Shredding system, solid raw material production apparatus, and solid raw material production method

Abstract

A shredding system comprising: a shredder that has a raw material reception port, a cutting blade, and a shredded matter discharge port; a cover that shields the region between the cutting blade and the shredded matter discharge port from external air; a water vapor inlet installed in the cover; and a water vapor supply device connected to the water vapor inlet.

Description

Crushing system, apparatus for producing solid raw materials, and method for producing solid raw materials

[0001] This disclosure relates to a crushing system, an apparatus for producing solid raw materials, and a method for producing solid raw materials.

[0002] CO (carbon monoxide) and H2 are produced by gasifying organic waste such as waste plastics, municipal solid waste, sewage sludge, waste FRP, biomass waste, automobile waste, and waste oil. ２ Chemical recycling of waste, utilizing hydrogen-containing gases as raw materials for chemical products, is attracting attention. Organic waste is crushed as needed, compressed or extruded to reduce its volume and solidify it, and then subjected to gasification treatment.

[0003] Patent Document 1 (Japanese Patent Publication No. 2001-232634) describes a method for molding granular waste plastic for chemical raw materials, characterized by compressing waste plastic having a total polyethylene content of 10 to 60% by mass using a compression molding machine of the type that presses the waste plastic into a hole mold.

[0004] Japanese Patent Publication No. 2001-232634

[0005] Organic waste may contain lithium-ion batteries. If organic waste containing lithium-ion batteries is crushed, a short circuit may occur in the crushed lithium-ion batteries, causing them to ignite and potentially ignite flammable materials in the presence of oxygen.

[0006] This disclosure provides a crushing system that can suppress or prevent ignition or combustion of crushed material in the crushing process of organic waste.

[0007] This disclosure encompasses the following embodiments: [Embodiment 1] A crushing system comprising: a crusher having a raw material receiving port, a cutting blade, and a crushed material discharge port; a cover that shields the area between the cutting blade and the crushed material discharge port from the outside air; a steam inlet installed in the cover; and a steam supply device connected to the steam inlet. [Embodiment 2] The crushing system according to Embodiment 1, further comprising a belt conveyor located below the crushed material discharge port, the crushed material discharge port opening toward the downward of the crusher, and the cover extending such as to shield at least a portion of the belt conveyor from the outside air. [Embodiment 3] The crushing system according to Embodiment 1 or 2, further comprising a magnetic separator located downstream of the crusher; a second cover that shields at least a portion of the magnetic separator from the outside air; and a second steam inlet installed in the second cover. [Aspect 4] The crushing system according to any one of aspects 1 to 3, wherein the cutting blade is a rotary cutting blade attached to a rotor having a horizontally extending rotating shaft. [Aspect 5] The crushing system according to any one of aspects 1 to 4, wherein the crusher is at least one selected from the group consisting of a single-axis shearing machine and a double-axis shearing machine. [Aspect 6] A solid raw material manufacturing apparatus comprising the crushing system according to any one of aspects 1 to 5 and a molding apparatus for molding the crushed material produced by the crushing system. [Aspect 7] A method for producing a solid raw material, comprising: preparing the crushing system according to any one of aspects 1 to 5; introducing organic waste into the raw material receiving port of the crushing system; injecting steam from the steam inlet to create a steam atmosphere around the cutting blade; and crushing the organic waste with the cutting blade to produce crushed material. [Aspect 8] The method according to aspect 7, wherein the organic waste includes at least one selected from the group consisting of waste plastics and paper. [Aspect 9] The method according to aspect 8, wherein the content of the waste plastic in the organic waste is 80% by mass or more. [Aspect 10] A method for producing a solid raw material, comprising crushing organic waste in a steam atmosphere to produce crushed material.

[0008] According to this disclosure, a crushing system is provided that can suppress or prevent the ignition or combustion of crushed material in the crushing process of organic waste.

[0009] The foregoing description shall not be deemed to disclose all embodiments of the present invention and all advantages relating to the present invention.

[0010] This is a schematic diagram showing a crushing system according to one embodiment. This is a schematic diagram showing a solid raw material manufacturing apparatus according to one embodiment.

[0011] The embodiments of the present invention will be described below with reference to the drawings, but the present invention is not limited to these forms, and various applications are possible within its spirit and scope of implementation.

