U.S. patent application number 11/907770 was filed with the patent office on 2009-04-23 for collapsible fluid storage tank.
This patent application is currently assigned to Caterpillar Inc.. Invention is credited to Christopher Ray Copple, Andrew O. Fonkalsrud, Matthew Edward Leustek.
Application Number | 20090103838 11/907770 |
Document ID | / |
Family ID | 40243864 |
Filed Date | 2009-04-23 |
United States Patent
Application |
20090103838 |
Kind Code |
A1 |
Fonkalsrud; Andrew O. ; et
al. |
April 23, 2009 |
Collapsible fluid storage tank
Abstract
A collapsible fluid storage tank is disclosed. The fluid storage
tank may include a bladder configured to store fluids, occupy a
variable space, and collapse as the stored fluid is depleted. The
fluid storage tank may also include at least one component
configured to connect the bladder to a machine.
Inventors: |
Fonkalsrud; Andrew O.;
(Grenoble, FR) ; Leustek; Matthew Edward;
(Metamora, IL) ; Copple; Christopher Ray; (Peoria,
IL) |
Correspondence
Address: |
CATERPILLAR/FINNEGAN, HENDERSON, L.L.P.
901 New York Avenue, NW
WASHINGTON
DC
20001-4413
US
|
Assignee: |
Caterpillar Inc.
|
Family ID: |
40243864 |
Appl. No.: |
11/907770 |
Filed: |
October 17, 2007 |
Current U.S.
Class: |
383/38 ; 137/1;
29/402.01; 383/127 |
Current CPC
Class: |
B60K 15/03177 20130101;
Y10T 137/0318 20150401; Y10T 29/49718 20150115; B60K 2015/03348
20130101; B60K 2015/03118 20130101 |
Class at
Publication: |
383/38 ; 137/1;
29/402.01; 383/127 |
International
Class: |
B65D 30/00 20060101
B65D030/00; B65D 30/22 20060101 B65D030/22 |
Claims
1. A fluid storage tank, comprising: a bladder, configured to:
store fluid; occupy a variable space; and collapse after the stored
fluid is depleted; and at least one connecting component,
configured to connect the bladder to a machine.
2. The fluid storage tank of claim 1, wherein the variable space is
proportional to the volume of the stored fluid.
3. The fluid storage tank of claim 1, wherein the bladder includes
a plurality of compartments.
4. The fluid storage tank of claim 3, wherein the plurality of
compartments are separated by non-permeable membranes for storing
different types of fluids.
5. The fluid storage tank of claim 4, wherein the plurality of
compartments include an outer compartment that substantially
embraces an inner compartment, one of the inner and outer
compartments serve as a heat sink for the remaining of the inner
and outer compartments.
6. The fluid storage tank of claim 4, wherein the plurality of
compartments include at least two adjacent compartments, a central
one of the at least two adjacent compartments serve as a heat sink
for the remaining of the at least two adjacent compartments.
7. The fluid storage tank of claim 1, wherein the at least one
connecting component includes one or more fluid passages to feed
fluid into the bladder and drain fluid from the bladder.
8. A method of storing fluid, comprising: connecting a bladder to a
machine; storing fluid in the bladder; varying a size of the
bladder; and collapsing the bladder as the stored fluid is
depleted.
9. The method of claim 8, wherein varying the size of the bladder
includes varying the size of the bladder proportional to a volume
of the stored fluid.
10. The method of claim 8, wherein storing fluid in a bladder
includes storing multiple different fluids in the bladder
simultaneously, and maintaining separation between the stored
fluids.
11. The method of claim 9, further including transferring heat from
one of the fluids to another of the fluids within the bladder.
12. The method of claim 8, further including flexing the bladder
around rigid components in a machine.
13. A method of gaining service access to a machine, comprising:
manually depleting fluid stored in a bladder; collapsing the
bladder as the stored fluid is depleted; and creating space in the
machine.
14. The method of claim 13, wherein manually depleting fluid stored
in the bladder includes manually depleting fluid stored in the
bladder via an inlet.
