Floating heating type rapid start diffusion pump

Abstract

The invention provides a floating heating type rapid start diffusion pump. The floating heating type rapid start diffusion pump comprises a pump body, pump oil, a pump core, an evaporation system, a cooling system, an injection system and a control system. A floating heating manner is adopted for the evaporation system. The evaporation system comprises an evaporator, a heater and a temperature measurement and control element. The evaporator is provided with a heating area and an oil storage area, the heating area and the oil storage area are separated through a middle partition plate and communicate with each other through oil holes in the partition plate. The heater is arranged in the heating area and heats the pump oil in the heating area so that the pump oil can be evaporated instantlyto become steam. The heater is fixed to the middle partition plate, the middle partition plate can float on the pump oil, and the heating area can always keep constant and unchanged within a normal pump oil range. A heating device is arranged on or around a steam guide pipe in the injection system, the temperature of the pump core and the steam can be increased, the rate and kinetic energy of theinjected steam are increased, and rapid start of the diffusion pump can be realized.

Description

technical field [0001] The invention relates to the field of vacuum pumps, in particular to a floating heating type quick start diffusion pump. Background technique [0002] Vacuum diffusion pump is currently one of the most widely and most important tools for obtaining high vacuum. Diffusion pump is mainly composed of pump body, pump oil, pump core, evaporation system, cooling system, injection system and control system. Under the low vacuum condition formed by the vacuum pump, the evaporation system makes the pump oil boil and evaporate, and the generated steam is ejected through the injection system at a very high speed, so that the gas molecules in the upper part of the pump diffuse into the steam, and the oil vapor flows through the pump through the cooling system. The lower part is condensed, and the released gas molecules are sucked away by the backing pump, and the condensed pump oil is returned to the evaporation system to be reheated, so that the cycle works to ach...

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Problems solved by technology

The evaporation system is one of the most important components of the diffusion pump. The existing evaporation system uses resistance heating (resistance wire, etc.) or electromagnetic induction heating to heat all the pump oil and the bottom of the diffusion pump. The disadvantages are The pump oil of the diffusion pump has a large heating capacity, slow heating speed, uneven heating, long start-up time of the diffusion pump, large heat loss, high power of the heating furnace, high energy consumption, low efficiency, high bottom temperature of the pump oil, and easy to boil , easy to decompose and deteriorate, the evaporation system and the cooling system cannot be completely separated (connected by the pump body), the internal friction is large, the resistance wire is easy to burn out, and the replacement of the resistance wire requires a long downtime. After the diffusion pump stops working, the pump oil remains for a long time In the high temperature state, it is easy to oxidize and deteriorate, which reduces the service life of the pump oil. The cooling speed of the evaporation system is slow, and the cooling system needs to prolong the working time, which increases the operating cost. In addition, because the diffusion pump is working, the amount of pump oil is constantly The reduction and composition are constantly changing, resulting in constant changes in the working conditions of the diffusion pump, making the vacuum degree prone to fluctuations; frequent addition of new oil is not only time-consuming and laborious, but also not conducive to the purification and fractionation of pump oil; the existing diffusion pump starts It takes 20-80 minutes. The reason for the slow start is that the pump oil heating rate is slow and the pump core needs pump oil to heat up.

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