KR100983368B1 - Automatic controlling method for the concentration of Cl in wastewater of blast furnace - Google Patents

Abstract

In the present invention, a small amount of dust collected from the concentration tank into the storage tank during the blast furnace treatment process is introduced into the automatic analysis device to analyze the concentration of chlorine in the dust in real time and to automatically adjust the replenishment amount of fresh water according to the result. Its purpose is to.

Automatic chlorine concentration control method in the blast furnace dust collection according to the present invention for achieving the above object, the filtration collected in the concentration tank in order to continuously measure the chlorine concentration in the blast furnace dust collection is transferred to the storage tank into the automatic analysis device Introducing; Pre-cleaning some of the devices in the automatic analyzer to measure the concentration of chlorine in the collected dust; Measuring the chlorine concentration in the dust collector while diluting the introduced dust collector with pure water and then diluting a proper amount reacting with chlorine by a predetermined amount; Rinsing all the instruments of the automatic analyzer after measuring the concentration of chlorine in the dust; And If the measured chlorine concentration is more than the reference value chlorine concentration automatic control method in blast furnace collection, characterized in that consisting of the step of automatically replenishing fresh water with a storage tank to adjust the chlorine concentration in the dust collection.

Blast Furnace Collection, Chlorine Concentration, Automatic Control

Description

Automatic controlling method for the concentration of Cl in wastewater of blast furnace}

1 is a conventional blast furnace dust collection treatment process diagram.

Figure 2 is a blast furnace dust collection process according to the present invention.

Figure 3 is a schematic diagram of an automatic chlorine concentration analysis device in the blast furnace dust collection according to the present invention.

Figure 4 is a graph showing the effect of automatically adjusting the chlorine concentration according to the present invention.

Figure 5 is a graph showing the conventional chlorine concentration control effect.

[Description of Reference Numerals]

10: wet damper 12: thickener

14: pond 16: circulation pump

18: automatic analyzer 20: pump

22: filter 30: dilution vessel

32: dilution sample tube 40: sample container

42: sample tube 50: reaction vessel

52: Cl electrode 54: stirrer

60: titrator 62: injector

R1: Pure water regulator (pressure controller) R2: Nitrogen regulator                 

V1 to V11: Valve 1 to Valve 11

The present invention relates to a method for automatically adjusting the chlorine concentration in the blast furnace dust collection, and more particularly, to a method for automatically adjusting the chlorine concentration in real time by controlling the fresh water replenishment by continuously measuring the chlorine concentration in the blast furnace dust collection will be.

1 is a view showing a conventional blast furnace dust collection process. In order to purify the blast furnace gas (blast furnace gas) generated in the blast furnace plant, the first dust catcher (not shown) to remove the dust in a cyclone method, and a second wet damper (bischoff scrubber) (10) ) To completely remove the small amount of dust that has not been removed. The blast furnace dust collecting through the wet dedusting machine 10 is transferred to the thickening tank 12, and natural sedimentation and flocculation sedimentation are carried out. The sludge filtered thereby is dehydrated through a drum filter and then processed into a cake form. Meanwhile, the supernatant water remaining in the concentration tank 12 after the flocculation settling is sent to the storage tank 14 and mixed with the supplemental water, and then recycled by the circulation pump 16.

In this blast furnace dust collection process, if the concentration of chlorine in the dust collector is higher than the standard value, the facility is corroded. Therefore, maintaining this chlorine concentration within the standard value has become a very important factor in extending the life of the facility. However, conventionally, after collecting the dust collection sample once a week to measure the concentration of chlorine in the blast furnace dust collecting has been analyzed using a silver nitrate titration method. The silver nitrate titration method is a method of measuring the concentration of chlorine ions using the timing point of chromic acid precipitation, focusing on the fact that chlorine ion and silver nitrate react quantitatively and then react with excess silver nitrate to precipitate silver chromic acid. to be.

However, this conventional method can not only prevent the corrosion of the facility because the analysis cycle is only once a week, but also takes too much time for analysis because the work such as sampling is performed manually. It is a factor that reduces the operating productivity of launching facilities.

The present invention has been proposed in order to solve this problem, a small amount of dust collected from the thickening tank transported to the storage tank during the processing process of the blast furnace dust flow into the automatic analysis device to analyze the chlorine concentration in the dust collection in real time and according to the result The purpose of the present invention is to provide a method for automatically adjusting the chlorine concentration in the blast furnace, which is configured to automatically adjust the replenishment of fresh water.

