Note: Descriptions are shown in the official language in which they were submitted.
WO 92/21808 2 1 10 4 ~ ~ PCl /US92/04~51
METHOD AND APPARATUS FOR DISSOLVING AND ACTIVATING
A SOLUBLE CLEANSING AGENT
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to methods and apparatus for
dissolving soluble cleansing agents, and more particularly, to such
S methods and apparatus for dissolving a discrete, predetermined amount
of such soluble cleansing agents.
2. DescriDtion of the Prior Art
The prior art is replete with methods and apparatus
(hereinafter ~Prior Art Systems") for dissolving cleansing agents for
a variety of applications, including dish or clothes washing
machines. A substantial percentage of these Prior Art Systems
operate by directing a liquid spray at a large supply of cleansing
agent (i.e., an amount sufficient for multiple application cycles)
which is supported by a screen. Typically the spray dissolves only a
portion of the large supply of cleansing agent resting on the screen.
United States Patents which disclose various examples of such Prior
Art Systems include 4,790,981 which issued to Mayre et al. on
December 13, 1988i 4,462,511 which issued on July 31, 1984 to Fulmer
et al.; 4,~020,865 which issued on May 3, 1977 to Moffat et al.;
3,850,344 which issued on November 26, 19764 to Burge et al.; and
3,595,438 which issued to Daley et al. on July 27, 1971.
One principal disadvantage to these Prior Art Systems is
that each cycle generally hydrates a greater amount of cleansing
agent than is actually dissolved and dispensed during that cycle.
Consequently, some quantity of hydrated cleansing agent remains in
the supply at the end of each cycle. This hydrated detergent dries
and can become caked. Caking is a significant problem since the
caked cleansing agent can be extremely tenacious; in many instances
becoming virtually insoluble by the apparatus.
30 Other Prior Art Systems utilize batch dissolution
processes. In other words, these Prior Art Systems dissolve a
predetermined discrete quantity of soluble cleansing agent in water
W 0 92/21808 ~ 1 1 0 ~ 0 8 P(~r/US92/04551
to form a cleansing liquor. U.S. Patent 4,489,455 issued to Spendel
on December 25, 1984 and U.S. Patent 4,555,019 issued to Spendel on
November 26, 1985 disclose a Prior Art System which dissolves a
discrete predetermined amount of cleansing agent to form a cleansing
liquor for use in a clothes washing machine. This Prior Art System
mixes a predetermined quantity of cleansing agent with water until
"the detergent composition is substantially dissolved or dispersed in
the water." Experience has shown that these batch Prior Art Systems
also have a caking disadvantage similar to the above Prior Art
Systems unless water is circulating in the mixing reservoir before
the cleansing agent is added thereto.
Another disadvantage to such batch Prior Art Systems is
they do not necessarily ~activate" today's sophisticated granular
cleansing agents. Current granular cleansing agents can include
various distinct components which must transform from their inactive
granular form to their active form to provide the desired beneficial
effects. For example, a bleaching system can include a bleach (e.g.,
sodium perborate monohydrate) and a bleaching activator (e.g.,
nonanoyloxybenzene sulfonate) which must react with each other to
become active. Other components react with the water itself to
become active. Thus, merely dissolving the granular cleansing agent
does not ensure the liquor is active; a sufficient mixing time must
elapse to permit the various reactions to occur.
SUMMARY OF THE INVENTION
In accordance with one aspect of the present invention a
method is provided for dissolving or dispersing and completely
activating a discrete predetermined amount of a granular cleansing
agent having an inactive ingredient. The method utilizes an
apparatus which includes an outer container which has a recirculation
outlet and a recirculation inlet. An inner container is located
within the outer container which has a screen wall portion. A
recirculation pump is attached to a recirculation line so that
solution in the containers may be removed-at the recirculation outlet
and returned through the recirculation inlet. The method includes
the steps of providing water to the outer container. Initiating
operation of the recirculation pump prior to substantial wetting of
WO 92/21808 2 1 1 0 i 0 8 PCI/US92/04551
the cleansing agent housed in the inner container such that solution
passes through the recirculation outlet and through the recirculation
inlet back into the outer container toward the cleansing agent in the
inner container. Diffusing the solution entering the outer container
from the recirculation outlet such that the solution provides energy
for dissolving or dispersing the entire predetermined quantity of
cleansing agent and preventing the cleansing agent from attaching to
the sides of either container. Delivering the solution to a
cleansing application only after the cleansing agent has been
dissolved or dispersed and substantially all of the ingredients in
the cleansing agent have become active.
