JP3232492B2 - Pre-cooling method automatic temperature control 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 method for pre-cooling aggregates such as sand and gravel in order to prevent cracks caused by a rise in temperature during casting of concrete and a subsequent drop in temperature. The present invention relates to a pre-cooling method automatic temperature control system for controlling the temperature of the above-mentioned kneading by controlling the temperature of the sand or gravel in the pre-cooling method to be lowered.

[0002]

2. Description of the Related Art As is well known, restraint stress acts on mass concrete as the temperature rises or falls due to the heat of hydration of cement, which may cause cracks.
A pre-cooling method is known as one of the methods for preventing such cracks. The pre-cooling method is mainly used in the summer season, and is a method of pre-cooling a part or the whole of a concrete material to lower the temperature at which concrete is poured.

Conventionally, in the pre-cooling method,
Temperature management during the production of concrete, in advance, predict the kneading temperature from the temperature of each concrete material, if there is a difference between the kneading temperature and the target kneading temperature,
For example, by injecting liquefied gas into sand, gravel, etc.,
The temperature of the sand, gravel or the like is lowered to bring the kneading temperature close to a target value.

A batcher plant (concrete plant) used in the conventional pre-cooling method is provided with a supply facility for each material, a storage unit, a measuring device, a mixer, a hopper, and the like. A temperature sensor for measuring the temperature of the material is provided. And
As shown in the flowchart of FIG. 5, first, the temperature of each material is measured by this temperature sensor (step a1). These measured temperatures are input to a computer (arithmetic processing unit), and the arithmetic processing unit calculates a kneading prediction temperature based on the measured temperatures (step a2).

[0005] Here, when the measured temperature of sand, gravel, etc. is high and the predicted kneading temperature is higher than the target kneading temperature, the worker injects liquefied gas into the sand and gravel of the batcher plant, The sand and gravel are to be cooled, and the injection amount of the liquefied gas was predicted by the operator based on his or her experience (step a3). Then, the worker operated the controller of the liquefied gas injection equipment attached to the batcher plant based on the values predicted by himself, set the amount of liquefied gas to be injected, and injected the liquefied gas. (Step a
4).

[0006] Then, the worker confirms the temperature of the sand and the gravel, and confirms the temperature of the concrete measured in the batcher plant and kneaded together with the cooling water in the mixer (step a5). When the concrete is continuously manufactured, the material temperature is continuously measured, the injection amount of the liquefied gas is predicted at any time as described above, and the liquefied gas is injected.

[0007]

By measuring the temperature of the concrete material and inputting it to a computer as described above, the kneading temperature can be predicted by the computer processing. The temperature control of the sand and the gravel which affects the rising temperature has been performed by the worker appropriately injecting the liquefied gas into the sand and the gravel based on his experience.

That is, at present, the temperature of sand and gravel is controlled by determining the injection amount of the liquefied gas based on the experience and intuition of the worker. Therefore, the optimal amount of the liquefied gas is not necessarily injected, and excessive use of the liquefied gas may cause an increase in cost or a large variation in the concrete kneading temperature for each batch.
Temperature control of sand and gravel has been a difficult task requiring skilled workers. Therefore, in order to promote labor saving in the production of concrete and the like, automation of temperature control of sand and gravel in the pre-cooling method has been required.

The present invention has been made in view of the above circumstances, and in the pre-cooling method, the temperature control of aggregates such as sand and gravel is automatically controlled to more strictly control the temperature at which the concrete is mixed. It is another object of the present invention to provide an automatic temperature control system for a pre-cooling method, which can save labor for manufacturing cooled concrete by the pre-cooling method.