Automatic chlorine concentration control method in the blast furnace dust collection according to the present invention for achieving the above object, the filtration collected in the concentration tank in order to continuously measure the chlorine concentration in the blast furnace dust collection is transferred to the storage tank into the automatic analysis device Introducing; Pre-washing some devices in the automatic analyzer to measure the concentration of chlorine in the collected dust; Measuring the chlorine concentration in the dust collector while diluting the introduced dust collector with pure water and then diluting a proper amount reacting with chlorine by a predetermined amount; Rinsing all the instruments of the automatic analyzer after measuring the concentration of chlorine in the dust; And, if the measured chlorine concentration is more than the reference value is made of the step of automatically replenishing fresh water in the reservoir to adjust the chlorine concentration in the dust collection.

In addition, the preliminary washing step may include discharging the dust collection in the sample pipe; Discharging the solution in the reaction vessel to the outside, and washing pure water into the dilution vessel and the dilution sample tube; Injecting pure water and nitrogen into the reaction vessel to wash; And discharging pure water in the reaction vessel to the outside.

In addition, the chlorine concentration measuring step is the step of injecting the dust collector into the sample container and sample tube; Injecting pure water stored in the dilution vessel into the reaction vessel by a predetermined amount in the preliminary washing step; Injecting the collected dust stored in the sample container into the reaction container by a predetermined amount; And measuring the concentration of chlorine in the dust collector while introducing a predetermined amount of the reaction reacting with chlorine from the titrator.

In addition, the complete washing step includes the step of washing the pure water into the dilution vessel, dilution sample tube and the reaction vessel; Injecting pure water into a sample container and a sample tube to wash the sample; Into the reaction vessel consists of a step of washing pure water and nitrogen.

Hereinafter, with reference to the accompanying drawings will be described in more detail the configuration of the method for automatically adjusting the chlorine concentration in the blast furnace dust collection according to the present invention. 2 is a view showing a blast furnace dust collecting treatment process according to the present invention. For the sake of understanding, the same reference numerals as in FIG. 1 are used for the same components.

Blast furnace dust collection process for implementing the control method of the present invention is the same as the conventional in that it consists of a wet dedusting machine 10, a concentration tank 14 and a storage tank 16 to purify the blast furnace dust collecting. That is, the dust-collected dust is removed by the wet vibration damper 10 composed of a bishop scrubber, etc. are transferred to the concentration tank 12, the flocculation is settled, and the storage tank 14 is combined with the replenishment water and recycled. However, in the present invention, a predetermined amount of dust collectors are introduced into the automatic analysis device 18 among the dust collectors that are transported by installing the sample pipe 24 in a pipe connecting the concentration tank 12 and the storage tank 14.

The automatic analysis device 18 is an apparatus for automatically analyzing the chlorine concentration by using a predetermined amount of collected dust collected as shown in FIG. The automatic analysis device 18 is supplied with pure water and nitrogen gas in addition to the dust collecting flowed through the sample pipe 24. The pure water and nitrogen are used to wash the various instruments constituting the automatic analyzer 18. The pure water is mixed in a predetermined ratio with the dust collection in the reaction vessel 50 described later may be used to make a sample for measuring the chlorine concentration.

The configuration of the various devices in the automatic analyzer 18 will be described along the path through which the dust, pure water and nitrogen are supplied. First, the dust collector is pumped by the pump 20 and passes through the filter 22. When the valve 2 (V2) is opened, the dust collected in the sample pipe 24 is discharged out of the device, and when the valve 3 (V3) is opened, it is introduced into the sample container 40 and the sample pipe 42. When the valve 5 (V5) is opened, the dust collected in the sample container 40 and the sample tube 42 is introduced into the reaction vessel 50, at which time the amount of dust collected into the reaction vessel 50 is It can be adjusted by the valve 4 (V4) connected to the sample pipe (42). Meanwhile, the dust collector stored in the reaction vessel 50 is discharged out of the apparatus as the valve 1 (V1) is opened.

On the other hand, pure water is conveyed by a pure water regulator (R1) and transferred into the automatic analyzer. When the valve 7 (V7) is opened, the dilution vessel 30 and the dilution sample tube 32 are introduced into the dilution container. When the valve 8 (V8) is opened, the pure water stored in the dilution vessel 30 and the dilution sample tube 32 is opened. Is introduced into the reaction vessel (50). When valve 10 V10 is opened, pure water is introduced into sample container 40 and sample tube 42.

On the other hand, nitrogen is pumped by the nitrogen regulator (R2) and transferred into the automatic analysis device, when the valve 6 (V6) is opened, nitrogen is introduced into the sample tube 42 and the sample container 40 and the valve 9 (V9) When is opened, nitrogen is introduced into the dilution sample tube 32 and the dilution vessel (30). Nitrogen introduced into the dilution sample tube 32 and the dilution vessel 30 is introduced into the reaction vessel 50 as the valve 8 (V8) is opened. On the other hand, nitrogen injection into the reaction vessel 50 is also made when the valve 5 (V5) and the valve 11 (V11) are open at the same time.

