Device for preparing ice crystal particle group with controllable particle size distribution based on liquid nitrogen spray quick freezing

Abstract

The utility model provides a kind of controllable particle size distribution ice crystal particle group preparation device based on liquid nitrogen spray quick freezing, utilize the atomization characteristics of gas auxiliary atomization water nozzle and realize the control of the particle size distribution of ice crystal particle group to multilayer vibrating screen, realize the controllable, stable, sustained generation of particle group.The ice crystal particle group preparation device proposed by the utility model includes quick freezing chamber, liquid nitrogen source and high-pressure nitrogen source, the upper portion in quick freezing chamber is equipped with replaceable gas auxiliary atomization water nozzle, gas auxiliary atomization water nozzle is connected with high-pressure nitrogen source and water simultaneously by pipeline, high-pressure nitrogen and water are jointly transported to gas auxiliary atomization water nozzle, under the assistance of high-pressure nitrogen, gas auxiliary atomization water nozzle sprays atomized water, forms tiny water droplet particle group;Quick freezing chamber is also provided with liquid nitrogen atomization nozzle, liquid nitrogen atomization nozzle provides liquid nitrogen spray, and water droplet particle group is rapidly frozen to form ice crystal particle group.

Description

Technical Field

[0001] This utility model relates to a device for preparing ice crystal particle swarms with controllable particle size distribution based on liquid nitrogen spray quick-freezing. Background Technology

[0002] When aircraft pass through clouds containing ice crystals, their engine core components face a severe risk of ice crystal icing (ICI). Ice crystals can melt and refreeze in the high-temperature compressor region, causing airflow blockage, component damage, or even engine shutdown, posing a significant flight safety hazard. International aviation airworthiness standards (such as FAA 14CFR-33 Appendix D and EASA CS-25) explicitly require verification of engine ice crystal icing tolerance. However, the physical characteristics of real high-altitude ice crystal environments (such as particle phase, size distribution, concentration, and temperature) are complex and variable. Traditional icing wind tunnel testing methods based on supercooled water droplets are insufficient to accurately simulate ice crystal impact, accumulation, and their unique icing physical processes. There is an urgent need to develop technologies that can stably, controllably, and realistically reproduce specific ice crystal particle groups in a ground-based laboratory environment to meet the pressing needs of engine development, certification, and research into the fundamental mechanisms of icing.

[0003] Current ground-based simulation technologies for generating ice crystal particle swarms primarily rely on large-scale refrigerated wind tunnels or complex cutting and grinding systems. These technologies suffer from limitations such as bulky equipment, high energy consumption, difficulty in controlling ice crystal particle characteristics (e.g., size and shape), slow response speed, and difficulty in achieving sustained and stable generation. These limitations restrict their widespread application in full-scale engine bench tests and high-frequency icing mechanism research. In particular, existing technologies often fall short of requirements for applications demanding precise simulation of specific ice crystal particle shapes, size distributions, and rapid dynamic responses (e.g., whole-engine ice crystal ingestion tests, ice crystal impact characteristics studies in ice wind tunnels, and experiments on surface ice crystal adhesion and icing physical processes). Therefore, there is an urgent need for a compact, fast-responding, flexible, and easily deployable ground-based ice crystal particle swarm generation technology capable of directly generating controllable ice crystal particle swarms that meet experimental requirements. This would provide crucial ground-based experimental support for engine icing airworthiness certification, enhancing ice wind tunnel testing capabilities, and deepening the understanding of the physical mechanisms of ice crystal icing. Summary of the Invention

[0004] To address the problems existing in the background technology, this utility model proposes a device for preparing ice crystal particle clusters with controllable particle size distribution based on liquid nitrogen spray quick-freezing. This device utilizes a gas-assisted atomizing water nozzle to generate a cluster of water droplets with controllable particle size distribution, and then uses two liquid nitrogen sprays to quickly freeze the water droplet clusters, thereby generating ice crystal particle clusters. This device utilizes the atomization characteristics of the gas-assisted atomizing water nozzle and a multi-layer vibrating screen to control the particle size distribution of the ice crystal particle clusters, achieving controllable, stable, and continuous generation of the particle clusters.