15. A machine, comprising: an engine compartment; an engine
disposed within the engine compartment; a plurality of rigid
machine components disposed within the engine compartment; and at
least one fluid storage tank disposed within the engine
compartment, the fluid storage tank including: a bladder,
configured to: store fluid; flex around the plurality of rigid
machine components disposed within the engine compartment; occupy a
variable space within the engine compartment; and collapse after
the stored fluid is depleted to gain access to the plurality of
rigid components; and at least one connecting component, configured
to connect the bladder to a machine.
16. The machine of claim 15, wherein the variable space is
proportional to the volume of the stored fluid.
17. The machine of claim 15, wherein the bladder include a
plurality of compartments, the plurality of compartments are
separated by non-permeable membranes for storing different types of
fluids.
18. The machine of claim 17, wherein the plurality of compartments
include an outer compartment that substantially embraces an inner
compartment, one of the inner and outer compartments serving as a
heat sink for the remaining of the inner and outer
compartments.
19. The machine of claim 17, wherein the plurality of compartments
include at least two adjacent compartments, a central one of the at
least two adjacent compartments serving as a heat sink for the
remaining of the at least two adjacent compartments.
20. The machine of claim 15, further including a bulkhead connected
with one or more fluid passages to feed fluids into the bladder and
drain fluids from the bladder.
Description
TECHNICAL FIELD
[0001] The present disclosure relates generally to a fluid storage
tank, and more particularly, to a collapsible fluid storage
tank.
BACKGROUND
[0002] Engine exhaust emissions are becoming increasingly
scrutinized by engine manufacturers. Internal combustion engines,
including diesel engines, gasoline engines, gaseous fuel-powered
engines, and other engines known in the art, exhaust a complex
mixture of air pollutants. The air pollutants are composed of
gaseous and solid compounds, including particulate matter, nitrogen
oxides (NOx), and sulfur compounds. One method that has been
implemented by engine manufacturers to comply with the regulation
of NOx exhausted to the environment has been to implement a
strategy known as selective catalytic reduction (SCR).
[0003] An SCR system works by releasing a reducing agent, such as
ammonia, into the engine exhaust flow in the presence of a
catalyst. The reducing agent reacts with the NOx in the exhaust
flow, on the surface coating of the catalyst, to create
environmentally friendly products, such as nitrogen gas and water.
In practice, ammonia is rarely used because it is toxic and
difficult to handle. Urea, relatively easy to handle, can be
converted to ammonia while heated and, thus, becomes a more popular
choice of reducing agent for engine manufacturers. Urea is
typically contained in a storage tank onboard an associated vehicle
and pre-heated and fed to the exhaust gases on-demand via an
injector or a pump.
[0004] To comply with increasingly stringent emissions standards
for vehicles enforced by governments and regulatory agencies,
manufacturers are required to include additional components that
operate to reduce the emitted exhaust gas. Fluid tanks such as, for
example, urea tanks in the SCR system, usually take up considerable
space in the machine otherwise reserved for the additional
components. Therefore, it is desirable to develop new storage
technologies to make space available for these additional
components in a typical vehicle.
[0005] Rigid tanks for storing urea, for example, steel tanks,
usually have defined shapes and fixed sizes. Such tanks do not make
the most efficient use of space. In particular, rigid tanks take up
the same size of space even when the stored urea is mostly
consumed. It is therefore desirable to use collapsible storage
tanks with variable shapes, so that space is more efficiently
utilized and additional components could be included without
increasing the size of the vehicle.
[0006] Incorporating additional components into a typical vehicle,
to comply with the stringent emissions standards, imposes
additional challenges on machine accessibility. For example, it
becomes difficult to secure some space for assembly and service
access of the vehicle. Therefore, collapsibility, beyond
flexibility, of the storage tank is desirable so that additional
space may be generated by depletion of the stored fluid.
[0007] Furthermore, for the purpose of urea storage, flexibility in
the storage tank is important for the additional reason that urea
may easily crystallize and vaporize. For example, the
crystallization point of urea is -11.degree. C. Therefore urea may
crystallize under extremely cold climatic conditions.
Crystallization of the urea may generate expansion forces large
enough to damage a rigid tank. In the other extreme, high
temperature may cause the urea to vaporize. High vapour pressure
generated within a rigid tank could also cause damage to the
tank.
