KR101639155B1 - Apparatus for measuring dew point of continuous heat treatment furnace and method thereof - Google Patents

Abstract

An apparatus and a method for measuring a dew point in a continuous heat treatment furnace are disclosed. The dew-point measuring apparatus of the continuous heat treatment furnace of the present invention comprises: a plurality of measurement valves respectively installed in a plurality of overpressure pipes connecting a plurality of points of a continuous heat treatment furnace and a dew point measurement chamber; A purge valve installed in a purge gas inlet pipe for supplying purge gas to the dew point measurement chamber; A dew point system for measuring the dew point of the internal gas in the continuous heat treatment furnace installed in the dew point measurement chamber; A reference dew point system provided in a dew point system storage room in which purge gas is introduced; A suction pump for sucking the internal gas and the purge gas in the continuous heat treatment furnace into the dew point measuring chamber; And a suction pump, a plurality of measurement valves and a purge valve are operated to receive and output dew points for a plurality of points from the drive dew point system to the continuous heat treatment path, and receives the dew point from the reference dew point system to judge whether or not the drive dew point system is normal And a control unit for controlling the display unit.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a dew-

The present invention relates to an apparatus and method for measuring dew point in a continuous heat treatment furnace, and more particularly, to a dew point measuring apparatus for measuring dew point in a continuous heat treatment furnace by comparing the dew point meter with a preliminary reference dew point meter, And more particularly, to a dew-point measuring apparatus and method therefor.

In general, it is well known that some steels do not respond well to galvanizing or galvanizing because of their specific surface reactivity.

Thus, the zinc plating capacity can be basically dependent on the proper removal of rolling oil residues and the prevention of excessive surface oxidation before being immersed in the bath of molten metal.

The selective oxide layer in the outermost layer of the strip surface is produced by oxidation by water vapor and segregation of alloying elements during subsequent heat treatment prior to immersion in a zinc bath for plating.

Therefore, in the continuous heat treatment furnace, the heat treatment is performed through the steps of (preliminary) heating, maintaining the temperature, cooling, over aging and cooling, and nitrogen and steam are supplied to perform dew point control to prevent excessive surface oxidation.

Related prior art is Korean Patent Laid-Open Publication No. 2014-0119104 (entitled "Continuous Annealing and Removal of High Strength Steel Strips for Applied Zinc Plating", October 10, 2014).

The present invention provides an apparatus and method for measuring dew point in a continuous heat treatment furnace capable of improving the reliability of a dew point system by verifying a dew point system for measuring a dew point of a continuous heat treatment furnace in comparison with a preliminary reference dew point system.

The present invention also provides a method for continuously measuring the dew point of a continuous heat treatment furnace through a single dew point system, drying the dew point system periodically through nitrogen purging to measure the dew point quickly and accurately, An apparatus for measuring dew point in a heat treatment furnace and a method therefor.

According to an aspect of the present invention, there is provided an apparatus for measuring a dew point in a continuous heat treatment furnace, comprising: a plurality of measurement valves respectively installed in a plurality of overpressure pipes connecting a plurality of points of a continuous heat treatment furnace and a dew point measurement chamber; A purge valve installed in a purge gas inlet pipe for supplying purge gas to the dew point measurement chamber; A dew point system for measuring the dew point of the internal gas in the continuous heat treatment furnace installed in the dew point measurement chamber; A reference dew point system provided in a dew point system storage room in which purge gas is introduced; A suction pump for sucking the internal gas and the purge gas in the continuous heat treatment furnace into the dew point measuring chamber; And a suction pump, a plurality of measurement valves and a purge valve are operated to receive and output dew points for a plurality of points from the drive dew point system to the continuous heat treatment path, and receives the dew point from the reference dew point system to judge whether or not the drive dew point system is normal And a control unit for controlling the display unit.

In the present invention, when the dew point is measured by operating one of the plurality of measurement valves for the first set time, the control unit operates the other one of the measurement valves after operating the purge valve during the second set time do.

