JPS5825538B2 - Device for determining the operating state in a continuous casting machine of the type with a rotating endless casting belt - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for determining the operating state of a continuous casting apparatus of the type with an endless casting belt adapted to confine molten metal.

The device according to the invention can be used to determine the molten metal pool level and also to determine the condition of the belt covering to protect and insulate the belt front surface from molten metal contacting the belt front surface. Can be used.

In practice, it is extremely difficult to measure the rate of molten metal supply and also to determine the level of the molten metal pool.

In many cases, the molten metal pool is closed from sight by equipment provided in the inlet area of the casting device.

Even if a small observation hole were made on one side, the surrounding insulating material and the slag and dross floating in the molten metal pool would prevent accurate determination of the exact level of molten metal. .

Additionally, the continuous motion of the casting belt and the high velocity liquid cooling fluid flowing rapidly along the heated belt backside prevents pool level determination.

Since the molten metal is at its highest temperature when it is led into the pool, the total amount of heat flow is greatest, and the intensive and continuous cooling of the back of the belt is absolutely It is necessary.

One embodiment of the invention is described in detail below.

The device according to the invention determines the level of the molten metal pool in continuous casting machines of the type with endless casting belts.

Such a method can also be used to determine the condition of an insulating and protective coating over a cast belt.

The method and apparatus employ one or more sets of at least two thermal sensing detection devices.

These sensing masses are mounted in a position surrounded by the cooling fluid so that their tips are relative to the floating water cooling surface of the endless casting belt.

A high velocity stream of cooling liquid is introduced against and moves along the backside of the belt.

The detection device is mounted within a streamlined jacket that offers little resistance to the high velocity flow of coolant directed thereto.

A sensing device is associated with the splash loading member.

The spring loaded member is suitably mounted to the frame of the casting apparatus to form a set of sensing devices such that the sensing devices are correctly positioned in place.

A spring loaded member urges the tip of the sensing device into contact with the moving casting belt.

The detection device is also configured such that the jacket shields the detection element of the detection device from lateral thermal effects due to the continuous rapid flow of coolant.

A highly conductive tip that contacts the backside of the belt transfers thermal energy from the belt surface.

One embodiment of the invention will now be described in detail with reference to the accompanying drawings.

In each drawing, corresponding reference symbols indicate corresponding components and features.

In FIG. 1, a continuous casting apparatus equipped with an embodiment of the invention is shown.

In this casting apparatus, molten metal 12 is supplied from a pouring box 14 and flows down through a pouring port 16 into a tundish 18 .

The rate of this flow is controlled by a tapered stop 20 attached to a control rod 22.

Molten metal is conveyed via nozzle 24 to inlet area 25 and directed into casting area C formed between upper and lower endless flexible casting belts 26 and 28.

These belts are made of steel or alloy steel.

Such steels have toughness and resistance to abrasion and physical damage, as well as resistance to thermal shock and thermal differential stress during casting.

As shown in FIGS. 2 and 4, each belt has a protective and insulating coating 29 on its casting surface (hereinafter referred to as the front surface).

Casting belts 26 and 28 are supported and driven by upper and lower carriages.

These carriages are attached to a framework (not shown) and are generally designated 30 and 32 in the drawings.

Each carriage has two main rolls 34 and 38 and 36 and 40 by which the casting belt is supported, driven and steered.

These belts consist of a large number of finned backup rollers 4
1 (FIG. 4) in a predetermined relationship along the casting zone C.

As such a backup roller, U.S. Patent No. 3,1
67.830 can be used.

Flexible endless dams 44 are formed on both sides of the casting area to confine the molten metal.

The dams 44 on both sides are guided toward the inlet by guide members 46.

In this regard, for example, U.S. Pat. No. 3,167,8
It is disclosed in No. 30.

During a casting operation, the two casting belts 26 and 28 are driven at the same linear velocity by a drive mechanism 47, such as that disclosed in the above-mentioned US patent.

The extremely large heat flow is absorbed by the high velocity layer 48 (FIGS. 2 and 4) of coolant moving through the upper and lower casting belts along their back faces 50 and 52, respectively.

This coolant, preferably water containing a corrosion inhibitor, is maintained in layer 48 in a manner such as that disclosed in the above-referenced US patent.

