Online continuous monitoring method and device for pH value of blast furnace gas condensate water

Abstract

The invention relates to an on-line continuous monitoring method and device for the pH value of blast furnace gas condensate water, the device comprises a condensate water collecting device, an on-line monitoring device and a condensate water discharging device, all parts of the device are specifically arranged, and setting of specific parameters in the monitoring method is matched to monitor the pH value of the blast furnace gas condensate water. Particularly, an interlocking setting mode and a pH monitoring component are set in detail, so that the device and the monitoring method can be used for quickly and efficiently monitoring the pH value of the blast furnace gas in real time, and the safety, timeliness and accuracy of the monitoring process are ensured.

Description

Technical Field

[0001] The present invention belongs to the field of air pollution control, in particular to the field of gas control and control in the field of iron and steel metallurgy, and specifically relates to an online continuous monitoring method and device for the pH value of blast furnace gas condensate. Background Art

[0002] During the smelting process of the blast furnace, various raw materials, fluxes, fuels, etc. will bring trace amounts of chlorine into the blast furnace. The Cl element in the sintered ore, lump ore, coke and various additives in the blast furnace will exist in the form of NaCl, KCl, CaCl2, etc. The materials in the blast furnace move from top to bottom, while the gas rises from bottom to top. Chlorine undergoes a series of reactions in a high-temperature reducing atmosphere and eventually enters the top gas in the form of HCl.

[0003] The existing blast furnace gas pipeline system does not fully consider the corrosion of HCl and other acidic gases on the back-end equipment and pipelines of the blast furnace, which will bring huge economic losses and safety hazards to the steel plant. Therefore, it is necessary to monitor the acidic gas in the blast furnace gas pipeline network, and at the same time, it is also necessary to monitor the acidic gas removal effect in the pipeline network equipped with a dechlorination device. The existing detection methods for the blast furnace gas pipeline network mainly include online monitoring method and condensate sampling detection method. Among them, the online monitoring method causes the specific acidic gas concentration detection to be inaccurate due to the complex components in the blast furnace gas, so that the acidity and alkalinity of the gas cannot be intuitively reflected; and the condensate sampling detection method is to sample the condensate of the blast furnace gas pipeline network at regular intervals, and then conduct laboratory analysis, and reflect the changes in the acidic components in the gas through the pH value of the water sample. Although this method is accurate, it has a certain hysteresis and cannot provide timely feedback to guide the blast furnace gas deacidification system and make timely adjustments to the working conditions, thereby consuming a lot of manpower and material resources.

[0004] China's invention patent publication CN114653181A discloses a method for analyzing trace amounts of hydrogen chloride in blast furnace gas, which uses a traditional absorption device to detect the content of hydrogen chloride in blast furnace gas. However, the device requires external blast furnace gas, configuration of absorption liquid, and manual analysis. This method has certain safety hazards, the detection results are not timely, and it consumes manpower and material resources. China's utility model patent announcement CN209927714U discloses a portable gas analyzer based on Fourier transform infrared spectroscopy technology, that is, it also records a portable gas analyzer, but because blast furnace gas contains complex components, the use of this analyzer for monitoring will lead to inaccurate detection results.

[0005] Therefore, for the steel industry, the acidic gases in blast furnace gas, mainly HCl, cause serious corrosion to pipelines and equipment. The existing online detection devices are not accurate due to the complex components of blast furnace gas. The traditional absorption detection results cannot timely reflect the fluctuations in the concentration of acidic gases in the gas. There is a certain lag in the technical problem, and it is urgent to develop a technical solution to solve this technical problem. Summary of the invention

[0006] In order to solve the above technical problems, the present invention utilizes the physical and chemical properties of acidic gases in blast furnace gas and, based on a large amount of experimental data, proposes a method and device for online continuous monitoring of the pH value of blast furnace gas condensate water, which can accurately and timely reflect the acidity and alkalinity state of blast furnace gas, and can construct an interlocking system for steel mills with deacidification treatment equipment installed at the front end to quickly adjust the deacidification effect, and solves the problem of real-time online and accurate monitoring of the acidity and alkalinity of blast furnace gas.

[0007] This is achieved through the following technical means:

[0008] An online continuous monitoring device for pH value of blast furnace gas condensate comprises a condensate collecting device, an online monitoring device and a condensate discharging device.

[0009] The condensed water collecting device includes a high-temperature gas discharge component, a condensation component and a low-temperature gas reflux component; the high-temperature gas discharge component is used to discharge the blast furnace gas in the blast furnace gas discharge pipeline into the condensation component, the condensation component is used to cool the discharged blast furnace gas and obtain condensed water and discharge the obtained condensed water, and the low-temperature gas reflux component is used to discharge the low-temperature blast furnace gas obtained after cooling back into the blast furnace gas discharge pipeline.

[0010] The online monitoring device includes a U-shaped water seal elbow and an online pH detection component. The U-shaped water seal elbow is used to perform U-shape enrichment of condensed water discharged from the condensation component to form a dynamic water seal to prevent gas from passing through the online monitoring device. The online pH detection component is arranged on the U-shaped water seal elbow and is used to perform real-time pH detection on the liquid in the U-shaped water seal elbow.

[0011] The condensed water discharge device is used to discharge the liquid discharged by the online monitoring device.

[0012] Preferably, the high-temperature gas discharge component includes a high-temperature gas discharge pipe, a branch inlet ball valve, a gas pressure reducing valve and an inlet pneumatic ball valve; the inlet of the high-temperature gas discharge pipe is connected to the blast furnace gas discharge pipeline, and the gas pressure in the high-temperature gas discharge pipe is lower than the gas pressure in the blast furnace gas discharge pipeline, the branch inlet ball valve, the gas pressure reducing valve and the inlet pneumatic ball valve are respectively arranged on the high-temperature gas discharge pipe, and the gas pressure reducing valve is used to reduce the gas pressure in the high-temperature gas discharge pipe.

