#unitdescription — Public Fediverse posts

@Su_G #BoilerManual #UnitDescription #Section1 #Page22

Answers for unit description

1. The five material flow paths in your boiler are

..........1. _____Fuel (coal)________________________

..........2. ____Air______________________________

..........3. ____Flue gas__________________________

..........4. ____Steam____________________________

..........5. _____________________________________

2. Studded tubes provide a surface for refractory and slag to adhere to. This provides a layer of insulation

which reduces heat absorption in the cyclone and maintains high gas temperature to liquify coal ash and

complete combustion.

3. Gas recirculation alters the pattern of heat absorption in the boiler. This allows control of furnace

absorption which will effect {sic} steam temperature.Gas recirculation is of particular importance during

startups when furnace absorption is limited to achieve high steam temperature.

4. Coal enters the cyclone at the radial burner where primary air meets it. Primary air picks up the coal and

forces it into the barrel where it is ignited. In the barrel high velocity secondary air is added to complete

combustion in the cyclone. The ash that remains melts into a liquid slag that collects on the cyclone barrel

tubes. Incoming coal particles become lodged in the slag and are scrubbed by the secondary air to

complete combustion.

------------------------------------------------- 22 ------------------------------------------------------
This concludes section 1, Unit Description, of the B&W Boiler Training Manual.
The next section, section 2, is FLUID CIRCULATION, 41 pages long, so a separate thread of posts will be issued for that, and I'll add that its coverage of the nature of water as a liquid and a gas has importance in understanding today's climate crisis insofar as a warming atmosphere is capable of retaining a higher level of moisture without precipitation, and it underscores the importance of atmospheric pressure as well. Those concerned over climate issues would do well to read that part. Simply follow the #BoilerManual hashtag.

@Su_G #BoilerManual #UnitDescription #Section1 #Page22

Answers for unit description

1. The five material flow paths in your boiler are

..........1. _____Fuel (coal)________________________

..........2. ____Air______________________________

..........3. ____Flue gas__________________________

..........4. ____Steam____________________________

..........5. _____________________________________

2. Studded tubes provide a surface for refractory and slag to adhere to. This provides a layer of insulation

which reduces heat absorption in the cyclone and maintains high gas temperature to liquify coal ash and

complete combustion.

3. Gas recirculation alters the pattern of heat absorption in the boiler. This allows control of furnace

absorption which will effect {sic} steam temperature.Gas recirculation is of particular importance during

startups when furnace absorption is limited to achieve high steam temperature.

4. Coal enters the cyclone at the radial burner where primary air meets it. Primary air picks up the coal and

forces it into the barrel where it is ignited. In the barrel high velocity secondary air is added to complete

combustion in the cyclone. The ash that remains melts into a liquid slag that collects on the cyclone barrel

tubes. Incoming coal particles become lodged in the slag and are scrubbed by the secondary air to

complete combustion.

------------------------------------------------- 22 ------------------------------------------------------
This concludes section 1, Unit Description, of the B&W Boiler Training Manual.
The next section, section 2, is FLUID CIRCULATION, 41 pages long, so a separate thread of posts will be issued for that, and I'll add that its coverage of the nature of water as a liquid and a gas has importance in understanding today's climate crisis insofar as a warming atmosphere is capable of retaining a higher level of moisture without precipitation, and it underscores the importance of atmospheric pressure as well. Those concerned over climate issues would do well to read that part. Simply follow the #BoilerManual hashtag.

@Su_G #BoilerManual #UnitDescription #Section1 #Page21

Questions for unit description

1. What are the five material flow paths in your boiler?
..........1. _____________________________________

..........2. _____________________________________

..........3. _____________________________________

..........4. _____________________________________

..........5. _____________________________________

2. What is the purpose of the full-studded tubes in the cyclone?

3. What is the purpose of gas recirculation?

4. How is the combustion of coal achieved in the cyclone furnace?

------------------------------------------------- 21 ------------------------------------------------------

@Su_G #BoilerManual #UnitDescription #Section1 #Page21

Questions for unit description

1. What are the five material flow paths in your boiler?
..........1. _____________________________________

..........2. _____________________________________

..........3. _____________________________________

..........4. _____________________________________

..........5. _____________________________________

2. What is the purpose of the full-studded tubes in the cyclone?

3. What is the purpose of gas recirculation?

4. How is the combustion of coal achieved in the cyclone furnace?

------------------------------------------------- 21 ------------------------------------------------------

@Su_G #BoilerManual #UnitDescription #Section1 #Page20

You have now been provided with a brief component description of the Babcock & Wilcox steam enerators at the Baldwin Power Station. The major steam generator auxiliaries, along with their functions and locations, have been described and a brief description of the combustion and heat transfer process has been presented. This information will provide you with the necessary foundation which will facilitate your understanding of the following detailed descriptions of the operating parameters and characteristics of your steam generating unit.

------------------------------------------------- 20 ------------------------------------------------------

@Su_G #BoilerManual #UnitDescription #Section1 #Page20

You have now been provided with a brief component description of the Babcock & Wilcox steam enerators at the Baldwin Power Station. The major steam generator auxiliaries, along with their functions and locations, have been described and a brief description of the combustion and heat transfer process has been presented. This information will provide you with the necessary foundation which will facilitate your understanding of the following detailed descriptions of the operating parameters and characteristics of your steam generating unit.

------------------------------------------------- 20 ------------------------------------------------------

@Su_G #BoilerManual #UnitDescription #Section1 #Page19

The combustion of the combustible elements and compounds of the fuel with all the oxygen requires a temperature high enough to ignite the constituents, mixing or turbulence, and sufficient time for complete conbustion. These factors are referred to as the three T's of combustion.

The heat released as a result of combustion is then transferred to the heat absorbing surfaces of the boiler. In boiler practice, the heat of combustion of a fuel is the amount of heat expressed in Btu, generated by the complete combustion, or oxydation, of a unit weight of fuel (1 lb.).

There are three modes of heat transfer; radiation, convectin and conduction. All the varied phases of heat transfer involve one or more of these modes coupled with a temperature difference between a heat source and heat receiver.

