Method for controlling vaporized water quality of walking beam furnace

Abstract

The invention discloses a method for controlling vaporized water quality of a walking beam furnace, which belongs to the technical field of steel rolling heating furnaces and comprises the following steps: S1, analyzing the following factors influencing the vaporized water quality one by one: water source quality, chemical agent parameters, equipment state and control compliance; s2, tracing the following factors influencing the vaporized water quality one by one: the water quality of a water replenishing end, the state of treatment equipment and section-by-section water quality detection of a circulating system; s3, checking the following key points one by one: parameters of a deaerator, parameters of a dosing system and the state of a blow-down valve; and S4, emergency treatment, including sewage discharge emergency treatment, medicament addition emergency treatment and pollution source emergency treatment. The scientific and reasonable control method is formulated by deeply analyzing various reasons causing the vaporized water quality of the heating furnace to exceed the standard.

Description

A method for controlling the quality of vaporized water in a walking beam furnace Technical Field

[0001] This invention belongs to the technical field of steel rolling heating furnaces, and particularly relates to a method for controlling the quality of vaporized water in a walking beam furnace. Background Technology

[0002] The walking beam furnace employs a water-beam column structure, which effectively supports the furnace body and withstands high-temperature environments. However, to protect the water beams from damage caused by the high-temperature combustion within the furnace, effective cooling measures are essential. Therefore, a vaporization cooling system is introduced to cool the water beam columns, while the water beams are externally coated with a layer of refractory insulation material to further enhance their high-temperature resistance. The operational stability of the vaporization cooling system directly affects the safety and efficiency of the entire furnace, and water quality is a key indicator for ensuring stable system operation. If the water quality does not meet standards, exceeding the limits can lead to a series of problems, such as corrosion, scaling, and blockage within the system. These problems not only affect the cooling effect but, in severe cases, may even cause explosions or leaks, forcing the furnace to shut down for maintenance, resulting in significant production losses and hindering the long-term stable operation of the vaporization system. Therefore, controlling the water quality of the furnace's vaporization cooling system is of paramount importance; it is a core element in ensuring safe equipment operation, extending service life, and improving production efficiency. Therefore, in practice, water quality parameters must be strictly monitored and managed to ensure that they are always within a reasonable range in order to avoid potential risks. Summary of the Invention

[0003] This invention provides a method for controlling the quality of vaporized water in a walking beam furnace. By deeply analyzing the various causes of excessive vaporized water quality in the furnace, a scientific and reasonable control method is formulated accordingly.

[0004] To achieve the above technical objectives, the present invention aims to provide a method for controlling the vaporization water quality of a walking beam furnace, comprising: S1, analyzing the following factors affecting the vaporization water quality one by one: water source quality, chemical reagent parameters, equipment status, and operational compliance; S2, tracing the following factors affecting the vaporization water quality one by one: water quality at the water supply end, treatment equipment status, and segmented water quality testing of the circulation system; S3, checking the following key points one by one: deaerator parameters, dosing system parameters, and drain valve status; S4, emergency treatment: including emergency treatment for wastewater discharge, emergency treatment for reagent dosing, and emergency treatment for pollution sources.

[0005] Furthermore, in S1: the analysis of water source quality includes: excessive hardness in the makeup water leading to scaling; high chloride and sulfate content causing corrosion; incomplete removal of oxygen and carbon dioxide accelerating oxidation and corrosion; chemical reagent parameters including dosage and reagent compatibility; equipment status including the status of the deaerator, the status of the sewage system, and the status of the vaporization cooling system; and operational compliance including whether online instruments are calibrated, whether the frequency of manual sampling and testing is sufficient, whether untreated raw water is directly added, and whether the system is emptied or maintained after shutdown.

[0006] Furthermore, in S3: check the deaerator parameters, including confirming that the temperature is ≥104℃, the pressure is 0.02MPa~0.05MPa, and there is no steam short circuit; check the dosing system parameters, including the liquid level of the chemical storage tank, the operating status of the metering pump, and pipeline blockage; check the status of the drain valve, including whether the drain valve opening meets the drain requirements.

