Rotary feeder and feeding system for polyolefin solid catalyst

Abstract

The invention relates to a rotary feeder for a polyolefin solid catalyst. The rotary feeder comprises a distributor (1) and a catalyst feeding rotary metering valve (6), wherein a channel divided into2-4 parts is arranged in the distributor (1), a catalyst is divided into 2-4 paths to flow to the catalyst feeding rotary metering valve (6) after entering the distributor (1), the catalyst feeding rotary metering valve (6) comprises a valve body (7) and a ball core (8), the ball core (8) is provided with a cavity (9), the cavity (9) receives the catalyst flowing out of the distributor (1) when the opening of the cavity faces upwards, the ball core (8) is rotated to enable the opening of the cavity (9) to face downwards, and the catalyst flows to a downstream pipeline to achieve feeding. Compared with the prior art, the feeder and the feeding system have the following characteristics that feeding is rapid, uniform and continuous, and catalyst particle morphology is not damaged.

Description

technical field [0001] The invention relates to the technical field of dry powder catalyst feeding, in particular to a rotary feeder and a feeding system for polyolefin solid catalysts. Background technique [0002] The gas phase polyolefin process is an important component in the polyolefin production process. At present, the main domestic gas-phase polyethylene processes are divided into: UCC's Unipol gas-phase fluidized bed process, BP's Innovene gas-phase fluidized bed process, Sinopec's GPE gas-phase fluidized bed process, etc. . In the production process, the catalyst is the core of the entire polymerization reaction. UCC's Unipol gas-phase fluidized bed process, BP's Innovene gas-phase fluidized bed process, etc. need to add solid catalysts. In order to ensure the long-term stable operation of the polymerization reaction, it is necessary to ensure the stability and reliability of the solid catalyst feeding rate, the accuracy of the metering, etc., so the solid catal...

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Problems solved by technology

[0005] The rotary feeder cannot distribute the catalyst during feeding, and the catalyst will be uneven and easy to diverge during the feeding process. The defects of this rotary feeder:

[0006] 1. The particle shape of the catalyst is damaged during the feeding process. Since the particle shape of the catalyst determines the particle shape of the resin, the catalyst particles are broken, which seriously affects the shape of the device product, resulting in a lot of fine powder inside the reactor;

[0007] 2. This rotary feeder is only suitable for rotary feeding of products at normal pressure. Since there are a large number of grooves on the ball, which affects the sealing of the valve body, the design pressure is 3.8MPa during the feeding process of polyethylene catalyst, and the sealing is very important. Important, poor sealing will cause the lower material to flow back to the upper part of the valve body, resulting in poor feeding and inaccurate measurement, which is not suitable for high-pressure working conditions;

[0008] 3. The angle between the sphere groove and the sphere inside the feeder is less than 90°. During the rapid rotation, the catalyst in the groove will fall to the surface of the sphere, resulting in inaccurate metering, and catalyst particles may remain on the sphere and the sphere. Between the sealing surfaces, the metal particles in the catalyst wear away with the ball and the sealing material for a long time, causing seal failure and leakage

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