Note: Descriptions are shown in the official language in which they were submitted.
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METAL FOAM DISPENSER AND METHOD OF USE
FOR POLYURETHANE FOAM DISPENSING
FIELD OF THE INVENTION
[0001] The
present invention is in the field of polyurethane foams. More particularly,
the
invention relates to dispensers for the production and provision of
polyurethane foams.
BACKGROUND OF THE INVENTION
[0002]
Polyurethanes, defined as polymeric substances having multiple urethane
linkages,
are a large family of polymers with widely ranging properties and uses. Types
of polyurethanes
include rigid and flexible foams; thermoplastic polyurethane; and other
miscellaneous types,
such as coatings, adhesives, sealants and elastomers. When mixed with a
blowing agent or gas,
they become foams which are less dense and can be used for, e.g., insulation,
flotation,
cushioning, gluing, and sound absorption. Flexible foams (e.g., cushions) are
generally open-
celled materials, while rigid foams (e.g., building insulation, floats)
usually have a high
proportion of closed cells.
[0003] The
process for making polyurethane foams typically involves the mixing of two or
more liquid components in a foam production dispenser. Within the dispenser, a
first liquid
component (component A or "A-side") supplying, for example, isocyanate, is
mixed with a
second liquid component (component B or "B-side") supplying, for example, a
blend of one or
more polyols or other isocyanate reactive materials usually in the presence of
one or more
catalysts and other additives. One or both of the components can also include
one or more
blowing agents which cause the foam to expand and reduce the viscosity of the
component, and
surfactant which controls the formation and structure of the foam cells and
facilitates the mixing
of the two components. While surfactants are not typically introduced
separately, these optional
components can alternatively be introduced by a third feed. If the components
do not include a
gaseous blowing agent, the resulting mixture may have a higher viscosity.
Larger diameter feed
channels and/or the application of a pressurized gas as a component may be as
necessitated to
address higher viscosity materials or a desired higher dispense rate.
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[0004] A
dispenser for receiving a fluid flow of each of the individual components and
for
selectively mixing the components together prior to dispensing the resulting
foam is sometimes
referred to as a foam gun. The dispenser typically includes a housing with an
inlet side for
receiving each component within a respective channel, a valve member
controlling the flow of
one or both components through the dispenser, a mechanical interface for
selectively receiving
a mix tube having a static mixer therein in which the components are mixed and
the foam is
created, and an outlet through which flows the foam.
[0005] The
inlet side of a typical foam dispenser is provided with a mechanical coupling
device for connecting an inlet end of each channel to a respective component
supply hose, tube,
or pipe. An outlet end of each channel is in fluid communication with a
respective portion of
the valve member, which may be a spool valve. A spool valve is in mechanical
communication
with a trigger or lever that is manipulated by an operator, much as in the
operation of a trigger
on a firearm. As the trigger is pulled, the spool valve is rotated within the
dispenser housing
from a closed orientation to an open orientation. Fluid channels formed on the
periphery of or
through the spool valve are brought into alignment with the outlet ends of the
channels, thus
allowing the components to flow around or through the spool valve. A resilient
member such
as a spring is typically employed in conjunction with the trigger for
automatically returning the
trigger to a rest position in which the spool valve is closed.
[0006] Foam
components which flow around or through the spool valve within the dispenser
housing then enter a mix tube having a static mixer. The mix tube may be
engaged with the
foam dispenser via a threaded coupling. This static mixer may force the
components to interact
and mix prior to exiting a respective mix tube outlet port. The mixing chamber
may be separable
from the remainder of the housing and disposable. Residual amounts of
components may
accumulate and partially or completely block the mixing chamber, thus
necessitating its
replaceability.
[0007] The use
of high pressure impingement for liquid component mixing may have
advantages in terms of allowing the use of higher viscosity ingredients which
may enhance the
properties of the foam. Foam dispensers configured for low pressure mixing
utilize a static
mixer. However, such low pressure dispensers are typically provided of plastic
with relatively
small channels which are otherwise inappropriate for use with high viscosity
components. The
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use of a separate gas stream facilitates the mixing of higher viscosity
components. However, a
plastic dispenser has a risk of fracturing and may have loose tolerances
between components
having fluid flow channels interfacing each other.
[0008] U.S. Pat. No. 10,035,155 to Heckert, et al. discloses a foam
dispenser including a
housing having a cylindrical bore in which is disposed a cylindrical spool
valve. The barrel-
shaped valve is configured to be inserted and removed from either side of the
housing. A trigger
having a forked upper extent is mechanically attached to the opposite ends of
the valve. This
requires precise dimensioning of the trigger forked portions to ensure that
channels formed
within the respective spool valve are accurately laterally aligned with
deformable sealing plugs
in at least two of the feed channels, on the one hand, and the respective
dispensing channels
leading to the mixing chamber, on the other hand.
[0009] In addition, the Heckert, etal., patent requires a nipple in each of
the at least two feed
channels of the housing that also contain deformable sealing plugs, an inner
end of each nipple
pressing directly against an outer end of the respective deformable sealing
plug. These
additional components increase the cost and complexity of the disclosed foam
dispenser.
[0010] Further, the spool valve in Heckert, et al., provides a flow passage
therethrough for
each of three components. Two configurations are shown and described, one in
which all three
flow passages are coplanar and one in which two flow passages are coplanar and
one flow
passage is angled. Both configurations, however, provide a flow path for each
component only
when the spool valve is rotated into an "open" position; when in a "closed"
position, the flow
passages are out of alignment both with the feed channels, on the one hand,
and the dispensing
channels, on the other hand.
[0011] What is needed are reusable dispensers that can accommodate higher
and lower
viscosity foam components and mixtures, and a spool valve that enables
efficient, accurate
delivery of foam components to a mixing chamber and automatic clearing of
component
channels to facilitate dispenser re-use.
