KR20230049294A - Spray drying process using nanobubbles and its method of controlling the shape of powder particles - Google Patents

Abstract

The present invention relates to a spray drying process using a nanobubble and a method for controlling a shape of a powder particle thereby. The present embodiment relates to the spray drying process. The spray drying process using the nanobubble of the present invention comprises: a nanobubble manufacturing step of supplying a gas to a solution for a certain period of a time through a nanobubble generator and mixing the nano-sized nanobubble into the solution; a solution spraying step of spraying the solution containing the nanobubble into a mixing chamber through a nozzle; a particle drying step of obtaining a dried solid particle by passing a hot air through the sprayed solution in the mixing chamber; and a step of setting a temperature condition of the hot air or a flow rate at which the solution is sprayed through the nozzle, and acquiring data on the shape or a size of the solid particle obtained in the particle drying step. Provided is a technology to predict the shape and the size of the powder particle and control the same to a desired shape and size.

Description

Spray drying process using nanobubbles and method for controlling the shape of powder particles by it

This embodiment relates to a spray drying process of a solution mixed with nanobubbles, and relates to a method for changing the state of a solution to be dried by adjusting variables necessary for the spray drying process and controlling the size and shape of powder particles to desired target values. will be.

The spray drying process is a drying method in which solid fine particles are obtained by exposing a solid and liquid mixture to a hot air stream to instantly evaporate the liquid from a solution phase.

For spray drying, a process of generating a high-temperature hot air stream for evaporating a liquid and a process of atomizing and spraying a mixture of liquid and solid using a nozzle or spray are required.

In the conventional spray drying process, a blower is used to introduce a drying medium such as external air into the system in the process of generating a high-temperature hot air stream.

In addition, in the conventional spray drying process, a rotary disk nozzle, a two fluid nozzle, a pressure nozzle, an ultrasonic nozzle ( Devices such as an ultrasonic nozzle and an atomizer are being used.

However, since the conventional spray drying process only controls the spray drying process by changing the type of nozzle or changing the device for supplying high-temperature hot air to atomize and spray the liquid mixture, There are limitations in controlling the size and shape of solid particles, which are final products obtained through the process.

In addition, the conventional spray drying process simply sprays and dries the mixed solution, and since the physical properties of the solution are not considered, the shape and size of the final product cannot be predicted, and the process is repeatedly performed to change the properties of solid particles. Since a product has to be changed to obtain a product, there arises a problem of increasing process cost.

Against this background, the purpose of this embodiment is, in one aspect, to provide a technique for predicting the shape and size of powder particles by spray-drying an aqueous solution mixed with nanobubbles and controlling them to a desired shape and size.

An object of this embodiment, on the other hand, is to control the operating conditions of the spray drying process, such as the temperature of the hot air provided to the spray drying or the spray amount of the solution, to more accurately control the shape and size of the particles of the final product To provide a technique will be.

Another object of this embodiment is to provide a technique for recovering powder particles of a desired size in a state in which the powder particles are not destroyed based on the obtained distribution data of powder particles in various states.

In another aspect, an object of this embodiment is to provide a technique for predicting and controlling the shape and size of particles of a final product by controlling the state of nanobubbles.

In order to achieve the above object, an embodiment of the present invention provides a nanobubble production step of supplying a gas to a solution for a certain period of time through a nanobubble generator and mixing nanobubbles of nano size with the solution; a solution spraying step of spraying the solution containing the nanobubbles into a mixing chamber through a nozzle; a particle drying step of passing hot air through the sprayed solution in the mixing chamber to obtain dried solid particles; And setting the temperature conditions of the hot air or the flow rate at which the solution is sprayed through the nozzle, and acquiring data on the shape or size of the solid particles obtained in the particle drying step, providing a spray drying process. can do.

In the spray drying process, the step of checking the state of the solid particles obtained through the particle drying step and changing the flow rate condition or temperature condition of the hot air may be further included.

The method may further include obtaining composition ratio data for each size of the solid particles obtained in the particle drying step in response to a temperature change of the hot air in the spray drying step.

In the spray drying process, the composition ratio data may be defined as the ratio of solid particles having a diameter less than or equal to the standard value and solid particles having a diameter exceeding the standard value.

In the spray drying process, the reference value may be defined as a mode or maximum value of the solid particle size obtained in the particle drying step.

In the spray drying process, as the temperature of the hot air increases, the rate at which the shape of the solid particles is destroyed is measured to define the maximum hot air temperature, and the temperature of the hot air can be maintained below the maximum hot air temperature.

The size of the solid particles may be defined by Gaussian dispersion of the size distribution of the solid particles obtained by changing the temperature of the hot air in the spray drying process.