Radiation is the transfer of heat energy between bodies without dependence on the presence of water in the intervening space. All matter radiates, and the transfer of heat (thermal radiation) is one important manifestation of this phenomenon. Radiation occurs when a hot object gives off heat in a straight line away from itself. Radiation is considered the primary mechanism of heat transfer in a furnace, with heat radiating from the hot fire to the cooler furnace walls.

Convection is the transfer of heat from one point to another within a fluid (gas or liquid) by the mixing of one part with another. Heat is transferred by convection when boiler flue gases pass over the tube surface and also when the steam or water pass over the internal surfaces of the tube. Convection is the primary mechanism of heat transfer which occurs in the convection pass of the boiler.

Conduction is the transfer of heat from one part of a body to another part of the same body, or from one body to another when they are in physical contact.

------------------------------------------------- 19 ------------------------------------------------------

@Su_G #BoilerManual #UnitDescription #Section1 #Page19

The combustion of the combustible elements and compounds of the fuel with all the oxygen requires a temperature high enough to ignite the constituents, mixing or turbulence, and sufficient time for complete conbustion. These factors are referred to as the three T's of combustion.

The heat released as a result of combustion is then transferred to the heat absorbing surfaces of the boiler. In boiler practice, the heat of combustion of a fuel is the amount of heat expressed in Btu, generated by the complete combustion, or oxydation, of a unit weight of fuel (1 lb.).

There are three modes of heat transfer; radiation, convectin and conduction. All the varied phases of heat transfer involve one or more of these modes coupled with a temperature difference between a heat source and heat receiver.

Radiation is the transfer of heat energy between bodies without dependence on the presence of water in the intervening space. All matter radiates, and the transfer of heat (thermal radiation) is one important manifestation of this phenomenon. Radiation occurs when a hot object gives off heat in a straight line away from itself. Radiation is considered the primary mechanism of heat transfer in a furnace, with heat radiating from the hot fire to the cooler furnace walls.

Convection is the transfer of heat from one point to another within a fluid (gas or liquid) by the mixing of one part with another. Heat is transferred by convection when boiler flue gases pass over the tube surface and also when the steam or water pass over the internal surfaces of the tube. Convection is the primary mechanism of heat transfer which occurs in the convection pass of the boiler.

Conduction is the transfer of heat from one part of a body to another part of the same body, or from one body to another when they are in physical contact.

------------------------------------------------- 19 ------------------------------------------------------

@Su_G #BoilerManual #UnitDescription #Section1 #Page18

COMBUSTION & HEAT TRANSFER

A boiler requires a source of heat at a sufficient temperature level to produce steam. At Baldwin, coal is the fuel utilized for the generation of steam and it is burned directly for this purpose in the cyclones and boiler furnace.

Combustion may be defined as the rapid chemical combination of oxygen with the combustible elements of fuel. There are just three combustible chemical elements of significance - carbon, hydrogen and sulfur. Sulfur is of minor significance as a heat source, but it can be of major significance in corrosion and environmental considerations.

The objective of good combustion is to release all of the heat while minimizing losses from combustion imperfections and superfluous air.

------------------------------------------------- 18 ------------------------------------------------------

@Su_G #BoilerManual #UnitDescription #Section1 #Page18

COMBUSTION & HEAT TRANSFER

A boiler requires a source of heat at a sufficient temperature level to produce steam. At Baldwin, coal is the fuel utilized for the generation of steam and it is burned directly for this purpose in the cyclones and boiler furnace.

Combustion may be defined as the rapid chemical combination of oxygen with the combustible elements of fuel. There are just three combustible chemical elements of significance - carbon, hydrogen and sulfur. Sulfur is of minor significance as a heat source, but it can be of major significance in corrosion and environmental considerations.

The objective of good combustion is to release all of the heat while minimizing losses from combustion imperfections and superfluous air.

------------------------------------------------- 18 ------------------------------------------------------

@Su_G #BoilerManual #UnitDescription #Section1 #Page17

The furnace wall tubes are bent to accommodate the cyclone furnaces, observation ports and access doors, sootblowers, recirculated gas ports, and test connections. The floor tubes are bent to form the slag tap openings to discharge the molten ash into the slag tank beneath.

An integral windbox is attached to the furnace wall, in the burner zone of the unit. The windbox provides air distribution to the cyclone furnaces.

Convection Pass Enclosure

With the exception of the roof tubes, the convection pass enclosure for both the horizontal and pendant sections is constructed of membrane tubes.

The portion of the roof over the furnace is constructed of membrane panels. The remainder of the roof, over the pendant and horizontal convection pass, is made of loose tubes suitably spaced to provide for penetration of superheater and reheater tube legs. The convection pass roof tubes are of flat stud construction (Figure 9) between the areas of tube penetration. These flat studs protect and hold in place the backup refractory at the roof line. Roof tubes, tie bars and seal boxes are arranged to form a structural grid to contain furnace or penthouse pressure. Seals around penetrating tube legs are constructed with a layer of refractory at the roof line. Shop applied seal plates welded to the tube legs are seal welded together during erection to afford a completely metallic enclosure.

As a further protection against leakage of dust laden gases into the penthouse, provision is made to pressurize the enclosure slightly above the furnace pressure.

------------------------------------------------- 17 ------------------------------------------------------

@Su_G #BoilerManual #UnitDescription #Section1 #Page17

The furnace wall tubes are bent to accommodate the cyclone furnaces, observation ports and access doors, sootblowers, recirculated gas ports, and test connections. The floor tubes are bent to form the slag tap openings to discharge the molten ash into the slag tank beneath.

An integral windbox is attached to the furnace wall, in the burner zone of the unit. The windbox provides air distribution to the cyclone furnaces.

Convection Pass Enclosure

With the exception of the roof tubes, the convection pass enclosure for both the horizontal and pendant sections is constructed of membrane tubes.

The portion of the roof over the furnace is constructed of membrane panels. The remainder of the roof, over the pendant and horizontal convection pass, is made of loose tubes suitably spaced to provide for penetration of superheater and reheater tube legs. The convection pass roof tubes are of flat stud construction (Figure 9) between the areas of tube penetration. These flat studs protect and hold in place the backup refractory at the roof line. Roof tubes, tie bars and seal boxes are arranged to form a structural grid to contain furnace or penthouse pressure. Seals around penetrating tube legs are constructed with a layer of refractory at the roof line. Shop applied seal plates welded to the tube legs are seal welded together during erection to afford a completely metallic enclosure.

