Method for controlling the removal of hydrogen sulfide from water in a degassing column

Abstract

The application provides a control method for removing hydrogen sulfide in water in a degassing tower. Detection units are arranged at the water inlet end and the water outlet end of the closed degassing tower respectively, so as to collect the ORP value and the pH value of the water inlet and the ORP value and the pH value of the water outlet, and obtain ΔORP and ΔpH. A double-parameter correlation characterization system with ΔORP as the core and ΔpH as the auxiliary is constructed. In combination with the operating parameters of the degassing tower, the precise online characterization of the degassing effect is realized. ΔORP has high sensitivity to reducing substances such as H2S and fast response speed, and can reflect the change of the H2S concentration in water in real time. ΔpH serves as an auxiliary parameter and can verify the reliability of the characterization result of ΔORP. The linkage of the two can effectively avoid the limitation of single parameter detection, improve the characterization precision and ensure the accuracy of the judgment of the degassing effect. Meanwhile, through the closed loop system of real-time monitoring-periodic verification-authoritative calibration, the accuracy of the characterization result is ensured, and the low cost and high precision are taken into account.

Description

Technical Field

[0001] This invention belongs to the field of water treatment degassing and detection technology, specifically relating to a control method for removing hydrogen sulfide from water using a degassing tower. Background Technology

[0002] Hydrogen sulfide (H2S), a volatile and unstable gas in water, is a common naturally occurring unstable odor-causing compound in drinking water such as mineral water. Its presence can cause foul smells in water, severely affecting the sensory quality and safety of drinking water. Therefore, degassing tower systems are widely used for H2S removal from water. For the treatment of drinking water such as mineral water, the degassing process not only needs to achieve efficient H2S removal but also needs to ensure hygiene and safety by maintaining a low level of microorganisms in the water. The synergy of these two aspects is a core requirement for ensuring water treatment quality. However, the traditional degassing tower process commonly used in the industry currently has significant hygiene deficiencies, and the methods for characterizing degassing effects are incomplete, making it difficult to meet the dual requirements of drinking water hygiene and safety as well as effective degassing.

[0003] The traditional degassing towers and associated characterization solutions currently used in the industry have the following core drawbacks: 1) The equipment structure is open and not sealed, and a large amount of unfiltered air directly enters the tower during the degassing process, which can easily cause secondary microbial pollution of the water body and violate the requirements for drinking water hygiene treatment; 2) Traditional degassing towers cannot characterize the degassing effect online, cannot be automatically adjusted in conjunction with the tower, and rely entirely on manual experience to operate. It is difficult to accurately control the degree of degassing, and problems of insufficient or excessive degassing are likely to occur. Insufficient degassing will result in excessive H2S residue, while excessive degassing will increase the risk of microbial pollution and operating energy consumption. Summary of the Invention

[0004] To address the technical problems existing in the prior art, the purpose of this invention is to provide a control method for removing hydrogen sulfide from water using a degassing tower.

[0005] In this embodiment of the invention, the control method for removing hydrogen sulfide from water using a degassing tower includes the following steps:

[0006] S1. Set up detection units at the inlet and outlet of the closed degassing tower to collect the ORP value and pH value of the inlet water, as well as the ORP value and pH value of the outlet water. Obtain the difference between the ORP value of the outlet water and the ORP value of the inlet water, ΔORP, and the difference between the pH value of the outlet water and the pH value of the inlet water, ΔpH. At the same time, collect the operating parameters of the degassing tower, including the vacuum pump pressure, the air volume of the blower box, the inlet and outlet water flow rate and the liquid level of the degassing tower.

[0007] S2. Using ΔORP as the core characterization parameter and ΔpH as the auxiliary characterization parameter, and combining the degassing tower operating parameters collected in step S1, establish a linear correlation between ΔORP and the amount of H2S removed from water, and clarify the linkage trend between ΔpH and ΔORP.

[0008] S3. Periodically collect water samples from the inlet and outlet of the degassing tower to be tested, quantitatively determine the H2S concentration in the water, and calibrate the safety threshold of ΔORP based on the correlation model in step S2.

[0009] S4. Based on the ΔORP safety threshold set in step S3, the effect of the degassing tower in removing H2S from water is characterized by real-time monitoring of ΔORP, ΔpH and operating parameters. ΔpH is introduced as a branch adjustment for abnormal interference. When ΔORP is lower than the safety threshold, or when the linkage trend between ΔpH and ΔORP deviates from the preset range, the operating parameters of the degassing tower are adjusted in a linkage manner to ensure that the degassing effect meets the standard.

[0010] Compared with the prior art, the advantages of the preferred technical solution of the present invention include:

[0011] 1. This invention constructs a dual-parameter correlation characterization system with ΔORP as the core and ΔpH as an auxiliary parameter. Combined with the operating parameters of the degassing tower, it achieves accurate online characterization of the degassing effect. ΔORP has high sensitivity and fast response speed to reducing substances such as H2S, and can reflect the changes in H2S concentration in water in real time. ΔpH, as an auxiliary parameter, can verify the reliability of the ΔORP characterization results. The linkage between the two can effectively avoid the limitations of single parameter detection, improve the characterization accuracy, and ensure the accuracy of the degassing effect judgment. At the same time, through a closed-loop system of real-time monitoring, periodic verification, and authoritative calibration, the accuracy of the characterization results is ensured, achieving a balance between low cost and high precision.

