Can You Pass This Science Mock Test Exam? Trivia Quiz
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- 1.In heat exchangers, which metallurgy is most prone to form waterside scale deposits?
- A.
SS
- B.
Admiralty
- C.
Copper
- D.
Mild steel
- 2.The localized (pitting) corrosion rate increases when:
- A.
The cathodic area and anodic area are similar
- B.
The anodic area is large, relative to the cathode.
- C.
The cathodic area is large, relative to the anode.
- D.
When sacrificial anodes are used.
- 3.Deposits usually lead to aggravated localized corrosion (pitting attack) because:
- A.
Decreased pH levels at the cathode.
- B.
A galvanic cell is set up between the manganese deposit and the metal.
- C.
Deficient oxygen levels under the deposit.
- D.
Increased pH levels at the anode.
- E.
Both (a) and (b).
- 4.To prevent white rust:
- A.
Maintain an alkalinity of less than 300 ppm
- B.
Maintain a pH below 8.3.
- C.
Keep calcium hardness below 50 ppm.
- D.
All of the above.
- E.
A and b
- 5.Chlorination of a water system with soluble iron or manganese will:
- A.
Stabilize the iron or manganese.
- B.
Oxidize the iron or manganese and prevent further corrosion.
- C.
Reduce the iron or manganese causing a severe corrosion potential
- D.
Oxidize the iron or manganese causing a potential for fouling.
- 6.The make-up water for a cooling water system is 100 GPM and contains 150 ppm of M-Alkalinity. You want to run the system at 5 cycles while maintaining 400 ppm M-Alkalinity in the recirculating water. What 98% of H2SO4 dosage is required?
- A.
8.4 pounds per day
- B.
1 pounds per day.
- C.
10 pounds per day.
- D.
84 pound per day.
- E.
None of the above.
- 7.Which of the following characteristic of corrosion is caused by anaerobic bacteria?
- A.
Red tubercules (iron oxide)
- B.
Cracking at grain boundaries
- C.
Precipitation of calcium hydroxide
- D.
Granules of black iron (iron sulfide)
- 8.Determine the Evaporation rate with the following information? Given: Your prospect has two-2500 ton chillers, one high efficiency fill tower, and a chilled water loop cooling a process. During your survey you discover the following: · The chilled water loop leaks at a rate of 8 gpm (Repairs will cost $2,700.) · The chiller head pressure has increased 2 psig · A clean machine will operate at 0.7 kw/ton · The two machines operate at 75% load for 6000 hours per year · The recirculation rate = 3gpm/ton · The average delta T is 8 degrees & cycles of concentration = 4.5 · Use 0.85% per 10 degree for evap calc.
- A.
27.5 million gallons /yr
- B.
32.4 million gallons /yr
- C.
53.6 million gallons/yr
- D.
47.3 million gallons/yr
- 9.The "C" factor for a heat exchanger
- A.
Considers water flow and pressure drop.
- B.
Is calculated by the formula, C = U (A) (LMTD) for a one pass exchanger.
- C.
Cannot be applied if there is a phase change on the process side (a gas condensed to a liquid).
- D.
Considers process side fouling.
- 10.A cooling tower has the following information provided. What is the expected blowdown? Water test show concentration ratio to be 3.5 Recirc rate = 40,500 gph or 153 m3/hr Delta temp across the tower = 15 degrees F or 8.33C Drift is approximately 0.1% of recirculation rate Basin is 1.25 ft (.38 m) H x 20 ft (6.1 m) W x 40 ft (12.2 m) L [ to account for the piping etc -add 25 % additional] In this area the evaporation is about 0.9% of the recirc rate per 10 deg F. [5.5 C] HINT: Blowdown = (Evaporation /cycles -1) - drift
- A.
83 gph [ .314 m3/hr]
- B.
182 gph [ .689 m3/hr]
- C.
283 gph [1.07 m3/hr]
- D.
383 gph [1.45 m3/hr]
- 11.Your customer asks you if the biocontrol program you are feeding also protects the plant personnel from Legionella. How do you respond?
- A.
The current cooling water program was designed to provide excellent cooling tower performance and protect personnel.
- B.
The current program is acceptable, but insist that the customer run Legionella test on the tower water at least once a year, just to be sure.
- C.
The current program was designed to provide good performance of heat exchangers and towers,but was not designed to meet a health standard.
- D.
The current program is acceptable if chlorine dioxide was added to the make up water to prevent Legionella from entering the tower system.
- 12.Which of the following is a false statement about 3D Biocontrol:
- A.
