Unit 11: Boiler Designs

Question 1

Mud Drum

Answer 1

Allows sediment to settle in the bottom drum of a watertube boiler

Question 2

Steam Drum

Answer 2

Top drum in a watertube boiler that allow steam to rise up through risers from the mud drum

Question 3

Fireside

Answer 3

Which ever side the heat or hot combustion gas is on a pipe inside a boiler.

Question 4

Waterside

Answer 4

The side of the pipe the water is on or in.

Question 5

Power Boiler Design Outlines

Answer 5

Steam Pressure is above 100 kPa / 15psig
Hot Water Pressure above 1.1 MPa
Temperature is above 120C
ASME I

Question 6

Heating Boiler Design Specifications

Answer 6

Steam Pressure is less than or equal to 100 kPa
Hot Water Pressure is less than or equal to 1.1 MPa
Temperature is is less then or equal to 120C
ASME I

Question 7

Shell

Answer 7

Main pressure vessel of a firetube boiler

Question 8

Drum

Answer 8

Main pressure vessel of a watertube boiler

Question 9

Heads

Answer 9

Is what encloses Shells or Drums at each end

Question 10

Tubesheet

Answer 10

Is a head of a firetube boiler

Question 11

Stays

Answer 11

are used for internal support of firetube boilers

Question 12

radiation is the transfer of heat through?

Answer 12

electromagnetic radiation
Radiation is the transfer of heat energy through space by electromagnetic radiation. Most of the electromagnetic radiation that comes to the earth from the sun is invisible. Only a small portion comes as visible light.

Question 13

Lowest Permisable Water Level in Firetube Boilers?

Answer 13

25 mm above the heating element/fireside tube.

Question 14

What is saturation temperature?

Answer 14

Saturation temperature means boiling point. The saturation temperature is the temperature for a corresponding saturation pressure at which a liquid boils into its vapor phase.

Question 15

When is forced circulation required in watertube boilers?

Answer 15

When pressures are higher around 12.5 MPa

Question 16

Continuous Blowdown Pipe

Answer 16

A pipe found just below the water line in a boiler and removes dissolved solids from the water. This prevents foaming which can cause water to leave with the steam.

Question 17

Foaming

Answer 17

When dissolved solids build up in boiler water it can cause foaming which causes moisture to attach itself to steam exiting.

Question 18

Baffles

Answer 18

Separates steam from the water in watertube boilers. The steam continues up risers and the water is sent back downcomers to the mud drum

Question 19

Scrubbers or Chevron Dryers

Answer 19

are used as steam separators. They move metal plates in different directions quickly stopping the water but steam can move quick enough to move around the plates.

Question 20

Waterwalls

Answer 20

Water piping that surrounds a boiler to increase refractory and efficiency

Question 21

Blowoff Valve

Answer 21

manually operated valve connected to the boiler for the intermittent discharge of boiler sediment.

Question 22

Blowoff Vessel

Answer 22

A pressure vessel that contains blowoff discharge until it is cool enough to enter back into the municipal sewer systems.

Question 23

ID fan

Answer 23

An induced fan that exhausts hot gases from the furnace after combustion. This is the opposite of a forced draft fan which sucks air into the furnace.

Question 24

A-type Watertube boiler

Answer 24

Has two mud drums

Question 25

D-Type Boiler

Answer 25

1 steam drum and 1 mud drum with bent tubes on one side of the boiler forming a d shape.

Question 26

O-Type Watertube Boiler

Answer 26

Compact and water-cooled and doesn’t use much radiant heat

Question 27

Steam Generating Unit

Answer 27

A large watertube boiler that has been field erected. These super large boilers generally have extra auxiliary equipment that is not present on smaller boilers. Such as superheaters, reheaters, economizers, and air heaters.

Question 28

Superheater

Answer 28

Are tubes that surround the furnace outlet to remove moisture from steam and further increase their sensible temperature.

Question 29

Reheater

Answer 29

Increases the temperature of steam leaving a turbine which further reduces the chance of condinsation.

Question 30

Economizer

Answer 30

Transfer waste heat from flue gas to feedwater. which reduces thermal shock of cold water entering boiler and increase efficiency of steam production.

Question 31

Flue Gas

Answer 31

Hot combustion gas that leaves the furnace is called flue gas

Question 32

One Pass fire tube boilers?

Answer 32

Vertical Firetube heating boilers