What is the purpose of supplying more oil to the bearing than they need for only lubrication?
a) Prevent loss of lubrication
b) Heat Control
c) Keep as much viscosity as possible around bearing
Answer: b
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Power Engineering Chapter 69
- Since a steam turbine requires no ____________, the exhaust steam contains no oil and can be used as a steam supply to low pressure systems or condensed for reuse as boiler feeder water.
- Larger, higher output machines us a shaft seal with many complex winding restrictions to the steam flow by fitting rings into the casing and shaft that form narrow passages for the steam to pass through. These are called _________________.
- There are 2 basic types of steam turbine categorized by the type of blading used. These are ______________ turbines and ______________ turbines.
- The stationary passage of reaction turbines is __________.
- A steam turbines exhaust can often supply a process with steam because _________.
- If a vibration occurs during start up of a turbine what should happen:
- The vast majority of turbine governors are of _____________ type.
- Which of the following are important functions served by the condenser:
- Place the overall boiler-turbine cycle in the correct order:
- The ___________ is designed to protect the machine against catastrophic wreck of the turbine caused by increased speed above the specified maximum.
- Preventing escaping steam along the shaft by creating pressure breakdowns that reduces steam leakage is not exactly the key feature of the Labyrinth Ring.
- High output machines, operating with high temp, high pressure steam usually utilize ________ type glands to prevent the escape of steam along the shaft.
- What is the purpose of the garter springs on the carbon packing rings?
- Journal Bearings are used to take the _______ of the shaft whereas Thrust bearings take the _______.
- The thrust bearing controls axial movement in the shaft by using oil Pressure in the journal bearing creating an oil wedge between the faces & thrust runner. This keeps turbine shaft in correct longitudinal position.
- Why is it important to segregate the high pressure and high temperature steam from the wheel casing?
- The _______ is located on the governor with a normal range of 10% above and 50% below the rated speed.
- At rest the governor valve is _________ to prevent accidental startup.
- In what ways is sticking prevented in the governor?
- The ______ is standard equipment and hydraulically operated, directly driven from the turbine shaft and mechanically sensing. It controls the steam flow by adjusting the control valve.
- Put the following steps of over-speed trip on a turbine in order:
- What is the normal tripping speed on a turbine?
- The top half may be removed without disturbing any other part or piping connections. The _______ has true center line support. There are no internal high-pressure joints and it is subject to exhaust pressure only.
- Inner and outer of ends of blades are stainless steel shrouded to confine steam to the blade passage and stiffen the blades against vibration. This is a description of _________.