previous embodiment in its control operation. The molding dryer control means 82 controls the frequency of the second inverter 66 based on the measurement result of the dust meter 71 instead of the measurement result of the moisture meter 74. In this control, if the measured value of the dust concentration generated from the molded and dried product is higher than the upper limit of the concentration (YES in step S12), and the frequency of the second inverter 66 is not above the reference value (i.e., the rotation speed of the drive roller 62A or driven roller 62B is above the reference value) (NO in step S31), the molding dryer control means 82 increases the frequency of the second inverter 66 and increases the rotation speed of the drive roller 62A and driven roller 62B according to the deviation between the target value of the dust concentration and the measured value (step S32). If the frequency of the second inverter 66 is above the reference value (YES in step S31), the frequency of the second inverter 66 is not changed.

[0087] If the measured concentration is lower than the lower concentration limit (YES in step S14), the mixing ratio control means 81 reduces the frequency of the first inverter 22 according to the deviation between the target value of dust concentration and the measured concentration to reduce the amount of high-moisture material to be treated, and at the same time reduces the frequency of the second inverter 66 according to the deviation between the target value of dust concentration and the measured concentration (step S15). If the dust concentration is higher than the lower concentration limit (NO in step S14), the frequency of the second inverter 66 is not changed.

[0088] The control operation based on the measurement of moisture content, which is performed in parallel with the control operations in steps S12 to S15 and steps S31 and S32 described above, will now be explained. If the measured moisture content is higher than the upper limit of moisture content (YES in step S17), the molding dryer control means 82 increases the opening of the steam pressure regulating valve 68 in accordance with the deviation between the measured moisture content and the target moisture content, thereby increasing the steam pressure supplied to the drive roller 62A and the driven roller 62B (step S18). If the measured moisture content is lower than the lower limit of moisture content (YES in step S19), the opening of the steam pressure regulating valve 68 is decreased in accordance with the deviation between the measured moisture content and the target moisture content, thereby decreasing the steam pressure (step S21). If the measured moisture content is not lower than the lower limit of moisture content (NO in step S19), the opening of the steam pressure regulating valve 68 is not changed. This second modified molding dryer system 1 also produces the same effects as the previous embodiment.

[0089] Next, we will explain the differences between the third modified example, the molding and drying system 1, and the second modified example.

[0090] Figure 7 is a flowchart showing the control operation of the molding and drying system of the third modified example.

[0091] The third modified molding and drying system 1 differs in its control operation from the second modified system. The mixing ratio control means 81 controls the frequency of the first inverter 22 based on the measurement result of the moisture meter 74 instead of the measurement result of the dust meter 71. In this control, if the moisture content measurement value is higher than the moisture content upper limit (YES in step S17), the mixing ratio control means 81 increases the opening of the steam pressure regulating valve 68 according to the deviation between the moisture content measurement value and the moisture content target value, and at the same time decreases the frequency of the first inverter 22 according to that deviation to reduce the amount of high-moisture material supplied to the mixer 4 (step S18). The moisture content upper limit used here is, for example, 20% WB. Furthermore, if the moisture content measurement value is lower than the moisture content lower limit (YES in step S19), the mixing ratio control means 81 reduces the opening of the steam pressure regulating valve 68 according to the deviation between the moisture content measurement value and the moisture content target value, and at the same time increases the frequency of the first inverter 22 according to that deviation to increase the amount of high-moisture material supplied to the mixer 4 (step S21). The moisture content lower limit used here is, for example, 10% WB.

[0092] In parallel with the control operations of steps S17 to S21 described above, the control device 8 executes steps S12, S14, S15, S31, and S32. In this third modified example, step S13, which was executed in the previous embodiment, is not provided. If the concentration measurement value is lower than the lower limit of concentration stored in the storage means (YES in step S14), the mixing ratio control means 81 reduces the frequency of the second inverter 66 according to the deviation between the target value of dust concentration and the concentration measurement value (step S15). This third modified example of the molding and drying system 1 also produces the same effects as the previous embodiment. Compared to the previous embodiment, the ability to adjust the moisture content of the molded and dried product is improved.

