KR101861031B1 - Oil diffusion pump and oil vapor generator used therefor - Google Patents

Abstract

Provided is an oil diffusion pump provided with a vapor generator capable of solving the problem when a heater wire is used as a working oil heating source. A vapor generator 70 is disposed in the casing 51 to operate the vapor generator 70 to vaporize the operating fluid 8 to vaporize the vapor and jet the vapor from the jets 53 and 53a, It is a vacuum pump that operates. The oil vapor generator 70 includes a tubular case 71 (heating target) extending in the installation direction, an induction coil 75 wound around the tubular member 71 via an insulating material 73, And a power supply means for applying alternating current to the power supply 75. The case 71 and the induction coil 75 are inserted into the casing in such a manner that they are immersed in the operating oil 8 stored in the casing 51. The power supply means is operated to apply alternating current to the induction coil 75 to heat the case 71 itself to evaporate the operating oil 8.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an oil diffusion pump,

The present invention relates to an oil diffusion pump which is connected to a vacuum container constituting various vacuum devices such as a vapor deposition device and a sputtering device and is suitable for use in vacuum exhausting the container, .

In the case of various vacuum apparatuses such as a vapor deposition apparatus and a sputtering apparatus, an oil diffusion pump is used as a vacuum pump used in an exhaust apparatus for evacuating the inside of a vacuum container constituting the apparatus. In the case of a conventional oil diffusion pump, it is known to use an electrothermal heater including a heater wire as a heating source of hydraulic oil accommodated in a boiler (Patent Document 1).

Japanese Patent Application Laid-Open No. 2007-23778

When a heater wire is used as a heating source for operating oil, there is an advantage that an apparatus can be formed at low cost. For example, a heating function is lost by disconnection of a heater wire, a leakage occurs due to an insulation failure of a heater wire, The occurrence of defects, the generation of rust in the heated body, and the like. In addition, since the heater wire is heated to a high temperature such that the oil diffusing pump operates at a high temperature during operation of the oil diffusion pump, it is necessary to pay attention to the place where the heater wire is installed. There is also a problem of the installation environment of the.

In addition, since the heater wire as the working oil heating source generates heat conduction loss in terms of energy efficiency, the heating efficiency is low and the power saving is prevented, and the following problems are also inherent.

(1) The start of heating is delayed (the startup time is long)

(2) poor thermal responsiveness,

(3) Since it is difficult to selectively heat the object to be heated, the periphery of the object to be heated is also heated.

According to an aspect of the present invention, there is provided a oil vapor generator capable of solving the problem when a heater wire is used as an operating oil heating source, and an oil diffusion pump provided with the oil vapor generator and contributing to power saving during operation .

The oil diffusion pump of the present invention is a vacuum pump in which a vapor generator is disposed in a jet disposed in a casing to operate the vapor generator to heat the operating oil to vaporize the vapor and jet the vapor in the jet from the jet to perform high vacuum exhaust operation .

The vapor generator includes an object to be heated, an induction coil electrically insulated and arranged in the vicinity of the object to be heated, and a power supply means for applying alternating current to the induction coil. And the power supply means is operated to apply an alternating current to the induction coil to heat the object to be heated to evaporate the operating oil.

The vapor generator of the present invention is used for heating hydraulic oil in an oil diffusion pump including a casing and a jet to make it a vapor. The vapor generator of the present invention is characterized in that the vapor generator of the present invention includes a target to be disposed in the jet in the casing so as to partially or completely immerse the hydraulic fluid stored in the casing of the oil diffusion pump, An induction coil electrically insulated from the induction coil, and a power supply means for applying alternating current to the induction coil. And the power supply means is operated to heat the object to be heated to vaporize the working oil.

In the above two inventions, the shape of the heated body constituting the vapor generator is not particularly limited, and for example, a plate shape, a tubular shape, or a combination of a plate shape and a tubular shape can be considered. For example, in the case of forming the heating target body in a cylindrical shape extending in the standing direction (Figs. 3 to 5), when the induction coil is wound around the heating target body via the insulating material (Figs. 3 to 5). When the heating target is constituted by a plate material such as a disk or the like, the induction coil may be arranged around the periphery of the heating target (for example, the back surface) via an insulating material. Power feeding means may be used, and power may be supplied using one system of induction coils and power feeding means. In either case, in the present invention, the heating target and the induction coil are inserted into the casing in such a manner that a part or all of the heating fluid and the induction coil are immersed in the working fluid stored in the casing.

