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14 Cards in this Set
- Front
- Back
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_________ __________ happens when water is heated and dissolved oxygen is released from the solution. This oxygen Then forms a small bubble that attached to the water tube. The oxygen attacks the metal to create localized pitting. This corrosion can lead to rapid failure of boiler tubes. |
Pitting Corrosion |
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__________ ___________ had the ability to absorb oxygen. Often referred to as ___________ _________. |
Sodium Sulfite, Oxygen Scavenger |
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2 Sodium Sulfites + 2 Oxygen = Sodium Sulfite |
2Na 2 SO 2 + 0 2 = 2Na 2 SO 4 |
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_____________ is used on high pressure stream plants to absorb oxygen. It is not typically used on low pressure steam plants because it is a slow reason to absorb oxygen. (Prevent Pitting & Corrosion) |
Hydrazine |
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Boiler water pH is maintained in a safe operating range. To the of a pH the result in acid corroding away the metal. Too high pH can result in __________ _________. |
Caustic Embrittlement |
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_____________ pH is maintained sufficiently high to prevent _________ ___________ of condensate return. |
Condensate, header gouging |
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In a condensate return system _________ _________ combine with water to produce ___________ ________. Carbonic acid is heavy and settles in low areas. This forms extremely pH levels. And cause __________ of the condensate return piping. |
carbon dioxide, carbonic acid, gouging |
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_________ are added to the boiler to test the stream & condensate lines. It boils off with the stream and condensate to protect the piping. |
Amines |
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2 Categories of Amines: |
Neutralizing Amines, Filming Amines |
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_______ _______ have a high pH so they neutralize the low pH from the carbonic acid. |
Nuetralizing Amines |
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________ ________ develop a coating on the pipes that protect the piping from localized low pH levels. |
Filming Amines |
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________ _________ is the boiler make up water that must be removed by blowdown to maintain the desired boiler water conductivity. |
Percent Blowdown |
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What is the percent blowdown needed on a boiler that has make up water with 275 ppm & a desired boiler conductivity of 4200 ppm? |
275ppm %BD = ----------------- 4200ppm %BD = 6.55% |
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Amount of Boiler Blowdown A boiler is operating 65% condensate return & is producing 50,000 poinds of steam per hour. The desired conductivity in the boiler is 2500ppm & the make up water contains 300ppm.
What is the percent of blowdown? What is the amount of blowdown needed? |
300 ÷ 2500 =.1200= 12% BD
M + .65 (50,000pph) = 50,000 +.12
Math: 65×50,000 = 3,250,000 = 32 500. Equation: M + 32,500 = 50,000 + .12 Math: 50,000 - 32,500 = 17,500 1 - .12 = .88
.88 ÷ 17,500 = 19,886.36 makeup
.12 × 19,886.36 = 2,386.36 pph |
