KR20020054402A - HCl concentration reducing apparatus by dehumidifing of exhausting gas of acid recycling plant - Google Patents

Abstract

PURPOSE: A system for reducing hydrogen chlorine concentration by dehumidification of exhaust gas of acid recycling plant is provided, which can lower hydrogen chlorine concentration contained in exhaust gas to atmosphere by promoting moisture condensation in the gas, which is carried out by contacting the exhaust gas with cold absorbent, thus conducting absorbing neutralization. The chlorine ion concentration is detected by conductance meter to improve control of absorbent. CONSTITUTION: The system comprises absorbent cooling equipment, absorbent concentration control equipment, convertible venturi equipment(300), a neutralizing tower(400), an absorber(500) and a wastewater collecting tank(470). The absorber, receiving the steam and hydrogen chlorine gas, discharges regenerated hydrochloric acid at the bottom and hydrochloric acid gas from the top. At the neutralizing tower(400), hydrochloric acid gas coming from the absorber(500) is neutralized by circulating caustic soda solution. The concentration of the hydrochloric acid gas effluent from neutralizing tower is lowered by passing through venturi scrubber(360). The absorbent concentration control equipment, receiving through absorbent recovering automatic valve(235a) the neutralizing solution discharged from the neutralizing tower(400) bottom and receiving condensate of venturi scrubber(360) through condensate discharge automatic valve(255a), supply absorbent to neutralizing tower(400) through heat exchanger(150) after the absorbent is cooled.

Description

HCl concentration reducing apparatus by dehumidifing of exhausting gas of acid recycling plant}

The present invention is a chlorine concentration reduction device by reducing the moisture of the acid recovery gas, more specifically, a chlorine concentration reduction device used in the acid recovery equipment for the recovery of waste hydrochloric acid used for strip (STRIP) cleaning in the steel mill cold rolling mill In particular, the present invention relates to a device capable of reducing the concentration of chlorine contained in the exhaust gas by reducing the moisture of the waste gas generated during the recovery process of the waste hydrochloric acid after the strip washing process.

1 is an overall system diagram of a conventional acid recovery facility.

In the conventional hydrochloric acid regeneration process, the waste hydrochloric acid used as cold-roll strip washing water is recovered and temporarily stored in the waste hydrochloric acid storage tank 10, and then spray-supplied from the concentrator 20 by a pump, and COG (COKE OVEN GAS). Contact the high temperature heat gas discharged from the iron oxide recovery tower 40 heated by the burner using the heat source as a heat source to concentrate by evaporation of water, and store the concentrated waste acid in the highly concentrated waste acid storage tank 30 and By the spray nozzle to go through the process of spraying the iron oxide recovery tower 40 above.

The concentrated acid sprayed as described above (concentrated waste hydrochloric acid) is pyrolyzed in the iron oxide recovery tower 40, and the iron oxide (Fe ₂ O ₃ ) is lowered in the iron oxide recovery tower 40 by its own weight (weight of iron oxide itself). After falling to the iron oxide storage tank 50 is stored by the transfer device, water vapor and chlorine gas is discharged to the concentrator 20 through the residual iron oxide removal tower 60 which is the next process is fine in the residual iron oxide removal tower 60 Iron oxide was extracted from the particles and subjected to a process of resupplying again to the iron oxide recovery tower 40.

Hydrochloric acid gas including water vapor is passed down the temperature while passing through the concentrator 20, removes residual iron oxide and mist (MIST) while passing through the condenser 70, fresh water sprayed from the upper in the absorber 500 18% regenerated hydrochloric acid was made in contact with 510, and the regenerated hydrochloric acid is recycled to the cold rolled strip (STRIP) wash water 530 via the regenerated hydrochloric acid storage tank 520.

The hydrochloric acid gas discharged from the absorber 500 is neutralized by the mixed solution (caustic soda + pure water) in the neutralization tower 400, and a part of the neutralized absorbed liquid is circulated by the pump 460 ( To the absorbent liquid). On the other hand, the wastewater generated in this process is transferred to the wastewater purification facility through the wastewater collection tank 470.

