In waste incineration flue gas purification system, powdered activated carbon as sorbent injection in flue gas, to absorb the aerosol particles and heavy metals such as Hg, injection enough amount of activated carbon can effectively reduce the concentration of dioxins/furans.
Existing technology it is will be activated carbon nozzle received reaction tower flue gas outlet pipe, depending on the flue gas flow make its dispersion in the flue gas, the export of activated carbon from scrubbing of flue gas in the outlet pipe is to as much as possible to extend the time of activated carbon in contact with flue gas in flue gas, the final activated carbon adsorption on the filter bag bag dust collector, continue to adsorption heavy metals such as Hg in flue gas, again with the cloth bag dust catcher ash removal, fell into the hopper, accompany fine ash discharge. Of activated carbon injection rate determines the efficiency of removing dioxins and Hg, according to relevant data show that when the activated carbon injection quantity is 25 mg/Nm3, effective removal of Hg is about 87. 5%, when the activated carbon injection of 50 mg/Nm3, effective removal of Hg is about 92. 5%, namely excess activated carbon injection, there is no guarantee that the same proportion to improve the effective removal of heavy metals such as Hg, it is not only wasteful, it is easy to cause system failure. The existing activated carbon injection control for single frequency converter, the feed accuracy is poor, waste, use cost smell makes feeding, and the easy cause system failure.
Aiming at these problems, the utility model provides a waste incineration flue gas purification special activated carbon injection control system, in the guarantee under the premise of flue gas purification effect, increase the amount of activated carbon injection with flue gas flow rate, improve the measurement precision of the activated carbon injection, and then improve the flue gas purification efficiency, save the cost.
Activated carbon for a waste incineration flue gas purification injection control system, the technical scheme is that it includes the distribution of spiral, the need for flue gas purification device, its characteristic is that its also include PLC system, each described in the interior of the flue gas evolution of the need for device are set up with weighing spiral, inverter, controller, flue gas flow detection device, injection pressure detecting device, activated carbon nozzle, weighing spiral described including to bunker, screw feeder, weighing sensor, described the spiral feeder to activated carbon nozzle corresponding stated, PLC system respectively connected each flue gas flow test device, the output end of the injection pressure detection device, PLC system two-way connection each controller respectively, each described controller two-way links mentioned in the corresponding frequency converter, the inverter control links mentioned in the corresponding screw feeder, weighing sensor described the output end of the link mentioned in the corresponding controller, PLC system control allocation screw connection stated, described in the distribution of spiral to each described respectively to bin. Its characteristics is further described in the PLC system Settings manually set each requires flue gas purification device activated carbon injection module.
After adopting the utility model structure, PLC receives the need for flue gas purification plant feedback by the flue gas flow detection device of flue gas flow signal, through the process data (such as flue gas composition) calculate each requires flue gas purification device corresponding to the amount of activated carbon injection needed, and output to the corresponding controller, PLC system at the same time give screw system operation instruction for distribution, distribution of spiral to the need for flue gas purification device to bin feeding, to assign bin's high quantitative closed after a spiral, running state feedback controller to the PLC system system at the same time, the controller by frequency converter control screw conveyor feeding speed (control the number of teeth on the spiral around a minute), and the reception of the weighing sensor signal, both compare, controller correction again, after repeated many times, the system stability in a feeding speed, ensure feeding accuracy. In the operation of the feed to give bin after low set quantitative feed controller gives the signal, PLC system start the distribution of the auger to bin feeding, to the discretion of the bunker set quantitative controller receives after weighing sensor signal is given. The above process automatic cycle operation, achieve the goal of continuous quantitative feeding. In addition, the PLC system receives the required injection pressure detection device feedback of flue gas purification device of injection pressure signal, according to the situation of pressure control feeding system of start-stop, prevent activated carbon block line; In guarantee under the premise of flue gas purification effect, increase the amount of activated carbon injection with flue gas flow rate, improve the measurement precision of the activated carbon injection, and then improve the flue gas purification efficiency, save the cost.