Shop at Amazon.ca

Friday, December 14, 2012

Difference between Centrifugal pumps and Positive Displacement pumps


Centrifugal Pump

Centrifugal pumps use a rotary vane impeller to impart kinetic energy by increasing the velocity of the liquid. This high velocity of the liquid will then produce a velocity head and at the same time producing a high flow rate.

Characteristics of Centrifugal Pump:
- higher power costs
- not self-priming
- gives less pressure to the fluids being pumped
- delivers a variable volume of fluid depending on the fluid's discharge pressure
- well suited for high flow conditions
- flow rate of liquid pumped varies depending on the system pressure or pressure head
- flow rate is inversely proportional to the viscosity of the liquid (flow is decreased if the viscosity is increased)
- centrifugal pumps has practical applications in pumping liquids with low viscosity
- run at higher speeds than positive displacement pumps (PD pumps)
- lower tolerance for entrained gases

Types of Centrifugal pumps:
1. Axial Flow - single stage, multistage
2. Radial Flow (Mixed Flow) - single suction, double suction
3. Peripheral Flow - single stage, multi-stage

Uses and Applications of Centrifugal pumps:
- general water supply for buildings
- overhead and pneumatic tank systems
- domestic water supply systems
- dairy farmers
- hot-water circulating service
- shallow wells and in deep wells
- booster fire pumps for fire protection systems
- construction companies
- cooling of engines, automotive factories
- sump, sewage drainage
- can handle abrasive, corrosive, dirty fluids
- hygienic purposes such as food, pharmaceuticals    
- irrigation and agriculture purposes
- chemical, petrochemical, fertilizer plants
- ship's bilge pumping
- cryogenics industry in extreme cold applications
- electric and power generation industries
- beverage, softdrink, soda, pop, distillery corporations
- textile, fabric industries
- pulp, paper industry
- and more...

-------------

 
Positive Displacement Pump

Positive displacement pumps apply a force (by using a piston, for example) to move a fixed volume of fluid inside the casing of the pump.

Characteristics of Positive Displacement Pump:
- lower power costs
- self-priming
- gives more pressure to the liquid being pumped
- delivers a constant volume of fluid even with varying discharge pressure
- used for low flow applications
- liquid pumped has a relatively constant flow regardless of the system pressure or pressure head
- flow rate is directly proportional to the viscosity of the liquid (flow is increased when viscosity is increased)
- positive displacement pumps are generally used for pumping liquids with high viscosity which in turn provides a higher volumetric efficiency
- creates a vacuum on the suction side of the pump thereby creating a suction lift
- higher tolerance for entrained gases

Types of Positive Displacement Pumps:
1. Reciprocating - piston/plunger, diaphragm
2. Rotary - single rotor, multiple rotor

Uses and applications of Positive Displacement Pumps:
- metering applications
- high viscosity application
- food, chocolate, beverage factories
- hazardous chemicals, slurries and pastes
- pharmaceutical products
- paint, resins, adhesives, glue industries
- fuel booster pumping systems
- lubricating oil systems
- pulp, paper, mill industry
- manufacturing applications
- diesel fuel handling and distribution 
- and more...

5 comments:

  1. The displacement of the pumps getting knowledge through reciprocatory and rotary is very nice to know. Thanks for sharing this useful post.
    industrial water pumping in coimbatore | electric pumps in coimbatore

    ReplyDelete
  2. I visited your blog for the first time and just been your fan and get many informative information about the pumps.
    Vacuum Pump repairs

    ReplyDelete
  3. Thanks for sharing relevant information about pumps, keep posting like this kind of content. Other than If you are looking for Centrifugal Pump Manufacturers, Vikas Pumps is one of the top leading industry. They are best in supplying all types of Water Treatment Plant such as:
    Monoblock Pump Manufacturers
    Chemical Pump Manufacturers
    Slat Conveyor Manufacturers
    Sludge Pump Manufacturers
    Sewage Pump Manufacturers

    ReplyDelete