The current desulfurization process generally adopts the lime/limestone method. The desulfurization and dust removal of this project are carried out simultaneously in the same device, which has a high level of operational safety for the desulfurization and dust removal system. This is the characteristic of the dual alkali desulfurization process.

Double alkali process flow

This project utilizes the excellent mass transfer and dust removal performance of the cyclone plate tower to carry out flue gas desulfurization and dust removal in the same scrubber. The integrated process of desulfurization and dust removal is cost-effective, and the fly ash removed contains a certain amount of alkali, which can be used for desulfurization and reduces the amount of desulfurizer used. The dual alkali desulfurization process has a relatively high desulfurization rate and operates relatively safely. Pure alkali is used to provide NA+, and lime milk is used as the regenerant.

The core equipment of the system is the XLB-130 cyclone plate tower used as the main tower, with a design technical specification of a dust removal rate of over 97% and a desulfurization rate of over 70%. Each unit consists of two main towers and a common auxiliary tower. The boiler flue gas is cooled by the spray section and enters the bottom of the main tower along the tangent direction. After desulfurization and dust removal inside the tower, it enters the auxiliary tower through the short flue at the top of the tower. After further defogging, it is sent to the auxiliary tower by the induced draft fan and then discharged into the chimney by the induced draft fan.

The circulating liquid enters from the top of the main tower, disperses into mist droplets on the cyclone tray, and fully contacts with the flue gas. It then flows from the bottom of the main tower into the ash settling tank through an open channel, where the removed fly ash is settled; The supernatant overflows into the regeneration reaction tank and undergoes regeneration reaction with lime milk introduced from the ash tank. The regeneration solution flows into the clarification tank to precipitate the CASO3 generated by the reaction and the CaSO4 generated by oxidation. In the clarification tank, the supernatant overflows to the pump front pool and is pumped back to the top of the main tower for recycling. The sediment from each pond is naturally dried using a sludge drying plant and regularly used for road construction or brick making.