[0013] Preferably, the condensation component includes a condenser shell, a cooling water pipe, a condensate collecting tank, a cooling water inlet, a cooling water outlet, a high-temperature gas inlet, a low-temperature gas outlet and a condensate outlet; the cooling water inlet is arranged at the bottom end of the condenser shell, and the cooling water outlet is arranged at the top end of the condenser shell; the cooling water pipe is arranged inside the condenser shell, and its two ends are respectively connected with the cooling water inlet and the cooling water outlet; the high-temperature gas inlet is opened at the top end of the condenser shell or the top end of the side wall, and the high-temperature gas inlet is connected with the outlet end of the high-temperature gas discharge pipe; the low-temperature gas outlet is opened at the bottom end of the condenser shell or the bottom end of the side wall; the condensate collecting tank is arranged at the lower part of the inside of the condenser shell, and the condensate outlet is arranged on the side of the condenser shell and is connected with the discharge port of the condensate collecting tank.

[0014] Preferably, the low-temperature gas reflux component includes a low-temperature gas discharge pipe, a pressure transmitter, a gas flowmeter, an outlet pneumatic ball valve and a branch outlet ball valve; the inlet end of the low-temperature gas discharge pipe is connected to the low-temperature gas outlet of the condensation component, and the outlet end of the low-temperature gas discharge pipe is connected to the blast furnace gas discharge pipeline. The pressure transmitter, the gas flowmeter, the outlet pneumatic ball valve and the branch outlet ball valve are all arranged on the low-temperature gas discharge pipe. The pressure transmitter and the inlet pneumatic ball valve and the outlet pneumatic ball valve are provided with an interlocking component. When it is detected that the gas pressure at the outlet end of the low-temperature gas discharge pipe is lower than the pressure of the blast furnace gas discharge pipeline or when it is detected that the gas pressure at the rear end of the gas pressure reducing valve is higher than the safety pressure threshold of the U-shaped water seal elbow, the inlet pneumatic ball valve and the outlet pneumatic ball valve are closed and an alarm is issued to prevent the gas in the low-temperature gas discharge pipe from flowing in reverse or the gas pressure fluctuation from penetrating the water seal of the U-shaped water seal elbow.

[0015] The branch inlet ball valve and the branch outlet ball valve are used to shut down the operation of the device as a whole when the device as a whole is not working or when the pneumatic ball valve is not closed tightly.

[0016] Preferably, the low-temperature gas reflux component further comprises an exhaust pipe, which is arranged between the gas flow meter and the outlet pneumatic ball valve; the exhaust pipe is used for exhausting when sampling or finishing an operation.

[0017] Preferably, the safety pressure threshold of the U-shaped water seal elbow is 18-25 kPa (preferably 20 kPa).

[0018] Preferably, the junction of the inlet of the high-temperature gas discharge pipe and the blast furnace gas discharge pipeline is point A, the junction of the outlet end of the low-temperature gas discharge pipe and the blast furnace gas discharge pipeline is point B, and a blast furnace gas waste pressure turbine power generation device (i.e., TRT) is arranged on the high-temperature gas discharge pipe between points A and B.

[0019] Preferably, the online monitoring device also includes a condensate discharge pipe, a condensate flowmeter, a condensate drain valve and a condensate outlet pipe; the inlet end of the condensate discharge pipe is connected to the condensate outlet of the condensation component, the outlet end of the condensate discharge pipe is connected to the inlet end of the U-shaped water seal elbow, the outlet end of the U-shaped water seal elbow is connected to the inlet end of the condensate outlet pipe, a condensate flowmeter is provided on the condensate discharge pipe, and a condensate drain valve is provided at the bottom end of the U-shaped water seal elbow.

[0020] The condensed water to be tested flows to the U-shaped water seal elbow, and an online pH detection component (existing known commercially available equipment) is installed on the U-shaped water seal elbow to achieve the purpose of real-time monitoring. Among them, the water seal height of the U-shaped water seal elbow is about 2.5m.

[0021] Preferably, the condensate discharge device includes an inlet valve, a gas drainer and a condensate discharge floor drain; the gas drainer includes an inlet pipe, an outlet pipe and a plurality of water seal pipes, the inlet pipe is connected to the condensate outlet pipe, the water inlet valve is arranged on the inlet pipe, the outlet pipe is connected to the condensate discharge floor drain via a pipe, and a plurality of water seal pipes are arranged sequentially in the gas drainer.

[0022] Preferably, the condenser shell is further provided with a flushing water inlet and a nitrogen replacement inlet, wherein the flushing water inlet is used for cleaning the inside of the condenser shell, and the nitrogen replacement inlet is used for evacuating the condenser shell with nitrogen before operation.

[0023] Preferably, the gas drainer of the condensate discharge device is also provided with a water replenishment port, and the condensate is discharged to the on-site drainage ditch through the gas drainer.

[0024] Preferably, the gas drainer is provided with a heat-insulating layer and a heating device, wherein the heat-insulating layer is arranged on the outer shell of the gas drainer, and the heating device is used for supplementing heat inside the gas drainer.

