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Патент USA US3097845

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July 16, 1963
A. A. J. QUINTIN
3,09 7,835
HEATING OF ZINC OVENS
Filed April 21, 1961
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United States
atent
1
3,097,835
Albert André Joseph Quintin, Overpelt, Belgium, assignor
HEATING OF ZINC OVENS
to Compagnie des Metaux d’Gverpeit-Lommel et tie
Corphalie, S.A., Overpelt-lez-Neerpelt, Belgium
Filed Apr. 21, 1961, Scr. No. iiMJlil
Claims priority, application Great Britain June 14, W69
6 Claims. (Cl. 263--37)
free
3,097,835
Patented July 16, 1963
2
The streams of liquid fuel travel thus in an opposite
direction to that of the combustion air which is heated
in the regenerators, rises in an upward direction and
brakes to a certain extent the speed of the thin streams
of. liquid fuel whilst becoming mixed with the vapours
of liquid fuel, and the latter is immediately lighted.
In order to completely vaporize the fuel before the
latter reaches the ?oor where the air is subdivided, the
injection of fuel is generally subdivided in the vertical
This invention relates to the heating of zinc ovens by 10 plane of the uprights of the oven into two or several
means of liquid fuel,
jets of a small diameter, for instance comprised between
For heating metallurgical furnaces with liquid fuel,
about half a millimetre and about one millimetre. Such
use is generally made of extra-heavy liquid fuel, which
is least expensive. Owing to its viscosity when cold, such
liquid fuel has to be heated before it is introduced into
the combustion chamber of the furnace, and is admitted in
a ?nely-divided form obtained by pulverization by means
of steam or air under pressure, or by means of mechanical
pulverizing devices.
For applying such a process, the
jets may have different diameters and directions, they may
be even oblique, the main object being to ensure a regular
conversion into vapour and combustion of the liquid fuel
along the entire height of the oven, at its various levels,
thus rendering the temperatures uniform. In certain
cases, in order to obtain uniform temperatures along the
entire height of the oven without liquid fuel reaching the
furnace should have a combustion chamber of a capacity 20 ?oor of the oven, it may be advantageous to inject a small
and shape such that at no moment shall any pulverized
portion of fuel gas into the oven at its lower level, together
liquid fuel come into contact with the surfaces to be
with the combustion air, thus ensuring an additional heat
heated.
Otherwise, a cracking takes place and carbon
in a form difficult ‘to burn, is deposited upon the surface
of the furnace, on which it hardens; such hard deposits
grow rapidly and disturb the passage of the ?ames and
thus the good working of the furnace.
When the combustion chamber of the furnace has in
at least one direction small dimensions, for instance when
it is obstructed by the objects to be heated, as is the case
for instance with zinc ovens with multiple retorts, which
generally are heated by means of gas (producer gas,
natural gas, etc.) the difficulty may be avoided more or
less satisfactorily by gasifying the liquid fuel outside
the cost of construction, and leads to losses of heat.
The present invention consists in a process for heating
the furnace in apparatus in which it is subjected to high
temperatures. Such an arrangement however increases
zinc ovens having a plurality of rctorts with liquid fuel
such as heavy fuel oil which consists in injecting thin,
non pulverized jets of said fuel between the retorts so
that under the combined effect of the contact with the
incandescent gases and of the radiation of the hot sur—
faces the liquid fuel is totally vaporized before it can
strike a solid surface and form carbonaceous deposits.
The vapours thus produced are in?amed and ensure
by their combustion the heating of the combustion cham
ing at the lower level of the retorts, allowing thus to reduce
the length of the streams of liquid fuel. Such an injec
tion of gas may advantageously be made by using carbon
monoxide (CO) as the gas, and namely the carbon mon
oxide gas which escapes from the rctorts. Such gas may
be collected in any convenient manner.
When the direction of gases in the oven is to be reversed,
that is generally every 15 to 30 minutes, the inlet of liquid
is closed for one half of fuel injecting devices in opera
tion on half the oven, the admission of air is reversed,
and the liquid fuel is admitted to the other half of inject
ing devices, this latter half receiving now the combustion
air which has been heated in the regenerators.
Such a heating arrangement with multiple injections of
liquid fuel at different points of the zinc oven, allows of
more regularly heating than what is generally obtained
with a gaseous fuel. It is indeed suf?cient to provide a
flow meter and a throttle valve for each injector in order
to maintain the required amount of fuel for each injector.
