Patent Application
20230398505
This application claims the benefit of priority to Japanese Patent Application No. 2022-095728, filed on Jun. 14, 2022, the entire contents of which are hereby incorporated by reference.
The present invention relates to a wet atomizer.
In a wet atomizer, raw material is pressurized to a high pressure of a maximal 245 MPa by a water jet, and high-speed ejection is performed from a fine nozzle having an ejection aperture of 0.05 to 0.5 mm. As a result, by colliding particles with other particles or hard members at the time of jetting, the shearing force generated by the nozzle passage and the counter flow, or the impact force by the jet cavitation, the secondary aggregated particles, which are mainly primary particles aggregated, are disintegrated or dispersed (e.g., Japanese Patent No. 3151706, hereinafter, Patent Literature 1).
In such a wet atomizer, a booster type (pressure increasing type) using a hydraulic drive is used for obtaining high pressure of 245 MPa. On the other hand, in the manufacture of pharmaceuticals, precision electronic components, and the like, there is a tendency to dislike the atmosphere itself in which driving oil is used in order to prevent pollution. An atomizer that uses a motor as a drive source and aims to have a small size has been proposed (for example, Japanese Patent No. 2897915, hereinafter, Patent Literature 2).
An electric wet atomizer which uses an electric motor as a drive source instead of a hydraulic drive and which is small in size and can be used in a simple laboratory or the like with a 100V power source is also proposed (for example, Japanese Patent No. 6045372, hereinafter, Patent Literature 3). The electric wet atomizer can easily replace the high-pressure packing sealing member attached in the cylinder.
A pump device capable of smoothly absorbing and supplying water by disposing a coil spring, a steel ball, or the like in a suction pipe and a discharge pipe, respectively is also proposed (for example, Japanese Utility Model Application Publication S51-47902, hereinafter, Patent Literature 4).
Even in the case of a small-sized wet atomizer, there are a plurality of variations in nozzle diameters at the time of injecting, refining, crushing, and dispersing a raw material. If it is desired to increase the throughput, a nozzle having a relatively large diameter is used. In this case, the amount of the raw material passing through the nozzle or the peripheral device increases, and the pressurization and depressurization energy when the plunger reciprocates in the high-pressure cylinder also increases. For this reason, outside air is taken in from a portion where the wet atomizer communicates with the outside, such as a nozzle or an ejection portion, and a blur occurs in an increase in pressure in the high-pressure cylinder that becomes a pressurizing chamber. This varies the pressure for processing the raw material, and the characteristics of the processed raw material become unstable.
In addition, in the valve structures as disclosed in Patent Literature 4, a fluid having low viscosity and high fluidity such as water is assumed. However, a wet atomizer often processes raw materials having high viscosity. Thus, even when such a valve structure is used, the raw material could adhere to the inside of the valve to cause clogging of the raw material. This cannot apply an appropriate pressure, and the characteristics of the raw material after the processing become unstable.
An object of the present invention is to provide a wet atomizer capable of stably increasing the pressure in a pressurizing chamber and performing a highly reproducible raw material process.
A first aspect of the present invention provides a wet atomizer, including:
The wet atomizer according to the present invention allows to stably increase the pressure in the pressurizing chamber, and to perform a highly reproducible raw material process.
Hereinafter, an embodiment will be described with reference to the drawings as appropriate.
As shown in
The wet atomizer 1 sucks raw material M from a suction port 3a into the high-pressure cylinder 3 by reciprocating motion of the plunger 4 to pressurize and discharge the sucked raw material M from a discharge port 3b. The wet atomizer 1 is configured by connecting the above-described components to a main body 1a. The wet atomizer 1 processes the raw material M by a pressing unit 1c and a display unit 1d operated by an operator while a drive source 20 is turned on and while the raw material M is supplied from a raw material tank 1b into the high-pressure cylinder 3.
The power transmission device 2 converts the rotational motion of a servo motor 21 into a reciprocating motion. The servo motor 21 has a hollow portion 21a therein. The power transmission device 2 is a high-efficiency screw mechanism 2a such as a ball-screw mechanism or a roller-screw mechanism.