[0025] A method for online continuous monitoring of the pH value of blast furnace gas condensate water, using the above-mentioned online continuous monitoring device for the pH value of blast furnace gas condensate water, comprises the following steps:

[0026] (1) Nitrogen is discharged into the condenser shell through the nitrogen replacement inlet provided on the condenser shell to evacuate the air in the condenser shell, and then cooling water is continuously discharged into the cooling water pipeline through the cooling water inlet and continuously discharged through the cooling water outlet. At the same time, the branch inlet ball valve and the inlet pneumatic ball valve are opened to discharge the blast furnace gas in the blast furnace gas discharge pipeline into the high-temperature gas discharge pipe, and the pressure of the discharged blast furnace gas is set to 15-20 kPa through the gas pressure reducing valve, and then the reduced-pressure blast furnace gas is discharged into the condenser shell through the high-temperature gas inlet through the high-temperature gas discharge pipe.

[0027] (2) The high-temperature blast furnace gas discharged into the condenser shell in step (1) is cooled by a cooling water pipeline to obtain low-temperature blast furnace gas and condensed water. The condensed water is collected by a condensed water collecting tank and discharged through a condensed water outlet, and the low-temperature blast furnace gas is discharged through a low-temperature gas outlet.

[0028] (3) The blast furnace gas discharged in step (2) passes through the pressure transmitter, gas flow meter, exhaust pipe, outlet pneumatic ball valve and branch outlet ball valve in sequence, and is discharged back to the blast furnace gas discharge pipeline through the low-temperature gas discharge pipe.

[0029] When it is detected that the gas pressure at the outlet end of the low-temperature gas discharge pipe is lower than the pressure of the blast furnace gas discharge pipeline, the inlet pneumatic ball valve and the outlet pneumatic ball valve are closed and an alarm is sounded to prevent the gas in the low-temperature gas discharge pipe from flowing in reverse.

[0030] (4) The condensed water discharged from step (2) is discharged into the condensed water discharge pipe, and the flow rate of the condensed water in the condensed water discharge pipe is controlled by a condensed water flow meter to be 0.5 to 0.95 m / s. 3 / h, control the water seal height of the U-shaped water seal elbow to be 2.3-5.5m, detect the pH of the condensed water in the U-shaped water seal elbow through the online pH detection component, and at the same time ensure that the U-shaped water seal elbow is always in a flowing state and the flow rate is maintained at 0.2-0.9m / s, and discharge the detected condensed water into the condensed water discharge device through the condensed water outlet pipe.

[0031] When it is detected that the gas pressure at the rear end of the gas pressure reducing valve is higher than the safety pressure threshold of the U-shaped water seal elbow, the inlet pneumatic ball valve and the outlet pneumatic ball valve are closed and an alarm is sounded to prevent the gas pressure fluctuation from breaking through the water seal of the U-shaped water seal elbow.

[0032] Through the heat exchange of the condenser, the gas temperature is reduced to below the dew point temperature, and condensed water will be produced.

[0033] (5) The condensed water discharged in step (4) is discharged into the gas drainer through the condensed water outlet pipe, and then discharged through the step-by-step water seals. This can further prevent the blast furnace gas from breaking through the water seals and prevent the blast furnace gas from leaking out.

[0034] Preferably, in step (1), the temperature of the high-temperature blast furnace gas discharged into the high-temperature gas discharge pipe is 130-180° C., and the flow rate of the blast furnace gas is 45-55 m / s. 3 / h; in step (2), the temperature of the low-temperature blast furnace gas obtained is 15-25°C.

[0035] As a preferred embodiment, the water content of blast furnace gas is 15g / m 3 about.

[0036] Preferably, the electrode installation position of the online pH detection component is located in the water-facing direction below the U-shaped water seal elbow. Such a setting makes the detection result more accurate, and a sleeve is provided at the position of the electrode installation of the U-shaped water seal elbow, and the sleeve is sleeved on the outside of the electrode. Such a setting is convenient for later maintenance.

[0037] Gas drainer equipment is installed to curb blast furnace gas leakage.

[0038] The technical effects of the present invention are:

[0039] (1) The present invention utilizes the physical and chemical properties of acidic gases in blast furnace gas, based on a large amount of experimental data, and finally obtains an online continuous monitoring device for the pH value of blast furnace gas condensate and a matching method. The blast furnace gas is firstly led out, and then cooled and condensed after contact with a pipeline with cooling water to obtain condensate, and then the pH of the continuously flowing condensate is continuously detected, and the condensate is specifically controlled and discharged, thereby realizing accurate and timely reflection of the acidity and alkalinity state of the blast furnace gas.

[0040] (2) The present invention can prevent the breakdown of the liquid seal and the backflow of blast furnace gas on the low-pressure side by providing two pneumatic ball valves for the inlet and outlet pipes, a low-temperature gas reflux pipe, a gas drainer and other devices, and by providing an interlocking system established by the pneumatic ball valve and the pressure transmitter, thereby fundamentally curbing the safety hazards caused by the leakage of blast furnace gas, thereby ensuring the safety of the overall device.

[0041] Compared with traditional absorption sampling, the present invention reacts to the acid-base status of blast furnace gas faster by installing an online continuous monitoring pH meter, thereby reducing the consumption of manpower and reagents; for steel mills with a blast furnace gas deacidification system (such as a dechlorination device) installed at the front end, the deacidification system can establish an interlocking system with the condensate water online continuous monitoring pH meter provided in the present invention, so that the relevant parameters of the deacidification system equipment can be adjusted in real time according to the real-time feedback value and trend curve, thereby greatly improving the deacidification efficiency and deacidification effect.

[0042] The effect of the monitoring device of the present invention is arbitrated by comparing the device equipped with a dechlorination device that absorbs HCl in blast furnace gas with alkali solution, and comparing the detection accuracy of the two methods of pH online monitoring of condensed water and HCl gas online analyzer. After the derivation and calculation of the pH value, the pH online monitoring method is more accurate for the detection of HCl in the gas and more intuitive for the acid-base balance in the gas, thereby proving that the accuracy of the online continuous monitoring device and the monitoring method of the present invention is very high.