[0005] The technical solution of this utility model to solve the above problems is:

[0006] This invention proposes a device for preparing ice crystal particle clusters with controllable particle size distribution based on liquid nitrogen spray freezing. Its unique feature is that it includes a freezing chamber, a liquid nitrogen source, and a high-pressure nitrogen source. The freezing chamber is an insulated cavity, and a replaceable gas-assisted atomizing water nozzle is installed in the upper part of the chamber. The gas-assisted atomizing water nozzle is simultaneously connected to the high-pressure nitrogen source and water through a pipeline. The high-pressure nitrogen and water are jointly delivered to the gas-assisted atomizing water nozzle. With the assistance of high-pressure nitrogen, the water sprayed from the gas-assisted atomizing water nozzle is atomized into a cluster of tiny water droplets. The freezing chamber also contains a liquid nitrogen atomizing nozzle connected to the liquid nitrogen source. The liquid nitrogen atomizing nozzle is used to provide liquid nitrogen spray to rapidly freeze the water droplet particle cluster, forming an ice crystal particle cluster.

[0007] Furthermore, the aforementioned gas-assisted atomizing water nozzle is equipped with a heating structure to increase the temperature of the gas-assisted atomizing water nozzle and prevent the gas-assisted atomizing water nozzle from freezing due to excessively low local temperatures.

[0008] Furthermore, the heating structure described above includes a heating wire and a wire. The heating wire is wound around the outer layer of the gas-assisted atomizing water nozzle, and the heating wire is connected to a power source via the wire.

[0009] Furthermore, the bottom of the aforementioned quick-freezing chamber is equipped with a valve, and below the valve is a multi-layer vibrating screen to screen ice crystal particles.

[0010] Furthermore, the lower part of the aforementioned multi-layer vibrating screen is provided with a collection chamber.

[0011] Furthermore, the aforementioned gas-assisted atomizing water nozzle is located at the center of the upper part of the quick-freezing chamber, with the nozzle pointing vertically downwards; the liquid nitrogen atomizing nozzle is set on the side wall of the quick-freezing chamber, with the nozzle pointing obliquely downwards.

[0012] Furthermore, the aforementioned liquid nitrogen atomizing nozzle is located below the gas-assisted atomizing water nozzle.

[0013] Furthermore, the number of the aforementioned liquid nitrogen atomizing nozzles is multiple, and the multiple liquid nitrogen atomizing nozzles are spaced apart on the side wall of the quick-freezing chamber.

[0014] Furthermore, the aforementioned gas-assisted atomizing water nozzle is connected to a high-pressure nitrogen source via a pipeline, and the pipeline is equipped with a gas supply valve.

[0015] Furthermore, the aforementioned ice crystal particle cluster preparation device also includes a water storage tank and a water pump. The gas-assisted atomizing water nozzle is connected to the water pump through a pipe, and the water pump is located inside the water storage tank.

[0016] In addition, this utility model also proposes a method for preparing ice crystal particle swarms, based on the above-mentioned controllable particle size distribution ice crystal particle swarm preparation device based on liquid nitrogen spray quick-freezing, including the following steps:

[0017] 1) Before starting the preparation, replace the corresponding gas-assisted atomizing water nozzles and multi-layer vibrating screens in advance according to the required ice crystal particle size and quantity;

[0018] 2) To prevent the gas-assisted atomizing water nozzle from freezing, first turn on the nozzle heating wire and adjust the heating voltage to make the nozzle temperature higher than the freezing point of water.

[0019] 3) Open the valves and use liquid nitrogen spray to pre-cool the quick-freezing chamber and the collection chamber;

[0020] 4) Once the pre-cooling temperature is reached, turn on the water pump and nitrogen supply valve. The gas-assisted atomizing water nozzle will start working, generating a group of water droplets. The water droplets will freeze rapidly under the action of liquid nitrogen spray and fall to the bottom of the quick-freezing chamber.

[0021] 5) Once a sufficient number of ice crystal particles have been generated, close the gas supply valve, liquid supply valve 16 and water pump, open the valves, and use a multi-layer vibrating screen to screen the ice crystal particles.