The hydrochloric acid gas discharged from the neutralization tower 400 is discharged into the atmosphere through the venturi 320, the venturi scrubber 360, the condenser 370, and the exhaust gas 380. Lose.

However, in the conventional hydrochloric acid gas purification device as described above, there is no device capable of monitoring the pressure difference between the absorber 500, the neutralization tower 400, the venturi scrubber 360, and the condenser 370 at the inlet / outlet side and the exhaust gas. Even if the chlorine concentration exceeded the legal standard, there was a problem that it was impossible to grasp the operation state.

In addition, if the concentration of sodium chloride (NaCl) and hydrochloric acid (HCl) in the circulating water (absorption liquid) of the neutralization tower 400 rises, it causes the chlorine gas (HCl GAS) emission standard exceeded (thiocyanic acid of the process test method) In the mercury method, the absorbance of sodium chloride (Nacl) is measured and hydrochloric acid (HCl) in the exhaust gas is high because the temperature of the gas discharged to the atmosphere through the discharger 380 (emission gas temperature: about 75 to 80 ° C) is high. ) Emissions exceeding the emission standard (15 ppm).

In addition, foreign matters such as condensed water are fixed in the venturi scrubber 360, so that pressure management of the equipment is poor, so that the flow rate of the absorbing liquid in the neutralization tower 400 can not be increased, and an internal element of the condenser 370 is provided. There is a problem that the removal efficiency of condensate containing hydrochloric acid is lowered because there is no condensate diffuse reflection prevention device in.

The present invention has been made to solve the above problems, the object is to reduce the temperature of the exhaust gas (EXHAUST GAS) discharged to the atmosphere absorbed liquid in the neutralizer for reducing the concentration of chlorine gas in the exhaust gas (neutralizing liquid) The cooling device, absorbent concentration management device that maintains the concentration of residual chlorine and sodium chloride in the absorbent solution by the conductivity optimally and neutralizes the exhaust gas, and increases the chlorine concentration by the condensate in the exhaust gas discharged to the atmosphere. In order to prevent the condensate removal efficiency to improve the chlorine concentration reducing device by reducing the moisture of the acid recovery gas with a conversion venturi controlled by the differential pressure.

1 is a schematic diagram of a conventional acid recovery facility;

2 is an overall system diagram of an acid recovery facility equipped with a chlorine concentration reducing device of the present invention;

3 is a block diagram of a conversion venturi of the present invention,

4 is a working flow chart of the absorbent liquid concentration management apparatus of the present invention;

5 is a block diagram of a PLC used in the absorbent liquid concentration management apparatus of the present invention,

Figure 6a is a flow chart of the conversion venturi of the present invention,

6B is a progress state diagram of the CONDITION unit and the ACTION unit at the time of the operation of the conversion type venturi of the present invention;

Fig. 6C is a block diagram of a PLC of a conversion venturi of the present invention.

<Description of Symbols for Main Parts of Drawings>

100: absorption liquid cooling device 120: cooling fan

140: fresh water supply automatic valve 150: heat exchanger

200: absorbent liquid concentration management device 210a, 210b: conductivity meter

220a, 220b: level gauge 225a, 225b: absorbent liquid discharge valve

230a, 230b: Pure water supply automatic valve 250a, 250b: Absorption liquid supply automatic valve

255a, 255b: Condensate drain valve 300: Convertible Venturi device

310: differential pressure gauge 320: venturi

330: knife valve 331: knife

332: straight gear (RACK) 333: DC drive motor

335: knife housing 360: Venturi scrubber (SCRUBBER)

370: condenser 380: discharger

400: neutralization tower 410: pure water supply automatic valve

420: temperature switch 440: NaOH tank

450: pure water tank 460: pump

470: wastewater collection tank 500: absorber

520: hydrochloric acid storage tank

The present invention for achieving the above object, the concentrated hydrochloric acid is supplied from the waste hydrochloric acid storage tank 10, the concentrated waste acid is a high concentration waste acid storage tank 30, steam and chlorine gas is concentrated condenser 70 discharged to the condenser 70 20,

An absorber 500 receiving the water vapor and the chlorine gas through the condenser 70 to discharge the regenerated hydrochloric acid to the lower part and the hydrochloric acid gas to the upper part;

The hydrochloric acid gas is supplied to the lower side and neutralized with a mixed solution of caustic soda (NaOH) and pure water injected from the upper side, and a portion of the neutralized liquid collected at the lower side is recycled to the upper side by using a pump 460 using an absorbent liquid. And a neutralization tower 400 for discharging the wastewater to the bottom and discharging the hydrochloric acid gas to the top.

