U.S. patent number 3,776,257 [Application Number 05/208,554] was granted by the patent office on 1973-12-04 for false walled pressure vessel.
This patent grant is currently assigned to WSF Industries, Inc.. Invention is credited to Henry J. Piegza.
United States Patent |
3,776,257 |
Piegza |
December 4, 1973 |
FALSE WALLED PRESSURE VESSEL
Abstract
A generally cylindrical pressure vessel for use in treating an
article with a fluid under high pressure characterized in that one
or more flat metal plates are arranged within the vessel so as to
define an article treating chamber and one or more balancing
compartments arranged intermediate the treating chamber and the
cylindrical side wall and/or double curved end wall or walls of the
vessel. The plates are capable of sustaining treating chamber
loadings not substantially in excess of the hydrostatic head of the
treating fluid; and a balancing fluid, which is introduced into the
compartments is employed to balance high treating chamber loadings
substantially in excess of the hydrostatic head. A control is
employed to sense and compare pressures in the treating chamber and
compartments and to terminate the introduction of fluid producing
the high treating chamber loadings when such pressures are out of
balance.
Inventors: |
Piegza; Henry J. (Clarence,
NY) |
Assignee: |
WSF Industries, Inc.
(Tonawanda, NY)
|
Family
ID: |
22775019 |
Appl.
No.: |
05/208,554 |
Filed: |
December 16, 1971 |
Current U.S.
Class: |
137/206;
220/600 |
Current CPC
Class: |
A23L
3/10 (20130101); F16J 12/00 (20130101); Y10T
137/3115 (20150401) |
Current International
Class: |
A23L
3/10 (20060101); F16J 12/00 (20060101); B65d
007/22 () |
Field of
Search: |
;220/10
;137/206,209 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Cohan; Alan
Claims
I claim:
1. A high pressure vessel for treating an article therewithin,
which comprises in combination:
a metal shell including a generally cylindrical side wall having an
access opening closeable by a metal door and at least one end wall
of double curvature configuration thereby to permit said shell to
withstand at least a high predetermined article treating internal
pressure;
a metal plate affixed to an inner surface of said shell whereby to
define a fluid sealed boundary between an article treating chamber
accessible through said access opening and a balancing compartment
arranged intermediate said plate and said inner surface;
means for admitting an article treating fluid into said treating
chamber and maintaining said treating fluid under said
predetermined treating pressure; and
means for supplying a balancing fluid differing from said treating
fluid to said balancing compartment at a pressure substantially
equal to said predetermined pressure, said plate being
characterized as being substantially flat and of a construction
able to withstand without failure a pressure in excess of that
corresponding to the hydrostatic head of either said treating fluid
or said balancing fluid but substantially less than said
predetermined pressure.
2. A pressure vessel according to claim 1, wherein said shell
vertically upstands, said plate is weld affixed to said inner
surface of said shell whereby to define a vertically extending
boundary between said treating chamber and said balancing
compartment, said treating fluid is a liquid, said means for
supplying said treating fluid includes means for maintaining the
level of said treating liquid below an upper end of said plate,
said means for supplying a balancing fluid supplies a gas under
said predetermined pressure to said balancing compartment, and said
means for maintaining said treating fluid under said predetermined
pressure places said treating chamber and said balancing
compartment in free flow communication adjacent said upper end of
said plate above said level of said treating fluid.
3. A pressure vessel according to claim 1, wherein said treating
fluid is a gas supplied to said treating chamber under said
predetermined pressure.
4. A pressure vessel according to claim 1, wherein said treating
fluid is a liquid and said means for admitting and maintaining said
treating fluid under said predetermined pressure includes means to
supply a pressurizing fluid to said treating chamber.
5. A pressure vessel according to claim 4, wherein said
pressurizing fluid and said balancing fluid are gas and supplied
from a common source.
6. A pressure vessel according to claim 4, wherein said
pressurizing fluid is a gas characterized as being non-reactive
with said treating liquid, and said balancing fluid is air.
7. A pressure vessel according to claim 4, wherein said
pressurizing fluid is a gas characterized as being non-reactive
with said treating liquid, and said balancing fluid is liquid.
8. A pressure vessel according to claim 1, wherein said plate is
peripherally weld affixed to said inner surface of said shell
immediately adjacent the junction of said side and said end wall,
thereby said balancing compartment is arranged intermediate said
plate and said end wall.