내지 260

인 상태로 유지될 수 있다.In the spray drying process, the drying temperature of the hot air is 200

to 260

can be maintained as

In the spray drying process, the number of nanobubbles included in the solution may be adjusted by changing the flow rate of the solution sprayed by the nozzle.

In the spray drying process, the liquid of the solution in the nanobubble preparation step may be distilled water, and the solid may be maltodextrin.

A step of recovering the dried solid particles through a cyclone in the spray drying process may be further included.

In the spray drying process, the cyclone adjusts the internal centrifugal force so that the solid particles are collected in the order of large particles to small particles.

In the particle drying step in the spray drying process, the hot air is introduced into the mixing chamber by a blower, and a heating device is installed in an inflow path between the blower and the mixing chamber to adjust the temperature of the hot air.

In the spray drying process, in the particle drying step, the sprayed solution forms a dry edge, and solid particles dried by the hot air may be obtained.

In the spray drying process, in the particle drying step, the sprayed solution may obtain dried solid particles through a vapor-gas replacement process.

In the spray drying process, the rate of breakage of solid particles may be adjusted by adjusting the state of hot air in the particle drying step.

As described above, according to the present embodiment, it is possible to more accurately predict and control the size and shape of the particles obtained by the spray drying process.

In addition, according to this embodiment, the spray drying process can be performed more simply and quickly, and the cost required for the spray drying process can be reduced.

1 is a diagram illustrating a process of injecting nanobubbles into an aqueous solution according to an embodiment.
2 is a view illustrating a spray drying process according to an embodiment.
3 is a flowchart illustrating a spray drying process using nanobubbles according to an embodiment.
4 is a flowchart illustrating a spray drying process of controlling the size of particles by adjusting the temperature of hot air according to an embodiment.
5 is a diagram showing the correlation between the nanobubble injection time and the number of nanobubbles.
6 is a first exemplary view illustrating a process of controlling the shape of particles in a spray drying process according to an embodiment.
7 is a second exemplary view illustrating a process of controlling the shape of particles in a spray drying process according to an embodiment.
8 is an enlarged first exemplary view of the shape of particles obtained in a spray drying process according to an embodiment.
9 is an enlarged second exemplary view of the shape of particles obtained in a spray drying process according to an embodiment.
10 is a view showing the existence ratio by size of particles obtained in a spray drying process according to an embodiment.
11 is a graph showing the accumulation of abundance ratios by size of particles obtained in a spray drying process according to an embodiment.
12 is a diagram comparing the distribution of particles by temperature in a spray drying process according to an embodiment.
13 is a first exemplary view showing the distribution of particles for each temperature obtained while changing the flow rate condition of a spray drying process according to an embodiment.
14 is a second exemplary view showing the distribution of particles for each temperature obtained while changing the flow rate condition of a spray drying process according to an embodiment.
15 is a third exemplary view showing the distribution of particles for each temperature obtained while changing the flow rate condition of a spray drying process according to an embodiment.

Hereinafter, some embodiments of the present invention will be described in detail through exemplary drawings. In adding reference numerals to the components of each drawing, it should be noted that the same components have the same numerals as much as possible even if they are displayed on different drawings. In addition, in describing the present invention, a detailed description of a related known configuration or function, which is determined to obscure the gist of the present invention, will be omitted.

In addition, in describing the components of the present invention, terms such as first, second, a, and b may be used. These terms are only used to distinguish the component from other components, and the nature, sequence, or order of the corresponding component is not limited by the term. When an element is described as being “connected,” “coupled to,” or “connected” to another element, that element is directly connected or connectable to the other element, but there is another element between the elements. It will be understood that elements may be “connected”, “coupled” or “connected”.

1 is a diagram illustrating a process of injecting nanobubbles into an aqueous solution according to an embodiment.

Referring to FIG. 1 , a nanobubble manufacturing system 100 may include a tank 10, a pump 20, a bubble generator 30, and the like.

In the nanobubble manufacturing system 100, the liquid and solid mixture contained in the tank 10 may be delivered to the bubble generator 30 through the pump 20, and the bubble generator 30 may transfer the liquid and solid mixture 11 and The gas 13 can be mixed to create bubbles. If necessary, each of the liquid and the solid may be delivered to the bubble generator 30 by a separate storage device or conduit.

Bubbles generated in the bubble generator 30 may be mixed with an aqueous solution to form an aqueous solution-bubble mixture 15, and the aqueous solution-bubble mixture 15 generated through a conduit or the like is transferred to another separate device for subsequent processes. can be performed.

The bubble generator 30 may generate bubbles of various sizes, such as nano-sized bubbles, micro-sized bubbles, and fine bubbles. When the bubbles generated by the bubble generator 30 include nano-sized bubbles, they may be defined as nano-sized bubbles, and bubbles of different sizes may be included.