In accordance with another aspect of the present invention
a method is provided for dissolving or dispersing a discrete
predetermined amount of a granular cleansing agent having an inactive
ingredient. The method utilizes an apparatus which includes an outer
container which has a recirculation outlet and a recirculation inlet.
An inner container is located within the outer container which has a
screen wall portion. A recirculation pump is attached to a
recirculation line so that solution in the containers may be removed
20 at the recirculation outlet and returned through the recirculation
inlet. The method includes the steps of providing water to the outer
container. Initiating operation of the recirculation pump prior to
substantial wetting of the cleansing agent housed in the inner
container such that solution passes through the recirculation outlet
25 and through the recirculation inlet back into the outer container
toward the cleansing agent in the inner container. Diffusing the
solution entering the outer container from the recirculation outlet
such that the solution provides energy for dissolving or dispersing
the entire predetermined quantity of cleansing agent and preventing
30 the cleansing agent from attaching to the sides of either container;
and such that a space is substantially immediately provided between
the screen wall portion of the inner container and the granular
cleansing agent upon initiating operation of the recirculation pump.
In accordance with another aspect of the present invention
35 an apparatus is provided for dissolving and completely activating a
granular cleansing agent prior to providing the cleansing liquor,
i.e., cleansing agent in solution form, to a cleansing application.
W o 92/21808 ~ ~ - PC~r/US92/04551
2110~08 4
The apparatus includes an outer container having a continuous side
wall sealed at its lowermost end to a bottom wall. The bottom wall
has a centrally located recirculation inlet and a recirculation
outlet therein. An inner container located within the outer
container which has a screen wall portion and a predetermined
quantity of cleansing agent housed therein. A recirculation pump is
attached to the recirculation line such that the solution may be
removed from the outer container at the recirculation outlet and
returned through a recirculation line inlet. Means for initiating
pumping of the solution prior to substantial wetting of the cleansing
agent from the outer container through the recirculation outlet and
through the recirculation inlet toward the cleansing agent in the
inner container through the screen wall portion of the inner
container. Means for diffusing the solution entering the outer
container such that the solution provides energy for dissolving or
dispersing the entire predetermined quantity of cleansing agent and
substantially preventing the cleansing agent from attaching to the
sides of either container, to form a cleansing liquor. Means for
delivering the solution to the cleansing application only after the
cleansing agent has been dissolved or dispersed and substantially all
of the ingredients in the cleansing agent have become active.
In accordance with another aspect of the present invention
an apparatus is provided for dissolving and completely activating a
granular cleansing agent prior to providing the cleansing liquor,
i.e., cleansing agent in solution form, to a cleansing application.
The apparatus includes an outer container having a continuous side
wall sealed at its lowermost end to a bottom wall. The bottom wall
has a centrally located recirculation inlet and a recirculation
outlet therein. An inner container located within the outer
container which has a screen wall portion and a predetermined
quantity of cleansing agent housed therein. A recirculation pump is
attached to the recirculation line such that the solution may be
removed from the outer container at the recirculation outlet and
returned through a recirculation line inlet. Means for initiating
pumping of the solution prior to substantial wetting of the cleansing
agent from the outer container through the recirculation outlet and
through the recirculation inlet toward the cleansing agent in the
W 0 92/21808 ` 2 1 1 0 4 ~ 8 P~/US92,0455l
inner container through the screen wall portion of the inner
container. Means for diffusing the solution entering the outer
conttiner such that the solution provides energy for dissolving or
dispersing the entire predetermined quantity of cleansing agent and
substantially preventing the cleansing agent from attaching to the
sides of either container; and such that a space is substantially
immediately provided between the screen wall portion of the inner
container and the granular cleansing agent upon initiating operation
of the recirculation pump.
