KR19990064870A - Diffusion pump using refrigerant and compressor - Google Patents

Abstract

The present invention relates to the cooling of a high vacuum oil diffusion pump. The conventional oil diffusion pump has cooled the surface of the pump by flowing the coolant through a cooling pipe attached to the outer wall of the pump container. However, if the cooling water cannot be obtained inexpensively and inexpensively, the recovered cooling water is cooled and circulated.Therefore, various problems such as clogging of the cooling water pipes occur during long-term use. In the case of productivity had to suffer. However, in the present invention, by using the elements of the refrigerator such as a refrigerant, a compressor condenser and the cooling tube of the diffusion pump to function as an evaporator of the refrigerator, the cooling tube is cooled, thereby cooling the surface of the pump. By eliminating the use of water, the cooling water pipe is removed, thereby facilitating the movement and significantly reducing the number of maintenance.

Description

Diffusion pump using refrigerant and compressor

Diffusion pumps were developed by Gaede, Germany in 1913, and have been developing for 50 years. The pump has been widely used to this day because of its simple structure and low cost, and high vacuum of less than 10 ^-6 Torr and relatively low maintenance cost. However, there is a problem with this because the surface of the pump container must be cooled with water. The present invention seeks to solve this problem by essentially not using water.

The oil diffusion pump is composed of a pump vessel diffusion oil, a boiler for heating and evaporating the diffusion oil, an electric heater as its heat source, and a jet for spraying the evaporated oil. A water-cooled pipe is wound around to return the injected oil vapor to the liquid, and an exhaust port is provided at the bottom of the pump container to send the compressed gas molecules to the rear flow pump. . Diffusion oil heated and evaporated by a boiler rises upwards through a cylindrical pipe and is sprayed at supersonic speed through a narrow gap jet facing downwards to cool the pump vessel. It hits the surface, cools down and returns to the liquid. The liquid oil flows into the boiler and evaporates again. At this time, the air molecules diffused into the jet stream collide with the injected oil vapor with downward momentum and have an average momentum downward, and are compressed at higher pressure through several stages. do. Compressed air molecules are discharged out of the vessel by a flow pump through an exhaust port located below the pump. Since the exhaust port is continuously exhausted by the flow pump, the pressure near the exhaust port maintains the maximum degree of vacuum that can be reached by the flow pump, so that the inlet side of the diffusion pump is far higher than the flow rate that can be reached by the flow pump. It is designed to reach high vacuum.

Diffusion pumps have been used inexpensively until now by using water as a coolant. But water is no longer an inexpensive and infinitely obtainable material, and even worse for mass production lines where long-term use of dozens or hundreds of diffusion pumps is required. In some cases, the recovered cooling water is cooled outside to allow the water to be reused. In this case, if the lumps made by corroding the inside of the cooling pipe of the copper diffusion pump made of copper and lumps of sediment in the water block the cooling pipe and the cooling water flow rate decreases, the pump is overheated and the vacuum is not maintained. Often you have to do it. The present invention is designed to achieve the result of improving the productivity by remarkably reducing the number of times to solve this problem and repair.

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

2 is a structural diagram of the present invention

Explanation of symbols for main parts of the drawings

1. Jet with diffused oil vapors

2. Pump container

3. Water cooling pipe

4. Flange for connection with vacuum box

5. Jets made of multiple stages

6. Heater for boiling diffusion oil

7. Diffusion oil

8. Oil diffusion pump

9. Compressor

10. Condenser

11.expansion valve or capillary tube

12. Cooling fan

As shown in FIG. 2, the present invention comprises a diffusion pump, a compressor, a condenser, and an expansion valve (or capillary tube). The diffusion pump is generally equipped with a copper pipe for the purpose of circulating water on the outside to cool the surface, and the pipe has both ends of an inlet and an outlet. . The inlet of the conduit is connected to the condenser via an expansion valve (or capillary tube) of the freezer and the outlet is connected to the inlet of the compressor. As a result, it is the same as replacing one evaporator with a cooling tube of a diffusion pump. After filling with an appropriate refrigerant inside and then compressing it with a compressor, the condensed and cooled refrigerant vaporizes through an expansion valve, cooling the cooling pipe in the same principle as a refrigerator, thereby cooling the surface of the diffusion pump, Condensed diffusion oil inside the diffusion pump. The refrigerant heated around the surface of the pump is sent to the condenser by the compressor, and as the condenser is heated, the refrigerant, which is hotter, is cooled by forced blowing by a fan and then vaporized through the expansion valve to cool the cooling tube. By repeating this operation, the diffusion pump can be used without water.

Through the present invention, there are effects that can solve many problems caused by circulating water in a mass production line using a large amount of diffusion pump, that is, productivity reduction due to frequent blockage of pipes and inconvenient movements. .

Claims (1)

A method of cooling a vessel surface of a pump for driving a diffusion pump by using a refrigerant and a compressor, and by cooling the condensed refrigerant through the cooling pipe of the diffusion pump.