Full wax oil under-refluxing overheat-removing and circulation ratio quantitative controlling coking-retarding apparatus and method

Abstract

The invention discloses full wax oil under-refluxing overheat-removing and circulation ratio quantitative controlling coking-retarding apparatus and method. The apparatus comprises a heating furnace, a coke tower and a fractionating tower. A heat exchange baffle is arranged in the fractionating tower and between a wax oil collecting tank and a heavy oil collecting tank. A high-temperature oil and gas inlet is arranged below the heat exchange baffle. The method comprises the steps that: the wax oil pumped from the wax oil collecting tank is subjected to under refluxing from top to bottom, such that the wax oil and high-temperature oil and gas are subjected to washing and heat exchange; heavy wax oil obtained by washing is delivered into a heavy wax oil collecting plate. Ratio controlling is adopted between circulation oil and raw material oil. When liquid level at the bottom of the fractionating tower is changed, flow rates of the raw material oil and the circulation oil can both be adjusted. After heat exchange, a part of heavy wax oil is delivered back to the heavy wax oil collecting plate for washing. Prior arts have problems, such as that the separation precision of coked wax oil and circulation wax oil is low, wax oil residual coke is high, wax oil dry point is high, circulation ratio fluctuation is high, and the fractionating tower is easy to get coked. With the apparatus and the method provided by the invention, the problems are solved. The operation is simple, flexible, and reliable.

Description

technical field [0001] The invention belongs to the field of petrochemical industry, and furthermore, relates to a delayed coking device and method with full wax oil under reflux for desuperheating and quantitative control of circulation ratio. Background technique [0002] Delayed coking process is a deep thermal cracking process for heavy oil. The heavy oil is rapidly heated to the required temperature (about 500°C) in the heating furnace and then enters the coke tower. High temperature thermal cracking and condensation reaction, the reaction produces dry gas, liquefied gas, gasoline, diesel oil, wax oil and coke. The three process parameters that have a greater impact on the economics of the delayed coking unit are coke tower top pressure, circulation ratio and heating furnace outlet temperature. The coke tower top pressure and heating furnace outlet temperature are controlled by the compressor and the heating furnace respectively. The circulation ratio is defined as the...

AI Technical Summary

Problems solved by technology

[0009] In order to solve the problems existing in the current delayed coking process, such as low separation precision of coking wax oil and circulating oil, high residual carbon and dry point of wax oil, large fluctuation of circulation ratio and easy coking of fractionating tower, etc.

The invention provides a delayed coking device and method with full wax oil under reflux to remove superheat and quantitative control of circulation ratio, which overcomes the defects in the existing delayed coking process and is simple, flexible and reliable in operation

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