[0007] Furthermore, in S4: emergency treatment for sewage discharge includes: increasing continuous sewage discharge and replenishing qualified demineralized water; emergency treatment for chemical dosing includes: treatment of pH exceeding standards, treatment of dissolved oxygen exceeding standards, and treatment of hardness / silicon exceeding standards; and emergency treatment of pollution sources.

[0008] Furthermore, the increased continuous sewage discharge includes: reducing the concentration ratio of circulating water to reduce the concentration of impurities.

[0009] Furthermore, the replenishment of qualified demineralized water includes: replacing water bodies with excessive levels of chlorine, and preferentially using softened water with low chlorine and low hardness.

[0010] Furthermore, if the pH is too high, add dilute hydrochloric acid or CO2 to adjust it; if the pH is too low, add NaOH or ammonia to adjust it.

[0011] Furthermore, treatment for excessive dissolved oxygen includes: sodium sulfite.

[0012] Further treatment for excessive hardness / silicon content includes adding scale inhibitors.

[0013] Furthermore, scale inhibitors include organophosphonates.

[0014] The advantages and positive effects of this invention are as follows: By deeply analyzing various causes of substandard vaporization water quality in the heating furnace, including key factors such as water source quality, chemical reagent parameters, equipment status, and operational compliance, and based on extensive historical operational experience, this invention has formulated a scientific and reasonable control method, successfully maintaining key indicators of the vaporization water quality in the heating furnace, such as pH value, dissolved oxygen, and hardness / silicon content, within reasonable ranges. This achievement significantly improves water quality consistency, reduces the risk of system failure, lays a solid foundation for the long-term safe and stable operation of the heating furnace vaporization system, and enhances overall energy efficiency and equipment lifespan. Detailed Implementation

[0015] The technical solutions of the embodiments of the present invention will be clearly and completely described below. The described embodiments are only some examples of the present invention, and not all examples. Obviously, the illustrated embodiments of the present invention demonstrate characteristic technical solutions. Based on the embodiments of the present invention, any other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present invention.

[0016] A method for controlling the vaporization water quality of a walking beam heater mainly includes: S1, analyzing the following factors affecting the vaporization water quality one by one: water source quality, chemical reagent parameters, equipment status, and operational compliance; specifically: Factor 1: Water source issues: whether the makeup water quality is up to standard; when the makeup water quality is not up to standard, the reasons are as follows: the hardness in the makeup water is too high, mainly referring to calcium ions (Ca... 2+ ) and magnesium ions (Mg 2+ If the concentration of these ions exceeds the standard, they are prone to forming insoluble precipitates such as calcium carbonate and calcium sulfate when exposed to high temperatures or pH changes, thus leading to scaling.

[0017] Chloride ions (Cl) - ) and sulfate (SO4) 2- When the content of these ions is high, they act as corrosive ions, damaging the protective film on the metal surface and causing pitting corrosion, crevice corrosion, or stress corrosion cracking, especially in stainless steel and carbon steel materials.

[0018] If dissolved oxygen (O2) and carbon dioxide (CO2) are not completely removed through degassing processes, they will participate in electrochemical reactions. Oxygen acts as an oxidant to promote the anodic dissolution of metals, while carbon dioxide forms carbonic acid and lowers the pH value. Together, they accelerate the oxidation and corrosion process, shorten the equipment life and increase maintenance costs.

[0019] The reasons for pretreatment failure are as follows: filter blockage or incomplete backwashing may cause suspended solids to enter the system, thereby contaminating downstream equipment or affecting water quality stability.

[0020] If the softening resin fails or is not regenerated sufficiently, it cannot effectively exchange sodium ions, resulting in insufficient removal of hardness ions such as calcium and magnesium from the water, which may cause scaling in pipes or reduce system efficiency.

[0021] Fouling or damage to the reverse osmosis (RO) membrane can significantly reduce desalination efficiency, increase the conductivity of the produced water, affect the overall water treatment performance, and even lead to substandard produced water.