9. A pressure vessel according to claim 1, wherein said means for
supplying said balancing fluid includes means for comparing
pressures in said chamber and said compartment and for controlling
said means for maintaining said treating fluid under said
predetermined treating pressure and said means for supplying
balancing fluid whereby to prevent differences in pressure between
said chamber and compartment from exceeding an amount producing
failure of said plate.
10. A pressure vessel according to claim 9, wherein said treating
fluid is a liquid, said means for admitting and maintaining said
treating fluid under said predetermined pressure includes means to
supply a pressurizing fluid to said treating chamber, said
pressurizing fluid is a gas characterized as being non-reactive
with said treating liquid, and said balancing fluid is air.
11. A pressure vessel according to claim 9, wherein said treating
fluid is a liquid, said means for admitting and maintaining said
treating fluid under said predetermined pressure includes means to
supply a pressurizing fluid to said treating chamber, and said
pressurizing fluid and said balancing fluid are gas and supplied
from a common source.
12. A pressure vessel according to claim 1, wherein said access
opening is in a wall of said shell remote from said one end wall,
said plate is weld affixed to said inner surface of said shell to
define said balancing compartment extending lengthwise of said
shell intermediate said plate and said cylindrical side wall.
13. In a high pressure vessel for treating an article of a given
configuration therewithin, said vessel having walls curved to
withstand at least a high predetermined article treating pressure
condition and a closeable access opening for removably positioning
said article within said vessel, said walls defining a chamber
characterized as having a configuration differing from said given
configuration whereby when said article is placed within said
chamber at least one portion of said chamber adjacent said curved
walls is unoccupied by said article and thus creates unusable
space, and means for admitting an article treating fluid into said
chamber and maintaining said treating fluid under said
predetermined treating pressure, the improvement for reducing the
quantity of treating fluid required to be admitted by an amount
corresponding essentially to said one portion of said chamber which
comprises in combination:
means fixed to said curved walls for forming a fluid sealed
boundary between said one portion and that portion of said chamber
occupied by said article whereby to divide said chamber into an
article treating chamber to be occupied by said article and a
balancing compartment comprising said one portion, said treating
chamber being in communication with said access opening and said
means for admitting treating fluid; and
means for supplying a balancing fluid differing from said treating
fluid to said balancing compartment at a pressure substantially
equal to said predetermined pressure, and said means fixed to said
curved walls including a flat metal plate forming a common boundary
of said treating chamber and said boundary compartment, said plate
being characterized as being of a construction able to withstand
without failure a pressure in excess of that corresponding to the
hydrostatic head of either said treating fluid or said balancing
fluid but substantially less than said predetermined pressure.
14. The improvement according to claim 13, wherein means are
provided for sensing pressures in said treating chamber and said
boundary compartment, for comparing pressures sensed in said
treating chamber and said boundary compartment, and for controlling
operation of said treating fluid admitting and pressure maintaining
means and said balancing fluid supply means whereby to prevent
differences in pressure in said treating chamber and compartment
from exceeding an amount producing failure of said plate.
Description
BACKGROUND OF THE INVENTION
Pressure vessels of the type having a cylindrical side wall and
either convex or concave end walls are commonly employed to enclose
an article or materials being subject to a high pressure treating
operation, such as for instance an impregnating operation. In that
an article being treated normally does not substantially fill the
pressure vessel because of its shape or size, there exists unused
areas within the vessel, which nevertheless must be filled with
impregnating material in order to insure that the article being
treated is fully immersed. Clearly, the need to employ quantities
of impregnant not actually used in the impregnating operation is at
all times an economic disadvantage.
With the above problem in mind, it has become common practice when
treating articles in reel form, to provide a plug or core
concentrically positioned within a vessel or tank for receipt
within the hub of the reel, as evidenced by U.S. Pat. No.
3,125,466.
However, attempts to provide treating chambers of non-circular
cross section and/or with flat end walls within cylindrical vessels
have met with only limited success. In this respect, the present
practice of filling unused bounding areas of a pressure vessel with
concrete or other filling material normally presents serious
expansion problems and greatly adds to both the cost and weight of
the vessel.
SUMMARY OF THE INVENTION
The present invention relates to high pressure vessels of the type
commonly used in the treating of an article with a fluid under
pressure, and more particularly to improvements in such vessels,
which minimize the volume of treating fluid required to be employed
therewithin.
