Causes and solutions of blockage of coke oven gas pipeline
1 Stagnant water
The fuel gas often contains water vapor. If the temperature is lowered or the pressure is increased, the steam will be condensed into water and flow to the lowest point of the condensate tank or pipeline. If the condensate reaches a certain amount and is not excluded in time, it will be cold. Solution: In order to prevent the accumulation of water in the pipe, a strict operation management system must be developed to regularly drain the condensate in the condensate tank. She should establish a position card and pumping records for a condensate tank, and record the pumping date and pumping volume as an important basis for determining the pumping cycle. In addition, abnormal conditions such as groundwater infiltration can be detected as early as possible.
When the pressure of groundwater is higher than the pressure of the gas in the pipeline, it may seep into the pipe with the loose joints of the pipeline, corrosion holes or cracks. It usually occurs in pipelines that have been in disrepair for a long time, the location where the pipeline is corroded or damaged, or the pipeline is loosened due to the quality problems of the application of the pipeline, or the depth of the pipeline does not meet the requirements, under the action of ground dynamic load. The place where the pipeline is disconnected or broken. Solution: When the amount of water in the condensate tank increases sharply, it may be caused by water leakage. At this time, the gas pipeline can be closed, and the gas higher than the infiltration pressure can be pressed. Repair the leaked location until it reaches normal gas transmission.
Artificial gas often contains a certain amount of naphthalene vapor, which condenses into a solid when the temperature decreases, or the naphthalene removal equipment is not perfect, so that the naphthalene adheres to the inner wall of the pipeline, which reduces the gas flow or completely blocks the pipeline. Or the branch pipe where the underground pipeline picks up the ground. Solution: To prevent and eliminate naphthalene, Dao first strictly controls the content of naphthalene in the factory fuel gas according to the regulations, so that the problem of naphthalene accumulation in the pipeline can be fundamentally solved. In addition, for urban gas pipelines, especially those within 1 to 2 kilometers of the factory, there is often drought naphthalene on the inner wall, and the Australian dollar must be cleaned regularly. Spray diesel can be used to spray heated diesel oil, volatile oil or mixed benzene, etc. into the tube to dissolve the naphthalene into the condensate tank and then discharge it with the condensate tank. It is also dissolved in warm water at 70 ° C, so it can also be separated at both ends of the Aussie pipeline, adding hot water or steam to remove naphthalene. But this method will cause the pipeline to expand and contract, and it is easy to loosen the flexible interface. Therefore, after cleaning and cleaning with this method, the gas pipeline should be tested for air tightness. The more serious parts of naphthalene accumulation in the low-pressure pipeline are generally concentrated on the branch pipes of the households. The wire can be connected to the steel wire for cleaning, or the underground pipe of the blocked part is dug out, and the naphthalene is sucked out by a vacuum pump.
4 Other impurities
In addition to the accumulation of naphthalene in the pipeline, the accumulation of other impurities may also cause a blocking accident. The main component of impurities is rust dust, which is often mixed with tar dust and accumulated in the pipeline. The corrosion of the steel pipe without inner wall coating or poor inner wall coating treatment is more serious than that of cast iron pipe, and the generated rust chips are mainly. The method of eliminating impurities is: to clean the Australian dollar in sections by dry pipe, usually about 50 meters as a clean Australian dollar section. . Sometimes when too much rust debris is firmly attached to the pipe wall, it is not easy to remove it. When removing rust, you should also pay attention to the possible corrosion pits on the pipe wall. If the pipe turning part, valve [J and drain are blocked, they can be removed for cleaning or replacement.
5 Pipeline slope
The slope of the gas pipeline is heavier than water, and the blockage is heavier. Using a reasonable slope is conducive to the removal of liquid accumulation and impurities. Therefore, the slope of the pipeline must be greater than 5%.
6 Operation management
The continuous discharge of liquid seals along the gas pipeline, the reasonable clearance of the pipeline, the collection effect of the electric tar tar and the quality of the naphthalene removal equipment are also aspects that cannot be ignored. In summary, to reduce the blockage of gas pipelines, we must improve the quality of clean coal gas, strengthen equipment operations, and strive to improve the efficiency of desulfurization and decyanation. Efforts should be made to improve the operating rate and the collection rate of the electric tar tar, reasonably control the operating temperature of AUD naphthalene, and minimize the tar content in the gas. Strengthen construction management and clean the gas pipeline 1 or 2 times a year. If the above comprehensive conditions are adhered to, the urban gas-gas transmission and distribution pipelines can be operated safely and normally.