RECONSTRUCTION OF GAS-CLEANING PLANTS OF LURGI-552 BURNING MACHINES AT PJSC «SEVGOK»

After completion of the gas-cleaning plant reconstruction for Lurgi-552-B burning machine at PJSC «SEVGOK» a decision was made to reconstruct the gas-cleaning plant of Lurgi-552-A burning machine as well, to ensure the required purification degree of exhaust gases less than 50 mg/nm³.

In 2018-2019 we developed design documentation for reconstruction of gas- cleaning plants  for the burning machine. The project implementation was planned to be divided into start-up complexes with the possibility of phased commissioning:

Start-up complex No. 1 – construction of an additional electric precipitator with a capacity of 639,900 nm³/h, a smoke exhauster, reconstruction of a high-voltage substation.

Start-up complex No. 2 – replacement of the existing electric precipitator with a capacity of 414,800 nm³/h in the heating zone.

Start-up complex No. 3 – replacement of the existing electric precipitator with a capacity of 414,800 nm³/h in the heating zone.

Start-up complex No. 4 – replacement of the existing electric precipitator with a capacity of 639,900 nm³/h in the drying zone.

Start-up complex No. 5 – replacement of the existing electric precipitator with a capacity of 639,900 nm³/h in the drying zone.

Start-up complex No. 6 – reconstruction of the existing exhaust electrostatic precipitator with a capacity of 226,800 nm³/h.

In order to carry out construction and installation works without the pellets production stop and without performance decrease of the burning machine, the following measures were taken:

installation of an electric precipitator and a fume exhauster for providing burning machine fume gas cleaning for the period of reconstruction of one of the existing electric precipitators in the drying and heating zones;

construction of additional air ducts for the possibility of redistributing flows to the additional electrostatic precipitator;

construction of a bypass air duct around the exhaust electrostatic precipitator.

All above-listedd measures made it possible to place the new electrostatic precipitators in place of the existing ones; there were no alternative locations on the densely built-up site.

The additional electric precipitator, built as part of implementation of start-up complex No. 1, will be used in the future for cleaning process gases from Lurgi-552-A burning machine with a subsequent growth of pellet production by 10%.
As part of the work, it was envisaged to use modern electrostatic precipitators of ZVVZ (Czech Republic), which ensure the required dust content in gases emitted into the atmosphere of less than 50 mg/nm³. At the outlet of each electrostatic precipitator a dust counter was installed to control gas-cleaning equipment operation parameters and to make it possible to reduce power consumption at the electrostatic precipitator when the required exhaust gas purification parameters are achieved.
During reconstruction of the exhaust electrostatic precipitator measures to preserve the casing and supporting part of the electrostatic precipitator were taken, which significantly reduced capital costs and construction and installation time.
Measures on reconstruction of the gas-cleaning plants of Lurgi-552-A burning machine reduced gross emissions of pollutants into the atmosphere by 447 t per year.