Pump Types...

In general, pumps may be classified according to their ; (1) principle of operation, (2) field of application, (3) operational duty, (4) type of construction and (5) method of drive. With respect to the principle of operation, pumps may be classified as kinetic - energy pumps or positive - displacement pumps. The principal types of pumps are shown below.

"Pump Types - Schema 1"... "Pump Types - Schema 2"... "Pump Types - Schema 3"...

Pump type	Purpose	Pump type	Purpose
	Screenings treatment stage to separate organic from inorganic material and to reduce the quantity of screenings		Preparation and dosing of conditioning agents such as calcium hydroxide in suspension, metal salt solutions and organic flocculants and precipitants
	Pumping raw effluent with simultaneous shredding of solids and fibrous materials		A heavy sludge pump delivering pressure filter output via pipes to the waste site or for incineration
	Gentle delivery of secondary sludges from the biological settling tank		Delivery of pasty high viscosity sludges from dewatering units direct to the waste site or for incineration
	Pumping primary sludge from the gravity thickener to the aerobic / anaerobic digester and / or to the dewatering unit		Emergency pump
	Recirculating of digested sludge, namely mixing of the anaerobic sludge digester's content		Mobile effluent pump
	Feeding thermal sludge conditioning installations using multi - stage pumps		Oil lagoon pump
	Stand - alone pump for feeding sludge into a disinfecting installation		Skimmer pump
	Filter press feeding and water extraction		Mobile universal pump
	Feeding various sludge dewatering installations such as centrifuges, rotary suction filters and screen filters		Waste site pump

Kinetic - Energy Pumps...

The principal components of kinetic - energy pumps are ; (1) the rotating element called impeller that imparts energy to the liquid being pumped, (2) the shaft on which the impeller is mounted, (3) the pump casing that includes the inlet and outlet passages for leading the liquid being pumped into and out of the pump, and the recuperating section which receives the liquid discharged from the impeller and directs it to the outlet passage and (4) the frame which supports the pump casing. Because rags and trash in wastewater would quickly clog the small passages in typical clearwater radial - flow pumps, the pumps used for untreated wastewaters are usually the single - end suction volute type, fitted with nonclog impellers.

Positive - Displacement Pumps...

Positive - displacement pumps are usually divided into two major categories ; reciprocating pumps and rotary pumps. Pneumatic ejectors and the Archimedean screw pump are also included under this category. The screw pump is based on the Archimedean screw principle in which a revolving shaft fitted with one, two, or three helical blades rotates in an inclined trough and pushes the wastewater up the trough. Screw pumps are commonly used in wastewater treatment plants to pump untreated wastewater and return waste activated sludge.

Info About Some Pumps...

Piston & Plunger Pumps : Designed for high pressure and low to medium volume. Used where high pressure is required for water, chemicals and heavy materials.


Gear Pumps : Designed for low to medium pressures for medium viscous materials. Used in hydraulic systems and supply systems for clean, non-abrasive materials.


Diaphragm Pumps : Designed for low pressure and high volume. Ideal general purpose pump. Will pump most materials even those that are abrasive, dirty and with solids.
Centrifugal Pumps : Designed for low pressure and high volume. Ideal for constant duty water and chemical supply and circulating systems.


Rotary Vane Pumps : Designed for low to medium pressures and volumes of low viscous materials. Ideal for light materials supply and circulating systems.


Roller Pumps : Designed for low to medium pressures of water containing additives. Ideal of agricultural spray systems for emulsions, fertilizers etc.
Flexible Impeller Pumps : Designed for low pressure, low volume systems with some solids. Ideal small general purpose pump for pumping sumps and dirty water and non-corrosive liquids.
Peristaltic Pumps : Designed for moving small amount of liquids or chemicals. Ideal metering pump for adding chemicals to a system.