JPH01189488A - Control to cooling oven for baked block - Google Patents

Abstract

PURPOSE:To enable more effective control by the surface temperature of baked blocks, by performing a cascade loop control so that the surface temperature in the baked block gets to a set point, by detecting the surface temperature in the baked block, and by using a detected signal as a set signal to the cascade to control the velocity of a grate and the flow rate of a cooling transfer medium. CONSTITUTION:The surface temperature of baked blocks is detected by a temperature sensor 23, and a detected value is input in a temperature controller 25 via a temperature transmitter 24. The temperature controller 25 is set so that the surface temperature of the baked block is to reach a set point of about 1,000 deg.C in the neighborhood of the outlet of a primary chamber 9. After the deviated portion of a signal is processed by a constant and others in arithmetic and logic units 26a and 26b, a result is input both into a pressure controller 17 and a flow rate controller 21 as set signals, and a cascade control loop is constituted. In order to detect the surface temperature, a sensor not in direct contact to the block such as a continuous radiating thermometer is recommendable. The accuracy in control is improved and a purpose to cool baked block can be truly achieved by constituting a cascade control loop by the surface temperature of the block.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a baked ingot cooling device, and particularly to an optimal control method for cooling the baked ingot.

[Conventional technology]

An example of a conventional baked ingot cooling device is shown in FIG. That is, the baked ingots 4 that have fallen from the rotary kiln 1 are transported by a back-and-forth movement of a grate 50 having a large number of ventilation holes, and these large baked ingots 4 are cut into an appropriate size by a hanger breaker 7 and sent to the next stage via a discharge conveyor 15. transported to the process.

Furthermore, the baked ingot 4 placed on the grate 5 is cooled by cooling air blown up from the cooling air chamber 9 at the bottom of the grate 5.

These cooling airs are discharged from an exhaust fan 12 as secondary air 13 and exhaust air 10 to the burner 3 for the kiln 1.

An example of a control method for a conventionally used ingot cooling device is shown in FIG. That is, the speed of the main body driving device 6a is adjusted so that the pressure in the first cooling air chamber 9 becomes constant using the pressure transmitter 16 and the pressure regulator 17. The speed of the main body drive device 6b for the second stage is adjusted by a ratio setting device 18 so that the speed is multiplied by a certain ratio.

Furthermore, in order to keep the amount of air supplied to the cooling air chamber 9 constant, the amount of cooling air is measured by the differential pressure generator 19, and the differential pressure transmitter 2
This is done by the damper operating device 22 which controls the airflow rate of the cooling fan 8 through the 0% flow rate controller 217.

However, in the prior art, although the purpose is to cool the baked ingot, the temperature of the baked ingot is controlled, and the surface of the baked ingot on the grate is occasionally checked using a radiation thermometer.

Also, when viewed in the cross-sectional direction of the classification due to the rotation of the kiln, which is unique to the baked ingot cooling system, the side in the direction of kiln rotation.

, resulting in the formation of so-called red rivers.

In addition, in Figures 2 and 3, 2 is a kiln hood, and 8 is a kiln hood.
1 is a cooling fan, 11 is a dust collector, 12 is an exhaust fan, 1
4 is bleed air.

[Problem to be solved by the invention]

The above-mentioned conventional technology does not take into consideration the cooling effect such as the temperature of the baked ingot after being cooled, and has a problem in the control method.

An object of the present invention is to eliminate the drawbacks of the prior art and provide a more effective method of controlling the surface temperature of baked ingots.

[Means to solve the problem]

The above object is achieved by continuously detecting the surface temperature of the baked ingot by a temperature detector and performing cascade loop control with respect to conventional grate speed control and cooling medium flow rate control.

[For production]

When controlling the surface temperature of the baked ingot, the positioning control is performed using the grate speed and the cooling air flow rate so that the target surface temperature is achieved as shown in Figs. 4 and 5. Phenomena such as transient overshoot or undershoot caused by the conventional control method shown in FIG. 1 are also eliminated.

