Circulating fluidized bed boiler and method for combusting by using yellow phosphorus exhausting gas

Abstract

The invention relates to a circulating fluidized bed boiler and a method for combusting by using yellow phosphorus exhausting gas. The circulating fluidized bed boiler comprises a combustion chamber, and the upper part of the combustion chamber is connected with a yellow phosphorus exhausting gas delivery system and a secondary air distribution device. A corrosive substance produced by the yellow phosphorus exhausting gas combusted in the combustion chamber and an added alkali solid substance undergo neutralization reaction so that the corrosive substance is thoroughly removed, the corrosion to the boiler is avoided, and the equipment made of conventional materials also can work for long term. The method has the advantages of simple process, convenient operation, low cost for removing the corrosive substance, and low expenses of equipment investment, operation and maintenance. The high-temperature flue gas in which the corrosive substance is removed can be directly discharged to the atmosphere after heat exchange, and does not pollute the environment. The safe use of the yellow phosphorus exhausting gas serving as energy is realized, and the solid fuel can be separately combusted when no yellow phosphorus exhausting gas is used as the fuel so as to provide a guarantee for the continuous operation of the combustion chamber.

Description

technical field [0001] The invention relates to a circulating fluidized bed boiler, especially a combustion chamber of a circulating fluidized bed boiler, especially a combustion chamber which can be used for burning solid fuel alone or mixed with yellow phosphorus tail gas, and adopts the A circulating fluidized bed boiler utilizes a method of burning yellow phosphorus tail gas. Background technique [0002] As a major yellow phosphorus producer, my country currently has an annual output of about 1.5 million tons of yellow phosphorus, accounting for 60% of the world's total. With the continuous expansion of yellow phosphorus production scale, yellow phosphorus production sites tend to be concentrated, making my country's annual yellow phosphorus tail gas emissions exceed 3.75 billion cubic meters. Typical composition table of yellow phosphorus tail gas: [0003] [0004] Explanation: (1) According to the process requirements, equipment status and personnel operation le...

AI Technical Summary

Problems solved by technology

However, due to the pH of the components in the yellow phosphorus tail gas 3 、H 2 S, COS, CS 2 , F 2 Produce phosphoric acid, hydrofluoric acid, SO after combustion 2 Such substances are corrosive, and the corrosiveness is related to the wall temperature of the metal. The higher the metal wall temperature, the stronger the corrosiveness. According to the current research, even the 316L steel with strong corrosion resistance cannot resist it when the wall temperature exceeds 250°C. Corrosion of the flue gas

After tens of hours of boiler operation, boiler pressure components such as heating surface pipes, tube sheets, etc. are corroded and perforated. If the boiler design is based on conventional gas and coal-fired boiler materials, the longest service life does not exceed 200 hours, even if anti-corrosion The 316L steel with strong capacity will also corrode the pressure components of the boiler after one year of boiler operation, which cannot guarantee the long-term safe operation of the boiler

In addition, the corrosive substances in the flue gas produced by the combustion of yellow phosphorus tail gas are not removed and directly discharged into the atmosphere, which cannot avoid environmental pollution.

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