Atomization effect test and characterization method of dual-channel airflow type nozzle

Abstract

The invention belongs to the technical field of atomization test devices, and relates to an atomization effect test and characterization method of a dual-channel airflow type nozzle. The testing system comprises a liquid conveying unit, a gas conveying unit, a double-channel airflow type nozzle device and a spraying pool. During an atomization test, a gas-phase medium is firstly conveyed by an air compressor, passes through a mass flow meter and then enters a gas inlet pipe of a nozzle through a surge tank; and the liquid-phase medium stored in the water storage tank is conveyed to the nozzle liquid inlet pipe by the water pump. And the two-phase medium converges at the outlet of the nozzle to form an atomization process. An atomized liquid drop counting chamber is arranged in the spraying pool and is used for evaluating SMD (Surface Mount Deposition) conditions of liquid drops outside an atomization field; a liquid drop collecting test tube is arranged under an outlet of the nozzle, and meanwhile, the atomization taper angle condition can be measured and calculated by utilizing an atomization field picture shot by a high-speed camera. Parameters required by the test can be rapidly adjusted by adjusting the flow of the conveying pump and the gas pressure stabilizing time, the test parameter debugging time is shortened, and rapid and stable test conditions are established.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of atomization test device, and relates to a method for testing and characterizing atomization effect of a double-channel airflow type nozzle. BACKGROUND

[0002] The airflow type nozzle is one of main components of a uranium nitrate flow fluidization denitration device, and whether the nozzle works normally directly affects the size and distribution of UO3 product particle size, and further affects product yield. The nozzle is usually composed of a liquid phase central channel, a gas phase channel, a threaded nozzle and a connecting flange. After daily maintenance and fault repair of the nozzle are completed, the nozzle needs to be subjected to atomization test to ensure that the nozzle meets the reliability of functions and performance. At present, the atomization test equipment for such double-channel airflow type nozzles still has the following problems: low test efficiency, insufficient special requirements and subjective effect evaluation. Therefore, it is necessary to design and build a special atomization test device for double-channel airflow type nozzles and a device for measuring atomization effect characterization factors. SUMMARY

[0003] The application aims to design a method for testing and characterizing atomization effect of a double-channel airflow type nozzle, and measure the advantages and disadvantages of the atomization effect by statistically analyzing the measured test data, so as to improve the efficiency and quality of the atomization test of such nozzles.

[0004] The technical solution for achieving the purpose of the application is as follows:

[0005] The application provides a system for testing atomization effect of a double-channel airflow type nozzle, which comprises a liquid delivery unit, a gas delivery unit, a double-channel airflow type nozzle device and a spray pool.

[0006] The liquid delivery unit comprises a water storage pool, a first one-way valve water pump, a float flowmeter and a second one-way valve which are sequentially connected through a high-pressure pipeline.

[0007] The gas delivery unit comprises an air compressor, a mass flow control meter, a pressure stabilizing tank with a pressure gauge and a third one-way valve which are sequentially connected through a high-pressure pipeline.

[0008] The double-channel airflow type nozzle device comprises a liquid inlet pipe, a gas inlet pipe, a nozzle inner pipe, a nozzle outer pipe and a connecting flange. The liquid inlet pipe is connected to the liquid delivery unit, and the gas inlet pipe is connected to the gas delivery unit. Liquid phase medium passes through the liquid inlet pipe, reaches the nozzle device outlet through the nozzle inner pipe, and is combined with high-speed airflow from the gas inlet pipe through the nozzle outer pipe to form a spray.

[0009] The spray pool is provided with a target plate, a counting pool, a droplet receiving test tube below the nozzle and a baffle thereof.

[0010] Optionally, the counting pool is hung on the target plate of the spray pool, and the center of the counting pool naturally falls horizontally with the outlet of the double-channel airflow type nozzle device.

[0011] Optionally, further comprising:

[0012] Image acquisition unit: high-speed camera located outside the spray pool.