The high-efficiency screw mechanism 2a includes a nut 21b and a screw shaft 21c. The high-efficiency screw mechanism 2a (roller-screw mechanism) is mounted inside the servo motor 21. Rotating the nut 21b of the high-efficiency screw mechanism 2a inside the servo motor 21 moves the screw shaft 21c forward or backward on a center axis.
The plunger 4 is coupled to an axially distal end of the screw shaft 21c. As a result, the forward or backward movement of the screw shaft 21c becomes a reciprocating movement of the plunger 4.
The servo motor 21 has a 100 V drive voltage and a 1.5 kW drive output. The high-efficiency screw mechanism 2a increases the power transmission efficiency. For this reason, the servo motor 21 driven by 100 V can also achieve high-pressure power.
The high-pressure cylinder 3 has a flow path 3c therein. The flow path 3c serves as a pressurizing chamber. The plunger 4 reciprocating in the flow path 3c increases the pressure in the flow path 3c and pressurizes the raw material M.
Many kinds of the raw material M and the solvent for pressurization (material, acidic or alkaline, etc.) are available. Thus, it is preferable to use a material such as stainless steel for the high-pressure cylinder 3 so as not to corrode the inside of the high-pressure cylinder 3.
The high-pressure cylinder 3 has a suction port 3a and a discharge port 3b. The suction port 3a sucks the raw material M supplied from a liquid supply pump (not shown). The raw material M after the pressurizing process is discharged from the discharge port 3b. For example, the suction port 3a may be disposed above the high-pressure cylinder 3. The discharge port 3b may be disposed below the high-pressure cylinder 3. Alternatively, the suction port 3a may be disposed above the high-pressure cylinder 3, and the discharge port 3b may be disposed on the left or right of the high-pressure cylinder 3.
The plunger 4 reciprocates inside the high-pressure cylinder 3 by the power transmission device 2 to pressurize the raw material M.
The drive controller 5 controls the reciprocating movement of the plunger 4. The drive controller 5 includes a sequencer 5a, a servo amplifier 5b, and an origin position detection sensor 5c. The drive controller 5 commands a target position of the plunger 4 from the sequencer 5a to the servo amplifier 5b. Here, the target position is a boost forward end position, a boost backward end position, and a disassembly backward end position of the plunger 4.
The origin position detection sensor 5c detects the boost backward end position of the plunger 4 as the origin. The drive controller 5 recognizes an origin serving as a reference for position control by the origin position detection sensor 5c prior to starting the reciprocating movement of the plunger 4. Further, a rotation angle detector 22 detects the rotation angle of the nut 21b of the high-efficiency screw mechanism 2a. Thus, the rotation angle detector 22 detects the current position. The rotation angle detector 22 is, for example, an encoder or a resolver.
The drive controller 5 controls the position of the plunger 4 by comparing the commanded target position with the current position detected by the rotation angle detector 22. This allows the wet atomizer 1 to surely suck the raw material M into the high-pressure cylinder 3 to pressurize and discharge the raw material M. The plunger 4 repeatedly moves forward and backward between the boost forward end position and the boost backward end position to suck and pressurize the raw material M. Here, the boost backward end position is a position that is retracted by one stroke from the boost forward end position.
The nozzle 6 atomizes the pressurized raw material M. The nozzle 6 has an orifice for the raw material M passing through to be atomized. The orifice has a diameter of 0.05 to 0.5 mm, for example.
As shown in
The nozzle 6 may be directly connected to the high-pressure cylinder 3. As shown in
The nozzle holder 9 includes an upper nozzle holder 9a. The high-pressure cylinder 3 includes a high-pressure cylinder-side connection portion 3d. The high-pressure cylinder-side connecting portion 3d and the upper nozzle holder 9a are connected to stably fix the nozzle 6 to the high-pressure cylinder 3. A screw groove is formed on an outer surface of the high-pressure cylinder-side connecting portion 3d and the inner surface of the upper nozzle holder 9a. The upper nozzle holder 9a is connected to the high-pressure cylinder-side connecting portion 3d by screwing the upper nozzle holder 9a so as to cover the high-pressure cylinder-side connecting portion 3d. The connection between the upper nozzle holder 9a and the high-pressure cylinder-side connection portion 3d is not limited to a screw. For example, the upper nozzle holder 9a and the high-pressure cylinder-side connecting portion 3d may be connected by connection between the concave portion and the convex portion or connection between the claw portion.
