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Патент USA US2105819

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Jan. 18, 1938.
R. M.>PARSON$
2,105,819
FURNACE
Original Filed June 16, 1934
W7
55
4 Sheets-Shéet l
36‘
33
54
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INVENTOR
ORNEY
Jan. 18, 1938.
2,105,819
R. M. PARSONS
FURNACE}
Original Filed Jun e 16, 1934
4 Sheets-Sheet 2
36
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45
"
BY
ORNEY
2,105,819
Patented Jan. 18, 1938
UNITED STATES PATENT OFFICE
2,105,819
FURNACE
Ralph M. Parsons, Mount Vernon, Ohio, assign
or to The Ralph M. Parsons Company, Mount
Vernon, Ohio, a corporation of Delaware
Application June 16, 1934, Serial No. 730,874
Renewed May 25, 1937
8 Claims. (Cl. 196-110)
This invention relates to furnaces and more ably the ?ame is caused to impinge directly on
the lower rows of tubes.
7
particularly to pipe stills for treating hydrocar
Other features of the invention consist in the
bon oils.
various details of construction and operation
In heating hydrocarbon oils to high tempera
5 tures such as temperatures required for fractional
distillation or for cracking, it is necessary to use
precautions to prevent carbonization or coking
of the oil, which tends to occur if the rate of
heat transfer to the oil in the various parts of
10 the furnace exceeds certain values, varying with
the temperature and nature of the oil. At the
same time it is desirable to provide for the max
imum permissible rate of heat transfer so as to
conserve fuel, to utilize ef?ciently the available
16 heat, and to reduce the size of the furnace for a
given output of oil.
It is accordingly an object of the present in
vention to provide a furnace having character
istics suited for the above purpose.
Another object is to provide a relatively cheap,
simple, efficient and dependable furnace for the
heat treatment of hydrocarbon oils.
A further object is to improve the details of
construction and method of operation of a fur
hereinafter more fully set forth. Although the *5
novel features which are believed to be charac
teristic of this invention will be more particularly
pointed out in the claims appended hereto, the
objects and advantages of the invention and the‘
manner in which it may be carried out may be 10
better understood by referring to the embodiment
thereof disclosed in the accompanying drawings
and more speci?cally described herein for pur
poses of illustration.
15
In the drawings:
Fig. 1 is a vertical longitudinal section through
a furnace embodying the present invention and
taken along the line l--l of Fig. 4;
Fig. 2 is a vertical transverse section of the fur—
nace taken along the line 2—-2 of Fig. 1 showing 26
the intermediate tube sheets and brackets;
Fig. 3 is a vertical transverse section of the
nace of the above type.
furnace taken along the line 3—3 of Fig. 1 show
ing the end tube sheets and brackets;
Fig. 4 is a horizontal section of the furnace 25'
Various other objects and advantages will be
apparent as the nature of the invention is more
taken on the line 4-4 of Fig.1;
Fig. 5 is a partial end section taken on the line
fully disclosed.
5—5 of Fig. 4;
In accordance with the present invention the
30 furnace is constructed to provide for the direct
flow of the furnace gases from the burners to the
stack connection without substantial change in
direction.
In a preferred embodiment the ?ow is
Fig. 6 is a partial perspective view of a tube
sheet;
30.
Fig. '7 is a broken perspective view of an inter
mediate bracket;
Fig. 8 is a broken perspective view of an end
upward throughout the furnace, and the stack
bracket;
is located directly thereover. This construction
reduces the resistance to the gas ?ow and permits
attached to the intermediate tube sheet;
the use of a relatively low and inexpensive stack.
Another feature of the invention is the pro
attaching the insulation to the end tube sheet;
vision of side wall tubes closely adjacent the path
40 of the ?ame, in a position to receive heat both by
radiation and convection so as to reduce the tem
perature of the ?ame to a value such that the
?ame may impinge directly upon certain oil tubes
without causing local overheating of the oil
therein. The side wall tubes also largely shield
the furnace walls from the intense radiant heat
of the ?ame and prevent the walls from being
damaged thereby.
