Replacement method for changing blast furnace gas heating of coke oven into coke oven gas heating

Abstract

The invention provides a replacement method for changing blast furnace gas heating of a coke oven into coke oven gas heating. The replacement method comprises the following steps: performing gas replacement when a coke oven gas adjusting turning plate is fully opened; after reversing of the coke oven is finished, closing blast furnace gas adjusting cocks of upflow at the machine side and the coke side at the same time; an iron plate is installed on the air door and adjusted to the set air door opening degree; sequentially opening coke oven gas adjusting cocks of ascending gas flow, reversing for the second time after gas supply to the ascending flame path is normal, and adjusting the suction force of a branch flue and determining the pressure of a coke oven gas pipeline after gas supply to all flame paths is normal; after the replacement is normal, the blast furnace gas header pipe shutter is closed, and the blast furnace gas pipeline is inserted into the blind plate. According to the method, the replacement efficiency is remarkably improved, the replacement operation time is shortened to the maximum extent, excessive reduction of the combustion temperature of the coke oven caused by the fact that the coke oven is changed into a coal gas heating type is avoided, the required thermal state of the coke oven can be continuously kept, and smooth production after replacement is kept.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of coking, and particularly relates to a replacement method for replacing high furnace gas with coke oven gas for heating of a coke oven. BACKGROUND

[0002] The coke oven is a core equipment for coking production, and is usually in a reheating form, and is equipped with two sets of heating systems of coke oven gas and high furnace gas to adapt to different production requirements. Compared with the high furnace gas, the coke oven gas has advantages of high calorific value, easy burning and simple heating control, and when the coke oven gas is used for heating, the fire adjusting operation is more convenient, the furnace temperature is more flexible to adjust, and the thermal stability of the coke oven is more favorable. Therefore, in actual production, the replacement operation from the high furnace gas heating to the coke oven gas heating is often required.

[0003] However, in the traditional replacement method, the replacement time is long, and in this process, the temperature of the coke oven is significantly reduced, and a large amount of time and gas is required to recover the required temperature in the subsequent temperature recovery, which affects the production continuity. Meanwhile, since the replacement operation is a dangerous operation, the traditional method is prone to safety hazards due to insufficient preparation work, operation link omissions and other problems, which hinders the smooth progress of the replacement work. SUMMARY

[0004] In order to solve the problems in the prior art, the present application aims to provide a replacement method for replacing high furnace gas with coke oven gas for heating of a coke oven, which can smoothly and quickly complete the replacement work of the two kinds of gas, maximally shorten the operation time, and avoid the too fast temperature reduction of the coke oven.

[0005] To achieve the above-mentioned purpose, the technical scheme of the present application is as follows: A replacement method for replacing high furnace gas with coke oven gas for heating of a coke oven, comprising: S1, during the maintenance time of the coke oven, steam or nitrogen is introduced into the coke oven gas pipeline to drive away air, and after steam or nitrogen is emitted from the vent pipe, the vent pipe is closed, and the pipeline is kept in a positive pressure state; S2, steam or nitrogen is introduced into the coke oven gas pipeline to drive away air, and the vent pipe is opened for venting according to the pipeline pressure, and at the same time, the steam or nitrogen is closed, and when there is no steam or nitrogen in the vent pipe, sampling is performed at the end of the coke oven gas pipeline to conduct an explosion test, and after the test is qualified, subsequent replacement operation is performed; S3, when the pressure of the coke oven gas main pipe is confirmed to be stable above the target value, and the coke oven gas adjusting flap is in a fully open position, the gas replacement is performed; S4, at the end of the coke oven reversing, the high furnace gas adjusting cock of the ascending gas flow is closed on the machine side and the coke side at the same time; S5, the following steps are sequentially performed from the end of the high furnace gas pipeline: S5.1, the small shaft of the gas weight of the ascending gas flow waste gas disc is removed; S5.2, connecting air cover plate and exchange pull rod; S5.3, remove the asbestos plate on the air inlet door, install an iron plate on the air inlet door, and adjust to the set air inlet opening; S6, from the end of the coke oven gas pipeline, open the coke oven gas regulating cock of the ascending gas flow in turn in groups of ten rows, and send the coke oven gas row by row; S7, observe the combustion of the corresponding combustion chamber from the top of the coke oven, and monitor whether the combustion is normal; after normal combustion, fully open the coke oven gas regulating cock of the ascending gas flow; S8, after normal gas feeding to the upward ascending fire channel, perform the second reversing on the other fire channel, and repeat S3-S7; S9, after normal gas feeding to all fire channels, check the combustion of all fire channels, adjust the smoke duct suction, and determine the coke oven gas pipeline pressure; S10, after replacement, close the blast furnace gas main valve, and insert the blind plate into the blast furnace gas pipeline.

