KR100862861B1 - Emergency gas supply unit for furnace - Google Patents

Abstract

The present invention prevents product surface defects in the annealing line by automatically supplying the mixed gas to the heating furnace when hydrogen, nitrogen, or a mixed gas thereof is not supplied at an appropriate pressure and flow rate, and detected below a predetermined value. The present invention relates to a mixed gas emergency supply apparatus for an improved furnace to prevent a hydrogen explosion in a furnace to prevent an equipment accident.

The present invention is controlled by a hydrogen production facility for producing hydrogen from sulfur-free Coke Oven Gas, a holder for storing the produced hydrogen, a pressure reducing control valve and a controller for reducing the hydrogen to a mixer and controlling the mixer. The front end of the mixer of the hydrogen line consisting of the hydrogen control valve located before is equipped with a flow meter for detecting the hydrogen flow rate and an automatic on-off valve, a nitrogen holder for storing the nitrogen supplied from the high pressure nitrogen line, and decompresses the nitrogen to the mixer A pressure gauge for detecting nitrogen pressure and an automatic on / off valve are mounted on the front end of the mixer of a nitrogen line, which is controlled by a pressure reducing control valve and a controller and is located before the mixer, and one side is connected to the mixer and the other side is Hydrogen and nitrogen mixed in the mixer connected to the furnace A mixed gas holder is connected to a mixed gas supply line for supplying a mixed gas to the heating furnace so that the mixed gas can be stored and supplied to the heating furnace in an emergency, and a pipe drawn out from the mixed gas holder to the mixed gas supply line is provided. A flow meter and an automatic control valve are mounted, and a flow meter for detecting the flow rate of the mixed gas is mounted at the front of the furnace to open and close the valves based on the detection signals of the flow meter and the pressure gauges, thereby adjusting the set amount from the mixer to the furnace. When the mixed gas is not supplied, a mixed gas emergency supply apparatus for a heating furnace including a controller for supplying the mixed gas from the mixed gas holder to the heating furnace is provided.

Continuous Annealing Line, Furnace, Mixed Gas, Hydrogen Gas, Nitrogen Gas, Emergency Supply Device

Description

Emergency Apparatus for Mixing Gas in Furnace {AN APPARATUS FOR SUPPLYING HNS GAS INTO HEATING FURNACE IN EMERGENCY}

1 is a system diagram showing a configuration of supplying a mixed gas consisting of nitrogen gas and hydrogen gas to a heating furnace of an annealing facility according to the prior art;

2 is a flowchart showing a step by step of supplying a mixed gas consisting of nitrogen gas and hydrogen gas to the heating furnace of the annealing equipment according to the prior art;

3 is a system diagram showing a configuration for supplying a mixed gas consisting of nitrogen gas and hydrogen gas to the heating furnace of the annealing equipment according to the present invention;

4 is a flowchart showing a step by step of supplying a mixed gas consisting of nitrogen gas and hydrogen gas to the heating furnace of the annealing equipment according to the present invention.

       <Description of the symbols for the main parts of the drawings>

101 ... High pressure nitrogen line 103 .... De-Oxo

104 ... Dryer 105,108,109 ... Pressure Reducing Valve

107,110 ... blender 111 .... Shiojigasu

116,118,119 .... Reducing control valve 124,125 ... Nitrogen flow meter

450 ... Controller 510,511 .... Control valve

516,517 Automatic on-off valves 518,519 .. Mixture gas holder                 

522,523 ... Flowmeter 600 .... Signal input

610 .... Emergency supply control 630 .... Emergency return control

The present invention relates to an automated apparatus for emergency supply of the mixed gas used in the heating furnace of the continuous annealing line and the plating line, and more specifically, hydrogen, nitrogen or mixed gas mixed with them cannot be supplied at an appropriate pressure and flow rate. When the gas is detected below a predetermined value, the mixed gas of the furnace is improved to automatically prevent the product surface defect of the annealing line and prevent the hydrogen explosion of the furnace by automatically supplying the mixed gas to the furnace. To an emergency supply device.