[0012] 2. This invention uses ΔORP and ΔpH as dual parameters to characterize the H2S removal effect, replacing the costly and complex online H2S detection instruments. It indirectly and quickly reflects the changes in H2S content and the degassing effect, greatly reducing the system investment cost (1 / 60 of the traditional online H2S instrument) and subsequent operation and maintenance costs. At the same time, by collecting operating parameters such as vacuum pump pressure, fan box air volume, inlet and outlet water flow rate and liquid level of the degassing tower in real time, the air volume of the fan box and the vacuum pump pressure are adjusted to maintain a stable negative pressure in the degassing tower. This ensures that H2S removal meets the standards and reduces the system's operating energy consumption. The structure is simple, the installation is convenient, and it is suitable for large-scale drinking water treatment scenarios.

[0013] 3. This invention utilizes a fan box and vacuum pump that operate continuously throughout the process. Its core objective is to remove hydrogen sulfide from water. Through a synergistic structure of continuous sterile clean air supply and continuous negative pressure suction, combined with a Pall ring packing layer in the degassing tower to increase the contact area between water and air, the water body can achieve full vacuum suction degassing during the falling process, thus achieving continuous and efficient removal of H2S and ensuring stable H2S removal effect.

[0014] 4. This invention uses a vacuum pump to draw air from the top outlet of the degassing tower and a fan box (containing primary, medium and high efficiency three-stage air filters) to supplement filtered sterile air into the lower air inlet of the degassing tower, forming a closed-loop air circulation. This ensures that odor-causing substances such as H2S in the water are fully removed, and that the water is exposed to controlled sterile air inside the degassing tower throughout the process. This effectively prevents the growth of microorganisms, avoids the deterioration of microbial indicators in the water, and achieves hygienic and controllable removal of odor-causing substances from the water, meeting the core hygiene requirements of drinking water treatment.

[0015] 5. The fan box of this invention is equipped with a three-stage air filter, which can thoroughly filter out large particulate impurities, fine dust and microorganisms in the air, ensuring that the air introduced into the degassing tower is sterile and clean; combined with the sealed hygienic degassing tower structure without dead corners and CIP cleaning function, it can realize all-round cleaning and disinfection inside the degassing tower, effectively prevent secondary microbial pollution of water bodies, realize the synergistic promotion of H2S removal and microbial hygiene control, and meet the requirements of drinking water hygiene treatment. Attached Figure Description

[0016] Figure 1 This is a flowchart of the control method for removing hydrogen sulfide from water using a degassing tower, as described in this embodiment.

[0017] Figure 2 This is a schematic diagram of the degassing tower in the embodiment.

[0018] The reference numerals in the accompanying drawings include: degassing tower 1, water collection section 1a, negative pressure chamber 1b, water inlet pipe 101, water outlet pipe 102, air inlet pipe 103, air extraction pipe 104, spray water distribution assembly 2, Pall ring packing layer 3, fan box 4, vacuum pump 5, online ORP meter 6, mobile pH meter 7, pressure sensor 8, air volume sensor 9, flow sensor 10, liquid level sensor 11, water inlet valve 12, water outlet valve 13, return water valve 14, CIP cleaning system 15. Detailed Implementation

[0019] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0020] This embodiment provides a control method for removing hydrogen sulfide from water using a degassing tower, such as... Figure 1 As shown, in a preferred embodiment, it includes the following steps:

[0021] S1. Set up detection units at the inlet and outlet of the closed degassing tower to collect the ORP (oxidation-reduction potential) value and pH value of the inlet water, as well as the ORP value and pH value of the outlet water. Obtain the difference between the ORP value of the outlet water and the ORP value of the inlet water, ΔORP, and the difference between the pH value of the outlet water and the pH value of the inlet water, ΔpH. At the same time, collect the operating parameters of the degassing tower, including the vacuum pump pressure, the air volume of the blower box, the inlet and outlet water flow rate and liquid level of the degassing tower.

[0022] S2. Using ΔORP as the core characterization parameter and ΔpH as the auxiliary characterization parameter, and combining the degassing tower operating parameters collected in step S1, establish a linear correlation between ΔORP and the amount of H2S removed from water, and simultaneously clarify the linkage trend between ΔpH and ΔORP. The process of constructing the correlation is as follows: Under stable operation of the degassing tower, change at least one parameter among the initial H2S concentration, fan box airflow, and vacuum pump pressure, and collect the corresponding ΔORP, ΔpH, and H2S removal amount. Through linear fitting or machine learning algorithms, establish a linear correlation equation between ΔORP and the amount of H2S removed, and simultaneously clarify the linkage trend between ΔpH and ΔORP.

[0023] 1) The linear relationship between ΔORP and H2S removal:

[0024]

[0025] in, yes The amount removed is determined by the effluent. Concentration - Influent Concentration, in mg / L; ΔORP is effluent ORP minus influent ORP, in mV; k is the linearity coefficient; b is a constant correction term.

