ESP installed in the power unit of a steel plant situated in Taiwan.


The current transformer rectifier set was old being in operation for many years. The main problems are listed below:

  1. Occurrence of signal interference problems leading to the disorder of the conventional controller operations and also high opacity rate.
  2. Frequent occurrence of keypad/display malfunction hindered the access of operation for parameters adjustment.
Old T/R Sets
Old T/R Sets


Tai & Chyun engineers went on site and collected the related information, for example type of coal burnt, emission rate, current consumed against the operating data (kV/mA/Spark) etc., and came up with the proposal of upgrading existing conventional T/R sets to High Frequency T/R set that will guarantee to improve the emitting characteristics and power supply efficiency as well. With this proposal, full planning and management of material, supervision, test and commissioning were smoothly performed and achieved the outstanding results.

Installation of New High Frequency T/R Sets
Installation of New High Frequency T/R Sets


After electrical field upgrade, the operating values were recorded as follows.

The ESP was functioning efficiently with high collection efficiency and low emission rate. The contract requirement for the emission rate was less than 10 mg/Nm3, but it is seen that the actual emission rate recorded were 2.7 mg/Nm3 and 1.3 mg/Nm3 for coal combustion and coal+10KN BFG combustion respectively. Also, around 47% of power was saved per year.

Type of Fuel Coal only Coal + 10 KN BFG
Operating Values Before 37.1 kV / 298.3 mA 35.2 kV / 299 mA
After 35.6 kV / 298.4 mA 36.7 kV / 298.5 mA
Boiler Loading (Ton / Hr) Before 195.2 197.2
After 188.1 191.8
Emission (at the Outlet) Before 5 mg/Nm3 N/A
After 2.7 mg/Nm3 1.3 mg/Nm3
Collection Efficiency 99.95 % 99.98 %
Power Saved (per year) 47.03 % 46.52 %