Note: Descriptions are shown in the official language in which they were submitted.
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ENVIRONMENTAL METHOD AND DEVICE TO SAIa'ELY RECOVER
AND REMOVE WASTE AMALGAMS FROM THE FLUID STREAM
OF A VACUUM OPERATED DENTAL EVACUATION APPARATUS
FIELD OF THE INVENTION
The present invention relates to an improvement in dental waste management
practice and equipment, designed to significantly reduce or eliminate the
uncontrolled
discharge of solid waste in the form of amalgams containing toxic metals such
as
mercury, tin, copper and silver from typical dental vacuum operated evacuation
systems.
The improved practice is based on a method which employs one or more sealed
and self
contained filtering devices designed to fit into any prior art dental
evacuation or aspirator
system. Each filtering device is then able to effectively isolate, retain and
recover said
solid amalgams for safe disposal and recycling without the need for any open
handling or
transfer of toxic waste materials at any time. Each device is located at the
intake side of
a vacuum system such as to prevent waste materials from traveling through
permanent
and concealed conduits of the system and over time depositing an obstructive
toxic film
on the conduit interior walls. The system's existing central filtering
apparatus may be
retained as back-up.
BACKGROUND OF THE INVENTION
It is generally recognized that all present day dental evacuation systems
employ a
central filtering apparatus for the purpose of separating waste solids from
its suction
fluids. Such apparatus may contain a plastic screen filter which is usually
designed to
collect larger solid waste particles, and/or may rely on gravity to separate
and deposit
solid waste materials into a permanent waste container of the apparatus by way
of a
baffle or reflector plate arrangement. The apparatus is mostly located beyond
the
impeller pump of a vacuum system, as part of the conduit portion leading to
the sewer
line. However, it is also recognized that such apparatus is unable to prevent
solid waste
materials like amalgams from entering the impeller pump, or to remove any of
the
smaller solids which may be too minute to respond to gravity or to be retained
in the filter
screen. Furthermore, the apparatus needs to be periodically opened and
manually
emptied, putting the operator into possible contact with the; toxic waste
materials.
Current dental evacuation systems are therefore considered environmentally
ine~cient
and hazardous.
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In US Pat. No. 6,149,812, Erickson discloses a dental environmental filter for
heavy metals and mercury hygiene. Such filter however relies on a deflector
baffle plate
to trap waste particles by way of gravity, which is contrary to Applicant's
invention.
In US Pat. No. 5,858,225., Nerli describes a dental filter with sanitary
handling for
removing waste from a dental cuspidor, consisting of a canister assembly
incorporating a
plastic filter basket for receiving waste. The plastic filter basket however
is intended to
trap only significant size solids and needs to be extracted by hand from the
opened
canister in order to remove the toxic waste. This again is contrary to the
present
disclosure.
In US Pat. No. 5,797,742, Fraker discloses an amalgam solids collecting and
separating apparatus. Such apparatus relies solely on gravity and valve
actions to
separate solids from liquids in a large canister, which then needs to be
opened and
emptied by hand in order to remove the waste material. This method and
apparatus is
also contrary to Applicant's disclosure.
When reviewing available prior art, it is apparent that existing dental
environmental waste recovery systems are inefficient and are only able to trap
waste
particles of sufficient weight (through gravity), or of sufficient size
(according to plastic
screen size), and that large amounts of small but very toxic waste particles
are therefore
able to contaminate the system and remain in the environment.
Accordingly, there is an urgent need for an economical and environmentally
safe
method and device which is effective in separating, recovering and containing
for
recycling dental amalgams and other toxic dental waste materials at a suitably
high ratio
from the operating fluids of typical high volume dental evacuation systems.
SUMMARY OF THE INVENTION
The present invention therefore discloses a method and device to provide
sealed
separation and removal of dental amalgam waste particles from dental
evacuation
equipment at a rate of at least 9~5%, for environmentally safe recycling. The
preferred
method consists of operating a closed circuit waste removal system in the
following
sequence:
The Method
A typical dental vacuum operated evacuation system is equipped with a sealed,
high density in-line transparent amalgam waste filter capsule near the
location of each
dental
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operating chair and at the start of the main vacuum line of the evacuation
system, just
beyond the system catch-all screen or multiple line conversion in that
location. A plastic
catch-all system screen of suitably open mesh in accordance with this
invention must be
installed to act as a separator fir larger objects that need retrieval, such
as crowns or
cotton swabs accidentally removed from an oral cavity with the aspirator,
which must be
prevented from entering the amalgam filter. Each transparent and sealed waste
filter
capsule of the present invention is installed in such a manner as to allow
constant visual
observation of its interior condition and to allow easy replacement, while the
open mesh
plastic catch-all screen just ah~;ad of this Location is easily accessible to
allow retrieval of
the larger objects.
It is therefore obvious that the herein disclosed disposable filter capsule
installed
in such location provides early a.nd complete filtering action before any
waste particles
are able to extensively enter the main vacuum system, causing damage and
contamination
especially to the under ground located conduit lines and to the impeller pump
equipment
of the system. Such disposable high density waste filter capsule is designed
to remove at
least 95% of all typical amalgam solid particles from the vacuum system, and
is of
economical construction to afTord continuous and repetitive replacements. The
waste
filter capsule is a sealed unit which, even after disconnection from the
vacuum system,
safely retains the contents o:f all collected waste materials without danger
of
contamination, completely eliminating manual contact.
Each spent waste filter capsule is then placed into a special shipping
container for
storage. When said shipping container, which may hold a multiple of filter
capsules, is
filled, it may be safely transported to a pre-determined recycling facility
for authorized
disposal.
