JP7616862B2 - Powder Feeding Device - Google Patents

Description

The present invention relates to a technology for supplying powder together with a carrier gas.

A powder supplying device that supplies powder together with a carrier gas is known as a powder supply source for DC plasma torches, high-frequency induction thermal plasma devices, and the like. Conventional powder supplying devices are equipped with a powder storage chamber that stores the powder, a stirring blade that stirs the powder stored in the powder storage chamber, and a supply plate with a groove that receives powder that falls from a hole provided in the powder storage chamber, and are designed to supply the powder that falls into the groove of the supply plate by entraining it in the flow of carrier gas (see Patent Documents 1 to 4).

JP 2010-65246 A JP 2005-68542 A Japanese Patent Application Publication No. 5-239625 Japanese Patent Application Publication No. 5-239627

However, conventional powder supplying devices have the problem that it is difficult to stably supply highly cohesive powder.

The objective of the present invention is to provide a technology that can supply highly cohesive powder more stably than ever before.

The present invention is a powder supplying device that supplies powder together with a carrier gas, and includes a powder storage chamber that stores powder, a stirring blade that stirs the powder stored in the powder storage chamber, a supply plate having a groove that receives the powder stirred by the stirring blade, an information input unit that inputs drive condition setting information including at least the type of powder, a first drive unit that rotates the stirring blade, a second drive unit that rotates the supply plate, and a control unit that controls the first drive unit and the second drive unit according to the drive condition setting information input by the information input unit.

The present invention makes it possible to supply highly cohesive powder more stably than ever before.

FIG. 1 is a schematic diagram showing a configuration example of a powder supplying device according to an embodiment of the present invention. FIG. 4 is a schematic diagram illustrating an example of a data table stored in an information storage unit. FIG. 11 is a schematic plan view showing an example of the arrangement of the blocking portion. 11 is a schematic cross-sectional side view showing an example of the arrangement of the blocking portion. FIG. FIG. 13 is a diagram showing the results of an experiment conducted under the experimental condition 1. FIG. 13 is a diagram showing the results of an experiment conducted under experimental condition 2. FIG. 13 is a diagram showing the change over time in the powder supply rate when a mixed material obtained by mixing yttria and yttrium fluoride in a mass ratio of 99.1:0.1 is used as the powder. FIG. 13 is a diagram showing the change over time in the powder supply rate when a mixed material obtained by mixing yttria and yttrium fluoride in a mass ratio of 99.5:0.5 is used as the powder. FIG. 11 is a diagram (part 1) showing the change over time in the powder supply rate when a mixed material in which yttria and yttrium fluoride are mixed in a mass ratio of 99:1 is used as the powder. FIG. 2 is a second diagram showing the change over time in the powder supply rate when a mixed material in which yttria and yttrium fluoride are mixed in a mass ratio of 99:1 is used as the powder. FIG. 11 is a diagram (part 1) showing the change over time in the powder supply rate when a mixed material in which yttria and yttrium fluoride are mixed in a mass ratio of 95:5 is used as the powder. FIG. 2 is a second diagram showing the change over time in the powder supply rate when a mixed material in which yttria and yttrium fluoride are mixed in a mass ratio of 95:5 is used as the powder. FIG. 11 is a diagram (part 1) showing the change over time in the powder supply rate when a mixed material in which yttria and yttrium fluoride are mixed in a mass ratio of 90:10 is used as the powder. FIG. 2 is a second diagram showing the change over time in the powder supply rate when a mixed material in which yttria and yttrium fluoride are mixed in a mass ratio of 90:10 is used as the powder. FIG. 11 is a diagram (part 1) showing the change over time in the powder supply rate when a mixed material in which yttria and yttrium fluoride are mixed in a mass ratio of 80:20 is used as the powder. FIG. 2 is a second diagram showing the change over time in the powder supply rate when a mixed material in which yttria and yttrium fluoride are mixed in a mass ratio of 80:20 is used as the powder.

Embodiments of the present invention will be described in detail below with reference to the drawings. In this specification and the drawings, elements having substantially the same functions or configurations are given the same reference numerals, and duplicate descriptions will be omitted.

