Wet Electrostatic Precipitators for Biomass Boilers in Sugar Factories

This project pertains to the dust removal renovation project of a 75T/h biomass boiler fueled by bagasse in a Yunnan sugar mill. The inlet dust concentration stands at 150 mg/Nm³, the inlet SO? concentration is 200 mg/Nm³, and the inlet flue gas temperature is 80°C. The requirement is that the outlet dust concentration should be less than 20 mg/Nm³. Currently, this wet electrostatic precipitator has been operating stably for over three years.

The boilers in sugar - cane sugar mills typically use bagasse generated from sugar production as fuel, which is a type of biomass boiler. Bagasse is a bio - fuel characterized by high moisture content, high volatile matter, low calorific value, relatively low nitrogen content, and low sulfur content. Chain - grate boilers are commonly employed. The combustion mechanism of bagasse involves both suspension combustion and layer combustion, with a large air supply. Consequently, a significant amount of flue gas is produced, featuring high oxygen content and high humidity.

Bagasse boilers have been in use for several decades, yet the treatment of their flue gas has only a history of about 20 years. With the continuous improvement of environmental protection standards, the control of dust emission concentration has become increasingly stringent. Boilers with a capacity of less than 50 t/h are being gradually phased out, and the full implementation of new emission standards requires the dust emission concentration to be ≤30 or 80 mg/Nm³. Ultra - low emission renovation has become an issue that every enterprise has to face.