Spraying impurity removal device

Abstract

The utility model relates to a spraying impurity removal device which comprises a liquid storage tank, a circulating pump, a shunting pipeline system, a combination of three nozzles and a U-shaped backflow separation pipe, and the three nozzles comprise the first nozzle, the second Venturi ultrasonic atomization nozzle and the third nozzle. The shunting pipeline system comprises a main pipeline and three branch pipelines, namely a first branch pipeline, a second branch pipeline and a third branch pipeline, a liquid outlet is formed in the bottom of the liquid storage tank, and the three nozzles are arranged above the top of the liquid storage tank side by side; a main pipeline of the shunting pipeline system is connected with a circulating pump from a liquid outlet to reach the top of the liquid storage tank and then is shunted into three branch pipelines, and a first branch pipeline, a second branch pipeline and a third branch pipeline are respectively connected with liquid inlets of the first nozzle, the second Venturi ultrasonic atomizing nozzle and the third nozzle; a hot gas inlet is formed in the side wall of the liquid storage tank, the U-shaped backflow separation pipe is arranged at the bottom of the liquid storage tank, and the inlet of the U-shaped backflow separation pipe is located above the liquid level in the liquid storage tank and faces the liquid level downwards.

Description

Technical Field

[0001] The utility model relates to a spray impurity removal device. Background Art

[0002] Alkoxylated fatty alcohols, in particular ethoxylated fatty alcohols, propoxylated fatty alcohols and ethoxylated-propoxylated fatty alcohols, such as C9 isomeric alcohol alkoxylates, C 12-14 Fatty alcohol alkoxylates, C 13 Isomeric alcohol alkoxylates, as nonionic surfactants, play an important role in a variety of industrial and everyday applications. These compounds exhibit excellent wettability, emulsification, and dispersibility, making them widely used in detergents, personal care products, and agricultural chemicals. Ethoxylated fatty alcohols, due to their excellent biocompatibility and low irritation properties, are commonly used in cosmetics and skincare products, effectively improving product feel and skin compatibility. Propoxylated fatty alcohols, on the other hand, offer improved temperature stability and foaming properties, making them suitable for cleaning applications in high-temperature environments. By adjusting the degree of alkoxylation, the performance of these nonionic surfactants can be optimized to meet the needs of diverse applications. Due to their superior performance and environmentally friendly properties, alkoxylated fatty alcohols will continue to occupy a significant position in the surfactant market in the future.

[0003] Alkoxylated fatty alcohols can be efficiently prepared by reacting fatty alcohols with ethylene oxide (EO) or propylene oxide (PO). This process, typically carried out with a catalyst at appropriate temperature and pressure, begins by combining fatty alcohols with ethylene oxide or propylene oxide to form nonionic surfactants with varying degrees of alkoxylation. The introduction of ethylene oxide and propylene oxide significantly improves the water solubility, wettability, and emulsification properties of fatty alcohols, enabling their wider application in industry and everyday life. By controlling the reaction conditions and the order in which the epoxides are added, the structure and properties of the final product can be tuned. For example, the addition of ethylene oxide can achieve higher hydrophilicity, while propylene oxide can increase the product's hydrophobicity. The resulting alkoxylated fatty alcohols are widely used in detergents, personal care products, and agricultural formulations. During the preparation of alkoxylated fatty alcohols using ethylene oxide (EO) and propylene oxide (PO), 1,4-dioxane may be produced as a byproduct. This is because under the reaction conditions, ethylene oxide and propylene oxide can undergo epoxide ring-opening reactions, especially in the presence of moisture or other catalysts. Epoxides may react with fatty alcohols to form 1,4-dioxane. 1,4-Dioxane is a cyclic compound containing two oxygen atoms and is generally considered a by-product, the formation of which affects the purity and performance of the final product.

[0004] Traditionally, 1,4-dioxane removal has been done using nitrogen bubbling or superheated steam. This involves continuously introducing large amounts of high-purity nitrogen or superheated steam into the liquid product, increasing the contact area between the gas and liquid phases through bubbling. This allows the 1,4-dioxane dissolved in the liquid phase to be transferred from the liquid product to the gas phase through stripping, where it is then discharged from the system with the tail gas. However, this method has low removal efficiency, requiring extended bubbling times to achieve ppm-level removal, resulting in increased energy consumption and waste of resources such as gas auxiliary materials.

