JP2542282B2 - Burner combustion control method for dryers for recycling waste materials - Google Patents

Description

TECHNICAL FIELD The present invention relates to a burner combustion control method for a drier for recycling waste asphalt pavement excavated by road construction or the like.

[Prior Art] When heating recycled aggregate with a dryer, a co-current heating method in which the flow direction of combustion gas and the flow direction of aggregate are the same is generally adopted. Since the combustion control of the burner is a co-current heating method, pay attention to the fact that the exhaust gas temperature becomes slightly higher than the heated aggregate temperature, and the exhaust gas temperature is detected by the dryer outlet in response to changes in the combustion amount. Since the response is quicker than the material temperature, the cascade control that controls the aggregate temperature by controlling the exhaust gas temperature is adopted (the exhaust gas temperature set value is the heated aggregate temperature set value + α).

Then, when the operation is started, the burner initial combustion is first performed. If the above-mentioned burner automatic combustion control is suddenly performed, the burner opening will be fully opened and the combustion amount will be the maximum because the exhaust gas temperature is low. The drum is heated by low combustion at a set combustion amount. Then, after a lapse of time, the aggregate supply start switch is turned on to start the aggregate supply to the dryer, and the burner opening is increased by catching the supply of the aggregate by the sensor provided near the dryer input port. It will shift to high combustion.

If the type of asphalt mixture to be manufactured changes, the composition of the aggregate that is supplied to the dryer is changed accordingly, and a new aggregate is added to the dryer in anticipation of when the aggregate with the previous composition is discharged from the dryer. We are supplying. Then, the burner combustion amount control at the time of this switching is controlled so that the exhaust gas temperature set value is set in advance even if the composition and supply amount of the aggregate to be supplied next changes.

[Problems to be Solved by the Invention] However, in the conventional method, at the time of switching from initial combustion to high combustion, or when switching the composition of the aggregate supplied to the dryer, the optimum exhaust gas temperature corresponding to the aggregate supplied to the dryer. It cannot be said that it is the set value. That is, the exhaust gas temperature is deeply related to the three factors of the composition of the aggregate supplied to the dryer, the supply amount, and the water content. If the optimum exhaust gas temperature is not set in consideration of these factors, the heating aggregate temperature set value is set. Convergence and stability are not accelerated.

In view of the above points, the present invention sets the optimum exhaust gas temperature according to the aggregate supplied to the dryer at the time of switching from initial combustion to high combustion in the waste material regeneration dryer or at the time of switching the composition of the aggregate supplied to the dryer. Provided is a burner combustion control method in a dryer for waste material regeneration, which aims to speed up convergence to the heated aggregate temperature set value and stability by setting a value and performing burner combustion control based on the exhaust gas temperature set value. It is a thing.

[Means for Solving the Problems] In order to achieve the above-mentioned object, the present invention provides a dryer for recycling waste materials in a drum at the time of switching from initial combustion to high combustion or at the time of switching the composition of the aggregate to be supplied to the dryer. Appropriate exhaust gas set temperature of exhaust gas derived from dryer by estimating the exhaust gas set temperature correction amount by performing fuzzy inference from the supplied and set mix type as the antecedent part of the fuzzy inference rule based on the supplied aggregate composition type Is determined, and the combustion amount of the burner is controlled so that the exhaust gas temperature derived from the dryer becomes the exhaust gas set temperature.

In addition, the amount of aggregate supply or the moisture content of the aggregate is used as the antecedent part of the fuzzy inference rule by changing the mixing type of the aggregate supplied to the drum, and the amount of correction of the exhaust gas temperature is estimated by performing fuzzy inference. Then, an appropriate exhaust gas set temperature of the exhaust gas derived from the dryer is determined, and the burner combustion amount is controlled so that the exhaust gas temperature derived from the dryer becomes the exhaust gas set temperature.

[Operation] In the burner combustion control method of the dryer for recycling waste materials according to the present invention, the mixing type of the aggregate supplied to the dryer,
Supply amount or water content as the antecedent part of fuzzy inference rules,
Fuzzy inference is performed based on the preset fuzzy set membership function and inference rules, the exhaust gas set temperature correction amount is estimated, the appropriate exhaust gas set temperature of the exhaust gas derived from the dryer is determined, and the burner combustion amount is determined. Since the temperature is controlled, it is possible to accelerate convergence to the set temperature of the heated aggregate and stability.

[Embodiment] An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows the overall structure of a dryer to which the present invention is applied.