[0012] In this disclosure, when "~" is used for a numerical range, the numbers at both ends are the upper and lower limits, respectively, and are included in the numerical range. If multiple upper or lower limits are listed, a numerical range can be created from all combinations of upper and lower limits. Similarly, if multiple numerical ranges are listed, separate numerical ranges can be created by individually selecting and combining upper and lower limits from those numerical ranges. Regarding reference numbers in drawings, elements with the same or similar numbers in different drawings are indicated as being the same or similar elements.

[0013] [Crushing System] A crushing system according to one embodiment includes a crusher equipped with a raw material receiving port, a cutting blade, and a crushed material discharge port; a cover that isolates the area between the cutting blade and the crushed material discharge port from the outside air; a steam inlet installed on the cover; and a steam supply device connected to the steam inlet. By injecting steam from the steam inlet installed on the cover to create a steam atmosphere around the cutting blade, preferably in the area between the cutting blade and the crushed material discharge port, the oxygen concentration in these areas can be reduced, thereby suppressing ignition caused by crushed lithium-ion batteries or the ignition of combustible materials contained in organic waste. In some cases, some of the injected steam may adhere to the crushed material as liquid water, preventing the spread of fire from combustible materials. On the other hand, simply spraying water on the crushed material alone will not provide the above-mentioned effect of suppressing ignition or fire.

[0014] Hereinafter, an exemplary embodiment of the crushing system will be described with reference to Figure 1. Figure 1 is a schematic diagram showing a crushing system 1 of one embodiment. The crushing system 1 comprises a crusher 10, a cover 20, a steam inlet 30, and a steam supply device 34. The steam inlet 30 is installed in the cover 20. The steam inlet 30 is connected to the steam supply device 34 via piping 32.

[0015] In Figure 1, the crusher 10 is depicted as a single-shaft shear, but the type of crusher is not limited to this. For example, crushers can be single-shaft shears, twin-shaft shears, pusher-type crushers, and screw-type crushers. The crushing system 1 may include multiple crushers 10. Multiple crushers 10 may be arranged in series and used for coarse crushing and secondary crushing, respectively.

[0016] The crusher 10 includes a hopper 11 having a raw material receiving port 12. As shown by the arrows in Figure 1, organic waste is fed into the hopper 11 from the raw material receiving port 12. The crusher 10 includes a cutting blade 13 fixed inside the crusher 10 and a cutting blade 14 that rotates and works in cooperation with the cutting blade 13 to shear the organic waste. The rotating cutting blade 14 is attached to a rotor 15 having a horizontally extending rotating shaft. The number, material, shape, and arrangement of the cutting blades 13 and 14 are not particularly limited and can be appropriately determined according to the type and amount of organic waste to be fed in. Below the rotor 15, a screen 16 is placed to allow crushed material smaller than a predetermined size to pass through. The organic waste is held on the screen 16 until it becomes smaller than the predetermined size and is then crushed by the cutting blades 13 and 14. The crusher 10 includes a pusher 18 that pushes the organic waste supplied from the hopper 11 toward the cutting blades 13 and 14. The hydraulic cylinder 19 drives the pusher 18 in a reciprocating direction, controlling the force with which the pusher 18 presses the organic waste against the cutting blades 13 and 14 to a predetermined range. The crushed material that has passed through the screen 16 is discharged to the outside of the crusher 10 from the crushed material discharge port 17 located below the crusher 10, as shown by the dotted arrow in Figure 1.

[0017] The cutting blade 14 is preferably a rotary cutting blade attached to a rotor 15 having a horizontally extending rotating shaft. Rotary cutting blades can crush organic waste with high throughput because they rotate at high speed to cut organic waste. However, when organic waste containing insulators such as waste plastics is crushed in a dry atmosphere, static electricity is generated, which may lead to ignition or fire. According to this disclosure, a water vapor atmosphere can be created around the cutting blade, so rotary cutting blades can be used advantageously. In addition, in this embodiment, gravity can be used to make the crushed material fall, so the mechanism for transporting the crushed material inside the crusher 10 can be reduced.

[0018] The crusher 10 is preferably at least one selected from the group consisting of a single-axis shearer and a double-axis shearer. A double-axis shearer is a device that crushes organic waste by shearing between the first cutting blade and the second cutting blade by facing a first rotor and a first cutting blade attached to the first rotor against a second rotor and a second cutting blade attached to the second rotor, and rotating the first rotor and the second rotor in opposite directions. Both single-axis and double-axis shearers can efficiently crush organic waste of various shapes and hardnesses by utilizing their high shearing force.

