MARINE ENGINEERING SELF EXAMINER, WATER TREATMENT- CAPT AJIT VADAKAYIL

WATER TREATMENT IN ENGINE ROOM

This is a questionnaire I made for my company Chief Engineers pre-joining interview.

Test to find out if a wanna be XXX chief engineer, is a pretender motor-man with a fake certificate of competency.

More than 30% marks -- Can be posted on a XXX ship

Less than 10% marks--  Don’t employ this pretender/ motor man

More than 70% marks--  He is an asset to XXX.

CORRECT ANSWERS---   + 2  marks

INCORRECT ANSWERS---   minus 2 mark

DID NOT ATTEMPT ---- minus 2 marks

Marine engineers at sea , 3 and 4 stripers-- you can see what you are worth!  Have a right estimate of your own professional expertise.

Here we go--

1) 1 ppm of chlorides in water means

a)1 mg/ litre

b)1 mg/ cum

c) 1 mg/ cc

d)none of above

2) Quality of the feed water in a steam plant changes during operation. Caused by this, the water is regularly tested. Which of the below statements describes the chemical mechanisms normally occuring?

a) Generation of carbonic acid causes the water quality to drift towards sour and lower the pH - number.

b) Generation of sulphur acid causes the water quality to drift towards sweet and rise the pH - number.

c) All of the mentioned alternatives.

d) Water is becoming sligthly less conductive and does not transfer heat.

3)Normally a boiler water sample should be taken

a)after the boiler has been blown down

b)before the boiler has been blown down or chemicals added

c)when the boiler has been refilled with makeup

d)from the highest point in the feed system

4).What is the main purpose of bottom-blowing a boiler?

a) To get rid of sludge in the water chamber.

b) To control that water is present in the water chamber, when the boiler is in active operation.

c) To adjust steam pressure when the burner capacity is excessive.

d) To check that we do not have any leak of smoke and gases in the combustion chamber.

5)Which of the following procedures decreases the total dissolved solids concentration in the water of an auxiliary boiler?

a)Hydrazine treatment of condensate

b)Frequent compounding

c)Chemical cleaning

d)Bottom blowing

6).What is an effective means of measuring total dissolved solids in  boiler water?

a) Conductivity test.

b) Alkalinity test.

c) Chloride test.

d) Not possible to test solids in boiler water.

7) Dissolved oxygen can be removed from the boiler water by 

a)frequent surface and bottom blows

b)dumping and refilling the boiler weekly

c)passing the water through absorbent filters

d)treating the water with chemical scavengers

8).What initial simple recommendation can we give to reduce oxygen in the boiler water?

a) Raise the feed water temperature.

b) Lower the feed water temperature.

c) Increase the boiler pressure.

d) Increase the "Blow down".

9)A continuous blow is used to 

a)regulate the density or salinity of boiler water

b)remove scum from the surface of boiler water

c)permit air to excapewhile raising steam in a cold boiler

d)remove sludge from the bottom of the water drum

 

10).What will you do if the PH-value in the boiler water is over 11?

a) Blow  the boiler and renew water until the PH-value is normal again.

b) Increase the dosage of chemicals.

c) Decrease the dosage of chemicals.

d) Nothing.

11)The end product of reactions occurring when boiler water is chemically treated, remain in the boiler and increase the need for 

a)acid cleaning

b)makeup feed

c)boiler blowdown

d)waterside corrosion treatment

12).Which of the below listed effects can be caused by the presence of Calcium in the boiler water?

a) Loss of alkalinity, corrosion of boiler metal surfaces, and loss of phosphate reserve in the boiler.

b) Passifying of boiler metal surfaces.

c) Increase of alkalinity and PH-value.

d) No negative effects.

13)The greatest deterrent to heat transfer from the fireside to the waterside of a boiler is 

a)water film

b)water eddies

c)gas film

d)gas eddies

14).For a low pressure boiler, after testing the water, You found the Chloride level to be 50 PPM, what action would You take?

a) Do nothing.

b) Increase dosage.

c) Blow down the boiler and reduce dosage.

d) Reduce dosage.

15)Oxygen corrosion in auxiliary boilers is prevented by treating the boiler feed tank  with either sodium 

a)sulfite or hydrazine

b)sulfite or hygroscopic sulfite

c)bromide or hydrazine

d)bromide or hygroscopic sulfite

16).For a low pressure boiler, after testing the water cloride level, it is found to be 500 PPM, what action would You take?

a) Blow down boiler and check condenser for leakage.

b) Do nothing.

c) Decrease dosage.

d) Increase dosage.

17)The MOST common cause of heat blisters developing on boiler generating tubes is due to

a)waterside deposits

b)fireside deposits

c)low water level

d)insufficient water circulation

18).If oil is found in the boiler water, what action would You take other than isolating the leak?

a) Dose with coagulent and blow down the boiler.

b) Blow down the boiler.

c) Do nothing.

d) Dose with coagulent.

