KR100749642B1 - Apparatus for controlling pH of the cooling water - Google Patents

Abstract

The present invention is mixed with pure water and diluted detergent in the first storage tank to cool the hot gas generated in the steelmaking process, and then supplied to the boiler tube through the second circulation tank to circulate and cool water flowing back into the steam drum A device for controlling the concentration of hydrogen ions, comprising: a pH detector installed in a sampling pipe branched from a supply line for supplying the cooling water from the second circulation tank to the boiler tube, and a cleaning agent in the first storage tank. And a supply means for supplying the gas and control means for controlling the supply amount of the cleaning agent supplied from the supply tank to the first storage tank according to the pH of the cooling water detected by the pH detector. And by measuring the pH of the boiler water for the steelmaking process of high pressure state in real time By maintaining the boiler tube to prevent rupture, it improves the productivity of the steelmaking process, eliminates major equipment accidents and safety accidents, and prevents environmental pollution.

Clearing agent, cooling coil, pH meter, cooling cooler

Description

Apparatus for controlling pH of the cooling water             

1 is a schematic diagram of pH detection and chemical injection of the hydrogen ion concentration control device according to the present invention;

2 is a block diagram showing a sample water cooling unit of the hydrogen ion concentration control device according to the present invention;

Figure 3 is a flow chart showing the pH detection and chemical dosage control process of the hydrogen ion concentration control device according to the present invention;

4 is a schematic diagram of pH detection and chemical injection according to the conventional embodiment;

5 is a system diagram showing the flow of boiler water for the steelmaking process according to a conventional embodiment.

6 is a perspective view showing a part of the steelmaking boiler tube;

<Description of Symbols for Major Parts of Drawings>

4: steam drum

6: sample water collection piping

7: feed tank                 

14: second chemical pump

15: second chemical tank

16: pressure reducing valve

17: pressure gauge

18: sample water injection valve

19: sample water cooling cooler

20: sample water cooling coil

21: cooling water injection valve

22: cooling water control valve

23: thermometer

24 pH meter

25: sump tank

26: sample water shutoff valve

The present invention relates to a device for controlling the pH (hydrogen ion concentration) of the cooling water (hereinafter referred to as 'boiler watering') circulating the boiler pipe to recover the waste heat of the steelmaking process, and more specifically, high temperature and high pressure Hydrogen ion concentration in the boiler water to maintain the pH of the boiler water by cooling the boiler water in the state of cooling to the room temperature in the cooling cooler and measuring the pH continuously and adjusting the supply of the cleansing agent according to the height of the measured pH. It relates to a control device.

In general, in the steelmaking process, a high temperature gas of about 1600 ° C. is generated, and a vertical forced circulation water pipe boiler is used to recover waste heat therefrom. 4 to 6, the hot gas of about 1600 ° C. generated during the blowdown of the converter 1 is about 900 ° C. by the cooling water circulating through the boiler tube 30 installed in the hood 2 and the radiator 3. Cool to a degree. At this time, the cooling water absorbs the heat emitted from the hot exhaust gas, and a part of the cooling water is evaporated. The mixed water in which the steam and the cooling water are mixed flows into the steam drum 4.

The diameter of the entire boiler is about 3500 mm and about 150 tubes 30 having a diameter of about 60 mm are connected in a cylindrical shape. The temperature of the boiler water flowing in the boiler tube 30 is about 250 ° C. and the pressure is about 14 to 38 bar.

Cooling water supplied to the boiler tube 30 is to remove impurities by using ion exchange resin in the pure water production equipment 13, which is a pretreatment process, in order to prevent rupture of the boiler tube 30 exposed to high temperature and high pressure environment. Treated and the hydrogen ion concentration is maintained at about 6.5-7.

Hereinafter, the supply and circulation of boiler water will be described. That is, the impurities are removed from the pure water production equipment 13, and the pure water maintained at a pH of about 6.5-7, that is, weakly alkaline, is collected in the pure water tank 11, and then the feed tank 7 by the pure water pump 12. Is sent by. In the first chemical tank 9, dilution water containing about 200 liters of water and about 16 kg of a multipurpose cleaning agent is supplied to the feed tank 7 through the first chemical pump 10. As a result, the pH of the cooling water mixed with pure water and dilution water rises to about 8.5. This cooling water is supplied to the steam drum 4 by the feed pump 8. The cooling water in the steam drum 4 is forcedly circulated by the high pressure pump 5 along the tube 30 provided in the hood 2 and the radiator 3 of the converter. At this time, the appropriate pH of the cooling water for preventing corrosion of the boiler tube 30 for steel making is preferably maintained at about 9.4 ~ 11.

