Liquid filling method and device for performing the method

Abstract

According to one embodiment of the present invention, a method for filling a narrow tube having a blocked end with a liquid comprises the steps of: injecting a volatile substance in a liquid state into the tube; sealing the pipe and connecting a vacuum forming device; vaporizing the volatile substance in the liquid state by operating the vacuum forming device to form a negative pressure so that the internal pressure of the tube is equal to or less than the vapor pressure of the volatile substance; and a step of applying pressure to fill the injected liquid. In the step of vaporizing the volatile substance in the liquid state, air present inside the tube is discharged to the outside of the tube by a negative pressure applied by the vacuum forming device. In the filling step of the injected liquid, if the pressure applied to the inside of the tube by filling is equal to or greater than the vapor pressure of the volatile substance, the volatile substance in the gaseous state condenses, thereby reducing the volume of the volatile substance, and reducing the volume of the volatile substance. And the injection liquid is filled into the internal space of the tube occupied by the volatile substance in the gaseous state.

Description

Technical Field

[0001] The present invention relates to a method for filling a liquid, and more particularly, to a method for injecting and filling a liquid into a narrow tube or space blocked at one end, and an apparatus for performing the method. Background Art

[0002] In various industrial fields, a technique of injecting and filling a liquid into a narrow tube or space (dead end channel or space) blocked at one end is utilized. However, if air preoccupying the space to be filled with the liquid cannot be removed or discharged to the outside, the injected liquid cannot be sufficiently filled. Even if the air trapped inside is compressed, there is still a problem that the injected liquid cannot be filled in an amount equivalent to the volume of the compressed air. Moreover, different from the case of a wide space, the air trapped in the narrow tube or space blocked at the end is more difficult to be discharged to the outside during the filling process of the injected liquid. This is because, in a narrow tube, the influence generated by the surface tension of the injected liquid becomes stronger, and the trapped air is difficult to penetrate through the liquid and be discharged to the outside (refer to Figure 1 ).

[0003] As known to the present inventors, in order to inject and fill a liquid into a narrow tube or space blocked at one end, the following two methods have been tried in the prior art. The first is a method of forming an outlet for discharging air in the blocked space and injecting while considering the loss of the injected material. In this method, not only material loss occurs, but also it cannot be applied in an environment where an outlet for the filling target space cannot be formed manually. The second is to form a high level of vacuum in the filling target space. However, forming a low pressure to sufficiently remove the internal air is not effective in terms of cost and difficulty. Moreover, when a vacuum that can be actually applied is applied, the internal air is not sufficiently removed. For example, even if the internal pressure is reduced to the level of 0.1 atm, there is still about 10% of air occupying the space, and thus the space occupied by this air cannot be filled with the injected liquid (if air is assumed to be an ideal gas, the formula PV = mRT can be applied, and when the temperature and volume are the same, the mass is proportional to the pressure). The filling by forming a high vacuum can only be applied to limited cases where the vapor pressure of the injected liquid is extremely low or the target filling rate is low. In the case where the vapor pressure of the injected liquid is relatively high, the internal pressure of the channel with a high vacuum is lower than the vapor pressure of the injected liquid, so vaporization of the injected liquid is induced. In order to solve the problem of inducing vaporization of the injected liquid and restricting the level of vacuum above the vapor pressure of the injected liquid, there is a problem point that the filling rate becomes low. Therefore, the filling by forming a high vacuum is only effective in limited cases where the vapor pressure of the injected liquid is extremely low or the target filling rate is low.

[0004] Thus, although there is a need for a technique in the related art that can completely fill a narrow tube or space blocked at one end, no effective solution has emerged until the present invention. Summary of the Invention

[0005] Technical Problem to be Solved by the Invention

[0006] An object of the present invention is to provide a method for achieving a significantly higher filling ratio compared to the prior art when injecting and filling a liquid into a narrow tube or space blocked at one end, or an apparatus for performing the method.

[0007] Moreover, an object of the present invention is to provide a method for achieving a significantly higher filling ratio compared to the prior art while using significantly simpler equipment and reduced costs, or an apparatus for performing the method.