BRIEF DESCRIPTION OF THE DRAWINGS
While the specification concludes with claims which
particularly point out and distinctly claim the invention, it is
believed the present invention will be better understood from the
following description of preferred embodiments taken in conjunction
with the accompanying drawings, in which like reference numerals
identify identical elements and wherein:
Figure 1 is a diagrammatic perspective view of a preferred
apparatus for carrying out the present dissolving process;
Figure 2 is a top plan view of the apparatus illustrated in
Figure l;
Figure 3 is a cross-sectional view taken along line 3-3 of
Figure 2;
Figure 4 is a cross-sectional view similar to Figure 3 of a
second preferred embodiment of an apparatus for carrying out the
present dissolving process;
Figure 5 is a cross-sectional view similar to Figure 3 of a
third preferred embodiment of an apparatus for carrying out the
present dissolving process;
Figure 6 is a cross sectional view taken along line 3-3 of
Figure 2, illustrating the water and granular cleansing agent prior
to initiating operation of the recirculation pump;
- Figure 7 is a cross sectional view similar to Figure 5,
illustrating the water and granular cleansing agent after initiating
operation of the recirculation pump; and
W 0 92/21808 ' 2 1 1 0 4 9 8 Pc~r/usg2/04s~1
~u~ a~s a cross sectional view similar to Figure 5,
illustrating the water and granular cleansing agent just prior to
complete dissolution or dispersion of the granular cleansing agent.
DESCRIPTION OF PREFERRED EMBODIMENTS
1. Preferred ApDaratus
Figure 1 provides a diagrammatic illustration of a
preferred apparatus (generally referred to as 20) of the present
invention for dissolving a soluble cleansing agent in accordance with
the method of the present invention. For convenience, the term
~granular" cleansing agent is used hereinafter to refer to any form
of ~soluble" cleansing agent, including soluble tablets. The instant
method and apparatus, however, is most preferably utilized with
granular cleansing agents.
The apparatus 20 of this embodiment includes an open top
outer container 22 which comprises a cylindrical side wall 24 and, as
seen in Figure 2, a bottom wall 26. A supply line 30 is located
above the outer container 22 to provide water to the outer container
22 through the open top, thereby providing a vacuum break. A
pressure regulator 32 in combination with a flow control valve 34,
such a needle valve, is located in the supply line 30 to ensure a
constant downstream pressure (and therefore, a constant flow rate)
which enables time based control of the quantity of water supplied to
the outer container 22.
Referring to Figure 3, the bottom wall 26 of the outer
container 22 has three openings located therein; a recirculation
outlet 36, a recirculation inlet 38 and an application delivery
outlet 40. The recirculation inlet 38 is located in the center of
the bottom wall 26. Neither the recirculation inlet 38 nor the
recirculation outlet 36 have any flow restrictions such as screens or
nozzles which could provide points for clogging. The recirculation
outlet 36 and the recirculation inlet 38 are placed in fluid
communication with each other via a closed loop recirculation line
42. Located along the recirculation line 42, intermediate the
recirculation outlet 36 and the recirculation inlet 38, is a
recirculation pump 44. The recirculation pump 44 is capable of
WO 92/21808 211~ ~ 0 8 PCr/US92/04551
passing materials typically found in granular cleansing agents and
any granular clumps which may find their way to the pump 44.
The application delivery outlet 40 is attached to an
application delivery line 46 which includes an application delivery
pump 48. The application delivery pump 48 operates to provide the
cleansing liquor to the cleansing application for use through the
application delivery line 46. The application delivery outlet 40
preferably has a screen 50 covering it to prevent material from
entering the application delivery line 46 which might clog any
downstream restrictions, such as nozzles. Utilizing two separate
pumps, i.e., a recirculation pump 44 and an application delivery pump
48, eliminates the need for valves which can tend to stick when
dealing with typical granular cleansing agents.
