Sept‘. 3, 1968
A. c. w. JOHNSON
3,399,833
LOW INTENSITY RADIANT HEATER SYSTEM AND BURNER THEREFORW
Filed Dec. 14. 1966
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INVENTOR.
ARTHUR C. W. JOHNSON
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BY
ATTORNEY
Sept; 3, 1968
A. c. w. JOHNSON
3,399,833
LOW INTENSITY RADIANT HEATER SYSTEM AND BURNER THEREFOR
Filed Dec. 14, 1966
4 Sheets-Sheet 2
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INVENTOR.
ARTHUR C. W_ JOHNSON
BY
ATTORNEY
SePt- 3, 1968 ~
A. c. w. JOHNSON
3,399,833
LOW INTENSITY RADIANT HEATER SYSTEM AND BURNER THEREFOR
Filed Dec. 14, 1966
4 Sheets-Sheet :5
88
,
‘
L-
INVENTOR.
ARTHUR c. w. JOHNSON
/
1
BY
ATTORNEY
Sept. 3, 1968
‘A. c. w. JOHNSON
3,399,833
LOW INTENSITY RADIANT HEATER SYSTEM AND BURNER THEREFOR
Filed Dec. 14, 1966
4 Sheets-Sheet 4
FIG. l2
INVENTQR.
ARTHUR c. w. JOHNSON
BY (£31m
ATTORNEY
United States Pate?to 73cc
3,399,833
Pivatented Sept. 3, I968
2
burner and heating system of ‘this invention is relatively
,
..
3,399,833
‘
v
'
"
_ LOW INTENSITY RADIANT HEATER SYSTEM
_'
AND BURNER‘ THEREFOR
‘
"
Arthur C.'W. Johnson, Troy, Mich.,‘assignor to Combus
' tion Research Corporation, Troy, Mich., a corporation
of Michigan
‘
'
‘
rosive vapors‘ and dirt and substances that'gum up~the
air passing components ‘and their ports, while ‘air-taken
from withina building having commercial‘ orE industrial
activity is usually dirty‘and maintenance charged. The ‘air
Filed Dec. 14,- 1966, Ser. No. 601,700
~26 Claims. (Cl. 237-53)
clean, b'ein'g' takenv from ‘outside of the building or from
within the building" if such air‘is relatively‘ freeof cor
-
ABSTRACT OF THE DISCLOSURE
This invention relates to a low intensity radiant heater
system and burner or a plurality of burners therefor, and
' required for combustion at the burner can be brought
into the heating, system from outside-‘of the building‘by
the‘ operation of the suction fan located adjacent the
output end of the system, if conditions within the build
ing do not permit. This air should be relatively free of
dust, dirt, fumes, vapors and other contaminants which
tem, wherein the air for the burner, and optionally the
normally are present within the con?nes of an industrial
building, manufacturing facility or other active commer
cial establishment. Inasmuch as the system is operated
ated and effected.
relatively low intensity, has a high enough temperature
more particularly to‘ a gas-, or optionally an oil-?red
burner unit in and associated with a radiant heating sys
under negative pressure (suction) at all times, the air
burner structure itself with its controls and piping, are
required for combustion should be relatively dirt free to
taken from an input section located outside of the struc
prevent clogging of the burner, a condition that ultimately
ture enclosing an area to be heated, and the products of
combustion from the burner(s) are discharged by an. ex 20 affects combustion e?‘iciency as time elapses. The system
can be completely independent of the environment within
haust fan at the output end of the system, outside of
which heating will be effected. The system, although of
the structure within which the radiant heating is gener
-
to allow a large percentage of its energy to be transferred
by direct and indirect radiation, but the burner unit is
- The invention generally involves a system in which the
chemical energy of the fuel is converted into thermal
energy to heat the wall of a conduit which in turn radi
ates'a large percentage of the conducted thermal energy
to a ground ?oor plane, directly but preferably in con
junction with a re?ector disposed above the conduit. The
preferred heating system further involves an input con
duit supplying air from outside a structure to be heated to
a burner conduit in the stream of flow, a burner unit, a
length of radiant conduit fabricated from materials hav
ing relatively high emissivity values, such as oxidized or
or painted steel, porcelainized steel, etc., heated by gas
radiation and convectively by the combustion gases gen
designed and/ or controlled so that it will not operate at
too high a temperature, permitting the use of ‘steel or
similar low cost conventional materials and yet avoid the
creation of problems of oxidation within the system lead
ing to the corrosive deterioration thereof. The system,
nevertheless, is e?icient and provides simple heating
means, particularly for industrial and commercial areas,
that avoid many of the heating problems inherent in sys
tems utilizing air currents within the building that can
only produce serious maintenance and replacement prob
lems, and which allow most of their heat energy to be
wasted in the upper reaches of the building and to be
substantially dissipated by air currents entering through
doors and cracks.
The system of this invention and the burner used
the output portion of the conduit for drawing (1) air 40
erated by the burner, an exhaust or suction fan located in
therein can be either gas or oil ?red. It is a high ef?ciency
through the input portion of the conduit into the burner
radiant heating system, offering high thermal efficiencies
unit ‘and (2) the products of combustion generated by
and consequent economy of operation. This bene?cial
the burner within the conduit for discharge outside of the
result is achieved by a large radiating surface that can
building in-which the radiant heater system functions.
Another function of the exhaust fan, particularly from a 45 be extended by the ‘system from the burner unit through
an entire structural area, with a minimum of localized hot
safety standpoint, is to draw room air into the ‘system
through the conduit connectors where leakage occurs or
a seal may be broken, instead of-—as in a pressure sys
spots due to local concentrations of combustion or con
version of the chemical energy of the fuel into thermal
energy to impart its heat into the system by convection
and radiant energy. The radiant component of thermal
within the inside of a building without producing severe
or serious corrosive problems such as result from the
use of a conventional high intensity unvented radiant
vection-type units. In fact, the heating system of this in
vention can also be re-circulating in design. A signi?cant
tem—discharging the dangerous products of combustion
50 result is that, by virtue of the inventive concept, an op
into an enclosed space through 'such leakage ports.
timum amount of heat can be given up by radiation
In brief, any fuel-?red heating system operates by con
energy is capable of being guided in conduits or de?ected 55 heating system producing a condensation of the products
of combustion in an inadequately vented building. Since
and directed by means of re?ectors so that broad band
the heating system of this invention is basically a radiant
areas or relatively con?ned areas can be heated by this
energy system, localized portions or areas of a building
‘structure can be heated more effectively than by con
the fuel is transferred or converted into thermal energy 60 vection means.
Although little or no attempt is normally made in com
to heat fluids such as air or water, which is usually di
radiant component. In more accepted conventional com
mercialspace heating systems the chemical energy in
mercial fuel-?red heating and burner systems to control
the mechanism, temperature and effects of the ?ame, in
the system of the instant invention such control has been
becomes easily deflected and dissipated by air currents.
Within the past decade, attempts have been made, with 65 attempted and effected in the following manner. All of
the air required for combustion in the burner and heating
varying degrees of ‘success, to introduce radiant heating
system, as well as some excess air, is introduced through
systems as a supplement for other methods of heating,
rectly or indirectly converted into warm air directed by
fans or gravity in such. a way that the thermal energy
suchas embedding hot water pipes in ?oor structures to
a regulated inlet section at the input end of the burner sys
tem. This inlet section is usually located outside of the
heat them by conduction.
The ‘heating system of this invention reduces the 70 building and in such event is provided with a bird screen
or shield over its input end. In some instances the inlet
amount of maintenance usually required and is substan
section is located within the building structure where
tially maintenance free, because air taken to use in the
3
" 373399.333‘
the air to be used for combustion is relatively dirt free
and is satisfactory for use with the burner unit and will
not substantially reduce the efficiency of the burner over a
period of time. The air is conducted to the burner unit
by a conduit which may, but need not necessarily, be of 61
the same diameter or cross-sectional magnitude as the
conduit of the heating system to which it is directly con
nected. The burner unit is preferably located relatively
close to the input end of the system, and the air brought
into the system is introduced into the burner assembly
in such quantity and at such a rate as to limit the tempera
ture of the products of combustion generated by the
burner. In so doing, the temperature of the radiant con
duit is controlled to a lower order of both temperature
and radiation. Thereby, the radiant conduit achieves a
more uniform temperature throughout and the radiant
drop is relatively less than those achieved by other sys
tems. Obviously, the temperature at the burner and in the
combustion area can be regulated over a wide range de
pending upon the amount of gas or fuel introduced at -
this point. Although the products of combustion leaving
the burner will be up to this controlled limit temperature,
they will also contain an excess of oxygen, so that the
percentage of such excess of oxygen will be inversely pro
portional to the amount of oxygen consumed by the com
bustion of the fuel gases.