[0008] Means for Solving the Technical Problem

[0009] The present invention relates to a liquid filling method and an apparatus for performing the method. A method for filling a narrow tube blocked at the end with a liquid according to an embodiment of the present invention includes the following steps: injecting a volatile substance in a liquid state into the inside of the tube; sealing the tube and connecting a vacuum forming device; operating the vacuum forming device to form a negative pressure so that the internal pressure of the tube becomes below the vapor pressure of the volatile substance, thereby vaporizing the liquid state volatile substance; and applying pressure to fill and inject the liquid.

[0010] In the step of vaporizing the liquid state volatile substance, air present inside the tube is discharged to the outside of the tube by the negative pressure applied by the vacuum forming device. In the step of filling and injecting the liquid, if the pressure applied inside the tube by the filling reaches above the vapor pressure of the volatile substance, the gaseous state volatile substance condenses, thereby reducing the volume of the volatile substance, and the injected liquid fills the internal space of the tube occupied by the gaseous state volatile substance.

[0011] Moreover, the scope of the present invention includes a liquid filling apparatus for performing the above liquid filling method.

[0012] In addition, an additional structure may be included in the liquid filling method and the apparatus for performing the method according to the present invention.

[0013] Advantages of the Invention

[0014] According to the present invention, a method for achieving a significantly higher filling ratio compared to the prior art when injecting and filling a liquid into a narrow tube or space blocked at one end, or an apparatus for performing the method, can be provided.

[0015] Moreover, according to the present invention, a method can be provided that achieves a significantly higher filling ratio compared to the prior art while using significantly simpler equipment and reduced costs compared to the prior art, or an apparatus for performing the method. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a diagram for explaining the reason why the air trapped in a narrow tube or space blocked at the end is difficult to be discharged to the outside during the filling process of injecting a liquid.

[0017] Figure 2 It is a diagram for explaining a liquid filling method based on an embodiment of the present invention.

[0018] Figure 3 It is a table listing the vapor pressures of various substances at room temperature.

[0019] Figure 4 It is a diagram showing the results of an acetone vaporization experiment.

[0020] Figure 5 It is a diagram showing the results of an experiment on injecting a filling substance in a vaporized state of acetone.

[0021] Figure 6 It is a diagram showing the results of a filling experiment using a gypsum model made to imitate teeth.

[0022] Figure 7 It is a diagram showing the results of a filling experiment using an actual extracted tooth. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0023] In the following detailed description of the present invention, reference is made to the accompanying drawings which illustrate specific embodiments of the invention that can be implemented. Such embodiments are described in sufficient detail so that those skilled in the art can practice the invention. The various embodiments of the present invention are different from each other, but it should be understood that these various embodiments are not mutually exclusive. For example, a specific shape, structure, and characteristic described in this specification can be implemented by changing from one embodiment to another without departing from the spirit and scope of the present invention. Also, it should be understood that the position or configuration of individual components in each embodiment can be changed without departing from the spirit and scope of the present invention. Therefore, the following detailed description is not intended to be limiting, but should be understood that the scope of the present invention includes the scope claimed in the claims and all scopes equivalent thereto.

[0024] Hereinafter, for the purpose of enabling those having ordinary knowledge in the technical field to which the present invention pertains to easily practice the present invention, several preferred embodiments of the present invention are described in detail with reference to the accompanying drawings.

[0025] Basic principle of the present invention

[0026] In the present invention, as a method for effectively removing air inside the filling target space, vaporization based on the boiling of a volatile liquid and condensation phenomenon based on compression are utilized. Generally, at the same weight, the volume occupied by a gas is approximately 1000 times that of a liquid. Instead of filling the filling target space with air, the space is filled with the vapor of a volatile liquid, and a liquid is filled and injected. At the same time, if the vapor of the volatile liquid is compressed to condense it and induce a phase change to the liquid state, the volume decreases sharply, thereby enabling a high filling rate to be ensured.

[0027] Explanation of the liquid filling method based on the present invention

[0028] Figure 2 It is a diagram for explaining the liquid filling method according to an embodiment of the present invention. Hereinafter, with reference to Figure 2 , the liquid filling method according to an embodiment of the present invention will be described.

[0029] As the first step, a volatile liquid is injected into the filling target space.

[0030] As the second step, the space is sealed and a vacuum forming device is connected.

[0031] As the third step, a vacuum is formed to create a pressure below the vapor pressure of the volatile liquid at normal temperature (or the temperature of the corresponding environment). Since it is only necessary to reduce the pressure below the vapor pressure, a high-level negative pressure forming device is not required.

