A low-temperature circulating fluidized bed flue gas desulfurization and dust removal equipment

Abstract

The invention discloses flue gas desulfurization and dust removal equipment of a low-temperature circulating fluidized bed. The equipment comprises a desulfurization reaction tower, a dedusting unit and a material returning unit, the equipment is internally provided with a heat exchange module, wherein the heat exchange module comprises a hot wall device; the hot wall device comprises at least one group of heating screens and at least one group of heat preservation layers, the heating screens comprise channels the ports of which are open for assisting a heating medium in circulating, the hot wall device is covered on heat dissipation wall surfaces of the desulfurization reaction tower and the dedusting unit, and the heating screens are positioned among the heat preservation layers and heat dissipation wall surfaces covered on the hot wall device. The flue gas desulfurization and dust removal equipment provided by the invention has the advantages that the worries of moisture condensation, scale formation and pasting bag of the desulfurization reaction tower and the dedusting unit are eliminated, the desulfurization adiabatic saturation temperature difference is controlled within 15 DEG C-5 DEG C, the desulfurization reaction efficiency is higher than 95% or even 99% under the condition that the molar ratio (Ca / S) of a calcium element and a sulfur element is less than 1.3, and the operational reliability of the equipment is still guaranteed.

Description

technical field [0001] The invention belongs to the technical field of environmental protection, and relates to a circulating fluidized bed flue gas desulfurization and dust removal equipment, in particular to a circulating fluidized bed flue gas desulfurization and dust removal equipment with improved desulfurization efficiency under the condition of ensuring working reliability. Background technique [0002] In the usual circulating fluidized bed flue gas desulfurization technology, most of the dust collected by the dust collector is returned to the desulfurization tower, so that the alkaline substances that have not participated in the reaction continue to react with the acidic gases in the flue gas to achieve The purpose of improving desulfurization efficiency and utilization rate of alkaline substances. Circulating fluidized bed flue gas desulfurization is through the mixing of water droplets, solid desulfurizer and flue gas. With the evaporation of water droplets, the ...

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Problems solved by technology

However, as the flue gas temperature of the desulfurization tower decreases, the water droplets in the desulfurization tower evaporate slowly and tend to condense and agglomerate. The solid particles on the surface of the bag are easy to agglomerate, forming a paste bag

[0003] At present, the desulfurization towers and dust collectors with various technologies of circulating fluidized bed flue gas desulfurization only adopt heat preservation measures on the surrounding and top heat dissipation walls to prevent condensation on the walls. Because of heat dissipation, the wall temperature is always lower than the flue gas temperature. In order to ensure the operating reliability of circulating fluidized bed flue gas desulfurization equipment, the current flue gas desulfurization adiabatic saturation temperature difference of various circulating fluidized bed flue gas desulfurization technologies can only be controlled at 15 ~ 25 ° C, that is, in coal-fired boiler flue gas desulfurization Among them, the flue gas desulfurization temperature is controlled at about 70°C. In addition, since no components are arranged in the circulating fluidized bed flue gas desulfurization tower, the two-phase flow of flue gas and circulating materials in the desulfurization tower will generate bubbles, channel flow, Phenomena such as particle clusters and wall-attachment lead to uneven distribution of desulfurizers in the flue gas, low relative movement speed between gas and solid, and low mass transfer intensity. Under the condition that the molar ratio (Ca / S) is less than 1.3, it is only about 90%

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