It is also possible to provide for each injection a small
pump of variable output remaining strictly constant for
each position of the regulating device.
In the heating arrangement of zinc ovens above de
scribed, the injecting devices for liquid fuel placed on
the roof of the oven above the narrow passages provided
in the masonry, which allow a passage to the streams of
ber. Such an arrangement avoids all gasifying arrange
ment outside the combustion chamber and consequently
liquid fuel, are subjected to radiation from the combustion
important losses of heat, excessive size. It represents a 50 chamber through the said passages during the period for
great simpli?cation of plant and ensures a maximum yield
which they deliver liquid fuel, and also during the period
of heat, since the totality of the heat contained by the
for which they are not working, when passing from one
fuel is liberated inside the combustion chamber where
reversal to another. An overheating of the injector and
it is utilized.
therefore of the liquid fuel, should be prevented in order
Generally zinc ovens have horizontal retorts, are heated
to avoid cracking and thus obstructions. For that pur
with producer gas or natural gas, and work with periodical
pose, a cooling of the injector may be ensured by a flow
of liquid and by a thin curtain of water droplets provided
reversal of ‘the gas and air inlets. In such ovens the
between the injector and the passage in the roof, obtained
space between the retorts is small.
for instance by injecting wet saturated water vapour. It
According to one feature of the present invention the
liquid fuel is injected in a downward direction into the 60 is obvious that during the period for which the injectors do
not work, it is also possible to provide a ?ap valve made
spaces between the vertical rows of retorts, preferably in
of a material which is non-conductive of heat and resists
the direction of a vertical plane passing through the up
well to the action of heat, which automatically closes the
rights supporting the roof of the oven, where owing pre
passage in the roof and protects the injecting device from
cisely to the presence of the upright, there is a space be
heat radiated by the oven.
tween the vertical rows of retorts which is just sufficient
One of the advantages of the persent invention is that
for such injection.
it
may
be readily applied at little cost to zinc ovens work
The diameter of the streams of liquid and the speed of
ing with reversals, and heated with combustible gas. The
their injection are such that the gasifying process is
heating arrangement by gas may be retained to pass from
achieved at the level of the lower row of retorts and no
liquid fuel heating to gas heating, when liquid fuel is no
liquid fuel reaches the floor of the zinc ovens, thus avoid
longer available.
ing its cracking and all production of hardened carbon.
FIGURES I to 3 of the accompanying drawings show
3,097,835
4
3
during the period of non-injection and also prevents the
a mode of applying the invention to a Zinc oven with 4
rows of retorts of the type working with reversals.
FIGURE 1 is a vertical section made in a zinc oven by
ensuing cracking, as the water vapour prevents any exces
sive cooling which would solidify the liquid fuel and
would make a rc-starting of the injection uncertain.
a plane perpendicular to the partitioning wall which di
vides the oven longitudinally in halves. The numeral 1
shows the said partitioning wall; the reference numerals
What i claim is:
l. A process for heating zinc ovens having an enclo
sure in which a plurality of retorts is provided between
2, 2 show retorts which are supported at the rear into
which incandescent gases pass which heat the surfaces
recesses provided in the wall, the numeral 3 shows the
of the retorts, which comprises moving combustion air
roof of the oven, the numerals 21, 21 show heat regenera<
tors with lattice-work packings, the numerals 4, 4 show 10 in an upward direction between the retorts, while inject
ing liquid fuel in a downwards direction between the ire
pipes through which combustion air heated in the re
torts in jets, controlling the diameter of the jets of liquid
generators is introduced into the combustion chamber
of the oven, whilst liquid fuel is injected into the corre
fuel and the speed of the jets to allow the liquid fuel to
be substantially completely converted into vapor state
under the combined effect of the contact with the incan
descent guses and of radiation of the hot surfaces of the
retorts before they reach the floor of the oven, thus
sponding half-oven, and through which leave the hot
gases produced by the combustion of liquid fuel during
the period which follows the reversal.
FIGURE 2, which is a view of the front wall of the
oven, shows uprights 17, supporting plates 18 upon which
avoiding carbonaceous deposits upon the inner surface
are supported the front part of the retorts 2, the axial
lines A—A and B—B showing the position of the axes of
the uprights and of the openings or passages 5 shown in
FIGURE 1.
of the oven or the retorts.