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SUMMARY OF THE INVENTION
[0012] It has
been discovered that a metal housing for a foam dispensing dispenser provides
certain advantages over the prior art devices. Higher component inlet
pressures may be used
without concern for the mechanical failure of dispenser parts. High strength
fastening
techniques may be employed at the interface between liquid supply lines and
the housing. The
improved tolerances between metal, machined components also enable the use of
high-pressure
liquids with less concern for leakage and fouling. A more rugged tool results
which facilitates
cleaning and re-use.
[0013] This
discovery has been exploited to develop the present disclosure, which, in
part,
is directed to a metal housing for a foam dispenser and which, in part, is
directed to an improved
spool valve. The housing is provided with a spool valve socket for selectively
receiving the
improved spool valve. A gas channel is provided within the spool valve for
enabling the flow
of gas through the liquid flow channels when the spool valve is disposed in an
off or closed
orientation. This flow of gas through the liquid channels in the off
orientation facilitates the
clearing of residual liquids from the flow path leading to the static mixer of
an attached mix
tube and thus avoids the unintentional mixing and clogging of the liquid
components.
[0014] In one
aspect, the disclosure provides a foam dispenser. The foam dispenser
comprises a metal housing having an inlet end, an outlet end, and a spool
valve socket
intermediate the inlet end and the outlet end. The spool valve socket extends
laterally between
opposite sides of the housing. Plural inlet channels are formed in the metal
housing between
the inlet end and the spool valve socket. Similarly, plural outlet channels
are formed in the
metal housing intermediate the spool valve socket and the outlet end. A metal
handle is in
mechanical communication with the metal housing proximate the inlet end
thereof A
substantially cylindrical spool valve having first and second opposite ends is
selectively
disposable within the spool valve socket. A removable spool valve facilitates
cleaning of the
spool valve and the housing. A trigger is mechanically couplable to the first
and second opposite
ends of the spool valve once the spool valve is disposed within the spool
valve socket. A
resilient member such as a coiled or leaf spring is intermediate the trigger
and the housing or
the handle for mechanically biasing the trigger away from the handle when
spool valve is
disposed within the spool valve socket and the trigger is coupled to the first
and second opposite
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ends of the spool valve. A mix tube with internal static mixer is configured
to be selectively
mechanically engaged with the outlet end of the metal housing. The mix tube
affixed to the
outlet end has an opening into an internal static mixer in registration with
the plural outlet
channels in the metal housing outlet end, and an outlet port.
[0015] In an
embodiment, the plural inlet channels in the metal housing inlet end are
substantially circular in cross-section and are provided with internal threads
for cooperatively
receiving feed supply lines having complimentary threaded grooves on an
external surface
thereof Other cross-sectional geometries may be employed.
[0016] In an
embodiment, the spool valve has, within the spool valve socket, a closed
orientation and an open orientation. The spool valve has first channels
therein. The inlet to
each channel in the spool valve is in registration with a respective one of
the plural inlet channels
and a respective one of the plural outlet channels when the spool valve is in
the open orientation
within the spool valve socket and is not in registration with a respective one
of the plural inlet
channels and a respective one of the plural outlet channels when the spool
valve is in the closed
orientation.
[0017] In an
embodiment, the spool valve further comprises at least one second channel
therein. The at least one second channel is in registration with a respective
one of the plural
inlet channels and a respective one of the plural outlet channels when the
spool valve is in the
open orientation and in the closed orientation.
[0018] In an
embodiment, the spool valve further comprises at least one third channel in
communication with the at least one second channel. The at least one third
channel is in
registration with a respective one of the plural outlet channels when the
spool valve is in the
closed orientation.
[0019] In an
embodiment, the spool valve comprises a first 0-ring intermediate each third
channel and the respective outlet channel when the spool valve is in the
closed orientation.
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[0020] In an
embodiment, the spool valve further comprises a second 0-ring on the spool
valve outer surface radially opposite each first 0-ring. The first and second
0-rings are
intermediate the spool valve and the spool valve socket.
[0021] In an
embodiment, the first and second 0-rings are each received within a respective
circular depression within an outer surface of the spool valve.
[0022] In an
embodiment, the spool valve comprises a valve body with a substantially
circular flange on one end of the valve body. The flange is coaxial with the
valve body and has
a diameter greater than the maximum diameter of the valve body.
[0023] In an
embodiment, the housing comprises a substantially circular recess on an outer
surface of a side of the housing about the spool valve socket. The recess is
dimensioned to
receive the spool valve flange therein.
[0024] In an
embodiment, the flange has a radial region of decreased diameter relative to
the remainder of the substantially circular flange and the substantially
circular recess has a
projection extending inwardly from an outer diameter of the recess. The
projection extends into
the radial region of decreased diameter when the spool valve is disposed
within the spool valve
socket.
[0025] In an
embodiment, the spool valve is rotatable within the spool valve socket in a
first
direction until the radial projection abuts a first end of the radial region
of decreased diameter
and is rotatable within the spool valve socket in a second, opposite direction
until the radial
projection abuts a second end of the radial region of decreased diameter.
Thus, the radial
projection cooperates with the radial region of decreased diameter to limit
the degree to which
the spool valve is rotatable within the spool valve socket.