[0022] Factor 2: Is the management of chemical agents reasonable? Reasons for insufficient or excessive dosage include: an imbalance in the addition ratio of corrosion inhibitors and scale inhibitors. Due to improper ratio control, a uniform and effective protective film cannot be formed on the metal surface, which significantly increases the risk of corrosion and scaling of pipelines and equipment, affecting the long-term stability of the system.

[0023] If pH adjusters, such as sodium hydroxide (NaOH), are not added in a timely manner, frequent and significant fluctuations in pH value can disrupt the balance of the aquatic chemical environment, potentially accelerating the corrosion process of metallic materials and interfering with the effectiveness of other treatment agents.

[0024] The consumption of oxygen scavengers, such as sodium sulfite, was not monitored and replenished in real time, resulting in a continuous increase in dissolved oxygen concentration in the water. This promoted oxidative corrosion reactions, leading to increased corrosion on the equipment surface and shortening the equipment's service life.

[0025] Incorrect drug compatibility: Different drugs react chemically (e.g., phosphate reacts with calcium ions to form calcium phosphate scale).

[0026] Factor 3: Equipment and operational malfunctions. The deaerator is faulty; the temperature / pressure of the thermal deaerator is insufficient (<104℃), resulting in low deaeration efficiency.

[0027] The resolver (vacuum deoxygenation) is poorly sealed, allowing air to leak in.

[0028] Abnormal sewage system: The automatic sewage valve is blocked or set incorrectly, and the concentration of impurities exceeds the standard.

[0029] Insufficient wastewater discharge (too high concentration ratio) or excessive wastewater discharge (waste of reagents).

[0030] A leak occurred in the vaporization cooling system; a ruptured furnace tube caused high-temperature media to mix into the cooling water, polluting the water quality.

[0031] Internal leakage in the heat exchanger allows process-side contaminants (such as oil and acidic substances) to enter the water system.

[0032] Factor 4: Operational and management oversights; monitoring failures include: uncalibrated online instruments (pH meter, oxygen meter), and data distortion.

[0033] The frequency of manual sampling and testing was insufficient, and abnormalities were not detected in a timely manner.

[0034] Violations include directly adding untreated raw water (such as tap water or groundwater).

[0035] If the system is not emptied or maintained after shutdown, microorganisms / corrosion products will grow.

[0036] Maintenance deficiencies include: failure to regularly clean pipes and heat exchangers, leading to the gradual accumulation of internal deposits, affecting equipment efficiency and increasing energy consumption. Additionally, failure to strictly adhere to predetermined maintenance schedules for filters, resin tanks, and RO units may cause problems such as filter clogging, decreased resin activity, and membrane element fouling.

[0037] Factor 5: External interference. When the load changes abruptly, the heating furnace will experience significant fluctuations in water temperature and pressure due to frequent start-ups and shutdowns or overload operation. These fluctuations not only accelerate the corrosion process on the metal surface, such as pitting and uniform corrosion, but may also cause added chemical agents (such as corrosion inhibitors and scale inhibitors) to decompose and become ineffective, thereby reducing system efficiency and shortening equipment life.

[0038] Seasonal factors have a significant impact. In summer, rising ambient temperatures cause water temperatures to rise, providing ideal conditions for the reproduction of microorganisms such as bacteria and algae. The proliferation of microorganisms can form biofilms, causing pipe blockages and reduced heat exchange efficiency, increasing maintenance requirements. In winter, under low temperatures, if insulation is insufficient, the water in the pipes may freeze, leading to pipe cracks. Refilling after a crack may introduce external contaminants, further polluting the system water and affecting overall operational stability.

[0039] S2. Trace the following factors that affect the quality of vaporized water one by one: water quality at the water supply end, status of treatment equipment, and water quality testing of each segment of the circulation system; conduct detailed water quality testing at the water supply end, including monitoring key indicators such as pH value, turbidity, and total dissolved solids; at the same time, comprehensively check the operating status of the water treatment equipment to confirm whether the filters, softeners, and disinfection devices are working properly; in addition, water quality sampling and analysis should be carried out on each section of the circulation system in sequence to ensure that the water quality from the system inlet to the end meets the standards and to prevent local pollution or water quality fluctuations.