In accordance with the present invention, thin, flat metal plates
are weld affixed to the cylindrical side wall and/or double curved
end wall of a conventional pressure vessel, so as to define an
article treating chamber bounded by one or more unusable space
occupying outer balancing compartments. The number of plates and
their arrangement within the pressure vessel will be dictated by
the normal size and/or shape of the article or articles to be
treated. Thus, where the article to be treated is in the form of a
reel, metal end plates would be employed to block off the unusable
space adjacent ends of the pressure vessel. Where the article to be
treated is of a generally rectangular cross-sectional
configuration, such as for instance pallet carried articles, four
side plates would be affixed to the cylindrical side wall of the
pressure vessel in order to define a treating chamber of
corresponding rectangular cross-sectional configuraton and, if
desired, one or more end plates may be employed, as indicated
above.
It is a particular feature of the present invention that
inexpensive or easy to handle fluid, as compared to the impregnant
or impregnant pressurizing fluid, is introduced into the balancing
compartments at a pressure corresponding to the greater than
atmospheric pressure applied to the impregnant within the treating
chamber. By this arrangement, the bounding plates need only have a
strength sufficient to withstand the hydrostatic pressure of the
impregnant and thus may be inexpensively formed and installed. To
insure against rupture of the bounding plates, the pressure of the
balancing fluid within the balancing compartments is continuously
compared with the pressure within the treating chamber by a
suitable control adapted to bleed off or terminate the introduction
of pressurizing and balancing fluids whenever an undesirable
disparity exists therebetween.
Depending upon the installation, the balancing fluid may be either
a gas, such as air or nitrogen, or a liquid, such as water.
DRAWINGS
The nature and mode of the present invention will now be more fully
described in the following detailed description taken with the
accompanying drawings wherein:
FIG. 1 is a vertical sectional view of a horizontally disposed
pressure vessel employing the present invention;
FIG. 2 is a sectional view taken generally along line 2--2 in FIG.
1;
FIG. 3 is a fragmentary vertically sectional view of the
horizontally disposed pressure vessel employing a modified form of
the present invention;
FIG. 4 is a vertical sectional view of an upstanding pressure
vessel incorporating a further modification of the present
invention;
FIG. 5 is a view similar to FIG. 4, but showing a further
modification of the present invention;
FIG. 6 is a schematic view illustrating a pressure responsive
control for use in the practice of the present invention.
FIG. 7 is a view similar to FIG. 1, but showing an alternative form
of the present invention.
DETAILED DESCRIPTION
The present invention possesses utility in combination with vessels
of the type employed in performing diverse high pressure fluid,
article treating operations, such as by way of example the oil
impregnation of metal castings and the cooking of meat products.
Normally, in performing these operations an article or group of
articles to be treated are placed within a treating chamber,
wherein the chamber is first placed under vacuum in order to remove
included gases from the article and is subsequently filled with a
treating fluid to a depth sufficient to immerse the article; the
treating fluid being maintained under a high pressure to insure
that the article is thoroughly impregnated with such fluid. When
the treating fluid is a liquid, a compatible gas is normally
applied to the surface of the liquid in order to establish the
desired high pressure condition, whereas when the treating fluid is
in a gaseous form, the treating gas is normally introduced into the
treating chamber at the desired pressure.
As by way of more specific illustration, reference is made
particularly to FIGS. 1 and 2 wherein the present invention is
shown as being incorporated within a conventional, horizontally
disposed high pressure vessel 10 of the type employed to impregnate
an article or group of articles with a liquid. Vessel 10 is shown
as including a metal shell 12 having a cylindrical side wall 14 and
a convex end wall 16; a metal door 18 for closing an access opening
to a treating chamber 20, such opening being defined for example by
an open end 22 of the shell; a conduit 24 for admitting treating
liquid to and withdrawing it from chamber 20; and a conduit 26 for
placing chamber 20 in communication with a source of vacuum and for
admitting a gas under pressure to and withdrawing it from chamber
20. As will be apparent, the illustrated cylindrical configuration
of side wall 12 and double curved configured end wall 16 and door
18 are conventionally employed to permit the vessel to withstand
high internal pressures determined by the pressure of pressurizing
gas admitted through conduit 26. Of course, the gas admitted via
conduit 26 will be compatible with the treating liquid.
