JPH0975760A - Controller for pulverizer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the desired quantity of a product by a pulverizer with good responsiveness by following up the load of the pulverizer even when the load is rapidly changed and to prevent the occurrence of wear and vibration due to the excess and deficiency of pressurizing force and the inconguity of classifying characteristics. SOLUTION: The same manipulated variables as those of an actual pulverizer are given to a pulverizer on-line dynamic characteristic simulation model to calculate the retention quantity of a material to be pulverized on a normal retention means, the particle size distribution of the material to be pulverized to be supplied to a consumer, and the particle size distribution of the material to be pulverized at the inlet of a classifying means by a first to a third arithmetic part 20-22. From these calculated data, a pressurizing force command signal to be applied to a pressurizing force adjusting means and a classifying characteristics command signal to be applied to a classifying characteristics adjusting means are obtained and stored in a memory part 23 in order. From the former calculated values stored in the memory part 23, an ordinary differential equation is solved by the first to the third arithmetic part 20-22 to calculate the present values.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for a crusher, and more particularly to realizing a good control response of the amount of product to be crushed and the particle size distribution and preventing the occurrence of a crusher failure. It relates to a suitable control device.

[0002]

2. Description of the Related Art FIG. 4 shows a conventionally known crusher and a control device for the crusher. As shown in this figure,
The crusher of this example has a turntable 6 which is a means for holding a material to be crushed, which is provided in the housing 20, a motor 5 which drives the turntable 6 to rotate, and a crusher which is pressed against the outer peripheral surface of the upper surface of the turntable 6. Crushing roller 8 as means,
Pressurizing force adjusting means 14 for adjusting the pressing force of the crushing roller 8 to the turntable 6, and the housing 2
Carrier air inlet 21 communicating with the lower part of 0 and outlet 2 of the crusher product opened at the upper part of the housing 20.
2, a vane 12 as a classifier provided on the upper part of the housing 20, an adjusting means 15 for the vane 12, and a feeder 2 for supplying the crushed raw material 1 to the turntable 6.
And a hopper 4 for guiding the material to be crushed 1 supplied from the feeder 2 to the substantially central portion of the upper surface of the turntable 6.

The raw material 1 to be ground conveyed by the feeder 2 is rotated by a turntable 6 via a hopper 4.
Supplied on. The raw material 1 to be crushed supplied onto the turntable 6 is sequentially transferred in the outer peripheral direction of the turntable 6 by the centrifugal force of the turntable 6 and is crushed by the crushing roller 8. The crushed raw material is blown upward by the carrier air 9 introduced from the carrier air introduction port 21. Vane 12 out of the crushed objects blown up
An object to be crushed (a crusher product) 10 having a particle size equal to or smaller than the set particle size is transported to a demand destination through a vane 12 and a discharge port 22. On the other hand, among the crushed objects blown up, the crushed objects having a particle size equal to or larger than the particle size set by the vane 12 are separated from the crusher product 10 by the vane 12,
The centrifugal force classification and collection object 13 becomes the object 13 and returns to the turntable 6 again. A crushed product with a particle size larger than this,
Since the gravity is large, it falls before reaching the vane 12, and becomes the gravity-classified collected object to be crushed 11, and the turntable 6 again.
Return to Therefore, the turntable 6 usually holds a mixture of the raw material to be ground 1, the gravity-classified and collected ground material 11, and the centrifugal-force-classified and collected ground material 13.

The feeder 2 adjusts the transportation speed of the raw material 1 to be ground according to a feeder command signal 3 from a signal output unit (not shown), and supplies the hopper 4 with the raw material 1 in an amount proportional to the command signal 3. The feeder command signal 3 is adjusted so that the flow rate of the crusher product 10 is not excessive or insufficient.
In this case, when the flow rate of the crusher product 10 can be measured online, the deviation between the measured value of the product flow rate and the target value is P
It may be adjusted by I adjustment. However, in many cases, since it is difficult to measure the flow rate of the crusher product 10 online, it is possible to measure the flow rate of the crusher product 10 and adjust the state quantity that is in a causal relationship. Reach the goal. For example, when the raw material to be crushed is coal and the customer is a drum boiler, the steam pressure of the drum boiler has a direct causal relationship with the flow rate of pulverized coal supplied to the burner, so the drum pressure is less than the target value. The PI command of the deviation is adjusted so that the feeder command signal 3 is adjusted.

