TSBC External Feedwater Treatment Flashcards
A continuous blow-off is
a) used to reduce the dissolved gases in the boiler
b) installed in the steam drum
c) used on every boiler
d) installed in the lower drum
e) used to reduce sludge
b) installed in the steam drum
Chemicals are fed to a water tube boiler
a) with a small centrifugal pump
b) into the top drum only
c) with a small positive displacement pump
d) into the bottom drum only
e) prior to operating the blow off valves
c) with a small positive displacement pump
When performing a water test be sure that:
1. all equipment is clean and in good working order
2. results are recorded carefully before making the test
3. test solutions, indicators, and reagents are fresh,
and at full strength
4. test reagents are filtered before use
a) 1, 2
b) 2, 3
c) 1, 3
d) 2, 4
e) 3, 4
c) 1, 3
Titrating is done with
a) a titrant
b) a zeolite
c) an antifoam
d) trisodium phosphate
e) a reagent
e) a reagent
Phenolphthalein is
a) an indicator
b) a reagent
c) a buffer
d) an acid softener
e) neutralizing agent
a) an indicator
When used as a term during boiler water testing, DS means
a) demineralized steam
b) drain solids
c) dissolved solids
d) dissolved sulphite
e) depleted salts
c) dissolved solids
Boiler water testing is done in the average power plant every
a) shift
b) week
c) month
d) time the boiler inspector requests it
e) time the chief engineer requests it
a) shift
Total alkalinity is measured
a) using methyl orange indicator and N50 sulphuric acid
b) to be sure that it is not more than 2500 ppm
c) to keep a check on the dissolved oxygen
d) to control sludge formation
e) by using phenophthalein and N50 sulphuric acid
a) using methyl orange indicator and N50 sulphuric acid
The conductivity meter is used to measure the
a) current
b) alkalinity
c) electrolyte
d) voltage
e) TDS
e) TDS
A residual of 20 to 40 ppm of sodium sulphite is to
be maintained in the boiler water to
a) keep down the sludge
b) prevent pitting in the boiler steam drum
c) prevent scaling the float in the low water cut-off
d) keep feed water lines free of algae
e) reduce the total chemical consumption
b) prevent pitting in the boiler steam drum
Boiler water chemicals are injected
a) in measured amounts once per year
b) after considering the water test readings
c) into the water softener
d) to prevent the water becoming too alkaline
e) each time after blowing down
b) after considering the water test readings
When conducting a TDS or Total Dissolved Solids test, the impurity which has a high conductivity and must be neutralized is a) sodium phosphate b) hydroxide alkalinity c) pH d) suspended solids e) sodium chloride
b) hydroxide alkalinity
The methyl orange or "M" alkalinity test indicates alkalinity a) due to carbonates only b) due to bicarbonates only c) due to hydroxides only d) caused by all dissolved impurities contributing to alkalinity e) due to organics only
d) caused by all dissolved impurities contributing to
alkalinity
The phenolphthalein or "P" alkalinity test does not indicate alkalinity due to a) hydroxides b) bicarbonates c) sulphates d) carbonates e) phosphates
b) bicarbonates
Alkalinity in boiler water may be due to calcium, sodium or
magnesium
a) hydroxides
b) carbonates and bicarbonates
c) bicarbonates
d) hydroxides and bicarbonates
e) hydroxides, carbonates and bicarbonates
e) hydroxides, carbonates and bicarbonates
Raw water has hardness due to
a) the salts of calcium and magnesium
b) suspended solids
c) organic material
d) dissolved gases
e) phosphates
a) the salts of calcium and magnesium
The water in a boiler should be kept
a) alkaline
b) neutral
c) acidic
d) at a pH of 14
e) at a pH of 7
a) alkaline
One element which leads to caustic embrittlement in boiler tubes is
a) concentration of sodium hydroxide
b) concentration of sodium chloride
c) overheating of boiler parts
d) concentration of sodium sulphite
e) excessive boiler pressure
a) concentration of sodium hydroxide
To prevent scale formation, inject
a) zeolite
b) sodium chloride
c) phenolphthalein
d) amines
e) phosphates
e) phosphates
The pH of the boiler water should be maintained at
a) neutral
b) slightly alkaline
c) 11.5
d) 10.5
e) 7
d) 10.5
The boiler blowoff should be used to
a) reduce steam pressure
b) reduce feedwater pressure
c) control the total dissolved solids
d) prevent scale formation
e) expel the sodium sulphite
c) control the total dissolved solids
Sodium sulphite is used in boilers to
a) prevent scale formation
b) prevent carryover
c) control dissolved solids
d) prevent oxygen corrosion
e) prevent foaming
d) prevent oxygen corrosion
Return line corrosion
a) can be controlled by feeding sodium bicarbonate
b) can be prevented by adding sodium phosphate
