Title of Invention

CLAMPING SYSTEM FOR INJECTION LANCES

Abstract There is disclosed a lance clamping system for injection lances comprising a base plate (12) having a supporting frame (5), a drive motor (9), mounted on said support frame, said motor being coupled to a set of gear boxes (8a & 8b) each said gear box linked to a pair of lead screws (4a & 4b) adopted to move forward and retract when required, each said lead screw (4a & 4b) being mounted on a lead screw support which itself is mounted on the said supporting frame (5), a set of rollers (1) mounted between the lead screws and operatively connected thereto such that the rollers(1) rotate in synchronization with the lead screws (4a & 4b), a limit switch(10) operatively connected to said lead screws (4a & 4b) and the sard rollers (1) having lance holding fingers (2).
Full Text Field of the Invention:
This invention relates to novel mechanism for clamping oxygen blowing lances in a basic oxygen converter.
Prior Art and Draw Backs:
In the usual basic oxygen furnace (converter), the lances used to blow oxygen into the furnace are normally in clamped position. But oxygen lances at SMS-I R.S.P are not in clamped position. So, due to this, the lances often vibrate during oxygen blowing.
These converters had been provided with lance clamping system but due to certain reasons, presently lances are without any clamp. So, undamped lances used to dangle and vibrate. Such dangling and vibration used to cause impingement of oxygen jet over the refractory and decreasing the lining fife.
This impingement of oxygen jet over the refractory not only decreased the lining life but also, to certain extent, disrupted the uniformly of oxygen blowing on the molten material and certain amount of oxygen was thus wasted.
It has already been attempted to solve this problem by designing a lance clamp.
In such a lance clamp, the linkages are actuated by pneumatic cylinders. But it was observed that due to modification of converter ignition hood, sufficient space was not available to accommodate the pneumatically operated lance clamp.
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Object of the invention
It is therefore become necessary to develop a novel lance clamp, which can be easily accommodated in the space available above the converter ignition hold.
It is therefore an object of the invention to propose a novel lance damp mechanism for BOF converters, which will totally avoid the vibrations of oxygen blowing lance.
It is another object of the invention to propose such a mechanism, which can be easily accommodated in the limited space available under the hold in the BOF,
Yet another object of the invention to propose such a lance clamp mechanism which will allow limited movement of the lance, may be even in clamped position of the lance.
A still further object is to propose such a mechanism, which can be actuated through a motor, a gear box and other auxiliaries.
These and other objects of the invention will be more clear from the following paragraphs.
Brief Statement of the Invention
According to this invention, there is provided a clamping system for injection lances comprising a base plate having a supporting frame, a drive motor mounted on said support frame, said motor being coupled to a set of gear boxes, each said gear box finked to a pair of lead screws adopted to move forward and retract when required, each said lead screw being mounted on a lead screw support which itself is mounted on the said supporting frame, a set of rollers mounted between the lead screws and operativeiy connected thereto such that the rollers rotate in synchronization with the lead screws, a limit switch operativeiy connected to said lead screws and the said roiier having lance
holding fingers.
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Preferably, the water cooling means is a pair of interconnected hollow structures, having a water inlet and a water outlet and the base plate is supported on said water cooling means to protect it from heat.
The mechanism is provided with a pair of gear boxes one or either side of the motor shaft and coupled thereto and each gear box is operatively connected to a lead screw on the motor drive side and each said lead screw is supported on said support frame.
In an ideal construction, each lead screw is provided with left hand nut and right hand nut assembly and is coupled to the gear box through couplings.
For the purpose of proper performance, both the left hand and right hand nut assemblies on the drive side and on the non-drive side are operatively interconnected for synchronization.
Both the left hand and right hand nut assemblies on the drive side are joined by a frame structure on which frame structure is supported one said roller and each said roller assembly is a tapered roller assembly and is provided with a pair of lance holding fingers.
In this mechanism, the lead screw nut assembly on the non-drive side is provided with a left hand and right hand nut assembly inter connected.
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The left hand and right hand nut assemblies are finked by a frame structure on which frame structure is mounted said roller assembly.
The pair of gear boxes are inter-finked operative^ with a limit switch.
For protection purposes, the lead screw on the drive side Is provided with a heat protecting cover and similarly, the lead screw on the non-drive side is also provided with a heat protecting cover
Still further, for better protection, there are provided a pair of cooling plates for the base plate one on the drive side and another on the non-drive side and both the cooling prates are inter connected, in which, one cooling plate is provided with a water inlet and the other cooling plate is provided with a water outlet and the cooling plate on the drive side is preferably provided with the
water inlet. Brief Description of the Accompanying Drawing:
In the accompanying drawings:
Figure 1 illustrates a general arrangement of the lance clamping mechanism and
Figure 2 illustrates the top view of Figure 1
As will be seen from the drawings, the lance damping mechanism LC consists of a roller assembly 1 having lance clamping fingers 2. The rollers are tapered rollers whose function is clearfy described hereafter.