In the present invention, it is possible to provide a flow path of the hydraulic oil that can be heated by operating the oil vapor generator in the casing of the oil diffusion pump.

In the present invention, it is possible to constitute the heat insulation between the vapor generator disposed in the casing and the bottom surface of the casing.

In the present invention, the induction coil of the vapor generator may be formed of a heat-resistant wire coated with insulation.

The oil vapor generator to be inserted into the oil diffusion pump of the present invention is a working oil heating source in which an induction coil is disposed in the vicinity of a heating target through an insulating material (for example, The induction coil is wound) and alternating current is applied to the induction coil to heat the object to be heated so that the operating oil is vaporized by the heat. And the object to be heated and the induction coil are inserted into the bottom of the casing in such a manner as to be immersed in the operating oil stored in the casing of the oil diffusion pump.

That is, according to the oil vapor generator inserted into the oil diffusion pump of the present invention, by applying alternating current to the induction coil instead of heating the induction coil, interlinkage is performed in a predetermined direction of the heated body (in the above- (Joule heat) is generated by generating an induction current, that is, an eddy current, in the heating object by the generated magnetic flux (induction heating). And heats the object to be heated (self-heating of the object to be heated) by the generated heat.

As a result, there is no consuming member such as a heater wire, so that the heat generating function is not lost by disconnection. Further, since the current to be heated is consumed by the heating target as a heating element, there is no case where a short circuit due to insulation failure occurs, and no contact failure of the terminal block due to high temperature occurs. In addition, the ability to locally heat the working oil heating source is advantageous in that the degree of freedom in selecting the location of the induction coil is increased.

Further, according to the oil vapor generator inserted into the oil diffusion pump of the present invention, the heating target and the induction coil are inserted into the operating oil stored in the casing of the oil diffusion pump in a partially or entirely submerged arrangement. Therefore, even when the temperature of the induction coil rises due to the temperature rise of the heating target, the cooling effect by the operating oil can be expected, and it is possible to prevent the abnormal heating. Therefore, for example, it is possible to suppress the upper limit temperature of the induction coil to a low level, compared to a system in which the induction coil is disposed outside the casing and air-cooled.

Since the oil diffusion pump of the present invention has the oil vapor generator of the present invention inserted in its casing, it is possible to consume all of the electric current applied to the induction coil of the oil vapor generator to the heating body as a heating element. As a result, the energy efficiency of the heating element is good, and power saving can be achieved.

It is not necessary to provide a hydraulic oil circulation pipe as a hydraulic oil passage on the atmospheric side (outside the casing, hereinafter) of the bottom portion of the casing by operating a hydraulic oil passage for heating by operating the oil vapor generator in the casing of the oil diffusion pump, thereby simplifying the casing can do.

The working oil passes through the flow path heated by the object to be heated so that the preheating can be expected in the flow passage during the flow of the operating fluid so that the state suitable for the generation of the vapor can be made.

As described above, in the oil diffusion pump of the present invention, a vapor generator as a heating source is disposed in the casing, and the conventional oil diffusion pump does not have a heating source outside the casing in which the heating source is provided. Therefore, the bottom portion of the casing can be substantially planarized, and the oil diffusion pump can be placed on the plane to improve the convenience.

Further, according to the embodiment of the present invention, since the upper end of the heating body as the heating element for winding the induction coil is exposed above the oil level of the operating oil that is in contact with the oil, the oil vapor rising from the oil surface, By contact with the upper part of the inner wall, the heated vaporized oil is heated in a short time. As a result, in the case of the oil diffusion pump in which such a vapor generator is inserted, it is possible not only to start the heating of the working oil (that is, to generate the vapor) in a shorter time, but also in energy efficiency.