Z. A process for heating zinc ovens having an enclo
sure in which a plurality of retorts is provided between
which incandescent gases pass which heat the surfaces
The said axial lines show also the position of the injec
of the retorts, which comprises moving combustion air in
tor shown in FIGURE 3.
The FIGURE 3 shows a section made in the arrange
an upward direction between the retorts while injecting
liquid fuel in a downwards direction in jets of between
about half a millimeter and about one millimeter diam
ment for the injection of liquid fuel, along a vertical plane
parallel to the partitioning wall and passing through the
eter controlling the speed of the jets to effect conversion
of the liquid fuel, into vapor state under the combined
effect of the contact with the incandescent gases and of
radiation of the hot surfaces of the retorts before they
reach the floor of ‘the oven, thus avoiding carbonaceous
axis of a vertical injector.
A horizontal metal ?ooring of lattice-work formation
not shown in the drawings, may be provided above
the roof of the oven. It SBI'VEES for the suspension of the
casings of fuel injecting devices and for the circulation of
the workmen who supervise and maintain the arrange
deposits upon the inner surfaces of the oven or the re
torts.
3. A zinc oven having an enclosed casing with a roof,
The numeral 7 shows a casing with two boxes 8 and 35 a floor and walls, a plurality of retorts inside the casing
supported on the walls, means for supporting the re
9, cooled by a water ?ow. The water is brought by con
torts inside the casing, uprights arranged in a plane for
duits 8' and 9', and leaves through conduits 8" and 9".
supporting the roof, means for causing combustion air
Wet saturated water vapor is brought through a conduit
to pass upwards between the retorts and for causing in
20 to the pipe 10 provided with ori?ces 11 through which
the water vapour escapes and forms a veil of vapours un ell) candescent gases formed in the oven to pass between
the retorts to heat the surfaces of the retorts, and down
derneath the injectors 13.
The numeral 12 shows a supporting block for the in
wardly directed means arranged upon the roof of the
oven for injecting thin jets of liquid fuel in a downward
jectors 13 which are screwed into the mas of the support
ment in good working order.
ing block, the ori?ces 14 of the injectors projecting thin
jets of liquid fuel through the roof of the oven.
The numeral 15 shows a conduit for bringing in the
liquid fuel and the numeral 16 shows a channel for its
distribution to the various injectors belonging to one and
the same block. Each block comprises preferably several
injectors of different diameters.
direction into the oven a sufficient distance into the oven
The various blocks are arranged above the passage 5
provided in the roof 3 of the oven and the supports are
?xed to the above mentioned metal ?ooring, by means of
the said uprights.
and between said retorts to cause said liquid fuel jets to
he completely converted into vapor state before they can
strike the floor of the oven.
4. A zinc oven as claimed in claim 3, in which the
means for injecting the thin jets of fuel in a downward
direction into the oven are arranged in the plane of
5. A zinc oven as claimed in claim 3, having means
associated with said means for injecting liquid fuel for
girders 6, 6.
providing a curtain of ?ne droplets of Water and steam
The block 12 is made independent from the casing 7.
It rests upon the machined and horizontal bearing surface
19. A sand joint 22 ensures if necessary, a tight joint.
It is thus possible to supervise the injectors in a rapid
and easy manner, whilst avoiding all disturbance of the
protecting the means for injecting liquid fuel against
radiation from the oven.
6. A Zinc oven as claimed in claim 3, having superim
posed parallel. horizontal rows of retorts, and means for
heating the ‘lowest row of retorts with carbon monoxide
gas which escapes from the interior of the retorts.
direction of the jets of liquid fuel, when the supporting
blocks are removed or replaced in position.
The water cooling of the boxes 8 and 9 and the ad
mission of wet saturated water vapour protects the in
jectors against any undesirable heating due to heat ra
diation from the combustion chamber, and protects the
entire arrangement against any deformations produced
by an excessive heating.
The above arrangement more particularly prevents an
overheating of the liquid fuel which remains stationary
References Cited in the ?le of this patent
UNITED STATES PATENTS
0
612104
876,891
893,560
1,048,420
2,386,429
Hegeler ______________ __ Oct. ll,
Ziesing ______________ __ Jan. 14,
Ziesing ______________ __ July 14,
Londress et al _________ __ Dec. 24,
Breyer ________________ __ Oct. 9,
1898
1908
1908
1912
1945
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