Semi-dry desulfurizing process in double feedback circular fluidized bed

Abstract

The present invention relates to improved coal burning flue desulfurizing purification process, and is especially semi-dry desulfurizing process in a double feedback circular fluidized bed. The technological process includes the following steps: 1. pre-dusting the fume in a deduster to separate most of the fly ash, desulfurizing the fume in a reaction tower, re-dusting in the deduster, and exhausting through the induced draft fan and chimney; 2. recycling partial the purified fume, merging with the pre-dusted fume and feeding to the reaction tower; 3. feeding desulfurizing ash with a fan to the reaction tower; and 4. returning partial fume through a cyclonic separating to the bottom inlet of the deduster and feeding the fly ash through the feeder to the material bin and the reaction tower. The present invention has the advantages of comprehensive utilization of fly ash to ensure the high circulation ratio running of the circular fluidized bed, high desulfurizing efficiency, etc.

Description

technical field [0001] The invention belongs to the technical field of environmental protection. The invention relates to an improvement of a coal-burning exhaust gas desulfurization purification process. Background technique [0002] At present, the circulating fluidized bed semi-dry desulfurization process used in power plant boilers with less than 300,000 units in China is the introduction of foreign technology. There are mainly the CFB-FGD reflux circulating fluidized bed desulfurization process in Germany, the NID desulfurization process in France, and the GSA desulfurization process jointly developed by Denmark and the United States. There are two types of return systems for circulating materials in the above-mentioned desulfurization processes: the air fluidized chute type and the repositioning type, and both require a certain gravity difference before the materials can return to the circulating fluidized bed reaction tower. The first two desulfurization processes a...

AI Technical Summary

Problems solved by technology

However, the resistance of the cyclone separator is very large, and the separated ash of the cyclone separator and the subsequent electrostatic precipitator (or bag filter) contains desulfurization products, which loses the value of comprehensive utilization.

In addition, in these three desulfurization processes, if the induced draft fan stops suddenly due to an accidental power outage, hundreds of cubic meters of flue gas with high dust concentration in the reaction tower will cause ash collapse due to the loss of the induced draft

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