Coke oven top space temperature

1. Is it necessary to change the standard temperature? Definitely not. There are actually many ways to address this issue; mainly, there are four methods, all of which are mentioned in books on coking. I can’t remember the specifics exactly

My suggestion is to strengthen the coal-loading process, make sure the coal is loaded properly, and do a good job of leveling it.

Change from coke oven gas heating to blast furnace gas heating! If the temperature in the space above the furnace is consistently too high, it could also be due to a problem with the internal design of the coke oven!

1. Increase the coal loading amount, adjust the position of the coal leveling rods, load as much coal as possible while maintaining an appropriate space at the top of the furnace； 2. Try to reduce the standard temperature, on the condition that no charring occurs at the burner tip ； 3. Appropriately change the type of gas used for heating; if blast furnace gas is used for heating, an appropriate amount of coke oven gas should be mixed in, or the heating method should be switched to coke oven gas. 4. Consider furnace body adjustment by using tongue bricks to regulate the opening degree of the chute.

What was said on the first floor might refer to a 4.3-meter ramming coke oven; you can check out in the forum the method I shared for cleaning the graphite in single-channel coke ovens. From the perspective of rammed coke ovens, here is my analysis of this issue: 1. The formation of graphite is not necessarily caused by high spatial temperatures. I have measured the spatial temperatures in my facility, and they are within the specified range; yet there is a lot of graphite on the oven roof. The main reason for this is that the volatile content of the coal used here is very high, averaging around 29% throughout the year, with values reaching up to 32% at times. 2. In rammed coke ovens, if the coal cakes are not compacted properly, localized collapse of the cakes can occur; in such areas there will be a shortage of coal cakes, and the temperature in that space will definitely be very high. 3. Many coking plants have management issues; the coal cakes in the 4.3-meter-high ramming coke ovens are not compacted to the required height. During the middle and night shifts, operators may reduce the height of these coal cakes from 4.1 meters to 3.8 or 3.9 meters. At the same absolute temperature, the temperature in a space with a height of 3.8 meters is definitely higher than that in a space with a height of 4.1 meters. 4. Graphitization is severe; if the volatiles content of the coal fed into the furnace is high, and the pressure control in the gas collection system is also high, then graphitization will be even more severe. Therefore, when looking at a problem, one should not focus only on the surface level and blindly lower the temperature threshold. The 4.3-meter ramming coke oven has a well-developed design in China, so there are definitely no issues with the design. For coke ovens of different types, the reasons are different. When posting in the future, remember to mention the type of furnace, so it’s easier for others to help identify the issue. This post was last edited by Yan Xiangsi on 2009-1-19 15:09.]

Personal work experience: 1. Cleaning issues – Cleaning is a necessary means to keep the furnace and all gas delivery equipment clean. It is not sufficient to focus only on process control without paying attention to operational practices; under the same process parameters, different cleaning methods and frequencies can lead to significant differences in results. 2. Roof space and roof space temperature: There is a close relationship between these two. Generally, the larger the roof space, the higher the temperature, which in turn accelerates the rate at which gas undergoes secondary cracking to form graphite. However, if the roof space is too small, it hinders the evacuation of raw gas, resulting in a longer residence time that also speeds up the growth of graphite. Therefore, it is necessary to maintain an appropriate roof space and roof space temperature. 3. Standard pressure of the gas collection pipe: Given the accelerating trend toward larger coke ovens in China in recent years, I believe that the design institutes’ determination of the standard pressure for such ovens is not entirely accurate. Therefore, it is recommended that these standards be adjusted based on the actual conditions in production, rather than following them mechanically. The effect of the collector pipe pressure on the graphite growth rate is also significant; generally, newly commissioned coke ovens maintain a collector pipe pressure that is higher than the standard value, with the aim of accelerating graphite growth. The same principle applies in reverse, but it is important to avoid negative pressure at the end stage of coking. 4. Employees should be made to understand the importance of constantly keeping an eye on growth graphite. In China, there are many coking enterprises that have had to suspend operations due to graphite-related problems; addressing such issues as soon as they arise yields the best results and requires the lowest costs. 5. As for the specific methods of cleaning, I won’t go into too much detail – my colleagues upstairs have already covered a lot of it. In any case, several methods need to be combined and used step by step to avoid damaging the furnace body during the cleaning process. If you have any further questions, feel free to leave me a message.