A bank of tubes, referred to herein as convec
50 tion tubes, is located in the upper part of the
furnace chamber, directly in the path of the fur
nace gases and is so disposed with respect to the
burners that the lower rows of such tubes re
ceive radiant heat from the ?ame as well as heat
55 by convection from the furnace gases.
Prefer
Fig. 9 is a sectional view showing the insulation 35
Fig. 10 is a sectional view showing the means of
Fig. 11 is an end elevation of the furnace;
Fig. 12 is a detail of the door hinge;
Fig. 13 is a detail of the door lock; and
40
Figs. 14 and 15 illustrate diagrammatically dif
ferent sequences of oil flow in the various tubes.
In the various figures like parts have been
designated by like reference characters.
45
Speci?c terms are used herein for convenience
of description but it is to be understood that
they are to be interpreted as broadly as the state
of the :art will permit.
Referring to the drawings, the furnace is shown 50
as comprising a pair of side walls I!) and a pair
of end walls H forming a rectangular furnace
chamber l2. The side and end walls may be
formed of refractory or heat insulating material
which may be arranged in two or more layers 55
2
2,105,819
or sections, preferably separated by an air space
to provide for expansion and to reduce the heat
loss. The furnace ?oor I3, consisting of con
crete or refractory material, may rest upon an
earth ?ll and may be provided with openings
l4 located in the longitudinal median line there
of to receive burners to be described. The walls
may rest upon a foundation 15 such as concrete.
15
20
25
30
35
40
’
45
'
50
of fuel therethrough and is thoroughly mixed
with the fuel so as to obtain rapid and complete
combustion. This construction accordingly elim
inates many operating adjustments and auxiliary
apparatus and improves the burner ef?ciency.
Furthermore, the cold air passing under the ?oor
l3 acts as a cooling means and prevents ex
cessive heating of the, floor and foundation,
thereby materially reducing the maintenance cost
An external framework of structural members
such as channels may provide the support for of the furnace.
the various furnace elements. This framework
The burner blocks may be entirely constructed
may comprise vertical members l5, spaced along a of super-refractory but due to the high cost
the side walls and anchored thereto as by angle thereof it is preferred to use only a lining of this
irons l7. Said vertical members may be an
material as indicated at (l2'at the points of great
chored to the foundation l5 as by rods 20 em
est heat. Such construction materially reduces
bedded therein and secured to angle irons 2!
the burner cost.
which may be secured to the vertical members
An inspection or clean~out door 50 may be lo
l6 as by welding.
cated in one wall of the furnace such ‘as a side
The vertical members l6 may be joined at wall Ill. This door may be hinged to a frame
their upper ends by transverse beams 22 and by 5| secured to the framework in any convenient
longitudinal beams or angle irons 23.
manner and seated in an opening 52 formed in
The furnace also comprises a hood 30 which the furnace wall for this purpose.
seats on the side and end walls and may be se
The oil is heated in an upper bank 53 of con
cured to the angle irons 23 which transfer the vection tubes and side wall tubes 10. The upper
weight of the hood 30 to the frame-work. The tube bank 53 may comprise a plurality of verti
hood may include a door 3| which may be hinged cally spaced rows of longitudinal tubes carried
as at 32 to permit automatic opening in response in end tube sheets 54 and intermediate tube
to explosions or puffs occurring in the furnace. sheets 55. The tubes of the different rows may
The hood 363 communicates with a stack 33 which be staggered so as to obtain the fullest effect of
may be provided with a damper 34 having an the heat of the combustion gases. The tube
arm 35 adapted for remote operation by suit
sheets 54 and 55' are each provided with upper
able means (not shown). The stack 33 may be
ears 55 which are engaged by stirrups 51 sup
relatively short and may be supported directly ported by vertical rods 58, which in turn are hung
by the hood 3!) and guyed if desired to the cor
from the transverse beams 22. The various
ners of the furnace as by guys 36.
