Processor, processing method, and combustion system of biomass

Abstract

To provide a processor of biomass capable of reducing load in pulverization of biomass.SOLUTION: A processor (5) of biomass includes: a crushing / classification part (10) that classifies a crushed material (CB) obtained by crushing biomass pellets (BM) based on a threshold value to obtain a small diameter crushed material (CB1) and a large diameter crushed material (CB2) having relatively larger particle diameter than small diameter crushed material (CB1); a blending / pulverization part (30) that blends the large diameter crushed material (CB2) with coal (RC) and pulverizes them to obtain a pulverization blend (MB); and a discharging part (50) that discharges one or both of the small diameter crushed material (CB1) and the pulverization blend (MB) to a combustor 7.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a biomass treatment device that is applied to, for example, a boiler system that uses biomass, which is organic matter derived from living organisms, such as wood pellets, as fuel. [Background technology]

[0002] A boiler system that uses a mixture of biomass and coal as fuel is known. For example, a mixed fuel can be obtained by mixing pelletized biomass and coal and then pulverizing them. However, this method of mixing and pulverizing the pelletized biomass is limited in that the amount of biomass that can be mixed is only a few percent of the heat generated by combustion in a boiler. Therefore, Patent Document 1 proposes a combustion system in which biomass pellets and coal are crushed in separate crushers, mixed and stored, and then the mixture is gasified and the resulting gas is used as fuel, in order to enable the mixing of more biomass. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-133749 [Non-patent literature]

[0004] [Non-Patent Document 1] Ishikawajima-Harima Technical Report Vol.44 No.6(2004-11) Summary of the Invention [Problem to be solved by the invention]

[0005] According to the proposal in Patent Document 1, a larger amount of biomass can be fed into the boiler. However, the combustion system proposed in Patent Document 1 has a complicated configuration, and requires separate heat sources for gasifying the biomass and coal.

[0006] Therefore, to simplify the configuration of the combustion system, it is necessary to crush the biomass pellets and coal in a mixed state. However, biomass is more difficult to crush than coal, and the crushing load when mixed with coal is large. Therefore, an object of the present invention is to provide a biomass treatment device that can reduce the load during biomass crushing, a treatment method that can be applied to the treatment device, and a combustion system that can be applied to the treatment device. [Means for solving the problem]

[0007] The biomass treatment device of the present invention comprises: a crushing and classifying unit that classifies crushed material obtained by crushing biomass pellets based on a threshold value to obtain small-diameter crushed material and large-diameter crushed material having a particle size relatively larger than that of the small-diameter crushed material; a mixing and crushing section for mixing and crushing the large-diameter crushed material and coal to obtain a crushed mixture; and an input section for inputting either or both of the small-diameter crushed material and the crushed mixture into the combustor.

[0008] The crushing and classifying unit preferably includes: Equipped with a second hopper that can store small-diameter crushed materials, A predetermined amount of small-diameter crushed material stored in the first hopper is fed into the combustor through the feeding section.

[0009] Preferably, a constant amount of small size crushed material is fed into the combustor, or a variable amount of small size crushed material is fed into the combustor.

[0010] Preferably, the crushing and classifying unit includes: Equipped with a second hopper that can store large-diameter crushed materials, The large-diameter crushed material stored in the second hopper is mixed with coal and crushed to produce a crushed mixture, which is then fed into the combustor via the feed section.

[0011] Preferably, a constant amount of the pulverized mixture is fed to the combustor, or a varying amount of the pulverized mixture is fed to the combustor.

[0012] Preferably, the crushing and classifying unit includes: A crusher for crushing biomass pellets, a classifier that classifies the crushed material from the crusher into small-diameter crushed material and large-diameter crushed material; and a circulation path for sending the large-diameter crushed material classified by the classifier toward the crusher.

[0013] The method for treating biomass of the present invention includes: A first step of classifying the crushed material obtained by crushing biomass pellets based on a threshold value to obtain small-diameter crushed material and large-diameter crushed material that is larger than the small-diameter crushed material; a second step of mixing the large-diameter crushed material obtained in the first step with coal and crushing the mixture to obtain a crushed mixture; and a third step of feeding one or both of the small-diameter crushed material obtained in the first step and the crushed mixture obtained in the second step into a combustor.

[0014] The threshold value is preferably: It is set in the range of 3.0 to 4.0 mm.