Normally, suitable means, such as beams 28 are employed to support
an article or an article carrier, such as a pallet within the
treating chamber. Also, it is conventional to arrange a suitable
level guage 30 within chamber 20 in order to control operation of
liquid flow control valve 32 via a suitable electric and/or
pneumatic admission-exhaust control 34, and to arrange a suitable
pressure sensor 36 within chamber 20 for the purpose of controlling
operation of gas flow control valve 38 via a suitable electric
and/or pneumatic admission-exhaust control 39. Thus, in operation
of a conventional system, after a vacuum is drawn to remove
included gases from an article within chamber 20, as by applying a
vacuum to conduit 26, an impregnating fluid is introduced into the
chamber to a height sufficient to immerse the article, as
determined by level gauge or sensor 30, and finally a compatible
gas is introduced over the impregnating liquid to maintain a
desired treating pressure thereon, as determined by sensor 36.
Conventionally, pre-set timing devices control operation of
controls 34 and 39 to provide for automatic operation of the
vessel.
As will be apparent, when the article to be treated, either because
of its shape or size does not completely fill chamber 20, there
will exist unused side and end areas of chamber 20, which
nevertheless must be filled with an ofttimes expensive impregnating
liquid. In other words, the walls of vessel 10 are necessarily
curved to withstand high article treating pressure conditions and
therefore define a vessel chamber, which has a configuration
normally differing from some given configuration (including size)
of an article to be treated, such that at least a portion of the
vessel chamber 20 adjacent its curved walls is unoccupied by the
article. This unoccupied portion is unusable space, which in a
conventional vessel construction must be filled by the article
treating fluid.
Thus, in accordance with the present invention, the vessel
illustrated in FIGS. 1 and 2 is modified by blocking off unoccupied
areas of chamber 20, which would not be required, as for instance
in the case of articles removably positioned in the chamber on a
rectangular pallet. To this end, vessel 12 is modified for instance
by affixing a bottom plate 40 and a pair of side plates 41, 42 to
vessel side wall 14 and end wall 16 as indicated in FIG. 1 to
provide three fluid sealed arcuate bounding compartments or
chambers 40a-42a, and by affixing a single metal plate 44 to end
wall 16 and side and bottom plates 40, 41 and 42 to provide a flat
closed end for chamber 20 and an end bounding compartment or
chamber 44a; compartments 40a-42a being end sealed relative to
vessel open end 22 by transverse flanges 46. Since the manner in
which plates 40, 41, 42 and 44 are mounted within vessel 10 and
connected to each other is a mere matter of choice or determined by
the configuration of the article to be treated, it will be
understood that end plate 44 may alternately extend completely
across inside of the vessel and the rear ends of plates 40, 41 and
42 joined thereto.
The thus defined compartments are placed in communication with
conduit 26 via branch conduits 48 for the purpose of continuously
establishing therewith pressure conditions corresponding to the
vacuum and gas pressure conditions existing within chamber 20. The
actual pressures existing within compartments 40a, 41a, 42a and 44a
are continuously monitored by suitable pressure sensors 40b, 41b,
42b and 44b and the output of such sensors continuously applied to
control 39, wherein they are compared with the output of treating
chamber pressure sensor 36. If one or more of the pressures sensed
in the compartments is different than that existing in chamber 20
by a predetermined amount because of line blockages or leaks,
control 39 may automatically control valve 38 to terminate the
vacuum treating or pressurizing operation and, if desired, over
control 34 for the purpose of exhausting impregnating treating
fluid through valve 32.
Devices for comparing the outputs of plural pressure sensors and
controlling the operation of flow control valves in accordance with
differences in sensed pressures are per se well known, and thus a
detailed description is believed unnecessary. However, to
facilitate understanding of present invention, reference may be
made to FIG. 6, wherein control 39 is shown as being pneumatically
operated and as including a plurality of diaphragm operated
electrical switches (only 39a and 39d being shown), which close
whenever the pressure in chamber line 36' from sensor 36 is more or
less than the pressures in the compartment lines from sensors
40b-42 b and 44b (only compartment lines 40b' and 44b' being shown)
by a predetermined amount. Upon closing of any of the diaphragm
switches, a circuit is established through a suitable control
device or relay 39', which in turn controls valve 38 and, if
desired, control 34. Of course, control 39 would preferably be of a
type capable of functioning under both pressure and vacuum
conditions.
