CN115406804B - Method for measuring influence of jet bubble crying on turbulent flow of gas-liquid bubbling fluidized bed - Google Patents
Method for measuring influence of jet bubble crying on turbulent flow of gas-liquid bubbling fluidized bed Download PDFInfo
- Publication number
- CN115406804B CN115406804B CN202211110071.8A CN202211110071A CN115406804B CN 115406804 B CN115406804 B CN 115406804B CN 202211110071 A CN202211110071 A CN 202211110071A CN 115406804 B CN115406804 B CN 115406804B
- Authority
- CN
- China
- Prior art keywords
- gas
- liquid
- bubbles
- bubble
- crying
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N11/00—Investigating flow properties of materials, e.g. viscosity, plasticity; Analysing materials by determining flow properties
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E30/00—Energy generation of nuclear origin
- Y02E30/30—Nuclear fission reactors
Landscapes
- Physics & Mathematics (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Indicating Or Recording The Presence, Absence, Or Direction Of Movement (AREA)
Abstract
The invention discloses a method for measuring the influence of jet flow bubbles on turbulent flow of a gas-liquid bubbling fluidized bed, which adopts a high-speed camera to measure images of the bubble flowing process, adopts a micro-pressure sensor to measure the liquid pressure at two different heights of a gas-liquid reactor, calculates the porosity of bubbles in the gas-liquid bubbling fluidized bed, reveals the turbulent flow characteristics of bubbles with complex size distribution influenced by the crying bubbles, and reveals the flow characteristics of uniformly flowing discrete small-size bubbles, the flow characteristics of crying bubbles inducing large-size bubbles, the flow characteristics of crying bubbles inducing to generate micro-size bubbles and the flow characteristics of crying bubbles inducing to influence the turbulent flow of the gas-liquid, thereby establishing a relation fitting formula of the specific surface area of the bubbles and the inlet volume flow rate of a straight pipe airflow distributor. The invention can provide an optimization strategy of unbalanced inlet jet flow conditions, increase the specific surface area of bubbles to improve the total mass transfer capacity, and provide a basis for optimizing the performance of the reactor.
Description
Technical Field
The invention belongs to the technical field of gas-liquid multiphase turbulence flow reactors, and particularly relates to a method for measuring the influence of crying of jet bubbles on turbulent flow of a gas-liquid bubbling fluidized bed.
Background
The gas-liquid bubbling fluidized bed reactor is widely applied in the fields of catalytic cracking industry, targeted bio-pharmaceuticals and new energy, and has the main advantages of simple mechanical structure, few moving parts, more economical operation cost, easily-controlled liquid flow pattern control and contact area between gas and liquid phases. The average size distribution of bubbles, the bubble generation frequency, the inter-phase contact area and the interaction among bubbles in the gas-liquid turbulent flow have great influence on the transfer behavior of heat and mass transfer, the conversion rate of products and the acquisition yield. The three main turbulent flows of gas and liquid in the gas-liquid bubbling fluidized bed are discrete uniform bubble flow, transitional flow and heterogeneous turbulent flow of bubbles with multiple size distributions, and the final purpose of optimization and control is to obtain small-size discrete uniform bubble flow. The occurrence of large-size bubbles in the system is a main factor for inducing coalescence, collision and rupture among the bubbles, and is harmful in that uneven turbulent flow of the bubbles and strong collision and fragmentation among the bubbles are caused, the size distribution of the bubbles is in a double-peak or multi-peak distribution, the uniform distribution state of the bubbles is destroyed, and the controllability of the turbulent flow of gas and liquid is very difficult.
The large number of jet holes of a straight tube gas flow distributor is unavoidable in manufacturing and design of the unbalanced character inlet jet. The flow of each jet hole depends on the local pressure driving force and the law of conservation of momentum, and the difficulty is how to select the momentum recovery coefficient, the jet aperture coefficient, the friction factor and the like. When the pressure drop of the air flow through the jet orifice is insufficient to support the liquid, the liquid is caused to flow back to clog or cover, interfering with the jet flow through the jet orifice, a phenomenon known as crying. At this time, it is necessary to cause the destruction of the balanced jet system to generate large-scale bubbles, and a large number of jet holes generate uneven bubble size. The research on how to destroy the bubble turbulence motion characteristics of the bubbling fluidized bed of the straight pipe jet distributor by the occurrence of large bubbles is still blank at present.
