Ultrasonic irradiation device

Abstract

The present invention provides an ultrasonic irradiation device that can simultaneously control the temperature of a liquid during ultrasonic irradiation, maintaining it within a predetermined temperature range from the set temperature for an extended period of time. [Solution] The ultrasonic irradiation device 1 comprises a plurality of ultrasonic tanks T1, T2 having internal spaces for containing liquid, a temperature sensor for detecting the temperature of the liquid in the ultrasonic tanks T1, T2, a heat exchanger for cooling the liquid in the ultrasonic tanks T1, T2, a heater provided along the outer surface of the ultrasonic tanks T1, T2, an ultrasonic transducer for irradiating the liquid in the ultrasonic tanks T1, T2 with ultrasonic waves of a predetermined frequency, and a stirring means for stirring the liquid in the ultrasonic tanks T1, T2. The plurality of ultrasonic tanks T1, T2 are arranged side by side in the vertical direction and connected via connecting pipes 2.

Description

[Technical Field]

[0001] The present invention relates to an ultrasonic irradiation device for irradiating a liquid with ultrasonic waves to perform various treatments such as dispersion of impurities in the liquid, and particularly relates to an ultrasonic irradiation device that can be used in the process of reducing impurity components (phosphorus compounds, metals, soap components, suspended solids, colloidal impurities, etc.) in liquid fats and oils including waste edible oil, fats and oils derived from brown grease, and the like. [Background Art]

[0002] When liquid fats and oils are used as fuel raw materials and the like, the presence of metals such as phosphorus (P) and iron (Fe), soap components and colloidal sludge causes increased pressure loss in downstream equipment, catalyst deactivation, coking and other problems. Therefore, when reusing fats and oils, it is necessary to efficiently reduce and remove these impurity components contained in the fats and oils.

[0003] It has been conventionally known to use ultrasonic waves to reduce and remove impurity components from fats and oils. For example, a desulfurization method for petroleum is disclosed, in which liquid petroleum is caused to collide with a special ceramic mixer to generate ultrasonic vibration, the petroleum is atomized by the vibration energy of its own ultrasonic waves, and sulfur molecules of stable petroleum molecules and foreign molecules can be released (see, for example, Patent Document 1).

[0004] A desulfurization method for light oil is also disclosed, which comprises an atomization step of subjecting sulfur-containing petroleum to ultrasonic vibration to separate it into a mixed fluid of atomized mist-like fine particles and a carrier gas, and residual petroleum that is not atomized, and a recovery step of separating and recovering petroleum from the mixed fluid obtained in the atomization step (see, for example, Patent Document 2).

[0005] In addition, an ultrasonic generator is also disclosed, in which a first ultrasonic transducer and a second ultrasonic transducer with different frequencies are vibrated simultaneously, and a pseudo-boiling phenomenon is generated in an area where the ultrasonic waves irradiated from each ultrasonic transducer overlap (see, for example, Patent Document 3). [Prior Art Documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2021-109903 [Patent Document 2] Patent No. 4806944 [Patent Document 3] Japanese Patent Publication No. 2012-66218 [Overview of the project] [Problems that the invention aims to solve]

[0007] However, conventional methods of treating liquids using ultrasonic vibrations as described above have drawbacks, such as the rapid rise in temperature due to the vibration of the ultrasonic transducer and the loss of liquid, causing the liquid to deviate from its target temperature range and making it difficult to perform stable ultrasonic irradiation over long periods of time.

[0008] Furthermore, while general temperature control (coolers or heaters alone) or simple frequency sweeps are used to solve this problem, these techniques have the drawback of being prone to processing inconsistencies and quality fluctuations due to runaway temperatures and unevenly distributed sound fields.

[0009] In particular, metal ions in oils and fats bind to phospholipids and fatty acids, making them difficult to release. This factor hinders the efficient removal and reduction of impurities from oils and fats through ion exchange and absorption / adsorption. Currently, there are no ultrasonic irradiation devices that can overcome this factor and contribute to the efficient removal and reduction of impurities from oils and fats.