[0043] By arranging a TRT on the high-temperature gas discharge pipe between point A where the inlet of the high-temperature gas discharge pipe meets the blast furnace gas discharge pipe and point B where the outlet end of the low-temperature gas discharge pipe meets the blast furnace gas discharge pipe, the gas pressure in the blast furnace gas discharge pipe at point B is much lower than the gas pressure at point A after the TRT pressure reduction and power generation treatment. As a result, when the blast furnace gas after the pressure reduction treatment of the high-temperature gas discharge pipe of the present invention returns to the blast furnace gas discharge pipe after condensation monitoring, there is generally no need to pressurize the low-temperature gas discharge pipe to achieve a pressure higher than the gas pressure in the blast furnace gas discharge pipe at point B, thereby ensuring normal monitoring of the branch gas flow.

[0044] (3) The present invention can obtain continuous condensate by reasonably setting the branch line blast furnace gas discharge pressure, discharge pressure and gas flow rate, and then coordinating the water seal height and water flow rate of the U-shaped water seal elbow. If one of the parameters (such as the discharge pressure, gas flow rate or water seal height, etc.) changes, it will cause the condensate amount to decrease or be excessive, thereby causing the condensate to be interrupted or the water seal effect of the U-shaped water seal elbow to deteriorate, which will not only cause discontinuity and inaccuracy in monitoring the pH value of the condensate, but may also cause the blast furnace gas to break through the water seal and cause a safety accident. Therefore, the above-mentioned parameters set by the present invention are closely coordinated with each other, and the setting of the various parameters of the present invention can ensure the achievement of the various technical effects of the present invention. The present invention achieves the safety and continuity of the entire device through the specific setting of each parameter. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 This is a schematic diagram of the arrangement of an online continuous monitoring device for the pH value of blast furnace gas condensate according to an embodiment of the present invention.

[0046] in:

[0047] 000- blast furnace gas discharge pipeline;

[0048] 101-Branch inlet ball valve; 102-Gas pressure reducing valve; 103-Inlet pneumatic ball valve; 104-High-temperature gas inlet; 105-Condenser shell; 106-Cooling water pipeline; 107-Cooling water outlet; 108-Condensate collecting tank; 109-Condensate outlet; 110-Cooling water inlet; 111-Cooling water replenishment port of pipe network; 112-Low-temperature gas outlet; 113-Pressure transmitter; 114-Gas flowmeter; 115-Emptying pipeline; 116-Outlet pneumatic ball valve; 117-Branch outlet ball valve; 118-Low-temperature gas discharge pipe; 119-High-temperature gas discharge pipe; 120-Drainage circulation components;

[0049] 201-U-shaped water seal elbow; 202-online pH detection component; 203-condensate flow meter; 204-condensate discharge pipe; 205-condensate drain valve; 206-condensate outlet pipe;

[0050] 301-gas drainer; 302-water supply port; 303-water supply valve; 304-water inlet valve; 305-condensate discharge floor drain, 306-inlet pipe, 307-water seal pipe, 308-outlet pipe. DETAILED DESCRIPTION

[0051] The process technology scheme of the present invention is further illustrated below by combining embodiments and drawings. The orientations involved in this specification are based on the orientations of the present invention during normal operation, and do not limit the orientations during storage and transportation. They only represent relative positional relationships, not absolute positional relationships. Specific implementation methods Unless otherwise described, each feature is only an example of a series of equivalent or similar features. Just to help understand the present invention, those skilled in the art should understand that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0052] Example 1

[0053] This embodiment is used to illustrate an online continuous monitoring device for the pH value of blast furnace gas condensate water set up in a blast furnace workshop of a steel plant. Figure 1 As shown, the monitoring device of this embodiment includes a condensate collection device, an online monitoring device and a condensate discharge device.

[0054] like Figure 1 As shown, the condensate collecting device includes a high-temperature gas discharge component, a condensation component and a low-temperature gas reflux component; the high-temperature gas discharge component is used to discharge the blast furnace gas in the blast furnace gas discharge pipeline into the condensation component, the condensation component is used to cool the discharged blast furnace gas and obtain condensate and discharge the obtained condensate, and the low-temperature gas reflux component is used to discharge the low-temperature blast furnace gas obtained after cooling back into the blast furnace gas discharge pipeline.

[0055] The online monitoring device includes a U-shaped water seal elbow and an online pH detection component. The U-shaped water seal elbow is used to perform U-shape enrichment of condensed water discharged from the condensation component to form a dynamic water seal to prevent gas from passing through the online monitoring device. The online pH detection component is arranged on the U-shaped water seal elbow and is used to perform real-time pH detection on the liquid in the U-shaped water seal elbow.

[0056] The condensed water discharge device is used to discharge the liquid discharged by the online monitoring device.

[0057] More specific Figure 1As shown, the high-temperature gas discharge component includes a high-temperature gas discharge pipe, a branch inlet ball valve, a gas pressure reducing valve and an inlet pneumatic ball valve; the inlet of the high-temperature gas discharge pipe is connected to the blast furnace gas discharge pipeline (for example, the present embodiment is arranged at the bag dust collector outlet of the blast furnace gas discharge pipe), and the gas pressure in the high-temperature gas discharge pipe is lower than the gas pressure of the blast furnace gas discharge pipeline, the branch inlet ball valve, the gas pressure reducing valve and the inlet pneumatic ball valve are respectively arranged on the high-temperature gas discharge pipe, and the gas pressure reducing valve is used to reduce the gas pressure in the high-temperature gas discharge pipe.

