JP3511421B2 - Method and apparatus for estimating flow rate fluctuation in staged grinding system - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stepwise crushing process of grains such as wheat flour and other crushed products, in which fluctuations in the flow rate of the crushed products in each crushing route when the grinding conditions such as the crushing degree are changed. A method and apparatus for estimating.

[0002]

2. Description of the Related Art In the process of milling grains such as wheat,
By combining a roll-type crusher and a multi-stage classification type sieving machine, sieving is repeated while gradually crushing the grain, and the endosperm at the center of the grain is taken out. The pulverized product pulverized in this way is classified into several types, and each is sent to a separate pulverizer, but in some cases, several pulverized products may be collectively processed. Such a milling method is called a step milling method, and unlike general closed circuit crushing and open circuit crushing, the number of crushing paths is very large, and it is difficult to control mainly the flow rate control, Until now, almost no actual control has been performed.

In the actual wheat milling process by this stepwise milling method, since the number of crushing paths is several hundreds, the crushing degree is changed, the quality of raw wheat is changed, and the roll gap is changed. It is difficult to accurately grasp the flow rate fluctuations in each crushing route. In fact, it is operated by many years of experience and intuition of a skilled operator, and the crushing system operates in an orderly manner and rarely causes a failure.

[0004]

However, in such a pulverization system by the stepwise milling method, in addition to the above factors, the flow rate of the pulverization route such as the water content of the raw grain, the average particle diameter of the stock, the composition of the stock, etc. Since there are many factors that have an influence, there is a demand for a method for promptly grasping the fluctuations in the flow rate of the crushing path due to these factors without actually operating the system.

The present invention has been made in view of the above points, and an object thereof is to promptly estimate a flow rate fluctuation in a crushing route due to an artificial or non-artificial factor in a crushing system by a stepwise milling method, It is an object of the present invention to provide an estimation method and an estimation device for a flow rate fluctuation of a pulverized material that enables an unskilled person to perform an accurate operation.

[0006]

[Means for Solving the Problems] In order to achieve the above object, the present invention corresponds to a classifying stage of a sifter in each process, when the crushing step by one set of crusher and sieving machine is a unit process. Prepare a flow rate distribution matrix that is a matrix with the flow rate when the pulverized material generated by the process flows out to another process, and calculate each element of the matrix by a predetermined arithmetic expression based on the grinding conditions Was used to estimate the flow rate of the pulverized material flowing out from each process in the pulverization system.

[0007]

According to the present invention, when the grinding condition is set, each element of the matrix is calculated based on a predetermined calculation formula. Each element of the matrix is estimated as the flow rate of crushed material from each process of the staged comminution system to other downstream processes.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described below with reference to the drawings.

Prior to the description of the embodiments, the basic concept of the flow fluctuation estimating method according to the present invention will be described.

Conventionally, a flour mill for test milling (test mill) has been known as an apparatus for evaluating wheat. This test mill is an apparatus for milling wheat as a sample by combining a roll-type crusher and a sieving machine in several stages. The example shown in FIG. 8 is a roll-type crusher having three brake rolls 1B to 3B. And three sets of midring rolls arranged on the downstream side, and a sieve (shifter) 1 combined with each roll.
It is composed of S _B , 2S _B , 3S _B , 1S _M , 2S _M , and 3S _M.

On the surface of the brake rolls 1B to 3B, 3 to 3
The tooth is inclined by 7 °, and its main role is to open the outer skin of wheat, take out the endosperm, and scrape off the endosperm remaining inside the developed skin. On the other hand, the surfaces of the midring rolls 1M to 3M are roughened, and their main role is to crush the endosperm part scraped off by the brake roll. The roll gap between the brake roll and the midling roll can be adjusted accurately. The sieving machines 1S _B , 2S _B , 3S _B and 3S _M are provided with two-stage screens a and b having meshes of the size (unit: μm) as shown in the drawing, and sieving machines 1S _M and 2S _M are shown in the drawing. Three-stage sieve a having a mesh of a specified size (unit: μm),
b and c are provided.