FIG. 1 is a schematic diagram showing an example of the configuration of a powder supplying device according to an embodiment of the present invention.
1, the powder supplying device 10 is a device that supplies powder together with a carrier gas. The powder supplying device 10 includes a powder supplying mechanism section 12, an information input section 14, a control section 16, a first driving section 18, a second driving section 20, a gas supply unit 22, and a powder supply monitoring section 24. The configuration of each section will be described below.

(Powder supply mechanism)
The powder supply mechanism 12 includes a powder storage chamber 32 for storing powder 30, an agitator blade 34 for agitating the powder 30 stored in the powder storage chamber 32, a supply plate 38 having a groove 36 for receiving the powder 30 agitated by the agitator blade 34, and a suction port unit 40 for sucking in the powder 30 that has entered the groove 36 of the supply plate 38.

The powder storage chamber 32 is a hollow container with a capacity capable of storing a predetermined amount of powder 30, and is also called a hopper. The powder storage chamber 32 is formed in a cylindrical shape. The bottom of the powder storage chamber 32 is open so that the powder 30 stirred by the stirring blade 34 can fall into the groove 36 of the supply plate 38. The powder 30 is stored in the powder storage chamber 32 by a gravity drop method from the top of the powder storage chamber 32.

The stirring blade 34 is disposed at the bottom of the powder storage chamber 32. A plurality of stirring blades 34 are attached to the outer surface of the rotating bracket 42. The stirring blades 34 fill the grooves 36 of the supply plate 38 with the powder 30 while stirring the powder 30 contained in the powder storage chamber 32. The rotating bracket 42 is attached to the upper end of the rotating shaft 46. The rotating bracket 42 is arranged concentrically with the rotating shaft 46 and rotates together with the rotating shaft 46. The rotating shaft 46 is attached with an O-ring 60 for airtight sealing. The number of stirring blades 34 is at least two, and preferably four. When four stirring blades 34 are provided, it is preferable to arrange the stirring blades 34 at equal intervals at a circumferential pitch of 90 degrees on the outer surface of the rotating bracket 42.

A stirring member 44 is attached to the rotating bracket 42. The stirring member 44 is a member that stirs the powder 30 in the powder storage chamber 32 by rotating together with the stirring blade 34 so as to prevent a bridge of the powder 30 from being formed inside the powder storage chamber 32. The stirring member 44 is made of a rectangular thin plate made of fluororesin, for example, and has a suitable degree of flexibility. The stirring member 44 is arranged to rise from the rotating bracket 42. The stirring member 44 is also attached at a position offset from the center of rotation of the rotating bracket 42 in the depth direction of FIG. 1.

The supply plate 38 is a rotating body that receives the powder 30 from the powder storage chamber 32 and supplies the received powder 30 to the suction port unit 40. The supply plate 38 is a so-called disk that is formed in a circular shape when viewed from above. The groove 36 is formed on the upper surface of the supply plate 38. When the supply plate 38 is viewed from above, the groove 36 is formed in an annular shape centered on the center of rotation of the supply plate 38. When the powder supply mechanism section 12 is viewed from above, the supply plate 38 is arranged so as to partially overlap with the powder storage chamber 32. As a result, a part of the groove 36 of the supply plate 38 is located inside the powder storage chamber 32, and the other part of the groove 36 is located outside the powder storage chamber 32.

The groove 36 is recessed into a predetermined shape from the top surface of the supply platen 38. The predetermined shape is, for example, a U-shape or a V-shape. The surface of the groove 36 is formed with irregularities (not shown) that suppress the slippage of the powder 30. The irregularities are formed, for example, by roughening the surface of the groove 36. A rotating shaft 48 is connected to the bottom surface of the supply platen 38. The supply platen 38 is disposed concentrically with the rotating shaft 48 and rotates integrally with the rotating shaft 48. An O-ring 62 for airtight sealing is attached to the rotating shaft 48.

The suction port unit 40 has a suction port 50 that sucks the powder 30 together with the carrier gas from the groove 36 of the supply plate 38. The suction port 50 is formed at one end of the powder suction pipe 52. The suction port 50 is arranged so as to face the groove 36 of the supply plate 38. A gas introduction pipe 54 is arranged on the outside of the powder suction pipe 52. The powder suction pipe 52 and the gas introduction pipe 54 have a double pipe structure with the powder suction pipe 52 as the inner pipe and the gas introduction pipe 54 as the outer pipe. A gas supply pipe 56 is connected to the gas introduction pipe 54. The gas supply pipe 56 branches off from the gas introduction pipe 54. The gas supply pipe 56 is a pipe that supplies a carrier gas. The carrier gas is a compressed inert gas. Examples of inert gases used as carrier gas include argon, helium, and nitrogen.

