On the recycling of hyposodium
Thread Content
Transfer the waste sodium hydroxide from the storage tank to the preparation system, using it in place of fresh water in the Venturi system thereby enabling recycling; this can save chlorine, achieve water-free discharge, and reduce acetylene losses. However, it generates large amounts of sodium sulfate which may crystallize under certain conditions. How should the tower be cleaned? Additionally, are there any safety concerns? Discussions are welcome
It’s a good idea; there will be no safety issues, as long as the effective chlorine content in the newly prepared solution meets the required standards. You can check the solubility of sodium sulfate and sodium phosphate, analyze the sodium sulfate content at any time, and replace it as needed.
There are many impurities in the spent sodium solution as well; could these affect the cleaning effect? The landlord needs to consider everything comprehensively.
Sodium sulfate is produced in large quantities on a daily basis – at a capacity of 100,000 tons per day, which means around ten tons of sodium sulfate are generated each day. Moreover, the crystallization temperature of sodium sulfate is 32 degrees Celsius, which makes washing the towers a challenging task. I wonder if any of you have experience with similar processes
Waste sodium contains dissolved acetylene, and if the Venturi mixing is uneven, chlorine coming into contact with acetylene can cause an explosion. This is just a guess; I wonder if there is any experience in operating it? ! Because in the past we also wanted to do this, but due to such concerns, we didn’t dare to do it online. Instead, a high-concentration sodium hypochlorite solution was prepared first, and then this high-concentration sodium hypochlorite was used in combination with the waste sodium hypochlorite; no blockage was observed in such cases.
I also have safety concerns; I’m afraid of the accumulation of chloroacetylene. If it’s prepared from defective sodium hydroxide, should that defective sodium hydroxide first be mixed with dilute alkali before being fed into the venturi to mix with chlorine? Is there such a practice?
How often should the SGH1966 discharge defective sodium hydroxide?
Effective utilization of waste sodium hypochlorite: The waste sodium hypochlorite in the purification unit is rich in acetylene gas and sulfur-phosphorus impurities. Under normal conditions, a closed-loop system is used for its handling; when its effective chlorine content falls below the set value, the waste sodium hypochlorite is sent to an acetylene generation waste liquid cooler for cooling, and then fed back into the generator for reuse, thereby ensuring the effective recovery of acetylene gas.
Waste sodium contains high levels of sulfuric and phosphoric acids, and acetylene has very low water solubility in acidic conditions. It is possible to mix some of the defective sodium hypochlorite with sodium hydroxide to adjust the pH value, and then combine it with concentrated sodium hypochlorite and water to prepare a sodium hypochlorite solution; this approach helps to save the amount of sodium hypochlorite and water used.
That’s how we used to handle it in the factory. But a large amount of sodium sulfate crystals cannot be dealt with; they need to be cleaned regularly, and at short intervals.
Waste sodium contains high levels of sulfuric and phosphoric acids, and acetylene has very low water solubility in acidic conditions. It is possible to mix some of the defective sodium hypochlorite with sodium hydroxide to adjust the pH value, and then combine it with concentrated sodium hypochlorite and water to prepare a sodium hypochlorite solution; this approach helps to save the amount of sodium hypochlorite and water used.