[0006] Further, during replacement, the coking time is at least 2 hours longer than the normal coking time.

[0007] Further, the required coke oven gas consumption is 15000m 3 / h based on 20 hours of coking.

[0008] Further, in S1, before the coke oven gas pipeline is connected to steam or nitrogen, the coke oven gas pipeline is sequentially cleaned by compressed air, and according to the coke oven gas consumption, the orifice plate is installed in the branch pipe orifice plate box, and the orifice plate box gasket is replaced.

[0009] Further, in S2, at least three burst tests are continuously performed.

[0010] Further, in S3, the coke oven gas main pipe pressure is stabilized at 4000Pa or more.

[0011] Further, in S5.3, the single air inlet opening during coke oven gas heating is 0.5-0.55 times the air inlet opening during blast furnace gas heating.

[0012] Further, by adjusting the smoke duct suction and the air inlet opening, the fire hole pressure is 0-5Pa.

[0013] Further, in S6, the coke oven gas regulating cock opening is 1 / 2.

[0014] Further, before replacement, the coke oven gas exchange system needs to be continuously operated for 24 hours or more under load, and no abnormalities are confirmed.

[0015] Compared with the prior art, the replacement method of the coke oven heated by blast furnace gas to coke oven gas in the present application has the following advantages: The replacement method for replacing the coke oven by the blast furnace gas with the coke oven gas for heating significantly improves the replacement efficiency, maximally shortens the replacement operation time, avoids the excessive decrease of the combustion temperature of the coke oven due to the replacement of the blast furnace gas with the coke oven gas for heating, and can continuously maintain the required thermal state of the coke oven to maintain the smooth production after the replacement.

[0016] Through the targeted safety measures (such as the burst test) and the adjustment of the thermal parameters, the operation safety is strengthened, the safety hidden danger is reduced, the thermal state of the coke oven can be maintained stably, the energy consumption and the time cost for the subsequent temperature recovery are reduced, in addition, the present application adapts to the actual production demand of the regenerative coke oven, provides the reliable technical support for the smooth, safe and efficient switching of the two kinds of gas heating systems, and has the significant technical value and the application prospect. DETAILED DESCRIPTION

[0017] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict.

[0018] In the description of the present application, it should be understood that the orientations or positional relationships indicated by the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like are only for the convenience of describing the present application and simplifying the description, and are not intended to indicate or imply that the devices or elements indicated thereby must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second" and the like are only for the purpose of description and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated thereby. Therefore, the features limited by "first", "second" and the like can explicitly or implicitly include one or more of the features. In the description of the present application, unless otherwise specified and limited, the meaning of "a plurality of" is two or more.

[0019] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connecting" should be understood in a broad sense, for example, it can be a fixed connection, or a detachable connection, or an integral connection; it can be a mechanical connection, or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or a communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0020] The present application will be described in detail below with reference to the embodiments.