[0013] A method for testing and characterizing the atomization effect of a double-channel airflow nozzle, comprising the following steps:

[0014] Step one: open the first one-way valve and close the second and third one-way valves, start the air compressor, and use the mass flow controller to pressurize the pressure tank;

[0015] Step two: start the water pump, draw the test liquid medium from the water tank through the first one-way valve; when the pressure gauge connected to the pressure tank reaches the specified value, open the third one-way valve to allow gas to pass through the nozzle inlet pipe, the nozzle outer pipe, and the nozzle device outlet;

[0016] Step three: open the second one-way valve to allow the liquid medium to pass through the nozzle inlet pipe, the nozzle inner pipe, and the nozzle device outlet to join the high-speed airflow, forming a spray flow that hits the fixed target plate in the spray pool and eventually falls into the spray pool through the bottom return port and flows into the water tank;

[0017] Step four: place the droplet receiving test tube directly below the nozzle device outlet and block it with a baffle; when the atomization process stabilizes, quickly remove the baffle and start timing; perform radial droplet reception and place the baffle back after a certain time; set up a camera position outside the spray pool at the same height as the spray device, and mount a high-speed camera; continuously take photos of the atomization field when the atomization process stabilizes; combine the droplet receiving test tube and the high-speed camera photos to collect and count the atomization cone angle;

[0018] Step five: hang a counting pool on the target plate, and the center of the counting pool when it naturally falls is concentric with the center of the nozzle device outlet. Before the atomization process starts, block the counting pool opening with a baffle and pull it away from the atomization field; remove the baffle and allow it to swing freely along a fixed radius once the atomization process is stable; this process is used to collect the SMD atomization effect characterization factor.

[0019] Optionally, the SMD measurement characterization method in step five includes:

[0020] Count the droplet samples captured by the swinging counting pool and calculate SMD according to the formula:

[0021]

[0022] where D i is the droplet diameter (m), and N i is the number of corresponding droplets.

[0023] Optionally, the characterization method of the radial droplet receiving in step four comprises:

[0024] The radial flow flux L is calculated by the formula: r (L / h):

[0025]

[0026] Wherein ρ is the density of the liquid (kg / m 3 ), m is the weight of the liquid in the droplet receiving device (kg); t is the liquid receiving time (s).

[0027] The beneficial technical effects of the present application are:

[0028] The atomization effect test and characterization method of the double-channel airflow nozzle of the present application can quickly adjust the required parameters of the test by adjusting the flow rate of the delivery pump and the gas pressure stabilization time, shorten the test parameter debugging time, and realize the establishment of stable test conditions. At the same time, the device is specially used for carrying out tests on double-channel airflow atomizing nozzles, and has high matching degree for nuclear chemical plant applications. In addition, a multi-dimensional atomization result characterization method is adopted, combined with high-speed imaging, particle size analysis and statistical methods, the atomization effect is converted into quantifiable indexes, avoiding the subjectivity of traditional visual evaluation. BRIEF DESCRIPTION OF DRAWINGS

[0029] Fig. 1 It is a structural schematic diagram of a double-channel airflow nozzle atomization effect test system;

[0030] Fig. 2 It is a double-channel airflow nozzle device structure diagram of a double-channel airflow nozzle atomization effect test system;

[0031] Fig. 3 It is a structure layout diagram of an atomization pool of a double-channel airflow nozzle atomization effect test system.

[0032] In the figure:

[0033] 1 - water storage tank; 2 - first check valve; 3 - water pump; 4 - float flowmeter; 5 - second check valve; 6 - air compressor; 7 - mass flow controller; 8 - pressure stabilizing tank; 9 - third check valve; 10 - nozzle device; 11 - spray pool; 12 - liquid inlet pipe; 13 - gas inlet pipe; 14 - nozzle outer pipe; 15 - nozzle inner pipe; 16 - connecting flange; 17 - nozzle support; 18 - droplet receiving test tube; 19 - target plate; 20 - counting pool. DETAILED DESCRIPTION

[0034] In order for those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the following described embodiments are only a part of the embodiments of the present application, not all. Based on the embodiments described in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0035] Referring to Figs. 1-3 The figure is a schematic diagram of the structure of each part of a spray effect test system of a double-channel airflow nozzle provided by the embodiments of the present application.

[0036] A spray effect test system of a double-channel airflow nozzle comprises a liquid delivery unit, a gas delivery unit, a double-channel airflow nozzle device 10, and a spray pool 11.

[0037] The liquid delivery unit comprises a water storage pool 1, a first one-way valve 2, a water pump 3, a float flowmeter 4, and a second one-way valve 5, which are sequentially connected through a high-pressure pipeline.

[0038] The gas delivery unit comprises an air compressor 6, a mass flow controller 7, a pressure stabilizing tank 8 with a pressure gauge, and a third one-way valve 9, which are sequentially connected through a high-pressure pipeline.

