GAS FIRED INFRARED RADIANT TUBE HEATING SYSTEM USING PLURAL BURNER ASSEMBLIES AND SINGLE GAS DELIVERY SYSTEM

SYSTEME DE CHAUFFAGE A TUBES RADIANTS A INFRAROUGE ALIMENTE PAR GAZ, COMPORTANT PLUSIEURS ENSEMBLES BRULEURS ET UN SEUL SYSTEME D'AMENEE DE GAZ

English Abstract

A gas fired infrared radiant heating system of improved thermal output. The
present invention solves problems associated with prior
art designs by providing a single gas delivery system for delivering
combustible gas to two or more burner assemblies. The invention
consists of a burner housing (10) with two or more burner assemblies (18),
each of which can be connected to a typical radiant tube
heat exchanger assembly (12). The homer housing contains a single gas delivery
system including a valve (14), a single control circuit
module (30), a single blower proving switch (50), and a single manifold (16)
which will distribute the gas to the multiple radiant tube heat
exchanger assemblies (12). In addition, in positive pressure configurations,
the burner housing will also have a single air fan (38), whereas
in negative pressure configurations of the heating system one or more exhaust
fans may be utilized. The foregoing design will provide a
higher thermal output without the heat distribution and installation cost
problems of the currently available infrared heaters.

French Abstract

L'invention concerne un système de chauffage radiant à infrarouge alimenté par gaz dont la puissance thermique est augmentée. Grâce à la présente invention, les problèmes associés aux dispositifs de l'art antérieur sont résolus par le fait que le système présenté comporte un seul système pour l'amenée de gaz combustible à au moins deux ensembles brûleurs. Le système selon l'invention est constitué d'un carter (10) et d'au moins deux ensembles brûleurs (18) dont chacun peut être relié à un ensemble échangeur de chaleur tubulaire radiant (12) classique. Le carter de brûleur contient un seul système d'amenée de gaz qui comporte une soupape (14), un seul module circuit de commande (30), un seul commutateur de détection d'air de ventilateur (50) et un seul collecteur (16) qui distribue le gaz aux différents ensembles échangeurs de chaleur (12) tubulaire radiant. En outre, lorsque le système de chauffage présente une configuration à pression positive, le carter de brûleur présente également un seul ventilateur (38), tandis que lorsque le système de chauffage présente une configuration à pression négative, il peut comporter plus d'un ventilateur d'évacuation. Le système présenté offre une puissance thermique supérieure sans présenter les problèmes relatifs à la distribution de chaleur et aux coûts d'installation connus avec les chauffages à infrarouge actuellement disponibles.

Claims

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1. A gas fired infrared radiant tube heating system for heating an
enclosed space, said system including two or more radiant tube heat
exchangers (12) positioned in the enclosed space which is to be heated,
each of the radiant tube heat exchangers having first and second ends;
the heating system being characterized by:
a common burner housing (10) which is connected to the first end
of the two or more radiant tube heat exchangers (12);
two or more separate burner assemblies (18) carried by the common
burner housing, there being one burner assembly (18) interconnected with
each of the radiant tube heat exchangers (12), each burner assembly
being capable of igniting and firing an associated radiant tube heat
exchanger (12); and
a single gas delivery system (14, 16, 30) mounted within the burner
housing and connected to a source of combustible gas, the single gas
delivery system being interconnected with the two or more separate
burner assemblies (18).
2. The gas fired infrared radiant tube heating system for heating an
enclosed space as set forth in claim 1 wherein the single gas delivery
system includes a single gas valve assembly (14).
3. The gas fired infrared radiant tube heating system for heating an
enclosed space as set forth in claim 1 or claim 2 wherein the single gas
delivery system includes a single manifold (16), the manifold having a
single inlet and two or more outlets, and wherein each of the burner
assemblies (18) is connected to one of the two or more outlets of the
single manifold.
4. The gas fired infrared radiant tube heating system for heating an
enclosed space as set forth in any one of claims 1 to 3 wherein the
single gas delivery system further includes a single control circuit
module (30) mounted within the burner housing, the control circuit
module monitoring ignition and operation of each of the burner
assemblies, and controlling the gas delivery.