On the other hand, the titrator 60 is also included in the automatic analysis device. The titrator 60 is connected to the Cl electrode 52 and the stirrer 54 installed in the reaction vessel 50 to operate these devices. The Cl electrode 52 is a device for measuring the chlorine concentration of the sample in the reactor, the stirrer 54 is a device for uniformly mixing the dust collection, pure water, titration solution simultaneously introduced into the reaction vessel 50, pure water only Even if it is put into operation will increase the cleaning effect. In addition, the injector 62 installed in the titrator 60 injects a predetermined amount of silver nitrate to be used for titration of silver nitrate into the reaction vessel 50 in detail.

The method for automatically adjusting the chlorine concentration in the blast furnace dust collecting according to the present invention using the automatic analysis device configured as described above will be described in more detail at each step.

First, a step of introducing the dust collector into the automatic analysis device 18 in real time through the sample pipe 24 installed on the transfer passage connecting the concentration tank 12 and the storage tank 14. In other words, unlike the conventional practice, which was performed once a week, in the present invention, the concentration of chlorine in the dust collector is analyzed in real time.

Next, before the chlorine concentration is measured using the dust collector introduced into the automatic analyzer 18, some devices constituting the automatic analyzer 18 are preliminarily washed for more accurate measurement. In this step, the pump 20 is operated with the valve 2 (V2) opened first to discharge the existing discharge water stored in the sample pipe 24 out of the apparatus. Open valve 1 (V1) and operate stirrer 54 to quickly discharge the existing solution stored in reaction vessel 50 out of the device, while operating pure water regulator R1 and opening valve 7 (V7). Thus, pure water is poured into the dilution vessel 30 and the dilution sample tube 32 and washed. Thereafter, the nitrogen regulator (R2) is operated and valves 8 (V8) and 9 (V9) are opened to purge the pure water and nitrogen stored in the dilution vessel 30 and the dilution sample tube 32 to the reaction vessel 50. Put into and wash. Finally, the preliminary washing step is completed by opening the valve 1 (V1) and operating the stirrer 54 to discharge the pure water stored in the reaction vessel 50 to the outside. In this preliminary washing step, the sample container 40 and the sample tube 42 constituting the automatic analyzer 18 are not washed. This is because the sample container 40 and the sample tube 42 do not need to be cleaned in advance because the dust collector is introduced in the measuring step described later. A summary of the work in the preliminary washing step is shown in Table 1 below.

Table 1

turn  Motion device Work content One Pump, filter, V2 Dust collection in the sample piping 2 V1, stirrer
R1, V7 Discharge of solution in the reaction vessel,
Pure water input into dilution vessel and dilution sample tube 3 R2, V8, V9 Pure and nitrogen feed into the reaction vessel 4 V1, stirrer Pure water discharge in reaction vessel

Next, after mixing and diluting the introduced dust collected with pure water, the chlorine concentration in the collected dust is measured while introducing a predetermined amount of a reactant reacting with chlorine. In this step, first, the dust collector pumped by the pump 20 in the state in which the valve 3 (V3) is opened is introduced into the sample container 40 and the sample tube 42 via the filter 22. As valve 8 V8 is opened, pure water stored in the dilution vessel 30 in the preliminary washing step is introduced into the reaction vessel 50 by a predetermined amount. On the other hand, as the valve 5 (V5) is opened, the dust collected in the sample container 40 is also introduced into the reaction container 50 by a predetermined amount, and the stirrer 54 is operated to be uniformly mixed with pure water to have a suitable concentration. Diluted. Finally, the titration liquid reacting with chlorine is introduced by a predetermined amount by the injector 62 installed in the titrator 60, mixed by the stirrer 54, and simultaneously collected by the Cl electrode installed in the reaction vessel 50. Chlorine concentration in the launch is measured in real time. A summary of the work in the chlorine measurement step is shown in Table 2 below.                     

[Table 2]

turn  Motion device Work content One Pump, filter, V3, V5 Dust collection into sample container and sample tube 2 V8 Pure water into the reaction vessel 3 V4, V5, Agitator Input a certain amount of dust collection into the reaction vessel 4 Injector, Stirrer Put a proper amount of titrant into the reaction vessel
Measurement of chlorine concentration in dust collection by Cl electrode

Next, after measuring the chlorine concentration in the dust collection step is to wash all the devices of the automatic analyzer 18 completely. In this step, pure water regulator R1 is first introduced into the dilution vessel 30, the dilution sample tube 32, and the reaction vessel 50 with valves 7 (V7) and 8 (V8) open. Wash. The pure water regulator R1 injects pure water into the sample container 40 and the sample tube 42 while the valve 10 V10 is opened and cleans it. In the sample container 40 and the sample tube 42, since only the dust collector is put in the previous step, it is necessary to clean more, and this step is repeated 2 to 3 times. Finally, in the state in which the valves 5 (V5) and 10 (V10) are opened, the pure water regulator (R1) is introduced into the reaction vessel (50) and washed. In this complete washing step, the nitrogen regulator (R2) is the dilution vessel (30), the dilution sample tube (32), and the sample vessel (40) while the valves 6 (V6) and 9 (V9) are opened to increase washing efficiency. Into the sample tube 42 and the reaction vessel 50, nitrogen may be added to further enhance the washing effect. In summary, the work in the complete cleaning step is shown in Table 3 below.

