Axial Pump Senatorlibya
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Transcript of Axial Pump Senatorlibya
ROTODYNAMIC PUMPS
Rotodynamic Pumps
Mixed flow
Axial flow
Centrifugal
Rotodynamic
Turbine
PUMP
Positive displacement
Diaphragm
Piston
Plunger
Reciprocating Rotary
Gear
Lobe
Sliding Vane
Screw
:Axial and Mixed flow
Axial and Mixed Flow Pumps are the normal choice for high-volume, low-pressure pumping duties and
particularly for large-scale primary water supplies, flood control, irrigation and drainage. Such types are available in
a wide range of sizes and capacities.
It is a general characteristic of such pumps that the power input curve is much flatter than that of a centrifugal
pump, thus input power demand does not vary very much with the working point. Hydraulic performance, however,
differs appreciably.
Rotodynamic Pumps
:Axial and Mixed flow
Axial flow pumps generate head pressure through an axial motion developed by a combination of propeller and
internal vane design. The combination induces fluids to travel strictly along the axial of the pump drive shaft.
The mixed flow pump employs a chamber /impeller /vane design to impart both an axial and radial motion to fluids
traveling downstream.
Rotodynamic Pumps
This powerful motion is created by lifting the fluids with an impeller, while simultaneously forcing fluids out against the
bowl like impeller chamber.
:Axial and Mixed flow
The outward movement known as an upper diffuser section. By combining axial and centrifugal motion, the
mixed flow pump generates greater head pressure to downstream fluids than is possible with a single motion
axial pump.
These differences are noted in the generated comparative H-Q curve.
Rotodynamic Pumps
:Axial and Mixed flow
Rotodynamic Pumps
Q
η ,H
P,
Hd
Q
η ,H
P,
Hd
Q
η ,H
P,
Hd
Q
η ,H
P,
Hd
Q
η ,H
P,
Hd
Q
η ,H
P,
Hd
:Axial and Mixed flow
Rotodynamic Pumps
In the case of a mixed flow pump, the H-Q curve tends to be steep,
with the point of maximum efficiency displaced towards maximum
capacity.
:Axial and Mixed flow
Rotodynamic Pumps
The H-Q curve of an axial flow pump has substantial falling characteristics although the actual head obtainable
is much lower.
Efficiency is higher over a greater (percentage) range of head than for
a centrifugal pump.
:Axial and Mixed flow
Rotodynamic Pumps
:General form
Driver Head shaft
Seal
Pump shaft
Impeller
Discharge elbow
Column assembly
Bowls
Suction bell
Axial and mixed flow pumps are commonly mounted vertically,
directly over a sump. This is most often the case when the source of
water is a river or reservoir.
Fluids enter through a flared suction bell that has been reinforced by
heavy vanes.
:Axial and Mixed flow
Rotodynamic Pumps
:General form
Driver Head shaft
Seal
Pump shaft
Impeller
Discharge elbow
Column assembly
Bowls
Suction bell
The vanes, in addition to lending support to the suction bell, act to
direct the liquid flow parallel to the drive shaft as it travels upstream.
Once past the suction bell, fluids encounter either an axial propeller or
a mixed flow impeller.
:Axial and Mixed flow
Rotodynamic Pumps
:General form
Driver Head shaft
Seal
Pump shaft
Impeller
Discharge elbow
Column assembly
Bowls
Suction bell
While differing in design, both are always dynamically balanced, one-
piece castings, mounted on a stainless steel pump shaft.
:Axial and Mixed flow
Rotodynamic Pumps
Driver:
Driver Head shaft
Seal
Pump shaft
Impeller
Discharge elbow
Column assembly
Bowls
Suction bell
The drive shaft may be encased in a tube or open, with supports properly
spaced for intermediate shaft bearings. Positive drive is provided
by a heavy-duty drive key and thrust collar.
A variety of drivers may be used, however, electric motors and right
angle gears are most common.
:Axial and Mixed flow
Rotodynamic Pumps
Driver:
Driver Head shaft
Seal
Pump shaft
Impeller
Discharge elbow
Column assembly
Bowls
Suction bell
These types of drivers can be grouped into two categories:
1. Hollow shaft drivers - the pump shaft extends through a tube in the
center of the rotor and is connected to the driver by a clutch assembly at
the top of the driver.
:Axial and Mixed flow
Rotodynamic Pumps
Driver:
Driver Head shaft
Seal
Pump shaft
Impeller
Discharge elbow
Column assembly
Bowls
Suction bell
These types of drivers can be grouped into two categories:
2. Solid shaft drivers - the rotor shaft is solid and projects below the
driver-mounting base. This type driver requires an adjustable
coupling between the pump and driver.
:Axial and Mixed flow
Rotodynamic Pumps
Column assembly:
Driver Head shaft
Seal
Pump shaft
Impeller
Discharge elbow
Column assembly
Bowls
Suction bell
The column assembly is of two basic types, either of which may be used
on close coupled units:
:Axial and Mixed flow
Rotodynamic Pumps
Column assembly:
The column assembly is of two basic types, either of which may be used
on close coupled units:
1. Open line shaft construction utilizes the liquid being pumped to
lubricate the line shaft bearings.
:Axial and Mixed flow
Rotodynamic Pumps
Column assembly:
The column assembly is of two basic types, either of which may be used
on close coupled units:
2. Enclosed line shaft construction has an enclosing pipe around the
line shaft and utilizes oil, grease or injected liquid to lubricate the line
shaft bearings.
:Axial and Mixed flow
Rotodynamic Pumps
Column assembly:
The column assembly will consist of column pipe, which connects the bowl assembly to the discharge
head and carries the pumped liquid to the discharge head, the shaft,
which connects the bowl assembly to the discharge head, the head
shaft, which connects the line shaft to the driver.