[0026] In
another aspect, the disclosure provides a method of generating foam. The
method
includes providing a foam dispenser. The foam dispenser includes in part a
metal housing
having an inlet end, an outlet end, and a spool valve socket intermediate the
inlet end and the
outlet end. The spool valve socket extends laterally between opposite sides of
the housing. The
metal housing also includes plural inlet channels formed in the housing
intermediate the inlet
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end and the spool valve socket, and plural outlet channels formed in the metal
housing
intermediate the spool valve socket and the outlet end. The foam dispenser
also includes a metal
handle in mechanical communication with the housing proximate the inlet end
thereof, a
substantially cylindrical spool valve having first and second opposite ends,
disposable within
the spool valve socket, and a trigger mechanically couplable to the first and
second opposite
ends of the spool valve. The foam dispenser also includes a resilient member
intermediate the
trigger and at least one of the housing and the handle for mechanically
biasing the trigger away
from the handle when spool valve is disposed within the spool valve socket and
the trigger is
coupled to the first and second opposite ends of the spool valve. The foam
dispenser further
includes a mix tube adapter for selectively receiving a mix tube with internal
static mixer. The
mix tube adapter is configured to enable a mix tube to be selectively
mechanically engaged to
the outlet end of the metal housing, the mix tube having an opening into the
static mixer in
registration with the plural outlet channels in the metal housing outlet end,
and an outlet port.
The method also includes connecting a respective liquid supply line to plural
ones of the plural
inlet channels in the metal housing and selectively actuating the trigger to
rotate the spool valve
within the spool valve socket from a closed orientation to an open
orientation. Once in the open
configuration, liquid provided by the liquid supply lines flows through the
spool valve to the
outlet end and into the static mixer, thus generating foam.
[0027] In an
embodiment, connecting a respective liquid supply line to plural ones of the
plural inlet channels comprises threading a male threaded connector provided
on an end of the
liquid supply line into a female threaded socket forming a portion of the
respective inlet channel.
[0028] In an
embodiment, the method further includes connecting a respective gas supply
line to at least one of the plural inlet channels in the metal housing.
[0029] In an
embodiment, the spool valve has plural first channels therein. Each of the
first
channels in the spool valve is in registration with a respective one of the
plural inlet channels
and a respective one of the plural outlet channels when the spool valve is in
the open orientation
within the spool valve socket. Each of the first channels in the spool valve
is not in registration
with a respective one of the plural inlet channels and a respective one of the
plural outlet
channels when the spool valve is in the closed orientation.
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[0030] In an
embodiment, the spool valve further includes at least one second channel that
is in registration with a respective one of the plural inlet channels and a
respective one of the
plural outlet channels when the spool valve is in the open orientation and in
the closed
orientation.
[0031] In an
embodiment, the spool valve further comprises at least one third channel in
communication with the at least one second channel. The at least one third
channel is in
registration with a respective one of the plural outlet channels when the
spool valve is in the
closed orientation.
[0032] In an
embodiment, the method further includes connecting a respective gas supply
line to at least one of the plural inlet channels that is in registration with
a respective one of the
at least one second channel of the spool valve. Gas delivered by the gas
supply line is flowed
through the respective one of the at least one second channel, into the
respective one of the at
least one third channel, and out through the respective one of the plural
outlet channels and into
the mix tube static mixer when the spool valve is in the closed orientation.
[0033] In an
embodiment, the method further includes connecting a respective gas supply
line to at least one of the plural inlet channels that is in registration with
a respective one of the
at least one second channel of the spool valve. Gas delivered by the gas
supply line is flowed
through the respective one of the at least one second channel and out through
the respective one
of the plural outlet channels and into the mix tube static mixer when the
spool valve is in the
open orientation.
[0034] In an
embodiment, the spool valve comprises a valve body and a substantially
circular flange on one end of the valve body. The flange is coaxial with the
valve body and has
a diameter greater than the maximum diameter of the valve body. The housing
comprises a
substantially circular recess on an outer face of the housing about the spool
valve socket for
receiving the spool valve flange therein. The flange has a radial region of
decreased diameter
relative to the remainder of the substantially circular flange and the
substantially circular recess
has a projection extending inwardly from an outer diameter of the recess. The
projection
extends into the radial region of decreased diameter when the spool valve is
disposed within the
spool valve socket. The step of selectively actuating the trigger to rotate
the spool valve within
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the spool valve socket from a closed orientation to an open orientation
includes rotating the
spool valve within the spool valve socket in a first direction until the
radial projection abuts a
first end of the radial region of decreased diameter and rotating the spool
valve within the spool
valve socket in a second, opposite direction until the radial projection abuts
a second end of the
radial region of decreased diameter. The radial projection thus cooperates
with the radial region
of decreased diameter to limit the degree to which the spool valve is
rotatable within the spool
valve socket.
[0035] In yet
another aspect, the disclosure provides a spool valve for use in a foam
dispenser. The spool valve includes a substantially cylindrical spool valve
body having first
and second opposite ends, a substantially cylindrical outer surface between
the first and second
ends, and an axis of symmetry about which the substantially cylindrical outer
surface is
equidistant. The spool valve further includes plural first channels formed
within the spool valve
body. Each of the first channels in the spool valve body lies within a plane
that is orthogonal to
the axis of symmetry. A first channel inlet of each first channel is on the
substantially cylindrical
outer surface and a first channel outlet of the first channel is on the
substantially cylindrical
outer surface. The respective first channel inlet and first channel outlet are
radially separated
by 120 degrees or more about the axis of symmetry.
[0036] The
spool valve further includes at least one second channel formed within the
spool
valve body. Each of the at least one second channel lies within a plane that
is orthogonal to the
axis of symmetry. Each of the at least one second channel has two second
channel inlets on the
substantially cylindrical outer surface and two second channel outlets on the
substantially
cylindrical outer surface. The second channel inlets and second channel
outlets are in mutual
communication within the spool valve body. The two second channel inlets and
the two second
channel outlets each are radially separated by between 5 and 30 degrees about
the axis of
symmetry. The respective second channel inlets and second channel outlets are
radially
separated by 120 degrees or more about the axis of symmetry.