As seen in Figures 1, a funnel 52 may be attached to the
outer container 22 or otherwise fixed above an inner container 54
located inside the outer container 22 to channel the detergent into
the inner container 54. The inner container 54 of this embodiment
has a solid cylindrical side wall 56 and a wire screen bottom wall
58. The wire screen of the bottom wall 58 is selected such that it
will support the granular product placed therein while permitting the
flow of solution therethrough without significantly reducing the
energy in the solution. (Although the term "solution" is used
herein, it is understood that initially the "solution" is pure
water.)
Attached to and extending radially outwardly from the
cylindrical side wall 56 are three equally spaced wire screen wing
walls 60. These wing walls 60 axially locate the inner container 54
centrally within the outer container 22. A diffuser 62 in the shape
of an inverted conical section centrally depends from the wire screen
bottom wall 58. Consequently, the apex 62a of the diffuser 62 is
located exactly above the center of the recirculation inlet 38.
The distance between the bottom wall 26 of the outer
- container 22 and the bottom wall 58 of the inner container 54 is also
important. A spacer pin 64 is attached to the bottom wall 58 of the
inner container 54 to assure that the inner container 54 is located
the correct distance from the bottom wall 26 of the outer container
22. This distance is best determined empirically to achieve the most
wo92/2l808 : - ~ 21 1 ~ ~ PC~r/US92/04SSl
vigorous turbulence at the surface of the solution. Furthermore,
designing an apparatus for a specific application will require a
certain amount of empirical analysis to determine the best dimensions
for variables, including the relative diameters of the containers, 22
5 and 54, the shape and size of the diffuser 62, the quantity of
granular cleansing agent to be activated, and the quantity and
velocity of the solution exiting the recirculation inlet 38.
One exemplary apparatus for dissolving up to about one (1)
cup of granular cleansing agent has the following components and
dimensions. The outer container 22 is made of stainless steel and
has a diameter of about four and three-quarter (4 3/4) inches and an
overall height of about six (6) inches. The recirculation line 42 is
made of three-eighths (3/8) inch stainless steel tubing on the
upstream side of the pump 44 and one-quarter (1/4) inch stainless
steel tubing on the downstream side of the pump 44. The application
delivery line 46 upstream of the pump 48 is made of three-eighths
(3/8) inch stainless steel tubing and downstream of the pump 48
flexible tubing such as Tygon tubing can be used. Tygon ~ tubing
is available from Norton Performance Products, Akron, OH. The
recirculation pump 44 and the application pump 48 are centrifugal
pumps such as 2E-38N pumps available from the Little Giant Pump
Company, Oklahoma City, OK. The inner container 54 has about a two
and one-half (2 1/2) inches inner diameter, and about a three and
five-eighths (3 S/8) inches overall height. The inner container 54
bottom wall 58 is made of 316-10 mesh stainless steel wire screen.
The diffuser 62 is a conical section having an 82- overall angle and
a maximum conical diameter of eleven-sixteenths (11/16) inch. A good
starting material for the diffuser 62 is the head of a large
stainless steel flat head screw. The apex 62a of the diffuser 62 is
aligned vertically above the center of the recirculation inlet 38 to
within about O.O10 inch. The bottom wall 58 of the inner container
64 is located about five-eighths (5/8) inch above the bottom wall 26
of the outer container 22.
Referring to Figure 4, a second preferred embodiment
utilizes an inner container 154 made completely of wire screen
(except for the diffuser 162). Instead of having the solid
cylindrical side 56 wall of Figure 3, the cylindrical side wall 156
W O 92/21808 2 l l b 4 ~ ~ Pc~r/us92/o4ssl
of this inner container 154 is made of the same wire screen as the
bottom wall 158 and the wing walls 160. Otherwise, the inner
container 154 of this embodiment has the same general structure as
the inner container 54 discussed above. The remaining components of
this apparatus 120, including the outer container 22, recirculation
line 42, recirculation pump 44, application delivery line 46 and
application delivery pump 48, are identical.