A suf?cient length of conduit is added to the burner
tube in order to reduce the products of combustion to a
temperature of approximately 200° F. so as to minimize
possible condensation problems before discharging them
through the exhaust assembly out of the building into
the atmosphere.
The burner of this invention is so constructed that the
?ame generated by the fuel-air combination is relatively
shielded, the ?ame being con?ned substantially to the
central portion of the radiant tube by means of a spin
vane plate mounting the burner jet and by air ports in
the plate adjacent the jet for greater efficiency of com
bustion. The ports and the spacing between the vanes of
to conserve energy without creating excessivelocal ?oor
temperatures uncomfortable to work under. In this way
the suspension hooks can be ?rst installed by chains at
tached to roof or ceiling beams, or installed by supporting
them from the steel trusses of the building, and the radi
ant conduit and superposed re?ector simply laid into the
complementary support of the suspension hooks.
The present inventionprovides ,a' low‘ intensity radiant
heater system in‘ which the heat is relatively uniformly
spread throughout the area to be heated and comprises
a radiant conduit, a burner unit serving to heat the con
duit, an air intake portion for the burner unit, and an
exhaust assembly discharging the products of combustion
to the atmosphere outside of the buildinggThe system is
capable of being mounted at a relatively .low height in
industrial buildings, most of them having an inside height
of from 12 to 16 feet. An inlet assembly preferably, but
not necessarily as indicated above, protrudes through a
wall of the structure and operatively connects a ?rst end
of the conduit to the outside of the structure. By installing
the inlet end of the conduit outside of the building struc
ture, the amount of dirt and contaminants that enter the
conduit are minimized. Such contaminants can affect the
air ports, reducing combustion e?‘iciency over prolonged
periods of time. Another advantage obtained from an inlet
section disposed outside of a building is the avoidance of
taking in explosive fumes, or fumes which may become
exploive when introduced to the burner unit. The exhaust
assembly includes a motor driven exhaust fan which cre
ates a negative pressure or suction throughout the conduit
and inlet assembly so that air is continually drawn through
the burner unit and the radiant conduit, and the products
of combustion and excess ‘air are expelled out of the
conduit through the exhaust assembly to the outside of
the structure.
A burner unit is operatively connected to the conduit at,
in or near the ?rst end of the conduit. The burner unit
includes a spin vane plate, and a spark igniter mounted
adjacent the burner jet. A source of fuel is provided with
the plate provide a total area for the passage of air 40 associated valve means and fuel pipes to conduct the
su?icient to produce and maintain combustion of the
fuel issuing from the burner jet, the excess quantity of
air passing through the spin vanes adjacent the inner sur
face of the conduit, whereby the ?ame of combustion and
the combustion products are surrounded substantially by
a cylinder of relatively cooler air, reducing the tempera
ture of the radiant conduit in and adjacent the burner
unit, and producing a more uniform combustion over a
longer distance within the central portion of the tube.
Such relatively concentric flow of the excess air adjacent
the inner wall of the conduit and about the products of
combustion tends to promote complete combustion of the
gases and in a more diffused manner over a longer distance
of travel in the radiant conduit.
The inventive system utilizes a re?ector positioned above
and about the radiant conduit so as to de?ect the radia
fuel to the burner jet. The spin vane plate is disposed in
the burner unit so that its major surface is transverse to
the stream of air being drawn into and through the con
duit, and there is a gap between the periphery of the spin
vane plate and the inside surface of the burner unit. The
spin vane plate has at least one air port therein disposed
near the burner jet, a plurality of slits therein adjacent
the periphery of the spin vane plate, and an angled vane
adjacent each of the slits. The spark igniter ignites at pre
determined times the fuel issuing from the burner jet to pro
duce a ?ame which heats the air and other substances
which in turn heat the conduit. An air port or ports in the
spin vane plate closely adjacent the jet supplies su?icient
air to the burner jet to ensure more rapid combustion of
the fuel. The slits and vanes of the spin vane plate cause
a portion of the incoming air to spin or swirl, which elon
gates the ?ame and keeps it central of the conduit. The
any other area to be heated. In‘ so doing, the radiant
gap between the periphery of the spin vane plate and the
energy is more e?iciently utilized. The re?ectors may be
inside surface of the burner unit tends to provide a tube
made in various shapes and are usually constructed of
of incoming air to surround the ?ame and stabilize it over
highly re?ective materials such as aluminum, nickeloid, 60 a longer distance, and simultaneously offsets the gas radi
chrome plated steel, polished stainless steel, etc., selected
ation effect on the conduit in the region of the maximum
to give the desired heating patterns and to con?ne and
combustion.
localize the radiant energy to areas requiring heat and
It should be understood that the burner unit of this
minimize the heat loss occasioned by free convection cur
invention is designed to operate at about 100,000-115,000
rents ?owing over the pipe. Some reradiation from the
B.t.u.’s per hour, which is comparable to the size and
primary heated tube will, of course, spread radiant energy
capacity of unit air heaters, but a larger burner can be
and heat to other areas, and the radiant ef?ciency can be
used for large commercial or industrial use witha capacity
affected if free convection currents are allowed to ma
of up to and including 400,000 B.t.u.’s without generating
terially cool the radiant conduit.
such high temperatures that expensive alloy or fragile
The heating system of this invention is designed to be
ceramic pipe constructions are necessary, and minimizing
erected and installed by means of open suspension hooks
the number of expensive control assemblies required to
tion emitted by the pipe toward the ?oor or toward
supporting the radiant conduit, the re?ectors being sup
ported by the radiant conduit and secured thereto by C
hooks and support plates at a height as low as practical
heat a particular area. Burner units presently available
with only 40,000 B.t.u.’s/hr. capability generate much
higher temperatures and crystallize the conduit piping
3,399,833
5,
due to overheating in the ?ame propagation area, as little
or no attempt is made‘ to control the effects of ?ame
impingement upon the radiant conduit. -
A re?ector is ‘disposed adjacent and usually directly
above the conduit to direct the radiation emanating from
the heated conduit toward the areas, usually'downward,
6
URE 9 showing a further modi?cation of the combination
of a spin vane plate and the burner jet.
FIGURE 12 is a diagrammatic outline in the general
form of a plan view of a heating system arranged with
parallel burners and radiant conduits connected together
by a manifold leading to a gas exhaust'section.
'
Referring to FIGURE 1, there is shown a ?rst embodi
ment of the present invention of. a low intensity radiant
‘It is an' object of the present invention to provide a
heater system 10 having a single run of radiant ‘conduit
heater system'which attains complete combustion “of a
fuel in a relatively low temperature conduit.
10 12 installed in a building, factory, plant, or other type
of structure 14. The building shown has a ?oor 16, a roof
‘Another object of the invention is to'provide an infrared
which are to be heated.- -
1
a
heater system‘which is completely independent of the air,
18, and walls 20 and 22. The work areas to be heated are
designated by the reference number 24. The radiant con
duit 12 may be positioned at any height above the ?oor
the area(s) to be heated.
16 and at any horizontal location, to heat a predeter
An additional object is to provide a radiant heater
mined area or portion of the radiation absorbing matter
system having a novel burner unit which controls the
within the building, as may be desired or required. The
temperature, permitting the use of relatively inexpensive
novel radiant heater system directs a high percentage of
conventional construction materials at optimum tempera
radiant heat only where needed, and limits the free ?ow
tures, and the ‘effects of the ?ame generated thereby.
' Another object is to provide a low temperature radiant 20 of such energy to those areas within the building which
require little or no heat, such as the space adjacent the
heater system which is always fully vented and which
roof 18 or areas normally unused or unoccupied by
prevents fuel leaks and reduces health and ?re hazards
workers or other persons.