The main reasons for the generation of crying of bubbles are the non-uniformity of jet hole diameter processing and the irrational structure of jet hole arrangement topology, so that large-scale bubbles appear in jet holes with larger jet hole diameters, and destructive disturbance is applied to uniform gas-liquid flow. The average size and physical properties of the bubbles will have a large impact on the gas-liquid flow characteristics. Numerous experimental and numerical modeling studies have demonstrated that to accurately grasp the trend of the bubble size variation, it is necessary to consider the initial size distribution of the bubbles at or near the surface of the gas flow distributor. Most studies assume that straight tube jet orifice jet velocities are balanced and that the size of bubbles generated by each jet orifice is uniformly and evenly distributed. The creation of different bubble initial sizes can change the apparent density of the bubble-liquid, affecting the ability to transfer heat and mass. Since the generation of different initial sizes of bubbles is a phenomenon which cannot be eliminated, the bubble generation method has to be studied to grasp the rule of influence on turbulent flow and reduce the damage to the minimum.
The current research is very deficient in the knowledge of the nature of the turbulent flow of the complicated gas-liquid two phases no matter in experimental research and basic theory search, such as the interaction among bubbles, between bubbles and liquid, the criterion of how the gas-liquid two phases realize the conversion of turbulent flow state and the judgment of flow shape, the movement collision, coalescence and fragmentation of deformed bubbles, the anisotropic dispersion characteristic of bubbles and the like. Conclusions based on empirical and semi-empirical properties are severely lacking in guidance on theoretical and basic laws. Although a large number of bubble turbulence flow experiments and numerical simulation researches have been carried out, the results are greatly uncertain due to differences of experimental devices, preparation, running, operating conditions and experimental test means, and unified theoretical guidance rules and experimental experience association cannot be obtained.
To date, few studies have been made on straight-tube gas flow distributor bubble crying, and no studies have been made to quantify its flow characteristics and turbulence of its gas-liquid, lacking: (1) Experimental basic data of the relation between the occurrence and occurrence frequency of large-size crying bubbles and jet holes, detachment of the surface of a distributor, aggregation in the motion process, average distribution of bubbles caused by crushing, specific surface area and the like; (2) Under the operating conditions of different jet flow directions, liquid phase working media and volume flow rates, crying the movement characteristics of bubbles and the data of influences on a complex gas-liquid multiphase turbulence system.
Disclosure of Invention
Aiming at the defects of the prior art, the invention provides a measuring method for the influence of crying of jet bubbles on turbulent flow of a gas-liquid bubbling fluidized bed, which is based on the condition that jet holes of a straight pipe gas flow distributor are downward, different inlet volume flow rates and liquid phase working media are water or polyether and water mixtures, and the damage degree of the crying bubbles, the regulation strategy of unbalanced inlet jet flow and the inherent correlation characteristics of crying bubbles and turbulent flow of gas-liquid are revealed, so that the heat transfer and mass transfer performance of heterogeneous turbulent flow of gas-liquid is optimized.
The invention provides a method for measuring the influence of jet flow bubble crying on turbulent flow of a gas-liquid bubbling fluidized bed, which comprises the following steps:
step one, a crying jet hole is formed in the bottom of the tail end of a straight pipe airflow distributor; the lower half part of the straight pipe airflow distributor is also provided with a plurality of uniform bubble jet hole groups which are distributed at equal intervals, and each uniform bubble jet hole group consists of a plurality of uniform bubble jet holes which are distributed at equal intervals along the axial direction. Fixing the straight pipe airflow distributor at the bottom of the gas-liquid reactor, and making the crying jet hole direction vertically downward. Compressed air is selected as a bubble gas source, and the liquid phase working medium is water.
Step two, the inlet volume flow rate of the straight pipe airflow distributor is gradually changed from 2.5L/min to 4.5L/min; under the condition of each inlet volume flow rate of the straight pipe airflow distributor, compressed air flows through the mass flow controller and the straight pipe airflow distributor, an inlet jet flow is formed at each jet hole of the straight pipe airflow distributor and enters the gas-liquid reactor, a high-speed camera is adopted to capture images of bubble generation, coverage, attachment, detachment and upward movement tracks on the surface of the straight pipe airflow distributor, the diameter distribution of the bubble, the bubble generation frequency and the specific surface area of the bubble are calculated by adopting image analysis software based on the captured images, the liquid pressure at two different heights of the gas-liquid reactor is measured by using two pressure sensors, and the bubble porosity in the gas-liquid bubbling fluidized bed is calculated according to dynamic pressure gradients of height position differences; wherein the gas-liquid bubbling fluidized bed comprises a straight pipe gas flow distributor and a gas-liquid reactor.
Bubble porosity ε g The calculation formula is as follows:
wherein ρ is l Is the density of liquid ρ g G is gravity acceleration, p h Is the liquid pressure at the h position of the gas-liquid reactor.
The calculation formula of the specific surface area A of the bubble at the position with the height h of the gas-liquid reactor is as follows:
wherein V is l Is the volume of liquid in the gas-liquid reactor, V b Is the sum of the volumes of all bubbles, D is the average diameter of the bubbles, a 3 Is a coefficient, a 3 ＝2。
And step three, replacing the liquid phase working medium with a polyether-water mixture, and repeating the step two.