Fig. 1 is a schematic configuration diagram showing a vacuum device according to an embodiment of the present invention.
Fig. 2 is a schematic structural cross-sectional view showing an oil diffusion pump as an example used in the vacuum apparatus of Fig. 1;
3 is a schematic structural cross-sectional view showing a main part of a vapor generator as an example used in the oil diffusion pump of FIG.
Fig. 4 is a schematic plan view of Fig. 3 viewed in the IV direction.
5 is a view showing another example of a main portion of the vapor generator corresponding to Fig.
6 is a view showing another example of the arrangement of the vapor generator inserted into the oil diffusion pump of this embodiment.
7 is a diagram showing another example of the arrangement of the vapor generator included in the oil diffusion pump of this embodiment.
Explanation of symbols
One… Vacuum system, 10 ... Vacuum container, 21, 23, 25 ~ 29 ... Pipeline, 31 ... Fine pumping valve, 33 ... Leak valve, 35 ... Rough pumping valve, 37 ... Auxiliary valve, 39 ... Leak valve,
50 ... Oil diffusion pump, 51 ... Casing, 53 ... Jet, 53a ... Jet nozzle, 55 ... Intake section, 57 ... Exit, 58 ... Water pipe, 59 ... Oil reservoir, 60 ... Rough pump,
70 ... The vapor generator, 70a ... Stands, 71 ... Case (an example of a heating target), 71a ... Inner region, 71b ... Outer region, 72 ... Base (base), 72a ... The opening, 73 ... Insulation material, 75 ... Induction coil, 76 ... Magnetic shield case,
8… Working fluid,
90 ... The bottom cover (flange), 92 ... Fastening means.

Hereinafter, an example of the present invention will be described with reference to the drawings.

As shown in Fig. 1, the vacuum apparatus 1 of the present example has a vacuum container 10. A variety of equipment necessary for forming (forming) a thin film, such as a film forming source (not shown) such as an evaporation source or a sputtering source, or a substrate holder for holding and holding a substrate to be processed, . The vacuum vessel 10 is connected to the downstream side of the conduit 21. A vacuum system (not shown) is connected to the vacuum vessel 10 to detect the atmospheric pressure (vacuum degree) in the vacuum vessel 10.

The downstream side of the suction pipe 23 is connected to the upstream side of the conduit 21 via a fine pumping valve 31. The upstream side of the suction pipe 23 is connected to the suction portion 55 of the oil diffusion pump 50. The downstream side of the branch conduit 25 is connected to the middle of the conduit 21. The downstream side of the conduit 26 is connected to the branch conduit 25 and the leak valve 33 is provided on the upstream side of the conduit 26. [

On the upstream side of the branch conduit 25, the downstream side of the conduit 27 is connected via a rough pumping valve 35. [ The upstream side of the conduit (27) is connected to the rough pump (60). The downstream side of the channel 28 is connected to the middle of the channel 27. The upstream side of the conduit 28 is connected to the exhaust portion 57 of the oil diffusion pump 50 via the auxiliary valve 37. [ A downstream side of the conduit 29 is connected to the connection portion of the conduit 28 of the conduit 27 and a leak valve 39 is provided on the upstream side of the conduit 29. A vacuum system (not shown) is connected to the pipeline 28 to detect the pressure in the oil diffusion pump 50.

The vacuum apparatus 1 of this embodiment has a control device (not shown) for controlling the operation of the apparatus 1 in addition to the above-described configuration. The control device provided in this example includes a main control circuit (not shown) including various processing circuits, a vacuum system driving circuit (not shown) connected to a vacuum system connected in the pipeline 21, and a rough pumping pump 60, (Not shown), and an oil diffusion pump control circuit (not shown) for controlling the operation of the oil diffusion pump 50.

The main control circuit is connected to the valves (the fine pumping valve 31, the leak valves 33 and 39, the rough pumping valve 35 and the auxiliary valve 37) Respectively. A rough pumping pump 60 is connected to the oil diffusion pump 50 so that the gas exhausted by the oil diffusion pump 50 through the auxiliary valve 37 is sucked by the rough pumping pump 60, do.

As shown in Fig. 2, the oil diffusion pump 50 of this embodiment has a cylindrical container (casing) 51 with a bottom portion closed. The bottom of the casing 51 is inserted with a vapor generator 70 for heating and vaporizing the operating oil 8, and the bottom of the casing 51 is substantially flat. The details of the vapor generator 70 will be described later. A jet 53 is arranged in the casing 51. The hydraulic fluid 8 heated by the vapor generator 70 is vaporized to absorb the vaporized vapor and is discharged through the nozzle 53a into the rough Pumping direction. An intake portion 55 is provided at an upper end of the casing 51 and an exhaust portion 57 is provided at a side surface of the casing 51.

Next, the operation of the oil diffusion pump 50 will be described.