On the other hand, the pressing force command signal 16 given to the pressing force adjusting means 14 is given by a function element 18. That is, since the crushing capacity of the crusher increases / decreases almost in proportion to the pressing force of the crushing roller 8 against the turntable 6, the pressing force command signal 16 changes to the supply amount of the material to be crushed 1 as indicated by the function element 18. It is given to increase or decrease the applied pressure in proportion. Further, the classification characteristic command signal 17 given to the vane adjusting means 15 is given by the function element 19. That is, in general, the crusher has a large supply amount of the raw material 1 to be crushed, and therefore the higher the load operation, the worse the particle size distribution of the crusher product 10 (the coarser particles increase). The signal 17 is a function element 19
As shown in, the classification setting is narrowed (the swirling force is increased and the collection efficiency of coarse particles is increased) as the supply amount of the raw material 1 to be ground increases.

[0006] Further, depending on the circumstances of the customer, there are cases where further improvement of the granularity is required during low load operation.
The setting method of the function elements 18 and 19 may be difficult to discuss uniformly as described above, but the pressing force command signal 16 and the classification characteristic command signal 17 depending on the supply amount of the raw material to be ground.
It is common in that it is a configuration that adjusts.

[0007]

The control circuit according to the prior art described above exhibits practically sufficient performance when the load of the crusher is constant or the rate of change of the load is low. For example, the response time constant of the crusher product when the supply amount of the crushed raw material 1 to the crusher is changed in a stepwise manner is T
When [min] is set, the change rate is 1 / (10T) [% / min]
Less than or equal to the level (usually T = 1 to 2 [min], so 0.05 to
In the case of 0.1 [% / min] or less), practically sufficient performance can be exhibited.

However, recently, 5 to 10 [% / min]
(25 from 50% load to 100% load)
It is necessary to change the load at a high speed (load change rate) of about 5 [minutes], and the following problems occur when the above-mentioned conventional technique is used.

In the high-speed load change region, the amount of the held object to be ground 7 is not uniquely determined as a function of the supply amount of the material to be ground 1, and therefore the amount of the object to be ground 7 held on the turntable 6 and the pressure command signal 16 are applied. Are unbalanced, resulting in economic inconvenience such as increased power consumption, increased wear of the turntable 6 and the crushing roller 8, and further engineering inconvenience such as increased vibration of the crusher, and the grain size of the crusher product 10. There is a functional inconvenience that the distribution is deteriorated and the increase of the crusher product 10 to the customer is delayed. That is, originally, the increase or decrease of the held crushed object 7 increases or decreases the amount of the crusher product 10, and the deviation between the raw material supply amount and the crusher product 10 increases or decreases the amount of the held crushed object 7. Therefore, due to the self-equilibrium property, the amount of the retained object to be ground 7 converges to a value commensurate with the supply amount of the raw material 1 when a sufficient time has passed, but this action cannot catch up in the high speed load change region. Therefore, it can be considered that the flow rate of the object to be crushed passing between the turntable 6 and the crushing roller 8 is always proportional to the amount of the object to be crushed 7 held, whereas the pressing force command signal 16 that controls the ability to process this is Since it is given by the function element 18 as a function of the feed amount of the crushed raw material 1, the actual amount of the crushed raw material 7 held on the turntable 6 and the pressing force command signal 16 become unbalanced. When such an imbalance occurs, when the amount of the held object to be ground 7 is too large as compared with the material to be ground 1 on the basis of the convergence value at the time of self-equilibrium described above, between the turntable 6 and the grinding roller 8. The pressing force command signal 16 becomes too small with respect to the flow rate of the crushed object passing through, causing deterioration of the particle size distribution after crushing. Typically, when the high-speed load is increased, the feeder command signal 3 is generally given by PI control from a higher-order control device (not shown), so that its change often includes overshoot. In addition, a so-called acceleration signal may be used to intentionally overshoot. In such a case, the amount of the held object to be crushed 7 increases rapidly with the overshoot of the supply amount of the crushed raw material 1, but the pressing force command signal 16 is also increased by the decreased feeder command signal 3 after the downward phase of the overshoot. As a result of the decrease, the above-mentioned imbalance is caused, the particle size distribution of the crusher product 10 is deteriorated, the flow rate of the crusher product 10 passing through the vane 12, which is a classification means, is sluggish, and the crusher product 10 to the customer is reduced.
Delays the increase. On the contrary, when the pressing force command signal 16 becomes excessive compared to the amount of the held crushed object 7, the unnecessary crushing pressure acts on the crushing roller 8, consuming unnecessary crushing power, Also, turntable 6 and crushing roller 8
Since it becomes easy to contact with, the disadvantages such as increased wear of the turntable 6 and the crushing roller 8 and vibration of the crusher occur.