[0022] 6) Collect the ice crystal particle clusters and store them in the collection chamber for later use.

[0023] Advantages of this utility model:

[0024] 1. This invention can achieve the large-scale, rapid, continuous and stable generation of ice crystal particle groups. By using liquid nitrogen spray to quickly freeze water spray, a large number of ice crystal particles can be prepared in a short time.

[0025] 2. This invention achieves controllable generation of ice crystal particle size distribution through two-stage control. First-stage control is achieved by adjusting the model of the gas-assisted atomizing water nozzle, enabling control over a large particle size range. Second-stage control of particle size distribution is achieved using a multi-layer vibrating screen.

[0026] 3. This utility model has high stability under extreme low-temperature conditions. It uses a heating wire to heat the gas-assisted atomizing water nozzle to prevent the nozzle from freezing at low temperatures. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the structure of the controllable particle size distribution ice crystal particle group preparation device based on liquid nitrogen spray quick-freezing proposed in this utility model.

[0028] Among them, 1-quick-freezing chamber, 2-gas-assisted atomizing water nozzle, 3-liquid nitrogen atomizing nozzle, 4-heating wire, 5, 17-power supply, 6-valve, 7-multi-layer vibrating screen, 9-collection chamber, 11-gas supply valve, 12-water storage tank, 13-water pump, 14-liquid nitrogen tank, 15-nitrogen cylinder, 16-liquid supply valve. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this utility model, not all of them. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model. Therefore, the following detailed description of the embodiments of this utility model provided in the accompanying drawings is not intended to limit the scope of the claimed utility model, but merely to represent selected embodiments of this utility model.

[0030] See Figure 1 This invention proposes a device for preparing ice crystal particle clusters with controllable particle size distribution based on liquid nitrogen spray freezing. The device includes a freezing chamber 1, a liquid nitrogen source, and a high-pressure nitrogen source. The freezing chamber 1 is a double-layered vacuum insulated cavity. A replaceable gas-assisted atomizing water nozzle 2 is installed in the upper part of the freezing chamber 1. The gas-assisted atomizing water nozzle 2 is simultaneously connected to high-pressure nitrogen and water through a pipeline. Both high-pressure nitrogen and water are jointly delivered to the gas-assisted atomizing water nozzle 2. With the assistance of high-pressure nitrogen, the water sprayed from the gas-assisted atomizing water nozzle 2 is atomized into liquid water, forming a cluster of tiny water droplets. A liquid nitrogen atomizing nozzle 3 is also installed in the freezing chamber 1 to provide liquid nitrogen spray. Due to the liquid nitrogen spray, the freezing chamber 1 maintains a low-temperature environment, rapidly freezing the water droplet particle clusters to form ice crystal particle clusters and preventing the ice particles from sticking together due to melting. By changing the type of the gas-assisted atomizing water nozzle 2, a particle size distribution of 1 to 10 can be achieved. 2 The wide particle size distribution range of μm is controlled at the primary level. The gas-assisted atomizing water nozzle 2 is connected to a high-pressure nitrogen source via a pipeline, and a gas supply valve 11 is provided on the pipeline.

[0031] Specifically, see Figure 1 The liquid nitrogen source is a liquid nitrogen tank 14, the high-pressure nitrogen source is a nitrogen cylinder 15, and the liquid nitrogen atomizing nozzles consist of two pressure atomizing liquid nitrogen atomizing nozzles. The high-pressure liquid nitrogen tank and high-pressure nitrogen gas are used to deliver liquid nitrogen to the nozzles and atomize it. The liquid nitrogen atomizing nozzles are installed on the side wall of the cavity, forming a certain angle with the gas-assisted atomizing water nozzles, facilitating sufficient and efficient freezing of water droplets.

[0032] As a preferred embodiment of this utility model, see [link to relevant documentation]. Figure 1 The gas-assisted atomizing water nozzle is located in a low-temperature quick-freezing chamber. To prevent the nozzle from freezing, the gas-assisted atomizing water nozzle 2 is equipped with a heating structure. The heating structure increases the temperature of the gas-assisted atomizing water nozzle 2 and prevents the gas-assisted atomizing water nozzle 2 from freezing due to excessively low local temperature.

