Note: Descriptions are shown in the official language in which they were submitted.
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~he present invention relates to a device which
makes it possible to inspect the interior of an enclosure,
for example for making some specific measurements.
-. ~he following description illus-tra-tes an application
of the device to the inspection of the burden in a
blast furnace. ~his is done, however, by way of eæample
and wi-thout implying c~ny limitation. A device according
to -the invention can be used for observing the interior
: : of ~n~ enclosure.
~here is a well-recognized interest in observing~
for example, -the evolution of -the shape of the upper
surface of the burden in a blas-t Iurnace, the
distribution of -the surface -tempera-tures from i-ts centre
to its periphery and the appearance of ho-t spots or cold
zones, etc. ~hese indications allow the operation of
the blast furnace to be improved, this depending on
appropriate addition of coke, ore, and flu~es as well
as on accurate dlstri.bution of these materials across
the whole of the upper surface of -the burden.
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~he value of all data is of course subo.rdinate
to the ~act of being able to correctly observe the burden
by means of a device which is as reliable as possible.
~heoretically, these conditions cannot easily be met~
because the space above the burden in the blas-t furnace
i 25 may con-tain a comp:ressed gas (for example~ at a pressure
of 2 kgjcm ) and is practi.cally always very dusty.
In order to observe thb charge inside a blast
furnace~ various devices have already been suggested
which are generally of the scanning t~e and .iorm a
com~onen~ of a~practically fi.~ed device, or o~ -the
telemetric type.
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. In mos-t cases~ -these devices permit observation of
~: the burden in a blast furnace ~hrough an inspec-tion window
of -transparent material permanen-tly cleanecl from inside
. ~he applicants have alread~ sugges-ted a device of this
t~pe whiGh comprises, on -thè one hand, an observation
or measuring instrument whose sigh-ting axis, or a-t least
i-ts ter~ninal par-tj is orienta-ted so as -to pass -through
an opèning and, on the o-ther hand, means for devia-ting
the si~l-ting axls of -the instrumen-tO Such a device makes it
~ possible to orientate the axis o~ -the ins-trument in an~.- ~ 10 directions compatible wi-th the aperture of -the ins-trument.
~` Some devices of this type have alread~ been availableon the marke-t, in particular -thermographic apparatus
whose means for cleviating the sighting axis o~ the camera
are po~gonal prisms. In general~ use of these devices
requires -the formation of a relativel~ large opening
: in the side wall as well as an insulating valve in
order -to be able to make all -the necessar~ measurements ins:Lde
the enclosure.
~'he present invention providcs a device which
comprises :` .
- an--observation or measuring instrumen-t,
- deflec-tors a-t least one of which Ls mobile to
ensure7 on the one harid, the passage of radia-tion from the
inside of the enclos-ure to an observation opening, preferabl~
of mini.mum size, and, on -the o-ther hand, transmission
of the sàid radia-tion to the observation or measuring
instrumen-t along a braken line -the end part of which
coincides wi-th the sighting a~is of the sald observation
or measuring instrumen-t7
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( - means for rot~ting the mobile deflector or deflec-tors
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.about an axis perpendicular to the plane formed b~ the said
s.igh-ting axis and its prolongation along -the said broken
line~
~ - means ~or rotating the deflector ass~mbly about an
: 5 axis cQincidin~ with a portion o~ the said bro.ken line,
- a suppor-t on which -there are ~ T~ on the one
hand~ the obse~vatlon or measuring ins-trumen-t and, on
the other hand, -the RXiS o.f rotation about which -~he de~lector
assemb~y is designed to rotate as well as me~ns for
rotating this assembly.
he de~lee-tors ma~ advantageously be :~o~med by
mirrors. ~he mirrors may be configured and arranged to
. ensure measurement or observation at as constant as possible
an angle independently o~ -the direction in ~uestion. Alternat
ively, the mirrors may be con~igured and arranged to
ensure as constant as possible a measurement or observation
o~ a surface in -the sigh-ted zone independently o~ the
direction in question.