_
to a minimum under the adverse operating conditions
The radiant conduit 12 is supported by conduit sup
usually present in industrial buildings.
ports 26 which are of an open C type design so that they
A further object is to provide an automatic ignition
fumes, or other substances within the structure enclosing
radiant ‘heater system which attains complete combus
tion of the fuel so that the CO produced is considerably
may be readily placed in position to suspend the conduit
12 (see FIGURE 3). Each conduit support 26 is hooked
less than 400 parts per million, and will maintain this
onto a suspension hook 28 which is connected to the roof
18 or roof support members by means'of a suspension
limit when conditions in the heated area are not con
du'cive to good operating conditions.
A further object is to provide a recirculating radiant
heater ‘system which allows larger burner units to be
bar or chain 30.
A regulated inlet section 32 permits all the air required
used, which’limits the number of units required to do a
for combustion, and some excess air, to enter the heater
system 10 only from outside of the building or structure.
givenv heating job and consequent cost of multiplicity,
The inlet section 32 includes a bird screen 34 and a
with a minimum ‘of controls, and which avoid oxidation
damper plate 36 having an air port 37 therein (see FIG
URE 2). The inlet section 32 protrudes through the
wall 20, the clean air brought in through the inlet section
of the system components while simultaneously limiting
and controlling the operating temperature in the system
to circa 930° F. where plain or treated aluminized steel
is used in the burner and the radiant conduit.
' These and other objects and advantages of the present
invention will be apparent to those skilled in the art upon
reference to the drawings'annexedv hereto and to the
speci?cation.
'1 '
"
'
32 being conducted to the burner unit 40 by a conduit 42.
In the ?rst embodiment of the invention illustrated, a
gaseous fuel is introduced into the burner unit 40 and is
there ignited by a spark igniter 44, which operates similar
to an automobile spark plug. The sprak igniter 44 is a
component of a direct spark ignition control system (see
FIGURE 1 is a-“side elevational view of a typical
installation=in a building of a ?rst embodiment of the
FIGURES 4 and 5), most of which is housed within a
control box 46. The control box 46 is mounted above and
'ra‘diantheater system of the present invention;
upon the burner unit 40.
FIGURE 2 is a v'ertical‘section view longitudinal of
a novelrburner unit-which-may ‘be used in the radiant
The fuel and air mixture ignited in the burner ‘unit
forms a ?ame which is regulated in the present invention.
The air entering the conduit 12 by way of the inlet section
32, the regulated ?ame and the products of combustion
formed by the burner unit 40 in the conduit 12 are always
under suction in this construction to prevent fumes and the
gases of combustion from entering the work area. This
negative pressure in the combustion chamber is produced
heater'system of the present invention;
FIGURE-‘3 is a transverse vertical section taken sub
stantially along line 3-—'-3 of FIGURE 2 looking toward
the gas jet and spin vane plate;
' 1 FIGURE 4 is a circuit‘diagram of a direct spark igni
tion control system;
> i‘
>
~FIGURE v5 is an enlarged top plan view of the control
box, ‘with its cover removed,"-showing the components
of the direct spark ignition control system;
‘ FIGURE 6 is a top pIan'vieW of a second embodiment
of the presentlinvention' illustrating a novel recirculating
radiant heater system; a‘
'
a
I
>
FIGURE 7 is an enlarged plan view of the inlet and
outlet section, the burner unit, and the fan zone of ‘the
recirculating system shown in FIGURE 6;
’
by an exhaust fan device 48 driven by its motor 50 located
in the exhaust assembly 52. The thermal radiation emitted
by the conduit 12 is re?ected and directed to the areas 24
to be heated by an elongated re?ector 54 (see FIGURES
l and 3) supported by and upon the conduit 12. The
60 motor driven exhaust fan device 48 is operatively con
nected to the downstream end of conduit 12 for creating
a reduced pressure or suction in the inlet section and the
main radiant conduit and for driving the gases and com
bustion products out through the exhaust assembly 52.
FIGURE 8 is a perspective view of the spin vane plate,
the fuel supply tube and burner jet and the air input 65 The exhaust assembly 52 has a portion thereof protruding
through the wall 22 so that the exhaust gases and products
damper combination, arranged in the burner unit tube
of combustion are discharged outside of the building. The
shown in broken lines;
~‘ FIGURE 9 is a fragmentary'vertical longitudinal sec
exhaust assembly 52 includes a bird screen 56.
FIGURE 2 shows some of the details of the burner unit
tion view through that portion of a burner conduit show
ing av modi?ed» combination of the spin vane plate, the 70 40 and its associated control box 46, illustrated generally
in FIGURE 1. The control box 46 and the re?ector 54
burner jet and its supply tube;
'
are supported on the conduit 12 by U-clamps 58 which
FIGURE 10 is'a fragmentary vertical elevational view,
allow free expansion between the re?ector 54 and the
partially in section, taken substantially on the line 10—10
of FIGURE 9;
radiant conduit 12. The burner unit 40 and control box
FIGURE 11 is a view similar to that shown in FIG
46 can thus be clamped together as one integral package
7
‘
.
and assembled with a small length of conduit 60 which
serves as a combustion chamber and is of the same cross
section as the radiant conduit 12. The control box 46 is
easily connected to a source of electricity and a source of
gaseous fuel, and is readily detachable from the conduit
60 or burner unit 40.
.
.
The gaseous fuel is admitted through a gas inlet pipe
62 (see FIGURES 3 and 5) leading to a gas valve 64 (see
FIGURES 4 and 5) housed within the control box 46.,
The gas valve 64 employed may be a combination gas
control which includes a manual ON-OFF gas cock 66,
90 between the circumference of the spin vane plate 78
and the inner wall surface of the conduit 60 is substan
tially concentric about the axis of the plate. The air pass
ing over the spin vane plate 78 through the annular clear
ance 90 tends to keep the inner wall of conduit 60 down
stream of the plate relatively cool and to surround the
central ?ame 'and' the swirling ?ow of air coming from
the blades 88 within a cylinder or tube of relatively cooler
air. This air?ow pattern contributes to the attainment of
10 an important feature of the present invention, namely, a
stable efficient ?ame, and consequent complete combus
ak90-volt operator 68, a pressure tap with plug 70, and a
pressure regulator 72. A gas lead-in pipe 74 (see FIG
URES 2, 3 and 5) emanates from the outlet side of the
tion of the fuel with more uniform temperatures through
out the system. The temperature generated by the burner
unit 40 in the conduit 12 therebeyond is so controlled that
combination gas control and communicates with the gas
it allows the use of low cost conventional construction
materials and tends to prevent recrystallization or ap
burner pipe 76 which lies generally axially of the conduit
60. The gas burner pipe 76 conducts the fuel gas through
the center of an air ?ow de?ecting member such as the
spin vane plate 78 to a burner jet 80 protruding from the
combustion chamber side of the spin vane plate 78.
The incoming air is regulated in part by the ori?ce 37
in damper plate 36 and by an air ?ow switch 82 which is
controlled by a thermostatic controller 104 positioned ad
preciable oxidation of portions of the burner unit 40 and
the portion of the radiant heater system immediately ad
jacent the burner unit, while producing sustained radiant
energy from the conduit 12 to heat work areas 24 at rela
tively high efficiencies and at relatively lower tempera
tures of operation. The straight through system having a
single mass ?ow achieves ‘a more uniform temperature
jacent and in the work areas 24. The exhaust fan motor 50
and more complete combustion at relatively low tempera
is controlled by the thermostatic controller 104, and the
air ?ow resulting from the exhaust fan operation causes
activation of the air ?ow switch 82 which energizes the
tures, ‘while producing approximately ?ve percent of CO2,
on the basis of natural gas. The system of this invention
utilizes an air to gas ratio of 20 to l, which is below the
burner control system 102. As best seen in FIGURE 3,
the spin vane plate 78 has a plurality of air ports 84 in the
lower in?ammability limits of combustion, and thus the
mixture in the conduit 12 is nonexplosive.
body of the plates relatively close to the burner jet 80. 3O
Directly below the spark igniter 44 and as a ?ame
The air ports 84 are of predetermined dimensions and are
check device, there is provided a short visual indicator
placed in predetermined locations relative to the burner
tube 92 (see FIGURES 2 and 3) having a ?at glass plate
jet 80 to ensure that sut?cient incoming air
at the burner jet 80 to produce a localized
mixture ‘with the fuel. The air ports 84 are
the body of the plate on a concentric bolt
is available
combustible
arranged in
circle inter
mediate the axis and the perimeter of the plate, and pref
erably in a medial zone therebetween. The function of the
air ports is to permit a quantity of air to pass through the
or window 94 forming part of its threaded bottom cover
96. The visual indicator tube 92 is preferably arranged
to face the ?oor 16 so that an individual standing under
the burner unit 40 can tell at a glance the nature and
condition of the flame, if any, by merely looking up
through the glass plate 94.
