Note: Descriptions are shown in the official language in which they were submitted.
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;~ The pres~nt invention relates to a device for de-termining
the proEile of a charge piled in a blast furnace.
Distribution of gas flow in a blast furnace is one of the
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most important factors for stable operation of the blast furnace.
The distribution of the gas flow is closely connected with the
piling condition of the material and fuel charged in the furnace.
Therefore, the piling condition of the chargel i.e., the profile
of the charge, must be controlled to keep the distribution of
gas 10w under control. Many blast furnaces are equipped with
a charge distributor plate for controlling the piling profile of
raw material and fuel, and consequently the distri~ution of gas
flow in the furnace.
It is desirable to be able to measure the pro~ile of the
charge at any time to control the distribution of gas flow.
; Various means for measuring the profile of the charge have been
proposed; these are generally classified as non-contacting systems,
using electromagnetic waves, ultrasonic waves, radioacti.ve rays,
etc., or as contacting systems employing a plumb measuring device.
The present invention belongs to the latter group, the con-
tacting systems. In one prior art structure, a wire rope runs
? through a guide pipe which moves horizontally in the radial
~; ~ direction in the furnace. To the end of the wire rope a plumb
is attached and hangs down, and the contact of the plumb with
the charge surface is detected by a detector outside the furnace,
and the depth of the charge surface from the guide pipe is meas-
ured. The guide pipe is moved in the radial direction, to measure
at several points in the radial direction and thereby estimate
the profile of the charge.
In the prior art as described above, the plumb is lifted
to the position of the guide pipe while the pipe is being moved,
so that the plumb will not swing with the movement of the guide
pipe. This has the disadvantage of taking too much time for the
measuring operation, i.e., lowering the plumb, detecting the
landing, raising the plumb, and shifting the guide pipe~ Because
~harges usually sink at a rate of abou-t 10 cm/min., when mcasure-
ments are made at sevcral points to determine the complete
profile, the time required from the firs-t measurement to the
last is too long because of changes to the profile of the charge
itself, resultin~ in the inability to make accurate measure-
ments of the configuration.
An object of the present invention is to provide a measuring
device ~or the piling profile of the charge of a blast furnace
capable of reducing measuring time by quickly detecting the land-
ing of the plumb. Ano-ther object is to provide a measuring device
with which reduced measuring time can be achieved by preventing
the swinging of the plumb.
' According to the invention, a measuring device for the profile
of a charge of a blast furnace, comprising a guide which can be
. inserted into a blast furnace to guide a loop of rope having at
its end a plumb slidably attached thereto, a load detector which
detects changes of tension of the rope, a drum for winding the
rope, a first revolution counter which detects rotation of the
drum, a drum driving device, a guide driving device for moving
the guide relative to the furnace, a second revolution counter
which detects the position of the guide, and detecting and
~: controlling means which receive signals from the load detector
and both revolution counters and estimates the profile.
The drum and the tension detector are mounted on a carriage
for the guide, the tension detector including a pulley around
which the rope passes.
The plumb has an eye hole through which can slide the looped
portion at the end of the ropel and the guide suppports a pair
of pulleys for the looped portion whereby the plumb is always
located midway between the pulleys.
The drawings illustrate, by way of example, an embodiment of
the invention.
In the drawings:
Fig. 1 is a diagrammatic illustration of a profile measuring
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device and oE portions of a blast furnace;
Fig. 2 is a sectional view of par-t of the device, on an
.. enlarged scale, indicating the rela-tion between a plumb and a
wire rope; and
Fig. 3 is a diagram indicating a trace of the motion of
the plumb.
; In the embodiment illustrated a guide pipe 3 can move longi-
tudinally of itself and radially through the furnace wall 2 of a !
blast furnace 1. The pipe 3 is fixed at one end to a carriaye 4.
Near the other end, two pulleys 5 and 5' are mounted in the guide
pipe 3 and can rotate freely. The pipe has an opening 6 below the
.~ pulleys 5 and 5'. A wire rope 7 runs through the pipe 3. The rope
. 7 has a looped portion 8 (see Fig. 2). One part of the loop 8
passes around the pulle~ 5 and another part passes around the pulley
5', and the looped portion hangs down into the.furnace through the
opening 6. The loop passes slidably through an eye-hole 10 of a
.~ plumb 9, whereby the plumb 9 is always located midway between the
:: two pulleys 5 and 5'. The object of this arrangement is to prevent
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swinging of the plumb movement of the guide pipe 3. The wire rope
; 20 7 passes around a pulley 12-and is wound around a wire drum 13 .in-
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stalled on the carriage 4. The pulley 12 which is part of a load
` detector 11 mounted on the carriage 4. The wire drum 13 can be
` rotated in either direction by a drum driving device 14.
The carriage 4 travels on a rail 15. A chain 18 has two ends,
one attached to the rear of the carriage 4 and the other attached
~:~ : to the front of the carriage, and the chain passes round a chain .
.
. ~ wheel 17 driven by a guide pipe driving device 16, so that the
carriage can be driven horizontally by rotation of the chain wheel
. 17. Signals from a revolution counter 19, installed on the shaft
of the chain wheel 17, are fed to a detector and controller 20,
which detects and stores the position of the guide pipe 3. An
operation starting signal can also be sent from the detector-
controller 20 to the guide pipe driving device 16. The detector-
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controller 20 can be fed with signals from the load detector 11.
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Further, the detec-tor-controller 20 sends out drive star-ting and
stopping command signals to the driving device 14. Revolution of
the wire drum 13 is detected by a revolution detector 21 on the
shaft of the drum 13, and signals from the detector 21 are received
and stored by the detector-controller 20. A timer 22 is also con-
nected to the detector-controller 20.