[0033] Specifically, the heating structure includes a heating wire 4, a wire, and a power supply. The heating wire 4 is wound around the outer layer of the gas-assisted atomizing water nozzle 2, and the heating wire 4 is connected to the power supply 5 through the wire, thereby appropriately increasing the temperature of the water spray. The power supply 5 is a DC power supply.

[0034] As a preferred embodiment of this utility model, see [link to relevant documentation]. Figure 1 The quick-freezing chamber 1 is equipped with a valve 6 at its bottom, and a multi-layer vibrating screen 7 is located below the valve 6 to screen ice crystal particles. By replacing the multi-layer vibrating screen, two-stage control of the ice crystal particle size can be achieved. A collection chamber 9 is located below the multi-layer vibrating screen 7. The collection chamber 9 is a heat-insulated chamber that allows for the collection and heat preservation of the generated ice crystal particles. The multi-layer vibrating screen 7 is powered by a power supply 17.

[0035] For example, by using a combination of 75-mesh and 150-mesh sieves, two-stage separation of ice crystal particle groups with a particle size distribution of 100-200μm can be achieved.

[0036] As a preferred embodiment of this utility model, see [link to relevant documentation]. Figure 1 The gas-assisted atomizing water nozzle 2 is located at the center of the upper part of the quick-freezing chamber 1, with the nozzle pointing vertically downwards. The liquid nitrogen atomizing nozzle 3 is disposed on the side wall of the quick-freezing chamber 1, with the nozzle pointing obliquely downwards. The liquid nitrogen atomizing nozzle 3 is located below the gas-assisted atomizing water nozzle 2, and there are multiple liquid nitrogen atomizing nozzles 3, spaced apart on the side wall of the quick-freezing chamber 1. The liquid nitrogen atomizing nozzles are installed on the side wall of the chamber, forming a certain angle with the gas-assisted atomizing water nozzle, to facilitate sufficient and efficient freezing of water droplets.

[0037] As a preferred embodiment of this utility model, see [link to relevant documentation]. Figure 1 The controllable particle size distribution ice crystal particle group preparation device based on liquid nitrogen spray quick-freezing also includes a water storage tank 12 and a water pump 13. The gas-assisted atomizing water nozzle 2 is connected to a high-pressure nitrogen source through a pipeline. The pipeline is equipped with a gas supply valve 11. The gas-assisted atomizing water nozzle 2 is connected to the water pump 13 through a pipeline. The water pump 13 is located inside the water storage tank 12. The pipeline is also connected to a liquid supply valve 16.

[0038] This invention also proposes a method for preparing ice crystal particle swarms, based on the above-mentioned controllable particle size distribution ice crystal particle swarm preparation device based on liquid nitrogen spray quick-freezing, mainly including the following steps:

[0039] 1) Before starting the preparation, replace the corresponding gas-assisted atomizing water nozzle 2 and multi-layer vibrating screen 7 in advance according to the ice crystal particle size and quantity requirements;

[0040] 2) To prevent the gas-assisted atomizing water nozzle 2 from freezing, first turn on the nozzle heating wire 4 and adjust the heating voltage to make the nozzle temperature higher than the freezing point of water (0℃).

[0041] 3) Open valve 6 and use liquid nitrogen spray to pre-cool the quick-freezing chamber 1 and the collection chamber 9;

[0042] 4) Once the pre-cooling temperature is reached, turn on the water pump 13 and the nitrogen supply valve 11. The gas-assisted atomizing water nozzle 2 starts working, generating a group of water droplets. The water droplets freeze rapidly under the action of liquid nitrogen spray and fall to the bottom of the quick-freezing chamber 1.

[0043] 5) Once a sufficient number of ice crystal particles have been generated, close the gas supply valve 11, the liquid supply valve 16, and the water pump 13;

[0044] 6) Collect the ice crystal particle clusters and store them in collection chamber 9 for later use.

[0045] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model. Those skilled in the art can still adjust the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Therefore, if these modifications and variations of the present utility model fall within the scope of the claims of the present utility model and their equivalents, the present utility model also intends to include these modifications and variations.

