U.S. patent application number 09/815428 was filed with the patent office on 2001-08-09 for galley waste disposal system and method.
This patent application is currently assigned to MAG Aerospace Industries, Inc.. Invention is credited to Rozenblatt, Mike M..
Application Number | 20010011391 09/815428 |
Document ID | / |
Family ID | 22135296 |
Filed Date | 2001-08-09 |
United States Patent
Application |
20010011391 |
Kind Code |
A1 |
Rozenblatt, Mike M. |
August 9, 2001 |
Galley waste disposal system and method
Abstract
A waste disposal system quietly and effectively evacuates solid,
liquid, and slurry food waste from a galley sink via a vacuum
action created when a normally closed flush valve momentarily opens
and eliminates the differential pressure between the sink and the
drain line. The system is automatically disabled when a clogged
condition is sensed. The sink bowl is equipped with a sealable
cover that cuts down the noise associated with vacuum pressure
evacuation systems to an acceptable level. The system also has a
rinse subsystem including a rinse valve for introducing rinse water
into the sink just before a flush operation commences. The sink
bowl includes an air inlet port in communication with an air inlet
duct that extends outside of and above the cart for providing cabin
pressure air to the sink. A controller controls the timing and
operation of the flush and rinse operations. The flush control
assembly is activated by depressing a flush switch above the
assembly which itself is operational only when a vacuum condition
is present in the drain line and when a proximity sensor indicates
that the sink cover is closed and sealed. An elbow-shaped pipe that
prevents rigid, elongate objects from becoming lodged in the drain
line connects the sink's disposal outlet to the flush valve
assembly.
Inventors: |
Rozenblatt, Mike M.;
(Manhatten Beach, CA) |
Correspondence
Address: |
CHRISTIE, PARKER & HALE, LLP
350 WEST COLORADO BOULEVARD
SUITE 500
PASADENA
CA
91105
US
|
Assignee: |
MAG Aerospace Industries,
Inc.
|
Family ID: |
22135296 |
Appl. No.: |
09/815428 |
Filed: |
March 22, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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09815428 |
Mar 22, 2001 |
|
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|
09076965 |
May 13, 1998 |
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6223361 |
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Current U.S.
Class: |
4/653 ; 4/321;
4/431; 4/668 |
Current CPC
Class: |
B64D 11/04 20130101;
E03C 1/28 20130101; E03F 1/006 20130101 |
Class at
Publication: |
4/653 ; 4/321;
4/431; 4/668 |
International
Class: |
E03C 001/12; E03D
001/00; E03C 001/02; E03C 001/182; F16K 031/00 |
Claims
What is claimed is:
1. An operator controlled aircraft galley waste disposal system,
connected to a vacuum waste system on the aircraft having a waste
holding tank and a source of vacuum in communication with the waste
holding tank, the galley waste disposal system comprising: a sink
bowl defining a waste receiving interior and a mouth, the sink bowl
having a waste disposal outlet; a waste drain line in communication
with the waste disposal outlet, the waste holding tank, and the
source of vacuum; a motorized flush valve assembly disposed between
the waste disposal outlet and the waste drain line, the assembly
having a flush valve movable between a normally closed and an open
position preventing and permitting flow therethrough, respectively,
the waste drain line enabling waste in the sink bowl to flow to the
waste holding tank when the flush valve is open; a controller
operatively connected to the flush valve assembly, which
selectively signals the flush valve assembly to move the flush
valve from the normally closed position to the open position; a
sensor connected to the controller and extending into the waste
drain line to detect a condition in the drain line in which it has
become clogged with waste, the controller, upon detection of a
clogged condition by the sensor, disabling the operation of the
flush valve assembly to prevent the flush valve from moving from
its normally closed position; and a cover having an underside,
wherein the cover is selectively and movably mounted over the sink
bowl for closing over and substantially sealing the mount of the
sink bowl, to reduce the sound perceived when waste flows from the
waste receiving interior to the waste holding tank and preventing
waste from leaking out of the bowl when the cover is in a closed
position; a cover detection device operatively connected to the
controller, wherein the detection device detects whether the cover
is closed; and wherein the controller enables the flush valve
assembly only when both the cover is closed, as indicated by the
cover detection device, and when the drain line is clear, as
indicated by the line sensor.
