JPH08170304A - Control method of aggregate supply in asphalt plant - Google Patents

Abstract

PURPOSE: To supply an aggregate storage bin with the quantity of aggregate corresponding to the aggregate usage of a shipping plied timber in proper quantities. CONSTITUTION: Level meters 10 are disposed into each compartment 9a-9d of an aggregate storage bin 9 while an aggregate supply controller 11 receiving signals from the level meters 10 and controlling the quantities of the cutting-off of aggregate hoppers 1a-1d is provided. The aggregate storage levels of the compartments 9a-9d are detected at every fixed timing by the level meters 10 and taken into the aggregate supply controller 11, the actual feed rates of aggregate to each compartment 9a-9d are arithmetically operated by the difference of preceding and current aggregate storage levels detected, and the actual feed rates and the aggregate compounding ratios of shipping plied timbers are compared. When there is difference, the quantities of the cutting-off of each variable speed feeder 2a-2d are corrected so that the actual feed rates of aggregate are brought close to the aggregate compounding ratios of the shipping plied timbers, and the shipping plied timbers are supplied with aggregate in proper quantities.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aggregate supply control method for an asphalt plant for producing an asphalt mixture which is a road paving material.

[0002]

2. Description of the Related Art Generally, in an asphalt plant, aggregates are cut out at a desired ratio from an aggregate hopper that stores various aggregates for each type, sent to a dryer that is a heating device by a bellcon for conveying aggregates, and heated by a dryer. After that, it is lifted to the upper part of the plant main body, sieved according to particle size by a vibrating sieve, and temporarily stored according to particle size in a compartment of an aggregate storage bin arranged below. Aggregate of various particle sizes is dispensed from each compartment based on the mix of asphalt mixture manufactured according to the shipping request, a predetermined amount is weighed and mixed with other materials such as asphalt with a mixer to manufacture an asphalt mixture. are doing.

At the time of manufacturing this composite material, the cutting of the aggregate material from the aggregate hopper is usually carried out by assembling the type of asphalt composite material to be shipped,
The cutting speed by the variable speed feeder of each aggregate hopper is stored in advance in the plant operation panel according to the mixture, and the cutting speed of each aggregate hopper is assigned according to the type of the shipment mixture material and the mixture by the start of shipment, The amount of aggregate that is commensurate with the amount of aggregate used in shipping is cut out from the aggregate hopper. Then, the total aggregate supply amount is measured by a conveyor scale arranged in the middle of transportation, and when the supply of the set total aggregate supply amount is completed, the cutting of the aggregate is stopped.

[0004]

However, in the above-mentioned conventional aggregate supplying method, various aggregates distributed and stored in each compartment of the aggregate storage bin are caused by the fluctuation of the aggregate particle size in the aggregate hopper and the vibrating sieve. In some cases, the storage ratio of the aggregate in the shipping compound may not be stored due to the efficiency of the equipment, clogging, etc. Bias may occur and some aggregates may run out of aggregate, while on the other hand, some compartments store large amounts of aggregate. Therefore, the plant operator needs to monitor the display screen of the operation panel to prevent the aggregate from running out, and a large amount of the supplied aggregate in the compartment was left after the day of shipping work. You have to do the troublesome work of removing the remaining material.

In view of the above points, the present invention controls the aggregate supply so that the actual supply ratio of the aggregate supplied to each compartment of the aggregate storage bin approaches the aggregate mixture ratio of the shipping mixture, and the shipment is performed. It is an object of the present invention to provide an aggregate supply control method for an asphalt plant capable of supplying an appropriate amount of aggregate that is suitable for the amount of various aggregates of a composite material, without excess or deficiency.

[0006]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention stores a desired amount of aggregates by type and allows a variable speed feeder to freely control the amount of cutout to obtain a desired ratio. After the aggregate is cut out with a dryer, which is a heating device, it is temporarily stored in each compartment of the aggregate storage bin of the plant by particle size, and aggregates of various particle sizes are prepared based on the mix of asphalt mixture to be manufactured. In an asphalt plant that weighs a predetermined amount and mixes it with other materials such as asphalt with a mixer to produce an asphalt mixture,
A level meter for detecting the storage amount is provided in each compartment of the aggregate storage bin, and an aggregate supply control device for controlling the cutout amount of each aggregate hopper by a signal from the level meter is provided, and the asphalt is preliminarily provided. The aggregate cutout ratio of the aggregate hopper is stored for each type of mix, and the aggregate cutout is cut out from each aggregate hopper at the aggregate cutout ratio corresponding to the type of the shipment mix according to the asphalt mix shipment command. At the same time, the aggregate level of each compartment is detected by the level meter at every predetermined timing, and the actual ratio of aggregate supply to each compartment is calculated from the difference between the detected aggregate storage levels of the previous time and this time. However, if there is a difference between the actual supply ratio and the aggregate mixture ratio of the shipping mixture, the variable speed feeders of the respective variable speed feeders should be adjusted so that the actual supply ratio of the aggregate to each compartment approaches the aggregate mixture ratio of the shipping mixture. Sequential compensation of cutout ratio It is characterized in that the the to.