[0037] In an
embodiment, the spool valve includes at least one third channel within the
spool valve body. Each of the at least one third channel has a first segment
that is parallel to
the axis of symmetry and at least one second segment that is orthogonal to the
axis of symmetry.
Each third channel has at least one outlet on the surface of the substantially
cylindrical outer
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surface. Each third channel interconnects a respective one of the at least one
second channel
with the at least one third channel outlet.
[0038] In an
embodiment, each second segment outlet and a first channel outlet lie within a
plane that is orthogonal to the axis of symmetry.
[0039] In an
embodiment, the first and second opposite ends are each orthogonal to the axis
of symmetry.
[0040] In an
embodiment, the first opposite end has a flange that has a diameter that is
greater than each of the second opposite end and the substantially cylindrical
outer surface, the
flange lying in a plane that is orthogonal to the axis of symmetry.
[0041] In an
embodiment, the flange has a radial region of decreased diameter relative to
the remainder of the flange. The region of decreased diameter is for receiving
a projection
extending inwardly from an outer diameter of a spool valve socket recess when
the spool valve
body is disposed within the spool valve socket.
[0042] In an
embodiment, the spool valve further comprises at least one pair of 0-rings on
the substantially cylindrical outer surface. Each pair of 0-rings has center
points lying within a
plane that is orthogonal to the axis of symmetry and are radially separated by
substantially 180
degrees about the axis of symmetry on the substantially cylindrical outer
surface.
[0043] In an
embodiment, each 0-ring is partially received within a respective circular
recess within the surface of the substantially cylindrical outer surface.
DESCRIPTION OF THE DRAWING
[0044] Various
aspects of at least one embodiment of the present invention are discussed
below with reference to the accompanying figures. It will be appreciated that,
for simplicity and
clarity of illustration, elements shown in the drawings have not necessarily
been drawn
accurately or to scale. For example, the dimensions of some of the elements
may be exaggerated
relative to other elements for clarity or several physical components may be
included in one
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functional block or element. Further, where considered appropriate, reference
numerals may
be repeated among the drawings to indicate corresponding or analogous
elements. For
purposes of clarity, however, not every component may be labeled in every
drawing. The
figures are provided for the purposes of illustration and explanation and are
not intended as a
definition of the limits of the invention. In the figures:
[0045] Fig. 1 is a side view of a foam dispenser with spool valve according
to the present
disclosure;
[0046] Fig. 2 is a perspective view of the foam dispenser of Fig. 1;
[0047] Fig. 3 is a side view of a handle for use in the foam dispenser of
Fig. 1;
[0048] Fig. 4 is a perspective view of a trigger for use in the foam
dispenser of Fig. 1;
[0049] Fig. 5 is a perspective view of a housing for use in the foam
dispenser of Fig. 1;
[0050] Fig. 6 is another perspective view of the housing of Fig. 5;
[0051] Fig. 7 is a side view of the housing of Figs. 5 and 6;
[0052] Fig. 8 is a detail view of a portion of the housing of Figs. 5 and
6;
[0053] Fig. 9 is a top section view of the housing of Figs. 5 and 6;
[0054] Fig. 10 is a rear view of the housing of Figs. 5 and 6;
[0055] Fig. 11 is a side section view of the housing of Figs. 5 and 6;
[0056] Fig. 12 is a bottom view of the housing of Figs. 5 and 6;
[0057] Fig. 13 is a bottom view of a spool valve for use in the foam
dispenser of Fig. 1;
[0058] Fig. 14 is a front view of the spool valve of Fig. 13 once rotated
90 degrees about a
respective axis of rotation;
[0059] Fig. 15 is a perspective view of the spool valve of Figs. 13 and 14;
[0060] Figs. 16A and 16B are first side section views of the spool valve of
Figs. 13-15;
[0061] Figs. 17A and 17B are second side section views of the spool valve
of Figs. 13-15;
[0062] Fig. 18 is a third side section view of the spool valve of Figs. 13-
15; and
[0063] Figs. 19A and 19B are side views of the spool valve of Figs. 13-15
interacting with
a portion of the housing of Figs. 5 and 6.
DESCRIPTION
[0064] In the following detailed description, numerous specific details are
set forth in order
to provide a thorough understanding of the various embodiments of the present
invention. It
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will be understood by those of ordinary skill in the art that these
embodiments of the present
invention may be practiced without some of these specific details. In some
instances, well-
known methods, procedures, components and structures may not be described in
detail so as
not to obscure the embodiments of the present invention.
[0065] Unless
defined otherwise, all technical and scientific terms used herein have the
same
meaning as commonly understood by one of ordinary skill in the art to which
this disclosure
belongs. The initial definition provided for a group or term herein applies to
that group or term
throughout the present specification individually or as part of another group,
unless otherwise
indicated.
[0066] The
present invention relates to a dispenser in which a polyurethane foam is mixed
and from which the mixture is dispensed to a target discontinuous or moving
continuous surface,
or open or closed mold or cavity, and a spool valve for use therein and for
use in other foam
dispenser configurations. Rigid pour-in-place and spray foams, as well as
other types of
polyurethane foams can be prepared within the dispenser. Pour-in-place systems
have slower
reactivity, allowing the foam to flow well before and during its expansion to
allow a (usually)
closed cavity to fill with foam (e.g., a refrigerator). Some spray foams have
very fast reactivity
to allow application to vertical and horizontal overhead open cavities (e.g.,
walls and underside
of roof decks). High pressure spray foam components are normally supplied in
55-gallon drums
or 275-gallon intermediate bulk containers (IBC's), though they could also be
in pressurized
cylinders. Low pressure spray foams are typically shipped and dispensed from
returnable or
disposable gas cylinders.