beams 22 are located above the hood 3!] and the
A row of burners 40 may be located at the rods 58 extend therefrom through the hood to
lower part of the furnace chamber l2 in a po
the stirrups supporting the tube sheets. Obvi~
sition to direct the ?ame upwardly. Preferably ously, any number of tube sheets may be em
said burners extend through the openings M in ployed although the four tube sheets disclosed
the ?oor l3. The burners 40 may comprise blocks have been found satisfactory in a particular in
of refractory material such as ?re clay or the
stance.
like having ?ared passages U shaped similar
The end tube sheets .54 may be formed of suit
to a Venturi tube so as to obtain an ei‘?oient
able material such as cast iron and may be
flow of gaseous. fuel and a thorough mixture of covered with moldable insulation 59 which may
the fuel and air for combustion. The outer ends be held in position by wires 65 (Fig. 10). Said
of the passages 4| may be lined with a super
Wires 60 may be secured, as by welding, to pins
refractory 42 such as high chrome non-metallic or nails 6|, which are cast directly in the tube
refractory, preferably mixed with basic refrac
sheet. The nails 6| may be bent over and the
tory oxides adapted to withstand the high tem
wires 65 may be twisted and/or welded thereto
peratures of the ?ame.
in the ?eld.
The burners '40 may be su?iciently long to
The intermediate tube sheets 55 may be made
permit partial combustion to take place therein
so that the ?ame may have reached a high tem
perature opposite the lower side wall tubes, to
55 be described.
Fuel supply pipes 43 extend to each burner 49
and terminate in jets 46 at the entrance to the
passages 41. The pipes 43 may be connected
to a main supply pipe 44 through valves 45 by
60 which the action of the various burners may be
individually controlled.
The air supply for the burners may be ob
tained directly from the outside by air ducts
M6 extending beneath the ?oor l3 and com
65. municating with the passages 4!. In this burner
the ?ow of the fuel gases through the passages
4i induces a flow of air through the ducts I45,
and the Venturi effect serves to effect mixing
of the air and fuel. The area of the passages
70 4i and the position and area of the jets 45 may
be such that the required air flow is induced
without additional blower means. It is to be
noted that all of the air for combustion is auto
matically drawn through the passages 4| of the
75. burners by the suction induced by the passage
10
20
25
30
35
40
of cast iron or of a material such as steel which
will permit wires (to be described) to be welded
thereto. They may also be covered with insula
tion 59 similar to that above mentioned which
may be secured thereto by wires l?l.
The wires I St may be looped and secured to
the tube sheet at intervals, as by welds 62, to
form a mesh or network about which the insu
lation may be applied.
Side ?anges 63 may be formed on the tube
sheets 54 and 5.5 to confine the insulation 59 and
to stiffen the structure. A lower ?ange 84 may
be positioned above the two lower rows of tubes
for the same purpose and the part below said
?ange 64 may be covered by insulation 65 which
may extend around the bottom 66 of the tube
sheets to protect the lower edge thereof. The
insulation on the intermediate tube sheets 55
may terminate at a point short of the upper rows
of tubes where the gases have cooled to a tem
perature such that protection for the tube sheet
is not required. The end tube sheets 54 are pref
erably completely insulated on both sides so as
60
2,105,819
to reduce heat loss through the end doors (to be
described).
A set of side wall tubes it is located adjacent
each side wall ill below the upper tube bank 53.
The width of the furnace chamber l2 is such
that the side wall tubes. are sui?ciently close to
the ?ame to receive heat both by radiation and
convection.
Tubes 752 are carried in end tube
brackets ‘H and intermediate tube brackets ‘i2.
The end tube brackets ‘H are preferably made
10
of cast iron or steel channels covered with insu
lation 8| similar to that above mentioned and
may be hung from the end tube sheets 54 as by
bolts 13.