[0026] The linear coefficient k is determined by the operating parameters of step S1 (vacuum pump pressure). Fan box air volume Degassing tower inlet and outlet water flow rates and degassing tower liquid level Dynamic correction, Multivariate linear association is used.

[0027] The constant correction term b represents the theoretical H2S removal rate of the degassing tower when ΔORP = 0. ,coefficient Calibration was performed using multiple regression analysis on multiple sets of steady-state operating data, with parameters updated monthly based on the operating data. The constant correction term b was obtained in the following manner:

[0028] Initial calibration (before system commissioning): During the stable operation of degassing tower 1, at least 10 sets of ΔORP data under different operating conditions (initial H2S concentration, air volume, negative pressure) were collected using the single variable method and compared with the actual values. The initial value of b is obtained by directly solving the data using the least squares linear regression method.

[0029] Routine calibration: Collect inlet and outlet water samples from degassing tower 1 weekly / bi-weekly, and determine the actual water quality using standard methods in the laboratory. Add the new data to the original dataset and re-regress, updating the b-value; if the deviation between the laboratory measured value and the equation calculated value exceeds 5%, immediately remove the abnormal data and recalibrate.

[0030] 2) The correlation trend between ΔpH and ΔORP:

[0031]

[0032] Among them, the function g( (This refers to the stable operating conditions of the degassing tower.) A linear function in one variable that varies with ΔORP, describing The function relating to ΔORP, where g'(x)>0 indicates monotonically increasing; the larger ΔORP is, the larger the corresponding ΔpH is, and the smaller ΔORP is, the smaller the corresponding ΔpH is.

[0033] , The steady-state values ​​are obtained by least squares fitting of more than 10 sets of data; actual measurements... A deviation from the theoretical value > ±5% indicates a deviation from the correlation trend, triggering parameter adjustment. ΔpH is positively correlated with ΔORP, meaning that when... When the removal effect is good and ΔORP increases significantly, ΔpH usually also increases. For example, when ΔORP increases from +5mV to +50mV (the set range of the ΔORP safety threshold), ΔpH simultaneously increases from +0.3 to +2, forming a stable linkage. This linkage trend is used to help verify the reliability of the ΔORP characterization results.

[0034] S3. Using standard laboratory methods ("Determination of Sulfides in Water - Flow Injection-Methylene Blue Spectrophotometry" (HJ 824-2017)), periodically collect influent and effluent samples from the degassing tower to quantitatively determine the H2S concentration. Specifically, gas chromatography-absorption spectroscopy or methods such as methylene blue spectrophotometry can be used for quantitative analysis of H2S in the water. Combined with the correlation model from step S2, calibrate the safety threshold for ΔORP, forming a closed-loop system of "real-time monitoring - periodic verification - authoritative calibration." According to drinking water hygiene standards (H2S concentration in water ≤ 0.05 mg / L), when the H2S concentration in water is ≤ 0.05 mg / L, combine the correlation equation from step S2 to obtain the ΔORP safety threshold, for example, +15 mV. The corresponding ΔORP ≥ safety threshold + 15 mV ensures that H2S removal meets the standards.

[0035] Establish a closed-loop calibration system: compare the H2S removal amount measured in the laboratory with the removal amount calculated based on the linear correlation equation of ΔORP. If the deviation exceeds 5%, calibrate the correlation equation parameters and the ΔORP safety threshold. Every quarter, entrust a third-party testing agency to conduct authoritative calibration using gas chromatography absorption spectroscopy to ensure the accuracy of characterization.

[0036] Specifically, one set of influent and one set of effluent water samples from the degassing tower are collected periodically (e.g., weekly or bi-weekly) and sent to the laboratory for determination using standard methods (e.g., methylene blue spectrophotometry). Concentration, and simultaneously record the influent ORP value and effluent ORP value displayed by the on-site detection unit (including the online ORP meter), calculate ΔORP; update ΔORP and The parameters k and b of the linear correlation equation of the removal amount are determined; the minimum qualified ΔORP, i.e. the safety threshold of ΔORP, is solved in reverse and written into the alarm logic of step S4.

[0037] Specifically, rolling least squares is used to fit and update k and b. Newly sampled data is included in the dataset, and outlier samples are removed if the deviation between the measured and calculated values ​​is greater than 5%. The safety threshold for ΔORP is... The specific method used is as follows:

[0038] Known water output Maximum concentration =0.05mg / L,

[0039] , For water intake Concentration, substitute

[0040] The result is obtained by transformation:

[0041]

[0042] The value falls within the range of 5mV to 50mV.

[0043] S4. Based on the ΔORP safety threshold set in step S3, the effect of the degassing tower in removing H2S from water is characterized by real-time monitoring of ΔORP, ΔpH and operating parameters. ΔpH is introduced as a branch adjustment for abnormal interference. When ΔORP is lower than the safety threshold, or the linkage trend between ΔpH and ΔORP deviates from the preset range (such as ΔORP increasing while ΔpH decreases), the operating parameters of the degassing tower are adjusted in a linkage manner to ensure that the degassing effect meets the standard.