19)Oil deposits can be removed from the waterside of boilers by "boiling out" with a/an

a)alkaline solution

b)acid solution

c)salt solution

d)kerosine solution

20).In a low pressure auxiliary boiler, what would you consider to be the maximum allowable chloride level?

a)300 PPM.

b)30 PPM

c)10 PPM

d)50 PPM

21)Oxygen content of boiler feed water at 50C is –

a)same as water at 90C

b)twice more than water at 90C

c)thrice more than water at 90C

d)4 times more than water at 90C

22.In a low pressure auxiliary boiler, what would You consider to be the normal operating range of phenolphthalein alkalinity—PPM CaCO3 ?

a)100 - 300

b)1-6

c)30-60

d)8 to 28

23)The bottom blow to remove solid matter ( not salinity ) of boiler is done by

a)one short blow with boiler running

b)one long blow with boiler cut off

c)several short blows when boiler is cut off

d)several short blows with boiler running.

24)On a chemical tanker discharging palm oils in Baltic in winter, some palm oil traces are found in the hotwell. This will cause –

a)foaming in the boiler

b)fluctuating water level in drum

c)wet steam on deck

d)all of above

25)What when present in boiler feed water causes scaling

a)sodium carbonate

b)sodium suphate

c)calcium sulphate

d)hydrazine

26)Impurities in boiler feed water causes-

a)scale formation

b)corrosion

c)water carry over

d)all of above

27)Boiler water reading records  shall be available on board ,as per class rules of -

a)chlorides/ phosphates

b)pH

c)Oxygen

d)All above

28)Common chemicals used to prevent formation of boiler tube scales are

a)calcium phosphate

b)magnesium hydroxide

c)sodium chloride

d)sodium phosphate

29)Thermal deaeriation in cascade tank/ hotwell removes dissolved oxygen up to—

a)10%

b)50%

c)95%

d)75%

30)Oxygen remaining after thermal deaeration is removed by chemical scavenging using

a)Hydrazine

b)sodium phosphate

c)sodium hydroxide

d)caustic soda

31)Sodium sulpite chemically combines with oxygen to form—

a)Nil dissolved solids

b) dissolved salts

c)nitrogen

d)none of above

32)Hydrazine causes—

a)cancer

b)tuberculosis

c)asthma

d)safe for use

33)Water / steam side of boiler is passivated at pH

a)3.5 to 5

b)10 to 11

c)13 to 14

d)7

34)Alkaline water changes from pink to colourless phenolphethelein at

a)8.3

b)12.9

c)1.8

d)2.9

35)Boiler water is tested for correct alkalinity to—

a)precipitate hardness salts to prevent scale

b)passivate with Fe3O4 film

c)maintain silica in solution to prevent scale

d)all above

36)Feed water and condensate pH value should be—

a)11 to 12.1

b)8.3 to 9

c)7 to 7.3

d)6.4 to 7.6

37)Boiler water pH should be in the range of

a)8 to 8.9

b)9.5 to 11

c)3.4 to 5.8

d)13 to 13.2

38)Cooling fresh water pH value should be-

a)8.3 to 10

b)12 to 13.1

c)5.2 to 7.1

d)7

39)Boiler feed water chloride value should be less than

a)0.249 ppm

b)3 ppm

c)15 ppm

d) 200 ppm.

40)Cooling fresh water ppm for chlorides should be max—

a)50

b)300

c)3

4)0.249

41)Hydrazine does the following—

a)scavenged dissolved oxygen

b)reduced red oxide to black oxide

c)raises the pH of condensate and feed water systems

d)all of above

42)Boiler feedwater testing is for—

a)hardness

b)oxygen

c)chlorides

d)all above

43)Factors affecting boiler water tube corrosion are

a)cavitation

b)dissolved solids gases

c)micro organisms

d)all of above

44)Condensate testing is for

a)pH

b)chlorides

c)ammonia

d)all above

45)The main purpose of boiler water treatment is to—

a)reduce hardness

b)increase pH

c)remove oxygen

d)all of above

46)Water carry over in boiler steam can be caused by

a)high concentration of dissolved solids

b)high alkalinity of feed water

c)high concentration of suspended solids

d)all of above

47)If oil enters the boiler, it will coat the

a)top tubes

b)bottom tubes

c)both top and bottom

d)middle tubes

48)Adding Hydrazine hydrate N2H2 to boiler water

a)removes oxygen

b)makes iron oxide sludge non adherent

c)increases alkalinity

d)all of above

49) It is better to provide a large volume of cooling water with a slight temperature differential between inlet and outlet cooling lines , than to provide a lesser but colder flow, with the same outlet temp

a)to avoid vapour pockets and local hot spots

b)to avoid scale deposition

c)to avoid thermal shock to liner due to cold water inlet

d)all of above

50)Sea water has ppm salt

a)330 ppm

b)3300 ppm

c)33000 ppm

c)33 ppm

Answers:

1a
2a
3b
4a
5d
6a
7d
8a
9a
10a
11c
12a
13c
14a
15a
16a
17a
18a
19a
20a
21d
22a
23c
24d
25c
26d
27d
28d
29d
30a
31b
32a
33b
34a
35d
36b
37b
38a
39c
40a
41d
42d
43d
44d
45d
46d
47b
48d
49d
50c

 CAPT AJIT VADAKAYIL

29 YEARS IN COMMAND