[Table 3]

turn  Motion device Work content One R1, V7
V8 Pure water is injected into the dilution vessel and dilution sample tube.
Pure water into the reaction vessel 2 R1, V10 Pure water input into sample container and sample tube (2 ~ 3 times) 3 R1, V5, V10 Pure water into the reaction vessel 4 R2, V6, V9 Nitrogen input for final wash

Next, the step of comparing the chlorine concentration in the dust collected in real time according to the above step with a predetermined reference value. This step is performed in a controller (not shown) connected to the titrator 60, and when the current chlorine concentration is above the reference value, the fresh water is automatically added to the reservoir 14 as supplementary water to reduce the chlorine concentration in the dust collector. Let's do it. At this time, in order to keep the level of the reservoir 14 constant, a certain amount is discharged to the outside of the reservoir 14 as discharge water at the same time as the replenishment water is added.

According to the present invention made as described above, as shown in FIG. 4, the concentration of chlorine in the dust collector is measured in real time, and accordingly, the fresh water is also supplemented in real time, so that the concentration of chlorine in the dust collector can be always maintained below the reference value. On the other hand, according to the conventional method, as shown in Fig. 5, the concentration of chlorine in the dust collector is measured only once a week, so if the chlorine concentration is excessively increased in the meantime, it is not possible to completely prevent corrosion of the facility. .

As described above, according to the method for automatically adjusting the chlorine concentration in the blast furnace dust collection according to the present invention, the chlorine concentration in the blast furnace dust collection is measured in real time and replenishment of fresh water is automatically performed if necessary, so that the chlorine concentration can always be kept below the reference value. This can effectively prevent corrosion of equipment.

Claims (5)

Injecting the dust collected in the concentration tank 12 into the automatic analysis device 18 after being filtered in the concentration tank 12 to continuously measure the concentration of chlorine in the blast furnace; Pre-cleaning some of the devices in the automatic analyzer 18 to measure the concentration of chlorine in the collected dust; Measuring the chlorine concentration in the dust collector while diluting the introduced dust collector with pure water and then diluting a proper amount reacting with chlorine by a predetermined amount; Rinsing all the instruments of the automatic analyzer 18 after measuring the chlorine concentration in the dust collector; And, if the measured chlorine concentration is more than the reference value chlorine concentration in the blast furnace dust collection method characterized in that it comprises the step of automatically replenishing fresh water to the reservoir 14 to adjust the chlorine concentration in the dust collection. The method of claim 1, wherein the preliminary washing step comprises: discharging dust collection in the sample pipe (24); Discharging the solution in the reaction vessel 50 to the outside, and washing pure water into the dilution vessel 30 and the dilution sample tube 32; Injecting pure water and nitrogen into the reaction vessel 50 to wash; And, the chlorine concentration automatic control method in the blast furnace dust collection, characterized in that consisting of the step of discharging the pure water in the reaction vessel to the outside. The method of claim 1, wherein the chlorine concentration measuring step comprises the steps of inputting the dust collecting into the sample container 40 and the sample tube (42); Injecting the pure water stored in the dilution vessel (30) into the reaction vessel (50) by a predetermined amount in the preliminary washing step; Injecting the dust collected in the sample container 40 into the reaction container 50 by a predetermined amount; And measuring the chlorine concentration in the dust collector by introducing a predetermined amount of the reactant reacting with chlorine from the titrator 60, thereby automatically adjusting the chlorine concentration in the blast furnace dust collection. The method of claim 1, wherein the complete washing step comprises the steps of washing pure water into the dilution vessel (30), the dilution sample tube (32) and the reaction vessel (50); Injecting pure water into the sample container (40) and the sample tube (42); Method for automatically adjusting the chlorine concentration in the blast furnace dust collection, characterized in that consisting of the step of washing the pure water into the reaction vessel (50).  The dilution vessel 30, the dilution sample tube 32, the sample vessel 40, the sample tube 42, and the reaction vessel 50, wherein the pure water is added to increase the washing effect. Automatically adjusting the chlorine concentration in the blast furnace dust collecting, characterized in that it further comprises the step of introducing nitrogen into.

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