Aeration sedimentation integrated pool gas-lifting type circulation measurement method

Abstract

The application discloses an aeration sedimentation integrated pool gas-lifting type loop flow measurement method, and belongs to the technical field of sewage treatment. The measurement method comprises the following steps: firstly, sealingly connecting a separation tank bottom with an aeration sedimentation integrated pool, installing a flowmeter measurement device gas-lifting type loop flow measurement pipeline on the separation tank, and installing a liquid flowmeter on the gas-lifting type loop flow measurement pipeline to record flow data under different gas amounts; then, opening a water inlet lifting pump, and recording a value on a water outlet flowmeter after water is discharged from a water outlet weir on the aeration sedimentation integrated pool; secondly, starting an aeration system, and adjusting a gas flowmeter on the aeration system; and recording a gas-lifting type loop flowmeter value on the liquid flowmeter under different gas amounts and recording an exhaust pipe liquid level height. The aeration sedimentation integrated pool gas-lifting type loop flow measurement method can accurately measure the gas-lifting type loop flow, is favorable for stable operation of the aeration sedimentation integrated pool, improves sludge-water separation efficiency, and improves water quality.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of sewage treatment, and particularly relates to a gas-lift loop flow measurement method for an aeration sedimentation integrated tank. BACKGROUND

[0002] The aeration sedimentation integrated tank, as a water treatment device integrating aeration and sedimentation functions, plays an important role in modern sewage treatment processes. The gas-lift loop reactor, as a core component of the aeration sedimentation integrated tank, realizes efficient mixing and mass transfer processes through the introduction of gas and the driving of loop flow, which is crucial for improving the treatment efficiency. However, the accurate measurement of the gas-lift loop flow has always been a technical difficulty in this field.

[0003] Currently, there are various methods for measuring the gas-lift loop flow, but each has obvious shortcomings. Although the PIV technology, as a non-contact fluid velocity measurement method, has the advantages of high precision and visualization, in the aeration sedimentation integrated tank, due to the special structure of the airlift bioreactor, the tracer particles have multidimensional motion, resulting in uneven flow velocity, which makes it difficult for the PIV technology to accurately measure the flow;

[0004] The volume expansion height method calculates the gas holdup by measuring the change in liquid volume expansion height caused by gas injection, and then estimates the flow of the gas-liquid two-phase. Although this method is simple and intuitive, in actual application, due to the complex structure of the airlift bioreactor of the aeration sedimentation integrated tank, the flow state of the gas-liquid two-phase is difficult to accurately describe, so the error of this method in the measurement of the gas-lift loop flow is large;

[0005] The electrical conductivity pulse tracer method uses the change of electrical conductivity as a tracer to determine the circulation speed of the liquid by measuring the change of electrical conductivity over time. However, in actual application, the change of electrical conductivity is disturbed by various factors, such as temperature, pressure, solution composition, etc., which may lead to inaccurate measurement results;

[0006] The dynamic dissolved oxygen method evaluates the gas-liquid mass transfer performance by measuring the change of dissolved oxygen in water, thereby indirectly reflecting the flow characteristics of the gas-lift loop. However, in the aeration sedimentation integrated tank, the change of dissolved oxygen is not only affected by the gas-liquid mass transfer, but also disturbed by various factors such as aeration air volume, pollutants, activated sludge, etc., so it is also difficult for this method to evaluate the gas-lift loop flow of the airlift bioreactor of the aeration sedimentation integrated tank.

[0007] In summary, the current gas-lift loop flow measurement methods have large errors in precision and application range, and cannot meet the demand for accurate measurement in complex reactor environments.

[0008] Therefore, the present application provides a gas-lift loop flow measurement method for an aeration sedimentation integrated tank to solve the above problems. SUMMARY

[0009] The application provides an aeration precipitation integrated pool gas-lift loop measurement method, aiming at solving the problems of the existing measurement methods such as the float method and the tracer method in the background art, which have large errors in precision and application range and cannot meet the demand for accurate measurement in a complex reactor environment.

