iPedia Free Information Center

Information about Pump

This article is about a mechanical device. For other uses of the term, see Pump (disambiguation).
Enlarge picture
An electrically driven pump (electropump) for waterworks near the Hengsteysee, Germany.
|
A pump is a device used to move liquids or slurries. A pump moves liquids from lower pressure to higher pressure, and overcomes this difference in pressure by adding energy to the system (such as a water system). A gas pump is generally called a compressor, except in very low pressure-rise applications, such as in heating, ventilating, and air-conditioning, where the operative equipment consists of fans or blowers.

Pumps work by using mechanical forces to push the material, either by physically lifting, or by the force of compression.

The earliest type of pump was the Archimedes screw, first used by Sennacherib, King of Assyria, for the water systems at the Hanging Gardens of Babylon and Nineveh in the 7th century BC, and later described in more detail by Archimedes in the 3rd century BC.[1] In the 13th century AD, al-Jazari described and illustrated different types of pumps, including a reciprocating pump, double-action pump with suction pipes, water pump, and piston pump.[2][3]

Types

Enlarge picture
A two-lobe pump (multiple rotor, positive displacement type)
Pumps fall into two major groups: rotodynamic pumps and positive displacement pumps. Their names describe the method for moving a fluid. Rotodynamic pumps are based on bladed impellers which rotate within the fluid to impart a tangential acceleration to the fluid and a consequent increase in the energy of the fluid. The purpose of the pump is to convert this energy into pressure energy of the fluid to be used in the associated piping system.

Positive displacement pumps

Enlarge picture
A lobe pump
Enlarge picture
Hand-operated, reciprocating, positive displacement, water pump in Košice-Ťahanovce, Slovakia (walking beam pump).
Enlarge picture
Mechanism of a scroll pump


A positive displacement pump causes a liquid or gas to move by trapping a fixed amount of fluid or gas and then forcing (displacing) that trapped volume into the discharge pipe. Positive displacement pumps can be further classified as either rotary-type (for example the rotary vane) or lobe pumps similar to oil pumps used in car engines. Another common type is the Wendelkolben pump or the helical twisted Roots pump. The low pulsation rate and gentle performance of this Roots-type positive displacement pump is achieved due to a combination of its two 90° helical twisted rotors, and a triangular shaped sealing line configuration, both at the point of suction and at the point of discharge. This design produces a continuous and non-vorticuless flow with equal volume. High capacity industrial "air compressors" have been designed to employ this principle as well as most "superchargers" used on internal combustion engines.

Reciprocating-type pumps use a piston and cylinder arrangement with suction and discharge valves integrated into the pump. Pumps in this category range from having "simplex" one cylinder, to in some cases "quad" four cylinders or more. Most reciprocating-type pumps are "duplex" (two) or "triplex" (three) cylinder. Furthermore, they are either "single acting" independent suction and discharge strokes or "double acting" suction and discharge in both directions. The pumps can be powered by air, steam or through a belt drive from an engine or motor. This type of pump was used extensively in the early days of steam propulsion (19th century) as boiler feed water pumps. Though still used today, reciprocating pumps are typically used for pumping highly viscous fluids including concrete and heavy oils. Another modern application of positive displacement pumps are diaphragm pumps commonly called "Sand Piper Pumps" and are used extensively for pumping water out of an area, and they generally use compressed air as a source of energy.

Centrifugal Pumps

Centrifugal Pumps are rotodynamic pumps which convert Mechanical energy into Hydraulic energy by centripetal force on the liquid. Typically, a rotating impeller increases the velocity of the fluid. The casing, or volute, of the pump then acts to convert this increased velocity into an increase in pressure. So if the mechanical energy is converted into a pressure head by centripetal force, the pump is classified as centrifugal. Such pumps are found in virtually every industry, and in domestic service in developed countries for washing machines, dishwashers, swimming pools, and water supply.

A wide range of designs are available, with constant and variable speed drives. Horizontal shafts are the most common. Single-stage pumps are usual in the smaller ratings. Pumps with up to 11 stages are in service. A demanding duty is boiler feed, and today's designs are typically 3 - 4 stage, with speeds of up to 6000 revolutions per minute.

After motors, centrifugal pumps are arguably the most common machine, and they are a significant user of energy. Given design margins, it is not unusual for a pump to be found to be over-sized, having been selected poorly for its intended duty. Running a constant speed pump throttled causes energy waste. A condition monitoring test can detect this condition and help size a smaller impeller, either new, or by machining the initial one, to achieve great energy reduction.

Pumps also wear internally, at a rate varying with the liquid pumped, materials of construction and operating regime. Again, condition monitoring can be applied to detect and quantify the extent and rate of wear and also help decide when overhaul is justified on an energy-saving basis.