Preferably, the average diameter D of the bubbles is calculated as follows:
wherein N is the number of bubbles, d i For the diameter of the ith bubble, a 1 And a 2 All are coefficients, a 1 ＝3，a 2 ＝2。
Preferably, after executing the third step, the method further comprises the following steps: under the working conditions that the liquid phase working medium is a mixture of polyether and water and crying jet holes of the straight pipe air flow distributor are downward, the specific surface area A of the bubbles and the inlet volume flow rate q of the straight pipe air flow distributor v The relation fit of (c) is as follows:
wherein a is 4 、a 5 、a 6 And a 7 Are coefficients.
Preferably, the diameter of the straight tube airflow distributor is 2.54mm.
Preferably, the diameter of the uniform bubble jet holes is 1.2mm, the number of the uniform bubble jet hole groups is 5, each uniform bubble jet hole group consists of 20 uniform bubble jet holes which are distributed at equal intervals along the axial direction, and the distance between every two adjacent uniform bubble jet holes is 15mm.
Preferably, the crying jet holes have a diameter of 1.9mm.
Preferably, the high speed camera is positioned at a distance of 40.0cm from the straight tube air flow distributor.
Preferably, the inlet volume flow rate of the straight tube airflow distributor varies by a step size of 0.25L/min.
The invention has the beneficial effects that:
the invention adopts a high-speed camera to measure images of a bubble flowing process, adopts a micro-pressure sensor for measuring a non-contact flow field to measure liquid pressure at two different heights of a gas-liquid reactor, calculates the porosity of bubbles in the gas-liquid bubbling fluidized bed according to dynamic pressure gradients of height position differences, thereby obtaining a bubble turbulence flowing characteristic of complex size distribution influenced by crying bubbles under the condition of liquid phase working medium of water or polyether and water mixture, recognizing the harm of crying bubbles to small-size uniform bubble turbulence flowing, grasping the inherent characteristic, revealing the flowing characteristic of uniform flowing discrete small-size bubbles under different inlet volume flow rates, the flowing characteristic of crying bubbles inducing large-size bubbles, the flowing characteristic of crying bubbles inducing to generate micro-size bubbles and the flowing characteristic of crying bubbles inducing to influence the gas-liquid turbulence flowing characteristic, establishing a relation fitting strategy of the specific surface area of the bubbles and the inlet volume flow rate of a straight pipe airflow distributor, increasing the specific surface area of the bubbles to improve the total mass transfer capacity, and providing a basis for optimizing the performance of the reactor.
Drawings
FIG. 1 is a flow chart of the present invention;
FIG. 2 is a schematic illustration of the measurement process of the present invention;
FIG. 3 is a schematic view of a straight tube airflow distributor according to the present invention;
FIG. 4 is a schematic diagram of one of the flow patterns of the bubbles under the working conditions of the present invention that the inlet volume flow rate is 2.5L/min and the liquid phase working medium is water or a mixture of polyether and water.
FIG. 5 is a schematic diagram of probability distribution of bubble diameters under the working conditions that the inlet volume flow rate is 2.5L/min and the liquid phase working medium is water or a mixture of polyether and water.
FIG. 6 is a schematic diagram of average diameters of bubbles under the working conditions of the present invention that the inlet volume flow rate is 2.5L/min and the liquid phase working medium is water or a mixture of polyether and water.
FIG. 7 is a schematic diagram of average diameters of bubbles under the working condition that the inlet volume flow rate is 2.5L/min, 3.5L/min or 4.5L/min and the liquid phase working medium is water or a mixture of polyether and water.
FIG. 8 is a schematic diagram of the frequency of bubble generation under the working condition that the inlet volume flow rate is 2.5L/min, 3.5L/min or 4.5L/min and the liquid phase working medium is water or a mixture of polyether and water.
FIG. 9 is a schematic diagram showing the bubble porosity distribution under the working condition that the inlet volume flow rate is 2.5L/min, 3.5L/min or 4.5L/min and the liquid phase working medium is water or a mixture of polyether and water.
FIG. 10 is a schematic diagram of specific surface area of bubbles at a position 40.0cm from the height of a straight pipe gas flow distributor under the working condition that the inlet volume flow rate is 2.5L/min, 3.5L/min or 4.5L/min and the liquid phase working medium is water or a mixture of polyether and water.
FIG. 11 is a graph of the relationship between the specific surface area of bubbles and the inlet volume flow rate of a straight tube gas flow distributor fitted in an embodiment of the present invention.
Detailed Description
The technical scheme of the present invention will be further described with reference to the accompanying drawings and examples, but the present invention is not limited to these examples.