The intermediate tube brackets 72 may be
15
formed of alloy steel so that insulation is not
required, thereby increasing the surface area of
the tubes available for heat transfer. Since
common bolts would tend to burn off if unpro
20 tected by the insulation and alloy bolts are ex
pensive, the brackets ll2 may be attached to the
tube sheets 55 by lugs ‘M formed on said brackets
and having apertures '15 (Fig. 7) adapted to pass
over and be supported by ears '16 extending from
25 opposite sides of the tube sheets .55. The ears
'16 may be received in suitable recesses in the side
walls it! which restrict transverse movement of
the assembly. The end tube sheets may be an
3
Another sequence is indicated in Fig. 14 in
which the oil enters the top row of tubes in the
convection bank 53, passes down through the
three upper rows, thence up through the three
lower rows, thence down through the remaining 5
tubes of the convection bank, thence through
the side wall tubes in the manner shown in Fig. 2.
This sequence of ?ow may be advantageous where
cooler oil is required in the lower tubes of the
convection. bank which are subjected to the great
est heat. The cooler oil in these tubes permits
a higher rate of heat transfer without carboniza
tion or local overheating of the oil.
A further modi?cation is shown in Fig. 15 in
which the cold oil ?ows downwardly through the 15
upper tubes of the convection bank, thence
through the side wall tubes, and ?nally through
the lower rows of tubes of the convection bank
in a transverse direction. In this modi?cation
the upper tubes of the convection bank constitute 20
a preheating section which extracts heat from the
gases before they are discharged to the stack.
The side Wall tubes which are heated both by
radiation and convection constitute the main
heating section in which the oil may, for exam 25
ple, be brought to cracking temperature, and the
lower tubes of the convection bank, which are also
heated both by radiation and convection, consti
chored by stays TI to a suitable portion of the
30 furnace framework.
tute a section in which heat may be transferred
at a rate to maintain the oil at the required tem 30
The lower ends of the brackets ‘H and 12 may
be held against the side walls H3 by stays Bil en
gaging ears 8! on said brackets and extending
through the side walls to the vertical members
35 it of the framework, to which they are secured.
perature.
Clearance is provided around the stays 85, par
ticularly at the inner ends thereof, to permit
movement in response to‘ expansion and con
traction of the tube sheets andbrackets.
40
The end walls H are provided with a door 82
opposite the ends of the upper bank of tubes and
with doors 83 opposite the side wall tubes, to
afford access thereto. Said doors may also be
lined with insulating material and may be hinged
45 to the framework by plates 88a. and. 81a (Fig. 12)
which may be welded to the framework and to
the doors respectively and receive hinge pins 88.
Similar plates 89 and 90 are welded to the door
and framework to receive a latch pin 9! (Fig. 13).
50 The plates may be attached by temporarily se
curing the door in place, as by spot welding, then
welding the plates in place and releasing the
door by breaking the spot weld. This ensures an
accurate ?t and requires only a minimum of time.
55 An inspection door 84 may also be provided in
one end wall H which may be hinged as at 85
to a liner 86 within an inspection aperture 81 in
the end wall II.
The various tubes may be connected for oil
60 flow in any desired sequence. A preferred se
quence for certain types of cracking is illustrated
in Fig. 2 in which the oil inlet is indicated by
pipe 92 which. leads to a tube in the top row of
the upper bank 53. The various tubes are inter
65 connected by suitable return bends to provide oil
fiow through the upper bank countercurrent to
the combustion gases, thence through one set of
side wall tubes countercurrent to- the flow of said
gases, thence through the other set of side wall
tubes concurrent with said gases, and out at pipe
93. The above sequence maintains an increasing
rate of heat transfer up to the point at which
the oil enters the side wall tubes, thence a some
what reduced rate of heating throughout the rest
75 of the circuit
It is obvious that various other modi?cations
may be employed and that the furnace is readily
adaptable for various uses by changing the con
nections to the various tubes.
It is to be noted that the position of the side
tubes close to the ?ame causes the tubes to
receive heat by convection as well as radiation
whereby the heat is more quickly extracted from
the ?ame. Such rapid extraction of heat serves 40
to reduce the temperature of the flame before it
impinges on the lower tubes of the upper bank and
to prevent carbonization or coking in such tubes
due to local overheating.