According to one embodiment, the bubble generator 30 may be a nanobubble generator. Nano-sized bubbles formed on the mixture have less buoyancy than micro-sized and fine bubbles, and may remain suspended in the mixture for a long time.

In particular, when air or oxygen is introduced into the aqueous solution in the form of micro bubbles, the amount of dissolved oxygen can be increased and the physical and chemical properties of the aqueous solution can be changed.

Since the characteristics of the aqueous solution may change depending on the number or concentration of nanobubbles included in the aqueous solution, the number or concentration of nanobubbles in the aqueous solution according to the operating time of the bubble generator 30 is measured to obtain a look-up table (LUT). ) can be formed.

The liquid and solid mixture 11 delivered to the bubble generator 30 may be any liquid or solid, respectively, depending on the desired final product.

2 is a view illustrating a spray drying process according to an embodiment.

Referring to FIG. 2, the spray drying system 200 includes a blower 110, a heating device 120, a nozzle 130, an aqueous solution storage device 140, a mixing chamber 150, a cyclone 160, and a recovery device ( 170) and the like.

Through the spray drying system 200, it is possible to evaporate the liquid from a solution in a mixture of solid and liquid and obtain only the solid.

The blower 110 serves to transport external air, and may include a pump (not shown) and the like. Types of the blower 110 may include a turbo blower, a ring blower, and a roots blower.

The air 111 passing through the blower 110 may be transferred to the heating device 120 and heated. The blower 110 may control the flow rate of hot air.

The type of the heating device 120 is not limited as long as it can transfer heat energy through conduction, convection, or radiation.

It is possible to increase the temperature of the air delivered by installing a heating device 120 around the conduit through which the air 111 passing through the blower 110 passes, and a temperature measuring device (not shown) and temperature around the heating device A control device (not shown) may be installed together to control the temperature of the hot air.

The heating device 120 is installed in the fluid passage between the blower 110 and the mixing chamber 150 to measure the temperature of the air 112, and defines the temperature as the first temperature (Temp. 1) to generate hot air temperature can be controlled. If necessary, the first temperature may be defined as a reference temperature.

As the type of heating device 120, a gas heater, an electric heater, a steam heater, and the like may be used.

The air 112 passing through the heating device may be transferred to the mixing chamber 150 and mixed with the solution 114 sprayed through the nozzle 140 in the mixing chamber 150 .

The solution storage device 130 may store the solution produced by the nanobubble manufacturing process of FIG. 1 described above.

The nozzle 140 can receive the solution 113 containing the nanobubbles delivered to the solution storage device 130 and deliver the solution to the mixing chamber 150, and the spraying method of the solution can be selected according to the type and size of the nozzle. You can choose.

As a method for controlling the nozzle 140, the type of nozzle, the size of the nozzle, the flow rate of the nozzle, the pressure of air used in the nozzle, and the like can be selected differently.

Types of the nozzle 140 include a rotary disk nozzle, a two fluid nozzle, a pressure nozzle, an ultrasonic nozzle, and an atomizer in order to atomize and spray the solution. ) may be used, but an arbitrary nozzle may be selected according to the drying conditions in the mixing chamber 150.

In the mixing chamber 150, the liquid phase and the hot air may contact each other in a co-current method, a counter-current method, or a mix-flow method.

In the co-current method, the hot air and the solution contact in the same direction, and in the counter-current method, the hot air and the solution contact in the opposite direction. The type of solution, the temperature and flow rate of the hot air may be selected differently.

The temperature inside the mixing chamber 150 is the second temperature (Temp. 2), the third temperature (Temp. 3), the fourth temperature (Temp. 4), the fifth temperature (Temp. 5), and the sixth temperature (Temp. 5), as necessary. It can be measured by dividing by temperature (Temp. 6), etc.

Depending on the temperature inside the mixing chamber 150, the material may expand at a temperature higher than a standard value, and the expansion of the material may be limited at a temperature lower than the standard value, so that the size of particles may be small.

The material 115 passing through the mixing chamber 150 may be transferred to the cyclone 160, and a portion of the material 116 may be recovered through the cyclone 160. Other parts of the material may be recovered in the recovery device 170. If necessary, the temperature of the material 115 transferred to the cyclone 160 may be measured and defined as a seventh temperature (Temp. 7).

The cyclone 160 may recover dry powdered product by airflow. Heavy particles that are not collected along with the air flow by the cyclone 160 may be recovered by the recovery device 170 .

The solid particles dried by the spray drying system 200 can be recovered, and the shape and size of the solid particles can be determined by the temperature of the hot air, the flow rate of the hot air, control of the spray nozzle, the number of nanobubbles, the input time of the nanobubbles, and the nanobubbles. The distribution of can be controlled by the size of the nanobubbles.