As shown in fig. 1, the method for measuring the influence of jet bubble crying on turbulent flow of a gas-liquid bubbling fluidized bed is specifically as follows:
step one, as shown in figures 2 and 3, a crying jet hole is formed in the bottom of the tail end of the straight pipe airflow distributor; the lower half part of the straight pipe airflow distributor is also provided with a plurality of uniform bubble jet hole groups which are distributed at equal intervals, and each uniform bubble jet hole group consists of a plurality of uniform bubble jet holes which are distributed at equal intervals along the axial direction. Fixing the straight pipe airflow distributor at the bottom of the gas-liquid reactor, and making the crying jet hole direction vertically downward. Compressed air is selected as a bubble gas source, and the liquid phase working medium is water.
And step two, changing the inlet volume flow rate of the straight pipe airflow distributor from 2.5L/min to 4.5L/min, wherein the changing step length is 0.25L/min. Under each inlet volume flow rate of the straight pipe airflow distributor, compressed air flows through the mass flow controller and the straight pipe airflow distributor, an inlet jet flow is formed at a jet hole of the straight pipe airflow distributor and enters the gas-liquid reactor, a high-speed camera arranged at a position 40.0cm away from the straight pipe airflow distributor is adopted to capture images of movement tracks generated, covered, attached, separated and upwards moved by bubbles on the surface of the straight pipe airflow distributor, image analysis software (such as ProAnalyst) is adopted to calculate the diameter distribution of the bubbles, the generation frequency of the bubbles and the specific surface area of the bubbles in the gas-liquid bubbling fluidized bed based on the captured images, two pressure sensors are adopted to measure the liquid pressure at two different heights of the gas-liquid reactor, and the bubble porosity in the gas-liquid bubbling fluidized bed is calculated according to the dynamic pressure gradient of the height position difference, so that the flow characteristics of uniformly flowing discrete small-size bubbles, the flow characteristics of crying bubbles inducing large-size bubbles, the flow characteristics of crying bubbles inducing small-size bubbles and the crying bubbles affecting the flow characteristics of the gas-liquid turbulence are analyzed; wherein the gas-liquid bubbling fluidized bed comprises a straight pipe gas flow distributor and a gas-liquid reactor. In the upward movement process of the scale coalescence and micro-size bubbles, the state of discrete uniform bubbles is destroyed, and strong collision and crushing among bubbles and non-uniform bubble turbulence state are presented; bubbles of various sizes undergo up-down back mixing and left-right swaying non-uniform flow structures; when bubbles with various sizes reach the surface of the gas-liquid, most bubbles are separated from the liquid phase and enter the air at the upper part of the gas-liquid reactor, so that the gas-liquid separation process is completed.
Bubble porosity ε g The calculation formula is as follows:
wherein ρ is l Is the density of liquid ρ g G is gravity acceleration, p h Is the liquid pressure at the h position of the gas-liquid reactor.
The calculation formula of the specific surface area A of the bubble at the position with the height h of the gas-liquid reactor is as follows:
wherein V is l Is the volume of liquid in the gas-liquid reactor, V b Is the sum of the volumes of all bubbles, D is the average diameter of the bubbles, a 3 Is a coefficient, a 3 ＝2。
And step three, replacing the liquid phase working medium with a polyether-water mixture, and repeating the step two.
Some parameters are listed in table 1 below:
TABLE 1
Preferably, the high-speed camera is a non-contact high-speed camera, and the non-contact high-speed camera is connected with a data acquisition and analysis system, as shown in fig. 2. The non-contact high-speed camera can be a high-speed camera of the American TSI company, and the data acquisition and analysis system can be a PIV system of the American TSI company.
Preferably, differential pressure sensors (comprising two pressure sensors at different height positions) are used to measure the liquid pressure at two different heights of the gas-liquid reactor, thereby establishing a bubble porosity distribution model.
Preferably, the straight pipe airflow distributor is made of stainless steel material; the experiment was performed at an ambient temperature of 10-20 c and 1 standard atmospheric pressure.
Preferably, the average diameter D of the bubbles is calculated as follows:
wherein N is the number of bubbles, d i For the diameter of the ith bubble, a 1 And a 2 All are coefficients, a 1 ＝3，a 2 ＝2。
Preferably, after executing the third step, the method further comprises the following steps: under the working conditions that the liquid phase working medium is a mixture of polyether and water and the jet hole of the straight pipe air flow distributor faces downwards, the specific surface area A of the bubble and the inlet volume flow rate q of the straight pipe air flow distributor v The relation fit of (c) is as follows:
wherein a is 4 、a 5 、a 6 And a 7 Are all coefficients, under the parameters of the above embodiments, the fitting curve is shown in figure 11, and a is obtained by fitting 4 ＝0.8815,a 5 ＝-0.6481，a 6 ＝0.1755，a 7 = -0.0134, fitting variance was 0.9967.