[0039] The double-channel airflow nozzle device 10 comprises a liquid inlet pipe 12, an air inlet pipe 13, a nozzle inner pipe 15, a nozzle outer pipe 14, and a connecting flange 16. The liquid inlet pipe 12 is connected to the liquid delivery unit, and the air inlet pipe 13 is connected to the gas delivery unit. Liquid-phase medium passes through the liquid inlet pipe 12, reaches the nozzle device outlet through the nozzle inner pipe 15, and converges with high-speed airflow from the air inlet pipe 13 through the nozzle outer pipe 14 to form a spray.

[0040] The spray pool 11 is provided with a target plate 19, a counting pool 20, a droplet receiving test tube 18 directly below the nozzle, and a baffle plate. The counting pool 20 is hung on the target plate 19 of the spray pool 11, and the center of the counting pool 20 naturally falls horizontally with the outlet of the double-channel airflow nozzle device 10. A high-speed camera is provided on the outside of the spray pool 11.

[0041] A spray effect test and characterization method of a double-channel airflow nozzle comprises the following steps:

[0042] The test conditions of the present embodiment are as follows: water flow rate 48 L / min, atomization gas flow rate 240 L / min, and pressure 0.3 MPa.

[0043] Step one: Before starting the test, open the first one-way valve 2, and close the second one-way valve 5 and the third one-way valve 9. Turn on the air compressor 6 to make the air pressure pass through the mass flow controller 7 and enter the pressure stabilizing tank 8 to increase the pressure.

[0044] Step two: start the water pump 3 to draw the test liquid water from the water storage tank 1 through the first one-way valve 2; when the pressure gauge connected to the steady pressure tube 8 reaches the limit, open the third one-way valve 9 to make the gas pass through the air inlet pipe 13 of the nozzle device 10, reach the nozzle device 10 outlet through the nozzle outer pipe 14, and reach the nozzle device 10 outlet;

[0045] Step three: open the second one-way valve 5 to make the liquid water pass through the liquid inlet pipe 12 of the nozzle device 10, reach the nozzle device 10 outlet through the nozzle inner pipe 15, and reach the nozzle device 10 outlet to combine with the high-speed gas flow. The formed spray flow is arranged on the fixed target plate 19 on the spray tank 11, and finally scatters in the spray tank 11 and flows into the water storage tank through the bottom return port;

[0046] Step four: the liquid droplet receiving test tube 18 prevents the nozzle device 10 outlet directly below, and is shielded by a baffle. When the atomization process tends to be stable, the baffle is quickly removed and timing is carried out. After the liquid receiving 10s, the baffle is put back. The water amount of the liquid receiving 10s is 6ml. According to the atomization radial flow flux Lr calculation formula in the application, the atomization radial flow flux Lr of this spray test is:

[0047]

[0048] A camera position is arranged outside the spray tank and parallel to the nozzle device 10, and a camera is carried. After the atomization process tends to be stable, the atomization field photos are continuously taken.

[0049] Equivalent processing is carried out, and the atomization effect representation factor of the application, the atomization cone angle, is about 16°.

[0050] Step five: a liquid droplet counting culture dish with a diameter of 90mm is hung on the target plate 19. The center of the culture dish naturally falls in the same center as the circle at the nozzle device 10 outlet. Before the atomization process starts, the culture dish is shielded by a baffle and is lifted to a position far away from the atomization field. After the atomization process is stable, the baffle is removed and is swung freely along the fixed radius once. The result can be used to collect the atomization effect representation factor, SMD (Sauter Mean Diameter).

[0051] Taking the counting result within a radius of 10mm from the center of the counting tank 20 as an example, the test data is counted. According to the statistics, the SMD of the atomization particles within the circle with a radius of 10mm at the center of the counting tank is calculated as follows:

[0052]

[0053] Wherein D i is the droplet diameter (mm), and N i is the corresponding droplet number.

[0054] The application has been described in detail with reference to the accompanying drawings and embodiments, but the application is not limited to the above-mentioned embodiments, and various changes can be made within the knowledge of those skilled in the art without departing from the purpose of the application. The contents not described in detail in the application can adopt the prior art.

