Note: Descriptions are shown in the official language in which they were submitted.
CA 02285808 1999-10-13
METHOD AND APPARATUS FOR RECYCLING GRAY WATER
SCOPE OF THE INVENTION
The present invention relates to a water saving apparatus and more
particularly, to an
apparatus adapted to collect and recycle household, industrial or commercial
gray water prior to
municipal and/or septic waste treatment for secondary use in flushing toilets
or urinals.
BACKGROUND OF THE INVENTION
Gray water, namely water which is discharged from baths, showers, sink drains,
or
washing machines, typically is drained directly into a septic system or
municipal sanitary sewer
for treatment. Increasingly, however, sewage treatment facilities have been
unable to cope with
the volumes of sewage. This, in turn, has resulted in untreated sewage being
discharged directly
into the environment where it poses a threat to the health of humans, animals
and plant life.
In areas where drought conditions exist or where water supply or delivery is
limited, as
for example, in water well or cistern supplied dwellings, the reliable supply
and conservation of
water is of increasing concern. In particular, sustained periods of drought
may result in
individuals having insufficient water for drinking or washing, giving rise to
the need to either
import water by truck or construct extensive irrigation systems or damming
systems, which in
turn may be environmentally harmful.
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In certain areas, water conservation efforts have resulted in laws mandating
the
installation of toilets which operate with a reduced water volume of six
litres or less. In addition
to the added expense of retrofitting exiting plumbing fixtures, such toilets
have proven less
reliable than conventional toilets which operate with larger water flows and
often necessitate
multiple flushes.
SUMMARY OF THE INVENTION
The present invention seeks to provide a compact recycling system which
enables a user
to recycle household, commercial or industrial gray water for secondary use
prior to septic or
sanitary treatment, and most preferably for secondary use to provide the
required flushing
volume for toilets, urinal cisterns or the like, hereinafter collectively and
generally referred to as
toilet cisterns.
Another object of the invention is to provide a compact system for recycling
gray water
which may be used by individual home or cottage owners to minimize both water
consumption
and the volume of sewage output.
A further object of the invention is to provide a gray water recovery system
which is both
economical to produce and easy to install.
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In furtherance of at least some of the foregoing objects, the present
invention provides a
gray water recycling system which is adapted to recirculate household,
commercial or industrial
gray water for secondary use prior to its discharge into a sewer system or
septic bed. More
particularly, the present system includes a reservoir which is adapted to
receive and retain therein
gray water from bath tubs, showers, sink drains or washing machines. An outlet
from the
reservoir is provided in fluid communication with infill line of a toilet or
urinal cistern. In use,
gray water which is collected in the reservoir is subsequently fed therefrom
through the outlet
and via the infeed line to the toilet tank or cistern to provide the necessary
flushing action.
The reservoir outlet may be located vertically above the toilet cistern to
provide the gray
water supply under a gravity feed. Alternately, the reservoir outlet could
also be positioned at or
vertically below the toilet cistern, and the gray water pumped from the
reservoir into the toilet
cistern by means of an electric or manually operated pump.
Optionally, a bromine, chlorine or other chemical dispenser may be provided in
the
reservoir to periodically supply chemicals to disinfect the gray water and/or
neutralize any
phosphates or the like which may exist in the gray water prior to its reuse.
To ensure that adequate water is supplied to the toilet cistern, the reservoir
may be
provided with a float activated switch which is operable to actuate valuing
and/or a pump to
supply either additional potable water directly to the reservoir or directly
to the outfeed line.
When the gray water level in the reservoir reaches a predetermined minimum
level, the float
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activated switch opens the valuing or activates the pump to provide a reliable
supply of water to
the toilet cistern.
Most preferably, the reservoir outlet is spaced a distance above the bottom of
the
reservoir to enable the settling of any sediment or sludge which may be
entrained in the reservoir
therein. An overflow outlet may also be provided at an uppermost end of the
reservoir to permit
the draining of excess gray water, if necessary.
Accordingly, in one aspect the present invention resides in a gray water
recovery
apparatus comprising,
(a) a holding tank;
(b) an inlet extending into the holding tank for supplying an inflow of gray
water
therein;
(c) an outlet leading outwardly from the holding tank for enabling the outflow
of gray
water therefrom;
(d) a conduit coupling the outlet to a toilet tank; and
(e) wherein the inlet is provided at a position spaced vertically above the
outlet.
BRIEF DESCRIPTION OF THE DRAWINGS
Reference is now made to the following detailed description taken together
with the
accompanying drawings in which:
CA 02285808 1999-10-13
Figure 1 shows a schematic view of a gray water recovery system using a gray
water
recovery apparatus in accordance with the present invention; and
Figure 2 shows a partial schematic view of the gray water recovery apparatus
of Figure 1.
DETAILED DESCRIPTION OF THE INVENTION
Reference is now made to Figure 1 which shows a gray water recovery system 10
in
accordance with the preferred embodiment of the invention, and which is used
to recycle
household gray water prior to its discharge into a municipal sewer system. The
gray water
recovery system 10 includes a recovery apparatus 12 which is adapted to
receive and temporarily
store waste gray water 8 fed directly from a sink 14. As will be described
hereafter, the stored
gray water 8 is then redirected to a toilet cistern 15 for secondary use in
providing the required
toilet flushing action prior to municipal treatment.