[0044] like Figure 2As shown, in this invention, the degassing tower 1 is provided with a Pall ring packing layer 3 to increase the contact area between water and air, forming a gas-liquid mass transfer layer; the air inlet of the degassing tower 1 is connected to a fan box 4 for introducing clean air into the degassing tower 1; the exhaust port of the degassing tower 1 is connected to a vacuum pump 5 for evacuating gas from the degassing tower 1, so that a stable negative pressure chamber 1b is formed in the upper part of the degassing tower 1.

[0045] Specifically, the upper side wall of the degassing tower 1 is provided with a water inlet, which is connected to the water to be treated through a water inlet pipe 101. A water inlet valve 12 for adjusting the flow rate is provided on the water inlet pipe 101. Preferably, the degassing tower 1 also includes a spray water distribution assembly 2 connected to the water inlet, consisting of multiple spray balls, capable of 360° spraying without dead angles, used to evenly distribute the incoming water onto the surface of the Pall ring packing layer 3. The Pall ring packing layer 310 is made of materials commonly used in the art, such as plastic (e.g., PP polypropylene), metal (e.g., stainless steel), or ceramic. The packing height is 1.8m, forming a uniform gas-liquid mass transfer layer to increase the contact area between the water and sterile clean air. The lower part of the degassing tower 1 is a water collection section 1a. A water outlet is provided at the bottom of the degassing tower 1, which is connected to a water storage device after treatment through a water outlet pipe 102. A water outlet valve 13 for adjusting the flow rate is provided on the water outlet pipe 102. The water to be treated enters the degassing tower 1 through the inlet pipe 101. After being evenly sprayed by the spray distribution assembly 2, the water flows downwards through the Pall ring packing layer 3, forming a thin liquid film on the packing surface and undergoing sufficient degassing. It then enters the lower water collection section 1a of the degassing tower 1 and is discharged from the lower outlet of the degassing tower 1, exiting through the outlet pipe 102 for subsequent processes. Preferably, the outlet pipe 102 is also connected to the inlet pipe 101 via a return water valve 14. When ΔORP is lower than the safety threshold, the degassed water that fails to meet the standards flows back to the inlet pipe 101 via the return water valve 14 and then enters the degassing tower 1 for further treatment.

[0046] An air inlet is provided on the lower middle side wall of the degassing tower 1. The fan box 4 is connected to the air inlet through the air inlet pipe 103. The fan box 4 uses a variable frequency fan and is equipped with a three-stage air filter: a primary filter (5μm filtration accuracy, removing large dust particles, hair, and other impurities), a medium filter (1μm filtration accuracy, removing fine dust and particulate matter), and a high-efficiency filter (0.3μm filtration accuracy, removing microorganisms, bacteria, viruses, and tiny impurities). This filter is used to filter the air entering the degassing tower 1 into sterile and clean air. An air extraction port is provided at the top of the degassing tower 1. A vacuum pump 5 is installed at the top of the degassing tower 1 and is connected to the air extraction port through the air extraction pipe 104. This pump is used to extract the gas rising from the Pall ring packing layer 3, creating a negative pressure chamber 1b in the upper part of the degassing tower 1. Outside air, filtered by the fan box 4, enters the lower part of the degassing tower 1 (the gas phase space below the Pall ring packing layer 3 and above the liquid surface of the water collection section 1a) through the inlet pipe 103. Inside the degassing tower 1, it flows counter-currently upwards through the Pall ring packing layer 3, where it fully contacts and transfers mass with the water sprayed from the top-down spray distribution assembly 2 on the surface of the Pall ring packing layer 3. This carries the removed H2S into the upper negative pressure chamber 1b of the degassing tower 1, and is finally discharged by the vacuum pump 5 located at the top of the degassing tower 1. Under the combined action of the fan box 4 and the vacuum pump 5, the negative pressure inside the degassing tower 1 is maintained stably through continuous air replenishment and continuous suction, ensuring the effective removal of H2S.

[0047] The degassing tower 1 is a closed, hygienic structure. The Pall ring packing layer 3 and water collection section 1a inside the tower are designed as a single unit of the same diameter, with no steps inside, achieving thorough cleaning of the inner wall without dead angles, thus meeting the requirements for microbial control (thorough cleaning even after microbial contamination). The top of the degassing tower 1 is equipped with a CIPCIP cleaning system 15 (including cleaning nozzles, a cleaning pump, and a chemical dosing port), allowing the CIP station to thoroughly clean the interior of the degassing tower 1 using acids, alkalis, disinfectants, and hot water, ensuring that the microbial population in the degassing tower 1 system is safe and controllable (without increasing microorganisms) and restoring the original level of microorganisms in the water. The water-contacting material of the degassing tower 1 is all SUS316L, and the seals are all made of EPDM material, effectively ensuring the corrosion resistance of water containing odorous substances (such as H2S, which is mostly acidic and corrosive), while also meeting the requirements of online chemical cleaning CIP. For example, degassing tower 1 undergoes online CIP cleaning every 7 days. Acid, alkali, disinfectant and hot water are sequentially introduced to circulate and clean the inner wall of degassing tower 1, Pall ring packing layer 3 and all pipelines. After cleaning, normal operation is restored.