Similarly to the above, in the high-speed load change region, the amount of the held object to be ground 7 is not uniquely determined as a function of the supply amount of the material to be ground 1, and therefore the amount of the object to be held 7 on the turntable 6 is There is an inconvenience that the classification characteristic command signal 17 becomes unbalanced and the particle size distribution of the crusher product 10 cannot be maintained well. That is, when the load change rate is high, the amount of the crushed object 7 to be held increases as described above, and in proportion to this, a large amount of coarse crushed objects are conveyed to the vane 12 which is a classifying means. If the classification characteristic command signal 17 is changed in proportion to the supply amount of the crushing raw material 1, the particle size distribution of the crusher product 10 cannot be maintained well.
Especially, in a typical control method in which the feeder command signal 3 includes an overshoot amount, such inconvenience becomes remarkable.

The present invention has been made in order to eliminate the disadvantages of the prior art, and not only when the load of the crusher is constant and when the load change rate of the crusher is low, An object of the present invention is to provide a crusher control device capable of stably supplying a crusher product having a good particle size distribution by following the response rate even when the load change rate is high.

[0012]

In order to achieve the above-mentioned object, the present invention comprises a means for holding a rotating object to be ground and a means for grinding the object to be ground provided in the vicinity of the outer periphery of the means for holding.
Attached to a crusher having a means for adjusting the pressure applied to the crushing means, and controlling the pressure applied to the crushing means according to the amount of material to be crushed supplied to the holding means,
In a controller of a crusher that supplies a crusher product having a required particle size distribution and a flow rate to a demand destination, each online operation model of the crusher is given the same operation amount as that of an actual crusher,
Calculates the amount of crushed material held on the holding means and the particle size distribution of the crushed object held for each fixed or variable period, and stores the calculated values in the storage unit for each calculation, In this case, the differential equation describing the online dynamic characteristic model is solved with reference to the previously calculated value, and the adjusting means is calculated from the amount of ground object possessed and / or the particle size distribution data of the object to be milled calculated this time. It is configured to obtain a pressing force command signal applied to the.

As other means, a rotating means for holding the object to be ground, a means for grinding the object to be ground provided near the outer periphery of the holding means, and a means for adjusting the pressure applied to the means for grinding. Attached to a crusher having a classifying means for selectively recirculating coarse particles of the material to be crushed that has passed through the crushing means to the holding means, and a classification characteristic adjusting means of the classifying means, In the controller of the crusher that controls the classification characteristics of the classifier according to the supply amount of the crushed object to the means, and supplies the crusher product with the required particle size distribution and flow rate to the demand destination, the crusher online The same operation amount as that of the actual crusher is given to the dynamic characteristic model, the crushed object holding amount and the particle size distribution of the held crushed object on the holding means are calculated for each constant or variable cycle, and for each calculation In the storage unit those calculated values By the way, in the calculation of this time, the differential equation describing the online dynamic characteristic model is solved by referring to the previously calculated value, and the amount of crushed object possessed and / or the particle size of the crushed object calculated this time are solved. The classification characteristic command signal applied to the classification characteristic adjusting means is obtained from the distribution data.

[0014]

According to the research conducted by the inventors of the present application, even if the amount of the raw material to be ground supplied from the feeder to the ground material holding means (turntable) is drastically changed, the ground material holding means holds the ground material. Calculate the total amount of crushed objects (amount of crushed objects) and the particle size distribution of the crushed objects supplied to the customer and / or the particle size distribution of the crushed objects at the entrance of the classifying means, and adjust the pressing force from these data. Force command signal applied to the means and /
Alternatively, if the classification characteristic command signal applied to the classification characteristic adjusting means is calculated and the pressing force of the crushing roller and / or the classification characteristic of the classifying means is adjusted, the amount of the material to be crushed and the pressing force command signal and / or the classification characteristic command The signal can always be balanced. Therefore, it is possible to supply a crusher product having a desired particle size and amount to a customer by responsively following a change in the supply amount of the pulverized raw material, and various engineering inconveniences due to a shortage of the pulverized material holding amount. Can be avoided.

