Treatment technology plan for coking dust

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Dust emissions from coke ovens: Dust emissions from various sections of coke plants in Europe (grams per ton of coke): https://pic4.zhimg.com/80/v2-e7481dbe3ee791ec64ea9c711b80e777_1440w.jpg The minimum value applies to newly built coke plants； The upper limit is for old coking plants ； Different **coke oven coal loading processes: In Europe, gas-tight connections are used between the coal holes in the coke ovens and the coal loading vehicles, while a negative pressure is created at the gas collection pipes/bridges; the aim is essentially to reduce the leakage of dust. In Japan, a smoke-free coal loading method is employed, with conventional connections used between the coal holes and the loading vehicles, but these connections are sealed using telescopic sleeves (which are soft connections, similar to sleeve guards on clothes); again, a negative pressure is generated at the gas collection pipes/bridges, also with the goal of reducing dust leakage. https://pic3.zhimg.com/80/v2-cb42521475a4d93b47938bdf3999ba72_1440w.jpg In the United States, a phased coal loading method is used, with conventional connections between the coal holes and the loading vehicles, meaning that coal is loaded one hole at a time; this approach does not prevent dust leakage, but rather prolongs the time over which dust is released in order to reduce its intensity. Different **coke oven coke extraction processes: In Europe and Japan, gas-tight connections are used between the coal holes in the coke ovens and the coal loading vehicles. https://pic1.zhimg.com/80/v2-0ff0d8ba373d019f9fca548b7ff8e550_1440w.jpg In Japan, sealing is carried out on both sides during coke extraction (simultaneously on the side where the coke is pushed out and on the side where it is extracted) ； Essentially, it is about preventing dust from escaping; https://pic4.zhimg.com/80/v2-1709861534fe99e2ba195d1a138bc25f_1440w.jpg. The dust emission levels (grams per ton of coke) mentioned in the environmental impact assessment report for a newly built coking plant in China: https://pic1.zhimg.com/80/v2-431f010bb271bbc5e75b3f7c78dc9efc_1440w.jpg. The dust emission levels of newly built coking plants in China are similar to those of older coking plants in Europe; however, they are 8 times higher compared to those of newly built coking plants in Europe. It is understood that the actual dust emission levels of newly built coking plants in China are much higher than the values specified in their designs ； The technical renovation plan maximizes the sealing of leak points during coal charging and coke discharging; simultaneously, it creates negative pressure at the collecting main/pipe bridge ； The negative pressure at the gas collection duct/tube bridge can prevent the escape of dust and smoke ； Sealing is crucial; the higher the degree of sealing, the cleaner the coal loading and coke discharge processes, and the easier it is to maintain negative pressure at the gas collection pipes/pipe bridges. The dust collection during coal charging and coke extraction in coke ovens operates on a principle similar to that of kitchen range hoods ； The installation height of the range hood is crucial for the effectiveness of kitchen exhaust: if it is installed too high, the efficiency of oil fume collection will be low ； Currently, some coking plants install high windproof nets and dust collection systems around the coking ovens in order to capture the unorganized exhaust emissions from these ovens. This approach is similar to installing kitchen exhaust fans at too great a height above the stoves, which results in low collection efficiency. https://pic2.zhimg.com/80/v2-ff363c78352ac715f9ce759d61ab9149_1440w.jpgGeneration of negative pressure at the gas collection ducts/pipe bridges: No technical modifications are required for systems that already use the PROVEN system; however, the following modifications are necessary for older pipe bridges. During coal loading and coke extraction, the pipe bridges are disconnected from the gas collection ducts, and the exhaust fan draws the dusty gas to the burner for combustion (due to excellent sealing, there is little leakage, thus only a small amount of gas is used) ； During coke discharge, both the pushing side and the discharging side are sealed. The coke blocks move toward the discharging side; their front portion is under positive pressure, while the rear portion is under negative pressure. Due to the sealing on both sides, the gas in front of the coke blocks moves backward ； Since a 100% double-sealing is not possible and there is still some leakage, this gas is drawn out by the negative pressure at the pipe bridge ； The coking process is fully applicable to tamping coke ovens ； Coke transport vehicles also need to be sealed; it is best to maintain a certain negative pressure even when transporting them to the coke quenching tower ； For top-loading furnaces, the smokeless coal loading method used in Japan can serve as a reference ； Expected result: Soot emissions should be reduced to, or even below, the levels observed in newly built coke ovens in Europe ；