【Daily Question No. 321】November 23, 2018
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【Daily Question No. 321】November 23, 2018: What are the reasons for pump cavitation at the bottom of the tower? The liquid level at the bottom of the tower is too low ； Fault in the inlet pipeline ； Due to improper operation, light oil was pressed to the bottom of the tower where it vaporized ； Water jacket leaking or steam leakage ； Clogging of the pump impeller, etc. (Unless otherwise specified, all questions and answers are based on hydrogenation units.) ) Correct: 3 wealth, Incorrect: 1 wealth ； Mass posting of posts – rated based on the lowest score ； Replies that are unrelated to the answer are considered spam and will be deleted immediately. For management purposes, if you need to view content from a few days ago, please go to https://bbs.hcbbs.com/home.php?mod=space&uid=3862647&do=thread&view=me&from=space through the summary post below
High temperature, low liquid level, low pressure
The liquid level at the bottom of the tower is too low； Clogging of the inlet pipeline filter ； Too high a temperature causes cavitation.
1. The liquid level at the bottom of the tower is too low, causing the instruments to malfunction. 2. Water in the light oil or an excessive amount of sealing oil leads to vaporization. 3. The steam valve used for purging is not tight, allowing steam to leak out. 4. The backflow rate is too high, resulting in an excess of light components being pushed into the bottom of the tower. 5. There is a pump failure or the standby pump is not properly preheated. 6. The inlet pipeline is blocked.
①The liquid level at the bottom of the tower is too low, resulting in cavitation, or gas enters the system； ②The oil is light; the temperature is too high ； ③Water in the oil at the bottom of the tower ； ④Faults in the intake line (such as detached valve elements or clogged filters) ； ⑤Mechanical failures of the pump itself ； ⑥String steam
1. Pump inlet filter clogged 2. Tower liquid level too low 3. Low bottom of tower temperature, medium containing water 4. Excessive pump outlet opening
The liquid level at the bottom of the tower is too low； Clogging of the inlet pipeline filter ； Too high a temperature causes cavitation
Pump evacuation at the bottom of the tower: drop in pump outlet pressure, decrease in current, abnormal noise, reduction in flow rate or it dropping to zero； The liquid level at the bottom of the tower rises ； Reasons for pump evacuation at the bottom of the tower: ① The liquid level at the bottom of the tower is too low, resulting in cavitation, or gas enters the system ； ②The oil is light; the temperature is too high ； ③Water in the oil at the bottom of the tower ； ④Faults in the intake line (such as detached valve elements or clogged filters) ； ⑤Mechanical failures of the pump itself ； ⑥String of steam. Vacuum distillation operation using the bottom pump: ① Reduce the pump outlet valve to maintain operation at as low a flow rate as possible ； ②After switching to the backup pump, stop the original pump, clean the filter screen at the pump inlet, and be careful to avoid burns when draining oil ； ③During processing, it is necessary to maintain a balance in the liquid levels of various towers; especially after the pump at the bottom of the vacuum tower stops working, attention should be paid to the liquid level in the circulation oil tank, or the reactor should be informed to reduce the amount of circulation oil ； ④When the bottom pump of the atmospheric tower is evacuated, attention must be paid to the quality of the side-stream product; if it does not meet the standards, action should be taken to transfer it to another tank for processing.
1. Blockage at the pump inlet 2. Low pressure at the pump inlet 3. Excessively high temperature of the liquid at the pump inlet
The liquid level at the bottom of the tower is too low； Fault in the inlet pipeline ； Due to improper operation, light oil was pressed to the bottom of the tower where it vaporized ； Water jacket leaking or steam leakage ； Clogging of the pump impeller, etc.