outcome 5

Question 1

Three types of pumps

Answer 1

1.Rotodynamic pumps
2.Reciprocating pumps
3.Rotary positive displacement pumps

Question 2

Rotodynamic pumps i.e. centrifugal and axial flow pumps can be operated at high speeds often directly coupled to electric motors ( T or F )

Answer 2

T

Question 3

short point about Rotodynamic pumps

Answer 3

1) can handle from small volumes to very large volumes.
2) can handle corrosive and viscous
3) overall efficiency is high in the case of these pumps
Rotodynamic pumps can be of radial flow, mixed flow and axial flow types according to the flow direction

Question 4

centrifugal pumps generally handle lower volumes at higher pressures

Answer 4

Radial flow

Question 5

handle comparatively larger volumes at medium range of pressures.

Answer 5

Mixed flow pumps

Question 6

can handle very large volumes, but the pressure against which these pumps operate is limited.

Answer 6

Axial flow pumps

Question 7

Working principle of CENTRIFUGAL PUMPS and advantage and disadvantage

Answer 7

Liquid enters the impeller axially due to suction. The impeller blades increase the fluid’s pressure and velocity. The volute casing, with its spiral shape, slows the fluid, converting some kinetic energy into pressure for efficient flow.

Simple design and easy to maintain.
Can handle large volumes of fluid.

Requires priming before starting
Efficiency drops at low flow rates

Question 8

losses between the fixed and rotating parts in the bearings and gland and packing.

Answer 8

Mechanical friction

Question 9

loss between the impeller surfaces and the fluid

Answer 9

Disc friction

Question 10

recirculation losses. The recirculation is along the clearance between the impeller and the casing due to the pressure difference between the hub and tip of the impeller

Answer 10

Leakage and recirculation

Question 11

When two (or more) pumps are arranged in serial their resulting pump performance curve is obtained by adding their heads at the same flow rate as indicated in the figure below.

Answer 11

Pumps in Serial - Head Added

Question 12

When two or more pumps are arranged in parallel their resulting performance curve is obtained by adding the pumps flow rates at the same head as indicated in the figure below.

Answer 12

Pumps in Parallel - Flow Rate Added

Question 13

In the case of pumps, the pressure is lowest at the inlet and cavitation damage occurs at the inlet. ( Tor F)

Answer 13

T

Question 14

For cavitation to occur the pressure at the location should be near the vapour pressure at the location T or F

Answer 14

T

Question 15

Reciprocating Pumps work principle and draw and advantage and disadvantage

Answer 15

Outward Stroke: The crank moves out, pulling fluid into the cylinder through the inlet valve. The delivery valve stays shut.

Return Stroke: The crank moves back, pushing fluid out through the delivery valve while the inlet valve closes.

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Simple and easy to use.
Can handle different types of fluids.

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Works slowly.
Needs regular care.
Not for large amounts of fluid.

Question 16

draw and how the gear pump work

Answer 16

Gear pumps are used for oil pumping.

Two gears inside a case turn to move oil.
Oil is carried from low pressure to high pressure.
The middle teeth seal the sides.
Pressure depends on oil thickness and gear fit.
One gear is powered by a motor.

Question 17

draw and how the lobe pump work

Answer 17

They have spinning lobes not like gears.
Oil moves between the lobes to the pressure side.
The lobes touch to stop leaks.
These pumps can carry more oil than gear pumps.

Question 18

draw and write the vane pump

Answer 18

This pump is used for oil and gas.

It has a rotor with sliding vanes.
Springs keep the vanes pressed on the casing.
Oil is trapped and moved to the pressure side.
Pressure is controlled by leakage.