[0032] As the fourth step, during the negative pressure formation process, a part of the air in the filling space is discharged to the outside. Subsequently, due to the reduced pressure, vaporization caused by boiling occurs in the volatile liquid. Through the operation of the vacuum forming device, a part of the internal air and vapor (vapor generated by the vaporization of the volatile liquid) is continuously discharged to the outside.

[0033] As the fifth step, during the negative pressure formation process, if all of the volatile liquid is vaporized, most of the air occupying the filling target space is discharged to the outside, and most of the space is filled with the vapor of the volatile liquid.

[0034] As the sixth step, a liquid is filled and injected. As the injected liquid is filled, the vapor of the volatile liquid is compressed, and the pressure inside the space rises.

[0035] As the seventh step, if the pressure rises and exceeds the vapor pressure of the volatile liquid, condensation begins, a phase change occurs, and the liquid volume becomes at the level of 1 / 1000 of the volume in the vapor state.

[0036] As the eighth step, if all of the volatile liquid has condensed to complete the filling, only about 0.1% of the entire space is filled with the volatile liquid, and the remaining space is entirely filled with the injected liquid.

[0037] Hereinafter, a detailed description will be given of the theoretical background of the liquid filling method based on one embodiment of the present invention described above.

[0038] First, an explanation will be given of the reason for using the volatile liquid in the present invention. In order for a substance in a liquid state to boil and vaporize, the pressure of the surrounding environment must be reduced to below the vapor pressure, which is an inherent physical property of the substance, at a specific temperature, or the temperature of the surrounding environment must be raised above the boiling point, which is an inherent physical property of the substance, at a specific pressure. When a liquid vaporizes into a gas state, the volume generally increases by approximately 1000 times. Conversely, when a gas liquefies into a liquid state, the volume decreases to the 1 / 1000 level. Therefore, if the gas filling the filling target space is compressed and condensed, the volume decreases rapidly, enabling filling without any empty space.

[0039] It is advantageous to use a volatile liquid that can be easily vaporized and liquefied near normal temperature and normal pressure. The vapor pressure of the volatile liquid is relatively low, and it can be vaporized by slightly reducing the pressure at normal temperature, so it can be easily converted into vapor inside the applicable target space. Figure 3 This is a table showing the vapor pressures of various substances at normal temperature (for reference, 1 atmospheric pressure is approximately 100 kPa).

[0040] Next, an explanation will be given of the principle of removing the internal air. After injecting the volatile liquid into the filling target space to form a negative pressure and vaporize it, the vapor of the volatile liquid can fill the internal space. Most of the air previously filling the space is discharged to the outside during the initial negative pressure formation process, and the air remaining thereafter can continue to be discharged together with a part of the vapor generated by the vaporization of the volatile liquid. At this time, diffusion rapidly occurs between the vapor of the volatile liquid and the air, so the internal space can be filled with the vapor of the volatile liquid in a short time. In particular, when the negative pressure is formed and the pressure decreases, the diffusion between gases proceeds more rapidly.

[0041] For example, at 1 atmospheric pressure, the general gas-gas diffusion coefficients D 1atm are as follows.

[0042] D 1atm ~10 -6 -10 -5 m 2 / s

[0043] In an environment where a negative pressure is formed for vaporization of a volatile liquid, resulting in a pressure at the level of 0.1 atmospheres, in the case of an ideal gas, the diffusion coefficients D 0.1atm increase by a factor of 10.

[0044] D 0.1atm ~10 -5 -10 -4 m 2 / s

[0045] If the depth of the space to be filled is set at the level of L~10 mm, the time t required for diffusion of the vapor is within several seconds.

[0046] t~L 2 / D 0.1atm ~10 0 -10 1 s

[0047] Next, the appropriate level of negative pressure will be described. Quantitatively, the target pressure (P) of the internal space must satisfy the following conditions. P 挥发性液体 is the vapor pressure of the volatile liquid at the ambient temperature.

[0048] P<P 挥发性液体

[0049] At this time, the type (and vapor pressure) of the volatile liquid and the target pressure of the internal space can be flexibly determined based on the vapor pressure characteristics of the injected liquid, the reactivity between the volatile liquid and the injected liquid, the compatibility between the volatile liquid and the target filling space, and the ease of forming a negative pressure in the target filling space. For example, if acetone is used as the volatile liquid, by reducing the pressure in the internal space to less than 0.3 atmospheres, boiling and vaporization of acetone can be achieved.

