How to solve the frequent clogging of the drain pipe in a solid-alkali dryer

1. The root cause of the clogging that occurs in solid-alkali dryers is the crystallization of concentrated alkali at certain temperatures； 2. Determine the corresponding freezing point based on the concentration of the concentrated alkali discharged ； 3. Carry out insulation treatment based on the freezing point to ensure proper drainage at the lower part; this is how we resolved the issue. :lol

The drain pipe of the solid alkali dryer used for drying vinyl chloride is often clogged, and there are various reasons for this; the main ones include: 1. Vinyl chloride liquid carrying solid impurities; 2. Low ambient temperature leading to alkali crystallization; 3. Large gaps in the grating that holds the solid alkali, allowing it to fall through; 4. Delayed drainage, resulting in the accumulation of impurities; 5. The vinyl chloride in the earlier stages being acidic, containing iron ions that react with the alkali and form substances that cause blockages.

Liu Lingmei, 021-64340000-2664, liulingmei2000@yahoo.com.cn. It’s a minor issue that can be easily resolved; please provide your contact information

Treatment 1: The root cause of the clogging that occurs in solid-alkali dryers is the crystallization of concentrated alkali at certain temperatures； 2. Determine the corresponding freezing point based on the concentration of the concentrated alkali discharged ； 3. Carry out insulation treatment based on the freezing point to ensure proper drainage at the lower part; this is how we resolved the issue

The colleagues mentioned above have explained the causes and solutions. In my experience, it depends on which type of alkali dryer is used, what substances are causing the blockage, as well as the configuration of the piping systems in your facility. To prevent crystallization of the alkali solution due to temperature differences in winter, insulation measures should be taken and the alkali solution should be drained regularly. As a corrective measure, the temperature at the site of crystallization can be increased to melt the crystals; the medium used for raising the temperature can be steam or hot water. It is advisable to use low-pressure steam or hot water delivered through hoses to heat the area where there is a blockage. The advantage of this method is that the amount of heat applied can be controlled, and the heating surface can be changed. During heating, care must be taken to avoid overheating other unrelated equipment and pipelines, which could lead to excessive pressure or increased temperature differences within them. For blockages caused by other impurities or fragments of solid alkali (situations where heating cannot resolve the issue), a pressure difference method can be employed: liquid with a pressure higher than that at the crystallization point (such as water or liquid VCM) can be used to push against the blockage, or the pressure at the blocked area can be relieved by allowing it to flow into pipelines with lower pressure. This treatment method carries significant risks, so extreme caution must be exercised when using it. Attention must also be paid to the design pressure of the relevant equipment and pipelines, as well as the pressure at which safety valves release pressure, and to any potential corrosion issues.

The main cause of blockage in the drain pipe of a solid-alkali dryer for drying vinyl chloride is generally alkali crystallization or fragments of solid alkali falling into the drain pipe.

Everyone conducted a detailed analysis of my question and came up with solutions; I am very grateful