3 is a flowchart illustrating a spray drying process using nanobubbles according to an embodiment.

Referring to FIG. 4 , the spray drying process 300 using nanobubbles may include a nanobubble preparation step (S301), a solution-phase nanobubble mixing step (S303), a solution spray drying step (S305), and the like. . All or some of the steps may be omitted or the order may be changed.

In the nanobubble production step (S301), nanobubbles may be produced by injecting a gas into a solution by the method of FIG. 1 or the like described above. A nanobubble is a bubble with a size of 1 to 999 nanometers and stays in a solution so that the properties of the gas in the solution can affect the solution. The size of nanobubbles can be changed according to the shape or size of solid particles, which are final products obtained by the spray drying process.

Illustratively, the liquid used in preparing the nanobubbles may be distilled water, the solid may be maltodextrin, and the gas may be air.

When the concentration of the aqueous solution used for mixing the nanobubbles is changed, the degree of mixing of the nanobubbles may be different.

Illustratively, the concentration of the solution may be a 25% by mass aqueous solution, but the concentration of the solution may be set differently if necessary.

In the step of mixing nanobubbles in solution (S303), the solution and nanobubbles may be mixed through a nanobubble generator (not shown), and the number of nanobubbles may be adjusted.

The amount of nanobubbles mixed with the solution may be controlled by adjusting the supply amount of the gas connected to the nanobubble generator, the supply amount of the solution connected to the nanobubble generator, or adjusting the operating time of the nanobubble generator.

Illustratively, the operating time of the nanobubble generator may be 1 hour and 30 minutes. In this case, the solution may have 200 million nanobubbles/ml or more.

If necessary, the operating time of the nanobubble generator may be set to a time to enter a period defined as a steady-state in which nanobubble generation is stabilized.

If necessary, in the step of mixing nanobubbles in solution (S303), a bubble stabilization step may be additionally included to separate generated nanobubbles and microbubbles.

Microbubbles can be removed when a solution in which nanobubbles and microbubbles are mixed is refrigerated at a temperature below room temperature. If necessary, refrigeration can be performed for several tens of minutes. In addition, refrigerated storage may be stored at 4 ° C. for 12 hours, but refrigerated storage conditions may be changed differently depending on the type of liquid and solid used.

In the spray drying step (S305) of the solution, solid particles included in the solution may be obtained by the above-described spray drying of FIG. 2 .

4 is a flowchart illustrating a spray drying process of controlling the size of particles by adjusting the temperature of hot air according to an embodiment.

Referring to FIG. 4, the spray drying process 400 using nanobubbles includes a nanobubble manufacturing step (S401), a step of separating solution phase nanobubbles and microbubbles (S403), and a step of adjusting the temperature and flow rate of hot air ( S405), spray drying of the solution (S407), and the like. All or some of the steps may be omitted or the order may be changed.

In the nanobubble manufacturing step (S401), the nanobubble manufacturing method of FIGS. 1 and 3 described above may be utilized.

In the step of separating nanobubbles and microbubbles in the solution (S403), a stabilization step may be performed to separate nanobubbles and microbubbles from the bubble-mixed solution.

A bubble generator (not shown) may be designed to form bubbles within a certain range, but nanobubbles and microbubbles may be mixed. In this case, nanobubbles and microbubbles may be separated by storing a solution in which nanobubbles and microbubbles are mixed for a certain period of time.

Illustratively, the microbubble disappearing time may be several tens of minutes, but the stabilization time may be defined differently depending on the characteristics of the liquid and solid used in the solution.

Illustratively, when a solid is used as maltodextrin, since the properties of the material may change at room temperature, it may be stored in a refrigerator at 4° C. for 12 hours or more.

The solution from which the microbubbles are separated reflects the characteristics of the nanobubbles better, so that the shape and size of the particles can be controlled more effectively during the spray drying process.

A step of exposing the solution to room temperature may be further included after the step of separating the solution-phase nanobubbles and microbubbles.

Since the shape of the particles may change rapidly due to the temperature difference between the hot air and the solution during the contact process between the hot air delivered by the blower and the solution in the spray drying process of FIG. 2, the solution can be stored at a constant temperature. In the case of injecting the solution into the spray drying device immediately after refrigeration, the characteristics of the nanobubbles may be damaged in certain cases.

Illustratively, a solution stored at room temperature for 2 hours may be introduced into a spray drying device.

In the step of adjusting the temperature and flow rate of the hot air (S405), the spray drying time and the shape and size of dried particles can be controlled by adjusting the temperature and flow rate of the hot air.

In the spray drying step (S407) of the solution, the spray drying method of FIGS. 2 and 3 described above may be used.

For example, when the nozzle used for spray drying is a two-fluid nozzle, the solution may be sprayed at a flow rate of 0.936 kg/h and an air pressure of 0.95 bar.

