Standard Technical Features of BTG System for Supercritical 660 ...
Standard Technical Features of BTG System for Supercritical 660 ...
Standard Technical Features of BTG System for Supercritical 660 ...
Create successful ePaper yourself
Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.
<strong>Standard</strong> <strong>Technical</strong> <strong>Features</strong> <strong>of</strong> <strong>BTG</strong> <strong>System</strong> <strong>for</strong> <strong>Supercritical</strong> <strong>660</strong>/800 MW Thermal Units10.5 Maintenance Requirements10.5.1 The design <strong>of</strong> the precipitators shall allow adequate space above and betweenthe adjacent fields to carryout necessary inspection and maintenance. Apermanent walkway shall be provided at each rapper level both <strong>for</strong> thedischarge and collecting plates.10.5.2 Minimum 2.0 m wide plat<strong>for</strong>ms shall be provided between the two casings <strong>of</strong>the ESPs to facilitate maintenance work and minimum 1.2 m wide plat<strong>for</strong>mshall be provided all around all ESP passes at intermediate and TR setelevation. The protection <strong>for</strong> the plat<strong>for</strong>m and the rapping motors fromexposure to rain shall also be provided.10.5.3 One staircase <strong>of</strong> minimum 0.85m clear width shall be provided between twoadjacent streams (casings) from ground to the ro<strong>of</strong> <strong>of</strong> the ESPs with landingsconnected at all plat<strong>for</strong>ms. As such, minimum three (3) staircases shall beprovided <strong>for</strong> ESP <strong>of</strong> <strong>660</strong> MW unit and five (5) staircases <strong>for</strong> ESP <strong>of</strong> 800 MWunit. Two adjacent staircases shall be located on opposite ends <strong>of</strong> the ESP.Further, the plat<strong>for</strong>ms between all the ESP casings shall be interconnected atleast at one intermediate elevation.10.5.4 Each compartment <strong>of</strong> individual stream <strong>of</strong> ESP shall be provided withisolation dampers at inlet and outlet <strong>for</strong> carrying out maintenance work whilethe remaining streams <strong>of</strong> ESP are in service by completely isolating itelectrically and grounding it. Suitable safety interlocks etc. shall be provided.10.5.5 A monorail system with movable trolley and an electrically operated hoistmounted on the precipitators ro<strong>of</strong> shall be provided <strong>for</strong> handling andmaintenance <strong>of</strong> TR sets, rapper motors, fans (if applicable) etc. By thisarrangement, it shall also be possible to lower the TR sets down to the groundlevel and/or onto a truck. Normal and special maintenance tools shall also befurnished <strong>for</strong> attending to different equipment.10.6 Model StudyComputer based model study using CFD technique or physical flow modelstudy shall be carried out to achieve optimum size and layout <strong>of</strong> the ducting,uni<strong>for</strong>m flue gas distribution, maximum particulate collection, minimum draftloss, minimum dust drop out and build up and minimum re-entrainment fromwithin the precipitator. The design <strong>of</strong> the duct work, guide vanes, flow splittersetc. shall be finalized based on results <strong>of</strong> the model study. The model studyshall also include a gas distribution study <strong>for</strong> the duct system around ESP t<strong>of</strong>ind out the effect <strong>of</strong> isolation <strong>of</strong> one stream <strong>of</strong> the ESP. CFD model study orphysical flow model study <strong>for</strong> the ESP may not be needed in case the same hasbeen earlier carried out <strong>for</strong> similar size and type <strong>of</strong> the ESP.10.7 Gas Distribution <strong>System</strong>Gas distribution system shall be provided at the precipitator inlet as well asoutlet sections to achieve uni<strong>for</strong>m gas distribution throughout the ESP with82
Change language