And under the working conditions that each jet hole of the straight pipe airflow distributor is downward, the inlet volume flow rate is 2.5L/min, and the liquid phase working medium is water or a mixture of polyether and water, crying bubbles and other uniform jet bubbles are displayed in the flow pattern images shown in (a) and (b) of fig. 4. Under the working condition, large-size bubbles on the surface and nearby areas of crying jet holes can be obviously observed, other jet holes obviously present small-size discrete uniform bubble flowing states, and the phenomena of coalescence, collision and crushing of the bubbles are not observed. The crying bubbles induce large-scale bubbles, the bubbles are gathered and broken, and obvious interaction exists between the bubbles. In addition, the liquid phase working medium of the polyether-water mixture is a better working condition of discrete uniform small bubble flow.
Under the working conditions that the jet hole of the straight pipe airflow distributor is downward, the inlet volume flow rate is 2.5L/min, and the liquid phase working medium is water or a mixture of polyether and water, the probability distribution of the bubble diameter is shown in figure 5, and the average bubble diameter is shown in figure 6. The bubble diameter is totally distributed between 2 and 5 mm; under the influence of crying bubbles, the liquid phase working medium is polyether and water which are compared with water mixture, and a large number of small-size uniform bubbles are generated; when the liquid phase working medium is a mixture of polyether and water, the average diameter of bubbles is 3.949mm, and when the liquid phase working medium is water, the average diameter of bubbles is 4.155mm.
The jet hole of the straight pipe airflow distributor is downward, the inlet volume flow rate is 2.5L/min, 3.5L/min or 4.5L/min, and the average diameter of bubbles is shown in figure 7 under the working condition that the liquid phase working medium is water or a mixture of polyether and water. It can be seen that with increasing inlet volume flow rate, the average diameter of the bubbles is also increasing, and with the same inlet volume flow rate, the liquid phase working medium is polyether and water, and the average diameter of the bubbles is smaller than that of water mixture. At an inlet volumetric flow rate of 2.5L/min, the average diameter of the bubbles is in the range of 3.5-4.5mm, and the diameters of the generated small-size uniform bubbles are smaller.
The jet hole of the straight pipe airflow distributor is downward, the inlet volume flow rate is 2.5L/min, 3.5L/min or 4.5L/min, the bubble occurrence frequency is shown as figure 8 under the working condition that the liquid phase working medium is water or polyether and water mixture, the bubble occurrence frequency is increased along with the increase of the inlet volume flow rate, the bubble occurrence frequency of the liquid phase working medium is obviously higher than that of the liquid phase working medium which is water, more small-size uniform bubbles are easy to generate, and the uniform flow performance is better.
The jet hole of the straight pipe airflow distributor is downward, the inlet volume flow rate is 2.5L/min, 3.5L/min or 4.5L/min, the bubble porosity distribution is shown in figure 9 under the working condition that the liquid phase working medium is water or a mixture of polyether and water, and the maximum bubble porosity occurs under the condition that the liquid phase working medium is a mixture of polyether and water and the maximum inlet volume flow rate, under the condition of the same inlet volume flow rate, the liquid phase working medium is water which is polyether and water mixture, the bubble porosity is larger, the bubble porosity is large, the number of small-size uniform bubbles in the gas-liquid system is increased, and the uniform flow performance is good.
The jet hole of the straight pipe air flow distributor is downward, the inlet volume flow rate is 2.5L/min, 3.5L/min or 4.5L/min, and the specific surface area of the air bubble at the position which is 40.0cm away from the height of the straight pipe air flow distributor is shown as figure 10 under the working condition that the liquid phase working medium is a polyether-water mixture, therefore, the specific surface area of the air bubble increases with the increase of the inlet volume flow rate, and the larger specific surface area of the air bubble means stronger mass transfer and heat transfer capability and higher energy exchange performance between the air and the liquid phase.
The invention can not avoid the damage and the reduction of the crying bubbles to a uniform flow system by unbalanced jet flow and crying bubbles of a straight pipe airflow distributor, but adopts a high-speed camera to measure images of the bubble flow process by arranging a crying jet hole at the tail end of the straight pipe airflow distributor, adopts a micro-pressure sensor for measuring a non-contact flow field to measure the liquid pressure at two different heights of the gas-liquid reactor, calculates the bubble porosity in a gas-liquid bubbling fluidized bed according to the dynamic pressure gradient of the height position difference, discloses that the adverse influence of the crying bubbles can be weakened by adding polyether bubble inhibitor when the polyether bubble is downwards injected, and discloses that the flow characteristics of the uniformly flowing discrete small-size bubbles, the flow characteristics of the crying bubbles inducing the large-size bubbles, the flow characteristics of the crying bubbles inducing the small-size bubbles and the crying bubbles affecting the flow characteristics of the gas-liquid turbulence, establishes the relation fitting strategy of the specific surface area of the bubbles and the inlet volume flow rate of the straight pipe airflow distributor, and improves the optimization strategy of the unbalanced inlet condition, increases the specific surface area to improve the total mass transfer capacity and the capacity of the reactor to the maximum extent.