[0015] The combustion system of the present invention comprises: The apparatus includes a combustor and the biomass treatment device described above. [Effects of the Invention]

[0016] According to the present invention, the amount of biomass to be mixed with coal and pulverized can be reduced, thereby reducing the load imposed by the biomass during pulverization. [Brief explanation of the drawings]

[0017] [Figure 1] 1 is a diagram showing the overall configuration of a combustion system 1 including a biomass treatment device 5 according to an embodiment. [Figure 2]1 is a diagram showing a crushing and classifying unit 10 in a biomass treatment device according to an embodiment. [Figure 3] FIG. 2 is a diagram showing a mixing and grinding section 30 in the biomass treatment device according to the embodiment. [Figure 4] FIG. 2 is a diagram showing an input section 50 of the biomass treatment device according to the embodiment. [Figure 5] FIG. 10 is a diagram showing the overall configuration of a biomass treatment device according to a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0018] Hereinafter, embodiments will be described with reference to the accompanying drawings. The processing device 5 according to the embodiment described below constitutes a combustion system 1 together with a combustor 7 as shown in FIG. 1. In the processing device 5, the crushed material CB of the biomass pellets BM is divided into two groups using a threshold value in the crushing and classification section 10. In the processing device 5, the small-sized crushed material CB1 is sent to the combustor 7 in its original form, while the large-sized crushed material CB2 is mixed with the coal RC, crushed, and then sent to the combustor 7. In this way, the processing device 5 can reduce the amount of biomass mixed with the coal RC and crushed, thereby reducing the crushing load caused by the biomass. Below, each component of the processing device 5 will be described in order, followed by a description of the processing procedure in the processing device 5, and then a description of the effects achieved by the processing device 5.

[0019] [Crushing and classifying section 10: see Figures 1 and 2] <Functions of the crushing and classifying unit 10> The crushing and classifying unit 10 crushes the supplied biomass pellets BM and classifies the crushed material CB obtained by crushing the biomass pellets BM using a threshold value to obtain small-diameter crushed material CB1 and large-diameter crushed material CB2, which is larger in size than the small-diameter crushed material CB1. The obtained small-diameter crushed material CB1 is sent to the feeding unit 50, and the large-diameter crushed material CB2 is sent to the mixing and crushing unit 30.

[0020] <Configuration of the crushing and classifying unit 10> The crushing and classifying unit 10, which performs the above functions, includes a conveyor 11 that transports biomass pellets BM from upstream, a fourth hopper 13 that temporarily stores the biomass pellets BM transported by the conveyor 11, and a crusher 15 that crushes the biomass pellets BM supplied from the fourth hopper 13 to generate crushed material CB. The crushed material CB after passing through the crusher 15 includes small-diameter crushed material CB1 and large-diameter crushed material CB2.

[0021] The crushing and classification section 10 includes a classifier 17 that separates crushed material CB into small-diameter crushed material CB1 and large-diameter crushed material CB2, a first conveying path 18 that conveys the small-diameter crushed material CB1 separated by the classifier 17 toward the feeding section 50, and a second conveying path 25 that conveys the large-diameter crushed material CB2 separated by the classifier 17 toward the mixing and crushing section 30.

[0022] The first conveying path 18 is equipped with a blower 19, a collector 21 on which the suction force of the blower 19 acts, a first hopper 22 that stores the small-diameter crushed material CB1 collected by the collector 21, and a first weighing machine 23 that weighs the small-diameter crushed material CB1 conveyed from the first hopper 22 and sends it to the feeding section 50. Note that a blower is a machine that blows air by rotating an impeller, and is a device that can collect dust by connecting an air intake port. The second conveying path 25 also includes a second hopper 26 that stores the large-diameter crushed material CB2 conveyed from the classifier 17, and a second weighing machine 27 that weighs the large-diameter crushed material CB2 conveyed from the second hopper 26 and sends it to the mixing and crushing section 30. Note that, between the fourth hopper 13 and the crusher 15, and between the crusher 15 and the classifier 17, etc., paths are formed by piping, but specific illustrations and explanations thereof are omitted.