The exhaust gas discharged from the acid recovery facility including a venturi 320 receiving the hydrochloric acid gas from the top of the neutralization tower 400 and discharged to the discharger 380 through the venturi scrubber 360 and the condenser 370. In the device to reduce the chlorine concentration,

The neutralized liquid discharged for recirculation at the lower portion of the neutralization tower 400 is supplied via the absorption liquid recovery automatic valve 235a, and the condensed water of the venturi scrubber 360 is supplied via the condensate discharge automatic valve 255a. Absorbent liquid is supplied to the upper portion of the neutralization tower 400 through the absorbent liquid supply inlet valve 240a, the absorbent liquid supply pump 245a, the absorbent liquid supply automatic valve 250a, and the heat exchanger 150, and the drain is discharged to the lower portion. An absorbent liquid concentration management apparatus 200 having an absorbent liquid discharge valve 225a for an absorbent liquid and including an absorbent liquid storage tank 205a equipped with a conductivity meter 210a and a level gauge 220a;

An absorbent liquid cooling device (100) for reducing the temperature of the absorbent liquid through the heat exchanger (150);

By installing a differential pressure gauge 310 and the knife valve 330 in the venturi 320, by changing the flow path by the front and rear differential pressure of the passing gas, by including a conversion type venturi 300 to maintain the differential pressure in a predetermined range Characterized in that configured.

In addition, in the present invention, the absorbent liquid concentration management device 200 is composed of two series of A series and B series of the same components, the conductivity meter (210a, 210b) detects the conductivity as high (high) When the A series to B series, or from B series to A series is characterized in that the operation is replaced.

In addition, in the present invention, the absorbent liquid cooling device 100 is a cooling fan 120 for receiving and cooling the coolant after heat exchange with the high temperature absorbent liquid from the heat exchanger 150, and a cooling water bay for recovering the cooling water after the cooling. A level of the coolant base 110 by the level 110 and a coolant supply pump 130 that pressurizes the coolant from the coolant base 110 and resuppresses the coolant to the heat exchanger 150. It characterized in that it comprises a fresh water supply automatic valve 140 for detecting fresh water supply.

In addition, in the present invention, the conversion type venturi 300 is a differential pressure gauge 310 for detecting the differential pressure of the front and rear piping of the venturi 320, and by changing the flow path by the detected differential pressure to maintain the differential pressure in a predetermined range It characterized in that it comprises a knife valve 330 and the absorbent liquid supply automatic valve 340 is installed on the inlet side of the discharge gas to control the supply of the absorbed liquid is injected.

EMBODIMENT OF THE INVENTION Hereinafter, the structure of this invention is described in detail with reference to an accompanying drawing.

2 is an overall system diagram of an acid recovery facility in which the chlorine concentration reducing device of the present invention is installed, FIG. 3 is a configuration diagram of the conversion type venturi of the present invention, FIG. 4 is a working flowchart of the absorbent liquid concentration management device of the present invention, and FIG. 5 is the present invention. 6A is a flow chart of the conversion venturi of the present invention, FIG. 6B is a progress diagram of the CONDITION unit and the ACTION unit during operation of the conversion venturi of the present invention, and FIG. It is a block diagram of the PLC of the conversion venturi of this invention.