The drum driving device 14 drives and stops the drum in
accordance with signals from the detector-controller 20.
The load detector 11 detects the load~ employing for e~ample
a strain-resistance load cell or a magnetrostrictive load meter,
and ~eeds a signal oE load change to the detector-controller 20,
causing it to send out a drum drive s-topping signal to stop the
driving of the drum.
The guide pipe driving device 16 employs for example, a
geared electric motor started by a signal issued from the de-
tector-controller 20 and stopped by limit switches (not shown in
the drawing) installed at a certain determined distance. Revolu-
tion of the chain wheel 17 is detected by the revolution counter
19, and its signal is fed into the detector-controller 20 and
stored in it.
Various types of known devices can be adopted as the re-
volution counters 19 and ~1.
In the drawing, reference numeral 23 indicates a blast
furnace charge, 24 is a bell, 25 is a hopper, 26 is a fresh charge,
27 is a movable charge distributor plate, 28 is an operating rod
and 29 is a gas seal fitting.
In operation of the illustrated embodiment, the free end
of the guide pipe 3 is moved by the guide pipe driving device 16
to the deepest measuring point, and stopped, then the drum driv-
ing device 14 is driven to feed out the wire rope 7 and lowerthe plumb 9. The load detector 11 is preadjusted to reduce output
signal to zero when the plumb 9 is housed in the guide pipe 3.
Because the looped portion B of the wire rope 7 passes through
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the eye hole 10 of the plumb 9, the plumb 9 is always located at
midway between the pulleys 5 and 5' when it is lowered as the rope
~ 7 is being fed out by rokation of the wire drum 13. Then, when
the plumb 9 reaches to the surface o-E the charge 23, the power
signal of the load detector 11 .is changed. The signal is fed to
;~ the detector-controller 20, which .in turn issues a commanding signal
to the drum driving device 14, causing the wire drum 13 to stop.
: During the foregoing operation, revolutions of the wire drum 13
: are detected by the revolution counter 21, and the signal fed to
; 10 the detecting controller 20 is converted to an indication of the
.. depth of the charge, and this depth value is stored.
' Soon after completion of the first measurement, a signal
,. from the detector-controller 20 operates the guide pipe driving
~ device 16 to move the guide pipe 3 in the direction of withdrawal
.. . from the furnace, and at the same time a signal is fed from the
detector-controller 20 to a timer 22 and the drum driving device
14, causing the latter to operate for a certain predetermined
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time preset by the timer to raise the plumb 9 a certain distance
~- only (h in Fig. 1). The distance h is as small as practicahle.
20 When the guide pipe 3 has been trans~erred to the next measuring
point, it is stopped by stopping the guide pipe driving device
16 by means of a limit switch. The position of this stop is de-
tected by the revolution counter 19, and a position signal is fed
. to the detector-controller 20 and is recorded. The plumb 9 is
caused to descend by a command signal from the detector-controlier
-~ 20 just before the guide pipe is stopped, to make the plumb con-
- . tact the charge 23 at almost the same time as the guide pipe 3
stops, and the depth at that position is measured. The same pro-
: cedure is repeated to measure the depth at several positions
until a position is reached near the furnace wall, and the profileof the charge is obtained.
The trace of the movement of the plumb 9 is shown hy a
broken line in Fig. 1. The shifting velocity of guide pipe 3
- can be synchronized with the lifting or lowering velocity of the
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plumb 9 in -the following rela-tion:
tan 1- ~ tan ~ -~ R
where, K is a correc-tion factor (a positive number),
is angle of repose of the ore,
1 is the horizontal pitch between measurements.
Levels at each measuring point can be measured in a short time,
and an accurate profile of the pile can be measured quickly by
; the processing of measurement signals by the detecting controller
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Figure 3 shows a trace of the plumb 9 taking the plumb
position as ordinate, and the position of the guide pipe 3 as
abscissa. In the drawing, wave form A indicates the state jus-t
prior to charging, and wave form B indicates that just after
charging, and an accurate profile can be measured as shown in
Fig. 3.
; In the operation described above the guide pipe is stopped
at the measuring points to detect landing of the plumb 9. An
~; alternate method is not to stop the guide pipe 3, but to lower
the plumb 9 as the guide pipe 3 is being moved in the direction of
~- 20 withdrawal, and the plumb 9 is pulled up as soon as it lands, and
- this process is repeated. In this latter case, although the
positions of measurement vary in accordance with the profile of
the charge, the profile can be measured by detecting the landing of~
the plumb 9 by the load detector ll and feeding this detecting
;~ signal, and the signal of the revolution counter 19, to the detector-
controller 20 for recording.
The direction of shifting the guide pipe 3 is not necessarily
in the withdrawal direction; instead the guide pipe can be moved
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from the furnace wall to the center of the furnace, and in this
case the distance h, by which the plumb 9 is pulled up, can be
`~ reduced to almost zero.
The present invention enables easy and speedy detection land-
ing o-f the plumb 9 being detected by measurement of the tension on
~ the wire by the load detector 11. The invention helps to shorten
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: the measuring t.ime and allows an accurate charge profile to be
obtained by way of the detector-controller 20 which receives
signals from the load detector 11, from the revolution counter
19 which detects the position of the guide pi.pe 3, and from the
revolution counter 21 which detects the revolution of the wire
. drum 13, and the detector-controller issues each necessary com-
mand signal.
, Running the looped portion 8 of the wire rope 7 throuyh the
eye hole of the plumb 9 keeps the plumb 9 supported from both
sides, and eliminates swinging of plumb 9 almost completely when
the guide pipe 3 is moved. This allows measurements to be made
with a short lifting distance and hence shortens the measuring
time.
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