[0023] The first hopper 22 and the second hopper 26 are provided for the purpose of storing small diameter crushed materials CB1 and large diameter crushed materials CB2, respectively, but it is not necessarily required to store the small diameter crushed materials CB1 and large diameter crushed materials CB2 during operation of the processing device 5. In other words, the small diameter crushed materials CB1 may pass through the first hopper 22 directly to be sent to the first weigher 23, and the large diameter crushed materials CB2 may pass through the second hopper 26 directly to be sent to the second weigher 27. The same applies to the fourth hopper 13 and the third hopper 33.

[0024] <Biomass pellet BM> Biomass pellets BM are pellets made by solidifying wood chips, and as an example, ones with a diameter of about 5 mm and a length of about 10 mm are used. Biomass pellets BM are mixed with coal RC and used as the raw material for combustion in combustor 7. However, rather than mixing biomass pellets BM with coal RC as is, they are mixed with the coal RC in a pulverizer 35, pulverized, and then combusted. As will be explained in more detail later, biomass pellets BM pose several challenges when it comes to pulverizing them, and as a result, there are three challenges to pulverizing them while mixed with coal RC.

[0025] <Crusher 15: Figure 2> The crusher 15 crushes the biomass pellets BM. Here, "crushing" refers to the process of breaking down clumps of fine particles into their original particles. For example, in the case of biomass pellet BM, it refers to breaking down the biomass pellet BM and returning it to the wood chips that make up the biomass pellet BM.

[0026] However, during the crushing process, the wood chips that make up the biomass pellets BM may be crushed into smaller wood chips. Therefore, the crushed material CB produced by the crusher 15 includes such small wood chips. While the wood chips are, for example, 3 mm or less in size, the crushed material CB also includes chips larger than the wood chips because the crusher 15 does not disintegrate all of the biomass pellets BM into wood chips. For example, two wood chips may be bonded together. In other words, the crushed material CB includes chips smaller than the threshold and chips larger than the threshold. The former corresponds to small-diameter crushed material CB1, and the latter corresponds to large-diameter crushed material CB2. This threshold is set so that the classified small-diameter crushed material CB1 can be combusted in the combustor 7. For example, a range of 3.0 to 4.0 mm is applied. In the following explanation, the threshold is assumed to be 3.5 mm.

[0027] Furthermore, as long as it can crush the biomass pellets BM, a machine called a pulverizer, mill, etc. can be used as the crusher 15. Examples of machines that can be used as the crusher 15 include a disc mill, an impact mill, and a hammer mill.

[0028] <Classifier 17: Figure 2> The crushed material CB from the crusher 15 is transported to a classifier 17 and sorted into small-diameter crushed material CB1 and large-diameter crushed material CB2. The classification standard is, for example, 3.5 mm, with small-diameter crushed material CB1 having a size of 3.5 mm or less and large-diameter crushed material CB2 having a size of more than 3.5 mm. However, since the classification accuracy in the classifier 17 is not perfect, wood chips larger than 3.5 mm may be mixed into the small-diameter crushed material CB1, and wood chips smaller than 3.5 mm may be mixed into the large-diameter crushed material CB2. A device that classifies by centrifugal separation is suitable as the classifier 17.

[0029] The classifier 17 has an inlet 17A that receives crushed materials CB from the crusher 15, a first outlet 17B through which small-diameter crushed materials CB1 are discharged, and a second outlet 17C through which large-diameter crushed materials CB2 are discharged. The small-diameter crushed materials CB1 discharged from the first outlet 17B reach the first conveying path 18, and the large-diameter crushed materials CB2 discharged from the second outlet 17C reach the second conveying path 25.

[0030] <First conveying path 18, second conveying path 25: Figure 2> The first conveying path 18 conveys the small diameter crushed materials CB1 supplied from the classifier 17 to the feeding section 50. The second conveying path 25 conveys the large diameter crushed materials CB2 supplied from the classifier 17 to the mixing and crushing section 30. The configurations of the first conveying path 18 and the second conveying path 25 have already been described. The small-diameter crushed material CB1 that is fed into the combustor 7 through the first conveying path 18 and the feeding section 50 is not crushed together with the coal RC. As an example, if the ratio of small-diameter crushed material CB1 to large-diameter crushed material CB2 in the crushed material CB is 50%:50%, the amount of biomass crushed together with the coal RC in the mixing and crushing section 30 can be reduced by 50% compared to crushing the entire amount of biomass pellets BM together with the coal RC. By being able to reduce the amount of biomass that is subjected to crushing in this way, the processing device 5 can achieve the effects described below. The ratio of the small diameter crushed materials CB1 and the large diameter crushed materials CB2 can be adjusted by adjusting the amount of small diameter crushed materials CB1 measured and discharged by the first weighing machine 23, and by adjusting the amount of large diameter crushed materials CB2 measured and discharged by the second weighing machine 27.