[0067] The
presently disclosed metal dispenser can accommodate multicomponent foams
that contain gaseous and/or liquid blowing agent, and those that do not. When
foams with
gaseous blowing agents are dispensed, the mixed components immediately expand
into a foam
or froth before they start to react. Once the reaction between the mixed
components starts, the
foam continues to rise until it achieves the final density when the foam is
cured. The "pre-
expansion" from the gaseous blowing agent prior to the polymerization reaction
provides
processing advantages for certain applications because the pressure exerted by
the rising foam
is greatly reduced. Liquid blowing agents like ECOMATEO, which cause the foam
to expand
when the heat from the polymerization reaction causes them to boil, can be a
part of either of
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the two liquid (e.g., polyol or isocyanate) components. When the liquid
mixture is dispensed,
the blowing agent goes from liquid to gas, causing the mixture to froth or
expand prior to the
polymerization reaction.
[0068] Alternatively, gaseous blowing agents (GBA's) that are gas at
ambient temperature
can be introduced as a third stream in place of air to froth the mixture as it
is dispensed. There
are two needs for a dispenser with a third component: (1) to assist in the
mixing of the two liquid
components, especially when they are high in viscosity; and (2) to eliminate
the need for a
gaseous blowing agent. The most common GBA being used today, HFC-134a, is
being phased
out by governmental regulation due to its adverse effects on global warming.
The alternative
"zero Global Warming Potential" GBA's available are typically unstable and can
cause
degradation of the polyol component when blended together. However, the use of
a separately
delivered GBA in a third stream significantly lowers the viscosity of the
polyol component, so
being able to introduce the third stream assists the mixing of the components
and to some degree
also "froths" the foam mixture.
[0069] Table 1 lists exemplary liquid and gaseous blowing agents.
TABLE 1
Short Name Chemical Name Liquid or Gas
Ecomate Methyl Formate Liquid
HFC-2451a 1,1,1,3,3-Pentafluoropropane Liquid
HFC-134a 1,1,1,2-Tetrafluoroethane Gas
HCF0-1233zd E trans-1-Chloro-3,3,3-trifluoropropene Liquid
HF0-1234ze(E) trans ¨ 1,3,3,3-tetrafluoropropene Gas
HFO- 1336mzzm(z) (Z)-1,1,1,4,4,4-Hexafluoro-2-butene Liquid
HF0-1336mzzm(e) (E)-1,1,1,4,4,4-Hexafluoro-2-butene Gas
Carbon dioxide Carbon dioxide Gas
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[0070] Water
may be incorporated into the polyol component, often in combination with
liquid and/or gaseous blowing agents. Once the polyol component is mixed with
the isocyanate
component, the water reacts with the isocyanate to create carbon dioxide,
which also acts as a
blowing agent.
[0071] Various
types of foam processes are described in the following, some of which may
be practiced using the metal foam dispenser and spool valve as disclosed
herein.
[0072] A first
pour-in-place insulation foam process uses a liquid blowing agent such as
ECOMATEO, HFC-245fa, HCF0-1234zd or HF0-1336mzzm(z). The B-side liquid
viscosity
is <1000 cps and is provided from an N2 pressured cylinder. The cylinder
pressure and/or
dispenser orifice size limit the foam pressure. A solvent-less urethane gun
(SLUG) with third
stream gas assist and external static mixer tube is used at 150-250 psi. The
Foam Supplies, Inc.
(FSI) ECOFOAMO is a commercial product example. It is a standard pour-in-place
system.
[0073] A second
pour-in-place insulation foam process also uses a liquid blowing agent such
as ECOMATEO, HFC-245fa, HCF0-1234zd or HF0-1336mzzm(z). The B-side liquid
viscosity is <1000 cps and is provided from an N2 pressurized cylinder. The
cylinder pressure
and/or dispenser orifice size limit the foam pressure. A two-component
dispenser with third
stream gas assist with external mixer tube, such as described herein, is used
at 150-250 psi. The
FSI ECOFOAMO is a commercial product example.
[0074] A third
pour-in-place insulation foam process uses a gaseous blowing agent such as
HFC-134a, HF0-1234ze(E) or HF0-1336mzzm(e). The B-side is provided from an N2
pressurized cylinder. The cylinder pressure and/or dispenser channel size
limit the foam
pressure. An FSI SLUGTM with third stream gas assist and external static mixer
tube is used at
150-250 psi. The FSI 87a series is a commercial product example. It is a
standard froth pour-
in-place system.
[0075] A first
high pressure spray foam insulation process uses a liquid blowing agent such
as ECOMATEO, HFC-245fa, HCF0-1234zd or HF0-1336mzzm(z). The B-side liquid
viscosity is between 500 and 1500 cps and is provided from a drum or IBC. The
liquid
component pressure and mixing ratio are controlled by a high pressure
mechanical proportioner,
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such as the Graco REACTOR . The components mix through a high pressure (1200-
1800 psi)
impingement dispenser with air assist such as the Graco FUSION dispenser. The
FSI
ECOSTARO ccSPF, FSI ecoroof, and FSI genspray are commercial product examples.
They
are standard high pressure spray foam systems.
[0076] A second
high pressure spray foam insulation process uses a liquid blowing agent
such as ECOMATEO, HFC-245fa, HCF0-1234zd or HF0-1336mzzm(z). The B-side liquid
viscosity is between 500 and 1500 cps and is provided from an N2 pressurized
cylinder. The
foam pressure is limited by a low pressure mechanical proportioner, such as
Titan HELIX . A
two-component dispenser with third stream gas assist with external mixer tube,
such as
described herein, or similar to the DuPont Ultra System or the Wayne Spray
Tech
PROPURGEO is used at below 150 psi. The FSI ECOSTARO ccSPF, FSI ecoroof, FSI
genspray, and DuPont Froth Pak Ultra are commercial product examples. They
enable high
viscosity components to be processed through a low pressure proportioner with
gas assist.