2. The system of claim 1, wherein the cover detection device is a
mechanical switch.
3. The system of claim 1, wherein the cover detection device is a
limit switch.
4. The system of claim 1, wherein the cover detection device is a
reed switch.
5. The system of claim 4, wherein the reed switch is embedded in
the bowl and further wherein a magnet is embedded in the cover such
that the reed switch is triggered when the cover is closed.
6. The system of claim 4, wherein the reed switch is embedded in
the cover and further wherein a magnet is embedded in the bowl such
that the reed switch is triggered when the cover is closed.
7. The system of claim 1, wherein the cover detection device is a
proximity sensor.
8. The system of claim 7, wherein the cover detection device is
selected from the group consisting of optical, ultrasonic, and
magnetic proximity sensors.
9. The system of claim 1, wherein the cover detection device is a
hall effect sensor embedded in the bowl and further wherein a
magnet is embedded in the cover such that the hall effect sensor is
triggered when the cover is closed.
10. The system of claim 1, wherein the cover detection device is a
hall effect sensor embedded in the cover and further wherein a
magnet is embedded in the bowl such that the hall effect sensor is
triggered when the cover is closed.
11. The system of claim 1, wherein the sensor for detecting a
clogged condition in the drain line is a vacuum pressure
sensor.
12. A system as defined in claim 11, wherein the detected pressure
level indicative of a clogged condition in the drain line and at
which the controller disables the operation of the flush valve is
at least one p.s.i.
Description
CROSS-REFERENCE TO RELATED APPLICATION(S)
[0001] This application is a continuation of patent application
Ser. No. 09/076,965, filed on May 13, 1998.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates to waste disposal systems and, in
particular, to a commercial aircraft galley waste disposal
system.
[0004] 2. Description of the Prior Art
[0005] In commercial aviation, it is necessary to dispose of
unwanted fluids and solids such as human waste and food waste.
Disposal of human waste is accomplished with the use of toilet
systems such as conventional vacuum toilet systems. Since about the
early 1980's, it has become common to use vacuum toilet systems in
large commercial aircraft. These vacuum waste systems typically
include a toilet bowl for collecting waste, a waste holding tank, a
vacuum pump, and a valve system for placing the toilet bowl in
communication with the waste holding tank. A rinse valve controls
the introduction of rinse water into the toilet. The system is
typically controlled by an electronic controller.
[0006] The problem of disposal of food waste has not yet been fully
addressed. During in flight operation of commercial aircraft, a
large quantity of food and beverage leftovers can accumulate on an
airplane, the volume depending on the number of the passengers and
the duration of the flight. This leftover waste can come in the
form of solids, liquids, and/or a mixture of the two, called
"slurry." Thus, the handling of this waste is an issue,
particularly on longer flights having many passengers. During such
flights, holding the waste in the aircraft galley (food preparation
area) on the trays and in the carts in which the food and beverages
are served for the duration of the flights is: 1) impractical
because of the relatively large quantity of food stored and served;
2) unsanitary; and 3) can be unsightly.
[0007] Currently, most commercial aircraft are equipped with galley
sinks. However, these sinks are intended for the disposal of fluid
waste only as they are connected to small diameter drain lines,
ranging from about one half to one inch in diameter, and
terminating at the aircraft drain mast for exhaustion to the
atmosphere. Unfortunately, such sink systems are unable to dispose
of slurry and solid food waste products.
[0008] In response to this problem, flight attendants have often
been instructed to dispose of solid and slurry food wastes into the
toilets which are located near the galleys. Conventional aircraft
vacuum toilets are effective for disposing of such food waste
products for a number of reasons. First, they are connected through
much larger lines, typically two inches in diameter, to waste
holding tanks. Further, conventional aircraft vacuum toilet systems
transfer waste from the toilet bowl to the waste holding tanks via
a differential pressure action, thereby ensuring immediate and
complete evacuation. In particular, the air pressure in the toilet
bowl is at cabin pressure (which is pressurized for the safety and
comfort of those on board), while the drain line is maintained at a
much lower air pressure from a source of vacuum. This source is
typically either a vacuum pump or the atmospheric pressure outside
of the airplane, which is very low at cruising altitudes of
thousands of feet above sea level. This differential reaches
approximately 8.5 p.s.i, at an altitude of about 35,000 feet. Thus,
when the flush valve separating the two atmospheres is opened, a
strong vacuum action results and powerfully draws the contents of
the toilet bowl into the waste holding tanks.