In general, the mixed gas used in the heating furnace of the continuous annealing line and the plating line is a mixture of hydrogen gas and nitrogen gas, and the hydrogen gas is supplied to the heating furnace while maintaining a purity of 99.999% and mixed with nitrogen.

This mixed gas is supplied to the heating furnace through a process as shown in FIG. 1, which is supplied with the sulfur-free Coke Oven Gas 111 from the decentralization facility of the energy center. Hydrogen is produced from the hydrogen production facility 114 from 111 and supplied to the annealing facility via a dryer 115, and at the same time, hydrogen gas is stored in the holder 117. Then, in the process of producing the hydrogen gas, the hydrogen production equipment 114 lowers the hydrogen pressure to 10 → 5 kg / cm 2 by the primary pressure reducing control valve 116, and the mixer 107 is mixed with nitrogen. 110).

On the other hand, nitrogen gas is withdrawn from the high-pressure nitrogen line 101 to remove the oxygen component contained in the dioxo (De-Oxo) 103, and dried through a dryer 104, A part is stored in the nitrogen holder 150, and the part of the moth is passed through the primary and secondary pressure reducing valves 105, 108, and 109 to 5 → 2 kg / cm &lt; 2 &gt; 110 is supplied to and mixed with the hydrogen gas.

Therefore, in the mixers 107 and 110, pure hydrogen gas and pure nitrogen gas are mixed at a predetermined ratio and supplied to the furnace side.

And this operation is to be automatically controlled to be made by the controller 190.

That is, as shown in FIG. 2, the controller 190 has an automatic or manual operation mode set in step 200, and receives nitrogen from the high pressure nitrogen line 101 to receive moisture through the dryer 104. After removing the pressure, the pressure is lowered through the first pressure reducing control valve 105, and then the pressure is lowered through the second pressure reducing control valves 108 and 109, and then supplied to the mixers 107 and 110, and hydrogen is Shiji gas. Receives 111 from the central supply to produce hydrogen in the hydrogen production equipment 114, and depressurizes to a predetermined pressure in the primary pressure reducing control valve 116, one line is the water (O2 + H2 = H2O), and the other line is supplied to the mixer 107, 110 by dropping the pressure in the secondary pressure reducing control valves 118, 119.

Then, the automatic control controller 190 confirms the concentration setting values of the mixers 107 and 110 in step 201, and enters the equipment operation in step 202.                         

After plant operation, the controller 190 receives a signal (4-20 mA) of the nitrogen flowmeters 124 and 125 provided at the front end of the mixers 107 and 110 in step 203 and the hydrogen in step 204. Control valves 120 and 121 are operated to supply hydrogen to the mixers 107 and 110, and then hydrogen flow signals (4 to 20 mA) from the inlet flow meters 122 and 123 of the mixers 107 and 110. In step 205, the flow rate ratio of hydrogen and oxygen is detected.

That is, in step 205, the hydrogen is compared to 3800Nm 3 / h ~ 3900Nm 3 / h, hydrogen is 180Nm 3 / h ~ 200Nm 3 / h in step 206 the hydrogen control valve 120, 121 operates and step (207) ) Additionally detects and compares the ratio of the titration, and if the titration ratio is not achieved, the hydrogen control valves 120 and 121 are precisely operated to supply the mixed gas to the heating furnace at a predetermined ratio.

In the process of supplying such mixed gas, if hydrogen is not supplied to the mixers 107 and 110 due to a failure of the primary pressure reducing control valve 116 of the hydrogen gas supply line, only nitrogen gas is supplied to the heating furnace, thereby heating the furnace. In, the annealing coil is oxidized and product defect occurs.

In addition, when nitrogen gas is not supplied at a constant pressure due to a failure of the primary pressure reducing control valve 105 in the process of removing water through the dryer 104 and being supplied, only nitrogen is supplied to the heating furnace, and the heating furnace is normally operated. Excessive pressure was maintained above the pressure to cause a natural explosion by hydrogen in the furnace has been a problem that is expensive to install and maintain the device.