[0019] The cover 20 blocks the area between the cutting blades 13 and 14 and the crushed material discharge port 17 from the outside air. The cover 20 only needs to block the area from the outside air to such an extent that the relative humidity around the cutting blades 13 and 14, preferably the relative humidity of the area between the cutting blades 13 and 14 and the crushed material discharge port 17, can be made higher than the relative humidity of the outside air by the water vapor injected from the water vapor inlet 30, and it is not required that the area be completely sealed from the outside air. In Figure 1, the cover 20 is a rectangular tube with the top and bottom open, and the sides of the cover 20 function to block the area from the outside air. The material of the cover 20 is not particularly limited, but it is preferably non-combustible, and more preferably metal. The inside of the cover 20 preferably has a surface treatment to prevent corrosion due to exposure to water vapor.

[0020] In one embodiment, as shown in Figure 1, the crushing system 1 further includes a belt conveyor 50 positioned below the crushed material discharge port 17, the crushed material discharge port 17 opening downward toward the crusher 10, and the cover 20 extending so as to shield at least a portion of the belt conveyor 50 from the outside air. In this embodiment, it is possible to suppress or prevent the ignition or combustion of the crushed material that falls from the crushed material discharge port 17, is placed on the belt conveyor 50, and is transported to the next process. This reduces or eliminates the need to separately install fire extinguishing equipment such as a sprinkler near the belt conveyor 50.

[0021] A steam inlet 30 is installed in the cover 20. The steam inlet 30 is not particularly limited, but can be formed, for example, by making a hole in the cover 20, attaching a flange around the hole, and connecting the flange to a connector. The piping 32 connects the steam inlet 30 to the steam supply device 34. The steam supply device 34 is not particularly limited, but examples include an electric boiler, a gas-fired boiler, and a waste heat recovery boiler. The steam supply device 34 may be other equipment or devices in the factory that produce steam as a by-product, or it may be a steam supply line shared with other equipment or devices.

[0022] In one embodiment, as shown in Figure 1, the crushing system 1 further comprises a magnetic separator 40 positioned downstream of the crusher 10, a second cover 21 that shields at least a portion of the magnetic separator 40 from the outside air, and a second steam inlet 31 installed in the second cover 21. As indicated by the arrows in Figure 1, the crushed material coming out of the crusher 10 is transported by a belt conveyor 50, and the magnetic separator 40 positioned on the belt conveyor 50 collects the metal contained in the crushed material. The magnetic separator 40 puts the collected metal into a container 41 and performs magnetic separation of the crushed material again. The remaining crushed material that was not collected by the magnetic separator 40 falls onto the belt conveyor 51 and is transported to the next process by the belt conveyor 51. By shielding at least a portion of the magnetic separator 40 from the outside air with the second cover 21 and injecting steam from the second steam inlet 31, a steam atmosphere can be created around the magnetic separator 40. This makes it possible to prevent or suppress the ignition of crushed materials such as crushed lithium-ion batteries collected by the magnetic separator 40, or the ignition of combustible materials collected by the magnetic separator 40 along with metal. In some cases, already ignited crushed materials or combustible materials can be extinguished in a water vapor atmosphere.

[0023] The second cover 21 only needs to be able to isolate the magnetic separator 40 from the outside air to the extent that the relative humidity around the magnetic separator 40 can be made higher than the relative humidity of the outside air by the water vapor injected from the second water vapor inlet 31, and it is not required that the magnetic separator 40 be completely sealed from the outside air. In Figure 1, the left side and bottom of the second cover 21 are open, and the other parts of the second cover 21 function to isolate the magnetic separator 40 from the outside air. The material and surface treatment of the second cover 21 are as described with respect to cover 20.

[0024] In Figure 1, the second steam inlet 31 is connected to the steam supply device 34 via piping 33. The second steam inlet 31 may be connected to the same steam supply device as the first steam inlet 30, or it may be connected to a different steam supply device.

[0025] [Apparatus for manufacturing solid raw materials] An apparatus for manufacturing solid raw materials according to one embodiment includes the crushing system described above and a molding apparatus for molding the crushed material produced by the crushing system.