I’ve just arrived at the coking plant; I now have some understanding of coking, and I’d like to learn more about coal blending. I hope the original poster can provide more information and guidance. Thank you!

Our company uses 4.3-meter rammed coke, and the same issues arose at the beginning of operations. The main reason for this is that rammed coke tends to experience localized coal collapse; in practice, it is necessary to ensure that the coal level is adequate and to level the coal properly in order to effectively address the problem of coal collapse. These issues can basically be resolved

After our unit installed a compressed air purging device on the coke pusher, combined with regular measures to prevent graphite formation, the results were quite good. Now, some large vehicles come equipped with a gas-blown graphite device from the factory, as requested by the users.

The design of coke ovens is now very mature. Graphite formation on the furnace top is certainly related to the type of coal fed into the furnace and the excessively high temperature in the furnace top area. If the type of coal cannot be changed, the heating gas can be depleted, which is the most direct method. There is also the reduction of the collector pipe pressure.

1. The temperature of the long graphite and that of the furnace roof are related to each other. 2. From a design perspective, as long as the heating level is properly designed, it shouldn’t be a problem related to the design of the coke oven. Moreover, the technology for 4.3-meter coke ovens is now quite mature; therefore, this isn’t an issue with the coke oven design. 3. An accident that occurred in a coking plant can provide some insights: that plant, due to a lack of low-carbon coal, took no measures and simply used three other types of coal for coking, which resulted in an excessive amount of graphite being produced. It’s possible that there is a problem with the coal mixture used there.

1. Adjust the pressure at the top of the regenerative chamber. Reduce the temperature in the furnace top space. 2. Install a cleaning graphite device on the coke pushing rod.

For 4.3-meter coke ovens, the excessive accumulation of graphite on the upper part of the furnace wall is likely due to too low a coal loading amount; it is possible to increase the coal loading appropriately and reduce the temperature in the space above the furnace roof.

I think it’s related to the high standard temperature; we have encountered this situation before, and it was resolved by lowering the standard temperature.

Just make sure the height of the coal pile is not too low; 4 meters is sufficient! ! Adjustments can also be made to the pressure system. The gas flow rate can be reduced a bit in this case. Reduce the heating of the high-temperature components a bit! !

The coal loading height is insufficient； The heating schedule settings need to be adjusted ； Strengthen cleaning

1. Strictly implement the coal loading and leveling system, ensuring that the coal is loaded completely and evenly； 2. Reduce the standard temperature as much as possible, provided that the conversation remains mature ； 3. Improve upward heating: enrich the gas and deplete it, adjust the regulating bricks and chutes as well as the outlet thickness, in order to delay the mixing of gas and air, etc. 4. Graphite cleaning system.

My view on the excessively high temperature in the coke oven’s upper space: The fundamental reason is that a large amount of heat accumulates in the upper part of the oven, which leads to an excessively high temperature there. 1. The standard temperature is too high. A reasonable standard temperature management system should be established, with the standard temperature varying according to the parameters of the coal fed into the furnace and the production requirements. I can give you a reference range: 1250----1320 on the machine side, and 1290----1370 on the focal side. The specific adjustments to be made depend on the actual conditions. 2. The coal loading amount is insufficient. A> The coal loading height is insufficient. Strengthen the packing of flat coal and modify the flat coal rods; the specific gravity of the coal pile fed into the furnace is too low. Reduce the issue of volatiles in the coal fed into the furnace. The temperature distribution width of the volatiles is insufficient, causing the volatiles in the coal to evaporate rapidly and within a narrow temperature range over a short period of time. Measure: Increase the coal blending width. B>The coal is too dry. ** C>The coal is too fine. Control fineness 4: The heating regime is unreasonable. A> The gas is too lean, with insufficient calorific value, resulting in a too long flame. B> Pressure regulation. When heating with high pressure, “negative pressure operation” is required. C> The adjustment of the brick thickness and the slope outlet width is unreasonable, resulting in an excessively long flame.

I think management should be addressed first. After all, what’s the use of the best process technologies and systems if they aren’t put into practice? What those upstairs have said is basically comprehensive; adding strict management and strict adherence to procedural rules would make it even more thorough.

I believe it is mainly caused by high ambient temperature; mechanical cleaning or high-pressure air blowing can be used, and for mechanical cleaning, the method of evacuating the furnace can be employed. Also, pay attention to the patency of the rising tube.