로 설정할 수 있으나, 이에 제한되는 것은 아니다.In addition, the temperature inside the spray dryer is 260 ℃, the flow rate of the internal hot air is 35

It can be set to, but is not limited thereto.

5 is a diagram showing the correlation between the nanobubble injection time and the number of nanobubbles.

Referring to FIG. 5 , the number of nanobubbles (particle/min) may be obtained differently according to the operating time (min) of the nanobubble generator.

A look-up table (LUT) may be formed by measuring the number or concentration of nanobubbles in an aqueous solution according to the operation time of the nanobubble generator, and a graph may be formed.

The number of nanobubbles in the solution can be calculated based on the average value by measuring the change according to the results of a plurality of experiments.

For example, when the nanobubble generator operates for 60 minutes, the number of nanobubbles in the solution may continuously increase, and between 60 and 150 minutes, the number of nanobubbles in the solution may decrease. It is not.

After a certain time, it may be in a steady-state in which the amount of change in the number of nanobubbles over time is within a reference range.

The nanobubble manufacturing process described in FIGS. 1, 3, and 4 may be controlled based on the data on the change in the number of nanobubbles.

6 is a first exemplary view illustrating a process of controlling the shape of particles in a spray drying process according to an embodiment.

Referring to FIG. 6, the method 600 for controlling the shape of particles in the spray drying process under conditions below the standard temperature includes a nanobubble input step (S610), a dry edge formation step (S620), and a steam bubble growth step (S630). , An annular ring forming step (S640), a vapor-gas replacement step (S650), a particle forming step (S660), and the like may be included.

In the step of introducing nanobubbles (S610), nanobubbles may be introduced into the solution under conditions of a certain temperature or less.

In the dry edge forming step (S620), the solid particles may form an edge. This can be defined as a dried edge.

In the vapor bubble growing step (S630), internal vapor bubbles may grow, which may be due to heating by hot air.

In the annular ring forming step (S640), the grown vapor bubbles may be merged to form one integrated bubble.

In the steam-gas replacement step (S650), steam may be evaporated by hot air and replaced with gas.

In the particle formation step (S660), the solid particles may have an annular ring due to gas expanded by high-temperature hot air.

7 is a second exemplary view illustrating a process of controlling the shape of particles in a spray drying process according to an embodiment.

Referring to FIG. 7 , the method 700 for controlling the size and shape of particles in the spray drying process at a condition equal to or higher than the standard temperature includes a nanobubble input step (S710), a dry edge formation step (S720), and a steam bubble growth step (S730). ), an annular ring forming step (S740), a vapor-gas replacement step (S750), a particle forming step (S760), and the like.

In the nanobubble injection step (S670), the nanobubble mixed solution produced by the nanobubble manufacturing method of FIGS. 1, 3, and 4 described above may be formed. If necessary, the nanobubbles may be insoluble gas.

Nano-sized bubbles may be uniformly distributed throughout the solution, and the number of nano-bubbles may be adjusted as shown in FIG. 5 described above.

In the dry edge forming step (S720), the solid particles may form an edge. This can be defined as a dried edge.

In the vapor bubble growing step (S730), internal nano-sized vapor bubbles may grow, which may be due to heating by hot air. Unlike the vapor bubbles of FIG. 6, the vapor bubbles of FIG. 7 may include a larger number of bubbles, and greater growth may occur depending on the ambient temperature and the number of nanobubbles.

In the annular ring forming step (S740), the grown vapor bubbles may be merged to form one integrated bubble. A large amount of nanobubbles can be included to form integrated bubbles of a larger size than the bubbles of FIG. 6 .

In the steam-gas replacement step (S750), steam may be evaporated by hot air and replaced with gas.

In the particle formation step (S760), the solid particles may have an annular ring due to gas expanded by high-temperature hot air. In this case, the size of the annular ring may be larger in FIG. 7 because a large amount of nanobubbles may be included to form integrated bubbles having a larger size than the bubbles in FIG. 6 .

Since the expansion of the solution containing the nanobubbles is greater, the diameter of the solid particles may be larger, and solid particles of a more unstable form may be formed.

Illustratively, unlike the solid particles of FIG. 6, the solid particles of FIG. 7 may be formed asymmetrically and irregularly, and in the particle drying step, the difference in shape and size of the solid particles generated by injecting hot air at a standard temperature or higher is a solid. It can be defined as the breaking phenomenon of particles.

6 and 7, the difference in shape and size of the solid particles may be defined according to the operating conditions of the spray drying process, such as the temperature of the incoming hot air, the flow rate of the hot air, and the flow rate of the solution sprayed from the nozzle.

8 is an enlarged first exemplary view of the shape of particles obtained in a spray drying process according to an embodiment.