[0010] The present invention has been made in view of the above problems, and aims to provide an ultrasonic irradiation device that irradiates a liquid with ultrasonic waves, which simultaneously controls the over-temperature rise / fall of the liquid during ultrasonic irradiation, maintains a predetermined temperature range for a long period of time, and as a result can uniformly disperse and atomize impurities in the liquid. [Means for solving the problem]

[0011] To achieve the above objective, the present invention provides an ultrasonic irradiation device for irradiating a liquid with ultrasonic waves, comprising: a plurality of ultrasonic tanks having internal spaces for containing liquid; a temperature sensor for detecting the temperature of the liquid in the ultrasonic tanks; a heat exchanger for cooling the liquid in the ultrasonic tanks; a heater provided along the outer surface of the ultrasonic tanks; an ultrasonic transducer for irradiating the liquid in the ultrasonic tanks with ultrasonic waves of a predetermined frequency; and a stirring means for stirring the liquid in the ultrasonic tanks, wherein the plurality of ultrasonic tanks are arranged in parallel in the vertical direction and connected via connecting pipes. The system further includes ultrasonic transducer correction means for correcting the output of the ultrasonic transducer according to the temperature detected by the temperature sensor. It is characterized by the following.

[0012] In this ultrasonic irradiation device, it is preferable that the predetermined frequency is within the range of 20 to 200 kHz, and that the predetermined frequencies of the ultrasonic transducers provided in each of the plurality of ultrasonic chambers are different.

[0013] In this ultrasonic irradiation device, the plurality of ultrasonic chambers consist of a first ultrasonic chamber and a second ultrasonic chamber located below the first ultrasonic chamber, wherein the first ultrasonic chamber irradiates the liquid with low-frequency ultrasound for a predetermined period of time or longer, and the second ultrasonic chamber irradiates the liquid with higher-frequency ultrasound for a predetermined period of time or longer.

[0014] In this ultrasonic irradiation device, the low frequency is preferably 26 kHz, the high frequency is preferably 38 kHz, and the predetermined period is preferably in the range of 30 to 60 minutes.

[0015] In this ultrasonic irradiation device, it is preferable that the ultrasonic transducer is held in the ultrasonic chamber in a hollow state, spaced apart from the bottom and sides of the ultrasonic chamber, using a fixing member; the heat exchanger is held vertically along the inner wall of the ultrasonic chamber; and the stirring means is arranged around the ultrasonic transducer.

[0017] In this ultrasonic irradiation device, it is preferable to include a temperature control means that maintains the temperature of the liquid in the ultrasonic chamber within a predetermined temperature range by coordinating the control of the heat exchanger, the heater, and the ultrasonic transducer based on the temperature detected by the temperature sensor.

[0018] In this ultrasonic irradiation device, the predetermined temperature range is a set temperature of 65 degrees ± 5 degrees, and the temperature control means preferably increases the refrigerant flow rate of the heat exchanger when the liquid temperature detected by the temperature sensor exceeds 70 degrees, while increasing the heater output when the liquid temperature detected by the temperature sensor falls below 60 degrees.

[0019] In this ultrasonic irradiation device, it is preferable that the stirring means comprises a stirring motor, a stirring rod connected to the stirring motor and extending downward, and a stirring propeller connected to the stirring rod, and that the stirring means comprises a circulating flow generation means for controlling the operation of the stirring motor so that τi ≥ τc, under the condition that the irradiation time τi of ultrasonic waves from the ultrasonic transducer is equal to or greater than the circulation time τc of the liquid. [Effects of the Invention]