The control unit may determine whether the driving dew point system is normal by receiving a dew point from the driving dew point system and the reference dew point system for a second set time after activating the purge valve.

The present invention is characterized in that the control unit further comprises an output unit for outputting a dew point inputted from the driving dew point system and a normal state of the driving dew point system to the upper control unit.

According to another aspect of the present invention, there is provided a method for controlling a dew point measuring apparatus in a continuous heat treatment furnace, including: operating a suction pump by a control unit; Switching the plurality of measurement valves while the control unit is operated for a first set time, respectively; The control unit receiving a dew point for each point of the continuous heat treatment furnace in which the selected one of the plurality of measurement valves is installed for a first set time from the drive dew point system; Operating the purge valve for a second set time when the control unit has elapsed the first set time to purge the dew point measurement chamber; Comparing the dew points inputted respectively from the reference dew point system provided in the dew point storage chamber with the drive dew point system at a second set time for the control unit to purgate the dew point measurement chamber; And determining whether the driving dew point system is normal according to a result of comparing the dew point by the control unit.

The present invention is characterized in that the step of switching the plurality of measurement valves while operating them for the first set time period is characterized in that the control unit sequentially circulates the plurality of measurement valves, respectively.

The method may further include outputting a dew point to each point input from the driving dew point system and a normal state of the driving dew point system to an upper controller through an output unit.

In the present invention, the dew point system storage chamber is provided so as to introduce purge gas.

The dew point measuring apparatus and method of the continuous heat treatment furnace according to the present invention can improve the reliability of the dew point system by verifying the dew point of the continuous heat treatment furnace in comparison with the preliminary reference dew point system.

In addition, the present invention can quickly and accurately measure the dew point by drying the dew point system periodically through the nitrogen purge when the dew point is measured cyclically through one dew point system for a plurality of points in the continuous heat treatment furnace.

1 is a block diagram showing a dew point measuring apparatus for a continuous heat treatment furnace according to an embodiment of the present invention.
FIG. 2 is a configuration diagram showing an installation state of a dew-point measuring apparatus in a continuous heat treatment furnace according to an embodiment of the present invention.
3 is a flowchart illustrating a method of controlling a dew point measuring apparatus in a continuous heat treatment furnace according to an embodiment of the present invention.

Hereinafter, an apparatus and method for measuring a dew point in a continuous heat treatment furnace according to the present invention will be described with reference to the accompanying drawings. In this process, the thicknesses of the lines and the sizes of the components shown in the drawings may be exaggerated for clarity and convenience of explanation. In addition, the terms described below are defined in consideration of the functions of the present invention, which may vary depending on the intention or custom of the user, the operator. Therefore, definitions of these terms should be made based on the contents throughout this specification.

FIG. 1 is a block diagram showing a dew-point measuring apparatus for a continuous heat-treating furnace according to an embodiment of the present invention, FIG. 2 is a diagram showing an installation state of a dew-point measuring apparatus according to an embodiment of the present invention to be.

1 and 2, the apparatus for measuring dew points in a continuous heat-treating furnace according to an embodiment of the present invention includes first to fifth measuring valves 40_1 to 40_5, a purge valve 50, 10, a suction pump 20, a reference dew point system 100, and a control unit 30 as well as an output unit 60.

The first to fifth measuring valves 40_1 to 40_5 are respectively installed in the first to fifth overpressure tubes 45_1 to 45_5 for connecting the plurality of points of the continuous heat treatment furnace 70 and the dew point measuring chamber 80, So that the internal gas of the continuous heat treatment furnace 70 can be introduced into or blocked from the dew point measuring chamber 80. [

In the present embodiment, the case where the dew point is measured with respect to five points through one driving dew point system 10 is illustrated by way of example, but the number of points measured through one driving dew point system 10 is more In this case, the number of the pressure tube 45 and the number of the measurement valve 40 can be adjusted.