[0058] The condensation component includes a condenser shell, a cooling water pipe, a condensate collecting tank, a cooling water inlet, a cooling water outlet, a high-temperature gas inlet, a low-temperature gas outlet and a condensate outlet; the cooling water inlet is arranged at the bottom end of the condenser shell, and the cooling water outlet is arranged at the top end of the condenser shell; the cooling water pipe is arranged inside the condenser shell, and the two ends are respectively connected with the cooling water inlet and the cooling water outlet; the high-temperature gas inlet is opened at the top end of the condenser shell or the top end of the side wall, and the high-temperature gas inlet is connected with the outlet end of the high-temperature gas discharge pipe; the low-temperature gas outlet is opened at the bottom end of the condenser shell or the bottom end of the side wall; the condensate collecting tank is arranged at the lower part of the inside of the condenser shell, and the condensate outlet is arranged on the side of the condenser shell and is connected with the discharge port of the condensate collecting tank.

[0059] The low-temperature gas reflux component includes a low-temperature gas discharge pipe, a pressure transmitter, a gas flowmeter, an emptying pipe, an outlet pneumatic ball valve and a branch outlet ball valve; the inlet end of the low-temperature gas discharge pipe is connected to the low-temperature gas outlet of the condensation component, and the outlet end of the low-temperature gas discharge pipe is connected to the blast furnace gas discharge pipeline. The pressure transmitter, the gas flowmeter, the emptying pipe, the outlet pneumatic ball valve and the branch outlet ball valve are all arranged on the low-temperature gas discharge pipe. The pressure transmitter and the inlet pneumatic ball valve and the outlet pneumatic ball valve are provided with an interlocking component. When it is detected that the gas pressure at the outlet end of the low-temperature gas discharge pipe is lower than the pressure of the blast furnace gas discharge pipeline or when it is detected that the gas pressure at the rear end of the gas pressure reducing valve is higher than the safety pressure threshold of the U-shaped water seal elbow, the inlet pneumatic ball valve and the outlet pneumatic ball valve are closed and an alarm is issued to prevent the gas in the low-temperature gas discharge pipe from flowing in reverse or the gas pressure fluctuation from breaking through the water seal of the U-shaped water seal elbow.

[0060] In this embodiment, the safety pressure threshold of the U-shaped water seal elbow can be set to 20 kPa.

[0061] like Figure 1As shown, a TRT is provided on the high-temperature gas discharge pipe between point A where the inlet of the high-temperature gas discharge pipe meets the blast furnace gas discharge pipe and point B where the outlet end of the low-temperature gas discharge pipe meets the blast furnace gas discharge pipe. In this way, even after the pressure reduction treatment, the pressure of the blast furnace gas passing through the outlet end of the low-temperature gas discharge pipe is higher than the pressure of the blast furnace gas in the high-temperature gas discharge pipe at point B, and no backflow of the blast furnace gas is caused.

[0062] like Figure 1 As shown, the online monitoring device also includes a condensate discharge pipe, a condensate flowmeter, a condensate drain valve and a condensate outlet pipe; the inlet end of the condensate discharge pipe is connected to the condensate outlet of the condensation component, the outlet end of the condensate discharge pipe is connected to the inlet end of the U-shaped water seal elbow, the outlet end of the U-shaped water seal elbow is connected to the inlet end of the condensate outlet pipe, a condensate flowmeter is arranged on the condensate discharge pipe, and a condensate drain valve is arranged at the bottom end of the U-shaped water seal elbow.

[0063] like Figure 1 As shown, the condensate discharge device includes an inlet valve, a gas drainer and a condensate discharge floor drain. The gas drainer includes an inlet pipe, an outlet pipe and a plurality of water seal pipes, the inlet pipe is connected to the condensate outlet pipe, the inlet valve is arranged on the inlet pipe, the outlet pipe is connected to the condensate discharge floor drain through a pipe, and the plurality of water seal pipes are arranged in sequence in the gas drainer.

[0064] Furthermore, in this embodiment, a flushing water inlet and a nitrogen replacement inlet can be provided on the condenser shell. The flushing water inlet is used to clean the inside of the condenser shell, and the nitrogen replacement inlet is used to empty the condenser shell with nitrogen before operation.

[0065] Furthermore, in this embodiment, a water supply port and a water supply valve are provided on one side of the gas drainer of the condensate discharge device, and the condensate is discharged to the on-site drainage ditch through the gas drainer.

[0066] In order to adapt to the use in cold areas, the gas drainer of this embodiment is provided with a heat-insulating layer and a heating device. The heat-insulating layer is arranged on the outer shell of the gas drainer, and the heating device is used to supplement the heat inside the gas drainer.

[0067] The electrode installation position of the online pH detection component of this embodiment is located in the water-facing direction below the U-shaped water seal elbow, and a sleeve is provided at the electrode installation position of the U-shaped water seal elbow, and the sleeve is sleeved on the outside of the electrode.

[0068] Example 2

[0069] This embodiment is an online continuous monitoring method for the pH value of blast furnace gas condensate water using the device of embodiment 1, comprising the following steps:

[0070] (1) The blast furnace gas is drawn out of the main pipeline (blast furnace gas discharge pipeline) after bag dust removal through a DN40 pipeline. Prior to this, nitrogen is first discharged into the condenser shell through the nitrogen replacement inlet set on the condenser shell to empty the air in the condenser shell, and then cooling water is continuously discharged into the cooling water pipeline through the cooling water inlet and continuously discharged through the cooling water outlet. The cooling water of the water-cooled condenser adopts a "bottom-in and top-out" transportation method. At the same time, the branch inlet ball valve and the inlet pneumatic ball valve are opened to discharge the blast furnace gas after dust removal in the blast furnace gas discharge pipeline into the high-temperature gas discharge pipe, and the pressure of the discharged blast furnace gas is set to 15-20kPa through the gas pressure reducing valve, and the gas flow rate is maintained at 50m 3 / h. Then the decompressed blast furnace gas is discharged into the condenser shell through the high-temperature gas inlet through the high-temperature gas discharge pipe.