As will be apparent, by maintaining the pressures existing in
compartments 40a, 41a, 42a and 44a essentially equal, plates 40,
41, 42 and 44 need only be of sufficient thickness or strength to
withstand with a slight margin of safety the hydrostatic pressure
imposed thereon by the treating liquid. As a result, the plates
forming common boundaries between the treating chamber occupied by
the article and balancing compartments may be formed of relatively
light weight, inexpensive, thin, flat metal stock and may be
economically fixed to the vessel wall surfaces as by welding.
If the pressurizing gas is relatively expensive, due for instance
to the requirement that such gas must be non-reactive with the
treating liquid, the boundary compartments may be isolated relative
to the pressurizing gas present in the treating chamber and
connected to a separate source of relatively inexpensive fluid
under pressure, such as air or water. This may be effected by
modifying the construction of FIG. 1, as indicated in FIG. 7, by
separately supplying the chamber with a non-reactive pressurized
gas via a valve controlled conduit shown as 26a. Thus, the conduit
arrangement and associated control would be essentially identical
to that hereinafter described with reference to FIG. 3, except that
conduit 24 would be retained for the purpose of admitting treating
liquid to and withdrawing such liquid from the chamber. In this
case, care should be taken in the design of the vessel to account
for both the hydrostatic pressure of the treating liquid and the
boundary liquid.
The construction illustrated in FIGS. 1 and 2 may be further
modified by deleting end plate 44 or all of side bottom plates
40-42 as required to accommodate the vessel to receive articles of
diverse sizes and/or shapes. If the side plates are omitted, the
end plate may be peripherally affixed to end wall 16 or to the side
wall 14 immediately adjacent end wall 16.
FIG. 3 illustrates a modified form of the present invention, having
utility where the treating fluid supplied via conduit 26 is a
relatively expensive gas and the balancing fluid is a relatively
inexpensive fluid, such as air supplied through a separate conduit
26' under the control of valve 38'. In that the treating fluid is a
gas, which occupies the whole of the treating chamber when under
pressure, it is preferable to additionally provide a top plate 50
to define a top boundary compartment 50a. Of course, compartment
50a would be placed in communication with conduit 26' and be
provided with a pressure sensor 50b. Since the "hydrostatic head"
of the treating gas is exceedingly small, the boundary plates need
only be of sufficient thickness to prevent puncture thereof in the
event of careless handling of articles within the vessel. If the
balancing fluid is a liquid such as water, the hydrostatic head of
the balancing fluid must be considered in designing the boundary
plates.
FIG. 4 illustrates the utilization of the present invention in
combination within a pressure vessel having a top opening
upstanding vessel 52 into which a treating liquid is admitted via a
conduit 54 to a level determined by sensor 56. In this form of the
invention, four vertically rising metal plates 58 have their
vertical marginal edges fixed to cylindrical side wall 60 of vessel
52 and their bottom marginal edges fixed to bottom end wall 62,
thereby to define a square cross-sectional treating chamber 64
bounded by four arcuate boundary compartments 66. In that sensor 56
serves to maintain the treating fluid within treating chamber 64 at
a level below the upper edges of plates 58, chamber 64 may remain
in fluid communication with compartments 66 adjacent the upper end
of the vessel. This greatly simplifies the construction, since a
compatible pressuring gas may be simultaneously supplied to the
treating chamber and compartments by a single conduit 70 under the
control of a single pressure sensor 72.
Reference is now made to FIG. 5, which illustrates a further
modification of the invention particularly adapted for use in
vessels employed in processing cylindrical articles. In this
construction, treating fluid such as an expensive gas is admitted
to and withdrawn from the cylindrical treating chamber 80 of an
upstanding vessel 82 by conduit 84 under control of chamber
pressure sensor 86, control 90 and valve 92. The unusable top and
bottom regions of the vessel adjacent vessel door 94 and bottom end
wall 96 are blocked off from chamber 80 by upper and lower end
plates 98 and 100 to define upper and lower boundary compartments
98a and 100a, respectively. A relatively inexpensive fluid, such as
air, is supplied to compartments 98a and 100a through a branched
conduit 102 under the control of valve 104, which is in turn
controlled by boundary compartment pressure sensors 98b and 100b
and control 90. Control 90, which may be of a construction similar
to that of control 39, serves to compare the pressures sensed by
sensors 86, 98b and 100b for the purpose of controlling valves 92
and 104, if a predetermined disparity exists between the pressures
in chamber 80 and compartments 98a and 100a.
* * * * *