[0007]

According to the aggregate supply control method of the present invention, the aggregate storage level of each compartment is detected at every predetermined timing when the aggregate is supplied, and the difference value between the previous and present aggregate storage levels is detected. The actual supply rate of aggregate distributed to each compartment by particle size is calculated. When the aggregate is being paid out during that time, the actual supply ratio is calculated in consideration of it.

If there is a difference between the actual supply ratio to each compartment and the aggregate compounding ratio of the shipping mixture, it is due to the fluctuation of the aggregate particle size in the aggregate hopper, the efficiency of the vibrating sieve,
There is an error due to the effect of clogging, etc.The actual supply ratio of aggregate to each compartment is corrected by correcting the cut-out ratio of the variable speed feeder of each aggregate hopper and the aggregate mixture ratio of the shipment mixture Supply control is performed so as to approach. As a result, it is possible to supply the aggregate storage bin with an appropriate amount of aggregate in proportion to the aggregate mixture ratio of the shipping mixture, and to prevent a part of the aggregate from being broken during shipment, and The amount of residual material is reduced, and the work of extracting the residual material is also reduced, which enables efficient aggregate supply control.

[0009]

Embodiments of the present invention will be described below with reference to the drawings.

Reference numerals 1a to 1d are aggregate hoppers for storing the aggregates for each type, and a predetermined amount of the aggregates is cut out by the variable speed feeders 2a to 2d, and a drawer conveyor 3 and a weighing conveyor 4 are provided.
It is charged into the dryer 5 which is an aggregate heating device via the, and is heated to a predetermined temperature by the hot air of the burner 6 while passing through the dryer 5.

The heated aggregate is lifted up to the upper part of the plant main body by the bucket elevator 7, the aggregate is sieved by the vibrating sieve 8 according to the particle size, and the aggregate is stored in the aggregate storage bin 9 in which the inside is divided into a plurality of particles. 9a to 9d are compartments for storing aggregates according to large gravel, medium gravel, small gravel, and particle size of sand, and a level meter 10 for detecting an aggregate storage level is provided in each of the compartments 9a to 9d. are doing. The illustrated level meter is a continuous level meter that uses a capacitance level meter, but in addition to this, the load cell can be used by separating the compartments, and the torque motor type and thermal The aggregate storage level may be continuously measured by using a large number of pairs.

Reference numeral 11 denotes an aggregate supply control device for controlling the cutting out of aggregates of the aggregate hoppers 1a to 1d.
A transmission / reception unit 13 that transmits and receives data from 0 and data with the operation panel 12, a calculation unit 14 that performs various calculations from the level data that has been taken in, a storage unit 15 that stores various data, an input unit 16 that inputs various setting data, Aggregate hopper 1a-
A speed setter 17 for setting the speed of the 1d variable speed feeders 2a to 2d is provided, and a control unit 18 for controlling each of these elements is provided.

The control of cutting out the aggregates from the above-mentioned aggregate hoppers 1a to 1d is performed by cutting out various aggregates at a cutting ratio according to the mixture of the aggregates in the shipping mixture, and each compartment 9a of the aggregate storage bin 9. Each compartment 9a by the level meter 10 of 9d
The aggregate storage level of ~ 9d is detected, and the aggregate supply rate and storage amount to each compartment are calculated from this aggregate storage level, and this is fed back to correct the cutting speed of the aggregate, Aggregate is supplied without excess or deficiency with respect to the amount of aggregate used.

The aggregates of various particle sizes stored in the compartments 9a to 9d are dispensed from the compartments 9a to 9d to the aggregate measuring tank 19 provided in the lower portion based on the aggregate composition of the shipping mixture, and weighed. Stone powder tank 20 and asphalt tank 21
22 with stone powder and molten asphalt weighed in
And mix for a predetermined time to produce an asphalt mixture.