~he ~ixed or movable mirrors can be pla~o and/or
cylindrical with a circularq or ellip-ticalq or ~arabolic
cross section~ and/or having ~n ellipsoi.d sux~ace por~ion
and/or a paraboloid sur~ace portion and/or a spherîcal
: surface portion.
Accordin.g ~o a par~icularly advantageou~ embodimen-'~
o~ the invention, the mirrors are p].ane and the axis o:~ ro-tation
o~ the movable mirror is located outside -the pa-th ~ollowed
by the radia-tion from the orlfice to the instrument.
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~, It is thus obtained that the common intersection of
the received radiation and the radiation reflected b~ the
movable mirror is subjected to combined rotary movement and
displacement during the displacement of the movable mirror.
According to a modification, one of the mirrors is
fixed and has a curvature such that at least one movable mirror
can be located on the path o~ the radiation from the orifice
to the instrument. A particularly advantageous embodiment is a
concave shape. The surface of the curved mirror can be either ~
10 continuous (which is preferred) or formed by facets. `
The device preferably comprises a diaphragm which
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ensures a constant aperture for the optical system used. The
optical circuit may comprise an element adapted to focus radiation
through the diaphragm~ or through the observation opening, onto
the surface of the instrument.
The movement of the movable de~lector or deflectors
may be derived through a cam or a rack. The movement of the
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movable deflector or deflectors and the rotation movement of
the deflector assembly are advantageously controlled by the
same motor by way of a differential system.
Moreover, the obser~ation or measuring instrument,
the deflector assembly, and the means for rotating this assembly
may be mounted on a support movable towards and away from an
opening formed in the side wall of the enclosure or of an
insulation valve. The end of the approaching movemént stroke
of the assembly comprising the
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observation ins-trument c~nd -the de~lectors~ in ~ront
of the opening lormed in -the side wall o~ the enclosure
to be in.spected or of` the insulati~g valve, ad~antageousl~
coincides with -the closing of a seal o~ a circular
space supplied with a fluid and ensuring injec-tion of this ~luid
all around the said assembly.
A shield protecting the optical sys-tem from the inner
atmosphere o~ the enclosure to be inspected is advantageous~
rigid with the support oE the observation instrument and with
the axis of rota-tion of the deflectors~ thereby making it
easier to clec~n it. A second shield is advantageously
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made rigid with the movable assembly o~ the deflectors in
order to tiC~ht seal -the element .Eormed b~ the observa-tio.n
instrument and the said deflec-tors. In -the case in which
. a single shield .is used, the shield can be made rigid
with the mo~able assembly of -the de~lec-tors in order
to tight seal the element Eormed ~y the observation instrume~*
and -the said de~lectors. In the case in whlch a single
~, shield is used, the shieid can be made rigid with the movable
i assembl~ of the deElectors in o:rder to tight seal the
; 20 optical s~stem.
¦ ~he suppo:rt to which the observation or measuring
instrume.nt and the axis o~ rotation of the de~lectors are
fixed, is advantageously contcained in a tigh-t ~ealed
casing so as to prevent an~ danger which mi~lt come
~rom the enclosure to be inspected.
¦ ~he~invention.will be described further? by wa~ of
.
¦ example only, wi-th reference to the accompanying drawings,
¦ in which ~or inspecting the in-terior o~ an enclosure~-
~IGURE 1 shows a device ~or inspecting the interior of
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an enclosure~ comprising a movable pl.ane mirror havlng
i .an axis o~ ro-tation located ~u-t,side the pa-th ~ollowed
. by radiation from an o~servation ope~ing to an observa-tion
ins-trument;
~IGURE 2 shows a device comprising a ~ixed concave mirror
, 5 and at least one movable mirror having an a~is of rotation
.l loca-ted on the path followed bg radiation ~xom an observa-tion
- openin.g to a.n obser~ation instrument; and ~G~E 3 sho~s a
;~ device movable towards and away from the opening formed
in thejside wall o~ the enclosure ~hose in-terior is to
: 10 be inspec-ted.