[0050] An experiment was carried out using acetone as the volatile liquid

[0051] The inventor of the present invention carried out an experiment to verify the performance of filling a liquid into a narrow tube or space blocked at one end by the method of the present invention described above. In this experiment, acetone was used as the volatile liquid. Acetone has a vapor pressure of 30 kPa at 25 °C. The vapor pressure at 36 °C is 48 kPa.

[0052] The inventor of the present invention carried out filling experiments on a total of three environments. In the first experiment, a model made of transparent acrylic was used so that the vaporization process and filling process of acetone could be observed from the outside. In the second experiment, a plaster model imitating a tooth was used. In the third experiment, an actual extracted tooth was used.

[0053] In the above three experiments, liquid-state acetone was injected into the root canals in the acrylic tubes or dental plaster models or the root canals of the actually extracted teeth. Then, in order to form a negative pressure to induce the vaporization of acetone, the inside of the narrow tube with a blocked end was filled with acetone vapor. Then, the injection of the filling material was carried out. During the injection of the filling material, the acetone vaporized due to the increased pressure was induced to change phase into a liquid state, and the filling was completed.

[0054] The first experiment using the acrylic model was generally carried out in two steps. The first step was the vaporization experiment of acetone, and the second step was the experiment of injecting the filling substance in the vaporized state of acetone.

[0055] In the acetone vaporization experiment, the inventor formed a negative pressure during the double boiling process in water at 35 - 45°C. The negative pressure level was gradually increased between 0 - 90 kPa, and during the increase of the negative pressure, direct inhalation of liquid-state acetone was prevented. Figure 4 It is a figure showing the results of the acetone vaporization experiment. Figure 4 The left photo on the is the state after 2 seconds of applying a negative pressure in the state where 40 μL of liquid-state acetone was injected into the inside of the narrow tube with a blocked end. It can be confirmed that acetone starts to vaporize in the state of small droplets. Figure 4 The middle photo on the is the state after 5 seconds of applying a negative pressure. It can be confirmed that the vaporized acetone occupies a wider space. Figure 5 The right photo on the is the state after 10 seconds of applying a negative pressure. It can be confirmed that the vaporized acetone occupies the entire narrow tube with a blocked end. Through this experiment, it was confirmed as follows: By forming a negative pressure, the vaporization of acetone can be achieved; by forming a negative pressure, the air existing inside the tube can be almost completely discharged to the outside, so that the vaporized acetone can occupy the entire space; the vaporization and complete occupation of the space by 40 μL of acetone takes about 10 seconds. In this experiment, 40 μL of acetone was used, and it was confirmed that the vaporization of this amount of acetone takes approximately 10 seconds or so, but such experimental results should not be understood as limiting the scope of the present invention. According to the size of the space to be filled, the amount of liquid-state acetone used can be changed, and according to the environment where the filling space is located, the time required for the vaporization of liquid-state acetone can also be different. Moreover, any method of forming a negative pressure can be applied except for the method of forming a negative pressure in the double boiling used in this experiment. Of course, other types of volatile liquids other than acetone can also be used.

[0056] In Figure 5 the results of the experiment of injecting the filling material in the vaporized state of acetone are shown. Figure 5 The left photo on the is the state before injecting the filling material in the state where acetone is completely vaporized and completely occupies the narrow tube with a blocked end. Figure 5The middle photo shows the intermediate state of the process of injecting the filling material in the same state. Observation Figure 5 From the middle photo, it can be confirmed that an opaque filling material has been injected and occupies more than 2 / 3 of the upper end of the tube, and the filling material has not yet reached the lower part of the tube. Figure 5 The photo on the right shows the state where the filling material has almost completely reached the lower end of the narrow tube blocked at the end and the filling is completed. In theory, at the very lower end of the tube, there is acetone in a liquid state rather than the filling material, but the proportion of the space occupied by the liquid-state acetone relative to the entire tube space is only 1 / 1000, and it can be confirmed with the naked eye that the filling material completely occupies the entire tube.