One exemplary apparatus 120 of this second embodiment for
dissolving up to about two-thirds (2/3) cup of granular cleansing
agent utilizes the same general components and dimensions as those
discussed above except for the inner container 154. For example, the
inner container 154 has a diameter of about three (3) inches and a
height of about two and one-half (2 1/2) inches. Although the
diffuser 162 would be of similar shape, i.e., having an 82- overall
angle, the maximum conical diameter is about seven-eighths (7/8)
inch. The diffuser I62 made from is the head of a large stainless
steel flat head screw. The apex 162a of the diffuser 162 is aligned
vertically above the center of the recirculation inlet 38 to within
about 0.010 inch. The bottom wall 158 of the inner container 154 is
located a distance of about five-eighths (5/8) inch from the bottom
wall 26 of the outer container 22.
In the embodiment illustrated in Figure 5, the inner
container 254 utilizes a portion of the side wall 224 of the outer
container as its side wall 256 and, like the previous embodiments,
has a wire screen as its bottom wall 258. The outer container 222 is
generally the same as the outer container 222 of the previous
embodiments. The upper portion of the supply line 230a has a vacuum
break above the top of the outer container 222 and the lower portion
of the supply line 230b extends down into the outer container 222
through the wire screen bottom wall 258 of the inner container 254 to
ensure that the granular cleansing agent located therein is not
wetted by the initial addition of water. The quantity of water
~ supplied to the containers, 222 and 254 is controlled by a water
level sensor 270. Such sensors 270 are well known to those skilled
in the art.
The recirculation line 242 and delivery line 246 utilize a
valve 272 and only one pump 244; i.e., the recirculation pump and the
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~ o
application delivery pump are one and the same. During the
recirculation period the valve 272 directs the flow of solution back
through the recirculation inlet 238 of the outer container 222, while
during the application period the valve 272 directs the solution
exiting the pump 244 to the application through the application
delivery line 246.
2. Preferred Method
Another aspect of this invention comprises a method of
dissolving and completely activating a discrete predetermined amount
of a granular cleansing agent. The process may utilize apparatus
similar to those described previously. For convenience, the
following description shall utilize the apparatus previously
described using Figure 1 through Figure 3.
Referring to Figure 6, the method operates on a discrete
predetermined quantity of the granular cleansing agent 74 located in
the inner container 54. Typical granular cleansing agents which may
be used in the method and apparatus of the present invention could
include a granular detergent prepared by mixing the following
ingredients:
SPRAY DRIED BASE GRANULE WEIGHT %
Sodium C13 linear alklbenzene sulfonate 10.3
Sodium C14 15 linear fatty alcohol sulfate10.3
Sodium sulfate 11 . 6
2.0r Sodium silicate 6.4
Polyethylene glycol (8000 M. Wt.) 0.6
Sodium tripolyphosphate 43.8
Optical brightner 0.3
C14 16 Fatty acid 3.0
Moisture and miscellaneous 7.2
Subtotal 93.5
ADMIX WEIGHT %
Silicone suds supressor* 4.5
Sodium carbonate 1.2
Protease 0.8
Total 100.0
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11
* Flakes containing ca. lOX by weight of a commercially
available silicone/silica fluid (ca. 75X polydimethyl
siloxane having a viscosity of 20 cs - 1500 cs at 25.0-C;
- about 15% siloxane resin; and about 10X silica aerogel
having an average ultimate particle size of about 12
millimicrons agglomerated to an average of 1.3 - 1.7
microns and having a surface area of ca. 325 m2/g) and ca.
90Z by weight of polyethylene glycol having a molecular
weight of about 8000 (PEG 8000) prepared as described in
U.S. Paten 4,652,392.