[0020] The ultrasonic irradiation device according to the present invention comprises a plurality of ultrasonic tanks having internal spaces for containing liquid, a temperature sensor for detecting the temperature of the liquid in the ultrasonic tanks, a heat exchanger for cooling the liquid in the ultrasonic tanks, a heater provided along the outer surface of the ultrasonic tanks, an ultrasonic transducer for irradiating the liquid in the ultrasonic tanks with ultrasonic waves of a predetermined frequency, and a stirring means for stirring the liquid in the ultrasonic tanks. The plurality of ultrasonic tanks are arranged side by side in the vertical direction and connected via connecting pipes. With this configuration, the ultrasonic irradiation device according to the present invention can simultaneously control the temperature of the liquid during ultrasonic irradiation, maintain the temperature within a predetermined range from the set temperature for a long period of time, and as a result, uniformly disperse and atomize impurities in the liquid. [Brief explanation of the drawing]

[0021] [Figure 1](a) is a side view of the ultrasonic irradiation device according to an embodiment of the present invention, (b) is a plan view of the above-mentioned ultrasonic irradiation device, and (c) is a front view of the above-mentioned ultrasonic irradiation device. [Figure 2] (a) is a plan view of a first ultrasonic tank provided in the above-mentioned ultrasonic irradiation device, and (b) is a side view of the first ultrasonic tank in a state where the side wall thereof is seen through. [Figure 3] (a) is a plan view of a second ultrasonic tank provided in the above-mentioned ultrasonic irradiation device, and (b) is a side view of the second ultrasonic tank in a state where the side wall thereof is seen through. [Figure 4] (a) is a plan view of an ultrasonic transducer provided in the above-mentioned first ultrasonic tank, and (b) is a plan view of an ultrasonic transducer provided in the above-mentioned second ultrasonic tank. [Figure 5] (a) is a reference diagram showing an example of the arrangement of ultrasonic transducers and a heat exchanger in a plan view of the above-mentioned first ultrasonic tank, and (b) is a reference diagram showing an example of the arrangement of the ultrasonic transducers and the heat exchanger in a side view of the above-mentioned first ultrasonic tank. [Figure 6] (a) is a reference diagram showing an example of the arrangement of an ultrasonic transducer and a heat exchanger in a plan view of the above-mentioned second ultrasonic tank, and (b) is a reference diagram showing an example of the arrangement of the ultrasonic transducer and the heat exchanger in a side view of the above-mentioned second ultrasonic tank. [Figure 7] (a) is a side view of a heat exchanger provided in the above-mentioned ultrasonic irradiation device, (b) is a front view of the above-mentioned heat exchanger, and (c) is a bottom view of the above-mentioned heat exchanger. [Figure 8] is a functional block diagram of the above-mentioned ultrasonic irradiation device. [Figure 9] is a flowchart showing an example of an operation procedure of the above-mentioned ultrasonic irradiation device. MODE FOR CARRYING OUT THE INVENTION

[0022] (Embodiment) An ultrasonic irradiation device according to an embodiment of the present invention will be described with reference to Figures 1 to 9. This ultrasonic irradiation device is a device for applying ultrasound of different frequencies to a liquid medium (for example, raw oils and fats containing impurities, solutions, suspensions, emulsions, dispersions, reaction mixtures, culture media, melts, etc.) to perform various processes (for example, dispersion, micronization, degassing, washing, activation, extraction, reaction acceleration, etc.).

[0023] The raw materials for the ultrasonic irradiation device of the present invention include liquid oils that have been treated as waste, such as waste cooking oil, by-product oils, brown grease, animal and vegetable oils, and industrial oils. Brown grease, for example, refers to oils separated and extracted from mixtures of oils, food residues, and water that accumulate in grease traps in restaurants and other establishments.

[0024] Furthermore, there are various methods for manufacturing these raw oils and fats. For example, they can be produced by recovering wastewater oil and fat accumulated in grease traps of restaurants, or floating oil accumulated in oil-water separators or raw water tanks of food processing plants that discharge oily wastewater, and then efficiently separating and removing sludge and water from these recovered wastewater oils and floating oils. This also includes SMO (Straight Mixed Oil), which is produced by modifying wastewater oils and fats that contain a large amount of beef tallow or lard without chemical synthesis. <Overall configuration of the ultrasonic irradiation device>

[0025] First, the overall structure of the ultrasonic irradiation device according to this embodiment will be described. In this embodiment, raw oil and fat will be used as the liquid introduced into the ultrasonic irradiation device 1. This raw oil and fat may, for example, be introduced into a standing tank, allowed to stand for a certain period of time, and then the precipitated components will be recovered. Subsequently, impurities contained in the oil and fat with a relatively high specific gravity may be recovered in advance by centrifugal separation. In other words, the ultrasonic application process and the temperature control process are performed when pre-manufactured and prepared raw oil and fat are introduced into the ultrasonic irradiation device.

