Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
CA 02832937 2013-11-13
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RADIANT TUBE HEATER
This is a divisional of Application No. 2,523,295 filed October 13, 2005.
BACKGROUND OF THE INVENTION
FIELD OF THE INVENTION
This invention relates to a radiant heater and in particular to a radiant
heater for
outdoor use.
DISCUSSION OF THE PRIOR ART
In general, there are several drawbacks to currently available radiant tube
heaters. For example, most such heaters are single or dual input units. There
are
some systems which have a variable input utilizing a variable speed control
vacuum
pump in combination with a negative pressure gas valve (see CA 2,040,095, T.
P.
Seel). When the vacuum is increased or reduced, the change in pressure affects
a
negative pressure sensitive regulator in the gas valve to vary the amount of
fuel to a
burner. Another product on the market employs a gas valve using a source of
compressed air to actuate a valve regulator and vary the fuel pressure which
changes
the input to a burner (see CA 2,239,956, Merritt et al). Both systems use air
pressure
to actuate a fuel regulator on a gas valve.
Another radiant heater problem involves outdoor patio heater systems. Most
outdoor patios do not have an overhead structure for the installation of
heaters. At
present, overhead patio heaters require an awning, roof or a custom made
support
system for installation. Custom made support systems require on-site cutting,
welding
and fabrication of material to build an assembly of sufficient structural
integrity to
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support heaters and withstand the elements of nature. Some patio heaters
include post
mounted "mushroom" style heaters attached to tubes, which are embedded in
concrete
or surface mounted on a patio. Disadvantages of these types of structures are
that a
tube or post is required for every heater, taking up space on a patio.
Moreover, gas
and/or electrical lines include underground pipes and conduits. During new
construction, supply lines must be buried prior to the installation of the
patio surface. In
the case of an installation on an existing patio, the patio surface must be
demolished to
an extent sufficient to permit installation of underground fuel and/or
electrical supply
lines which is a costly undertaking.
Yet another problem with radiant heaters for patios is that the heat level or
output of currently available patio heaters is controlled manually. If it is
too hot or cold
on a patio, it is necessary to adjust the heater manually to vary the amount
of heat
emanating from the heater. Moreover, existing radiant tube heaters are
operated using
a high voltage such as 110 or 220 volts. Some components of currently existing
heating units are low voltage, namely 24 volts. Such units utilize a step down
transformer mounted inside a burner box housing to provide the 24 volts
required for
the low voltage components. One of the key elements of the heaters is a blower
for
providing combustion air which requires high voltage for effective operation.
GENERAL DESCRIPTION OF THE INVENTION
An object of the present invention is to provide solutions to the above-
identified
problems in the form of a relatively simple, variable input, radiant tube
heater, which is
cost effective and easy to produce. The space requirements for such a system
are
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relatively small, the components are readily available, and the system is easy
to
operate.
Another object of the invention is to provide a modular support system for
radiant
patio heaters which is easy to assemble on site, and which can readily be
secured to
existing patio surfaces using standard, readily available fasteners.
Yet another object of the invention is to provide a low voltage radiant
heater,
which is relatively safe to operate, easy to install thus requiring low skill,
cost effective,
and has decreased space requirements because there are fewer components inside
of
the heater burner box. Because of the low voltage there is no chance of
electrocution,
no need for special protected wire and installation can be effected without an
electrician.
According to one aspect the invention relates to a variable input, radiant
tube
heater comprising a housing; a burner in said housing; a reflector connected
to said
housing; a burner tube in said housing; a gas inlet line for introducing fuel
into said
burner; a blower attached to said housing for blowing air into said housing; a
24 volt
motor in said blower for operating the blower; a gas pressure regulator in
said gas inlet
line for regulating the flow of fuel to the burner; and a transformer remote
from said
heater for supplying 24 volt power to said blower motor.
According to another aspect, the invention relates to a variable input,
radiant
tube heater comprising a housing; a burner in said housing, a reflector
connected to
said housing; a burner tube in said housing; a gas inlet line for introducing
fuel into said
burner; a blower attached to said housing for blowing air into said housing; a
gas
pressure regulator in said gas inlet line for regulating the flow of fuel to
the burner; said
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regulator including a valve in said gas inlet line, and a valve operator for
opening and
closing said valve; and an electrical control connected to said valve operator
for
controlling operation of said valve operator.
