by 1.What is the use of De-aerator in steam system ?
- -to remove excess air from system
2.Write the typical pressure range of a) Super High pressure ( SHP ) steam system b) High pressure ( HP ) steam system c) Medium pressure steam system
a) 1000 to 1200 psig.
b) 400-800 psig
c) 180-200 psig
d) 50-60 psig
3. What is meant by a) Raw water b) Fire water
- RW; used for all purposes throughout the plant
- FW; used only in specific units such as boilers, and usually must be treated for purity
4. What is meant by feed water treatment system in boiler?
- The process by which suspended and dissolved solids are removed from the water used in a plant
5.What is the necessity of boiler feed water treatment system in boiler? ( or Name two problems which occur in the boiler if the water is not treated )
- All impurities be removed
6.What causes foaming of water in boiler?
- High concentrations of dissolved solids in boiler water
7.What is the effect of Foaming of water in boiler or centrifugal pump?
- carry over of impurities and deposits on turbine blades or impeller blades
8.Name the 4 important factors which causes corrosion in the boiler surfaces.
- Excess acidity or alkalinity,
- High levels of oxygen and carbon dioxide,
- High temperature,
- Stress, or high levels of ammonia or sulfur-bearing gases
9.Name 4 important steps of preventing corrosion.
- maintaining pH levels in boiler feed water
- removing dissolved oxygen from water,
- using chemical treatments,
- Following established out-of-service and blow-down procedures
10.What is meant by Flocculation?
- A term used to describe the bridging together of coagulated particles
11.Give 2 examples for water softening agents.
- Lime-soda
- Soda ash
12.What is meant by Ion exchange process?( or Demineralization Process )
- Process that passes raw water through both anion and cation exchange resins, which results in pure water
13.What is the use of resins in Ion exchange process?
- To remove electrically charged particles (ions) from water
14.What is meant by Blow down in boiler.
- a term used to describe the process in which water is removed from the boiler system, when the suspended solids concentrate in the water is more, or chemical treatment reaches a point at which it is no longer effective.
15.Write the 2 situations , in which blow down is to be done in boiler.
- Electric conductivity of the water
- The capacity of water to conduct electricity.
16.Which property of water decides the blow down in boiler.
- suspended solids concentrate in the water is more
17.Name the 4 important components of refrigeration system.
- Compressor
- Shell and tube condenser (Cooling tower)
- Expansion device
- Evaporator
18.What is the use of flare systems in process plants?
- To safely remove excess hydrocarbons from a variety of plant processes
19.What is meant by pressure storage tanks?
- Pressure storage tanks are used to store volatile liquids, which have a vapor pressure greater than 18 psi