[0026] As shown in Figure 1, the ultrasonic irradiation device 1 is equipped with a plurality of rectangular parallelepiped-shaped first ultrasonic tanks T1 and second ultrasonic tanks T2 (2 in this embodiment) for applying ultrasonic waves of different frequencies to oils and greases. These ultrasonic tanks T1 and T2 are arranged side by side along the vertical direction and connected via connecting pipes 2.

[0027] The first ultrasonic chamber T1 irradiates the liquid with 26kHz ultrasound. The second ultrasonic chamber T2 irradiates the liquid with 38kHz ultrasound. In other words, the first ultrasonic chamber T1 applies low-frequency ultrasound to the liquid for a predetermined period of time or longer, and then the second ultrasonic chamber T2 applies higher-frequency ultrasound to the liquid for a predetermined period of time or longer. The frequencies in ultrasonic chambers T1 and T2 are basically fixed to a single frequency (e.g., 26kHz or 38kHz), but it is certainly possible to change the setting depending on the application (i.e., this may include "frequency sweep" or "sequential irradiation" as an arbitrary configuration).

[0028] The ultrasonic irradiation device 1 controls the temperature of the oil in the ultrasonic baths T1 and T2 to a desired temperature (for example, 60-70 degrees, more preferably 60-65 degrees), and then applies ultrasonic waves of different frequencies to the oil for a predetermined period of time.

[0029] As shown in Figure 2, the first ultrasonic bath T1 contains an ultrasonic transducer 11 for generating ultrasonic waves, a stirring means 12 for stirring the liquid, a planar heater 13 for controlling the liquid temperature, a heat exchanger 14, a float switch 15, and multiple temperature sensors 16. The second ultrasonic bath T2 has the same internal configuration as the first ultrasonic bath T1, as shown in Figure 3. Liquids such as oils and greases containing impurities are introduced into the first ultrasonic bath T1 through an inlet 17a (e.g., 25A) integrally formed on the top lid 17 of the first ultrasonic bath T1. On the other hand, the liquid after ultrasonic treatment is discharged to the outside through an outlet 18.

[0030] As shown in Figures 4(a) and 5, the ultrasonic transducer 11 placed inside the first ultrasonic chamber T1 is a rectangular parallelepiped ultrasonic transducer having dimensions of, for example, W410*D390*H90mm, an output of 1200W, and a weight of 25kg. It is held inside the first ultrasonic chamber T1 in a hollow state, spaced apart from the bottom and sides of the chamber T1 (for example, 150mm away from the bottom of the chamber T1), using fixing members 11a such as L-shaped hooks connected to its four corners. Here, an ultrasonic transmitter (ultrasonic transducer correction means) is connected to the ultrasonic transducer to make the duty cycle of the ultrasonic output variable, and the transducer vibrates at a predetermined frequency according to the ultrasonic transmission signal, irradiating the liquid inside with ultrasonic waves.

[0031] As shown in Figures 4(b) and 6, the ultrasonic transducer 11 in the second ultrasonic chamber T2 is a rectangular parallelepiped ultrasonic transducer having dimensions of, for example, W380*D355*H80mm, an output of 1200W, and a weight of 17kg. It is held in a hollow state, spaced apart from the bottom and sides of the second ultrasonic chamber T2 (for example, 160mm away from the bottom of the second ultrasonic chamber T2), using fixing members 11a such as L-shaped hooks connected to its four corners. The numerical dimensions shown in Figures 4 to 7 are in millimeters.

