Regenerative type lithium steam filtration system of lithiation wall treatment gas pumping system

Abstract

The invention discloses a regenerative type lithium steam filtration system of a lithiation wall treatment gas pumping system. The regenerative type lithium steam filtration system of the lithiation wall treatment gas pumping system is installed between an EAST lithiation wall treatment gas pumping molecular pump and an EAST device vacuum chamber; in the EAST lithiation wall treatment period, when passing through the filtration system, gas containing lithium steam and other particles can sequentially collide with four umbrella-shaped baffle systems to be adsorbed on the umbrella-shaped baffle systems, and therefore the probability that these harmful gas molecules reach the molecular pump is reduced, and protection on the molecular pump can be achieved; and after being used for a period of time, the filtration system can perform washing, baking and gas pumping operation to be regenerated by means of its regenerative system, so that lithium coatings and other harmful substances attached to the baffle systems and pipeline device walls can be removed, and subsequent continuing use is facilitated. The successful development of the system can reduce influences of lithium steam and other harmful gas molecules on the molecular pump to the maximum extent in the EAST lithiation process.

Description

technical field [0001] The invention relates to the fields of high vacuum technology and magnetic confinement fusion technology, in particular to a reproducible lithium vapor filter system for a lithiated wall treatment pumping system. Background technique [0002] Impurity suppression and particle recycling are important research topics in tokamak plasmas. At present, lithiation wall treatment has become a routine wall treatment method in EAST, and it is a favorable guarantee for obtaining high parameters in EAST physical tests. Lithiated wall treatment is mainly to coat a layer of lithium film on the first wall of the tokamak device by means of glow discharge or ion cyclotron discharge during lithium evaporation to modify the first wall of the plasma and improve the quality of the plasma. the goal of. [0003] Since lithiation is mainly achieved by means of glow discharge or ion cyclotron discharge mode to achieve lithium evaporation coating, therefore, in order to maint...

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Problems solved by technology

[0003] Since lithiation is mainly achieved by means of glow discharge or ion cyclotron discharge mode to achieve lithium evaporation coating, therefore, in order to maintain glow discharge or ion cyclotron discharge, it is necessary to have a set of air extraction unit for real-time pumping of EAST device to ensure EAST The internal pressure of the device is stable at 0.59a (glow discharge mode) or 0.059a (ion cyclotron discharge mode); in the experiment, it was found that due to the high concentration of lithium vapor inside the tokamak device during the lithiation wall treatment process, the molecular During the pumping process of the pump unit, a large amount of lithium vapor will be removed along with the pumping process. When the lithium vapor encounters the cold fan blade, it will adhere to the molecular pump fan blade. With the increase of lithiation time and the number of lithiation Increase, the lithium layer attached to the molecular pump blade will become thicker and thicker, which will increase the operating burden of the molecular pump on the one hand; on the other hand, some lithium atoms will be attached to the bearing of the molecular pump, which will weaken the operating flexibility of the bearing In the third aspect, when the lithium film attached to the molecular pump reaches a certain thickness, it will fall off with the rotation of the molecular pump blades. The fallen lithium coating fragments are very harmful to the high-speed molecular pump blades. If it is serious, it will affect the normal operation of the molecular pump, and if it is serious, it may break the molecular pump

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