Further, when connected by a screw or the like inside the flow path, the raw material M flows in the flow path, or the raw material M is clogged. This might cause rust such as a screw. Thus, the upper nozzle holder 9a is preferably fitted from the outer side of the high-pressure cylinder-side connecting portion 3d. This suppresses the occurrence of nozzle clogging, rust, and the like.
The nozzle holder 9 may include a lower nozzle holder 9b. The lower nozzle holder 9b is connected to the upper nozzle holder 9a. The lower nozzle holder 9b fixes a first check valve 7a, a first elastic member 8a, and the discharge port 3b. The upper nozzle holder 9a has a receiving portion 9aa. The lower nozzle holder 9b has a protrusion 9ba. By connecting the receiving portion 9aa and the protrusion 9ba, the lower nozzle holder 9b is connected to the upper nozzle holder 9a to serve as the nozzle holder 9.
The first check valve 7a and the first elastic member 8a are arranged below (downstream of) the nozzle 6. As a result, the nozzle 6 for performing the high-pressure processing is located inside the apparatus, and the external air is less likely to be sucked in.
If the first check valve 7a and the first elastic member 8a are directly connected to the high-pressure cylinder 3, and the nozzle 6 is disposed below the first check valve 7a, the first check valve 7a and the first elastic member 8a are disposed in a high-pressure environment. Thus, the first check valve 7a and the first elastic member 8a are easily damaged. If the first check valve 7a and the first elastic member 8a are damaged, a sealing failure or clogging of the raw material M may occur, which may adversely affect the properties of the processed raw material M ejected from the nozzle 6.
Further, when the nozzle 6 has larger diameter, the external air might be sucked in, and the processing of the raw material M becomes unstable.
As in the present embodiment, by disposing the first check valve 7a and the first elastic member 8a below the nozzle 6, the loads applied to the first check valve 7a and the first elastic member 8a are reduced, and it is possible to prevent the sealing failure and the clogging of the raw material M. This stabilizes the atomization processing and the emulsification processing of the raw material M.
Further, the small-sized raw material M ejected from the nozzle 6 and atomized by colliding with the spherical 6a is sealed with the first check valve 7a and the first elastic member 8a. This achieves less adverse effect due to particle size or pressure increase as compared with the case where the nozzle 6 is disposed below the first check valve 7a as in the conventional art to seal the raw material M having a large size prior to the atomization. This achieves more efficient sealing performance.
As shown in
As shown in
The first check valve 7a is disposed on the side of the discharge port 3b. Specifically, the first check valve 7a is disposed downstream (lower in
When the plunger 4 is repeatedly reciprocated in the high-pressure cylinder 3 while the air remains in the high-pressure cylinder 3, the pressure in the high-pressure cylinder 3 is not appropriately increased due to the influence of the sucked air. In this case, the quality of the processed raw material M varies.
Arranging the first check valve 7a as in the present embodiment enables to stably increase the pressure in the high-pressure cylinder 3. The first check valve 7a is, for example, a spherical ball.
In addition, the first check valve 7a is adjusted to the same position in a normal state by the first elastic member 8a disposed below the first check valve 7a. The first elastic member 8a presses the first check valve 7a toward the upstream side, which is the valve closing direction. That is, the first elastic member 8a presses the first check valve 7a toward the nozzle 6 (upward in
The second check valve 7b is disposed on the side of the suction port 3a. Specifically, the second check valve 7b is disposed upstream (upward in
When the plunger 4 is repeatedly reciprocated in the high-pressure cylinder 3 while the air remains in the high-pressure cylinder 3, the pressure in the high-pressure cylinder 3 is not appropriately increased due to the influence of the sucked air. In this case, the quality of the processed raw material M varies.
Arranging the second check valve 7b as in the present embodiment enables to stably increase the pressure in the high-pressure cylinder 3. The second check valve 7b is, for example, a spherical ball.
In addition, the second check valve 7b is adjusted to the same position in a normal state by the second elastic member 8b disposed below the second check valve 7b. The second elastic member 8b presses the second check valve 7b toward the upstream side, which is the valve closing direction. That is, the second elastic member 8b presses the second check valve 7b toward the other side (upward in
When the raw material M passes through the first check valve 7a, the second check valve 7b does not allow the raw material M to pass through. When the raw material M passes through the second check valve 7b, the first check valve 7a does not allow the raw material M to pass through. This allows to effectively manage the pressure in the high-pressure cylinder 3.