~
An open end of a pressure sensing tube 98 (see FIG
plate relatively adjacent the burner jet 80 to feed the 40 URES 2, 3 and 5) communicates with the interior of
same with some oxygen so as to support combustion but
the visual indicator tube 92 for sensing the pressure or
to provide only enough oxygen at this point for such pur
negative pressure in the combustion chamber of the
pose and not to develop complete combustion.
burner unit on the downstream side of the spin vane
The spin vane‘plate is arranged with a perimeter of
plate 78. The pressure sensing tube 98 communicates with
radial slits 86 and adjacent angled radial vanes or blades
the air ?ow switch 82 (FIGURE 5) mounted in the con
88 formed in the outer circumferential portion of the spin
trol box 46. Another pressure sensing tube 100 (see
vane plate 78. The outer diameter of the spin vane plate
FIGURES 2, 3 and 5) communicating with the air ?ow
is less than the inside diameter of conduit 60, leaving a
switch 82 senses the pressure upstream of the spin vane
relatively small concentric opening 90 between the blades
plate 78. The air flow switch 82 operates as a pressure
at the perimeter of the plate and the inner surface of the
regulator switch or control for the gas valve 64 to con
conduit 60 for the free passage of air, much of which
trol the operation thereof in response to the difference
?ows through as a tube of air adjacent and about the spin
in pressures sensed by the pressure sensing tubes 98 and
nin'g, swirling air ?ow generated by the angled vanes 88.
100. There are two taps (connections) to the switch 82
The clean air sucked in by the motor driven exhaust fan
so that it can sense the differential pressure over the spin
48 is caused to swirl, spin and undergo a relatively helical
vane plate 78, thus measuring and monitoring the air flow.
motion as it passes through the slits 86 and over the angled
The switch 82 is adjustable to accurately determine and
vanes 88. The swirling air feeds and elongates the ?ame
monitor the safe ?ow condition, and when so adjusted
generated at the burner jet so that the ?ame is caused to
to shut the system 102 down if the air ?'ow conditions
extend a substantial distance downstream of the burner
do not correct themselves to meet the differential limits
jet 80 and into the main radiant conduit 12. At the same 60 set by the adjustment of the switch. The switch 'is cali
time, the ?ame gases and the products of combustion are
brated to remain open upon a predetermined differential
fed by the spinning, swirling, helical ?ow of air relatively
in pressure, and when such differential is' absent the switch
concentric about the ?ame and then, or relatively simul
closes and causes the operator 68 to close the gas‘ valve 64.
taneously, by the outer more cylindrical ?ow of air ad
The burner unit>40 is provided with an automatic spark
jacent the inner surface of the conduit 12 which came
ing system and time trial ignition device with fail safe
through the gap 90 between the spin vane plate 78 and the
controls. This comprises a direct‘spark ignition system
conduit 60.
102 such as is illustrated in FIGURES 4 and 5. The con
At this time there is no way of precisely determining the
trol system shown and described in'connection with the
?ow pattern of the input air, the ?ame gases and the prod
present embodiment is for a gas-?red unit. An oil-?red
ucts of combustion as they come through the burner, the
unit would be equipped with a'different sensor to suit the
conduit 60 and the radiant conduit 12. But What appear
particular requirements of oil safety equipment; Such
to be features of the ?ow pattern may be deduced from
sensor could be either a' stack switch or a lead sulphite
some operating results of the system. These results will be
cell.
described more fully below.
As shown in FIGURES 2 and 3, the clearance or gap
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The direct spark ignition system 102 shown ignites the
burnerjet 80 by mcans of'the spark igniter 44 each'timc
3,399,833
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This eliminates continuous pilot operation during the
OFF-period and OFF-season, andmakes relighting a pilot
burner unnecessary. If the spark igniter “fails to light
the ‘burner jet 80, the ignition system automatically-locks
tion of air, ?ame gases and the products of combustion.
The same recirculating and exhaust fan 130 also forces
combustion products through the outer exhaust conduit
128 to the atmosphere outside the building.
reset for operation only by manually resetting and lower
ing the line voltage thermostat controller 104 setting for
several minutes, and then returningthe controller to its
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Among the several advantages of a recirculating sys
tem 126 are larger burner units-up to 400,000 B.-t.u./hr.
or more, resulting in fewer ‘control boxes required per
out in a safety shutdown condition, and the lighting of
an alarm signal. lightrThe ignition system can then be
normal setting.
10
and the main radiant conduit 12 to produce a recircula
the line voltage thermostat controller 104 calls for heat.
system and consequent reduction in‘ cost; more uniform
and higher operating temperatures—from about 500
degrees to 930 degrees F. with consequent higher average
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As shown in FIGURE 4, a.power supply feeds the line
voltage thermostat controller 104 which is connected in
series with a manually operable toggle switch 120, and
with the air ?ow switch ‘82. These components and the
conduit temperatures
power supply are connected to an ignition timer 108. The
ignition timer 108 is a component-part of a bridge circuit
which includes a heater-operated safety switch to shut off
ferent structural and operational requirements for a
resulting - in a higher radiant
et?ciency and with less ?ue gas losses due to a minimum
of excess air present in the burner unit.
'
It is to be understood, of course, that there are dif
burner serving a recirculating system than for a burner
in a single run system. Additional consideration and atten
tion must also be given to the purge cycle and the method
the gas valve 64 and the spark igniter 44 in the event
that the contacts of a ?ame sensor 110 do not open to 20 of ignition as described below, the signi?cance of which
is markedly greater in a recirculating system. In either
balance the bridge circuit.
I
The ignition timer 108 is connected to an ignition
case, however, the advantage present in having the sys
transformer 112 which provides suf?cient voltage (e.g.,
4200 volts nominal) ‘to operate the spark igniter 44. The
stem under negative pressure provides a means for con
ignition transformer 112 should be connected to a com
trol and safety that is not present and cannot be provide
25
in a pressure system.
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mon ground 114 with the mounting bracket of the spark
The spin vane plate 78, control box 46, and ignition
igniter 44. The ignition timer 108 is also connected to the
control system 102 are basically the same as used in the
‘flame sensor 110 which reacts to temperature change.
single run embodiment. However, higher capacity control
The contacts of the ?ame sen-sor_110 open-on a tempera
components are required in the recirculating system. For
ture rise (burner jet on) to balance the bridge circuit 30 example, a larger gas valve 64 which has a gas capacity
which will shut off the spark igniter. 44. The contacts of
of 400,000 B.t.u./hr. natural gas may be required. In
the ?ame sensor 110 close on atemperature fall (burner
the single run controls, such gas valve may be of 180,000
jet off) to unbalance the bridge circuit for the next igni
B.t.u/hr. capacity.
tion cycle. The spark igniter 44 is connected across the
As best seen in FIGURE 7, the downstream section
secondary winding 116 of the ignition transformer 112,
and operates similar to an automobile spark plug. The
ignition timer 108_is also: connected to the gas valve 64
which controls the quantityof gasisupplied to the burner
jet' 80. The ‘actual mounting of thecomponents of the
control system "may be seen best in‘ FIGURE 5 which
gives a top viewof the control box 46 with its cover
132 of the burner unit conduit 60 is modified. This sec
tion 132 tapers inwardly at its end to form a venturi in
the area where the conduit 60 communicates with the
radiant conduit 12.
There are some differences in function of the burner
40 unit 40 in the recirculating system 126 over that in the
single run system. One of these is the length of ?ame. It
can be materially shorter in the recirculating system. An
The *manual'toggle switch 120 is employed in series with
other is the reduction in the helical swirling of the air
“the 'air ?ow'switch 82, which is provided with a ?ne
and the mixture of ?ame and gases as they approach the
adjustment screw1'124'operatively connected to the air 45 downstream section 132.