The casting 58 is transported and guided out of the casting apparatus by feed rollers 60.

Two of these rollers are shown in FIG.

Five heat-sensitive detection devices 62a are used to determine the position of the pool P of molten metal in the inlet area 25 of the casting apparatus.
, 62b, 62c, 62d and 62e are provided, which detecting devices engage against the cooling back surface 52 of the lower belt 28 near this inlet area.

A predetermined number of detection devices can be used to determine the pool level.

However, the number of sensing devices in set 62 should not be such as to impede movement of coolant 48 along back surface 52.

As shown in FIG. 4, these heat sensing detection devices 62a to 6
2e is located between the backup rollers 41, so that interference by these rollers is avoided.

Each detection device has an individual support arm 64a. 64b, 64
c, 64d and 64e, which arms are attached to and extend laterally from lower carriage 32.

The first detection device 62a1 or the first and second detection devices 6
2a and 62b (or more detection devices) can be mounted in the groove 63 of the lower inlet roll 36 below the upper limit of the pool P between the ridges 65 of this roll.

Mounting fingers 69 (FIG. 3) extend upstream from arm 64c into each groove 63 to support each sensing device therein.

However, any other suitable device may be used to mount the sensing device in a fixed position relative to the cooling backside 52 of the belt.

Instead of engaging the lower belt, a set of detection devices 62 is placed on the cooling back surface 5 of the upper casting belt 26 near the inlet area 25.
The position of the pool P can also be determined by attaching it relative to 0.

In the case of a dual-belt casting machine, the position of the pool P is determined using, for example, one set of detection devices 62 and another set of detection devices 162 that engage the back surfaces of both casting belts 26 and 28, as shown in the figure. It is advantageous to decide.

In order to monitor the condition of the belt coating 29, the belt 26
and 28.
It is advantageous to use and other sets of detection devices 170.

If desired, all four sets of sensing devices 62, 162, 70 and 170 can be used in a dual belt casting machine.

Or a set of detection devices 62° 162.70 and 170
A combination of one, two, three or four of these may also be used.

As shown in FIGS. 1 and 2, the sets of detectors 162 and 170 for the upper belt are located further downstream than the set of detectors for the lower belt.

This is because the downward slope of the casting zone C positions the molten metal surface of the pool P in an inclined relationship to both casting belts 26 and 28.

The set of pool level detection devices 62a-62e are positioned to span predetermined pool locations.

That is, the set 62 extends in the longitudinal direction (ie, from the upstream side to the downstream side) in the moving direction of the belt.

leading detector
62 a is located at a point above the predetermined pool position;
trailing detectpr
) 62e is located at a point below the predetermined pool position.

The remaining detection devices 62b, 62c and 62d are located between the front detection device and the rear detection device.

Each heat sensitive detection device responds to local changes in belt temperature on the cooling backside 52 of the belt adjacent the tip of the detection device.

Of course, when a local area of the casting belt is in contact with the molten metal being cast, the temperature at the backside of the casting belt increases in that area due to the increased amount of heat transfer.

In view of the extremely large cooling effect of the rapidly flowing coolant, the amount of temperature increase at the back surface 52 is not very large.

However, it can be effectively sensed by the process described below.

That is, the set of detection devices 62 includes detection devices 62a, 62b, 62c, 62d in the direction of movement of the belt.
and 62e or detection devices 162a, 162b, 162c, 162d and 1
62e (or at each longitudinal position of all of these sensing devices) to sense upstream or downstream transitions in the position of the pool P. do.

Each of the detection devices in set 62 or 162 (or both) includes a pool level data output monitor 66 (
(Fig. 1).

Any suitable monitoring device may be used as such a monitor to indicate the temperature changes recorded by the individual sensing devices in this pool level set 62 and 162.

For example, the monitor 66 can include a sequence of electrical relays that control colored lights, each relay connected to a corresponding detection device 62a-62e or 162a-162e.
respond to.

Each relay will energize a light when its respective detection device senses a significant temperature increase.

The caster working wheel can then manually adjust the control 71 to adjust the flow of molten metal to the caster until a predetermined pool level is maintained.

Any other monitoring device can easily be used, such as a recording pen or a sequence of audible signals.

