【Weekly Topic】How to gradually reduce coking time? (January 25, 2011---February 3)
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This post was last edited by Desert Poplar on 2011-1-27 at 10:21. With major domestic steel mills raising the prices of key steel products recently, domestic coking enterprises have also resumed production. The main problem is how to restore the coking time as soon as possible. Please share your thoughts. This post is on this topic; my forum has chosen this subject as the weekly topic for this week, so I invite everyone to participate actively. All participants will receive a reward, with big prizes for those who answer well! Coal charging for the coke oven has begun, with a coking time of 36 hours. How can this coking time be gradually reduced? In other words, if it were reduced to 20 hours all at once, the furnace would not be able to withstand it. To protect the furnace, it is reduced to 32 hours after a few days, then to 28 hours after another few days, and so on… When will it finally reach 20 hours?
It is necessary to understand the calculation of related coking times. Slightly increase the standard temperature, measure the temperature at the center of the coke cake, and check whether the coke cake is mature. If it shrinks too quickly, there is indeed a risk of problems; having a large amount of burnt material isn’t something to take lightly
Such a long coking time – it seems that here it’s currently 17 hours. It used to be longer before; back then, blast furnace gas was used for heating, but after switching to coke oven gas, the coking time was significantly reduced
It mainly depends on whether the temperature at the furnace tip and the straight-through temperature can keep up. I happened to encounter this situation; when it first started operating, the cycle time was 36 hours – the first batch of coal was loaded on November 25, 2010. Now that time has been reduced to 24 hours, with plans to cut it further to 22 hours by the end of this month. It took so long to reduce the coking time because the temperature at the furnace tip couldn’t be raised enough. In the past couple of days, additional heating was applied to the furnace tip to bring its temperature up to 1100 degrees, which allows for a reduction of one hour per week until the target of 22 hours is reached. Did you also start using a seven-meter coke oven?
Our last coke oven produced coke on November 25, 2010. The turnaround time for the first batch was 60 hours, while that for the second batch was 48 hours. After stabilizing at 48 hours for three cycles, the goal was to achieve uniform temperature regulation in the oven; thereafter, the temperature and production volume were increased daily. By mid-December, the designed turnaround time had been basically achieved
This post was last edited by Lu Zigu on 2011-1-20 at 10:05. For our first furnace (5.5m ramming type), the cycle time for the first batch of operations was 48 hours, while it was 36 hours for the second batch; this time gradually decreased to 32 hours, and the furnace operated stably for a week. (This was mainly due to the need for equipment calibration and maintenance; we only had one day after installing the main equipment to carry out adjustments, and all the operators were beginners!) Fortunately, no major mistakes occurred); it was then gradually adjusted to a 25-hour design standard (which took about over half a month).
Agree with the 4th floor. The key to reducing the coking time lies in whether the furnace temperature is appropriate. I believe that, under proper control of the furnace temperature, the coking time can be reduced in a step-by-step manner, starting fast and then slowing down; for example, the reduction from 36 hours to 25 hours can be done more quickly, while the reduction to 20 hours should be done more slowly.
It is recommended to first clarify the details of your furnace, including its size. The responses given so far refer to various types of furnaces, and not all of them may be suitable for your situation
We’re about to start work. We’ve considered this issue before, but we haven’t quite understood it – is the standard temperature for a long turnover time determined based on the normal coking time and heat consumption?
Priority should be given to whether the furnace temperature can keep up and whether the expansion of the furnace body is uniform; secondly, there are issues related to the large-scale equipment and the operation by personnel
Reply to 1# wangshaobo: For every 1-hour change in coking time, the standard temperature change is as follows: 35 hours – standard temperature change >40; 25–30 hours – 20–25; 10–15 hours – basically no change. To determine whether the standard temperature is too low, it is necessary to wait until the coke is extracted and check whether the center of the coke cake is black. As a precaution, it’s advisable to measure the temperature at the center of the coke cake. The nominal temperature of each furnace is closely related to factors such as the furnace type and coal blending ratio; please provide more specific details