The gases discharged by the recirculating fan 130 are
?ow switch 82._An_ electrical service cable 122 may option
118
removed.‘
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ally ‘be used for’ protecting the input electrical wiring
‘for the control box'46. '
A'riumber of single run heater systems can be arranged
with their conduits ,12‘conn'ected to a manifold having a
single exhaust fan 48 to draw ‘the products of combustion
from the‘ conduit-s 12 and the manifold and discharge
them through an outlet section '52 to the outside of the
passed through the opening 134 into conduit 128 and
into the area of the venturi 136 formed by the" tapering
end 132 of conduit 60 and the end portion 138 of con
duit 128 there adjacent which terminates at its con
junction with the main radiant conduit 12 in a ?ow
restricting tapering juncture 140. The pressure generated
by the fan 130 is such that the gases will ?ow into the
main conduit 12 and backwardly out the conduit 128
Negative pressure in'the combustion chamber of the
toward its exit end at the bird screen 56. To balance the
burner unit, allows the system controls to achieve full or
?ow of gases in either direction, a perforated plate 142
vmore than‘ their rated ‘capacity: A negative pressure
is disposed about the conduit 42 and within the conduit
throughout the‘ system up to the‘exhaust fan eliminates
128. The plate 142 has a total area‘ of perforated open
leakage of ‘gases into‘ the's-pace areas being heated, ‘re
ings 144 sufficient to allow an exit ?ow of gases out of
moving a health haia‘rdj' and ‘causing all gases to be drawn 60 conduit 128 in proportion to a ?ow of such gases through
into rather than out "of‘the joints of the system.
the venturi area 136 and into'the main conduit 12 for
‘FIGURES 6 ‘and 7’relate to-_‘andjillustrate another em
recirculation through the conduit, The constriction
bodiment of the invention which‘involves a recirculating
effected by the tapering juncture 140 tends to limit the
type of low intensity radiant vheater system. Reference
?ow of gases toward the conduit 12 while the perforated
numerals-corresponding to‘ those employed in connection
area in plate 142 tends to limit the ?ow out of the exit
with the single run embodiment are also used in connec
conduit
128. These factors are adjustable and controllable
tion with. the recirculating embodiment where the ele
and have a correlation to the output capacity and pressure
'ments‘ involved are substantially‘i-dentical or functionally
of the recirculating suction fan 130 in the venturi area
In the recirculating heater system .126, the inlet as 70 136, the tempera-ture of the exhaust gases in such area
136 and the temperature desired and to-be achieved in
sembly and the exhaust assembly are formed with con
the main radiant conduit 12.
>
centric or coaxial conduits 42 and 128, respectively.
Since the exit ?ow of gases through conduit 128 abou
Clean outside air is induced into the inner inlet conduit
the input air conduit 42 is at a relatively elevated tempera
42 by-a recirculating and exhaust fan 130 driven by a
motort50 which createsa suction in the inlet conduit 42 75 ture, the incoming air will become somewhat heated,
structure
similar.
14.
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depending upon the length of the input conduit, and when
the proximal end 170 of the tube portion 166, in which
so heated the pressure drop across the spin vane plate 78
will be somewhat less than is present in the straight run
one or more air ports 172 are disposed adjacent the
embodiment. Under such circumstances, the angularity
of the blades 88 in the spin van plate should be reduced
in order to increase the pressure drop across the plate to
a point and within a__ range, which is not critical, that
effects a more ef?cient and more stable ?ame.
_
digital end of the burner jet 168. Thus, as air is drawn
into the burner conduit 60, some of it passes through the
port or ports 172 to intermix with the fuel issuing from
the burner jet 168 to form a combustible mixture inv tube
162, ready for ignition at the vdigital end of tube portion
164, and some of the air passes through the spin plate
‘Although a re?ector 54 for directing radiation from
at the blades 88 to issue in a swirling helical ?ow pattern
the conduit 12 is not illustrated in FIGURES 6 andv 7 for 10 and gradually intermix and feed thev ?ame propagated
the recirculating heater system 126, it is to be understood
that such re?ector is a preferred component of the system
and is very necessary to obtain maximum utilization of
the radiant component when such a system is not located
in an oven-type enclosure.
Recirculation of the products of combustion tends to
establish a more uniform temperature in the main radiant
conduit 12, an important feature of the recirculating
from the tube 162.
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Although the building structure 14 is illustrated and
described above as a complete ‘housing structure, it will
be understood that such structure 14 may be a room
or enclosed area within an outer building structure. In
such event, the input air can be derived from within or
without the outer building structure, and the exhausted
products of combustion discharged to the atmosphere
radiant heater system 126. It also makes the system more
outside of the outer building structure.
efficient in that less fuel is required to maintain the sys 20
Although the description given above is that for a gas
tem at a desired temperature. A controlled minimum
?red burner unit, it should be understood that an oil
amount of excess air is drawn into the burner unit, to
?red burner may also be used, and such variation in
produce a complete combustion, but not so much is
burner components and controls as may be ‘required is
sucked in as will tend to establish any more than a mini—
fully within the skill of persons trained in the art to which
mum temperature gradient in the conduit 12. If the con
duit temperatures drop appreciably below 500 degrees F.
in the recirculating conduit 12, the radiant e?iciency will
of course drop appreciably and the percentage of convec
tive losses rise proportionately. The higher the conduit
temperature, the higher the radiant ef?ciency. For the
relatively low cost steel conduit utilized in these systems,
the invention pertains.
_
representative control system, presently available,
is illustrated and described above. Other similar spark
ignition or ?ring ignition systems are also available for
use with the burner units of this invention. The control
system described operates as follows. When the tempera
ture in the area to be heated falls below the preselected
whether aluminized or not, the optimum maximum
operating temperature would appear to be about 930
degrees F. in the conduit.
A modi?cation of the spin vane plate 78 and its com
temperature setting of the thermostat 104, the contacts
at the thermostat close energizing the exhaust fan motor
50 and, simultaneously, the burner circuits. The exhaust
bination with the burner jet 80 is illustrated in FIGURES
burner unit of the particular system. The air ?ow through
9 and 10, wherein the air ports 150 are located at the
central opening 152 admitting the jet shank 154 and
extending radially outwardly a distance past the outer
fan 48 or 130 draws air through each inlet section and
any burner unit 40 creates a differential pressure across
the spin vane plate 78. The air ?ow switch 82 senses
this dilferential pressure, closes its contacts, and com
edges of a jet securing fastener such as nut 156. The 40 pletes the circuit to the direct spark ignition system 102.
open area of the ports 150 is such that su?icient air is
In the spark ignition system the gas valve 64, the igni
drawn therethrough by the action of exhaust fan 48 or
tion transformer 112, and the safety switch heater of the
130 to provide a combustible mixture with the fuel issu
ignition timer 108 are thus energized causing the burner
ing from the burner jet, but which is sufficiently limited
to ignite. The ?ame sensor 110 detects the heat of the
so that maximum combustion Will not be effected until
?ame and opens its contact, thus balancing the bridge
the helically swirling stream of air coming from the spin
vane blades 88 have begun to intermix with the ?ame
propagated by the combustible mixture at the burner jet.
Another consideration involved, of course, is ?ame
stability. The open free area and the location of the air
ports 150 should be such that air is fed to the burner
jet at such velocity and rate that it will not smother nor
underfeed the ?ame. Persons skilled in the art will easily
be able to adjust such feature of the air ports to suit
the requirements of particular applications of the inven
tive burner unit and heater system.
of the control circuit. When the bridge is balanced the
current through the safety switch heater stopsand the
safety switch timing system 108 is de-activated. The cir
cuit is now in “run” condition.
In the event that the?ame sensor contact does not
open within the 30 to 40 second timing interval of the
the spark ignition system. The system thus deenergized
the spark ignition system. The system thus deenerized
will remain in this state until the power to the entire
circuit has been removed for a period of 2 .to 5 minutes.