[0093] Next, the fourth modified molding and drying system 1 will be described. The control operation of the fourth modified molding and drying system 1 also differs from that of the previous embodiment. The mixing ratio control means 81 takes into account the measurement results of the moisture meter 74 in addition to the measurement results of the dust meter 71, and controls the frequency of the first inverter 22 based on these measurement results. The storage means of the control device 8 stores a first adjustment value, which is the frequency of the first inverter 22 corresponding to the dust concentration, and a second adjustment value, which is the frequency of the first inverter 22 corresponding to the moisture content. The mixing ratio control means 81 obtains the first adjustment value corresponding to the measurement result of the dust meter 71 from the storage means, and obtains the second adjustment value corresponding to the measurement result of the moisture meter 74 from the storage means. Then, it adds (superimposes) the second adjustment value to the obtained first adjustment value and controls the frequency of the first inverter 22 using the result of the addition. Alternatively, the storage means of the control device 8 may store functions with dust concentration as a variable and functions with moisture content as a variable, and calculate the above-mentioned first and second adjustment values ​​using these functions. Alternatively, instead of adding the second adjustment value to the first adjustment value, the control device 8 may store a first overall adjustment value, which is the frequency of the first inverter 22 corresponding to all combinations of dust concentration and moisture content, in its storage means. The first overall adjustment value stored in the storage means may then be obtained from the measurement results of the dust meter 71 and the moisture meter 74 to control the frequency of the first inverter 22. This fourth modified example of the molding and drying system 1 also provides the same effects as the previous embodiment.

[0094] Next, we will describe the fifth modified molding and drying system 1. The control operation of the fifth modified molding and drying system 1 also differs from that of the previous embodiment. The molding and drying machine control means 82 takes into account the measurement results of the dust meter 71 in addition to the measurement results of the moisture meter 74, and controls the frequency of the second inverter 66 based on these measurement results. The storage means of the control device 8 stores a third adjustment value, which is the frequency of the second inverter 66 corresponding to the dust concentration, and a fourth adjustment value, which is the frequency of the second inverter 66 corresponding to the moisture content. The molding and drying machine control means 82 then acquires the third adjustment value corresponding to the measurement result of the dust meter 71 and the fourth adjustment value corresponding to the measurement result of the moisture meter 74. Then, it adds (superimposes) the third adjustment value to the acquired fourth adjustment value and controls the frequency of the second inverter 66 using the result of the addition. Alternatively, the storage means of the control device 8 may store functions with dust concentration as a variable and functions with moisture content as a variable, and calculate the above-mentioned third and fourth adjustment values ​​using these functions. Alternatively, instead of adding the third adjustment value to the fourth adjustment value, the control device 8 may store a second overall adjustment value, which is the frequency of the second inverter 66 corresponding to all combinations of dust concentration and moisture content, in its storage means. The second overall adjustment value stored in the storage means may then be obtained from the measurement results of the dust meter 71 and the moisture meter 74 to control the frequency of the second inverter 66. This fifth modified example of the molding and drying system 1 also provides the same effects as the previous embodiment.

[0095] The present invention is not limited to the embodiments described above, and various modifications can be made within the scope of the claims. For example, in this embodiment, the ratio of the amount of high-moisture material to be treated and the amount of dried material to be treated supplied to the mixer 4 is adjusted by increasing or decreasing the amount of high-moisture material supplied from the first supply device 2, but it may also be adjusted by increasing or decreasing the amount of dried material supplied from the second supply device 3 to the mixer 4. In that case, a cushion hopper may be provided between the dryer 32 and the mixer 4. In addition, an example of using a continuous conduction heat transfer type dryer having a multi-tube heating tube as the dryer 32 is shown, but other types of dryers may be used as long as they can dry the material to be treated. Furthermore, the mixer 4 may be omitted, and the material to be treated may be supplied directly from the first supply device 2 and the second supply device 3 to the hopper section 61 of the molding dryer 6. In that case, it is preferable to add a stirring function to the hopper section 61 to stir the material to be treated and mix the high-moisture material and the dried material within the hopper section 61.

