Ash collapse problem in fluidized bed furnaces
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Dear experts: Our plant uses a slurry feed system, and recently there were two major incidents of ash collapse, which caused fluctuations in the temperature at the bottom of the boiling zone; however, the bottom pressure as well as the temperatures in the upper and middle sections remained unchanged. So, no stop was made to deal with it. After a few more days of operation, the gas concentration began to fluctuate. A shutdown for inspection revealed severe scorching inside the furnace, forcing the need to remove the furnace contents and clean it again. I hope the experts can offer some guidance to prevent similar accidents from occurring.
Hello: Regarding the ash collapse in the fluidized bed furnace, please pay attention to the temperature of the furnace, the concentration of the slurry, the uniformity of the air supply, and the operations carried out by the staff. Check whether there is sufficient air flow in the ducts in areas where the ash deposit thickness is high.
The main issue is still an excessively large expansion angle. When designing a fluidized bed furnace, the expansion angle of the furnace should be determined based on the type of ore, in order to prevent excessive ash accumulation in the expansion section.
The newly built roasting furnace collapses and loses ash as soon as it is turned on, which can be attributed to a design issue. If it runs for a long time, it is generally not related to the device. It is possible to determine whether the ash is accumulated on the top of the furnace or on its walls by examining the uniformity of material distribution, the operation performed by personnel, and inspections inside the furnace.
With the same boiling furnace and the same operators, since a heat exchange tank was installed on the boiling furnace in 2005, the phenomenon of furnace collapse has been virtually eliminated and occurs very rarely; during major repairs, little ash accumulation is found on the expansion layer. :)
It mainly controls the temperature of the boiling furnace, and also analyzes the lead and zinc content in the raw materials. When considering ash accumulation on the furnace top, it is also necessary to take into account whether the reaction shifts backward
Hehe, years ago we often encountered situations where the ash in the furnace collapsed, and the chimney cover on top of the furnace would fly outside the wall. It was solved over the past few years.