[0010]

An automatic temperature control system for a pre-cooling method according to the present invention provides a concrete plant using a pre-cooling method for manufacturing cooled concrete by cooling aggregate in advance. A liquefied gas is injected into a storage unit to cool the aggregate, and a pre-cooling method automatic temperature control system for controlling the kneading temperature of concrete by automatically controlling the amount of the liquefied gas injected. A temperature sensor provided in a storage section of each concrete material of the concrete plant, and an injection amount calculation for calculating an injection amount of the liquefied gas based on the temperature of each concrete material measured by the temperature sensor. Device and injection control for controlling injection of liquefied gas based on the injection amount of liquefied gas obtained by the injection amount calculation device Comprising a device, the bubbler amount calculation
The device is equipped with each concrete measured by the temperature sensor.
Temperature of concrete based on the temperature of material
Kneading temperature calculating means for predicting the kneading temperature and the kneading temperature
Kneading prediction temperature and prediction calculated by the
Of the liquefied gas based on the set target temperature
An injection amount calculating means for calculating an injection amount;
The amount calculation means is operated in the concrete plant.
Twice in case of continuous concrete production
The above kneading temperature when performing batch processing after
Instead of the kneading predicted temperature obtained by the calculation means
The temperature provided in the mixer of the concrete plant.
Of the previous batch process output by the
Calculate the injection amount based on the heat-up temperature
Also, the injection amount calculating means detects the
The kneading temperature is adjusted to a preset upper or lower limit.
Recalculates and sets the injection amount when the number exceeds the specified number of times continuously
Re-setting is performed within the range of the preset limit value.
It is a configuration that is performed by increasing or decreasing the set value within
Sign.

[0011]

[0012]

[0013]

According to the above construction, the predicted kneading temperature of concrete is calculated by the kneading temperature calculating means of the injection amount calculating device based on the measured temperature of each concrete material, and the predicted kneading temperature is set in advance as the predicted kneading temperature. The injection amount of the liquefied gas is obtained by the injection amount calculating means based on the kneading target temperature .

Therefore, the amount of the liquefied gas to be injected is automatically set based on the predicted temperature at which the liquefied concrete is injected, and the liquefied gas is injected. Thus, it is possible to accurately control the temperature at which the liquefied gas is injected. Become. Furthermore, when batch processing of concrete production is repeatedly performed continuously, the injection amount of the liquefied gas is obtained based on the concrete kneading temperature in the previous batch processing instead of the predicted concrete kneading temperature. In addition, it becomes possible to more accurately control the kneading temperature in accordance with the current situation.
Moreover, the kneading temperature detected at the end of each batch rises.
If the limit or lower limit is exceeded continuously for a specified number of times
First, recalculate the injection volume and set it again, and
To reset it, increase or decrease the set value within the limit value range
So that the kneading temperature can be changed slowly
And a rapid change in temperature can be prevented.

[0015]

[0016]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a basic configuration of an automatic temperature control system for a precooling method according to this embodiment. As shown in FIG. 1, the automatic temperature control system
B / P operation panel 1 for controlling and operating concrete material supply, measurement, kneading, etc. by a batcher plant (B / P) not shown, and liquefied gas to aggregates such as sand and gravel in the batcher plant Liquefied gas injection controller 2 for controlling the injection amount of liquefied gas, arithmetic processing unit (personal computer) 3 for manufacturing process management for transmitting liquefied gas injection amount data to the liquefied gas injection amount controller 2, A monitor processing unit (personal computer) 4 for monitoring the manufacturing process.

The B / P operation panel 1, the liquefied gas injection amount controller 2, the manufacturing process management processor 3, and the monitor processor 4 are connected to each other online. In addition, the batcher plant performs the production of the cooling concrete for each batch, and in order to produce a large amount of the cooling concrete, the batch processing of the production of the cooling concrete is continuously and repeatedly performed. . Further, in the batcher plant, a temperature sensor (not shown) is installed in a storage section of each concrete material such as fine aggregate, coarse aggregate, cement, etc., and is output from each temperature sensor, and is output from each concrete material. A signal indicating the temperature is input to the B / P operation panel 1 and the arithmetic processing unit 3 for manufacturing process management. Further, temperature sensors (not shown) are also provided in the mixing water tank and the mixer (not shown), and a signal output from each temperature sensor and indicating a water temperature or a kneading temperature is transmitted to the B / P.
The data is input to the operation panel 1 and the arithmetic processing unit 3 for manufacturing process management.