As a further protection against leakage of dust laden gases into the penthouse, provision is made to pressurize the enclosure slightly above the furnace pressure.

------------------------------------------------- 17 ------------------------------------------------------

@Su_G #BoilerManual #UnitDescription #Section1 #Page16

------------------------------------------------- 16 ------------------------------------------------------
Alt = Figure 7 Studded tube construction shows a cross section of 3 tubes whose sides are separated by flat metal and then showing 3 radial studs each that then are coated by refractory (that's a term you might as well use the word "insulation" instead, although they're similar but not alike).
Figure 8 Ribbed tube construction shows a length of tube cut lengthwise to show inner ribs protruding from the inner walls in helical pattern.

@Su_G #BoilerManual #UnitDescription #Section1 #Page16

------------------------------------------------- 16 ------------------------------------------------------
Alt = Figure 7 Studded tube construction shows a cross section of 3 tubes whose sides are separated by flat metal and then showing 3 radial studs each that then are coated by refractory (that's a term you might as well use the word "insulation" instead, although they're similar but not alike).
Figure 8 Ribbed tube construction shows a length of tube cut lengthwise to show inner ribs protruding from the inner walls in helical pattern.

@Su_G #BoilerManual #UnitDescription #Section1 #Page15

Furnace Wall

The water wall furnace is a combustion chamber in which 14 ten foot diameter cyclone furnaces are evenly distributed along the lower section of the front and rear walls. The furnace stands approximately180 feet tall and is 60 feet wide by 33 feet deep.

The furnace walls utilize a gas-tight membrane construction (Figure 6). The lower portion of the furnace is full-studded construction (Figure 7) up to an elevation of 11 feet above the upper cyclone. Internally, the wall tubes are ribbed to maintain effective heat transfer in the high heat input areas of the furnace. This ribbed tube construction (Figure 8) ends at elevation 611' for Unit 1, and 549' for Unit 2.

------------------------------------------------- 15 ------------------------------------------------------
Alt = Figure 6 Membrane wall construction shows a section of 4 tubes side-by-side connected by metal sheets between them; above this section shows a cross-section of those tubes.

@Su_G #BoilerManual #UnitDescription #Section1 #Page15

Furnace Wall

The water wall furnace is a combustion chamber in which 14 ten foot diameter cyclone furnaces are evenly distributed along the lower section of the front and rear walls. The furnace stands approximately180 feet tall and is 60 feet wide by 33 feet deep.

The furnace walls utilize a gas-tight membrane construction (Figure 6). The lower portion of the furnace is full-studded construction (Figure 7) up to an elevation of 11 feet above the upper cyclone. Internally, the wall tubes are ribbed to maintain effective heat transfer in the high heat input areas of the furnace. This ribbed tube construction (Figure 8) ends at elevation 611' for Unit 1, and 549' for Unit 2.

------------------------------------------------- 15 ------------------------------------------------------
Alt = Figure 6 Membrane wall construction shows a section of 4 tubes side-by-side connected by metal sheets between them; above this section shows a cross-section of those tubes.

@Su_G #BoilerManual #UnitDescription #Section1 #Page14

UNIT CONSTRUCTION

The boiler may be regarded as having two distinct areas (based upon the type of heat transfer taking place), the furnace and the convection pass. This distinction is graphically illustrated in Figure 5.

------------------------------------------------- 14 ------------------------------------------------------
Alt = simplified sketch of the entire furnace which can be imagined to be in the shape of an inverted fish hook with the barb on the right side of the page. The labeled Furnace area is along the shank; the convection pass is the horizontal bit between the shank and the barb. Cyclone locations and unlabeled tube areas near the barb part are indicated but not labeled.

@Su_G #BoilerManual #UnitDescription #Section1 #Page14

UNIT CONSTRUCTION

The boiler may be regarded as having two distinct areas (based upon the type of heat transfer taking place), the furnace and the convection pass. This distinction is graphically illustrated in Figure 5.

------------------------------------------------- 14 ------------------------------------------------------
Alt = simplified sketch of the entire furnace which can be imagined to be in the shape of an inverted fish hook with the barb on the right side of the page. The labeled Furnace area is along the shank; the convection pass is the horizontal bit between the shank and the barb. Cyclone locations and unlabeled tube areas near the barb part are indicated but not labeled.

@Su_G #BoilerManual #UnitDescription #Section1 #Page13

{image of the sectional side view of Unit One looking south, in detail, but doesn't actually have a page number. Image is too large and print too small to be accommodated on this instance. I'll try posting it in piecemeal fashion later.}

------------------------------------------------- 13 ------------------------------------------------------

@Su_G #BoilerManual #UnitDescription #Section1 #Page13

{image of the sectional side view of Unit One looking south, in detail, but doesn't actually have a page number. Image is too large and print too small to be accommodated on this instance. I'll try posting it in piecemeal fashion later.}

------------------------------------------------- 13 ------------------------------------------------------

@Su_G #BoilerManual #UnitDescription #Section1 #Page12

18- Windbox - A chamber surrounding the cyclone through which pre-heated air is supplied under

pressure for combustion of the fuel.

{This is all there is on page 12!}

------------------------------------------------- 12 ------------------------------------------------------

@Su_G #BoilerManual #UnitDescription #Section1 #Page12

18- Windbox - A chamber surrounding the cyclone through which pre-heated air is supplied under

pressure for combustion of the fuel.

{This is all there is on page 12!}

------------------------------------------------- 12 ------------------------------------------------------

@Su_G #BoilerManual #UnitDescription #Section1 #Page11

8 - Convection Pass - A gas tight enclosure which houses the primary superheater (PSH), secondary superheater (SSH), reheater superheater (RSH pendant and horizontal) and economizer.

9 - Sootblower (IR) - Mechanical device located in the furnace area and used to maintain the heat absorbing capacity of the furnace walls by clearing tube surfaces of deposits.