[0071] (2) The high-temperature blast furnace gas discharged into the condenser shell in step (1) is cooled by a cooling water pipeline to obtain low-temperature blast furnace gas and condensed water (the acidic gas and water vapor in the gas are reduced to below the dew point through the cooling water heat exchange pipeline to generate condensed water). The condensed water is collected by a condensed water collection tank and discharged through a condensed water outlet, and the low-temperature blast furnace gas is discharged through a low-temperature gas outlet. The average temperature of the blast furnace gas after heat exchange is 20°C.

[0072] (3) The blast furnace gas discharged in step (2) passes through the pressure transmitter, gas flow meter, exhaust pipe, outlet pneumatic ball valve and branch outlet ball valve in sequence, and is discharged back to the blast furnace gas discharge pipeline through the low-temperature gas discharge pipe.

[0073] Among them, the pressure transmitter establishes an interlocking system with the front and rear two pneumatic ball valves (inlet pneumatic ball valve and outlet pneumatic ball valve). When the pressure after the pressure reducing valve is higher than the liquid seal safety pressure of 20kPa or the low-temperature gas outlet pressure is lower than the pressure of the low-pressure side blast furnace gas main pipeline, an alarm will occur and the pneumatic ball valve will automatically close to prevent gas pressure fluctuations from breaking through the rear-end liquid seal and backflow of the low-pressure side gas main pipeline.

[0074] (4) The condensed water discharged from step (2) is discharged into the condensed water discharge pipe, and the flow rate of the condensed water in the condensed water discharge pipe is controlled by a condensed water flow meter to be 0.75m 3 / h, the water seal height of the U-shaped water seal elbow is controlled to be 2.5m, the pH of the condensed water in the U-shaped water seal elbow is detected by the online pH detection component, a drain valve is set at the bottom of the U-shaped pipe for later maintenance, and the pipelines of the monitoring system (such as condensed water discharge pipe, U-shaped water seal elbow, etc.) are DN25 stainless steel pipes to ensure that the condensed water is always in a flowing state and the flow rate is maintained at 0.5m / s. The condensed water after detection is discharged to the condensed water discharge device through the condensed water outlet pipe. The electrode installation position is located in the water-facing direction below the U-shaped elbow, and the detection result is more accurate. The electrode installation position is installed in a sleeve manner after the drain valve for later maintenance.

[0075] (5) The condensed water discharged in step (4) is discharged into the gas drainer through the condensed water outlet pipe, passes through the step-by-step water seal, and then discharged.

[0076] In this embodiment, a dechlorination device is installed on the blast furnace gas discharge pipeline. The device of the present invention detects the detection result accuracy and reaction time of the online pH meter during the process of the dechlorination device blowing from an offline state to a blowing rate of 50 kg / h and then to a blowing rate of 100 kg / h. The results shown in Table 1 are obtained by taking the results of three monitorings at different times. Table 1 is a data table related to the detection result accuracy and stabilization time of multiple groups of online pH detection components under different blowing intensities of the dechlorination device in Example 2 of the present invention.

[0077] Table 1

[0078]

[0079] From Table 1, it can be seen that the three groups of experiments all show that when the dechlorination device is not operating, the pH value in the blast furnace gas is maintained in a strongly acidic state (more than two points), and when the dechlorination device spraying amount reaches a medium intensity of 50kg / h, the pH value is significantly increased, and basically maintained in a relatively weakly acidic state between 4 and 5, indicating that the device of the present invention can display the dechlorination effect of the dechlorination device in real time. When the dechlorination device spraying amount reaches an intensity of 100kg / h, the pH value is further significantly increased to a neutral level close to 7, and the pH value curve stabilization time is basically around 10min, which shows that the device of the present invention can monitor the pH value of blast furnace gas in real time and quickly.

[0080] Comparative Example 1

[0081] In this comparative example, no branch pipeline is set, but the cooling water pipeline, condensate collection tank and condensate outlet are directly set in the blast furnace gas exhaust pipeline. By monitoring the pH value of the collected condensate, it is found through 10 hours of testing that not only the condensate is often interrupted, but also the stabilization time of the pH value is very difficult to determine. This is because there is too much gas that does not participate in condensation in the blast furnace gas exhaust pipeline, which has a very unstable effect on the condensation process. This further proves that the overall device specifically set up in the present invention is stable and reliable for online continuous monitoring of the pH value of condensate.

[0082] Comparative Example 2

[0083] The other settings of this comparative example are the same as those of Example 1 and Example 2, except that the pressure of the blast furnace gas discharged into the high-temperature gas discharge pipe is adjusted to 6-10 kPa through the gas pressure reducing valve, and the flow rate of the blast furnace gas is correspondingly reduced. Except for the parameters naturally affected by the pressure, the other parameters are kept the same as those of Example 2. During the test, it was found that the water seal height in the U-shaped water seal elbow slowly decreased until the water seal effect was lost, and the pneumatic valve was closed to end the test. It can be proved that the pressure parameters set by the present invention and the parameters such as the water seal height set by the present invention are closely coordinated and have a coordinated effect. Changing one or two of the parameters will cause the other parameters to fail or be unsuitable for the present invention, thereby causing the effect to fail.

