Information
-
Patent Grant
-
6817319
-
Patent Number
6,817,319
-
Date Filed
Tuesday, November 25, 200321 years ago
-
Date Issued
Tuesday, November 16, 200420 years ago
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Inventors
-
Original Assignees
-
Examiners
Agents
-
CPC
-
US Classifications
Field of Search
US
- 122 23511
- 122 23523
- 122 23515
- 122 23516
- 122 273
- 122 338
- 122 351
-
International Classifications
-
Abstract
A boiler (10) in which a liquid medium is heated and steam is generated. The boiler (10) includes a housing (12), and a burner (25) for generating hot combustion gases within the housing (12). The boiler also includes a lower drum (30) for receiving the liquid medium, and an upper drum (36) for receiving steam which is generated. A plurality of first tube banks (44) are disposed on both sides of the upper drum (36). The first tube banks (44) including a plurality of first fluid tubes (42) for establishing fluid communications between the lower and upper drums (30, 36), with each first fluid tube defining at least one inwardly extending portion (52). Also provided are a plurality of second tube banks (46) disposed on both sides of the upper drum (36), with the second tube banks (46) being disposed substantially opposite the first tube bank (44). The second tube banks (46) including a plurality of second fluid tubes (43) for establishing fluid communications between the lower and upper drum (30, 36), with each second fluid tube (43) defining at least one inwardly extending portion (68) which is longer than the inwardly extending portions (52) of the first fluid tubes (42), whereby the first and second tube banks define a combustion area (82) within said housing, and cooperatively define with the housing (12) at least a first level of passageways for communicating hot gases across the housing.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
Not Applicable
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not Applicable
BACKGROUND OF THE INVENTION
1. Field of Invention
This invention relates to a boiler for heating a liquid and generating steam. More specifically, the present invention is related to water-tube boilers wherein water is heated in tubes which pass through a combustion chamber.
2. Description of the Related Art
Water-tube boilers are well known in the art. In a typical water-tube boiler, water is heated in tubes that pass through a combustion chamber. The heat from the combustion gases within the combustion chamber is transferred to the water inside the tubes, and the water is converted into steam. The steam which is generated is typically routed to a drum such that the steam is available for various uses, including power generation and heating. In order to maximize the efficiency of the boiler it is desirable to position the boiler tubes within the combustion chamber such that there is efficient transfer of heat from the hot gases generated within the combustion chamber to the water within the boiler tubes. In an effort to improve the transfer of heat to the water within the boiler tubes, boilers have been designed which incorporate a plurality of tubes disposed in tube banks, with the tubes being bent in various configurations. Typical of such boiler designs is the boiler disclosed in U.S. Pat. No. 5,050,542. In this boiler banks of tubes are used to create superposed passageways within the combustion chamber through which the heated gases consecutively pass, in an effort to achieve greater exposure of the tubes, and the water therein, to the heated gases. Other water-tube boiler designs are disclosed in U.S. Pat. Nos. 5,870,976; 4,357,907; 4,355,602; 4,612,879; 3,518,973; 3,195,516; and 1,304,499.
BRIEF SUMMARY OF THE INVENTION
The present invention provides a boiler for generating steam or for heating a liquid medium such as water. The boiler includes a housing having opposite sidewalls, first and second opposite end walls, a base, and a roof. A burner is mounted on the first end wall of the housing for generating hot combustion gases within the housing. The boiler also includes a lower drum for receiving the liquid medium, and an upper drum for receiving the liquid medium and steam generated from the liquid medium, with a steam outlet being provided in the upper drum. A plurality of first fluid tubes are provided which establish fluid communication between the upper and lower drums, with the first fluid tubes being arranged in first tube banks disposed within the housing on both sides of the upper and lower drums. Each of the first fluid tubes is bent to form a pair of inwardly extending portions such that a serpentine configuration is defined. A plurality of second fluid tubes are also provided which establish fluid communication between the upper and lower drums, with the second fluid tubes being arranged in second tube banks disposed within the housing on both sides of the upper and lower drums. In this regard, the first and second tube banks are alternately positioned along each side of the upper and lower drums, and each first tube bank is oppositely disposed from a second tube bank on the opposite side of the upper and lower drums.
Each of the second fluid tubes is bent to form a pair of inwardly extending portions such that a serpentine configuration is defined, the inwardly extending portions of the second fluid tubes being longer than the inwardly extending portions of the first fluid tubes. As a consequence of the configurations of the first and second fluid tubes, and the differing lengths of their respective inwardly extending portions, the first and second tube banks define a combustion area, a first level of passageways for communicating hot gases which defines three separate passageways, a second level passageway for communicating hot gases, and a third level of passageways for communicating hot gases which defines three separate passageways. Further, gas flow is permitted between the first level passageways and the third level passageways so as to allow both linear and serpentine gas flow through the passageways at such levels.
The boiler also includes a plurality of oppositely disposed third fluid tubes proximate the second end wall of the housing for communicating fluid between the lower and upper drum, and a plurality of oppositely disposed fourth fluid tubes proximate the first end wall of the housing for communicating fluid between the lower and upper drum. The third fluid tubes are bent to permit hot gases to be communicated from the combustion area to the first level passageways and from the second level passageway to the third level passageways. The fourth fluid tubes are bent to permit hot gases to be communicated from the first level passageways to the second level passageway and from the third level passageways to the upper interior portion of the housing.