Another typical granular cleansing agent could include a
bleaching component and be prepared by mixing the following
ingredients:
SPRAY DRIED BASE-GRANULE WEIGHT %
Sodium C13 linear alklbenzene sulfonate 7.3
Sodium C14 15 linear fatty alcohol sulfate 7.3
Sodium sulfate 8.2
1.6r Sodium silicate 8.2
Polyethylene glycol (8000 M. Wt.) 0.3
Sodium polyacrylate 0.7
Sodium tripolyphosphate 29.6
Optical brightner 0.2
C14 16 Fatty acid 2.2
Moisture and miscellaneous 6.0
Subtotal 70.0
ADMIX WEIGHT %
Sodium Cg alkyloxybenzene sulfonate* 7.5
Sodium perborate monohydrate 8.9
Sodium citrate 3.2
Protease 0.6
Silicone suds supressor** 3.1
Sodium carbonate 6.7
Total 100.0
W 0 92/21808 2 11 0 ~ 0 8 12 PC~r/USs2/04551
* Cylindrical particles O.9mm diameter by 1.5 - 3.0 mm long,
containing 83% nonanoyloxybenzene sulfonate, 5X
polyethylene glycol 8000, 5% palmitic acid and 3% C12
linear alkylbenzene sulfonate.
** Flakes containing ca. lOX by weight of a commercially
available silicone/silica fluid (ca. 75% polydimethyl
siloxane having a viscosity of -20 cs - 1500 cs at 25.0-C;
about 15X siloxane resin; and about lOZ silica aerogel
having an average ultimate particle size of about 12
millimicrons agglomerated to an average of 1.3 - 1.7
microns and having a surface area of ca. 325 m2/g) and ca.
90% by weight of polyethylene glycol having a molecular
weight of about 8000 (PEG 8000) prepared as described in
U.S. Patent 4,652,392.
Water is provided to the outer container 22 through the
supply line 30 prior to initiating operation of the recirculating
pump 44. One function of this initial amount of water is to enable
the recirculation pump 44 to purge any dry granular cleansing agent
74 which may have found its way into the pump 44. Without the water,
the recirculation pump 44 may bind upon start-up. Prior to
substantial wetting of the cleansing agent 74i preferably prior to
the water level reaching the bottom wall 58 of the inner container
54, operation of the recirculation pump 44 is initiated. The
recirculation pump 44 draws solution from the outer container 22
through the recirculation outlet 36 and returns the solution to the
outer container 22 through the recirculation inlet 38. The solution
returning to the outer container 22 through the recirculation inlet
38 is directed towards the diffuser 62 and the cleansing agent 74
located in the inner container 54.
This solution impinging upon the diffuser 62 is diffused as
it enters the inner container 54 through the wire screen bottom wall
58. As seen in Figure 7, this diffused solution preferably floats
the granular cleansing agent 74 off of the bottom wall 58 of the
inner container 54 substantially immediately; and/or substantially
W O 92/21808 - 2 1 1 Q ~ ~ 8 P(~r/USg2/04S51
_ 13
immediately dissolves or disperses the lowermost granular cleansing
agent 74 so there is a space between the bottom wall 58 and the
remaining granular cleansing agent 74. As it rises, some undissolved
or undispersed granular cleansing agent 74 may flow over the top of
the inner container 54 and into the recirculation system where the
- turbulence and other mechanical action of the recirculation pump 44
dissolves or disperses it.
As seen in Figure 7, water preferably continues to be added
to the outer container 22 even after operation of the recirculation
pump 42 is initiated. As seen in Figure 8, as the additional water
raises the solution level in the containers, 22 and 54, a floating
island of granular cleansing agent 74 tends to form. This floating
island of granular cleansing agent 74 is subjected to ever changing
turbulence as the solution level rises and gradually disappears as it
dissolves or disperses.
The solution exiting the recirculation inlet 38 provides
energy for dissolving or dispersing the entire predetermined quantity
of cleansing agent 74 and preventing the cleansing agent 74 from
attaching to the sides of either container, 54 or 22. In the
preferred embodiment of Figure 3, this energy is somewhat confined to
the space within the inner container 54 by the solid cylindrical side
wall 56. In the embodiment of Figure 4, the energy is permitted to
exit and return to the inner container 154. Each embodiment sets up
its own patterns of turbulence in the inner container, 54 or 154.
Pumping of the water through the recirculation lines 42 via
the recirculation pump 44 is preferably ceased only after the
cleansing agent 74 has been dissolved or dispersed and substantially
all of the ingredients in the cleansing agent 74 have become active.
To become active, some components are transformed by a reaction with
the water itself; other components are transformed by reacting in
solution with other components in the granular cleansing agent 74.