The present invention includes an absorption liquid cooling device (100) consisting largely of a cooling fan (120), a cooling water bay (110), a fresh water supply automatic valve (140), a cooling water supply pump (130), and a heat exchanger (150); Absorption liquid concentration management device 200 for managing the concentration of the absorbing liquid to neutralize the exhaust gas flowing from the bottom of the neutralization tower 400; Venturi 320, the differential pressure gauge 310, the knife valve 330, the conversion type venturi 330 consisting of an automatic liquid supply valve 340.

The absorbent liquid concentration management apparatus 200 is provided with absorbent liquid storage tanks 205a and 205b, and on the upper part thereof, conductivity meters 210a and 210b and absorbent liquid storage tank 205a (for monitoring the concentration of the absorbent liquid to neutralize the exhaust gas). Level gauges 220a and 220b are installed to monitor the level of the absorbent liquid in 205b, and the absorbent liquid supply pumps 245a and 245b for supplying the stored absorbent liquid to the neutralization tower 400 and the conversion venturi 300 are provided. It is installed on the side, and the absorbent liquid supply inlet valve 240a, 240b and the absorbent liquid supply automatic valves 250a, 250b are installed in the front and rear pipes of the absorbent liquid supply pump 245a, 245b to supply the absorbent liquid. have.

In addition, the absorbent liquid recovery valves 235a and 235b for recovering the absorbent liquid collected in the lower portion of the neutralization tower 400 to the absorbent liquid storage tanks 205a and 205b and for supplying the condensed water of the venturi scrubber 360 Condensate discharge automatic valves 255a and 255b are installed on respective pipes connected to the upper portions of the absorbent liquid storage tanks 205a and 205b. An absorbent liquid discharge automatic valve 225a, 225b capable of draining the internal absorbent liquid is provided below the side surfaces of the absorbent liquid storage tanks 205a, 205b.

Absorption liquid concentration management device 200 configured as described above is divided into two series (A, B series) of the same configuration to enable replacement operation by the conductivity meter (210a) (210b), the conductivity meter (210a) When 210b monitors the concentration of the absorbent liquid in the absorbent liquid storage tanks 205a and 205b and sends an exchange operation signal to each series (A series and B series) at the same time as the alarm rich, the signal of the interlock setting value by the interlock setting is established. , A, B series of operation is configured to switch.

When the absorbent liquid neutralizes the high-temperature exhaust gas introduced from the neutralization tower 400 by the absorbent liquid concentration management apparatus 200 configured as described above, the temperature of the absorbent liquid is increased. To configure the absorption liquid cooling device 100 to cool the elevated temperature of the absorption liquid, and configured to fill the cooling water bay 110 with fresh water through the fresh water supply automatic valve 140, the cooling water bay 110 The internal cool fresh water is sent to the heat exchanger 150 through the cooling water supply pump 130 so as to lower the temperature of the absorption liquid supplied through the absorption liquid storage pumps 245a and 245b. Thereafter, the cooling water whose temperature rises due to the heat exchange is recovered to the cooling fan 120 provided on the cooling water base 110, and heat is released by driving the cooling fan to be recycled to the cooling water.

On the other hand, the neutralization tower 400, the temperature switch 420 is installed in the exhaust gas exhaust pipe, the automatic supply of pure water supply valve 410 is opened by the temperature monitoring by spraying the cold pure water through the nozzle from the neutralization tower 400 , It is configured to lower the temperature of the exhaust gas flowing into the neutralization tower 400, the pure water supply automatic valve 410 is configured to be connected to the pure water storage tank and piping.

The conversion type venturi 300 installed in the exhaust gas outlet pipe of the neutralization tower 400 is provided with a differential pressure gauge 310 to monitor the front and rear pressure, the knife valve 330, the absorption liquid supply automatic valve 340, the venturi 320 is installed.

As shown in FIG. 3, the venturi 320 has a milk carton shape and a knife valve 330 is installed by reducing the central portion of the barrel. The knife housing 335 of the knife valve 330 is fixedly installed by welding in the inside of the reduced portion which reduces the central portion of the venturi 320, and the venturi 320 is opened by opening and closing the knife 331. The capacity of the flowing exhaust gas is controlled.

