Downflow type pre-polymerization tower

Abstract

The present invention discloses a downflow type pre-polymerization tower. The tower comprises a cylindrical tower body, an upper dome and a lower dome, wherein the upper dome is arranged on the top of the tower body, and the lower dome is arranged on the bottom of the tower body. The tower is characterized in that: the internal of the tower body is provided with a plug flow work area; a conical umbrella plate is arranged between the plug flow work area and the upper dome; a gas phase space is arranged between the plug flow work area and the lower dome; the central axis position of the tower body is provided with a gas phase channel, wherein the gas phase channel penetrates the whole plug flow work area. According to the present invention, the designed plug flow work area is formed by adopting a plurality of trays and a plurality of baffles, wherein the trays and the baffles are staggeredly arranged, such that the material is always at the repeatedly states of plug flow and overflow, and the sufficient mass transfer area and the sufficient small molecule removal space are provided so as to ensure the removals of the small molecules and the non-condensable gases, wherein the material flows downward; the tower of the present invention is applicable for the pre-condensation polymerization process or the pre-polymerization process of aromatic polyesters, is further applicable for the preparation process of saturated polyesters or unsaturated polyesters, and is especially applicable for the polymer preparation process requiring the removal of a large amount of the small molecules during the polymerization process.

Description

technical field [0001] The invention relates to a reaction tower used in the precondensation stage between the two stages of esterification and final polycondensation in the process of polymer preparation and the prepolymerization stage in some polymer preparation processes, which belongs to the technical field of chemical industry, and particularly relates to A downflow prepolymerization tower. Background technique [0002] In the production process of polymer materials such as polyethylene terephthalate (PET), polytrimethylene terephthalate (PTT), polybutylene terephthalate (PBT) and other conventional aromatic polyesters In the process, it is necessary to add a pre-condensation stage between the two stages of esterification and final polycondensation. In this stage, the late reaction of esterification is carried out, even if the esterification rate is increased to more than 99%, the polycondensation reaction is carried out at the same time, and the pressure changes during...

AI Technical Summary

Problems solved by technology

Therefore, due to these problems, it is the most reasonable to use a pipeline reactor or a tower reactor to realize the precondensation process in terms of the reaction principle. However, the design of this type of reactor is still very complicated, consumes a lot of materials, consumes a lot, and costs high

And in the preparation of some other polymer materials such as polybutylene succinate (PBS), the preparation of saturated polyesters such as polybutylene succinate (PBS), polyterephthalic acid / butylene succinate copolyester (PBST), and need There is no effective equipment on the market for the preparation of polymers such as polylactic acid (PLA) that removes a large number of small molecules

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