Claims (8)
1. The method for measuring the influence of jet bubble crying on turbulent flow of a gas-liquid bubbling fluidized bed is characterized by comprising the following steps of: the method comprises the following steps:
step one, a crying jet hole is formed in the bottom of the tail end of a straight pipe airflow distributor; the lower half part of the straight pipe airflow distributor is also provided with a plurality of uniform bubble jet hole groups which are distributed at equal intervals, and each uniform bubble jet hole group consists of a plurality of uniform bubble jet holes which are distributed at equal intervals along the axial direction; fixing a straight pipe airflow distributor at the bottom of the gas-liquid reactor, and enabling the crying jet hole direction to be vertically downward; compressed air is selected as a bubble gas source, and the liquid phase working medium is water;
step two, the inlet volume flow rate of the straight pipe airflow distributor is gradually changed from 2.5L/min to 4.5L/min; under the condition of each inlet volume flow rate of the straight pipe airflow distributor, compressed air flows through the mass flow controller and the straight pipe airflow distributor, an inlet jet flow is formed at each jet hole of the straight pipe airflow distributor and enters the gas-liquid reactor, a high-speed camera is adopted to capture images of bubble generation, coverage, attachment, detachment and upward movement tracks on the surface of the straight pipe airflow distributor, the diameter distribution of the bubble, the bubble generation frequency and the specific surface area of the bubble are calculated by adopting image analysis software based on the captured images, the liquid pressure at two different heights of the gas-liquid reactor is measured by using two pressure sensors, and the bubble porosity in the gas-liquid bubbling fluidized bed is calculated according to the liquid pressure gradient at the gas-liquid reactor h; the gas-liquid bubbling fluidized bed comprises a straight pipe gas flow distributor and a gas-liquid reactor;
bubble porosity ε g The calculation formula is as follows:
wherein ρ is l Is the density of liquid ρ g G is gravity acceleration, p h The liquid pressure at the h position of the gas-liquid reactor;
the calculation formula of the specific surface area A of the bubble at the position with the height h of the gas-liquid reactor is as follows:
wherein V is l Is the volume of liquid in the gas-liquid reactor, V b Is the sum of the volumes of all bubbles, D is the average diameter of the bubbles, a 3 Is a coefficient, a 3 ＝2；
And step three, replacing the liquid phase working medium with a polyether-water mixture, and repeating the step two.
2. Method for measuring the effect of jet bubble crying on turbulent flow of a gas-liquid bubbling fluidized bed according to claim 1, characterized in that: the average diameter D of the bubbles was calculated as follows:
wherein N is the number of bubbles, d i For the diameter of the ith bubble, a 1 And a 2 All are coefficients, a 1 ＝3，a 2 ＝2。
3. Method for measuring the effect of jet bubble crying on turbulent flow of a gas-liquid bubbling fluidized bed according to claim 2, characterized in that: after the third step is executed, the method further comprises the following steps: under the working conditions that the liquid phase working medium is a mixture of polyether and water and crying jet holes of the straight pipe air flow distributor are downward, the specific surface area A of the bubbles and the inlet volume flow rate q of the straight pipe air flow distributor v The relation fit of (c) is as follows:
A＝a 4 +a 5 *q v +a 6 *q 2 v +a 7 *q 3 v
wherein a is 4 、a 5 、a 6 And a 7 Are coefficients.
4. A method of measuring the effect of jet bubble crying on turbulent flow of a gas-liquid bubbling fluidized bed according to claim 1, 2 or 3, characterized in that: the diameter of the straight pipe airflow distributor is 2.54mm.
5. A method of measuring the effect of jet bubble crying on turbulent flow of a gas-liquid bubbling fluidized bed according to claim 1, 2 or 3, characterized in that: the diameter of the uniform bubble jet holes is 1.2mm, the number of the uniform bubble jet hole groups is 5, each uniform bubble jet hole group consists of 20 uniform bubble jet holes which are distributed along the axial direction at equal intervals, and the distance between every two adjacent uniform bubble jet holes is 15mm.
6. A method of measuring the effect of jet bubble crying on turbulent flow of a gas-liquid bubbling fluidized bed according to claim 1, 2 or 3, characterized in that: the crying jet hole has a diameter of 1.9mm.
7. A method of measuring the effect of jet bubble crying on turbulent flow of a gas-liquid bubbling fluidized bed according to claim 1, 2 or 3, characterized in that: the high-speed camera is arranged at a position which is 40.0cm away from the straight pipe airflow distributor.