Next, a method for controlling the supply of aggregate based on the aggregate storage level of the aggregate storage bin 9 will be described with reference to the flowcharts of FIGS. S1 to S2 in the figure
Reference numeral 2 denotes a step representing each procedure of the flowchart.

First, before the operation is started, the type of asphalt mixture and the composition thereof are registered in the operation panel 12 as an initial setting (S1). At the time of supplying the aggregate, a cutting ratio for setting the cutting speed of the aggregate from each of the aggregate hoppers 1a to 1d is registered corresponding to the type of the asphalt mixture (S2). Then, if the total supply amount of various aggregates per hour is set, each aggregate hopper 1a-1
The cutting speed of d is determined. The cutting speeds of the aggregate hoppers 1a to 1d may be directly recorded according to the cutting ratio of each aggregate determined by the type of asphalt mixture.

When the registration is completed, it is judged whether or not to continue the compound registration for another mixture type (S3). If it is completed, the process proceeds to END to complete the registration operation, and if it is continued, the process proceeds to step S1. Perform registration work for all mix types to be returned and manufactured.

Next, the operation of the plant is started and the operation panel 1
When the type of the composite material to be shipped and the planned shipment amount are input to 2, the aggregate supply control device 11 side receives the mixture content of the shipment composite material via the data transmission / reception unit 13 (S4), and then receives the planned shipment amount. Yes (S5). When the content of the mixture is received, next, the cut-out ratios of the aggregate hoppers 1a to 1d corresponding to the content of the mixture are read (S6). Further, the required supply amount of each aggregate is calculated and set based on the mixture content of the shipping mixture and the planned shipping amount (S7). At this time, it is advisable to take into account the supply amount of each aggregate by adding a plus α to the calculated aggregate supply amount so that the supply amount does not become insufficient.

When each aggregate supply amount is set, the target level of aggregate storage of the aggregate storage bin 9 is calculated based on each aggregate supply amount (S8). The target level of this aggregate storage bin is the aggregate storage level reached by each aggregate when the amount of each aggregate supply is sent to the corresponding compartment 9a-9d of the aggregate storage bin 9. This aggregate storage level is 0% empty,
It is advisable to display it in% with the full amount as 100%. In addition,
There is no problem if each aggregate supply amount is an amount that can be stored in the corresponding compartments 9a to 9d. However, if the aggregate amount is large and overflow occurs when the total amount is supplied, for the time being, it is 90 % Is set as the target level, and if there is shipping payment for aggregates, the target level will be revised sequentially.

Since the target level is the final target storage level to be stored in the aggregate storage bin, the actual stop of cutting of the aggregate is the target level minus the amount of aggregate retained during the transportation process. It is necessary to stop the cutting of the aggregate when the stock level is reached. Therefore, the predicted target level is calculated by subtracting the amount of aggregate accumulated in the conveying process from the target level, and this is set as the target level for aggregate supply control (S9).

When the setting of the predicted target level is completed, the aggregate supply can be started. The cutting speed is commanded from the speed setter 17 to the variable speed feeders 2a to 2d of the aggregate hoppers 1a to 1d based on the cutting ratio of the aggregates set by turning on the aggregate supply start switch. A predetermined amount of aggregate is cut out from the material hoppers 1a to 1d (S1).
0). A transfer timer is started at the same time when the cutting of the aggregate is started (S11). This transfer timer sets the time for the cut aggregate to reach the aggregate storage bin 9.

When the transfer timer counts up and the aggregate cut out from the aggregate hoppers 1a to 1d starts to be supplied to the aggregate storage bin 9, the operating condition of the plant is detected and the asphalt mixture is shipped (bone It is determined whether or not the material is paid out (S12). If the asphalt mixture is not shipped, the aggregate storage level of the aggregate storage bin 9 is gradually increasing without paying out the aggregate, and the aggregate storage level is set at predetermined time intervals. It is determined whether or not the measurement timer for measuring has counted up, and if it has not been counted up, it waits for counting up, and if it is counted up, the level meter 10 arranged in each of the compartments 9a to 9d Then, the storage level of each aggregate is received (S14). The aggregate storage level thus received is sequentially displayed on the screen of the operation panel 12 so that the operator can easily monitor it.

Further, when the asphalt mixture is being shipped, the aggregate storage level is measured at time intervals of one batch process. Then, it is judged whether or not the kneading for one batch is completed (S15). If the kneading is not completed yet, the kneading completion is awaited, and when the kneading is completed, the process proceeds to the next step. First, since one batch of aggregate was discharged, the expected target level of aggregate storage should be reduced by one batch, so it is necessary to correct this amount.

