What could be the unknown substance being produced inside the pipes at the chlorine liquefaction unit? I seek advice from experts!
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This post was last edited by sunjl1981 on 2013-1-6 at 23:26. The liquid chlorine handling unit in our plant has been in operation for four years, and blockages have appeared in the pipes used to empty the eight liquid chlorine storage tanks. When the valves were opened and the pipes were inspected, it was found that their interiors were completely blocked by a yellow substance (which is quite hard; when exposed to air, a small amount of it turns into a red oily substance)! I would like to ask the experts: what are the components of this substance? How was it formed? Thank you! # ， ， &
It could be acidic sludge, or it might be a substance formed as a result of pipe corrosion.
Impurities such as sulfuric acid sludge, chlorides, sodium sulfate, etc. Last edited by limingshuguang on 2008-1-7 14:01]
The residues of calcium sulfate, ferric trichloride, and sulfuric acid; the red substances are mainly compounds formed by iron and sulfuric acid, and they become deliquescent in air.
Corrosion occurs for two reasons: 1. As mentioned by the original poster, the affected area is on the evacuation pipeline of the liquid chlorine storage tank, which should normally be in a closed state and is used only during major maintenance operations to empty the tank or in emergency situations. Therefore, the most likely corrosion products are iron salts, as the presence of large amounts of water leads to corrosion of the inner wall of the carbon steel pipe； In addition to the areas mentioned by the original poster, the evacuation tube of the liquid pocket may also experience the same issue. 2. Another issue is that of acidic sludge; due to the poor performance of sulfuric acid mist eliminators or improper level control, sulfuric acid ends up entering the subsequent liquefaction and liquid chlorine systems. This phenomenon can also occur in the liquid chlorine storage tanks or in the dead ends of the system, although the appearance of the corrosive substances, or impurities, differs from what was described by the original poster.
In our plant’s liquefaction unit, this phenomenon has also occurred in submersible pumps and liquid chlorine storage tanks. I have analyzed this substance, and 70-90% of its composition is sulfuric acid (which turns into a liquid when exposed to air); the remainder consists of rust, calcium sulfate, as well as barium sulfate. (Was barium sulfate introduced as a result of the use of low-quality sulfuric acid?) I’m not quite sure. ) The main reason for this problem is the poor performance of the acid mist filter; it is recommended to replace the filter, preferably with an imported one. I would appreciate your advice.
Thank you to the experts for their guidance. Our factory is experiencing this problem: we drain the sulfuric acid mist suppressant weekly, but nothing comes out. Over time, the vacuum valves on our storage tanks get clogged, and the drainage pipes in the intermediate tanks are also blocked by this substance! May I ask the experts whether this substance might contain a small amount of nitrogen trichloride?
Primarily, the acid mist capture efficiency in the chlorine treatment section at the front is poor; it is recommended to use those from Monsanto. The yellow substance is mainly sulfates, while the red substance, in my opinion, is a mixture of nitrogen trichloride and rust. This post was last edited by limingshuguang on 2008-1-8 at 10:53
Our factory has also encountered a similar situation: the discharge port of the liquefied gas-liquid separator became blocked. When it was disassembled for maintenance, yellow substance was found there. I think it’s iron chlorides and sulfates.
1: Sulfuric acid in the acid mist collector should be discharged promptly. 2: Check the filter element inside the acid mist collector. (Home-made filters need to be replaced annually.) 3: I agree with the opinion on the main components expressed on the 3rd floor.