[0021] A replacement method for replacing the coke oven by the blast furnace gas with the coke oven gas for heating, specifically comprising: S1, coke oven maintenance time, steam or nitrogen is introduced into the coke oven gas pipeline to drive air, after the steam or nitrogen is emitted from the diffuser pipe, the diffuser pipe is closed, and the pipeline is kept at positive pressure; S2, coke oven gas is introduced into the coke oven gas pipeline to drive steam or nitrogen, and the diffuser pipe is opened for diffusion according to the pipeline pressure, and the steam or nitrogen is closed, when there is no steam or nitrogen in the diffuser pipe, sampling is performed at the end of the coke oven gas pipeline to perform an explosion test, and after the explosion test is qualified, subsequent replacement operation is performed; S3, confirming that the pressure of the coke oven gas main pipe is stable above the target value, and the coke oven gas adjusting flap is in the fully open position, the gas replacement is performed; S4, at the end of the coke oven changeover, the blast furnace gas adjusting cock of the updraft gas flow is closed at the same time on the coke side in the blast furnace basement, and the CO concentration monitoring equipment is arranged in the basement to ensure the safety of the operation; S5, in the regenerator, the following is sequentially performed from the end of the blast furnace gas pipeline: S4.1, the small shaft of the blast furnace gas waste gas disc coal bucket of the updraft gas flow is unloaded; S4.2, the air cover plate and the exchange pull rod are connected; S5.3, the asbestos plate on the air inlet door is removed, the air inlet door iron plate is installed, and the air inlet door opening is adjusted to the set opening; S6, the blast furnace gas adjusting cock of the updraft gas flow is sequentially opened from the end of the coke oven gas pipeline in groups of ten rows, and the coke oven gas is sent row by row; Specifically, when the gas is sent, it should be checked in time whether there is gas leakage, if leakage is found, the corresponding cock should be immediately closed, and fire sources should be strictly prevented, and then treatment is performed; S7, the combustion of the corresponding combustion chamber is observed from the top of the coke oven, and whether the combustion is normal is monitored; after the combustion is normal, the blast furnace gas adjusting cock of the updraft gas flow is fully opened; S8, after the gas is normally sent to the updraft fire channel, the second changeover is performed on the other fire channel, and S3-S7 are repeated; S9, after the gas is normally sent to all fire channels, the combustion of all fire channels is checked, the smoke duct suction is adjusted, it is determined that the pressure regulation of the coke oven gas pipeline is normal, the temperature and flow instrument work is normal; when the pressure of the gas pipeline decreases too much and is lower than 500 Pa, heating should be stopped; S10, after the replacement is normal, the blast furnace gas main pipe on-off device is closed, and the blast furnace gas pipeline is inserted into the blind plate.

[0022] In a preferred embodiment of the present application, during replacement, the coking time is prolonged by at least 2 hours based on the normal coking time.

[0023] Specifically, during the replacement, the original standard temperature is kept unchanged, and then adjusted according to the coke chamber coke cake temperature and the maturation, and the coking time can be appropriately prolonged according to the furnace temperature, so as to provide sufficient time buffer for the replacement operation of the coke oven gas and the blast furnace gas. At the same time, prolonging the coking time can slow down the coking process of the coal in the coke oven, reduce the rapid loss of heat caused by the switching of the heating system during the replacement period, effectively inhibit the excessive drop of the temperature of the coke oven, help to maintain the required thermal stability of the coke oven, reduce the energy consumption and time cost of the subsequent recovery of the furnace temperature, and at the same time, ensure that the coke can still mature normally during the replacement period, avoid the influence of temperature fluctuation on the coke quality, so as to ensure the continuity and stability of the production before and after the replacement.

[0024] In a preferred embodiment of the present application, the required coke oven gas consumption is 15000 m 3 / h, calculated according to the coking time of 20 hours.

[0025] Specifically, before the heating gas system of the coke oven is changed from the blast furnace gas to the coke oven gas, in order to ensure the safe and stable operation of the production after the change of the gas type, the required coke oven gas amount is 15000 m 3 / h, calculated according to the coking time of 20 hours.

[0026] In a preferred embodiment of the present application, in S1, before the coke oven gas pipeline is connected to the steam or nitrogen, the coke oven gas pipeline is sequentially cleaned by compressed air, and the orifice plate is installed in the branch pipe orifice plate box according to the coke oven gas consumption, and the gasket of the orifice plate box is replaced.

[0027] Specifically, according to the coke oven gas consumption, the orifice plate is installed in the branch pipe orifice plate box, the gas flow of each branch pipe can be accurately controlled through the throttling effect of the orifice plate, the supply amount of the coke oven gas is matched with the heating demand (such as the coking time, the standard furnace temperature, etc.), the waste of energy caused by excessive flow or the poor heating effect caused by insufficient flow is avoided, the thermal state of the coke oven is stabilized, and the heating efficiency is improved.

[0028] Replacing the gasket of the orifice plate box can eliminate the sealing failure hidden danger caused by the aging and damage of the old gasket, ensure that the connection part of the orifice plate box and the pipeline is tight and does not leak, and prevent the coke oven gas from leaking In a preferred embodiment of the present application, in S2, at least three burst tests are continuously performed.

[0029] In a preferred embodiment of the present application, in S3, the main pipe pressure of the coke oven gas is stabilized at more than 4000 Pa.

[0030] Specifically, single burst test may result in distorted results due to sampling bias, accidental errors or gas instantaneous state fluctuations. By at least three consecutive tests, accidental factors can be effectively avoided to ensure that the test results truly reflect the actual state of the coke oven gas, reduce the risk of misjudgment, and provide reliable safety basis for subsequent replacement operation.