The operating oil 8 is heated to near the boiling point by the vapor generator 70 to be vaporized to fill the inside of the jet 53 and the nozzle 53a To the inner surface of the side wall of the casing 51. The suction gas (air in the vacuum container 10) sucked from the suction unit 55 is ejected from the exhaust unit 57 by colliding with the advancing direction of the classification (jet flow). As a result, the evacuation in the vacuum container 10 proceeds. In Fig. 2, " circle (o) " schematically shows the state of the oil vaporized vapor. Further, after the jet nozzle 53a ejects the vapor so that the hydraulic fluid 8 does not enter the vacuum container 10, the suction unit 55 is opened.

Since the casing 51 is cooled by the water cooling pipe 58, the vapor of the hydraulic fluid 8 attached to the inner wall of the casing 51 is cooled and condensed to return to the oil storage tank 59 below the casing 51 Is reheated by the vapor generator (70) and is again vaporized and circulated.

3 and 4, the vapor generator 70 of this embodiment is inserted into the bottom of the casing 51 of the oil diffusion pump 50 shown in Fig. 2 via a plate-shaped mount 70a. The stage 70a is supported by a lower cover (flange) 90 from the atmosphere side. A heat insulating material (not shown) may be interposed between the base 70a and the lower lid 90. The lower cover 90 is freely detachably attached to the bottom surface of the casing 51 by fastening means 92 such as a bolt and the atmosphere side of the bottom of the casing 51 is formed substantially flat.

A tubular case 71 as an example of a heating target is disposed above the mounting table 70a (upward direction in Fig. 3). The case 71 is supported by a base 72 having an opening 72a near its center in the lower end of the case 71 in this example. The base 72 is supported by the base 70a via a leg 70b having a predetermined height so that a clearance is formed so that the operating oil 8 can pass through the base 70a. In this example, the gap between the base 72 and the mount 70a formed by the above-described leg portion 70b functions as a preheating passage for the working oil. In addition, by providing this gap, the vapor generator 70 disposed in the casing 51 of the oil diffusion pump 50 is thermally insulated from the bottom surface of the casing 51.

Further, a flange case (not shown) in which the base 72 having the opening 72a is integrated as the case 71 may be used. Further, the base 72 may be supported above the base 70a via an insulating disk member (not shown) of the induction coil 75 to be described later.

The case 71 of this example is made of a material to be heated. As the material to be heated, at least one of stainless steel, carbon steel, and general structural rolled steel specified in JIS-G3101 is used.

As the stainless steel, all kinds of SUS such as SUS304, SUS303, SUS302, SUS316, SUS316L, SUS316J1, SUS316J1L, SUS405, SUS430, SUS434, SUS444, SUS429, SUS430F, SUS302 can be used. Carbon steels include high carbon steels, such as low carbon steels or hard steels with low carbon content such as mild steel. General structural rolled steels include SS330, SS400, SS490 and SS540.

Among them, it is preferable that the case 71 of a ferromagnetic material having a low electrical resistance of the resistivity of the material such as soft steel up to 10 × 10 ^-8 Ωm to 20 × 10 ^-8 Ωm. When the case 71 is made of a ferromagnetic material having a low electric resistance (mild steel or the like), the amount of eddy current generated by application to the induction coil 75 due to low electrical resistance becomes large, The amount of self-heating by itself can be large and high efficiency can be expected.

It is also preferable to construct the casing 71 with the SS400 having high availability, which is general steel. In this case, since the object to be heated at a high temperature is also immersed in the operating oil at all times in a vacuum atmosphere, the rust prevention performance can be expected. It is also possible to form the case 71 with a molded article having a clad material on the surface of the induction coil 75 of the material to be heated, for example.

In this embodiment, the base 72 for supporting the lower end of the case 71 may be made of a material to be heated.

The case 71 has a structure in which the peripheral wall extends in the direction of installation (vertical direction). The case 71 has both the inner region 71a and the outer region 71b constituting the oil reservoir 59 (see Fig. 2), and the operating oil 8 is charged and stored therein. For example, when the case 71 is formed to have a height of 120 mm, the hydraulic oil 8 is charged so that the oil level L at the time of stopping the operation of the vapor generator 70 is about 30 mm. In this case, when the operation of the oil vapor generator 70 is started, the oil level L of the hydraulic oil 8 is reduced to, for example, about 10 mm.

In this embodiment, as described later, since the induction heating is realized by the low-frequency alternating current (low-frequency induction heating), it is preferable that the case 71 has a thickness within the range of 5 mm to 12 mm.

