Aeration and sedimentation integrated tank airlift circulation measurement method

Abstract

The invention discloses an aeration and sedimentation integrated pool airlift type circulation measuring method, and belongs to the technical field of sewage treatment.The measuring method comprises the following steps that firstly, the bottom of a separation box is connected with an aeration and sedimentation integrated pool in a sealed mode, and then a flowmeter measuring device airlift type circulation measuring pipeline is installed on the separation box; a liquid flow meter is arranged on the airlift type circulation measuring pipeline to record flow data under different air flows; then, opening a water inlet lifting pump, and recording a numerical value on a water outlet flow meter after water flows out of a water outlet weir on the aeration and sedimentation integrated tank; secondly, an aeration system is started, and a gas flow meter on the aeration system is adjusted; and the numerical value Q1 of the airlift circulating pipe flowmeter on the liquid flowmeter and the liquid level height of the exhaust pipe are recorded under different gas quantities. According to the method for measuring the airlift circulation of the aeration and sedimentation integrated tank, the flow of the airlift circulation can be accurately measured, the stable operation of the aeration and sedimentation integrated tank is facilitated, the mud-water separation efficiency is improved, and the effluent quality is improved.

Description

Technical Field

[0001] The present application relates to the technical field of sewage treatment, and in particular to an airlift circulation measurement method for an aeration-sedimentation integrated tank. Background Art

[0002] As a water treatment equipment integrating aeration and sedimentation functions, the aeration-sedimentation integrated tank occupies an important position in modern sewage treatment technology. Its core component, the airlift loop reactor, achieves efficient mixing and mass transfer processes through the introduction of gas and circulation promotion, which is crucial to improving treatment efficiency. However, the accurate measurement of airlift loop flow has always been a technical difficulty in this field.

[0003] At present, there are many methods for measuring airlift circulation flow, but each has obvious shortcomings. Although PIV technology is a non-contact fluid velocity measurement method with the advantages of high precision and visualization, in the aeration sedimentation integrated tank, due to the structural irregularities of the upflow bioreactor, the tracer particles have multi-dimensional movement, resulting in uneven flow velocity, making it difficult for PIV technology to accurately measure;

[0004] The volume expansion height rule is to estimate the gas holdup by measuring the change in liquid volume expansion height caused by gas injection, and then estimate the flow rate of gas and liquid phases. Although this method is simple and intuitive, in practical applications, due to the complex structure of the upflow bioreactor of the aeration sedimentation integrated tank, the flow state of gas and liquid phases is difficult to accurately describe, so this method has a large error in the measurement of airlift circulation flow;

[0005] The conductivity pulse tracer method uses the change of conductivity as a tracer and determines the circulation rate of the liquid by measuring the change of conductivity over time. However, in practical applications, the change of conductivity is interfered by many factors, such as temperature, pressure, solution composition, etc. These factors may lead to inaccurate measurement results.

[0006] The dynamic dissolved oxygen law evaluates the gas-liquid mass transfer performance by measuring the changes in dissolved oxygen in water, thereby indirectly reflecting the flow characteristics of the airlift circulation. However, in an aerated sedimentation integrated tank, the change in dissolved oxygen is not only affected by the gas-liquid mass transfer, but also by multiple factors such as aeration air volume, pollutants, and activated sludge. Therefore, this method is also difficult to use when evaluating the airlift circulation flow of an upflow bioreactor in an aerated sedimentation integrated tank.

[0007] In summary, the current airlift circulation flow measurement method has large errors in accuracy and scope of application, and cannot meet the needs of accurate measurement in complex reactor environments.

[0008] Therefore, the present application provides an airlift circulation measurement method for an aeration and sedimentation integrated tank to solve the above problems. Summary of the invention

[0009] The present application provides an airlift circulation measurement method for an aeration and sedimentation integrated tank, aiming to solve the problems that the existing measurement methods proposed in the background technology, such as the float method, the tracer method, etc., have large errors in accuracy and scope of application, and cannot meet the needs of accurate measurement in complex reactor environments.

