【Daily Question】June 30 – Issues related to starting centrifugal pumps (+2 for the first 80 participants, +3–8 extra points for correct answers...)
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This post was last edited by whthday on 2015-7-6 at 14:25. The Mechanical Section has introduced the \"Question of the Day\" feature, which aims to foster an active atmosphere for technical discussions and guide the direction of such exchanges. It also provides users with financial rewards, helping them experience various cool features. 【Daily Question】 Fill-in-the-blank: When a centrifugal pump is started, it runs idle, fails to draw in liquid, and the vacuum level at the inlet is low; in this case, the pump is experiencing the _________ phenomenon, and the possible causes are __________________ or ____________________. Answer: Air entrapment, lack of pump priming, and imperfect shaft sealing. Requirement for answering the question: Please reply with the answer you consider correct; if you provide a detailed explanation or analysis of the question or answer, an additional reward will be given. Extra rewards will be awarded if your answer is correct and your explanation is thorough and accurate. Feel free to answer. Please note: We will close this thread after 24 hours, and at that time we will announce the best reply (the best assistance), as well as the answer and explanation. Do not submit answers repeatedly. As a reward for your effort, if you post a topic in this section within two days that provides a detailed explanation of the knowledge points related to this question, please reply/comments in this post to let us know, and we will have a moderator award you + Charm. It is not allowed to simply copy and paste; original content is preferred, with at least some organization by the user along with personal insights and opinions. After registration, we will rank based on the content of the posts: the last-place contestant will receive +1 charm, the second-to-last +2 charm, and so on, with the highest score getting +5 charm. Call for weekly topics and daily questions (prizes for participation) [Mechanical Section] Collection of essential knowledge [Seeking manufacturer sponsorship] (long-term campaign) [Rewards for recommending valuable content] Summary of daily questions and answers related to mechanical equipment for 2015
Cavitation: Too low inlet pressure, too high inlet temperature
Cavitation phenomenon: Cause – insufficient suction volume, or too high a suction height
【Daily Question】 Fill-in-the-blank: When a centrifugal pump is started, it runs idle, fails to draw in liquid, and the vacuum level at the inlet is low; in this case, the pump experiences a _____cavitation_____ phenomenon. The possible causes are ________the inlet valve being closed______ or __________leaks in the inlet pipe_____.
Air lock; the pump has not been filled, and the filling is incomplete
When a centrifugal pump is started, it runs idle, fails to draw in liquid, and shows a low vacuum level at the inlet; in such cases, the pump suffers from air locking. The reason for this may be that the pump has not been filled with liquid or that the shaft seal is not tight enough
Cavitation may be caused by insufficient exhaust or inadequate liquid filling at the inlet, as well as air in the inlet
When a centrifugal pump is started, it runs idle, fails to draw in liquid, and shows a low vacuum level at the inlet; in such cases, the pump experiences __pressure buildup__. The possible reasons for this are ________ the outlet valve not being open________ or __________ the outlet pipeline being blocked____.
Answer: Gas binding； No priming pump, or the shaft seal is not tight enough
Cavitation occurs in centrifugal pumps due to air inside the pump or air leaks in the suction pipeline.
Answer: Air entrapment, caused by insufficient priming of the pump or leaks in the inlet pipeline.