The purge valve 50 is installed in a purge gas inflow pipe 55 for supplying purge gas to the dew point measurement chamber 80 and is opened and closed under the control of the control unit 30 to purge the dew point measurement chamber 80, (80) is switched and the drive dew point system (10) is dried.

The drive dew point system 10 is provided in the dew point measurement chamber 80 and measures the dew point of the internal gas of the continuous heat treatment furnace 70 and supplies the measured dew point to the control unit 30.

Here, the driving dew point system 10 may be a capacitance sensor for measuring a dew point by using a change in capacitance between electrodes according to the water content contained in the internal gas.

That is, when the dielectric substance mediated between the electrodes absorbs moisture, the polarization current increases to increase the capacitance, and when dried, the polarization current decreases and the capacitance decreases. Thus, the drive dew point system 10 measures the dew point by increasing and decreasing the capacitance which varies with the moisture content.

The suction pump 20 sucks the internal gas and the purge gas of the continuous heat treatment furnace 70 into the dew point measurement chamber 80 to measure the dew point or purge the internal gas sucked into the dew point measurement chamber 80.

The reference dew point system 100 is provided in a dew point system storage room 90 in which purge gas is introduced. At this time, a plurality of reference dew point systems 100 may be provided in the dew point system storage room 90,

The dew point system storage room 90 is provided with the reference dew point system 100 and the zeolite as the moisture absorbent 120 so that the atmosphere of the dew point system storage room 90 can be kept dry and clean, ) Can be maintained in a high-precision state.

The control unit 30 operates the suction pump 20, the first to fifth measurement valves 40_1 to 40_5 and the purge valve 50 so that the dew point for a plurality of points of the continuous heat treatment furnace 70 is set to the drive dew point system (10).

That is, through the one drive dew point system 10, the first through fifth pressure boosters 70 are provided at each point so that the internal gas can be sucked from a plurality of points to measure the dew point with respect to the plurality of points of the continuous heat treatment furnace 70, The suction pump 20 is operated and individually selected through the first to fifth measurement valves 40_1 to 40_5, and the dew point is measured by sucking the internal gas from each of the points, So that the dew point can be measured.

Also, before measuring the dew point for each point, the purge valve 50 is operated to purge the dew point measurement chamber 80, thereby minimizing the influence of the previous point.

For example, the control unit 30 may operate the first measurement valve 40_1 of the first to fifth measurement valves 40_1 to 40_5 for a first set time to measure the dew point, 50 is operated to suck nitrogen gas to purge the dew-point measurement chamber 80. Thereafter, the second measurement valve 40_2 is operated for a first set time to measure the dew point, and then the purge valve 50 is operated for a second set time to suck nitrogen gas to purge the dew point measurement chamber 80. [

This process is repeatedly performed by sequentially circulating the first to fifth measurement valves 40_1 to 40_5, and the dew point is supplied to the upper control device (not shown).

The control unit receives the dew point from the drive dew point system 10 and the reference dew point system 100 when the purge valve 50 is operated to purge the dew point measurement chamber 80 during the second set time, And outputs the normal state to the host controller 110.

That is, when the dew point deviation generated between the dew point input from the driving dew point system 10 and the dew point input from the reference dew point system 100 exceeds a setting deviation that can be determined as an abnormality of the driving dew point system 10, The system 10 can be judged as defective.

The output unit 60 not only outputs the dew point of a plurality of points inputted from the driving dew point system 10 to the host controller 110 but also outputs the dew point of the driving dew point system 10 to the host controller 110 ), The dew point control is performed based on the dew point of each point to supply nitrogen gas when the dew point is high and to supply the steam when the dew point is low, so that the constant dew point can be maintained, or the faulty state of the drive dew point system 10 is warned So that the driving dock system 10 can be checked and replaced.

