KR100225323B1 - Baffle of continuous refrigerant circulating type diffusion pump - Google Patents

Abstract

The present invention relates to a baffle of a continuous refrigerant circulation diffusion pump, and in particular, a liquid nitrogen trap that is not commonly used is removed to significantly reduce the volume of the diffusion pump, and a baffle having a cooling function using a continuous circulation refrigerant is provided. In order to prevent contamination of the vacuum system and to implement a high-purity vacuum, a baffle for preventing backflow of the oil vapor of the diffusion pump, a cooling plate formed inside the baffle to cool the oil vapor, And a coolant tube formed to surround the outside of the cooling plate, and a coolant supply unit supplying a coolant to the coolant tube.

Description

Baffle of Continuous Refrigerant Circulation Diffusion Pump (DIFFUSION PUMP)

1 is a cross-sectional view of a conventional diffusion pump.

2 is a perspective view of a conventional baffle.

3 is a cross-sectional view of a conventional baffle.

4 is a cross-sectional view of the diffusion pump of the present invention.

5 is a cross-sectional view of the baffle of the present invention.

6 is a block diagram of a refrigerant pipe applied to the baffle of the present invention.

7 is an embodiment of the present invention cold plate.

8 is another embodiment of the present invention cold plate.

9 is an internal state diagram of the refrigerant supply unit of the present invention.

* Explanation of symbols for main parts of the drawings

100: refrigerant supply unit 101: cooling plate

101 ': Lower end of cooling plate 102: With refrigerant

104: baffle 110: temperature sensor

111 compressor 112 controller

113 condenser 114 capillary tube

The present invention relates to a continuous refrigerant circulation diffusion pump, in particular to combine the water-cooled baffle and the liquid nitrogen trap of the diffusion pump having a cooling function to economically prevent contamination of the vacuum system and achieve a high purity vacuum The baffle structure of the diffusion pump.

As shown in FIG. 1, a conventional diffusion pump includes a heater 11 to which power is applied through a power line 12, a boiler 10 operated by heat generation of the heater 11, and the boiler ( The steam chimney 9 through which the oil vapor in 10 is moved, and the cooling water line 7 formed along the outer wall of the diffusion pump case 8.

In the drawings, reference numeral 2 denotes a nitrogen case, and 6 denotes a nozzle.

The conventional diffusion pump configured as described above vaporizes the oil in the boiler 10 by generating heat in the heater 11. The vaporized oil is raised through the nozzle 6 in a vapor state and ejected.

And the oil vapor spouted at high speed acts to collect the surrounding air molecules in the downward direction of the pump, thereby increasing the air pressure in the lower part of the pump and drawing it out again through the auxiliary pump (13). The oil vapor is hit by the pump inner wall is cooled by the cooling water (5), and is collected again in the boiler (10).

When the oil vapor is ejected through the nozzle, it is ejected down the pump, but a small amount of steam flows back into the vacuum system, although a small amount of backflow steam can cause significant contamination under high vacuum.

In order to solve this problem, most of the conventional diffusion pumps use a baffle 4 in which cooling water 5 at 5 to 10 ° C. is injected and a cooling plate 14 is installed therein, as shown in FIGS. 2 and 3. The liquid nitrogen (1) was injected into the liquid nitrogen trap (3) in the nitrogen case (2) for more efficient cooling.

Here, the oil vapor is cooled and turned into a liquid. As a result, when the liquid nitrogen trap 3 is installed, backflow of the oil vapor is blocked and a high vacuum system can be secured.

However, due to the difficulty and cost of handling liquid nitrogen, it is avoided to use it except for precise experiments, and it is inconvenient because the cooling effect is not large due to the increase in the volume of the pump due to the nitrogen trap. Diffusion pumps without liquid nitrogen traps caused contamination of the vacuum system by oil vapors. That is, when using a baffle by the cooling water is not cooled enough to reduce the vacuum efficiency of the diffusion pump has occurred.

In view of the above, the present invention provides a cooling plate formed inside the baffle to cool oil vapor, a refrigerant pipe formed to surround the outside of the cooling plate, and a refrigerant supply unit supplying refrigerant to the refrigerant pipe. The aim is to prevent contamination of the diffusion pump vacuum system and to obtain a high purity vacuum.

The present invention is described in detail below with reference to FIGS.

First, as shown in FIG. 4, a baffle 104 for preventing oil backflow of the diffusion pump and a cooling plate 101 formed inside the baffle 104 to cool the oil vapor as shown in FIG. And a coolant tube 102 formed surrounding the outer side of the cooling plate 101 and a coolant supply unit 100 supplying a coolant to the coolant tube 102.

