PFBC HGCU Test facility. Technical progress report, Fourth quarter, CY 1994

During this quarter, the Tidd Hot Gas Clean Up System completed a 691-hour test run which began during the third quarter. Table 1 summarizes all test runs since initial operation. Following this test run the system was shut down and the filter opened for inspection and recandling. The system remained out of service during the remainder of the quarter. In addition to monitoring and evaluating the performance of the HGCU system during testing, engineering effort was devoted to posttest inspection of the APF (Advanced Particle Filter) and evaluation of the effects of totally spoiling the primary cyclone. In addition, the authors worked with Westinghouse in the selection of replacement candles that were installed during the fourth quarter. During the unit outage this quarter, the primary cyclone upstream of the APF was modified to force all of the ash to pass through the cyclone and enter the APF without using spoiling air. Appendices to this report describe the dust shroud support strap design; an analysis of the effect of support-transferred vibrations on the failure of ceramic candle filters; the Tidd APF operation; the Tidd APF boroscope inspection; a general inspection of Tidd filter internals; tally of Tidd filters; ash formations in the W-APF-October 1994 post-test inspection; characterization of the as-manufactured and PFBC-exposed 3M CVI-SiC composite filter matrix; strength characterization of the first and second generation candle filters after 1,705 hours of PFBC operation at Tidd; and filters used in the December 1994 recandling effort at Tidd