[0031] [Mixing and grinding section 30; see Figures 1 and 3] <Functions of the mixing and grinding unit 30> The mixing and crushing section 30 mixes and crushes the supplied coal RC and large-diameter crushed material CB2. This crushing is preferably aimed at obtaining a particle size that will provide high combustion efficiency for the coal RC in the combustor 7. As an example, the particle size of the coal RC that is suitable for this combustion efficiency is an average particle size (Dp50) of 40 μm.

[0032] <Configuration of the mixing and grinding unit 30> The mixing and crushing section 30, which performs the above functions, includes a conveyor 31 that transports the coal RC from upstream, and a third hopper 33 that temporarily stores the coal RC transported by the conveyor 31. The mixing and crushing section 30 also includes a crusher 35 that mixes and crushes the coal RC supplied from the third hopper 33 and the large-diameter crushed material CB2 supplied, and a feed fan 37 that transports the crushed mixture MB produced by the crusher 35 toward the feeding section 50.

[0033] <Crusher 35> The crusher 35 crushes the large-diameter crushed material CB2 in addition to the coal RC. The coal RC is crushed into smaller particles than its original lump state, and an example of the resulting product is pulverized coal PC with an average particle size (Dp50) of 40 μm. The large-diameter crushed material CB2, which has a diameter of more than 3.5 mm, is crushed to a particle size of 3.5 mm or less under the crushing conditions required to obtain the pulverized coal PC. The large-diameter crushed material CB2 crushed by the crusher 35 is referred to as pulverized biomass PB. In the combustor 7, the pulverized coal PC is required to have a very small particle size, for example, an average particle size (Dp50) of 40 μm, from the standpoint of combustion efficiency. However, even if the pulverized biomass PB has a particle size significantly larger than that of the pulverized coal PC, the combustion efficiency of the pulverized coal PC is not reduced. For example, even if the pulverized biomass PB has a particle size approximately 100 times larger than that of the pulverized coal PC, combustion efficiency is not impaired. Therefore, if the particle size of the pulverized biomass PB is 3.5 mm (3500 μm) or less, the combustion efficiency of the pulverized coal PC with an average particle size (Dp50) of 40 μm will not be reduced.

[0034] Any pulverizer may be used as the pulverizer 35 as long as it can achieve the purpose of obtaining the pulverized mixture MB. As a preferred example, a type known as a vertical pulverizer is selected. The pulverized mixture MB, which is a mixture of pulverized coal PC and pulverized biomass PB obtained in the pulverizer 35, is transported to the input section 50 via an outlet (not shown) by air blown by the feed fan 37.

[0035] [Input unit 50: see Figures 1 and 4] The feeding section 50 feeds the small-diameter crushed materials CB1 produced and transported in the crushing and classifying section 10 and the pulverized mixture MB produced and transported in the mixing and crushing section 30 into the combustor 7. As an example, the feeding section 50 merges the small-diameter crushed materials CB1 and the pulverized mixture MB and feeds them into the combustor 7 by compressed air.

[0036] For this purpose, the feeding section 50 is provided with a fuel pipe 51 through which the pulverized mixture MB discharged from the mixing and pulverizing section 30 is transported and which is connected to the combustor 7, and a confluence path 53 through which small-diameter crushed materials CB1 are joined to the pulverized mixture MB transported through the fuel pipe 51. The confluence path 53 is provided with a blower 54 which generates compressed air, and an ejector 55 which pressure-feeds the small-diameter crushed materials CB1 transported by receiving air from the blower 54 towards the fuel pipe 51.