According to yet another aspect the invention relates to a modular supporting
system for outdoor radiant heaters comprising a frame including at least one
hollow
beam for receiving fuel and electrical lines and supporting a radiant heater;
a plurality of
posts for supporting said beam at ends thereof; and saddles for connecting
said beam
to said posts, each said saddle having a closed bottom end, side walls and an
open top
end.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is described below in greater detail with reference to the
accompanying drawings, wherein:
Figure 1 is a partly sectioned view of the inlet end of a low voltage radiant
tube
heater in accordance with the present invention;
Figure 2 is a partly sectioned view of the inlet end of a variable gas input
radiant
tube heater in accordance with the present invention;
Figure 3 is a cross-sectional view of a gas inlet housing used in the heater
of Fig.
2;
Figure 4 is a schematic isometric view of a support system for a patio radiant
heater assembly with an automatic temperature control in accordance with the
present
invention;
Figure 5 is a collection of isometric views of elements of the support system
of
Figs. 4.; and
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*
Figure 6 is a schematic cross-sectional view of a burner and controls for the
burner used in the assembly of Fig. 4.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to Fig. 1, a radiant heater in accordance with the invention
includes a
housing 1 carrying a burner 2, a reflector 3 and a burner tube 4. Gas is fed
into the
burner 2 via an inlet line 6 containing a valve 7. Combustion air is fed
through one end
of the housing 1 into the burner tube 4 by a blower 8. In accordance with a
first aspect
of the present invention, the motor 9 of the blower 8 is a 24 volt motor. High
voltage is
fed via lines 10 from a source thereof to a transformer 11, which is mounted
on a wall
or other location remote from the radiant heater. The transformer 11 is
connected to
the blower motor by lines 12. Taps 13 can draw low voltage from the lines 12
for
feeding current to other low voltage components of a burner assembly.
' With reference to Fig. 2, a variable input, radiant tube heater in
accordance with
the invention includes most of the basic components of the heater of Fig. 1,
namely a
housing 1 carrying a burner 2, a reflector 3, a burner tube 4, a gas inlet
line 6 and a
blower 8. A gas pressure regulator indicated generally at 15 is inserted into
the inlet
line 6 for regulating the flow of fuel to the burner 2. The pressure regulator
15 can be
integral with an on/off gas valve, i.e. both elements can be defined by a
single
component.
As best shown in Fig. 3, the pressure regulator 15 includes a casing 16 with a
resilient partition 17, e.g. a diaphragm extending thereacross. Fuel entering
the casing
16 from the inlet line 6 is discharged to the burner 2 via a line 19. The top
end of the
gas inlet line 6 can be closed by a valve plate 20 mounted on the bottom end
of a valve
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stem 21. The valve stem 21 extends through the partition 17 and the top end 23
of the
casing 16 to a valve operator defined by a solenoid or stepper motor 24, which
is
adapted to move the valve stem 21 and the plate 20 up or down to open and
close the
valve as well as to regulate the amount of fuel flowing from the top end of
the inlet line
6. A helical spring 26 on the valve stem 21 above the partition 17 regulates
fuel
pressure as it relates to incoming fuel pressure from the line 6. The spring
pressure is
altered by the solenoid or stepper motor 24 to allow a selected amount of fuel
to flow to
the burner 2. When a stepper motor is used to cause valve stem movement and/or
spring tension, the motor is reversible for opening and closing the valve.
Operation of
the solenoid or stepper motor 24 is controlled by a control 27 which can be
adjusted
manually or by means of a thermostat (not shown). The control 27 is connected
to the
solenoid or stepper motor 24 by lines 28 and to a source of electrical power
by lines 30.
The solenoid or stepper motor 24 is sensitive to the amount of electrical
power it
receives. The control 27 employs a rheostat or some type of pulse generator
which is
manually or automatically (using a thermostat) manipulated.
The above described system is cost effective and easy to produce. The space
requirements for components is relatively small, and the components are
readily
available. Finally, the system is simple to operate.
