JPH01253590A - High-vacuum pump - Google Patents

Abstract

PURPOSE:To improve the exhaust speed by arranging a low-temperature panel connected to a cooling device on the intake port side of a casing in a vacuum pump applying momentum to molecules of the gas sucked through the intake port and discharging them through an exhaust port via the rotation of blades. CONSTITUTION:An intake port 11 and an exhaust port 12 are formed on the upper section and the lower side section of a casing 10. A molecular pump M provided with blades 14 rotated by a motor 13 is arranged in this casing 10. Momentum is applied to molecules of the gas sucked into the casing 10, and they are discharged through the exhaust port 12. In this case, a cooling device 15 and a low-temperature panel 16 thermally integrally connected to it are arranged on the upstream side of the blades 14. The cooling device 15 cools the operating gas compressed by a compressor 21 with a radiator 20 then generates the cold by the expansion of the operating gas guided via the forward passage 19a of a heat exchanger 19. Steam and CO2 or the like are condensed and discharged in the low-temperature panel 16.

Description

DETAILED DESCRIPTION OF THE INVENTION OBJECTS OF THE INVENTION Field of Industrial Application The present invention relates to high vacuum pumps, and in particular to high vacuum pumps in the form of molecular pumps.

(Prior Art) In order to generate high vacuum, molecular pumps have conventionally been employed, for example, as disclosed in the catalog of "Mitsubishi Turbo Molecular Vacuum Pump" published by Mitsubishi Electric Corporation. This molecular pump performs a pumping action by imparting large momentum to gas molecules.

(Problem B to be solved by the invention) However, although molecular pumps have the advantage of being able to pump out all kinds of gases, they have the disadvantage of slow pumping speed.

Therefore, when a molecular pump is employed in a vacuum device, there is a problem in that it takes time to exhaust water vapor, which is the largest amount of water vapor that needs to be evacuated in the vacuum device.

Therefore, the technical objective of the present invention is to increase the pumping speed of a high vacuum pump.

[Structure of the invention]

(Means for Solving the Problems) The technical means taken in the present invention to solve the above-mentioned technical problems are as follows: [A casing with an intake port and an exhaust port, a wing disposed in the casing, and a wing] It has a motor that rotates the
In high vacuum pumps, gas molecules sucked into the casing from the intake port when the blades are rotated by the motor are given momentum by the blades and are discharged from the exhaust port. A high-vacuum pump with a low-temperature panel was constructed.

(Function) In this configuration, gases with a relatively high condensation temperature such as water vapor and carbon dioxide are condensed and exhausted by the low-temperature panel, while gases with a relatively low condensation temperature such as nitrogen, oxygen, hydrogen, neon, and helium are molecules. Exhausted by a pump. In other words, since the molecular pump is not in charge of exhausting gas with a relatively high condensation temperature, the overall pumping speed can be increased.

(Example) In FIGS. 1 and 2, an intake port 11 and an exhaust port 12 are formed in the upper and lower side parts of the casing 10, respectively. A molecular pump M equipped with blades 14 rotated by a motor 13 is disposed within the casing 10 . When the blade 14 is rotated, the casing 1 is removed from the intake port 11.
The gas molecules sucked into the air are given momentum by the blades 14 and are discharged from the exhaust port 12.

A cooling device 15 and a low-temperature panel 16 that is thermally integrated with the cooling device 15 are disposed upstream of the blade 14, that is, between the intake port 11 and the blade 14. That is, the cooling device 5 in the form of a turbo expander is fixed to the casing 10 via a bracket 17. A cold head 15c of the cooling device 15 is fixed to a low temperature panel 16.

Therefore, the inlet boat 15a of the cooling device 15 includes the piping 18, the outgoing road 19a of the heat exchanger 19, and the radiator 20.
It is connected to the discharge port of the compressor 21 via. Also,
The outlet port (15b) of the cooling device 15 is connected to the pipe 22
and the compressor 21 via the return passage 19b of the heat exchanger 19.
connected to the inlet of the

The working gas compressed by the compressor 21 is cooled by the radiator 20 and then transferred to the outgoing road 19a of the heat exchanger 19 and the piping 18.
and then reaches the cooling device 15. There, the working gas is expanded, and this expansion causes the working gas to generate cold in the cold head 15c.
9 returns to the compressor 21 via the return path 19b. When the working gas passes through the return passage 19b of the heat exchanger 19,
The working gas passing through the outgoing road 19a of the heat exchanger 19 is cooled. In other words, cold is generated by the reverse Brighton cycle.

Low temperature panel 1 thermally connected to cold head 15c
6 condenses and exhausts gases with a relatively high condensation temperature, such as water vapor and carbon dioxide, and exhausts gases with a relatively low condensation temperature, such as nitrogen, oxygen, hydrogen, neon, and helium, with a molecular pump M. Thus, a high vacuum can be generated.

〔Effect of the invention〕

In the present invention, gases with relatively high condensation temperatures such as water vapor and carbon dioxide are condensed and exhausted by the low-temperature panel, and nitrogen and
Gases with relatively low condensation temperatures, such as oxygen, hydrogen, neon, and helium, are pumped out using molecular pumps. In other words, since the molecular pump is not in charge of exhausting gas with a relatively high condensation temperature, the overall pumping speed can be increased.

[Brief explanation of the drawing]

FIG. 1 is a plan view of an embodiment of a high vacuum pump according to the present invention, and FIG. 2 is a sectional view taken along line 1--2 in FIG. 10: Casing, 11: Intake port, 12: Exhaust port, 13
: motor, 14: blade, 15: cooling device, 16: low temperature panel.

Claims (1)

[Claims] It has a casing with an intake port and an exhaust port, a blade disposed in the casing, and a motor for rotating the blade, and when the blade is rotated by the motor, the gas sucked into the casing from the intake port. A high vacuum pump in which molecules are given momentum by blades and then discharged from the exhaust port.A high vacuum pump has a low-temperature panel that is thermally connected to a cooling device on the intake port side of the casing.