Referring to FIG. 8 , it is possible to confirm the surface shape and size of the particles obtained in the spray drying process under conditions of a standard temperature or less. It may be solid particles formed by the method of FIG. 6 .

9 is an enlarged second exemplary view of the shape of particles obtained in a spray drying process according to an embodiment.

Referring to FIG. 9 , it is possible to confirm the surface shape and size of the particles obtained in the spray drying process under conditions of a reference temperature or higher. It may be solid particles formed by the method of FIG. 7 .

Based on the simulation results of FIGS. 6 to 9, the shape and size of solid particles obtained by controlling conditions such as the temperature and flow rate of the hot air used in the spray drying process or the flow rate of the solution introduced through the nozzle can be adjusted. .

10 is a diagram showing the existence ratio by size of particles obtained in a spray drying process according to an embodiment.

Referring to FIG. 10 , it can be seen the distribution of solid particles obtained according to the presence or absence of nanobubbles in an aqueous solution having a concentration of 25% by mass of maltodextrin (Maltodextrin DE-20).

Compared to a solution containing nanobubbles (NBO Solution) and a solution without nanobubbles (NBX Solution), the diameter corresponding to the x-axis may decrease in the solution containing nanobubbles, and the diameter corresponding to the y-axis may decrease. The number of particles may increase.

11 is a graph showing the accumulation of abundance ratios by size of particles obtained in a spray drying process according to an embodiment.

Referring to FIG. 11, comparison of the abundance ratio of solid particles by size obtained from a solution containing nanobubbles (NBO Solution) and a solution not containing nanobubbles (NBX Solution) in the spray drying process under the same conditions as in FIG. 10 can

12 is a diagram comparing the distribution of particles by temperature in a spray drying process according to an embodiment.

Referring to FIG. 12, it is possible to compare the diameter and number of solid particles obtained through the spray drying process according to the inlet temperature of the hot air.

Illustratively, as in the experimental conditions B-1, B-2, and B-3, the solid obtained through the spray drying process when the inlet temperature of the hot air defined as the first temperature is 160 ° C, 200 ° C, and 260 ° C The diameter and number of particles can be compared.

As another example, the diameter and number of solid particles obtained through the spray drying process in the case of adjusting the flow rate of hot air can be compared.

Referring to Table 1 below, as in the experimental conditions B-1-1, B-1-2, B-2-1, B-2-2, B-3-1, B-3-2, nanobubbles An example comparing the characteristics of the solid particles according to the presence or absence of and the inlet temperature of the hot air can be confirmed.

Referring to the experimental conditions B-1-1 in Table 1 below, when the inlet temperature of hot air is 160 ° C and nanobubbles are included, it can have a specific surface area of 0.427 (m / g), It may have a geometric mean diameter of 2.35 (um).

Referring to the experimental conditions B-1-2 in Table 1 below, when the hot air inlet temperature is 160 ° C and does not contain nanobubbles, it can have a specific surface area of 0.222 (m / g), , and may have a geometric mean diameter of 2.88 (um).

Referring to the experimental condition B-2-1 of Table 1 below, when the hot air inlet temperature is 200 ° C and nanobubbles are included, it can have a specific surface area of 0.418 (m2 / g), It may have a geometric mean diameter of 2.18 (um).

Referring to the experimental condition B-2-2 of Table 1 below, when the hot air inlet temperature is 200 ° C and does not contain nanobubbles, it can have a specific surface area of 0.393 (m / g), , and may have a geometric mean diameter of 2.71 (um).

Referring to the experimental condition B-3-1 in Table 1 below, when the hot air inlet temperature is 260 ° C and nanobubbles are included, it can have a specific surface area of 0.759 (m / g), It may have a geometric mean diameter of 2.10 (um).

Referring to the experimental conditions B-3-2 in Table 1 below, when the hot air inlet temperature is 160 ° C and does not contain nanobubbles, it can have a specific surface area of 0.609 (m / g), , and may have a geometric mean diameter of 2.41 (um).

According to one embodiment, when nanobubbles are mixed into a solution, the average diameter can be reduced by about 15 to 20% and the specific surface area can be increased by about 15% or more compared to the result of a general solution without nanobubbles. It is not.

Test no. Inlet Air Temp(℃) NB O,X Specific Surface
Area
(m2/g) Geometric
Mean Diameter (um) B-1-1 160 O 0.427 2.35 B-1-2 160 X 0.222 2.88 B-2-1 200 O 0.418 2.18 B-2-2 200 X 0.393 2.71 B-3-1 260 O 0.759 2.10 B-3-2 260 X 0.609 2.41

13 is a first exemplary view showing the distribution of particles for each temperature obtained while changing the flow rate condition of the spray drying process according to an embodiment.

