JP2001065826A - Furnace temperature controller for melting furnace - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve response by bringing furnace temperature to an object temperature more rapidly by fixing a fuel supply amount to a control input at that time when a deviation becomes a predetermined value in the course of ordinary control. SOLUTION: A burner 3 is provided for heating and melting the surface of an article a flowing down and supplied to a main chamber 1, and a sensor 8 is provided for detecting h the temperature tp in the main chamber. Fuel supply control means 9 is provided for controlling the amount Q of fuel supply to the burner 3 such that a deviation between a target temperature ts and a detection temperature tp by the sensor 8 becomes a predetermined value based upon the deviation itself. The fuel supply control means includes a control section 10 for expanding the deviation Δt in an early time and excessively controlling the amount Q of fuel supply employing the amount of fuel supply for bringing the expanded deviation to a predetermined value as a target value, and then returning the target value to the amount of fuel supply for bringing the deviation to the predetermined value for a time up to the final of the interval to hereby ordinarily controlling the amount Q of fuel supply.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention provides a burner for heating and melting the surface of a material to be melted (waste, etc.) which is supplied to a main chamber such as a waste melting furnace. Fuel supply control means for providing a sensor for detecting, and for every set time interval, controlling a fuel supply amount to the burner based on a difference between a target temperature and a temperature detected by the sensor so that the difference becomes a predetermined value. The present invention relates to a furnace temperature control device of a melting furnace provided with the above.

[0002]

2. Description of the Related Art In a melting furnace such as a waste melting furnace, the temperature in the furnace is maintained at a set value (target value) in order to stably perform melting. Conventionally, a thermocouple, a radiation thermometer, etc. The temperature of the main chamber is detected by the sensor described above, and the amount of fuel supplied to the burner is adjusted so that the detected temperature becomes the target temperature, so as to maintain the furnace temperature at the target temperature.

[0003]

However, in the case of the above-mentioned conventional technique, the fuel supply amount is controlled from the beginning to the end of the interval by setting the fuel supply amount as a target value to make the deviation a predetermined value. The response was poor because the temperature was raised and lowered relatively slowly to avoid the problem. As a result, it has been impossible to cope with a case where the temperature of the molten material suddenly rises due to collapse, or a case where the temperature suddenly decreases due to the melted surface being clogged.

An object of the present invention is to improve responsiveness.

[0005]

The features, functions and effects of the present invention according to claim 1 are as follows.

[Features] A burner is provided for heating and melting the surface of the material to be melted and supplied to the main chamber, and a sensor for detecting the temperature of the main chamber is provided. In a melting furnace provided with fuel supply control means for controlling an amount of fuel supplied to the burner based on a deviation from a temperature detected by the sensor so that the deviation becomes a predetermined value, the fuel supply control means may include an interval. Initially, the fuel supply amount is excessively controlled with the target value being the fuel supply amount for enlarging the deviation and making the enlarged deviation a predetermined value,
After that, a control unit is provided that normally controls the fuel supply amount by returning the target value to the fuel supply amount that makes the deviation a predetermined value during the time until the end of the interval.

[Operation] At the beginning of the interval, if the detected temperature is lower than the target temperature by excessive control, the fuel is excessively supplied to rapidly increase the furnace temperature, and the detected temperature is lower than the target temperature. If it is too high, it is supplied too low to rapidly lower the furnace temperature.After that, the furnace temperature is slowly raised and lowered under normal control to reach the target temperature. The temperature can be quickly controlled, and overshoot can be prevented as much as possible.

[Effect] Accordingly, the responsiveness is improved, and it is possible to quickly and surely cope with a rapid change in the furnace temperature.

The features, functions and effects of the present invention according to claim 2 are as follows.

[Features] In the present invention according to claim 1, the control unit fixes the fuel supply amount to the control amount at the time when the deviation reaches a predetermined value during the normal control. It is in.

[Operation] When the deviation becomes a predetermined value during the normal control, the fuel supply amount is fixed to the control amount at that time, so that the furnace temperature is more quickly brought to the target temperature. be able to.

[Effect] Therefore, the responsiveness can be further improved.

The features, functions and effects of the present invention according to claim 3 are as follows.

[Features] In the present invention according to claims 1 and 2, the control unit operates when the deviation is equal to or larger than the set value, and when the deviation is smaller than the set value, the fuel supply for setting the deviation to a predetermined value. The second control unit that controls the fuel supply amount using the amount as a target value is configured to operate.

[Operation] When excessive control is performed, overshoot may occur depending on the deviation. On the other hand,
Excessive control is required mainly when the temperature inside the furnace fluctuates rapidly and the deviation is large. Focusing on the above points, excessive control is performed only when the deviation is equal to or more than the set value, and when the deviation is smaller than the set value, the fuel supply amount is controlled with the fuel supply amount that sets the deviation to a predetermined value as a target value. Therefore, in both cases where the deviation is large and small, it is possible to quickly control the furnace temperature to the target temperature while preventing overshoot.

