Video 6 C1: The fluid effects that kill pumps

Question 1

what are three hydraulic effects that ruin a pump?

Answer 1

1. priming
2. cavitation
3. vortexing

Question 2

what does priming mean?

Answer 2

most pumps are primed so that it can move fluids more easily, by filling it with liquid to remove air from the pump and suction line

Question 3

what are some examples of self-priming pump?

Answer 3

1. submersible pumps; where it is always underwater, where air can’t find it’s way inside
2. positive displacement pumps; where the pump can create a vacuum and draw air through

Question 4

important for the pump to remain primed because….

Answer 4

it can lose its prime and stop working all together, and leads to damage (such as cavitation)

Question 5

how do vortices occur?

Answer 5

when the water accelerates in a circular pattern around an outlet

Question 6

why are vortices bad for pumps?

Answer 6

because the water is being flung to the outer rims, allowing for air to dip below the surface. if enters the suction line, it’ll take up space and create a bubble in the impeller- which reduces the pump’s efficiency, performance, and prime

Question 7

what is the easiest solution to vortexing?

Answer 7

submergence- getting the intake pipe as far as possible below the water surface (making it deeper)

Question 8

what are some ways that you can reduce the probability of vortexing?

Answer 8

1. reduce velocity of the flow
2. maintain clearance between walls/suction line
3. build a model to test