In the present embodiment, a single raw material tank 1b and a single nozzle 6 are disposed on the high-pressure cylinder 3, but the present invention is not limited thereto. A plurality of raw material tanks 1b and a plurality of nozzles 6 may be disposed on the high-pressure cylinder 3. This also increases the process flow rate.
In the present embodiment, the pressure in the high-pressure cylinder 3 is mechanically maintained constant by the first check valve 7a and the second check valve 7b, but the present invention is not limited thereto. For example, the first check valve 7a and the second check valve 7b may be electrically automatically switched on or off in response to the operation of the pressing unit 1c or the processing time of the raw material M.
As shown in
The display unit 1d displays information acquired by the pressure detector 10. This allows the operator to check the state of the pressure in the high-pressure cylinder 3.
The pressure detector 10 is connected to a pressure detector connecting portion 10a of the high-pressure cylinder 3 via a pressure detection sealing 10b. This enables to accurately measure the pressure in the high-pressure cylinder 3.
Further, directly connecting the pressure detector 10 to the high-pressure cylinder 3 eliminates an additional space for detecting the pressure of the raw material M.
The display unit 1d will be described with reference to
The nozzle diameter setting unit 11 allows any one of a plurality of nozzle diameters to be selected. For example, there are three types of setting buttons, and one of 0.1 mm, 0.15 mm, 0.20 mm nozzle diameters is to be selected. The number of setting buttons is not limited to three, and may be changed as appropriate, for example, five types of setting. In addition to selecting each specific nozzle diameter, the numerical value may be manually adjusted.
The ejection pressure setting unit 12 allows a target ejection pressure to be selected. For example, there are three types of setting buttons, and one of 50 MPa, 100 MPa, 150 MPa is to be selected. The number of setting buttons is not limited to three, and may be changed as appropriate, for example, five types of setting. In addition to selecting each specific pressure, the numerical value may be manually adjusted.
The solvent specific gravity setting unit 13 allows a solvent for using to be selected. For example, there are three types of setting buttons, and any one of water, solvent A (ethanol), and solvent B (organic solvent) is to be selected. The number of setting buttons is not limited to three, and may be changed as appropriate, for example, five types of setting.
An advanced-retracted speed calculation unit 15 calculates an advanced-retracted speed of the plunger 4 based on the nozzle diameter set by the nozzle diameter setting unit 11, the target ejection pressure set by the ejection pressure setting unit 12, and the solvent specific gravity set by the solvent specific gravity setting unit 13. The advanced-retracted speed calculated by the advanced-retracted speed calculation unit 15 may be displayed on the display unit 1d.
A measured pressure display unit 14, which displays the ejection pressure measured by the pressure detector 10, may be arranged in the display unit 1d.
In addition, a numerical value relating to an environmental load such as the amount of carbon dioxide may be displayed on the display unit 1d by using the amount of electric power corresponding to the process time in using 100 V power supply.
The raw material M may be forcibly sucked into the high-pressure cylinder 3 from the raw material tank 1b by using a liquid supply pump (not shown).
A control unit (not shown) may be arranged to combine the pressure adjustment in response to the torque and the rotational speed of the servo motor 21 and the pressure adjustment in the high-pressure cylinder 3 by the pressure detector 10. This achieves highly accurate pressure management.
Specifically, when the pressure detected by the pressure detector 10 is lower than a preset value, the rotational speed of the servo motor 21 may be increased by a signal from the control unit to adjust the pressure in the high-pressure cylinder 3.
A modification of the nozzle 6 will be described with reference to
The inner chip 6Bd has a through-hole 6Bf and a nozzle groove 6Bg. The through-hole 6Bf allows the raw material M that has reached a high pressure in the high-pressure cylinder 3 to pass into the nozzle 6B. The nozzle groove 6Bg is a recess communicating with the through-hole 6Bf. In the nozzle 6B of the modification, the through-hole 6Bf and the nozzle groove 6Bg constitute an L-shaped cross-section. Thus, it is possible to reduce the diameter of the through-hole 6Bf and to effectively impart the shear caused by the flow having different flowing direction due to the nozzle groove 6Bg.