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5. The gas fired infrared radiant tube heating system for heating an
enclosed space as set forth in any one of claims 1 to 4 further
characterized by the combination of a single fan (38) used to force
flame through the two or more radiant tube heat exchangers (12).
6. The gas fired infrared radiant tube heating system for heating an
enclosed space as set forth in any one of claims 1 to 3 wherein the
single gas delivery system further includes a single control circuit
module (30) mounted within the burner housing, the control circuit
module monitoring ignition and operation of each of the burner
assemblies, and controlling the gas delivery; and a single fan (38) used
to force flame through the two or more radiant tube heat exchangers
(12), the operation of the fan (38) being controlled by the single
control circuit module (30).
7. The gas fired infrared radiant tube heating system for heating an
enclosed space as set forth in claim 5 wherein the fan (38) is a exhaust
fan.
8. The gas fired infrared radiant tube heating system for heating an
enclosed space as set forth in claim 7 wherein each of the radiant tube
heat exchangers is connected at the second end to the exhaust fan (38).
9. The gas fired infrared radiant tube heating system for heating an
enclosed space as set forth in claim 5 wherein the fan (38) is a blower
fan connected to the burner housing (10).
10. The gas fired infrared radiant tube heating system for heating an
enclosed space as set forth in claim 9 wherein each of the radiant tube
heat exchangers (12) extends in a straight line away from the burner
housing (10), each of the radiant tube heat exchangers being connected
to a stack (48) at the second end.

Description

CA 02311520 2000-OS-25
WO 99/27307 PCTNS98/12528
GAS FIRED INFRARED RADIANT TUBE HEATING SYSTEM
USING PLURAL BURNER ASSEMBLIES
AND SINGLE GAS DELIVERY SYSTEM
TECHNICAL FIELD
The present invention relates generally to gas fired
infrared heaters, and more particularly to a gas fired
infrared radiant tube heating system which utilizes plural
burner assemblies mounted in a common housing along with a
single gas valve and a single control circuit module, the
flame from each of the plural burner assemblies being
forced through an associated radiant tube heat exchanger.
BACKGROUND OF THE INVENTION
Gas fired infrared radiant tube heaters have been
developed in many forms. They vary by input, length, size
of the radiant tube heat exchanger, also called an radiant
pipe or emitter tube, as well as by other factors.
Typical prior art patents are US 3,394,886, US 3,416,512,
EP 0 070 360, GB 2,189,314 A, CA 1,011,314, and
GB 2,274,703. There has been an increasing need for
heaters with greater thermal output. An infrared radiant
tube heater's output capacity is generally limited by the
type and size of the tubular heat exchanger connected to
it. Thus, there is an effective maximum fueling rate for
a radiant pipe of a given diameter and length. A major
drawback to the continuing trend of higher thermal output
from a single burner assembly is that the heat
distribution is generally poor. This is because as
fueling rates are increased for radiant pipes of a given
diameter and length, hot spots will be created. Unless
the building in which such a heater is installed is of
sufficient height, there will likely be uncomfortable
conditions below the hottest portion of the heat
exchanger. The easiest way to solve this problem is to
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install more heating systems at a lower thermal output
thus eliminating the large hot spot from a larger heater
and providing more even distribution of the infrared heat.
This method causes installation costs to be higher than
that of an installation with the higher thermal output
burners, as each burner system is provided with its own
valve and control circuit module.
OBJECTS AND SUMMARY OF THE INVENTION
It is an object of the present invention to provide a
gas fired infrared heater which provides higher thermal
outputs without the heat distribution and installation
cost problems of the currently available infrared heaters.
More particularly, it is an object of the present
invention to provide a gas tired infrared radiant tube
heating system for heating an enclosed space, said system
including two or more radiant tube heat exchangers, a
common burner housing which is connected to the two or
more radiant tube heat exchangers, two or more separate
burner assemblies carried by the common burner housing,
there being one burner assembly interconnected with each
of the radiant tube heat exchangers, each burner assembly
being capable of firing an associated radiant tube heat
exchanger, and a single gas delivery system mounted within
the burner housing and connected to a source of
combustible gas, the single gas delivery system being
interconnected with the two or more separate burner
assemblies.
It is a further object of the present invention to
provide a system of the type set forth above with a single
gas valve assembly.
It is yet another object of the present invention to
provide a system of the type set forth above with a single
manifold, the manifold having a single inlet and two or
more outlets, and wherein each of the burner assemblies is
connected to one of the outlets of the single manifold.
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It is another object of the present invention to
provide a system of the type set forth above with a
single control circuit module mounted within the burner
housing, the control circuit module monitoring ignition
and operation of each of the burner assemblies, and
controlling the single gas delivery system.
In accordance with this invention, the problems
associated with the prior art and other problems are
solved by providing a burner housing capable of igniting
and supervising a plurality of gas flames. Thus, the
invention consists of a burner housing with two or more
burner ports, each of which can be connected to a typical
radiant tube heat exchanger assembly. The burner housing
will contain a single gas valve, single control circuit
module, and single blower proving switch. In addition,
in positive pressure configurations it will also have a
single air fan. A manifold from the gas valve will
distribute the gas to the multiple burner assemblies.
The foregoing design will provide a higher thermal output
without the heat distribution and installation cost
problems of the currently available infrared heaters.
The foregoing objects and advantages of this
invention will be more fully understood after a
consideration of the following detailed description taken
in conjunction with the accompanying drawings in which
preferred forms of this invention are illustrated.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top view of a dual flame radiant tube
heating system of this invention utilizing an exhaust
fan.
FIG. 2 is a side cutaway view of the housing shown
in FIG. 1.
FIG. 3 is a sectional view taken generally along the
line A-A showing the flame igniter and the flame sensor.

