📋 Tender Overview
New wet electrostatic precipitator system applied for BOF primary gas cleaning Dust content of off gas reduced to approximately 5 milligrams per standard cubic meterIn late 2020 Primetals Technologies received the final acceptance certificate FAC for a newly installedadvanced gas cleaning system based on wet electrostatic precipitator WESP technology. This firstproject was successfully implemented at Changzhou Eastran Special Steel Co. Ltd. in Chinas Jiangsuprovince. Based on very strict requirements of the local city government an emission limit of 10 mgNmwas requested for the steelmaking plant with two 80t basic oxygen furnaces BOF. PrimetalsTechnologies developed a suitable solution for the customer in terms of performance and minimal spacerequirement. The contract was signed in February 2019 and the plants for both BOF lines werecommissioned in March 2020. Clean gas dust emission values of approximately 5 mgNm weremeasured during the performance tests later in 2020 and the final acceptance certificate wassubsequently issued by Changzhou Eastran.The technical concept of this newly developed ultra-low emission technology is based on dust removalfrom off gas by electrostatic precipitation. Wet-type electrostatic precipitators have been used in iron- steel industry for decades already however the special nature of the BOF process with its toxic andexplosive off gas and the batch-process type operation required some special design features for thisnew application.The WESP is located in between the existing wet type gas cleaning plant and the ID fan. One mainadvantage of this configuration is that the old gas cleaning plant can remain unchanged as all the deepcleaning down to the required emission limit is done in the WESP. At the same time maintenancerequirements for the ID fan such as regular manual cleaning and re-balancing are greatly reduced as theoff gas is already ultra-clean when entering the ID fan.For this project Primetals Technologies have also implemented two special technology packages forWESP operation in an existing gas cleaning system a process safety module for minimization ofexplosion risk and an Energy saving module for reduced ID fan power consumption.This new innovative technology application is especially useful for revamping- and upgrading projects ofold and inefficient wet-type BOF gas cleaning systems due to its space saving single-tower design andthe almost unlimited range of application in terms of converter size and inlet dust concentrations.Moreover the WESP can be built and tested offline as was the case in the project at ChangzhouEastran. The tie-in to the existing gas cleaning system was then carried out within only three days duringa planned BOF relining shutdown.