The dryer 1 rotatably supports a cylindrical drum 2 on a machine base 3 and rotates the drum 2 at a predetermined speed by a drum driving motor (not shown). A large number of scraping blades 4 are arranged inside the drum 2, and the scraping blade 4 scrapes up the aggregate fed by the aggregate conveying device 5 and rolls down in the drum 2 while dropping it in a curtain shape. During the heating, the aggregate is heated to a desired temperature by being brought into contact with the hot air sent from the burner 6.

The dryer 1 is provided with an aggregate temperature sensor 7 for detecting the temperature of the heated aggregate discharged from the drum 2 and a temperature sensor 8 for detecting the temperature of the exhaust gas, and the aggregate for supplying the dryer 1 with the aggregate. The conveyor 5 is provided with a conveyor scale 9 for detecting the amount of aggregate supplied and a moisture meter 10 for detecting the moisture content of the aggregate, and signals from these sensors are input to the burner combustion controller 11. Further, the burner combustion control device 11 is connected with a compounding setter 12 for instructing a compounding composition of the aggregates to be supplied to the dryer 1 from an aggregate hopper (not shown) stored for each particle size, and data concerning the composition. Is input to the burner combustion control device 11 from this mixture setting device 12. Then, as described later, a burner opening control signal fuzzy inferred by the burner combustion control device 11 based on these signals and data is output to the control motor 14 for controlling the combustion amount via the driver 13. .

First, a method of performing fuzzy control according to the mixing type of the aggregate supplied to the drum at the time of switching from the initial combustion to the high combustion in the waste material recycling dryer or at the time of switching the mixing of the supplied aggregate to the dryer will be described.

The mix type of the supply aggregate set by the mix setter 12 is read into the fuzzy control unit 15 of the burner combustion control device 11, and the fuzzy control unit 15 determines an appropriate exhaust gas temperature correction amount from these input signals. Therefore, fuzzy reasoning is performed based on the membership function of the fuzzy set and the reasoning rules.

FIG. 2 is a membership function for qualitatively evaluating the mix type of asphalt mixture. C in the figure
(I) (i = 1 to 7) is a constant that fixes the shape of the membership function and is determined as appropriate. PB, PM, PS, ZR, NS, NM, NB
Is a name given to the membership function for qualitatively evaluating the rank of the combination type C, and has the following meanings.

PB: Positive Big PM: Positive Medium PS: Positive Small ZR: Zero NS: Negative Small NM: Negative Medium NB: Negative Big The size of this mixture is the size of the material, for example, small dense grains, large coarse grains, etc. Determine as appropriate. The vertical axis in the figure is the membership value. The current combination type C detected using this membership function is qualitatively evaluated.

FIG. 3 is an inference rule for qualitatively determining the exhaust gas set temperature correction amount ΔT from the qualitative relationship of the mixture type C. For example, if one of the inference rules in FIG. 3 is described, the rule IF (C is PM) THEN ΔT is PM is represented.

This means that "if the rank of the blending type C is moderately large" (preceding part), "increase the set amount of exhaust gas temperature correction amount moderately" (consequent part).

FIG. 4 is a membership function for converting the qualitatively determined exhaust gas temperature correction amount into a quantitative value. ΔT (i) (i = 1 to 7) in the figure is a constant that defines the shape of the membership function, and is a correction amount for the currently set exhaust gas temperature, which is appropriately determined. P
B, PM, PS, ZO, NS, NM, and NB are names given to the membership function to qualitatively express the magnitude of the exhaust gas temperature correction amount, and are the names used in Fig. 3. It corresponds to. The vertical axis of the figure is the membership value. The applied inference rule qualitatively determines which membership function the exhaust gas temperature correction amount belongs to. When the set exhaust gas temperature correction amount is specified by multiple memberships based on multiple inference rules, the weighted average value corresponding to each membership value is used as the actual correction amount. The exhaust gas set temperature currently set is corrected by the fuzzy inferred exhaust gas set temperature correction amount to determine the optimum set temperature, so that the exhaust gas temperature detected by the temperature sensor 8 becomes the determined exhaust gas set temperature. The burner opening signal is output to the control motor 14 via the driver 13 to adjust the combustion amount of the burner 6.

Next, a method of fuzzy control based on the aggregate supply amount detected by the conveyor scale 9 for detecting the aggregate supply amount to the drum 2 will be described.

The burner combustion control device 11 repeatedly detects the amount of aggregate supplied to the drum 2 via the conveyor scale 9 in a predetermined control cycle. The aggregate supply amount M (Ton / H) detected by the conveyor scale 9 is taken into the burner combustion control device 11 and input to the fuzzy control unit 15. Fuzzy controller
In 15, the fuzzy reasoning is performed based on the membership function of the fuzzy set and the reasoning rule to determine the exhaust gas temperature correction amount from the input signal.