The spin vane plate 78 performs several functions in
cluding
the generation of a swirling helical ?ow stream
in shape, that extends from the digital end of the burner
of air directed by the blades 88, the production of a sub
jet to the inner edges of the blade slits 86 of the blades
stantial pressure drop across the plate, and because of
88, which could occasion a toroidal ?ow pattern from 60 its reduced perimeter, the generation of a tubular stream
the jet tip to the spin vane plate in the event that the
of air within and adjacent the inner wall surface of the
combustible mixture at the burner jet is of too lean pro
burner conduit 60. The angularitylof the blades 88 is
portions. In such event, the air ports 150 should be
such as to generate a substantial pressure drop. The plate
slightly elongated and/ or widened in order to increase the
then becomes an equalizing disc serving heater systems
amount and extent of air ?ow to the burner jet, to im
of various lengths and minimizing the pressure losses
prove the ?ame propagation and ?ame stability.
which
marked changes in radiant conduit lengths neces
A second modi?cation at the burner jet involves a
sarily produce. However, the gap between the blades 88
similar introduction of air to the burner jet at or adjacent
and their angularity are not critical, but when arrived
its digital end such that a combustible mixture is attained
at for a main conduit run of say 60-70 feet can also
downstream of the spin vane plate. Such modi?cation is
serve for runs up to about 100 feet, or for runs'appreci
illustrated in FIGURE 11, wherein the spin vane plate
ably less than 60 feet.
78 is provided with a central opening 160‘ in which a
The spin vane plate 78 is supported on the digital end
burner jet tube 162 is ?xedly secured, a portion 164
extending forwardly of the plate 78 and a portion 166
of the gas pipe 76 and secured thereto in any suitable
extending rearwardly. The burner jet 168 is secured in
manner, preferably by a nut or nuts on the threaded end
There may be an area of reduced pressure, conical
3399533
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of pipe 76, The proximal end of pipe 76 is secured to the
wall of conduit 60 at the opening through which the pipe
is passed for connection to the gas pipe '74. When so
secured, the spin vane plate 78 is positioned substantially
optionally be coated on the inside surface with aluminum
andblack on the outer surface, or porcelain coated to
minimize oxidation.
With radiant heaters of the type disclosed herein, the
concentric in the conduit 60 so that ‘a’ substantially even
higher the temperature of the radiant conduit the higher
gap 90 is present about the perimeter of the plate 78 and
within the conduit 60. Should the spin vane plate become
eccentric, a wire‘ type spider form (not shown) can be
mounted upon-the 'gas'pipe 76 adjacent the plate and
the ratio of radiant to convective energy. Therefore, in
the recirculation system, the individual burner units can
the fuel gas to the burner.
though the products of combustion are normally dis
be of higher capacity and the temperature of the radiant
can be more easily controlled to maintain higher radiant
bearing upon the inner surface of the conduit 60 to main 10 efficiencies for a complete system from inlet to outlet,
while limiting the temperature of the radiant conduit for
tain the spin vane plate in concentric relationship to the
other practical considerations.
inner surface of the conduit.
Since the present invention derives its combustion air
The exhauster fans 48 and 130 have been described
from outside the building or the enclosure to be heated
as single speed impeller type centrifugal fans. However,
and exhausts its waste material to outside the building,
single suction turboblowers may also be used, and multi
the present heating system is normally completely inde
speed motors may be found desirable in particular ap
pendent of the atmosphere or conditions within the build
plications. In some oven applications, it may be neces
ing unless air is taken from within such building. Al
sary or desirable to provide a proportioning control for
Y‘
.
In the single run system, in which there is a 20 to 1 20 charged into well ventilated atmospheric areas outside of
the heated structure, it is also possible to discharge such
air to gas ratio with the products of combustion at a
noxious fumes to an area within the structure if such
temperature below their lower in?ammability limits, the
latter area and the structure are suitably, adequately and
CO2 output at the exhaust end of the system is approxi
positively vented and ventilated. The system design keeps
mately 5.00% or less of the total exhaust output.
As illustrated in FIGURE 12, the single run radiant 25 dust, dirt, corrosive fumes, gummy materials, oxidizing
materials, and explosive fumes out of the burner and sys
tem. Thus, the system eliminates major maintenance prob
lems and is maintained at substantially initial operating
with individual air intake sections 32, burner units 40
settings and conditions, conditions that usually are easily
and radiant conduits 12_v communicating with and exhaust
ing into a manifold conduit 180 connected to an exhaust 30 a?ected by a lack of maintenance. Further, the system
system, such’as' is shown‘g'enerally in FIGURES 1-5 and
8 can be combined in number and arranged in a series
of this invention can be designed in sizes comparable to
unit air heaters, and yet not have the same large number of
expensive multiple units to obtain the same total heating
effect.
section 182'including a conduit 184 connected to and
communicating with the’manifold 180, an exhaust fan
48 and its motor drive 50, and a gas exhaust discharge
pipe or tube 186. Two types of such multiple arrange
ments are illustrated in FIGURE 12, and it will be under
Having described the invention in its simplest forms,
it is to be understood that the features of construction
may be changed and varied in greater or lesser degree
without departing from the essence of the invention de
stood that other arrangements of ‘multiple heater units
and conduits can also be designed to serve the areas to
be heated'as' particular requirements for heating may
dictate.
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?ned in the appended claims.
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‘ There is a minimum of excess airlin the recirculating 40
system. The CO2 present in the‘maint'radiant conduit
portion of this system will’ normally ‘be in the order of
11 to 12% ," minimizing thermal energy. waste in the ?ue
gases. .The amount of air taken'in at the inlet section of
the recirculating system \will'be appreciably less than that
taken ‘in _for the single, 'r'un'condui‘fsystem, the air to gas
ratio beingfaboutr‘ll to l'instead'of about 20 to 1 for the
single .run system. ‘For this reason,‘ it is not advisable to
.allow_,~fullgas to be admitted, loading the system with an
explosive mixture in 2 to 4 seconds, and it will be neces
‘
I claim:
1. A low intensity radiant heater system for a structure
having areas to be heated wherein said system is closed
throughout its extent and open only at its outer ends,
comprising:
45
an air inlet conduit passing through a wall of said
structure,
>
said inlet conduit having an air input end openly
communicating with the atmosphere on the out
side of said structure,
50
sary to start the-burner on a reduced ga's input, as by a
pilot light. This is’. done by additional switching controls
operating through supervisory contacts in the timing or
controller switch, with an extra pilot or main gas valve.
, The air flow ‘switch 82v operatesas a purge time delay
unit. ‘Such delay "period, can be controlled by the adjusting
screw 124 on the air ?ow' switch 82,,“the purge time being
variable (as for instance for a minimum of four multiple
changes of air) before 'ignitfion'of the fuel gas can be 60
‘effected. Such purgeftirne‘delay ‘period is of course im
portant in any heating 'system,',but"it is of particular im
portance in the recirculatingsystem where the amount of
excessair available is 'at 'a markedly reduced level.
,,_To' improve'theradiant efficiency the outer surface of 65
the conduit 12’ should be a black‘ body emitter for maxi
m‘ur'n'radiant effect. The color or condition of the conduit
will not affect the 'c'onvectivecoo‘ling action of air cur
rents passing over it.'On the other ‘hand, to minimize the
radiation effect in a localized area, the outer surface of 70
the ‘conduit can be made ‘re?ective over such area.
, .Normally, the radiant conduit ‘12 is made up of tube
lengths cut from standard lengths of 6 to 20 feet or more,
joined together with sleeve type outer' couplings. The
tube material is of relatively light gage cold or hot rolled
75
steel, in lock seam, seamless or spiral form, and it may
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a, burner unit for said heater system comprising
a conduit conjoined to and communicating with
the output end of said inlet conduit,
an air ?ow limiting damper at the air input end
of said burner. conduit,
an air ?ow de?ecting member generating a sub
stantial pressure drop on the downstream side
thereof arranged concentrically within said burn
er conduit and having substantially the entire
perimeter of said member spaced slightly apart
from said burner conduit, whereby to initially
effect a relatively tubular stream of air ?ow
along and adjacent the inner wall surface of
said burner conduit and a relatively helically
swirling stream of air ?ow within said tubular
stream and closely adjacent and progressively
interspersing and intermixing therewith, a fuel
jet secured to said air ?ow de?ecting member
axially thereof and therethrough and directed
downstream thereof for the discharge of fuel,
ports through the body of said air ?ow de?ecting
‘member and spaced outwardly of said burner
jet for the passage of air relatively adjacent the
burner jet for effecting a combustible mixture of
air and fuel adjacent the exit end of said burner
jet and so spaced in said body as to produce a
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relatively stable and efficient ?ame propagation,
,
v16
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A
v,
responsive device to continue the igniting function
controlled means in said burner conduit for ignit
during the absence of ?ame for a predetermined time
ing said combustible mixture,
delay period and to discontinue such function during
means for supplying and controlling the supply of
fuel to said burner jet,
Q1
a main radiant conduit operatively located in the areas
to be heated, andconjunctively secured to and com
the presence of a ?ame.