(Information input section)
The information input unit 14 is configured using, for example, a touch panel. The information input unit 14 is a part for inputting drive condition setting information as one of the input information. The drive condition setting information is information for setting the drive condition to be applied when driving the powder supplying device 10. The drive condition setting information input by the information input unit 14 includes various information, one of which is the type of powder 30. The type of powder 30 is information for specifying the type of powder 30 handled by the powder supplying device 10. When the powder 30 handled by the powder supplying device 10 is a mixed material obtained by mixing a main material and a secondary material, the type of the main material and the type of the secondary material may be input as the type of powder 30. In that case, the type of powder 30 to be input may include the mixing ratio of the secondary material. Other drive condition setting information may include, for example, the powder supply rate (g/min), the rotation speed (rpm) of the supply plate 38, the type of carrier gas, and the flow rate (L/min) of the carrier gas. The information input unit 14 may also be provided with a power button for turning the power of the powder supplying device 10 on and off, a start button for starting the operation of the powder supplying device 10, a stop button for stopping the operation of the powder supplying device 10, etc.

(Control Unit)
The control unit 16 is a part that controls the operation of the entire powder supplying device 10. The control unit 16 has a rotation ratio setting unit 64, a drive control unit 66, and an information storage unit 68. The rotation ratio setting unit 64 is a part that sets the rotation ratio between the supply platen 38 and the stirring blade 34 according to the type of powder 30 input by the information input unit 14. The drive control unit 66 is a part that drives and controls each part of the powder supplying device 10 (the powder supplying mechanism unit 12, the first drive unit 18, the second drive unit 20, and the gas supply unit 22).

The information storage unit 68 is a section that stores various information necessary for controlling the operation of the powder supplying device 10. For example, as shown in FIG. 2, the information storage unit 68 stores a data table that associates the type of powder 30 with the rotation ratio between the supply plate 38 and the stirring blade 34. This data table may be created based on the results of an experiment or simulation in which the rotation ratio is changed for each type of powder 30. When the type of powder 30 is input from the information input unit 14, the rotation ratio setting unit 64 reads out from the information storage unit 68 and sets the rotation ratio that corresponds to the input type of powder 30.

In this embodiment, as an example, the rotation ratio is set to 1:1 when the type of powder 30 is yttria (Y ₂ O ₃ ), 1:2 when the type of powder 30 is zirconia (ZrO ₂ ), and 1:4 when the type of powder 30 is alumina (Al ₂ O ₃ ). The drive control unit 66 controls the first drive unit 18 and the second drive unit 20 based on the rotation speed of the supply platen 38 input by the information input unit 14 and the rotation ratio set by the rotation ratio setting unit 64.

(First Drive Unit)
The first drive unit 18 is composed of a first motor 70 and a first motor driver 72. The first motor 70 is a motor that serves as a drive source for rotating the supply platen 38. The first motor 70 rotates the supply platen 38 via the rotating shaft 48. The first motor driver 72 is a driver that controls the drive of the first motor 70 in response to instructions from the drive control unit 66.

(Second Drive Unit)
The second drive unit 20 is composed of a second motor 74 and a second motor driver 76. The second motor 74 is a motor that serves as a drive source for rotating the agitating blade 34. The second motor 74 rotates the agitating blade 34 via the rotating shaft 46. The second motor driver 76 is a driver that controls the drive of the second motor 74 upon receiving instructions from the drive control unit 66.