[0009] While disposing food waste in aircraft toilets is effective
for its removal from the cabin, several problems and disadvantages
have been identified. First, it can be quite unsanitary for a
flight attendant to enter into a lavatory to dump food waste into a
toilet bowl while working with food in the galley. For example,
given the time demands on flight attendants, there is a
possibility, and perhaps even a likelihood, that they will fail to
wash their hands each time they exit the lavatory. Second,
requiring attendants to dispose of food wastes in toilets is both
inconvenient and inefficient. The process requires the attendant to
carry the container holding the waste from the galley to the
lavatory, open the door, bend down to the level of the toilet bowl
and pour the waste into the bowl, taking care that it does not
spill anywhere but in the bowl. This may have to be repeated
several times until all or enough of the food waste is flushed down
the toilet. Further, using a toilet bowl requires, of course, that
one be available. However, availability of the lavatories is
subject to their occupancy by the passengers. It would be
inefficient for an attendant attempting to complete the task of
cleaning up after a meal to have to wait until a toilet became
available. Additionally, requiring flight attendants to use toilets
for the disposal of food waste appears unprofessional and can be
distasteful to the flying public.
[0010] One approach to the general problem of food waste disposal
during in flight operation of commercial aircraft, which has come
to the inventor's attention, has been a proposed design for a
galley sink system based closely upon existing aircraft vacuum
toilet designs. Thus, such a sink system would include a drain line
having a much larger diameter than conventional galley sinks and
would operate on the same differential pressure, or vacuum, theory
used by conventional vacuum toilet designs.
[0011] While generally effective for disposing of solid, liquid and
slurry food wastes, implementing one of the conventional vacuum
toilet designs into a galley sink system is unsatisfactory for
numerous reasons. First, these designs do not account for the
potential for clogged drain lines. In particular, if and when the
drain line of a conventional vacuum toilet becomes clogged, flush
cycles may continue to operate and rinse water may continue to be
introduced into the bowl despite the lack of pressure differential
between each side of the flush valve (i.e. between the bowl and the
drain line). Thus, the system is enabled until the stoppage is
identified by an individual and the problem is corrected. Under
this condition, the toilet bowl itself could even eventually begin
to fill with a mixture of rinse water and black, or human waste,
water. However, due to sanitation concerns and health and safety
regulations, this situation would be unacceptable in a galley sink
environment, where the sink bowl may not become contaminated with
either used sink water, called grey water, rising from the clogged
sink drain line, or black water rising from the aircraft's main
drain line.
[0012] A second problem concerns the potential for large objects
being dropped or flushed into the drain line. Certain objects often
found in a galley, including chopsticks, cutlery, and large bones,
while too large to be disposed of by a galley sink system, could
inadvertently enter into the sink bowl, and, because of their
elongate and relatively narrow shapes, pass the sink bowl's waste
disposal outlet, enter into the drain line and become lodged
therein. Other objects, such as solid food waste that would
normally pass through the system could then become engaged with the
lodged object, eventually leading to a clogged condition. Even
worse, the large object could find its way into the flush valve
assembly and cause the flush valve to malfunction or break. Thus,
such an obstructed object must be promptly removed from the drain
line. However, with conventional drain line designs, its removal
would be quite burdensome, requiring disassembly of the galley sink
drain line. Further, the lodged object may not be identified until
only after one of the aforementioned, or other, resultant problems
arise. Thus, a need exists for a galley sink system that prevents
such an object from becoming lodged in the drain line while
permitting other food wastes to enter into the line for
disposal.
[0013] Another problem with the earner galley sink design relates
to noise. A loud flushing sound is created when the flush valve
opens and the differential pressure across it forcefully draws the
waste down the drain. The lid, or shroud, of the earlier galley
sink design, based closely on conventional toilet shrouds, somewhat
helps reduce the noise output, but not to a sufficient degree. This
noise level has generally not been objectionable for aircraft
toilets because they are located within lavatories whose doors are
typically closed when flushing occurs. Therefore, the noise is
relatively isolated from the passengers during flushing. Also, the
toilet bowl height, typically at sixteen inches, is almost three
feet away from the typical passenger's ears, thus reducing the
impact of high sound level. However, this same level of noise would
be unacceptable in the galley of the aircraft. The galley is
typically in an open area and close to at least some passengers who
could hear the flushing noise even with a conventional toilet-type
lid covering the sink. Further, the sink in a galley is mounted
much higher off of the floor, typically 44 inches high, and is
closer to the ears of the operators than is the case with toilets.
Thus, a definite need exists for a galley waste disposal that is
quiet enough in operation not to disturb passengers and
attendants.
[0014] A further problem of the earlier galley sink design and
conventional toilet designs relates to the potential for overflow
of waste onto the floor or into the cabinet which may house the
sink. Since the top of the sink must be covered for the sake of
noise reduction, in order to allow cabin pressure air to enter the
bowl to create the differential pressure needed for vacuum
flushing, an overlapping shroud design has been suggested. In this
sink design, which is similar to conventional toilet designs, a
shroud covers over the sink but maintains an opening around the
perimeter, or mouth, of the bowl to allow air to enter. One problem
that can arise is that when the sink bowl starts to fill up with
waste to be disposed, excess fluid could overflow under the shroud
and into the cabinet without the attendant recognizing the overfill
condition. Such fluid waste entrapped in the cabinet could cause
erosion and odor problems and would likely require frequent
maintenance. Thus, a need exists for a galley sink system that
eliminates the potential for overflow spillage, particularly in the
cabinet which houses it, if there is one.
[0015] U.S. Pat. No. 5,165,457, issued to Olin et al., describes a
vacuum toilet sewer arrangement for a toilet bowl including an air
tight lid made of relatively soundproof material to the reduce the
noise associated with vacuum flushing action. Enablement of a
function impulse, such as a user-operated push button, can be made
dependant on the closing of the lid. Further, an air tube is
connected to the toilet bowl in order to provide the ambient air
necessary for efficient vacuum flushing. While incorporating these
toilet system features into a galley sink disposal system would
address some of the aforementioned problems, the potential concern
that is unique to a vacuum galley sink system, namely the clogged
drain situation, is not addressed by this patent.
[0016] In sum, there exists a definite need for a galley waste
disposal system that prevents a backup into the sink bowl upon a
clogged drain condition, that is quiet in operation, that cannot
overflow into the cabinet in which it is housed, and that does not
permit elongate objects that could get stuck in the drain line from
entering the line.
SUMMARY OF THE INVENTION
[0017] The present invention constitutes a system and method for
food waste disposal designed to solve the problems that have been
discussed. In accordance with the broadest embodiment of the
present invention, an operator controlled aircraft galley waste
disposal system is connected to a vacuum waste system on the
aircraft having a waste holding tank and a source of vacuum in
communication with the waste holding tank. This vacuum source is
either the ambient pressure of the air outside of the aircraft or
an artificial source, such as a vacuum pump.
[0018] The aircraft waste disposal system includes a sink bowl,
defining a waste receiving interior and a mouth and having a waste
disposal outlet, and a waste drain line in communication with the
waste disposal outlet, the waste holding tank, and the source of
vacuum. Further, a flush valve assembly is disposed between the
waste disposal outlet and the waste drain line and has a flush
valve that is movable between normally closed and opened positions
to prevent and permit flow therethrough, respectively, such that
the waste drain line enables waste collecting in the sink bowl to
flow to the waste holding tank when the flush valve is open. The
system also includes a controller operatively connected to the
flush valve assembly, to selectively signal the flush valve
assembly to open the flush valve to flush the waste in the sink
bowl, and a sensor connected to the controller and extending into
the waste drain line to detect a condition in the drain line in
which it has become clogged, or plugged, with waste. When the
sensor detects such a clogged condition, the controller disables
the operation of the flush valve assembly to prevent the flush
valve from moving from its normally closed position. Thus, any
standing waste that may build up in the drain, whether it be grey
water coming from the unit's sink bowl, or grey and black water
from other upstream galley sinks and toilets connected to the unit
via the aircraft's main waste drain line, will not further build up
due to subsequent flushes and will not have the opportunity to rise
to the level of the sink bowl and come in contact with any fluid
within it.
[0019] The clogged condition can be sensed in a variety of ways. In
the preferred embodiment, the sensor is a vacuum pressure sensor
that extends into the waste drain line to detect a pressure level
in the waste drain line indicative of a clogged condition. The
pressure level indicates the presence or absence of a clogged
condition in the following way. As is well understood, an
unobstructed drain line in a vacuum-operated system is maintained
in a vacuum condition, i.e. at a very low pressure relative to the
aircraft ambient pressure. However, in the event that waste plugs
the sink's drain line or the main drain line at a point downstream
of the sensor, the drain line upstream of the plug will no longer
be at this low pressure level the next time the flush valve
momentarily opens. Instead, it will adjust to the aircraft ambient,
thereby eliminating pressure differential needed for proper vacuum
action. Accordingly, when the sensor detects such a pressure in the
drain line indicative of a clogged situation, it signals the
controller to disable the flush valve assembly, preventing the
valve from opening. In one preferred embodiment, the sensor signals
the controller to disable the flush valve assembly when it detects
a drain line pressure above a preset threshold, for example, 1
p.s.i of differential pressure.
[0020] In another embodiment, the sensor is a liquid or slurry
level sensor residing inside the drain line. When a clogged
condition develops, subsequent flushing operations will cause the
waste plug to rise in the line. When the plug rises to and above
the level of the sensor, the sensor detects the fluid or waste and
signals the controller to disable the flush valve assembly.
[0021] In an even more detailed embodiment, the galley sink system
includes a rinse subsystem having a rinse valve and a rinse line
connected to the rinse valve and terminating in the sink mouth,
through which rinse water is selectively introduced into the waste
receiving interior for rinsing the bowl just prior to the opening
of the flush valve. The rinse subsystem is controlled by the
controller and is also disabled when the sensor detects a clogged
condition.
[0022] In an even more detailed embodiment of the present
invention, a cover that completely seals the sink bowl opening is
included. This cover reduces the audible noise associated with
flushing to an acceptable level. The particular structure that
accomplishes this is a hinged cover that swings and springs closed
after the waste to be disposed of is placed in the sink. In an
embodiment in which the sink is mounted in a cabinet, such as a
half cart, the sealed cover also prevents waste from unknowingly
overflowing into the cabinet. The cover may also include a seal
attached to its underside to provide an even more complete seal
when the cover is closed over the sink bowl.
[0023] Since the sink is completely sealed at the top by the cover,
the waste receiving interior of the sink includes an air inlet port
which is in fluid communication with an air inlet duct that extends
above the entire assembly. This provides the ambient cabin air
pressure in the sink bowl needed for the differential pressure
action. Thus, with the introduction of a sealed and sound-deadening
cover and a direct air duct into the sink, the problems of noise,
overfilling and spillage into the cabinet, and the resulting
maintenance and odor issues are completely prevented.
[0024] In still another embodiment, in order to prevent elongate
objects that are too large for the system to dispose from becoming
lodged in the drain line, the galley sink system includes an
elbow-shaped pipe directly connected at one end to the sink bowl's
waste outlet. Both the pipe diameter and bend radius range from one
inch to two inches in size. In the preferred embodiment, the pipe
has a diameter of 1.5" and a bend radius of 1.5", each with
standard tolerances. A pipe of this diameter and radius only traps
in its bend, preventing the passage of, rigid elongate objects that
are large enough to become stuck in the drain. Smaller objects that
can pass this elbow-shaped pipe can equally safely pass through the
rest of the drain line. Further, the bend in the pipe is located
very close to the sink drain outlet so that any elongate objects
that do become stuck in the pipe bend protrude into the sink bowl
interior and can be easily removed by hand.
[0025] In order to ensure that the system will not operate with the
cover open, a further embodiment includes a cover having at least
one magnet embedded therein and a sink bowl having a sensor, such
as a proximity sensor, embedded therein to sense the magnet when
the cover is closed and to signal the controller to enable the
flush valve assembly only when it senses that the cover is
closed.
[0026] In another embodiment, an anti-siphon valve is positioned
above the sink to prevent reverse flow of contaminated water into
the potable water supply to insure that the aircraft water system
remains safe for human consumption. In still another embodiment,
the counter top of a half cart cabinet and the sink comprise a
unitary, stainless steel structure.
[0027] Another feature of the present invention is the provision of
a cover readily changeable in its mounting orientation. Since
galley configurations vary from aircraft to aircraft or even within
one aircraft, a cover is provided which can be installed in a
variety of galley positions. In one particular embodiment, the
cover may be mounted and hinged at the rear, left, or right sides
of the galley sink top, depending on the location of the system. In
the preferred embodiment, the cover is constructed from stainless
steel metal encapsulating sound deadening material. The cover has a
substantially square or rectangular shape and at one end is
provided with a shaft at each end. Each shaft is designed as an
integrated rolling cam having positioning "notches." As the cover
is opened or closed the cams rotate and engage, or lodge into, a
corresponding indentation within the square sink top opening via a
spring force. In this way the cover can be spring-forced into
desired positions, such as the open and closed positions. The cover
may also be disengaged from the sink top so the unit could be
easily cleaned.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] FIG. 1 is an elevational view of one side of the preferred
embodiment of the galley waste disposal system of the present
invention with the cover in a closed position;
[0029] FIG. 2 is an elevational view of a second side of the system
shown in FIG. 1; and, FIG. 3 is a top view of the system shown in
FIG. 1 with the cover closed.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0030] The invention summarized above and defined by the enumerated
claims may be better understood by referring to the following
detailed description, which should be read in conjunction with the
accompanying drawings. This detailed description of a particular
preferred embodiment, set out below to enable one to build and use
one particular implementation of the invention, is not intended to
limit the enumerated claims, but to serve as a particular example
thereof. The particular example set out below is the preferred
specific implementation of an aircraft galley waste disposal system
and method, namely, one that provides a sink, a drain line, a flush
valve assembly having a normally closed flush valve, a rinse
subsystem having a rinse valve and rinse outlet, a controller and a
sensor extending into the drain line. It also includes a cover
which completely seals the mouth of the sink when flushing the
waste, and an air inlet subsystem which draws air into the sink
bowl from a duct that terminates above the sink. The invention,
however, may also be applied to other types of systems and
equipment as well.
[0031] Referring to FIGS. 1 and 2, a particular embodiment of a
galley waste disposal system 10 is shown. A sink bowl 14 is
installed in a galley of an aircraft. The mouth 15 of the sink bowl
14 is positioned in the galley at approximately waist height to a
typical standing cabin flight attendant. The sink bowl 14 has a
waste receiving interior 17 for collecting therein the waste to be
disposed of and a disposal outlet 30 near its bottom of
approximately 1.5 inches in diameter. This is substantially larger
than the diameter of conventional galley sinks in order to
accommodate the passage of solid and slurry food waste. In
operation, waste passes the disposal outlet 30, through an
elbow-shaped pipe 31, through a flush valve assembly 18 having a
normally closed valve that is momentarily open, and down the waste
drain line 20, having an approximately two inch diameter, for
evacuation into a waste holding tank (not shown).
[0032] The disposal system 10 is also equipped with a rinse
subsystem comprising a rinse valve 22 connected through a rinse
line to a rinse outlet 24 in the bowl 14 for introducing a rinsing
liquid into the bowl at the start of a flush cycle and just prior
to the opening of the valve of the flush valve assembly 18. Also
shown is an anti-siphon valve 44 that exists above the cabinet and
is permanently secured in this position.
[0033] The flush valve assembly 18 and rinse subsystem are
controlled by an electronic controller 40 which interfaces with the
aircraft power and vacuum waste control systems, and provides power
to the flush valve assembly 18 and rinse valve 22. It will be
appreciated that designing the controller 40 into such a vacuum
waste disposal system is performed in a manner that is well
understood. Under normal operating conditions, when a flush switch
60, mounted on top of the unit, is depressed by the operator, a
flush cycle is initiated in the flush controller 40. In particular,
a small amount of rinse water is injected into the sink 14 via
rinse outlet 24, and, subsequently, the flush valve opens allowing
the vacuum in the waste system to rapidly draw the mixture of water
and waste down the drain line 20 and into the waste holding
tank.
[0034] However, if a waste clog develops in the line, rendering the
vacuum action in the drain line ineffective, flush cycles must
cease in order to prevent a buildup of standing waste water into
the sink. Accordingly, the present invention includes a sensor 65
extending into the drain line 20 which is capable of identifying
such a condition and signaling the controller 40 to disable the
flush valve assembly and rinse subsystem.
[0035] In the preferred embodiment, the sensor 65 is an air
pressure sensor that extends into the drain line 20 to sense the
pressure inside the line. The sensor is connected to the controller
40 and continuously provides information to the controller relating
to the pressure inside the drain line. One example of an acceptable
pressure sensor is a stainless steel, "Process Transmitter--Model
CIP-Ultra," manufactured by SENSOTEC (Columbus, Ohio). It is
understood, however, that other air pressure sensors known in the
art are equally acceptable alternatives. Under normal conditions,
the sensor reads a relatively very low pressure in the line
indicative of a proper vacuum condition. However, in the event of
the development of a clog anywhere downstream of the sensor 65,
whether it be in the galley sink disposal system's drain line 20 or
the aircraft's main waste drain line, as soon as the valve assembly
18 opens its flush valve for a subsequent flush cycle, or as soon
as the flush valve of any other vacuum sink or vacuum toilet
upstream of the unit opens, that portion of the system's drain line
20 that is above the clog will transition to the relatively high
aircraft cabin pressure. When the pressure sensor 65 detects this
condition, which, in one preferred embodiment, is a pressure of 1
p.s.i, or above, it provides this clogged-condition information to
the controller 40, which, in turn, disables the (1) flush valve
assembly 18, thus maintaining its flush valve in its
normally-closed and sealed position, and (2) rinse subsystem to
keep the rinse valve 22 closed, until the sensor detects a normal
vacuum condition in the line (i.e. after the clog is cleared and
the pressure drops below 1 p.s.i.).
[0036] Pressure sensing is not the only suitable means of sensing a
clogged drain situation. For example, a liquid level sensor located
inside the drain line can be implemented in order to identify the
presence of standing (or rising) water in the line, thus indicating
a potential clogged situation. It is understood that other clog
detection methods known to those skilled in the art are acceptable
alternatives. In sum, the waste disposal system 10 of the present
invention is inoperable unless a sensor provides data indicative of
a clear drain line.
[0037] Connected to and adjacent to the sink's disposal outlet 30
is a specially-designed elbow-shaped pipe 31. Both the pipe
diameter and bend radius range in size anywhere from 1.0" to 2.0".
In the preferred embodiment, the pipe diameter and bend radius are
each 1.5" with standard tolerances. This pipe traps in its bend,
and prevents the passage of, only rigid elongate objects that are
large enough to become stuck in the drain. Smaller objects that are
able to pass this elbow-shaped pipe 31 can equally safely pass
through the rest of the drain line. Further, the bend in the pipe
31 is located very close to the sink drain outlet 30 so that any
elongate objects that do become stuck in the pipe bend will also
protrude into the waste receiving interior 17 of the sink bowl 14
and can be easily removed by hand. This design tends to eliminate
the potential for rigid elongate objects, such as broken
chopsticks, that are too large to pass through the drain line, from
becoming lodged therein, which could result in a system
malfunction, and costly and time intensive maintenance and
repair.
[0038] The sink 14 is shown with a cover 34 in its closed position
and hinged to the sink with pins 36. In the preferred embodiment,
the cover is constructed from stainless steel encapsulating a
sound-deadening material. Referring to FIG. 3, the two pins 36 have
integrated shafts 37 that are formed as rolling cams having
positioning "notches." As the cover is opened or closed the cams
rotate and the notches engage, or lodge into, a corresponding
indentation within the sink top opening via a spring force (not
shown). In this way, the cover can be spring-forced into desired
positions, such as the open or closed position. The pins 36 can be
pulled outwardly by grasping their heads 38 for disengaging the
cover 34 from the sink top, so the unit could be easily cleaned. In
the particular embodiment shown in FIGS. 1, 2 and 3, the cover 34
is hinged at the back side of the galley sink top, when facing the
system. It is understood, however, that based on the space
available and the location of the sink in the particular aircraft
galley, the cover 34 may alternatively be hinged in another
acceptable orientation, so that the cover swings open to the left
over the right of the unit, for example. In another embodiment, the
galley system is designed with one cover that may be hinged in any
of the desirable orientations discussed above. In other words, the
cover is selectively hingeable to the sink top so that it may swing
open to the left, right, or back of the sink bowl when facing the
system.