FIG. 5 is a membership function for qualitatively evaluating the magnitude of the aggregate supply amount M. M (i) (i in the figure
= 1 to 7) are constants that define the shape of the membership function and are determined as appropriate. PB, PM, PS, ZR, NS, NM, and NB are names given to the membership function in order to qualitatively evaluate the magnitude of the aggregate supply amount M, and their meanings are as described above. The vertical axis of the figure is the membership value. Current aggregate supply amount M detected using this membership function
Is qualitatively evaluated.

FIG. 6 is an inference rule for qualitatively determining the exhaust gas set temperature correction amount ΔT from the qualitative relationship of the aggregate supply amount M. The rule is read in the same way as described with reference to FIG. For example, if one of the inference rules is described, the rule IF (M is PM) THEN ΔT is PM is represented.

This is "if the aggregate supply is medium"
(Antecedent part) means "Increase the amount of exhaust gas temperature correction to a medium level" (Consequent part). If the amount of aggregate supplied to the dryer is medium, the amount of exhaust gas temperature adjustment should be increased. Combustion control is performed by adjusting the exhaust gas set temperature by increasing it moderately.

FIG. 7 is a membership function for converting the qualitatively determined exhaust gas temperature correction amount into a quantitative value. Since this is the same as that shown in FIG. 4, description thereof will be omitted. The exhaust gas set temperature currently set is corrected by the fuzzy inferred exhaust gas set temperature correction amount to determine the optimum set temperature, so that the exhaust gas temperature detected by the temperature sensor 8 becomes the determined exhaust gas set temperature. The burner opening signal is output to the control motor 14 via the driver 13 to adjust the combustion amount of the burner 6.

Further, a method of fuzzy controlling the aggregate supplied to the drum 2 by the moisture content of the aggregate detected by the moisture meter 10 for detecting the moisture content will be described.

Also in this case, similar to the fuzzy control by the aggregate supply amount,
The burner combustion control device 11 repeatedly detects the moisture content of the aggregate supplied to the drum 2 by the moisture meter 10 in a predetermined control cycle, and the moisture content W of the aggregate detected by the moisture meter 10 is W.
(%) Is taken into the fuzzy control unit 15 of the burner combustion control device 11, and the fuzzy control unit 15 determines the appropriate exhaust gas temperature setting correction amount ΔT (° C) from these input signals by the fuzzy set membership. Fuzzy inference is performed based on the function and inference rules.

FIG. 8 is a membership function for qualitatively evaluating the magnitude of the water content W of the aggregate. W (i) in the figure
(I = 1 to 7) is a constant that defines the shape of the membership function and is determined as appropriate. PB, PM, PS, ZR, NS, NM, and NB are names given to the membership function in order to qualitatively evaluate the magnitude of the water content W, and their meanings are as described above. The vertical axis of the figure is the membership value. Current water content W detected using this membership function
Is qualitatively evaluated.

FIG. 9 is an inference rule for qualitatively determining the exhaust gas set temperature correction amount ΔT from the qualitative relationship of the water content W of the aggregate. The rule is read in the same way as described with reference to FIG. For example, if one of the inference rules is written, the rule IF (W is PM) THEN ΔT is PM is represented.

This is "if the water content of the aggregate is medium"
(Antecedent part), "Increase the set amount of exhaust gas temperature correction moderately" (consequent part).

FIG. 10 shows a membership function for converting the exhaust gas set temperature correction amount qualitatively determined into a quantitative value, which is the same as that shown in FIG.

The exhaust gas set temperature currently set is corrected by the fuzzy inferred exhaust gas set temperature correction amount to determine the optimum set temperature, so that the exhaust gas temperature detected by the temperature sensor 8 becomes the determined exhaust gas set temperature. The burner opening signal is output to the control motor 14 via the driver 13 to adjust the combustion amount of the burner 6. Then, after a lapse of a predetermined time, the normal burner combustion control is started, and the heated aggregate temperature is converged to the set value while the exhaust gas set temperature is corrected by the heated aggregate temperature detected by the aggregate temperature sensor 7.

Note that, here, the exhaust gas set temperature correction amount was determined by performing individual fuzzy inference based on the composition type, aggregate supply amount, and moisture content of the aggregate, but these fuzzy inferences were all performed in parallel to correct the exhaust gas set temperature. If the amount is determined, more highly accurate combustion control can be performed.

