KR200243124Y1 - Humidity control device in high frequency induction furnace - Google Patents

Abstract

The present invention relates to a humidity control device in a high frequency induction furnace that can prevent the generation of stains of the steel plate by the water droplets by controlling the humidity in the furnace to prevent the generation of water droplets in the high frequency induction furnace for drying the plated steel sheet, In the present invention, the temperature information detected by the intake pipe of the furnace and the humidity information detected by the exhaust pipe of the furnace accurately detect the current humidity state inside the furnace, and is supplied to the inside of the furnace in accordance with the humidity state. By controlling the temperature of the air, the temperature difference between the fume temperature inside the furnace and the air temperature supplied to the furnace from the outside, while maintaining the optimum humidity in the furnace to generate water droplets in the furnace This is to be avoided.

Description

High Frequency Induction Furnace Humidity Control Device

The present invention relates to a humidity control apparatus in a high frequency induction furnace, in particular, by controlling the humidity in the furnace to prevent the generation of water droplets in the high frequency induction furnace to dry the plated steel sheet, it is possible to prevent the occurrence of stains of the steel sheet by the water droplets. It relates to a humidity control device in a high frequency induction furnace.

1 is a configuration diagram of a conventional high frequency induction heating furnace, referring to FIG. 1, a plating apparatus 10 is plated with an organic solution, and the plated steel sheet 1 is a high frequency induction heating furnace 20. After drying, the cooling apparatus 30 considers and outputs the steel sheet heated during the drying process.

The conventional high frequency induction heating furnace (20) is a device for drying the plated steel sheet (1) plated with an organic solution in the plating apparatus 10, the fume (fume) which is an unnecessary gas in the drying process of the plated steel sheet (1) In order to remove this fume, the exhaust pipe 21 is installed on one side of the heating furnace, and then the exhaust fan 23 is mounted on the exhaust pipe 21, and the intake pipe 22 is installed on the other side of the heating furnace. After that, the blower 25 is attached to the intake pipe 22.

Briefly describing the fume removal process, the exhaust fan 23 of the exhaust pipe 21 and the blower 25 of the intake pipe 22 continue to operate while the plated steel sheet 1 is dried. Exhaust fan (23) of the operation to discharge the fume (3) in the high-frequency induction furnace 20 to the outside, the blower (25) of the intake pipe (22) is operated to air (A) Is introduced into the high frequency induction heating furnace 20.

On the other hand, in the process of drying the plated steel sheet 1, the moisture of the liquid contained in the surface of the plated steel sheet 1 is vaporized into the moisture of the gas, this vaporized water is contained in the fume.

However, in the conventional high frequency induction furnace, in the process of removing the fume, water droplets inside the high frequency induction furnace due to the temperature difference while the high temperature fume inside the high frequency induction furnace meets the incoming gas at room temperature. There was a problem in that the water droplets fall on the plated steel sheet and cause stains on the plated steel sheet, thereby degrading the quality of the plated steel sheet.

The present invention is devised to solve the above problems, and therefore, an object of the present invention is to control the humidity in the furnace to prevent the generation of water droplets in the high frequency induction furnace to dry the plated steel sheet, thereby reducing the It is to provide a humidity control device in a high frequency induction furnace that can prevent the occurrence of stains.

1 is a block diagram of a conventional high frequency induction heating furnace.

2 is a block diagram of a humidity control device installed in a high frequency induction heating furnace according to the present invention.

3 is a detailed configuration diagram of the humidity control device of FIG.

Explanation of symbols on the main parts of the drawings

1: steel sheet 2: atmosphere gas

3: Hume 4: Water Drop

10 plating device 11: organic solution

20: high frequency induction furnace 21: exhaust pipe

22: intake pipe 23: exhaust fan

24: stack 25: blower

26 Inverter 27 Matching Panel

28: coil 30: cooling device

40: temperature sensor 50: humidity sensor

60: temperature control unit 70: relative humidity control unit

80: sensor error detection unit 90: automatic suntex position

100: steam amount control valve 110: heat exchanger

120: alarm 130: steam pipe

As a technical means for achieving the above object of the present invention, the device of the present invention, the apparatus for controlling the humidity in the high-frequency induction furnace, steam pipe for supplying steam to the heat exchanger; A heat exchanger installed by cutting the middle of the intake pipe and installed to penetrate the steam pipe; A temperature sensor installed at a rear intake pipe of the heat exchanger; A humidity sensor installed in an exhaust pipe of the heating furnace; A relative humidity control unit for setting a reference value according to the detection signal from the humidity sensor, comparing the reference value with the detection signal from the temperature sensor, and outputting a valve control signal according to the comparison result; An I / P converter for converting the provided valve control signal into air pressure; A steam amount regulating valve for adjusting the opening rate of the front end steam pipe of the heat exchanger by air pressure from the I / P converter; Characterized in having a.

