The aim of modernization the system of dust removal from flue gas coming from stoker boilers based on cyclone batteries is obtaining dust emission level below the admissible limit of 100 mg/Nm3 for 6% O2.
To improve efficiency of existing cyclone battery, additional flue gas circulation system with bag filter and fan of appropriate capacity is provided. Some part flue gas supplied to the cyclone battery circulates through the filter and is delivered to the main flue gas collector, downstream of the flue gas exhaust fan. For providing high effectiveness of whole system, negative pressure is produced in a dust tank of the cyclone battery, and flue gas is sucked off from a dust tank by a booster fan. Produced negative pressure additionally causes dust suction from cyclones to the tank and limits uplifting air in the bottom part of cyclone.
Basic advantage of the system is lack of necessity of alteration existing deduster, and possibility to use the system with closed circulation through the bag filter, and bag replacement without start-up. The bag filter capacity is designed proportionally less than the capacity of the whole system, which reduces price and operating costs.
Prior to the execution of the modernization, the expert evaluation must be carried out, whether the condition of cyclone battery and whole system, guarantee final profitability of the project. Sufficient space for the device is also required.