Kinetic Pumps

  1. Continuous energy addition
  2. Conversion of added energy to increase in kinetic energy (increase in velocity)
  3. Conversion increased velocity to increase in pressure
  4. Conversion of Kinetic head to Pressure Head.
  5. Meet all heads like Kinetic , Potential, and Pressure

Positive Displacement

  1. Periodic energy addition
  2. Added energy forces displacement of fluid in an enclosed volume
  3. Fluid displacement results in direct increase in pressure

Application

Enlarge picture
metering pump for gasoline and additives
Pumps are used throughout society for a variety of purposes. Early applications includes the use of the windmill or watermill to pump water. Today, the pump is used for irrigation, water supply, gasoline supply, air conditioning systems, refrigeration (usually called a compressor), chemical movement, sewage movement, flood control, marine services, etc.

Because of the wide variety of applications, pumps have a plethora of shapes and sizes: from very large to very small, from handling gas to handling liquid, from high pressure to low pressure, and from high volume to low volume.

Pumps as public water supplies

One sort of pump once common worldwide was a hand-powered water pump over a water well where people could work it to extract water, before most houses had individual water supplies.

From this came the expression "parish pump" for "the sort of matter chattered about by people when they meet when they go to get water", "matter of only local interest".

Today, hand operated village pumps are still used in resource poor settings. A pump improves the safety of a well by protecting the water source from contaminated buckets. Pumps like the Afridev pump (pictured) are designed to be cheap to build and install, and easy to maintain with simple parts that can be sold in the local market by for-profit wholesalers. This means that a community has the resources to support its own pump, even when any charities or government funding has moved on.

Power source

Enlarge picture
19th century Dutch diesel pump in Rijswijk, Netherlands


Pumps may be powered by an internal combustion engine, electric motor, manually (as with the hand pump used for pumping groundwater, called walking beam pump), or by wind power (common for irrigation). Solar power has been used to power an electric motor, for remote locations.[1]

See also

Enlarge picture
Domestic Central Heating Pump

References

1. ^ Stephanie Dalley and John Peter Oleson (January 2003). "Sennacherib, Archimedes, and the Water Screw: The Context of Invention in the Ancient World", Technology and Culture 44 (1).
2. ^ Al-Jazari, The Book of Knowledge of Ingenious Mechanical Devices : Kitáb fí ma'rifat al-hiyal al-handasiyya, translated by P. Hill (1973). Springer.
3. ^ Derek de Solla Price (1975). Review of Ibn al-Razzaz al-Jazari, The Book of Knowledge of Ingenious Mechanical Devices. Technology and Culture '''16 (1), p. 81.

Further reading

External links

A pump is a mechanical device used to move fluids and slurries.

Pump may also refer to:
  • Pump (shoe)
  • Pump (album), by Aerosmith
  • Pump can refer to two different Caribbean drums, one each used in the music of Barbados and St Maarten

..... Click the link for more information.
Liquid is one of the four principal states of matter. A liquid is a fluid that can freely form a distinct surface at the boundaries of its bulk material.

Characteristics

A liquid's shape is determined by, not confined to, the container it fills.
..... Click the link for more information.
slurry is, in general, a thick suspension of solids in a liquid and may be:
  • A mixture of water and cement to form concrete
  • A mixture of water, gelling agent, and oxidiers used as an explosive
  • A mixture of water and Bentonite used to make slurry walls

..... Click the link for more information.
Water is a common chemical substance that is essential to all known forms of life.[1] In typical usage, water refers only to its liquid form or state, but the substance also has a solid state, ice, and a gaseous state, water vapor.
..... Click the link for more information.
Gas is one of the four major states of matter, consisting of freely moving atoms or molecules without a definite shape. Compared to the solid and liquid states of matter a gas has lower density and a lower viscosity.
..... Click the link for more information.
<includeonly></includeonly>A gas compressor is a mechanical device that increases the pressure of a gas by reducing its volume. Compression of a gas naturally increases its temperature.
..... Click the link for more information.
HVAC may also stand for High-voltage alternating current
HVAC (pronounced either "H-V-A-C" or, occasionally, "aitch-vak") is an initialism/acronym that stands for "heating, ventilation, and air conditioning".
..... Click the link for more information.
Archimedes' screw, Archimedean screw, or screwpump, is a machine historically used for transferring water from a low-lying body of water into irrigation ditches.
..... Click the link for more information.
Sennacherib (in Akkadian Śïn-ahhe-eriba "(The moon god) Śïn has Replaced (Lost) Brothers for Me") was the son of Sargon II, whom he succeeded on the throne of Assyria (705 BC–681 BC).
..... Click the link for more information.
Ancient Mesopotamia