[0037] In the feeding section 50, the pulverized mixture MB, which is carried through the fuel pipe 51 by the flow of compressed air by the feed fan 37, is joined with small-diameter crushed materials CB1, which are pressure-fed by the action of the ejector 55, to form a combined mass JO, which is then fed into the combustor 7. The particle sizes of the components of this combined mass JO are as follows, for example, and good combustion in the combustor 7 is ensured. Small diameter crushed material CB1:≦3.5mm Crushed biomass PB:≦3.5mm Pulverized coal PC: Dp50=40μm

[0038] [Processing procedure in processing device 5] The procedure for producing the pulverized mixture MB using the processing device 5 described above comprises the following steps 1, 2, and 3. Steps 1, 2, and 3 are performed in the order that they were initially performed when the processing device 5 started operating, and if operation continues, for example, steps 1 and 2 will be performed simultaneously in parallel.

[0039] First step: The crushed material CB obtained by crushing the biomass pellets BM is classified using a threshold value into small-diameter crushed material CB1 and large-diameter crushed material CB2, which is larger than the small-diameter crushed material CB1. Second step: The large-diameter crushed material CB2 separated in the first step and the coal RC are mixed and crushed to obtain a crushed mixture MB. Third step: The small-diameter crushed material CB1 obtained in the first step and the crushed mixture MB obtained in the second step are fed into a combustor 7.

[0040] [Feeding pattern of small-diameter crushed material CB1 and crushed mixture MB] The feeding patterns of the small-diameter crushed material CB1 and the pulverized mixture MB in the procedure of the processing device 5 explained above will be described. The feeding patterns include three patterns: a first pattern in which the feeding amount is constant, a second pattern in which the feeding amount varies, and a third pattern in which only the pulverized mixture MB is fed into the combustor 7.

[0041] In the combustion system 1, the pulverizer input amount, which is the amount of biomass input to the pulverizer 35, is preferably 3 wt.% or less. In addition, in the combustion system 1, the combustor input amount, which is the total amount of biomass input to the combustor 7, can exceed 3 wt.%. The pulverizer input amount and the combustor input amount are defined as follows: Crusher input amount: The ratio of the total amount of coal RC and biomass (large-diameter crushed material CB2) input into the crusher 35 to 100% Combustor input amount: The ratio of the total amount of coal (pulverized coal PC) and biomass (the combined amount of small-diameter crushed material CB1 and large-diameter crushed material CB2) input into the combustor 7 to 100%

[0042] <Pattern 1: Constant input amount> In the first pattern, a certain amount of small-diameter crushed material CB1 and a certain amount of crushed mixture MB are fed into the combustor 7. The crushed mixture MB contains pulverized coal PC and crushed biomass PB. Therefore, the small-diameter crushed material CB1 and crushed biomass PB are fed into the combustor 7 so that the combined biomass target amount is, for example, 3 wt.% relative to the pulverized coal PC. To adjust the biomass target amounts of the small-diameter crushed material CB1, crushed biomass PB, and pulverized coal PC in this manner, the weighing of the small-diameter crushed material CB1 by the first weigher 23 corresponding to the first hopper 22, the weighing of the large-diameter crushed material CB2 by the second weigher 27 corresponding to the second hopper 26, and the weighing of the coal RC by the third weigher 34 corresponding to the third hopper 33 may be controlled. Note that the biomass target amount referred to here is the amount of biomass to be fed into the combustor 7, which is set as a target in advance.

[0043] <Pattern 2: Input fluctuation> In the second pattern, one or both of the amount of small-diameter crushed material CB1 fed into the combustor 7 and the amount of pulverized mixture MB fed into the combustor 7 are varied. In principle, it is sufficient to operate the treatment device 5 in the first pattern with a constant input amount. However, it may be necessary to vary the biomass input amount depending on the combustibility and operating conditions of the combustor 7. For example, the biomass input amount to the combustor can be temporarily increased, for example, to 5 wt.% or 7 wt.%, or temporarily decreased, for example, to 2 wt.% or 1 wt.%. When varying this biomass input amount, it is advantageous to adjust the input amount of small-diameter crushed material CB1.

[0044] The ratio of pulverized biomass PB to pulverized coal PC in the pulverized mixture MB can also be varied. If the target amount of pulverized biomass PB to be mixed with pulverized coal PC is set to 1.5 wt.%, the amount of pulverized biomass PB mixed with pulverized coal PC can be reduced to 1 wt.% or increased to 3 wt.%.