With respect to operation of the boiler of the present invention, water, or another liquid medium, is supplied to the lower drum and the first second and third fluid tubes. The burner is used to generate hot gases in the combustion area defined by the fluid tubes, and such combustion gases travel toward the second end wall of the housing. The configuration of the third fluid tubes allows the hot combustion gases from the combustion area to be communicated to the first level passageways proximate the second end wall of the housing. The hot combustion gases then travel down the first level passageways toward the first end wall of the housing where the configuration of the fourth fluid tubes allows the gases to be communicated to the second level passageway. The hot combustion gases then travel down the second level passageway toward the second end wall of the housing where the configuration of the third fluid tubes allows such gases to be communicated to the third level passageways. The gases then travel down the third level passageways toward the first end wall of the housing where the configuration of the fourth fluid tubes allows the gases to be communicated to the upper portion of the housing where the gases travel across the housing to be exhausted through a flue opening in the housing which is provided in the roof of the housing proximate the second end wall. As the hot gases pass through the various passageways, heat from the gases is transferred to the fluid within the various fluid tubes, and steam is generated in the upper drum.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
The above-mentioned features of the invention will become more clearly understood from the following detailed description of the invention read together with the drawings in which:
FIG. 1
is a perspective view, in section, of a boiler of the present invention;
FIG. 2
is a perspective view of a boiler of the present invention;
FIG. 3
is a perspective view of the heat exchanger assembly of a boiler of the present invention;
FIG. 4
is a side elevation view of the upper and lower drums and downcomers of a boiler of the present invention;
FIG. 5
is a plan view, in section at A—A of
FIG. 8A
of the heat exchanger assembly of a boiler of the present invention;
FIG. 6A
is an end view of fluid tubes of the heat exchanger assembly of a boiler of the present invention;
FIG. 6B
is an end view of fluid tubes of the heat exchanger assembly of a boiler of the present invention;
FIG. 7A
is an end view of fluid tubes of the heat exchanger assembly of a boiler of the present invention;
FIG. 7B
is an end view of fluid tubes of the heat exchanger assembly of a boiler of the present invention;
FIG. 8A
is an end view of fluid tubes of the heat exchanger assembly of a boiler of the present invention; and
FIG. 8B
is an end view of fluid tubes of the heat exchanger assembly of a boiler of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
A boiler in accordance with the present invention is illustrated generally at
10
in the drawings. The boiler
10
can be utilized for heating water to generate steam which can be used for heating, power generation, or various other applications. However, it will be understood that liquid mediums other than water can be used, and for certain applications the boiler
10
can be used for producing a heated liquid rather than steam. Therefore, any references herein to the use of water as a medium, or to the application of the boiler
10
to the generation of steam, are not intended as limitations to the scope of the appended claims.
The boiler
10
generally includes a housing
12
having a base
14
, and first and second sidewalls
16
and
18
, respectively. The housing
12
also has first and second end walls
20
and
22
, respectively, and a roof
24
. As illustrated in broken lines in
FIG. 2
, a burner
25
is mounted on the first end wall
20
. As will be discussed further below, the burner
25
is used to generate hot gases within the housing
12
. In this regard, an opening
26
accessing the interior of the housing
12
is provided in the end wall
20
to accommodate the mounting of the burner
25
, and to facilitate the heating of the interior of the housing
12
. Further, the roof
24
is provided with a flue opening
28
through which combustion gases are exhausted from the housing
12
.
The boiler
10
also includes a heat exchanger assembly
29
having a lower drum
30
for receiving water, or another liquid medium, to be heated in the boiler
10
. The lower drum
30
is mounted so as to extend across the interior of the housing
12
proximate the base
14
. In this regard, in the preferred illustrated embodiment the lower drum
30
spans the interior of the housing
12
, and a first end
32
of the lower drum extends through the first end wall
20
, and a second end
34
of the lower drum
30
extends through the second end wall
22
of the housing
12
. An upper drum
36
is also provided for receiving water, or another liquid medium, and the steam generated from the heating process. The upper drum
36
is mounted so as to extend across the interior of the housing
12
proximate the roof
24
. In the preferred illustrated embodiment, the upper drum
36
spans the interior of the housing
12
, and a first end
38
of the upper drum extends through the first end wall
20
, and a second end
40
of the upper drum
30
extends through the second end wall
22
of the housing
12
. Further, the upper drum
36
is provided with a steam outlet
39
through which the steam generated by the boiler
10
is removed from the upper drum
36
.