As described above, according to the apparatus for measuring dew point in the continuous heat treatment furnace according to the embodiment of the present invention, the reliability of the dew point system can be improved by verifying the drive dew point measuring dew point of the continuous heat treatment furnace in comparison with the preliminary reference dew point system It is possible to quickly and accurately measure the dew point by drying the dew point system periodically through the nitrogen purge when the dew point is measured circulatingly through one dew point system to a plurality of points in the continuous heat treatment furnace, The life of the sensor can be increased by periodically measuring the dew point system while drying it.

3 is a flowchart illustrating a method of controlling a dew point measuring apparatus in a continuous heat treatment furnace according to an embodiment of the present invention.

3, in the control method of the dew-point measuring apparatus of the continuous heat treatment furnace according to the embodiment of the present invention, the controller 30 activates the suction pump 20 (S12).

The suction pump 20 is for sucking in the internal gas of the continuous heat treatment furnace 70 or for sucking the purge gas, The fifth measurement valves 40_1 to 40_5 and the purge valve 50 may be operated at the same time, and the order is not limited thereto.

Thereafter, the control unit 30 activates the measurement valve 40 (S14). For example, the first measurement valve 40_1 of the first to fifth measurement valves 40_1 to 40_5 is operated.

In this embodiment, five dies are sequentially circulated through one driving dock system 10 to measure the dew point, respectively. However, the present invention is not limited thereto, and the measurement point and the number may be variously applied as needed.

When the first measurement valve 40_1 is operated as described above, the internal gas is sucked into the dew point measurement chamber 80 at the point of the continuous heat treatment furnace 70 provided with the first overflow pipe 45_1 by the suction pump 20. At this time, the control unit 30 receives the measured dew point through the driving dew point system 10 (S16).

The control unit 30 outputs the input dew point to the host controller through the output unit 60 (S18).

Thereafter, the controller 30 counts a time period during which the first measurement valve 40_1 has been operated, and determines whether the first set time has elapsed (S20). If it is determined in step S20 that the first set time has not elapsed, the flow returns to step S16 to continuously receive and output the dew point from the drive dew point system 10.

However, if the first set time has elapsed in step S20, the control unit 30 stops the operation of the measurement valve 40 (S22). When the first measurement valve 40_1 is operated in step S14, the operation of the first measurement valve 40_1 is stopped. Then, the control unit 30 activates the purge valve 50 (S24).

When the purge valve 50 is operated as described above, the internal gas of the continuous heat treatment furnace 70, which has been sucked into the dew point measuring chamber 80, is purged by the nitrogen gas sucked through the purge valve 50, ) Can be dried.

Thereafter, the control unit 30 receives the dew point from the driving dew point system 10 (S26). The dew point is also input from the reference dew point system 100 provided in the dew point system storage room 90 (S28).

Then, the control unit 30 sets the deviation of the dew point generated between the dew point input from the drive dew point system 10 and the dew point input from the reference dew point system 100 to an error of the drive dew point system 10 (S30).

At this time, if the dew point deviation exceeds the set deviation, the controller 30 determines that the driving dew point system 10 is defective and outputs the defective state to the host controller 110 through the output unit 60 (S32).

Thereafter, the control unit 30 determines whether the second set time has elapsed after activating the purge valve 50 (S34). If the second set time has not elapsed in step S34, the controller 30 returns to step S24 until the second set time has elapsed, thereby maintaining the operating state of the purge valve 50.

However, if the second set time has elapsed in step S34, the control unit 30 stops the operation of the purge valve 50 (S36).

Then, the control unit 30 returns to step S14 to operate the second measurement valve 40_2 of the first to fifth measurement valves 40_1 to 40_5, and then repeats the above process.

In this way, while the dew point control is performed by the host controller 110, the control unit 30 also performs steps S14 to S28 for the third, fourth, and fifth measurement valves 40_3, 40_4, The dew point of each point is received through the drive dew point system 10, and the dew point is output to the host controller 110.

The dew point deviation of the drive dew point system 10 and the reference dew point system 110 is compared during a second set time for purging the dew point measurement chamber 80 to determine whether the drive dew point system 10 is normal, And outputs it to the control device 110.