In this example, the inner region 71a of the case 71 communicates with the outer region 71b of the case 71 via the opening 72a of the base 72 (see FIG. 3).

An induction coil 75 is wound around the outer periphery of the case 71 via an insulating material 73. As a result, the induction coil 75 is electrically insulated from the outer circumference (an example in the vicinity) of the case 71. The insulating material 73 can be composed of, for example, a polyimide film having a thickness of about 10 m to 180 m, mica, or a solvent of an insulating material on the outer surface of the heating target.

A conductor constituting the induction coil (75) is a heat-resistant wire with a small electrical resistance and a high heat-resistant temperature. Examples of such materials include an alumite wire obtained by anodizing an aluminum wire. The diameter of the conductor constituting the induction coil 75 is preferably in the range of 2 mm to 4 mm. The number of windings of the induction coil 75 is preferably in the range of 7 to 14 layers.

The induction coil 75 is connected to a power supply means (not shown) for supplying electricity to the induction coil 75. The power supply condition of the power supply means is controlled by a controller (not shown).

Since the induction coil 75 is inserted into the operating oil 8 in such a manner that a part or all of the induction coil 75 is immersed in the operating oil 8 together with the case 71, the induction coil 75 is abnormally heated above the temperature of the operating oil 8 And the cooling effect by the operating oil 8 can be expected even when the temperature of the induction coil 75 itself rises. Also, the temperature rise of the induction coil 75 contributes to the heating of the operating oil 8, contributing to the energy saving effect.

Next, the operation of the vapor generator 70 will be described.

First, an AC is applied to the induction coil 75 by operating the power supply means. The frequency of the alternating current to be applied to the induction coil 75 is not particularly limited. For example, a low frequency alternating current of several tens of Hz to several hundreds of Hz may be used. The same effect can also be obtained by feeding high-frequency alternating current. Further, although the current control method is used for controlling the power supply means, it may be a power control method. Hereinafter, a case of applying a low frequency alternating current by the current control method will be exemplified.

When the alternating current of 50 Hz or 60 Hz is applied to the induction coil 75 by operating the power supply means, a magnetic flux linking up and down in the installation direction of the case 71 is generated, An eddy current is generated to generate a joule heat. By heating the case 71 itself with this heat, the operating oil 8 stored in the inner region 71a of the case 71 is directly heated. Vaporized from the oil level in the case 71 is further heated by being brought into contact with the high temperature part of the upper part of the case 71 exposed above the oil level to become a sufficiently heated high temperature vapor to rise in the jet 53, As shown in FIG.

Since the casing 51 of the oil diffusion pump 50 is cooled by the water cooling pipe 58 as described above, the vapor of the hydraulic fluid 8 attached to the inner wall of the casing 51 is cooled and condensed, (Equivalent to the oil reservoir 59 in Fig. 2) of the lower case 71 of the oil separator 71 shown in Fig. The inner region 71a of the case 71 is communicated with the outer region 71b of the case 71 via the opening 72a of the base 72 The operating fluid 8 flows into the inner region 71a of the case 71 through the gap between the base 72 formed by the leg portion 70b and the mount 70a through the opening 72a of the base 72 , Reheated by the vapor generator (70), and the hydraulic oil (8) circulates again by being vaporized.

Further, in this example, when the base 72 supporting the lower end of the case 71 is made of the material to be heated, the base 71 as well as the base 72 can be used as the heating target. In this case, it is possible to preheat the operating fluid 8 that has been cooled in the casing 51 and returned to the outer region 71b of the case 71 in the gap (i.e., the flow path) between the base 72 and the mount 70a , Contributing to the improvement of the evaporation efficiency of the operating oil 8 when reheating in the inner region 71a.

When the base 70a supporting the base 72 from the back surface via the leg portion 70b is formed of the material to be heated in the same manner as the case 71 and the base 72, Can also be expected to act as.

In the case of the vapor generator 70 of the present embodiment, the outer periphery of the tubular case 71 made of a mild steel material or a material to be heated such as SS400 as the heating source of the operating oil 8 is filled with an insulating material 73 The case 71 is heated by applying a low frequency alternating current to the induction coil 75 and the operating oil 8 is vaporized by the heat. There is no problem of disconnection because the induction coil 75 is not heated and the exothermic function is lost by disconnection and the exhaust function of the oil diffusion pump 50 is not hindered. In addition, a short circuit due to insulation failure does not occur. In addition, the induction coil 75 itself does not become a heating element, and because it enters the casing 51, there is no case where the contact failure of the terminal block due to high temperature deterioration occurs.

