Note: Descriptions are shown in the official language in which they were submitted.
BACKGROUND OF THE INVENTION
This invention relates to new and useful improve-
ments in the utilization of waste heat, particularly waste
heat which is in exhaust fluids from clothes dryers, sanitary
drains and the like.
Normally, this waste heat is not utilized inasmuch
as clothes dryers are usually vented exteriorly of the building
and sanitary drain water from sinks, dishwashers, baths and
the like is diverted directly to the sanitary sewer system.
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With the present day energy situation, any saving of
such waste heat is desirable.
SUMrlARY OF THE INVENTION
The present invention utilizes such waste heat by
passing the waste fluid be it air or water, through a heat ex-
changer through which also passes a water carrying element con-
nected in series between the conventional cold water inlet to
the building and the hot water tank normally used to raise the
temperature of this water before use. This means that the water
in many instances, is tempered insofar as the temperature is
concerned thus utilizing this waste heat and lowering the re-
quirements of the source of heat for the hot water tank.
One aspect of the invention consists of a heat exchanger
and storage tank assembly to be used in conjunction with a source
of heat from waste fluids, including a source of water for said
storage tank and a connection from said storage tank to a con-
ventional hot water heater tank, said heat exchanger and storage
tank assembly comprising in combination a heat exchanger and a
storage tank operatively connected thereto, said heat exchanger
including a container and a water carrying element therein, in-
let conduit means connecting said container to said source of
waste fluid, outlet conduit means connected to said container
for discharge of said waste fluid after same has passed through
said container, said water carrying element within said container
having inlet and outlet ends and being in series between said
source of water and said storage tank, the water from said source
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of water flowing through said element and to said storage tank,
a water re-circulating conduit extending from said storage tank
to the inlet end of said water carrying element, and a one-way
valve in said water circulating conduit whereby water flows by
convection, from said storage tank to said inlet end of said
water carrying element, through said water carrying element and
back to said storage tank, said storage tank being situated at
a level above said heat exchanger.
With the foregoing in view, and other advantages as
will become apparent to those skilled in the art to which this
invention relates as this specification proceeds, my invention
consists essentially in the arrangement and construction of parts
all as hereinafter more particularly described, reference being
had to the accompanying drawings in which:
DESCRIPTION OF THE DRAWINGS
Figure 1 is a schematic partially cross sectioned view
of the invention shown in conjunction with a sanitary drain sys-
tem.
Figure 2 is a view similar to Figure 1, but showing
the invention incorporated with heated air exhausting from, for
example, a clothes dryer.
In the drawings like characters of reference indicate
corresponding parts in the different figures.
DETAILED DESCRIPTION
.
Proceeding therefore to describe the invention in de-
tail, the invention consists of a storage tank 10 and a heat ex-
changer assembly collectively designated 11 with the storage
tank situated at an elevation above the heat exchanger assembly,
the purpose of which will be hereinafter described.
The storage tank is a conventional closed tank having
a water inlet conduit 12, a water outlet conduit 13 leading to
the conventional hot water tank Inot illustrated) and a circu-
lation conduit 14 extending from adjacent the base of the stor-
age tank 10, the purpose of which will hereinafter become appar-
ent.
The heat exchanger assembly consists of a closed con-
tainer 15 having a smaller container 16 situated therein and in
the present embodiment, both of these tanks are cylindrical with
the smaller tank 16 being substantially concentrically placed
within the outer tank 15. However, it will be appreciated that
any other convenient shape can be utilized.
The smaller container 16 is secured by the upper end
thereof to the upper side 17 of the closed tank 15 and hence is
in itself a closed upper ended tank or container.
The lower end 18 of the smaller container terminates
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spaced from the base 19 of the closed container 15 and this
lower end 18 is preferably open.
A water carrying element collectively designated 20
is situated within the containers 15 and 16 and preferably
takes the form of a copper coil or similar water carrying ele-
ment adapted to convey water through the heat exchanger.