Here, the cleansing agent is a product added to the circulating water circulating the boiler pipe to function such as preventing the formation of scale (scale) of the boiler pipe, adjusting the pH of the circulating water, deoxygenation and sludge and scale dispersion It is commercially available as.

In general, since the electrode of the pH detector is easily damaged in an atmosphere of high temperature and high pressure, the pH measurement of the boiler irrigation in the high temperature and high pressure state as described above is not made continuously, and simply extracted boiler irrigation from litmus test paper. Through the color change that appears through. As a result, the pH of the boiler water was not measured accurately.

On the other hand, the dilution water in which water and the cleansing agent are mixed in the first chemical tank 9 is supplied to the feed tank 7 under the condition that the pH of the pure water produced in the pure water production facility 13 is constant. However, as described above, the pH of the cooling water circulating in the boiler tube 30 is not kept constant. As a result, the pH of the cooling water cannot be maintained at the desired target value by the dilution water supplied from the first chemical tank 9 to the feed tank 7.

On the other hand, when the pH of the pure water falls to the abnormality of the pure water production equipment 13 or the low water is supplied to the boiler tube 30, the corrosion of the boiler tube exposed to the high temperature and high pressure atmosphere rapidly proceeds. . At this time, when the boiler tube is ruptured during the operation of rapidly increasing the boiler pressure, the boiler tube flows into the converter of the cooling water steelmaking process and there is a risk of explosion and the like, and the process is stopped for a long time to repair the ruptured portion. There are problems such as this is expected.

The present invention has been made to solve the conventional problems as described above, to measure the pH of the boiler irrigation in real time to prevent rupture due to corrosion of the boiler tube exposed to the atmosphere of high temperature and high pressure and also constant The purpose is to provide a control device for hydrogen ion concentration in boiler water that can be maintained at a level.

In order to achieve the above object, according to the present invention, after mixing with the pure water and the diluted detergent in the first storage tank to cool the hot gas generated in the steelmaking process is supplied to the boiler tube through the second circulation tank and circulated And a device for controlling the hydrogen ion concentration of the cooling water flowing back into the steam drum includes a pH detector installed in a sampling pipe branched from a supply line for supplying the cooling water from the second circulation tank to the boiler tube, A supply tank for supplying a cleaning agent to a first storage tank, and control means for controlling a supply amount of the cleaning agent supplied from the supply tank to the first storage tank according to a pH of the cooling water detected by the pH detector. It is characterized by.

Hereinafter, a preferred embodiment of the present invention will be described with reference to FIGS. 1 to 3 and the same configuration adopts the same reference numeral.

According to the present invention, the sampling pipe 6 is branched from the cooling water supply pipe for supplying the cooling water from the steam drum 4 to the boiler tube 30, and the sampling pipe 6 has a pressure reducing valve 16 and a pressure gauge ( 17) and the sample water injection valve 18 are sequentially installed, and the sample water flowing along the sampling pipe 6 is maintained at a temperature of about 250 ° C. and a pressure of about 14 to 38 bar.

The sample water cooling unit for cooling the sample water to room temperature is made of an airtight cylindrical shape, and the sample water cooling cooler 19 and the sample water cooling cooler to which a cooling fluid pipe is connected to enable communication of the cooling fluid. 19) The sample water cooling coil 20 is mounted in a zigzag shape and the sample water collection pipe 6 is connected to enable communication of the sample water. A cooling fluid inlet valve 21 for controlling the flow of the cooling fluid is installed in the piping for the cooling fluid, and a cooling fluid control valve 22 is installed at the first discharge end of the sample water cooling cooler 19 through which the cooling fluid is discharged. do. The second discharge end of the sample water cooling coil 20 through which the sample water is discharged is provided with a thermometer 23 for measuring the temperature of the sample water and a collecting tank 25 for collecting the sample water.                     

A pH meter 24 for measuring in real time the pH of the sample water of the boiler water cooled to room temperature is provided behind the thermometer 23 at the first discharge end of the cooling coil 20.

In addition, the chemical input unit for supplying the crude liquid of the feed solution to the feed tank (7) is made of a 200 L size of a closed cylindrical shape and the second chemical tank (15) having a closed cover installed on top, and the second chemical tank ( And a second chemical pump 14 installed in a supply pipe for supplying the cleansing agent of the raw liquid from 15).

On the other hand, the control unit for controlling the supply amount of the cleaning agent supplied to the feed tank 7 and the cooling fluid supply amount is connected to various sensors and valves motor controller 28 (MCC) for controlling the operation of the motor, and the motor controller 28 A controller 27 (PLC) for controlling the operation of the controller and a monitor 29 for displaying the control state of the controller 27 in real time.

Hereinafter, the operation of the hydrogen ion concentration control device of the boiler irrigation water according to the present invention.