The refrigerant supply unit 100 includes a temperature sensor 110 for sensing a temperature of the baffle 104, a controller 112 for adjusting a refrigerant circulation amount of the compressor 111 through a signal of the temperature sensor 110, and A condenser 113 for liquefying a refrigerant that has become a gas of high temperature and high pressure in the compressor 11, and a capillary tube 114 for evaporating as the liquefied refrigerant passes to cool the baffle.

The lower end portion 101 ′ of the cooling plate 101 is formed to be inclined at a predetermined angle so that oil vapor does not directly pass through the cooling plate.

Referring to the operation of the diffusion pump according to the present invention configured in this way as follows.

When oil vapors for vacuum in the diffusion pump are injected through the nozzle 6, the injected oil vapors are cooled by the cooling water and liquefied again, where a small amount of oil vapor is introduced into the vacuum system by the backflow phenomenon.

Here, the role of the baffle 104 of the present invention becomes important. The refrigerant flows into the baffle 104 from the refrigerant supply unit 100 through the refrigerant pipe 102, and the introduced refrigerant circulates along the refrigerant pipe 102 to allow the refrigerant to flow. The temperature is spread evenly inside the baffle and then flows out again.

At this time, the circular refrigerant tube can be a circular structure of 3 to 4 stages depending on the structure to increase the cooling effect, and by using copper excellent in thermal conductivity to keep the inside of the baffle 104 at low temperature, minus 20 ℃ ~ minus 190 The temperature of the coolant at degrees Celsius is evenly spread in the baffle 104.

Due to the action of the baffle 104 is to liquefy the backflow oil vapors, and as a result it is possible to have a higher vacuum degree than the baffle using the cooling water than the baffle using the cooling water.

In addition, the baffle structure larger than the diameter of the diffusion pump is made to increase the cooling effect, so that the cooling function is performed in a wide area.

In addition, the present invention is provided with an inclined angle to the lower end 101 'in order to prevent the oil vapor rising from the diffusion pump directly pass through the cooling plate 101, the oil vapor collides with the lower end 101' cooling effect To increase.

As the material of the present invention, the baffle 104 is made of stainless steel, and the refrigerant pipe 102 and the cooling plate 101 are made of copper having high thermal conductivity. Refrigerant materials can be handled relatively easily using Freon gas, LP gas, liquid nitrogen gas, CFC or HFC used in air conditioners and refrigerators. have.

By using the heat of vaporization of these refrigerants. In case of Freon or LP gas, it can be cooled to minus 20 ℃ ~ below 50 ℃ and liquid nitrogen to minus 190 ℃.

In addition, as shown in FIG. 7, the cooling plate 101 may be formed in a honeycomb shape to increase the cooling effect. The denser the honeycomb shape, the better the cooling function. In another embodiment, the cooling plate may be formed in a plate shape as shown in FIG. 8 to improve the cooling effect.

As described above, the present invention not only reduces the volume of the diffusion pump by removing the liquid nitrogen trap which is not generally used, but also uses a refrigerant that provides the same effect as when using a nitrogen trap, thereby contaminating the vacuum system. It is an invention that can prevent and to implement a high purity vacuum.

Claims (6)

In the baffle structure located at the top of the diffusion pump to prevent the oil vapor of the diffusion pump to rise back flow, the refrigerant pipe is formed in a continuous multi-stage along the inner surface of the baffle to guide the refrigerant to the refrigerant pipe; A baffle for a continuous refrigerant circulation diffusion pump comprising a coolant supply unit and a plurality of cooling plates surrounded by the coolant tube and in contact with the coolant tube for heat transfer and formed in a flow direction of oil vapor. The baffle of claim 1, wherein the refrigerant supplied from the refrigerant supply unit is a freon gas. The baffle of claim 1, wherein the refrigerant supplied from the refrigerant supply unit uses LP gas, liquid nitrogen gas, CFC, or HFC. The baffle of claim 1, wherein the cooling plate is formed in a honeycomb shape so that the temperature of the refrigerant can easily spread into the baffle. The baffle of claim 1, wherein the cooling plate and the refrigerant pipe are made of a copper material to increase thermal conductivity. The baffle of claim 1, wherein the lower end of the cooling plate is inclined at a predetermined angle so that the rising oil vapor does not collide and pass directly through the cooling plate.