10-Sootblower (IK) - Mechanical device located in the convection pass areas (on the sidewalls) of the unit and used in order to clear deposits on tubes and maintain heat absorption capability.

11-Penthouse - Sealed and pressurized enclosure above the boiler roof which houses outlet headers, interconnecting piping, main steam and reheat lines.

12-Slag Tank - For storage and removal of molten coal/ashwhich flows from the furnace floor.

13-Economizer - A heat recovery device designed to transfer heat from the products of combustion (flue gas) to the entering feedwater.

14-Superheater - A group of tubes which absorb heat from the products of combustion (flue gas) to raise the temperature of the vapor passig through the tube above the temperature corresponding to its pressure.The superheater is divided into the primary superheater (PSH) and secondary supeheater (SSH).

15- Reheater - A heat transfer tube bank for heating steam after it has surrendered some of its original heat energy doing work in the high-pressure section of a steam turbine. The reheater is divided into pendant (hanging) and horizontal sections.

16- Gas Recirculation - Recirculated flue gas introduced in the vicinity of the initial burning zone of the furnace and used for steam temperature control.

17- Gas Tempering - Recirculated flue gas introduced near furnace outlet and used for control of gas temperature.

------------------------------------------------- 11 ------------------------------------------------------

@Su_G #BoilerManual #UnitDescription #Section1 #Page11

8 - Convection Pass - A gas tight enclosure which houses the primary superheater (PSH), secondary superheater (SSH), reheater superheater (RSH pendant and horizontal) and economizer.

9 - Sootblower (IR) - Mechanical device located in the furnace area and used to maintain the heat absorbing capacity of the furnace walls by clearing tube surfaces of deposits.

10-Sootblower (IK) - Mechanical device located in the convection pass areas (on the sidewalls) of the unit and used in order to clear deposits on tubes and maintain heat absorption capability.

11-Penthouse - Sealed and pressurized enclosure above the boiler roof which houses outlet headers, interconnecting piping, main steam and reheat lines.

12-Slag Tank - For storage and removal of molten coal/ashwhich flows from the furnace floor.

13-Economizer - A heat recovery device designed to transfer heat from the products of combustion (flue gas) to the entering feedwater.

14-Superheater - A group of tubes which absorb heat from the products of combustion (flue gas) to raise the temperature of the vapor passig through the tube above the temperature corresponding to its pressure.The superheater is divided into the primary superheater (PSH) and secondary supeheater (SSH).

15- Reheater - A heat transfer tube bank for heating steam after it has surrendered some of its original heat energy doing work in the high-pressure section of a steam turbine. The reheater is divided into pendant (hanging) and horizontal sections.

16- Gas Recirculation - Recirculated flue gas introduced in the vicinity of the initial burning zone of the furnace and used for steam temperature control.

17- Gas Tempering - Recirculated flue gas introduced near furnace outlet and used for control of gas temperature.

------------------------------------------------- 11 ------------------------------------------------------

@Su_G #BoilerManual #UnitDescription #Section1 #Page10

These material streams are all essential to the operation of the unit. They will be discussed in greater detail in

a later section of this manual.

COMPONENTS
LOCATION, DESCRIPTION & FUNCTION

See Figure 4 for the location of the following boiler components:

1 - Forced Draft Fan (FD)

2 - Feeders

3 - Cyclones

4 - Induced Draft Fan (ID)

5 - Air Heater

6 - Gas Recirculation Fans (GR)

7 - Furnace

------------------------------------------------- 10 ------------------------------------------------------

@Su_G #BoilerManual #UnitDescription #Section1 #Page10

These material streams are all essential to the operation of the unit. They will be discussed in greater detail in

a later section of this manual.

COMPONENTS
LOCATION, DESCRIPTION & FUNCTION

See Figure 4 for the location of the following boiler components:

1 - Forced Draft Fan (FD)

2 - Feeders

3 - Cyclones

4 - Induced Draft Fan (ID)

5 - Air Heater

6 - Gas Recirculation Fans (GR)

7 - Furnace

------------------------------------------------- 10 ------------------------------------------------------

@Su_G #BoilerManual #UnitDescription #Section1 #Page9

at the economizer inlet header. It passes upward through the economizer to collecting headers. It then passes through downcomer piping to the vicinity of the cyclone furnaces, where multiple pipe connections route the water to each cyclone. The cyclones, which are interconnected, discharge the fluid through multiple connections to a mixing bottle located under the furnace. Here the fluid from all cyclones is mixed to eliminate temperature imbalances in the fluid. From this bottle, the fluid flows to the inlet headers of the furnace floor and side walls, and passes upward through the furnace wall tubes. It is mixed enroute to balance fluid conditions.

From the upper furnace wall headers, the fluid is routed through pipes to the roof inlet header and then through the roof tubes to the roof outlet header where mixing again takes place. It passes through a pipe distribution system to the lower convection pass (CP) enclosure headers and up through the CP side walls, discharging to the upper headers. Pipes convey the fluid to a common header from where it is routed to the primary superheater inlet header.

The fluid is collected and mixed before entering the primary superheater and is partially mixed again as it flows from the primary to the secondary superheater. Side-to-side crossover connections between the primary and secondary superheaters reduce temperature imbalances due to uneven flue gas distribution. The secondary superheater discharges steam to the main steam outlet, which flows to the high pressure (HP) stage of the turbine.

Low pressure steam (HP exhaust) is introduced to the reheater inlet header and flows through the reheater tubes to outlet headers and on to the intermediate (IP and low pressure (LP)stages of the turbine.

From the LP turbine the steam flows through the condenser, condensate polisher, low pressure heaters and deaerator before being reintroduced into the boiler by the feed pumps.

-------------------------------------------------- 9 ------------------------------------------------------

@Su_G #BoilerManual #UnitDescription #Section1 #Page9

at the economizer inlet header. It passes upward through the economizer to collecting headers. It then passes through downcomer piping to the vicinity of the cyclone furnaces, where multiple pipe connections route the water to each cyclone. The cyclones, which are interconnected, discharge the fluid through multiple connections to a mixing bottle located under the furnace. Here the fluid from all cyclones is mixed to eliminate temperature imbalances in the fluid. From this bottle, the fluid flows to the inlet headers of the furnace floor and side walls, and passes upward through the furnace wall tubes. It is mixed enroute to balance fluid conditions.