[0084] Comparative Example 3

[0085] The other settings of this comparative example are the same as those of Example 1 and Example 2, except that the pressure of the blast furnace gas discharged into the high-temperature gas discharge pipe is adjusted to 38-45 kPa through the gas pressure reducing valve, and the flow rate of the blast furnace gas is correspondingly increased. Except for the parameters naturally affected by the pressure, the other parameters are kept the same as those of Example 2. During the test, it was found that when the gas pressure was increased, the flow rate increased, and the detected water content was not as high as that of 20 kPa (only 10 g / m 3 The water content in the coal gas is stable, which means that the condensed water in the coal gas is not completely condensed at high flow rate, which affects the detection; the flow rate increases, the flow rate of the condensed water increases, and the electrode detection result is unstable. This further proves that the pressure parameters set by the present invention and the parameters such as the water seal height set by the present invention are closely coordinated and have a coordinated effect.

[0086] The technical principles and examples of the present invention are described above in conjunction with specific embodiments. The above embodiments and comparative examples of the present invention are all examples and do not have a limiting effect on the protection scope of the technical solution. The technical effects that are not compared can be clearly described through the textual description of the technical effects, and do not mean that the invention is low in height. These descriptions are only for explaining the principles and examples of the present invention and cannot be interpreted as limiting the protection scope of the present invention in any way. Based on the explanations herein, those skilled in the art can think of other specific implementations of the present invention without creative labor, and these methods will fall within the protection scope of the present invention.

Claims

1. An online continuous monitoring device for pH value of blast furnace gas condensate, characterized in that: It includes a condensate collection device, an online monitoring device and a condensate discharge device; The condensed water collecting device comprises a high-temperature gas discharge component, a condensation component and a low-temperature gas reflux component; the high-temperature gas discharge component is used to discharge the blast furnace gas in the blast furnace gas discharge pipeline into the condensation component, the condensation component is used to cool the discharged blast furnace gas and obtain condensed water and discharge the obtained condensed water, and the low-temperature gas reflux component is used to discharge the low-temperature blast furnace gas obtained after cooling back into the blast furnace gas discharge pipeline; The online monitoring device includes a U-shaped water seal elbow and an online pH detection component. The U-shaped water seal elbow is used to perform U-shaped enrichment of condensed water discharged from the condensation component to form a dynamic water seal to prevent gas from passing through the online monitoring device. The online pH detection component is arranged on the U-shaped water seal elbow and is used to perform real-time pH detection on the liquid in the U-shaped water seal elbow. The condensed water discharge device is used to discharge the liquid discharged by the online monitoring device.

2. The device for online continuous monitoring of pH value of blast furnace gas condensate according to claim 1, characterized in that: The high-temperature gas discharge component includes a high-temperature gas discharge pipe, a branch inlet ball valve, a gas pressure reducing valve and an inlet pneumatic ball valve; the inlet of the high-temperature gas discharge pipe is connected to the blast furnace gas discharge pipeline, and the gas pressure in the high-temperature gas discharge pipe is lower than the gas pressure in the blast furnace gas discharge pipeline. The branch inlet ball valve, the gas pressure reducing valve and the inlet pneumatic ball valve are respectively arranged on the high-temperature gas discharge pipe, and the gas pressure reducing valve is used to reduce the gas pressure in the high-temperature gas discharge pipe; The condensing component includes a condenser shell, a cooling water pipeline, a condensed water collecting tank, a cooling water inlet, a cooling water outlet, a high-temperature gas inlet, a low-temperature gas outlet and a condensed water outlet; the cooling water inlet is arranged at the bottom end of the condenser shell, and the cooling water outlet is arranged at the top end of the condenser shell, the cooling water pipeline is arranged inside the condenser shell, and the two ends are respectively connected with the cooling water inlet and the cooling water outlet, the high-temperature gas inlet is opened at the top end or the top end of the side wall of the condenser shell, the high-temperature gas inlet is connected with the outlet end of the high-temperature gas discharge pipe, the low-temperature gas outlet is opened at the bottom end or the bottom end of the side wall of the condenser shell, the condensed water collecting tank is arranged at the lower part of the inside of the condenser shell, and the condensed water outlet is arranged at the side of the condenser shell and is connected with the discharge port of the condensed water collecting tank; The low-temperature gas reflux component includes a low-temperature gas discharge pipe, a pressure transmitter, a gas flowmeter, an outlet pneumatic ball valve and a branch outlet ball valve; the inlet end of the low-temperature gas discharge pipe is connected to the low-temperature gas outlet of the condensation component, and the outlet end of the low-temperature gas discharge pipe is connected to the blast furnace gas discharge pipeline. The pressure transmitter, the gas flowmeter, the outlet pneumatic ball valve and the branch outlet ball valve are all arranged on the low-temperature gas discharge pipe. The pressure transmitter and the inlet pneumatic ball valve and the outlet pneumatic ball valve are provided with an interlocking component. When it is detected that the gas pressure at the outlet end of the low-temperature gas discharge pipe is lower than the pressure of the blast furnace gas discharge pipeline or when it is detected that the gas pressure at the rear end of the gas pressure reducing valve is higher than the safety pressure threshold of the U-shaped water seal elbow, the inlet pneumatic ball valve and the outlet pneumatic ball valve are closed and an alarm is issued to prevent the gas in the low-temperature gas discharge pipe from flowing in reverse or the gas pressure fluctuation from penetrating the water seal of the U-shaped water seal elbow.

3. The device for online continuous monitoring of pH value of blast furnace gas condensate according to claim 2, characterized in that: The safety pressure threshold of the U-shaped water seal elbow is 18-25 kPa; The low-temperature coal gas reflux component further includes an exhaust pipe, which is arranged between the coal gas flow meter and the outlet pneumatic ball valve; The junction of the inlet of the high-temperature gas discharge pipe and the blast furnace gas discharge pipeline is point A, and the junction of the outlet end of the low-temperature gas discharge pipe and the blast furnace gas discharge pipeline is point B. A blast furnace gas waste pressure turbine power generation device is arranged on the high-temperature gas discharge pipe between points A and B.