Referring to FIG. 13, when the flow rate of the solution sprayed through the nozzle is 0.20 g / s, the number of solid particles per diameter (Diameter) of the solid particles obtained through the spray drying process according to the inlet temperature of the hot air Alternatively, the volume of solid particles per diameter can be compared.

Illustratively, as in the experimental conditions C-1, C-2, and C-3, the solid obtained through the spray drying process when the inlet temperature of the hot air defined as the first temperature is 160 ° C, 200 ° C, and 260 ° C The diameter and number of particles can be compared.

Examining the experimental condition C-1, by comparing data with and without nanobubbles, particles with a small diameter increase through a graph of the number of solid particles by diameter (Diameter), and at the same time, the diameter ( Through the volume graph of solid particles by diameter, it can be seen that particles with large diameters also increase.

Examining the experimental condition C-2, by comparing data with and without nanobubbles, particles with a small diameter increase through a graph of the number of solid particles by diameter (Diameter), and at the same time, the diameter ( Through the volume graph of solid particles by diameter, it can be seen that particles with large diameters also increase.

Examining the experimental condition C-3, by comparing data with and without nanobubbles, particles with a small diameter are reduced through a graph of the number of solid particles by diameter (Diameter), and at the same time, the diameter ( Through the graph of the volume of solid particles by diameter, it can be seen that particles with large diameter also decrease.

In addition to the experimental conditions C-1 to C-3, the change in the number of nanobubbles according to the diameter and the change in volume according to the diameter according to the temperature change of the hot air can be obtained as data, and the target solid particles can be obtained.

In the experimental conditions C-1 and C-2, the small and large particles increased at the same time, but in the experimental condition C-3, it can be confirmed that the particle destruction phenomenon occurs.

Since it is possible to obtain a recipe for making particles with a small diameter as well as particles with a large diameter by using the growth of nanobubbles, the characteristics of the particles to be obtained can be defined by adjusting the conditions of the detailed process.

14 is a second exemplary diagram showing the distribution of particles for each temperature obtained while changing the flow rate condition of a spray drying process according to an embodiment.

Referring to FIG. 14, when the flow rate of the solution sprayed through the nozzle is 0.26 g / s, the number of solid particles per diameter (Diameter) of the solid particles obtained through the spray drying process according to the inlet temperature of the hot air Alternatively, the volume of solid particles per diameter can be compared.

Illustratively, as in the experimental conditions D-1, D-2, and D-3, the solid obtained through the spray drying process when the inlet temperature of the hot air defined as the first temperature is 160 ° C, 200 ° C, and 260 ° C The diameter and number of particles can be compared.

Experimental conditions D-1, D-2, and D-3, same as experimental conditions C-1, C-2, and C-3, spray flow rate 0.26g/s or less, drying temperature 200℃ or less, number of nanobubbles 2X10 ⁸ pieces/ml level And a similar pattern was obtained at the average nanobubble diameter level of 300 nm.

15 is a third exemplary view showing the distribution of particles for each temperature obtained by changing the flow rate condition of a spray drying process according to an embodiment.

Referring to FIG. 15, when the flow rate of the solution sprayed through the nozzle is 0.32 g / s, the number of solid particles per diameter (Diameter) obtained through the spray drying process according to the inlet temperature of the hot air Alternatively, the volume of solid particles per diameter can be compared.

Illustratively, as in the experimental conditions E-1, E-2, and E-3, the solid obtained through the spray drying process when the inlet temperature of the hot air defined as the first temperature is 160 ° C, 200 ° C, and 260 ° C The diameter and number of particles can be compared.

Experimental conditions E-1, E-2, and E-3, same as experimental conditions C-1, C-2, and C-3, spray flow rate of 0.32g/s, drying temperature of 200℃ or less, number of nanobubbles 2X10 ⁸ /ml level And a similar pattern was obtained at the average nanobubble diameter level of 300 nm.

However, as in the experimental condition E-3, it can be confirmed that the destruction of solid particles occurs more mainly under the condition of a drying temperature of 260 ° C.

Under the above experimental conditions, the maximum temperature at which the physical properties of the solution containing dextrin does not change can be set as the upper limit of 260 ° C, and the minimum drying temperature that can be achieved when an appropriate flow rate is obtained in the spray drying device is set as the lower limit of 160 ° C. can

In addition, when the temperature condition of the solution is about 200° C., expansion of the bubbles may occur appropriately, and the size of the particles may be increased without bursting the particles. When the temperature condition of the solution is set to the maximum temperature of 260 ℃, the rapid expansion of the bubble causes a lot of particle destruction.

It can be seen that even if the condition of the flow rate of the sprayed solution is changed in the above experimental conditions, the pattern of the number versus diameter or the volume versus diameter of the obtained solid particles does not change significantly.

