HEAT EXCHANGE UNIT

ECHANGEUR DE CHALEUR

English Abstract

ABSTRACT
A heat exchange unit incorporating an electrically
heated boiler mounted within a housing, the boiler
having extending therethrough at least one air tube
arranged so that air can be drawn or blown therethrough
to be heated by the boiler before it is passed from
the housing through an outlet, the electrically
heated boiler having a supply tank connected thereto
to maintain a desired water level within the boiler,
the boiler having a steam outlet in the upper end
thereof through which steam can flow to one or more
condensor tubes or coils in which the steam condenses
before flowing under gravity back through an inlet
to the boiler, the latent heat of evaporation given
up by the condensing steam can be collected by
surrounding the condensor with air or water to
be heated. The housing within which the boiler
is mounted can have a series of baffles or scoops
which direct the flow of drawn or blown air so that
it passes through successive levels of air tubes
through the boiler before being passed over the
boiler and out the outlet in the housing.

Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A heat exchange unit incorporating an electrically
heated boiler mounted within a housing, the boiler having
extending therethrough at least one air tube arranged so
that air can be drawn or blown therethrough to be heated
by the boiler before it is passed from the housing
through an outlet, the electrically heated boiler having
a supply tank connected thereto to maintain a desired
water level within the boiler, the boiler having a steam
outlet in the top thereof through which steam can flow
to one or more condensor tubes or coils in which the steam
condenses before flowing under gravity back through an
inlet or inlets to the boiler, the latent heat of
evaporation given up by the condensing steam can be
collected by surrounding the condensor with air or water
to be heated.
2 A heat exchange unit as claimed in claim 1 wherein
the housing within which the boiler is mounted has a
series of baffles or scoops which direct the flow of
drawn or blown air so that it passes through successive
levels of air tubes through the boiler before it is passed
over the top of the boiler and from the outlet in the
housing.
3. A heat exchange unit as claimed in claim 1
wherein the connection between the supply
tank and the electrically heated boiler is a pipe
arranged to allow a back flow of heated water from
the boiler to the supply tank to heat the water
therein.

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4. A heat exchange unit as claimed in claim 3,
wherein the end of the pipe within the supply tank extends to
a point near to the base of the supply tank.

5. A heat exchange unit as claimed in claim 1,
wherein the steam outlet in the top of the boiler is con-
nected to a coil or to a series of tubes through which the
steam flows and in which the steam condenses before it is
returned to the boiler.

6. A heat exchange unit as claimed in any one of
claims 1 to 3, wherein the condensor tubes or coils are
placed within a hot water reservoir which is heated by the
latent heat of evaporation given up by the condensing steam.

7. A heat exchange unit as claimed in claim 5,
wherein the coils or tubes are mounted within a casing
through which air can circulate so that air can surround
the coils or tubes and be heated, the heated air being
allowed to flow from air outlets, louvres in the
casing to allow the warm air to heat the area in which the
casing is situated.

8. A heat exchange unit incorporating an electri-
cally heated boiler mounted within a housing, the housing
having extending therethrough at least one air tube arranged
so that air can be drawn or blown therethrough to be heated
by the heated water within the boiler before the heated air
is passed from the housing through an outlet, the electri-
cally heated boiler having a supply tank connected thereto
to maintain a desired water level within the boiler and
supply tank, the boiler having at least one pair of outlets
and inlets therein, the outlets and inlets being connected
to a hot water cylinder so that water therein can flow under
a thermosyphon effect to heat the water within the hot water
cylinder.




9. A heat exchange unit as claimed in any one of
claims 1 to 3, wherein the outlet from which heated air is
blown or drawn is connected to ducting to transfer the
heated air to where it is required within a building.

10. A heat exchange unit as claimed in claim 1,
when the boiler is constructed from a heavy gauge metal
material and the housing within which it is mounted is con-
structed from a lighter gauge sheet metal material.

11. A heat exchange unit as claimed in claim 10,
wherein the housing has in a wall thereof an inspection
cover which allows access to the heating elements, fan and
thermostats therein.