[0096] Furthermore, even if a constituent element is included only in the description of each of the modified examples described above, that constituent element may be applied to other modified examples as well. [Explanation of Symbols]

[0097] 1. Molding and drying system 2 1st supply device 3 Second supply device 6 Molding dryer 8 Control device 62 pairs of rollers 71 Dust meter 74 Moisture meter

Claims

1. A first supply device for supplying the material to be processed, A second supply device that supplies a workpiece with a lower moisture content than the workpiece supplied from the first supply device, A molding dryer that obtains a molded and dried product by passing a workpiece supplied from the first supply device and a workpiece supplied from the second supply device between a pair of heated rollers, and A dust meter for measuring the concentration of dust generated from the molded and dried product, A molding and drying system characterized by comprising a control device that controls, based on the measurement results of the dust meter, the ratio of the amount of material to be processed supplied from the first supply device to the molding and drying machine and the amount of material to be processed supplied from the second supply device to the molding and drying machine, and at least one of the rotation speeds of the pair of rollers.

2. The molded and dried product is equipped with a measuring device for measuring the moisture content or temperature, The molding and drying system according to claim 1, characterized in that the control device controls, based on the measurement results of the measuring device, at least one of the following: the ratio of the amount of material to be processed supplied from the first supply device to the molding and drying machine and the amount of material to be processed supplied from the second supply device to the molding and drying machine, the rotation speed of the pair of rollers and the amount of heating of the pair of rollers, other than those controlled based on the measurement results of the dust meter.

3. The system includes a mixer that mixes the material to be processed supplied from the first supply device and the material to be processed supplied from the second supply device and supplies the mixture to the molding dryer. The molding and drying system according to claim 2, characterized in that the control device controls the mixing time in the mixer based on the measurement results of the dust meter and the measurement results of the measuring device.

4. It is equipped with a receiving section for receiving the molded and dried product that falls from the molding dryer, The molding and drying system according to any one of claims 1 to 3, characterized in that the dust meter measures the dust generated when the molded and dried product falls into the receiving section.

5. A first supply device for supplying the material to be processed, A second supply device that supplies a workpiece with a lower moisture content than the workpiece supplied from the first supply device, A molding dryer that obtains a molded and dried product by passing a workpiece supplied from the first supply device and a workpiece supplied from the second supply device between a pair of heated rollers, and A dust meter for measuring the concentration of dust generated from the molded and dried product, A measuring device for measuring the moisture content or temperature of the molded and dried product, A molding and drying system characterized by comprising a control device that controls the ratio of the amount of material to be processed supplied from the first supply device to the molding and drying machine and the amount of material to be processed supplied from the second supply device to the molding and drying machine based on the measurement results of the dust meter, and controls at least one of the rotation speed of the pair of rollers and the amount of heating of the pair of rollers based on the measurement results of the measuring device.

6. A first supply device for supplying the material to be processed, A second supply device that supplies a workpiece with a lower moisture content than the workpiece supplied from the first supply device, A molding dryer that obtains a molded and dried product by passing a workpiece supplied from the first supply device and a workpiece supplied from the second supply device between a pair of heated rollers, and A dust meter for measuring the concentration of dust generated from the molded and dried product, A measuring device for measuring the moisture content or temperature of the molded and dried product, A molding and drying system characterized by comprising a control device that controls, based on the measurement results of the dust meter and the measurement results of the measuring device, the ratio of the amount of material to be processed supplied from the first supply device to the molding and drying machine and the amount of material to be processed supplied from the second supply device to the molding and drying machine, and at least one of the rotation speeds of the pair of rollers.

7. A control method for a molding and drying system comprising: a first supply device for supplying a material to be processed; a second supply device for supplying a material to be processed having a lower moisture content than the material supplied from the first supply device; and a molding and drying machine for molding and drying the material supplied from the first supply device and the material supplied from the second supply device to obtain a molded and dried product, wherein A dust concentration measurement step for measuring the concentration of dust generated from the molded and dried product, A control method for a molding and drying system, comprising a ratio control step that controls the ratio between the amount of material to be processed supplied from the first supply device to the molding and drying machine and the amount of material to be processed supplied from the second supply device to the molding and drying machine, based on the dust concentration measured by the dust concentration measurement step.

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