(Gas supply unit)
The gas supply unit 22 is composed of a gas supply unit 78 and a gas flow control unit 80. The gas flow control unit 80 controls the flow rate of the carrier gas supplied by the gas supply unit 78. The gas flow control unit 80 controls the flow rate of the carrier gas upon receiving an instruction from the drive control unit 66. For example, when the flow rate of the carrier gas input by the information input unit 14 is 5 (L/min), the drive control unit 66 instructs the gas flow control unit 80 to set the flow rate of the carrier gas to 5 (L/min), and upon receiving this instruction, the gas flow control unit 80 adjusts the opening degree of a flow control valve (not shown) to control the flow rate of the carrier gas to 5 (L/min). The gas supply unit 78 may be treated as one of the elements constituting the powder supplying apparatus 10, or may be treated as a separate element from the elements constituting the powder supplying apparatus 10. When the gas supply unit 78 is treated as a separate element from the elements constituting the powder supplying apparatus 10, the gas supply unit 22 is composed only of the gas flow control unit 80.

(Powder supply monitoring unit)
The powder supply monitoring unit 24 is composed of a rate measurement unit 82 and a display unit 84. The rate measurement unit 82 is a unit that measures the supply rate (g/min) of the powder 30 supplied through the powder suction pipe 52. The measurement result of the rate measurement unit 82 is provided to the drive control unit 66 and the display unit 84. When the supply rate of the powder 30 provided by the rate measurement unit 82 falls below a threshold rate, the drive control unit 66 stops driving each unit of the powder supplying device 10 (the powder supply mechanism unit 12, the first drive unit 18, the second drive unit 20, and the gas flow control unit 80). The supply rate of the powder 30 falls below the threshold rate when, for example, a bridge of the powder 30 is formed in the powder storage chamber 32 or when the powder 30 is clogged in the powder suction pipe 52. The display unit 84 is a unit that displays various information including the supply rate of the powder 30 measured by the rate measurement unit 82. The display unit 84 is composed of, for example, a liquid crystal display, an organic EL display, or the like. When the information input unit 14 is configured by a touch panel, the touch panel may form the display unit 84. In other words, the touch panel may function as both the information input unit 14 and the display unit 84.

Next, the operation of the powder feeding device according to the embodiment of the present invention will be described.
First, the operator operates the touch panel or the like of the information input unit 14 to input drive condition setting information, and then the operator presses the start button of the information input unit 14. Then, in the powder supplying mechanism 12, under the control of the drive control unit 66, the first drive unit 18 rotates the supply plate 38, the second drive unit 20 rotates the stirring blade 34, and the gas flow rate control unit 80 supplies carrier gas through the gas supply pipe 56.

As a result, the powder 30 contained in the powder storage chamber 32 is stirred by the rotation of the stirring blade 34. At that time, the stirring member 44 rotates together with the stirring blade 34. In addition, a part (upper part) of the stirring member 44 is curved and deformed by the centrifugal force generated when the stirring blade 34 rotates. The bending and deformation of the stirring member 44 is a phenomenon caused by the flexibility of the stirring member 44 itself. As a result of the bending and deformation of the stirring member 44 in this way, a part of the stirring member 44 described above slides along the inner wall of the powder storage chamber 32. In addition, the shape of the rotating stirring member 44 is irregularly deformed while receiving resistance due to contact with the powder 30. Therefore, the stirring member 44 rotates while moving over a wide range within the powder storage chamber 32. As a result, inside the powder storage chamber 32, the agglomeration of the powder 30, which is the source of the agglomeration, can be broken down by the stirring member 44 before the highly cohesive powder 30 grows into agglomerates. This prevents the formation of a bridge of powder 30 inside the powder storage chamber 32. Therefore, almost the entire amount of powder 30 put into the powder storage chamber 32 can be sent to the powder suction pipe 52 via the groove 36 of the supply plate 38.

As described above, the powder 30 stirred by the stirring blade 34 enters the groove 36 of the supply plate 38. The powder 30 that has entered the groove 36 is transported to the suction port 50 as the supply plate 38 rotates. If the surface of the groove 36 is uneven, the powder 30 is prevented from slipping at the contact interface between the surface of the groove 36 and the powder 30. Therefore, the powder 30 that has entered the groove 36 at the bottom of the powder storage chamber 32 can be reliably transported to the suction port 50 as the supply plate 38 rotates.