The heat exchanger
29
also includes a plurality of fluid tubes
42
and a plurality of fluid tubes
43
within the housing
12
which establish fluid communication between the lower drum
30
and the upper drum
36
thereby allowing water, or another medium, to be communicated from the lower drum
30
to the upper drum
36
. As will be discussed with respect to
FIGS. 6A and 6B
, in the preferred embodiment two different configurations of the fluid tubes
42
are provided and two different configurations of the fluid tubes
43
are provided. However, both configurations of such fluid tubes will be generally referred to herein as fluid tubes
42
and
43
. The fluid tubes
42
and
43
are arranged in opposing tube banks, with each tube bank being made up of a plurality of tubes disposed adjacent to one another. For example, in the preferred illustrated embodiment of
FIG. 5
, the tube banks
44
are made up of a plurality of the tubes
42
and the opposing tube banks
46
are made up of a plurality of the tubes
43
. First and second downcomers
45
and
47
are also provided to allow liquid water, or another liquid medium, to be communicated from the upper drum
36
to the lower drum
30
. In the preferred illustrated embodiment the second downcomer
47
is provided with an inlet
49
(see
FIG. 4
) through which the heat exchanger assembly
29
is supplied with water, or another liquid medium. It will, however, be recognized that the inlet
49
could alternatively be located in other components of the assembly
29
.
As noted above, in the preferred embodiment two different configurations of the fluid tubes
42
and
43
. are provided. In
FIGS. 6A and 6B
the different configurations of the tubes
42
are referenced as
42
′ and
42
″ and the different configurations of the tubes
43
are referenced as
43
′ and
43
″. As illustrated, each of the tubes
42
′ defines a lower leg portion
48
which extends a selected distance from the lower drum
30
outwardly toward the associated sidewall
16
or
18
of the housing
12
, and bends to define an upwardly extending portion
50
. Each of the tubes
42
′ also defines at least a first inwardly extending portion
52
having a first tube run
54
, a reverse bend
56
, and a second tube run
58
. The first tube run
54
extends inwardly from the upwardly extending portion
50
and away from the operatively associated sidewall
16
or
18
to the reverse bend
56
. The second tube run
58
extends from the reverse bend
56
to a point at or proximate the operatively associated sidewall. In the preferred illustrated embodiment, a second inwardly extending portion
52
a
is provided above the inwardly extending portion
52
with a second reverse bend
60
extending between the inwardly extending portions
52
and
52
a
. As illustrated, the inwardly extending portion
52
a
has a first tube run
54
a
, a reverse bend
56
a
, and a second tube run
58
a
. Accordingly, the first and second inwardly extending portions
52
and
52
a
, with the second reverse bend
60
therebetween, define a serpentine configuration. From the inwardly extending portion
52
a
each tube
42
′ extends upwardly proximate the operatively associated sidewall
16
or
18
, and is routed to the upper drum
36
via a further tube run
62
. It will be understood by those skilled in the art that further inwardly expending portions
52
can be provided to extend the length of the serpentine portion of the tube if desired. It will also be understood that a single portion
52
can be used if desired.
As illustrated in
FIG. 6B
, the fluid tubes
42
″ are similar in configuration to the fluid tubes
42
′. However, the lower leg portion
48
″ of the fluid tube
42
″ is angularly disposed so as to engage the lower drum
30
at a different angle, and at a different point along the circumference of the drum
30
than the lower leg portion
48
of the fluid tube
42
′. Similarly, the further tube run
62
″ is angularly disposed so as to engage the upper drum
36
at a different angle than the further tube run
62
of the fluid tube
42
′. In this regard, in the tube banks
44
the adjacent fluid tubes
42
alternate between the fluid tubes
42
′ and
42
″, and the different angular disposition of the lower leg portions
48
″ and further tube runs
62
″ allows the adjacent fluid tubes to engage the upper and lower drums at different circumferential positions. This construction allows the openings
31
in the lower drum
30
and openings
37
in the upper drum
36
, through which the fluid tubes communicate with the upper and lower drums, to be radially offset (see
FIG. 4
) such that the fluid tubes
42
′ and
42
″ can be positioned in close proximity to one another without compromising the structural integrity of the drums
30
and
36
. Given the close proximity of the fluid tubes
42
′ and
42
″, the tube banks
44
define a wall of fluid tubes along much of the length of the fluid tubes
42
.
As illustrated in FG.
6
A, each of the tubes
43
′ defines a lower leg portion
64
which extends a selected distance from the lower drum
30
outwardly toward the associated sidewall
16
or
18
of the housing
12
, and bends to define an upwardly extending portion
66
. Each tube
43
′ also defines at least a first inwardly extending portion
68
having a first tube run
70
, a reverse bend
72
, and a second tube run
74
. The first tube run
70
extends inwardly from the upwardly extending portion
66
, and away from the operatively associated sidewall
16
or
18
, to the reverse bend
72
. The second tube run
74
extends from the reverse bend
72
to a point at or proximate the operatively associated sidewall. In the preferred illustrated embodiment, a second inwardly extending portion
68
a
is defined above the inwardly extending portion
68
with a second reverse bend
76
extending between the inwardly extending portions
68
and
68
a
. As illustrated, the inwardly extending portion
68
a
has a first tube run
70
a
, a reverse bend
72
, and a second tube run
76
a
. Accordingly, the first and second inwardly extending portions
68
and
68
a
, with the second reverse bend
76
therebetween, define a serpentine configuration. From the inwardly extending portion
68
a
, each tube
43
′. extends upwardly proximate the operatively associated sidewall
16
or
18
, and is routed to the upper drum
36
via a further tube run
78
. It will be understood by those skilled in the art that further inwardly expending portions
68
,
68
a
can be provided to extend the length of the serpentine portion of the tube if desired. It will also be understood that a single portion
68
can be used if desired.