[0008] In addition, for the purpose of urea storage, efficient heat
dissipation is desirable. Urea is pre-heated to generate ammonia
before it is injected onto the exhaust gas flow. High temperature
may occur near an associated heating element and/or the urea
storage tank. Therefore, in order to avoid localized over-heating,
it is important to include a heat sink that absorbs redundant
heat.
[0009] One urea storage container is described in published U.S.
Application No. 2002/0081239 to Palesch et al. ("the '239
publication"). The '239 publication describes a storage container
containing a urea solution used for exhaust gas after treatment.
The storage container includes walls at least partially formed by a
flexible pressure membrane. The storage container described in the
'239 publication is configured to be placed inside a pressure
chamber, into which compressed air is supplied. The external
pressure generated by the compressed air deforms the flexible
pressure membrane. Therefore the urea flows into a urea conveying
conduit by pressure loading.
[0010] Although the urea storage container described in the '239
publication may be effective for storing and supplying urea, it may
be problematic. For example, the container described in the '239
publication offers only minimal flexibility in varying its size and
shape, and it still occupies nearly the same amount of space even
when the stored urea is mostly consumed. As a result, it does not
effectively make space to fit in additional components required by
stringent emissions standards.
[0011] Furthermore, the container described in the '239 publication
may provide insufficient accessibility for assembly and service of
an associated vehicle. For similar reasons as described above, the
container described in the '239 publication can not collapse even
after the stored urea is depleted and, therefore, the container may
be unable to generate space for service personnel to access the
machine.
[0012] In addition, the solution provided by the '239 publication
may lack reliability when used for storing urea. For example, the
urea storage container is placed in a pressure chamber and, thus,
the flexible wall can deform only inward away from the pressure
chamber. However, expansion generated by crystallization or
vaporization of the stored urea applies outward forces on walls of
the chamber. As a result, the container and chamber described in
the '239 publication may be incapable of absorbing the generated
expansions.
[0013] Finally, the container described in the '239 publication may
be inefficient in heat dissipation. For example, no heat
dissipation device is provided to absorb redundant heat associated
with a urea heater placed inside the pressure chamber. Therefore,
the container described in the '239 publication may experience
over-heating and bear an excessively high temperature.
[0014] The present disclosure is directed at overcoming one or more
of the problems set forth above.
SUMMARY OF THE DISCLOSURE
[0015] In one aspect, the present disclosure is directed to a fluid
storage tank. The fluid storage tank may include a bladder
configured to store fluids, occupy a variable space, and collapse
as the stored fluid is depleted. The fluid storage tank may also
include at least one connecting component configured to connect the
bladder to a machine.
[0016] In another aspect, the present disclosure is directed to a
method of storing fluids. The method may include connecting the
bladder to a machine. The method may also include storing fluids in
a bladder and varying the size of the bladder. The method may
further include collapsing the bladder as the stored fluid is
depleted.
[0017] In yet another aspect, the present disclosure is directed to
a method of gaining service access to a machine. The method may
include manually depleting fluid stored in a bladder. The method
may also include collapsing the bladder as the stored fluid is
depleted and creating space in the machine.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] FIG. 1 illustrates an engine compartment consistent with an
exemplary disclosed embodiment;
[0019] FIG. 2 illustrates an exemplary collapsible urea storage
tank at a full condition, consistent with an exemplary disclosed
embodiment shown in FIG. 1;
[0020] FIG. 3 illustrates an exemplary collapsible urea storage
tank at a partially filled condition, consistent with an exemplary
disclosed embodiment shown in FIG. 1;
[0021] FIG. 4 illustrates an exemplary collapsible urea storage
tank at an empty and collapsed condition, consistent with an
exemplary disclosed embodiment shown in FIG. 1;
[0022] FIG. 5 illustrates an exemplary collapsible fluid storage
tank that includes three compartments, consistent with a disclosed
embodiment; and
[0023] FIG. 6 illustrates an exemplary collapsible fluid storage
tank that includes two compartments, consistent with a disclosed
embodiment.
DETAILED DESCRIPTION
[0024] FIG. 1 illustrates an engine compartment 100 consistent with
an exemplary disclosed embodiment. Engine compartment 100 may
contain several components having rigid exteriors, including a
power source 101, a battery 102, and a power conversion device 103.