The side wall tubes partly shield the side walls 45
it from they direct heat of the flame and reduce
the quantity of heat applied to the side walls so
as to prevent heating of the walls to radiance.
The upper tubes of the bank 53 are heated
substantially entirely by convection whereas the 50
lower tubes of said bank and the side wall tubes
besides convection heat also receive radiant heat.
The construction accordingly provides a bank of
convection tubes above the radiantly heated tubes
and enclosedwithin the samev furnace chamber. 55
This feature is important as it avoids any sub
stantial change in direction of the furnace gases
after passing the radiantly heated tubes. In this
way the resistance to gas flow is reduced to a
minimum and the required ?ow of gases may be 60
obtained without using a high, expensive stack
or a blower.
The side wall tubes prevent appreciable heat
loss by absorption of the side walls and roof.
The end walls are of comparatively small area 65
and the heat loss produced thereby is not great.
It is contemplated that the side walls may be’
made comparatively thin and of inexpensive ma
terial since they are nearly completely shielded
from the flame and are not required to absorb 70
a large amount of radiant heat and to transfer
such heat by reradiation to the tubes.
The mounting of all tubes directly from the out
side framework simpli?es the construction prob
lem since a minimum of weight is carried by the
2,105,819
tion may likewise be applied at the point of as
side wall tubes onto the lower tubes of said con
vection bank, and means to withdraw combus
tion gases from the top of said combustion cham
ber in substantially a direct line with said burn
ers, whereby combustion gases pass through said .5
furnace upwardly without substantial change in
direction, said side wall tubes being spaced to
shield the side walls from the radiant heat of
sembly.
the flame and being disposed adjacent the path
Although any standard method of joining the
structural members may be employed, it is pre
of the flame to receive heat both by radiation and 10
convection for rapidly extracting heat therefrom
before the ?ame impinges on the lower tubes of
furnace walls. By suspending the side wall tubes
directly from the upper tuba sheets, relative
movement between the tubes due to expansion is
avoided and the necessity for expansion couplings
is eliminated.
The tube sheets and brackets are so formed as
to be readily assembled in the ?eld.
10
ferred to use all welded construction.
The insula
This may
be accomplished by use of simple welding devices
which are readily available at the point of as
15 sembly.
Although the invention has been illustrated as
embodied in a speci?c device, it is to be under
stood that various changes and substitutions may
be made therein by a person skilled in the art.
20 The invention is accordingly to be limited only
by the scope of the following claims when inter
preted in View of the prior art.
What is claimed is:
1. In a furnace of the class described, a tube
25 chamber, a bank of tubes in the upper part there
of, tube sheets supporting said tubes, a structural
framework, said tube sheets being supported by
said framework and having ears formed at the
lower part thereof, additional tubes below said
30 bank, brackets carrying said additional tubes,
said brackets being hung on said ears and sup
ported thereby whereby the entire set of tubes
may expand and contract as a unit.
2. In a furnace of the class described, a side
wall, a set of side wall tubes, tube supports car
rying said tubes, means suspending said supports,
and a link extending through said side wall to
hold the lower part of said supports thereagainst,
said side walls having su?icient clearance around
said link to permit vertical movement of said
supports due to expansion thereof.
3. In combination, a furnace wall, a tube sheet
the convection bank.
6. An upshot oil still comprising, in combina
tion, a rectangular combustion chamber, a con
vection chamber above said combustion chamber
and formed as a continuation thereof, a bank of
horizontal, longitudinally extending convection
tubes carrying hydrocarbon oil substantially ?ll
ing said convection chamber, transverse tube 20
sheets carrying said convection tubes, a row of
horizontal radiant heat tubes extending verti
cally below said convection tubes, brackets sus
pended from said tube sheets carrying said radi
ant heat tubes, a row of burners at the bottom
of said combustion chamber and spaced longi
tudinally thereof to direct the ?ame past said
radiant heat tubes toward the lower tubes of said
convection bank, and means to withdraw com
bustion gases from the top of said combustion ’
chamber in substantially a direct line with said
burners whereby the combustion gases pass
through said furnace upwardly without substan
tial change in direction, said radiant heat tubes
being disposed adjacent the path of the ?ame to
receive heat both by radiation and convection for
rapidly extracting heat therefrom before the
?ame impinges upon the lower tubes of the con
vection bank.