The powder 30 thus transported to the suction port 50 is sucked into the powder suction pipe 52 by the flow of carrier gas introduced from the gas supply pipe 56 through the gas introduction pipe 54. The carrier gas flows from the outlet at the lower end of the gas introduction pipe 54 so as to immediately turn around to the suction port 50, and the powder 30 in the groove 36 is sucked into the suction port 50 together with the carrier gas by this flow. At this time, as shown in FIG. 3, it is preferable to provide a damming portion 86 in the suction port unit 40. The damming portion 86 is arranged to protrude into the groove 36. The damming portion 86 is a portion that dams the powder 30 at a position opposite the suction port 50 in the rotation direction A of the supply platen 38. If the damming portion 86 is provided in the suction port unit 40, the powder 30 transported by the rotation of the supply platen 38 can be reliably sucked into the suction port 50. The powder 30 sucked into the suction port 50 flows through the powder suction pipe 52 together with the carrier gas and is supplied to a powder supply destination (not shown) (e.g., a plasma chamber, etc.).

The configuration of the powder supply mechanism 12 is not limited to the configuration shown in FIG. 1, but may be any configuration that includes a powder storage chamber, stirring blades, and a supply plate, receives powder stirred by the stirring blades in a groove in the supply plate, and supplies the powder that has entered the groove together with carrier gas.

When the powder supply mechanism 12 is operated as described above, the drive control unit 66 controls the gas supply unit 22 in accordance with the drive condition setting information input by the information input unit 14. Specifically, if the flow rate of the carrier gas input by the information input unit 14 is 10 (L/min), the drive control unit 66 controls the gas supply unit 22 so that the carrier gas is supplied through the gas supply pipe 56 at a flow rate of 10 (L/min).

In addition, the rotation ratio setting unit 64 sets the rotation ratio between the supply platen 38 and the stirring blade 34 in accordance with the drive condition setting information input by the information input unit 14, and the drive control unit 66 controls the first drive unit 18 and the second drive unit 20 based on the rotation ratio set by the rotation ratio setting unit 64. As a specific example, if the type of powder 30 input by the information input unit 14 is zirconia, the rotation ratio setting unit 64 sets the rotation ratio between the supply platen 38 and the stirring blade 34 to 1:2 by referring to a data table (see FIG. 2) previously stored in the information storage unit 68, and transmits this setting result to the drive control unit 66. If the rotation speed of the supply platen 38 input by the information input unit 14 is 40 rpm, the drive control unit 66 controls the first drive unit 18 and the second drive unit 20 to rotate the supply platen 38 at 40 rpm and the stirring blade 34 at 80 rpm according to the rotation ratio setting described above.

By controlling the operation of each part of the powder supplying device 10 by the control unit 16 in this way, even if the powder 30 contained in the powder storage chamber 32 is a highly cohesive powder such as yttria, the stirring blades 34 and supply plate 38 can be rotated at a rotation ratio suitable for that powder. Therefore, the highly cohesive powder 30 can be supplied more stably than before.

The effects of this embodiment will be described below with reference to specific experimental results.
First, in the experiment, a powder supplying device (model number: TP-99140FDR) manufactured by JEOL Ltd. was used, and a supplying test was carried out under experimental condition 1, which is the standard specification.

<Experimental Condition 1>
(1) Rotation ratio of the supply plate 38 and the stirring blade 34 = 1:4
(2) Rotation speed of the supply plate 38=50 (rpm)
(3) Rotation speed of the stirring blade 34=200 (rpm)
(4) Stirring member 44: None (5) Blocking portion 86: None (6) Type of carrier gas: Argon (7) Flow rate of carrier gas: 5 (L/min)
The results of the experiment carried out under the above-mentioned experimental condition 1 are shown in Fig. 5. The vertical axis of Fig. 5 indicates the powder supply rate, and the horizontal axis indicates time. As shown in the graph of Fig. 5, in this experiment, the rotation speed of the stirring blade 34 was too fast compared to the rotation speed of the supply plate 38, so that the powder formed a bridge in the powder storage chamber 32, and the powder 30 did not fall under its own weight, so the powder supply was reduced and it was not possible to supply the powder, which was a failure example.
In order to solve the above problem, an experiment was carried out under the experimental condition 2 that made full use of the contents of this embodiment. Note that the conditions of yttria and a particle size distribution of several μm were inputted into the input unit 14.