12. A heat exchange unit as claimed in any one of
claims 1 to 3, wherein the housing is formed as a cavity
wall within which a layer of insulation material is fitted.

13. A heat exchange unit as claimed in any one of
claims 1 to 3, wherein the heat exchange unit is sited in
a commercial or home situation.




11

Description

835~
This invention relates to a heat exchange
unit and more particularly relates to a heat
exchange unit which can be used in both industrial
and home situations to provide heated air and/or
heated water.
An object of the present invention is to
provide a heat exchange unit which may be used
in a home or industrial situation, which heat
exchange unit provides from a single source of heat
a supply of heated air and/or a supply of heated
water.
A further object of the present invention
is to provide a heat exchange unit which offers
to the public a useful alternative choice.
Further objects and advantages of the present
invention will become apparent from the following
descriptions which are given by way of example only.
According to a first aspect of the present
invention there is provided a heat exchange unit
incorporating an electrically heated boiler mounted
within a housing~ the boiler having extending there-
through at least one air tube arranged so that -
air can be drawn or blown therethrough to be heated
by the boiler before it is passed from the housing
through-an outlet, the electrically heated boiler
having a supply tank connected thereto to maintain
a desired water level within the boiler, the boiler
having a steam outlet in the upper end thereof through
which steam can flow to one or more condensor tubes




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or coils in which the steam condenses be~ore flowiny
under gravit~ back through an inlet to the boiler,
the latent heat of evaporation given up by the
condensing steam can be collected by surrounding the
condensor with air or water to be heated.
The housing within which the boiler is mounted
can be provided with a series of baffles or scoops
which direct the flow of drawn or blown air so that
it passes through successive levels of air tubes
through the boiler before being passed over the
boiler and out the outlet in the housing.
The supply tank can be connected to the
electrically heated boiler by a pipe through which
water can pass to maintain the water leve? within
the boiler and supply tank at a predetermined level.
The end of the pipe can be arranged to allow a
back flow of heated water from the boiler to the
supply tank to heat the water therein.
The steam outlet in the upper end of the
boiler can be connected to a coil or to a series
of tubes so that steam can flow therethrough to
condense before being returned to the boiler. The
condensor coil or tubes can be fitted within a hot
water storage reservoir which is heated by the
latent heat or evaporation given up by the condensing
steam.
The steam outlet to the coil or tubes can
alternatively be mounted within a suitable casing
provided with air inlets so that air can surround

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the coil or tubes to be heated, the heated air being
allowed to flow via convection through outlets in
the casing to heat the area in which the casing is
situated.
According to a second aspect o~ the present
invention there is provided a heat exchange unit
incorporating an electrically heated boiler mounted
within a housing, the boiler having extending there-
through at least one alr tube arranged so that air
can be drawn or blow therethrough to be heated by
the heatea water within the boiler before it is
passed from the housing through an outlet, the
electrically heated boiler having a supply tank
connected thereto to maintain a desired water level
within the boiler and supply tank, the boiler having
at least one pair of outlets and inlets therein,
the outlets and inlets being connected to a hot
water cylinder so that water therein can flow under
a thermosyphon effect to heat the water within the
hot water cylinder.
The outlet from which heated air is blown or
drawn can be connected to ducting to transfer the
heated air to where~er it is required within a building.
Further aspects of the present invention which
should be considered in all its novel aspects will
become apparent from the following descriptions
which are given by way of example only.
Embodiments of the present invention will be
described with reference to the accompanying drawings

in ~hich:
Eigure 1: shows a section through a heat
exchange unit according to the present invention;
Figure 2: shows a section taken on the line
II - II through the heat exchange unit shown in

Figure l; and
Fi~ure 3: shows a plan view of an example of
housing in which the boiler of the heat exchange
unit can be mounted.
The heat exchange unit according to the present
invention can be used in a number of situations, for
example, in the home or in an industrial situation.
The present invention can, for example, be used as
a substitute for an open or closed type fire.
The example of heat exchange unit shown
includes an electrically operated boiler generally
indicated by arrow 1. The boile r is mounted within
a box shaped housing 2. The boiler 1 and the
outer housing 2 are preferably constructed from sheet
metal materials. The boiler 1 has at least one
electrically operated heating element 3 therein
and has on an end wall thereof a thermostat (not
shown). In the example shown the housing 2 has
in an end wall 4 thereof an inspection cover 5 which
allows access to the heating elements 3 and thermostat
for repair and/or maintenance purposes. The end
wall of the housing can also have mounted thereon
an on/off switch and/or an appropriate fuse or fuses
as required by the Electrical Wiring Regulations.