Engine compartment 100 may further include a collapsible fluid
storage tank 200. Power source 101 may be any type of machine
component configured to provide power to a machine. Power source
101 may embody, for example, a diesel engine, a gasoline engine, a
natural gas engine, a turbine engine, or a fuel cell operable to
generate a power output. Battery 102 may be a rechargeable battery
that supplies electric energy to an associated machine and/or to
power source 101. Power-conversion unit 103 may be any type of
device configured for converting at least a portion of the power
output supplied by power source 101 into another form. For example,
power-conversion unit 103 may be a generator, a hydraulic pump, or
an electric motor.
[0025] Collapsible fluid tank 200 may include a collapsible bladder
for storing fluid. The stored fluid may be any type of fluid used
by the machine and/or power source 101, such as, for example, urea,
fuel, engine oil, transmission oil, coolant, and brake fluid. Fluid
storage tank 200 may further include one or more connecting
components to seal the bladder and connect it with an engine
compartment or other components in the engine compartment. Fluid
storage tank 200 may have a variable size and a variable shape.
When filled with fluid, fluid storage tank 200 may flex around
rigid components such as power source 101, battery 102, and
power-conversion unit 103, and efficiently occupy small spaces
among these rigid components. When the stored fluid is depleted,
fluid storage tank 200 may collapse and occupy only minimal space.
As fluid storage tank 200 collapses, spaces around power source
101, battery 102, and power-conversion unit 103 may become
available for assembly and service access. Fluid storage tank 200
will be illustrated and described in greater details with regard to
FIG. 2.
[0026] FIG. 2 illustrates an exemplary collapsible urea storage
tank at a full condition, consistent with an exemplary disclosed
embodiment shown in FIG. 1. Collapsible storage tank 200 may
include, among other things, a collapsible bladder 201, a plurality
of connecting components 202, at least one outlet 203, and at least
one inlet 205.
[0027] Collapsible bladder 201 may be fabricated from any suitable
fluid-impervious elastomeric material, such as, for example,
fiber-reinforced membrane and rubber membrane. The size of
collapsible bladder 201 may vary due to the distending and
contracting of the elastomeric wall. Collapsible bladder 201 may be
mounted or connected to other components of a mobile machine via
connecting components 202. For example, consistent with one
disclosed embodiment, connecting component 202 may be a bulkhead or
rigid panel that seals the bladder and connects the bladder to a
wall of engine compartment 100. The bulkhead may include one or
more holes and connectors that connect the bladder with fluid
passages. Connecting component 202 may also be a non-rigid
component such as, for example, a pin that sticks through
collapsible bladder 201 and mounts it to engine compartment
100.
[0028] Fluid may be pumped into collapsible bladder 201 by a pump
204 via inlet 205. One terminal of inlet 205 may be connected to
collapsible bladder 201 via connecting component 202. A fluid
depletion valve 206 may be installed at an opposing terminal of
inlet 205. Fluid depletion valve 206 may be turned on to allow
fluid flow into or out of inlet 205. While turned off, fluid
depletion valve 206 may act as a closure of inlet 205 to prevent
the effusion of the stored fluid. One terminal of inlet 205 may be
manufactured to have threads, for easy connection of an external
fluid pipe 207, which may connect an external or off-board fluid
container 208.
[0029] Stored fluid may flow out of collapsible bladder 201 to
other parts of the exhaust treatment system through outlet 203. One
terminal of outlet 203 may be connected to collapsible bladder 201
via connecting component 202. The opposing terminal of outlet 203
may be connected to a fluid consumer (not shown), such as a urea or
fuel injector, or a hydraulic pump.
[0030] FIG. 2 shows that when fluid is pumped into bladder 201 by
pump 204, bladder 201 may distend to occupy a larger space, as
compared to when empty. The elastomeric material expands an amount
corresponding to the volume of the stored fluid. FIG. 3 shows that,
with the consumption of the stored fluid via outlet 203, bladder
201 may gradually contract and reduce its size. As the stored fluid
is depleted from the bladder, as shown in FIG. 4, bladder 201 may
further contract and collapse into a space-saving volume. Depletion
of the stored fluid may be caused by consumption of the stored
fluid through outlet 203, and may also be caused by manual emptying
of the stored fluid via inlet 205 and fluid depletion valve
206.