<Experimental Condition 2>
(1) Rotation ratio of the supply plate 38 and the stirring blade 34 = 1:2
(2) Stirring member 44: Yes (3) Blocking portion 86: Yes (4) Type of carrier gas: Argon (5) Flow rate of carrier gas: 5 (L/min)
The results of an experiment conducted under the above-mentioned experimental condition 2 are shown in Fig. 6. In this experiment, the rotational speed of the supply platen 38 was increased stepwise while the rotation ratio (1) was kept constant. As a result, it was found that the powder did not form a bridge in the powder storage chamber 32 and the powder could be supplied continuously.

Here, the inventors of the present invention have conducted extensive research from various viewpoints in consideration of the fact that powder clogging is likely to occur in the powder suction pipe 52 when highly cohesive yttria powder is supplied together with a carrier gas. As a result, they have found that powder clogging can be eliminated simply by mixing a small amount of fluorine-based particles with yttria. Specifically, they have found that using a mixed material in which yttria, the main material of the powder 30, is mixed with yttrium fluoride (YF ₃ ) as a secondary material has a significant effect on preventing powder clogging. Specific experimental results are given below for explanation. The following experimental results were obtained using a powder supplying device (model number: TP-99140FDR) manufactured by JEOL Ltd., and the following experimental condition 3 was applied.

(Experimental Condition 3)
Type of powder 30: Mixture of yttria and yttrium fluoride Amount of powder put into powder storage chamber 32: 200 g
Carrier gas type: argon Carrier gas flow rate: 5 (L/min)
Damming section 86: Yes Rotation ratio of supply plate 38 to stirring blade 34 = 1:2

FIG. 7 is a graph showing the change over time in the powder supply rate when a mixed material in which yttria and yttrium fluoride are mixed in a mass ratio (mass %) of 99.1:0.1 is used as a powder, in which the vertical axis represents the powder supply rate and the horizontal axis represents time.
In FIG. 7, during the first period T1, the rotation speed of the supply platen 38 is changed in the order of 20 (rpm) → 40 (rpm) → 60 (rpm) → 80 (rpm) → 100 (rpm), and during the second period T2, the rotation speed of the supply platen 38 is changed in the order of 100 (rpm) → 150 (rpm) → 200 (rpm).
As shown in FIG. 7, the powder supply rate remains at a nearly constant level during the first period T1 in which the rotational speed of the supply platen 38 changes from 20 (rpm) to 100 (rpm), and increases as the rotational speed of the powder 30 increases during the second period T2 in which the rotational speed exceeds 100 (rpm). In addition, the supply of powder can be continued even after 12 minutes have passed since the start of the experiment. This shows that a significant effect can be obtained in the stable supply of powder by simply mixing 0.1% yttrium fluoride into the main material yttria. On the other hand, when yttrium fluoride is not mixed, the supply stops due to powder clogging less than 4 minutes after the start of the experiment, as shown in FIG. 4 above.

FIG. 8 is a graph showing the change over time in the powder supply rate when a mixed material in which yttria and yttrium fluoride are mixed in a mass ratio (mass %) of 99.5:0.5 is used as a powder, in which the vertical axis represents the powder supply rate and the horizontal axis represents time.
In FIG. 8, the rotation speed of the supply platen 38 is changed in the order of 20 (rpm)→40 (rpm)→60 (rpm)→80 (rpm)→100 (rpm)→150 (rpm)→200 (rpm).
8, the powder supply rate increases stepwise as the rotation speed of the supply platen 38 changes. Moreover, the powder supply can be continued even after 12 minutes have passed since the start of the experiment.

9 and 10 are graphs showing the change over time in the powder supply rate when a mixed material in which yttria and yttrium fluoride are mixed in a mass ratio (mass %) of 99:1 is used as a powder, in which the vertical axis represents the powder supply rate and the horizontal axis represents time.
In FIG. 9, the rotation speed of the supply platen 38 is changed in the order of 20 rpm, 40 rpm, 60 rpm, 80 rpm, and 100 rpm, and in FIG. 10, the rotation speed of the supply platen 38 is kept constant at 200 rpm.
As shown in FIG. 9, the powder supply rate increases slightly with the change in the rotation speed of the supply platen 38, but overall, it remains at a nearly constant level regardless of the rotation speed of the supply platen 38, and the rate fluctuation (pulsation) is also suppressed to a small level. In addition, the powder supply can be continued well even after 12 minutes have passed since the start of the experiment. In the experiment, the image of the powder sprayed together with the carrier gas through the powder suction pipe 52 was taken with a video camera, and it was confirmed in the video image that the powder was supplied stably like water when the rotation speed of the supply platen 38 was 100 (rpm). On the other hand, when the rotation speed of the supply platen 38 was set to a constant speed of 200 (rpm), as shown in FIG. 10, the powder supply rate remains at a nearly constant level, and the rate fluctuation is also suppressed to a very small level. From this, it was found that the supply of powder becomes extremely stable just by mixing 1% yttrium fluoride with the main material yttria.