[0077] A first
low pressure spray foam insulation foam process uses a gaseous blowing agent
such as HFC-134a, HF0-1234ze(E) or HF0-1336mzzm(e). The B-side estimated
viscosity of
liquid under pressure in the cylinder is <50 cps and is provided from an N2
pressurized cylinder.
The cylinder pressure and/or dispenser channel size limit the foam pressure. A
two-component
dispenser with external static mixer tube is used at 150-250 psi. The FSI
Spritzer, FSI
Thermafroth or DuPont Froth Pak are commercial product examples. They are a
standard low
pressure systems.
[0078] A second
low pressure spray foam insulation foam process uses a liquid blowing
agent such as ECOMATEO, HFC-245fa, HCF0-1234zd or HF0-1336mzzm(z). The B-side
liquid viscosity is between 500 and 1500 cps and is provided from an N2
pressurized cylinder.
The cylinder pressure and/or dispenser channel size limit the foam pressure. A
two-component
dispenser with third stream gas assist with external mixer tube, such as
described herein, is used
at 150-250 psi. This is a low pressure spray foam system that does not require
a gaseous blowing
agent.
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[0079] With reference to the attached drawings, disclosed is a foam
dispenser having a metal
housing and a spool valve for use therein and for us in foam dispensers of
other configurations
and construction, whether having a housing of metal or plastic.
[0080] With reference to Figs. 1-12, a foam dispenser 100 comprises a
housing 102 and a
handle 104. Preferably, at least the housing is formed of metal; the handle
may be of metal as
well. In one embodiment, the metal chosen is aluminum due to its strength and
relatively low
weight, though other metals or metal alloys may be utilized. An advantage of
providing at least
the housing in metal, particularly when a third, gaseous stream is employed,
is that higher
pressure mixing can be accommodated as compared to that realizable with a
plastic housing.
Higher pressure mixing allows higher viscosity components to be utilized.
Metal also enables
a durable housing and/or spool valve that may be cleaned and reused.
[0081] The housing 102 includes a rearward face or inlet end 120, a forward
face or outlet
end 122, a first side 126, a second side 128, a top face 140, a bottom face
142. In an illustrated
embodiment, the housing has a roughly rectangular solid shape, though other
configurations
may be employed. Disposed laterally through the housing, from the first side
to the second side,
is a substantially cylindrical spool valve socket 124. A mix tube adapter 110
is disposed on the
forward face of the housing. In one embodiment, the mix tube adapter is
integrally formed
with the housing in order to provide a more rigid, breakage resistant unitary
structure. The mix
tube adapter is configured to selectively receive a mix tube with internal
static mixer, which
may be of a standard form factor. Mutually cooperating screw threads may
enable the secure,
releasable connection between mix tube and housing via the mix tube adapter.
In use, liquids
and optionally a gas are received within the mix tube, once engaged with the
mix tube adapter,
and are mixed to generate a foam that is dispensed from the mix tube in a
conventional manner.
[0082] With respect to Figs. 9-11, plural inlet channels 130A, 130B, 130C
are disposed or
formed within the housing, each providing a fluid channel or pathway between
the housing
rearward face 120 and the spool valve socket 124. Similarly, plural outlet
channels 132A, 132B,
132C are disposed or formed within the housing, each providing a fluid channel
or pathway
between the spool valve socket and the mix tube adapter 110 at the forward
face 122 of the
housing. The inlet and outlet channels are preferably circular in cross-
section for minimized
resistance to fluid flow therein though other cross-sectional geometries may
be employed.
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[0083] As viewed in Figs. 6, 7, and 8, disposed within the rearward face or
inlet end 120 of
the housing 102 are sockets 134A, 134B, 134C, each for and in communication
with a respective
one of the inlet channels 130A, 130B, 130C. The sockets in one embodiment
include internal
threads 136A, 136B, 136C formed into the metal of the housing and are
dimensioned to
releasably receive external, complimentary threads formed on one end of a
respective supply
line. The supply lines may connect the housing to containers or other sources
of liquids and/or
gases utilized in the foam production process. Preferably, the sockets are
formed orthogonally
to the rearward face. Selectively mating the supply lines to the housing via
complimentary
internal and external metal threads enables the provision of fluids at higher
pressures than would
otherwise be employable with a prior art plastic housing receiving supply
lines via quick connect
or other types of easily releasable fittings.
[0084] In the illustrated embodiment, there are three inlet channels 130A,
130B, 130C and
three complimentary outlet channels 132A, 132B, 132C. This embodiment includes
two inlet
channels 130A, 130C and respective sockets 134A, 134C that each lie within a
respective
horizontal plane between the housing rearward face or inlet end 120 and the
spool valve socket
124. Disposed laterally between these two inlet channels is a third inlet
channel 130B which is
provided at an angle between the rearward face or inlet end and the spool
valve. In particular,
socket 134B and the rearmost end of this inlet channel 130B are disposed below
the plane of
the inlet channels 130A, 130C and respective sockets 134A, 134C. The
forwardmost end of
this inlet channel 130B within the spool valve socket 124 is also below the
plane of the other
two inlet channels 130A, 130C, but higher than the respective rearward-most
end, as best seen
in Figs. 6,10 and 11.
[0085] With respect to Figs. 9 and 11, the outlet channels 132A, 132B, 132C
lie within the
same substantially horizontal plane, from the spool valve socket 124 to the
forward face or outlet
end 124 of the housing 102 and through the mix tube adapter 110 for engagement
with a
conventional mix tube (not shown) mounted thereon. The plane of the outlet
channels may be
the same plane as contains the two horizontal inlet channels 130A, 130C.
