Diffusion pump capable of achieving rapid starting, floating heating and rotating injection

Abstract

The invention discloses a diffusion pump capable of achieving rapid starting, floating heating and rotating injection. The diffusion pump comprises a pump body, pump oil, a pump core, an evaporation system, a cooling system, an injection system and a control system, the evaporation system of the pump adopts a heating mode of floating heating, the evaporation system comprises an evaporator, a heater and a temperature measuring and temperature 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 amiddle partition plate and communicate with each other through an oil hole in the partition plate, the heater is arranged in the heating area, and is used for heating the pump oil in the heating areato enable the pump oil to be instantly evaporated to become steam, the heater is fixed on the middle partition plate, the middle partition plate can float in the pump oil, the top of a steam guide pipe in the injection system is provided with a rotating spray head, a series of nozzles are arranged on the periphery of the rotating spray head, when steam is sprayed out of the nozzles, the rotatingspray head can rotate at a high speed, a heating device is arranged on the steam guide pipe or around the steam guide pipe so that the temperature of the pump core and the steam can be improved, and rapid starting of the diffusion pump can be realized.

Description

technical field [0001] The invention relates to the field of vacuum pumps, in particular to a fast-start floating heating rotary jet 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 t...

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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 Reduced, the composition is constantly changing, resulting in continuous 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 the pump oil; the existing diffusion pump It takes a long time to start, about 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; the nozzle of the existing diffusion pump is a fixed umbrella-shaped diffusion nozzle, and the steam After spraying from the nozzle, a stable umbrella-shaped airflow is formed, and the extracted air molecules enter the steam flow by means of diffusion movement. The disadvantages are that the contact surface between steam and air is small, the combination method is passive, the extraction force is small, and the vacuuming efficiency is low. Low, low ultimate vacuum

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