From the upper furnace wall headers, the fluid is routed through pipes to the roof inlet header and then through the roof tubes to the roof outlet header where mixing again takes place. It passes through a pipe distribution system to the lower convection pass (CP) enclosure headers and up through the CP side walls, discharging to the upper headers. Pipes convey the fluid to a common header from where it is routed to the primary superheater inlet header.

The fluid is collected and mixed before entering the primary superheater and is partially mixed again as it flows from the primary to the secondary superheater. Side-to-side crossover connections between the primary and secondary superheaters reduce temperature imbalances due to uneven flue gas distribution. The secondary superheater discharges steam to the main steam outlet, which flows to the high pressure (HP) stage of the turbine.

Low pressure steam (HP exhaust) is introduced to the reheater inlet header and flows through the reheater tubes to outlet headers and on to the intermediate (IP and low pressure (LP)stages of the turbine.

From the LP turbine the steam flows through the condenser, condensate polisher, low pressure heaters and deaerator before being reintroduced into the boiler by the feed pumps.

-------------------------------------------------- 9 ------------------------------------------------------

@Su_G #BoilerManual #UnitDescription #Section1 #Page8

Fuel Flow
Following the diagram in Figure 2, mined coal is delivered to the plant site and stored in a ready pile or in the storage pile. The coal is later reclaimed, sent through a crusher, and placed in the bunkers which are located above the feeders. This crushed coal is dischaged from the feeders to the cyclone coal inlet at a rate dictated by unit load.

Air and Gas Flow

Air and gas flow is the result of the combination of Force Draft (FD) and Induced Draft (ID) creating differential pressures which sustain flow through the boiler system. The FD fans (3) create the positive (above atmosphere) pressure required to force incoming air through the air heater and ducts to the windbox and cyclones. the ID fans (3) are suction fans which create the negative (below atmosphere) pressure necessary to draw the flue gases through the furnace to the stack. The ID fans also maintain the furnace at a slightly negative pressure.

Air from the FD fans is heated in the tubular air heater and distributed to the cyclones in the form of primary, secondary and tertiary air.

Hot flue gases created through combustion in the cyclones is drawn by the ID fans across tube surfaces in the furnace and convection pass. Its heat is transferred to the tube metal and thus to the water or steam in the tubes. This gas then flows past the economizer and exits the boiler. Flue gas exiting the boiler is drawn through the tubular air heater, precipitator, and ID fans and exits to the atmosphere through the stack.

Water and Steam Flow

Following the diagram in Figure 3, feedwater is introduced into the unit

-------------------------------------------------- 8 ------------------------------------------------------

@Su_G #BoilerManual #UnitDescription #Section1 #Page8

Fuel Flow
Following the diagram in Figure 2, mined coal is delivered to the plant site and stored in a ready pile or in the storage pile. The coal is later reclaimed, sent through a crusher, and placed in the bunkers which are located above the feeders. This crushed coal is dischaged from the feeders to the cyclone coal inlet at a rate dictated by unit load.

Air and Gas Flow

Air and gas flow is the result of the combination of Force Draft (FD) and Induced Draft (ID) creating differential pressures which sustain flow through the boiler system. The FD fans (3) create the positive (above atmosphere) pressure required to force incoming air through the air heater and ducts to the windbox and cyclones. the ID fans (3) are suction fans which create the negative (below atmosphere) pressure necessary to draw the flue gases through the furnace to the stack. The ID fans also maintain the furnace at a slightly negative pressure.

Air from the FD fans is heated in the tubular air heater and distributed to the cyclones in the form of primary, secondary and tertiary air.

Hot flue gases created through combustion in the cyclones is drawn by the ID fans across tube surfaces in the furnace and convection pass. Its heat is transferred to the tube metal and thus to the water or steam in the tubes. This gas then flows past the economizer and exits the boiler. Flue gas exiting the boiler is drawn through the tubular air heater, precipitator, and ID fans and exits to the atmosphere through the stack.

Water and Steam Flow

Following the diagram in Figure 3, feedwater is introduced into the unit

-------------------------------------------------- 8 ------------------------------------------------------

@Su_G #BoilerManual #UnitDescription #Section1 #Page7 is entirely block diagram, Figure 3 Boiler fluid cycle (water-steam-condensate), and I'm afraid my coloring job caused low contrast on the labels. I erased as much of that as I could, but still not sure it'll be readable. (Yeah--had to rework that image, sorry)

Alt = A block diagram with blocks set out over each edge of the paper with arrows indicating that the flow is circular; in the middle is a simplified circular array of double-sided arrows with the bottom side labeled WATER; left side labeled "WATER/STEAM MIXTURE"; top labeled "STEAM"; right side labeled "CONDENSATE".

The inner right side is parallel to the blocks on the outer right side labeled in top-down order and order of flow direction, "Condensor", Condensate pump", and "Condensate polisher".

The inner bottom side is parallel to the outer bottom set of blocks in order from right to left, in flow order, labeled "LP heaters", "Deaerator", "Boiler feed pumps", and "HP heaters".

The inner left side is parallel to the outer left side blocks but the order of flow is from bottom up. Labeled in flow order are: "Economizer", "Downcomers", "Cyclones", "Mix bottles", "Furnace", "Mix bottles", and "Roof inlet header".

The inner top side is parallel to the outer top row of blocks labeled "Roof tubes", "Convection pass", "PSH", "SSH", "HP turbine", "RH", and "IP & LP turbine". PSH = Primary Super Heater; SSH = Secondary Super Heater; HP = High Pressure; RH = Re Heater; IP = Intermediate Pressure; LP = Low Pressure.

-------------------------------------------------- 7------------------------------------------------------

@Su_G #BoilerManual #UnitDescription #Section1 #Page7 is entirely block diagram, Figure 3 Boiler fluid cycle (water-steam-condensate), and I'm afraid my coloring job caused low contrast on the labels. I erased as much of that as I could, but still not sure it'll be readable. (Yeah--had to rework that image, sorry)

Alt = A block diagram with blocks set out over each edge of the paper with arrows indicating that the flow is circular; in the middle is a simplified circular array of double-sided arrows with the bottom side labeled WATER; left side labeled "WATER/STEAM MIXTURE"; top labeled "STEAM"; right side labeled "CONDENSATE".

