Weekly Topic: What factors can cause an increase in the resistance of the desulfurization tower?

Moderator Yan, there may be issues with your regeneration process – the level of by-products is too high, which causes crystallization to occur when the temperature drops. When the temperature rises, crystallization decreases and the system pressure difference gradually falls.

When the gas temperature is increased, the gas density changes and the effective amount of gas decreases; it is therefore normal for the resistance to decrease as well. Of course, the main reason is still blockage of the desulfurization tower or operation under overload.

Hello, do you have high resistance in the first stage of separation or in the second stage? Our company usually experiences higher resistance in the second stage of separation

As mentioned above, it’s necessary to read the question carefully; the original poster was talking about the desulfurization of semi-water gas, and of course that refers to desulfurization.

The issue of whether regeneration is necessary, or whether the sulfur foam cannot be properly recovered – analyze the sulfur content in the lean solution.

1. The quality of the gas entering the tower is poor; coal ash, tar, and other impurities carried in the gas accumulate over time on the surface of the packing, creating resistance. Furthermore, when balancing resources, the head plant recycled both the flash vapor from System II and the off-gases from coal refining to the main gas pipeline; although this increased production capacity, the poor quality of the gases led to an increase in the resistance in the normal distillation column. 2. The purification conversion process uses sulfur-resistant, wide-range catalysts, requiring H2S levels to be maintained above 150 mg/m3; when the production load is low, only by reducing the solution circulation rate can the H2S levels be kept within the specified range. However, this also leads to a decrease in the spray density and uneven spraying, resulting in semi-dry or dry areas in the packing section of the tower, which creates resistance. In the second half of 2008, due to market factors, the old system operated at low load, often shutting down repeatedly; sulfur paste accumulated in the packing section, quickly creating resistance. Based on the inspection of the packing in the constant-draw tower at the end of 2008, significant cross-flow and wall flow were observed in the tower. Some of the packing inside the tower was relatively clean, while other parts were severely clogged; in addition, sulfur deposits were found on the tower walls. 3. If the packing is broken or deformed and not replaced in a timely manner during maintenance, sulfur blockage can occur in the packing section; this also leads to blockages in the tray-type liquid distributor. In severe cases, the broken packing can block the impeller of the rich liquid pump, resulting in a reduced circulation rate as well as blockages in the injector nozzles. At the same time, due to increasing environmental pressures, the wash water used for removing the packing from the tower must be recycled. Moreover, the amount of wash water used has to be controlled in line with environmental regulations, which results in a significantly reduced cleaning efficiency. Some of the packing still retains sulfur deposits when reinstalled, leading to an increase in resistance after the system is put into operation. 4. Poor regeneration of the desulfurization solution, uneven distribution of regeneration air, insufficient amount of regeneration air, abnormal sulfur melting, and poor control over sulfur foam overflow can all lead to an increase in suspended sulfur in the solution, thereby increasing the resistance in the packing section. 5. The sulfur melting system does not operate efficiently; sulfur production is low, and it is not possible to obtain sulfur paste, which leads to an increase in suspended sulfur in the solution and an increase in system resistance.

If the temperature of the desulfurization solution is low, its viscosity increases. Could it be that by raising the intake air temperature, the temperature of the solution also rises?

This post was last edited by dyscb666 on 2011-2-8 at 16:40. 1. The design is unreasonable, such as the overflow-type distributor, etc. 2、The quality of gas purification is poor, due to inadequate washing before desulfurization, ineffective electrostatic dust removal, and insufficient operational management. 3. Low regeneration efficiency, poor regeneration effect, and high suspended sulfur. If the spray pipe in the regeneration tank is blocked, the amount of air drawn in by suction is insufficient, resulting in poor flotation ； The injector group is not evenly adjusted, resulting in an uneven distribution. 4. The temperature of the sulfur-melting return material is too high; it is returned to the system without undergoing cooling and settling. 5. The sulfur melting system is not properly managed; the sulfur that has been separated out is not fully melted and thus returns to the system. 6. The components of the desulfurization solution do not meet the process requirements. 7. Packing deformation, uneven air flow distribution ； The pressure plate was not pressed properly and was flipped over by the airflow, etc.

As the operating temperature of the desulfurization tower decreases, the viscosity of the desulfurization fluid increases, which in turn raises the resistance within the tower； At higher operating temperatures, the desulfurization capacity of the desulfurization solution decreases ； Therefore, the operating temperature of the desulfurization tower should be maintained at around 40 degrees

I’ve learned from all of you! But what exactly is the reason?