[0031] In a preferred embodiment of the present application, in S5.3, the single damper opening degree during coke oven gas heating is 0.5-0.55 times the damper opening degree during blast furnace gas heating.

[0032] Specifically, the appropriate damper opening degree can ensure that the combustion reaction in the flue is sufficient and stable, and reduce the temperature fluctuations caused by unbalanced air quantity. This precise control can make the coke cake heat evenly, ensure the uniformity of coke maturity, avoid quality defects caused by uneven heating, and thus maintain the continuity and product quality stability of the production after replacement.

[0033] At the same time, sufficient combustion can reduce the residual unburned gas in the furnace or pipeline, reduce the concentration of toxic gases such as carbon monoxide caused by incomplete combustion, and improve the economy and safety of the coke oven operation from the aspects of energy consumption control and safety protection.

[0034] In a preferred embodiment of the present application, the pressure at the fire hole is adjusted to 0-5 Pa by adjusting the flue suction and damper opening degree.

[0035] Specifically, the pressure range is a slightly positive pressure state, which can be adjusted by the cooperation of the flue suction and the damper opening degree to avoid leakage of coke oven gas from the fire hole due to too high pressure at the fire hole, and prevent external cold air from being sucked into the vertical flue when the pressure is too low. At the same time, this pressure state can ensure that the waste gas generated by combustion in the vertical flue is smoothly discharged, forming a dynamic balance with the supply of air and gas, ensuring that the combustion reaction is sufficient and stable, making the temperature of each vertical flue of the coke oven uniform, and thus ensuring that the coke cake is heated uniformly and the coke maturity is uniform, and finally realizing the precise control of the thermal state of the coke oven, improving the production safety, energy utilization efficiency and product quality stability.

[0036] In a preferred embodiment of the present application, in S6, the coke oven gas regulating cock opening degree is 1 / 2.

[0037] Specifically, the coke oven gas has high calorific value and sensitive combustion reaction, and when the cock opening degree is controlled at 1 / 2, the gas delivery pressure and combustion demand can be balanced to avoid sudden increase in gas flow due to too large opening degree, or insufficient flow due to too small opening degree.

[0038] In a preferred embodiment of the present application, the preparation work before the replacement of coke oven gas by blast furnace gas heating includes: (1) Ensure supply: ensure sufficient and stable supply of coke oven gas after replacement. (2) Pipeline system treatment: The coke oven gas pipeline system (including main pipe, cross pipe, nozzle, vertical pipe, etc.) is comprehensively inspected, oiled and lubricated, cleaned, washed and maintained, and the cross pipe, vertical pipe and branch pipe are sequentially cleaned with compressed air to ensure that the pipeline and components are unobstructed, tight, good and leak-free. (3) Accessory preparation and installation: Prepare the coke oven gas orifice plate and install it according to the initial calculation amount, and replace all orifice plate box gasket. (4) Auxiliary system inspection: Check the steam access hole valve on the coke oven gas and blast furnace gas pipeline to ensure that steam can be accessed. (5) Adjusting equipment inspection: Ensure that the coke oven gas main pipe adjusting flap rotates flexibly and the shaft end is tight; oil and lubricate the gas pipeline valve to ensure that it adjusts flexibly, switches in place and is tight and leak-free; check and confirm that the coke oven gas adjusting cock and exchange cock are not damaged, clean and oil and lubricate them to ensure that they rotate flexibly and do not leak; check the basement coke oven gas exchange tie rod, handle, chain, chain wheel and bracket, etc., and oil and lubricate them.

[0039] (6) Component and tool preparation: Prepare the coke oven gas inlet door opening adjusting iron plate, small shaft and split pin connecting the air cover plate on the exhaust gas disc to ensure that the transmission chain is normal; prepare the wrench for opening and closing the blast furnace gas adjusting cock and the iron wire for adjusting the amount of vertical flue gas.

[0040] (7) Instrument and system testing: Ensure that the electrical instruments and actuators are operating normally; before replacement, the coke oven gas exchange system is continuously operated for more than 24 hours under load to confirm that there is no abnormality and that the exchange direction is consistent with the exhaust gas exchange direction.

[0041] In a preferred embodiment of the present application, the heating system includes: (1) The standard temperature and coking time when the coke oven is heated by coke oven gas instead of blast furnace gas: The existing standard temperature is maintained unchanged, and then adjusted according to the carbonization chamber coke cake temperature and maturity. The coking time can be appropriately extended according to the furnace temperature.