 The present invention is to solve the conventional problems as described above, when hydrogen, nitrogen or mixed gas mixed with them is not supplied to the heating furnace of the annealing equipment at the proper pressure and flow rate, the mixed gas to the heating furnace automatically The purpose of the present invention is to provide a mixed gas emergency supply apparatus for an improved furnace to prevent product surface defects in the annealing line and prevent hydrogen explosion in the furnace to prevent equipment accidents.

In order to achieve the above object, the present invention, when the hydrogen gas and nitrogen gas constituting the mixed gas used in the heating furnace of the continuous annealing line and the plating line is abnormally supplied, by emergency measures to the normal mixing in the heating furnace In the device for supplying gas,

Hydrogen production equipment for producing hydrogen from sulfur-free Coke Oven Gas, holders for storing the produced hydrogen, pressure-controlled control valves and controllers that decompress hydrogen and send it to the blender and are located before the mixer. In front of the mixer of the hydrogen line consisting of a control valve is equipped with a flow meter for detecting the hydrogen flow rate and an automatic on-off valve, a nitrogen holder for storing the nitrogen supplied from the high-pressure nitrogen line, a pressure-reducing control valve for reducing the nitrogen to send to the mixer and A pressure gauge for detecting nitrogen pressure and an automatic on / off valve are mounted on the front end of the mixer of the nitrogen line, which is controlled by a controller and is formed of a nitrogen flowmeter positioned before the mixer, and one side is connected to the mixer and the other is connected to the heating furnace. A mixed gas of hydrogen and nitrogen mixed in the mixer A mixed gas holder is connected to the mixed gas supply line for supplying the gas to the heating furnace so that the mixed gas can be stored and supplied to the heating furnace in an emergency, and the pipe drawn out from the mixed gas holder to the mixed gas supply line has a flow meter. It is equipped with an automatic control valve, the front end of the furnace is equipped with a flow meter for detecting the flow rate of the mixed gas to open and close the valves on the basis of the detection signal of the flow meter and the pressure gauge to set the mixed gas from the mixer to the heating furnace If it is not supplied, by providing a mixed gas emergency supply apparatus for the heating furnace characterized in that it comprises a controller for supplying the mixed gas from the mixed gas holder to the heating furnace.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.                     

As shown in FIG. 3, the mixed gas emergency supply apparatus 1 of the heating furnace according to the present invention automatically turns on and closes the nitrogen gas before it is supplied to the mixers 107 and 110, respectively. The mixer 107 is provided with an off valve 516 and 517 and a device capable of supplying a mixed gas to a heating furnace in the event of an abnormality of a nitrogen line, that is, a mixed gas holder 518 and 519 capable of storing the mixed gas. It is installed at the rear end of 110.

In addition, the pipes connected to the heating furnace in the holders 518 and 519 are equipped with control valves 510 and 511 which operate by receiving a controller 450 signal of a hydrogen or nitrogen line, and a mixed gas at the rear end thereof. Flowmeters 512 and 513 are respectively provided for checking whether a proper flow rate is supplied for emergency supply.

The feedback signals 4 to 20 mA of the flow meters 512 and 513 are electrically connected to the control valves 510 and 511 through the controller 450.

In addition, the hydrogen line is provided with an automatic on / off valve 514 and 515 for shutting off the hydrogen line when the pressure measured by the pressure gauges 126 and 127 of the nitrogen line is below a predetermined value. 107) and 110 are installed on the outlet pipe of the mixed gas holders 518 and 519 by installing flowmeters 522 and 523 for detecting the mixed gas flowing into the heating furnace from the mixers 107 and 110. And configured for comparative control with the emergency supply flow meters 512 and 512.

On the other hand, the hydrogen gas and nitrogen gas are mixed and supplied to the heating furnace from the mixers 107 and 110 at an appropriate ratio, and the hydrogen supply amount is abnormally reduced, or the nitrogen supply pressure is excessively lowered. In this case, or when the flow rate of the mixed gas is excessively lowered, the controller 450 which controls to supply an appropriate amount of the mixed gas from the mixed gas holders 518 and 519 provided at the rear end of the mixers 107 and 110 is provided. A signal input unit 600 for receiving various signals therein; an emergency supply control unit 610 for supplying a mixed gas according to a control sequence set in advance based on these signals; and a facility for supplying the mixed gas in an emergency state. The emergency return control part 630 etc. which return to an initial state and restart are provided.

