Note: Descriptions are shown in the official language in which they were submitted.
;7353
The present invention relates to a radiant heater.
BACKGROUND OF THE INVENTION
The criterion Eor evaluating a radiant heater are
output, efficiency and versatili-ty. Output is impor-
5 tant, as in applications such as soil sterilization thesterilization will not occur unless specified heat
levels are attained. Efficiency is important as fuel
costs may determine whether use o~ -the heater for a
specific application is economically viable. Ver-
10 satility is important as heating requirements fromindustry to industry, or even within a single industry,
vary with the application.
SUMMARY OF T~E I~VENTION
The primary object of the present invention is to
15 provide an improved radiant heater.
Broadly, the present invention provides a radiant
heater which is comprised of a housing; a combustion
chamber in the housing, the combustion chamber defining
a central axis and having an in-take end having an intake
20 opening thereat and an exhaust end having a discharge
opening thereat, the chamber defining a flow passage for
products of combustion along the central axis; a heat
exchange chamber surrounding the intake end of the
combustion chamber; a heat exchanger disposed within the
25 heat exchange chamber, the heat exchanger having a pipe
ormed into a plurality of coils one end of which is
adapted to be connected to means Eor circulating fluids;
radiator means surrounding the combustion chamber, the
radiator means defining the exhaust end of the combus-
3~ tion chamber for :radiating heat radially outwardly ofthe exhaust end of the combustion chamber, radiator
means having a plurality of fluid flow passages disposed
in planes containing the central axis, each of the
passages having an inlet end communicating with -the
35 combustion chamber and an outlet end opening into the
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353
lleat exchange chamber, whereby p:roducts oE combustion
enter the passage inlets and Elow therealong and into
the heat exchange chamber; and reflector means surround-
ing the radiator means for reflectlng axially outwardly
5 of the housing heat radiated by the radiator means.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other features of the invention will
become more apparent from the :Eollowing description in
which reference is made -to the appended drawings,
10 wherein:
FIGURE l is a perspective view of a preferred
embodiment of the invention.
FIGURE 2 is a sectional view of a preferred
embodiment of the invention taken at section line 2-2 of
15 FIGURE 1.
FI~URE 3 is a sectional view of a portion of a
preferred embodiment of the inven-tion taken at section
line 3-3 of FIGURE 2.
FIGURE 4 is a section view of a preferred embodi-
20 ment of the invention taken a-t section line 4-4 of
FIGURE l~
FIGURE 5 is a cut away view of a preferred embodi-
ment o:E the invention.
ETAILED DESCRIPTION_OF_HE I ENTION
The preferred embodiment of the invention is a
radiant heater generally designated by reference numeral
10, which is illustrated in and will now be described
with reference to FIGURES 1 through 5.
The primary components of radiant heater 10 are, a
30 housing 12, a combustion chamber 14, a heat exchange
cha-mb~r 16, a heater exchanger 18, a radiator ~0 and a
reflector 22.
,, ~'-
3~
Housing 12 is generally cy:~ndrical in cross-
section, having a central core port 'on 13, and an outer
circum~erence portlon 15, which are secured in relat~ve
position by a plurality of struts 1. whi~-h ~re welded 'o
portions 13 and 15. Attached to ~.ousing 12 are front
and rear mounting brackets 24 and 26. Rear mounting
brackets 24 has apertures 28 wh'ch are adapted to
receive a f ixed shaf t 30 . The ends 32 of f ixed shaft 30
are received in apertures 34 o~ su?ports 36, in order
that housing 12 may be mounted in fa^tory premises or on
a platform 19 of a trailer 21 as i:~ustrated in FIGUR~
1. Front mounting bracket 26 is ada?ted to be connected
to hydraulic mounts 23 on platform 19, $n order that the
central axis 38 of radiant heater 10 may be adjusted
verticall~. :Radiant heater 10 is not capable of
lateral ad~ustment, other than through relatiYe
posltioning of pla~form 19 upon which heater 10 i5
mounted.
Combustion cha~er 14 is disposed within housing
12, and defines central axis 38. Combustion chamber 14
has an intake end 40 having an $ntake opening 42
thereat. Positioned at intake opening 42 ls a gas
burner 44. Combustion air is provided to burner 44
through fresh air inlet 46, which is connected by ~r
duct 48 to end 50 of burner 44. Conbustion chamber 14
has an exhaust end 52 having a discharge opening 54
thereat. Combustion chamber 14 deflnes a flow passage
for products of combustion along oentral axls 38.
Intake end 40 of combustion chamber 14 progressively
increases in slze about central axis 38 from intake
opening 42 towards discharge opening 54. Exhaust end
52 of combustion chamber 14 progressively decreases in
slze from intake end 40 to discharge opening S~ of
combustlon chambcr 14.