The control device 71 can include a manually adjustable lead screw or a motor-driven lead screw to raise and lower the stopper 20.

The monitor and controller 66 may be provided with automatic controls to regulate the supply of molten metal.

As shown in FIG. 1, control device 66 is connected to control device 71 by a circuit 67. As shown in FIG.

This control device 71 moves the stopper 20 to control the flow of molten metal.

The motor drive controller 71 may include a servomechanism coupled to the controller 66 for fully automatic flow regulation.

As shown in FIG. 3, the pool position detection device sets 62a-
62e are staggered back and forth across the width of the belt to avoid significant obstruction in the rapid flow F of the coolant.

In the above-described method of controlling the position of pool P, the rate of molten metal fed is controlled manually or automatically, and the molten metal fed is at a casting rate determined by the rate of movement of belts 26 and 28. made to be balanced.

Another method that can be used in controlling the pool position is that the feed rate of molten metal 12 can be stabilized at a predetermined value and that the casting by a small amount can be used to balance the actual feed of molten metal. This is a method that allows you to gradually change the speed of the device.

As shown in FIG. 1, the control device 66 includes an electric circuit device 7
3 to the drive mechanism 47.

This drive mechanism 47 rotates rolls 38 and 40 simultaneously and in the same phase.

The control device 66 is also connected by a circuit device 75 to a drive mechanism 76 for the delivery conveyor roll 60 .

First, the speed of the casting machine and the delivery roll 60 can be automatically matched to the supply of molten metal to control the position of the pool P.

In many cases, it is preferred that the supply of molten metal be adjustable and that the casting apparatus be operated at a constant speed.

This is because constant speed operation facilitates the operation of the rolling and processing equipment that is often provided in the line of the foundry for the product 58.

Five thermal sensing devices 62e, 70a, 70b, 70c and 70d (
A second set 70 or 170 (FIGS. 1 and 2) of FIG. 3) can be provided near one or two belts.

These are preferably positioned at uniformly spaced points across the width of the belt, as shown in FIG.

A predetermined number of detection devices can be used in the set 70 or 170 and a plurality of data sensing devices are provided.

However, the number of detection devices in set 70 or 170 is
The number should not be so large that it significantly obstructs the coolant flow P.

If desired, the rear detection device 62e in the pool level sensing set 62 can be one of the detection devices in the coverage monitoring set 70, as shown in FIG.

In set 70 (and 170), all detection devices can be mounted on a single support arm 64e or 164e.

Any other attachment device suitable for securing the set of coating condition detection devices in position relative to the cooling backside of the casting belt may be used.

The belt coverage detection device set 70 or 170 is positioned in line with the pool level rear detection device 62e or 162e.

This is because in this longitudinal position the molten metal must always be in positive contact with the entire width of the casting belt.

An indication of the coating condition is the temperature on the back side of the belt when the coating on the front side of the belt is in contact with the molten metal being cast.

The set of coverage detection devices are thus positioned at laterally spaced locations across the vicinity of the pool P.

As shown in FIG. 3, a set of coating state detection devices 62e, 7
0a, 70b, 70c and 70d are connected to the coating state monitor 72.

The monitor includes a temperature recording indicator for each temperature sensed.

The operator relates the temperature to various belt coating characteristics using a table of data based on past operating experience for the type of coating 29 used.

Of course, when another set of detection devices 170 is used, it is also connected to the monitor 72.

A monitor 72 is connected to the drive mechanisms 47 and 46 to monitor the casting apparatus when the quality of the coating 29 has deteriorated, i.e. when the insulation and protective properties of the coating have become too uneven for casting a quality product. Can be stopped automatically.

Embodiments of heat sensitive detection devices for use in both pool level detection device set 62 and coverage condition detection device set 70 are shown in detail in FIGS. 4, 5, and 6.

FIG. 4 shows an elevational sectional view of the detection devices 62c and 62d.

Each detection device has a jacket 80 made of a lubricious material of low thermal conductivity, such as polytetrafluoroethylene, such as "Teflon."

This jacket 80 is streamlined to the flow F near its tip and near the backside 52 of the belt.

As shown in FIG. 5, the streamlined cross section 82 is formed by a parabolic front surface 84 and a V-shaped pointed rear surface 86.