This test mill has brake rolls 1B-3
B, Midring Roll 1M-3M, Sieve 1S _B , 2S
_{With B} , 3S _B , 1S _M , 2S _M , 3S _M , wheat grains are 3 types of flour (up flour) in the brake system, 3 types of flour (up flour) in the midling system, and large bran and small bran. Separate into 8 final mills. The raw material and stock are all transported by air in the test mill, and after the sample is put into the hopper, the rest is automatically milled. The crushing time is 15 to 30 minutes per 1 kg.

The crushing process by this test mill will be briefly described.

Wheat grains are put into the brake roll 1B from a hopper (not shown). Flour milled by the brake roll 1B enters the total amount sifter 1S _B, sieving a, it is classified by particle size into three types of passages by b. That is, a part of the material passing through the sieves a and b is sent to the brake roll 2B via the path A, and the material passing through both a and b is taken out as "1B upstream powder" and passed through only the sieve a. Is sent to the midring roll 1M. The flow rate of each passage will vary by sieve mesh of grindability and Sifter 1S _B of the brake roll 1B, about the grinding varies even in the same roll operation by factors such as the order tempered wheat.

Classification operation by the brake roll 2B and the sieve 2S _B , the midring roll 1M and the sieve 1S _M ,
Subsequent brake roll 3B and sieve 3S _B , midring roll 2M and sieve 2S _M , midring roll 3
The classification operation by M and the sieving machine 3S _M is the same except that the mesh of the screen is different, and thus the description thereof is omitted.

By the way, the inventors of the present invention have a "matrix" in which the flow rate of flour in each passage in the crushing process of wheat by the test mill is such that the destination of the passage is "row" and the inflow side passage is "column". I realized that it can be expressed as an element of. When this matrix is called a "flow rate distribution matrix" D, the flow rate distribution matrix D is composed of elements d _ij as shown in FIG. 1, and if a crushing process by a set of rolls and a sieve is a unit process, the element d _ij represents the flow rate of ground wheat directly flowing from process i to process j, and the sum of (i + 1) rows is process i.
, And the sum of each column represents the total input to process i. Further, in the milling process consisting of n processes, this flow distribution matrix D is (n
The matrix has +1) rows and (n + 2) columns.

[0017] The amount of wheat grain to be introduced now from the hopper to the brake roll 1B and x _1B, (1) the passage to be sent from the brake roll 1B and Sifter 1S _B to the brake roll 2B flow x
_{2B (1B)} = y _1B2B · x _1B Flow rate of passage flour sent to 1M _{midring roll} x _{1M (1B)} = y _1B1M · x _1B 1B Amount of passage extracted as upstream powder F x
_{F (1B)} = y _1BF · x _1B . Here, for example, y _1B2B
Is the rate of passages sent from process 1B to process 2B. The same applies hereinafter. Similarly, the passage to be sent to the brake roll 3B (2) brake rolls 2B and Sifter 2B _S flow x
_{3B (2B)} = y _2B3B · x _2B Flow rate of passage sent to 1M _{midring roll} x
_{1M (2B)} = y _2B1M · x _2B 2B Passage amount taken out as powder F x x
_{F (2B)} = y _2BF · x _2B . Similarly (3) from the brake roll 3B and Sifter 3B _S passages sent to Mydrin growl 1M flow x
_{1M (3B) = y 3B1M ·} x 3B 3B amount of passage taken out as an upstream powder F x
_{F (3B)} = y _3BF · x _3B Amount of passage extracted as large bran BR x _BR =
It becomes y _3BBR1 x _3B . On the other hand, (4) Flow rate x of the passage sent from the midring roll 1M and the sieving machine 1S _M to the midling roll 2M x
_{2M (1M) = y 1M2M ·} x 1M 1M amount of passage taken out as an upstream powder F x
_{F (1M)} = y _1MF · x _1M . (5) Flow rate x of the passage sent from the midring roll 2M and the sifter 2S _M to the midling roll 3M x
_{3M (2M) = y 2M3M ·} x 2M 2M amount of passage taken out as an upstream powder F x
_{F (2M)} = y _2MF · x _2M . (6) Amount of passage x extracted as 3M upstream powder F from the midring roll 3M and the sieving machine 3S _M x
_{F (3M)} = y _3MF · x _3M Amount of passage taken out as small bran BR x _BR2
= Y _3MBR · x _3M .