[0005] like Figure 4 As shown, conventionally, impurities in the liquid phase are removed by injecting N2 into the liquid product, or by introducing superheated steam. The rotation of the agitator in the reactor promotes the coalescence and breakage of bubbles, enhancing the impurity removal effect. This conventional stripping method uses the liquid product as the continuous phase and the gas as the dispersed phase. Limited by the large bubble size and the low frequency of gas-liquid surface renewal in the reactor, the 1,4-dioxane impurity enters the bubbles from the liquid phase at a relatively slow mass transfer rate. Even with the addition of a gas distributor at the gas inlet to enhance breakage and uniform bubble distribution, only large bubbles on the order of tens of millimeters to centimeters can be obtained. Furthermore, because the density difference between the gas and the product liquid is nearly 1,000 times, bubbles easily coalesce to form large bubbles during spontaneous buoyancy, significantly reducing the specific surface area for mass transfer and deteriorating the mass transfer effect. Therefore, conventional bubbling stripping equipment often requires approximately 4-20 hours to complete impurity removal, seriously affecting production efficiency. Utility Model Content

[0006] In response to the shortcomings of the existing technology, the utility model provides a new impurity removal device based on a spray design, which can greatly improve the efficiency of removing volatile impurities such as 1,4-dioxane impurities from liquid products, achieve rapid purification and save energy.

[0007] The utility model discloses a spray impurity removal device comprising a liquid storage tank, a circulation pump, a diversion pipeline system, a combination of three nozzles and a U-shaped reflux separation pipe, wherein the three nozzles comprise a first nozzle, a second venturi ultrasonic atomizing nozzle and a third nozzle, the diversion pipeline system comprises a main pipeline and three branch pipelines, namely a first branch pipeline, a second branch pipeline and a third branch pipeline, wherein a liquid outlet is provided at the bottom of the liquid storage tank, and the three nozzles are arranged side by side above the top, the main pipeline of the diversion pipeline system is connected to the circulation pump from the liquid outlet and then diverted into three branch pipelines after reaching the top of the liquid storage tank, the first branch pipeline, the second branch pipeline and the third branch pipeline are respectively connected to the liquid inlets of the first nozzle, the second venturi ultrasonic atomizing nozzle and the third nozzle, and a hot gas inlet is provided on the side wall of the liquid storage tank, the U-shaped reflux separation pipe is arranged at the bottom of the liquid storage tank, the inlet of the U-shaped reflux separation pipe is arranged at the bottom of the liquid storage tank, the inlet of the U-shaped reflux separation pipe is located above the liquid level in the liquid storage tank and the inlet is downward facing the liquid level.

[0008] The present invention's spray impurity removal device is specifically designed for removing volatile impurities, such as 1,4-dioxane, from alkoxylated fatty alcohol liquid products. By utilizing a specially designed three-nozzle combination, including a Venturi ultrasonic atomizing nozzle, and their arrangement, combined with a hot gas feed design, the device can uniformly atomize the alkoxylated fatty alcohol liquid, which is pumped in from a liquid storage tank, into extremely small droplets of approximately 10 μm. This provides a very large specific surface area for gas-liquid mass transfer, accelerating the transfer of impurities from the liquid phase to the gas phase. By controlling the feed hot gas temperature, the flow rate, and the residence time of the liquid material, only volatile impurities, such as 1,4-dioxane, are transferred from the liquid phase to the gas phase during the impurity removal process, resulting in rapid and efficient impurity removal.

[0009] Compared with the traditional bubbling steam stripping impurity removal device commonly used in this field, the device of the utility model fully utilizes the advantages of high mass transfer efficiency of the spray process through the design of new nozzles and their arrangement, diversion pipe diameter design, U-shaped reflux separation, etc., and can quickly remove 1,4-dioxane impurities using less gas such as N2 or water vapor, reducing the energy consumption and auxiliary material consumption of the post-processing purification section and improving cost advantages. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 This is a schematic structural diagram of the spray impurity removal device of the present invention.

[0011] Figure 2 It is a schematic cross-sectional structure diagram of the second nozzle in the spray impurity removal device of the present invention.

[0012] Figure 3a 、 3b It is a cross-sectional structural schematic diagram and a top view schematic diagram of the first nozzle and the third nozzle in the spray impurity removal device of the present invention.

[0013] Figure 4 Schematic diagram of a conventional bubbling stripping device in the prior art. DETAILED DESCRIPTION

[0014] The preferred embodiments of the device of the present invention are described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate the present invention and do not limit the scope of the present invention in any way.