[0045] The reason why fluctuations in the amount of biomass input, i.e., increases and decreases, can be easily accommodated in this way is because the first hopper 22, second hopper 26, and third hopper 33 are provided. For example, if it is assumed that the input amount of small-diameter crushed material CB1 is to be increased, a large amount of small-diameter crushed material CB1 can be stored in the first hopper 22, and when the input amount is increased, the amount of small-diameter crushed material CB1 discharged from the first hopper 22 can be increased.

[0046] <Third pattern> In the third pattern, only the pulverized mixture MB is fed into the combustor 7, and the small-diameter crushed material CB1 is not fed. The third pattern is an emergency operation of the processing device 5, in which, in the event that small-diameter crushed material CB1 is no longer sent to the feeding section 50, only the pulverized mixture MB is used to continue combustion in the combustor 7. In this case, preferably, large-diameter crushed material CB2 and coal RC are supplied to the pulverizer 35 so that the amount of biomass in the pulverized mixture MB becomes the target biomass amount.

[0047] [Biomass Issues] Before explaining the effects of the processing device 5, we will explain the following three issues that must be recognized when atomizing biomass pellets BM. The processing device 5 was designed to address the following three issues. Problem 1: Biomass is not very brittle, so a large amount of power is required to crush it. Issue 2: Biomass acts as a buffer, hindering the efficiency of crushing into pulverized coal PC. Issue 3: Biomass is highly abrasive, resulting in a short lifespan for the grinding elements of the grinder.

[0048] <Issue 1: Crusher power> Biomass pellets BM and coal RC can also be fed into the mixing and crushing section 30 for crushing. However, biomass is not easily crushed by shearing due to its low brittleness, and its high friction coefficient requires a large amount of power for crushing. Therefore, when biomass pellets BM are mixed with coal RC and crushed, the power (electricity) input to the crusher increases. It has been reported that mixing 3 wt.% of biomass with coal RC increases the crusher's power consumption by 130% (Non-Patent Document 1). If the amount of biomass pellets BM mixed with coal RC exceeds 3 wt.%, for example, when fed into the crusher 35, the electric motor that drives the crusher 35 may become overloaded and stop operating.

[0049] <Issue 2: Poor pulverization of pulverized coal PC> To effectively utilize biomass, it is desirable to increase the amount of biomass mixed with coal RC. However, the biomass, which is not brittle, acts as a buffer and the crushing force may not reach the coal RC. Therefore, the desired particle size of pulverized coal PC, for example, an average particle size (Dp50) of 40 μm, cannot be obtained. This may reduce the combustion efficiency of the combustor 7 and result in the generation of unburned carbon. It has been reported that the fineness of coal (= sieve passing rate) when no wood is added (= 0%) is 99.7% when passing through a 100 mesh (= 150 μm) sieve, whereas when the wood mixing rate is increased to 3%, the fineness of coal decreases to about 99.2% (Non-Patent Document 1).

[0050] <Issue 3: Reducing the lifespan of pulverizer elements> For example, when a vertical crusher is used as the crusher 35, there is a demand for suppressing the wear of the crushing rollers and crushing table that are components of the crusher 35, thereby reducing the running costs of the combustion system 1 including the processing device 5. However, the cellulose component contained in biomass is extremely abrasive. Abrasiveness here refers to a measure of whether or not a mating material is easily worn. According to the inventors' findings, when 3 wt.% biomass is added to RC coal and crushed, the lifespan of the crushing rollers and crushing table of a vertical crusher is reduced to one-third to one-fifth of that of a normal RC coal without biomass. Replacing worn crushing rollers and crushing tables can take about a week per crusher. When four or five vertical crushers are installed in one boiler, the time required to replace the crusher components becomes significant.

[0051] <Solutions for Issues 1 to 3> As explained above, reducing the amount of biomass (biomass pellets BM) mixed with the coal RC and pulverized can solve or mitigate problems 1 to 3. However, this reduces the amount of biomass available for combustion, preventing effective use of the biomass. The processing device 5 provides a solution to this bottleneck, which will be disclosed in the next section on the effects of the processing device 5.

[0052] [Effects of the processing device 5] The processing device 5 provides the following first, second, third, fourth and fifth effects. The first to third effects correspond to the above-mentioned problems 1 to 3.