When the base 72 for supporting the lower end of the case 71 is also made of a material to be heated, the base 72 can also be heated by applying a low frequency AC to the induction coil 75, thereby improving the efficiency of vaporization It is also possible.

When the base 70a supporting the base 72 from the back is also made of a material to be heated there is a possibility that the base 70a can be used as an object to be heated by applying a low frequency AC to the induction coil 75, An improvement in the efficiency of the conversion can be expected. In this case, by providing a heat insulating material (not shown) between the base 70a and the lower cover 90, the vaporizing efficiency can be further improved.

Since the oil vapor diffusing pump 50 of this embodiment is inserted with the vapor generator 70 of the present embodiment, all the current that has flown into the induction coil 75 of the vapor generator 70 is supplied to the case 71 (or the case 71 and the base 72) can be consumed by the oil diffusion pump 50. As a result, it is possible to improve the energy efficiency by promoting energy saving and contributing to the shortening of the heating start time of the operating oil 8 Which can be shortened).

Since the main part (the case 71, the insulator 73 and the induction coil 75) of the present example is inserted in a state in which the lower end is arranged above the flat base 70a, the casing 51 It is possible to form the atmospheric side of the bottom portion substantially flat. As a result, it is also possible to provide an oil diffusion pump 50 that can be placed on a flat surface, thereby improving convenience.

The vapor generator 70 of this embodiment is configured to be exposed above the oil level L of the hydraulic oil 8 in contact with the upper end U of the case 71 as a heating element for winding the induction coil 75 Therefore, the oil vapor rising from the oil level L comes into contact with the upper portion of the case 71 exposed above the oil level L, so that the heated oil vapor is further heated to generate sufficiently heated oil vapor. As a result, in the case of the oil diffusion pump 50 in which the vapor generator 70 of the present embodiment is inserted, it is possible to raise the temperature of the jet steam from the jet 53, which is very advantageous in realizing the improvement of the exhaust speed.

The foregoing examples are provided for the purpose of facilitating understanding of the present invention and are not described in order to limit the present invention. Therefore, each element disclosed in the above embodiments is intended to include all design modifications and equivalents falling within the technical scope of the present invention.

For example, in the above-described example, the outer circumferential portion of the induction coil 75 is exposed through the insulating material 73 to the outer circumference of the case 71 of a single structure formed of mild steel material, SS400, The case 71 is formed to have a double structure of an inner wall of the case and an outer wall of the case and the outer region 71b, the outer wall of the case, the insulating material 73, and the outer case 71 (see FIG. 3) The structure of the induction coil 75, the insulating material 73, the inner wall of the case, and the inner region 71a.

In this case, since the operating oil 8 stored in the outer region 71b can be heated together with the operating oil 8 stored in the inner region 71a, the heating efficiency of the operating oil 8 can be dramatically improved It is expected.

The tubular object to be heated is not limited to the plate material of the example, and a porous metal body or a net that allows the working oil to pass through in the constitution using the material to be heated may be wound.

Although the outer periphery of the induction coil 75 is exposed in the above example (see FIG. 3), the present invention is not limited to this embodiment. For example, as shown in FIG. 5, 5) may be covered with the magnetic shield case 76 formed of a material different from the material of the case 71. In this case, With this configuration, it is possible to expect that the heating efficiency when the case 71 is heated by application of the alternating current to the induction coil 75 is increased by one layer, which is preferable.

Further, in the above-described example, the tubular case 71 is used as the heating object constituting the vapor generator 70, but the present invention is not limited to this case, and a plate material (not shown) such as a disk- And it is also possible to arrange so that a part or whole of the plate member is immersed in the operating oil 8 in which the entire plate member is stored. In this case, the induction coil 75 can be disposed around the periphery of the plate material, for example, the back surface of the plate member (the bottom side of the casing 51) via the insulating material 73. In this way, the effect of the present example can be realized.

In the above-described example, the single oil diffusion pump 50 is provided with one oil vapor generator 70. However, the present invention is not limited to this embodiment. In particular, in the case of enlarging the oil diffusion pump, It is also possible to dispose a plurality of the vapor generators 70 of this embodiment in the bottom portion of the casing 51 as shown in Fig.

Example

Next, examples (comparative examples) and comparative examples of the present invention will be described.