A straight gear (RACK) 332 is fixed to the center of one side of the knife 331 by welding, the linear gear 332 is engaged with the pinion gear of the drive motor 333 is driven forward and backward. The drive motor 333 is preferably composed of a DC motor capable of forward rotation and reverse rotation.

When the DC drive motor 333 rotates, the power of the drive motor 333 is transmitted to the linear gear 332 by a pinion gear fixed to the drive motor shaft with a key, so that the forward rotation of the drive motor 333, The linear gear 332 is moved back and forth according to the reverse rotation, the knife 331 to adjust the flow rate of the exhaust gas flowing through the venturi 320 in the knife housing 335.

The configuration of the conversion type venturi 300 configured as described above will be described in more detail.

When the differential pressure is detected by the differential pressure gauge 310 for monitoring the pressure difference between the front and rear ends of the venturi 320, the driving motor 333 rotates forward or reverse by the detection signal to control the knife valve 330. .

That is, when the differential pressure is less than 250mmH ₂ O, the differential pressure value is transmitted to the drive motor 333 by the differential pressure gauge 310, the DC drive motor 333 is rotated in reverse to close the knife valve 330, venturi 320 Since the output pressure is reduced by reducing the flow rate of exhaust gas passing through), the differential pressure is increased to maintain the normal range (average: 300 mmH ₂ O).

When the differential pressure exceeds 400mmH ₂ O, the differential pressure value is transmitted to the drive motor 333 by the differential pressure gauge 310 so that the DC drive motor 333 rotates forward to open the knife valve 330 and venturi 320. Since the output pressure is increased by increasing the flow rate of the exhaust gas passing through the gas, the pressure difference is reduced to maintain a normal range (average: 300 mmH ₂ O).

The operation of the present invention configured as described above will be described in detail.

According to the present invention, the chlorine concentration in the high-temperature exhaust gas (chlorine gas: HCl GAS) discharged through the absorber 500 and the pretreatment process before the absorber (iron oxide in waste hydrochloric acid after washing the cold rolled strip, regeneration hydrochloric acid recovery process) In order to satisfy 15 ppm), the following operation is performed.

First, the absorption liquid (neutralizing liquid) concentration management apparatus is demonstrated.

A portion of the absorbent liquid (neutralized liquid) supplied from the caustic soda (NaOH) storage tank 440 and the pure storage tank 450 and sprayed from the neutralization tower 400 at a constant concentration is automatically absorbed to recover the absorbent liquid. The absorbent liquid storage tanks 205a and 205b flow into the absorbent liquid storage tanks 205a and 205b through the valves 235a and 235b, and the absorbent liquid concentrations are managed by the conductivity meters 210a and 210b provided above the absorbent liquid storage tanks 205a and 205b.

When the absorbent liquid introduced into the absorbent liquid storage tanks 205a and 205b flows into the absorbent liquid supply pump 245a and 245b through the absorbent liquid supply inlet valve 240a and 240b, the absorbent liquid supply pump 245a and 245b is The absorbent liquid is sent to the heat exchanger 150 via the absorbent liquid supply automatic valves 250a and 250b, where heat exchange is performed by the cooling water supplied from the absorbent liquid cooling device 100, and the temperature of the absorbent liquid is reduced.

The reduced absorbent liquid is supplied to the conversion type venturi 300 through the absorbent liquid supply automatic valve 340, and is also supplied to the upper nozzle of the neutralization tower 400 and is discharged from the lower portion of the neutralization tower 400. Sufficient contact is made between the internal filling and the neutralization of chlorine gas in the exhaust gas.

After the absorption process is completed, the absorbent liquid is collected at the bottom of the neutralization tower 400 and overflows a predetermined liquid to the absorbent liquid storage tanks 205a and 205b of the absorbent liquid concentration management apparatus 200 through the absorbent liquid recovery valves 235a and 235b. When the circulation of the absorbent liquid is repeated, the circulation of the absorbent liquid is repeated, and the conductivity of the absorbent liquid is increased by increasing the concentration of chlorine in the absorbent liquid. Thus, the neutralization absorption of chlorine gas in the exhaust gas by the absorbent liquid is not normal. The concentration of chlorine in the house goes up. Therefore, the monitoring operation by the conductivity meter (210a, 210b) is made to replace the operation of the absorbent liquid concentration management device 200.