Claims

1. A device for preparing ice crystal particle swarms with controllable particle size distribution based on liquid nitrogen spray freezing, characterized in that: Includes a quick-freezing chamber (1), a liquid nitrogen source, and a high-pressure nitrogen source; The quick-freezing chamber (1) is an insulated cavity. The upper part of the quick-freezing chamber (1) is equipped with a replaceable gas-assisted atomizing water nozzle (2). The gas-assisted atomizing water nozzle (2) is connected to a high-pressure nitrogen source and water through a pipeline. The high-pressure nitrogen and water are transported to the gas-assisted atomizing water nozzle (2). With the assistance of high-pressure nitrogen, the water sprayed by the gas-assisted atomizing water nozzle (2) is atomized into liquid water to form a group of tiny water droplets. The quick-freezing chamber (1) is also equipped with a liquid nitrogen atomizing nozzle (3), and a high-pressure nitrogen source is connected to the liquid nitrogen atomizing nozzle (3); The liquid nitrogen atomizing nozzle (3) is used to provide liquid nitrogen spray to rapidly freeze the water droplet particle group to form an ice crystal particle group.

2. The apparatus for preparing ice crystal swarms with controllable particle size distribution based on liquid nitrogen spray freezing according to claim 1, characterized in that: The gas-assisted atomizing water nozzle (2) is provided with a heating structure to increase the temperature of the gas-assisted atomizing water nozzle (2) and prevent the gas-assisted atomizing water nozzle (2) from freezing due to local low temperature.

3. The apparatus for preparing ice crystal swarms with controllable particle size distribution based on liquid nitrogen spray freezing according to claim 2, characterized in that: The heating structure includes a heating wire (4) and a wire. The heating wire (4) is wound around the outer layer of the gas-assisted atomizing water nozzle (2). The heating wire (4) is connected to a power source (5) through the wire.

4. The apparatus for preparing ice crystal swarms with controllable particle size distribution based on liquid nitrogen spray freezing according to any one of claims 1-3, characterized in that: The quick-freezing chamber (1) is equipped with a valve (6) at the bottom, and a multi-layer vibrating screen (7) is provided below the valve (6) to screen ice crystal particles.

5. The apparatus for preparing ice crystal swarms with controllable particle size distribution based on liquid nitrogen spray freezing according to claim 4, characterized in that: The multi-layer vibrating screen (7) is provided with a collection chamber (9) at the bottom.

6. The apparatus for preparing ice crystal swarms with controllable particle size distribution based on liquid nitrogen spray freezing according to any one of claims 1-3, characterized in that: The gas-assisted atomizing water nozzle (2) is located at the center of the upper part of the quick-freezing chamber (1), with the nozzle pointing vertically downwards; the liquid nitrogen atomizing nozzle (3) is set on the side wall of the quick-freezing chamber (1), with the nozzle pointing obliquely downwards.

7. The apparatus for preparing ice crystal swarms with controllable particle size distribution based on liquid nitrogen spray freezing according to claim 6, characterized in that: The liquid nitrogen atomizing nozzle (3) is located below the gas-assisted atomizing water nozzle (2).

8. The apparatus for preparing ice crystal swarms with controllable particle size distribution based on liquid nitrogen spray freezing according to claim 7, characterized in that: The number of liquid nitrogen atomizing nozzles (3) is multiple, and the multiple liquid nitrogen atomizing nozzles (3) are spaced apart on the side wall of the quick-freezing chamber (1).

9. The apparatus for preparing ice crystal swarms with controllable particle size distribution based on liquid nitrogen spray freezing according to claim 8, characterized in that: The gas-assisted atomizing water nozzle (2) is connected to a high-pressure nitrogen source via a gas supply valve (11).

10. The apparatus for preparing ice crystal swarms with controllable particle size distribution based on liquid nitrogen spray freezing according to claim 9, characterized in that: It also includes a water storage tank (12) and a water pump (13). The gas-assisted atomizing water nozzle (2) is connected to the water pump (13) through a pipe. The water pump (13) is located inside the water storage tank (12).

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