Claims

1. A system for testing the atomization effect of a dual-channel airflow nozzle, characterized in that, It comprises liquid delivery unit, gas delivery unit, double-channel gas flow nozzle device (10), spray pool (11); Liquid delivery unit: water storage tank (1), first one-way valve (2), water pump (3), float flow meter (4) and second one-way valve (5) are sequentially connected through high-pressure pipeline; Gas delivery unit: air compressor (6), mass flow controller (7), pressure tank (8) with pressure gauge and third one-way valve (9) are sequentially connected through high-pressure pipeline; Double-channel gas flow nozzle device (10) comprises liquid inlet pipe (12), gas inlet pipe (13), nozzle inner pipe (15), nozzle outer pipe (14) and connecting flange (16); liquid inlet pipe (12) is connected with liquid delivery unit, gas inlet pipe (13) is connected with gas delivery unit; liquid medium passes through liquid inlet pipe (12) and reaches nozzle device outlet through nozzle inner pipe (15) and enters from gas inlet pipe (13), and high-speed gas flow passing through nozzle outer pipe (14) is combined to form spray; Spray pool (11) is provided with target plate (19), counting pool (20), droplet receiving test tube (18) directly below nozzle and its baffle.

2. The system for testing the atomization effect of a dual-channel airflow nozzle according to claim 1, wherein The counting pool (20) is hung on the target plate (19) of the spray pool (11), and the center of the counting pool (20) is horizontally aligned with the outlet of the double-channel gas flow nozzle device (10) when the counting pool (20) naturally falls.

3. The system for testing the atomization effect of a dual-channel airflow nozzle according to claim 1, wherein It further comprises: Image acquisition unit: high-speed camera located outside the spray pool (11).

4. A method for testing and characterizing the atomization effect of a dual- channel air-blast nozzle, characterized in that, It comprises the following steps: Step one: open the first one-way valve (2) and close the second one-way valve (5) and the third one-way valve (9), start the air compressor (6), and increase the pressure in the pressure tank (8) through the mass flow controller (7); Step two: start the water pump (3), and draw the liquid medium for test from the water storage tank (1) through the first one-way valve (2); when the pressure gauge connected to the pressure tank (8) reaches a limited value, open the third one-way valve (9) to make the gas pass through the gas inlet pipe (13) of the nozzle device (10) and reach the nozzle device outlet through the nozzle outer pipe (14); Step three: open the second one-way valve (5) to make the liquid medium pass through the liquid inlet pipe (12) of the nozzle device (10) and reach the nozzle device outlet through the nozzle inner pipe (15) to combine with the high-speed gas flow, and the formed spray flow is sprayed on the fixed target plate (19) of the spray pool (11) and finally scattered in the spray pool (11) and flows into the water storage tank (1) through the bottom backflow port; Step four: the droplet receiving test tube (18) is placed directly below the outlet of the nozzle device (10) and shielded by the baffle, and when the atomization process tends to be stable, the baffle is quickly removed and timed, radial droplet receiving is performed, and the baffle is put back after the liquid is received for a certain time; a camera site is arranged outside the spray pool (11) at the same height as the spray device (10), a high-speed camera is carried, and photos of the atomization field are continuously taken after the atomization process tends to be stable; the droplet receiving test tube (18) and the high-speed camera photos are combined to collect and count the atomization cone angle representing the atomization effect factor; Step five: The counting pool (20) is hung on the target plate (19) and the center of the circle when the counting pool (20) naturally falls is concentric with the center of the circle at the outlet of the nozzle device (10). Before the atomization process starts, the opening of the counting pool (20) is shielded by a baffle and is lifted to a position far away from the atomization field. After the atomization process is stable, the baffle is removed and is allowed to swing freely along a fixed radius once. This process is used to collect the atomization effect characterization factor SMD.

5. The method of claim 4, wherein the method is characterized in that, The characterization method of SMD measurement in step five includes: The droplet sample captured by the swinging of the statistical counting pool (20) is counted, and SMD is calculated according to the formula: Where D i Where N is the droplet diameter (m). i This corresponds to the number of droplets.

6. The method of claim 4, wherein the method is characterized in that, The characterization method of radial droplet receiving in step four includes: The radial flow rate L is calculated by the formula in connection with the liquid mass m collected by the droplet receiving test tube (18) and the receiving liquid time t r (L / h): where p is the density of the liquid (kg / m 3 ), m is the weight of the liquid in the droplet receiving device (kg); and t is the receiving time (s).

Images