[0010] To achieve the above purpose, the present application provides the following technical solution: a method for measuring airlift circulation in an aeration-sedimentation integrated tank, comprising the following steps:

[0011] S1. The bottom of the separation box is sealed and connected to the aeration sedimentation integrated tank, and then an airlift circulation measurement pipeline is installed on the separation box, and a liquid flow meter is installed on the airlift circulation measurement pipeline to record the flow data under different gas volumes;

[0012] S2. Turn on the water inlet lift pump, wait for water to flow out of the outlet weir on the aeration and sedimentation integrated tank, and record the value on the outlet flow meter;

[0013] S3, start the aeration system and adjust the gas flow meter on the aeration system 4; record the flow meter value Q1 of the airlift circulation pipe on the liquid flow meter under different gas volumes and record the liquid level height of the exhaust pipe;

[0014] S4, calculate the sum of the resistance coefficients of the airlift circulation pipeline system ∑ε1;

[0015] S5. Based on the energy equation, a mathematical model of the airlift circulation pipeline system is established;

[0016] S6, bringing the airlift circulation tube flow meter value Q1 under different gas volumes into the mathematical model to calculate the relevant values ​​of the upflow area;

[0017] S7, dismantle the separation box and the airlift circulation measurement pipeline, restore the normal operation of the aeration sedimentation integrated tank 1, and calculate the sum of the resistance coefficients of the downflow zone of the upflow bioreactor ∑ε2;

[0018] S8. Bring it into the newly created mathematical model to calculate the actual airlift circulation flow Q2.

[0019] Preferably, in S4, the sum of the resistance coefficients ∑ε1 of the airlift circulating pipeline system includes the resistance coefficients of the inlet and outlet of the air chamber separation box, the resistance coefficient of the circulating pipeline and the resistance coefficient of the elbow.

[0020] Preferably, in S5, the liquid flow rate U in the downflow zone is first calculated according to the following formula: d：

[0021]

[0022] Where Q1 is the flow meter value of the airlift circulation tube; U d is the liquid velocity in the downflow zone, in m / s; A d is the cross-sectional area of ​​the airlift circulation pipe.

[0023] Preferably, in S5, the upflow area related values ​​are calculated according to the following formula:

[0024]

[0025] Among them, e d is the gas content in the downflow zone; e1 is the gas content in the upflow zone; U d is the liquid velocity in the downflow zone, in m / s; u1 is the liquid velocity in the upflow zone, in m / s; L1 is the height of the upflow zone, in m; L d is the height of the downflow zone of the airlift circulating pipeline system, in meters; ∑ε1 is the sum of the resistance coefficients of the airlift circulating pipeline.

[0026] Preferably, in S7, the sum of the resistance coefficients of the downflow zone of the upflow bioreactor ∑ε2 includes the resistance coefficient of the separation box outlet and the resistance coefficient of the reflow gap of the upflow bioreactor.

[0027] Preferably, in S8, the liquid flow rate u2 in the downflow zone of the upflow bioreactor is first calculated according to the following formula:

[0028]

[0029] Among them, e d is the gas holdup in the downflow zone of the airlift circulation pipeline system; e2 is the gas holdup in the downflow zone of the upflow bioreactor; u d is the liquid velocity in the downflow zone of the airlift circulation pipeline system, in m / s; L d is the height of the downflow zone of the airlift circulation pipeline system, in m; L2 is the height of the downflow zone of the upflow bioreactor, in m; ∑ε1 is the sum of the resistance coefficients of the downflow zone of the airlift circulation pipeline; ∑ε2 is the sum of the resistance coefficients of the downflow zone of the upflow bioreactor; u2 is the liquid flow rate in the downflow zone of the upflow bioreactor, in m / s.