According to the present invention configured as described above, since the plurality of mixers 107 and 110 and the plurality of mixed gas holders 518 and 519 which supply the mixed gas to the plurality of heating furnaces are arranged in the same structure with each other, One of them, i.e., the one located on the upper side in FIG. 3 will be mainly described, but it is noted that this description applies equally to the one on the lower side.

As described above, the present invention is a hydrogen flow meter in step 601 as a method of emergency supply control of the mixed gas when the signal input unit 600 provided in the controller 450 has a hydrogen flow rate of 50 Nm 3 / h or less. When the flow rate of 122 is 50 Nm 3 / h or less, if a low detection is detected below 7.2 mA from the normal input signal 4 to 20 mA, this signal is input.

In addition, the signal input unit 600 detects the nitrogen pressure from the pressure gauge 126 of the nitrogen supply line and when the nitrogen pressure is excessively low, the pressure of the nitrogen pressure gauge 126 is 0.2 in step 602 as an emergency supply control method. When it is below Kg / Cm2, if it detects below 7.2mA at 4 ~ 20mA of input signal, this signal is inputted.

In addition, the signal input unit 600 is a method of controlling when the flow rate of the mixed gas supplied to the inside of the heating furnace is less than 1000Nm3 / h, the nitrogen control valve 108 for preventing product defects and the control for preventing hydrogen explosion While the valve 120 is operating to supply a mixed gas of nitrogen 3800 Nm 3 / h and hydrogen 185 Nm 3 / h, when the mixed gas flow rate is 1000 Nm 3 / h or less in the mixed gas flow meter 522 in step 603, an input signal These signals are inputted when 4 mA to 20 mA or less are detected.

The signal input unit 600 supplies the mixed gas to the heating furnace normally through the emergency supply control unit 610, which receives a signal from the hydrogen flow meter 122 in step 604 of the signal input unit 600. In the operation control, the signal is converted to digital through an A / D (analog / digital) converter (not shown). When the ratio of hydrogen is received at 810 to 830 DIGIT in step 611, the output signal is received in step 614. To the control valve 510 to open it, and then supply the mixed gas of the mixed gas holder 518 whose pressure is maintained at about 4 Kg / Cm 2 or more to the heating furnace.

In this process, the flow meter 512 transmits the flow value to the controller 450 and precisely adjusts the control valve 510 such that the mixed gas of 3900 Nm 3 / h to 4000 Nm 3 / h is supplied from the flow meter 522. .

In addition, the emergency supply control unit 610 converts an analog signal into a digital signal through an A / D (analog / digital) converter in arithmetic control from the pressure gauge 126 of the nitrogen supply line in step 605. In step 612, when the ratio of nitrogen receives a signal of 1470 to 1500 DIGIT, the output signal is sent to the control valve 510 in step 614 to open it, and then the mixed gas of the mixed gas holder 518 is heated. To feed the furnace.

In this process, the flow meter 510 transmits the flow value to the controller 450 and precisely adjusts the control valve 510 such that the mixed gas of 3900 Nm 3 / h to 4000 Nm 3 / h is supplied from the flow meter 522. will be.

In addition, the emergency supply control unit 610 is a method of controlling when the flow rate of the mixed gas is less than 1000Nm3 / h first detected in step 603 when the flow rate of the mixed gas in the flow meter 522 is less than 1000Nm3 / h The detection signal of 6 mA or less is converted into a digital signal through an A / D (analog / digital) converter in step 606, and in step 613, a flow rate of the mixed gas receives a signal of 819 to 830 DIGIT. At 614, the output signal is sent to the control valve 510 to open it, and then the mixed gas of the mixed gas holder 518 is supplied to the heating furnace. In this process, the flow meter 510 transmits the flow value to the controller 450 and precisely adjusts the control valve 510 such that the mixed gas of 3900 Nm 3 / h to 4000 Nm 3 / h is supplied from the flow meter 522. .

