What is the working principle of the centrifugal pump?

CENTRIFUGAL PUMP WORKING PRINCIPLE

A Pump is generally used to induce flow or raise the pressure of a liquid. Centrifugal pumps are a category of Dynamic pumps. The working principle of centrifugal pumps involves imparting energy to the liquid by means of a centrifugal force developed by the rotation of an impeller that has several blades or vanes. The basic centrifugal pump theory of working comprises of the following working stages.

- Liquid enters the pump casing at the impeller eye.

- Velocity energy is imparted to the liquid by means of the centrifugal force produced by rotation of the impeller and the liquid is radially pushed out towards the impeller periphery.

- The velocity energy of liquid is converted to pressure energy by directing it to an expanding volute design casing in a volute type centrifugal pump or diffusers in a turbine pump.

Pumps are primarily classified as dynamic pumps and positive displacement pumps. As explained in theory above, dynamic pumps operate by developing a high liquid velocity. Positive displacement pumps operate by forcing a fixed volume of liquid. The dynamic action in the centrifugal pump working principle makes it comparatively lesser efficient than positive displacement pumps. However they operate at relatively higher speeds thus permitting a high liquid flow rate in relation to the physical size of the pump. They also usually require lesser installation and maintenance cost. Because of these advantages centrifugal pumps are the most commonly used pumps in industries.

What is the firing order of an engine?

The firing order is the sequence of power delivery of each cylinder in a multi-cylinder reciprocating engine.

This is achieved by sparking of the spark plugs in a gasoline engine in the correct order, or by the sequence of fuel injection in a Diesel engine.

When designing an engine, choosing an appropriate firing order is critical to minimizing vibration and achieving smooth running, for long engine fatigue life and user comfort, and heavily influences crankshaft design.

In case of 4 cylinder engine: the four crankpins are in one plane, 180o opposed. Since two pistons each are at the extreme position, the inline design permits following firing orders: 1-3-2-4 or 1-3-4-2

1-3-2-4

1-3-4-2

In case of 6 cylinder engine: the crankpins are in one plane, 120o apart. The inline design permits following firing orders: 1-5-3-6-2-4 or 1-4-2-6-3-5

1-5-3-6-2-4 or 1-4-2-6-3-5

What is ultimate tensile strength?

Ultimate tensile strength or simply, tensile strength, is the measure of the maximum stress that an object/material/structure can withstand without being elongated, stretched or pulled.

Tensile properties of a material indicate how it will react to forces applied on it in tension. As you can imagine, some materials break when a great deal of force is applied to them, while others get elongated or physically deformed in some other way. Materials that break very sharply are said to undergo a ‘brittle failure’.

On the other hand, there are some materials that can handle/withstand a great deal of stress while being pulled or stretched before breaking. The term ‘ultimate tensile strength’ (or UTS) is used to refer to the maximum stress that a material can handle before becoming elongated, stretched or pulled.

Often shortened to just tensile strength (TS) or ultimate strength, ultimate tensile strength quantifies the force required to pull a material to the point where it breaks.