[0040] S3. Check the following key points one by one: deaerator parameters, dosing system parameters, and drain valve status; inspect the deaerator: confirm that the deaerator operating temperature is not lower than 104 degrees Celsius to ensure effective removal of dissolved oxygen and avoid corrosion problems; check whether the pressure is maintained between 0.02MPa and 0.05MPa to ensure normal system operation; carefully check for steam short circuits to ensure efficient heat exchange process and no energy loss.

[0041] Inspect the dosing system: check the liquid level in the chemical storage tank to ensure sufficient chemical supply and prevent dosing interruptions; confirm that the metering pump is operating normally, including no abnormal noise, vibration or flow deviation; check the pipeline for blockages, leaks or crystallization to ensure a smooth dosing process.

[0042] Check the status of the drain valve: check whether the opening of the drain valve is set appropriately so as to effectively discharge accumulated impurities according to system requirements; confirm whether the drain operation meets the operating requirements to avoid excessive draining leading to resource waste or insufficient draining affecting system performance.

[0043] S4. Emergency Response: This includes emergency response to sewage discharge, emergency response to chemical dosing, and emergency response to pollution sources.

[0044] Immediately increase the frequency and flow rate of continuous wastewater discharge to rapidly reduce the concentration factor of the circulating water system, thereby effectively reducing the concentration of impurities and harmful ions in the water. Simultaneously, replenish a large amount of qualified demineralized water to replace the currently excessive water. Softened water or demineralized water with low chloride ion content and low hardness should be prioritized to avoid introducing new pollutants. Care should be taken to control the replenishment rate to maintain the system's water balance.

[0045] For targeted application of agents to address pH issues: If the pH is too high, it can be neutralized and adjusted by adding dilute hydrochloric acid or introducing CO2. Note that the application points should be dispersed and the application rate should be slow to prevent local over-acidity.

[0046] If the pH is too low, NaOH solution or diluted ammonia water needs to be added. When adding, it should be done slowly and with thorough stirring to avoid forming a high-alkaline area that could lead to equipment corrosion.

[0047] If dissolved oxygen exceeds the standard, sodium sulfite, a chemical oxygen scavenger, should be added immediately. It is generally added at a ratio of 10:1 by mass to dissolved oxygen. The dosage must be accurately calculated and injected evenly into the system.

[0048] If the hardness or silicon content exceeds the standard, the dosage of scale inhibitor should be increased. For example, organic phosphonate agents can be used. In addition, sewage discharge should be strengthened to prevent the scaling trend from worsening.

[0049] Isolate the source of contamination and quickly investigate potential leaks within the system, including checking for ruptured boiler pipes and internal leaks in heat exchangers. Once a faulty device is identified, it should be immediately isolated by disconnecting it from the system to prevent contaminants from continuously entering the circulating water system. The faulty component should then be repaired or replaced.

[0050] Continuously monitor water quality changes and dynamically adjust sewage discharge and chemical dosing strategies based on test results until the system returns to normal operating levels.

[0051] S5. Long-term prevention mechanism: Establish an emergency plan for water quality anomalies: Develop detailed standards for water quality exceeding thresholds, covering key parameters such as pH value, turbidity, and residual chlorine content, and set specific values ​​according to industry standards; clarify the handling authority of personnel at all levels, including emergency operation authorization, decision-making process, and reporting responsibilities; standardize the reporting process to ensure that information can be transmitted to relevant departments and responsible persons in a timely and accurate manner when an anomaly occurs, and record the handling process for review.

[0052] Personnel Training: Regularly organize systematic training for operators, with in-depth explanations of the scientific significance of water quality parameters and their impact on treatment processes, such as the role of pH in corrosion control and the correlation between turbidity and disinfection effectiveness; the training also includes detailed explanations of equipment linkage principles, such as how the control system responds to parameter changes and methods for fault diagnosis and troubleshooting; through a combination of theoretical teaching, practical exercises, and regular assessments, ensure that operators fully master the skills and can apply them proficiently.