[0057] Figure 6 It is a figure showing the results of the filling experiment using a plaster model imitating a tooth. In the filling experiment using a tooth plaster model, the inventor used two control groups. The first is the condition where negative pressure is formed but liquid-state acetone is not injected, so acetone vaporization is not caused either, corresponding to Figure 6 the left side. The second is the condition where after injecting liquid-state acetone, the filling material is injected under the state of applying the same negative pressure to vaporize the acetone, corresponding to Figure 6 the right side. In both control groups, the filling pressure was set to 150 kPa. Observation Figure 6 It can be confirmed that in the first control group, the gradually narrowing tube formed in the tooth plaster model was only filled about half. On the other hand, in the second control group, that is, on the side where the filling material was injected under the state of injecting and vaporizing acetone, it can be confirmed that the same-shaped tube was completely filled. In the Figure 6 control group shown in the figure, the end of the tube was in a completely sealed state.

[0058] Figure 7 It is a figure showing the results of the filling experiment using an actually extracted tooth. In this experiment, the inventor used three control groups. The first is the condition where no negative pressure is applied and no injection and vaporization of acetone are applied, corresponding to Figure 7 the left side. The second is the condition where negative pressure is applied but no injection and vaporization of acetone are applied, corresponding to Figure 7 the middle. The third is the condition where acetone is injected and, under the state of applying the same negative pressure as the second control group to vaporize it, the filling material is injected, corresponding to Figure 7 the right side. In the three control groups, the filling pressure was set to 150 kPa. Observation Figure 7 It can be confirmed that the control group applying the filling method based on the present invention has overwhelmingly excellent filling performance.

[0059] As described above, the present invention has been described by using specific matters such as specific constituent elements, limited embodiments, and drawings. However, this is only provided to help a more comprehensive understanding of the present invention. The present invention is not limited to the described embodiments. Those with ordinary knowledge in the technical field to which the present invention pertains can make various modifications and changes based on such descriptions.

[0060] Therefore, the idea of the present invention should not be limited to the embodiments described above. Not only the scope of the claims described later, but also all scopes equivalent to or equivalently changed from the scope of the claims fall within the scope of the idea of the present invention.

Claims

1. A liquid filling method, which is a method for filling a narrow tube with a blocked end with liquid, and the liquid filling method includes the following steps: A step of injecting a volatile substance in a liquid state into the inside of the tube; A step of sealing the tube and connecting a vacuum forming device; A step of operating the vacuum forming device to form a negative pressure so that the internal pressure of the tube becomes below the vapor pressure of the volatile substance, thereby vaporizing the volatile substance in the liquid state; and A step of applying pressure to fill and inject the liquid, In the step of vaporizing the volatile substance in the liquid state, air present inside the tube is discharged to the outside of the tube by the negative pressure formed by the vacuum forming device, In the step of filling the injected liquid, if the pressure applied inside the tube by filling reaches above the vapor pressure of the volatile substance, the gaseous volatile substance condenses, so that the volume of the volatile substance decreases, and the injected liquid fills the internal space of the tube occupied by the gaseous volatile substance.

2. The liquid filling method according to claim 1, wherein, The volatile substance is acetone.

3. A root canal filling method, which includes the following steps: A step of injecting a volatile substance in a liquid state into the root canal; A step of sealing the upper end of the root canal and connecting a vacuum forming device; A step of operating the vacuum forming device to form a negative pressure so that the pressure inside the root canal becomes below the vapor pressure of the volatile substance, thereby vaporizing the volatile substance in the liquid state; and A step of applying pressure to fill the filling material, In the step of vaporizing the volatile substance in the liquid state, air present inside the tube is discharged to the outside of the tube by the negative pressure formed by the vacuum forming device, In the step of filling the filling material, if the pressure applied inside the tube by filling reaches above the vapor pressure of the volatile substance, the gaseous volatile substance condenses, so that the volume of the volatile substance decreases, and the filling material fills the internal space of the tube occupied by the gaseous volatile substance.

4. The root canal filling method according to claim 3, wherein, The volatile substance is acetone.

5. A liquid filling device for performing the method according to claim 1.

6. The liquid filling device according to claim 5, wherein, The volatile substance is acetone.

7. A root canal filling device for performing the method according to claim 3.

8. The root canal filling device according to claim 7, wherein, The volatile substance is acetone.

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