The B / P operation panel 1 is a well-known one, and controls a batcher plant for supplying, measuring, kneading, etc. each concrete material by setting the amount of each concrete material in advance. It is. Also, B /
The P operation panel 1 is installed in a storage unit for coarse and fine aggregates of the batcher plant based on a signal to be described later from the liquefied gas injection amount controller 2 and is an injection device (not shown in the drawings) for injecting liquefied gas. ) Has a function of controlling the start and stop of the injection of the liquefied gas in the above. Liquefied gas injection controller 2
Has a function of outputting a signal for controlling the start and stop of the injection of the liquefied gas to the B / P operation panel 1, and the liquefied gas injection amount described later input from the arithmetic processing unit 3 for manufacturing process management. Based on the data, the injection time of the liquefied gas is determined so that the liquefied gas is injected into the storage part of the aggregate by the injection amount of the liquefied gas injection amount data, and the injection start and the injection are determined based on the injection time. The injection stop signal is output to the B / P operation panel 1.

The manufacturing process control arithmetic processing unit 3 calculates a kneading predicted temperature from a temperature signal indicating the temperature of each concrete material input from the temperature sensor and sets a preset kneading temperature target value. Calculates the injection amount of liquefied gas necessary to lower the aggregate temperature in order to bring the temperature closer to the kneading temperature, and outputs the injection amount to the liquefied gas injection amount controller 2 as liquefied gas injection amount data. It is supposed to.

The monitor arithmetic processing unit 4 includes a temperature signal from each temperature sensor input to the manufacturing process management arithmetic processing unit 3, a calculation result by the manufacturing process management arithmetic processing unit 3, and the B / P operation panel 1. Are transmitted from the manufacturing process management processor 3 via a communication line, and these data can be monitored at a remote location. The monitor processing unit 4 is installed in a place where there are many engineers such as a head office, a branch office, and a research facility of a company that manufactures concrete, and there is any change or abnormality in the concrete manufacturing process. In this case, the engineer at the head office, branch office or research facility gives instructions to the operator or technician who operates the batcher plant while monitoring the data of the manufacturing process by the monitor arithmetic processing unit 4. It is.
Therefore, technicians at the head office, branch offices, or research facilities can give accurate instructions to the site while monitoring data in real time as well as at the site, and can respond appropriately to abnormalities in the concrete manufacturing process, and The burden on workers and technicians can be reduced.

Hereinafter, the temperature control of aggregates such as sand and gravel by the pre-cooling method automatic temperature control system having the above configuration will be described with reference to the flowchart of FIG. First, the temperature of each concrete material including the mixing water in the storage section is measured by each of the temperature sensors (step b1), and a temperature signal indicating the temperature is output to the arithmetic processing unit 3 for manufacturing process management. Next, the arithmetic processing unit 3 for manufacturing process management calculates the estimated kneading temperature of the cooling concrete from the temperature of each material based on the following equation in order to determine the injection amount of the liquefied gas in the first batch of the batcher plant. (Step b2).

(Equation 1) T: Predicted kneading temperature ρi: Weight Ci: Specific heat Ti: Material temperature i: Each material temperature H: Mixer rotation heat

Next, the arithmetic processing unit 3 for manufacturing process management comprises:
The injection amount of the liquefied gas of the first batch is calculated from the difference between the calculated expected kneading temperature and the preset target temperature based on the following equation (step b3). LN2−W × ΔT × A = f (ΔT) LN2: Liquefied gas injection amount ΔT: Cooling width (° C.): (Predicted kneading temperature) − (Target kneading temperature) W: 1 m ³ / ° C. Liquefied gas injection amount A: Concrete amount per batch of mixer

Then, the determined injection amount of the liquefied gas is:
Transmitted to the liquefied gas injection controller 2 as data,
The liquefied gas injection controller 2 sets the injection time based on the liquefied gas injection amount, outputs a liquefied gas injection start and stop signal to the B / P operation panel 1, and based on the signal, the B / P The operation panel 1 controls the injection of the liquefied gas (step b4). Then, a liquefied gas is injected into the aggregate. Then, each material is measured and supplied by the batcher plant and kneaded in the mixer. Then, in the mixer, the kneading temperature is measured by the temperature sensor and output to the arithmetic processing unit 3 for manufacturing process management, which is checked by the operator (step b5).