[0086] The housing 102 further comprises a handle 104. In a first,
illustrated embodiment,
the handle is also provided of metal and is either integrally formed with the
housing or is
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attached thereto. Such attachment may be by way of threaded fasteners (not
shown) screwed
into threaded holes 112 formed in the bottom face 142 of the housing, as shown
in Fig. 12. In
Figs. 1, 2 and 3 the handle is illustrated as extending downward and backward
for ease of use,
though other configurations may be employed.
[0087] With
respect to Figs. 13-19B, a spool valve 200 having a substantially cylindrical
spool valve body 202 is configured and dimensioned to be rotatably received
within the spool
valve socket 124, though the disclosed and described spool valve may also be
used within foam
dispensers other than that described herein, as long as such alternative foam
dispensers are
provided with a cooperatively dimensioned circular recess 240 and projection
244, as described
below. Preferably, the spool valve is also provided of metal such as aluminum.
A metallic
housing and metallic spool valve enable fabrication with more precise
tolerances, enabling a
more fluid-tight connection therebetween. The spool valve has first and second
ends 206, 208
which are mutually parallel. The spool valve also has an axis of symmetry 250
therethrough.
[0088]
Extending from each of the first and second ends 206, 208 along the axis of
symmetry
are respective first and second tabs 210, 212. In the illustrated embodiment,
each tab is a
rectangular solid. Both tabs in the illustrated embodiment are coplanar and
are preferably
integrally formed with the remainder of the spool valve 200. Each tab is
provided with a socket
214 in the illustrated embodiment. These sockets may be internally threaded
for receiving a
threaded fastener (not shown) therein.
[0089] The foam
dispenser 100 also comprises a trigger 106 having first and second arms
107A, 107B dimensioned to extend on either side of the housing 102 for
selective engagement
with the tabs 210, 212 of the spool valve 200. Each arm may have a bore 114
that may be
aligned with a respective tab socket 214 whereby a threaded fastener may
extend through the
bore and engage with the threaded socket, thereby releasably affixing the
trigger to the spool
valve. In this manner, rotational actuation of the trigger with respect to the
handle 104 causes
rotation of the spool valve within the spool valve socket 124. A resilient
member 108, disposed
between the trigger and the handle or the housing body 102, biases the trigger
away from the
handle, thus rotating the spool valve into a closed orientation, as will be
discussed subsequently.
Compression of the resilient member, such as by an operator squeezing the
trigger relative to
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the handle, causes the rotation of the spool valve into an open orientation.
The resilient member
may be a coiled spring, a leaf spring, a torsion spring, etc., as known to one
skilled in the art.
[0090] The
spool valve also comprises at the first end 206 thereof a flange 204 that is
coplanar with the second end 208, coaxial with the spool valve body 202, and
orthogonal to the
axis of symmetry 250. The diameter of the flange is greater than that of the
spool valve body.
The housing 102 comprises a substantially circular recess 240 on the second
side 128 of the
housing 102 about the spool valve socket 124 for receiving the spool valve
flange 204 therein
when the spool valve body is fully received within the spool valve socket.
[0091] The
spool valve flange 204 has a region of decreased diameter 242 relative to the
remainder of the substantially circular flange along one radial portion
thereof, as shown in Figs.
19A and 19B. The substantially circular recess 240 about the spool valve
socket 124 has a radial
projection 244 extending inwardly, as shown in Figs. 6, 7 and 8. When the
spool valve 200 is
disposed within the spool valve socket, the radial projection extends into the
region of decreased
diameter. The spool valve is thus rotatable within the spool valve socket in a
first rotational
direction until the radial projection mechanically interferes with one end of
the radial region of
decreased diameter. Likewise, the spool valve is rotatable in a second,
opposite rotational
direction within the spool valve socket until the radial projection
mechanically interferes with
the other end of the radial region of decreased diameter. The radial region of
decreased diameter
is configured on the edge of the flange, with respect to channels within the
spool valve such that
the spool valve rotation is limited by interference with the radial projection
between a first, open
orientation and a second, closed orientation.
[0092] The
spool valve 200 has plural first channels 220 therein and at least one second
channel 222 therein, with reference to Figs. 16A, 16B, 17A, and 17B. Each of
the first channels
in the spool valve lies within a plane that is orthogonal to the axis of
symmetry 250 and has a
respective first channel inlet 260 on the substantially cylindrical outer
surface of the spool valve
body 202 and a respective first channel outlet 262 on the substantially
cylindrical outer surface
of the spool valve body. In a first embodiment, the respective first channel
inlet and first channel
outlet are radially separated by 120 degrees or more about the axis of
symmetry. In the
illustrated embodiment, the respective first channel inlet and first channel
outlet are radially
separated by 180 degrees about the axis of symmetry.
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[0093] The first channel inlet 260 and the first channel outlet 262 are in
registration with a
respective one of the plural inlet channels 130A, 130C and a respective one of
the plural outlet
channels 132A, 132C when the spool valve is in the open orientation, as shown
in Fig. 17A.
The same plural inlet channels 130A, 130C are effectively closed by the spool
valve body 202
when the spool valve is in the closed orientation, as shown in Fig. 17B, at
which point neither
the first channel inlet 260 or first channel outlet 262 align with any other
channel.
[0094] The spool valve also has at least one second channel 222 formed
within the spool
valve body 202, each second channel lying within a plane that is orthogonal to
the axis of
symmetry 250, as shown in particular in Figs. 16A and 16B. Each second channel
has two
second channel inlets 264 on the substantially cylindrical outer surface of
the spool valve body
202 and two second channel outlets 266 on the substantially cylindrical outer
surface of the
spool valve body 202. In the illustrated embodiment there is one second
channel 222 disposed
intermediate two first channels 220 along the length of the spool valve body.