[0048] like Figure 2As shown, in step S1 of this invention, the detection unit includes an online ORP meter and a mobile pH meter. For example, an online ORP meter is installed on the inlet pipe 101 and the outlet pipe 102 of the degassing tower 1, and a mobile pH meter is configured. The online ORP meter is used to collect the inlet ORP value and the outlet ORP value in real time, and the mobile pH meter is used to collect the inlet pH value and the outlet pH value periodically. Subsequently, ΔORP (outlet ORP value - inlet ORP value) and ΔpH (outlet pH value - inlet pH value) can be calculated as the core judgment basis for H2S removal effect. When the H2S concentration in the water is ≤0.05mg / L, for example, the measured data is ΔORP=(-113)-(-129)=+16mV, and the measured data is ΔpH=7.62–6.90=+0.52.

[0049] Operating parameters are collected through sensors, including a pressure sensor (8), an air volume sensor (9), a flow rate sensor (10), and a liquid level sensor (11). For example... Figure 2 As shown, pressure sensor 8 is located at the inlet of vacuum pump 5 to collect the vacuum pressure of negative pressure chamber 1b of degassing tower 1 in real time, and is used to monitor the stability of negative pressure in degassing tower 1; air volume sensor 9 is installed at the outlet of fan box 4 to collect the air volume of fan box 4 in real time, and is used to provide feedback on the effect of air volume adjustment; there are two flow sensors 10, both of which are electromagnetic flow sensors 10, installed at the inlet and outlet of degassing tower 1 respectively, to collect the inlet and outlet flow rates in real time, and are used to monitor the water treatment volume and avoid abnormal liquid level in degassing tower 1 due to imbalance of inlet and outlet flow rates; liquid level sensor 11 is installed on the side wall of the lower part of degassing tower 1 to collect the liquid level height in the tower in real time.

[0050] The degassing tower 1 of this invention operates under negative pressure and is sealed. When the internal cavity of the degassing tower 1 needs to be replenished due to a drop in liquid level, the airflow of the fan box 4 is increased to introduce filtered clean air into the degassing tower 1 for replenishment. When the internal cavity of the degassing tower 1 needs to be vented due to a rise in liquid level, the pressure of the vacuum pump 5 is increased (increasing the suction volume) to vent the air, maintaining a stable negative pressure inside the degassing tower 1. This achieves a hygienic state (introducing sterile air) within the negative pressure cavity for respiration. Preferably, a vacuum breaker is installed on the degassing tower 1 to prevent excessive negative pressure from causing deformation of the tower body.

[0051] The degassing tower 1 of this invention adopts a continuous water inlet and outlet operation mode. The water to be treated continuously enters from the upper inlet of the degassing tower 1 through the water inlet pipe 101, is degassed by the Pall ring packing layer 3, and then continuously flows into the lower water collection section 1a, and is then continuously transported to the subsequent process through the water outlet pipe 102. During normal operation, the inlet and outlet water flow of the degassing tower 1 is dynamically balanced, and the liquid level remains relatively stable. However, when the inlet and outlet water flow of the degassing tower 1 is momentarily unbalanced or the negative pressure inside the tower fluctuates, the liquid level of the degassing tower 1 will fluctuate. For example, when the inlet water flow decreases instantaneously, the outlet water flow is not adjusted in time, or the pumping speed of the vacuum pump 5 increases instantaneously, the liquid level inside the degassing tower 1 will drop. When the liquid level of the degassing tower 1 is lower than the set lower limit (e.g., set to 0.6 m), the volume of the upper negative pressure chamber 1b of the degassing tower 1 increases, resulting in an abnormal increase in the vacuum degree (e.g., exceeding -0.08 MPa). At this time, the system automatically increases the air intake of the blower box 4 to replenish the air and maintain the stability of the negative pressure inside the degassing tower 1.

[0052] In this invention, it is preferable that the liquid level in degassing tower 1 is maintained within a set range (e.g., 0.6–1.0 m, with a reference of 0.8 m), and has the following characteristics:

[0053] 1) Ensure stable degassing efficiency: If the liquid level in degassing tower 1 is too high, it will submerge the bottom of the Pall ring packing layer 3, reducing the effective gas-liquid contact area and lowering the H2S removal rate; if the liquid level in degassing tower 1 is too low, it will result in an excessively large gas phase space below the Pall ring packing layer 3, uneven negative pressure distribution, and insufficient local degassing.

[0054] 2) Maintaining the safety of the negative pressure system: If the liquid level in the degassing tower 1 exceeds the set range, it will disrupt the stable volume of the negative pressure chamber 1b inside the degassing tower 1, causing a large fluctuation in the vacuum level. This will not only increase the energy consumption of the vacuum pump 5 and the blower box 4, but may also cause the tower body to deform due to excessive negative pressure, or introduce unfiltered air from the outside due to insufficient negative pressure.

[0055] 3) Ensure safe operation of equipment: When the liquid level of degassing tower 1 is lower than the set lower limit (0.6 m), the water outlet pipe 102 is prone to sucking in air, causing the subsequent water pump to run dry; when the liquid level of degassing tower 1 is higher than the set upper limit (1.0 m), the water in degassing tower 1 is prone to backflow into vacuum pump 5 and blower box 4, damaging the equipment.

[0056] 4) Meets CIP cleaning requirements: The fixed liquid level range ensures that the cleaning solution can completely cover the inner wall of the tower during CIP cleaning, achieving cleaning and disinfection without dead corners.