The support system of the present invention is a modular, track system which
is
easy to assembly on site, and which can readily be secured to existing patio
surfaces
using industry standard fasteners.
Referring to Figs. 4 and 5, the patio heater support system of the present
invention includes a rectangular frame indicated generally at 32 supported by
a plurality
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of posts 33. The posts 33 are mounted on or in baseplates 34 which are bolted
or
otherwise connected to a patio surface 36. The frame 32 is defined by a
plurality of
generally U-shaped beams 37, which may include inwardly extending
strengthening
flanges 38 (Fig. 5) on the top ends thereof. The beams 37 are connected to the
posts
33 by a variety of mounting saddles including end mounting saddles 40 and 41,
and
intermediate mounting saddles 42.
As best shown in Fig. 5, one form of end mounting saddle 40 includes a bottom
plate 43, which a sleeve 44 extending downwardly therefrom for mounting on the
top
end of a post 33. An end plate 45 is used to connect the saddle to one side of
a beam
37. A pair of side plates 47 at the other end of the plate 43 are used to
connect the
saddle to a second beam 37 perpendicular to the beam connected to the plate
45.
Gaps 48 between the end plate 45 and the side plates 47 are adapted to receive
the
ends of other beams when interconnecting beams perpendicular to each other.
The end mounting saddle 41 includes a baseplate 49 with a sleeve 50 extending
downwardly therefrom, an end plate 51 and a pair of side plates 52. The saddle
41 is
used on the end of a central beam 37 when the frame 32 is large enough to
require two
contiguous, rectangular sections.
The intermediate mounting saddle 42 includes a baseplate 54, a sleeve 55
extending downwardly from the baseplate 54 and a pair of sides 56. The saddle
42 is
used between the ends of a beam 37 for supporting the beam in an elevated
position.
A mounting bracket 58 is used to connect a pair of beams 37 end to end on
opposite sides of a third beam 37 perpendicular to the first two beams. The
bracket 58
includes a baseplate 59 and a pair of L-shaped sides 60 extending inwardly
from each
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end of the baseplate 59 for attachment to a pair of beams 37. A third beam 37
is
inserted between the sides 60 perpendicular to beams resting on the baseplate
59
between the ends of such sides 60.
Beams 37 can be spliced end to end using a generally U-shaped splicer 62
defined by a baseplate 63 and a pair of rectangular sides 64. An L-shaped end
cap 66
is used to close any open ends of the beams 37 at the corners of the finished
frame 32.
A bracket 68 is used to connect the free end of a beam 37 to a wall 69 of a
building or
to another vertical structure such as a fence to anchor the support structure
in position.
The bracket 68 includes a baseplate 70, side walls 71 and short end walls 72.
Bolts or
screws extend through the end walls 72 into a vertical support structure, and
bolts or
screws extending through the sidewall 71 connect the bracket to a beam 37
resting on
the baseplate 70.
Referring to Figures 4 and 6, the beams 37 support a plurality of radiant
heaters
75. Gas lines 6 to the heaters are housed in the beams 37, which also carry
electrical
wires (Fig. 6) for operating the blower 8 and a gas flow regulator 15.
The automatic temperature control system includes a control 77 and an infrared
sensor 78 suspended from the center of the frame 32 (Fig. 4). The control 77
and
sensor 78 can be mounted at other locations on the frame 32, and more than one
sensor could be used. Electrical power for operating the system is fed to the
control via
lines 10, a transformer 11 and lines 80. The controller 77 is also connected
to a remote
control panel 81 which can be mounted in a post 33 (Fig. 4). Lines 82 connect
the
control 77 to the blower 8 and to the gas pressure regulator 15.
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In operation, the patio surface 36 is heated by infrared waves 83 (Fig. 6)
from
the heaters 75. An infrared beam 85 from the sensor 78 is aimed at a target,
e.g. the
surface 36 of the patio or a table. The reflected beam provides an indication
of the
temperature of the target, and the control 77 adjusts the flow of current to
the blower
and to the gas pressure regulator 15 to vary the heat output of the radiant
heaters 75.
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