[0030] Preferably, in S8, the flow rate Q of the airlift circulation flow rate is calculated according to the following formula: 2：

[0031] Q2=u2×A2

[0032] Among them, u2 is the liquid flow rate in the downflow zone of the upflow bioreactor, in m / s; A2 is the cross-sectional area of ​​the downflow zone of the upflow bioreactor; Q2 is the flow rate of the airlift circulation flow.

[0033] Preferably, in order to facilitate the disassembly and assembly between the separation box and the aeration sedimentation integrated tank, a flange sealing plate is provided between the separation box and the aeration sedimentation integrated tank, and the separation box and the aeration sedimentation integrated tank are fixedly connected through the flange sealing plate; the connection of the flange sealing plate tightly connects the two flange sealing plates together through fasteners such as bolts, and when the separation box and the aeration sedimentation integrated tank need to be disassembled, only the bolts need to be loosened to easily separate the two, without complicated cutting or destructive disassembly work. This design greatly simplifies the disassembly and installation process and improves work efficiency.

[0034] The airlift circulation measurement method of the aeration and sedimentation integrated tank builds an airlift circulation pipeline test system and establishes a mathematical model for airlift circulation calculation, thereby measuring the airlift circulation flow under different aeration conditions. It can be applied to the working conditions of the aeration and sedimentation integrated tank to accurately measure the airlift circulation flow, can effectively guide the structural parameter design of the upflow bioreactor, is conducive to the stable operation of the aeration and sedimentation integrated tank, improves the mud-water separation efficiency, and improves the effluent water quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 A schematic diagram of the structure of an airlift circulation measurement method for an aeration and sedimentation integrated tank Figure 1 ;

[0036] Figure 2 A schematic diagram of the structure of an airlift circulation measurement method for an aeration and sedimentation integrated tank Figure 2 .

[0037] In the figure:

[0038] 1. Aeration and sedimentation integrated tank; 11. Inlet lifting pump; 12. Outlet weir

[0039] 2. Separation box;

[0040] 3. Airlift circulation measurement pipeline; 31. Liquid flow meter;

[0041] 4. Aeration system; 41. Gas flow meter;

[0042] 5. Flange sealing plate. DETAILED DESCRIPTION

[0043] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0044] This embodiment provides a method for measuring the airlift circulation in an aeration and sedimentation integrated tank. Figure 1-Figure 2 As shown, the measuring method comprises the following steps:

[0045] S1, the bottom of the separation box 2 is sealed and connected to the aeration sedimentation integrated tank 1, and then the airlift circulation measurement pipeline 3 is placed on the separation box 2, and a liquid flow meter 31 is installed on the airlift circulation measurement pipeline 3 to record the flow data under different gas volumes;

[0046] S2, turn on the water inlet lift pump 11, and after the water is discharged from the water outlet weir 12 on the aeration sedimentation integrated tank 1, record the value on the water outlet flow meter;

[0047] S3, start the aeration system 4, and adjust the gas flow meter 41 on the aeration system 4; record the flow meter value Q1 of the airlift circulation pipe on the liquid flow meter 31 and the liquid level height of the exhaust pipe under different gas volumes;

[0048] S4, calculate the sum of the resistance coefficients of the airlift circulation pipeline system ∑ε1;

[0049] S5. Based on the energy equation, a mathematical model of the airlift circulation pipeline system is established;

[0050] S6, bringing the airlift circulation tube flow meter value Q1 under different gas volumes into the mathematical model to calculate the relevant values ​​of the upflow area;

[0051] S7, dismantle the separation box 2 and the airlift circulation measurement pipeline 3, restore the normal operation of the aeration sedimentation integrated tank 1, and calculate the sum of the resistance coefficients of the downflow zone of the upflow bioreactor ∑ε2;

[0052] S8. Bring it into the newly created mathematical model to calculate the actual airlift circulation flow Q2.

[0053] Specifically, in S4, the sum of the resistance coefficients of the airlift circulating pipeline system ∑ε1 includes the resistance coefficients of the inlet and outlet of the air chamber separation box, the resistance coefficient of the circulating pipeline and the resistance coefficient of the elbow.