In addition, the controller 450 includes a signal output unit 620 connected subsequent to the emergency supply control unit 610, and the signal output unit 620 is performed at step 614 of the emergency supply control unit 610. After the control valve 510 is opened, the hydrogen on / off valve 514 is shut off at step 621 and the automatic on / off valve 516 is shut off at the same time to shut off the nitrogen line at step 622. The mixed gas is supplied to the heating furnace only through the control valve 510 of the holder 518.

In addition, the emergency return control unit 630 is operated after the signal output unit 620 as described above, which finds and repairs each cause of the equipment failure in the nitrogen supply line and the hydrogen supply line, and returns it to normal production. After the maintenance of the normal equipment is performed, if the reset button (SET BUTTON) is pressed on the operation screen in step 631, the hydrogen automatic on-off valve 514 is opened in step 632 and at the same time step 633. Open the nitrogen automatic on / off valve 516 at 185 Nm 3 / h at the flow meter 122, and flow the nitrogen flow at 3800 Nm 3 / h at the flow meter 124, and at step 634 the control valve. Blocking the supply from the mixed gas holder 518 by blocking the 510 to allow a normal 3900 Nm 3 / h ~ 4000 Nm 3 / h mixed gas flows in the flow meter 522, and in step 635 the flow rate of the mixed gas controller (450) Continuously detected and transmits.

As described above, the mixed gas emergency supply device 1 of the heating furnace according to the present invention has an abnormality in the primary pressure reducing control valve of hydrogen (H2) and the supply flow rate of the mixed gas is excessively low, When the pressure is excessively low, and when the flow rate of hydrogen is excessively low, each of the valves is controlled so that the mixed gas preset in advance from the mixed gas holders 518 and 519 provided at the rear end of the mixers 107 and 110. It is possible to effectively prevent equipment accidents such as product surface defects and hydrogen explosion in the furnace of the annealing line by supplying the gas immediately.

Claims (4)

In the apparatus for supplying the normal mixed gas to the heating furnace by emergency measures when the hydrogen gas and nitrogen gas constituting the mixed gas used in the heating furnace of the continuous annealing line and the plating line is abnormally supplied, Hydrogen production facility 114 for producing hydrogen from sulfur-free Coke Oven Gas 111, holder 117 for storing the produced hydrogen, and decompresses the hydrogen to the mixers 107 and 110. The mixer 107 of the hydrogen line, which is controlled by the pressure reducing control valves 116, 118, 119 and the controller 190, and is composed of the hydrogen control valves 120, 121 located before the mixer 107, 110. (110) In front of the 110 is equipped with a flow meter (122) 123 for detecting the hydrogen flow rate and automatic on-off valves (514, 515), nitrogen holder (150) for storing the nitrogen supplied from the high-pressure nitrogen line 101 ), A nitrogen flow meter which is controlled by the pressure reducing control valves 105, 108, 109 and the controller 190 that sends nitrogen to the mixers 107, 110 and is reduced before the mixers 107, 110. In front of the mixer 107 (110) of the nitrogen line consisting of 124, 125, pressure gauges (126, 127) for detecting nitrogen pressure and automatic on-off Valves 516 and 517 are mounted, one side of which is connected to the mixers 107 and 110 and the other side of which is connected to the heating furnace to mix mixed gas of hydrogen and nitrogen mixed in the mixers 107 and 110. The mixed gas holders 518 and 519 are connected to the mixed gas supply line for supplying the heating furnace so that the mixed gas can be stored and supplied to the heating furnace in an emergency, and the mixed gas holders 518 and 519 are connected to the mixed gas supply lines. Flow meters 512 and 513 and automatic control valves 510 and 511 are mounted on the pipes drawn out to the mixed gas supply line, and flow meters 522 and 523 which detect the flow rate of the mixed gas at the front end of the heating furnace. And valves 514, 515, 516, 517, 510 and 511 based on the detection signals of the flow meters 122, 123, 522, 523 and the pressure gauges 126, 127. ) By opening and closing the mixed gas holder of the mixed gas holder (107) and (110) when the set amount of the mixed gas cannot be supplied to the heating furnace. And a controller (450) for supplying the mixed gas from the 518 (519) to the furnace. delete delete delete

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