7. The system de?ned in claim 1, and including
a control box for said burner unit, affixed thereto and
supported thereon, having
municating with the output end of said burner con
, duit for convective and radiative absorption of the
thermal energy progressively generated by the inter
mixing of the burner ?ame, said swirling helical
stream of air, said tubular stream of air, and the
resultant products of combustion,
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automatic ignition‘ system components,
valve means for controlling the supply of fuel to
10
said burner jet,
and an air ?ow switch including means. responsive
to a decrease in the differential pressure across
both sides of the air ?ow de?ecting member
for regulation of said valve means.
and an output assembly comprising
a conduit for the exhaustion of said products of
combustion having its discharge opening in an
8. A recirculating low intensity radiant heater system
for a structure having space areas to be heated wherein
said system is open at its outer ends and closed through
area open to the atmosphere on the outside of
the space areas being heated by said radiant con~
out its entire intermediate extent, comprising
air intake and gas exhaust sections,
duit,
and a controlled power driven exhaust fan device
a radiant conduit disposed in said space areas to be
connected to and communicating with said main
radiant conduit and said output conduit,
and means for controlling the input quantity and rate
a burner unit communicating with said air intake section
of air and fuel into said burner so as to attain and
a gas exhaust device communicating with and connected
heated,
and said radiant conduit,
maintain a relatively uniform though gradually de
to said radiant conduit for constantly maintaining a
creasing operating temperature in and consequent
relatively predetermined negative pressure in said in
radiation of energy from said main radiant conduit
take section, said burner unit and said radiant con
throughout the effective length of said conduit, and
duit, and for constantly maintaining a positive pres
to control the maximum and minimum temperature
limits over the effective length of said conduit and 30
the rate of decrease of such temperature within said
limits.
2. The system de?ned in claim 1, and including
means for suspending said air inlet conduit, said burner
conduit, said main radiant conduit and said output
assembly from the superstructure of said structure
ori?ce-occluding character,
3. The system de?ned in claim 1, wherein
said exhaust fan draws all of the gases entering said
main radiant conduit through any of its openings to
it and discharges the same to the atmosphere out
side of said structure.
4. The system de?ned in claim 1, and including
a re?ector supported upon and disposed adjacent at
least said main radiant conduit and throughout the
effective length of said conduit to re?ect and direct
radiant energy emitted by said conduit toward the
said gas exhaust section having its gas exhaust dis
charge opening in an area open to the atmos
phere outside of the space areas being heated by
said radiant conduit,
said burner unit comprising
- a burner conduit conjoined to and communi
cating with said air intake section,
an air ?ow de?ecting member generating a
substantial pressure drop on the down
stream side thereof arranged concentrically
with said burner conduit and having sub
stantially the entire perimeter of said mem
ber spaced slightly apart from said burner
conduit, whereby to initially effect a rela
tively tubular stream of air ?ow along and
areas to be heated.
5. The system de?ned in claim 1, and including
an air ?ow switch,
a ?rst tubular pressure-sensing member communicat
ing with said switch and operatively connected there~
to, and having its digital end disposed in said burner
unit conduit downstream of said air ?ow de?ecting
member and adjacent the zone of ?ame propagation,
adjacent the inner wall surface of ' said
burner conduit and a relatively helically
swirling stream of air ?ow within said tu
bular stream and closely adjacent and pro
a second tubular pressure-sensing member communicat
gressively interspersing and intermixing
ing with and operatively connected to said switch,
and having its digital end disposed in said burner unit
conduit upstream of said air ?ow de?ecting member,
therewith,
supplying and controlling the supply of fuel to said
burner jet for operatively controlling the shut~olf of
said fuel supply to said burner jet when the pressures
'
member axially thereof and therethrough
and directed downstream thereof for the
'
ports through the body-of said air ?ow de
?ecting member and spaced outwardly of
65
tions.
. The system de?ned in claim 1, and including
a thermally responsive device in said burner unit for
sensing the presence or absence of a ?ame, disposed
downstream of said burner jet,
70
and a visual indicator in said burner unit having a
eratively responsive to the sensing of said thermally
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discharge of fuel,
on both sides of said air ?ow de?ecting member
?ame issuing from said burner jet and said means for
igniting said combustible mixture, control means op
,
a fuel jet'secured to said air ?ow de?ecting
means connecting said air ?ow switch with said means 60
transparent element‘therein disposed for viewing the
haust section is located,
said air intake section having its air intake opening
disposed for admission of air which is relatively
free of dirt and contaminants of a corrosive or
having areas to be heated.
reach predetermined relatively equilibrium propor
sure above atmospheric pressure in said gas exhaust
section so as to discharge some of the products of
combustion from said radiant conduit to the atmos
phere in the area where the exit end of said gas ex
said burner jet for the passage of air rela
tively adjacent the burner jet for effecting a
combustible mixture of air and fuel adja
cent the exit end of said burner jet and so
spaced and of such magnitude in said body
as to produce a relatively stable and e?icient
?ame propagation,
.
controlled'means in said burner conduit for
igniting said combustible mixture,
and means for supplying and controlling the
supply of fuel to said burner jet,
3,399,833
17
18
controlled means in said burner conduit for igniting
one end of said radiant conduit being con
joined to and communicating with said gas
exhaust section and forming a venturi junc
tion therewith, the other end of said radiant
conduit being conjoined to and communi- 5
eating with said gas exhaust device, for
convective and radiative absorption of the
thermal energy progressively generated by
the intermixing of the burner ?ame, said
swirling helical stream of air, said tubular 10
stream of air, and the resultant products
said combustible mixture,
and means for supplying and controlling the supply of
fuel to said ‘burner jet.
14. The structure de?ned in claim 13, and including
an air ?ow limiting damper at the air input end of said
burner conduit.
15. The structure de?ned in claim 13, wherein
said ports through said body are disposed radially of
and closely adjacent the axis of said fuel jet, and com
prise elongated slots through said body.
16. A burner unit for a low intensity radiant heater
system wherein said heater system is open at its outer
ends and closed throughout its entire intermediate extent,
of combustion,
said burner conduit having its discharge
end disposed in and spaced apart from
said venturi junction,
15 comprising
and means for controlling the input quantity and rate
a burner conduit adapted to be conjoined to and com
of air and fuel into said burner so as to attain and
-m-unicate with an air intake section,
maintain a relatively uniform though gradually de
an air ?ow de?ecting member generating a substantial
creasing operating temperature in and consequent
pressure drop on the downstream side thereof ar
radiation of energy from said radiant conduit through- 20
out the effective length of said conduit, and to control the maximum and minimum temperature limits
over the effective length of said conduit and the
rate of decrease of such temperature within said
limits.
25
9. The system de?ned in claim 8, and including
a re?ector supported upon and disposed adjacent but
spaced from said radiant conduit throughout the ef-
ranged concentrically in said burner conduit and hav
ing substantially the entire perimeter of said mem
ber spaced slightly apart from said burner conduit
whereby to initially eifect a relatively tubular stream
of air ?ow along and adjacent the inner wall surface
of said burner conduit and a relatively helically swirl~
ing stream of air ?ow within said tubular stream and
closely adjacent and progressively interspersing and
intermixing therewith,
fective extent thereof to re?ect and direct radiant
energy emitted by said conduit toward the areas to 30
a fuel jet secured to said air ?ow de?ecting member
axially thereof and therethrough and directed down
‘be heated.
10. The system de?ned in claim 8, and including
means for suspending said air intake section, said burner
unit, said radiant conduit and said gas exhaust section from the superstructure of said structure having 35
areas to be heated.
11. The system de?ned in claim 8, wherein
said air intake section and said gas exhaust section are
stream thereof, comprising
a burner jet,
a tubular member having one end conjoined to and
and communicating with said burnerjet and hav
ing its discharge end disposed through and ex
tending downstream of said air ?ow de?ecting
member, and having at least one air port through
its wall for the admission of air adjacent said
arranged concentrically,
‘
burner jet to effect a combustible mixture of
said air intake section being disposed concentrically 40
within and spaced apart from said gas exhaust
section.
air and fuel adjacent the exit end of said
burner jet,
controlled means in said burner conduit for igniting
’ 12. The system de?ned in claim 11, and including
a perforated plate arranged between said air intake sec
tion and said gas exhaust section to vent exhaust 45
said combustible mixture,
and means for supplying and controlling the supply
gases discharged from said gas exhaust device to the
17. The structure de?ned in claim 16, and including
an air ?ow limiting damper at the air input end of said
burner conduit.