8. A method of measuring the effect of jet bubble crying on turbulent flow of a gas-liquid bubbling fluidized bed according to claim 1, 2 or 3, characterized in that: the inlet volume flow rate change step length of the straight pipe airflow distributor is 0.25L/min.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211110071.8A CN115406804B (en) | 2022-09-13 | 2022-09-13 | Method for measuring influence of jet bubble crying on turbulent flow of gas-liquid bubbling fluidized bed |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211110071.8A CN115406804B (en) | 2022-09-13 | 2022-09-13 | Method for measuring influence of jet bubble crying on turbulent flow of gas-liquid bubbling fluidized bed |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN115406804A CN115406804A (en) | 2022-11-29 |
| CN115406804B true CN115406804B (en) | 2023-05-12 |
Family
ID=84165818
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202211110071.8A Active CN115406804B (en) | 2022-09-13 | 2022-09-13 | Method for measuring influence of jet bubble crying on turbulent flow of gas-liquid bubbling fluidized bed |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115406804B (en) |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103861532A (en) * | 2014-03-03 | 2014-06-18 | 北京旭荣工程设计有限公司 | Homogeneous three-phase reactor for jet aeration |
| CN110781601A (en) * | 2019-11-01 | 2020-02-11 | 清华大学 | Numerical prediction method for size of bubbles in gas-liquid mixed delivery pump |
| CN114787749A (en) * | 2019-12-13 | 2022-07-22 | 麦格纳国际公司 | Multi-hole disperser assisted jet and spray impingement cooling system |
Family Cites Families (26)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH1143090A (en) * | 1997-05-30 | 1999-02-16 | Ishikawajima Harima Heavy Ind Co Ltd | Method of analyzing blowout bubble in vessel |
| US6322056B1 (en) * | 1999-09-28 | 2001-11-27 | Gerhardt Van Drie | Submarine type liquid mixer with aeration |
| CA2446889A1 (en) * | 2003-10-27 | 2005-04-27 | Robert J. Pinchuk | A method for converting a liquid feed material into a vapor phase product |
| RU2007132868A (en) * | 2005-02-01 | 2009-03-10 | Дзе Юниверсити Оф Ньюкасл Рисерч Ассошиэйтс Лимитед (Au) | METHOD AND APPARATUS FOR CONTACTING BUBBLES AND PARTICLES IN A FLOTATION SEPARATION SYSTEM |
| US20080193340A1 (en) * | 2007-02-09 | 2008-08-14 | Cocco Raymond A | Fluidized bed sparger |
| CN101226169B (en) * | 2007-10-16 | 2011-08-31 | 中国石油化工股份有限公司 | Method for testing fluid bed reactor distributing plate |
| AU2011200090B2 (en) * | 2008-06-12 | 2016-01-07 | Winwick Business Solutions Pty Ltd | System for cultivation and processing of microorganisms, processing of products therefrom, and processing in drillhole reactors |
| JP2010182287A (en) * | 2008-07-17 | 2010-08-19 | Steven C Kays | Intelligent adaptive design |
| US8765460B2 (en) * | 2009-12-14 | 2014-07-01 | Atle B. Nordvik | Photobioreactor system for mass production of microorganisms |
| CA2765283A1 (en) * | 2012-01-24 | 2013-07-24 | Enersul Inc. | Bubble degassing of liquid sulfur |
| CN202661389U (en) * | 2012-06-17 | 2013-01-09 | 郭敏强 | Optimal simulation research system for foam characteristics based on foam flooding in oilfield exploitation |
| US9448093B2 (en) * | 2012-08-15 | 2016-09-20 | Aspect Ai Ltd. | Measurement of properties of fluids using MRI |
| US11440815B2 (en) * | 2013-02-22 | 2022-09-13 | Anschutz Exploration Corporation | Method and system for removing hydrogen sulfide from sour oil and sour water |
| CN204320263U (en) * | 2014-12-05 | 2015-05-13 | 长岭炼化岳阳工程设计有限公司 | A kind of liquid-gas oxidation reactor |
| CN104624070A (en) * | 2015-01-29 | 2015-05-20 | 于小波 | Gas-liquid mixing system and gas-liquid mixing method |
| CN106237953B (en) * | 2016-09-10 | 2018-01-23 | 天津大学 | The small gas-liquid bubble column reactor of photocatalysis |
| RU169823U1 (en) * | 2016-09-12 | 2017-04-03 | Федеральное государственное бюджетное учреждение науки Институт прикладной механики Российской академии наук (ИПРИМ РАН) | Device for spraying and igniting liquid fuel |
| CN106732308A (en) * | 2017-01-13 | 2017-05-31 | 浙江大学 | A kind of micro- bubbling gas-liquid reactor |
| CN107032306B (en) * | 2017-06-15 | 2023-07-14 | 扬州惠通科技股份有限公司 | System and method for producing hydrogen peroxide by fluidized bed |
| CN108079708B (en) * | 2017-12-15 | 2019-11-05 | 中国石油大学(北京) | A kind of circulation scrubbing tower gas distributor and its design method |