[0095] The second channel inlets 264 and second channel outlets 266 are in
mutual
communication within the spool valve body 202. In a first embodiment, the two
second channel
inlets are radially separated by between 5 and 30 degrees about the axis of
symmetry 250, and
the two second channel outlets are radially separated by between 5 and 30
degrees about the
axis of symmetry. In the illustrated embodiment, the separation between inlets
and between
outlets is 17.5 degrees. In one embodiment, the minimum separation between a
second channel
inlet and a second channel outlet is 120 degrees. In the illustrated
embodiment, this minimum
separation is 145 degrees.
[0096] The spool valve 200 also has at least one third channel 224 within
the spool valve
body 202. Each third channel has a first segment 224A that is parallel to the
axis of symmetry
250 and at least one second segment 224B that is orthogonal to the axis of
symmetry, each
second segment of the at least one third channel having a respective outlet
268 on the surface of
the substantially cylindrical spool valve body 202. Each spool valve third
channel outlet and a
first channel outlet 132A, 132C lie within a plane that is orthogonal to the
axis of symmetry.
Each of the third channels thus interconnects a respective one of the at least
one second channel
222 with at least one second segment outlet 268.
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[0097] In the illustrated embodiment, the one inlet channel 130B is
connected to one outlet
channel 132B via the spool valve second channel 222 when the spool valve 200
is rotated into
the open orientation, as illustrated in Fig. 16A, via a second channel inlet
264 and a second
channel outlet 266. In the same open orientation, the two inlet channels 130A,
130C are
connected to two outlet channels 132A, 132C via a first channel inlet 260 and
first channel outlet
262 of a respective first channel 220, as illustrated in Fig. 17A.
[0098] However, in the closed orientation, the one inlet channel 130B is
connected to two
outlet channels 132A, 132C via the spool valve second channel 222 and the
spool valve third
channel 224, as illustrated in Fig. 17B. The same inlet channel 130B is also
connected to an
outlet channel 132B when the spool valve is rotated to the closed orientation,
as illustrated in
Fig. 16B. In this manner, when the spool valve is closed, gas supplied within
the middle inlet
channel 130B flows through the respective spool valve second channel 222 to
the respective
outlet channel 132B, as well as through the spool valve third channel 224,
comprised of first
and second segments 224A, 224B, to the other outlet channels 132A, 132C that
otherwise flow
liquid when the spool valve is in the open orientation. Thus, gas may be used
to clear residual
liquids from the liquid bearing outlet channels 132A, 132C and from the mix
tube attached to
the mix tube adapter 110. This may prolong the usable life of the mix tube and
lessen the
frequency of cleaning cycles for the housing 102.
[0099] The first segment 224A of the spool valve third channel may be
formed as a
cylindrical bore through the length of the spool valve body 202, parallel to
the axis of symmetry
250. To prevent gas from flowing out the first and second ends 206, 208 of the
spool valve, an
outer portion of the first segment may be blocked such as through the use of a
set screw (not
shown) in the first segment at each of the first and second ends 206, 208.
[00100] To inhibit the lateral flow of liquids and gases along the surface of
the spool valve
200 when disposed within the spool valve socket 124, the spool valve may
further be provided
with peripheral grooves 270, orthogonal to the axis of symmetry 250, for
receiving therein 0-
rings (not shown).
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[00101] A method of using the foregoing foam dispenser 100 with spool valve
200 includes
connecting a liquid supply line to plural inlet channels 130A, 130C. The
trigger 106 is
selectively squeezed or actuated to rotate the spool valve within the spool
valve socket 124 from
a closed orientation to an open orientation, whereby liquid flows through the
spool valve to the
outlet end of the housing, as described above. Releasing the trigger allows
the resilient member
108 to bias the trigger away from the handle 104, bringing the spool valve
into the closed
orientation, whereby liquid is prevented from flowing through the spool valve.
[00102] The method may also include connecting a gas supply line to an inlet
channel 130B.
In the open orientation, gas is flowed from a respective inlet channel 130B to
a respective outlet
channel 132B. In the closed orientation, gas is flowed from the respective
inlet channel 130B
to the respective outlet channel 132B and to the outlet channels 132A, 132C
otherwise used to
flow liquid when in the open orientation, thereby enabling the clearing of
these liquid outlet
channels and the mix tube affixed to the mix tube adapter 110.
[00103] While the illustrated embodiment of the spool valve 200 includes one
second channel
222 laterally disposed intermediate two first channels 220, a further
embodiment of the spool
valve of the present invention may further include a fourth channel also
intermediate two first
channels along with the second channel 222. Such a spool valve may then
provide a gaseous
blowing agent through one of the second and fourth channels and a gas for
liquid channel
clearing through the other of the second and fourth channels when in the
closed orientation. The
channel providing gas for liquid channel clearing would thus be connected to
the liquid outlet
channels 132A, 132C when the spool valve is in the closed orientation, such as
via structures
akin to the third channel 224 as described above.
[00104] The foregoing description has been directed to particular embodiments.
However,
other variations and modifications may be made to the described embodiments,
with the
attainment of some or all of their advantages. It will be further appreciated
by those of ordinary
skill in the art that modifications to the above-described systems and methods
may be made
without departing from the concepts disclosed herein. Accordingly, the
invention should not be
viewed as limited by the disclosed embodiments. Furthermore, various features
of the described
embodiments may be used without the corresponding use of other features. Thus,
this
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description should be read as merely illustrative of various principles, and
not in limitation of
the invention.
[00105] Many changes in the details, materials, and arrangement of parts and
steps, herein
described and illustrated, can be made by those skilled in the art in light of
teachings contained
hereinabove. Accordingly, it will be understood that the following claims are
not to be limited
to the embodiments disclosed herein and can include practices other than those
specifically
described, and are to be interpreted as broadly as allowed under the law.
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