[0057] In step S4 of this invention, the specific method of linkage adjustment is as follows: when ΔORP is lower than the safety threshold (e.g., +15mV), or when the linkage trend between ΔpH and ΔORP deviates from the preset range (ΔpH and ΔORP change in opposite directions, or their correlation coefficient or change ratio exceeds the preset normal range), it indicates that H2S removal is not up to standard. Figure 2As shown, at least one parameter of the fan box 4 air volume and the vacuum pump 5 pressure is automatically adjusted, for example, by increasing the air volume of the fan box 4 and increasing the pressure of the vacuum pump 5, while simultaneously adjusting the inlet and outlet water flow rate and liquid level of the degassing tower 1 until ΔORP recovers to above the safe threshold.

[0058] Specifically, adjustments can be made in the following ways;

[0059]

[0060] in, This represents the target ΔORP value, in mV, which is the minimum safety threshold that needs to be achieved. The air volume of the fan box is expressed in m³ / h. The air-to-water ratio is the ratio of the air volume of the fan box to the inlet and outlet water flow rates. It directly determines the gas-liquid contact area and mass transfer efficiency. The larger the ratio, the better the H2S removal effect. This refers to the influent flow rate, expressed in m³ / h. This refers to the vacuum pump pressure, measured in MPa. It is usually a negative pressure, and the larger the absolute value, the better the effect. The liquid level in the degassing tower affects the residence time τ of water in the degassing tower. The level-to-flow ratio is directly proportional to the residence time τ of water in the degassing tower (τ = effective volume in the tower / influent flow rate). A larger ratio indicates a longer water residence time and more complete H2S removal. (Function) It is a multivariate linear function:

[0061]

[0062] Among them, coefficients A, B, C, and D were calibrated using multiple linear regression fitting through steady-state multi-condition tests of the degassing tower.

[0063] 1) Adjustment of fan box airflow (main variable, fastest response)

[0064]

[0065] in, t represents the target air volume of the fan box at time t, in m³ / h, and t represents the real-time output air volume of the fan. The air volume is the basic air volume of the fan box, in m³ / h, which is the reference air volume when the degassing tower is operating normally. The proportional coefficient for adjusting the air volume of the fan box, in m³ / (h·mV), is determined by the project: using the Ziegler-Nichols method or the critical proportionality method, combined with on-site commissioning. Let ΔORP be the deviation value at time t. = – ; The integral coefficient for adjusting the airflow of the fan box, in m³ / (h·mV·s), is determined by the engineering specifications and is related to the proportional coefficient. Synchronous debugging is used to eliminate static errors in the system and ensure that ΔORP eventually stabilizes above the safe threshold.

[0066] Increasing the airflow of the fan box can directly provide a larger gas-liquid contact area, quickly removing water. The lower ΔORP falls, the more... The larger the value, the greater the opening of the damper in the fan box or the frequency of the inverter.

[0067] 2) Adjustment of vacuum pump pressure (changing boiling point and escape potential energy)

[0068]

[0069] in, The target pressure of the vacuum pump at time t is expressed in MPa. The vacuum pump base pressure, in MPa, is determined experimentally: the vacuum pressure at which the H2S in the effluent stably meets the standard under the rated flow rate of the degassing tower. The proportional coefficient for vacuum pump pressure regulation, in MPa / mV, determines the immediate adjustment range of the deviation on the negative pressure, and is set by the engineering team; determined in conjunction with on-site commissioning, it determines the immediate adjustment range of the deviation on the negative pressure. This is the differential coefficient for vacuum pump pressure regulation, in MPa·s / mV, determined by engineering tuning: and proportional coefficient. Synchronous adjustment is used to predict the trend of deviation changes and suppress the rapid decline of ΔORP, thereby preventing overshoot.

[0070] Reducing the absolute pressure inside the degassing tower (i.e., increasing the absolute value of the negative pressure) can significantly reduce... Its solubility in water makes it difficult to remove. It was forced out.

[0071] 3) Adjustment of inlet and outlet water flow rates of the degassing tower (sacrificing output to maintain water quality)

[0072]

[0073] in, The target influent and effluent flow rates of the degassing tower at time t are expressed in m³ / h. The target processing flow rate designed for the degassing tower, in m³ / h, is the rated output of the equipment. This is the proportional coefficient for adjusting the influent flow rate, measured in m³ / (h·mV), and is determined by engineering tuning and on-site commissioning, thus determining the deviation. The range of flow rate adjustment.

[0074] When the air volume of the blower box and the vacuum degree inside the degassing tower have reached their limits, in order to ensure the output water If the water flow rate is within acceptable limits, the water residence time τ in the degassing tower should be increased.

[0075] 4) Adjustment of degassing liquid level (optimization of gas-liquid contact height)

[0076]

[0077] in, The target liquid level setpoint for the degassing tower at time t, in meters (m). The optimal reference liquid level for the degassing tower, measured in meters (m), is typically 0.8m, balancing degassing efficiency, negative pressure stability, and equipment safety. This is the liquid level adjustment amount, in meters (m), satisfying... , and deviation Positive correlation This is the proportional coefficient for liquid level regulation, set by the engineering department, with a deviation... = – , The larger the value, the lower the ΔORP; the larger the value, the higher the liquid level and the greater the liquid holdup. The liquid holdup in the degassing tower can be changed by adjusting the opening of the outlet valve at the outlet end of the degassing tower.