'7. An upshot oil cracking still comprising, in
combination, a rectangular, elongated combus
rigidly supported with respect thereto, said tube
tion chamber, a convection chamber above said
combustion chamber and formed as a continua
sheet having a transverse lug entering a recess
tion thereof, a bank of horizontal, longitudinally
45 in said wall, a tube carrying bracket adapted to
hang over and be supported by said lug, and
means securing the lower end of said bracket
against said wall while permitting vertical move
ment of said bracket in response to expansion
50 and contraction thereof.
4. In combination, a furnace wall, a tube sheet
extending convection tubes carrying hydrocar
bon oil substantially ?lling said convection
chamber, transverse tube sheets carrying said
convection tubes, a row of horizontal side wall
radiant heat tubes on both longitudinal side walls
below said convection tubes, a plurality of verti
cal brackets supported only at one end, each
rigidly supported with respect thereto, said tube
bracket extending in supporting engagement with
sheet having a transverse lug entering a recess
in said wall, a tube carrying bracket adapted to
55 hang over and be supported by said lug, and
means securing the lower end of said bracket
against said wall while permitting vertical move
ment of said bracket in response to expansion and
contraction thereof, said means comprising rods
60 extending through enlarged openings in said wall
and anchored externally thereof.
5. An upshot oil still comprising, in combina
tion, a rectangular combustion chamber, a con
vection chamber above said combustion chamber
65 and formed as a continuation thereof, a bank of
horizontal, longitudinally extending convection
tubes carrying hydrocarbon oil substantially ?ll
ing said convection chamber, transverse tube
sheets carrying said convection tubes, a row of
70 horizontal side wall tubes on both side walls be
low said convection‘ tubes, brackets suspended
from said tube sheets carrying said side wall
an entire row of said radiant heat tubes, a row
of burners at the bottom of said combustion
chamber spaced along the center line thereof to '
direct a ?ame upwardly between said rows of
side wall tubes onto the lower tubes of said con
vection bank, and means to- withdraw combus
tion gases from the top of said combustion cham
ber in substantially a direct line with said burn
ers, whereby combustion gases pass through said
furnace upwardly without substantial change in
direction, said side wall tubes being spaced to
shield the side walls from the radiant heat of
the ?ame and being disposed adjacent the path
of the ?ame to receive heat both by radiation and
convection for rapidly extracting heat therefrom
before the ?ame impinges on the lower tubes of
the convection bank.
8. An upshot oil cracking still comprising, in
combination, a rectangular, elongated combus
tubes, a row of burners at the bottom of said com
tion chamber, a convection chamber above said
bustion chamber spaced along the center line
combustion chamber and formed as a continu
75 thereof to direct a ?ame between said rows of
ation thereof, a bank of horizontal, longitudinal 75.
2,105,819
1y extending convection tubes carrying hydro
in
carbon, oil substantially ?lling said convection
chamber, transverse tube sheets carrying said
convection tubes, a row of horizontal, longitudi
nally extending radiant heat tubes, said row ex
tending vertically below said convection tubes, a
plurality of vertical brackets supported only at
one end, each bracket extending in supporting
engagement with the entire row of said radiant
10 heat tubes, a row of burners at the bottom of said
combustion chamber and spaced longitudinally
thereof to direct the ?ame upwardly past said
radiant heat tubes onto the lower tubes of said
5
convection bank, and means to withdraw com
bustion gases from the top of said combustion
chamber in substantially a direct line with said
burners whereby the combustion gases pass
through said furnace upwardly Without substan
tial change in direction, said radiant heat tubes
being disposed adjacent the path of the flame to
receive heat both by radiation and convection for
rapidly extracting heat therefrom before the
?ame impinges upon the lower tubes of the con- 10
vection bank.
RALPH M. PARSONS.
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