[0015] like Figure 1As shown, the spray impurity removal device of the present invention includes a liquid storage tank 1, a circulation pump 2, three nozzles 3, 4, and 5, a diversion pipeline system 6, and a U-shaped reflux separation pipe 7. The liquid storage tank 1 is used to add liquid from which impurities are to be separated, and the feeding level of the liquid in the liquid storage tank is generally 70%-85% of the volume of the liquid storage tank. In a specific embodiment, the liquid is an alkoxylated fatty alcohol liquid product from an alkoxylated fatty alcohol production device. A liquid outlet 8 is provided at the bottom of the liquid storage tank 1, and three nozzles are arranged side by side above the top of the liquid storage tank 1, namely a first nozzle 3, a second nozzle 4, and a third nozzle 5. In a preferred embodiment, the second nozzle 4 is arranged directly above the center of the top of the liquid storage tank, and the first nozzle 3 and the third nozzle 5 are arranged on the left and right sides of the second nozzle 4 at equal intervals, and the spacing is preferably 15-20 times the nozzle outlet diameter of the second nozzle. In another preferred embodiment, the second nozzle 4 is arranged with its nozzle axis perpendicular to the horizontal plane of the liquid storage tank, the first nozzle 3 is arranged on the left side of the second nozzle 4 with its nozzle axis forming an angle of 70-75 degrees, preferably about 75 degrees, to the horizontal plane of the liquid storage tank, and the third nozzle 5 is arranged on the right side of the second nozzle 4 with its nozzle axis forming an angle of 80-85 degrees, preferably about 85 degrees, to the horizontal plane of the liquid storage tank.

[0016] The main line of the branch piping system 6 connects to the circulation pump 2 from the liquid outlet 8 to the top of the liquid storage tank, where it branches into three branch lines. The first branch line, the second branch line, and the third branch line are respectively connected to the liquid inlets of the first nozzle 3, the second nozzle 4, and the third nozzle 5. The liquid in the liquid storage tank is pumped into these three nozzles through the liquid outlet 8 by the circulation pump 2. A hot gas inlet 9 is provided on the side wall of the liquid storage tank 1 for connection to a hot gas source. The hot gas can be nitrogen or water vapor.

[0017] In one specific embodiment, the hot gas inlet 9 is positioned below the second nozzle 4 at a distance 4-5 times the diameter of the second nozzle outlet. This position positions the hot gas entry point directly opposite the main portion of the jet divergence angle, i.e., below the initial and transitional sections of the divergence angle, where the atomized droplets of the jet have stabilized. The hot gas inlet is positioned at a 90-degree angle to the intermediate second nozzle 4. This design ensures that the hot gas remains within the tank for a sufficiently long time, for example, approximately two hours, with a gas velocity of up to 0.2 m / s. The hot gas temperature is typically 50-60°C.

[0018] The second nozzle 4 is preferably a Venturi ultrasonic atomizing nozzle based on the Venturi effect, such as Figure 2As shown, its structure includes a nozzle body 1' and a resonance cavity 2'. The nozzle body 1' includes an air inlet 3', a liquid inlet 4', a vertical channel 5' with a venturi tube structure at the end, and a nozzle outlet 6'. Specifically, the hot gas entering the liquid storage tank through the hot gas inlet 9 is sucked into the throat of the venturi tube from the nozzle's air inlet 3' by the suction action of the venturi ultrasonic atomizing nozzle under the drive of the pressure difference. The high-speed airflow is accelerated by the venturi tube to generate a high-speed airflow. The liquid in the liquid storage tank is pumped into the channel 5' through the nozzle's liquid inlet 4' via a circulating pump through a second branch pipe. After that, it mixes with the gas in the venturi tube. The high-speed airflow carries the liquid into the resonance cavity 2'. Since the gas has been accelerated to subsonic speed by the throat of the venturi tube, the high-speed airflow entrained with the liquid flow causes high-frequency vibration in the resonance cavity. This high-frequency vibration then causes the entrained liquid flow to break up, dispersing into extremely small droplets with a diameter of about 10μm. In a preferred embodiment, according to the pressure loss requirements, the shape of the resonance cavity 2' is designed to be truncated cone-shaped rather than a conventional cylindrical shape, so as to facilitate the increase of the spray angle of the Venturi ultrasonic atomizing nozzle to 100-110 degrees under small diameter conditions, preferably about 106 degrees. Combined with the vertical channel 5' provided inside the nozzle, a solid rather than hollow conical spray angle can be ensured.