[0031] Bladder 201 may include one or more compartments for storing
different types of fluid. Consistent with one disclosed embodiment,
FIG. 5 illustrates an exemplary fluid storage tank 200 that
includes three compartments. A first compartment 301 may store a
first type of fluid, a second compartment 302 may store a second
type of fluid, and a third compartment 303 may store a third type
of fluid. The three compartments may be arranged adjacent each
other and separated by non-permeable membrane walls 304. Membrane
walls 304 may be fabricated from any fluid-impervious elastomeric
material, so that the different types of fluid do not filter
through the walls and mix with each other. The three compartments
may be connected to separate inlets and outlets 306 via a common
bulkhead 305. Each of the three compartments may distend and
contract corresponding to the volumes of the stored fluids. In one
example, the first compartment 301 may store urea, the second
compartment 302 may store coolant, and the third compartment 301
may store oil. The coolant stored in central compartment 302 may
absorb heat from the urea and the oil stored in the other two
compartments 301 and 303. For purposes of illustration, three
compartments are shown in FIG. 5. However, one skilled in the art
will recognize that collapsible bladder 201 may include any
suitable number of compartments.
[0032] Consistent with another disclosed embodiment, FIG. 6
illustrates an exemplary fluid storage tank 200 that includes two
compartments. An inner compartment 401 may be completely embraced
by an outer compartment 402. Inner compartment 401 may store a
first type of fluid, and outer compartment 402 may store a second
type of fluid. The wall of inner compartment 401 may be fabricated
from the same fluid-impervious elastomeric material as the outside
wall of collapsible bladder. 201. Inner compartment 401 and outer
compartment 402 may be connected to separate inlet and outlet 404
via a common bulkhead 403.
[0033] In one example, inner compartment 401 may store urea. Urea
may be injected into the engine exhaust flow, and be used as a
reducing agent in the selective catalytic reduction (SCR) process.
Urea may be pre-heated by a heating element 405 before it flows out
via outlet 404 and injected onto the exhaust gas flow. Heating
element 405, for example, a heating pipe, may be placed near the
urea storage compartment 401. Outer compartment 402 may store a
relatively large volume of fuel or coolant and absorb redundant
heat generated by heating element 405. Therefore, outer compartment
402 may serve as a heat sink, and may effectively avoid localized
over-heating at inner compartment 401.
INDUSTRIAL APPLICABILITY
[0034] The disclosed collapsible fluid storage tank may be utilized
to store any type of fluid such as, for example, urea, fuel,
coolant, engine oil, transmission oil or hydraulic fluid. According
to one embodiment of the present application, different types of
fluid may be stored in the several compartments of a collapsible
fluid storage tank.
[0035] With the incorporation of a collapsible bladder 201, more
efficient usage of space may become possible. For example,
collapsible bladder 201, made from elastomeric material, may change
its shape and fill in the space around connecting components
located within the engine compartment 100. Therefore, additional
components required by stringent emissions standards may be
accommodated in a typical machine.
[0036] Furthermore, the incorporation of a collapsible bladder may
gain accessibility to the machine. For example, the fluid stored in
collapsible storage tank 200 may be manually depleted via inlet
205, and collapsible bladder 201 may collapse to occupy a minimal
space. As a result, service personnel may gain access for assembly
and service of the machine.
[0037] In addition, elastomeric characteristic of the bladder wall
may absorb the expansions generated by crystallization and
vaporization of the stored fluid, for example, urea. Therefore, the
present application may minimize the potential damage of the
storage tank due to expansions.
[0038] Finally, the collapsible bladder may store several different
types of fluid and use one fluid as the heat sink for another. For
example, a collapsible bladder may store fuel or coolant in one
compartment and urea in another proximal (adjacent or surrounding)
compartment. Therefore, the redundant heat generated during the
urea heating process may be absorbed by the fuel or coolant
compartment.
[0039] It will be apparent to those skilled in the art that various
modifications and variations can be made to the disclosed fluid
storage tank without departing from the scope of the invention.
Other embodiments will be apparent to those skilled in the art from
consideration of the specification and practice of the disclosed
fluid storage tank. It is intended that the specification and
examples be considered as exemplary only, with a true scope being
indicated by the following claims and their equivalents.
* * * * *