The inner right side is parallel to the blocks on the outer right side labeled in top-down order and order of flow direction, "Condensor", Condensate pump", and "Condensate polisher".

The inner bottom side is parallel to the outer bottom set of blocks in order from right to left, in flow order, labeled "LP heaters", "Deaerator", "Boiler feed pumps", and "HP heaters".

The inner left side is parallel to the outer left side blocks but the order of flow is from bottom up. Labeled in flow order are: "Economizer", "Downcomers", "Cyclones", "Mix bottles", "Furnace", "Mix bottles", and "Roof inlet header".

The inner top side is parallel to the outer top row of blocks labeled "Roof tubes", "Convection pass", "PSH", "SSH", "HP turbine", "RH", and "IP & LP turbine". PSH = Primary Super Heater; SSH = Secondary Super Heater; HP = High Pressure; RH = Re Heater; IP = Intermediate Pressure; LP = Low Pressure.

-------------------------------------------------- 7------------------------------------------------------

@Su_G #BoilerManual #UnitDescription #Section1 #Page6 is mostly block diagram so an image of the whole page is better posted here, with alt text.

-------------------------------------------------- 6------------------------------------------------------

Alt = Left side of diagram is a column of 4 blocks labeled FUEL FLOW; in descending order are blocks labeled "Mine", "Yard", "Bunker", and "Feeder" with a flow arrow pointing at the bottom block in the middle column labeled "Cyclone".

The center column is labeled AIR FLOW with, in descending order, 2 blocks with the top block ("F.D. Fan") pointing to the second block ("Air heater") but the second block points to the third column's third block, as well as to the center's 2 center blocks set side-by-side (from right to left "Secondary air" and ""Primary & tertiary air"), each of those in turn pointing down to the block labeled "Cyclone".

Third column (right side) is labeled GAS FLOW with six blocks total but in 2 groups of 3. Top 3 group of blocks, in top-down order, are "Stack", I.D Fan", and "Precipitator"--the last block of which is pointed to by the second block ("Air heater") in the middle column. The bottom set of 3 blocks on the right side are "Economizer", "Convection pass", and "Furnace"--first block of which ("Economizer") points to the middle column's block "Air heater". The middle column's bottom block "Cyclone" points to the right column's block "Furnace". At the bottom the image is labeled "Fig. 2 Boiler material streams (fuel-air-gas)." Below Figure 2 is the following text:

MATERIAL STREAMS

1. Fuel flow
2. Air and gas flow
3. Fluid flow - water/steam

@Su_G #BoilerManual #UnitDescription #Section1 #Page6 is mostly block diagram so an image of the whole page is better posted here, with alt text.

-------------------------------------------------- 6------------------------------------------------------

Alt = Left side of diagram is a column of 4 blocks labeled FUEL FLOW; in descending order are blocks labeled "Mine", "Yard", "Bunker", and "Feeder" with a flow arrow pointing at the bottom block in the middle column labeled "Cyclone".

The center column is labeled AIR FLOW with, in descending order, 2 blocks with the top block ("F.D. Fan") pointing to the second block ("Air heater") but the second block points to the third column's third block, as well as to the center's 2 center blocks set side-by-side (from right to left "Secondary air" and ""Primary & tertiary air"), each of those in turn pointing down to the block labeled "Cyclone".

Third column (right side) is labeled GAS FLOW with six blocks total but in 2 groups of 3. Top 3 group of blocks, in top-down order, are "Stack", I.D Fan", and "Precipitator"--the last block of which is pointed to by the second block ("Air heater") in the middle column. The bottom set of 3 blocks on the right side are "Economizer", "Convection pass", and "Furnace"--first block of which ("Economizer") points to the middle column's block "Air heater". The middle column's bottom block "Cyclone" points to the right column's block "Furnace". At the bottom the image is labeled "Fig. 2 Boiler material streams (fuel-air-gas)." Below Figure 2 is the following text:

MATERIAL STREAMS

1. Fuel flow
2. Air and gas flow
3. Fluid flow - water/steam

@Su_G #BoilerManual #UnitDescription #Section1 #Page5
"
Each boiler delivers a maximum continuous main steam flow of 4,200,000 pounds per hour (lb/hr) to a Westinghouse steam turbine generator at 2620 pounds per square inch (PSI) and 1005 F in order to produce a nominal electrical generating capacity of 600 megawatts (MW). At full load the boiler reheater cycle provides 3,788,000 lb/hr of steam to the turbine generator at a pressure of 521 PSI and a temperature of 1005 F. The maximum continuous steam flow is based upon a feedwater temperature of 481 F. Each unit is capable of maintaining normal full load with one cyclone out of service. {A cyclone is where the fire happens}

It is necessary to control steam temperature to correct for fluctuations caused by operating variables. Above 33% load, main steam temperature is controlled by firing rate and two (2) spray attemperators {spray nozzles}. Reheat steam temperature is controlled over 80% load by gas recirculation and one (1) attemperator.

B&W Scope of Supply

*Boiler
*Bypass System
*Economizer
*Primary Superheater
*Secondary Superheater
*Reheat Superheater
*Cyclones
*Air Heater
*Flues and Ducts
*Platform Steel
*Refractories and Insulation {still asbestos, folks}
*Accessories
"
-------------------------------------------------- 5 ------------------------------------------------------

@Su_G #BoilerManual #UnitDescription #Section1 #Page5
"
Each boiler delivers a maximum continuous main steam flow of 4,200,000 pounds per hour (lb/hr) to a Westinghouse steam turbine generator at 2620 pounds per square inch (PSI) and 1005 F in order to produce a nominal electrical generating capacity of 600 megawatts (MW). At full load the boiler reheater cycle provides 3,788,000 lb/hr of steam to the turbine generator at a pressure of 521 PSI and a temperature of 1005 F. The maximum continuous steam flow is based upon a feedwater temperature of 481 F. Each unit is capable of maintaining normal full load with one cyclone out of service. {A cyclone is where the fire happens}

It is necessary to control steam temperature to correct for fluctuations caused by operating variables. Above 33% load, main steam temperature is controlled by firing rate and two (2) spray attemperators {spray nozzles}. Reheat steam temperature is controlled over 80% load by gas recirculation and one (1) attemperator.