4. The device for online continuous monitoring of pH value of blast furnace gas condensate according to claim 2 or 3, characterized in that: The online monitoring device also includes a condensate discharge pipe, a condensate flowmeter, a condensate drain valve and a condensate outlet pipe; the inlet end of the condensate discharge pipe is connected to the condensate outlet of the condensation component, the outlet end of the condensate discharge pipe is connected to the inlet end of the U-shaped water seal elbow, the outlet end of the U-shaped water seal elbow is connected to the inlet end of the condensate outlet pipe, a condensate flowmeter is provided on the condensate discharge pipe, and a condensate drain valve is provided at the bottom end of the U-shaped water seal elbow.

5. The device for online continuous monitoring of pH value of blast furnace gas condensate according to claim 4, characterized in that: The condensate discharge device includes an inlet valve, a gas drainer and a condensate discharge floor drain; the gas drainer includes an inlet pipe, an outlet pipe and a plurality of water seal pipes, the inlet pipe is connected with the condensate outlet pipe, the inlet valve is arranged on the inlet pipe, the outlet pipe is connected with the condensate discharge floor drain through a pipe, and a plurality of water seal pipes are arranged in sequence in the gas drainer.

6. The device for online continuous monitoring of pH value of blast furnace gas condensate according to claim 2 or 5, characterized in that: The condenser shell is also provided with a flushing water inlet and a nitrogen replacement inlet. The flushing water inlet is used to clean the inside of the condenser shell, and the nitrogen replacement inlet is used to empty the condenser shell with nitrogen before operation.

7. The device for online continuous monitoring of pH value of blast furnace gas condensate according to claim 2 or 5, characterized in that: The gas drainer of the condensate discharge device is also provided with a water supply port, and is also provided with a heat preservation layer and a heating device. The heat preservation layer is arranged on the outer shell of the gas drainer, and the heating device is used to supplement heat in the gas drainer.

8. A method for online continuous monitoring of pH value of blast furnace gas condensate, characterized in that: The method is carried out using the online continuous monitoring device for pH value of blast furnace gas condensate water according to any one of claims 1 to 7, comprising the following steps: (1) nitrogen is discharged into the condenser shell through a nitrogen replacement inlet provided on the condenser shell to evacuate the air in the condenser shell, and then cooling water is continuously discharged into the cooling water pipeline through the cooling water inlet and continuously discharged through the cooling water outlet, and at the same time, the branch inlet ball valve and the inlet pneumatic ball valve are opened to discharge the blast furnace gas in the blast furnace gas discharge pipeline into the high-temperature gas discharge pipe, and the pressure of the discharged blast furnace gas is set to 15-20 kPa through the gas pressure reducing valve, and then the decompressed blast furnace gas is discharged into the condenser shell through the high-temperature gas inlet through the high-temperature gas discharge pipe; (2) cooling the high-temperature blast furnace gas discharged into the condenser shell in step (1) through a cooling water pipeline to obtain low-temperature blast furnace gas and condensed water, the condensed water is collected through a condensed water collecting tank and discharged through a condensed water outlet, and the low-temperature blast furnace gas is discharged through a low-temperature gas outlet; (3) the blast furnace gas discharged in step (2) passes through the pressure transmitter, gas flow meter, exhaust pipe, outlet pneumatic ball valve and branch outlet ball valve in sequence, and is discharged back to the blast furnace gas discharge pipeline through the low-temperature gas discharge pipe; When it is detected that the gas pressure at the outlet end of the low-temperature gas discharge pipe is lower than the pressure of the blast furnace gas discharge pipeline, the inlet pneumatic ball valve and the outlet pneumatic ball valve are closed and an alarm is sounded to prevent the gas in the low-temperature gas discharge pipe from flowing in reverse; (4) The condensed water discharged from step (2) is discharged into the condensed water discharge pipe, and the flow rate of the condensed water in the condensed water discharge pipe is controlled by a condensed water flow meter to be 0.5 to 0.95 m / s. 3 / h, control the water seal height of the U-shaped water seal elbow to be 2.3-5.5m, detect the pH of the condensed water in the U-shaped water seal elbow through the online pH detection component, and ensure that the U-shaped water seal elbow is always in a flowing state and the flow rate is maintained at 0.2-0.9m / s, and discharge the detected condensed water to the condensed water discharge device through the condensed water outlet pipe; When it is detected that the gas pressure at the rear end of the gas pressure reducing valve is higher than the safety pressure threshold of the U-shaped water seal elbow, the inlet and outlet pneumatic ball valves are closed and an alarm is sounded to prevent the gas pressure fluctuation from breaking through the water seal of the U-shaped water seal elbow; (5) The condensed water discharged in step (4) is discharged into the gas drainer through the condensed water outlet pipe, passes through the step-by-step water seal, and then discharged.

9. The method for online continuous monitoring of pH value of blast furnace gas condensate according to claim 8, characterized in that: In step (1), the temperature of the high-temperature blast furnace gas discharged into the high-temperature gas discharge pipe is 130-180° C., and the flow rate of the blast furnace gas is 45-55 m / s. 3 / h; in step (2), the temperature of the low-temperature blast furnace gas obtained is 15-25°C.

10. The method for online continuous monitoring of pH value of blast furnace gas condensate according to claim 8, characterized in that: The electrode installation position of the online pH detection component is located in the water-facing direction below the U-shaped water seal elbow, and a sleeve is provided at the electrode installation position of the U-shaped water seal elbow, and the sleeve is sleeved on the outside of the electrode.

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