The vacuum degree of the fluidized bed in the vertical tube furnace cannot be increased

The vacuum degree of the fluidized bed in the vertical tube furnace cannot be pumped up, which may be caused by factors such as gas leakage, vacuum unit problems, insufficient cleanliness of the vacuum chamber or pipeline, unreasonable vacuum gauges or control methods. The following are specific reasons and solutions:

1. Leakage problem
External air leakage:
Reason: Components such as vacuum chambers, vacuum pipelines, valves, etc. have poor sealing or damage, leading to external air infiltration.
Detection method: Use flame method (the principle of using airflow to deflect flames) to gradually search near suspicious points, or use professional leak detection instruments.
Solution: After finding the leakage point, perform sealing treatment or replace the damaged parts.
Internal air leakage:
Reason: There are water cooling points and other components in the vacuum chamber that have internal leaks, causing cooling water or other media to seep into the vacuum chamber.
Detection method: After the vacuum system reaches a certain pressure value, start the relevant systems separately, observe the reading changes of the vacuum gauge, and preliminarily determine the direction of the internal leakage point.
Solution: After identifying the internal leakage point, repair or replace the relevant components.

2. Vacuum unit problem
Insufficient pumping capacity:
Reason: The pumping rate of vacuum pumps (such as mechanical pumps, diffusion pumps, molecular pumps, etc.) is too low or the vacuum degree is not high.
Testing method: Check the working status of the vacuum pump, including speed, oil level, oil quality, etc., and compare the performance parameters of the vacuum pump.
Solution: Replace or repair the vacuum pump to ensure that its pumping capacity and vacuum degree meet the requirements.
Oil pollution or oxidation:
Reason: The oil in the vacuum pump is contaminated or oxidized, resulting in a decrease in pumping efficiency.
Detection method: Observe the color and odor of the vacuum pump oil to determine whether it is contaminated or oxidized.
Solution: Replace the vacuum pump oil with a new one and regularly clean the vacuum pump.

3. Insufficient cleanliness of vacuum chamber or pipeline
The vacuum chamber is too dirty:
Reason: There is dust, oil stains, or other impurities in the vacuum chamber, which increases the amount of air released.
Testing method: Observe the cleanliness of the vacuum chamber and check for any obvious impurities.
Solution: Thoroughly clean the vacuum chamber to remove impurities such as dust and oil stains.
Vacuum pipeline leakage:
Reason: The vacuum pipeline has poor sealing or damage, resulting in air leakage.
Testing method: Use professional leak detection equipment to test the vacuum pipeline.
Solution: After finding the leakage point, perform sealing treatment or replace the damaged pipeline.

4. Vacuum gauge or control method issues
Unreasonable selection of vacuum gauge:
Reason: The vacuum gauge used has insufficient accuracy or mismatched range, resulting in inaccurate measurement of vacuum degree.
Testing method: Compare the performance parameters of the vacuum gauge with the actual measurement requirements to determine whether it is reasonable.
Solution: Replace the vacuum gauge with a higher precision and a more matching range.
Control method error:
Reason: In the process of vacuum degree control, the correct control method (such as upstream control mode, downstream control mode, etc.) was not adopted, resulting in insufficient control accuracy.
Detection method: Analyze the data during the vacuum degree control process to determine whether the control method is reasonable.
Solution: Adopt the correct control method, such as using upstream and downstream control modes according to the vacuum degree range for control.