Pellet manufacturing device

Abstract

To provide a pellet manufacturing device capable of stably and reliably solidifying a plant-derived raw material to manufacture high-quality pellets.SOLUTION: A pellet manufacturing device 1 comprises: an extruder 10 that extrudes a plant-derived raw material M to produce a pellet P; a sprinkler device 60 that sprinkles water on the raw material M; and a control device 70 that controls the sprinkler device 60. The extruder 10 is equipped with a die 20 having a forming hole 21 therethrough, and a temperature sensor 80 for measuring a temperature of the die 20. The control device 70 causes the sprinkler device 60 to spray water when a temperature of the die 20 is equal to or higher than an upper limit temperature in a set temperature range, and causes the sprinkler device 60 to stop spraying water when a temperature of the die 20 is equal to or lower than a lower limit temperature in a set temperature range.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a pellet manufacturing apparatus. [Background technology]

[0002] It is known that pellets made by compressing plant-derived raw materials are used as fuel to convert energy from petroleum resources such as kerosene and heavy oil to biomass resources. There is a method in which the plant-derived raw material is forced into the forming holes of the die by a roller, and the raw material extruded from the forming holes is cut to produce pellets. Furthermore, in the above-mentioned pellet manufacturing method, there is a method in which the surface temperature of the pellet is measured immediately after molding and the surface temperature is controlled to fall within a predetermined range, thereby reliably solidifying the raw material (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-252783 Summary of the Invention [Problem to be solved by the invention]

[0004] In the conventional pellet manufacturing apparatus described above, it is difficult to measure the surface temperature of the pellets immediately after molding with high accuracy, making it difficult to stably solidify the raw material.

[0005] An object of the present invention is to solve the above-mentioned problems and to provide a pellet manufacturing apparatus that can stably and reliably solidify plant-derived raw materials to produce high-quality pellets. [Means for solving the problem]

[0006] To solve the above problems, the present invention provides a pellet manufacturing apparatus comprising an extruder that extrudes plant-derived raw materials to produce pellets, a sprinkler device that sprinkles water on the raw materials, and a control device that controls the sprinkler device's watering. The extruder comprises a die having a forming hole through which the raw materials are forced, and a temperature sensor that measures the temperature of the die. The control device causes the sprinkler device to sprinkle water when the temperature is equal to or higher than the upper limit of a set temperature range, and stops the sprinkler device from sprinkling water when the temperature is equal to or lower than the lower limit of the set temperature range.

[0007] The moisture content of the raw material has a significant effect on the solidification of plant-derived raw materials by extrusion molding. Furthermore, when the raw material is extruded through the forming holes of a die, the die temperature decreases if the raw material has a high moisture content, and increases if the raw material has a low moisture content. In this way, the moisture content of the raw material and the die temperature are correlated. In the present invention, the temperature range of the die when a raw material having a moisture content suitable for extrusion molding is calculated in advance, and the moisture content of the raw material is adjusted by spraying water on the raw material and adjusting the temperature of the die so that the temperature falls within that temperature range, thereby adjusting the moisture content of the raw material so that the raw material solidifies reliably. Since the die temperature can be easily and accurately measured, the pellet manufacturing apparatus of the present invention can accurately adjust the moisture content of the raw material based on the die temperature, thereby enabling the pellet manufacturing apparatus of the present invention to stably and reliably solidify the raw material and produce high-quality pellets.

[0008] The extruder can use a flat die system in which the extruder is equipped with a plurality of rollers that roll on the upper surface of the die and a cutting blade that is arranged on the lower surface of the die, and the molding hole penetrates from the upper surface to the lower surface of the die. For example, when the raw material is grass, the amount of lignin contained in the raw material is small, so low-temperature molding is desirable that does not rely solely on the thermal softening of lignin, but also utilizes the thermal softening of cellulose, hemicellulose, etc. at low temperatures below 100°C. Also, because grass is soft, it is difficult to powder the raw material. The flat die extruder described above can extrude the raw material in chip form (small pieces), making it easier to process the raw material. Furthermore, the flat die extruder can lower the die temperature when extruding the raw material compared to a ring die extruder, making it possible to produce high-quality pellets even when the raw material is grass.