Further, as the through-hole 6Bf and the nozzle groove 6Bg are L-shaped in a cross-sectional view of the nozzle 6B of the modification, it is difficult to suck the outside air into the high-pressure cylinder 3. This effectively prevents air from being sucked in the first check valve 7a and the second check valve 7b to make the pressure in the high-pressure cylinder 3 uniform.
Next, a method of using the wet atomizer 1 according to the present embodiment will be described.
First, the operator drives the drive source 20 to bring the power transmission device 2 and the drive controller 5 into a standby state. Further, the operator connects the raw material tank 1b to the suction port 3a of the high-pressure cylinder 3.
Next, while the wet atomizer 1 is prepared, the pressing unit 1c and the display unit 1d are operated to set the pressure applied to the raw material M, and thus the atomization process of the raw material M is started.
The processing time, the number of times of processing, and the like can also be set as appropriate. After completion of the designated work, the processed raw material M is filled in a container to be stored.
By setting the nozzle diameter, the ejection pressure, and the solvent specific gravity using the nozzle diameter setting unit 11, the ejection pressure setting unit 12, and the solvent specific gravity setting unit 13, the advanced-retracted speed of the plunger 4 is calculated, and then the drive controller 5 can set an appropriate operating value. Further, it is possible to adjust the pressurizing pressure for processing the raw material M while checking the actual pressure measured by the pressure detector 10.
The wet atomizer 1 according to the present embodiment enables to prevent excess air from being taken in, for example, even when the nozzle diameter is changed. This stably increases the pressure in the pressurizing chamber to perform the raw material process with high reproducibility.
In the wet atomizer 1, the change in the discharge amount was verified between the case where the check valve 7 and the elastic member 8 are disposed and the case where the check valve 7 and the elastic member 8 are not disposed. The nozzle 6 has a diameter of 0.1 mm, and 0.15 mm, respectively.
In case of using the nozzle 6 having a diameter of 0.1 mm, 40 MPa and 60 MPa discharge pressure, which is a pressure-zone often used, was measured, although the largest 100 MPa was assumed. The discharge rate of 3.0 ml/shot was measured as an appropriate value.
In case of the discharge pressure of 40 MPa, and when the check valve 7 and the elastic member 8 were disposed, the discharge rate was 3.0 ml/shot. On the other hand, when the check valve 7 and the elastic member 8 were not disposed, the discharge rate was 2.8 ml/shot.
In case of the discharge pressure of 60 MPa, and when the check valve 7 and the elastic member 8 were disposed, the discharge rate was 2.9 ml/shot. On the other hand, when the check valve 7 and the elastic member 8 were not disposed, the discharge rate was 2.8 ml/shot.
In case of using the nozzle having a diameter of 0.15 mm, 5 MPa and 15 MPa discharge pressure, which is a pressure-zone often used, was measured, although the largest 20 MPa was assumed. The discharge rate of 3.0 ml/shot was measured as an appropriate value.
In case of the discharge pressure of 5 MPa, and when the check valve 7 and the elastic member 8 were disposed, the discharge rate was 2.9 ml/shot. On the other hand, when the check valve 7 and the elastic member 8 were not disposed, the discharge rate was 2.7 ml/shot.
In case of the discharge pressure of 15 MPa, and when the check valve 7 and the elastic member 8 were disposed, the discharge rate was 2.9 ml/shot. On the other hand, when the check valve 7 and the elastic member 8 were not disposed, the discharge rate was 2.8 ml/shot.
According to the verification test, it was confirmed that arranging the check valve 7 and the elastic member 8 increases the discharge rate and stabilizes the processing amount.
In the case where the check valve 7 and the elastic member 8 are not disposed as in the conventional structure, air bleeding work may be performed about 4 to 10 times for stabilizing the discharge rate depending on the raw material M. On the other hand, in the case where the check valve 7 and the elastic member 8 are disposed as in the present embodiment, it was confirmed that the discharge rate is stabilized by performing the air bleeding operation of about 2 to 3 times.
As described above, the present invention is not limited to the above-described embodiments, and the present invention can be appropriately modified without departing from the gist thereof.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2022-095728 | Jun 2022 | JP | national |
