Why Does the Vacuum Distillation Column Fail?

1. Pipeline leakage

The leakage of the pipeline will cause the vacuum degree of the distillation tower to drop sharply. There are two main reasons: on the one hand, the leakage of the pipeline will cause the gas to enter the distillation tower and increase the internal pressure; on the other hand, the leakage of the pipeline will cause the vacuum degree of the distillation tower to drop sharply. The loss of gas from the top part causes the vacuum degree inside the tank to drop sharply, making it impossible to maintain the designed vacuum degree.

2. Tray clogging

During the distillation process, it is easy to deposit scale and carbon on the trays, causing the tray holes to become clogged, thereby affecting the normal operation of the distillation tower. When the tray holes are blocked, it will affect the flow of gas inside the distillation tower, affect the distillation separation effect, and cause the quality of the distillation product to decrease. If not cleaned in time, more and more tray holes will be clogged, affecting the normal operation of the distillation tower.

3. Tray damage

The tray is damaged. Damage to the trays will reduce the working efficiency of the distillation tower, and will also produce pressure on the packing, packaging and other equipment below the trays, causing further damage. Tray damage may result from excessive negative pressure, or equipment aging, corrosion, damage, etc. If not repaired in time, the tower plate may be completely destroyed, causing great losses.

4. Tube corrosion

The corrosion of the tubes is mainly due to the chemical reactions such as acid corrosion and alkali corrosion caused by the medium at the bottom of the tower and the tray during the production process, which leads to corrosion, rust and other problems on the surface of the tubes, thereby affecting the vacuum degree of the distillation tower. . If not handled in time, the tubes may rupture, affecting the safety of the entire distillation tower.

5. Is the tower top condenser working normally?

The temperature of the refrigerant fluctuates, causing the gas phase load of the tower to fluctuate, and the condenser cannot completely reduce the temperature and completely condense, turning into a partial condenser. If the above phenomena occur, consider lowering the refrigerant temperature appropriately.

6. Vacuum line is blocked

Blockage of the vacuum pipeline will directly lead to a decrease in vacuum degree. Vacuum pipelines are usually heated by hot water, steam, etc. However, uneven heating or poor insulation can cause pipeline blockage, resulting in poor vacuum. Therefore, you can check the insulation of the vacuum line selection. situation, check the supply pressure and temperature of the hot water or steam pipeline, and whether the steam trap is working properly.

7. Vacuum pump failure

When the steam jet pump airflow passes through the nozzle, it mainly converts pressure into kinetic energy. Since the pressure inside the pump and the pressure at the outlet will form a significant pressure difference, the working steam can flow smoothly in the pipeline. However, during use, the nozzle is subject to long-term damage. The high-speed flushing of steam causes the nozzle to wear and also causes the vacuum pump to operate unstable.

8. Changes in feed composition

Fluctuations in feed volume or feed temperature may also cause vacuum fluctuations, which require inspection and analysis from the process raw materials or feed valves.

In short, the reasons for poor vacuum in the distillation tower are not only the above eight reasons, but other reasons such as improper operation and equipment aging may also cause problems. In order to ensure production safety, companies need to regularly maintain and inspect distillation towers, and troubleshoot and solve problems in a timely manner.