~he device illustrated in ~IGURE 1 has a measuring
'l instrument in the form of a pyrome-ter P having a sighting.
~' axis 1. ~he p-yrometer P is mo~mted i.ndirectly on a
:.
support 2. The prolongation of the sighting axis 1 is
~oId~d op~,'c~,I
,~, 15~ deviated along a ~ Y~ ~}}~ path by the action o~
de~lectors formed by plane mirrors 3, 4~ 5, 6 and passes
through an observation ori~ice 8 before entering the
enclosure (not shown) the temperature of whose interior
is -to be measured. ~he ori~ice 8 is located in front o~
a transparen-t shleld 9. A diaphragm 7 delimi-ts a constant
aperture ~or the optical s~stem.
:~ ~he plane mirrors 3, 4, 5 are fixed wi-th respect
to one another and onl~T the plane mirror 6 is mo~Table~
in -the sense tha-t l-t can rotate abou-t an axis 10
perpendicular to -the plane con-taining the sightin~ ~is
. 1 and.its prolongation . The axis 10 is located outside
: the pa-th followed b~ -the radia-tion from the orifice 8
. to the p~Trome-ter P. The posit~ons ~f the common i~tersecti.ons
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11 and 12 between the incident beam and the beam reflected by ~.
the movable mirror 6 in two different positions of the mirror 6 .
clearly show that these intersections are subjected to a combined
rotary and translational movement during the displacement ;; -
of the movable mirror 6.
The movement of the mirror 6 is obtained as follows. ;;~
A tube 13 rigidly fixed to the support 2 is connected to a
movable tube 14 by means of needle bearings 15. Within the : -;
movable tube 14, a second movable tube 16 is kept in position
by two needle bearings 17. Rotary movement is transmitted to
the tubes 14 and 16 by means of toothed rings 18 and 19 as
well as a differential comprising two toothed wheels 20, 21
and a motor 22 mounted on the support 2. A position indicator
23 is also pro~ided. A cam 24 is located at the end of the tube
16, the movement of the cam 24 displacing the axis of a ro~ler `
25 mounted on the rotatable arm 26 rigid with the mirror 6.
A return spring 27 acting on the rotatable arm 26 urges the `;
roller 25 to contact with the cam 24. The shape of the cam
; ; 24 may be such as to defice a trajectory of a predetermined
given shape across the surface to be inspected in the enclosure.
.~ ~ The assembly of the mirrors 3, 4, 5, 6 i5 rotatable
about an axis which coincides with the sighting axis 1 and is
: fixed with respect to the support 2. ~.
The system formed by the components 18, 19, 20 and 21, ~ `
: drives of the tubes 14 and 16 at different predetermined speeds
so that, if the tube 14 effects for example 10 rotations, .
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the tube 16 effects 11 rotations in the same direc~ion.
Consec~uently, during the 10 rotations of the tube 14, the mirror
6 effects a complete forward and backward movement, since the
tubes 14 and 16 perform a complete revolution relative to each
other.
Scanning of the surface to be insepcted inside the
enclosure is ensured by two movements: on the one hand, the
movement provided b~ the rotation of the movable mirror 6, and, ~ -
on the other hand, that provided by the rotation of the assembly ~ :
of the mirrors3, 4, 5, 6 about an axis coinciding with the
sighting axis 1.
An air box 28 is provided in front of the shield 9 :~
so as to act as a cushion between the shield and the inside of .
the enclosure. The air box 28 is fed from a circular space 29
by way of conduits 30.
It is possible to readily disassemble the shield 9
from its support, which is mounted on the air box 28, which is,
in turn, bolted to a cooling water jacket 31.