The replacement operation of the absorbent liquid concentration management apparatus 200 is performed as shown in the operation flowchart of FIG. 4 and the PLC configuration diagram of FIG. 5.

The case where A series is circulated and B series waits is demonstrated first.

The level of the A series (Y1) is HIGH (monitored by the level gauge 220a), and the conductivity increases as the A series absorbent liquid is circulated, and the conductivity is detected by the conductivity meter 210a. HIGH), B series (Y2) operates and it is operated by switching from A series to B series.

When the B series absorbing liquid supply automatic valve 250b and the absorbing liquid supply inlet valve 240b are opened, the B series pure water supply automatic valve 230b operates to supply pure water by the B series level gauge 220b, thereby absorbing liquid storage tank 205b. To control the water level.

When the opening of the automatic valve is completed, the absorbent liquid supply pump 245b is then started and the condensate discharge automatic valve 255b for draining the condensate generated by the venturi scrubber 360 is opened, and the absorbent liquid recovery automatic valve 235b is opened.

If the absorbent liquid return automatic valve 235b does not open within the predetermined time of the B series timer T2, the alarm is activated. When all the above operations are completed, the A series absorbent liquid supply pump 245a is stopped and the absorbent liquid discharge automatic valve 225a is closed. The remaining automatic valve is stopped while draining the absorbent liquid in the absorbent liquid storage tank 205a to complete the replacement operation.

After the operation is completed, the B-based absorbent concentration monitoring is performed by the B-based conductivity meter 210b.

Next, the case where the B series is circulated and the A series is waiting will be described.

When the level of the B series (Y2) is high (monitored by the level gauge 220b) and the B series absorbent liquid is circulated, the conductivity increases, and when the conductivity is detected by the conductivity meter 210b, the A series becomes high. (Y1) operates to switch from B series to A series.

When the A series absorbent liquid supply automatic valve 250a and the absorbent liquid supply inlet valve 240a are opened, the A series pure water supply automatic valve 230a operates to supply pure water by the A series level gauge 220b, thereby absorbing liquid storage tank 205a. To control the water level.

When the opening of the automatic valve is completed, the absorbent liquid supply pump 245a is then started and the condensate discharge automatic valve 255a for draining the condensate generated by the venturi scrubber 360 is opened, and the absorbent liquid recovery automatic valve 235a is opened.

If the absorbent liquid return automatic valve 235a is not opened within the predetermined time of the A series timer T1, the alarm is activated. When all the above operations are completed, the B series absorbent liquid supply pump 245b is stopped and the absorbent liquid discharge automatic valve 225b is stopped. The remaining automatic valve is stopped while draining the absorbent liquid in the absorbent liquid storage tank 205b to complete the replacement operation.

After the operation is completed, the A-based absorbent concentration monitoring is performed by the A-based conductivity meter 210a.

Second, the absorbent liquid cooling device 100 will be described.

Absorption liquid cooling device 100 is used to install the cooling so as the temperature of the absorption liquid absorbs and neutralizes the exhaust gas of the high temperature coming from the neutralization tower 400 as described above rises.

The coolant stored in the coolant bay 110 is sent to the heat exchanger 150 via a pipe through the coolant supply pump 130. The coolant introduced into the heat exchanger 150 is contacted with the absorbent liquid to exchange heat with the absorbent liquid at high temperature, and then recovered to the cooling fan 120. After the heat is released into the atmosphere by the start of the cooling fan 120, Recovered to the cooling water bay 110 is reused as cooling water.

When the recirculation is performed as described above, the cooling water evaporation and scattering by the cooling fan 120 is generated, and the amount of cooling water stored in the cooling water bay 110 is reduced, which is sensed by the level gauge, and thus, a fresh water supply automatic valve ( Since the fresh water is supplied to 140 and the fresh water is supplied, the water level of the cooling water base 110 is increased, and the fresh water supply automatic valve 140 is closed again by the detection of the level gauge to maintain the cooling water at a predetermined level. Will be done.