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FIG. 4 is a somewhat schematic view of the electrical
controls, including the control circuit board module shown
in FIG. 2.
FIG. 5 is a schematic view of the gas valve.
FIG. 6 is a view similar to FIG. 1 but showing the
use of a blower fan rather than an exhaust fan, this
figure showing in full lines two exhaust stacks and in
dotted line a single exhaust stack.
FIG. 7 is a view of a gas fired infrared radiant tube
heating system which employs a single gas valve and more
than two radiant tube burner assemblies mounted in a
single housing, each of the burner assemblies being
connected to radiant tubes, this design employing a blower
fan.
DETAILED DESCRIPTION
The heating system of this invention includes a
housing 10 to which two or more radiant tube heat
exchangers may be connected, two radiant tube heat
exchangers 12 being shown in FIGS. 1 and 6, and more than
two being shown in FIG. 7. The heat exchangers may be U-
shaped as shown in FIG. 1, or they may be straight as
shown in full lines in FIG. 6. Each of the heat
exchangers is of conventional construction and will
typically be mounted below a heat exchanger reflector (not
shown), the heat exchanger and reflector being supported
from the ceiling of a structure in a conventional manner,
(also not shown). In accordance with this invention, the
housing 10 is provided with a single gas delivery system
including a valve assembly 14, suitable controls which
will be described below, and a manifold in the form of T
16, the inlet of the manifold being connected to the
discharge side of valve assembly 14. It should be noted
that instead of a single T, as shown in FIG. 2, other
forms of manifolds may be employed when more than two
burner assemblies are connected to the valve assembly 14
as shown in FIG.~7.
As shown in FIG. 2, each of the outlets of the
manifold is connected to a burner assembly 18. Each
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burner assembly includes a cup 20 having suitable
apertures 22, an apertured stem 23, connected to a gas
pipe 24 provided with a suitable orifice, the gas pipe
being connected to the outlet of the manifold. Mounted
5 downstream of each burner assembly 18, but upstream of
the associated heat exchanger 12, is a flame igniter 26,
and a flame sensor 28 best shown in FIG. 3. In
accordance with this invention, the single gas delivery
system includes a single control circuit module or
circuit board 30 for controlling the operation of the
valve 14, as well as other components. The circuit board
30 receives its power from a transformer 32 which is also
mounted within the housing 10. As is conventional, a
thermostatically controlled relay 34 (FIG. 4) is
positioned in a power line 36 to a source of electricity,
such as a 120 volt power line (not shown). A fan 38
{which is an exhaust fan in the FIG. 1 embodiment, but a
blower in the FIGS. 6 and 7 embodiments) is provided for
causing a flow of air through the burner assemblies 18
and through the radiant tubes 12 and into suitable
exhaust stacks 48. The fan 38 will be operated when the
relay switch 34 is closed. A normally open switch 40 is
mounted in one of the power lines 42 which extends
between the circuit board 30 and the transformer 32, the
switch being responsive to blower proving switches 50
responsive to pressure (in the FIG. 6 embodiment) or to
vacuum (in the FIG. 1 embodiment) in pressure lines 44.
The circuit board or control circuit module 30 is
provided with suitable spark generators 46 for initiating
spark to each flame igniter 26, there being a spark
generator for each flame igniter. Each flame sensor 28
is in turn connected with a suitable control device 52 on
the circuit board 30.
In operation, the heating system shown in the
various figures is operated in a manner similar to other
thermostatically controlled heating appliances. Thus,
operation is initiated by a thermostat or other suitable
control device which causes relay 34 to close. The
combustion air fan 38 is energized and combustion air