The gray water recovery apparatus 12 is provided in direct fluid communication
to a sink
drain 16 via conventional ABS or PVC drain pipe 18. The recovery apparatus 12
includes a
PVC or other plastic tank or water reservoir 20 sized to hold between 20 and
300 gallons of
waste water and more preferably between about 100 and 200 gallons. The
reservoir 20 is
characterized by an upwardly located water inlet 22, a gray water outlet 24,
and a fluid overflow
outlet 26 which is spaced above the outlet 24 and marginally below the inlet
22. The drain pipe
18 is coupled to the inlet 22, such that gray water 8 which drains from the
sink 14 may move
directly along the pipe 18 and into the reservoir 20. Preferably, the
reservoir 20 and reservoir
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inlet 22 are provided at a height vertically below the sink drain 22, such
that the gray water
which is drained from the sink 14 moves under gravity.
In any alternate embodiment, the inlet 22 and/or reservoir 20 could be
positioned at a
height vertically above the sink 14. With such a configuration, waste gray
water 8 could be
pumped vertically upwardly through the inlet 22 and into the reservoir 20 by
means of a pump
(not shown).
The outlet 24 is shown as being provided through a sidewall of the reservoir
20 at a
position spaced a distance of between approximately 10 to 20 inches above the
reservoir bottom
28. The spacing of the outlet 24 above the reservoir button 28 advantageously
permits the
collection and retention of any accumulated sludge or silt 25 which is
entrained within the
reservoir 20. A conventional PVC or ABS reservoir outlet conduit pipe 30
connects the outlet 24
to a pump 32, providing fluid communication therebetween. Figure 1 shows best
a pump outlet
conduit 34 leading from the pump 32 which in turn is connected to the cistern
15, with the pipe
30, pump 32 and pipe 34 providing fluid communication between the reservoir 20
and the toilet
tank or cistern 15.
The pump 32 may be selectively activated from a non-operating to an operating
configuration. In the non-operating configuration, the pump 32 prevents
movement of gray
water 8 therepast. This in turn results in the accumulation and increase in
the volume of gray
water 8 stored within the reservoir 20. When operated, the pump 32 draws gray
water 8 from the
reservoir 20 through the outlet 24 and reservoir outlet pipe 30 in the
direction of arrow 35
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(Figure 1). Gray water 8 is moved by the pump 32, along the pump outlet
conduit 34 and into
the cistern 15.
In a simplified embodiment, it is envisioned that the pump 32 would be used to
supply
gray water 8 to the toilet cistern 15 upon demand by the triggering of a float
activated switch 36
located within the cistern 15, and which is electrically linked to the pump.
Alternately, the pump
32 may be used to fill a secondary storage tank (not shown) which is provided
either under
pressure or spaced vertically above the cistern 1 S to enable the supply of
gray water under
gravity.
Figure 2 shows best the overflow outlet 26 as being used to maintain the level
of gray
water 8 in the reservoir 20 at a maximum level, and preventing the backflow of
gray water 8
along the conduit tube 18. The overflow outlet 26 is provided in direct fluid
communication
with the sanitary sewer and permits the escape of gray water 8 from the
reservoir 20 in the
direction of arrow 37. This enables excess gray water 8 to directly bypass the
toilet for
treatment. In the embodiment shown, the outlet 26 is positioned marginally
beneath the reservoir
inlet 22. It is to be appreciated, however, that the overflow outlet 26 could
be provided above
the inlet opening 22 by altering the configuration of the conduit tube 18, or
by positioning a
check valve therein to prevent the backflow of gray water 8 through the inlet
22 and to the sink
14.
Figures 1 and 2 show best a float switch 40 as being located within the
reservoir 20.
Most preferably, the float 40 is positioned within the reservoir tank 20
marginally above the
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outlet orifice 24. The float switch 40 is adapted for vertical movement with
changes in the level
of gray water 8 stored in the reservoir 20. The float switch 40 is provided in
electrical
communication with a solenoid valve 42 which regulates water flow along a
potable water
supply line 44. The supply line 44 is in turn connected to the conduit tube
18, upstream of the
reservoir inlet 22. With this configuration, when insufficient gray water 8
remains in the
reservoir 20, the float switch 40 activates the solenoid valve 42 to an open
configuration and
provides the flow of additional potable water from the supply line 44 into the
reservoir 20 via
inlet 22. Although not shown, alternately, the solenoid regulated potable
water supply line 44
could be provided in direct communication with the conduit 34 to supply
potable water directly
to the toilet cistern 15, if needed.
Figures 1 and 2 additionally show the apparatus 12 as including a chemical
dispenser 48
which is adapted for continuous, timed or intermittent operation. The
dispenser 48 is used to
introduce gray water treating chemicals such as bromine, chlorine or the like
into the reservoir
20, to disinfect the gray water 8 and/or neutralize any phosphates or other
contaminants which
may exist therein.
Although the preferred embodiments describe the use of the gray water recovery
apparatus 12 as supplying gray water 8 to a toilet cistern 1 S, the invention
is not so limited. It is
to be appreciated that the present apparatus may be used to supply gray water
for secondary use
in flushing urinals in home, commercial or industrial environments, without
departing from the
spirit and scope of the invention.
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While the preferred embodiment of the invention describes the gray water
recovery
apparatus 12 as being used to recycle gray water 8 from a sink 14, it is to be
appreciated that the
apparatus sink 12 could equally be used to recycle gray water 8 from other
single or multiple
sources, including by way of non-limiting examples, bathtubs, showers and/or
washing
machines.
While the preferred embodiment discloses the reservoir 20 as being a preferred
size
between 100 and 200 gallons when adapted for residential use, it is to be
appreciated that larger
or smaller sized reservoirs may also be used, depending upon the intended
application.
Although the detailed description of the invention describes and illustrates
various
preferred embodiments, the invention is not so limited. Many modifications and
variations will
now occur to persons skilled in the art. For a definition of the invention,
reference may be had to
the appended claims.