If an existing system is converted, the prior art main waste filter of the
system,
which is usually located beyond the impeller pump and near the system main
sewage
drain, may now be employed strictly as an emergency back-up in case of failure
of the
disclosed sealed capsule filtering provisions of the present invention.
This environmental procedure represents a preferred embodiment of the present
invention, providing a secure and closed circuit dental waste removal method,
which
easily assures constant and equal protection for every single-chair or
multiple-chair dental
practice.
The Device:
The preferred method heretofore described incorporates a preferred device of
the
present invention consisting of a sealed transparent manifold capsule
containing a dense
filter arrangement from artificial or natural fibers, able to separate at
least 95% at a
maximum of
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microns of dental amalgam waste solids from the fluids of a typical vacuum
operated
dental evacuation system. The ratio of filter surface area, relative to the
fluid volume and
pressure of the vacuum employed in the system, must be sufficiently large as
not cause
any operating obstruction until said filter surface area is contaminated and
the sealed
capsule is ready for replacement.
Said sealed capsule is equipped with an inlet port that communicates with the
interior area of such capsule and is connectable to the vacuum source of the
system. The
inlet port receives the operating .fluid of the vacuum system by way of a
typical aspirator
or evacuation tool which may transport a combination of solids and liquids
originating
from a dental patient's oral cavity. Such solids are separated from the
operating fluids
and/or liquids by way of the dense filter assembly of natural or artificial
fibers, suitably
located in the interior of the capsule.
The sealed capsule is further equipped with an outlet port that also
communicates
with the interior area of the capsule, which outlet port is separated from
said inlet port
through the interior filter arrangement. The outlet port is connected to the
vacuum source
of the system by way of a continuous conduit leading to the impeller pump.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 of the drawings appended hereto illustrates the unique method of the
present invention, comprising the schematics of a typical dental evacuation
system and
locations and sequence of the various required components of the system
including a high
density filtering device of the present invention, which provide the means for
the system
to separate and collect toxic amalgam waste particles in accordance with the
disclosure.
Figure 2 of the drawings appended hereto depicts a cut-away isometric view of
a
typical device in accordance with the present invention, incorporating a
preferred high
density amalgam filter enclosed in a transparent and sealed, disposable
capsule, which is
shown located in its unique location SA and SB in Figure 1.
Figure 3 of the drawings appended hereto depicts a view of a further typical
device in accordance with the present invention, this time incorporating a
high density
amalgam filter of alternate shape and configuration.
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DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT
Referring now to Figure 1 of the drawings, there is shown, in a general
schematic
layout, the operating method of a dental evacuation system located in a
typical dental
practice, comprising an impeller pump assembly 1., which provides the vacuum
power to
remove waste fluids and particles from oral cavities of dental patients, and
is equipped at
its outlet side with an exit conduit connection 2 to the sewer line for
disposal of the
system's waste materials. Said pump assembly 1 is further equipped at its
inlet side with
a primary vacuum intake conduit 3, which may divide into secondary vacuum
intake
conduits 4 to connect to individual dental chair locations 8. The primary
intake conduit 3
is commonly concealed within the floor space of a dental office and is
therefore
inaccessible. The secondary intake conduit 4 terminates at a vacuum manifold 6
which
allows connection of the various dental oral suction tools 7. The vacuum
manifold 6 is
equipped with a catch-all removable grate trap to separate larger dental
particles for
manual recovery. Within the secondary vacuum intake conduit 4, just downstream
from
vacuum manifold 6, is the preferred location for the device of the present
invention, a
high density amalgam filter contained in its transparent, sealed and
disposable filter
capsule 5. Said sealed capsule S located at this particular location, together
with the
catch-all grate trap and vacuum manifold 6, provides the environmental
filtering means to
prevent any amalgam particles from entering the primary vacuum conduits 3 and
the
impeller pump assembly 1 , eliminating damage from toxic deposits within the
system
and the discarding of toxic waste materials into sewage drain 2.
In Figure Z of the drawings there are shown, in cut-away front elevation, the
details of a sealed filter capsule 10 as indicated at location 5 in Fig. 1,
comprising a
transparent, substantially cylindrical container 13, having a single inlet
port 11 which
extends to the interior of the container, and a single outlet port 1 t which
is connected to a
vacuum source 17 by way of conduit 4. 'fhe inlet port is separated from the
outlet port in
the interior of the sealed capsule through tilter arrangement 14. Said filter
arrangement is
constructed from natural or artificial fibers at a density to facilitate
separation of
amalgam waste particles at a rate of 95°~0, up to a maximum of 10
microns. The filter
arrangement 14 is further designc;d to incorporate a surface area sufficient
to allow waste
filtering without substantially interfering with the volume and vacuum
velocity of the
evacuation system until the filter surface area is blocked by waste sediments
to an extent
that the capsule needs to be replaced. Said filter arrangement 14 is located
such as to
separate particles in the interior of the transparent body 13 of sealed
capsule 10, allowing
a view of the collected waste 1S in order to constantly evaluate the level of
operating
function of the filter assembly. When the sealed filter capsule
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is removed from the system for replacement, the capsule inlet port 11 may be
sealed
with the attached rubber seal encl cap 18, which prevents escape of any waste
material 15
from the interior body 13 of said filter capsule assembly 10.
In Figure 3 of the drawings is further shown a view of another amalgam filter
capsule assembly 10. This time; the capsule assembly accommodates an alternate
filter
configuration 19 especially designed to withstand collapse of its fibrous
filtering material
through amalgam waste material being drawn against its surface area by the
system's
vacuum action.