In FIGURE 2, the observation ins~rument is a pyrometer
P having a sighting axis 41. This pyrometer is fixed on a support
42. The deflectors are formed by mirrors 43, g4, ~5, 46. A
: diaphragm 47 ensures a constant aperture for the optical ~ ;
system used. The optical path is folded along a non-rectilinear
path in a plane containing the axis 41 under the action of the ~
mirrors 43 to 46 and passes through an observation orifice 48 ~.
before entering the enclosure the temperature in which is to
be measured. The orifice 48 is located in front of a transparent ~ ;
shield 49. `-
The mirrors 43 and 44 are plane and fixed; the mirror ~ :
46 is cylindrical and fixed. The mirror 45 is plane and
can rotate about an axis 50 perpendicular to the
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plane containiny the sighting axis 41 and its prolongation.
The axis 50 is located on the said prolongation. Rotary movement
of the mirror 45 can be obtained by means of a cylindrical cam
51 and a roller 52 which displaces a bent arm 53 actuating a
rack system 54.
The surface of the mirror 46 is port on of a right
circular cylinder. The curvature of the mirror 46 is such that
it is possible to use the pivoting mirror 45 to locate the path
followed by the radiation from the orifice 48 to the pyrometer
1 0 P .
The assembly of the mirrors 43, 44~ 45, 46 can rotate
about an axis which coincides with the sighting axis 41 and
is fixed with respect to the support 42.
Scanning of the surface to be inspected inside the
enclosure is ensured by two movements: on the one hand, the
movement given by the oscillation of the movable mirror 45 and,
on the other hand, that given by the rotation of the assembly
of mirrors 43, 44, 45, 46 about an axis coinciding with the
sighting axis 41.
The angular position of these two movements is adjusted `
to selectively position the optical path so that it is directed
to the part of the surface to be observed, e.g. for the measure-
ment of the temperature of the burden in a blast furnace. An
air box 55 is provided in front of the shield 49 to act as a
cushion between the shield and the inside of the furnace. The
air box 55 is fed by a circular space 56. It is possible to
easily disassemble the shield 49 from its support, which is
mounted on the air box 55, which is, in turn, bolted to a
cooling water jacket 57.
In FIGURE 3, the assembly 61 formed by the system
of mirrors is connected to a pyrometer 62 in the case of
a measurement of the temperature of the burden in a
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~las-t fl~nace. Rotatlonalmovement o~ the assembly 61
is con-trolled b-y a reduction gear 6~. ~urthermore~
~IGUR~ 3 shows a loca-tion 64 ~or con-trol devices
indispensable for mailitainlng transparent the shield
' designed to protect the op-tical system agains-t the
internal atmosphere of the enclosure, to be inspscted.
~o be able to move the components 61, 62~ 63 7 64
near -to and awa~ from an opening f'ormed in the side
of the enclosure whose in-ternal temperatures are to
be measured, -the said components are mou~-ted on a s~pport
' 10 65 which is displaced along guides 66 and 67 by a jack 68.
~he components 61 to 68 are located in,an enclosure
69 under pressure, which rests on,shaft 70 attached to
~i a support plate 71 fixed -to -the pla-ting of' the blast ~urnace.
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' '~his approaching movement ma~es i-t possible -to
,"1 15 , obtain an extremely large observation field 73 independently
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~' of the ratio,of thickness to useful diameter of the~' ~ ' shaft 70. One,end posl-tion'o~ -the movement -towards and
awa~ ~rom the isolation val~e 69 is determined by the
value of the said o'~servation field 73,, whereas the
other end position is chosen so as to comple-tely withdraw
¦ 1, the componen-ts 61 to 6~ ~rom -the shaft.
~he stroke limit 72 of the approaching movement of the
components 61 -to 64 rela-tlve -to the isola-tion enclosure
69 coincides with the closing o~ a seal 74 of a circular
space 75 fed wi-th air. Coilsequently -the air contained
in -the circular space 75 is discharged ~rom -thls space
,, and enters the ass~bly 61 and -the shaft 70 and thus
assis-ts in keeping these in good working condition.
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