To further explain FIGS. 6 and 7, if the amount falling from the kiln increases and the layer thickness increases, the pressure will increase and the grate speed will increase. Since the air volume decreases due to the increased resistance of the layer, the damper opening degree increases. Therefore, the pressure becomes even greater and the grate velocity becomes even faster. In this way, overshoot occurs regardless of temperature.

From Figures 4 and 5, if the surface temperature falls below the target value during the above process, cascade control works to reduce the grate speed and damper opening 1f, so the above overshoot can be suppressed. .

[Embodiments of the invention]

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

The example shown in FIG. 1 is the control method of the present invention. That is, in contrast to the conventional grate speed control using the first chamber pressure and damper opening control using the cooling air flow rate, the temperature sensor 23 detects the surface temperature of the baked ingot, and the temperature controller 24 detects the surface temperature of the baked ingot. 25.

The temperature controller 25 is set so that the surface temperature of the baked ingot reaches a target value (approximately 1000° C.) near the exit of the first chamber 9, and a signal corresponding to this deviation is sent to the calculator 26a.

26b performs arithmetic processing on constants, etc., and then inputs them as setting signals to the pressure regulator 17 and flow rate regulator 21 of the control system of the conventional system, thereby forming a cascade control loop.

The 26 computing units are configured to perform calculation processing of response delay in the great speed control and air volume control loop, and calculation processing of differences in control characteristics between respective pressures and flow rates.

For detecting the surface temperature, it is preferable to use a detector that does not come into direct contact with the baked ingot, such as a continuous radiation thermometer.

On the other hand, in order to prevent the red river IK that is formed due to the classification caused by the rotation of kiln 1, it is best to incorporate the surface temperature on the side of the red river 1 into the temperature control as the most effective. .

A control method for preventing red rivers is shown in, for example, Japanese Patent Application No. 54874/1983.

According to the control method of the present invention, the grate speed control based on the pressure in the first chamber and the damper opening control based on the amount of cooling air were each independent control systems, but based on these control results,
By creating a cascade control loop based on the surface temperature of the baked ingot, control accuracy is further improved and the objective of true cooling of the baked ingot can be achieved.

Other embodiments of the present invention will be described. In the example shown in Figure 1, the two control plans of first chamber pressure control and cooling air flow rate control are simultaneously controlled in cascade, but the capacity (size) of the ingot cooling system depends on the cooling There may be cases where cascade control of the air flow rate is more effective; in this case, the pressure controller 17 is connected to the temperature controller 2.
The number of adjustment signal tones from 5 is not included, and a normal stationary control loop is used.

Furthermore, the precision of these control loops can be improved by implementing DDC (digital direct control) using a control computer or the like.

〔Effect of the invention〕

According to the present invention, as mentioned above, the cooling effect, which is the original purpose of cooling the baked ingot, is controlled while continuously checking the surface temperature of the baked ingot, so that the baked ingot (clinker, etc.) of stable quality is produced. We will be able to provide it.

[Brief explanation of the drawing]

FIG. 1 is a control system diagram of a sintered ingot cooling device according to an embodiment of the present invention, FIG. 2 is a system diagram of a control method for a sintered ingot cooling device according to the prior art, and FIG. 3 is a functional explanatory diagram of the sintered ingot cooling device. Figures 4 and 5 are diagrams showing the relationship between surface temperature and grate speed according to the present invention, as well as diagrams showing the relationship between surface temperature and damper opening degree. Similarly, FIG. 7 is a diagram showing the relationship between the air volume and the damper opening degree. Figure 4 Figure 5 Figure 6 Figure 7

Claims (1)

[Claims] In a baked ingot cooling device that transports a baked ingot on a grate having a large number of ventilation holes and cools the baked ingot with a cooling medium introduced from the bottom of the grate, the surface temperature of the baked ingot is detected and Using the detection signal as a cascade setting signal for grate speed control and coolant flow control,
A control method for a baked ingot cooling device characterized by performing cascade loop control so that the surface temperature of the baked ingot reaches a target value.