B&W Scope of Supply

*Boiler
*Bypass System
*Economizer
*Primary Superheater
*Secondary Superheater
*Reheat Superheater
*Cyclones
*Air Heater
*Flues and Ducts
*Platform Steel
*Refractories and Insulation {still asbestos, folks}
*Accessories
"
-------------------------------------------------- 5 ------------------------------------------------------

@Su_G #BoilerManual #UnitDescription #Section1 #Page4
"
the use of pulverized coal firing was a major improvement over stoker firing, which contributed greatly to capacity.

The result is that today a single boiler can produce 10,000,000 pounds of steam per hour by burning more than 500 tons of coal per hour. Operating pressure in these large units range from 2,500 to almost 4,000 psi and steam temperature is usually 1,000 F or higher. These boilers operate dependably and safely, and remain in service for years {by my count, decades}.

But, for the full potential of the boilers to be realized, they must be opeated and maintained properly, and this job has become more difficult as the boilers have become more sophisticated. The purpose of this section of the training program is to familiarize you with the B&W boilers, and to help you realize all the benefits that 100 years of experience have incorporated into their design.

INTRODUCTION

The Baldwin Power Station, Units 1 and 2 consist of Babcock & Wilcox Universal Pressure (UP) boilers as seen in the attached side views. Practically of identical design, these cyclone-fired {explained later} balanced draft {forced and induced drafts} UP boilers are comprised of a water-cooled slag tap furnace {explained later} superheater, reheater, economizer and air heater. The units are designed to utilize crushed coal as the primary fuel with fuel oil as an ignition medium.
{The units actually utilized pulverized coal; after the coal was crushed, it went through a milling process before being loaded into the boilers}
"
-------------------------------------------------- 4 ------------------------------------------------------

@Su_G #BoilerManual #UnitDescription #Section1 #Page4
"
the use of pulverized coal firing was a major improvement over stoker firing, which contributed greatly to capacity.

The result is that today a single boiler can produce 10,000,000 pounds of steam per hour by burning more than 500 tons of coal per hour. Operating pressure in these large units range from 2,500 to almost 4,000 psi and steam temperature is usually 1,000 F or higher. These boilers operate dependably and safely, and remain in service for years {by my count, decades}.

But, for the full potential of the boilers to be realized, they must be opeated and maintained properly, and this job has become more difficult as the boilers have become more sophisticated. The purpose of this section of the training program is to familiarize you with the B&W boilers, and to help you realize all the benefits that 100 years of experience have incorporated into their design.

INTRODUCTION

The Baldwin Power Station, Units 1 and 2 consist of Babcock & Wilcox Universal Pressure (UP) boilers as seen in the attached side views. Practically of identical design, these cyclone-fired {explained later} balanced draft {forced and induced drafts} UP boilers are comprised of a water-cooled slag tap furnace {explained later} superheater, reheater, economizer and air heater. The units are designed to utilize crushed coal as the primary fuel with fuel oil as an ignition medium.
{The units actually utilized pulverized coal; after the coal was crushed, it went through a milling process before being loaded into the boilers}
"
-------------------------------------------------- 4 ------------------------------------------------------

@Su_G #BoilerManual #UnitDescription #Section1 #Page3
"
vessel. This design would limit the consequences of a pressure part rupture.

While several water tube boiler designs were patented between the late 1700's and the mid 1800's, it was not until 1856 that a significant breakthrough occurred. The design incorporated inclined water tubes connecting water spaces at the front and rear of the furnace with a steam space above. It provided better water circulation and more heating surface than other designs, along with a reduced steam explosion hazard.

Steam was originally used for local heat and power generation. With the advent of practical electric power generation and distribution, utility companies were formed to serve customers over wide areas {see also the Rural Electrification Authority--REA--movement considerably later}. The first such electric generating station in America was the Brush Electric Light Company in Philadelphia. Four 73 hp {horse power} B&W boilers were installed in this plant in 1881. The first utility plant to use steam turbine exclusively for electric power generation was the Fisk Steet Station of Commonwealth Edison in 1903. Ninety-six B&W boilers, rated at 500 hp each, drove the turbines. The boilers operated at 170 psi {pounds per square inch} and 70 F superheat.

Boiler size and unit efficiency are, of course, much greater today than in the early 1900's {keep in mind that this manual is circa 1980s} Several technical advances have made these increases possible. Primary among these is the use of water cooled furnace walls. The water cooled walls greatly reduce refractory maintenance problems {this reads as "insulationary maintenance problems"}, lower gas temperatures leaving the furnace, help reduce fouling and slagging {again, to be explained later} and provide more heating surface with better circulation characteristics to generate more steam.

Improvements in metal technology and separation devices have allowed the use of higher operating pressures and higher steam temperatures for increased capacity and higher efficiency. The increasing use of economizers, air heaters, feedwater heaters, and multi-stage turbines with reheaters have also greatly improved cycle efficiency. Also,
"
-------------------------------------------------- 3 ------------------------------------------------------

@Su_G #BoilerManual #UnitDescription #Section1 #Page3
"
vessel. This design would limit the consequences of a pressure part rupture.

While several water tube boiler designs were patented between the late 1700's and the mid 1800's, it was not until 1856 that a significant breakthrough occurred. The design incorporated inclined water tubes connecting water spaces at the front and rear of the furnace with a steam space above. It provided better water circulation and more heating surface than other designs, along with a reduced steam explosion hazard.

Steam was originally used for local heat and power generation. With the advent of practical electric power generation and distribution, utility companies were formed to serve customers over wide areas {see also the Rural Electrification Authority--REA--movement considerably later}. The first such electric generating station in America was the Brush Electric Light Company in Philadelphia. Four 73 hp {horse power} B&W boilers were installed in this plant in 1881. The first utility plant to use steam turbine exclusively for electric power generation was the Fisk Steet Station of Commonwealth Edison in 1903. Ninety-six B&W boilers, rated at 500 hp each, drove the turbines. The boilers operated at 170 psi {pounds per square inch} and 70 F superheat.