Therefore, the level amount corresponding to the aggregate amount paid out for one batch is subtracted from the predicted target level, and the value is reset as the predicted target level (S16). In addition,
How much the level (%) is lowered by paying out the aggregate for one batch is appropriately calculated in advance for each of the compartments 9a-9b, and more preferably for each height position of the storage level of each of the compartments 9a-9b. And set it.

As described above, the predicted target level will be corrected and set for each batch during shipping.

Next, in step S14, each aggregate storage level is received. When the storage level of each aggregate is received from each of the compartments 9a to 9d, the storage level of the previous time and the storage level of this time are compared, and the actual supply ratio of each aggregate storage bin is calculated from the difference ( S17). This actual supply ratio indicates the ratio of the aggregate amount substantially supplied to each of the compartments 9a to 9d between the previous storage level detection and the current storage level detection. Note that if the aggregate has been paid out during this period, the actual supply ratio is calculated in consideration of it.

The calculated actual supply ratio to each of the compartments 9a to 9d and the aggregate mixture ratio of the shipping mixture are compared (S1).
8) It is determined whether there is a difference (S19). If there is a difference between the two, it means that there is an excess or deficiency of the supply of specific aggregate relative to the amount of aggregate used in the shipping mix, so that the actual supply ratio should be close to the aggregate mix ratio of the shipping mix. Aggregate hopper 1a-
The cutout ratio from 1d is corrected (S20). For example, variable speed feeder 1a is increased by 5%, variable speed feeder 1b
Is reduced by 3%. It should be noted that how much difference should be made and how much the cutout ratio should be corrected is determined in advance. Further, the aggregate compounding ratio of the shipping mixture is the composition ratio of the aggregates having various particle sizes in the shipping mixture, and the particle size of the aggregates is different for each compartment 9a.
9d corresponds to those stored respectively.

As described above, the difference between the actual supply ratio of each of the compartments 9a to 9d and the aggregate mixing ratio is that the aggregate hoppers 1a to 1 are different.
This is because the variation in the particle size of the aggregate in d and the sieving of the synthetically supplied aggregate are not performed as ideal. Therefore, the correction amount of the cutout ratio of the aggregate is calculated so that the amount of the aggregate corresponding to the aggregate composition of the shipping mixture is stored in each of the compartments 9a to 9d of the aggregate storage bin 9, and the speed setter 1 is operated.
The speed correction is performed from 7 to the variable speed feeders 2a to 2d, and various aggregates are supplied to the shipping mixture without excess or deficiency.

When correcting the cutout ratio of the aggregate, the correction amount is determined in consideration of the following points. First, correction is performed so that the aggregate grain size of the aggregate does not deviate from the predetermined range. Also, make sure that the proportion of sand, etc., does not become too large and exceeds the capacity of the dryer. The correction value is displayed on the display device so that the operator can easily understand it.

Next, in step S21, it is determined whether the storage level of each aggregate has reached the predicted target level. If there is no difference in step 19, the process directly proceeds to step S21, and it is determined whether or not the storage level of each aggregate has reached the predicted target level. If the predicted target level has not been reached, the process returns to step S12, and a series of operations is repeated from confirmation of shipment. Further, when the predicted target level is reached, it is judged whether or not there is a next shipment (S2
2) If the product is shipped, the process returns to step S4 to repeat a series of operations from the reception of the mixture content. If the product is not shipped, the process goes to END to stop the aggregate supply. If the supply of the aggregate is stopped, each of the compartments 9a to 9d reaches a desired storage level at the time when the aggregate is fed into the aggregate storage bin during the transportation process.

In this manner, the actual supply ratio is calculated by detecting the storage level of the aggregate stored in each of the compartments 9a to 9d of the aggregate storage bin, and the actual supply ratio and the aggregate mixture of the shipping mixture. The ratio is compared, and if there is a difference, the cutout amount is corrected based on the difference value amount, and supply control is performed so that the ratio of the aggregate stored in each of the compartments 9a to 9d approaches the aggregate supply mixing ratio. Of.

Therefore, an appropriate amount of aggregate is supplied to the shipping mixture without excess or deficiency, some aggregates do not run out of aggregate, and the aggregate is concentrated in a specific compartment. Since the aggregate is not stored in a large amount, the driving operation becomes easy, and the amount of the residual material after the completion of the shipping work is reduced, and the residual material extraction work can be processed in a short time.
Furthermore, the amount of heating of the aggregate can be minimized without excessive supply of the specific aggregate, and the fuel consumption can be reduced.