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flow is proven through the means of a single (or
multiple) pressure switch 50. After combustion air is
proven, the control circuit module 30 will allow for a
pre-purge period of 30-45 seconds. After this period,
the multiple spark generators 46 are energized which
cause the flame ignitors 26 to spark, and the gas valve
14 is opened via solenoid 56. Gas then flows through the
manifold 16 to the burner assemblies 18. Gas is then
mixed with combustion air in a combustion chamber and the
mixed gas and air are ignited by the associated igniter
26. The fire (or flame) and associated flue gases are
drawn along the radiant tube heat exchangers 12 under a
negative pressure in the FIG. 1 embodiment to a common
flue gas exhauster and stack 48. Thus, the heat of the
fire and flue gases is transferred to the radiant tube
heat exchanger 12. When the tubing temperature is higher
than the ambient temperature, it will begin to radiate
infrared energy. This energy is radiated from the
radiant tube in all directions. A reflector (not shown)
is placed above the top side of the radiant tube 12 to
contain connective and radiant energy. The reflector
then directs the radiant energy downward into the space
below that is being heated.
This heater as described above can also be
constructed with the combustion air blower positioned at
the upstream side of the burner and mixing chamber as
shown in FIG. 6. In this case the flame and hot flue
gases from the burner assemblies are forced along the
radiant tube heat exchanger under a positive pressure
from a blower 38. Flue gases exit through a common
exhaust stack 48 as shown in dotted lines or through
separate stacks 48 shown in full lines.
While a single fan has been shown in the various
figures, it should be appreciated that in a negative
pressure system which employs an exhaust fan, such as
shown in FIG. 1, it is possible to use two exhaust fans
if the radiant tubes 12 do not come together. Thus, if
the radiant tubes were straight, as shown in full lines
in FIG. 6, and if the heating system was a negative

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pressure system, there would be one exhaust fan between
each radiant tube heat exchanger and the associated
exhaust stack 48.
While a preferred form of this invention has been
described above and shown in the accompanying drawings,
it should be understood that applicant does not intend to
be limited to the particular details described above and
illustrated in the accompanying drawings, but intends to
be limited only to the scope of the invention as deffined
by the following claims.
What is claimed is:

Representative Drawing