Centrifugal pump design and analysis

CENTRIFUGAL PUMP DESIGN AND ANALYSIS

Centrifugal Pumps are the most popular and commonly used type of pump for the transfer of fluids. In simple words, it is a pump that uses a rotating impeller to move water or other fluids by using centrifugal force. These are the undisputed pump choice especially for delivering liquid from one location to another in numerous industries including agriculture, municipal (water and wastewater plants), industrial, power generation plants, petroleum, mining, chemical, pharmaceutical, and many others.

Centrifugal pumps are generally designed and suitable for liquids with a relatively low viscosity that pours like water or light oil. More viscous liquids such as 10 or 20 wt. oils at 68-70 deg F will require additional horsepower for centrifugal pumps to work. For viscous liquids of more than 30 wt. oils, positive displacement pumps are preferred over centrifugal pumps to help lower energy costs.

Working of a Centrifugal Pump :-

Let us understand in detail, how a Centrifugal pump works. Centrifugal pumps are used to induce flow or raise a liquid from a low level to a high level. These pumps work on a very simple mechanism. A centrifugal pump converts rotational energy, often from a motor, to energy in a moving fluid.

The two main parts that are responsible for the conversion of energy are the impeller and the casing. The impeller is the rotating part of the pump and the casing is the airtight passage which surrounds the impeller. In a centrifugal pump, fluid enters into the casing, falls on the impeller blades at the eye of the impeller, and is whirled tangentially and radially outward until it leaves the impeller into the diffuser part of the casing. While passing through the impeller, the fluid is gaining both velocity and pressure.

Applications of Centrifugal Pumps:

The fact that centrifugal pumps are the most popular choice for fluid movement makes them a strong contender for many applications and as mentioned previously, they are used across numerous industries. Supplying water, boosting pressure, pumping water for domestic requirements, assisting fire protection systems, hot water circulation, sewage drainage and regulating boiler water are among the most common applications. Outlined below are some of the major sectors that make use of these pumps:

1. Oil & Energy- pumping crude oil, slurry, mud; used by refineries, power generation plants
2. Industrial & Fire Protection Industry - Heating and ventilation, boiler feed applications, air conditioning, pressure boosting, fire protection sprinkler systems.
3. Waste Management, Agriculture & Manufacturing -Wastewater processing plants, municipal industry, drainage, gas processing, irrigation, and flood protection
4. Pharmaceutical, Chemical & Food Industries -paints, hydrocarbons, petrochemical, cellulose, sugar refining, food and beverage production
5. Various industries (Manufacturing, Industrial, Chemicals, Pharmaceutical, Food Production, Aerospace etc.) -for the purposes of cryogenics and refrigerants.

Types of Centrifugal Pumps

Centrifugal Pumps are classified into many types based on many categories, they are

Based on number of impellers in the pump,

1. Single stage pump
2. Two-stage pump
3. Multi-stage pump

Based on orientation of case-split,

1. Axial split Pump
2. Radial split Pump

Based on type of impeller design,

1. Single suction Pump
2. Double suction Pump

Based on the basis compliance with industry standards,

1. ANSI pump – (American National Standards Institute)
2. API pump – (American Petroleum Institute)
3. DIN pump – DIN 24256 specifications
4. ISO pump – ISO 2858, 5199 specifications
5. Nuclear pump – ASME (American Society of Mechanical Engineers) specifications

Based on type of volute

1. Single volute Pump
2. Double volute Pump

Based on where the bearing support is,

1. Overhung
2. Between-bearing

Based on on shaft orientation

1. Horizontal Pump
2. Vertical Pump

Procedure :-

1. designing the 3D model of an centrifugal pump with number of blades is equal to 6
2. set a 1000 rpm rotating speed of the region and also create a lids at inlet and outlet ends
3. setup a new flow simulation project and insert their boundary conditions are as follows Environmental pressure 1 bar at velocity 20 m/s

4. add surface goal of mass flow rate and also total pressure at inlet and total pressure at outlet
5. calculate the different outlet velocity and this simulation is done by this values 10 m/s , 15 m/s , 20 m/s 25 m/s in input variables to study its nature

Case 1 :-

Outlet Velocity Flow at 10 m/s (Design Point 1)

Velocity flow

Pressure

Case 2 :-

Outlet Velocity Flow at 15 m/s (Design Point 2)

Velocity flow

Pressure

Case 3 :-

Outlet Velocity Flow at 20 m/s (Design Point 3)

Velocity flow

Pressure

Case 4 :-

Outlet Velocity Flow at 25 m/s (Design Point 4)

Velocity flow

Pressure

Output Values:

Average Total Pressure at Inlet & Outlet and Mass Flow Rate at Outlet for 4 Design points for different Outlet Velocities has been calculated and given below.

Results :-

Average total pressure at inlet

Average total pressure at outlet

Mass flow rate at outlet

Refrence :-

https://www.powerzone.com/resources/glossary/centrifugal-pump

https://en.wikipedia.org/wiki/Centrifugal_pump

https://skill-lync.com/projects/centrifugal-pump-design-and-analysis-121