[0032] As shown in Figure 7, the heat exchanger 14 is a water-cooled heat exchanger with variable refrigerant flow rate control. It has a configuration in which a refrigerant flows through the inside of a wound flexible tube (15A x 3.4m (SUS316L)) 14c, which is held vertically along the inner wall of the ultrasonic bath 2, using two cap nuts (silicone packing G3 / 4 (SUS304), etc.) 14a and a C channel (40mm x 20mm SUS, etc.) 14b. Three sets of this heat exchanger 14 are installed in the first ultrasonic bath T1 to efficiently cool the liquid.

[0033] The heater 13 is a planar silicone rubber heater (three-phase 200V) made by sandwiching a nickel alloy between silicone rubber sheets, for example, to heat the liquid from the bottom surface (or the front, back, left, and right sides) of the first ultrasonic chamber T1. The surface of the heater 13 may be fitted with a SUS (stainless steel) waterproof cover using gaskets and screws, and may have a structure in which insulating material is sealed inside. By sealing insulating material in this way, the temperature inside the first ultrasonic chamber T1 can be maintained within the range of 60-70 degrees for a long time, and as a result, the efficient separation of impurities in the first ultrasonic chamber T1 can be promoted.

[0034] The float switch 15 is a level meter capable of detecting the presence of liquid inside it. This float switch 15 is a measuring instrument that measures the liquid level inside the first ultrasonic tank T1 by utilizing the fact that a float moves up and down due to the weight of the liquid.

[0035] The temperature sensor 16 is a temperature sensor that measures the temperature of the liquid in the first ultrasonic bath T1 by utilizing the fact that the electrical resistance of a semiconductor or similar material changes with temperature.

[0036] As shown in Figure 2, the stirring means 12 includes a stirring motor 12a, a stirring rod 12b connected to the stirring motor 12a and extending downward, and a stirring propeller 12c connected to the stirring rod 12b. The stirring propeller 12c is positioned in pairs to the side of the ultrasonic transducer 11 to efficiently circulate the oil to which ultrasonic waves have been applied by the ultrasonic transducer 11 within the first ultrasonic tank T1. The stirring propeller 12c is positioned so that the circulation direction of the liquid oil is vertical and so that the liquid oil flows efficiently around the ultrasonic transducer 11. The stirring means 12 may also be a device that includes the stirring propeller 12c and a flow guide member or an external loop circulation pump. <Functional Configuration of Ultrasonic Irradiation Device 1>

[0037] Next, a functional block diagram of the ultrasonic irradiation device 1 according to this embodiment will be described with reference to Figure 8. The ultrasonic irradiation device 1 includes an ultrasonic transducer 11, a stirring means 12, a heater 13, a heat exchanger 14, a float switch 15, and a temperature sensor 16. In addition to these, it includes an ultrasonic transducer correction unit 81 that corrects the duty cycle or output to the ultrasonic transducer 11 according to the temperature detected by the temperature sensor 16, a circulation flow generation unit 82 that controls the stirring means 12 to include upward circulation, and a temperature control unit 83 that maintains the temperature of the liquid in the ultrasonic tanks T1 and T2 at a set temperature Tset ± 5℃ by coordinating control of the heat exchanger 14, heater 13, ultrasonic transducer 11, and stirring means 12 based on the temperature detected by the temperature sensor 16. <Operating Procedure for Ultrasonic Irradiation Device>

[0038] Next, the operating procedure of the ultrasonic irradiation device 1 will be explained with reference to the flowchart shown in Figure 9. First, the raw oil is introduced into the first ultrasonic tank T1 through the inlet 17a connected to the inflow pipe (S91). Then, a float switch 15 installed inside detects the liquid level, and when it exceeds a predetermined liquid level, the float switch 15 turns ON (Yes in S92), and the inflow of oil is automatically stopped (S93).

[0039] Next, the heater 13 and ultrasonic transducer 11 are activated to irradiate the oil inside with ultrasonic waves of a predetermined frequency (e.g., 26 kHz) (S94). At this time, the temperature control unit 83 combines the ultrasonic transducer 11, heater 13, water-cooled heat exchanger 14, and stirring means 12 to automatically control the oil temperature to a set temperature of 65 degrees ± 5 degrees (S95).