Burner 44 has a ~uel pump 45 wh~ch draws fuel fro~
fuel tank 47 through filter 49 and fuel suctlon l~ne S1.
~.~6~7~5~
Burner 44 is a two stage burner an~ has a firs~ s~age
no~zle 53 and a second stage noz~:~ 55. The flow of
fuel from fue~ pump 45 to no~z:Gs 53 and 55 are
controlled by solenoid valves 57, ~:~1ch oPe~ to permit
the passage of fuel at 34 second in-ervals. Should the
air fuel mlxture ~ail to ignlte, soleno~d valves 57
remain closed in order to prevent an excess of fuel from
be~ng pumped into burner 44. Excess fuel is returned to
fuel tank 47 through fuel return lir.e 59. The presence
1O of solenoid valves 57 and fuel returr. line S9 are safety
features to prevent the pos~ibil~ty of explosion~.
Burner 44 can be adapted for operation on any of a
number of fuels, ~uch as propane, ~atural gas, diesel
fuel, kerosene, and the like.
Radiator 20 is ~in the ~or- of a corrugated
conical shell having a. la~yer end 56 concentrically
disposed about axi~ 38 and ad~ace~.t intake end 40 of
combustion chamber 14, and a ~maller end 58
20 concentrically disposed about axis 38. Radiator 20
defines exhaust end 52 of co~bustion chamber 14 and
serves to radiate heat radlally outwardly of exhaust end
52 of combustion chamber 14. Radiator 20 ha~ a
plurality of corrugations 61 disposed in plane~ 62
25 containing central axis 38. Corrugation~ 61
are open with the exception of an 18 inch portion remote
from smalicr end 58, which is enclosed form~ng fluld
flow pa6sages 60. Passages 60 have an lnlet end opening
64 communlcat~ng with combustion chamber 14 and an
30 outlet end 66 remote communicating with heat exchange
chamber 16. Products of co~bustion from combu~tion
chamber 14 flow from smaller end 5B of con$cal radiator
20, along open corrugations 61 ev~ntually
entering passage inlets 64 of passages 60, throu~h
35 outlets 66 and into heat exchange chamber 16. In
order that the flow of exhaust gases from inlet end 64
to outlet end 66 may be retarded t~ retain heat wlthin
radiator 20 baffl~ partitions 68 and a splral ba~le 70
7~3S~3
are disposed in passages 60, as ls lllustrated ln
FIGURE 3.
Conical radiator 20 has an 'rregular exterior
s surface 72, which can be attributed to the ~resence of
corrugati~ns 61, which ~re present c~. both the interior
and exterior surfaces. Corrugations 61 serve to provide
a greater surface area for the ~adiation of heat.
~eflector 22 surrounds radiator 20 for reflecting
10 axially outwardly of housing 12 heat rad~ated by
radiator 20. Radiator 20 is ~ade ou~ of materials which
are known by the trade name "Ferrotherm 4816".
Ferrotherm 4816 was oriyinally develop~d for use in
atomic reactors, and has a composi~ion which includes
15 79.9% nickel and .29% titanium for resistance to
tempera-ture, aud 1.2% aluminum fo: flexibility. The
surface of reflector 2~ ~s sub~ec~ed to a treatment
which is described by Krupp Industries of Germany as
being "glo-heated". The applicant has attempted to
20 obtain further particulars of this treatment for the
purpose of making a full and comp.ete disclosure, and
has been advised that the treatment i5 a trade secret of
Krupp Industries.
Heat exchange chamber 16 surro~nds intake end 40 of
combustion cha~ber 14. Heat exchange chamber 16 has two
ann~lar rlngs, a collector ring 76 and an exhaus~ ring
7R. Collector ring 76 communicates with outlet end 66
of each of passages 60. Exhaust ring ~ has an opening
80 which is connected to exhaust duc~ 82. There are
two openings 77, whlch permit communication of exhaust
gases betwesn collector ring 76 and exhaust ring 78.
Exhaust ring 78 i5 smaller in size than collector ring
76 as the air has cooled down and contracted somewhat by
the time it reaches exhaust ring 78.
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A heat exchanger la i5 disr~sed within heat
exchange chamber 16. Heat exchange~ lB is comprlsed of
two of pipes, 84 and 8~, confi~urec in coils. Pipe 84
i5 posltiolled in collector ring 76, Pipe 34 is
5 connected at one end 85 to cold ai~ intake duct BP and
at the opposite end 89 to hot air o-:~let duct 90. Plpe
84 i5 formed into nine coils 92 w :hin collector ring
76. An air blower 94 is connected to cold air intake
duct 88 at end 85 of pipe 84 to blow ambient air through
10 pipe 84. As air circulates within coils 92 of plpe 84,
the air becomes heated by the products of combustion in
collector ring 76. End 89 of pipe a4 is adapted to be
connected to the duct wor~ of a hot alr heating system
(not shown). Pipe 86 is positioned in exhaust ring 78.