[0053] <First effect> In the processing device 5, the crushing and classification section 10 crushes and classifies the biomass pellets BM, separating them into small-diameter crushed material CB1 and large-diameter crushed material CB2. Only the large-diameter crushed material CB2 is mixed with the coal RC and crushed. Therefore, the amount of biomass mixed with the coal RC and crushed in the mixing and crushing section 30 can be reduced, and the increase in power input to the crusher 35 can be reduced. This prevents the electric motor that drives the crusher 35 from being overloaded and tripping. The amount of biomass fed into the combustor 7 is the total amount of small-diameter crushed material CB1 and large-diameter crushed material CB2, and can be at least the same as the amount of biomass pellets BM fed in. Furthermore, the processing device 5 can increase the amount of biomass that can be fed into the combustor 7 and burned compared to conventional combustion systems that mix and crush coal and biomass, ensuring effective use of biomass. As described above, the processing device 5 can solve the first problem while also making effective use of biomass.

[0054] <Second effect> As described in the first effect, the processing device 5 can reduce the amount of biomass mixed and pulverized with the coal RC in the mixing and pulverizing section 30. Therefore, the amount of buffer material used when pulverizing the coal RC can be reduced, which can reduce the interference with the pulverization of the pulverized coal PC in the pulverizer 35. Since the amount of biomass fed into the combustor 7 is the same as that of the first effect, the treatment device 5 can solve the second problem while also making effective use of biomass.

[0055] <Third effect> As described in the first effect, the processing device 5 can reduce the amount of biomass mixed and crushed with the coal RC in the mixing and crushing section 30. Therefore, the processing device 5 can reduce the amount of biomass that comes into contact with the elements of the crusher 35, such as the crushing rollers and crushing table, thereby reducing the amount of wear on these elements and thereby reducing the running costs of the combustion system 1.

[0056] <Fourth effect> The processing unit 5 is provided with a buffer function as will be explained below. The processing device 5 includes a fourth hopper 13 for storing biomass pellets BM, a first hopper 22 for storing small-diameter crushed material CB1, a second hopper 26 for storing large-diameter crushed material CB2, and a third hopper 33 for storing coal RC. Therefore, by crushing a large amount of biomass pellets BM in the processing device 5 and storing a large amount of small-diameter crushed material CB1 in the first hopper 22, any amount of biomass (small-diameter crushed material CB1) can be fed into the combustor 7 while taking into account the overall combustion system 1. For example, to increase the amount of biomass, the mixing ratio with respect to the pulverized coal PC can be increased to 5% or 7%, and to decrease the amount of biomass, the mixing ratio with respect to the pulverized coal PC can be decreased to 1% or 2%. This allows the amount of small-diameter crushed material CB1 to be adjusted as needed depending on the combustibility and operating conditions of the combustor 7, enabling efficient and flexible operation of the combustion system 1. In addition to the operating status of the combustion system 1, even if there is a problem that makes it impossible to prepare the biomass raw material, biomass pellets BM, the combustion system 1 can be operated for the time being using the biomass pellets BM, small-diameter crushed material CB1 and large-diameter crushed material CB2 stored in the fourth hopper 13, the first hopper 22 and the second hopper 26.

[0057] <5th effect> The processing device 5 can reliably ensure the transportation and on-site storage of biomass pellets BM, as described below. Biomass pellets BM can significantly reduce transportation costs by increasing the bulk density (=reducing the volume) compared to biomass chips. In other words, when the bulk density of biomass chips is 80-120 kg / m 3 On the other hand, biomass pellets BM can be cut and compressed to a bulk density of 500-600 kg / m 3 It has been enlarged to. The processing device 5 takes advantage of the large bulk density of the biomass pellets BM, crushes the biomass pellets BM at the site where they are used, classifies them according to a predetermined value, and feeds one of the small-diameter crushed materials CB1 directly into the combustor 7, while feeding the other large-diameter crushed materials CB2 into the crusher 35. Crushing and classification are carried out on-site using biomass pellets BM, so transportation from the biomass production site to the site of use, storage on-site, and even operation can be reliably guaranteed.

[0058] The processing device 5 has been described above as a preferred embodiment of the present invention, but it is possible to select and discard the configurations described in the above embodiment or to change them to other configurations as appropriate without departing from the spirit of the present invention.

[0059] [Attachment of circulation route: See Figure 5] In this embodiment, a circulation path 16 can be provided to return a portion of the large diameter crushed material CB2 to the crusher 15 for repeated crushing, rather than transporting the portion to the mixing and crushing section 30. In this way, the biomass that was the large diameter crushed material CB2 becomes small diameter crushed material CB1, and can be fed into the combustor 7 without being mixed with the coal RC.