The Nalco Bio-Index is determined by measuring the fluorescent signal of both the unreacted and reacted Bio-Reporter Material and determining the ratio.
- B.
Using too much oxidizing biocide with the Nalco Bio-Reporter can make the tower turn blue
- C.
The Bio-Reporter can be used to monitor bioactivity for a baseline before starting a 3D Bio-controlled program.
- D.
The Bio-Index is independent of Bio-Reporter concentration.
- 13.When interpreting 3D Trasar performance parameters, for both the 3D Bio-Index and the Nalco scale Index, a value of 25 would mean that the system was under:
- A.
Low stress
- B.
Mild Stress
- C.
High Stress
- D.
Alarm conditions
- 14.Which of the following is the most true statement about Nalco Scale Index?
- A.
It measures total polymer consumption.
- B.
It measures the rate of polymer consumption.
- C.
It measures the amount of scale that is forming.
- D.
It measures the rate of change of pH, and conductivity.
- 15.In closed cooling water systems, the primary cause of pump seal failure is:
- A.
High ph
- B.
Microbiological attack
- C.
Too high inhibitor dosage
- D.
Particulate erosion
- 16.Which of the following types of closed system inhibitors should you avoid for a system with hard water makeup, and a high heat flux (caster mold water)?
- A.
Azole.
- B.
Silicate
- C.
Nitrite
- D.
Molybdate
- 17.The functions of HSP (high stress polymer) and TRC-233 in a cooling water program are:
- A.
Iron dispersancy.
- B.
Particulate dispersancy.
- C.
Calcium phosphate and zinc hydroxide control.
- D.
All of the above
- E.
A) and b).
- 18.Key corrosion control tests for a multifunctional AZ-lite program are:
- A.
Monitoring the soluble zinc and difference between filtered & unfiltered total phosphate
- B.
Monitoring the soluble zinc and difference between filtered & unfiltered ortho phosphate.
- C.
Monitoring the difference between soluble & total zinc.
- D.
Monitoring the soluble zinc and filtered total phosphate.
- 19.You have a magnesium silicate-scaling problem in your cooling system. How would you best manage this problem?
- A.
Adjust tower pH up.
- B.
Adjust SiO2 levels in tower to a maximum of 150 ppm.
- C.
Adjust pH or cycles so that magnesium silicate is soluble.
- D.
Clarify the makeup water
- 20.For a stabilized phosphate program, the mechanism for corrosion control is:
- A.
High levels of orthophosphate film over the entire metal surface.
- B.
Formation of a passive gamma iron oxide film at the cathode.
- C.
Precipitation of protective ortho-phosphate films at the cathode, as a result of locally high pH levels.
- D.
Formation of a passive gamma iron oxide film at the anode and precipitation of a polyphosphate film at the cathode.
- 21.The following can generally be used to determine the cooling water flow rate through an exchanger:
- A.
Ultrasonic flow meter
- B.
Heat balance
- C.
Pump curve
- D.
A) and b) only
- E.
All of the above
- 22.A four-pass heat exchanger has 560, 1.27 cm (1/2 inch) OD, 20 BWG (0.9 mm or 0.035-inch wall thickness) tubes. What is the water velocity through each tube if diagnostic Trasar studies show 127 cubic meter/hr (560 GPM) of water flow?
- A.
0.68 m/sec (2.25 ft/sec)
- B.
2.70 m/sec (8.9 ft/sec)
- C.
1.68 m/sec (5.5 ft/sec)
- D.
1.00 m/sec (3.3 ft/sec
- 23.The NCM ( Nalco Corrosion Monitor) 100:
- A.
Provides a pitting corrosion rate.
- B.
Replaces corrosion coupon testing.
- C.
Measures trends in corrosivity.
- D.
None of the above.
- E.
Replaces corrosion coupon testing and Measures trends in corrosivity.
- 24.A heat exchanger condenses a gaseous ethanol stream of known flow rate at 216ºF and then cools the condensed material down to 110ºF. In order to determine the water flow required to achieve this, you need to know:
- A.
Inlet and outlet temperatures of the water, heat of vaporization of water plus the specific heat of water.
- B.
Inlet and outlet temperatures of the water, specific heat, heat of vaporization and condensation temperature of the process liquid
- C.
Heat of vaporization, heat of condensation, and specific heat of the process side and the water.
- D.
Temperatures of the water, surface area of the heat exchanger, and the U value of the heat exchanger.
- 25.The Liquid to Gas (L/G) factor for a cooling tower is important! What things affect L/G?
- A.
Recirculation rate
- B.
Fan Speed
- C.
Fill Cleanliness.
- D.
All of the above
- E.
Only a) and c)
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