【Daily Question: Pump Equipment】Short Answer Question 2019.2.21
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This post was last edited by 3983596_FPPZ on 2019-2-22 at 12:41. Rules for the bg2.png quiz: 1. If the answer is incorrect, +2 wealth will be given for active participation; if the answer is somewhat reasonable but not specific enough, +5 wealth will be given; if the answer is correct, +8 wealth will be given. 2. Rewards for answers are available once per person only. 3. Each reply allows scoring for only one person. 4. The answer and its explanation will be visible after responding. 5. The reward is valid for 48 hours; no reward will be given if the deadline is exceeded. Studying* and winning awards again; come by here every day. Briefly explain the advantages and disadvantages of a low inlet flow velocity in centrifugal pumps (large pipe diameter, large pump inlet diameter, large impeller inlet diameter) for both the pump and the pipelines Answer: Advantages: 1. Low flow rate, which helps to increase the NPSHA of the device; the pump is less prone to cavitation ； 2. Minimal erosion of pipelines, especially with media containing particles ； 3. Does not easily generate static electricity ； 4. Low pressure drop of the inlet filter ； 5. Within the same cross-section, the flow of the medium is uniform, resulting in low hydraulic losses ； Disadvantages: 1. For the same flow rate, a larger pipe diameter is required, resulting in higher pipeline costs ； 2. For some media prone to precipitation, too low a flow rate can easily lead to deposition and blockages ； 3. The impeller inlet is large, the mouth ring diameter is large, resulting in high leakage.
Advantages: 1. Low flow rate, which helps to increase the NPSHA of the device and reduces the risk of cavitation in the pump； 2. Minimal erosion of pipelines, especially with media containing particles ； 3. Does not easily generate static electricity ； 4. Low pressure drop of the inlet filter ； 5. Within the same cross-section, the flow of the medium is uniform, resulting in low hydraulic losses ； Disadvantages: 1. At the same flow rate, a larger pipe diameter is required, resulting in higher pipeline costs ； 2. For some media prone to precipitation, too low a flow rate can easily lead to deposition and blockages ； 3. The inlet flow velocity is low, the inlet cross-sectional area is large, the pump’s net positive suction head is low, so cavitation is less likely to occur ； 4. The impeller inlet is large, the mouth ring diameter is large, resulting in high leakage.
Advantages: 1. Low flow rate, which helps to increase the NPSHA of the device and reduces the risk of cavitation in the pump； 2. Minimal erosion of pipelines, especially with media containing particles ； 3. Does not easily generate static electricity ； 4. Low pressure drop of the inlet filter ； 5. Within the same cross-section, the flow of the medium is uniform, resulting in low hydraulic losses ； Disadvantages: 1. For the same flow rate, a larger pipe diameter is required, resulting in higher pipeline costs ； 2. For some media prone to precipitation, too low a flow rate can easily lead to deposition and blockages ； 3. The inlet flow velocity is low, the inlet cross-sectional area is large, the pump’s net positive suction head is low, so cavitation is less likely to occur ； 4. The impeller inlet is large, the mouth ring diameter is large, resulting in high leakage.
Cavitation does not occur easily, which helps to improve shaft efficiency. . . . Actually, I came in to check the answers: L
Advantage: Good cavitation margin； Disadvantage: The pump is large in size.
Reducing the flow rate in the pump inlet pipeline lowers pressure drop losses and prevents cavitation in the pump; a lower flow rate of the medium also reduces the risk of erosion corrosion (this is not comprehensive – I hope the original poster can provide more guidance)
Cavitation is low, impeller pressure is high, and power increases
Advantages: improved cavitation resistance, lower losses； Disadvantage: Increased cost of pipeline installation.
The inlet flow velocity is low, resulting in insufficient flow rate, which can easily damage the pump. The pipeline transport volume is low, and the pressure head does not meet the required levels
Advantages: 1. Low flow rate, resulting in minimal erosion of the pipelines, especially with media containing particles. 2. The low flow rate helps to increase the net positive suction head of the device, reducing the likelihood of cavitation. 3. The flow rate is low, making it difficult to generate static electricity and thus reducing the risk of static discharge fires. 4. The flow rate is low, resulting in a reduced pressure drop across the inlet filter. 5. Low flow velocity, uniform flow, and low hydraulic loss. Disadvantages: 1. Low flow rate; under the same operating conditions, a larger pipe diameter is required, resulting in increased costs. 2. The flow rate is low; in media containing solids, deposition and blockages are likely to occur. 3. The inlet of the impeller is large, as is the diameter of the collar, resulting in higher leakage rates.