U.S. patent number 3,628,508 [Application Number 04/887,942] was granted by the patent office on 1971-12-21 for waste-heat boilers and like gas/liquid heat transfer systems.
Invention is credited to Joachim Kummel.
United States Patent |
3,628,508 |
Kummel |
December 21, 1971 |
WASTE-HEAT BOILERS AND LIKE GAS/LIQUID HEAT TRANSFER SYSTEMS
Abstract
A waste-heat boiler, for use in a system having two units in
tandem in the direction of gas flow and with at least one unit
having a valved bypass, has a three-section cylindrical housing in
which a plurality of heat-exchange pipes extend axially. At one
housing end is a gas inlet and at the opposite end a gas outlet. An
outer row of the pipes is welded together to form a gastight wall
that defines an annular insulating chamber with the housing
interior. Another such circular row of pipes forms another wall
having openings at each end near the inlet and outlet. This other
wall forms an annular gas chamber with the first-mentioned wall, in
which chamber the rest of the pipes are located. A central, axial
bypass passage through the boiler is pipe-free and has a valve for
blocking gas flow and forcing air through the other chamber. The
three housing sections are axially displaceable relative to one
another and the two walls are similarly relatively displaceable,
the outer wall being fixed to the top housing section. FIELD OF THE
INVENTION The present invention relates to a gas-liquid
heat-exchange unit and, more particularly, to a waste-heat boiler
intended for use with cracking gases, power-plant combustion waste
gases, power fluids and the like. BACKGROUND OF THE INVENTION A
waste-heat boiler generally consists of a cylindrical housing
through which extremely hot, often in the neighborhood of
1,000.degree. C., compressed gas is passed in which are mounted
coils or other heat-exchanger means for absorbing the heat of the
gas for use elsewhere. Water can be boiled with this heat and
thence used as steam to run turbines or the like. Furthermore, the
heat-exchange unit serves to lower the temperature of the gas upon
which it operates to acceptable levels for other uses or for
disposal. Such devices present several problems. There is usually
no means of efficiently regulating the gas flow through them since,
when no heat is needed, the circulation of liquid through the coils
cannot simply be stopped because the inevitable large buildup of
heat would assuredly rupture the coils and otherwise ruin the
device. Furthermore, since such devices are used often in
conjunction with gases carrying any of a multitude of contaminants,
their interiors must be periodically cleaned. Ports having doors
are generally provided to give access to the device during this
cleaning operation. These doors, however, present a leak hazard and
usually make the thorough insulation of the boiler impossible.
Another problem is the requirement for thermal insulation, the
interior of the housing being often lined with refractory brick or
the like to prevent excessive heat loss. Such brick greatly
increases the bulk and cost of such a boiler. It should be noted
that conventional waste-heat boiler systems may include two such
boilers in tandem or series in the direction of gas flow, both of
which can be provided with tube bundles or nests for the passage of
water, but one of which is provided with a valved bypass for its
tube nest. OBJECTS OF THE INVENTION It is, therefore, a general
object of the present invention to provide an improved gas-liquid
heat-exchange unit for the above-described purposes. A more
specific object is to provide a waste-heat boiler which overcomes
the above-mentioned disadvantages, i.e. which is easy to clean,
whose heat-exchange rate can be easily regulated, which is readily
assembled and taken apart, and which is relatively compact and
inexpensive. SUMMARY OF THE INVENTION In accordance with the
present invention, the above objects are obtained by a unit having
a hollow elongated housing having an upper outlet and a lower
inlet. First axially extending wall means, consisting mainly of a
ring of parallel pipes welded together in gastight relationship
generally cylindrical defines with the interior of the housing a
closed axial compartment which acts as an insulating zone for the
boiler. Second axially extending annular wall means within the
first, and similarly formed, define an annular axially elongated
chamber open at its upper end toward the outlet and at its lower
end toward the inlet. This second wall further defines an axial
bypass passage through the center of the housing, with a valve in
the passage serving to regulate air flow therethrough and thereby
force air at a measured rate through the chamber. Each wall is
formed by a respective member of a pair of coaxial, separable, but
nested members. Means for passing liquid through both walls is
provided in the form of the customary pumps and loads. The boiler,
according to the present invention, solves several problems in a
surprisingly effective manner. It permits the adjustment of the
heat-exchange rate by means of a valve which determines the
proportion of the hot air which passes straight through the central
bypass passage and the proportion diverted through the exterior
heat-exchange chamber which is, according to another feature,
provided with its own heat exchanger means in the form of axially
extending pipes. Cleaning is easy since the housing, first wall,
and second wall can be easily separated from each other by axially
displacing them relative to each other. The outer insulating
chamber formed between the first wall and the housing insulates
well while adding no additional weight to the device.
Inventors: |
Kummel; Joachim
(Castrop-Rauxel, DT) |
Family
ID: |
5717396 |
Appl.
No.: |
04/887,942 |
Filed: |
December 24, 1969 |
Foreign Application Priority Data
|
|
|
|
|
Dec 24, 1968 [DT] |
|
|
P 18 17 002.0 |
|
Current U.S.
Class: |
122/7R;
122/338 |
Current CPC
Class: |
F22B
1/1846 (20130101) |
Current International
Class: |
F22B
1/18 (20060101); F22B 1/00 (20060101); F22b
001/18 () |
Field of
Search: |
;122/7,235,338 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
|
|
|
|
|
|
|
869,394 |
|
May 1961 |
|
GB |
|
1,354,149 |
|
Jan 1964 |
|
FR |
|
Primary Examiner: Sprague; Kenneth W.
Claims
I claim:
1. A gas-liquid heat-exchange unit comprising:
a hollow elongated housing having an inlet at one end and an outlet
at the other end;
first axially extending annular wall means defining with the
interior of said housing a closed axially extending annular
compartment;
second axially extending annular wall means within said first wall
means and forming therewith an annular axially elongated chamber
open at one end toward said inlet and at the other end toward said
outlet, said second wall means forming an axially extending
substantially central bypass passage having one end open toward
said inlet and another end open toward said outlet, said wall means
each being formed by a respective member of a pair of substantially
coaxial axially relatively displaceable separable nested members;
and
means for passing liquid through both said wall means and valve
means in said passage between the ends thereof for selectively
blocking gas flow through said passage and thereby forcing gas to
flow through said chamber.
2. The unit defined in claim 1 wherein said housing constitutes a
third member substantially coaxially nested with said two
first-mentioned members.
3. The unit defined in claim 1 wherein said housing is arranged
upright and said input is below and substantially axially in line
with said output.
4. The unit defined in claim 1 wherein said valve means includes an
axially displaceable slider displaceable into and out of a position
blocking said gas flow.
5. A gas-liquid heat-exchange unit comprising:
a hollow elongated housing having an inlet at one end and an outlet
at the other end;
first axially extending annular wall means defining with the
interior of said housing a closed axially extending annular
compartment;
second axially extending annular wall means within said first wall
means and forming therewith an annular axially elongated chamber
open at one end toward said inlet and at the other end toward said
outlet, said second wall means forming an axially extending
substantially central bypass passage having one end open toward
said inlet and another end open toward said outlet, said wall means
each being formed by a respective member of a pair of substantially
coaxial separable nested members;
means for passing liquid through both said wall means and valve
means in said passage between the ends thereof for selectively
blocking gas flow through said passage and thereby forcing gas to
flow through said chamber; and
heat exchanger means in said chamber between said wall means.
6. A gas-liquid heat-exchange unit comprising:
a hollow elongated housing having an inlet at one end and an outlet
at the other end;
first axially extending annular wall means defining with the
interior of said housing a closed axially extending annular
compartment;
second axially extending annular wall means within said first wall
means and forming therewith an annular axially elongated chamber
open at one end toward said inlet and at the other end toward said
outlet, said second wall means forming an axially extending
substantially central bypass passage having one end open toward
said inlet and another end open toward said outlet, said wall means
each being formed by a respective member of a pair of substantially
coaxial separable nested members; and
means for passing liquid through both said wall means and valve
means in said passage between the ends thereof for selectively
blocking gas flow through said passage and thereby forcing gas to
flow through said chamber, said wall means each consisting of a
plurality of axially extending conduits joined longitudinally.
7. The unit defined in claim 6 wherein said members are axially
displaceable relative to each other.
8. A gas-liquid heat-exchange unit comprising:
a hollow elongated housing having an inlet at one end and an outlet
at the other end;
first axially extending annular wall means defining with the
interior of said housing a closed axially extending annular
compartment;
second axially extending annular wall means within said first wall
means and forming therewith an annular axially elongated chamber
open at one end toward said inlet and at the other end toward said
outlet, said second wall means forming an axially extending
substantially central bypass passage having one end open toward
said inlet and another end open toward said outlet, said wall means
each being formed by a respective member of a pair of substantially
coaxial separable nested members; and
means for passing liquid through both said wall means and valve
means in said passage between the ends thereof for selectively
blocking gas flow through said passage and thereby forcing gas to
flow through said chamber, said housing comprising a top section, a
middle section, and a base section, all three said sections being
axially displaceable relative to one another.
9. The unit defined in claim 8 wherein said second wall means is
displaceable relative to said sections.
10. The unit defined in claim 9, further comprising heat exchanger
means including a plurality of axially extending pipes in said
chamber between said walls, said outlet being a conduit extending
axially into said passage, said valve means being in said conduit,
said housing further comprising a ring between said middle section
and said base section, said wall means each being a plurality of
longitudinally joined pipes, the pipes of said second wall means
extending out of said housing through said ring, said first wall
means including a first substantially circular manifold received in
said top section and a plurality of feeder pipes passing through
said top section and extending substantially axially, said first
wall means further including a substantially circular second
manifold received in said top section surrounding said conduit and
a substantially circular ring of insulating material, said second
manifold being at least partially embedded in said ring block and
said block tightly abutting said top section.
Description
DESCRIPTION OF THE DRAWING
The above and other objects, features, and advantages will become
more fully apparent in the following description, reference being
made to the drawing, in which:
FIG. 1 is an axial section through a boiler according to the
present invention;
FIG. 2 is a similar section showing the boiler partially pulled
apart for cleaning; and
FIGS. 3--5 are transverse sections taken along lines III-III, IV-IV
and V-V respectively.
SPECIFIC DESCRIPTION
The boiler comprises basically an elongated, cylindrical housing 1
consisting of a base 17 formed with an inlet 16 and lined with
refractory brick 19, a central wall section 6, and an upper
endpiece 14 mounting a conduit 37 serving as outlet 15.
Within this housing 1 are a plurality of generally axially
extending pipes 3 through which water is circulated via pumps as
will be described below. Between the pipes 3 are spaces 2, and an
empty central axial bypass passage 4 completely free of
heat-exchanger pipes 3 extends up through the boiler. The outer row
of pipes 3, those most remote from the housing axis A, are all
longitudinally joined by welding so that they form a gastight wall
7. This wall 7, along with a steel bellows 20 abutting a flange
portion 28 of a central housing ring member 18 by means of a ring
27, and a steel bellows 21 welded to the top 14 and to a manifold
13 for the pipes 3, form a substantially closed compartment 38.
Since feeder pipes 8 and 9 for the pipes 3 and the circular
manifolds 13 for these pipes are in this closed annular compartment
38, the gas therein is cooled, thereby obviating any necessity of
lining the housing 1 with insulation, the relatively cool gas in
the compartment 38 serving very well as insulation.
The inner row of pipes 3 is similarly welded together to form a
wall 33. Here, however, every other pipe is bent out at both the
upper and lower ends of this wall 33 to form openings 12 through
which gas can pass.
The conduit 37 is formed with two axially spaced sets of apertures
25 and 26 either of which can be blocked by a valve body in the
form of a slider 5. A control rod 24 mounts this slider 5 which is
in the form of a hollow cylindrical shell and is axially
displaceable in the conduit 37.
The top 14 of the housing 1 is provided with a large hole through
which pass feeder pipes 39 for the wall 33 and the conduit 37, its
flange 40 defining an annular gap therewith. A circular ring 22 of
insulating material seals this gap. The outwardly flared lower ends
of the pipe array forming the wall 33 lead out through a potted
seal 34 and through the ring 18 to join one of the manifolds 13. A
pump 29 and a load 30 are connected in series with the pipes of the
wall 33 to pump water up through them, while a similar pump 31 in
series with load 32 pumps water up through the wall 7 and the
heat-exchanger pipes 3 between walls 33 and 7.
The pipes 3 forming the wall 7 and in the space 10 between the wall
7 and the wall 33 are rigidly connected to the top 14 of the
housing 1. Bolts 35 hold the top 14 and the middle section 6
together while bolts 36 clamp the ring 18 and the base 17 of the
housing together.
In normal operating conditions, hot compressed gas enters the
boiler at 16. If the slider 5 is in its lowered position, it blocks
the apertures 26 and the gas will flow mainly up through the spaces
2 between the pipes 3 in the chamber 10 between the walls 7 and 33.
The water in these pipes is heated and transformed into steam which
is used to do work in the loads 30 and 32 which are, for example,
steam turbines. Should there be no need for such steam, or only a
minor need, the member 5 is lifted to block the apertures 25 so
that the gas flows straight up the pipe-free bypass passage 4, into
the openings 26 and out through the outlet 15. During this type of
operation only a slight amount of water is pumped by the pumps 29
and 31 to prevent damage to the boiler.
In order to clean, repair or inspect the boiler, the bolts 35 and
36 are removed. The sections 14, 6, the ring 18 and the base 17 are
then all pulled axially apart, as shown in FIG. 2. It can be seen
that the wall 33 and the insulation ring 22 pull away from the
upper section, while the conduit 37 can even be pulled up out of
the housing 1. The section 6 can be dropped so that the pipes 3 are
all completely exposed. Pipes 41 connected to the manifold 13 of
the pipes forming the wall > are rigidly fixed in the top
section 14.
In practice, a boiler as described above can be used in either the
upright or horizontal position, the former being generally
preferred. Furthermore, the waste-heat boiler herein described is
advantageously used in series with a boiler having no valve and no
bypass passage, such as that described in German Pat. No.
1,027,685.
As is readily apparent from FIG. 2, the apparatus may be assembled
by permanently mounting the outlet duct 15 so that it remains
axially fixed or setting this outlet duct in place so that its
annular transverse flange 40 is as the location desired for the
upper hood or dome 14 of the housing. This dome or hood, which
carries the header 13a for the water tubes 3 of the outer chamber
2, is then urged axially upwardly (arrow B in FIG. 2), until its
collar 60, having an inwardly turned edge 61, is in alignment with
the flange 40, i.e., is coplanar therewith in a plane extending
transversely to the axis of the device. At this point, the
intermediate section 6 of the housing, which is cylindrical, may be
urged axially upwardly (arrow C) to define with the wall 7 of
welded pipe, the outermost compartment 38 in which the risers 8 and
9 are provided. It will be recalled that the bellows-type seals 20
and 21, together with the gastight welding of the pipes 7 in
contiguous relation (FIG. 3), ensure that compartment 38 will
remain substantially free of the hot gases and is heated only by
conduction.
At this point the bypass member of the assembly of coaxially nested
bodies may be inserted axially upwardly with the space enclosed by
the nest of spaced-apart tubes 3 to establish wall 33 of
interconnected and gastight pipes forming the bypass channel. The
lower portion 23 of the outlet duct 15 extends axially into this
bypass channel which is formed with a pair of ring-shaped discs 62,
63 which are welded to the inner wall 33 of the bypass passage and
define a pair of axially aligned openings 64, 65 closely receiving
the tube 15. Thus, when the valve 5 is closed, the bypass passage
cannot be traversed by the hot gases. The bypass member of the
assembly is axially advanced upwardly (arrow D) until the upper
surface 66 of the heat-resistant potting compound 22, in which the
header 13b is anchored, engages the underside 61 of the collar 60
and the underside 67 of the flange 40 to provide a seal between the
bypass passage and the outlet tube 15 on the one hand and between
the outer chamber 2 and the housing portion 14 on the other hand.
This operation, moreover, brings the upper surface 68 of the
potting mass 34 and the ring 18, in which the outwardly turned ends
of the tubes of wall 33 are imbedded into engagement with the
underside 69 of the flange 70 of intermediate housing portion 6 to
form a gastight seal here as well. An upwardly turned cylindrical
tubular boss 71 along the inner boundary of the mass 34 cooperates
with the ring 27 and the bellows 28, previously mentioned, to seal
the compartment in which the tube bundle 3 is provided. It will be
recalled that the bypass channel is free from tube bundles.
Thereafter, the inlet tube or member 16, 17, 19 may be applied so
that its flange 72 sealingly engages the underside 73 of the ring
18. Of course, disassembly is in the opposite direction and the
parts may be assembled and disassembled in the reverse manner. In
this case, the inlet member 16, 17, 19 will first be fixed and the
bypass member seated thereon to be followed by intermediate housing
portion 6, dome 14 and the associated pipes, and the outlet duct
15.
When the valve 5 is closed, i.e., passages 26 are blocked, the gas
entering through the inlet 16 flows in the direction of arrow E
into the surrounding chamber and thence through the latter (arrow
F), in heat exchange with the tubes 3, finally emerging (arrow G)
beyond the barriers 62 and 63 to flow into the outlet 15 through
the windows 25. When, however, the valve 5 is opened, the principal
flow is via openings 26 (arrows H) into the outlet 15.
* * * * *