Enhancing Dust Collection Efficiency through ESP Mechanical Rehabilitation

As long been known that Electrostatic Precipitator (ESP) is the most effective and efficient equipment in reducing particulate emission in plants of all kinds of heavy industries with relatively high reliability and long life-span, comparing to other types of air pollution control equipment.

With increasing awareness of air pollution severity nowadays, governmental rules and regulations are becoming more stringent than ever. These act as a driving force for plants to keep improving their emission control in order to meet such requirements.

And when it comes to one of the air pollution control equipment, Electrostatic Precipitator (ESP), Tai & Chyun has long developed and accumulated numerous experiences in solving various ESP problems both mechanical and electrical aspects. These include provision of high quality ESP parts, timely response and solution for any ESP problems, and on-site services such as ESP inspection & troubleshooting, supervision of installation & maintenance, and ESP turn-key rehabilitation & upgrade.

One of the most critical and commonly found ESP problems is deterioration of ESP mechanical internal parts and electrical components after decades of day and night operation. Such deterioration results in corrosion that comes from moisture and high temperature inside the ESP, wear and tear from aging and long-term operation, inaccurate electrical readings due to old and obsolete controller, and many more.

In this context, we focus on the problem of corrosion of ESP mechanical internal parts. This problem always poses big concern and pressure for plants that require 24hr operation and at the same time oblige to governmental emission control regulation. Corroded parts also cause an ESP to trip (short circuit), which reduce the dust collection efficiency and performance of the ESP tremendously and in turn affect production and revenue of the plant. Thus, a solution to this problem is ESP mechanical rehabilitation is necessary.

Here is the case study of a bagasse-fueled biomass plant in Thailand that we would like to share with regards to ESP mechanical rehabilitation as mentioned above. Its Chinese 3-field ESP capacity is 12MW for a Power Boiler of 60 TPH. The plant experienced severely damaged ESP internal parts due to leakage of air from air pre-heater tube that contains moisture as well as seriously corroded Collecting Plate / Electrode (CE) & Discharge Electrode (DE), main ESP components that fell from its position and caused field 1 & 2 to trip. Before the rehabilitation, only field 3 was able to operate with extremely low performance.

As such, Tai & Chyun proposed a solution of CE & DE Replacement for field 1 & 2 and maintenance for field 3. Since the customer wished to have the problem solved the soonest, we were given a very tight schedule of only 6 weeks to fabricate parts and complete the entire project so operation could be resumed.

Thus, kick-off meeting and site survey with the plant’s in-charge personnel was one of the most important processes to ensure that both party had an agreement and mutual understanding of the following works to come and be done together. This includes availability of manpower, space, and resources, timeframe, crane & scaffolding requirement, safety training, etc.

Throughout the entire project, we encountered quite a few difficulties along the way, i.e., delayed part delivery due to heavy traffic at port, changing & raining weather, and space constraint. However, our experienced engineers never stopped adjusting work plan and ultimately were able to complete the project in 11 days despite limited shutdown schedule, with satisfactory results that the plant planned for rehabilitation for field 3 as well.

Once the project had been completed, a detailed and comprehensive report was submitted to plant’s personnel with all the important information regarding ESP works done and recommended spare part list that the plant could purchase and keep in stock for future urgent needs.

After the rehabilitation, field 1 & 2 have been revived and started running stably without any trips or occurrences of sudden shutdown. Above pictures show mechanical parts after rehabilitation and below table shows operating data comparison that proves dust collection efficiency has been improved.

In summary, ESP mechanical rehabilitation has proved that it can greatly enhance dust collection efficiency, which in turn reduces particulate emission considerably, providing stable, smooth, efficient, and reliable production for plants.