Next, the temperature control when the second and subsequent batch processes are continuously performed will be described with reference to the flowchart shown in FIG. 3 and the graph of the temperature change of the mixer shown in FIG. In the arithmetic processing unit 3 for manufacturing process management,
A temperature signal indicating the kneading temperature measured and output by the temperature sensor of the mixer is read (step c).
1) After completion of one batch (step c2), the lowest temperature in the mixer in each batch is specified (step c3).
Next, an upper limit value and a lower limit value are set in advance with a predetermined width with respect to the target value of the kneading temperature, and it is determined whether the minimum temperature in the mixer for each batch exceeds the upper limit value or the lower limit value ( Step c4). Next, when the minimum temperature in the mixer for each batch exceeds the upper limit value or the lower limit value, the number of times (batch number) is counted, and it is determined whether or not the count value reaches three times (step c5).
The count value is reset when the minimum temperature in the mixer for each batch returns to the target value, or exceeds the target value and conversely exceeds the lower limit value or upper limit value, or reaches three times. It is checked whether the minimum temperature in the mixer for each batch has exceeded the upper limit value or the lower limit value three times in succession. That is, it is determined that the upper limit has been exceeded three consecutive times in the portion indicated by reference numeral 8 in the graph of FIG. In the graph of FIG. 4, a white triangle 6 indicates the minimum temperature for each batch, and a vertical line 7 indicates a break between batches.

When the lowest temperature in the mixer for each batch exceeds the upper limit or the lower limit three times in a row as shown in the figure (portion 9 in FIG. 4), the liquefied gas is injected again. While calculating the input amount (step c
6) The liquefied gas injection amount is transmitted to the liquefied gas injection controller 2 to reset the liquefied gas injection amount (step c7), and the liquefied gas injection amount is changed from the next batch. I do. In the calculation in step c6, unlike the calculation formula for obtaining the liquefied gas of the first batch, the kneading temperature of the previous batch is used instead of the kneading prediction temperature. That is, the cooling width ΔT is obtained by (kneading target temperature) − (previous kneading temperature). Instead of directly calculating the amount of injected liquefied gas, the increase / decrease value ΔΔliquefied gas of the amount of injected gas with respect to the amount of injected liquefied gas of the previous batch is calculated using an arithmetic expression f (a) obtained experimentally in advance. It has become.

That is, f (ΔT) = Δliquefied gas. Then, the .DELTA. Liquefied gas is added to the liquefied gas injection amount of the previous batch to obtain the next liquefied gas injection amount. Note that a limit value is set in advance for the Δ liquefied gas, and when the Δ liquefied gas exceeds the limit value by the above calculation, the value of the Δ liquefied gas is set to the limit value. I have. As described above, when the minimum temperature in the mixer for each batch exceeds the upper limit or the lower limit three times, the injection amount of the liquefied gas is changed,
By providing the limit value, it is possible to prevent the temperature value from vibrating up and down during temperature control in the mixer.

According to the automatic temperature control system of the pre-cooling method as described above, the amount of liquefied gas injected can be determined without relying on the intuition and experience of the operator, and the burden on the operator can be reduced, and Since it is possible to manage the production of the cooling concrete even if it is not a worker who has performed the above, labor saving of the production of the cooling concrete by the pre-cooling method can be achieved. In addition, since the liquefied gas injection amount is determined based on the kneading predicted temperature calculated by the manufacturing process arithmetic processing device or the kneading temperature of the previous batch, the cooling concrete is more accurately compared to the conventional method. Can be controlled. Therefore,
Since the kneading temperature can be controlled accurately, the quality of the cooled concrete can be improved.

Further, the monitor processing unit allows a technician at a remote location to monitor the manufacturing process of the cooled concrete, and when there is any change or abnormality in the manufacturing process, a worker at the site can be monitored. Since an accurate instruction can be given, any change or abnormality in the manufacturing process can be easily dealt with, and the burden on the site worker can be reduced.

[0029]

As described above in detail, according to the automatic temperature control system of the precooling method of the present invention, the temperature of each concrete material is measured by the temperature sensor, and the injection amount calculation device calculates the injection amount of the liquefied gas. Calculation and the injection control device controls the injection of the liquefied gas based on the injection amount, so that the cooling concrete can be more accurately compared to the case where the operator determines the injection amount of the liquefied gas based on experience and intuition. Can be controlled, and the quality of concrete can be improved.