However, for each of the physical quantities described above, is it impossible to perform online measurement (measurement method for obtaining instantaneous values moment by moment)?
Or very difficult.

Therefore, an on-line dynamic characteristic model of the target crusher is constructed, and the same operation amount as that of the actual crusher, for example, the feed amount of the material to be crushed, the turntable rotation speed,
By giving the carrier air flow rate, classification vane opening, etc., the amount of crushed material held and the particle size distribution of the crushed object supplied to the customer and / or the particle size distribution of the crushed object at the classification means inlet are constantly calculated. And further obtain a pressing force command signal and / or a classification characteristic command signal based on these calculated values. When each of these signals is applied to the pressing force adjusting means and / or the classifying means adjusting means, it is possible to constantly balance the amount of crushed material and the pressing force command signal and / or the classification characteristic command signal. You can obtain various technical and engineering effects.

It should be noted that both the particle size distribution of the material to be ground supplied to the customer and the particle size distribution of the material to be ground at the inlet of the classification means are calculated, and both the pressing force command signal and the classification characteristic command signal are obtained. It is more preferable to control both the pressing force adjusting means and the classifying means adjusting means, but the particle size distribution information of either one is obtained by calculation, and one of the command signals is obtained, and only one of the adjusting means is obtained. Even if it is controlled, better results can be obtained than in the prior art.

[0018]

EXAMPLE An example of the present invention will be described below by taking a typical coal crusher as an example. First, as a calculation method of a dynamic characteristic simulation model of a coal crusher necessary for carrying out the present invention, the inventor of the present application gave a lecture at an academic meeting of the China Branch of the Society of Instrument and Control Engineers on December 13, 1991. Explain things. This simulation model has a particle size distribution of only 4
It has the feature that it can be simulated with two variables and high accuracy can be obtained with low calculation amount. In addition to the above, various calculation methods of the dynamic characteristic simulation model of the coal crusher applicable to the present invention have been proposed in the past. For example, the model proposed by the inventor of the present application (feature Wish sho 63-131342
It is also possible to use statistical processing of real machine data, arithmetic methods using artificial intelligence, and the like.

(1) Phenomena in the crusher (1.1) Notation of particle size distribution The particle size distribution can be defined by the mass ratio of particles having a particle size of ξ or less in the particles passing through the cross section in a short time, and its density function is g
It is written as (ξ), and a subscript indicating the place is appropriately added. The relationship with the sampled stationary mass particle size distribution density f (ξ) is expressed by the following equation using the mass flow rate Q. g (ξ) ≡E {Q | (ξ, ξ + dξ)} f (ξ) / E {Q} (1) (1.2) Grinding mechanism When subscripts ip and op are given to various quantities before and after grinding,
The particle size distribution has the following relationships. g _op (ξ) = ∫ _-∞ g _{op | ip} (ξ | η) g _ip (η) dη (2) Here, if the particle size ξ is taken as the logarithmic axis, the conditional probability density g
_{op | ip} is the grinding distribution constant (Power
Technology, Vol.29, pp.263-275 (1981), ibid, Vol.33, pp.1
13-125 (1982), ibid., Described in Vol.33, pp.127-134 (1982)), and this is designated as s. g _{op | ip} (ξ | η) = s (ξ−η) (3) Regarding the mass flow rate, the following equation is obtained assuming that there is no accumulation in the crushing mechanism. E {Q _op } = E {Q _ip } (4) (1.3) Classification Mechanism For the j-th classification mechanism, each “particle passage” is an independent event, and if Θ _j is an indicator, , Classification efficiency c _j (ξ) (Miraku et al.
Powder Engineering Journal, Vol. 25, pp. 430-436 (1988)) and the following relationships. P _r {Θ _j = 0 | (ξ, ξ + d ξ)} = c _j (ξ) (5) P _r {Θ _j = 1 | (ξ, ξ + d ξ)} = 1-c _j (ξ) (6) Classification inlet When the subscripts ij, rj, and oj are given to the quantities relating to charcoal, circulating charcoal, and passing charcoal, respectively, the following equation representing the particle size distribution density is obtained by the Bayes theorem.