Therefore, the elements of the flow rate distribution matrix D are expressed by the following equation 1.

[0019]

## EQU1 ## d ₁₁ = x _1B d ₂₂ = y _1B2B · x _1B , d ₂₄ = y _1B1M · x _1B , d ₂₇ = y _1BF · x _1B d ₃₃ = y _2B3B · x _2B , d ₃₄ = y _2B1M · _{x 2B, d 37 = y 2BF} · x 2B d 44 = y 3B1M · x 3B, d 47 = y 3BF · x 3B, d 48 = y 3BBR · x 3B d 55 = y 1M2M · x 1M, d 57 = y _{1MF · x 1M d 66 = y} 2M3M · x 2M, raw wheat to be put into _{d 67 = y 2MF · x 2M} d 77 = y 3MF · x 3M, d 78 = y 3BBR · x 3M further brake roll 1b from the hopper When the amount of grains is V, the total input to each process can be expressed by the following equation 2.

[0020]

[ _Formula 2] x _1B = V, x _1M = (y _1B1M · x _1B ) + (y _2B1M · x _2B ) + (y _3B1M · x _3B ) x _2B = y _1B2B · x _1B , x _2M = y _1M2M · _{x 1M, x 3B = y 2B3B} · x 2B, whereas _{x 3M = y 2M3M · x 2M} , the present inventors have found that the a grinding wheat flowing into the process flow (the amount of stock), the composition of a grinding wheat, minced Outflow stock properties of the process when changing grinding conditions such as average particle size of crushed wheat, water content of raw wheat, roll interval of roll machine of process (flow distribution ratio to next process, composition, average particle size ), The following experiment was carried out.

In the experiment, the variation of the tempering of the raw wheat grain was substituted by the difference of the raw water content, and the target water content at the time of grinding was set to 14%, 16% and 18%, and the roll gap was There were 3 types of tightening, standard and loosening. The roll gaps at each stage are as shown in Table 1. Outflow stock properties were measured for a total of 9 conditions in which these were combined. The grinding time is 15 minutes per Kg, and the sample used for one experiment is about 10 Kg.

After starting the operation of the test mill and waiting for the output of each final product to stabilize, per unit time per route G, F, E, D, C, B, A shown in FIG. Was measured. By measuring from the downstream path in this way, it is possible to avoid that the flow fluctuation that occurs on the downstream side at the time of stock collection affects the measured value. Using the measurement results of the flow rate and the particle size distribution, the flow rate value and the average particle size of the stock of all paths in the test mill were calculated for each experiment.
The average particle size was represented by 50% particle size (particle size with respect to 50% of weight cumulative distribution). In addition, the "composition" of each stock was calculated using the stock flow rate value of the first stage downstream for each process. The term "composition" as used herein refers to the proportion of the portion of each stock that finally reaches the upstream powder.

Some of the results of the experiment are shown in FIG. 3 in the form of Table 1. Table 1 is an example of Process 2B. In the experiment shown in Table 1, for example, the composition of the stock for the process (hereinafter referred to as “process 3B”) containing the brake roll 3B at the raw water content of 16.1% is 16.4% because the stock for the process 3B is 16.4%. It means that 4% became powder.