c) can be prevented by adding sodium sulphite
d) can be controlled by feeding amines
e) can be controlled by adding polymers
d) can be controlled by feeding amines
Sodium sulphite chemical will
a) prevent corrosion due to oxygen in the boiler water
b) precipitate with calcium and magnesium
c) prevent scale adhering to the tubes
d) control foaming
e) control return line corrosion
a) prevent corrosion due to oxygen in the boiler water
Foaming of water in the boiler
a) is due to a high concentration of dissolved gases
b) can be controlled by adding sodium phosphate
c) can be controlled by adding more neutralizing amines
d) can be controlled by adding sulphur to the feedwater
e) can be controlled by the bottom and continuous blow downs
e) can be controlled by the bottom and continuous blow downs
Sludge conditioning in a boiler
a) is controlled by the continuous blow down
b) is to prevent pollution from the water blown down from
the boiler
c) prevents the sludge precipitates from adhering to the boiler
plates and tubes
d) is done to mix the sludge with the boiler water
e) neutralizes the sludge forming substances
c) prevents the sludge precipitates from adhering to the boiler
plates and tubes
The pH of the water in the boiler
a) is controlled with sodium hydroxide
b) could be controlled with amines
c) must have a value of 7
d) is controlled by adding treated water
e) should be neutral
a) is controlled with sodium hydroxide
Internal water treatment is
a) used with low pressure boilers only
b) adding chemicals to the boiler water
c) adding a coagulant to the settling tank
d) measuring the pH of the feedwater
e) adding chemicals to the steam in the boiler
b) adding chemicals to the boiler water
Sludge is usually removed from the boiler by
a) filtering the water before it leaves the boiler
b) raking it into a sludge trap
c) vacuuming it from the bottom
d) blowing down through the bottom blow down connection
e) blowing down through the continuous blow down
d) blowing down through the bottom blow down connection
Excess sulphite is necessary to prevent
a) pitting
b) hardness
c) carry over
d) acidity
e) sludging
a) pitting
Carbon dioxide causes return line corrosion and may be
a) removed in the deaerator
b) absorbed by sodium sulphite
c) the result of bicarbonate decomposition
d) neutralized in the boiler with sodium hydroxide
e) neutralized with filming amines
c) the result of bicarbonate decomposition
Two common chemicals used for deaeration are Na SO and 2 3 a) NaOH b) H SO 2 4 c) N H 2 4 d) Na PO 3 4 e) Na (HCO ) 2 3 2
c) N H
2 4
A sludge conditioner will keep precipitated dissolved solids
fluid and well dispersed and
a) permit their removal through a CBD
b) in solution
c) prevent them from adhering to the metal
d) is usually a non-organic compound
e) is injected prior to the water softener
c) prevent them from adhering to the metal
Relative to internal treatment, it is customary to
a) precipitate dissolved solids with a “precipitator”
b) cause dissolved solids to remain in solution
c) filter out dissolved solids
d) treat the dissolved solids so they remain dispersed
e) condition the dissolved solids so they do not adhere to
metal
a) precipitate dissolved solids with a “precipitator”
An acceptable pH value for boiler water is
a) 7.00
b) 6.95
c) 8.35
d) 10.50
e) 11.75
d) 10.50
A normal operating pressure range for a deaerator is
a) 70 to 100 kPa
b) 30 to 50 kPa
c) 100 to 150 kPa
d) 10 to 25 kPa
e) 5 to 35 kPa
a) 70 to 100 kPa
In order to prevent the waste of steam through a deaerator vent, the component used is a a) cyclone separator b) chevron drier c) scrubber d) vent condenser e) dry pipe
d) vent condenser
The zeolite inside a water softener is used to
a) regenerate the brine solution
b) rinse the softened water
c) exchange sodium for calcium and magnesium
d) exchange soda for calcium and magnesium
e) exchange calcium for magnesium
d) exchange soda for calcium and magnesium
Pitting of boiler metal may be prevented by
a) heating the boiler feed water to between 80 and 105 degrees
Celsius before it enters the boiler
b) cooling the feed water to between 4 and 16 degrees Celsius
c) the addition of sodium chloride to the feed water
d) agitating the feed water before it enters the boiler
e) the addition of sodium sulphate to the feed water
a) heating the boiler feed water to between 80 and 105 degrees
Mechanical deaeration
a) removes the dissolved gases from the water
b) is done with the aid of chemicals
c) is used to remove calcium and magnesium from the water
d) is used to remove oxygen only
e) removes all dissolved gases and solids from the water
a) removes the dissolved gases from the water
Sodium zeolite softeners
a) remove all dissolved solids from the water
