Strip steel oxidation prevention control method for preheating non-oxidation furnace

Abstract

The invention belongs to the technical field of heat treatment, and particularly relates to a strip steel oxidation prevention control method for a preheating non-oxidation furnace. A preheating section is provided with a supplemented air adjusting valve, and a gas content analyzer and an O2 content analyzer are arranged in a flue. The method comprises the following steps that: S1, a theoretical amount FPhAirL of air required to be supplemented when fuel gas and H2 introduced into a non-oxidation section are just burnt out is calculated; S2, an excess coefficient G is set, and the actual amount FPhAirS of air needing to be supplemented is calculated according to the excess coefficient G and the theoretical amount FPhAirL of air needing to be supplemented; and S3, the calculated actual amount FPhAirS of air needing to be supplemented serves as a set value of an air adjusting valve PID controller, and the output of the air adjusting valve PID controller acts on a supplemented air adjusting valve. According to the invention, the changes of the oxygen content and the gas content in the flue are monitored, and the cascade PID control is utilized to realize the automatic closed-loop control of the after-burning air flow of the preheating section, so that the system can autonomously control the oxygen content of a preheating non-oxidation furnace while ensuring the safety of the flue, and a non-oxidation heating function of the preheating non-oxidation furnace is realized.

Description

technical field [0001] The invention belongs to the technical field of heat treatment, and in particular relates to an anti-oxidation control method for preheating a non-oxidation furnace. Background technique [0002] The preheating non-oxidizing furnace is a heating furnace with an inert protective atmosphere, which can prevent the strip steel from being oxidized during the heating process, and has the characteristics of high heating efficiency and fast speed. The preheating non-oxidation furnace uses open flame heating method, and mostly uses coke oven gas or natural gas. [0003] The furnace section is divided into two parts: the preheating section and the non-oxidizing section: the non-oxidizing section is the main heating section. In order to realize the non-oxidizing function of heating, the non-oxidizing section adopts the combination of gas and air, and the combustion is carried out in an appropriate amount of gas. ; while there is no excessive gas composition in t...

AI Technical Summary

Problems solved by technology

[0004] However, in actual production, due to the continuous change of furnace conditions, and the H 2 It takes time for the combustible gas to blow from the rear process section to the front of the furnace with the air flow, that is, there is a hysteresis, so the amount of air added to the preheating furnace is often uncertain

If the total amount of air added to the preheating furnace is not enough, combustible gas will enter the flue, which will cause serious safety hazards; if the amount of air added is too much, the strip steel will be oxidized in the preheating section, affecting Strip Properties

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