Third, the conversion venturi 300 will be described.

When neutralization of the exhaust gas by the absorbent liquid of the absorbent liquid concentration management apparatus 200 in the neutralization tower 400, water in the exhaust gas becomes saturated and is introduced into the conversion venturi 300 and discharged through the knife valve 330. do. The flow rate control by the knife valve 330 is made in such a way that the pressure difference between the front and rear end pressure of the venturi 320 by the pressure gauge 310 is made in such a way that the opening and closing of the knife valve 330 is organically, Maintained so that the flow rate through the conversion venturi 300 is constant, the water in the supersaturated state contained in the exhaust gas is condensed to remove moisture, and neutralization is in the exhaust gas flowing into the conversion venturi 300. Since less amount of chlorine gas is introduced, the absorbent liquid is supplied through the absorbent liquid supply automatic valve 340 to be sprayed through the nozzle to completely remove the residual chlorine gas.

The exhaust gas that has passed through the conversion venturi 300 is collected by the condensate and venturi 320 injected by the venturi scrubber 360, the condensate and the absorbent liquid is absorbed through the condensate discharge automatic valve (255a) (255b) storage tank ( 205a) and 205b are recovered and reused as absorbent liquid, and the exhaust gas is once again removed by the condenser to remove a small amount of water in the exhaust gas and then discharged to the atmosphere through the discharger.

The operation of the conversion venturi 300 will be described in more detail. The conversion venturi 300 of the present invention operates to maintain a constant pressure at all times by monitoring the differential pressure gauge 310 while the driving motor 333 repeats reverse rotation and forward rotation.

The case where the differential pressure is less than 250 mmH ₂ O will be described first.

When the differential pressure of the front and rear pressure passing through the knife 331 is detected by the differential pressure gauge 310 installed at the front and rear ends of the venturi 320, and the differential pressure is less than 250 mmH ₂ O, the DC driving motor 330 is reversely rotated. When the drive motor 330 is rotated in reverse, the pinion gear fixed to the drive motor shaft is rotated in reverse and the linear gear 332 is pushed forward. At this time, the knife 331 fixed to one side of the straight gear 332 by welding. Since the forward pressure inside the knife housing 335 reduces the discharge gas flow rate through the venturi to reduce the exit pressure, the pressure difference (differential pressure) with the venturi 320 inlet pressure is increased.

The driving time of the driving motor is determined within 5 seconds by the reverse rotation timer NTM 002, and if the differential pressure is less than 250 mmH ₂ O even after exceeding 5 seconds, the above process is repeated to maintain the differential pressure in a predetermined range (average 300 mmH ₂ ). O)

The case where the differential pressure exceeds 400 mmH ₂ O will be described.

When the differential pressure of the forward and backward pressure passing through the knife 331 is detected by the differential pressure gauge 310 installed at the front and rear ends of the venturi 320 and the differential pressure exceeds 400 mmH ₂ O, the DC driving motor 330 is rotated forward. When the drive motor 330 is rotated forward, the pinion gear connected to the drive motor shaft is rotated forward and the linear gear 332 is pushed backward. At this time, the knife 331 fixed by welding to one side of the straight gear 332 is rotated. Since the pressure is increased from the inside of the knife housing 334 while increasing the discharge gas flow rate through the venturi, the pressure difference (differential pressure) with the venturi 320 inlet pressure is reduced.

The driving time of the drive motor is determined within 5 seconds by the forward rotation timer NTM 001. When the differential pressure exceeds 400 mmH ₂ O even if it exceeds 5 seconds, the above process is repeated to maintain the differential pressure in a certain range. 300mmH ₂ O)

The chlorine concentration reducing device of the present invention, by reducing the moisture of the acid ash discharge gas, by lowering the temperature of the exhaust gas discharged to the atmosphere by the absorption neutralization in contact with the cold absorbent liquid, to reduce the water condensation in the supersaturated exhaust gas By activating, the concentration of chlorine in the exhaust gas discharged to the atmosphere through the discharger can be reduced to prevent air pollution, and the chlorine ion concentration in the absorbent liquid is constantly monitored by a conductivity meter to improve the management of the absorbed liquid. In addition, the work load of the operator can be reduced by improving the absorption neutralization reaction of the exhaust gas, and the effective value of the exhaust gas can be efficiently managed by removing moisture in the exhaust gas by the conversion venturi.