Further, since it is not necessary for the operator to determine the injection amount, the burden on the operator can be reduced, and the labor for manufacturing the cooling concrete by the pre-cooling method can be reduced. In addition, the injection amount calculation processing device calculates the kneading predicted temperature from the temperature of each concrete material by the kneading temperature calculating means, and injects the liquefied gas based on the kneading predicted temperature by the injection amount calculating means. Since the injection amount is determined, the predicted kneading temperature, which has been conventionally used for reference, can be effectively used, and the injection amount of the liquefied gas can be made accurate.

Furthermore, in the production of cooling concrete, when batch processing is continuously repeated, when determining the amount of liquefied gas to be injected in the second and subsequent batch processing, the temperature is replaced with the predicted kneading temperature. Thus, the injection amount of the liquefied gas is determined based on the kneading temperature in the previous batch, so that the injection amount of the liquefied gas can be determined more in accordance with the current situation.

Further, the injection amount calculation means terminates each batch.
The kneading temperature detected every time is higher than the preset upper limit value.
Or, if the lower limit is exceeded continuously for a predetermined number of times,
Recalculate and set again.
Configuration by increasing or decreasing the set value within the limit value
Therefore, slowly change the kneading temperature
And a rapid change in temperature can be prevented.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a basic configuration of an automatic temperature control system for a precooling method according to an embodiment of the present invention.

FIG. 2 is a flowchart for explaining a control method in the precooling method automatic temperature control system.

FIG. 3 is a flowchart for explaining a control method in the second and subsequent batch processes in the pre-cooling method automatic temperature control system.

FIG. 4 is a graph for explaining a control method in the precooling method automatic temperature control system.

FIG. 5 is a flowchart for explaining a temperature control method in a conventional pre-cooling method.

[Explanation of symbols]

1 B / P operation panel (injection control device) 2 Liquefied gas injection controller (injection control device) 3 Processing unit for manufacturing process management (injection amount operation device, kneading temperature operation device, injection amount operation device 4) Monitor processing unit (monitor processing unit)

──────────────────────────────────────────────────続 き Continuation of front page (72) Inventor Mitsuaki Watanabe 1-3-2 Shibaura, Minato-ku, Tokyo Shimizu Corporation (56) References JP-A-2-169205 (JP, A) JP Hei 2-124432 (JP, A) Japanese practice Hei 5-35216 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) B28C 7/02 E04G 21/02 103

Claims (1)

(57) [Claims] In a concrete plant using a pre-cooling method for manufacturing cooled concrete by cooling aggregates in advance, a liquefied gas is injected into a storage section of the aggregates to cool the aggregates. And, a pre-cooling method automatic temperature control system for controlling the temperature of the concrete kneading by automatically controlling the injection amount of the liquefied gas, provided in the storage section of each concrete material of the concrete plant respectively Temperature sensor, an injection amount calculating device for calculating an injection amount of the liquefied gas based on the temperature of each concrete material measured by the temperature sensor, and a liquefied gas calculated by the injection amount calculating device. ; and a bubbler control device for controlling the bubbler of the liquefied gas based on the bubbler amount, the bubbler calculation unit is measured by the temperature sensor Re
Of concrete based on the temperature of each concrete material
Kneading temperature calculating means for estimating the kneading temperature;
Kneading determined by the kneading temperature calculating means
Based on the predicted temperature and the preset kneading target temperature
Injection amount calculating means for calculating the injection amount of liquefied gas.
The injection amount calculating means is provided for the concrete plant.
To manufacture concrete continuously and repeatedly.
In performing the second and subsequent batch processes,
Predicted kneading temperature obtained by the unloading temperature calculating means
In place of the concrete plant mixer
Of the previous batch processing output by the temperature sensor
Calculate the injection amount based on the concrete kneading temperature,
In addition, the injection amount calculation means detects each injection at the end of each batch.
The upper limit or lower limit of the preset kneading temperature
If the value exceeds the predetermined number of times continuously, recalculate the injection amount.
Re-setting and re-setting are based on the preset limit value.
An automatic temperature control system for a pre-cooling method, characterized in that the preset value is increased or decreased within a range .