As illustrated in
FIG. 6B
, the fluid tubes
43
″ are similar in configuration to the fluid tubes
43
′. However, the lower leg portion
64
″ of each fluid tube
43
″ is angularly disposed so as to engage the lower drum
30
at a different angle than the lower leg portion
64
of the fluid tube
43
′. Similarly, the further tube run
78
″ is angularly disposed so as to engage the upper drum
36
at a different angle than the further tube run
78
of the fluid tube
43
′. In this regard, in the tube banks
46
, the adjacent fluid tubes
43
alternate between the fluid tubes
43
′ and
43
″, and the different angular disposition of the lower leg portions
64
″ and further tube runs
78
″ allows the adjacent fluid tubes to engage the upper and lower drum at different circumferential positions. Thus, the fluid tubes
43
′ and
43
″ can be positioned in close proximity to one another without compromising the structural integrity of the drums
30
and
36
, and given the close proximity of the fluid tubes
43
′ and
43
″, the tube banks
46
define a wall of fluid tubes along much of the length of the fluid tubes
43
.
It will be noted that the inwardly extending portions
52
and
52
a
of the tubes
42
are shorter than the inwardly extending portions
68
and
68
a
of the tubes
43
. In this regard, inwardly extending portions
52
and
52
a
of the fluid tubes
42
extend inwardly to a point short of and selectively spaced from a plane
80
intersecting the axes of the lower drum
30
and the upper drum
36
, the plane
80
being proximate the center of the housing
12
in the preferred embodiment. The inwardly extending portions
68
and
68
a
of the fluid tubes
43
extend inwardly to a point beyond the plane
80
such that the inwardly extending portions of the opposing tubes
42
and
43
terminate at least in close proximity to one another. Moreover, as illustrated in
FIG. 5
, the heat exchanger assembly
29
includes alternating tube banks
44
and
46
on each side of the upper and lower drums
36
and
30
. As a consequence of this construction the tubes
42
and
43
define a combustion area
82
in which the burner
25
generates hot combustion gases, and a series of stacked passageways through which such combustion gases are channeled to the upper portion
83
of the interior of the housing
12
. As illustrated in
FIGS. 6A and 6B
, the inwardly extending portions
52
and
68
of the opposing, and alternating, tube banks
44
and
46
define passageways
84
,
86
, and
88
at a first level above the combustion area
82
which communicate hot combustion gases received from the combustion area. Between the inwardly extending portions
52
and
68
and the inwardly extending portions
52
a
and
68
a
a passageway
90
is defined on a second level above the combustion area
82
which communicates hot combustion gases received from the passageways
84
,
86
, and
88
. Further, the inwardly extending portions
52
a
and
68
a
of the alternating tube banks
44
and
46
define passageways
92
,
94
, and
96
at a third level above the combustion area
82
, which communicate hot combustion gases received from the passageway
90
to the upper portion
83
of the housing
12
.
As illustrated in
FIG. 5
, the alternating disposition of the tube banks
44
and
46
provide not only for linear gas flow down the passageways
84
,
86
, and
88
, but provides for a serpentine flow between such passageways as illustrated by the arrows in FIG.
5
. Similarly, both linear and serpentine gas flow is provided through the passageways
92
,
94
, and
96
. This complex combination of linear and serpentine gas flow down the passageways enhances the heat transfer from the combustion gasses within the passageways to the fluid medium within the tubes
42
and
43
thereby increasing the efficiency of the boiler
10
.
The heat exchanger assembly
29
also includes structures for directing the gas flow from the combustion area
82
to the passageways
84
,
86
and
88
, from the passageways
84
,
86
and
88
to the passageway
90
, from the passageway
90
to the passageways
92
,
94
and
96
, and from the passageways
92
,
94
and
96
to the upper portion
83
of the housing
12
. In this regard, in the preferred illustrated embodiment the boiler
10
is provided with at least a pair, and in the illustrated embodiment four pair, of opposing fluid tubes
98
disposed proximate the second end wall
22
of the housing
12
, and at least a pair, and in the illustrated embodiment three pair, of opposing fluid tubes
100
disposed proximate the first end wall
20
of the housing
12
. The fluid tubes
98
are bent differently from the tubes
42
and
43
to allow combustion gasses to flow from the combustion area
82
to the passageways
84
,
86
and
88
, and from the passageway
90
to the passageways
92
,
94
and
96
. Further, the fluid tubes
100
are bent differently from the tubes
42
and
43
to allow combustion gasses to flow from the passageways
84
,
86
and
88
to the passageway
90
, and from passageways
92
,
94
and
96
to the upper portion
83
of the housing
12
.
