Impulse turbine Mechanism deals with the Impluse force action-reaction . As we all know the Netwon 3rd law of motion," Every action has equal and opposite reaction", the same is work on this. As the water fall on the blade of the rotor it generate the impact force on the blade surface, The blade tends to give the same reaction to the fluid, but the rotor is attached to the rotating assembly, it absorb the force impact and give the reaction in the direction of the fluid flow.Thus the whole turbine rotates. The rotation speed of the turbine depends on the fluid velocity, more the fluid velocity, greater the rotation speed, ans greater the speed means more power generation. regards, Alpesh Prajapati India. BE Mech. (alpesh_engg@Yahoo.co.in)
A diagram of an impulse turbine is in related links.
1) Impulse turbine 2) reaction turbine
No, turbine Helios has a special mechanism that Helios doesn't. This mechanism is powered by a ripcord and spins the turbine Helios.
A two stage impulse contains 2 stages. One stage is a stator and rotor, therefore a 2 stage impulse turbine contains a stator-rotor-stator-rotor.
No, an impulse turbine does not make use of a draft tube. In impulse turbines, the water is directed through nozzles to create high-velocity jets that strike the turbine blades, causing them to spin. Since the pressure is atmospheric at the exit of the turbine, a draft tube is not required to recover pressure or energy, as it is in reaction turbines.
Water is blasted at the buckets one by one or more jets mounted in the surroundings casing. Momentum is transferred from water to buckets and a torque is created, causing the wheel to rotate. That's why it is an impulse turbine.
In an impulse turbine, the stage is a set of moving blades behind the nozzle. In a reaction turbine, each row of blades is called a "stage." A single Curtis stage may consist of two or more rows of moving blades.
Basically governing of a turbine is controlling the speed of the turbine as the load keeps varying. The turbine needs to rotate at a constant speed. The governing of an impulse turbine is done by varying the jet of water that hits the buckets of the runner. This is done by using a spear arrangement in the pen stock. A pen stock is a type of pipe that provides the jet of water.
The difference between impulse and reaction turbine goes here...... 1) In case of an impulse turbine the pressure remains same in the rotor or runners, but in case of reaction turbine the pressure decreases in runners as well as stators also. 2) In case of impulse turbine the pressure drop happens only in the nozzle part by means of its kinetic energy. In case of Reaction one the stators those are fixed to the diaphragm act as a nozzle.
That is how fast the steam is actually moving in the turbine. For impulse turbines it is twice as fast as the turbine blades. In reaction turbines it is the same speed as the blades. Because the blades of a turbine cannot move faster than 4500 feet per second without self destructing as it overcomes the centripetal force of the turbine wheels, the steam turbine is designed such that no turbine will exceed more than ~1150 feet per second on its tip speed. Thus the steam velocity through the turbine will be less than ~1150 fps for a reaction turbine and less than ~2300 fps for an impulse turbine, or about ~1570 mph, more than twice the speed of sound.
it takes time to reach its mechanism.
in the case of impule turbine total energy at inlet is kinetic energy and in case reaction turbine energy at inlet is kinetic and pressure......