A feeding system for polyolefin solid catalyst

Abstract

The invention discloses a charging system of polyolefin solid catalysts. The charging system comprises a catalyst tank and a rotary feeder; an feed outlet of the catalyst tank is connected with the upper part of the rotary feeder through a first pipeline; the lower part of the rotary feeder is connected with a second pipeline; the first pipeline and the second pipeline are provided with valves; the rotary feeder comprises a housing, a cylindrical body, and a connecting shaft; a cavity is formed in the housing; the cylindrical body is arranged in a transverse manner; the surface of the cylindrical body is provided with a circular groove; the cylindrical body is arranged in the cavity, is pressed against the cavity firmly, and is capable of rolling in the cavity along the transverse direction axis; the connecting shaft is arranged on the transverse direction axis of the cylindrical body; the housing is provided with a hole corresponding to the connecting shaft; and the connecting shaft is designed to penetrate the hole. The pipeline on the tank bottom of the catalyst tank of the charging system is provided with the rotary feeder, and catalyst charging amount can be controlled throughadjusting the rotating speed of the rotary feeder, so that continuous, accurate, and stable introduction of solid catalysts into a polymerization reactor can be realized using the charging system.

Description

technical field [0001] The invention relates to the field of olefin polymerization, in particular to a feeder for a granular solid polyolefin catalyst and a matching catalyst feed system. Background technique [0002] At present, most of the catalysts used in olefin polymerization in industry are solid particle type, and the feeding of this solid particle type catalyst is usually added by a specially designed catalyst feeding device, such as the solid catalyst feeding device adopted on the Unipol polyethylene device; there is also a After a complex preparation process, the catalyst is prepared into a certain concentration of slurry or paste, and then sent into the reactor with a metering system. In the above two methods, the equipment investment of the former is very high, the adding process is easy to block, and there is no accurate and effective method to know the catalyst content in the catalyst feeder. The preparation process of the latter is extremely complicated, and ...

AI Technical Summary

Problems solved by technology

This invention can realize small dose of powder feeding, but the material is easy to deposit on the inner wall of the material channel, resulting in measurement error

[0005] Chinese patent CN101811011A discloses a catalyst automatic feeding method. The fluidization conveying air pipeline is set to continuously feed the fluidizing conveying air into the feeder. A fluidizing conveying air regulating valve and a flow meter are arranged on the fluidizing conveying air pipeline. Feeding regulating valve, a connecting pipe is set between the top of the feeder and the pipe section of the discharge pipe near the outlet of the discharge valve. , the catalyst circulates in the connected circulation loop at the top of the feeder, which reduces the deposition and clogging during the catalyst delivery process, and the problem of unstable feeding, but the circulation device of this equipment is set on the top of the feeder, and strong fluidization is required during the circulation process Conveying air, the device generally uses compressed air as the fluidized conveying air, so the equipment cost is relatively high, and the invention also requires the fluidized conveying air to ensure that the internal pressure of the feeder is constantly lower than or equal to the catalyst tank charging pressure and higher than the regeneration pressure. The pressure of the device is higher, which requires higher equipment and increases the production cost

This invention can continuously add solid catalyst into the reaction system under normal pressure, but due to the lack of catalyst metering device, the amount of catalyst added cannot be controlled

Moreover, this feeding system uses a catalyst tank and an intermediate tank. The catalyst feeding process is long, and the catalyst is easy to accumulate and remain in the intermediate tank, resulting in waste of catalyst.

[0007] At present, there is a lack of a catalyst feeder with a simple structure, easy maintenance, and solid polyolefin catalyst particles that can be continuously, smoothly and accurately added to the polymerization reactor, as well as a matching catalyst feed system.

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