[Example]

In this example, the oil diffusion pump 50 (FIG. 2) shown after the insertion of one oil vapor generator 70 (FIG. 3) as an operating oil heating source was prepared and evaluated under the following conditions.

(Oil diffusion pump 50)

Diameter of exhaust port: 250 mm,

· Exhaust speed: 2,900 L / sec,

The ultimate pressure in the vacuum container: 6.7 x 10 < ^-6 > Pa (Pascal)

· Required power: 0.7 ㎾,

· Operating fluid: Lion S, 1 L.

(The vapor generator 70)

Height of case 71: 120 mm,

· Oil level (L) level of operating oil: 30 mm (at standstill), 10 mm (at operation).

[Comparative Example]

In this example, an oil diffusion pump of a conventional structure in which an electric heater using a heater wire (nichrome wire) as a working oil heating source was disposed at the bottom of the pump was prepared and evaluated under the following conditions.

(Conventional oil diffusion pump)

Diameter of exhaust port: 250 mm,

· Exhaust speed: 2,900 L / sec,

The ultimate pressure in the vacuum container: 6.7 x 10 < ^-6 > Pa (Pascal)

· Power consumption: 2.0 ㎾ (200 V),

· Operating fluid: Lion S, 1 L.

[evaluation]

The operating power was measured using the oil diffusion pump of each example. Specifically, the power supply portion to the nichrome wire (comparative example) and the induction coil (embodiment) was measured with a clamping power meter, and power (power at startup, power at operation) was calculated from voltage, current and power factor, (Conventional ratio) of the total amount of the catalyst. As a result, it was found that the operating power of the embodiment is reduced by 40% in the conventional operation and reduced by 65% in the conventional operation.

The temperature (side, bottom) of each example oil diffuser pump was measured. As a result, the side temperature (atmospheric side) of the Example was 170 占 폚. It can be seen that the heating can be concentrated in the inner tube of the boiler with a reduction of 26% compared with the comparative example (230 ° C), which can contribute to power reduction. Also, the bottom surface temperature of the example was 120 캜. It has been found that the heat loss can be largely suppressed as compared with the comparative example in which the heater block is exposed at a very high temperature (red heat state). It has also been found that it is possible to achieve levels that do not require consideration of damage to the floor.

Claims (9)

An oil diffusion pump in which a vapor generator is disposed in a jet disposed in a casing to operate the vapor generator so as to heat the operating oil to form a vapor, jet the vapor in the jet from the jet,
The vapor generator includes a heated body,
An induction coil electrically insulated and arranged in the vicinity of the heating target body, and
And a power feeding means for applying an alternating current to the induction coil,
The object to be heated and the induction coil are inserted into the casing in such a manner that part or all of the object to be heated is immersed in the working oil stored in the casing,
Wherein the power feeding means is operated to heat the heating target body to vaporize the working oil. The method according to claim 1,
Wherein the material to be heated of the oil vapor generator is a tubular shape extending in an upright direction and an induction coil is wound around the tubular heating target through an insulating material. The method according to claim 1,
Wherein the material to be heated of the vapor generator is in the form of a plate and an induction coil is disposed around the plate-shaped heating target through an insulating material. 4. The method according to any one of claims 1 to 3,
An oil diffusion pump having an operating oil passage in a casing. 4. The method according to any one of claims 1 to 3,
An oil diffusion pump that does not have a heating source at the bottom of the atmospheric casing. 4. The method according to any one of claims 1 to 3,
An oil diffusion pump configured to thermally isolate a casing bottom surface from a vapor generator disposed in the casing. 4. The method according to any one of claims 1 to 3,
Wherein the induction coil is composed of a heat-resistant wire coated with insulation. A vacuum apparatus having an exhaust apparatus for evacuating a vacuum container, characterized by using the oil diffusion pump according to any one of claims 1 to 3 as the exhaust apparatus. 1. A vapor generator for heating operating oil in an oil diffusion pump including a casing and a jet to produce a vapor,
Wherein the oil pump is inserted into a casing in the oil diffusion pump,
A target to be disposed in the jet so as to partially or entirely immerse the working fluid stored in the casing,
An induction coil electrically insulated and disposed in the vicinity of the heating target so as to partially or completely immerse the working fluid stored in the casing;
And a power supply means for applying an alternating current to the induction coil,
And the power supply means is operated to heat the object to be heated to vaporize the working oil.

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