Device for removing bubbles in pitch through vacuum auxiliary temperature differential method and bubble removing method thereof

Abstract

The invention discloses a device for removing bubbles in pitch through a vacuum auxiliary temperature differential method and a bubble removing method thereof. The device comprises a bubble removing kettle and a buffering tank and further comprises a heating part used for supplying heat to the bubble removing kettle, a pitch soaking stirrer, an inert gas inlet pipeline and a vacuum pump system, the bubble removing kettle and the buffering tank are communicated through a first communicating valve, a waste discharge valve is connected to the bottom of the buffering tank, and the buffering tank and the vacuum pump system are communicated through a second communicating valve. The temperature differential method is introduced into a traditional bubble removing method, medium and low molecules in pitch are volatilized fully at a high temperature by means of stirring, the temperature is reduced below the pitch softening point, the characteristic that an bubble film is easy to crack when being converted into the solid state from the liquid state is utilized, low-molecule volatile matter is drawn in a vacuum mode, and then temperature raising vacuum auxiliary sedimentation treatment is adopted for removing a small quantity of residual bubbles. The bubble removing rate can reach 99.9%, and pitch fiber with the size larger than 4 km can be spun continuously and stably.

Description

technical field [0001] The invention belongs to the technical field of pitch-based carbon fiber pitch spinning, and in particular relates to a device and method for removing air bubbles in pitch by a vacuum-assisted temperature difference method, which is used for the melting of mesophase pitch, a key process in the preparation of pitch-based carbon fiber continuous filaments. Pre-spinning treatment for spinning. Background technique [0002] Due to the wide molecular weight distribution of asphalt, the low molecular weight volatile matter vaporizes at the spinning temperature to form fine air bubbles, which will cause filament breakage during spinning. Therefore, removing the air bubbles in the molten asphalt is the key to ensure smooth spinning and stable carbon filament quality. Pre-spinning treatment. At present, there are mainly three methods for asphalt melting and degassing, namely, static degassing method, pressurized degassing method and vacuum degassing method. Am...

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Problems solved by technology

However, there are the following deficiencies: firstly, this method is mainly used in analytical experiments in the petrochemical industry, and cannot be applied industrially; in addition, it is mainly aimed at the degassing of asphalt with low softening point and low viscosity, and is not suitable for the degassing of asphalt with high softening point and high viscosity. Bubble

[0004] Comprehensive analysis shows that among the existing asphalt degassing methods, there is no mature technology that is more suitable for the industrial degassing method of high softening point asphalt, which seriously hinders the development of pitch-based carbon fiber continuous filament preparation technology

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