Effect Of Ultrasonication Treatment On Blast Furnace Circulating Water

The reliability of circulating water system is definitely important to theblast furnace. If the circulating water quality gets worse, the scaleformation will appearon the water pipe, there is not only reducing the heat transferring and cooling capacity,but also increasing the resistance of the cooling system, either adding the energyconsuming. Consequently, the good water quality is significant to prolong the workinglife of cooling facilities, even blast furnace.At present, Adding scale-inhibitor and corrosion-inhibitor is the main methods toprevent scaling and corroding from the circulating water of blast furnace, but usinginhibitor of phosphate, zinc and chromic will pollute water environment.Ultrasonication is the way which is automation, reliable, efficient and pollution free, forthis reason it is applied to petroleum, chemical, electric and heating industry.The paper made the small equipment and imitated the heat transferring of cooling wall,discussed the formation of CaCO₃fluenced by ultrasonic frequency, power and velocityof circulating water and analysised the relation of Ca²⁺concentration and electricconductivity between ultrasonic frequency, power and velocity of circulating water. Thecrystalloid variation characteristic of CaCO₃has been researched and the results willprovide some experiences to blast furnace circulating water treatment.This work adopted the orthogonal method to research the variation of Ca²⁺concentration in different ultrasonic frequency, power and velocity of circulating water.The results indicated the primary sequence is ultrasonic frequency, velocity ofcirculating water and ultrasonic power, the best combination is ultrasonic frequency:30kHz, velocity of circulating water:0.6m/s, and ultrasonic power:400W（100W/cm²）.The microcosmic analysis indicated energy from cavatition could shorten time ofCaCO₃nucleary induction period and stabilize the crystalloid at small size andaragonite. Using the ultrasonication to treat the circulating water of furnace bottom,tuyere, hotting blast valve and colling wall will enhanced the heat transferringefficiency, prolong the working life of cooling facilities and reduce the cost ofproduction.