Method for controlling upper-middle temperature of catalytic cracking raising pipe

Abstract

The invention provides a method for controlling the upper-middle temperature of a catalytic cracking raising pipe, comprising the following steps of: atomizing a medium which is easy to vaporize, such as an oil-water mixture, by using an incondensable dry gas, and injecting into a reactor by selecting a nozzle with an atomization function; and fast vaporizing on the downstream position of a spray nozzle positioned on the upper-middle appropriate position of the catalytic cracking raising pipe, wherein a temperature reducing amplitude can maximally reach 20 DEG C. The invention can also eliminate water attack vibration noises generated when vapors contact with the medium and reduce the yield of the incondensable dry gas about 0.3 percent and the coke yield about 0.2 percent.

Description

technical field [0001] The invention relates to a method for controlling the temperature in the upper part of a catalytic cracking riser. Background technique [0002] The catalytic cracking unit in the petroleum refining process is the main refining unit for the lightening of heavy oil. It processes heavy raw oil (petroleum fractions above 350°C, referred to as heavy oil or raw oil). The target products for production are gasoline, diesel and liquefied petroleum gas. The products include dry gas and oil slurry, and the generated coke adheres to the catalyst and is burned through the catalyst regeneration process. The riser is commonly used as a reactor, with a total length of about 35-45 meters. The heavy oil is atomized from the heavy oil nozzle at the lower part of the riser and sprayed into it. It is mixed with the catalyst at about 690°C from the regenerator. The common reaction temperature is 515-535°C. The catalytic cracking process of a prolific gas is even as high ...

AI Technical Summary

Problems solved by technology

Excessive cooling in the side wall area causes high boilers to condense and adhere to the catalyst again and turn into coke, causing losses; the oil-gas reaction that has not been cooled in time cannot be effectively controlled, and the production of more dry gas and coke is also a waste

[0008](2) After the terminator and the steam meet in front of or inside the nozzle, the steam is condensed. Due to the sharp change in the volume of the steam, water hammer occurs, causing noise and making the equipment damaged

If the measure of stopping the introduction of steam is taken when the vibration occurs, the nozzle will be blocked by the backflow of the catalyst inside the reactor when the terminator is interrupted for some reason, and it will fail.

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