[0054] Further, in S5, the liquid flow rate U in the downflow zone is first calculated according to the following formula: d：

[0055]

[0056] Then calculate the relevant values ​​of the upflow area according to the following formula:

[0057]

[0058] Among them, e d is the gas content in the downflow zone; e1 is the gas content in the upflow zone; U dis the liquid velocity in the downflow zone, in m / s; u1 is the liquid velocity in the upflow zone, in m / s; L1 is the height of the upflow zone, in m; L d is the height of the downflow zone of the airlift circulation pipeline system, in meters; ∑ε1 is the sum of the resistance coefficients of the airlift circulation pipeline; A d is the cross-sectional area of ​​the airlift circulation pipe, and Q1 is the flow meter value of the airlift circulation pipe.

[0059] Furthermore, in S7, the sum of the resistance coefficients of the downflow zone of the upflow bioreactor ∑ε2 includes the resistance coefficient of the separation box outlet and the resistance coefficient of the reflow gap of the upflow bioreactor.

[0060] Furthermore, in S8, the liquid flow rate u2 in the downflow zone of the upflow bioreactor is first calculated according to the following formula:

[0061]

[0062] Then calculate the flow rate Q of the airlift circulation flow according to the following formula: 2：

[0063] Q2=u2×A2

[0064] Among them, e d is the gas holdup in the downflow zone of the airlift circulation pipeline system; e2 is the gas holdup in the downflow zone of the upflow bioreactor; u d is the liquid velocity in the downflow zone of the airlift circulation pipeline system, in m / s; L d is the height of the downflow zone of the airlift circulation pipeline system, in m; L2 is the height of the downflow zone of the upflow bioreactor, in m; ∑ε1 is the sum of the resistance coefficients of the downflow zone of the airlift circulation pipeline; ∑ε2 is the sum of the resistance coefficients of the downflow zone of the upflow bioreactor; u2 is the liquid flow rate in the downflow zone of the upflow bioreactor, in m / s; A2 is the cross-sectional area of ​​the downflow zone of the upflow bioreactor; Q2 is the flow rate of the airlift circulation volume.

[0065] In addition, in order to facilitate the disassembly and assembly between the separation box 2 and the aeration and sedimentation integrated tank 1, a flange sealing plate 5 is provided between the separation box 2 and the aeration and sedimentation integrated tank 1, and the separation box 2 and the aeration and sedimentation integrated tank 1 are fixedly connected through the flange sealing plate 5;

[0066] The flange sealing plates 5 are tightly connected together by fasteners such as bolts. When the separation box 2 and the aeration sedimentation integrated tank 1 need to be disassembled, the two can be easily separated by simply loosening the bolts without complicated cutting or destructive disassembly. This design greatly simplifies the disassembly and installation process and improves work efficiency.

[0067] Measurement data

[0068] Through the above-mentioned airlift circulation measurement method, the measured values ​​are as follows:

[0069]

[0070] The above is only a preferred specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can make equivalent substitutions or changes according to the technical solution and concept of the present application within the technical scope disclosed in the present application, which should be covered by the protection scope of the present application.

Claims

1. A method for measuring airlift circulation in an aeration-sedimentation integrated tank, characterized in that: The following steps are involved: S1, sealingly connecting the bottom of the separation box (2) to the aeration and sedimentation integrated tank (1), installing an airlift circulation measurement pipeline (3) on the separation box (2), and installing a liquid flow meter (31) on the airlift circulation measurement pipeline (3) to record flow data under different gas volumes; S2, turning on the water inlet lift pump (11), and after water is discharged from the water outlet weir (12) on the aeration sedimentation integrated tank (1), recording the value on the water outlet flow meter; S3, starting the aeration system (4) and adjusting the gas flow meter (41) on the aeration system (4); recording the flow meter value Q1 of the airlift circulation pipe on the liquid flow meter (31) and recording the liquid level height of the exhaust pipe under different gas volumes; S4, calculate the sum of the resistance coefficients of the airlift circulation pipeline system ∑ε1; S5. Based on the energy equation, a mathematical model of the airlift circulation pipeline system is established; S6, bringing the airlift circulation tube flow meter value Q1 under different gas volumes into the mathematical model to calculate the relevant values ​​of the upflow area; S7, dismantling the separation box (2) and the airlift circulation measurement pipeline (3), restoring the normal operation of the aeration sedimentation integrated tank (1), and calculating the sum of the resistance coefficients ∑ε2 of the downflow zone of the upflow bioreactor; S8. Bring it into the newly created mathematical model to calculate the actual airlift circulation flow Q2.