[0009] Giant miscanthus (Miscanthus × giganteus) can be used as the raw material. Giant miscanthus, a member of the Miscanthus genus, can be cultivated in low-temperature environments with little fertilizer, and is a perennial plant with sustainable productivity and the ability to store carbon in the soil. Furthermore, because giant miscanthus has a low moisture content at harvest, it can be used as a raw material for pellets without having to adjust the moisture content using a dryer after harvest. The pellet manufacturing apparatus of the present invention can produce high-quality pellets from giant miscanthus, an environmentally friendly crop of regenerative agriculture.

[0010] Furthermore, when the raw material is Giant Miscanthus, the upper limit temperature is set to 83.0°C and the lower limit temperature is set to 82.4°C, which makes the pellets less likely to crumble.

[0011] It is preferable that the pellet manufacturing apparatus is provided with a raw material supply device that supplies the raw material to the extruder, and that the raw material supply device and the extruder can be mounted on the bed of a vehicle. In this configuration, pellets can be produced in the field where the raw materials are harvested, thereby improving pellet production efficiency compared to when the raw materials are transported from the field to a factory. [Effects of the Invention]

[0012] The pellet manufacturing apparatus of the present invention can easily and accurately measure the die temperature, and by adjusting the moisture content of the raw material based on the die temperature, the raw material can be solidified stably and reliably to produce high-quality pellets. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a side view showing a pellet manufacturing apparatus according to an embodiment of the present invention. [Figure 2] 1 is an overall configuration diagram showing a pellet manufacturing apparatus according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0014] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail with reference to the accompanying drawings. FIG. 2 is a diagram showing the overall configuration of a pellet manufacturing apparatus according to an embodiment of the present invention. In this embodiment, as shown in FIG. 2, a pellet manufacturing apparatus 1 for manufacturing fuel pellets P using Giant Miscanthus as a raw material will be described. Giant miscanthus is a grass of the Miscanthus genus. In this embodiment, chips (small pieces) of giant miscanthus harvested from a farm field are used as the raw material M.

[0015] FIG. 1 is a side view showing a pellet manufacturing apparatus according to an embodiment of the present invention. 1, the pellet manufacturing apparatus 1 includes an extruder 10, a raw material supply device 50, a water sprinkler device 60, and a control device 70. In the pellet manufacturing apparatus 1 of this embodiment, the extruder 10, the raw material supply device 50, and the water sprinkler device 60 can be loaded onto the loading platform T1 of a truck T.

[0016] 2, the extruder 10 is a granulator that produces pellets P from a raw material M. In this embodiment, a flat die type extruder 10 is used. The extruder 10 comprises a cylindrical housing 11, a die 20 housed within the housing 11, a plurality of rollers 30 that roll on the upper surface of the die 20, a cutting blade 12 arranged on the lower side of the die 20, and a temperature sensor 80 that measures the temperature of the die 20.

[0017] An inlet 11a through which raw material M is introduced is opened at the upper end of the housing 11, and an outlet 11b through which pellets P are discharged is opened at the peripheral wall of the housing 11. In the housing 11, the die 20, the rollers 30, and the cutting blade 12 are accommodated in the space between the inlet 11a and the outlet 11b.

[0018] The die 20 is a disk-shaped metal member with two flat surfaces arranged above and below the die 20. The die 20 is disposed directly below the injection port 11a. A plurality of forming holes 21 penetrate the die 20 from the top surface to the bottom surface.

[0019] The rollers 30 are cylindrical metal members with an outer circumferential surface formed around a horizontal axis. The lower end of the outer circumferential surface of the rollers 30 is in contact with the upper surface of the die 20. In this embodiment, multiple rotors 30 are arranged at intervals around the circumference of the die 20. The rotation axis of each roller 30 is connected to a support shaft 31 erected at the center of the upper surface of the die 20. The support shaft 31 is rotated around its axis by a drive mechanism (not shown), causing each roller 30 to roll around the upper surface of the die 20 in the circumferential direction of the die 20.

[0020] The cutting blade 12 is disposed on the lower surface side of the die 20. The cutting surface of the cutting blade 12 is disposed parallel to and close to the lower surface of the die 20. The cutting blade 12 can be reciprocated along the lower surface of the die 20 by a drive mechanism (not shown).

[0021] A temperature sensor 80 for measuring the temperature of the die 20 is provided inside the housing 11. The temperature measured by the temperature sensor 80 is output to the control device 70, which will be described later.

