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Lvl. 3 - Gas Exam 1 > G1-G3 Assignments > Flashcards

G1-G3 Assignments Flashcards

1
Q

List seven performance characteristics of an atmospheric burner:

  1. complete _______
  2. rapid _______ of flames
  3. quiet _______
  4. immediate _______
  5. stable _____
  6. uniform _____
  7. wide ________ rate
A
  1. complete combustion
  2. rapid carryover of flames
  3. quiet operation
  4. immediate ignition
  5. stable flame
  6. uniform heating
  7. wide turndown rate
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2
Q

List the six main components of an atmospheric burner.

A
  1. burner ports
  2. burner head
  3. venturi
  4. orifice
  5. mixing tube
  6. primary air shutter
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3
Q

Why is a luminous flame yellow?

A

does not premix gas and air before combustion

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4
Q

Explain the operation of an atmospheric burner.

A

Premix of some combustion air before ignition produces a blue or bunsen flame which is smaller and more stable

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5
Q

State Bernoulli’s Theorem.

A

when velocity increases, pressure decreases and vice versa

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6
Q

What are the limits of flammability of natural gas?

A

4–14% gas to air mix

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7
Q

What are two methods of measuring flame speeds?

A
  1. bunsen burner

2. 1 in diameter tube

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8
Q

What is the flame speed of natural gas for each measurement method?

A
  1. bunsen burner – 12 in/sec

2. tube method – 25 in/sec

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9
Q

Referring to the graph in Figure 6, which is the fastest burning gas: hydrogen or acetylene?

A

hydrogen (see graph fig 6) G1

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10
Q

When referring to the graph in Figure 6, what is the burning velocity of acetylene?

A

8.6 ft/sec ( see graph fig 6) G1

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11
Q

Name the three zones of a bunsen flame.

A
  1. inner cone
  2. outer cone
  3. outer mantle
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12
Q

In which zone of the bunsen flame is the gas completely burned?

A

outer cone

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13
Q

The maximum flame speed of natural gas occurs at what mixture of gas and air ?

A

10%

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14
Q

What is port loading?

A

amount of gas-air mixture going through a port

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15
Q

For most applications, what is the port loading for natural gas?

A

25,000-30,000btus per square inch of port area

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16
Q

What are two most common results of unstable flames?

A

flashback, liftoff

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17
Q

Under what conditions does flashback occur?

A
  1. reduced flow velocity
  2. faster burner gases
  3. underfed burner
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18
Q

Under what conditions does flame liftoff occur

A
  1. lower burning speed
  2. increased flow velocity
  3. shallow ports
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19
Q

What conditions may cause a waving flame?

A
  1. cracked heat exchanger

2. draft

20
Q

What conditions cause a flame rollout?

A

over-firing or vent blockage

21
Q

On a non-aerated pilot burner, what would cause a lazy yellow flame?

A

orifice too large

22
Q

On a non-aerated pilot burner, what causes a noisy lifting blowing flame?

A

high gas pressure

23
Q

On an aerated pilot burner, what conditions cause a small blue flame? (3)

A
  1. low gas pressure
  2. clogged pilot burner orifice
  3. clogged filter
24
Q

On an aerated pilot burner, what conditions may cause a hard sharp flame? (2)

A
  1. orifice too small

2. use of manufactured gas

25
Q

List the three main functions of a pilot burner.

  1. to ignite _____ burner flame
  2. to provide a mount for the ________
  3. to heat the __________ or power pile
A
  1. to ignite main burner flame
  2. to provide a mount for thermocouple
  3. to heat thermocouple or powerpile
26
Q

List the two main types of pilot burners.

A
  1. aerated

2. non-aerated

27
Q

Name two types of single port burners.

A
  1. inshot

2. upshot

28
Q

What are some of the advantages of a multiport burner?

  1. provide good _____ transfer
  2. spread flames for secondary ___ to reach them
  3. provide stable ____ flames
A
  1. provide good heat transfer
  2. spread flames for secondary air to reach them
  3. provide stable blue flames
29
Q

Name some common types of multiport burners.

A
  1. drilled port
  2. drilled pipe
  3. slotted port
  4. ribbon port
30
Q

What are some of the advantages of cast iron drilled port burners with small raised bosses for each port?

  1. provide greater ____ length reducing flashback
  2. more opportunity for secondary ____ to surround the flame jet
A
  1. provide greater port length reducing flashback

2. more opportunity for secondary air to surround the flame jet

31
Q

What is the range of port sizes for drilled port burners.

  1. no larger than #__
  2. no smaller than #__
A
  1. no larger than #29

2. no smaller than #42

32
Q

What are the critical factors in a drilled pipe burner design?

  1. port ___
  2. total port ___
  3. ratio of port area to cross _____
  4. total _____
  5. distance from mixer to first ____
A
  1. port size
  2. total port area
  3. ratio of port area to cross section
  4. total length
  5. distance from mixer to first port
33
Q

What are the disadvantages of the slotted port burner?

  1. because slots must be ______ subject to plugging
  2. _____ of slot causes warping in hot places
A
  1. because slots must be narrow subject to plugging

2. length of slot causes warping in hot places

34
Q

Which type of fuel gas is specified for a sandpan burner?

A

CH4

35
Q

Which type of burner uses a ceramic burner for a radiating surface?

A

Infrared radiant burner.

36
Q

Which type of burner is arranged so that the streams of gas/air mixture intersect each other to slow velocity and maintain a stable flame through a wide turndown?

A

barber burner

37
Q

Where in relation to the combustion chamber would the combustion air blower be located in a forced draft burner system?

A

upstream of the combustion chamber

38
Q

What is the name for a class of burners that do not require assistance from a fan to supply combustion air or to vent the flue products according to the Natural Gas and Propane Installation code?

A

natural draft burner

39
Q

Which type of burner is equipped with a blower that produces just enough pressure to overcome the resistance of the burner and the appliance?

A

forced draft burner

40
Q

Which type of burner has the fan located at the flue outlet of the appliance?

A

induced draft burner

41
Q

Which type of burner is equipped with a fan or blower that produces sufficient pressure to overcome the resistance of the burner only?

A

fan assist burner

42
Q

Which type of burner mixes the required amount of air and gas before ignition?

A

pre-mix burner

43
Q

What device does an aspirating burner use to regulate the gas supply?

A

zero governor

44
Q

Which type of burner mixes the required air and gas with a mechanical device?

A

blower mix burner

45
Q

Which component of a dual fuel burner directs the air fuel mixture to the appropriate part of the combustion chamber?

A

the blast tube

Lvl. 3 - Gas Exam 1 (10 decks)

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