Hereinafter, with reference to the accompanying drawings for the high-frequency induction furnace humidity control device according to the present invention will be described in detail. In the drawings referred to in the present invention, components having substantially the same configuration and function will use the same reference numerals.

2 is a configuration diagram of a humidity control device installed in a high frequency induction heating furnace according to the present invention, and FIG. 3 is a detailed configuration diagram of the humidity control device of FIG. 2.

2 and 3, in the high frequency induction furnace humidity control apparatus according to the present invention, 40 is a temperature sensor, which is supplied to the inside of the furnace through the intake pipe 22 of the high frequency induction heating furnace (20). It is installed in the intake pipe 22 at the rear end of the heat exchanger 110 to detect the temperature of the air to be output and output a detection signal (resistance value) that is temperature information. 50 is a humidity sensor, which detects the humidity of the fume discharged to the outside through the exhaust pipe 21 of the high frequency induction furnace 20 and outputs a sensing signal (current value), which is humidity information, to the exhaust pipe of the heating furnace. It is installed in (21).

60 is a temperature controller, which compares the detection signal from the temperature sensor 40 with a preset reference value and outputs a valve control signal (current value) according to the comparison result. Is set in consideration of the internal temperature of the heating furnace 20 and the temperature of the air flowing into the interior.

In addition, the temperature control unit 60 includes an R / V conversion unit 61 for converting a resistance value from the temperature sensor 40 into a voltage value, and a preset reference value and the R / V conversion unit 61. PID control unit 63 outputs a valve control signal by performing PID control based on the voltage value of.

Reference numeral 70 denotes a relative humidity control unit, which sets a reference value according to the detection signal from the humidity sensor 50, compares the reference value with the detection signal from the temperature sensor 50, and compares the valve control signal according to the comparison result. The control unit for outputting the function.

In addition, the relative humidity control unit 70 converts the current value from the humidity sensor 50 into a voltage value, and the resistance value from the temperature sensor 40 as a voltage value. A reference value is set with reference to the voltage value from the R / V converter 72 and the I / V converter 71 to be converted, and the set reference value and the voltage value from the R / V converter 72 are set. The PID control unit 73 outputs a valve control signal by performing OID control on the basis of.

80 is a sensor abnormality detection unit, which detects an abnormality of the temperature sensor 40 based on the detection signal from the temperature sensor 40, and the humidity sensor 50 based on the detection signal from the humidity sensor 50. The control unit detects an abnormality and outputs a switching control signal, and outputs an alarm control signal when the two sensors 40 and 50 detect an abnormality at the same time.

In addition, the sensor abnormality detecting unit 80 converts the resistance value from the temperature sensor 40 into a voltage value, and a current value from the humidity sensor 50 as a voltage value. Abnormality of high level when the voltage value from the I / V converter 82 to be converted and the R / V converter 81 is 95% or more or 5% or less with respect to the preset maximum voltage value (5V). High level when the voltage value from the first logic circuit section 83 and the I / V converter section 82 for outputting a detection signal is greater than or equal to 95% or less than or equal to 5% with respect to a predetermined maximum voltage value (5V). A second logic circuit 84 for outputting the in-switching control signal and an AND gate 85 for outputting an alarm control signal by ANDing the two signals from the first and second logic circuits 83 and 83.

90 is an automatic selection switch, which means that one of the NC contact (OFF) connected to the output terminal of the relative humidity control unit 70 and the NO contact (ON) connected to the output terminal of the temperature control unit 60 is the sensor abnormality. The electronic switch selectively connects to the common contact COM according to the switching control signal from the detector 80 to provide a valve control signal through the selected contact to the I / P converter 140.

100 is a steam amount control valve, which is a valve for controlling the opening rate of the front end steam pipe 130 of the heat exchanger 110 by the air pressure from the I / P converter 140. 110 is a heat exchanger, which is installed by cutting the middle of the intake pipe 22 and is installed to penetrate the steam pipe therein. 120 denotes an alarm, which is operated by an alarm control signal from the sensor error detection unit 80 to alert the two sensors to be abnormal at the same time.

130 is a steam pipe, which is a pipe for supplying steam to the heat exchanger 110. 140 is an I / P converter, which provides a function of converting the provided valve control signal into air pressure.

Operation according to the device of the present invention configured as described above will be described in detail below based on the accompanying drawings.