[0053] Simulated drills for sudden water quality issues: Regular simulated emergency drills are conducted, covering a variety of emergency scenarios, such as sudden drop in pH value, pipe bursts causing pollution, abnormal algae growth, or chemical leaks. The drill process is designed to include event identification, emergency response activation, implementation of treatment measures (such as adjusting chemical dosage and isolating pollution sources), internal coordination and external communication, as well as post-event evaluation and summary. Through repeated drills, the team's rapid response capability and collaborative processing efficiency are improved.

[0054] Data traceability: Use professional historical data management software (such as SCADA system or data analysis platform) to collect and store water quality data, conduct trend analysis and pattern recognition; deeply analyze the patterns of exceeding standards, such as seasonal corrosion tendency, parameter fluctuations caused by equipment aging or external factors; based on the analysis results, optimize preventive measures, such as adjusting maintenance cycle, improving treatment process, and establish early warning mechanism to achieve data-driven long-term management.

[0055] The above description is only a preferred embodiment of the present invention. It should be noted that, for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for controlling the quality of vaporized water in a walking beam furnace, characterized in that, include: S1. Analyze the following factors affecting the quality of vaporized water one by one: water source quality, chemical reagent parameters, equipment status, and operational compliance; S2. Trace the following factors affecting the quality of vaporized water one by one: water quality at the water supply end, treatment equipment status, and water quality of the circulation system segment by segment; S3. Check the following key points one by one: deaerator parameters, dosing system parameters, and drain valve status; S4. Emergency treatment: including emergency treatment for sewage discharge, emergency treatment for chemical dosing, and emergency treatment for pollution sources.

2. The method for controlling the vaporization water quality of a walking beam furnace according to claim 1, characterized in that, In S1: Analysis of water source quality includes: excessive hardness in the makeup water leading to scaling; high chloride and sulfate content causing corrosion; incomplete removal of oxygen and carbon dioxide accelerating oxidation and corrosion; chemical reagent parameters including dosage and reagent compatibility; equipment status including deaerator status, sewage system status, and vaporization cooling system status; and operational compliance including whether online instruments are calibrated, whether manual sampling and testing frequency is sufficient, whether untreated raw water is directly added, and whether the system is emptied or maintained after shutdown.

3. The method for controlling the vaporization water quality of a walking beam furnace according to claim 1, characterized in that, In S3: Check the deaerator parameters, including confirming that the temperature is ≥104℃, the pressure is 0.02MPa~0.05MPa, and there is no steam short circuit; check the dosing system parameters, including the liquid level of the chemical storage tank, the operating status of the metering pump, and pipeline blockage; check the status of the drain valve, including whether the drain valve opening meets the drain requirements.

4. The method for controlling the vaporization water quality of a walking beam furnace according to claim 1, characterized in that, In S4: Emergency treatment for sewage discharge includes: increasing continuous sewage discharge and replenishing qualified demineralized water; Emergency treatment for chemical dosing includes: treatment of pH exceeding the standard, treatment of dissolved oxygen exceeding the standard, and treatment of hardness / silicon exceeding the standard; Emergency treatment of pollution sources.

5. The method for controlling the vaporization water quality of a walking beam furnace according to claim 4, characterized in that, The increased continuous sewage discharge includes: reducing the concentration ratio of circulating water and reducing the concentration of impurities.

6. The method for controlling the vaporization water quality of a walking beam furnace according to claim 4, characterized in that, The replenishment of qualified demineralized water includes: replacing water bodies with excessive levels of chlorine, and prioritizing the use of softened water with low chlorine and low hardness.

7. The method for controlling the vaporization water quality of a walking beam furnace according to claim 4, characterized in that, When the pH is too high, add dilute hydrochloric acid or CO2 to adjust it; when the pH is too low, add NaOH or ammonia to adjust it.

8. The method for controlling the vaporization water quality of a walking beam furnace according to claim 4, characterized in that, Treatment for excessive dissolved oxygen includes: adding sodium sulfite.

9. The method for controlling the vaporization water quality of a walking beam furnace according to claim 4, characterized in that, Treatment for excessive hardness / silicon content includes adding scale inhibitors.

10. The method for controlling the vaporization water quality of a walking beam furnace according to claim 9, characterized in that, Scale inhibitors include organophosphonates.