[0040] For example, when the temperature sensor 16 detects a temperature above a set temperature (e.g., 65°C ± 5°C), the temperature control unit 83 starts the operation of the heat exchanger 14, and if necessary, coordinates control with the ultrasonic transducer correction unit 81 to correct the duty cycle or output to the ultrasonic transducer 11 to reduce it, and if necessary, stops the operation of the ultrasonic transducer 11. As an example, when the temperature detected by the temperature sensor 16 T > 67°C, the cooling level using the heat exchanger 14 is increased to reduce the duty cycle to the ultrasonic transducer 11. Subsequently, when the detected temperature reaches 68°C, the ultrasonic transducer 11 is stopped.

[0041] On the other hand, if the temperature sensor 16 detects a temperature below the set temperature (e.g., 65°C ± 5°C), the temperature control unit 83 prioritizes heating the liquid by increasing the output of the heater 13, stopping the operation of the heat exchanger 14, and, if necessary, coordinating control with the ultrasonic transducer correction unit 81 to correct by increasing the duty cycle or output to the ultrasonic transducer 11. For example, when the detected temperature T < 63°C, the heater 13 is increased, cooling using the heat exchanger 14 is reduced, and the duty cycle of the ultrasonic transducer 11 is increased after the temperature returns to 65°C (hysteresis 59 / 61°C, etc., is adjusted depending on the application).

[0042] In other words, the temperature control unit 83 enables closed-loop coordinated control of a two-way temperature governor: a water-cooled heat exchanger 14 (variable refrigerant flow rate) + a bottom or side heater 13 (variable output), and allows for the use of duty cycle / output correction of the ultrasonic transducer 11 as needed.

[0043] Furthermore, the circulating flow generation unit 82 performs a mechanism for uniform exposure of the entire volume. This mechanism manages the circulation time τc of the liquid in the first ultrasonic tank T1 using a circulating flow generation mechanism (stirring propeller 12c, flow guide member, loop piping, etc.) that includes upward circulation, and controls the operation so that the entire volume of the liquid passes through the sound field of the ultrasonic transducer 11 multiple times, satisfying the ultrasonic irradiation time τi > τc (preferably k × τc, k ≥ 2). The circulating flow generation unit 82 may also define the circulation time τc using an external loop circulation pump.

[0044] Then, once the oil temperature is controlled within the set temperature range (e.g., 65°C ± 5°C) as described above (Yes in S95), and after a predetermined irradiation time τi = 30 to 60 minutes has elapsed (Yes in S96), the ultrasonic irradiation is stopped (S97). Finally, the oil treated with ultrasonic waves is automatically discharged through the connecting pipe 2 to the second ultrasonic tank T2 below (S98). This discharge is performed using, for example, an automatic valve.

[0045] Thus, the ultrasonic irradiation device 1 constantly monitors the temperature of the oil and grease using the temperature control unit 83 even during ultrasonic irradiation, suppressing the temperature rise caused by the self-heating of the ultrasonic transducer 11 and maintaining the desired temperature range for a long period of time. Furthermore, while maintaining this temperature range, it is controlled to uniformly apply a predetermined frequency to the oil and grease to be treated for a predetermined period of time or longer.

[0046] Next, the same treatment as in the first ultrasonic tank T1 is performed in the second ultrasonic tank T2 from which the oil has been discharged, but this time, the ultrasonic transducer 11 irradiates with ultrasonic waves of a higher frequency (for example, 38 kHz). Finally, when the amount of oil treated in the second ultrasonic tank T2 has accumulated in the transport tank 3 is greater than a predetermined amount, the ultrasonically treated oil is sent via transport piping 4 or the like to an ultrasonic tank with a catalyst, for example, in the next step, and the medium contact step is performed.