In the present embodiment, the dew point is measured by sequentially operating the measurement valve 40. However, the dew point may be measured in various ways, for example, by setting the order at random for controlling the dew point of the continuous heat treatment furnace 70 The dew point can also be measured by operating the measuring valve 40.

As described above, according to the control method of the dew-point measuring apparatus of the continuous heat treatment furnace according to the embodiment of the present invention, the drive dew point system for measuring the dew point of the continuous heat treatment furnace is verified and compared with the preliminary reference dew point system, In addition to improving reliability, it is also possible to quickly and accurately measure the dew point by drying the dew point system periodically through nitrogen purge when measuring the dew point in circulation through one dew point system for a plurality of points in a continuous heat treatment furnace And the lifetime of the sensor can be increased by periodically measuring the dew point system while drying it.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. I will understand.

Accordingly, the true scope of the present invention should be determined by the following claims.

10: drive dew point system 20: suction pump
30: control unit 40: measuring valve
45: pressure pipe 50: purge valve
55: purge gas inlet pipe 60: output section
70: continuous heat treatment furnace 80: dew point measuring chamber
90: Dew point storage room 100: Reference dew point
110: upper control device 120: desiccant

Claims (8)

A plurality of measurement valves respectively installed in a plurality of overpressure pipes connecting the plurality of points of the continuous heat treatment furnace and the dew point measurement chamber;
A purge valve installed in a purge gas inlet pipe for supplying purge gas to the dew point measurement chamber;
A drive dew point meter for measuring a dew point of the internal gas introduced into the dew point measurement chamber and flowing into the continuous heat treatment furnace;
A reference dew point system provided in a dew point system storage room in which the purge gas is introduced;
A suction pump for sucking the internal gas of the continuous heat treatment furnace and the purge gas into the dew point measuring chamber; And
The dew point is received from a plurality of points of the continuous heat treatment path from the drive dew point system by operating the suction pump, the plurality of measurement valves, and the purge valve, and receives the dew point from the reference dew point system, And a control unit for determining whether the system is normal or not.
The apparatus according to claim 1, wherein the control unit operates one of the plurality of measurement valves for a first predetermined time to measure a dew point, operates the purge valve for a second set time, The dew point of the continuous heat treatment furnace.
3. The apparatus according to claim 2, wherein the control unit receives the dew point from the driving dew point system and the reference dew point system for the second predetermined time after operating the purge valve, and determines whether the driving dew point system is normal or not The dew point of the continuous heat treatment furnace.
2. The dew-point measuring apparatus according to claim 1, further comprising an output unit for outputting a dew point inputted from the driving dew point system and a normal state of the driving dew point system to the upper control unit by the control unit .
Operating the suction pump by the control unit;
Switching the plurality of measurement valves while each of the plurality of measurement valves is operated for a first set time;
Receiving a dew point for each point of the continuous heat treatment furnace in which the selected measurement valve among the plurality of measurement valves is installed during the first set time from the drive dew point system;
Operating the purge valve for a second set time when the control unit elapses the first set time to purge the dew point measurement chamber;
Comparing the dew points inputted from the reference dew point system provided in the drive dew point system and the dew point system storage room at the second set time for purging the dew point measurement chamber by the control unit; And
And determining whether the driving dew point system is normal according to a result of comparing the dew point by the control unit.
6. The continuous heat treatment furnace according to claim 5, wherein the step of switching the plurality of measurement valves while operating the plurality of measurement valves for the first predetermined time period is performed by sequentially circulating the plurality of measurement valves, respectively, A method of controlling a dew point measuring apparatus.
The method as claimed in claim 5, further comprising the step of: the controller outputting a dew point for each point input from the driving dew point system and a normal state of the driving dew point system to an upper controller through an output unit A method of controlling a dew point measuring apparatus in a heat treatment furnace.
The control method of a dew-point measuring apparatus according to claim 5, wherein the dew point storage chamber is provided so as to introduce purge gas.

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