[0078] When ΔORP is consistently greater than or equal to the safety threshold and the liquid level in degassing tower 1 is stable between 0.6 and 1.0 m, it indicates that H2S removal has met the standard and the system maintains stable operation with the current operating parameters (air volume of fan box 4, pressure of vacuum pump 5, inlet and outlet water flow rate and liquid level).

[0079] When ΔORP < safety threshold, it indicates that H2S removal is not up to standard. Increase the airflow of fan box 4 in order of priority, or simultaneously increase the pressure of vacuum pump 5 to improve gas-liquid contact efficiency, until ΔORP recovers to above the safety threshold and stable operation resumes. If the abnormality persists, open the return water valve 14 to return the substandard water to the inlet via the inlet pipe 101 for reprocessing.

[0080] In another preferred embodiment of the present invention, step S4 further includes an abnormal degassing effect warning step: when ΔORP remains below the safety threshold for a certain period of time (e.g., 5 minutes), or when the linkage trend between ΔpH and ΔORP deviates from the preset range, an alarm is triggered (specifically, an industrial-grade audible and visual alarm can be set to issue an alarm, such as emitting a yellow light and intermittent prompt sound to prompt operational intervention), and abnormal data (including ΔORP, ΔpH, and operating parameters) are recorded, and the inlet and outlet water flow rates of the degassing tower 1 are automatically reduced to maintain low-load operation of the system, making it easier for staff to troubleshoot faults (such as air filter blockage in the fan box 4, online ORP meter 6 malfunction, etc.).

[0081] This invention uses a PLC control module as its core, equipped with PID+feedforward composite control logic, and links the variable frequency fan of the fan box 4 with the inlet valve 12 and outlet valve 13 to dynamically adjust parameters such as inlet and outlet water flow and liquid level. The response time is <30 seconds, ensuring that the H2S concentration of the output water is stably up to standard (<0.05mg / L).

[0082] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A control method for removing hydrogen sulfide from water using a degassing tower, characterized in that, Includes the following steps: S1. Detection units are installed at the inlet and outlet of the closed degassing tower to collect the ORP value and pH value of the inlet water, as well as the ORP value and pH value of the outlet water. The difference between the ORP value of the outlet water and the ORP value of the inlet water, ΔORP, and the difference between the pH value of the outlet water and the pH value of the inlet water, ΔpH, are obtained. At the same time, the operating parameters of the degassing tower are collected, including the vacuum pump pressure, the air volume of the blower box, the inlet and outlet water flow rates and liquid levels of the degassing tower. S2. Using ΔORP as the core characterization parameter and ΔpH as the auxiliary characterization parameter, and combining the degassing tower operating parameters collected in step S1, establish a linear correlation between ΔORP and the amount of H2S removed from water, and clarify the linkage trend between ΔpH and ΔORP. S3. Periodically collect water samples from the inlet and outlet of the degassing tower to be tested, quantitatively determine the H2S concentration in the water, and calibrate the safety threshold of ΔORP based on the correlation model in step S2. S4. Based on the ΔORP safety threshold set in step S3, the effect of the degassing tower in removing H2S from water is characterized by real-time monitoring of ΔORP, ΔpH and operating parameters. ΔpH is introduced as a branch adjustment for abnormal interference. When ΔORP is lower than the safety threshold, or when the linkage trend between ΔpH and ΔORP deviates from the preset range, the operating parameters of the degassing tower are adjusted in a linkage manner to ensure that the degassing effect meets the standard.

2. The control method for removing hydrogen sulfide from water using a degassing tower according to claim 1, characterized in that, The degassing tower is equipped with a Pall ring packing layer to increase the contact area between water and air, forming a gas-liquid mass transfer layer; the air inlet of the degassing tower is connected to a fan box to introduce clean air into the degassing tower; the exhaust port of the degassing tower is connected to a vacuum pump to draw gas from the degassing tower, so that a stable negative pressure chamber is formed in the upper part of the degassing tower.

3. The control method for removing hydrogen sulfide from water using a degassing tower according to claim 2, characterized in that, During the operation of the degassing tower, when the degassing tower needs to be replenished due to a drop in liquid level, filtered clean air is introduced through the fan box to replenish the gas. When the degassing tower needs to be vented due to a drop in liquid level, the vacuum pump is used to vent the gas.

4. The control method for removing hydrogen sulfide from water using a degassing tower according to claim 1, characterized in that, In step S1, the detection unit includes an online ORP meter and a mobile pH meter. The online ORP meter is used to collect the influent ORP value and the effluent ORP value in real time, and the mobile pH meter is used to collect the influent pH value and the effluent pH value periodically. And / or the operating parameters are acquired through sensors, including a pressure sensor, an air volume sensor, a flow rate sensor, and a liquid level sensor; the pressure sensor is located at the air inlet of the vacuum pump and is used to acquire the vacuum pressure of the negative pressure chamber of the degassing tower; the air volume sensor is installed at the air outlet of the fan box and is used to acquire the air volume of the fan box; the flow rate sensor includes two sensors, which are respectively installed at the water inlet and water outlet of the degassing tower and are used to acquire the water inlet flow rate and water outlet flow rate; the liquid level sensor is installed at the bottom of the degassing tower and is used to acquire the liquid level inside the degassing tower.