11 and 12 are graphs showing the change over time in the powder supply rate when a mixed material in which yttria and yttrium fluoride are mixed in a mass ratio (mass %) of 95:5 is used as a powder, in which the vertical axis represents the powder supply rate and the horizontal axis represents time.
In FIG. 11, the rotation speed of the supply platen 38 is changed in the order of 20 (rpm) → 40 (rpm) → 60 (rpm) → 80 (rpm) → 100 (rpm), and in FIG. 12, the rotation speed of the supply platen 38 is changed from 150 (rpm) to 200 (rpm).
As shown in Fig. 11, the powder supply rate increases slightly as the rotation speed of the supply platen 38 changes, but overall it remains at a nearly constant level regardless of the rotation speed of the supply platen 38, and rate fluctuations are kept small. Furthermore, the supply of powder continues satisfactorily even 10 minutes after the start of the experiment. On the other hand, when the rotation speed of the supply platen 38 is changed from 150 (rpm) to 200 (rpm), as shown in Fig. 12, the powder supply rate remains at a nearly constant level regardless of the difference in the rotation speed of the supply platen 38.

13 and 14 are graphs showing the change over time in the powder supply rate when a mixed material in which yttria and yttrium fluoride are mixed in a mass ratio (mass %) of 90:10 is used as a powder, in which the vertical axis represents the powder supply rate and the horizontal axis represents time.
In FIG. 13, the rotation speed of the supply platen 38 is changed from 20 (rpm) to 40 (rpm), and in FIG. 14, the rotation speed of the supply platen 38 is changed from 100 (rpm) to 150 (rpm) to 200 (rpm) in that order.
As shown in Fig. 13, the powder supply rate increases slightly as the rotation speed of the supply platen 38 changes, but overall it remains at a nearly constant level regardless of the rotation speed of the supply platen 38, and rate fluctuations are kept small. This tendency also appears when the rotation speed of the supply platen 38 is changed in the order of 100 rpm → 150 rpm → 200 rpm, as shown in Fig. 14. Furthermore, the powder supply continues satisfactorily even 15 minutes after the start of the experiment.

15 and 16 are graphs showing the change over time in the powder supply rate when a mixed material in which yttria and yttrium fluoride are mixed in a mass ratio (mass %) of 80:20 is used as a powder, in which the vertical axis represents the powder supply rate and the horizontal axis represents time.
In FIG. 15, the rotation speed of the supply platen 38 is changed in the order of 20 (rpm) → 40 (rpm) → 60 (rpm) → 80 (rpm) → 100 (rpm), and in FIG. 16, the rotation speed of the supply platen 38 is changed in the order of 100 (rpm) → 150 (rpm) → 200 (rpm).
As shown in Fig. 15, the powder supply rate increases stepwise as the rotation speed of the supply platen 38 changes, and small fluctuations in the rate are also suppressed. This tendency is also observed when the rotation speed of the supply platen 38 is changed in sequence from 100 (rpm) to 150 (rpm) to 200 (rpm), as shown in Fig. 16. Furthermore, the powder supply continues satisfactorily even after about 25 minutes have passed since the start of the experiment.

From the above, it has been proven that mixing yttrium fluoride as a secondary material with yttria, which is the main material of the powder, can suppress clogging of the powder and achieve a stable supply of the powder. In particular, when a mixed material consisting of yttria as the main material and yttrium fluoride as the secondary material is used as the powder 30 handled by the powder supplying device 10, this is extremely preferable because the problem of contamination can be limited to the fluorine source. In addition, when yttrium fluoride is mixed with yttria, the mass ratio of yttrium fluoride is preferably 0.1% or more by mass, and more preferably 1% or more by mass.