[0019] Due to the suction effect of the Venturi nozzle, the gas entering the liquid storage tank is sucked into the nozzle throat driven by the pressure difference and ejected again by the nozzle. Therefore, the turbulent intensity of the gas near the droplets is large, and the gas-liquid mass transfer coefficient will not be affected by the low gas phase flow rate. The turbulent kinetic energy in the high turbulent kinetic energy area of ​​the injection part is greater than 1J / kg, which can effectively promote the rapid transfer of liquid impurities from the liquid phase to the gas phase.

[0020] The first nozzle 3 and the third nozzle 5 can be special-shaped nozzles, such as Figure 3a 、 3b As shown, its structure includes a semicircular liquid channel with a semi-conical constriction at the end and a nozzle outlet. The first and third nozzles produce droplets with diameters up to centimeters, primarily used to fill corners not reached by the second, central, Venturi ultrasonic atomizing nozzle. They have a spray angle of 40-50 degrees, for example, 43 degrees, creating a semi-conical spray area to minimize interference with the spray area of ​​the second central nozzle, inhibit droplet coalescence, and maintain a large specific surface area for gas-liquid mass transfer.

[0021] In a particular embodiment, the second branch line connecting the second Venturi ultrasonic atomizing nozzle has a diameter of DN50 and serves as the main line, ensuring that the majority of the flow is ejected from the second nozzle, forming a solid conical spray angle that covers most of the central circular surface. The first and third branch lines connecting the first and third nozzles, respectively, have a diameter of DN25 and serve as auxiliary lines, responsible for transporting part of the liquid product to the two half-nozzles for ejection, filling the corners and improving spray uniformity. By actively performing this flow distribution, the segregation phenomenon of the circulating liquid flow after entering the nozzle can be suppressed, so that the droplets maintain a more even distribution on the spray surface, and the uniformity of the spray droplets is ensured at the source.

[0022] In another preferred embodiment, the nozzle outlet diameter of the middle second Venturi ultrasonic atomizing nozzle is 0.1-0.2 times the diameter of the liquid storage tank, preferably about 0.11 times, and the nozzle outlet diameters of the first nozzle and the third nozzle on the left and right sides are 0.05-0.12 times the diameter of the liquid storage tank, preferably about 0.062 times.

[0023] The liquid in the liquid storage tank is pumped to three nozzles through a circulation pump. Most of the liquid is instantly atomized into extremely small droplets through the second ultrasonic atomizing nozzle in the middle. The atomized droplets come into contact with the hot gas, causing volatile impurities in the droplets, such as 1,4-oxadiazolidine, to transfer from the liquid phase to the hot gas. The impurity-containing gas exhaust is discharged from the U-shaped reflux separation pipe 6 set at the bottom of the liquid storage tank, and the atomized droplets fall back into the liquid at the bottom of the liquid storage tank. This process is circulated for a certain period of time until the volatile impurities in the liquid in the liquid storage tank are effectively removed. The U-shaped reflux separation pipe 6 is a basically U-shaped pipe with its inlet facing downwards towards the liquid surface of the liquid in the liquid storage tank. This structural design can prevent droplets from entering the pipeline, ensure the free discharge of exhaust gas, and minimize the entrainment of droplets. The possible small amount of entrained droplets can be recovered by gravity sedimentation. Specifically, through the U-shaped tube, the slowly flowing gas will carry a small amount of liquid droplets, slow down at the elbow of the U-shaped tube, and then separate in the vertical pipe section with the help of gravity acceleration and density difference. The liquid product refluxes and gathers in the elbow section of the U-shaped tube to act as a partial liquid seal, and the recovered product liquid is regularly discharged during production operations.

[0024] The spray impurity removal device of the present invention is particularly suitable for efficiently removing volatile impurities such as 1,4-dioxane from alkoxylated fatty alcohol liquid products. Compared with the traditional steam stripping process such as nitrogen bubbling method, which usually disperses gas in liquid in the form of bubbles, uses liquid as the continuous phase and bubbles as the dispersed phase to remove impurities, the spray impurity removal device of the present invention uses liquid in the form of micron-sized droplets as the dispersed phase and gas as the continuous phase. Without using a stirring paddle, a specially designed ultrasonic atomizing nozzle is combined with a continuously flowing hot gas setting, so that the liquid product is dispersed in the gas in the form of extremely small droplets with a diameter as low as about 10μm, forming a large gas-liquid contact area and a very short diffusion path, significantly improving the mass transfer rate of volatile impurities such as 1,4-dioxane from the liquid phase to the gas phase, thereby significantly improving the removal efficiency of volatile impurities. For example, the volume-based gas-liquid mass transfer coefficient can be reduced from about 0.01s -1 Improved to about 0.05s -1 Under the same gas introduction conditions, the average bubble particle size is reduced from 10mm to 10μm, and the mass transfer specific surface area is increased by 1000 times. Combined with the above-mentioned enhancement effects, the single-pot batch impurity removal time can be shortened from the conventional approximately 4-20 hours to about 2 hours, greatly improving the efficiency of impurity removal.

