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Патент USA US2412568

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Dec. 17, 1946.
Filed Feb. 5, 1945
Patented Dec. 17,’ 1946
John E. Donahue and Leo W. Schrader, Elizabeth,
N. J., assignors to Standard Oil Development
Company, a corporation of Delaware
Application February 5, 1943, Serial No. 474,790
3 Claims. (Cl. 122-—510).
The present invention relates to improvements
in furnace construction, and more particularly,
to an improved means for supporting and pro
tecting the tube return headers in a furnace.
For illustration, one concrete embodiment of
this invention is shown in the sectional perspec
tive view of the accompanying drawing.
It has heretofore been the common practice in
constructing tube chambers in furnaces, particu
larly in the radiant section, to support the sets
or banks of tubes and the individual tubes of the
sets or banks by tube sheets and intermediate
hangers exposed to the effect of heat and gases
from the combustion chamber. These tube sheets
and hangers must be constructed from special
alloys in order to enable them to resist the cor
roding effect of the gases and the intense heat in
the combustion section of the furnace. The use
of these heat resistant alloys increases the cost
of the heater materially, particularly when it is
realized that in a typical installation, using long
horizontal tubes, as many as three intermediate
alloy tube supports per pair of tubes are required.
in addition to those used at the tube ends to sup
port the header boxes.
By eliminating the use of end alloy tube sheets
protecting the header boxes and header-box sup~
ports and supporting the tubes, a large part of
after reading the following description and claims
and after considering the accompanying drawing
which is a perspective view of the preferred form
of this invention with parts cut away.
The portion of the furnace structure chosen
for illustration comprises side Wall I, end walls 2
and 3, and roof 4 forming the usual combustion
section of a furnace. Disposed across the com
bustion space are roof tubes 5 which terminate in
the customary type of return headers 6. These
return headers are enclosed in a housing 1 pro
vided with hinged doors 8 which permit ready ac
cess to the ?ttings, header boxes, and the like.
This housing may be attached to the furnace
in any suitable manner; for example, it may be
attached to the furnace wall by means of sup
_ porting I-beams 9 and brackets In. That portion
of the housing nearest the furnace interior is
constructed of a suitable refractory material
forming wall I l which serves to screen the hous
ing, the headers, and other ?ttings contained
therein from the effects of the radiant heat of the
furnace and from the combustion gases. This
wall is preferablysupported on top of the usual
, furnace wall 3 and is connected to the roof 4
thru I-beam l2, although it may be simply a
continuation of wall 3. The wall II may also be
additionally supported by means of steel plate I 3.
this cost could be avoided.
Where tubes 5 pierce thru wall t2, the opening
Consequently, one of the primary objects of the 30 between the tubes and the refractory brick may
present invention is the provision of a construc
be sealed in any desirable manner as by asbestos
rope packing l4.
tional arrangement in the radiant section of the
furnace whereby the tubes are supported at their
The tube headers may be supported in the
ends in such a way that the relatively expensive
housing by resting them on rollers l5 which are
alloy tube sheets are replaced by less expensive
in turn supported by angle-iron supports I6 rest
refractory and the return headers are shielded
ingon I-beam IT, or they may be supported in
from the direct heat of the furnace and are pro
any other desirable manner, such as by U-bolts
tected from the action of the flue gases.
or J-bolts, so that the headers are free to ex-,
Another important object of the present in
pand or contract with the tubes in accordance
vention is to provide an arrangement whereby the
the change in temperature and conditions
tube headers are independently supported behind
in the combustion zone of the furnace.
a wall which protects them from the combustion
The present invention, therefore, eliminates
gases, the supports being so arranged that the
the usual alloy tube sheet for supporting the ends
tube headers, supports, chamber walls, etc., may
move relative to one another under the in?uence 45 of furnace tubes, particularly in the radiant sec
tion of the furnace, and provides, instead, means
of expansion and contraction forces without
for supporting the tube headers independently
strains or stresses leading to deterioration and,
behind a tile wall which acts to protect the
Still another object of this invention is to pro
headers and ?ttings from the intense heat of the
vide a special type of tube header support so con 50 combustion zone and from the oxidizing effect
structed as to assist in carrying out the forego
of the combustion gases. Furthermore, the head
ing objects.
ers and their supports and tubes are free to ex
Many additional objects as well as advan
pand or contract in accordance with the tem
tageous uses and purposes of the invention will
perature changes in the furnace.
be or should be fully appreciated and understood 55 The nature and objects of the present in—
vention having thus been set forth and a speci?c
illustrative embodiment of the same given, what
is claimed and desired to be secured by Letters
Patent is:
1. In a furnace, the combination comprising
bottom, top and side walls forming a combustion
zone in said furnace, tubes disposed across said
combustion zone and extending through said side
walls, in sealed relation thereto, and provided for
longitudinal movement through said walls, head
er members connecting the ends of each tube with
an adjoining tube exteriorly of the combustion
substantially horizontally, forming a substantial
ly right angle with said tubes.
3. In a furnace the combination comprising
bottom, top and side walls forming a combustion
zone in said furnace, tubes horizontally disposed
across said combustion zone and extending with
free play through said side walls, return headers
for each end of said tubes horizontally disposed
outside said walls and connecting pairs of tubes
arranged in the same horizontal plane and indi
vidual roller means exterior and independent of
said walls for loosely supporting said headers in
dividually and arranged beneath and substan
zone, and means, independent of said side walls,
tially parallel to said headers, said headers being
supporting each of said header members for
to move independently from the motions of
sliding movement with its connected tubes, with
any other header and without affecting the
respect to the supporting means and to any other
means supporting any other header.
header member.
2. A furnace according to‘ claim 1 wherein
said supporting means comprise rollers arranged
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