Euphrates Tigris
Cities / Empires
Sumer: Uruk ' Ur ' Eridu
Kish ' Lagash ' Nippur
Akkadian Empire: Akkad
Babylon ' Isin ' Susa
Assyria: Assur Nineveh
..... Click the link for more information.
Domestic water supply or system (DWS) is a comprehensive term for the potable water supply systems in residential, commercial, institutional, and industrial buildings.
..... Click the link for more information.
Hanging Gardens of Babylon (also known as Hanging Gardens of Semiramis) and the walls of Babylon (near present-day Al Hillah in Iraq) are considered one of the original Seven Wonders of the World. They were built by Nebuchadnezzar II around 600 BCE.
..... Click the link for more information.
Ancient Mesopotamia

Euphrates Tigris
Cities / Empires
Sumer: Uruk ' Ur ' Eridu
Kish ' Lagash ' Nippur
Akkadian Empire: Akkad
Babylon ' Isin ' Susa
Assyria: Assur Nineveh
..... Click the link for more information.
The 7th century BC started the first day of 700 BC and ended the last day of 601 BC.

Events



  • 700 BC to 600 BC — Baudhayana Sulbasutra, an orally transmitted Vedic Sanskrit text on altar construction, contains the earliest extant verbal statement of the

..... Click the link for more information.
Archimedes of Syracuse (Greek: Άρχιμήδης c. 287 BC – c. 212 BC) was an ancient Greek mathematician, physicist and engineer.
..... Click the link for more information.
The 3rd century BC started the first day of 300 BC and ended the last day of 201 BC. It is considered part of the Classical era, epoch, or historical period.

The first few decades of the century are characterized by a balance of power between the Greek Hellenistic kingdoms
..... Click the link for more information.
As a means of recording the passage of time, the 13th century was that century which lasted from 1201 to 1300. In the history of European culture, this period is considered part of the High Middle Ages, and after its conquests in Asia the Mongol Empire stretched from Korea to
..... Click the link for more information.
Ibn Ismail ibn al-Razzaz al-Jazari (1136-1206) (Arabic: أَبُو اَلْعِزِ بْنُ إسْماعِيلِ بْنُ
..... Click the link for more information.
A reciprocating engine, also often known as a piston engine, is a heat engine that uses one or more pistons to convert pressure into a rotating motion. This article describes the common features of all types.
..... Click the link for more information.
Suction is the creation of a partial vacuum, or region of low pressure. The pressure gradient between this region and the ambient pressure will propel matter toward the low pressure area.
..... Click the link for more information.
Water is a common chemical substance that is essential to all known forms of life.[1] In typical usage, water refers only to its liquid form or state, but the substance also has a solid state, ice, and a gaseous state, water vapor.
..... Click the link for more information.
piston is a rigid, lubricated sliding shaft that fits tightly inside the opening of a cylinder. Its purpose is to change the volume enclosed by the cylinder, to exert a force on a fluid inside the cylinder, to cover and uncover ports, or some combination of these.
..... Click the link for more information.
angular frequency ω (also referred to by the terms angular speed, radial frequency, and radian frequency) is a scalar measure of rotation rate. Angular frequency is the magnitude of the vector quantity angular velocity.
..... Click the link for more information.
In mechanics, a diaphragm is a sheet of a semi-flexible material anchored at its periphery and most often round in shape. It serves either as a barrier between two chambers, moving slightly up into one chamber or down into the other depending on differences in pressure, or as a
..... Click the link for more information.
centripetal force is the external force required to make a body follow a circular path at constant speed (speed being the magnitude of velocity). The force is directed inward, toward the center of the circle. Hence it is a force requirement, not a particular kind of force.
..... Click the link for more information.
kinetic energy of an object is the extra energy which it possesses due to its motion. It is defined as the work needed to accelerate a body of a given mass from rest to its current velocity.
..... Click the link for more information.
FLUID (Fast Light User Interface Designer) is a graphical editor that is used to produce FLTK source code. FLUID edits and saves its state in text .fl files, which can be edited in a text editor for finer control over display and behavior.
..... Click the link for more information.
Displacement may refer to:
  • Displacement (vector), in Newtonian mechanics, specifies the position of a point in reference to an origin or to a previous position

..... Click the link for more information.
windmill is a machine designed to convert the energy of the wind into more useful forms using rotating blades. The term also refers to the structure it is commonly built on. In much of Europe, windmills served to grind grain, later applications include pumping water.
..... Click the link for more information.
Milldam

A watermill is a structure that uses a water wheel or turbine to drive a mechanical process such as flour or lumber production, or metal shaping (rolling, grinding or wire drawing).
..... Click the link for more information.


This article is copied from an article on Wikipedia.org - the free encyclopedia created and edited by online user community. The text was not checked or edited by anyone on our staff. Although the vast majority of the wikipedia encyclopedia articles provide accurate and timely information please do not assume the accuracy of any particular article. This article is distributed under the terms of GNU Free Documentation License.
Herod_Archelaus


page counter