Referring to FIGS. 2 and 3, when the high frequency induction heating furnace 20 according to the present invention is operated, the fume inside the heating furnace 20 passes through the exhaust pipe 21 through the exhaust fan 23. At the same time as the outside is discharged to the outside, the outside air is introduced into the heating furnace 20 through the intake pipe 22, the blower 25 and the heat exchanger (110).

As such, during the drying process for the plated steel sheet 1 in the heating furnace 20, the humidity control apparatus in the high frequency induction heating furnace according to the present invention performs the following operation.

First, the temperature sensor 40 detects a temperature of air introduced through the intake pipe 22 behind the heat exchanger 110 and detects a detection signal having the temperature information by the temperature control unit 60 and the relative humidity control unit ( 70) and the sensor abnormality detecting unit 80 are provided. The detection signal output from the temperature sensor 40 is provided as a resistance value corresponding to temperature information.

In the operation of the temperature controller 60, first, the R / V converter 61 of the temperature controller 60 converts the resistance value, which is the detection signal, into a voltage value (range: 1 to 5V) to control the PID controller ( 63), the PID controller 63 performs PID control based on a preset reference value (range: 0 to 200 ° C) and the provided voltage value in an internal reference value (SV) setting unit. When the input voltage value is small based on the reference value, a large valve control signal is output to increase the steam supply amount, while a large valve control signal is output to reduce the steam supply amount. . This valve control signal is output as a current value and the range is 4 to 20 mA.

For example, the voltage range 1 to 5 V, the set temperature range 0 to 200 ° C., and the current value range 4 to 20 mA are set in correspondence with each other as shown in Table 1 below.

percent(%) Voltage value (V) Set temperature (℃) Current value (mA) 0 One 0 4 5% 1.2 10 4.8 ... 50% 3 100 12 55% 3.2 110 12.8 ... 95% 4.8 190 19.2 100% 5 200 20

If the PID controller 63 of the temperature controller 60 sets the set temperature to 110 ° C, the voltage value from the R / V converter 61 is 3.2V (this 3.2V is Less than 110 ° C.), the detected temperature is less than the set temperature, so that the amount of steam supplied is increased to increase the temperature of the supply air through the intake pipe 22 to 12.8 mA (this is 12.8). mA also corresponds to 110 ° C.), on the contrary, if the input voltage value is greater than 3.2 V, this means that the sensed temperature is greater than the set temperature, so that the output current value is less than 12.8 mA.

On the other hand, the humidity sensor 50 detects the humidity of the fume discharged to the outside through the exhaust pipe 21 of the heating furnace 20, the relative humidity control unit 70 and the sensor abnormality detection unit detects the detection signal having this humidity information Provided by 80 each. The detection signal output from the humidity sensor 50 is provided as a current value corresponding to humidity information.

Operation of the relative humidity control unit 70, first, the current value (range: 4 to 20 mA), which is the detection signal, in the I / V conversion unit 71 of the relative humidity control unit 70, the voltage value (VN) ( When converted into a range of 1 to 5V, and provided to the PID control unit 73, the internal reference value setting unit of the PID control unit 73 sets the reference value SV based on the voltage value.

The reference value set by the reference value setting unit of the relative humidity control unit 70 is obtained by the following equation (1).

Here, a is a slope (increase in output / increase in input), x is a voltage value VN from the I / V converter 71 (temperature range, a voltage value corresponding to 0 to 100 ° C), and b is Constant, but is set to 5 in the embodiment of the present invention.

In addition, when the R / V converter 72 of the relative humidity controller 70 converts the resistance value of the sensed signal into a voltage value and provides the voltage to the PID controller 73, the PID controller 73 is configured to be internal. PID control is performed based on the reference value set by the reference value SV setting unit and the provided voltage value. When the input voltage value is small based on the reference value, the steam supply amount is reduced to reduce the intake pipe 22. In order to increase the humidity in the furnace 20 to a normal state by lowering the temperature of the air through, a small value of the valve control signal is output. Output the valve control signal. The valve control signal is output as a current value which is the same signal as the valve control signal output from the temperature control part 60, and the range is 4 to 20 mA.

For example, when the reference value set by the relative humidity control unit 70 is 110 ℃, if the input voltage value is less than 3.2V, this means that the detected humidity is less than the set reference value to output the current value at this time If the input voltage is greater than 3.2 V, the detected humidity is greater than the set reference value, and the output current is greater than 12.8 mA.

On the other hand, the operation of the sensor abnormality detection unit 80 will be described. First, the R / V conversion unit 81 of the sensor abnormality detection unit 80 converts the detection signal from the temperature sensor 40 into a voltage value. When provided to the first logic circuit section 83, the first logic circuit section 83 has an on-contact point formed when the voltage value is greater than or equal to 95% (4.8V) or less than 5% (1.2V). Output Setting to 95% and 5% of the voltage value is for detecting the abnormality of the sensor and may be set to a different value.

