Module 3. 6-9

Question 1

Process done to control purity and pH of water by removing undesirable ions and exchanging them with acceptable ions.

Answer 1

Demineralization

Question 2

Exchange of ion between a solid substance (called resin) and an aqueous solution (coolant or makeup water)

Answer 2

Ion exchange

Question 3

Resin beads are insoluble in ___, ____ and ____

Answer 3

water, acids, bases

Question 4

Two types of ion exchange resin:
1. Resins exchange in positive ions.
2. Resins exchange in negative ions.

Answer 4

Cation Resin
Anion Resin

Question 5

Extremely large molecules that are formed by the combination of many molecules of one or two compounds in a repeating structure that produces long chains

Answer 5

Polymers

Question 6

A device which exchanged undesirable ions with desirable ones.

Answer 6

Ion exchanger

Question 7

An ion exchanger in which H+ (for cation resins) and OH- (for anion resins) are present on the sites of resin beads

Answer 7

Demineralizer

Question 8

Two classification of Ion Exchanger:
1. Cation and anion resins are separated
2. Mixture of cation and anion resin

Answer 8

1. Single Bed
2. Mixed Bed

Question 9

In GMEC, the volume ratio is _____ cation resin to ____ anion resin

Answer 9

one-part, two-part

Question 10

The amount of impurity that a given amount of resin is capable of removing; it has units of moles/ml, equivs/ml or moles/gm

Answer 10

Exchange capacity

Question 11

The strength of the ionic bond between the resin and an ion varies with the particular ion.

Answer 11

Affinity

Question 12

3 Resin Bed Malfunctions:

Answer 12

1. Overheating
2. Breakthrough and exhaustion
3. Channeling

Question 13

The anion resins begins to decompose slowly at about 140F and the decomposition become rapid above 180F

The cation resin is stable up to about 250F

Ion exchanger is set to 120F Limit

Answer 13

Overheating

Question 14

Impurity ions begin to appear in the solution after it has passed through the resin.

Answer 14

Breakthrough

Question 15

When the concentration of impurities is the same before and after the solution passes through the resin

Answer 15

Exhaustion

Question 16

Indicators of depleted exchange capability of resins

Answer 16

Breakthrough and exhaustion

Question 17

It is a condition in which the resin allows a direct flow of water through the ion exchanger.

Answer 17

Channeling

Question 18

It can mostly results from improper filling of the ion exchanger with resin

Answer 18

Channeling

Question 19

If insufficient water is mixed with the resin when it is added ,the resin column may contain _____ or ______

Answer 19

pockets, voids

Question 20

Classification of the cation resins at the bottom an anion resins on top of the resin column

Answer 20

Backwashing

Question 21

Exchanging impurity in the exchange sites of the resin with H+ and OH- from acid and caustic

Answer 21

Regeneration

Question 22

Cutting acid and caustic dosing, allowing only dilution water to flow.

Answer 22

Slow rinse

Question 23

Draining of excess fluid

Answer 23

Vent and Partial Drain

Question 24

Done to make sure that the resins are mixed again

Answer 24

Air mix

Question 25

The resin is rinsed by running water through the vessel from top to bottom and out of the drain, until a low conductivity reading indicates that the ion exchanger is ready to return to service

Answer 25

Final Rinse

Question 26

The degree to which an object conducts electricity, it is the reciprocal of resistance

Answer 26

Conductance

Question 27

The measure of the ease at which an electric charge can passes through material, reciprocal of resistivity

Answer 27

Conductivity

Question 28

High purity water that has been distilled and/or de-ionized so it will have a specific resistance of ______ ohms

Answer 28

500,000

Question 29

Presence of oxygen can promote _____ at area on the metal surface

Answer 29

pitting

Question 30

Oxygen in the solution inside the ____ will be depleted initially by the corrosion reaction:

Answer 30

pitting, 2Fe + O2 = 2FeO

Question 31

The three condition for Chloride SCC to occur:

Answer 31

Presence of chloride ions,
dissolved oxygen,
metal is under tensite stress

Question 32

How does Carbon Dioxide end up in boiler water?

Answer 32

1. Dissolved carbon dioxide
2. Presence of bicarbonates and carbonates in water

Question 33

Dissolve oxygen together with carbon dioxide is how many percent more corrosive than if the two were acting alone.

Answer 33

40%

Question 34

Solution to manage carbon dioxide and oxygen

Answer 34

1. Manage pH level at an alkalinic level pH (9 and 11)

Question 35

Deaeration Steps:
1. Reduce surface tension
2. Oxygen and carbon dioxide lose solubility
3. Mechanical agitation and scrubbing to liberate the gases
4. Oxygen and carbon dioxide in gaseous form

Answer 35

1. Spraying or filming
2. Heating
3. Scrubbing
4. Releasing

Question 36

Solution to manage carbon dioxide and oxygen

Answer 36

2. Chemical Addition
   
   • Trisodium Phosphate (Na3PO4)
   • Disodium Phosphate (Na2HPO4)
   • Ammonia (NH3)

Question 37

Solution to manage carbon dioxide and oxygen

Answer 37

3. Chemical: Oxygen and Carbon Dioxide Scavenger
   
   • Hydrogen gas
   • Hydrazine

Question 38

Solution to manage carbon dioxide and oxygen

Answer 38

4. Mechanical: DE aeration
   
   • used to strip feedwater from the non condensable gases oxygen and carbon dioxide to prevent damage of the components downstream.