Admin Table of Contents
What is a barring gear used for?
The barring gear assembly also initiates rotation of the shaft during a startup phase prior to injection of steam in the steam turbine. The rotation speed of the shaft during turning phases is low and constant.
What is a barring device?
Engine barring devices are connected to engines. Known barring devices have been used to rotate crankshafts of engines and adding features to these known devices increases the complexity and cost of such devices. The subject barring device (10) includes a shaft (32) adapted for both axial and rotational movement.
What is barring of compressor?
The compressor should be fitted with a barring device (barring gear), which can be manual, electrical or pneumatic. This device is used only for maintenance, while the compressor is stopped.
What is barring in turbine?
Barring gear (or “turning gear”) is the mechanism provided to rotate the turbine generator shaft at a very low speed after unit stoppages. When it stops completely, there is a tendency for the turbine shaft to deflect or bend if allowed to remain in one position too long.
What is a turning gear?
A jacking gear (also known as a turning gear) is a device placed on the main shaft of an engine or the rotor of a turbine. The jacking gear rotates the shaft or rotor and associated machinery (such as reduction gears and main turbines), to ensure uniform cool-down. Without turning, hogging or sagging can occur.
Which gas cooling is used in large generator units of steam plant?
Many power generators over 150 MW in capacity utilize hydrogen as a cooling method to transfer heat from the power generating winding enclosure to the heat exchanges known as H2 coolers. Hydrogen cooled power generators are more efficient and have less mass of materials of construction than their air-cooled cousins.
What is the meaning of call barring?
Meaning of call barring in English a phone service that allows users to stop receiving calls from particular numbers or stops someone from making calls to particular numbers: You can use call barring to prevent someone from making international calls.
Why do we use turning gears?
A reversible electric motor which, through a system of gears, can be used to turn slowly a large diesel engine or steam turbine and gearbox assembly. It enables precise positioning for overhaul or examination. The engaging and disengaging of the turning gear is accomplished by the lever.
Why are generators cooled with hydrogen?
Hydrogen is used to cool the windings of large power plant generators because of hydrogen’s high heat capacity and low density.
Why do they use hydrogen to cool generators?
So why use hydrogen to cool a generator? Despite its reputation, hydrogen gas has qualities that make it a superior heat transfer media and internal atmosphere for a generator. Hydrogen is much less dense that air. Cooling fans can move up to fourteen (14) times as much hydrogen as air using the same amount of power.
Is call barring the same as call blocking?
Call barring is not actually a standard call blocking feature, it will block all the calls of a selected type. However, it can be handy in certain situations when you don’t want calls from certain types of numbers, For example, you can block all calls from international numbers.