In this embodiment, the coil, which may be made from
any convenient material, includes a first portion 21 situated
within the smaller container 16 and having a plurality of sub-
stantially constant pitch and constant diameter coils extending
from adjacent the upper end of the smaller container 16 to ad-
jacent the lower end 18 thereof whereupon these coils expand in
diameter and continue upwardly at the same pitch and substan-
tially with the said larger diameter spaced around the smaller
container 16 in the volume defined between the smaller container
16 and the closed container 15, said outer coils being identi-
fied by reference character 23.
The upper end of the smaller or inner coils 21 is con-
nected to a water inlet conduit 24 which in turn is connected to
the source of cold water supply (not illustrated) normally pro-
vided and the upper end of the outer coils 23 is connected to
an outlet conduit 25 which extends to the aforementioned storage
tank inlet conduit 12.
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A waste fluid inlet conduit 26 is provided and in
this embodiment, consists of a conduit extension extending to
the associated clothes dryer outlet (not illustrated). This
enters the smaller inner container 16 at the upper end 17 there-
of.
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~ utl~t eollcluit 27 extends from the upper
end of the outer casing 15 externally of the smaller casing
16.
The aforementioned circulating conduit 14 connects
with the water inlet conduit 12 at the T junction 28 and this
conduit 14 is provided with a one-way valve 29 allowing water
to move only in the direction of arrow 30.
In operation, and under normal circumstances, water
will pass through the hot water heater to the outlet (not il-
lustrated) under pressure of water entering the inlet 24,passing through coils 21 and 23 and through the storage tank
10 .
However, when the clothes dryer (not illustrated)
is in operation, warm air therefrom at approximately 52C,
will enter the heat exchanger and will transfer heat to the
water within coils 21 and 23, said water normally entering
the coils at approximately 14C.
This, of course, tempers the temperature of the
water entering the storage tank 10 and hence the hot water
heater tank (not illustrated).
If water is being drawn from the hot water tank
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then water will normally flow through the heat exchanger,
through the storage tank and hence to the hot water tank, picking
up heat from the clothes dryer if it is in operation. However,
if water is not being drawn off during the operation of the
clothes dryer, the position of the tank 10 superior to that of
the heat exchanger 11, will cause water to circulate through con-
duit 14, through the coils 21 and 23 and back to the storage tank
10 with one-way valve 29 preventing cold water from entering from
the source of cold water. The convection circulation thus set up
will gradually raise the temperature of the water within the
storage tank 10 so that when it is demanded by the hot water tank,
it is already tempered thus requiring less heat from the hot
water heater to raise it to the desired temperature.
It should be observed that a condensate drain 31 is
provided at the base of container 15 with a P trap 32 therein.
This is necessary since air entering the container 15 will be
at approximately 100% relative humidity and air leaving will be
at a lower temperature so that condensation and water accumula-
tion will occur.
Dealing next with the embodiment shown in Figure 1,
where similar parts are utilized, similar reference characters
have been used.
In this particular embodiment, the source of waste
fluid takes the form of warm water from sinks, baths, dish-
washers and the like. It normally passes through a drain
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c~nduit 33 t~ s.ll~it.lly sew~r (l~t illust.rated). In this
embodiment, a temperature sensing valve 34 is provided in
conduit 33 just prior to same entering the heat exchanger
11 in a position similar to conduit 26. This temperature
sensing valve by-passes water passing through conduit 33
which is below a pre-determined temperature, said by-passed
water entering the sanitary sewer through the by-pass con-
duit 35.
If however, the water is of a sufficient tempera-
ture, it enters the heat exchanger and passes therethrough ina manner similar to the air in the previous embodiment, over-
flowing through outlet 36 and hence to the sanitary sewer via
drain conduit 37.
Otherwise, the operation of this embodiment is iden-
tical with that of the previously described embodiment, onceagain tempering the water to the storage tank and hence the
water passing to the hot water tank.
Since various modifications can be made in my in-
vention as hereinabove described, and many apparently widely
different embodiments of same made within the spirit and scope
of the claims without departing from such spirit and scope,
it is intended that all matter contained in the accompanying
specification shall be interpreted as illustrative only and
not in a limiting sense.
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