[0010] To achieve the above object, the application provides the following technical scheme: an aeration precipitation integrated pool gas-lift loop measurement method, comprising the following steps:

[0011] S1, sealingly connecting the bottom of a separation tank with the aeration precipitation integrated pool, installing a gas-lift loop measurement pipeline on the separation tank, and installing a liquid flow meter on the gas-lift loop measurement pipeline to record flow data under different gas amounts;

[0012] S2, opening the water inlet lifting pump, and recording the value on the water outlet flow meter after the water outlet weir on the aeration precipitation integrated pool discharges water;

[0013] S3, starting the aeration system and adjusting the gas flow meter on the aeration system 4; recording the gas-lift loop pipe flow meter value Q1 on the liquid flow meter under different gas amounts and recording the exhaust pipe liquid level height;

[0014] S4, calculating the sum of the resistance coefficients of the gas-lift loop pipeline system ;

[0015] S5, establishing a mathematical model of the gas-lift loop pipeline system according to the energy equation;

[0016] First, the liquid flow rate U in the downflow zone is calculated according to the following formula d：

[0017]

[0018] wherein Q1 is the gas-lift loop pipe flow meter value; U d is the liquid flow rate in the downflow zone, in units of m / s; A d is the cross-sectional area of the gas-lift loop pipe.

[0019]

[0020] wherein e d is the gas holdup in the downflow zone; e1 is the gas holdup in the upflow zone; U d is the liquid flow rate in the downflow zone, in units of m / s; u1 is the liquid flow rate in the upflow zone, in units of m / s; L1 is the height of the upflow zone, in units of m; L d is the height of the downflow zone of the gas-lift loop pipeline system, in units of m; is the sum of the resistance coefficients of the gas-lift loop pipeline.

[0021] S6, the gas-lift loop flow meter under different gas amount is brought into the mathematical model, and the relevant value of the upflow zone is calculated;

[0022] S7, the separation tank and the gas-lift loop measurement pipeline are removed, the normal operation of the aeration sedimentation integrated pool 1 is restored, and the sum of the resistance coefficients of the downflow zone of the upflow bioreactor is calculated ;

[0023] S8, the newly built mathematical model is brought in, and the gas-lift loop flow Q2 of the actual operation can be calculated;

[0024] First, the liquid flow rate u2 of the downflow zone of the upflow bioreactor is calculated according to the following formula:

[0025]

[0026] Wherein, ed is the gas holdup of the downflow zone of the gas-lift loop pipeline system; e2 is the gas holdup of the downflow zone of the upflow bioreactor; u d is the liquid flow rate of the downflow zone of the gas-lift loop pipeline system, unit m / s; L d is the height of the downflow zone of the gas-lift loop pipeline system, unit m; L2 is the height of the downflow zone of the upflow bioreactor, unit m; is the sum of the resistance coefficients of the downflow zone of the gas-lift loop pipeline; is the sum of the resistance coefficients of the downflow zone of the upflow bioreactor; u2 is the liquid flow rate of the downflow zone of the upflow bioreactor, unit m / s.

[0027] Preferably, in S4, the sum of the resistance coefficients of the gas-lift loop pipeline system includes the resistance coefficients of the inlet and outlet of the gas chamber separation tank, the resistance coefficients of the loop pipeline, and the resistance coefficients of the elbow.

[0028] Preferably, in S7, the sum of the resistance coefficients of the downflow zone of the upflow bioreactor includes the resistance coefficient of the outlet of the separation tank and the resistance coefficient of the backflow gap of the upflow bioreactor.

[0029] Preferably, in S8, the flow rate Q 2：

[0030]

[0031] Wherein, u2 is the liquid flow rate of the downflow zone of the upflow bioreactor, unit m / s; A2 is the cross-sectional area of the downflow zone of the upflow bioreactor; Q2 is the flow rate of the gas-lift loop flow.

[0032] Preferably, in order to facilitate disassembly between the separation tank and the aeration sedimentation integrated tank, flange sealing plates are arranged between the separation tank and the aeration sedimentation integrated tank, and the separation tank and the aeration sedimentation integrated tank are fixedly connected through the flange sealing plates; the connection of the flange sealing plates is that two flange sealing plates are tightly connected together through bolts and other fasteners, and when it is necessary to disassemble the separation tank and the aeration sedimentation integrated tank, the two can be easily separated by only loosening the bolts, without the need for complex cutting or destructive disassembly work. This design greatly simplifies the disassembly and installation process, and improves work efficiency.

[0033] The aeration sedimentation integrated tank gas-lift circulating flow measurement method measures the gas-lift circulating flow under different aeration amounts by building a gas-lift circulating pipeline test system and establishing a mathematical model for gas-lift circulating calculation, can accurately measure the gas-lift circulating flow under the working conditions of the aeration sedimentation integrated tank, can effectively guide the structural parameter design of the airlift bioreactor, is conducive to the stable operation of the aeration sedimentation integrated tank, improves the sludge-water separation efficiency, and improves the water quality. BRIEF DESCRIPTION OF DRAWINGS

[0034] Figure 1 It is a structural diagram of an aeration sedimentation integrated tank gas-lift circulating flow measurement method Figure One ;

[0035] Figure 2 It is a structural diagram of an aeration sedimentation integrated tank gas-lift circulating flow measurement method Figure Two .