G _rj (ξ) = c _j (ξ) g _ij (ξ) / r _j (7) g _oj (ξ) = [1-c _j (ξ)] g _ij (ξ) / (1-r _j ) (8) where r _j = ∫ _-∞ c _j (ξ) g _ij (ξ) d ξ (9) The flow rate around the classification mechanism is calculated as follows.

E {Q _rj } = E {Θ _j Q _ij } = r _j E {Q _ij } (10) E {Q _oj } = E {(1-Θ _j ) Q _ij = (1-r _j ) E {Q _ij } (11) (1.4) Mixing mechanism The circulating coal from the classifying mechanism (j = 0, ..., n) and the coking coal (subscript _ib ) are mixed and the outflow coal (subscript _ob ) is mixed. Consider the mechanism of Here, the following relation is assumed between the coals G _b and Q _ob held by the mixing mechanism. E {Q _ob } = E {P} E {G _b } (12) P is independent of particle size, and in order to justify this assumption, in order to justify this assumption, a virtual classification mechanism (j = 0)
Considering the ξ-dependent grinding rate constant elucidated by L. Austin et al. Here, paying attention to the above equations (1) and (12) and assuming that the particle size does not change due to mixing, a mass balance equation of particles belonging to (ξ, ξ + dξ) can be obtained.

E {P} ¹ (d / dt) E {Q _ob } g _ob (ξ) = Σ _{j = 0} E {Q _rj (ξ) + E {Q _ib } g _ib (ξ) −E {Q _ob } g _ob (ξ) (13) (2) Mathematical description of the model (2.1) Parameterization of distribution density When Ξ follows distribution density g (ξ), the moment normalized by λ and ρ (affine transformation) is used. Think v _k (λ, ρ) = E {[(Ξ−λ) / ρ]} (14) At this time, the cumulant β _k (λ, ρ) is obtained correspondingly. In this model, the distribution density is organized by the following four parameters. μ = v ₁ (0,1), σ = [v ₂ (0,1)] ^{1 2} (15) Skewness: β ₃ (μ, σ) = v ₃ (μ, σ) (16) Excess: β ₄ (μ, σ) = v ₄ (μ, σ) ³ (17) From these, the Edgesworth expansion coefficient α _k can be uniquely obtained,
The distribution density can be specifically displayed. g (ξ) = Σ _k α _k p (ξ; μ, σ) h _k ([ξ−μ] / σ) (18) where p (ξ; μ, σ) is a Gaussian distribution and h _k is the kth order Is the Hermitian polynomial of.

(2.2) Grinding Mechanism Substituting the above-mentioned equation (3) into equation (2) results in a superposition integral, which results in the sum of Kyumuland and obtains the following. v _1op (μ _ip , σ _ip ) = v _1s (μ _ip , σ _ip ) (19) v _2op (μ _ip , σ _ip ) = 1 + v _2s (μ _ip , σ _ip ) (20) v _3op (μ _ip ,) _{σ ip) = v 3ip (μ} ip, σ ip) + v 3s (μ ip, σ ip) (21) v 4op (μ ip, σ ip) = v 4ip (μ ip, σ ip) + v 4s (μ ip, σ _ip ) + 6v _2s (μ _ip , σ _ip ) (22) Here, the subscript s indicates the pulverization distribution constant s, and the others indicate the particle size distribution density g. Furthermore, μ _op , σ _op , β ₃ (μ _op , σ
_op ), β ₄ (μ _op , σ _op ) are the above-mentioned equations (15) to (17)
It can be calculated using the formula and the following formula.

V _k (λ, ρ) = (ρ ₀ / ρ) Σ _{j = 0 k} C _j · v _j (λ ₀ , ρ ₀ ) [(λ ₀ −λ) / ρ ₀ ] (23) (2 .3) Classification mechanism c _j (ξ) can be approximated by using appropriate τ _mj , λ _mj , and ρ _mj . c _j (ξ) _{≈Σ m} τ _mj p (ξ; λ _mj , ρ _mj ) (24) g _ij (ξ) is the form of the equation (18), and the equations (7) and (7)
From equation (10), various amounts of circulating coal can be specifically obtained.

E {Q _rj } g _rj (ξ) = E {Q _ij } Σ _m p (ξ; λ _mrj , ρ _mrj ) Σ _k α _rjmk h _k ([ξ−λ _mrj ] / ρ _mrj ) (25 ) Here is the following relationship.