2. The airlift circulation measurement method for an aeration-sedimentation integrated tank according to claim 1, characterized in that: In S4, the sum of the resistance coefficients of the airlift circulating pipeline system ∑ε1 includes the resistance coefficients of the inlet and outlet of the air chamber separation box, the resistance coefficient of the circulating pipeline and the resistance coefficient of the elbow.

3. The airlift circulation measurement method for an aeration-sedimentation integrated tank according to claim 1 is characterized in that: In S5, the liquid flow rate U in the downflow zone is first calculated according to the following formula: d： Where Q1 is the flow meter value of the airlift circulation tube; U d is the liquid velocity in the downflow zone, in m / s; A d is the cross-sectional area of ​​the airlift circulation pipe.

4. The airlift circulation measurement method for an aeration-sedimentation integrated tank according to claim 3 is characterized in that: In S5, the relevant values ​​of the upflow area are calculated according to the following formula: Among them, e d is the gas content in the downflow zone; e1 is the gas content in the upflow zone; U d is the liquid velocity in the downflow zone, in m / s; u1 is the liquid velocity in the upflow zone, in m / s; L1 is the height of the upflow zone, in m; L d is the height of the downflow zone of the airlift circulating pipeline system, in meters; ∑ε1 is the sum of the resistance coefficients of the airlift circulating pipeline.

5. The airlift circulation measurement method for an aeration-sedimentation integrated tank according to claim 1, characterized in that: In S7, the sum of the resistance coefficients of the downflow zone of the upflow bioreactor ∑ε2 includes the separation box outlet resistance coefficient and the upflow gap resistance coefficient of the upflow bioreactor.

6. The airlift circulation measurement method for an aeration-sedimentation integrated tank according to claim 1, characterized in that: In S8, the liquid flow rate u2 in the downflow zone of the upflow bioreactor is first calculated according to the following formula: Among them, e d is the gas holdup in the downflow zone of the airlift circulation pipeline system; e2 is the gas holdup in the downflow zone of the upflow bioreactor; u d is the liquid velocity in the downflow zone of the airlift circulation pipeline system, in m / s; L d is the height of the downflow zone of the airlift circulation pipeline system, in m; L2 is the height of the downflow zone of the upflow bioreactor, in m; ∑ε1 is the sum of the resistance coefficients of the downflow zone of the airlift circulation pipeline; ∑ε2 is the sum of the resistance coefficients of the downflow zone of the upflow bioreactor; u2 is the liquid flow rate in the downflow zone of the upflow bioreactor, in m / s.

7. The airlift circulation measurement method for an aeration-sedimentation integrated tank according to claim 6, characterized in that: In S8, the flow rate Q of the airlift circulation flow is calculated according to the following formula: 2： Q2=u2×A2 Among them, u2 is the liquid flow rate in the downflow zone of the upflow bioreactor, in m / s; A2 is the cross-sectional area of ​​the downflow zone of the upflow bioreactor; Q2 is the flow rate of the airlift circulation flow.

8. The airlift circulation measurement method for an aeration-sedimentation integrated tank according to claim 1, characterized in that: A flange sealing plate (5) is provided between the separation box (2) and the aeration and sedimentation integrated tank (1), and the separation box (2) and the aeration and sedimentation integrated tank (1) are fixedly connected via the flange sealing plate (5).

Images