Tlie functions of the tapered rollers are: 1. They hold the iance centrally.
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2. They facilitate vertical movement of the lance during clamping condition.
The roller assembly is operated by means of lead screws 4a and 4b, suitably supported on a supporting frame 5. There is provided a nut assembly 3 with right handed (RH) and left handed (LH) nuts to help forward and backward movement of the nut assembly.
Numeral 6 shows the cover provided for the protection of the lead screw from the effect of heat and dust. This cover is provided on the drive side, that is from the side of the driving motor 9.
Similarly, there is also provided a cover 7 for the lead screw from the non-drive side.
The lead screws 4a, 4b are operated by the motor 9 through gear boxes 8a, 8b respectively.
The operation or movement of the lead screws are controlled by a limit switch 10 conveniently connected to the gear boxes 8a, 8b and suitably synchronized.
The motor and gear box section is provided with a heat protection cover 11.
The lead screws support, the motor and the gear boxes are mounted on a supporting frame 5 which itself rests on a base plate 12. The base plate is protected from heat by a cooling plate 13 or a pair of cooling plates 13a, 13b one on the drive side and another on the non-drive side and are inter connected. The cooling plate/s is/are a hollow structure/s having a water inlet 14 and a water outlet 15.
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The Operation of the Mechanism:
Taper rollers 1 (4 NOS.) have been provided for clamping the lance so that limited movement of the lance may be achieved even in clamped position of the lance.
Maximum and minimum opening (Maximum opening is the distance between two opposite rollers when the clamp is in full opening condition and minimum 0pening is the distance between two opposite rollers when the clamp is in cfamped cmMon) is sensed and controlled through rotary fimft switch. Snap acmn iimU sw$€h&s (Nor shown in Hie drawings) also have bmn used for add^onal safety.
Heat resfetanr matertafe ftave been selected for the structural lead screws, nuts and other components.
Two numbers of coofing plates have been installed over the trolley frame. The base frame, over which the lance clamping mechanism has been mounted, is provided with heat shield, and positioned over the cooling piate/s. One heat protection cover has been installed for the protection of pear boxes, couplings, motor and ton swiicnas. Cooling tan (not shown) has been installed for cooling of complete system whereas compressed air has bsen introduced in the heat protection cover tor cooiing of motor, gear boxes and (imit switches.
The Unce Is towered through operation of iance drive switch for oxygen blowing. Lance clamp is actuated from the control panel situated in control pufpft. Lance gets clamped only alter descending certain distance into tfte converter and lance movement is possible v&fi inching facility during damped condition also. Lance is de-ciamped from the lance clamp panel The lance gets de-clamped automatically in case of abnormalities like failure of gas cleaning plant, water supply to lance. Interlocks have been provide to take care of any mal-peration.
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This innovation has application of the equipment in the following ways: -
o This innovation which was never designed/expected for tackling dangling
of lance while blowing oxygen is being tested successfully during oxygen
blowing in BOF converters.
o An equipment in which four numbers of roller assemblies {Item No 2) are
being used for clamping the lance as indicated in above drawing.
o An equipment which was not designed to clamp the lance during blowing
operation through motor and gear box arrangement in limited space is
being used in the limited space smoothly.
o Incorporation of completely new design for clamping oxygen lance during
oxygen blowing.
o Incorporation of heat protection cover, cooling plate, cooling fan, flame
protection cone, skull protection cover.
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We Claim :
1) A clamping system for injection lances comprising a base plate (12) having a supporting frame (5), a drive motor (9) mounted on said support frame (5), said motor (9) being coupled to a set of gear boxes (8a, 8b), each said gear box (8a, 8b) linked to a pair of lead screws (4a & 4b) adopted to move forward and retract when required, each said lead screw (4a &. 4b) being mounted on a lead screw support which itself is mounted on the said supporting frame (5), a set of rollers mounted between the lead screws (4a & 4b) and operatively connected thereto such that the rollers rotate in synchronization with the lead screws ( 4a & 4b)t a limit switch (10) operatively connected to said iead screws ( 4a & 4b) and the said roller having iance holding fingers (2),
2) A clamping system for injection lances as claimed in claim 1, wherein, said
base piate (12) is provided with water-cooling means.
3) A damping system for injection iances as in claim l, wherein, said water
cooling means in a pair of interconnected hollow structures (I3a& 13b),
having a water inlet (14) and a water outlet (15) and the base piate (12)
is supported on said water cooling means to protect it from heat.
