What is pressure and velocity compounding for impulse turbine?

Compounding of impulse turbine Compounding is achieved by using more than one set of nozzles, blades, rotors, in a series, keyed to a common shaft; so that either the steam pressure or the jet velocity is absorbed by the turbine in stages.

How does the pressure and velocity vary in an impulse reaction turbine?

In a reaction turbine both the nozzles and blades act as expanding nozzles. Therefore, the static pressure decreases in both the fixed and the moving blades. The fixed blades act as nozzles and direct the flow to the moving blades at a velocity slightly higher than the velocity of the moving blades.

What is pressure compounding in impulse turbine?

Pressure compounding is the method in which pressure in a steam turbine is made to drop in a number of stages rather than in a single nozzle. This method of compounding is used in Rateau and Zoelly turbines.

What is difference between pressure and velocity compounding?

Difference between velocity compounding and pressure compounding are: Pressure of the steam remains constant in every fixed blade and moving blades except in the first nozzle in velocity compounding whereas in pressure compounding turbine pressure of steam increase in every nozzle.

What is meant by velocity compounding?

In velocity-compound staging a set of stationary nozzles is followed by two sets of moving blades with a stationary row of impulse blades between them to redirect the flow. Ideally this allows twice as much power to be extracted than from a single impulse stage for…

What is the main purpose of velocity pressure compounding the steam turbine?

Compounding of steam turbine is used to reduce the rotor speed. It is the process by which rotor speed come to its desired value. A multiple system of rotors are connected in series keyed to a common shaft and the steam pressure or velocity is absorbed in stages as it flows over the blades.

How does pressure and velocity change as the flow proceeds through the runner of the impulse turbine?

Working Principle of Impulse Turbine Therefore, only pressure changes occur in the nozzles. The application of the curved blades is to change the velocity of the flow. This strike causes a change in momentum and based on the law of conversation of energy, a force is applied to the turbine blades.

What is velocity compounding?

What is velocity compounding in turbine?

Velocity Compounding. Impulse Turbine – velocity compounding. A velocity-compounded impulse stage consists of a row of fixed nozzles followed by two or more rows of moving blades and fixed blades (without expansion). This divides the velocity drop across the stage into several smaller drops.

What is meant by velocity compounding in turbine?

What are the advantages of velocity compounding?

Advantages and disadvantages of velocity compounding

• Fewer number of stages and length of turbine is short.
• Due to fewer stages, the space required and initial cost is less.
• Low-pressure operation, so the leakage of steam is less.

What do you mean by compounding of impulse steam turbine Why is it necessary?

Compounding of steam turbines is the method in which energy from the steam is extracted in a number of stages rather than a single stage in a turbine. In all turbines the rotating blade velocity is proportional to the steam velocity passing over the blade.

Why is compounding done in turbines?

The compounding of steam turbine is done to reduce the speed of the rotor by arranging the number of stages of the turbine on a single rotor. As a result, the energy of the steam is taken partially by each stage of the turbine, resulting in a reduction in turbine speed.

What are the advantage of velocity compounding?

Advantages and disadvantages of velocity compounding Fewer number of stages and length of turbine is short. Due to fewer stages, the space required and initial cost is less. Low-pressure operation, so the leakage of steam is less.

Which of the following is pressure compounded turbine?

Q.	Which of the following is a pressure compounded turbine?
B.	Curtis turbine
C.	Rateau turbine
D.	All of the above
Answer» c. Rateau turbine

What are the advantages of velocity compounded impulse turbine?

Advantages

• Fewer number of stages and length of turbine is short.
• Due to fewer stages, the space required and initial cost is less.
• Low-pressure operation, so the leakage of steam is less.
• Since it works at low-pressure turbine, blades need not be very strong, stress on housing also reduced.

What are the advantages and disadvantages of velocity compounded impulse turbine?

Advantages and disadvantages of velocity compounding Due to fewer stages, the space required and initial cost is less. Low-pressure operation, so the leakage of steam is less. Since it works at low-pressure turbine, blades need not be very strong, stress on housing also reduced. Reliable and easy to operate.