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    Item type:Publication,
    Effect of Rapping Frequency and Intensity in Electrostatic Precipitator Efficiency
    (2023-01-01)
    Banthoengjai, Thanpilin
    ;
    Wiangtong, Theerayod
    ;
    Pattanadech, Norasage
    ;
    Pannil, Pittaya
    Electrostatic precipitator (ESP) is one of air pollution control equipment which widely use in biomass power plant. There is a rapping system in ESP use for removing ash from collecting plate (CP) and discharge electrode (DE). Rapping frequency and intensity of rappers effect the efficiency of ESP because they relate to dust quantity in ESP. Dust layer at CP, which has $108\ \Omega\mathrm{m}$ of resistivity, can cause back corona. Back corona can cause spark in dust layer. To prevent back corona, ESP should operate at lower voltage. Therefore, ESP efficiency is also lower. A chance of ash accumulation is depended on ion charged in dust particle. Rapping cause re-entrainment of dust particle which is uncharged. Re-entrainment dust particle increase uncharged dust in charging area. Therefore, charging process require more ion to charge more dust particle but generating more ion can cause spark over in ESP. There is the appropriate rapping frequency and intensity of rapping due to ESP condition. To study the effect of rapping system in ESP, the experiment was set in 9 cases. The rapping system in the experiment was set as different round trip time (RTT), which determine the rapping frequency, and lifting distance, which determine the intensity. There are 3 different RTT, 2, 3, and 4 minutes, and 3 lifting distance, 8, 10, and 12 inches. Total suspended particulate (TSP) was measured by EPA Method 5 and analyzed by Isokinetic and Gravimetric method to compare the efficiency of ESP in each case. Changing in rapping frequency and intensity of rapping system affect TSP. In case which lifting distance is 8 and 10 inches, TSP tend to decrease when rapping frequency was decreased, means higher efficiency of ESP. On the other hand, TSP tend to increase when rapping frequency was decreased in case of lifting distance is 12 inches. The lowest TSP was the case with 4 minutes RTT and 8 inches lifting distance. From the experiment, there is an appropriate value of rapping frequency and intensity of rapping system. Setting rapping system improve ESP efficiency.
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    Item type:Publication,
    Dissolved Gas Analysis of Palm Oil Compared with Mineral Oil from Different Types of Breakdown Voltage
    (2020-10-25)
    Suksagoolpanya, Suthat
    ;
    Jongvilaikasem, Korraya
    ;
    Jariyanurat, Kitipod
    ;
    Banthoengjai, Thanpilin
    ;
    Jeenmuang, Siwakorn
    Natural products are required instead of chemical materials for saving the environment. Nowadays, the palm oil is a new alternative liquid insulation that may be used in a transformer. Normally, the characteristics of liquid insulation can be investigated and analyzed by various methods. One of the diagnosis methods widely used is a dissolved gas analysis technique (DGA). The propose of this paper is to study the interpretation of dissolved gases in the palm oil compared with that of in the mineral oil which is caused by different kinds of breakdown phenomena, i.e. AC breakdown, positive lightning impulse breakdown, and negative lightning impulse breakdown. An AC breakdown voltage test according to IEC 60156 was performed by using 3 difference gap spacing which were 1.0, 1.5, and 2.0 mm. For lightning impulse tests, the test cell was contained needle-sphere electrodes with 10, 15, and 20 mm gap different spacing. The lightning impulse tests were performed in accordance with IEC 60897. Each experiment was performed for 5, 10, and 15 times. For a material preparation, the mineral oil and the palm oil was heated at 80oC for 12 hours. Then, it was naturally cooled before filling into the test cell to perform AC and lightning impulse breakdown tests. After that, the mineral oil and the palm oil was sampled out of the test cell to perform the DGA experiment. The dissolved gases from the mineral oil and the palm oil were interpreted by applying IEC and IEEE gas interpretation techniques. It was found that the breakdown voltages of the palm oil were less than the mineral oil but the palm oil generates more dissolved gases than the mineral oil. Moreover, Duval pentagon for natural ester fluid seemed to be the most suitable method to interpret dissolved gases in the palm oil compared with the IEC ratio, Doernenburg ratio, Roger ratio, and Duval triangle.