More specifically, in the preferred embodiment two different configurations of the fluid tubes
98
are provided, and in
FIGS. 7A and 7B
, such different configurations are referenced as fluid tubes
98
′ and
93
″. Each of the tubes
98
′ defines an a lower leg portion
102
which extends a selected distance from the lower drum
30
outwardly toward the associated sidewall
16
or
18
of the housing
12
, and bends to define an upwardly extending portion
104
. Each tube
98
′ also defines at least one inwardly extending portion
106
having an inwardly extending and substantially horizontal tube run
108
, a substantially vertical tube run
110
, and an outwardly extending and substantially horizontal tube run
112
. It will be recognized that the inwardly extending portions
106
of the opposing fluid tubes
98
′ are disposed above the first level of passageways
84
,
86
and
88
) such that the tubes
98
′ allow fluid communication between the combustion area
82
and the first level of passageways proximate the second end wall
22
. However, fluid communications between the first level passageways and the passageway
90
is inhibited proximate the second end wall
22
. Further, the inwardly extending portions
106
provide an open area and fluid communications between the second level passageway
90
and the third level passageways
92
,
94
and
96
proximate the second end wall
22
while inhibiting fluid communication between the third level passageways and the upper portion
83
of the housing
12
. From the inwardly extending portion
106
each tube
98
′ extends upwardly proximate the operatively associated sidewall
16
or
18
, and is routed to the upper drum
36
via a further tube run
114
. It will be noted that in the preferred embodiment the inwardly extending portions
106
extend inwardly to a point short of the plane
80
and a baffle
115
is disposed between the inwardly extending portions
106
of opposing fluid tubes
98
′.
As illustrated in
FIG. 7B
, the fluid tubes
98
″ are similar in construction to the tubes
98
′. However, the lower leg portion
102
″ of each fluid tube
98
″ is angularly disposed so as to engage the lower drum
30
at a different angle than the lower leg portion
102
of the fluid tube
98
′. Similarly, the further tube run
114
″ is angularly disposed so as to engage the upper drum
36
at a different angle than the further tube run
124
of the fluid tube
98
′. In this regard, alternating tubes
98
′ and
98
″ are used, and the different angular disposition of the lower leg portions
102
″ and further tube runs
114
″ allows the adjacent fluid tubes to engage the upper and lower drum at different angles facilitating the close disposition of the fluid tubes
98
.
With respect to the fluid tubes
100
, in the preferred embodiment two different configurations of the fluid tubes
100
are provided, and in
FIGS. 8A and 8B
, such different configurations are referenced as fluid tubes
100
′ and
100
″. Each of the tubes
100
′ defines a lower leg portion
116
which extends a selected distance from the lower drum
30
outwardly toward the associated sidewall
16
or
18
of the housing
12
, and bends to define an upwardly extending portion
118
. Each tube
100
′ also defines at least one inwardly extending portion
120
having an inwardly extending and substantially horizontal tube run
122
, a substantially vertical tube run
124
, and an outwardly extending and substantially horizontal tube run
126
. It will be recognized that the inwardly extending portions
120
of the opposing fluid tubes
100
′ are disposed above the combustion area
82
such that they inhibit gas flow from the combustion area
82
to the first level of passageways. Further, the inwardly extending portions
120
provide an open area and fluid communications between the first level passageways
84
,
86
and
88
and the second level passageway
90
proximate the first end wall
20
of the housing
12
. From the inwardly extending portion
120
the tube
100
′ extends upwardly proximate the operatively associated sidewall
16
or
18
, and is routed to the upper drum
36
via a further tube run
128
such that gas flow between passageway
90
and the third level passageways
90
,
92
and
94
is inhibited, but gas flow between the third level passages and the upper portion
83
of the housing
12
proximate the first end wall
20
is permitted. It will be noted that in the preferred embodiment the inwardly extending portions
120
extend inwardly to a point short of the plane
80
, and a baffle
130
is disposed between the inwardly extending portions
120
of opposing fluid tubes
100
′.
As illustrated in
FIG. 83
, the fluid tubes
100
″ are similar in construction to the tubes
100
′. However, the lower leg portion
116
″ of each fluid tube
100
″ is angularly disposed so as to engage the lower drum
30
at a different angle than the lower leg portion
116
of the fluid tube
100
′. Similarly, the further tube run
128
″ is angularly disposed so as to engage the upper drum
36
at a different angle than the further tube run
128
of the fluid tube
100
′. In this regard, alternating tubes
100
′ and
100
″ are used, and the different angular disposition of the lower leg portions
116
″ and further tube runs
128
″ allows the adjacent fluid tubes to engage the upper and lower drum at different angles to facilitate the close disposition of the fluid tubes
100
.
Whereas the fluid tubes
98
and
100
provide the preferred structures for communicating hot gases between the combustion area, and the various levels of passageways, to the upper portion of the housing, it will be understood that other structures such as conduits or baffles could alternatively be used.
With respect to operation of the boiler
10
, water, or another liquid medium, is supplied to the heat exchanger assembly
29
through the inlet
49
and is communicated into the fluid tubes
42
,
43
,
98
, and
100
. The burner
25
is used to generate hot combustion gases in the combustion area
82
defined by the fluid tubes
42
and
43
, and such combustion gases travel toward the second end wall
22
of the housing
12
. The configuration of the tubes
98
allow the hot combustion gases from the combustion area to be communicated to the first level passageways
84
,
86
and
88
proximate the second end wall
22
. The hot combustion gases then travel down the first level passageways toward the first end wall
20
of the housing
12
, and the configuration of the fluid tubes
100
allows the gases to be communicated to the second level passageway
90
. The hot combustion gases then travel down the passageway
90
toward the second end wall
22
, and the configuration of the fluid tubes
98
allow such gases to be communicated to the third level passageways
92
,
94
and
96
. The gases then travel down the third level passageways toward the first end wall
20
, and the configuration of the fluid tubes
100
allows the gases to be communicated to the upper portion
83
of the housing where the gases travel across the housing to be exhausted through the flue opening
28
which is disposed proximate the second end wall
22
.
