Treatment Methods For Evaporator Blockage

The blockage of evaporator tubes is a common fault state during the operation of MVR evaporators or multi effect evaporators.
There are various reasons for tube blockage, and targeted treatment is needed in actual production.
1. The main component of pipeline scaling is the hardness scale layer.
The quick method is mechanical cleaning, commonly using high-pressure water guns for high-pressure flushing or preparing corresponding chemicals for chemical cleaning. But for calcium sulfate hardness scaling, chemical cleaning takes a longer time. If the evaporative material can be subjected to hardness removal treatment or sulfate removal in advance, the scaling cycle can be greatly extended. Sodium carbonate enrichment and scaling are also within this category.
2. Foreign object blockage
The most common foreign object blockage is caused by scarring on the wall of the evaporation tank and falling off into the column pipe. The observed phenomenon is complete blockage of the column pipe, with no hardness scaling on the pipe wall or a thick hardness scaling layer, and the main blockage is salt. Due to the blockage of the pipes, it is difficult to dissolve them by soaking them in clean water, and only a water gun flushing method can be used.
3. Organic matter coking blockage
Some organic compounds may undergo polymerization or carbonization due to concentration and long-term high-temperature concentration, and gradually become blocked by salt particles after coking on the pipe wall. In this situation, regular alkaline cleaning should be used to clean the equipment to avoid clogging of the pipes and difficulties in cleaning.
4. No hardness, no scar blocks on the tank wall, no foreign objects but blocked pipes
All the blockages are salt, which may be due to equipment design defects, insufficient height of the evaporation chamber, or excessive evaporation intensity. The material is locally overheated, evaporated, and crystallized in the upper half of the column. The solution is to reduce the evaporation intensity and increase the circulation rate of the circulation pump to extend the blockage cycle.
5. Scaling in evaporators such as zinc sulfate, manganese sulfate, and magnesium sulfate should be treated differently.