Venturi Scrubber System. The function of the Venturi Scrubbing System is to remove fly ash and sulfur dioxide (SO2) from the flue gas by washing with a recycled liquor. This system, together with a related monitoring device, is composed of three scrubber trains each at Units 1 and 2, each containing a venturi throat, counter-current sprays, mist eliminators, recycle tank, recycle pumps, steam coil-type reheater, soot blowers, induced draft (“ID”) fan, effluent liquor pumps and lines, and pond return pumps. Flue gas first passes down through the venturi throat section and is thoroughly mixed with the liquor. The liquor drops out into the integral recycle tank with the absorbed ash and some absorbed SO2. Gas then passes upward through sprays and demisters where downward flowing liquor finishes the SO2 absorption job. The liquor drops out into the recycle tank. The gas passes on through a reheater before entering the ID fans and exiting out the stack. Spent liquor is pumped to an ash disposal pond by effluent liquor pumps and clear water is returned to the cycle by the pond return pumps. The ash pond is divided into two sections each of which is used on alternate years. One section is to be left to dry and the deposited ash will be disposed of as required while the other section is in use. Ash mixed with water enters the active pond and moves slowly toward the outlet. Before reaching the outlet, most of the ash has settled out and decanted water is returned to the cycle for reuse. The pond will also have adequate capacity for disposal of the smaller amounts of ash from the ash disposal system (see Ash Disposal System below).
Venturi Scrubber System. The function of the Venturi Scrubber System is to remove fly ash and SO2 from the flue gas washing with a recycled liquor. The scrubbers were designed and installed by Combustion Equipment Associates and Inc. Particulate loading in the scrubber gases shall be equal to or less than 0.18 grains per actual cubic foot measured at the reheater outlet condition (equivalent to 0.02 grains per actual cubic foot in the stack). SO2 in the scrubber gases are equal to or less than one pound of SO2 per million BTU of heat released in the furnace. The design conditions are for a flue gas flow of 1,430,000 cubic feet per minute per generating unit at 291OF. This system, together with a related monitoring device, is composed of three scrubber trains each at Units 1 and 2, each containing a venturi throat, counter-current sprays, mist eliminators, recycle tank, recycle pumps, steam coil-type reheater, soot blowers, ID fan, effluent liquor pumps and lines, and pond return pumps. Flue gas first passes down through the venturi throat section and is thoroughly mixed with the liquor. The liquor drops out into the integral recycle tank with the absorbed ash and some absorbed SO2. Gas then passes upward through sprays and demisters where downward flowing liquor completes the SO2 absorption process. The liquor again drops out into the recycle tank. The gas passes on through a reheater before entering the ID fans and exiting out the stack. Spent liquor is pumped to a fly ash slurry disposal pond by effluent liquor pumps and clear water is returned to the recycle tank by the pond return pumps. The Venturi Scrubber System is composed of scrubber vessels, venturi throats, recycle tanks, agitators, recycle pumps, counter-current sprays, wash trays, wash tray recycle tank, wash tray recycle pumps, wash tray pond, mist eliminators and cleaning sprays, steam coil reheaters, soot blowers, ID fans, isolation dampers, effluent tank, effluent pumps, fly ash pond, pond return pumps, lime (alkali) system, valves, pipelines, wiring, electric services, electric motors, valve actuators, motor controls, automatic analog control system, related measuring instruments and monitoring devices and all other related auxiliary electric, mechanical, and civil equipment.