It will be recognized that as a consequence of the configuration of the fluid tubes
42
and
43
, and the resulting complex combination of linear and serpentine gas flow through the first and third level passageways, there is an efficient exchange of heat from the combustion gases to the liquid within the tubes
42
and
43
. Further, heat is transferred to liquid within the tubes
98
and
100
, and liquid within the upper and lower drums
36
and
30
. As the liquid is heated, steam is generated in the upper drum
36
, and removed from the boiler
10
through the steam outlet
39
. The water or other medium within the upper drum
36
which remains in a liquid state is communicated through the downcomers
45
and
47
to the lower drum
30
for recirculation.
In view of the above, it will be recognized by those skilled in the art that the boiler
10
provides great advantages over the prior art. The configuration of the fluid tubes
42
,
43
,
98
and
100
provides for a flow of hot gas through the boiler
10
which greatly increases heat transfer to the liquid within the various tubes, and greatly increases the efficiency of the boiler
10
when compared to boilers of the prior art. While the present invention has been illustrated by description of several embodiments and while the illustrative embodiments have been described in considerable detail, it is not the intention of the applicant to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications will readily appear to those skilled in the art. The invention in its broader aspects is therefore not limited to the specific details, representative apparatus and methods, and illustrative examples shown and described. Accordingly, departures may be made from such details without departing from the spirit or scope of applicant's general inventive concept.
Claims
- 1. A boiler in which a liquid medium is heated, said boiler comprising:a housing having first and second ends; a lower drum for receiving the liquid medium, at least a portion of said lower drum being disposed within said housing; an upper drum at least a portion of which is disposed within an upper portion of said housing, said upper drum having an outlet; at least a first tube bank disposed within said housing on a first side of said upper drum, said first tube bank including a plurality of first fluid tubes for establishing fluid communication between said lower drum and said upper drum, each said first fluid tube defining at least one inwardly extending portion; at least a second tube bank disposed within said housing on a second side of said upper drum, said second tube bank being disposed substantially opposite said first tube bank, said second tube bank including a plurality of second fluid tubes for establishing fluid communication between said lower drum and said upper drum, each said second fluid tube defining at least one inwardly extending portion which is longer than said inwardly extending portions of said first fluid tubes of said first tube bank, whereby said first and second tube banks define a combustion area within said housing, and cooperatively define with said housing at least a first level of passageways for communicating hot gases; a burner for generating hot gases within said combustion area; and means for communicating hot gases from said combustion area to said first level of passageways and for communicating hot gases from said first level of passageways to said upper portion of said housing, whereby heat from said hot gases is transferred to the liquid medium within said first and second fluid tubes thereby heating the liquid medium.
- 2. The boiler of claim 1 wherein said boiler further comprises at least one said first tube bank on said second side of said upper drum, and at least one said second tube bank on said first side of said upper drum, said first tube bank on said second side of said upper drum being disposed substantially opposite said second tube bank on said first side of said upper drum, whereby said first level of passageways defines at least three passageways providing linear paths for hot gases to travel.
- 3. The boiler of claim 1 wherein said boiler comprises a plurality of said first and second tube banks alternately disposed on said first side of said upper drum, and a plurality of first and second tube banks alternately disposed on said second side of said upper drum, each said first tube bank being disposed opposite one said second tube bank, whereby said first level of passageways defines at least three passageways providing linear paths for hot gases to travel and whereby serpentine gas flow between said three passageways is permitted.
- 4. The boiler of claim 1 wherein each said first fluid tube defines a second inwardly extending portion above said first inwardly extending portion of said first fluid tube, and wherein each said second fluid tube defines a second inwardly extending portion above said first inwardly extending portion of said second fluid tube, whereby said first and second tube banks define said first level of passageways, a second level passageway, and a third level of passageways.
- 5. The boiler of claim 4 wherein said boiler comprises a plurality of said first and second tube banks alternately disposed on said first side of said upper drum, and a plurality of first and second tube banks alternately disposed on said second side of said upper drum, each said first tube bank being disposed opposite one said second tube bank, whereby said first and third levels of passageways each define at least three passageways providing linear paths for hot gases to travel and whereby serpentine gas flow between said passageways of said first level of passageways is permitted and serpentine gas flow between said passageways of said third level of passageways is permitted.