Α _rjmk = α 0 _rjmk τ _mj · exp {− (μ _ij −λ _mj ) ² / [2 (σ _ij ² + ρ _mj ² )]} (26) λ _mrj = (ρ _mj ² μ _ij + σ _ij ² λ _mj ) / (σ _ij ² + ρ _mj ² ) (27) ρ _mrj = ρ _mj σ _ij / (σ _ij ² + ρ _mj ² ) ^{1 2} (28) In addition, α _0rjmk is the addition formula of Hermite polynomial It is obtained by applying and organizing the coefficients. Σ _k α _ijk h _k ([ρ _mrj / σ _ij ] [ξ _{−λ mrj} ] / ρ _mrj + [λ _mrj −μ _ij ] / σ _ij ) (29) The above equation (25) is the distribution density is a weighted _{mixture, v k (λ mrj, ρ} mrj) from _α 0rjmk for the subscript _m is values are found unique, the same λ, v _k of ρ is because it can be weighted addition,
After all, using the above-mentioned equations (23) and (15) to (17), μ _rj , σ _rj , β ₃ (μ _rj , σ _rj ), β ₄ (μ _rj , σ _rj ).
Can be calculated. The same argument applies to the passing coal with the subscript _oj .

(2.4) Mixing mechanism When normalized by properly selected λ _b and ρ _b , the above (13)
A differential equation for v _kob is obtained from the equation.

E {P} ¹ (d / dt) E {Q _ob } v _kob (λ _b , ρ _b ) = Σ _{j = 0} E {Q _rj } v _krj (λ _b , ρ _b ) + E {Q _ib } v _kib (λ _b , ρ _b ) -E {Q _ob } v _kob (λ _b , ρ _b ) (30) Formula (23), Formula (15) to Formula (17) are applied, Generally, μ, σ, β ₃ (μ, σ), β ₄ (μ, σ) and v _k (λ, ρ)
Since the mutual conversion of is possible, the conclusions of (3.2) and (3.3) can be substituted to solve (30). At this time
By adopting the approximation, stable numerical calculation became possible.

(3) Analysis Example FIG. 2 shows an example of dynamic characteristic analysis of a coal pulverizer having a two-stage classification mechanism subsequent to the pulverization mechanism. FIG. 3 shows the particle size distribution (form of E {Q} g (ξ)) of each part after 3 minutes have passed in this case.

FIG. 1 shows an example of the control device according to the present invention. The control device of this example includes a first arithmetic unit 20, a second arithmetic unit 21, a third arithmetic unit 22, and the first arithmetic unit 2.
The storage unit 23 stores the calculation data of 0 for each calculation, and calculates both the pressing force command signal 16 and the classification characteristic command signal 17.

In FIG. 1, reference numerals 24, 25, and 28 are signals representing particle size distribution information, and are signals (15) described above.
Equation, mean, variance given by equation (16), equation (17),
Contains Skilliness and Excess.

The first calculation unit 20 knows the supply amount of the crushed raw material 1 from the particle size distribution information 24 of the crushed raw material and the feeder command signal 3 (see FIG. 4), and the above equation (19) to First
Solve equation (30). At this time, v _{1s to} v _{4s in the} equations (19) to (22) and j in the equations (24) to (29)
When = 0, the various coefficients in these equations are functions of the pressing force. Therefore, the pressing force command signal 16 is used to know the present pressing force and consider it. Also, the formula (24) to the formula (2)
When j = 1, 2 in the equation (9), the coefficients in these equations are functions of the setting of the classifying means, and this is taken into consideration by the classification characteristic command signal 17. Further, when finally solving the equation (30), the equation is an ordinary differential equation, and when it is solved by numerical integration, it is always necessary to solve the equation one time before (one time before the integration time width). Since the crushed material holding amount and the particle size distribution are necessary, the current calculated values 25 and 26 are stored in the storage unit 23 until the next time (after a lapse of one integration time width), and signals 27 and 28 are stored. Is given to the first arithmetic unit 20 as

The second computing unit 21 knows the current amount of crushed material and its particle size distribution from the signals 26 and 25, respectively, and obtains a proper pressing force command signal 16. The third computing unit 22 also obtains an appropriate classifier setting signal 17 by the same input.