[Effect] Accordingly, control performance according to the temperature condition can be exhibited.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIG. 1, in a melting furnace, a material a to be melted flows down from the periphery of the main chamber 1 to the outer periphery of a main chamber 1 having a slag port 1a formed at the bottom. A burner is provided on the ceiling of the main chamber 1 for heating and melting the surface of the material a to be melted and supplied from the storage section 2 to the main chamber 1 with a combustion flame. A fuel valve 5 for adjusting a fuel supply amount is provided in a fuel supply path 4 to the burner 3, and air for adjusting an air supply amount in a combustion air supply path 6 to the burner 3 is provided. It is configured with a valve 7 interposed.

The furnace temperature control device of the melting furnace is provided with a sensor 8 (thermocouple, radiation thermometer, etc.) for detecting the temperature tp in the main chamber 1, and FIG. As shown in FIG. 3, the target temperature ts and the temperature tp detected by the sensor 8 are set at intervals of a set time T (eg, 90 seconds).
Is determined by a predetermined value (0,
0, etc.), the fuel supply amount Q to the burner 3 is controlled and the air supply amount is corrected and controlled in accordance with the control of the fuel supply amount Q. That is, the fuel valve 5 and the air The fuel supply control means 9 for operating the valve 7 is provided.

At the beginning of the interval, the fuel supply control means 9 sets the fuel supply amount Q as a target value with the fuel supply amount Qa for multiplying the deviation Δt by a coefficient larger than 1 to make the enlarged deviation a predetermined value. A control unit 10 is provided which controls the fuel supply amount Q normally by over-controlling and thereafter returning the target value to the fuel supply amount Qb for setting the deviation Δt to a predetermined value during the time until the end of the interval. And (a) and (b) in FIG.
As shown in the figure, the deviation Δt
Becomes a predetermined value, the fuel supply amount Q is fixed to the control amount Qc at that time.

The correction (increase / decrease) of the air supply amount corresponding to the fuel increase / decrease is the product of the combustion amount and the theoretical amount of fuel air.

[Alternative Embodiment] In the above embodiment, the control unit 10 is always operated regardless of the magnitude of the deviation Δt. However, as shown in FIG. A second control unit 11 for controlling the fuel supply amount Q using the supply amount Qb as a target value is provided. The control unit 10 is operated when the deviation Δt is equal to or more than a set value, and the second control unit is operated when the deviation Δt is less than the set value. The control unit 11 may be operated.

[Brief description of the drawings]

FIG. 1 is a schematic longitudinal sectional view

FIG. 2 is a graph showing a relationship between a deviation and a fuel supply amount.

FIG. 3 is a graph showing a relationship between a deviation and a fuel supply amount.

FIG. 4 is a schematic longitudinal sectional view showing another embodiment.

[Explanation of symbols]

 Reference Signs List 1 main chamber 3 burner 8 sensor 9 fuel supply control means 10 control unit 11 second control unit tp temperature T set time ts target temperature Δt deviation Q fuel supply amount Qa fuel supply amount Qb fuel supply amount

Continued on the front page F term (reference) 3K061 AA05 AB03 AC01 BA06 CA01 DB11 DB20 3K062 AA05 AB03 AC01 BA02 CA03 CB03 DA01 DB05 DB13

Claims (3)

[Claims] 1. A burner (3) for heating and melting a surface of a material (a) to be melted and supplied to a main chamber (1) is provided, and a temperature (tp) of the main chamber (1) is detected. A sensor (8) is provided, and a target temperature (ts) and a temperature (t) detected by the sensor (8) are set at intervals of a set time (T).
A fuel supply control means (9) is provided for controlling the fuel supply amount (Q) to the burner (3) based on the deviation (Δt) from (p) so that the deviation (Δt) becomes a predetermined value. In the melting furnace, the fuel supply control means (9) sets the fuel supply amount (Qa) at the beginning of the interval as a target value with the fuel supply amount (Qa) for expanding the deviation (Δt) to a predetermined value. Q) is excessively controlled, and thereafter, a control unit (normally controls the fuel supply amount (Q) by returning the target value to the fuel supply amount (Qb) that makes the deviation (Δt) a predetermined value until the end of the interval. A furnace temperature control device for a melting furnace comprising 10). 2. The control section (10) fixes the fuel supply amount (Q) to the control amount at the time when the deviation (Δt) reaches a predetermined value during normal control. A temperature control device in a melting furnace according to the above. 3. The control unit (10) operates when the deviation (Δt) is equal to or larger than a set value, and when the deviation (Δt) is smaller than the set value, the fuel supply amount for setting the deviation (Δt) to a predetermined value. (Qb)
3. The furnace temperature control device for a melting furnace according to claim 1, wherein the second control unit (11) that controls the fuel supply amount (Q) with the target value as a target value is operated. 4.