- 6. A boiler in which a liquid medium is heated, said boiler comprising:a housing having first and second ends, and an upper interior portion; a lower drum for receiving the liquid medium, at least a portion of said lower drum being disposed within said housing; an upper drum at least a portion of which is disposed within an upper portion of said housing, said upper drum having an outlet and first and second sides; a plurality of first tube banks disposed within said housing on each said first and second side of said upper drum, each said first tube bank including a plurality of first fluid tubes for establishing fluid communication between said lower drum and said upper drum, each said first fluid tube defining at least a first inwardly extending portion; a plurality of second tube banks disposed within said housing on each said first and second side of said upper drum, each said second tube bank being disposed substantially opposite one of said first tube banks; each said second tube bank including a plurality of second fluid tubes for establishing fluid communication between said lower drum and said upper drum, each said second fluid tube defining at least a first inwardly extending portion which is longer than said inwardly extending portions of said first fluid tubes of said first tube banks, said first and second tube banks being alternately disposed along said first and second sides of said upper drum, whereby said first and second tube banks define a combustion area within said housing and cooperatively define with said housing at least a first level of passageways for communicating hot gases, said first level of passageways including first, second and third passageway, whereby linear flow of hot gases is permitted through said first, second and third passageways, and serpentine flow of hot gases is permitted between said first, second and third passageways; a burner mounted at said first end of said housing for generating hot gases within said combustion area; and means for communicating hot gases from said combustion area to said first level of passageways proximate said second end of said housing, and for communicating hot gases from said first level of passageways to said upper interior portion of said housing whereby heat from said hot gases is transferred to the liquid medium within said first and second fluid tubes thereby heating the liquid medium.
- 7. The boiler of claim 6 wherein each said first fluid tube defines a second inwardly extending portion, and each said second fluid tube defines a second inwardly extending portion, said second inwardly extending portion each of said second fluid tubes being longer than said second inwardly extending portions of said first fluid tubes, whereby said first and second tube banks define a second level passageway between said first and second inwardly extending portions of said first and second fluid tubes, and said first and second tube banks define a third level of passageways defining first, second and third passageways.
- 8. The boiler of claim 7 wherein said means for communicating hot gases from said combustion area to said first level of passageways proximate said second end of said housing, and for communicating hot gases from said first level of passageways to said upper portion of said housing, further communicates hot gases from said first level of passageways to said second level passageway proximate said first end of said housing, communicates hot gases from said second level passageway to said third level of passageways proximate said second end of said housing, and communicates hot gases from said third level of said passageways to said upper interior portion of said housing proximate said first end of said housing.
- 9. The boiler of claim 8 wherein each said first fluid tube defines a lower leg portion which extends a selected distance from said lower drum outwardly toward an associated sidewall of said housing, and bends to define an upwardly extending portion communicating with said first inwardly extending portion of said first fluid tube, each said first and second inwardly extending portion of each said first fluid tube having a first tube run extending inwardly away from said associated sidewall of said housing and a reverse bend extending from said first tube run to a second tube run extending toward said associated sidewall of said housing, each said first fluid tube having a further reverse bend joining said first and second inwardly extending portions of said first fluid tube, and each said first fluid tube extending upwardly from said second inwardly extending portion and defining a further tube run terminating at said upper drum, and wherein each said second fluid tube defines a lower leg portion which extends a selected distance from said lower drum outwardly toward an associated sidewall of said housing, and bends to define an upwardly extending portion communicating with said first inwardly extending portion of said second fluid tube, each said first and second inwardly extending portion of each said second fluid tube having a first tube run extending inwardly away from said associated sidewall of said housing and a reverse bend extending from said first tube run to a second tube run extending toward said associated sidewall of said housing, each said second fluid tube having a further reverse bend joining said first and second inwardly extending portions of said second fluid tube, and each said second fluid tube extending upwardly from said second inwardly extending portion and defining a further tube run terminating at said upper drum.
- 10. The boiler of claim 9 wherein said means for communicating hot gases from said combustion area to said first level of passageways proximate said second end of said housing, and for communicating hot gases from said first level of passageways to said upper portion of said housing includes a plurality of oppositely disposed third fluid tubes proximate said second end of said housing communicating between said lower drum and said upper drum, and a plurality of oppositely disposed fourth fluid tubes proximate said first end portion of said housing communicating between said lower drum and said upper drum, said third fluid tubes being bent to permit hot gases to be communicated from said combustion area to said first level passageways, and from said second level passageway to said third level passageways, said fourth fluid tubes being bent to permit hot gases to be communicated from said first level passageways to said second level passageway, and from said third level passageways to said upper interior portion of said housing.
- 11. The boiler of claim 10 wherein each said third fluid tube defines a lower leg portion which extends a selected distance from said lower drum outwardly toward an associated sidewall of said housing and bends to define an upwardly extending portion, each said third tube defining at least one inwardly extending portion having an inwardly extending tube run, an upwardly extending tube run, and an outwardly extending tube run, said third fluid tube extending upwardly from said inwardly extending portion of said third fluid tube and defining a further tube run terminating at said upper drum.
- 12. The boiler of claim 11 wherein each said fourth fluid tube defines a lower leg portion which extends a selected distance from said lower drum outwardly toward an associated sidewall of said housing and bends to define an upwardly extending portion, each said fourth fluid tube defining at least one inwardly extending portion having an inwardly extending tube run, an upwardly extending tube run, and an outwardly extending tube run, each said fourth fluid tube extending upwardly from said inwardly extending portion of said fourth fluid tube and defining a further tube run terminating at said upper drum.