5. The control method for removing hydrogen sulfide from water using a degassing tower according to claim 1, characterized in that, In step S2, the process of constructing the correlation is as follows: under the stable operation of the degassing tower, at least one parameter among the initial H2S concentration, fan box air volume, and vacuum pump pressure is changed, and the corresponding ΔORP, ΔpH, and H2S removal amount are collected. Through linear fitting or machine learning algorithms, a linear correlation equation between ΔORP and H2S removal amount is established, and the linkage trend between ΔpH and ΔORP is clarified.

6. The control method for removing hydrogen sulfide from water using a degassing tower according to claim 5, characterized in that, In step S2, 1) The linear relationship between ΔORP and H2S removal: in, yes The amount removed is determined by the effluent. Concentration - Influent Concentration; ΔORP is effluent ORP minus influent ORP; k is the linearity coefficient; b is a constant correction term; 2) The correlation trend between ΔpH and ΔORP: Among them, the function g( ) is a linear function of ΔpH as a function of ΔORP under stable operating conditions of the degassing tower, and satisfies g'(x)>

0.

7. The control method for removing hydrogen sulfide from water using a degassing tower according to claim 6, characterized in that, The specific process of step S3 is as follows: Periodically take one water sample from each of the inlet and outlet of the degassing tower and send them to the laboratory for testing using standard methods. Concentration, and at the same time, record the influent ORP value and effluent ORP value displayed by the on-site detection unit, and calculate ΔORP; Update ΔORP and The parameters k and b of the linear correlation equation for the amount of material removed; The minimum acceptable ΔORP, i.e. the ΔORP safety threshold, is calculated in reverse and written into the alarm logic of step S4.

8. The control method for removing hydrogen sulfide from water using a degassing tower according to claim 1, characterized in that, The ΔORP safety threshold is set in the range of +5mV to +50mV. When the H2S concentration in the water is ≤0.05mg / L, the corresponding ΔORP is ≥ the safety threshold, ensuring that H2S removal meets the standard.

9. The control method for removing hydrogen sulfide from water using a degassing tower according to any one of claims 1-8, characterized in that, In step S4, the linkage adjustment method is as follows: when ΔORP is lower than the safety threshold, or when the linkage trend between ΔpH and ΔORP deviates from the preset range, at least one parameter among the fan box air volume and vacuum pump pressure is automatically adjusted, and the inlet and outlet water flow rate and liquid level of the degassing tower are adjusted simultaneously until ΔORP recovers to above the safety threshold. Specifically, the adjustment is carried out in the following way. in, The target ΔORP value is the minimum safety threshold that needs to be achieved. This refers to the air volume of the fan box; This indicates the air-to-water ratio, which is the ratio of the fan box air volume to the inlet and outlet water flow rates. This refers to the influent flow rate; This refers to the vacuum pump pressure. The liquid level in the degassing tower affects the residence time τ of water in the degassing tower. The liquid level-to-flow rate ratio is directly proportional to the residence time τ of water in the degassing tower (τ = effective volume in the tower / inlet water flow rate). The larger the ratio, the longer the residence time and the more complete the degassing. function It is a multivariate linear function: Among them, coefficients A, B, C, and D were calibrated by multiple linear regression fitting through steady-state multi-condition tests of the degassing tower; 1) Adjustment of air volume in the fan box in, Let t be the target air volume of the fan box at time t, and the real-time output air volume of the fan. This refers to the basic air volume of the fan box and the reference air volume during normal operation of the degassing tower. The proportional coefficient for adjusting the air volume of the fan box is set by the engineering department; Let ΔORP be the deviation value at time t. = – ; The integral coefficient for regulating the air volume of the fan box is determined by the engineering setup. 2) Adjustment of vacuum pump pressure in, The target pressure of the vacuum pump at any given time; The vacuum pump's base pressure is determined experimentally. The proportional coefficient for vacuum pump pressure regulation determines the deviation. The instantaneous adjustment range of negative pressure is determined by engineering settings; The differential coefficient for vacuum pump pressure regulation is determined by engineering parameters; 3) Adjustment of inlet and outlet water flow rates of the degassing tower in, The target inlet and outlet water flow rates of the degassing tower at any given time; The target processing flow rate is designed for the degassing tower; The proportional coefficient for adjusting the influent flow rate is determined by the engineering specifications. 4) Adjustment of degassing liquid level in, The target liquid level setpoint for the degassing tower at time t; The optimal reference liquid level for the degassing tower; For liquid level adjustment, to meet , and deviation Positive correlation This is the proportional coefficient for liquid level regulation, set by the engineering department, with a deviation... = – .

10. The control method for removing hydrogen sulfide from water using a degassing tower according to any one of claims 1-8, characterized in that, Step S4 also includes an abnormal degassing effect warning step: when ΔORP remains below the safety threshold for a certain period of time, or when the linkage trend between ΔpH and ΔORP deviates from the preset range, an alarm is triggered and abnormal data is recorded.

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