Boiler size and unit efficiency are, of course, much greater today than in the early 1900's {keep in mind that this manual is circa 1980s} Several technical advances have made these increases possible. Primary among these is the use of water cooled furnace walls. The water cooled walls greatly reduce refractory maintenance problems {this reads as "insulationary maintenance problems"}, lower gas temperatures leaving the furnace, help reduce fouling and slagging {again, to be explained later} and provide more heating surface with better circulation characteristics to generate more steam.

Improvements in metal technology and separation devices have allowed the use of higher operating pressures and higher steam temperatures for increased capacity and higher efficiency. The increasing use of economizers, air heaters, feedwater heaters, and multi-stage turbines with reheaters have also greatly improved cycle efficiency. Also,
"
-------------------------------------------------- 3 ------------------------------------------------------

@Su_G #BoilerManual #UnitDescription #Section1 #Page2

coil in a still. To prevent a deficiency of combustion air, a bellows was used to force air to the combustion zone and gases through the flue in what was probably the first instance of forced draft.

As the demand for power increased, the single flue was replaced by many gas tubes which increased the heating surface. More water was exposed to the heat from flue gases. While this fire tube design was popular until about 1870, it was also dangerous. Many disastrous explosions resulted from the direct heating of the pressure shell which contained large amounts of water at saturation temperature. {folks, saturation is when steam under pressure can't take in any more water and there's water still left in the tank, and I'm getting ahead of myself when I mention that this is what the "flashtank" is for}

Boiler designers recognized that one way to overcome the deficiencies of the fire tube boilers was to develop a water tube design which would have most of the heating surface consist of water filled tubes rather than the walls from the combustion zone to the large single containment

Alt = Line image depicting a Hero's Steam engine, a round vessel with two steam ports on opposite sides with depiction of steam coming out of the jets, and suspended over an ornate cauldron holding a blazing fire.

-------------------------------------------------- 2 ------------------------------------------------------

@Su_G #BoilerManual #UnitDescription #Section1 #Page2

coil in a still. To prevent a deficiency of combustion air, a bellows was used to force air to the combustion zone and gases through the flue in what was probably the first instance of forced draft.

As the demand for power increased, the single flue was replaced by many gas tubes which increased the heating surface. More water was exposed to the heat from flue gases. While this fire tube design was popular until about 1870, it was also dangerous. Many disastrous explosions resulted from the direct heating of the pressure shell which contained large amounts of water at saturation temperature. {folks, saturation is when steam under pressure can't take in any more water and there's water still left in the tank, and I'm getting ahead of myself when I mention that this is what the "flashtank" is for}

Boiler designers recognized that one way to overcome the deficiencies of the fire tube boilers was to develop a water tube design which would have most of the heating surface consist of water filled tubes rather than the walls from the combustion zone to the large single containment

Alt = Line image depicting a Hero's Steam engine, a round vessel with two steam ports on opposite sides with depiction of steam coming out of the jets, and suspended over an ornate cauldron holding a blazing fire.

-------------------------------------------------- 2 ------------------------------------------------------

@Su_G #BoilerManual #UnitDescription #Section1 #Page1 of 22 in this section
"
UNIT DESCRIPTION

PURPOSE & OBJECTIVES

This section of the Operating Training Manual will provide you with brief component descriptions for the two Babcock and Wilcox steam generators located at the Baldwin Power Station. The major steam generator auxiliaries such as the forced and induced draft fans, the gas recirculation fans and the air heater will be described, including their functions and locations. The various design parameters such as flows, pressures and temperatures are included, together with a brief description of the combustion and heat transfer process.

HISTORY OF STEAM GENERATION

Steam has long been one of man's most dependable servants, and is still used today to perform many varied and vital functions. Over 90% of the new electric generating capacity being installed in the U.S.A. utilizes steam. Steam also powers most of the sorld's naval vessels, and is an integral part of many industrial processes.

The early steam boilers consisted of little more than a kettle filled with water and heated from the bottom similar to Hero's steam engine which is shown in Figure 1. {the referenced figure appears on Page 2} Boilers in use in the early 1700's still used the kettle principle but burned the fuel in an enclosed furnace to direct more heat to the boiler kettle.

In the mid 1700's, boiler designers noted that nearly half of the heat from the fire was lost because of the very short contact time of the hot gases with the boiler heating surface. To improve boiler efficiency, an ntegral furnace was developed with the fuel actually burned in a container enclosed within the water vessel. A smoke flue wound through the water from the combustion chamber to the atmosphere much like a
"
-------------------------------------------------- 1 ------------------------------------------------------

@Su_G #BoilerManual #UnitDescription #Section1 #Page1 of 22 in this section
"
UNIT DESCRIPTION

PURPOSE & OBJECTIVES

This section of the Operating Training Manual will provide you with brief component descriptions for the two Babcock and Wilcox steam generators located at the Baldwin Power Station. The major steam generator auxiliaries such as the forced and induced draft fans, the gas recirculation fans and the air heater will be described, including their functions and locations. The various design parameters such as flows, pressures and temperatures are included, together with a brief description of the combustion and heat transfer process.

HISTORY OF STEAM GENERATION

Steam has long been one of man's most dependable servants, and is still used today to perform many varied and vital functions. Over 90% of the new electric generating capacity being installed in the U.S.A. utilizes steam. Steam also powers most of the sorld's naval vessels, and is an integral part of many industrial processes.

The early steam boilers consisted of little more than a kettle filled with water and heated from the bottom similar to Hero's steam engine which is shown in Figure 1. {the referenced figure appears on Page 2} Boilers in use in the early 1700's still used the kettle principle but burned the fuel in an enclosed furnace to direct more heat to the boiler kettle.

In the mid 1700's, boiler designers noted that nearly half of the heat from the fire was lost because of the very short contact time of the hot gases with the boiler heating surface. To improve boiler efficiency, an ntegral furnace was developed with the fuel actually burned in a container enclosed within the water vessel. A smoke flue wound through the water from the combustion chamber to the atmosphere much like a
"
-------------------------------------------------- 1 ------------------------------------------------------