During this mixing and reacting period, the amount of water in which
the components of the granular cleansing agent 74 are reacting is
limited. This limited amount of water speeds the rate at which the
various components will find and react with their corresponding
components. Furthermore, the total time period for the recirculation
period utilizing typical granular cleansing agents 74 is preferably
WO 92/21808 2 1 1 0 4 0 8 14 P~r/US92/o4S~l
from about one (1) minute to about ten (10) minutes, more preferably
from about two (2) minutes to about seven (7) minutes and most
preferably from about three (3) minutes to about five (5) minutes.
Once substantially all of the components within the
cleansing agent 74 are transformed, an active cleansing liquor is
available for use in a cleansing application. Preferably, operation
of the application delivery pump 48 is not initiated until after the
cleansing liquor has become active. It may be desirable to add an
additional amount of water from the supply line 30 beginning
simultaneously with the start-up of the application delivery pump 48.
Such additional water will cause the concentration of the cleansing
liquor being delivered to gradually decrease. This decrease may be
desirable to reduce the amount of residue remaining on the apparatus
20 after use.
The recirculation pump 44 can be turned off at any time
after dissolution or dispersion of the granular cleansing agent 74.
However, the recirculation pump 44 preferably operates at least until
the cleansing agent 74 has become active, since the turbulence it
provides aids the necessary reactions. Operation of the
recirculation pump 44, however, is generally ceased prior to the
water level within the outer container 22 falling to a point at which
the recirculation pump 44 would begin to spray water out the top of
the outer container 22. The application delivery pump 48 continues
to operate until all of the liquor is delivered. It is preferable
with time based apparatus, to permit the application delivery pump 48
to run a short period of time after all the active cleansing liquor
is calculated to be delivered to the application. This will ensure
that no liquor remains within the outer container 22 at the end of
the cycle.
One time based example of the instant method which may
utilize either the preferred embodiment of Figure 3 or the preferred
embodiment of Figure 4. Place a predetermined quantity of cleansing
agent in the inner container. Beginning at time zero (hereinafter
"Initiation") and continuing for thirty-eight (38) seconds add 1.4
liters of water to the outer container. Seven (7) seconds after
Initiation, begin operation of the recirculation pump. Three hundred
(300) seconds after Initiation, begin adding additional water to the
WO 92/21808 1 1 0 '10 ~3 PCI`/US92/04551
outer container at the same rate as before for between about thirty
(30) seconds and about one-hundred thirty-five (135) seconds. Forty
(40) seconds after the conclusion of the addition of this additional
water the recirculation pump ceases operating. The application
delivery pump is timed to cease operating about thirty (30) seconds
after all the water is dispensed to ensure the container is
completely drained.
The instant method and apparatus can dissolve or disperse a
discrete predetermined quantity of cleansing agent without caking
problems. This method and apparatus can also deliver a fully active
cleansing liquor to any cleansing application, thereby ensuring full
cleansing action immediately. Further advantages are achieved when
this method and apparatus is used in conjunction with a cleansing
application which utilizes a minimum amount of water. In such
minimum water cleansing applications sufficient water is not
available, e.g. in a reservoir, to permit the various reactions
necessary to activate the cleansing agent. Consequently, very little
additional activation will take place in the cleansing application
itself. Therefore, it is particularly important in these minimum
water applications to deliver a completely active liquor to the
cleansing application.
Such a minimum water cleansing application is disclosed in
U.S. Patent 4,489,455 issued to Spendel on December 25, 1984 and U.S.
Patent 4,555,019 issued to Spendel on November 26, 1985, the
disclosure of each is hereby incorporated herein by reference. This
cleansing application basically involves spraying a relatively small
amount of cleansing liquor onto clothes while agitating the clothes.
Heat energy is preferably supplied to the clothes during the spraying
and agitation process by recirculating moist humid air through a
heater.
Although particular embodiments of the present invention
have been shown and described, modifications may be made to the
- invention without departing from the teachings of the presentinvention. Accordingly, the present invention comprises all
embodiments within the scope of the appended claims.