The results of the partial correlation analysis and the multiple correlation analysis carried out in order to know the effect of each grinding condition on each outflow stock property from the experimental data shown in Table 1 are shown in Table 2 in FIG. After considering the results, the present inventors formulate the relationship between the grinding conditions and each outflow stock property, and set the outflow stock property for each process as an objective variable and the grinding condition as an explanatory variable. A multiple regression equation represented by the equation 3 was assumed. A list of explanatory variables is shown in Table 3 in FIG. 5, and the partial regression coefficient β and the constant α of the multiple regression equation obtained from the measurement data are shown in Table 4 in FIG.

[0025]

[Equation 3] The case is the composition, and the case is the average particle diameter. k represents a grinding condition, and takes 1 to 5 representing the above-mentioned 5 grinding conditions.

In this way, the element y _ij of the equation for _obtaining each element d _ij of the flow rate distribution matrix D can be obtained.

Next, in order to confirm that the above multiple regression equation is appropriate, the present inventor obtains a regression value by the above multiple regression equation and compares it with an actual measurement value for the flow distribution ratio of the outflow stock of each process. I compared them. This result is shown in FIG. As is clear from this figure, since the correlation is sufficiently high, it was confirmed that the flow rate change of the outflow stock due to the grinding conditions can be obtained by using the above multiple regression equation.

FIG. 2 is a block diagram showing the structure of the estimating device for estimating the flow rate fluctuation in the present invention.

This estimating device estimates the flow rate fluctuation of the pulverized material on the assumption that the test mill shown in FIG. 8 is used. In FIG. 2, 1 is the amount of inflow stock,
It is a grinding condition input unit for inputting grinding conditions such as the composition, average particle size, water content, and roll gap of the roll machine of each process, which is composed of a keyboard and a mouse. Reference numeral 2 is a memory for storing the expressions represented by the above formulas 1, 2, and 3 which are operation expressions necessary for calculating each element _dij of the flow rate distribution matrix D shown in FIG. Based on the grinding condition input from the condition input unit 1, each calculation unit 4 which calculates each element d _ij of the flow rate distribution matrix D, that is, the flow rate of the outflow stock, using the calculation formula stored in the memory 2, is a calculation unit. For example, it is a display unit having a liquid crystal structure for displaying the flow rate of the outflow stock calculated by 3.

In the memory 2, the coefficients α _ij and β _{ij of the} multiple regression equation defined by the equation 3 as the element y _ij of the equation for _obtaining each element d _ij of the flow rate distribution matrix D (for example, as shown in Table 4 It is calculated by statistical means from the actual measurement value of the test mill assumed to be used).

Next, a method for estimating flow rate fluctuations when crushing wheat grains using the test mill shown in FIG. 8 will be described.

First, when, for example, V is set as the flow rate x _{1B of} wheat grains to be fed to the brake roll 1B from the grinding condition input unit 1, the arithmetic unit 2 uses the arithmetic expressions of the equations 1 and 2 stored in the memory 2. Therefore, the flow distribution matrix D
The elements d ₂₂ to d ₇₈ of are calculated. As a result, the flow rate of stock flowing out from each process is obtained, and the display unit 4
Is displayed in.

Here, from the grinding condition input unit 1 to the grinding condition 1
Assuming that the standard roll gap of the brake roll 1B is changed from the standard 470 μm to the looser 520 μm, the arithmetic unit 3 reads the multiple regression equation stored in the memory 2 to obtain a value y for the roll gap 520 μm. _ij is calculated, and the elements d ₂₂ to d _{78 of the} flow rate distribution matrix D are calculated according to the mathematical expressions of Equations 1 and 2. As a result, the flow rate of the stock flowing out from each process becomes a value different from the values so far, and is displayed on the display unit 4. The same applies when other grinding conditions are changed.

As described above, the flow rate of the stock flowing out from each process can be immediately known by arbitrarily changing the grinding conditions.