- 13. The boiler of claim 8 wherein said means for communicating hot gases from said combustion area to said first level of passageways proximate said second end of said housing, and for communicating hot gases from said first level of passageways to said upper portion of said housing includes a plurality of oppositely disposed third fluid tubes proximate said second end of said housing communicating between said lower drum and said upper drum, and a plurality of oppositely disposed fourth fluid tubes proximate said first end portion of said housing communicating between said lower drum and said upper drum, said third fluid tubes being bent to permit hot gases to be communicated from said combustion area to said first level passageways, and from said second level passageway to said third level passageways, said fourth fluid tubes being bent to permit hot gases to be communicated from said first level passageways to said second level passageway, and from said third level passageways to said upper interior portion of said housing.
- 14. A boiler in which a liquid medium is heated, said boiler comprising:a housing having first and second ends, and an upper interior portion; a lower drum for receiving the liquid medium, at least a portion of said lower drum being disposed within said housing; an upper drum at least a portion of which is disposed within an upper portion of said housing, said upper drum having an outlet and first and second sides; a plurality of first tube banks disposed within said housing on each said first and second side of said upper drum, each said first tube bank including a plurality of first fluid tubes for establishing fluid communication between said lower drum and said upper drum, each said first fluid tube defining a lower leg portion which extends a selected distance from said lower drum outwardly toward an associated sidewall of said housing and bends to define an upwardly extending portion communicating with a first inwardly extending portion of said first fluid tube, said first inwardly extending portion including a first tube run extending inwardly from said upwardly extending portion away from said associated sidewall of said housing and including a reverse bend extending from said first tube run to a second tube run extending toward said associated sidewall of said housing where said first fluid tube defines a further reverse bend, said first fluid tube further defining a second inwardly extending portion including a first tube run extending inwardly from said further reverse bend away from said associated sidewall of said housing and including a reverse bend extending from said first tube run to a second tube run extending toward said associated sidewall of said housing, said first fluid tube extending upwardly from said second inwardly extending portion and defining a further tube run terminating at said upper drum; a plurality of second tube banks disposed within said housing on each said first and second side of said upper drum, each said second tube bank being disposed substantially opposite one of said first tube banks, each said second tube bank including a plurality of second fluid tubes for establishing fluid communication between said lower drum and said upper drum, each said second fluid tube defining a lower leg portion which extends a selected distance from said lower drum outwardly toward an associated sidewall of said housing and bending to define an upwardly extending portion communicating with a first inwardly extending portion of said second fluid tube, said first inwardly extending portion of said second fluid tube including a first tube run extending inwardly from said upwardly extending portion away from said associated sidewall of said housing and including a reverse bend extending from said first tube run to a second tube run extending toward said associated sidewall of said housing where said second fluid tube defines a further reverse bend, said second fluid tube further defining a second inwardly extending. portion including a first tube run extending inwardly from said further reverse bend of said second fluid tube away from said associated sidewall of said housing, and including a reverse bend extending from said first tube run of said second inwardly extending portion of said second fluid tube to a second tube run extending toward said associated sidewall of said housing, said second fluid tube extending upwardly from said second inwardly extending portion and defining a further tube run terminating at said upper drum, said first and second inwardly extending portions of said second fluid tubes being longer than said first and second inwardly extending portions of said first fluid tubes, and said first and second tube banks being alternately disposed along said first and second sides of said upper drum, whereby said first and second tube banks define a combustion area within said housing, cooperatively define with said housing at least a first level of passageways for communicating hot gases, define a second level passageway for communicating hot gases, and cooperatively define with said housing a third level of passageways, said first level of passageways including a first, second and third passageways and said third level of passageways including first, second and third passageway; a burner mounted at said first end of said housing for generating hot gases within said combustion area; and a plurality of oppositely disposed third fluid tubes proximate said second end of said housing communicating between said lower drum and said upper drum, and a plurality of oppositely disposed fourth fluid tubes proximate said first end portion of said housing communicating between said lower drum and said upper drum, said third fluid tubes being bent to permit hot gases to be communicated from said combustion area to said first level passageways, and from said second level passageway to said third level passageways, said fourth fluid tubes being bent to permit hot gases to be communicated from said first level passageways to said second level passageway, and from said third level passageways to said upper interior portion of said housing.
- 15. The boiler of claim 14 wherein each said third fluid tube defines a lower leg portion which extends a selected distance from said lower drum outwardly toward an associated sidewall of said housing and bends to define an upwardly extending portion, each said third tube defining at least one inwardly extending portion having an inwardly extending tube run, an upwardly extending tube run, and an outwardly extending tube run, said third fluid tube extending upwardly from said inwardly extending portion of said third fluid tube and defining a further tube run terminating at said upper drum.
- 16. The boiler of claim 15 wherein each said fourth fluid tube defines a lower leg portion which extends a selected distance from said lower drum outwardly toward an associated sidewall of said housing and bends to define an upwardly extending portion, each said fourth fluid tube defining at least one inwardly extending portion having an inwardly extending tube run, an upwardly extending tube run, and an outwardly extending tube run, each said fourth fluid tube extending upwardly from said inwardly extending portion of said fourth fluid tube and defining a further tube run terminating at said upper drum.
- 17. The boiler of claim 14 wherein said boiler includes a first downcomer disposed outside of said housing for establishing fluid communication between said upper drum and said lower drum.
- 18. The boiler of claim 17 wherein said boiler includes a second downcomer disposed outside of said housing for establishing fluid communication between said upper drum and said lower drum.
US Referenced Citations (11)