【Daily Question: Pump Equipment】Fill-in-the-blank question, 2019.2.14
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Rules for the fill-in-the-blank questions in bg2.png: 1. If both blanks are answered incorrectly, +2 wealth is awarded for active participation; if one blank is answered incorrectly and the other correctly, +5 wealth is given; if both blanks are answered correctly, +8 wealth is awarded. 2. If only one answer is provided, unless it is clear which question’s answer it is, a correct answer earns +5 wealth points, while an incorrect answer earns +2 wealth points; in all other cases, it is counted as active participation and grants +2 wealth points. 3. Rewards for answers are available once per person only. 4. Each reply allows scoring for only one person. 5. The answer and its explanation will be visible after responding. 6. The reward is valid for 48 hours; no reward will be given after that period. The student has won awards again; come by here every day. For pumps with a volute-shaped flow channel, the flow pattern of the liquid inside is such that, from the partition to the outlet, the flow velocity of the liquid within the volute increases circumferentially; as a result, the efficiency of these pumps is ( ) higher than that of pumps with a spiral-shaped flow channel. Answer: Gradually increase, less than
The cross-sectional area of the flow channel is constant everywhere; the fluid velocity increases continuously as it flows through the channel. The fluid exiting the chamber collides with the uniform fluid inside the impeller, resulting in significant losses and thus lower efficiency compared to spiral designs
In pumps with an outlet volute that has an annular flow channel, the flow pattern of the liquid is such that as it moves from the partition to the outlet, the velocity of the liquid within the volute increases circumferentially; therefore, the efficiency of these pumps is (higher than) that of pumps with an outlet volute that has a spiral-shaped flow channel.