Forced internal recirculation type external cooler for catalytic cracking catalyst

Abstract

The invention provides a forced internal recirculation type external cooler for a catalytic cracking catalyst. At least two gas distributors are arranged at the internal bottom of the cooler, and each gas distributor is accessible to fluidized gas independently and can control the gas flow. A plurality of cooling tubes in vertical arrangement are arranged above the gas distributors. Apart from the gas distributors, the cooling tubes and matched fixed parts thereof, no additional components are arranged in the cooler. By controlling the different gas flows of at least two gas distributors, the superficial gas velocity and the bed density in different cross section areas in the cooler are caused to be different and the internal circulation of particles in a bed is strengthened, so the update velocity of the particles on a heat transfer wall is improved and the heat transfer efficiency of the particles and the wall is effectively improved. The cooler has the advantages of simple structure, high heat transfer efficiency and flexible regulation, and can also be used as a themosistor for a catalytic cracking regenerant. In addition, the invention also provides a catalytic cracking device containing the cooler and a catalytic cracking method.

Description

technical field [0001] The invention relates to a catalytic cracking catalyst heat exchange device, in particular to a forced internal mixing type catalytic cracking catalyst external heat extractor, which can also be used as a catalytic cracking regeneration catalyst thermostat, belonging to the petrochemical industry technology field. Background technique [0002] In the petroleum refining industry, catalytic cracking is one of the important secondary processing processes of petroleum. In the catalytic cracking process, heavy macromolecular petroleum hydrocarbons are cracked into small molecular hydrocarbons under high temperature environment and under the catalytic action of molecular sieve catalysts. . In my country, catalytic cracking is the most important means of lightening heavy oil. The vast majority of commercial gasoline and a large part of commercial diesel and chemical raw materials in China come from catalytic cracking. [0003] The catalytic cracking unit is...

AI Technical Summary

Problems solved by technology

Chinese patent 200720091980.5 proposes an obliquely inserted external heat extractor, in which a series of obliquely inserted heat extraction pipes are arranged, and vertical ribs are arranged on the heat extraction pipes to increase the heat transfer area. The length of the heat pipe in this type of heat extractor is shorter than that of the traditional heat pipe, which is conducive to prolonging its service life. However, the heat extraction efficiency of this inclined heat pipe is generally low, because there is often an air cushion below it, and there will be an air cushion above it. A certain particle fluidization dead zone will greatly reduce the overall heat transfer efficiency of the heat pipe

On the one hand, the setting of the heat-taking pipe isolation tube limits the heat-taking area in the unit space, which is unfavorable for the further improvement of the heat-taking efficiency; Safe and reliable operation, the loss caused by unplanned shutdown due to equipment failure can easily offset the economic benefits brought by the new equipment, the existence of the partition tube will undoubtedly increase the difficulty of equipment manufacturing and potential application risks

The set porous sieve plate and feeding pipe are mainly to facilitate the first introduction of hot catalyst into the bottom of the inner ring area of ​​the partition tube, and to allow the fluidization gas at the bottom to pass through without affecting the flow of the catalyst and then flow from the heat collector. Outflow from the top, this structural design further increases the complexity and manufacturing difficulty of the heat extraction equipment

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