4) A damping system for injection lances as claimed in anyone of claims 1 to
3, wherein there are provided a pair of gear boxes (8a, 8b) one or either
side of the motor shaft (9) and coupled thereto.
5) A clamping system for injection lances as claimed in claim 4, wherein each
gear box (8a & 8b) is operatively connected to a lead screw (4a & 4b) on
the motor drive (9) side and each said lead screw is supported on said
support frame (5).
6) A clamping system for injection lances as claimed in claim 5, wherein each
lead screw (4a & 4b) is provided with left hand nut and right hand nut
assembly (3) and is coupled to the gear box (8a & 8b) through couplings.
7) A clamping system for injection iances comprising as claimed in claim 6f
wherein, both the left hand and right hand nut assemblies (3) on the drive
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side and on the non-drive side are operativeiy interconnected for synchronization.
8) A clamping system for injection lances as claimed in anyone of claims 6
and 7, wherein, both the left hand and right hand nut assemblies (3) on
the drive side are joined by a frame structure (5) on which frame structure
is supported one said roller.
9) A clamping system for injection lances as claimed in claim 8, wherein,
each said roller assembly (1) is a tapered roller assembly (1) and is
provided with a pair of fance holding fingers (2).
10) A damping system for injection lances as claimed in anyone of claims 1 to
9, wherein, the lead screw nut assembly (3) on the non-drive side is
provided with a left hand and right hand nut assembly (3) operativeiy inter
connected.
11) A damping system for injection lances as claimed in claim 10, wherein,
the left hand and right hand nut assemblies (3) are linked by a frame
structure on which frame structure is mounted said roller assembly (1),
12) A clamping system for injection lances as claimed in anyone of claims 1 to
11, wherein, the pair of gear boxes (Sa, 8b) are inteMinked cooperatively
with a limit switch (10).
13) A damping system for injection lances as claimed in anyone of claims 1 to
12, wherein, the lead screw (4a & 4b) on the drive side is provided with a
heat protecting cover (6).
14) A clamping system for injection lances as claimed in anyone of claims 1 to
13, wherein the lead screw (4a & 4b) on the non-drive side is provided
with a heat protecting cover (7).
15) A clamping system for injection iances as claimed in anyone of claims 1 to
14, wherein, there are provided a pair of cooling plates (13a and 13b) for
the base plate (12) one on the drive side and another on the non-drive
side.
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II
16) A clamping system for injection iances as claimed in claim 15, wherein,
both the cooling plates (13A and 13b) are inter connected,
17) A clamping system for injection lances as claimed in anyone of claims 5
and 16, wherein, one cooling plate (13a) is provided with a water inlet
(14) and the other cooiing plate (13b) is provided with a water outlet (15).
18) A clamping system for injection lances as claimed in claim 17, wherein,
the cooling plate (13a) on the drive side is preferably provided with the
water inlet (14),
19) A clamping system for injection lances substantially as herein described
with reference to the accompanying drawings.
There is disclosed a lance clamping system for injection lances comprising a base plate (12) having a supporting frame (5), a drive motor (9), mounted on said support frame, said motor being coupled to a set of gear boxes (8a & 8b) each said gear box linked to a pair of lead screws (4a & 4b) adopted to move forward and retract when required, each said lead screw (4a & 4b) being mounted on a lead screw support which itself is mounted on the said supporting frame (5), a set of rollers (1) mounted between the lead screws and operatively connected thereto such that the rollers(1) rotate in synchronization with the lead screws (4a & 4b), a limit switch(10) operatively connected to said lead screws (4a & 4b) and the sard rollers (1) having lance holding fingers (2).

Documents:


Patent Number 208558
Indian Patent Application Number 0621/CAL/2001
PG Journal Number 31/2007
Publication Date 03-Aug-2007
Grant Date 02-Aug-2007
Date of Filing 02-Nov-2001
Name of Patentee STEEL AUTHORITY OF INDIA LIMITED
Applicant Address DORANDA, RANCHI 834002, JHARKHAND, INDIA.
Inventors:
# Inventor's Name Inventor's Address
1 PANDEY KEDAR NATH DORANDA, RANCHI 834002, JHARKHAND, INDIA.
2 DUTTA TAPAS KANTI DORANDA, RANCHI 834002, JHARKHAND, INDIA
3 ROY GALINA PETROVNA DORANDA, RANCHI 834002 JHARKHAND, INDIA
4 KUMAR SATYENDRA DORANDA, RANCHI 834002, JHARKHAND, INDIA
5 SAHU ASIM KUMAR DORANDA, RANCHI 834002, JHARKHAND, INDIA
PCT International Classification Number P23G 5/00
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 NA