[0026] Figure 2 schematically shows a solid raw material manufacturing apparatus according to one embodiment. The solid raw material manufacturing apparatus 100 includes the crushing system described above (only the crusher 10, cover 20, magnetic separator 40, container 41, and belt conveyor 50 are shown for simplification) and a molding apparatus 56. As shown by the arrows and dotted arrows in Figure 2, the crushed material generated by crushing organic waste in the crusher 10 is magnetically separated by the magnetic separator 40 on the belt conveyor 50, transported by the flight conveyor 54 and belt conveyor 52, and then fed into the quantitative feeder 55. A predetermined amount of crushed material is supplied from the quantitative feeder 55 to the molding apparatus 56, and solid raw materials are manufactured by molding the crushed material in the molding apparatus 56. The manufactured solid raw materials are transported by the belt conveyor 53 to the next process, such as drying, gasification, inspection, and packaging.

[0027] The molding apparatus 56 is not particularly limited, and a compression molding apparatus or an extrusion molding apparatus can be used. Examples of molding apparatuses include a flat die type, a ring die type, and a screw type.

[0028] [Method for Manufacturing Solid Raw Materials] A method for manufacturing solid raw materials according to one embodiment includes: preparing the crushing system described above; introducing organic waste into the raw material receiving port of the crushing system; injecting steam from the steam inlet to create a steam atmosphere around the cutting blade; and crushing the organic waste with the cutting blade to produce crushed material.

[0029] Organic waste is not particularly limited, but examples include waste plastics, paper, waste clothing, municipal solid waste, sewage sludge, biomass waste, waste fiber-reinforced plastics (FRP), automobile waste, waste tires, household appliance waste, construction waste, medical waste, and various industrial wastes. From the viewpoint of low compositional variability, high calorific value, and low moisture content, it is preferable that the organic waste includes at least one selected from the group consisting of waste plastics and paper. Multiple types of organic waste may be combined.

[0030] The content of waste plastics in organic waste is preferably 80% by mass or more, more preferably 90% by mass or more, and even more preferably 95% by mass or more. When organic waste containing a high content of waste plastics is crushed, the crushed material is prone to ignition. According to this disclosure, such ignition can be effectively suppressed or prevented. From organic waste containing a high content of waste plastics, a solid raw material with a high calorific value, suitable for chemical recycling by gasification, can be produced.

[0031] Organic waste can be fed into the raw material receiving port of the crushing system using a belt conveyor or similar means.

[0032] Steam is injected through a steam inlet to create a steam atmosphere around the cutting blade. Preferably, the area between the cutting blade and the crushed material discharge port is made into a steam atmosphere, and more preferably, the area from the cutting blade to at least a portion of the belt conveyor located below the crushed material discharge port is made into a steam atmosphere. This can suppress ignition caused by crushed lithium-ion batteries or the ignition of combustible materials contained in organic waste. In some cases, some of the injected steam may adhere to the crushed material as liquid water, preventing the spread of fire from combustible materials. The amount of water contained in the steam atmosphere is such that the relative humidity is preferably 90% RH or higher, more preferably 95% RH or higher, and even more preferably 100% RH.

[0033] The amount of water present in the water vapor atmosphere is preferably 5 g / m³, as the sum of water present in both water vapor and liquid form. ３ More preferably, 10 g / m ３ More preferably 20 g / m² ３ That concludes the explanation. The amount of water in the water vapor atmosphere is preferably 100 g / m³, as the sum of water vapor and water present in liquid form. ３ The following applies:

[0034] In an embodiment using a magnetic separator, it is preferable to inject steam from the second steam injection port to create a steam atmosphere around the magnetic separator. This can prevent or suppress the ignition of crushed materials such as crushed lithium-ion batteries collected by the magnetic separator, or the ignition of combustible materials entrained by metals and collected by the magnetic separator. In some cases, it is possible to extinguish the already ignited crushed materials or the ignited combustible materials within the steam atmosphere. The amount of moisture contained in the steam atmosphere is such that the relative humidity is preferably 90% RH or more, more preferably 95% RH or more, and even more preferably 100% RH.

[0035] The water contained in the steam atmosphere, as the sum of water present as steam and liquid water, is preferably 5 g / m ３ or more, more preferably 10 g / m ３ or more, and even more preferably 20 g / m ３ or more. The water contained in the steam atmosphere, as the sum of water present as steam and liquid water, is preferably 100 g / m ３ or less.