[0022] As shown in FIG. 1, the raw material supply device 50 includes a hopper 51 and a conveyor 52 extending obliquely upward from the bottom of the hopper 51. A rotary blade (not shown) is provided inside the hopper 51. When Giant Miscanthus harvested in the field is put into the upper opening of the hopper 51, it is crushed into chips inside the hopper 51 to produce raw material M (see Figure 2). A discharge section 52a provided at the tip of the conveyor 52 is positioned directly above the inlet 11a of the extruder 10. The raw material M (see Figure 2) in the hopper 51 is fed into the inlet 11a of the extruder 10 by the conveyor 52.

[0023] 2, in the extruder 10, when the raw material M is fed into the inlet 11a of the housing 11, the raw material M is placed on the upper surface of the die 20. Then, when the rollers 30 roll on the upper surface of the die 20, the raw material M placed on the upper surface of each die 20 is forced into each forming hole 21 by the outer circumferential surface of each roller 30, and is extruded from each forming hole 21 on the lower surface side of the die 20. The raw material M extruded from each forming hole 21 to the lower surface side of the die 20 is cut to a predetermined length by the cutting blade 12 to form a large number of pellets P. Then, each pellet P falls to the bottom of the housing 11 and is discharged to the outside from the discharge port 11b of the housing 11.

[0024] The pellet manufacturing apparatus 1 of this embodiment includes a sprinkler device 60 that sprinkles water onto the raw material M, and a control device 70 that controls the sprinkling of water by the sprinkler device 60. The sprinkler device 60 includes a sprinkler nozzle 61 , a water storage tank 62 , a pump 63 , and a connecting hose 64 .

[0025] The water spray nozzle 61 is provided at the inlet 11a of the extruder 10. A connecting hose 64 connects the water spray nozzle 61 to a pump 63. Water is pumped up from a water storage tank 62 by the pump 63 and supplied to the water spray nozzle 61 through the connecting hose 64. The water is then sprayed from the water spray nozzle 61 onto the raw material M in the housing 11.

[0026] The control device 70 is a computer, and controls the sprinkling of water from the sprinkler nozzles 61 in accordance with the temperature of the die 20 measured by the temperature sensor 80. The control device 70 stores a preset temperature range. When the temperature of the die 20 is equal to or higher than the upper limit temperature of the set temperature range, the control device 70 drives the pump 63 to spray water from the spray nozzle 61 . In addition, when the pump 63 is driven (water is being sprayed from the spray nozzle 61) and the temperature of the die 20 falls below the lower limit temperature of the set temperature range, the control device 70 stops the pump 63 and stops the spraying of water from the spray nozzle 61.

[0027] Here, when raw material M is extruded through each forming hole 21 of the die 20, there is a correlation in which if the moisture content of raw material M is high, the temperature of the die 20 decreases, and if the moisture content of raw material M is low, the temperature of the die 20 increases.

[0028] In this embodiment, the moisture content of raw material M, which is Giant Miscanthus, when it solidifies reliably through extrusion molding is calculated in advance through experiments, and the temperature range of the die 20 when raw material M with that moisture content is extruded is set as the set temperature range. In other words, the control device adjusts the water content of the raw material M so that it solidifies reliably by spraying water onto the raw material M and adjusting the temperature of the die 20 so that it falls within the set temperature range.

[0029] In this embodiment, the upper limit temperature of the set temperature range is set to 83.0 degrees, and the lower limit temperature of the set temperature range is set to 82.4 degrees. Therefore, in the control device 70, when the temperature of the die 20 is 83.0 degrees or higher, the pump 63 is driven to start spraying water onto the raw material M from the spray nozzle 61. Furthermore, when the temperature of the die 20 drops to 82.4 degrees or lower while the pump 63 is being driven, the control device 70 stops the pump 63 and stops the spraying of water onto the raw material M from the spray nozzle 61.

[0030] In the pellet manufacturing apparatus 1 as described above, the temperature of the die 20 can be easily and accurately measured by the temperature sensor 80. Furthermore, in the pellet manufacturing apparatus 1, the moisture content of the raw material M can be adjusted accurately based on the temperature of the die 20, so that the raw material M can be solidified stably and reliably to produce high-quality pellets P.