[0047] Thus, the ultrasonic irradiation device 1 has a temperature control process that manages and controls the temperature rise / fall of the oil during ultrasonic treatment to maintain the set temperature for a long period of time, and a circulation flow generation mechanism that can control the entire volume of the liquid to pass through the sound field of the ultrasonic transducer 11 multiple times. Furthermore, by providing separate ultrasonic baths T1 and T2, ultrasonic treatment processes can be performed using two different frequencies, one long and one short. In other words, the ultrasonic irradiation device 1 can disperse and atomize impurities in the oil, for example, to maximize the effect of the adsorbent on impurities in subsequent processes. In the first ultrasonic bath T1, a low frequency (e.g., 26 kHz) promotes cavitation and physically destroys impurities, and then in the second ultrasonic bath T2, a high frequency (e.g., 38 kHz) homogenizes the dispersion.

[0048] In other words, in ultrasonic irradiation device 1, (1) cavitation effect: Ultrasonic irradiation generates and collapses microbubbles, creating a localized high temperature, high pressure, and high shear field. (2) Promotion of mass transfer: In oils and fats, metal ions in the oils and fats are temporarily released more easily from fatty acids and phospholipids. (3) Improved reactivity: The finely milled particles have an increased specific surface area, which can improve the contact efficiency with ion exchange resins, zeolites, and activated carbon that are subsequently subjected to chemical reactions.

[0049] The purified oils and fats obtained after all stages of the process for reducing impurities in oils and fats are useful not only as raw materials for sustainable aviation fuel (SAF), but also as various biofuels, chemical, food, cosmetic, and lubricant base materials.

[0050] As described above, the present invention is an ultrasonic irradiation device 1 for irradiating a liquid with ultrasonic waves, comprising: a plurality of ultrasonic tanks T1, T2 having internal spaces for containing liquid; a temperature sensor 16 for detecting the temperature of the liquid in the ultrasonic tanks T1, T2; a heat exchanger 14 for cooling the liquid in the ultrasonic tanks T1, T2; a heater 13 provided along the outer surface of the ultrasonic tanks T1, T2; an ultrasonic transducer 11 for irradiating the liquid in the ultrasonic tanks T1, T2 with ultrasonic waves of a predetermined frequency; and a stirring means 12 for stirring the liquid in the ultrasonic tanks T1, T2. The plurality of ultrasonic tanks T1, T2 are arranged side by side in the vertical direction and connected via connecting pipes 2. With this configuration, the ultrasonic irradiation device 1 can suppress the temperature rise caused by the self-heating of the ultrasonic transducer 11 and realize a two-way temperature governor (cooling + heating + ultrasonic duty cycle coordination) that can uniformly expose the entire amount of material to be processed to the sound field while maintaining a desired temperature range for a long period of time.

[0051] In other words, even if the ultrasonic transducer 11 generates its own heat, the liquid in the ultrasonic baths T1 and T2 can be kept within the set temperature Tset ± 5°C, thereby stabilizing the quality of processes that are highly temperature-dependent (dispersion, extraction, reaction). Furthermore, the cooperation between the circulating flow generation unit 82 and the sound field arrangement reduces unevenness in ultrasonic irradiation of the liquid, even if the scale of the ultrasonic baths T1 and T2 is large, thereby improving reproducibility. In other words, the entire amount of material to be processed is uniformly exposed to the sound field, suppressing dead zones / hot spots within the ultrasonic irradiation device 1. In particular, this ultrasonic irradiation device 1 is compatible with brown grease, and can be applied to high-value-added cleaning technology for oils and fats by reducing and removing impurities from brown grease.

