NEWs

Breakthrough the cleaning process for long-distance and high altitude gray pipelines

In October 2022, our company received the task of cleaning the ash pipeline of Yangquan Sunshine Power Plant. The project has a pipeline length of 10 kilometers, with a height difference of 75 meters between the low and high points of the pipeline. There are both buried pipes and pipelines on small slopes, and many of them are connected by clamps, which poses a severe challenge to the cleaning work. The previous cleaning process of adding acid cleaning agents to the mortar pool and using the mortar pump to discharge acid cleaning, while controlling the amount of acid added based on the discharged ash water, can no longer meet the cleaning requirements of this project. In order to minimize or avoid leakage of the buried pipes in the front section, the cleaning of the front section should be as light as possible, while the cleaning of the rear section should be heavier.

In order to meet the customer's cleaning requirements and achieve better cleaning results, combined with the actual working conditions on site, after sufficient on-site discussions and multiple modifications to the process plan, it was finally decided to adopt the "graded, segmented injection of cleaning agents relay cleaning" process to clean the grey water pipeline. The specific measures are as follows:
1. Add 10% acid to the mortar pool;
2. Add 30% acid to the partition area and connect it to the ash pipeline using a dedicated pump station. When the mortar pump stops using the pipeline, use the pump station to spray the prepared acid pickling agent onto the ash pipeline. In order to achieve the cleaning solution reaching the ash discharge outlet on the mountaintop, pumps with the same parameters were started for relay at 3.5 kilometers under the bridge and 8 kilometers halfway up the mountain;
3. Add 30% acid to the acid point under the bridge. When adding acid to this point, the pump station in the partition will start first to provide water source and corrosion inhibitor for the acid point under the bridge. At the same time, the acid point on the halfway side of the mountain that is started will relay;
4. Add 30% acid at the foot of the mountain. When starting at this point, the partition will start first, and this point will provide water source and corrosion inhibitor for the subsequent acid adding points. At the same time, the acid adding points halfway up the mountain will continue to relay;
5. In order to achieve the purpose of relay, the acid adding points under the bridge, at the foot of the mountain, and halfway up the mountain are separated from the ash discharge pipes by corresponding butterfly valves. Water intake points and cleaning solution inlet points are respectively set in front of and behind the valves at each point.

Our on-site technicians used their brains and carefully designed, overcoming the height difference and the resistance of gas generated after acid washing reaction. They completed the multi-point acid addition of the pipeline, avoiding the previous phenomenon of over washing caused by acid addition from one end. They overcame various difficulties encountered during cleaning and successfully completed the cleaning task of the first grey water pipeline of the project, receiving high praise from the customer. At the same time, they also entrusted us with the cleaning task of the second grey water pipeline.
The smooth implementation of this project has made us deeply realize that as long as we use our brains, think seriously, and have the courage to innovate, we can overcome any difficulties.
This construction technique is a breakthrough in a new cleaning solution, pioneering the use of multi-point acid addition for grey water pipelines.