[0031] It is difficult to powder giant miscanthus harvested from a field, but the flat die type extruder 10 can extrude the raw material M in chip form, making it easy to use giant miscanthus as raw material M. Furthermore, when Giant Miscanthus is used, if the temperature of the die 20 is high, the quality of the pellets P deteriorates. However, the flat die type extruder 10 can reduce the temperature of the die 20 when extruding the raw material M compared to the ring die type, and therefore can produce high quality pellets P from Giant Miscanthus. In addition, because Giant Miscanthus has a low moisture content at the time of harvest, it can be used as raw material M without having to adjust the moisture content using a dryer after harvest. In this way, the pellet manufacturing apparatus 1 of this embodiment can manufacture high-quality pellets P from giant miscanthus, which is an eco-friendly crop of environmentally friendly regenerative agriculture.

[0032] In addition, in the pellet manufacturing apparatus 1 of this embodiment, the upper limit temperature of the set temperature range is set to 83.0 degrees and the lower limit temperature of the set temperature range is set to 82.4 degrees, making the pellets P made from Giant Miscanthus as the raw material M less likely to crumble.

[0033] In the pellet manufacturing apparatus 1 of this embodiment, as shown in FIG. 1, the raw material supply device, extruder, and sprinkler device 60 can be mounted on the loading platform T1 of a truck T (vehicle), so that pellets P (see FIG. 2) can be efficiently produced in a field where giant miscanthus is harvested.

[0034] Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments and can be modified as appropriate within the scope of the invention. 2, in the pellet manufacturing apparatus 1 of this embodiment, Giant Miscanthus is used as the raw material M, but the raw material M is not limited thereto, and various plants can be used as the raw material. The upper and lower limit temperatures of the set temperature range are set according to the type of raw material to the upper and lower limits of the temperature at which the raw material is likely to solidify by extrusion molding.

[0035] When Giant Miscanthus is used as raw material M, pellets P can be produced by setting the upper limit temperature of the set temperature range to 83.5 degrees and the lower limit temperature to 82.0 degrees, but more preferably, the upper limit temperature of the set temperature range is set to 83.0 degrees and the lower limit temperature to 82.4 degrees, which makes the pellets P less likely to crumble.

[0036] In the sprinkler device 60 of this embodiment, a constant flow rate of water is sprayed from the sprinkler nozzles 61 onto the raw material M, but a flow rate adjustment valve may be provided so that the amount of water sprayed from the sprinkler nozzles 61 (the amount of water sprayed relative to the amount of raw material M introduced) increases as the temperature of the die 20 increases. In this way, the temperature of the die 20 can be efficiently reduced.

[0037] In this embodiment, a flat die type extruder 10 is used, but the type of extruder (granulator) is not limited thereto, and for example, a ring die type extruder may be used. [Explanation of symbols]

[0038] 1. Pellet manufacturing equipment 10 Extruder 11. Housing 11a Inlet 11b Outlet 12 cutting blade 20 dice 21 Molding hole 30 Roller 31 Spindle 50 Raw material supply equipment 51 Hopper 52 Conveyor 52a Discharge section 60 Sprinkler System 61 Watering nozzle 62 Water Tank 63 Pump 64 Connecting hose 70 Control device 80 Temperature Sensor M Raw material P pellets T-track T1 Cargo bed

Claims

1. an extruder for extruding plant-derived raw materials to produce pellets; A sprinkler device that sprinkles water on the raw material; a control device for controlling the sprinkler device; The extruder a die having a forming hole through which the raw material is forced; a temperature sensor for measuring the temperature of the die; The control device If the temperature is equal to or higher than the upper limit temperature of a set temperature range, water is sprayed from the water spray device, A pellet manufacturing apparatus, characterized in that when the temperature is equal to or lower than the lower limit temperature of the set temperature range, the water sprinkler stops sprinkling.

2. The extruder A plurality of rollers that roll on the upper surface of the die; a cutting blade disposed on the lower surface side of the die, 2. The pellet manufacturing apparatus according to claim 1, wherein the molding hole penetrates from the upper surface to the lower surface of the die.

3. 2. The pellet manufacturing apparatus according to claim 1, wherein the raw material is giant miscanthus.

4. The upper limit temperature is 83.0 degrees, 4. The pellet manufacturing apparatus according to claim 3, wherein the lower limit temperature is 82.4 degrees.

5. a raw material supplying device that supplies the raw material to the extruder; 2. The pellet manufacturing apparatus according to claim 1, wherein the raw material supply device and the extruder are mountable on the bed of a vehicle.

Images