In addition, in situations where contamination such as fluorine sources is not an issue and a stable supply of powder is a priority, a mixed material other than the combination of yttria and yttrium fluoride may be used. In other words, the secondary material may be a fluorine-based particle (solid) other than yttrium fluoride, or a liquid or gas, as long as it improves the fluidity (slipperiness) of the main material. Also, one example of a particle other than a fluorine-based particle is carbon particles, which contribute to improving slipperiness.

<Modifications, etc.>
The technical scope of the present invention is not limited to the above-described embodiments, but also includes forms in which various modifications and improvements are made within the scope that can derive specific effects obtained by the constituent elements of the invention and their combinations.

The present invention can also be widely applied to powder supplying devices for microparticle injection, aerosol deposition, cold spray, etc., and is particularly preferably applied to powder supplying devices that supply highly cohesive powder together with a carrier gas.

In addition to being realized as a powder supplying device, the present invention may also be realized as a powder supplying method using the above-mentioned mixed material as powder 30, or as a powder used in the powder supplying device or powder supplying method. Preferred aspects in these cases are described below.

(Preferred embodiment of powder supply method)
[Appendix 1]
1. A method of supplying powder with a carrier gas, comprising:
a mixed material obtained by mixing a main material of the powder with a secondary material that improves the fluidity of the main material is used as the powder.
[Appendix 2]
The main material is yttria,
2. The powder feeding method of claim 1, wherein the secondary material is a fluorine-based particle.
"Appendix 3"
the fluorine-based particles are yttrium fluoride;
The powder feeding method according to claim 2, wherein the mixing ratio of the yttrium fluoride is 0.1% or more by mass ratio.

(Preferred embodiment of powder)
[Appendix 3]
A powder used in a powder supplying apparatus or a powder supplying method that supplies a powder together with a carrier gas, comprising:
A powder obtained by mixing a main material of the powder with a secondary material that improves the fluidity of the main material.
[Appendix 4]
The main material is yttria,
The powder according to claim 3, wherein the secondary material is a fluorine-based particle.
"Appendix 5"
the fluorine-based particles are yttrium fluoride;
The powder according to claim 4, wherein the mixing ratio of the yttrium fluoride is 0.1% or more by mass ratio.

REFERENCE SIGNS LIST 10 powder supplying device 14 information input section 16 control section 18 first driving section 20 second driving section 30 powder 32 powder storage chamber 34 stirring blade 36 groove 38 supply board 40 suction port unit 44 stirring member 50 suction port

Claims (7)

A powder supplying apparatus for supplying a powder together with a carrier gas, comprising:
A powder storage chamber that stores the powder;
a stirring blade for stirring the powder contained in the powder storage chamber;
A supply plate having a groove for receiving the powder stirred by the stirring blade;
an information input unit for inputting driving condition setting information including at least the type of powder;
A first drive unit that rotates the stirring blade;
A second drive unit that rotates the supply platen;
a control unit that controls the first drive unit and the second drive unit in accordance with the drive condition setting information input by the information input unit ,
The control unit sets a rotation ratio between the supply platen and the stirring blade in accordance with the input driving condition setting information, and controls the first driving unit and the second driving unit based on the set rotation ratio.
Powder feeder. The powder supplying device according to claim 1 , further comprising a flexible agitating member arranged in the powder containing chamber so as to rotate together with the agitating blade. 3. The powder supplying device according to claim 1, further comprising an intake unit having an intake port for sucking the powder together with the carrier gas from the groove of the supply platen, and a blocking portion for blocking the powder that has entered the groove at a position opposite to the intake port. 4. The powder supplying device according to claim 1, wherein the surface of the groove is formed with irregularities that suppress slippage of the powder. 5. The powder supplying device according to claim 1, wherein the type of powder input by the information input unit includes at least a type of a main material of the powder and a type of a secondary material to be mixed with the main material. The powder supplying device according to claim 5 , wherein the type of powder further includes a mixing ratio of the sub-material. The type of the main material includes yttria,
6. The powder feeding apparatus of claim 5 , wherein the secondary material type includes yttrium fluoride.

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