[0036] Crush the organic waste with a cutting blade to produce crushed materials. The organic waste is preferably crushed to a size of, for example, 5 mm to 100 mm.

[0037] It is preferable to form the obtained crushed materials. Forming is preferably compression molding or extrusion molding because it can reduce the volume of the crushed materials and improve their quantitative accuracy, enabling stable supply to the gasification process. The shape of the formed product is not particularly limited, but it is preferably a pellet. The forming temperature can be, for example, 100°C to 300°C, preferably 110°C to 250°C, and more preferably 120°C to 230°C.

[0038] The bulk density of the formed product can be, for example, 0.05 g / cm ３ to 2.0 g / cm ３ and is preferably 0.05 g / cm ３ to 0.6 g / cm ３ , more preferably 0.1 g / cm ３ to 0.5 g / cm ３ . The length of the formed product is preferably 1 cm or more on the short side.

[0039] In one embodiment, a method for producing a solid raw material is provided, which includes crushing organic waste in a steam atmosphere to generate a crushed product. The organic waste, the relative humidity of the steam atmosphere, the conditions and apparatus of the crushing process are as described above.

[0040] Examples of the solid raw material produced by the above method include solid fuel. From the perspective of transportation efficiency, the solid fuel is more preferably Refuse Derived Fuel (hereinafter also referred to as "RDF") using municipal solid waste as a solidified fuel or Refuse Derived Paper and Plastics Densified Fuel (hereinafter also referred to as "RPF") using waste plastics as a solidified fuel, and is even more preferably RPF from the perspectives of less variation in composition, high calorific value, and low moisture content. The solid raw material can be used as a raw material for the production of synthesis gas (a mixed gas of hydrogen gas and carbon monoxide gas) using, for example, a two-stage gasification apparatus including a low-temperature gasification furnace and a high-temperature gasification furnace.

[0041] The present invention is not limited to the above embodiments, and it is obvious to those skilled in the art that various improvements and modifications of the present invention can be made without departing from the scope and spirit of the present invention.

[0042] 1 Crushing system 10 Crusher 11 Hopper 12 Raw material inlet 13, 14 Cutting blades 15 Rotor 16 Screen 17 Crushed product outlet 18 Pusher 19 Hydraulic cylinder 20 Cover 21 Second cover 30 Steam inlet 31 Second steam inlet 32, 33 Pipes 34 Steam supply device 40 Magnetic separator 41 Container 50, 51, 52, 53 Belt conveyors 54 Flight conveyor 55 Quantitative feeder 56 Forming device 100 Solid raw material production device

Claims

1. A crushing system comprising: a crusher equipped with a raw material receiving port, a cutting blade, and a crushed material discharge port; a cover that isolates the area between the cutting blade and the crushed material discharge port from the outside air; a steam inlet installed in the cover; and a steam supply device connected to the steam inlet.

2. The crushing system according to claim 1, further comprising a belt conveyor positioned below the crushed material discharge port, wherein the crushed material discharge port is open toward the downward direction of the crusher, and the cover extends such as to shield at least a portion of the belt conveyor from the outside air.

3. The crushing system according to claim 1 or 2, further comprising: a magnetic separator disposed downstream of the crusher; a second cover that shields at least a portion of the magnetic separator from the outside air; and a second steam inlet installed in the second cover.

4. The crushing system according to claim 1 or 2, wherein the cutting blade is a rotary cutting blade mounted on a rotor having a horizontally extending rotating shaft.

5. The crushing system according to claim 1 or 2, wherein the crusher is at least one selected from the group consisting of a single-axis shear and a double-axis shear.

6. A solid raw material manufacturing apparatus comprising a crushing system according to claim 1 or 2, and a molding apparatus for molding the crushed material produced by the crushing system.

7. A method for producing a solid raw material, comprising: preparing a crushing system according to claim 1 or 2; introducing organic waste into the raw material receiving port of the crushing system; injecting steam from the steam inlet to create a steam atmosphere around the cutting blade; and crushing the organic waste with the cutting blade to produce crushed material.

8. The method according to claim 7, wherein the organic waste includes at least one selected from the group consisting of waste plastics and paper.

9. The method according to claim 8, wherein the content of the waste plastic in the organic waste is 80% by mass or more.

10. A method for producing a solid raw material, comprising crushing organic waste under a steam atmosphere to produce crushed material.

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