Further, in the present invention, since the proper amount of aggregate is constantly supplied to the mixture of aggregates in the shipping mixture without excess or deficiency, for example, the amount of aggregate cut out from the aggregate hoppers 1a to 1d is determined by the conveyor. If the total amount of aggregate + α of the shipping mixture is supplied by measuring on a scale, an appropriate amount of the aggregate is supplied to the shipping mixture without excess or deficiency.

In the present invention, each compartment 9a-
The actual supply rate of aggregate to 9d and the mixture ratio of aggregate of shipping mixture are compared to correct the cut-out rate of each variable speed feeder 2a to 2d.
Each variable speed feeder 2 is compared with the actual supply amount of aggregate to the aggregate and the set supply amount of each aggregate calculated from the aggregate mixture ratio of the shipping mixture.
Even if the cutout amounts a to 2d are corrected, the total aggregate cutout amount per unit time is set to be substantially constant, so that they are essentially equivalent and belong to the technical scope of the present invention. is there.

[0035]

As described above, in the aggregate supply control method for an asphalt plant according to the present invention, the level meter 1 for detecting the storage amount in each of the compartments 9a to 9d of the aggregate storage bin 9 is provided.
0 is provided, and an aggregate supply control device 11 that receives a signal from the level meter and controls the cutout amount of the aggregate hoppers 1a to 1d is provided. When the aggregate is supplied, the level meter 10 is used at predetermined timings. The actual supply ratio of each aggregate is calculated from the detected aggregate storage level of each of the compartments 9a to 9d, and the actual supply ratio is compared with the aggregate mixture ratio of the shipping mixture. When there is a difference, the actual supply ratio is shipped. Since the amount of aggregate cut out from the aggregate hoppers 1a to 1d is adjusted to match the aggregate mixture ratio of the aggregate, an appropriate amount of aggregate that is suitable for the amount of various aggregates used in the shipment mixture is used. It can be supplied to the aggregate storage bin 9 without any shortage,
There is no possibility that some of the aggregate will run out of aggregate, and a large amount of aggregate will not be stored in a specific compartment, which will make the operation easier and make it easier to operate after shipping. The amount of residual material is reduced, and the work of extracting the residual material can be processed in a short time, so that the aggregate is efficiently supplied.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a schematic configuration of an asphalt plant that employs an aggregate supply control method of the present invention.

FIG. 2 is a flowchart showing a procedure of an aggregate supply control method of the present invention.

FIG. 3 is a flowchart showing a procedure of an aggregate supply control method of the present invention.

[Explanation of symbols]

1a to 1d ... Aggregate hopper 2a to 2d ... Variable speed feeder 3 ... Drawer conveyor 4 ... Weighing conveyor 5 ... Dryer 9 ... Aggregate storage bin 9a-9d ... Compartment chamber 10 ... Level meter 11 ... Aggregate supply controller 12 ... Operation board

Claims (1)

[Claims] 1. An aggregate is cut out at a desired ratio from an aggregate hopper in which aggregates are stored for each type and the amount of cutting can be freely controlled by a variable speed feeder, and after heating by a dryer that is a heating device, a plant It is temporarily stored in each compartment of the main body's aggregate storage bin by particle size, and a certain amount of aggregate with various particle sizes is weighed based on the mix of asphalt mixture to be manufactured, and mixed with other materials such as asphalt by a mixer. In an asphalt plant that manufactures asphalt mixture, a level meter for detecting the storage amount is arranged in each compartment of the aggregate storage bin, and the cutout amount of each aggregate hopper is controlled by a signal from the level meter. Equipped with an aggregate supply control device, the aggregate cutout ratio of the aggregate hopper is stored in advance for each type of asphalt mix, and shipped according to the asphalt mix shipping instruction. At the same time as starting the cutout of aggregate from each aggregate hopper at the aggregate cutout ratio corresponding to the mix type, the aggregate level of each compartment was detected by the level meter at every predetermined timing, and the previous time was detected. The actual supply rate of aggregate to each compartment is calculated from the difference in the aggregate storage level between this and this time, and if there is a difference between the actual supply rate and the aggregate mixture ratio of the shipping mixture, the aggregate to each compartment The method of controlling the supply of aggregate in an asphalt plant, wherein the cutting ratio of each variable speed feeder is sequentially corrected so that the actual supply ratio of the above approaches the aggregate mix ratio of the shipping mixture.