Pumps, Classification of pumps and their working

3. PUMP
S
DYNAMIC
PUMPS
POSITIVE
DISPLACEMENT
PUMPS
RECIPROCATING
PUMPS
SPECIAL EFFECT
PUMPS
CENTRIFUGAL
PUMPS
SINGLE
ROTOR
DIAPHRAG
M
PISTON,
PLUNGER
TURBINE
PUMPS
JET
PUMPS
PERIPHE
RAL
MIXED
FLOW
AXIAL
FLOW
MULTIPLE
ROTOR
ROTARY PUMPS

4. 1. POSITIVE
DISPLACEMENT
PUMPS
• Positive displacement pump makes the
fluid move by trapping a fixed amount and
forcing the trapped volume into the
discharge pipe.
• It has an expanding cavity on the suction
side and a decreasing cavity on the
discharge side.
• Liquid flows into the pump as the cavity
on the suction side expands and the liquid
flows out of the discharge as the cavity
collapses.
• The volume is constant through each
cycle of operation.
• A positive displacement pump has a
constant flow machine.
• A positive displacement pump is used to
produce continuous flow.
•A safety value on the discharge side is
provided to avoid the busting of output
line.

5. 1.1 RECIPROCATING PUMPS
• Fluid is pumped by a plunger travelling back and forth in a
chamber.
• Valves for intake and discharge operate in conjugation with
the plunger to transfer the fluid.
• In this, the fluid is transferred by the motion of either a
piston or plunger moving in a cylinder or by the flexing of a
diaphragm.
• On the suction stroke, the volume of the pump cavity
increases, lowering the pressure inside the cavity.
• This causes the suction valve to open, allowing the fluid to
flow into the cavity. At the same time, the discharge valve is
closed, preventing backflow .
• On the discharge stroke, the volume of pump cavity
decreases, causing the pressure inside the cavity to increase.
• This increased pressure closes the suction valve and opens
the discharge valve, forcing the fluid out of pump.
• The compressed air is directed through an air valve into the
left chamber, and then into right chamber.
• The reciprocating motion of the two flexible diaphragms
creates an action that automatically provides and alternating
suction and discharge in each chamber.
• This force moves the liquid from the inlet to outlet of pump.
• Valves in inlet and outlet piping control the intake and
discharge flow through the diaphragm chamber.
• They are used in food industry. In sugar industries, piston
pumps are used to pump slurry.

7. 1.2 ROTARY PUMPS
• They are of 2 types : gear and screw. The
operate in the same way, except that the screw
pump contains a modified gear.
• In rotary gear pumps, lobes rotate inside the
casing with very little clearance. The bi- wing
design causes less shear due to minimum rotor
to rotor contact. They also handle solids and
delicate products.
• The fluid enters the spaces between the lobes
as they pass the inlet, and then its carried
around and forced out of outlet.
• They are used in several industries including
food, chemical, pharmaceutical, pulp/ paper,
and cosmetics.
• Bacteria free operation is vital in food and
pharmaceutical industries to ensure freshness,
flavor, color, and the self life.
• Its used in industries where sanitation is must,
including beverage, dairy, candy, canned food,
cosmetics, etc.
• In petroleum industry its used to transport
both crude and refined products.

9. 2. DYNAMIC PUMPS
• These are the most recognized
centrifugal and axial type pumps
and are operated by developing
high liquid velocity, which is
converted to pressure in a diffusing
flow passage.
• These pumps are low in efficiency
than positive displacement pumps.
• They operate at relatively higher
speeds, thus providing higher flow
rates in relation to the physical size
of pumps.
• They are low maintenance, than
positive displacement pumps.

10. 2.1 CENTRIFUGAL PUMPS
• They are use to transport of fluids by conversion
of rotational kinetic energy to hydrodynamic energy
of the fluid flow.
• The rotational energy comes from an engine or
electric motor.
• The fluid enters the pump , impeller along or near
to rotating axis and is accelerated by impeller,
flowing radially outward into diffuser from where it
exists.
• These pumps are designed to operate within a
range of temperature and pressure.
• They produce heat, which causes liquid expansion
and vaporization, leading to excessive pressure.
• The liquid flowing inside the inlet starts to
vaporize due to the vacuum conditions.
• The liquid- vapor feed travels through the pump
and the pressure increases upon reaching the
outlet, causing condensation.
• They are used in construction industry as a sump
pump to remove water from ditches, streams etc.
• Used in steel, paper, oil, appliance, wine industry .
• They can handle everything from clear liquids to
corrosive slurries.

11. `

12. PROBLEMS OF CENTRIFUGAL
PUMPS
Corrosion
inside the
pump is
caused by
fluid
properties
Leakage
tables place
along rotating
shaft.
Wear of the
impeller can
be worsened
by suspended
solids.
Overheating
occurs due to
low flow