[0052] Furthermore, the present invention is not limited to the configuration of the above embodiment, and various modifications are possible without changing the spirit of the invention. For example, this ultrasonic irradiation device may be combined with other devices and processes. [Industrial applicability]

[0053] The ultrasonic irradiation device according to the present invention is applicable to applications such as dispersing and atomizing impurities contained in oils and fats, food and cosmetics, fine chemicals, battery slurries, catalyst inks, bio-based culture media and extracts, and semiconductor cleaning solutions. In particular, the present invention is effective in adding value to waste cooking oil and brown grease, pretreatment of aviation and land transport fuel supply chains, stabilizing the quality of raw materials for chemicals, food and cosmetics, and regenerating lubricating oils. [Explanation of symbols]

[0054] 1 Ultrasonic irradiation device 2. Connecting pipes 11. Ultrasonic transducer 11a Fixing member 12. Stirring means 12a Stirring motor 12b Stirring rod 12c stirring propeller 13 Heater 14 Heat exchanger 15. Float switch 16 Temperature Sensor 17 Top lid 17a Inlet 18 Outlet 81 Ultrasonic transducer correction unit (ultrasonic transducer correction means) 82 Circulating flow generation section (circulating flow generation means) 83 Temperature control unit (temperature control means) T1 First ultrasonic bath T2 Second ultrasonic bath

Claims

1. An ultrasonic irradiation device that irradiates a liquid with ultrasonic waves, Multiple ultrasonic chambers having internal spaces for containing liquid, A temperature sensor for detecting the temperature of the liquid in the ultrasonic bath, A heat exchanger for cooling the liquid in the ultrasonic chamber, A heater provided along the outer surface of the ultrasonic chamber, An ultrasonic transducer that irradiates the liquid in the ultrasonic tank with ultrasonic waves of a predetermined frequency, The system comprises stirring means for stirring the liquid in the ultrasonic chamber, The aforementioned plurality of ultrasonic chambers are arranged side by side in the vertical direction and connected via connecting pipes. An ultrasonic irradiation device further comprising an ultrasonic transducer correction means for correcting the output of the ultrasonic transducer according to the temperature detected by the temperature sensor.

2. The predetermined frequency is within the range of 20 to 200 kHz, and The ultrasonic irradiation apparatus according to claim 1, characterized in that the predetermined frequencies of the ultrasonic transducers provided in each of the plurality of ultrasonic chambers are different.

3. The plurality of ultrasonic chambers consist of a first ultrasonic chamber and a second ultrasonic chamber located below the first ultrasonic chamber. The first ultrasonic chamber irradiates the liquid with low-frequency ultrasound for a predetermined period of time or longer. The ultrasonic irradiation apparatus according to claim 2, characterized in that the second ultrasonic chamber irradiates the liquid with ultrasonic waves of a higher frequency for a predetermined period of time or longer.

4. The aforementioned low frequency is 26 kHz. The aforementioned high frequency is 38 kHz. The ultrasonic irradiation device according to claim 3, characterized in that the predetermined period is in the range of 30 to 60 minutes.

5. The ultrasonic transducer is held within the ultrasonic chamber using a fixing member, in a hollow state, spaced apart from the bottom and sides of the ultrasonic chamber. The heat exchanger is held vertically along the inner wall of the ultrasonic chamber. The ultrasonic irradiation device according to claim 1, characterized in that the stirring means is arranged around the ultrasonic transducer.

6. The ultrasonic irradiation apparatus according to claim 1, further comprising a temperature control means for maintaining the temperature of the liquid in the ultrasonic tank within a predetermined temperature range by coordinating control of the heat exchanger, the heater, and the ultrasonic transducer based on the temperature detected by the temperature sensor.

7. The aforementioned predetermined temperature range is set to 65 degrees ± 5 degrees. The ultrasonic irradiation apparatus according to claim 6, characterized in that the temperature control means increases the refrigerant flow rate of the heat exchanger when the temperature of the liquid detected by the temperature sensor exceeds 70 degrees, and increases the heater output when the temperature of the liquid detected by the temperature sensor falls below 60 degrees.

8. The stirring means comprises a stirring motor, a stirring rod connected to the stirring motor and extending downward, and a stirring propeller connected to the stirring rod. The ultrasonic irradiation apparatus according to claim 1, further comprising a circulating flow generation means for operating the stirring motor such that τi ≥ τc, under the condition that the ultrasonic irradiation time τi from the ultrasonic transducer is equal to or greater than the liquid circulation time τc.

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