Further, although the membership functions used in this embodiment are all triangular, the present invention is not limited to this, and various curves may be adopted according to the characteristics of the dryer for recycling waste materials and the knowledge of operators. Also, the essence of the present invention does not change. Further, the essence of the present invention does not change even if the number of membership functions as well as the number of membership functions is arbitrarily set.

[Effects of the Invention] As described above, according to the burner combustion control method for a dryer for waste material regeneration according to the present invention, at the time of switching from initial combustion to high combustion in the dryer or at the time of switching the mixture of the aggregate to be supplied to the dryer. Fuzzy inference is performed based on the composition type, supply amount, and / or water content of the aggregate supplied to the dryer, and the exhaust gas set temperature correction amount is determined to correct the determined exhaust gas set temperature and the optimum set value. Is set and the burner combustion is controlled based on this exhaust gas temperature set value, so that convergence to the heated aggregate temperature set value and stabilization can be accelerated.

[Brief description of drawings]

FIG. 1 is a diagram showing the overall structure of a dryer for recycling waste materials applied to one embodiment of the present invention, FIG. 2 is a diagram showing a rank evaluation membership function of a combination type, and FIG. 3 is based on a combination type. FIG. 4 is a diagram showing an example of an exhaust gas set temperature correction amount prediction rule, FIG. 4 is a diagram showing a membership function for an exhaust gas set temperature correction amount based on a mixture type, and FIG. 5 is a diagram showing a membership function for evaluating aggregate supply amount evaluation. FIG. 6 is a diagram showing an example of an exhaust gas set temperature correction amount prediction rule based on an aggregate supply amount,
FIG. 7 is a diagram showing a membership function for correcting the exhaust gas set temperature based on the aggregate supply amount, FIG. 8 is a diagram showing a membership function for evaluating the water content of the aggregate, and FIG. 9 is a water content of the aggregate. FIG. 10 is a diagram showing an example of an exhaust gas set temperature correction amount prediction rule based on FIG. 10, and FIG. 10 is a diagram showing an exhaust gas set temperature correction amount membership function based on the water content of an aggregate. 1 ... Dryer for recycling waste materials, 6 ... Burner, 8 ... Temperature sensor, 9 ... Conveyor scale, 10 ... Moisture meter, 11 ...
… Burner combustion control device, 12 …… Composite setting device, 13 …… Driver, 14 …… Control motor

Claims (4)

(57) [Claims] 1. A fuzzy inference rule for the type of aggregate supplied to the drum at the time of switching from initial combustion to high combustion in a dryer for recycling waste materials or when changing the composition of aggregate supplied to the dryer. The exhaust gas temperature derived from the dryer is determined by performing fuzzy inference based on the mixture type that is set to be supplied, estimating the exhaust gas temperature setting correction amount, and determining the appropriate exhaust gas set temperature of the exhaust gas derived from the dryer. A burner combustion control method for a dryer, comprising controlling the burner combustion amount so that the temperature is maintained. 2. A fuzzy inference rule is applied to the amount of aggregate supplied to the drum at the time of switching from initial combustion to high combustion at the waste material recycling dryer or at the time of switching the composition of the aggregate supplied to the dryer. As a part, fuzzy inference is performed from the set aggregate supply amount to estimate the exhaust gas set temperature correction amount to determine the appropriate exhaust gas set temperature of the exhaust gas derived from the dryer, and the exhaust gas temperature derived from the dryer is the exhaust gas temperature A burner combustion control method for a dryer, which comprises controlling the burner combustion amount so as to reach a set temperature. 3. The moisture content of the aggregate supplied to the drum at the time of switching from the initial combustion to the high combustion in the dryer for recycling waste materials, or when the composition of the aggregate to be supplied to the dryer is switched, the precondition of the fuzzy inference rule. Part, the fuzzy inference is performed from the moisture content of the supplied aggregate to estimate the exhaust gas set temperature correction amount and determine the appropriate exhaust gas set temperature of the exhaust gas derived from the dryer, and the exhaust gas temperature derived from the dryer is A burner combustion control method for a dryer, comprising controlling the combustion amount of the burner so that the exhaust gas has a set temperature. 4. When the dryer for recycling waste materials is switched from initial combustion to high combustion, or when the composition of the aggregates supplied to the dryer is switched, the composition type of the aggregates supplied to the drum, the aggregate supply amount, and The moisture content of the aggregate is used as the antecedent part of the fuzzy inference rule to perform fuzzy inference, estimate the correction amount of the exhaust gas temperature, determine the appropriate exhaust gas temperature set for the exhaust gas derived from the dryer, and exhaust gas discharged from the dryer. A burner combustion control method for a dryer, comprising controlling the burner combustion amount so that the temperature becomes the exhaust gas set temperature.