[0025] In addition, the spray impurity removal device of the present invention does not require a motor to drive, but only needs the circulation pump originally existing in the alkoxylated fatty alcohol production system to provide power. By consuming a certain dynamic pressure head to achieve droplet breakage, energy savings of up to about 70% can be achieved.

[0026] The present invention may have many other embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art may make various corresponding changes and modifications based on the present invention, but these corresponding changes and modifications should all fall within the scope of protection of the claims attached to the present invention.

Claims

1. A spray impurity removal device, comprising a liquid storage tank, a circulation pump, a diversion pipeline system, a combination of three nozzles and a U-shaped reflux separation pipe, characterized in that: The three nozzles include a first nozzle, a second Venturi ultrasonic atomizing nozzle and a third nozzle, and the diversion pipeline system includes a main pipeline and three branch pipelines, namely a first branch pipeline, a second branch pipeline and a third branch pipeline, wherein a liquid outlet is provided at the bottom of the liquid storage tank, and the three nozzles are arranged side by side above the top, and the main pipeline of the diversion pipeline system is connected to the circulation pump from the liquid outlet to the top of the liquid storage tank and then diverted into three branch pipelines, the first branch pipeline, the second branch pipeline and the third branch pipeline are respectively connected to the liquid inlets of the first nozzle, the second Venturi ultrasonic atomizing nozzle and the third nozzle, and a hot gas inlet is provided on the side wall of the liquid storage tank, and a U-shaped reflux separation pipe is arranged at the bottom of the liquid storage tank, and its inlet is located above the liquid level in the liquid storage tank and the inlet faces downward towards the liquid surface.

2. The spray impurity removal device according to claim 1, characterized in that: The structure of the second Venturi ultrasonic atomizing nozzle includes a nozzle body and a resonance cavity. The nozzle body includes an air inlet, a liquid inlet, a vertical channel with a Venturi tube structure at the end, and a nozzle outlet.

3. The spray impurity removal device according to claim 2, characterized in that: The resonant cavity is designed to be in a truncated cone shape.

4. The spray impurity removal device according to claim 2, characterized in that: The nozzle outlet diameter of the second Venturi ultrasonic atomizing nozzle is 0.1-0.2 times the diameter of the liquid storage tank.

5. The spray impurity removal device according to claim 1, characterized in that: The first nozzle and the third nozzle are special-shaped nozzles, and their structures include a liquid inlet, a semicircular channel with a semi-conical contraction port at the end, and a nozzle outlet.

6. The spray impurity removal device according to claim 5, characterized in that: The nozzle outlet diameters of the first nozzle and the third nozzle are 0.05-0.12 times the diameter of the liquid storage tank.

7. The spray impurity removal device according to any one of claims 1 to 6, characterized in that: The second venturi ultrasonic atomizing nozzle is arranged directly above the center of the top of the liquid storage tank, and the first nozzle and the third nozzle are arranged at equal intervals on the left and right sides of the second venturi ultrasonic atomizing nozzle.

8. The spray impurity removal device according to claim 7, characterized in that: The distance is 15-20 times the nozzle outlet diameter of the second Venturi ultrasonic atomizing nozzle.

9. The spray impurity removal device according to any one of claims 1 to 6, characterized in that: The diameter of the second branch pipeline connected to the second Venturi ultrasonic atomizing nozzle is DN50, and the diameters of the first branch pipeline and the third branch pipeline respectively connected to the first nozzle and the third nozzle are DN25.

10. The spray impurity removal device according to any one of claims 1 to 6, characterized in that: The second Venturi ultrasonic atomizing nozzle is arranged in a manner that its nozzle axis is perpendicular to the horizontal plane of the liquid storage tank, the first nozzle is arranged on the left side of the second nozzle with its nozzle axis forming an angle of 70-75 degrees with the horizontal plane of the liquid storage tank, and the third nozzle is arranged on the right side of the second nozzle with its nozzle axis forming an angle of 80-85 degrees with the horizontal plane of the liquid storage tank.

11. The spray impurity removal device according to any one of claims 1 to 6, characterized in that: The hot gas inlet is located below the second venturi ultrasonic atomizing nozzle at a distance 4-5 times the diameter of the nozzle outlet.

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