[0036] In the figure:

[0037] 1, aeration sedimentation integrated tank; 11, water inlet lifting pump; 12, water outlet weir

[0038] 2, separation tank;

[0039] 3, gas-lift circulating flow measurement pipeline; 31, liquid flow meter;

[0040] 4, aeration system; 41, gas flow meter;

[0041] 5, flange sealing plate. DETAILED DESCRIPTION

[0042] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0043] The embodiment provides a gas-lifting loop measurement method for an integrated aeration sedimentation tank, as shown in the figure. Figures 1-2 The measurement method comprises the following steps.

[0044] S1, sealingly connecting the bottom of the separation tank 2 with the integrated aeration sedimentation tank 1, then connecting the gas-lifting loop measurement pipeline 3 to the separation tank 2, and installing a liquid flow meter 31 on the gas-lifting loop measurement pipeline 3 to record flow data under different gas amounts;

[0045] S2, opening the water inlet lifting pump 11, and recording the value on the water outlet flow meter after water is discharged from the water outlet weir 12 on the integrated aeration sedimentation tank 1;

[0046] S3, starting the aeration system 4, adjusting the gas flow meter 41 on the aeration system 4, recording the gas-lifting loop flow meter value Q1 on the liquid flow meter 31 under different gas amounts, and recording the exhaust pipe liquid level height;

[0047] S4, calculating the sum of the resistance coefficients of the gas-lifting loop pipeline system ;

[0048] S5, establishing a mathematical model of the gas-lifting loop pipeline system according to an energy equation;

[0049] First, the liquid flow rate U of the downflow zone is calculated according to the following formula d：

[0050]

[0051] wherein Q1 is the gas-lifting loop flow meter value; U d is the liquid flow rate of the downflow zone, in the unit of m / s; A d is the cross-sectional area of the gas-lifting loop.

[0052] Then, the relevant values of the upflow zone are calculated according to the following formula:

[0053]

[0054] wherein e d is the gas holdup of the downflow zone; e1 is the gas holdup of the upflow zone; U d is the liquid flow rate of the downflow zone, in the unit of m / s; u1 is the liquid flow rate of the upflow zone, in the unit of m / s; L1 is the height of the upflow zone, in the unit of m; L d is the height of the downflow zone of the gas-lifting loop pipeline system, in the unit of m; is the sum of the resistance coefficients of the gas-lifting loop pipeline.

[0055] S6, bringing the gas-lifting loop flow meter value Q1 under different gas amounts into the mathematical model to calculate the relevant values of the upflow zone;

[0056] S7, remove the separation tank 2 and the gas-lift loop measuring pipe 3, restore the normal operation of the aeration sedimentation integrated tank 1, and calculate the sum of the resistance coefficients of the down-flow zone of the up-flow biological reactor ;

[0057] S8, the newly built mathematical model can be used to calculate the actual running gas-lift loop flow Q2;

[0058] First, calculate the liquid flow rate u2 of the down-flow zone of the up-flow biological reactor according to the following formula:

[0059]

[0060] Then, calculate the flow rate Q of the gas-lift loop flow according to the following formula: 2：

[0061]

[0062] Where ed is the gas holdup of the down-flow zone of the gas-lift loop pipe system; e2 is the gas holdup of the down-flow zone of the up-flow biological reactor; u d is the liquid flow rate of the down-flow zone of the gas-lift loop pipe system, unit m / s; L d is the height of the down-flow zone of the gas-lift loop pipe system, unit m; L2 is the height of the down-flow zone of the up-flow biological reactor, unit m; is the sum of the resistance coefficients of the down-flow zone of the gas-lift loop pipe system; is the sum of the resistance coefficients of the down-flow zone of the up-flow biological reactor; u2 is the liquid flow rate of the down-flow zone of the up-flow biological reactor, unit m / s

[0063] Specifically, in S4, the sum of the resistance coefficients of the gas-lift loop pipe system includes the resistance coefficients of the inlet and outlet of the gas chamber separation tank, the resistance coefficients of the loop pipe, and the resistance coefficients of the elbow.

[0064] Further, in S7, the sum of the resistance coefficients of the down-flow zone of the up-flow biological reactor includes the resistance coefficient of the outlet of the separation tank and the resistance coefficient of the backflow gap of the up-flow biological reactor.