:Axial and Mixed flow
Rotodynamic Pumps
Column assembly:
Column pipe may be either threaded or flanged and may contain bearings
if required for the particular unit.
Note: Some units will not require a column assembly, having the bowl assembly connected directly to the
discharge head.
:Note
:Axial and Mixed flow
Rotodynamic Pumps
Discharge head assembly:
The column assembly is of two basic types, either of which may be used
on close coupled units:
:Axial and Mixed flow
Rotodynamic Pumps
The discharge head supports the driver and bowl assembly as well as
supplying a discharge connection (the underground discharge
connection will be located on one of the column pipe sections below the
motor stand).
Discharge head assembly:
:Axial and Mixed flow
Rotodynamic Pumps
A shaft sealing arrangement is located in the discharge head to seal
the shaft where it leaves the liquid chamber. The shaft seal will usually
be either a packing box or mechanical seal assembly.
Discharge head assembly:
:Axial and Mixed flow
Rotodynamic Pumps
Bowl assemblies:
The bowl assembly consists of impellers rigidly mounted on the
bowl shaft, which rotate and impart energy to the fluid.
The bowls (or diffusers) contain the fluid at increased pressure and direct
it vertically to the next stage and eventually to the column pipe.
:Axial and Mixed flow
Rotodynamic Pumps
Bowl assemblies:
The suction bell or case directs the fluid into the first stage impeller.
Bearings are located in the suction bell, discharge case, and between
each impeller.
Impeller
:Axial and Mixed flow
Rotodynamic Pumps
Bowl assemblies:
The rotating element is mounted in an individual housing, which is
usually replaceable and situated just above the section bell, close to the
pump inlet.
The housing may be bronze, stainless steel or any other material
similar to the impeller.? Why
Impeller
:Axial and Mixed flow
Rotodynamic Pumps
Bowl assemblies:
The same resistance to shock.
The same thermal extension.? WhyTo keep a clearance between
impeller and casing as designed (performance of the
pump).
Impeller
:Axial and Mixed flow
Rotodynamic Pumps
Bowl assemblies:
After emerging from the housing, fluids travel past an upper diffuser
chamber and out through the guide case.
The guide case, consisting of a column pipe and discharge elbow is
of welded steel plate or cast iron.
:Axial and Mixed flow
Rotodynamic Pumps
Bowl assemblies:
Sections are flanged or bolted together.
A registered fit is used to maintain proper alignment on all mated parts.
:Axial and Mixed flow
Rotodynamic Pumps
Pullout options, which make for easier maintenance and inspection,
are a common feature of these pumps, the best designs permit
removal of the entire bowl assembly (including all rotating parts, diffuser,
impeller housing and suction bell) through the outer shell, without
disturbing either the discharge or floor plate connections.
Pullout options:
Channel impeller pumps:
Rotodynamic Pumps
A channel impeller pump employs an impeller with turbine-type blades mounted on the periphery running in
an annular channel (or channels) surrounding the periphery of the wheel.
In practice, only two main subtypes emerge, known generally as the peripheral pump and side channel pump
respectively.
Rotodynamic Pumps
The main difference is in the form and positioning of the channels:
Channel impeller pumps:
The peripheral pump has a double-sided channel in which the liquid circulates, this channel being located partly in
the cylindrical part of the casing and partly in the side plates.
The side-channel pump has two channels cut in the side plates only, adjacent to each side of the impeller blades.
Rotodynamic Pumps
Characteristics are quite different, eg the side-channel pump is self-priming and can develop a much higher
head, although its efficiency is lower. Hence, the two are distinct types.
Channel impeller pumps:
The peripheral pump is also known as a regenerative pump.
Rotodynamic Pumps
H-QEfficiency
BHP
HEAD,BHP & Efficiency
100%
Peripheral
Capacity
Channel impeller pumps:
Rotodynamic Pumps
H-Q
Efficiency
BHP HEAD,BHP & Efficiency
100%
Side-channel
Capacity
Channel impeller pumps:
Rotodynamic Pumps
H-Q
Efficiency
BHP HEAD,BHP & Efficiency
100%
Side-channel
Capacity
H-QEfficiency
BHP
HEAD,BHP & Efficiency
100%
Peripheral
Capacity
Channel impeller pumps:
Rotodynamic Pumps
Centrifugal
Regenerative
Axial flow
Axial flow
Capacity
HEAD
Regenerative pumps have a substantially straight and
sleep H-Q curve.
Pressure developed tends to rise sharply with decreasing
capacity making this type unsuitable for discharge
regulation by throttling. Power output falls with increasing
capacity.
Channel impeller pumps:
Rotodynamic Pumps
Mixed flow
Axial flow
Centrifugal
Rotodynamic
Turbine
PUMP
Positive displacement
Diaphragm
Piston
Plunger
Reciprocating Rotary
Gear
Lobe
Sliding Vane
Screw
Turbine pumps (Regenerative:(
Rotodynamic Pumps
Turbine pumps obtain their name from the many vanes
machined into the periphery of the rotating impeller. Heads
over 900 feet are readily developed in a two-stage
pump.
Turbine pumps (Regenerative:(
Rotodynamic Pumps
The impeller, which has very tight axial clearance and uses pump channel rings, displays minimal recirculation losses. The channel rings provide a circular channel around the
blades of the impeller from the inlet to the outlet.
Turbine pumps (Regenerative:(
Rotodynamic Pumps
Liquid entering the channel from the inlet is picked up
immediately by the vanes on both sides of the impeller and pumped through the channel
by the shearing action. The process is repeated over and
over with each pass imparting more energy until the liquid is
discharged .