b) remove calcium and magnesium from the water
c) are regenerated with an acid solution
d) are regenerated with an alkaline solution
e) remove all dissolved solids and suspended matter
from the water
b) remove calcium and magnesium from the water
Hot lime-soda softeners
a) can treat larger quantities of water than the cold
process type
b) will remove all dissolved solids from the water
c) are mostly used in small heating plants
d) are only used when using well water
e) are used mostly in large power plants
a) can treat larger quantities of water than the cold
process type
Lime-soda softeners
a) remove all dissolved solids from the water
b) must be backwashed periodically
c) remove all dissolved solids and gases from the water
d) changes the pH of the water
e) remove the scale forming dissolved solids
c) remove all dissolved solids and gases from the water
Coagulants added to water
a) make the water soft
b) will remove fine particles more readily
c) remove the dissolved solids
d) causes the fine particles to float to the surface
e) remove chemicals not used up
b) will remove fine particles more readily
Water filters must be cleaned
a) if the water becomes hard
b) when the dissolved solids are high
c) by backwashing the filter media
d) by chemically cleaning the filter media
e) once per shift
c) by backwashing the filter media
Filters are used
a) for external water treatment
b) to remove dissolved solids
c) to remove calcium bicarbonates
d) for internal treatment
e) to remove hardness
a) for external water treatment
The capacity of a sodium zeolite softener will drop due to zeolite attrition at about a) 5% per year b) 3% per year c) 15% per year d) 1% per year e) 7% per year
b) 3% per year
Zeolite of a sodium zeolite softener may be discharged to the sewer during the a) injection stage of a regeneration b) service stage c) slow rinse stage of a regeneration d) fast rinse stage of a regeneration e) backwash stage of a regeneration
e) backwash stage of a regeneration
The regenerant used to regenerate an anion demineralizer is
a) sodium hydroxide
b) sulphuric acid
c) sodium chloride
d) hydrochloric acid
e) sulfamic acid
a) sodium hydroxide
The regenerant used to regenerate a cation demineralizer is
a) hydrochloric acid
b) sodium chloride
c) caustic soda
d) sodium hydroxide
e) sulphuric acid
e) sulphuric acid
During the regeneration of a sodium zeolite water softener in
the “Rinse” stage, the item(s) going to the sewer is/are
a) calcium sulphate
b) sulphates and bicarbonates
c) calcium and magnesium ions
d) sodium bicarbonates and sulphates
e) magnesium bicarbonate
c) calcium and magnesium ions
The result of adding Al (SO ) to the raw water is 2 4 3 a) a higher pH b) floc c) corrosion d) pitting e) sublimation
b) floc
A method of treatment which is often used in conjunction with settling tanks is a) deaeration b) zeolite softening c) demineralizing d) lime soda softening e) filtration
e) filtration
Feedwater for a high pressure boiler should be
a) treated with phosphate
b) treated with phenolphthalein
c) treated city water
d) treated with salt
e) softened water
e) softened water
Temporary hardness in feedwater is caused by
a) calcium sulphate
b) sodium nitrate
c) magnesium bicarbonate
d) calcium carbonate
e) magnesium sulphate
c) magnesium bicarbonate
Which of the following is an example of dissolved solids?
a) magnesium sulphate
b) oxygen
c) clay
d) sand
e) carbon dioxide
a) magnesium sulphate
Which of the following is an example of suspended matter?
a) sodium
b) sand
c) salt
d) calcium
e) magnesium
b) sand
Boiler water with a pH of 6 is considered
a) alkaline
b) basic
c) acidic
d) neutral
e) acceptable for boiler water
c) acidic
Corrosion products in feedwater can cause
a) slag deposits in superheaters
b) decreased steam pressure
c) increased steam pressure
d) increase in boiler efficiency
e) tube failure
e) tube failure
Boiler water with an alkalinity that is too high will likely
a) have a lot of scale
b) show signs of pitting
c) have a low pH
d) foam
e) have grooving on its surfaces
d) foam
Boiler surfaces may have what appears to be blisters which are composed of a) iron oxide b) sodium sulphite c) caustic soda d) ferric sulphate e) chelates
a) iron oxide
Dissolved solids in raw water
a) cause pitting of boiler surfaces
b) cause grooving of piping surfaces
c) are organic matter
d) cannot be removed with filters
e) cause corrosion of boiler surfaces
d) cannot be removed with filters
Boiler water is treated in order to prevent
a) sludge, mud, pitting, corrosion
b) foaming, corrosion, carryover, sludge
c) sludge, corrosion, scale, carryover
d) scale, sludge, mud, pitting
e) foaming, carryover, pitting, corrosion
c) sludge, corrosion, scale, carryover