Claims (4)

The concentrated hydrochloric acid is supplied from the waste hydrochloric acid storage tank 10, the concentrated waste acid is a high concentration waste acid storage tank 30, and the condenser 20 separates and discharges water vapor and chlorine gas into the condenser 70, An absorber 500 receiving the water vapor and the chlorine gas through the condenser 70 to discharge the regenerated hydrochloric acid to the lower part and the hydrochloric acid gas to the upper part; The hydrochloric acid gas is supplied to the lower side and neutralized with a mixed solution of caustic soda (NaOH) and pure water injected from the upper side, and a portion of the neutralized liquid collected at the lower side is recycled to the upper side by using a pump 460 using an absorbent liquid. And a neutralization tower 400 for discharging the wastewater to the bottom and discharging the hydrochloric acid gas to the top. The exhaust gas discharged from the acid recovery facility including a venturi 320 receiving the hydrochloric acid gas from the top of the neutralization tower 400 and discharged to the discharger 380 through the venturi scrubber 360 and the condenser 370. In the device for reducing the chlorine concentration, The neutralized liquid discharged for recirculation at the lower portion of the neutralization tower 400 is supplied via the absorption liquid recovery automatic valve 235a, and the condensed water of the venturi scrubber 360 is supplied via the condensate discharge automatic valve 255a. Absorbent liquid is supplied to the upper portion of the neutralization tower 400 through the absorbent liquid supply inlet valve 240a, the absorbent liquid supply pump 245a, the absorbent liquid supply automatic valve 250a, and the heat exchanger 150, and the drain is discharged to the lower portion. An absorbent liquid concentration management apparatus 200 having an absorbent liquid discharge valve 225a for an absorbent liquid and including an absorbent liquid storage tank 205a equipped with a conductivity meter 210a and a level gauge 220a; An absorbent liquid cooling device (100) for reducing the temperature of the absorbent liquid through the heat exchanger (150); By installing a differential pressure gauge 310 and the knife valve 330 in the venturi 320, by changing the flow path by the front and rear differential pressure of the passing gas, by including a conversion type venturi 300 to maintain the differential pressure in a predetermined range Chlorine concentration reduction device by reducing the moisture of the acid ash discharge gas, characterized in that configured. According to claim 1, The absorbent liquid concentration management device 200 is composed of two series of A series and B series of the same component, the conductivity meter (210a, 210b) detects the conductivity as high (high) Lower chlorine concentration reduction device by reducing the moisture of the acid-recovery exhaust gas, characterized in that the replacement operation from the A series to B series, or B series to A series. According to claim 1 or claim 2, The absorption liquid cooling device 100 is a cooling fan 120 for receiving and cooling the cooling water after the heat exchanger and the high-temperature absorption liquid and heat exchange in the heat exchanger 150, and the cooling water after the cooling The cooling water base 110 to be recovered, the cooling water supply pump 130 for pressurizing the cooling water from the cooling water base 110 and supplying the cooling water back to the heat exchanger 150, and the cooling water base by the level gauge ( Chlorine concentration reduction device by reducing the moisture of the acid ash discharge gas, characterized in that it comprises a fresh water supply automatic valve 140 for supplying fresh water by sensing the level of 110. According to claim 1 or 2, The conversion venturi 300 is a differential pressure gauge 310 for detecting the differential pressure of the front and rear piping of the venturi 320 and the differential pressure by varying the flow path by the detected differential pressure range Knife valve 330 to be maintained as, and the absorbent liquid supply automatic valve 340 is installed on the inlet side of the discharge gas is supplied to control the absorbing liquid is injected to reduce the moisture of the acid ash discharge gas characterized in that it is configured Chlorine concentration reduction device.