Although the above embodiment has been described by exemplifying the crushing of wheat grains, the present invention is not limited to this, and can be similarly applied to the case of crushing other crushed products, and the same effect can be obtained. .

[0036]

As described above, according to the present invention,
It is possible to quickly calculate and grasp the flow rate fluctuation of the outflow stock of each process in the pulverization system when the pulverization conditions are changed, without actually operating the stage pulverization system. As a result, experienced operators have the experience and intuition of system control when the grinding conditions such as the input amount and composition or the degree of tempering of crushed material such as wheat grains, or the crushing degree by the crusher of each process change. You can do it quickly and reliably without relying on it. In particular, it is effective in quality control and operation in the wheat milling process in which the number of crushing paths is very large.

[Brief description of drawings]

FIG. 1 shows a flow distribution matrix that is the basis of a method for estimating flow fluctuation according to the present invention.

FIG. 2 is a block diagram of an apparatus for implementing the method for estimating flow rate fluctuation according to the present invention.

FIG. 3 shows the effluent stock properties of Process 2B in an experiment conducted under different grinding conditions as Table 1.

FIG. 4 shows a partial correlation coefficient and a multiple correlation coefficient between the flow distribution ratio and each grinding condition as an example of outflow stock properties.

FIG. 5 shows explanatory variables of the multiple regression equation as Table 3 for each destination process.

FIG. 6 shows a partial regression coefficient of a multiple regression equation with respect to a flow distribution ratio as an example of an outflow stock property.

FIG. 7 is a diagram comparing a regression value based on a multiple regression equation and an actual measurement value with respect to an outflow stock in each process.

FIG. 8 shows a schematic configuration of a mill for test milling to which a flow rate fluctuation estimating method according to the present invention is applied.

[Explanation of symbols]

1 Grinding condition input section 2 memory 3 operation unit 4 Display

─────────────────────────────────────────────────── ─── Continuation of front page (56) References JP-A-1-135546 (JP, A) JP-A-6-91186 (JP, A) JP-B-36-12166 (JP, B1) (58) Field (Int.Cl. ⁷ , DB name) B02C 25/00 B02C 4/06

Claims (4)

(57) [Claims] 1. A step-type crushing system comprising a plurality of combinations of a crusher and a sieving machine, the plurality of combinations being arranged in parallel and / or in series, and one set of the crusher and the sieving machine. When the crushing process by the machine is used as a unit process, a flow rate distribution matrix that is a matrix with the flow rate when the crushed product generated corresponding to the classifying stage of the sifter in each process flows out to another process is prepared Then, the flow rate fluctuation estimation method is characterized in that the flow rate of the pulverized material flowing out from each process in the pulverization system is estimated by calculating each element of the matrix with a predetermined arithmetic expression based on the pulverization conditions. 2. The method for estimating flow rate fluctuation according to claim 1, wherein the stepwise pulverizing method in which a roll pulverizer and a sieving machine are combined is a wheat flour milling method. 3. The method for estimating a flow rate fluctuation according to claim 1, wherein the predetermined arithmetic expression includes a multiple regression equation in which a property of a pulverized product flowing out from each process is an objective variable and a pulverizing condition is an explanatory variable. . 4. A stepwise crushing system comprising a plurality of combinations of a crusher and a sieving machine, the plurality of combinations being arranged in parallel and / or in series, and one set of the crusher and the sieving machine. When the crushing process by the machine is used as a unit process, a crushing condition input unit for inputting the crushing condition of the crushed product, a storage unit for storing an arithmetic expression for calculating the flow rate of the crushed product flowing out from each process, An arithmetic unit for calculating the flow rate of the pulverized material flowing out from each process based on the arithmetic expression stored in the storage unit when a predetermined crushing condition is input from the crushing condition input unit, and an arithmetic operation by the arithmetic unit And a display unit for displaying the measured flow rate.