8~3~
It is also envisaged that the floor, walls and top
of the housing 2 can be formed as a cavity wall
(not shown) within which is positioned insulation
so as to reduce loss of heat therefrom.
The water level A within the boiler 1 is
maintained by a flow of water from a supply tank 7.
The water level A within the boiler 1 and supply
tank 7 are the same and are governed by a ball cock
valve 8 (Figure 3). The flow of water between
the supply tan~ 7 and the boiler 1 is by way of the
connecting pipe 9. The supply tank 7 can include
an overflow pipe 10.
The boiler 1 has extending therethrough a
number of air tubes 11 (shown dotted in Figure 1)
through which air can pass to be heated by the
hot water within the boiler 1. In the example of
boiler 1 shown there are three levels of air tubes
11 with six tubes 11 in each level. The open
ends 12 of the tubes 11 can be seen in Figure 3
The boiler 1 can include a drain pipe 13.
The boiler 1 when operating is a main source
of heat and the flow of hot air can be
controlled by a double bladed tangential fan 14 which
-draws or pushes air into inlet pipes 15. The inlet
pipes 15 direct air in the direction of the arrows
(Figure 1) through the first level of air tubes 11
against a baffle 17 at the other end of the housing 2
which baffle directs the flow to the middle level of air
tubes back to the first end of the housing 2 above
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the inlet pipes lS to a second baffle 17 which directs
the flow to the upper level of air tubes 11 at
the other end of which is a baffle 17 which directs
the air over the top 18 of the boiler 1 to the
outlet 16. The outlet 16 from the housing 2 can
be connected to ducting (not shown) to transfer
the heated air to wherever it is required within a
building. Alternatively the outlet 16 can be a
series of apertures or louvres near to the upper
edge of the housing 2 to allow air to be blown
into the space or room in which the housing 2 is
situated.
The flow of air around the boiler 1 can be
in the direction of the arrows shown in Figure 1,
that is, the cold air is initially blown through
the inlet pipes 15 and through successive levels
of the air tubes 11 before the air passes up and
over the top 18 of the boiler and through the
outlet 16.
The boiler 1 has in the -top 18 thereof a
steam outlet 19 through which steam flows to
-condensor tubes or coils 21 in which the steam
~ay condense giving up its latent heat of evaporation
'o the material surrounding the condensor tubes
or coils 21. The condensed water returning to
the boiler through the return pipe 20. The return
pipe 20 can have therein a pressure relief tube 22
draining back to the supply tank 7.
The condensor tubes or coils 21 can be
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9~33~
surrounded for example as shown in Figure 1 by water
in a hot water storage tank 23. The tank 23 can be
provided with additional heating elements (not shown)
as required Eor use during the summer when the
boiler 1 is not in use or when an extra supply of
hot water is required. The storage tank 23 is
provided with a supply outlet and inlet and insulatio~
in known manner.
As an alternative to the example shown the
steam outlet 19 from thè boiler 1 can be connected
to a radiator or to a series of coils (not shown)
within a casing which acts as a radiator heater.
The casing has air flowing therethrough or there-
around so that the area in which it is sited is
heated by conyection.
In use the boiler 1 according to the present
invention can be ~itted to supply at least heated
air/and or hot ~ater in the manner described.
Thus by this invention there is provided a
heat exchange unit ~or use in a home or industrial
situation which provides f~o~ a single source a
supply of heated air and~or a supply of heated water.
A particular example of the present invention
has been described herein by way of ex~mple and
it is envisaged that improvements and modifications
to the invention may take place without departing
from the scope of the appended claims.


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