Improvement of Hot–side Precipitator Performance with Sodium Conditioning—An Interim Report

Abstract

The development of an unexpected, time-dependent degradation of performance of hot-side precipitators collecting ash from certain coals (usually low-sodium, low-sulfur coals) has caused serious problems at a number of major utility installations. One of the authors 1 recently offered an interpretation of the performance degradation based on the concept that a very thin layer of fly ash, tenaciously held to the collection electrode for a long time, develops very high resistivity. It has been demonstrated as a part of this research project that the layer adjacent to the collection electrode becomes deficient in sodium ions, the principal charge carrier. The phenomenon is sometimes called electrode polarization or sodium depletion. A detailed treatment of the sodium depletion experiments, as well as other related experiments, will be presented in future publications. This article gives a brief presentation of results obtained to date from a research program designed to implement a remedial approach (sodium conditioning) to this problem, on a full-scale installation.

Flue gas conditioning for reducing suspended particulate matter from thermal power stations

“…Sodium has an influence on the morphological characteristics of the fly ash and lowers the ash fusion temperature during which the surface conduction is dominant [22,61,80]. Gooch et al [81] have evaluated the effectiveness of sodium conditioning as a means of improving the efficiency of the ESPs. It has been concluded that the conditioning depends on ash composition, and design and operating parameters of the ESP.…”