18. The structure de?ned in claim 13, and including
atmosphere.
13. A burner unit for a low intensity radiant heater
system wherein said heater system is open at its outer
ends and closed throughout its entire intermediate extent, 50
comprising
a burner conduit adapted to be conjoined to and com
municate with an air intake section,
an air flow de?ecting member generating a substan
tial pressure drop on the downstream side thereof 55
arranged concentrically in said burner conduit and
having substantially the entire perimeter of said member spaced slightly apart from said burner conduit,
whereby to initially effect a relatively tubular stream
of air ?ow along and adjacent the inner wall surface 60
of said burner conduit and a relatively helically swirl-
of fuel to said burnerjet.
an air flow switch,
a ?rst tubular pressure-sensing member communicat
ing with said switch and operatively connected there
to, and having its digital end disposed in said burner
unit conduit downstream of said air ?ow de?ecting
member and adjacent the zone of ?ame propaga
tion,
a second tubular pressure-sensing member communi
eating with and operatively connected to said switch,
and having its digital end disposed in said burner unit
conduit upstream of said air ?ow de?ecting member,
means connecting said air ?ow switch with said means
ing stream of air ?ow within said tubular stream and
supplyiqg and controlling the supply of fuel to said
closely adjacent and progressively interspersing and
bllfnel' l¢t for operatlvfely controlllng the Shut-01f 0f
intermixing therewith,
,
a burner fuel jet secured to said air ?ow de?ecting 65
member axially thereof and therethrough and directed
‘downstream thereof for tile (ilscharge of filel’
ports through the body of said air ?ow de?ecting mem-
said fuel supply to said burner jet when the pres
sures on both sldes 9f 531d a11'_?°w 'dCfPCtIPE mem
23533:}! Predetermmed relatlvely equlhbnum Pro‘
19. The structure de?ned in claim 16, and including
an air ?ow Switch
ber and spacied °utlvardly (if sald burner Jet f.“ the 70
Passage of an Idanydy afhacent the, burner let for
a ?rst tubular pressure-sensing member communicating
with said switch and operatively connected thereto,
effecting a combustible mixture of‘ arr and fueladav
lacent the exit end of Said burner Jet and 3'0 Spaced
and of such magnitude in Said body as to produce a
relatively stable and e?icient ?ame propagation,
75
and having its digital end disposed and Said burner
unit conduit downstream of said air ?ow de?ecting
member and adjacent the zone of ?ame propagation,
a second tubular pressure-sensing member communi
19
3,399,833
20
cating with and operatively connected to said switch,
and having its digital end disposed in said burner
stantially the entire perimeter of said mem
ber spaced slightly apart from said burner
conduit, whereby to initially effect a rela
tively tubular stream of air ?ow along and
adjacent the inner wall surface of said
burner conduit and a relatively helically
swirling stream of air ?ow within said tu
bular stream and closely adjacent and pro
‘unit conduit upstream of said air ?ow de?ecting
member,
means connecting said air ?ow switch with said means
supplying and controlling the supply of fuel to said
burner jet for operatively controlling the shut-off of
said fuel supply to said burner jet when the pressures
on both sides of said air ?ow de?ecting member
reach predetermined relatively equilibrium propor
tions.
gressively interspcrsing and intermixing
therewith,
10
a fuel jet secured to said air flow de?ecting
20. The system de?ned in claim 8, and including
member axially thereof and therethrough
an air flow switch,
a ?rst tubular pressure-sensing member communicat
and directed downstream thereof for the
discharge of fuel,
ing with said switch and operatively connected there
to, and having its digital end disposed in said burner
unit conduit downstream of said air ?ow de?ecting
member and adjacent the zone of ?ame propagation,
ports through the body of said air ?ow de
?ecting member and spaced outwardly of
said burner jet for the passage of air rela
tively adjacent the burner jet for effecting
a second tubular pressure-sensing member communi
a combustible mixture of air and fuel ad
cating with and operatively connected to said switch, 20
and having its digital end disposed in said burner
unit conduit upstream of said air ?ow de?ecting
jacent the exit end of said burner jet and
so spaced and of such magnitude in said
body as to produce a relatively stable and
member,
e?icient ?ame propagation,
means connecting said air ?ow switch with said means
supplying and controlling the supply of fuel to said
burner jet for operatively controlling the shut-off of
said fuel supply to said burner jet when the pressures
on both sides of said air flow de?ecting member
reach predetermined relatively equilibrium propor
tions.
30
21. The structure de?ned in claim 13, wherein
said ports through said body are disposed radially of
and spaced from the axis of said fuel jet intermediate
the axis and the outer perimeter of said air ?ow
de?ecting member, and comprise openings of a total
area su?icient to pass air forming a combustible mix
ture with the fuel issuing from said burner jet,
said ports being so disposed through said body as to
substantially limit the amount of reduced pressure
immediately adjacent the downstream face of said
air ?ow de?ecting member.
22. A low intensity radiant heater system for a struc
ture having space areas to be heated, comprising
a plurality of air intake conduit sections each having
its air intake opening disposed for admission of air
which is relatively free of dirt and contaminants of
a corrosive or ori?ce-occluding character,
a burner unit communicating with and connected to
each air intake conduit section,
a radiant conduit disposed in an area to be heated and 50
communicating with and connected to a burner unit,
a manifold conduit connected to and communicating
with the exhaust discharge end of each radiant con
duit to conduct the exhaust gases therefrom,
a gas exhaust section including a gas exhaust fan device
communicating with and connected to said manifold
conduit for constantly maintaining a relatively pre
determined negative pressure in each said air intake
sections, said burner units, said radiant conduits and
said manifold conduit, and for constantly maintain 60
ing a positive pressure above atmospheric pressure in
an exhaust gas discharge tube connected to and com
municating with said exhaust fan device, said gas
controlled means in said burner conduit for
igniting said combustible mixture,
and means for supplying and controlling the
supply of fuel to said burner jet,
each said radiant conduit producing radiant emis
sive energy upon convective and radiative ab
sorption of the thermal energy progressively
generated by the intermixing of the burner
?ame, said swirling helical stream of air, said
tubular stream of air, and the resultant products
of combustion,
and means for controlling the input quantity and
rate of air and fuel supply into each said burner
unit so as to attain and maintain a relatively
uniform though gradually decreasing operating
temperature in and consequent radiation of en
ergy from each said radiant conduit through
out the effective length of each said radiant
conduit, and to control the maximum and mini
mum temperature limits over the effective length
of said conduit and the rate of decrease of such
temperature within said limits.
23. The system de?ned in claim 22, and including
a re?ector supported upon and disposed adjacent but
spaced from each said radiant conduit throughout
the effective extent thereof to re?ect and direct ra
diant energy emitted by each said radiant conduit
toward the areas to be heated.
24. The system de?ned in claim 22, and including
means for suspending each said air intake section, each
said burner unit, each said radiant conduit and said
gas exhaust section from the superstructure of said
structure having areas to be heated.
25. The system de?ned in claim 22, and including
an air ?ow limiting damper at the air intake end of
each said burner conduit.
26. The system de?ned in claim 22, wherein
said air intake sections, said burner units and said ra
diant conduits are arranged in a parallel series.
exhaust discharge tube having its discharge opening
References Cited
UNITED STATES PATENTS
in an area open to the atmosphere outside of the 65
space areas being heated by said radiant conduits,
each said burner unit comprising
a burner conduit conjoined to and communi
cating with said air intake section,
an air ?ow de?ecting member generating a 70
substantial pressure drop on the down
stream side thereof arranged concentrically
with said burner conduit and having sub
2,391,447 12/1945 Edge.
2,505,313
4/1950
2,759,472
2,941,525
8/ 1956 Cartter.
6/ 1960 Harsh?eld.
Wagoner __________ __ 237—53
3,212,493 10/1965 Lacey.
FREDERICK KETTERER, Primary Examiner.