| CN111007153B (en) * | 2018-10-08 | 2020-10-30 | 浙江大学 | Detection method for gas-liquid dispersion state of jet bubbling reactor |
| CN111359539B (en) * | 2020-02-17 | 2022-03-18 | 华东理工大学 | Gas-liquid reaction method and gas-liquid reaction device capable of entering reaction preparation state in advance |
| RU2736838C1 (en) * | 2020-04-24 | 2020-11-20 | Валентин Станиславович Сизиков | Method of processing granular materials in a vibro-bubbled layer and device for its implementation |
| CN113144929B (en) * | 2021-05-08 | 2022-09-16 | 中海石油(中国)有限公司 | Premixing homogeneous coupling type bubble generator |
| CN115046728B (en) * | 2022-05-12 | 2023-06-27 | 台州学院 | Device and method for measuring bubble coalescence and breaking event of straight pipe airflow distributor of gas-liquid biological bubbling fluidized bed |
| CN114950284B (en) * | 2022-05-19 | 2023-01-10 | 台州学院 | Gas jet flow optimization method for gas-liquid bubbling fluidized bed |
-
2022
- 2022-09-13 CN CN202211110071.8A patent/CN115406804B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103861532A (en) * | 2014-03-03 | 2014-06-18 | 北京旭荣工程设计有限公司 | Homogeneous three-phase reactor for jet aeration |
| CN110781601A (en) * | 2019-11-01 | 2020-02-11 | 清华大学 | Numerical prediction method for size of bubbles in gas-liquid mixed delivery pump |
| CN114787749A (en) * | 2019-12-13 | 2022-07-22 | 麦格纳国际公司 | Multi-hole disperser assisted jet and spray impingement cooling system |
Also Published As
| Publication number | Publication date |
|---|---|
| CN115406804A (en) | 2022-11-29 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Lin et al. | Quantitative analysis and computation of two‐dimensional bubble columns | |
| US10265671B2 (en) | Tapered fluidized bed reactor and process for its use | |
| Yadav et al. | Design aspects of ejectors: Effects of suction chamber geometry | |
| Fan et al. | Hydrodynamic characteristics of inverse fluidization in liquid—solid and gas—liquid—solid systems | |
| CN114950284B (en) | Gas jet flow optimization method for gas-liquid bubbling fluidized bed | |
| Fournol et al. | Solids entrainment in a large gas fluidized bed | |
| Rahman et al. | Enhancement of entrainment rates in liquid–gas ejectors | |
| Gao et al. | Dynamic behaviors of two droplets impacting an inclined superhydrophobic substrate | |
| CN115406804B (en) | Method for measuring influence of jet bubble crying on turbulent flow of gas-liquid bubbling fluidized bed | |
| Savari et al. | Detecting stability of conical spouted beds based on information entropy theory | |
| Southwell et al. | The effect of swirl on flow stability in spray dryers | |
| Shuai et al. | Classification and identification of gas–liquid dispersion states in a jet bubbling reactor | |
| CN101306285A (en) | Pulse blowing bag type dust precipitator and design method of its blowing tube | |
| Chen | Hydrodynamics, stability and scale-up of slot-rectangular spouted beds | |
| Hou et al. | Modelling of inclusion motion and flow patterns in swirling flow tundishes with symmetrical and asymmetrical structures | |
| CN115046728B (en) | Device and method for measuring bubble coalescence and breaking event of straight pipe airflow distributor of gas-liquid biological bubbling fluidized bed | |
| Agrawal | Performance of venturi scrubber | |
| Zhou et al. | Analysis of gas-solid flow characteristics in a spouted fluidized bed dryer by means of computational particle fluid dynamics | |
| Aminzadeh et al. | Numerical investigation on oscillation behavior of a non-isothermal self-excited jet in a cavity: the effects of Reynolds number and temperature differences | |
| Wang et al. | Turbulent fluidization and transition velocity of Geldart B granules in a spout–fluidized bed reactor | |
| Behie et al. | Heat transfer from a grid jet in a large fluidized bed | |
| Liu et al. | CPFD simulation of gas-solid flow in dense phase zone of pant-leg fluidized bed with secondary air | |
| Wang et al. | A new gas–liquid mass transfer enhancement method for a multi-downcomer sieve tray: Bubble breakup by falling droplets | |
| Sanchez-Forero et al. | Experimental and numerical investigation of gas-liquid flow in a rectangular bubble column with centralized aeration flow pattern | |
| Shen et al. | Study of a downward gas jet in a two–dimensional fluidized bed |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |