Note: Descriptions are shown in the official language in which they were submitted.
NOZZLE COOLED BY HEAT PIPE MEANS
BACKGROUND OF THE INVENTION
This invention relates to nozzles, and more
specifically to nozzles of the type that are operative for
providing fuel, air, etc. into the interior of a boiler or some
other similar form of apparatus, and wherein a requirement
exists that a cooling of the nozzle be effected.
In those applications wherein a nozzle is employed
for purposes of supplying fuel, or air, etc. to the interior of
a boiler or other similar form of apparatus, it is customary to
~.
have the nozzle extend through a penetration which is provided
for this purpose at a preselected location in a given one of
the wall members that collectively define the combustion area
of the boiler or other llke apparatus. Further, the
orientation of the nozzle is commonly such that the nozzle lies
in a plane that extends substantially horizontally. Moreover,
when the nozzle is so positioned it may either bear a
substantially flush fit with the inside surface of the
respective one of the wall members of the boiler that is
penetrated thereby or else it may project inwardly beyond the
inside surface of the respective one of the boiler wall
members. Lastly, note is taken here of the fact that the inner
surface of the boiler wall members may be covered with some
suitable form of refractory material such that the flush fit of
the nozzle is relative to the refractory material that covers
the boiler wall member rather than relative to the boiler wall
member per se.
'~`
After extended periods of use of +he boiler, such
nozzles have been known to exhibit signs of damage. Moreover,
the cause of such damage is known to be attributable to
exposure to the very high temperature to which the outlet,
i.e., exit, end of the nozzle is subjected. The susceptibility
of the nozzle to incur such damage appears to be particularly
prevalent in the case of those applications wherein the nozzle
projects inwardly beyond the inside surface of the boiler wall
members as well as in those applications wherein the boiler
wall members are covered with a refractory material. As
regards the latter type of appiication, the refractory material
after a period of time wears away such that the outlet end of
the nozzle if it had not originally been exposed, i.e.,
originally bore a flush fit relative to the refractory covered
boiler wall member, now becomes exposed by virtue of the
existence of a reduced thickness of refractory material
covering the boiler wall member~
The nature of the damage incurred by the nozzle
commonly is in the form of some +ype of deformation of the exit
end of the nozzle. More specifically, the exit end of the
nozzie becomes deformed such that the desired flow of fuei, or
air, etc. through the nozzle is impaired. This in turn
adversely affects not only the operation of the nozzle itself,
but also the functioning of the boiler generally. Ultimately,
this gives rise to a need to replace the damaged nozzle.
However, to do so requires that the boiler be shutdown, i.e.,
be unusable for a period of time.
There have been various attempts made at extending
the operating life of these nozzles. For example, one approach
that has been tried is that of fabricating the nozzles of
material which has a higher melting temperature. However, in
addition to being in general relatively more costly to provide,
the performance achievable therewith has proven to be less than
~ ~ desired. Accordingly, another approach that has been pursued
is that of attempting to effect a cooling of the nozzle. More
specifically, it has been known to employ nozzles which are
: cooled with water. In accord therewith, water is circulated in
~5~7
an annulus that surrounds the nozzle. Such water cooied
nozzles, though, have not been free of failure. In this
regard, the most common cause of failure of water cooled
nozzles has been found to be overheating. In addition,
however, failures of water cooled nozzles have also been known
to occur that are believed to have been caused by
intergranular/transgranular attack by a polythionic acid from
the outside to the inside. Such failure attributable to acid
a-ttack of the water cooled nozzle is deemed to be capable of
being obviated through the judicious selection of materials
that are characterized by the fact that they are known not to
be subject to acid corrosion.
~ ith reference to the subject of the overheating of
water cooled nozzles, such overheating is known to be due to
several causes. For example, an insufficient supply of cooling
water imputable to weld failure is known to be a cause of such
overheating. Also, overheating is known to have been caused by
the presence in the annulus through which the cooling water
flows of so-called "dead" or quiet zones. The latter are zones
in the annulus through which there is an insufficient flow of
water froln the standpoint of that needed to effect a cooling of
the nozzle. Yet another reason for such overheating has been
the occurrence of a buildup in the annulus through which the
cooling water flows of scale and particles that are deposited
out from the cooling water. A buiIdup of this nature
ultimately can have the effect of interfering with the flow of
coolant, i.e., cooling water, such that hot spots become
created which subsequently leads to overheating and finally to
a failure of the nozzle. Lastly, in those instances wherein a
multiplicity of nozzles are cooled through the use of a common
cooling water distribution system an unequal distribution of
the flow of cooling water as between each of the nozzles can
give rise to overheating of a nozzle because of an insufficient
flow of cooling water thereto.
The probleM of overheating associated with the use of
water cooled nozzles lias been addressed, but unfortunately to
date has not been successfully resolved. Thus, for instance in
8~
an endeavor +o eliminate weld failures, improved +echniques of
welding have been relied upon in the fabrication of wa+er
cooled nozzles. Also, to avoid "dead" or quiet zones, use has
been made of water baffles to better direct the flow of the
coolina water so that such zones are eliminated. Moreover,
filters have been installed in the coolin~ water supply to
prevent or minimize the buiIdup of scale and the particles that
might otherwise act to block coolin~ water flow and thus cause
hot spots that subsequen+ly lead to overheating and ul+imate
failure of nozzles. Further, in the case of multiple nozzles
that are served by a common coolin~ wa+er distribution sys+em,
changes have been effec+ed in +he dis+ribu+ion system +o ensure
+hat a sufficien+ flow of cooling water is received by each
nozzle.
No+wi+hs+anding all of the aforedescribed effor+s,
+he performance sought from wa+er cooled nozzles has not been
attainable +o date therewi+h. Consequen+ly, a need has been
evidenced for a new and improved form of cooling means that is
operable for purposes of effecting a cooling of nozzles, and in
particular nozzles of +he +ype +hat are intended to be employed
to accomplish the in+roduc+ion of fuel, or air, e+c. in+o +he
in+eFior of a subs+an+ially closed area in which combus+ion
+akes place. Moreover, such a new and improved form of cooling
means for nozzles desirably should be advan+a~eously
charac+erized by +he fac+ tha+ problems associa+ed with water-
borne chemical deposi+s, par+icula+es and scales are avoided
therewi+h; that the failure of a nozzle does not occasion the
venting of cooling water into +he area wherein combus+ion is
taking place such that +he removal of slag from +he combustion
area is adversely affec+ed +herewi+h; that minimal usage is
required therewith of fiIters, pumps, manifolds, valves, etc.;
that hot spots, which if they do occur, can give rise to a
nozzle failure, are inherently precluded from occurring
therewith; and that no on off mode exists therewith which could
in the event of a power failure produce component failure,
etc.
S~8~
--5--
It is, therefore, an object of the present invention
to provide a nozzle that is equipped with means operative for
effecting a cooling of the nozzle.
It is another object of the present invention to
provide such a nozzle wherein the means for e~fecting the
cooling thereof comprises heat pipe means.
It is still another object of the present invention
to provide such a nozzle equipped with heat pipe cooling means
which avoids the problems that water-borne chemical deposits,
particulates and sealing give rise to.
A further object of the present invention is to
provide such a nozzle equipped with heat pipe cooling means
which is operative as a self-contained unit thus eliminating
the requirement for employing externally valves, filters,
manifolds, pumps, etc r
A still further object of the present invention is to
provide such a nozzle equipped with heat pipe cooling means
that inherently minimizes the possibility for the development
of hot spots.
Yet another object of the present invention is to
provide such a nozzle equipped with heat pipe cooling means
that does not make use of an on-off mode which in the event of
a power loss could cause component failure, etc.
Yet still another object of the present invention is
to provide such a nozzle equipped with heat pipe cooling means
that is advantageously characterized in that it is relatively
inexpensive to produce, yet despite being relatively simple in
construction is capable of providing reliable operation.
SUMMARY OF THE INVENTION
In accordance with the present invention, there is
provided heat pipe means employable in an apparatus embodying a
combustion chamber and a nozzle assembly, which includes a tube
that communicates with the interior of the combustion chamber.
The heat pipe means, which is operative for cooling the tube,
is arranged in wrapped around relation relative to the tube.
The heat pipe means, which has an evaporator end and a
condenser end, contains a supply of coolant fluid and has a
C810770
5~7
--6--
fluid flow path established therewithin for the coolant fluid.
The coolant fluid as a l-iquid flows by capillary action along
the fluid flow path From the condenser end to -the evaporator
end. At the evaporator end the coolant fluid absorbs heat from
the combustion chamber so as to become vaporized. Then, as
vapor the coolant fluid flows along the fluid flow path from
the evaporator end to the condenser end. At the condenser end
the coolant fluid is cooled so as -to condense. The coolant
fluid is continuously circulated along the fluid flow path
within the heat pipe means so as to thereby effect a cooling of
the tube around which the heat pipe means is wrapped.
; .
C810770
BRIEF DESCRIPTION OF THE DRAWING
Figure 1 is a schematic representation of an
appara+us embodying a combustion chamber of the type with which
a nozzle equipped with heat pipe cooling means constructed in
accordance with the present invention is intended to be
employed;
~ Figure 2 is a side elevafional view of a portion of
; the interior wall surface of the apparatus of Figure 1
illustrating the manner in which a penetration thereof is
effected by a nozzle equipped with heat pipe cooling means
constructed in accordance with the present invention;
Figure 3 is a cross~sectional view of a nozzle
equipped with a first embodiment of heat pipe cooling means
constructed in accordance with the present invention
illustrated in the installed condition;
Figure 4 is a cross-sectional view of a nozzle
equipped with a second embodiment of heat pipe cooling means
constructed in accordance with the present invention
illustrated in the installed condition; and
Figure 5 is a cross-sectional view on an enlarged
scale of a portion of the nozzle equipped with the second
embodiment of a heat pipe cooling means shown in Figure 4,
illustrating the nature of the construction of the condenser
end thereof.
DESCRIPTION OF A PREFERRED EMBODIMENT
Referring now to the drawing and more specifically to
Figure 1 thereof, there is depicted therein a schematic
representation of an apparatus, generally designated by
reference numeral 10, that embodies a combustion chamber 12 of
the type with which the sub~ject matter of the present invention
is particularly suited to be utilized. Insofar as the
apparatus 10 is concerned, the nature of the construction
thereof is only indirectly related to the subject matter of the
_ present invention. Accordingly, it is not deemed necessary to
sef forth herein a detailed description of the nature of the
construction of the apparatus 10. Rather, the brief
description thereof which follows hereinaf+er is deemed to be
--8--
sufficient for purposes of obtaining an understanding of the
nature of the present invention. Firally, note is to be taken
here of the fact that the apparatus 10, as illustrated in
Figure 1, is intended simply to be representative of those
various forms of apparatus which embody a combustion chamber in
which combustion occurs, and wherein the introduction of the
fuel, or air, etc., which is burned in this combustion chamber,
is effected by nozzle means. In this regard, hy way of
exemplification but not limitation, the apparatus 10 is
intended to encompass coal gasification apparatus, steam
generation apparatus, etc.
With further reference to Figure 1 and the apparatus
10 depicted therein, the latter for purposes of acquiring an
understanding of the nature of the present invention includes a
plurality of suitably interconnected wall members 14, which
collectively enclose laterally the previously mentioned
combustion chamber 12, i.e., that area of the apparal-us 10 in
which combustion takes place. In accord with one form of
construction that the apparatus 10 may embody, each of the wall
members 14, as best understood with reference to Figure 2,
consists of a muItiplicity of vertically extending tubes 16.
The latter tubes 16, as illustrated in Figure 2, further are
suitably interconnected one with another by means of coplanar
metal web portions 18. Thus, taken together the tubes 16 and
the web portions 18 define the boundary of the combustion
chamber 12. To this end, the na-ture of the construction of a
combustion chamber 12 is that of an all-metal, gas-tight
enclosure. As illustrated in Figure 2, the tubes 16 and web
portions 18 may be suitably covered with a layer 20 of
conventional type refractory material of predetermined
thickness.
Turning again to a consideration of Figure 1, in a
manner to which further reference will be had hereinafter, the
- - apparatus 10 embodies means, generally designated in Figure 1
of the drawing by the reference numeral 22, through which there
is effected the introduction into the combustion chamber 12 of
the fuel, air, etc. +hat are required for combus+ion. In
87
conclusion, simply stated the mode of operation of +he
apparatus 10 is such that -the gaseous produc-ts of the
combustion taking place within the combustion chamber 12 flow
upwardly towards the portion of the apparatus 10 +hat is
denoted by reference numeral 24 in Figure 1. On the other
hand, the solid products of +he combustion taking place within
the combustion chamber 12 exit from the apparatus 10 through
+hat portion thereof which is identified by means of the
reference numeral 26 in Figure 1.
There will now be set forth a description of one
embodiment of a nozzle assembly that is provided with hea-t pipe
cooling means constructed in accordance with the present
invention. For this purposs, reference will be had in
particular to Figure 3 of the drawing. Thus, in the latter
Figure there is illustrated a nozzle assembly, generally
designated therein by reference numeral 28. In the interest of
maintaining clarity of illustration in the drawing, only one
such noz71e assembly 28 is depicted in Figure 3. -However, it
is to be understood that in accord with normal industry
practice, the means 22, shown in Figure 1, with which the
apparatus 10 is provided would commonly consist of a plurality
of such nozzle assemblies 28. Continuing with a description of
the nozzle assembly 28 of Figure 3, the assembly 28 is intended
to be operative for purposes of effec+ing the introduction of
fuel, or air, etc. into the combustion chamber 12 of the
apparatus 10. To this end, as is best understood with
reference to Figure 2 of the drawing, the nozzle assembly 28
has one end thereof, seen at 30 in Figure 2, which projects
through, i.e., penetrates a given one of the wall members 14 of
the apparatus 10 such that the nozzle assembly 28 has one end
thereof, i.~., the end denoted by the reference numeral 30,
which communicates with the interior of the combustion chamber
12 and the other snd thereof which is located externally of the
- - combustion chamber 12 so as to be readily accessible for
connection to a suitable source of supply of fuel, or air,
etc.
75~7
--10--
lnsofar as the above is concerned, it should
furthermore be understood that the erd of tha nozzle assembly
28 which is denoted by the reference numeral 3n in Figure 2 may
make either a flush fit wi+h or may project outwardly of the
exterior surface of the layer 20 of refractory material,
depending on the nature of the particular application in which
the nozzle assembly 28 is bein~ utilized. In addition, fhere
exists applications in which the end 30 of the nozzle assembly
28 originally is located such as to make a flush fit with the
exterior surface of the layer 20 of refractory material, but as
the latter material becomes worn away, i.e., takes on a reduced
thickness, the end 30 of the nozzle assembly 28 assumes a
position wherein it projects outwardly of the layer 20 of the
refractory material to a measureable extent into the interior
of the combustion chamber 12 of the apparatus 10. Accordingly,
the present invention is not to be taken as being limited to a
nozzle assembly, e.g., the nozzle assembly 28 of Figure 3 or
the as of yet unidentified nozzle assembly of Figure 4,
whicheither makes a flush fit with the exterior surface of the
2û respective wall member 14 that is penetrated thereby, or
projects outwardly thereof, but rather should be viewed as
encompassing both of these forms of cons+ruction as well as
that wherein the nozzle assembly originally makes a flush fit
with the refractory covered wall member 14 but as the
refractory wears away, the nozzle assembly assumes a
relationship relative to the wall member 14 wherein the nozzle
assembly projects outwardly thereof.
Referring still to Figure 3 of the drawing, the
nozzle assembly 28 is depicted therein in the installed
condi-tion relative to the wall member 14. More specifically,
as illustrated therein, the nozzle assembly 28 projects
through, i.e., penetrates, the wall member 14 such that the end
30 of the nozzle assembly 28 communicates with the interior of
- the combustion chamber 12, whereas -the other end thereof, i.e.,
that denoted by the reference numeral 32 in Figure 3, is
located externally of the wall member 14 so as to be readily
accessible for connec-tion to a suitable source of supply of
fuel, or air, etc. To this end, the nozzle assembly 28 in
accord with the embodiment thereof illustrated in Figure 3 has
a portion thereof which extends th~ough one of the web portions
18 and the layer 20 of refractory material, which collectively
constitute the wall member 14 at the location thereof whereat a
penetration thereof is had by the nozzle assembly 28. In
addition, as depicted in Figure 3 the nozzle assembly 28 is
also made to pass through a metal sheet-like member 34, the
la1-ter being suitably positioned in juxtaposed relation to the
exterior surface of the web portion 18. In accord with the
illustration of Figure 3, the layer 20 of refractory material
is shown as having been worn away from an original thickness
thereof denoted in Figure 3 by means of the phantom line 36 to
the solid line position thereof denoted in Fiqure 3 by
reference numeral 38. Note should be taken here of the fact
that in accord with the illustration of Figure 3 the original
thickness of the layer 20 of the refractory material was
suitably preselected such that the end 30 of the nozzle
assembly 28 was made to have a flush fit with the exterior
surface of the layer 20.
Continuing with a description of the structure
embodied by the nozzle assembly 28, the latter includes a
suitably dimensioned, cylindrically-shaped, tube-like member,
referred to hereinafter as the tube 40. The latter tube 40
functions as the means by which fuel, or air, etc. is
introduced from the exterior of to the interior of the
combustion chamber 12. The direction of flow of the substance
through the tube 40 is denoted by means of the arrow 42 in
Figure 3. Although not shown in Figure 3 in the interest of
maintaining clarity of illustration therein, it is to be
understood that the end 40a of the tube 40 is suitably
connected to a source of supply ~not shown) of the particular
substance which it is desired to have introduced into the
_ interior of the combustion chamber 12 by means of the tube 40.
In accord with the present invention, the nozzle
assembly 28 further includes heat pipe cooling means, oenerally
designated in Figure 3 by the reference numeral 48. Moreover,
87
in accord with the form thereof which is shown in Figure 3, the
heat pipe cooling means 48 includes ? Cy lindrical member 50
which is suitably secured through the use of any conventional
form of securing means (not shown) in mounted, surrounding
relation to the tube 40 along at least a portion of the length
of the latter. More specifically, the cylindrical member 50 is
made to extend in surrounding relation to the tube 40 from at
least the end 40b of the latter to at least a point along the
length thereof, which is located externally of -the wall member
14 when the nozzle assembly 28 occupies the installed position
thereof relative to the wall member 14, i.e., the nozzle
assembly 28 bears the same relationship to the wall member 14
as that shown in Figure 3.
The cylindrical member 50 of the heat pipe cooling
means q~ which is positioned in concentric relation to at least
a portion of the length of the cylindrically configured tube,
i.e., nozzle, 40 is of double-wall construction such that a
chamber-like area, i.e., region,` is formed therewithin. A
divider means 52 is suitably supported through the use of any
conventional form of supporting means (not shown) within the
aforesaid chamber-like area such that the latter is divided
thereby into a first compartment 54 and a second compartment
56. In accord with the form of the invention which is
illustrated in Figure 3 of the drawing, the divider ~eans 52
comprises a cylindrically configured metal member which
preferably is perforated along at least a portion of the length
thereof for a purposes that is ye+ to be described.
One of the first and second compartments 54 and 56,
respectively, is provided therewithin for at least a portion of
the length thereof with a material that has the functional
attributes of a wick, iOe., is capable of functioning in the
manner of a wick. There are known to exist a number of
materials that are suitable for use for this purpose. In this
_ regard, the selection of a particular material for use in a
given application should be based upon a consideration of among
other things the following: the noncorrosiveness of the
material relative to the coolant with which it is to be
as~
employed, and the temperature -~o which the material is to be
subjected. To this end, In accord with the preferred forM of
the invention the material comprises a felt-like metal
material. Moreover, the latter material also possesses the
characteristic of being porous. The term porous as used herein
is intended to refer to the fact that the material is such that
coolant will pass there~hrough by rneans of capillary action.
The placement of the material 58 is determined based
on a consideration of the surface which it i5 desired to cool.
For example, when the primary concern is the cooling of the
exterior surface of the nozzle assembly 28 including the tip
portion 30 thereof, the material 58 is positioned within the
first compartment 54. Namely, the material 58 is positioned
within the heat pipe cooling rneans 48 in the manner illustrated
~5 in Figure 3. On the other hand, if it is the interior surface
of the tube 40 including the tip portion 30 thereof that is to
be cooled the material 58 would be positioned within the second
compartment 56. The method of placement of the material 58
within the heat pipe cooling means 48 is not depicted in the
drawing inasmuch as it is deemed to be readily understandable
without reference to an illustration thereof. That is, such an
illustration is no+ deemed essential for purposes of acquiring
an understanding of the subJect matter of the present
invention. Lastly~ when it is desired to effect a cooling of
both the exterior surface of the noz~le assembly 28 and the
interior surface of the tube 40, a form of construction is
employed such as that depicted in Figure 4 and to which further
reference will be had hereinafter.
For a purpose yet to be described, the heat pipe
cooling means 48 further includes heat dissipating means,
generally designated in Figure 3 by means of the numeral 60.
The heat dissipating means 60 may take various forms. For
example, the heat dissipating means 60 may take a form wherein
the mode of operation thereof is such that the heat dissipation
effected thereby is accomplished by means of the radiative
action of one or more passive heat transfer elements. To this
end, reference is had to Figure 3 of the drawing wherein the
~S~37
-14-
heat dissipating means 60 depicted therein is suitably
supported on the exterior surface of the cylindrical member 50
in mounted, surrounding reiation thereto through the ~se of any
suitable conventional form of supporting means (not
shown).Fur+hermore, in accord with the illustration ot the
nozzle assembly 28 that appears in Figure 3, the heat
dissipating means 60 comprises a member consisting of a
multiplicity of fin-like segments that extend outwardly in a
radial direction from the exterior surface of the cylindrical
member 50. However, the heat dissipating means 60 could
equally well withou+ departing from the essence of the present
invention take the form of an expanded metal passive heat
transfer element (not shown).
Continuing, ins+ead though of accomplishing the heat
dissipation through the radiative action of passive heat
transfer elements, the heat dissipation could also without
' departing from the essence of the present invention be effected
through the use of an activa coolant loop (not shown) suitably
provided in encircling relation to the exterior surface of the
cylindrical member 50 adjacent the end of the nozzle assembly
28 denoted by the reference numeral 32 in Figure 3. Further,
for this purpose there could be circulated in the aforesaid
coolant loop which is intended to be representative of an
active version of the heat dissipating means 60, any suitable
type of coolant, e.g., water.
With further reference to Figure 3, the chamber-like
area with which the cylindrical member 50 is provided contains
a suitable amount of coolant fluid. The latter coolant fluid
as described more fully hereinafter flows along a fluid flow
path with which the heat pipe cooling means 48 is suitably
provided. In addition, in accord with the mode of construction
of the embodiment of the invention that is illustrated in
Fiqure 3 of the drawing, there is included within the fluid
flow path with which the heat pipe coolin~ means 48 is provided
a reservoir, the latter bein~ denoted in Figure 3 by the
reference numeral 62. ~oreover, the reservoir 62 contains a
suitable supply of coolant fluid. As will be described more
5~B~
-15-
fully hereinafter in the course of setting forth a description
of the mode of operation of the nozzle assembly of Figure 3,
the coolant fluid flows from the reservoir 62 by means of
outlet pipe 64 into the cylindrical rnember 50, and more
particularly to and along the length of the first compartment
54. From the first compartment 54, the coolant fluid enters
the second compartment 56 and flows along the length thereof.
Thereafter, the coolant fluid leaves the second compartment 56
and enters the reservoir 62 by means of the inlet pipe 66.
Finally, as will be further discussed hereinafter in connection
with the description of the structure that is depicted in
Figures 4 and 5, the reservoir 62 may be provided with a
passive pump means (not shown) operative to assist in the
recirculation of the coolant fluid along the fluid flow path
with which the heat pipe cooling means 48 is provided.
A description will now be had of the mode of
operation of the nozzle assembly 28 equipped with the heat pipe
cooling means 48, the latter being constructed as illustrated
in Figure 3. In accord therewith, one end of the heat pipe
ZO coollng means 48, i.e., that end thereof which is located at
the end 30 of the nozzle assembly 28, is designed to function
as the evaporator, i.e., hot, end of the heat pipe cooling
means 48, whereas the other end of the heat pipe cooling means
48 is designed to function as the condenser, i.e., cold, end
thereof. Thus, In accordance with the mode of operation of the
nozzle assembly 28, the nature of the fluid flow path with
which the heat pipe cooling means 48 is provided is such that
coolant fluid, preferably consisting of water, flows from the
reservoir 62, in the form of a liquid into the first
compartment 54 of the cylindrical member 50. This takes place
at the condenser end of the heat pipe cooliny means 48. In the
form of a liquid, the water then flows by means of capillary
action which is induced by virtue of the wick-like attributes
_ of the material 58 along the length of the ~irst compartment 54
to the evaporator end of the heat pipe cooling means 48. At
the evaporator end of the heat pipe cooliny means 48, the
liquid coolant, i.e., water, absorbs sufficient heat from the
:
S1~7
combustion taking place within the combustion chamber 12 that
the water vaporizes. As a vapor, the coolant then flows back
from the evaporator end of the heat pipe cooling rneans 48,
i.e., along the lenath of the second cornpartment 56, to the
condenser end of the heat pipe cooling means 48. At the
condenser end of -the heat pipe cooling means 48, the coolant
becomes cooled and condenses~ The aforementioned cooling of
the coolant is effected by means of the operation of the heat
dissipating means 60. Having completed its passage through the
fluid flow path of the heat pipe coolina means 48, the coolant
which is once again in the form of a liquid reenters the
reservoir 62 from the second compartment 56 through the inlet
pipe 66. The coolant as a liquid thereafter leaves the
reservoir 62 through the outlet pipe 64 to recommence its
travel along the flow path established therefor within the
cylindrical member 50 of +he heat pipe cooling means 48 whereby
the coolant fluid functions to effect the cooling desired of
the tube, i.e., nozzle 40.
In accord with the embodiment of the heat pipe
cooling means 48 illustrated in Figure 3, the divider member 52
is depicted as being perforated along a portion of the ien~th
therec~f. The function of these perforations is to enable the
cooiant fluid, should it become vaporized before reaching the
end 30 of the nozzle assembly 28, to pass therethrough for
purposes of reaching the second compartment 56 from the first
compartment 54, rather than necessitating that the vapor travel
around the end of the divider member 52, if the latter were not
perforated, to enter the second compartment 56 from the first
compartment 54. The intent, thus, in providing the member 52
with perforations is to minimize thereby the possibility that
the existence of vapor bubbles amidst the otherwise liquid
coolant might serve to disadvantageously affect the flow by
rneans of capillary action of the iiquid coolant within the
first compartment 54.
~ ~ 35 As depicted in Figure 3, the nature of the
construction of the heat pipe cooling means 48 is such that it
includes the reservoir 62. The sole function, however, of the
37
reservoir 62 is to provide a reservoir of coolant fluid in the
event that makeup fluid should be required. That is, should a
loss of coolant occur during the course of +he continuous flow
of the coolant along the fluid flow path that is established
within the cylindrical member 50 of the heat pipe cooling means
48, the intent is that this coolant which is lost would be
replaced by fluid contained in the reservoir 62, i.e" the
level of the fluid in the reservoir 62 would simply drop. The
function of the reservoir 62, therefore, is not to provide a
head for the coolant fluid that flows through the heat pipe
cooling means 48. Accordingly, the reservoir 62 is not deemed
to be essential to the operation of the heat pipe cooling means
48. Consequently, contemplated within the present invention is
a nozzle assembly 28 equipped with a heat pipe cooling means
that embodies the same form of construction as the heat pipe
cooling means 48 that is illustrated in Figure 3 but with the
omission therefrom of the reservoir 62.
Finally, although the coolant fluid for purposes of
the description of the mode of operation of the nozzle assembly
28 equipped with the heat pipe cooling means 48 constructed in
accord with the illustration of Figure 3 has been identified to
be water, it is contemplated that other forms of coolant fluid
could be utilized in lieu of water without departing from the
essence of the present inventlon. To this end, the coolant
fluid that is ultimately selected for employment in the nozzle
assembly 28 equipped with the heat pipe cooling means 48 is
determined based upon a consideration, among others, of factors
such as the noncorrosiveness of the coolant fluid in terms of
the materials with which it would come in-to contact durina the
course of its flow through the heat pipe cooling means, the
capability of the coolant fluid to withs+and the temperatures
to which it will be subjected as a function of the temperature
which will exist within the combustion chamber 12, the
_ capability of the coolant fluid to effect a cooling of the tube
40 to the temperature desired, etcO
Considering next Figures 4 and 5 of the drawing,
~here is depicted therewithin another embodiment of a nozzle
-18-
assembly that i5 equipped with a heat pipe cooling means
constructed in accord wi+h the teachings of the present
invention. More specifically, the heat pipe cooling means
illustrated in Figures 4 and 5 embodies a modified form of
construction from that embodied by the heat pipe coolina means
48 shown in Figure 3. Namely, the principal difference bet~een
the neat pipe cooling means 48 of Figure 3 and the heat pipe
cooling means depicted in Figures 4 and 5 resides in the nature
of the divider means with which each of the two heat pipe
cooling means is provided. Accordingly, for ease of
understanding, the structure embodied in the nozzle assembly
equipped with heat pipe cooling means in accord wi+h the
present invention which is shown in Figures 4 and 5 that finds
correspondence in the structure of the nozzle assembly 28
equipped with a heat pipe cooling means 48 constructed in
accord with the illustration of Figure 3 has been designated in
both Figure 3 and Figures 4 and 5 through the use of the same
reference numerai, but with the addition of a prime to the
reference numeral in the case of the structure appearing in
Figures 4 and 5.
Therefore~ with further reference in particular to
Figure 4 of the drawing, there is depicted therein a nozzle
assembly 28' equipped with a heat pipe cooling means 48', the
latter being designed to be operative to effect a cooling to
the extent desired of the tube 40' of the nozzle assembly 28'.
Like the nozzle assembly 28 of Figure 3, the nozzle assembly
28' of Figures 4 and 5 is depicted as being in an installed
condition relative to the wall member 14'. That is, the nozzle
assembly 28' penetrates a web portion 18', which with the layer
20' of refractory material combines to comprlse 1-he wall member
14'. The layer 20' of refractory material through the use of
the solid line denoted by the reference numeral 38' in Figure 4
is depicted therein as having been worn away. However, the
original thickness of the iayer 20' is also illustrated in
Figure 4 through the use therein of the phantom line that is
identified by means of the reference numeral 36'. Lastly,
there is provided in juxtaposed relation to the exterior
- l 9 -
surface of the web portion 18' a sheet-llke metal member 34'
through which the nozzle assembly 28' additionally passes.
The tube 40' is intended to be operative to effect
the introduction of fuel, or air, etc. into the combustion
chamber 12. The direction of flow through the tube 40' of the
substance that is selected to be introduced therethrough into
the combustion chamber 12 is denoted by the arrow 42'.
AIthough not shown tn Figures 4 and 5 in the interest of
maintaining clarity of illustration therein, the tube 40' has
the end 40a' thereof suitably connected in fluid flow relation
to a suitable source of supply of the particular substance that
it is desired to have flow through the tube 40' into the
combustion chamber 12.
Referring again to Figures 4 and 5, suitably
supported through the use of any suitable conventional form of
support means tnot shown) in mounted, surrounding relation to
the tube 40' is the heat pipe cooling means 48'. The heat pipe
cooling means 48' has one end thereof, i.e., the end thereof
that is adjacent to the end 30' of the nozzle assembly 28',
which is operative as an evaporator, i.e., hot, end, and the
other end thereof which is operative as a condenser, i.e., cold
end. Moreover, the heat plpe cooling means 48' includes a
cylindrical member 50' which is of double wall construction
such that there exists between the walls thereof a suitably
dimensioned chamber-like area, i.e., region.
A divider means 52' is suitably supported within the
chamber-like area of the cylindrical member 50' such as to
divide the interior of the latter into a first compar+ment 54'
and a second compartment 56'. Each of the first and second
compartments 54' and 56', respectively, preferably contain a
suitable amount, for purpose yet to be described, of a material
58' which has the functional attributes of a wick. To this
end, the material 58' preferably is identical in all respects
_ to the material 58 that has been described hereinbefore in
connection with the discussion of the structure depicted in
Figure 3. Accordingly, it is not deemed necessary to set forth
at this point by way of reiteration a detailed description of
S~87
-20-
the nature of the ma+erial 58'. Further, as was briefly
mentioned previously herein, the form of construction depicted
in Figure 4, i.e., the placement of the material 58' in both of
+he compartments 54' and 56' is particularly suitable for use
in those applications wherein a need exists to effect a cooling
of both the interior and exterior surfaces of the tube 40'
including the tip 30' thereof.
Continuing, in accord with the form thereof which is
shown in Figure 4 of the drawing, the divider means 52'
comprises a cylindrically configured member 68 that is of
lesser d7ameter than the cylindrical member 50' and which is
positioned within the chamber-like area of the latter so as to
be concentric with the tube 40'. Further, as best seen with
reference to Figure 4, the cylindrical member 68 is of double
wall construction such that a chamber exists therewithin.
Lastly, preferably the cylindrical member 68 is perforated
substantially throughout.
Completing the description of the nature of the
construction of the noz~le assembly 28', a suitable amount of
coolant fluid is provided within the cylindrical member 50'.
There is also established within a heat pipe cooling means 48'
a flow path for the coolant fluid. Further, the heat pipe
cooling means 48' is provided with a suitable form of heat
dissipating means 60'. Although the heat dissipating means 60'
may take several forms, in accord with the illustrated
embodiment of the heat pipe cooling means 48' the heat
dissipating means 60' consists of a member embodying a
multiplicity of fin-like segments which is suitably mounted in
surroundins relation to the exterior surface of the cylindrical
member 50' such that the fin-like segments of the former extend
outwardly in a radial direction from the latter. As regards
the other forms which the heat dissipating means 60' may
embody, they are the same as those to which reference was had
_ hereinbefore in connec+ion with the discussion of the heal
dlssipating means 60 of Figure 3. To this end, any of these
alternative forms of construction mentioned in connection with
the heat disstpating means 60 of Figure 3 are suitable for
employment as the heat dissipating means 60' of Figure 5.
Finally, in accord with the illustration of Figures 4
and 5, the fluid flow path with which the heat pipe cooling
means 48 is provided encompasses the reservoir 62' and the
inlet and outlet pipes 66' and 64', respectively, that are
cooperatively associated with the reservoir 62'. Like the
reservoir 62 with which the heat pipe cooling means 48 of
Fiaure 3 is provided, the reservoir 62' is intended to serve
primarily as a source of rnakeup fluid, and is not required for
purposes of providing a head for the coolant fluid that flows
through the heat pipe cooling means 48'. ~owever, when
employed, and as illustrated in Figures 5 and 3, the reservoirs
62' and 62, respectively, preferably each contain a suitable
amount of material 58' and 58, respectively. Also, the inlet
and outlet pipes 66' and 64', respectively, are each provided
with a suitable amount of the material 58' in the case of the
heat pipe cooling means 48' of Figures 4 and 5, while the inlet
and outlet pipes 66 and 64, respectively, in similar fashion
are provided with a suitable amount of the material 58 in the
case of the heat pipe cooling means 48 of Figure 3. The
function of the material 58 that is placed within the reservoir
62 and the inlet and outlet pipes 65 and 64, respectively, is
to enable the passage of the coolant fluid therethrough to be
effected by means of capillary action. Likewise, the material
58' performs the same function in the case of the reservoir 62'
and the inlet and outlet pipes 66' and 64', respectively.
For some applications, it may be deemed desirable to
employ a passive pump at the condenser end of the heat pipe
cooling means. Such a passive pump, denoted by the reference
numeral 70, is illustrated in Figure 5 of the drawing. The
primary function of the passive pump 70 is to assist in the
recirculation and the otherwise removal of the condensate from
- - the conaenser end of the heat pipe cooling means 48'. As will
be set forth more fully hereinafter in connection with a
description of the mode of operation of the heat pipe coolin~
means 48' of Figures 4 and 5, at the condenser end of the heat
~ ~t~ 7
-22-
pipe cooling rneans 48' +he coolant fluid which has previously
been vaporized is now cooled through the action of the heat
dissipatin~ means 60' such that the vapor condenses. It is
this condensate which the passive pump 70 is designed to
remove.
Continuina with a description of the passive pump 70
of Figure 5, as depicted therein the pump 70 is in the form of
converging walls. However, there exists other applications
wherein the passive pump 70 may be in the form of a structure
wherein the walls divergeO More specifically, in those
instances wherein the nozzle assembly 28 or 28' is construc+ed
of materials which are selected to be hydrophilic, i.e.,
wetting, a passive pump 70 embodying conver~ing walls is
preferably employed. On the other hand, when the nozzle
assembly 28 or 28' is constructed of materials selected to be
non-wetting, i.e., hydrophobic, a passive pump 70 havin~q walls
that diverge in the direction of coolant flow is preferably
used. Finally, a passive pump may also be utilized for
purposes of establishing a desired direction of coolant flow in
the case of a heat pipe cooling means that is provided with a
reservoir.
Insofar as concerns the mode of operation of the
nozzle assembly 2R' of Figures 4 and 5, the mode of operation
thereof is substantially the same as that of the nozzle
assembly 28 of Figure 3. One major difference therebetween,
however, resides in the fact that whereas in the case of the
nozzle assembly 28 of Figure 3, the coolant fluid, i.e., water,
flows in the form of a liquid through the first compar+ment 54
from one end thereof to the other by capillary action, and then
after being vaporized returns +o the condenser end of the heat
pipe cooling means 48 in the form of a vapor by flowing through
the second compartment 56 from one end thereof to the other, in
the case of the nozzle assembly 28' of Figures 4 and 5, the
coolant fluid, i.e., water, flows in the form of a liquid by
capillary action simultaneously through hoth the first
compartment 54' and thè second compartment 56' from one end
thereof to the other, and after becoming vaporized returns to
-23-
the condensor end of the heat pipe cooling means ~8' by passing
through the perforations provided for this purpose in the
cylindrical member 68 and flowing the length of the chamber
that exists within the cylindrical member 68 whereupon the
vapor passes through -I-he perforations adjacent the other end of
the cylindrical member 68, is cooled through the action of the
heat dissipating means 60', condenses, and in +he form of a
liquid flows into the reservoir 62' through the inlet pipe
66'. Thereafter, the coolant fluid, i.e., water, in the form
of a liquid leaves the reservoir 62' by means of the outlet
pipe 64', enters the first and second compartments 54' and 56',
- respectively, and recommences i+s flow along the fluid flow
path that is established therefor in the heat pipe cooling
means 48'. A further difference between the nozzle assembly 28
as illustrated in Figure 3 and the nozzle assembly 28' as
depicted in Figures ~ and 5 resides in the fact that the latter
includes a passive pump 70 which as has been described
previously herein is intended to be operative for purposes of
assisting in the recircula+ion and otherwise removal of
~0 condensate from the condenser end of the nozzle assembly 28'.
; Summarizing, the following concepts are encompassed
within the subject matter of the present invention~ First, the
general concept of a heat pipe cooling means being arranged to
wrap around a nozzle, in the manner that is illustrated in
Figure 3 and described herein, so as to effect a cooling of the
exterior surface of the nozzle including the nozzle tip.
Secondly, the concept of placing the wick-like material of the
heat pipe cooling means in the compartment thereof that is
located immediately adjacent to the bore of the nozzle so that
a cooling of +he interior surface of the nozzle including the
nozzle tip can be effected. Thirdly, the concept of providing
a heat pipe cooling means wherein, in the manner that is
illustrated in Figures 4 and 5 and described herein, the wick-
like material is provided immediately adjacent to the interior
wall, i.e., bore, of the nozzle as well as immediately adjacent
to the outermost, i.e., exterior surface, of the noz~le, and
such that the wick-like material is ~joined, i.e., comes
~1~a5~L~37
-24-
together, at the nozzle tip, but is separated along the axis,
i.e., length, of the nozzle by two concentric perforated tubes
or cylindrical screens that are suitabiy arranged so as to
provide an annular space therebetween extending axially along
the length of the nozzle for purposes of accommodating the flow
of vapor to the condenser end of the nozzle assembly, all of
which has the combined effect of providing a cooling of both
the interior and the exterior surfaces of the nozzle including
the tip portion thereof. Fourthly, whether the heat pipe
cooling means embodies a form of construction suitable for
effecting the cooling of the exterior surface of the nozzle, or
one suitable for effecting a cooling of the interior surface of
the nozzle, or one suitable for effecting a cooling of both the
interior and the exterior surfaces of the nozzle, the concept
of effecting a cooling of the condenser end of the heat pipe
cooling means by means of the radiative action of passive heat
transfer elements, e.g., fin-like metal segments or expanded
metal, or by means of an active circulating loop through which
a suitable coolant such as water is made to flow whereby the
cooling action provided by either the passive system or the
active system is sufficient to effect a condensing of the vapor
when it reaches the condenser end of the heat pipe cooling
means. Fifth, whether the heat pipe cooling means is intended
to be operative for purposes of effecting a cooling of the
exterior surface, or the interior surface, or both the exterior
and the interior surfaces of the nozzle, the concept of
providing at the condenser end of the heat pipe cooling means a
passive pump, the function of which is to assist in the
recirculation and otherwise in the removal of the coolant
condensate from the condenser end of the heaf pipe cooling
means to the reservoir and/or to the evaporator end of the heat
pipe cooling means9 and embodying a form of construction
wherein a condensing nozzle is provided thereby which
_ - alternatively can be made to either converge in the direction
of condensate flow if the condensing nozzle is wet~ed, i~e.,
hydrophilic, relative to the coolant, or diverging if the
condensing nozzle is or is largely non-wetted, i.e.,
87
-25-
hydrophobic, relative to the coolant so as to pinch or restrict
the condensed coolant discharge passageway from the cavity area
in which the wick-like material is emplaced if wetted, or so as
to expand the area of the circular passa~qeway if the latter is
5 formed of non-wetted materials. Sixth, the concept whereby the
materials of which the nozzle assembly equipped with heat pipe
cooling means is constructed are selected so as to themselves
be or to have coatings applied thereto which are either wetting
or non-wetting relative to the coolant so as to promote
10 effective and efficient coolin~ action by the heat pipe coolinq
means. In particular, that +he perforated +ubes or screens
where used for purposes of isolating, in the manner depicted in
Figures 4 and 5, the coolant liquid from the coolant vapor be
non-wetting, i.e., hydrophobic, with respect to the coolant
15 whether the iatter be water or some other coolant; that the
innermost surfaces of the inner and the outer envelope walls of
r the nozzle be of a material or be coated with a material which
is wetted, i.e.j hydrophilic, rela+ive to the coolant whether
the latter be water or some other coolant; and that the coolant
20 reservoir, if employed, be of or be coated with a material
which is not or essentially is not wetted by the coolan+.
Seventh, the concep+ that in the event that a coolant reservoir
is utilized, that it be esfablished whether the coolant
supplied to/from the reservoir always flows in one direction
25 and if this is so established that a passive pump be emplaced
in the fluid flow path between the reservoir and -the coolant
flow passageway from which the condensed coolant is discharged
so as to be operative to assist in pumping the coolant towards
the evaporator end of the heat pipe cooling means.
In accordance with the present invention there has
thus been provided a new and improved nozzle that is equipped
with means operative for effecting a cooling of the nozzle.
~oreover, the means which the nozzle of the presen-~ invention
embodies for effecting the cooiing thereof comprises heat pipe
cooling means. In addition, in accord with the present
invention a nozzle equipped wlth heat pipe coolin~ means is
provided which avoids -the problems that are occasioned by the
-26-
presence of water-borne chemical deposits, particulates and
scallng. Further, the nozzle equipped with heat pipe cooling
means of the present invention is operative as a self-contained
unit thus eliminating the requirement for employing externally
located valves, fiIters, manifolds, pumps, etc. Additionally,
in accordance with the present invention a nozzle equipped with
heat pipe cooling means is provided that inherently minimizes
the possibility for the development of hot spots. Also, the
nozzle equipped with heat pipe cooling means of +he present
invention does not make use of an on-off mode which in the
event of a power loss could cause component failure, e+c.
Furthermore, in accord with the present invention a nozzle
equipped with heat pipe cooling means is provided that is
advantageously characterized in that it is relatively
inexpensive to produce, yet despite being relatively simple in
construction is capable of providing reliable operation.
While two embodiments of my invention have been
shown, it will be appreciated that other modifications thereof,
some of which such as the omission of +he reservoir 62, the
employment of a passive pump 70, the use of wetted or non-
wetted materials, etc. have either been explici+ly mentioned or
alluded to hereinabove, may still be readily made thereto by
those skilled in the art. 1, therefore, intend by the appended
claims to cover the modifications expiicitly mentioned or
alluded to herein as well as all other modifications, which
fall within the true spirit and scope of my invention.
What is claimed is:
