U.S. patent application number 11/070184 was filed with the patent office on 2005-07-07 for method and system for controlling a drying process.
This patent application is currently assigned to General Electric Company. Invention is credited to Fyvie, Thomas Joseph, Hallman, Darren Lee.
Application Number | 20050144989 11/070184 |
Document ID | / |
Family ID | 46304062 |
Filed Date | 2005-07-07 |
United States Patent
Application |
20050144989 |
Kind Code |
A1 |
Hallman, Darren Lee ; et
al. |
July 7, 2005 |
Method and system for controlling a drying process
Abstract
A dry cleaning device includes a cleaning enclosure suitable for
receiving clothing articles and a cleaning fluid, typically a
solvent based cleaning fluid, and circuitry coupled to the dry
cleaning device for sensing at least one operational parameter of
the dry cleaning device and for calculating a retained cleaning
fluid content in the articles disposed within the cleaning
enclosure based on the at least one operational parameter.
Alternatively, the circuitry may calculate the amount of cleaning
fluid returned to the system during the cleaning process.
Inventors: |
Hallman, Darren Lee;
(Clifton Park, NY) ; Fyvie, Thomas Joseph;
(Schenectady, NY) |
Correspondence
Address: |
GENERAL ELECTRIC COMPANY
GLOBAL RESEARCH
PATENT DOCKET RM. BLDG. K1-4A59
NISKAYUNA
NY
12309
US
|
Assignee: |
General Electric Company
|
Family ID: |
46304062 |
Appl. No.: |
11/070184 |
Filed: |
March 2, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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11070184 |
Mar 2, 2005 |
|
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10127001 |
Apr 22, 2002 |
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Current U.S.
Class: |
68/19 |
Current CPC
Class: |
D06F 43/08 20130101;
D06F 43/086 20130101 |
Class at
Publication: |
068/019 |
International
Class: |
D06F 029/00 |
Claims
1. A dry cleaning device, comprising: a cleaning enclosure
configured to receive articles and a cleaning fluid; and circuitry
coupled to said dry cleaning device for sensing at least one
operational parameter of said dry cleaning device and calculating a
retained cleaning fluid content in said articles based on said at
least one operational parameter.
2. A dry cleaning device according to claim 1, wherein said
circuitry controls a drying process for said dry cleaning device
based on the calculated retained cleaning fluid content.
3. A dry cleaning device according to claim 1, wherein said
circuitry includes at least one sensing device.
4. A dry cleaning device according to claim 3, wherein said at
least one sensing device is a temperature sensor.
5. A dry cleaning device according to claim 4, further comprising
an air management system for circulating an airflow through said
cleaning enclosure and wherein said temperature sensor senses a
temperature of said airflow and said circuitry calculates the
retained cleaning fluid content based on said sensed
temperature.
6. A dry cleaning device according to claim 3, wherein said at
least one sensing device is a vapor pressure sensor to sense a
vapor pressure of the cleaning fluid in the cleaning enclosure and
said circuitry calculates the retained cleaning fluid content based
on said sensed vapor pressure.
7. A dry cleaning device according to claim 3, wherein said
cleaning enclosure includes a rotatable basket and said at least
one sensing device is a torque load sensor to sense a torque load
measurement while said basket rotates with said articles at a known
speed and said circuitry calculates the retained cleaning fluid
content based on said sensed torque load measurement.
8. A dry cleaning device according to claim 3, further comprising a
fluid processing system configured to receive the cleaning fluid
after usage within the cleaning enclosure, wherein said at least
one sensing device is a weight sensor adapted to sense the weight
of said cleaning fluid within said fluid processing system and said
circuitry calculates the retained cleaning fluid content based on
said sensed weight measurement.
9. A dry cleaning device according to claim 3, further comprising a
fluid processing system configured to receive the cleaning fluid
after usage within the cleaning enclosure, wherein said at least
one sensing device is a volume sensor adapted to sense the volume
of said cleaning fluid within said fluid processing system and said
circuitry calculates the retained cleaning fluid content based on
said volume measurement.
10. A dry cleaning device according to claim 1, wherein said
circuitry is configured to provide a calibrated model that is
representative of a drying process and said circuitry calculates
the retained cleaning fluid content based on said model in
conjuction with said sensed operational parameters.
11. A method for controlling a drying process in a dry cleaning
device that uses a cleaning fluid to clean articles, the method
comprising: sensing at least one operational parameter of the dry
cleaning device; calculating a retained cleaning fluid content in
the articles based on the sensed operational parameter; and
controlling the drying process based on the calculated retained
cleaning fluid content.
12. A dry cleaning device for cleaning articles with a solvent
based cleaning fluid, comprising: a cleaning enclosure configured
to receive the articles; a fluid processing system that supplies a
solvent based cleaning fluid to the cleaning enclosure; an air
management system that supplies an airflow to the cleaning
enclosure; at least one sensing device configured to sense an
operational parameter of the dry cleaning device; and a controller
responsive to the at least one sensing device, wherein the
controller is configured to calculate the retained solvent based
cleaning fluid content in the articles based on the sensed
operational parameter and control the drying process based on the
calculated retained cleaning fluid.
13. A dry cleaning device for cleaning articles with a solvent
based cleaning fluid, comprising: a means for receiving articles; a
means for introducing said solvent based cleaning fluid into said
means for receiving articles upon introduction of said articles; a
means for determining at least one operational parameter of said
dry cleaning device; and and a means for calculating a retained
solvent based cleaning fluid content in said articles based on said
at least one operational parameter.
14. A dry cleaning device for cleaning articles with a solvent
based cleaning fluid in accordance with claim 13, further
comprising means for controlling a drying process for said dry
cleaning device based on the calculated retained solvent based
cleaning fluid content.
15. A dry cleaning device for cleaning articles with a solvent
based cleaning fluid, comprising: a cleaning enclosure configured
to receive the articles; a fluid processing system that supplies a
solvent based cleaning fluid to the cleaning enclosure; an air
management system that supplies an airflow to the cleaning
enclosure; at least one sensing device configured to sense an
operational parameter of the dry cleaning device; and a controller
responsive to the at least one sensing device, wherein the
controller is configured to calculate the amount of returned
solvent based cleaning solution based on the sensed operational
parameter and control the drying process based on the calculated
returned cleaning fluid.
16. A dry cleaning device in accordance with claim 1, wherein said
circuitry locks the cleaning enclosure until the calculated
retained fluid content is less than a predetermined value.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This patent application is a continuation-in-part of
co-pending and commonly assigned U.S. patent application Ser. No.
10/127,001, entitled "Apparatus and Method For Article Cleaning,"
filed Apr. 16, 2002, which Patent Application is hereby
incorporated by reference.
BACKGROUND
[0002] The invention relates generally to article cleaning
apparatuses and more specifically to a method and system for
controlling a drying process in a dry cleaning apparatus.
[0003] Solvent based article cleaning systems, better known as "dry
cleaning" systems, typically include washing or rinsing systems and
drying systems, for cleaning articles such as objects of clothing,
drapes, upholstery or similar textiles. Before the articles may be
reused after cleaning, they should be substantially devoid of the
solvent based cleaning fluid. If the solvent is not substantially
removed from the articles, the articles will feel oily to the touch
and will require additional cleaning prior to use.
[0004] In addition, if the solvent is not substantially recovered
after the dry cleaning process is completed, the solvent will need
to be replaced more frequently, driving up the cost per usage by
the consumer and potentially requiring an overall increase in the
periodicity of cartridge or solvent replacement and servicing.
[0005] Currently, to achieve removal of the solvent, conventional
systems typically employ a time-based drying cycle that may not
accurately indicate the residual amount of the solvent based
cleaning fluid in the articles.
[0006] Accordingly, development of improved systems and methods for
controlling these drying cycles to ensure solvent recovery in dry
cleaning systems is desired.
BRIEF DESCRIPTION
[0007] A dry cleaning device includes a cleaning enclosure suitable
for receiving clothing articles and a cleaning fluid, typically a
solvent based cleaning fluid, and circuitry coupled to the dry
cleaning device for sensing at least one operational parameter of
the dry cleaning device and for calculating a retained cleaning
fluid content in the articles disposed within the cleaning
enclosure based on the at least one operational parameter.
Alternatively, the circuitry may calculate the amount of cleaning
fluid returned to the system during the cleaning process.
DRAWINGS
[0008] These and other features, aspects, and advantages of the
present invention will become better understood when the following
detailed description is read with reference to the accompanying
drawings in which like characters represent like parts throughout
the drawings, wherein:
[0009] FIG. 1 is a schematic of a dry cleaning device according to
an embodiment of the invention.
[0010] FIG. 2 is a graphical illustration of data collected that is
related to one embodiment of the instant invention.
[0011] FIG. 3 is a graphical illustration of data collected that is
related to another embodiment of the instant invention.
[0012] FIG. 4 is a graphical illustration of data collected that is
related to another embodiment of the instant invention.
[0013] FIG. 5 is a flow chart that is representative of one method
of operation associated with the instant invention.
DETAILED DESCRIPTION
[0014] A dry cleaning device 10 comprises a cleaning enclosure 12
suitable for receiving clothing articles (not shown) and a cleaning
fluid, typically a solvent based cleaning fluid, introduced via an
inlet line 14, as shown in FIG. 1. Additionally, dry cleaning
device 10 further includes circuitry 16 coupled to the dry cleaning
device 10 for sensing at least one operational parameter of the dry
cleaning device 10 and for calculating a retained cleaning fluid
content in the articles disposed within the cleaning enclosure
based on at least one operational parameter.
[0015] As used herein, the term Retained Moisture Content ("RMC")
is defined as: (weight of the articles with moisture--dry weight of
the articles)/(dry weight of articles).
[0016] As used herein, the term moisture refers to liquids retained
in the clothes from the solvent, the water and any combination
thereof.
[0017] As used herein, the term "articles" is defined, for
illustrative purposes and without limitation, as fabrics, textiles,
garments, and linens and any combination thereof.
[0018] As used herein, the term "solvent based cleaning fluid" is
defined for illustrative purposes and without limitation, as
comprising a cyclic siloxane solvent and, optionally, a cleaning
agent. If water is present in a solvent based cleaning fluid, the
water is typically present in an amount in a range from about 1
percent to about 8 percent of the total weight of the solvent based
cleaning fluid. In another embodiment of the present invention, if
water is present in the solvent based cleaning fluid, the water is
typically present in an amount in a range from about 1 percent to
about 2 percent of the total weight of the solvent based cleaning
fluid. In one example, the cyclic siloxane solvent is
decamethylcyclopentasiloxane (hereinafter referred to as D5).
[0019] As used herein, the term, "cleaning agent" is defined for
illustrative purposes and without limitation, as being selected
from the group consisting of sanitizing agents, emulsifiers,
surfactants, detergents, bleaches, softeners, and combinations
thereof.
[0020] As used herein, the term, "water based cleaning fluid" is
defined for illustrative purposes and without limitation, as
comprising water and, optionally, a cleaning agent.
[0021] As used herein, the term, "cleaning process" is defined, for
illustrative purposes and without limitation, as utilizing a
solvent cleaning process, water cleaning process, and any
combination thereof.
[0022] The dry cleaning device 10 further comprises an air
management system 18 and a fluid processing system 20 and a
controller 22 that is coupled to the cleaning enclosure 12, the air
management system 18, and the fluid processing system 20. The
controller 22 is configured to perform a variety of cleaning
processes. A cleaning process typically includes at least three
main steps, a washing step, a spinning step and a drying step.
[0023] The cleaning enclosure 12 of FIG. 1 typically comprises a
rotatable basket 24 coupled to a motor 26. The rotatable basket 24
has a plurality of holes 28. The motor 26 rotates the rotatable
basket 24. The direct drive orientation of the rotatable basket 24
and the motor 26 is provided for illustrative purposes and it is
not intended to imply a restriction to the present invention. While
the cleaning enclosure 12 is shown comprising a rotatable basket 24
and an accompanying motor 26, other types of non-rotating cleaning
enclosures are contemplated in this invention.
[0024] In accordance with one embodiment of the instant invention,
upon introduction of articles within cleaning enclosure 12 and
initiation of a cleaning process by a user via a user control
interface (not shown), a solvent based cleaning fluid is introduced
within the cleaning enclosure 12 and the controller 22 initiates a
washing step of the cleaning process. The articles are typically
agitated together with the solvent based cleaning fluid to clean
the articles. After the washing cycle is completed, the solvent
based cleaning fluid is drained to the fluid processing system 20.
The draining of solvent based cleaning fluid typically recovers
about 75%-90% of the solvent based cleaning fluid that was
originally introduced. Most of the remaining solvent based cleaning
fluid is retained within the articles.
[0025] Next, the articles are typically centrifuged in a spinning
step in order to recover additional solvent based cleaning fluid.
The spinning step typically recovers about an additional 5%-15% of
the solvent based cleaning fluid bringing the total recovery to
about 95% of the introduced amount.
[0026] Next, the articles are submitted to a drying step of the
cleaning process. The articles are typically tumbled in cleaning
enclosure 12 and dried using air management system 18. Hot, dry air
is forced over the articles, heating the articles and the solvent
based cleaning fluid and vaporizing the solvent based cleaning
fluid. The vapor flows from the cleaning enclosure 12 to the air
management system 18 where the vapor is condensed and the
condensate is gravity fed back to the fluid processing system 20
via drain 36. The drying step of the cleaning process typically
recovers about an additional 3% to 4.5% bringing the total
recovered solvent based cleaning fluid to about 99.5% of the
introduced amount.
[0027] As discussed above, because the solvent based cleaning
solution is relatively expensive and the replacement involves the
end-user replacing the solvent, typically via a cartridge insert,
it is important to ensure that the recovered amount of the solvent
based cleaning fluid is as close to 100% as reasonably possible.
Currently, the appropriate controls are not available and most
systems use an ineffective drying time approximation to determine
the amount of residual solvent based cleaning fluid. This drying
time approximation is not a robust technique and results in
ineffective recovery of the cleaning fluid or alternatively,
over-drying of the articles.
[0028] There are a variety of novel arrangements that can be
utilized to ensure that the maximum quantity of the solvent based
cleaning fluid is efficiently recovered after a cleaning process is
completed, a number of which will be discussed below.
[0029] According to one embodiment of the instant invention,
controller 22 is configured to sense operational parameters of the
dry cleaning device 10, calculate the solvent based cleaning fluid
content in the articles or alternatively the amount of the solvent
based cleaning fluid returned to the fluid processing system 20,
and based on that calculation, control the drying step of the dry
cleaning device 10.
[0030] In general, the operational parameters relate to the
operation of dry cleaning device 10, and the operational parameters
may include, for example, cleaning fluid inflow or outflow rates,
cleaning fluid vapor pressure inside the cleaning enclosure 12,
airflow inflow or outflow rates, airflow inlet and outlet
temperatures, various wash cycles (rinse, tumble, drying) times,
basket rotation speeds, article weight, cleaning fluid weight and
volume, among various others, and various such operational
parameters that will occur to those skilled in the art. It is
appreciated that drying process parameters (e.g. spin time, airflow
temperatures, basket vapor pressure) form a subset of the
operational parameters of dry cleaning device 10. The controller 22
is configured to receive and interpret a state of at least one of
such operational parameters.
[0031] Controller 22 typically comprises a digital signal
processor, configured to receive and execute instructions. The
controller 22 may further comprise, or be associated with a data
storage device (not shown in the figures) for storing various data
including instructions and operational parameters. In one
embodiment, the controller 22 includes simulation models for
various operating cycles of the dry cleaning device 10. Controller
22 also comprises instructions for correlating an operational
parameter of the dry cleaning device to the retained solvent based
cleaning fluid content in the articles or the amount of solvent
based cleaning fluid returned. Such correlation can be accomplished
using many conventional techniques including, for example, using a
lookup table or a plot.
[0032] In one embodiment of the instant invention, the dry cleaning
device 10 includes at least one temperature sensor 110 coupled to
the controller 22 and in communication with the air management
system 18 such that the temperature sensor 110 senses the
temperature of the airflow flowing between the air management
system 18 and the cleaning enclosure 12 during the drying step of
the cleaning process. According to one technique, an inlet
temperature of the airflow entering into cleaning enclosure 12 is
sensed, and the inlet temperature is correlated to the retained
cleaning fluid content by controller 22. According to another
technique, an outlet temperature of the airflow exiting the
cleaning enclosure 12 is sensed, and the outlet temperature is
correlated to the retained cleaning fluid content by controller 22.
According to yet another technique, a difference between the outlet
temperature and the inlet temperature of the airflow is calculated,
and the difference is correlated to the retained cleaning fluid
content by controller 22.
[0033] More specifically, and with respect to FIG. 2, the graphical
display illustrates the relationship between an airflow inlet
temperature, an airflow outlet temperature and the retained
cleaning fluid content. FIG. 2 illustrates that the inlet and
outlet temperatures converge as the retained cleaning fluid content
decreases. It is also observed from FIG. 2 that the difference
between the inlet and outlet temperatures decreases with decreasing
retained cleaning fluid content. The rate of variation of the inlet
or outlet temperatures, or the difference between the inlet and
outlet temperatures, with respect to the retained cleaning fluid
content may be empirically determined, and this data may then be
used to correlate a current state of these parameters to ascertain
a current state of the retained cleaning fluid content in articles,
during the drying process by controller 22.
[0034] In another embodiment of the instant invention, the dry
cleaning device 10 (FIG. 1) includes at least one pressure sensor
120, typically a gas specific vapor pressure sensor, coupled to the
controller 22 and disposed adjacent to the enclosure 12 such that
pressure sensor 120 is positioned to sense the vapor pressure
within cleaning enclosure 12 during the drying step of the cleaning
process. The vapor pressure of the cleaning fluid inside the
cleaning enclosure 12 is sensed by pressure sensor 120 and
correlated by controller 22 to the retained cleaning fluid content.
As shown in FIG. 3, the vapor pressure is nearly constant during a
portion of the drying process and begins to gradually drop off
until finally stabilizing. Using either the empirical data
surrounding the stabilization or the rate of change of the vapor
pressure, the retained cleaning fluid content can be calculated. In
fact, in FIG. 3, it can be seen that the rate of change of the
vapor pressure undergoes a slope change right in the region of the
1% RMC location. It is further illustrated in FIG.3 that the final
vapor pressure measurement is not constant and is highly dependent
on the type of fabrics being washed. The vapor pressure
measurements or the calculated rate of change may also be combined
with a change over time calculation or a model or both to calibrate
and improve the accuracy of the RMC calculation. As discussed
above, the vapor pressure can be directly measured by pressure
sensor 120 or may be inferred based on certain measurements from
pressure sensor 120, for example inferring vapor pressure from
infrared measurements.
[0035] In another embodiment of the invention, the dry cleaning
device 10 (FIG.1) includes at least one torque load sensor 130
coupled to the controller 22 and disposed adjacent the rotatable
basket 24 to sense the torque load measurement on the motor 26
during the cleaning process. One implementation of this embodiment
may include rotating the basket at a known rotational velocity
after the introduction of articles and prior to introduction of the
cleaning fluid to establish a baseline torque load. This technique
utilizes the fact that the motor 26, having a known torque curve,
requires a specific motor torque to tumble articles and this
required torque increases as the weight of the articles increase.
With an amount of cleaning fluid being retained in the articles,
the article weight increases from a dry state of the articles, and
correspondingly the torque required to rotate these articles is
higher. This increase in the torque load is therefore indicative of
the excess weight in the articles due to the cleaning fluid, and
accordingly the torque load required to rotate the motor 26 is
correlated by controller 22 to the retained cleaning fluid
content.
[0036] In another embodiment of the invention, the dry cleaning
device 10 includes at least one weight sensor 140 coupled to the
controller 22 and to the fluid processing system 20 to sense the
weight of the returned cleaning fluid during the cleaning process.
Since the beginning weight of the cleaning fluid is a known value,
the controller 22 would control the drying process to ensure that a
certain predetermined weight of cleaning fluid is returned before
ending the cleaning process. In one embodiment, for example, the
predetermined weight is in the range between about 99.1 percent of
the initial weight of the cleaning fluid to about 99.9 percent of
the initial weight of the cleaning fluid. In another embodiment,
for example, the predetermined weight is in the range between about
99.3 percent of the initial weight of the cleaning fluid to about
99.7 percent of the initial weight of the cleaning fluid.
[0037] In another embodiment of the invention, the dry cleaning
device 10 includes at least one volume sensor 150 coupled to the
controller 22 and to the fluid processing system 20 to sense the
volume of the returned cleaning fluid during the cleaning process.
Since the beginning volume of the cleaning fluid is a known value,
the controller 22 would control the drying process to ensure that a
certain predetermined volume of cleaning fluid is returned before
ending the cleaning process. In one embodiment, for example, the
predetermined volume is in the range between about 99.1 percent of
the initial volume of the cleaning fluid to about 99.9 percent of
the initial volume of the cleaning fluid. In another embodiment,
for example, the predetermined volume is in the range between about
99.3 percent of the initial volume of the cleaning fluid to about
99.7 percent of the initial volume of the cleaning fluid.
[0038] Another method to ensure recovery of a significant
percentage of the cleaning fluid is to embed a calibrated model of
the drying process within controller 22 to predict RMC based on the
physics of the drying process. Such a model would utilize the
airflow temperatures flowing into and out of the air management
system 18, as well as the airflow based on a fixed value and
pressure drop model of the dry cleaning system 10. From these known
or calculated values, the vapor pressure and RMC can be predicted.
The RMC can be predicted quite accurately as shown in the FIG. 4
below for six runs with different starting RMC values. This
accuracy holds not only for the constant rate portion of the drying
cycle, but also for the tail end, where the drying rate is much
lower and the final RMC is much closer to the preferred value
(typically between 0% and 1%).
[0039] An additional measure to ensure recovery of cleaning
solution is to lock the system user out of the cleaning enclosure
12 until the RFC calculated by controller 22 is less than a
predetermined value, for example, 0.5%.
[0040] FIG. 5 illustrates, with the help of a flow diagram, a
specific method for controlling the drying process, according to
one embodiment of the invention. The drying process is started SI
in the cleaning enclosure 12, and at least one operational
parameter is sensed S2. Based on the sensed operational parameter,
a value of the retained cleaning fluid content in the articles or
the amount of cleaning fluid returned is calculated S3. An
ascertainment S4 is made, of whether the condition of the retained
cleaning fluid content is less than a predetermined value, or the
amount of returned cleaning fluid is more than a predetermined
value, is met. If the condition is not met, the drying process is
continued. If the condition is met, however, the drying process is
stopped.
[0041] While only certain features of the invention have been
illustrated and described herein, many modifications and changes
will occur to those skilled in the art. It is, therefore, to be
understood that the appended claims are intended to cover all such
modifications and changes as fall within the true spirit of the
invention.
* * * * *