As shown in FIG. 1, each pump is operated to supply cooling water to the boiler tube. In the first chemical tank 9, 200 L of water and 16 kg of a clean water are mixed by the first chemical pump 10. It is continuously put into the feed tank (7), the second chemical tank (15) is stored in the blue liquid of the raw liquid and the second chemical pump 14 is maintained in a stopped state.

In this state, in order to continuously measure the pH of the boiler water for the steelmaking process, the cooling fluid injection valve 21 is opened to supply the cooling fluid to the sample water cooling cooler 19 while supplying the sample water to the sampling pipe 6. When the shutoff valve 26 is opened, the sample water at high temperature and high pressure flows into the cooling coil 20 through the sample water collection pipe 6.                     

That is, when the sample water arrives at the pressure reducing valve 16, the pressure reducing valve 16 lowers the pressure of the sample water to a low pressure of about 1 bar, and at this time, the pressure gauge 17 measures the sample water pressure. When the pressure of the sample water is 1 bar or less, the sample water injection valve 18 is opened so that the sample water flows into the cooling coil 20. However, when the pressure of the sample water is 1 bar or more, the sample water injection valve 18 is closed. This opening and closing operation of the sample water injection valve 18 is performed quickly to adjust the injection amount and pressure of the sample water.

The sample water passing through the sample water injection valve 18 is cooled by the low temperature cooling fluid flowing into the sample water cooling cooler 19 while passing through the sample water cooling coil 20 at its own pressure, and then discharged. Passed through 24 is collected in the sump (25). The pH meter 24 measures the pH of the sample water in real time, and the pH measurement is transmitted to the controller 27 and displayed numerically on the monitor 29.

At this time, the temperature of the sample water passing through the pH meter 24 is measured by a thermometer 23 installed in the discharge end of the cooling coil 20, this temperature measurement is provided to the controller 27. The controller 27 adjusts the opening and closing degree of the cooling fluid control valve 22 according to the temperature measurement so that the temperature of the sample water passing through the cooling coil 20 is adjusted.

On the other hand, when the pH of the sample water measured by the pH meter 24 falls below the target value, for example, 9.4 or less, the second chemical pump 14 is started to inject the fresh water cleaning agent into the feed tank 7 The feeding operation is stopped when the pH of the sample water reaches a target value, for example, 10. When the pH of the sample water is measured to be 11 or more, the first chemical pump 10 is also stopped to stop the dilution water from being fed into the feed tank 7, after which the pH is measured by the pH measuring device 24. When the pH of the sample water is lowered to 10 or less, the first chemical pump 10 is operated again so that the dilution water mixed with water and the cleansing agent is introduced into the feed tank 7.

The continuous operation as described above works in conjunction with the program set in advance in the controller 27.

According to the present invention, it is possible to improve the productivity of the steelmaking process by maintaining the pH of the boiler water for the steelmaking process for high temperature and high pressure in real time to prevent the rupture of the boiler tube due to corrosion, and also serious equipment accidents and safety accidents Eliminate factors and prevent environmental pollution.

The foregoing is merely illustrative of the preferred embodiments of the present invention and those skilled in the art to which the present invention pertains recognize that modifications and variations can be made to the present invention without departing from the spirit and gist of the invention as set forth in the appended claims. shall.

Claims (4)

Hydrogen ions of the cooling water mixed with pure water and diluted detergent in the first storage tank and then supplied to the boiler tube through the second circulation tank to circulate the hot gas generated in the steelmaking process and flow back into the steam drum. In the apparatus for controlling the concentration, A pH detector installed in a sampling pipe branched from a supply line for supplying the cooling water to the boiler tube from the second circulation tank; A supply tank for supplying a cleaning agent to the first storage tank; And a control means for controlling a supply amount of the cleaning agent supplied from the supply tank to the first storage tank according to the pH of the cooling water detected by the pH detector. The method of claim 1, The control means supplies a cleaning agent from the supply tank to the first storage tank when the pH of the cooling water detected by the pH detector is lower than or equal to a target value, and when the pH of the cooling water detected by the pH detector is higher than or equal to a target value. 2, the hydrogen ion concentration control device of the boiler water, characterized in that to operate to stop the supply of cleaning agent to the storage tank. The method of claim 1, And a cooling means for lowering the temperature of the cooling water flowing through the sampling pipe is provided in front of the pH detector. The method of claim 3, A thermometer for measuring the temperature of the cooling water is provided between the pH detector and the cooling means, wherein the control means flows for heat exchange with the cooling water passing through the cooling means in accordance with the temperature of the cooling water measured by the thermometer. Hydrogen ion concentration control device for boiler water, characterized in that for controlling the supply amount of the medium.

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