According to the above experimental results, desired particles can be prepared by defining the state of the solid particles as small particles, large particles, or an appropriate mixing ratio of small particles and large particles.

Reflecting the above experimental results, the spray drying process may include setting the temperature condition of the hot air or the flow rate at which the solution is sprayed through the nozzle, and obtaining data on the shape or size of the solid particles.

In addition, the spray drying process may further include checking the state of the solid particles obtained through the particle drying step and changing the flow rate condition or temperature condition of the hot air.

In addition, the spray drying process may further include obtaining composition ratio data for each size of the solid particles obtained in the particle drying step in response to the temperature change of the hot air. Here, the composition ratio data may be defined as a ratio of solid particles having a diameter less than or equal to the standard value and solid particles having a diameter exceeding the standard value. The reference value may be defined as the mode or maximum value of the solid particle size obtained in the particle drying step.

In addition, in the spray drying process, the maximum hot air temperature is defined by measuring the rate at which the shape of the solid particles is destroyed as the temperature of the hot air is increased, and the temperature of the hot air can be maintained below the maximum hot air temperature.

In addition, the spray drying process may define the size of the solid particles by Gaussian dispersion of the size distribution of the solid particles obtained by changing the temperature of the hot air. The size distribution of solid particles actually obtained may have an asymmetrical Gaussian distribution rather than a symmetrical Gaussian distribution, and may appear similar to the graphs of FIGS. 13 to 15 described above.

In addition, the spray drying process may maintain the drying temperature of the hot air at 200 ° C to 260 ° C.

In addition, in the spray drying process, the number of nanobubbles included in the solution can be adjusted by changing the flow rate of the solution sprayed by the nozzle. It is possible to improve the probability of bubble inclusion by changing the size of the nozzle or changing the spray amount of the nozzle while maintaining the size of the droplet.

In addition, the cyclone of the spray drying process may adjust the internal centrifugal force so that the solid particles are collected in the order of large particles to small particles. When small particles and large particles of the obtained solid particles exist at the same time, the operating state of the cyclone may be variously adjusted to separate and obtain each solid particle.

In addition, in the particle drying step of the spray drying process, the rate of breakage of solid particles can be adjusted by adjusting the state of hot air.

Claims (15)

A nanobubble preparation step of supplying gas to a solution for a certain period of time through a nanobubble generator and mixing nanobubbles of nano size with the solution;
a solution spraying step of spraying the solution containing the nanobubbles into a mixing chamber through a nozzle;
a particle drying step of passing hot air through the sprayed solution in the mixing chamber to obtain dried solid particles; and
Setting the temperature conditions of the hot air or the flow rate at which the solution is sprayed through a nozzle, and acquiring data on the shape or size of the solid particles obtained in the particle drying step. According to claim 1,
Confirming the state of the solid particles obtained through the particle drying step, and further comprising the step of changing the temperature condition of the hot air or the flow rate at which the solution is sprayed through a nozzle, the spray drying process. According to claim 1,
Further comprising the step of obtaining composition ratio data for each size of the solid particles obtained in the particle drying step in response to the temperature change of the hot air. According to claim 3,
The composition ratio data is defined as the ratio of solid particles having a diameter below the standard value and solid particles having a diameter exceeding the standard value, the spray drying process. According to claim 4,
The reference value is defined as the mode or maximum value of the solid particle size obtained in the particle drying step. According to claim 1,
As the temperature of the hot air increases, the maximum hot air temperature is defined by measuring the rate at which the shape of the solid particles is destroyed, and the temperature of the hot air is maintained below the maximum hot air temperature. According to claim 1,
The spray drying process of defining the size of the solid particles by Gaussian dispersion of the size distribution of the solid particles obtained by changing the temperature of the hot air. According to claim 1,
The drying temperature of the hot air is maintained at 200 ° C to 260 ° C, spray drying process. According to claim 1,
The spray drying process of controlling the number of nanobubbles included in the solution by changing the flow rate of the solution sprayed by the nozzle. According to claim 1,
The spray drying process, wherein the liquid of the solution in the nanobubble preparation step is distilled water, and the solid is maltodextrin. According to claim 1,
Further comprising the step of recovering the dried solid particles through a cyclone, the spray drying process. According to claim 1,
The cyclone controls the internal centrifugal force so that the solid particles are collected in the order of large particles to small particles, the spray drying process. According to claim 1,
In the particle drying step, the hot air is introduced into the mixing chamber by a blower,
A spray drying process in which a heating device is installed in an inlet path between the blower and the mixing chamber to control the temperature of the hot air. According to claim 1,
In the particle drying step, the sprayed solution forms a dry edge and obtains solid particles dried by the hot air. According to claim 1,
Spray drying process of controlling the rate of breakage of solid particles by controlling the state of hot air in the particle drying step.

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