In addition, the I / V conversion unit 82 of the sensor abnormality detection unit 80 converts the detection signal from the humidity sensor 50 into a voltage value and provides the second logic circuit unit 84 with the second logic circuit unit 84. When the voltage value is 95% or more or 5% or less, the logic circuit unit 84 forms an on-contact point and outputs a high level that is a switching control signal.

In addition, the two output signals of the first and second logic circuits 83 and 84 are logically multiplied by the end gate 85 and output. The output signals are alarm control signals, which are abnormal for both sensors. High level is detected only when is detected. The alarm 120 connected by the alarm control signal makes an alarm, so that the related person can hear this alarm and know that the two sensors are abnormal.

When the humidity sensor 50 operates normally, the automatic selection switch 90 provides the valve control signal from the relative humidity control unit 70 to the I / P converter 140 through the NC contact OFF. When the humidity sensor 50 is detected abnormally, as the second logic circuit 84 of the sensor error detection unit 80 outputs a high level switching control signal, the automatic selection switch 90 contacts the NC contact. It is switched from the (OFF) to the NO contact (ON), the valve control signal from the temperature control unit 60 is provided to the I / P converter 140.

When the I / P converter 140 converts the current value, which is the valve control signal, into air pressure and provides the steam amount control valve 100 installed in the steam pipe 130, the steam amount control valve 100 is applied to the air pressure. As the opening degree is adjusted accordingly, the amount of steam provided to the heat exchanger 110 is adjusted, and thus the degree of heating of air heated by steam in the heat exchanger is adjusted.

As described above, in the present invention, the temperature information detected by the intake pipe of the heating furnace and the humidity information detected by the exhaust pipe of the heating furnace accurately detect the humidity of the current inside the heating furnace, and the external heating is performed according to the humidity condition. By controlling the temperature of the air supplied into the furnace, the temperature difference between the temperature of the fume inside the furnace and the temperature of the air supplied to the furnace from the outside is kept at the same time, while maintaining the optimum humidity in the furnace. It is to prevent the generation of water droplets inside.

According to the present invention as described above, by controlling the humidity in the furnace to the optimum state to prevent the generation of water droplets in the high-frequency induction furnace to dry the plated steel sheet, it is possible to prevent the occurrence of stains of the steel plate by the water droplets, accordingly The effect is to obtain a high quality of.

The above description is only a description of one embodiment of the present invention, the present invention is capable of various changes and modifications within the scope of the configuration.

Claims (3)

In the device for controlling the humidity in the high frequency induction furnace, Steam pipe 100 for supplying steam to the heat exchanger; A heat exchanger (110) installed by cutting the middle of the intake pipe (22) and installed to penetrate the steam pipe (130); A temperature sensor 40 installed at a rear end intake pipe 22 of the heat exchanger 110; A humidity sensor 50 installed in the exhaust pipe 21 of the heating furnace; A relative humidity control unit 70 sets a reference value according to the detection signal from the humidity sensor 50, compares the reference value with the detection signal from the temperature sensor 50, and outputs a valve control signal according to the comparison result. ); An I / P converter 140 for converting the provided valve control signal into air pressure; Steam amount control valve 100 for adjusting the opening rate of the front end steam pipe 130 of the heat exchanger 110 by the air pressure from the I / P converter 140; Humidity control device in high-frequency induction furnace, characterized in that provided with. According to claim 1, wherein the humidity control device, A temperature controller 60 for comparing the detected signal from the temperature sensor 40 with a preset reference value and outputting a valve control signal according to the comparison result; A sensor abnormality detection unit 80 for detecting an abnormality of the humidity sensor 50 based on the detection signal from the humidity sensor 50 and outputting a switching control signal when the abnormality is detected; Switching control from the sensor abnormality detecting unit 80 to one of the NC contact OFF connected to the output terminal of the relative humidity control unit 70 and the NO contact ON connected to the output terminal of the temperature control unit 60. An automatic selection switch (90) for selectively connecting to a common contact (COM) according to a signal and providing a valve control signal through the selected contact to the I / P converter (140); Humidity control device in high frequency induction furnace characterized in that it further comprises. According to claim 1, wherein the humidity control device, After detecting the abnormality of the temperature sensor 40 based on the detection signal from the temperature sensor 40, the abnormality of the humidity sensor 50 is detected based on the detection signal from the humidity sensor 50, A sensor abnormality detection unit 80 for outputting an alarm control signal when two sensors 40 and 50 are detected to have an abnormality at the same time; An alarm 120 operating by an alarm control signal from the sensor error detection unit 80; High frequency induction furnace humidity control device characterized in that it further comprises.