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

[0066] The connection of the flange sealing plates 5 is achieved by fasteners such as bolts to tightly connect the two flange sealing plates 5 together. When it is necessary to disassemble the separation tank 2 and the aeration sedimentation integrated tank 1, the bolts are only loosened, and then the two can be easily separated without complicated cutting or destructive disassembly work. This design greatly simplifies the disassembly and installation process, and improves the work efficiency.

[0067] Through the above-mentioned air-lift loop measurement method, the measurement values are as follows:

[0068] The above merely describes the preferred specific embodiments of the present application, but the protection scope of the present application is not limited thereto, and any person skilled in the art can make equivalent replacements or changes according to the technical solution and concept of the present application within the technical range disclosed by the present application, which should be covered within the protection scope of the present application.

Claims

1. A method for measuring airlift circulation in an integrated aeration and sedimentation tank, characterized in that: Includes the following steps: S1. Seal the bottom of the separation box (2) to the aeration sedimentation integrated tank (1), install the airlift circulation measurement pipe (3) on the separation box (2), and install the liquid flow meter (31) on the airlift circulation measurement pipe (3) to record the flow data under different air volumes. S2. Turn on the inlet booster pump (11). After the water flows out from the outlet weir (12) on the aeration sedimentation tank (1), record the value on the outlet flow meter. S3. Start the aeration system (4) and adjust the gas flow meter (41) on the aeration system (4); record the flow count value Q1 of the airlift loop tube on the liquid flow meter (31) under different gas volumes and record the liquid level height of the exhaust pipe; S4. Calculate the sum of resistance coefficients for the airlift circulation pipe system. ; S5. Based on the energy equation, establish a mathematical model of the airlift circulation pipeline system; First, calculate the liquid velocity U in the downflow region using the following formula. d： ； Where Q1 is the flow rate count value of the airlift loop pipe; U d A represents the liquid velocity in the downflow region, in m / s. d The cross-sectional area of ​​the airlift circulation pipe; Then calculate the relevant values ​​for the upflow region using the following formula: ； Among them, e d e1 is the gas holdup in the downflow region; e1 is the gas holdup in the upflow region; U d U1 represents the liquid velocity in the downflow region, in m / s; u1 represents the liquid velocity in the upflow region, in m / s; L1 represents the height of the upflow region, in m; L d The height of the descending zone in an airlift-type circulating pipeline system, in meters (m). This is the sum of the resistance coefficients of the airlift circulation pipe; S6. Substitute the flow count value Q1 of the air riser circulation pipe under different air volumes into the mathematical model to calculate the relevant values ​​of the riser region; S7. Remove the separation box (2) and the airlift circulation measurement pipe (3), restore the aeration sedimentation integrated tank (1) to normal operation, and calculate the sum of the resistance coefficients of the downflow zone of the upflow bioreactor. ; S8. Substitute the data into the newly created mathematical model to calculate the actual airlift circulation flow rate Q2. First, calculate the liquid velocity u2 in the downflow zone of the upflow bioreactor using the following formula: ； Where ed 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 The liquid velocity in the downflow zone of the airlift circulation pipe system, in m / s; L d L1 represents the height of the downflow zone in the airlift circulation pipeline system, in meters; L2 represents the height of the downflow zone in the upflow bioreactor, in meters. This is the sum of the resistance coefficients in the downflow zone of the airlift circulation pipe; denoted as , where is the sum of the resistance coefficients in the downflow zone of the upflow bioreactor; u2 is the liquid velocity in the downflow zone of the upflow bioreactor, in m / s.

2. The airlift circulation measurement method for an integrated aeration sedimentation tank according to claim 1, characterized in that: In S4, the sum of the resistance coefficients of the airlift circulation pipe system This includes the resistance coefficients at the inlet and outlet of the gas chamber separator, the resistance coefficient of the circulating pipeline, and the resistance coefficient of the elbow.

3. The airlift circulation measurement method for an integrated aeration sedimentation tank according to claim 1, characterized in that: In S7, the sum of the resistance coefficients in the downflow zone of the upflow bioreactor. This includes the resistance coefficient at the outlet of the separator and the resistance coefficient of the reflux gap in the upflow bioreactor.

4. The airlift circulation measurement method for an integrated aeration sedimentation tank according to claim 1, characterized in that: In S8, the flow rate Q of the airlift circulation is calculated according to the following formula. 2： ； Where u2 is the liquid velocity 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; and Q2 is the flow rate of the airlift circulation.

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

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