[0042] (2) Coke oven gas flow The total flow of coke oven gas required by the coke oven is about 15000m 3 / h, calculated for 20 hours of coking.

[0043] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A method for replacing blast furnace gas heating in a coke oven with coke oven gas heating, characterized in that, include: S1. During coke oven maintenance, steam or nitrogen is introduced into the coke oven gas pipeline to drive out the air. After steam or nitrogen comes out of the vent pipe, the vent pipe is closed to maintain positive pressure in the pipeline. S2. Introduce coke oven gas into the coke oven gas pipeline to drive out steam or nitrogen, and open the venting pipe for venting. At the same time, close the steam or nitrogen. When there is no steam or nitrogen in the venting pipe, take a sample at the end of the coke oven gas pipeline for an explosion test. After passing the test, proceed with the subsequent replacement operation. S3. Confirm that the pressure of the main coke oven gas pipe is stable above the target value and that the coke oven gas regulating flap is in the fully open position, and then carry out gas replacement. S4. When the coke oven reversal is completed, starting from the end of the blast furnace gas pipeline, the blast furnace gas regulating valve for the rising airflow is simultaneously closed on both the machine and coke sides. S5. Start executing sequentially from the end of the blast furnace gas pipeline: S5.1 Remove the small shaft of the gas feeder from the blast furnace gas waste gas pan; S5.2 Connect the air cover to the exchange rod; S5.3 Remove the asbestos board from the air inlet damper, install an iron plate on the damper, and adjust it to the set damper opening. S6. Starting from the end of the coke oven gas pipeline, open the coke oven gas regulating valve for the rising airflow in groups of ten rows, and send coke oven gas row by row. S7. Observe the combustion status of the corresponding combustion chamber from the top of the coke oven and monitor whether the combustion is normal; after the combustion is normal, fully open the coke oven gas regulating valve for the upward airflow. S8. After the gas supply to the rising fire channel is normal, the other fire channel is reversed for the second time, and S3-S7 are repeated. S9. After all flues are supplying gas normally, check the combustion status of all flues and adjust the suction of the branch flues to determine the pressure of the coke oven gas pipeline. S10. After the replacement is normal, close the blast furnace gas main pipe switch and insert a blind flange into the blast furnace gas pipeline.

2. The replacement method for heating a coke oven by changing from blast furnace gas to coke oven gas according to claim 1, characterized in that: During replacement, the coking time should be extended by at least 2 hours beyond the normal coking time.

3. The replacement method for heating a coke oven by changing from blast furnace gas to coke oven gas according to claim 2, characterized in that: Assuming a coking time of 20 hours, the required coke oven gas consumption is 15,000 m³ / h.

4. The replacement method for heating a coke oven by changing from blast furnace gas to coke oven gas according to claim 1, characterized in that: In S1, before steam or nitrogen is introduced into the coke oven gas pipeline, the coke oven gas pipeline is first cleaned sequentially with compressed air, and orifice plates are installed in the orifice plate box according to the coke oven gas consumption, and the pressure gasket of the orifice plate box is replaced.

5. The replacement method for heating a coke oven by changing from blast furnace gas to coke oven gas according to claim 1, characterized in that: In S2, at least three consecutive burst tests shall be conducted.

6. The replacement method for heating a coke oven by changing from blast furnace gas to coke oven gas according to claim 1, characterized in that: In S3, the pressure of the main coke oven gas pipe is kept stable above 4000Pa.

7. The replacement method for heating a coke oven by changing from blast furnace gas to coke oven gas according to claim 1, characterized in that: In S5.3, the opening degree of a single damper during coke oven gas heating is 0.5 to 0.55 times that of the damper opening during blast furnace gas heating.

8. The replacement method for heating a coke oven by changing from blast furnace gas to coke oven gas according to claim 7, characterized in that: By adjusting the suction force of the flue and the opening of the damper, the pressure of the inspection hole is made to be 0-5 Pa.

9. The replacement method for heating a coke oven by changing from blast furnace gas to coke oven gas according to claim 1, characterized in that: In S6, the opening of the coke oven gas regulating valve is 1 / 2.

10. The replacement method for heating a coke oven by changing from blast furnace gas to coke oven gas according to claim 1, characterized in that: Before replacement, the coke oven gas exchange system must be operated continuously under load for more than 24 hours to confirm that there are no abnormalities.