[0039] When the cover 34 is closed over the mouth 15 prior to a
flush cycle, an essentially air tight seal is created thereby
preventing liquid or slurry waste from overflowing and oozing out
the top of the sink. To help create an air tight closure, a seal,
such as a rubber grommet (not shown), attached to the perimeter of
the underside of the cover 34, can be included.
[0040] As further shown in FIG. 3, since during a flush cycle the
sink is sealed from above by the cover 34, a subsystem is included
in order to provide cabin pressure to the otherwise sealed bowl 14.
This is required, as discussed above, to establish the differential
pressure necessary between the bowl and the drain line for
accomplishing vacuum flushing action. In particular, the air inlet
subsystem includes an air inlet port 32 in the sink bowl 14
connected to an air inlet duct (not shown) that exists out of and
terminates above the cabinet containing the system 10. Also shown
is a baffle 70 located within the sink bowl 14 and coveting the air
inlet port 32. The baffle 70 is provided to visually mask the inlet
32 into the bowl 14. It is also used to direct the airflow towards
the bottom of the bowl 14 to prevent fluid from splashing all over
the its interior and the cover 34 interior.
[0041] The waste disposal system 10 also includes a cover detection
device 50 which indicates whether the cover 34 is in a closed
position or an open position. The cover detection device signals
this condition to the flush controller 40. The waste disposal
system is inoperable unless the flush controller detects that the
cover is in the closed position, via the cover detection device 50,
and that the drain line 20 is clear, which is indicated by the
sensor 65. Thus, the flush controller also functions as a safety
interlock device in that the flush controller will not allow the
waste disposal system to be operated unless both the cover is
closed and the drain line is clear.
[0042] The cover detection device 50 for indicating whether the
cover is closed may take many forms. One suitable device for the
cover detection device is a mechanical switch such as a plunger
type limit switch. Switches of this type are well known in the art
and operate upon the principle that an electrical connection is
made in the switch when a spring loaded plunger is depressed. Such
a limit switch may be installed either into the sink bowl or into
the cover. In either case, the switch plunger would be depressed
when the cover is closed. Another form of suitable switch is a reed
switch. This form of switch has two thin reeds in close proximity
and typically within a sealed chamber. The switch is activated when
a magnet pulls the reeds into contact allowing a current to pass
through the reeds. In the present invention, the reed switch may be
molded into the sink bowl or sink base and the magnet may be
attached to the cover. When the cover is closed the magnet pulls
the reeds into electrical contact. Those skilled in the art will
understand that this configuration may be reversed and that the
magnet may be located in the sink or sink base and the reed switch
may be attached to the cover. Many other mechanical switches are
also suitable and are known to those skilled in the art.
[0043] The cover detection device 50 may also be in the form of a
proximity sensor. Many types of proximity sensors are suitable.
Representative types include ultrasonic sensors, optical sensors,
and magnetic sensors such as hall effect sensors. In the preferred
embodiment, the cover detection device 50 is a hall effect
proximity sensor built into the sink top. The proximity sensor
enables the flush switch 60 only when it detects a magnet embedded
in the side of the cover 34 indicating a "cover-closed" position.
The proximity sensor is mounted on the unit below the sink at the
center line of the cover. By embedding magnets in two or more sides
of the cover on the centerline of each side, the cover position may
be easily changed to suit the particular installation orientation
without any loss of functionality. It is understood that
alternative position sensing systems may be implemented in place of
a hall effect proximity sensor system.
[0044] Having thus described an exemplary embodiment of the
invention, it will be apparent that further alterations,
modifications, and improvements will also occur to those skilled in
the art. Such alterations, modifications, and improvements, though
not expressly described or mentioned above, are nonetheless
included and implied to be within the spirit and scope of the
invention. Accordingly, the foregoing discussion is intended to be
illustrative only; the invention is limited and defined only by the
various following claims and equivalents thereto.
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