In the above embodiment, both the pressing force command signal 16 and the classification characteristic command signal 17 are calculated.
It is also possible to calculate only the pressing force command signal 16 and make the amount of the crusher product follow the change in the amount of the crushed object held. In this case, the control device may include a first arithmetic unit 20, a second arithmetic unit 21, and a storage unit 23 that stores the arithmetic data of the first arithmetic unit 20 for each arithmetic operation. it can.

Further, in order to obtain a more sensitive centrifugal force classifying characteristic, a rotary classifier which gives centrifugal force to the object to be crushed by rotating blades driven by an electric motor is adopted in place of the vane of FIG. In some cases, it can be carried out in exactly the same manner as in the above embodiment.

[0036]

As described above, according to the present invention,
Since the pressing force of the crusher is adjusted according to the amount and size distribution of the material to be crushed in the crusher, there is no excessive material to be crushed in the crusher even when the load changes at high speed. It is possible to prevent a decrease in outlet particle size distribution, a slow increase in coal output, and an increase in operating power. Further, it is possible to prevent wear due to unnecessary pressurization and vibration due to an excessively small amount of material to be ground. On the other hand, when the classification characteristics of the classification means are also adjusted,
In addition to this, since the classification setting of the crusher is adjusted according to the amount of material to be crushed and the particle size distribution in the crusher, a good particle size distribution of the crusher product is maintained even when the high speed load changes. it can.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a control device according to an embodiment.

FIG. 2 is an operation example diagram of a coal crusher dynamic characteristic model.

FIG. 3 is an operation example diagram of a coal crusher dynamic characteristic model.

FIG. 4 is a configuration diagram of a control device according to a conventional example.

[Explanation of symbols]

 2 feeder 3 feeder command signal 6 crushed object holding means 7 crushed object 8 crushing means 10 crusher product 12 classifying means 16 pressing force command signal 17 classification characteristic command signal 20, 21, 22 computing section 23 storage section 24 covered Particle size distribution information of crushed raw material 25 Particle size distribution information of retained crushed object 26 Amount of crushed object retained 27 Amount of crushed object retained (previous value) 28 Particle size distribution information of retained crushed object (previous value)

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Takahiro Taketomo 6-9 Takaracho, Kure-shi, Hiroshima Babcock Hitachi Kure Factory

Claims (2)

[Claims] 1. A crusher having a rotating means for holding an object to be ground, a means for grinding an object to be ground provided near the outer circumference of the holding means, and a means for adjusting a pressing force applied to the grinding means. A control device for a crusher that is attached and controls the pressure applied to the crushing means according to the supply amount of the crushed material to the holding means, and supplies the crusher product having a required particle size distribution and flow rate to the demand destination. In the above, by providing the online dynamic characteristic model of the crusher with the same operation amount as that of the actual crusher, the crushed object holding amount and the particle size distribution of the crushed object to be held on the holding means are set at constant or variable intervals. And store the calculated values for each operation in the storage unit, and in this operation, solve the differential equation that describes the online dynamic characteristic model by referring to the previous calculated value, Calculated amount of crushed material And / or a control device for a crusher, which obtains a pressing force command signal applied to the adjusting means from the particle size distribution data of the held crushed object. 2. A rotating means for holding the crushed object, a crushing means for crushing the crushed object provided in the vicinity of the outer circumference of the holding means, a means for adjusting a pressing force applied to the crushing means, and the crushing means. An object to be crushed to the holding means is attached to a crusher having a classifying means for selectively recirculating coarse particles of the passed crushed material to the holding means, and a classification characteristic adjusting means of the classifying means. In the controller of the crusher that controls the classification characteristics of the classification means according to the supply amount of the crusher and supplies the crusher products with the required particle size distribution and flow rate to the demand destination, the online dynamic characteristic model of the crusher is used as an actual machine. The same operation amount as that of the crusher is given to calculate the holding amount of the crushed object on the holding means and the particle size distribution of the held crushed object at constant or variable cycles, and the calculated values for each calculation. Is stored in the storage unit and is used for this calculation. In this case, the differential equation describing the online dynamic characteristic model is solved with reference to the previously calculated value, and the classification characteristic is calculated from the amount of ground material retained and / or the particle size distribution data of the material to be ground calculated this time. A control device for a crusher, characterized by obtaining a classification characteristic command signal applied to an adjusting means.