15 Pipe 86 is connected at one end 95 ~~ cold water intake
duct 96 and at the opposite end 97 ~o hot water outlet
duct 98. Cold wa.ter intake duct 56 is adapted to be
connected to a water -source (not shown) . A manual
control valve 100 is placed at ene 95 of pipe 36 to
20 control wate~.flow. Pipe B6 is fo~ed into three coils
102, within exhaust rin~ 78. As water circulates
through coils 102 of pipe 86, the water becomes heated
by the products of combustion within exhaust ring ~8.
End 37 of pipe 86 is adapted to be connected to a
network of pipes forming a hot water heating system (not
shown).
To operate radiant heater 10, burner 44 is
connected to fuel tan~ 47, and air is drawn through
fre h air inlet 46 via alr duct 48 until the air/fuel
mixture is ignited wlthin combustion chamber 14. The
products of combustion pass through intake opening 42 at
intake end 40 of combustion chamber 14 and move along
centra~ axis 33 to discharge opening 54 at discharge end
52 of combustion chamber 14. At discharge end 52 the
products of combustion pass through di~charge open~ng 54
into inlet end 64 of pas~age 60. ~he movement of the
73~
products of combustion along passas~ 60 is retarded by
baffle partitlons 68 and a spir~: ba'fle 70 within
passages 60. When the products of combus~iorl reach the
outlet end 66 of passage 60, the p-,ducts of combustion
are discharge~ into collector rins 76 of heat exchange
chamber 16. The products of combust'on then flow around
collector ring ~6 of heat exchange c:~amber 14, thsn into
exhaust ring 78 of heat exchange chamber 14, finally
being vented out a single exhaust d~t B2.
At the same time as the above described combustion
cycle is opera~ing, two other :~eatlng cycles are
operating within heat exchange chamber 16. With one of
these cycles, air is blown by blower 94 via cold air
15 inlét duc~- 8~ into pipe 84. Air circula~es through
~oils 92 of p1pe 84 until it reaches hot air outlet duct
90. As the air pas5~s through coi:s 92 of p~pe 84 it
becomes heated by the products o' combustion within
collecto~l r~ng 76. Hot air outle~ duct 90 serves a
20 secondary function of preheating t~.e air which enters
through fresh air 'inlet 46 into barner 44. This i5
accomplished by placing air duct 4~ and hot air outlet
ducS 90 in close proximity such that a partial heat
exchan~e ta~es place. Preheatins the alr entering
25 ~urner 44, assists in combustion, provided the air is
not heated to too great an extènt. Prehea~ing the air
to approximately 50 degrees celslus is viewed as
acceptable. Due to the tendency o~ air to expand when
heated, heating the air to too great an ext~nt can
30 create an undesirable bac~ pressure within the system.
With the other of these cyc:es, water 1B drawn
through cold water intake 96 into plpe 86. As wa~r
circulates around coils 102 o~ plpe 86, the w~ter is
35 heated by the products of combustion within exhaust rin~
~8. Water flowlng from hot water outlet 98, is heated
and can either be used as such or can be connected to a
hot water heating system t not shown).
i'7;3S3
The output of heat from radiat-r 20 is enhanced by
c o r r u g a t i o n s 6~ a n d -e f lecto r 22 .
Corrugations 61 serve to provlde ~ larger surface area
for the radiat~on of heat. Re'lector 22 reflects
Gutwardly the heat of radiator 20.
It will be apparent to one s~i:led in the art that
an increased output can be obtained from radiant heater
lO by virtue of baffle partitions ~a and spiral ba~fle
lO ~ retarding the movement of produc~s of combustlon and
thereby retaining heat within radiator 20. Ie will
similarly be apparent that a greater efficiency o f
operation is ~btained by preheating air intake lnto
burner 44, and through use of heat exchange ch~mber 16
15 and heat exchanger 18 to give othe- ~or~s of heat from
- the same fuel source. It will si311arly be apparent
that radiant heater lO, has increased versatility and
adaptabi.lity as radiant heat, hot hater, or heated air
can be supplied as the appllcation aemands. It will be
20 apparent to one skilled in the art ~hat radiant heater
10, can be adapted to provide steam heating, by
circulating water within heat exchan~er 18 until ~t
beco~es converted to steam.
Radiator 20 is constructed to be able to with~tand
te~peratures approaching 1500 degrees centigrade. ~n
controlled tests conducted by the Alberta Re~earch
Councll, the radiant heat produced was between 1150 and
1250 degrees cent~grade, and hot air output wa~ 600
30 cubic feet per minute at a temperature of 680 degrees
c~ntigrade~