[0060] As an example, let's assume that the amount of biomass pellets BM fed into the crusher 15 is 100, and the amount of initially classified small-diameter crushed material CB1 and large-diameter crushed material CB2 is 50:50. Then, let's assume that half of the 50 large-diameter crushed material CB2, or 25, is returned to the crusher 15 and crushed, and half of that remains as small-diameter crushed material CB1 and the remaining half remains as large-diameter crushed material CB2. In this case, 62.5% of the fed biomass pellets BM becomes small-diameter crushed material CB1 and 37.5% becomes large-diameter crushed material CB2, thereby reducing the amount of biomass mixed and crushed with the coal RC in the mixing and crushing section 30. Therefore, the treatment device 5 equipped with the circulation path 16 can more significantly achieve the first to third effects described above.

[0061] The treatment device of the present invention can be applied not only to the installation of a new combustion system but also to an existing combustion system. In particular, even a combustion system equipped with a combustor dedicated to coal can be operated as a biomass combustion system by adding the treatment device of the present invention. [Explanation of symbols]

[0062] 1 Combustion system 5 Processing equipment 7. Combustor 10 Crushing and classification department 11 Conveyor 13 Fourth Hopper 15 Crusher 16 Circulation Route 17 Classifier 17A Loading entrance 17B 1st export exit 17C 2nd exit 18 First transport route 19 Blower 21 Collector 22 First Hopper 23 1st weighing machine 25 Second transport route 26 Second Hopper 27 Second weighing machine 30 Mixing and grinding section 31 Conveyor 33 Third Hopper 34 Third weighing machine 35 Crusher 37 Supply fan 50 Input section 51 Fuel pipe 53 Merging Route 54 Blower 55 Ejector BM Biomass Pellets CB crushed material CB1 Small diameter crushed material CB2 Large diameter crushed material PB crushed biomass RC coal PC pulverized coal MB Grinding Mixture JO Confluence

Claims

1. a crushing and classifying unit that classifies crushed materials obtained by crushing biomass pellets based on a threshold value to obtain small-diameter crushed materials and large-diameter crushed materials having particle sizes larger than those of the small-diameter crushed materials; a mixing and crushing section for mixing and crushing the large-diameter crushed material and coal to obtain a crushed mixture; and an input section that inputs the small-diameter crushed material and the crushed mixture into a combustor.

2. The crushing and classifying unit a first hopper capable of storing the small-diameter crushed material; The small-diameter crushed material stored in the first hopper is charged into the combustor through the charging section. The biomass treatment device according to claim 1 .

3. A fixed amount of the small size crushed material is introduced into the combustor, or Varying amounts of the small size crushed material are fed into the combustor. The biomass treatment device according to claim 2 .

4. The crushing and classifying unit a second hopper capable of storing the large-diameter crushed material; The large-diameter crushed material stored in the second hopper and the coal are mixed and crushed to produce a crushed mixture, which is then fed into the combustor via the feeding section. The biomass treatment device according to claim 1 .

5. A quantity of the pulverized mixture is introduced into the combustor; or Varying amounts of the pulverized mixture are introduced into the combustor. The biomass treatment device according to any one of claims 1 to 4.

6. The crushing and classifying unit a crusher for crushing the biomass pellets; a classifier that classifies the crushed material produced by the crusher into the small-diameter crushed material and the large-diameter crushed material; A circulation path for sending the large diameter crushed material classified by the classifier toward the crusher, The biomass treatment device according to claim 1 .

7. A first step of classifying crushed material obtained by crushing biomass pellets using a threshold value to obtain small-diameter crushed material and large-diameter crushed material larger in size than the small-diameter crushed material; a second step of mixing the large-diameter crushed material obtained in the first step with coal and crushing the mixture to obtain a crushed mixture; a third step of feeding the small-diameter crushed material obtained in the first step and the crushed mixture obtained in the second step into a combustor; A method for processing biomass comprising:

8. The threshold value is Set in the range of 3.0 to 4.0 mm. The method for treating biomass according to claim 7.

9. the combustor; The biomass treatment device according to claim 1; A combustion system comprising:

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