Flow F after cooling is indicated by an arrow.

The smooth plastic surface 80 reduces friction against the belt.

At this mounting end, the insulating jacket 80 has a circular cross-section 88 (FIG. 6).

A circular portion 88 of jacket 80 is a slip fit within tubular bracket 90.

A tubular bracket 90 is attached to each support arm 64c, 646, etc.

Spring 92 urges the slip-fit jacket 80 toward the back surface 52 of the belt.

Each insulating jacket 80 has an axial bore 94 into the end of which is press fit a highly thermally conductive metal sleeve 100 made of, for example, steel.

The highly thermally conductive sleeve 100 is attached to the end of the jacket 80 to form a closed end 102 .

Closed end 102 contacts and slides against belt surface 52 during movement.

A thermally responsive voltage generating element 104, such as a thermistor or thermocouple, is connected to the sleeve 100 with a lead wire 106.
The sleeve is inserted into the sleeve in contact with the end 102 of and embedded in an electrically insulating waterproof material 108, such as epoxy resin or the like.

Lead wire 106 is connected to one or both of suitable monitor and control devices 66 and 72.

Heat is transferred from the belt through the closed end 102 of the cap to the sensing element 104.

With such a detection device arrangement, thermally responsive element 104
are insulated from side cooling effects by the flow of cooling fluid.

However, the axial heat flow transferred from the molten metal through the belt and the cap 100 that engages the belt is easily detected.

The invention can also be applied to casting belts of wheel-belt casting machines to monitor operating conditions such as the level of the pool of molten metal at the inlet as well as the coating condition of the belt.

This wheel-belt casting apparatus is described in U.S. Patent No. 3,42
No. 9,363.

[Brief explanation of the drawing]

FIG. 1 is a side cross-sectional view of a continuous casting apparatus with a series of heat sensitive detection devices for determining molten metal pool level and/or belt coverage. FIG. 2 is an enlarged view of a part of FIG. 1. FIG. 3 is an enlarged cross-sectional view taken along line 3--3 of FIG. 2, showing the location of the two sets of individual thermal sensing detectors of the detector. FIG. 4 is a sectional view taken along line 4-4 in FIG.
FIG. 2 is an enlarged view showing two heat sensing detection devices. 5 is an enlarged sectional view taken along line 5-5 in FIG. 4, and FIG. 6 is an enlarged sectional view taken along line 6-6 in FIG. 4. 12... Molten metal, 26, 28...
Casting belt, 52... Cooling back, 62, 16
2. t-40, 170... 1 set of heat sensing detection devices.

Claims (1)

Claims: 1. At least one endless flexible rotary casting belt with a casting surface that engages the molten metal to be cast and a back surface that is cooled by a cooling liquid, the casting surface being made of an insulating material. device for determining the operating state of a continuous casting machine of the type covered with a coating, the heat sensitive detection device being positioned in a predetermined position in contact with the back side of said casting belt. a device for pressing the heat sensitive detection device against the back surface of the casting belt to ensure detection of heat transfer from the back surface of the casting belt; and a device for cooling the heat sensitive detection device on the back surface of the casting belt. The thermally sensitive and detecting device comprises a thermal isolator for thermally insulating it from a flow of liquid, the thermal isolator being configured to minimize interference with the flow of cooling liquid. 2. Apparatus according to claim 1, characterized in that each of the heat sensitive detection devices has a tip made of a highly thermally conductive material. 3. The apparatus according to claim 1, wherein a support device is provided extending across the vicinity of the back side of the casting belt, and a set of heat sensitive detection devices is attached to the support device;
An apparatus characterized in that the heat sensing devices are arranged in spaced locations relative to the casting belt. 4. The apparatus according to claim 3, wherein the molten metal pool is placed at the entrance to the casting region, and the set of heat sensitive detection devices are positioned near the entrance of the casting region so as to occupy a desired position relative to the molten metal pool. Apparatus characterized in that it is arranged at upstream and downstream positions relative to the movement of the casting belt. 5. In the apparatus according to claim 4, when the continuous casting apparatus is of the multi-belt type having upper and lower casting belts, at least two sets of heat sensing detection devices and a first set of a first support device for retaining a set of heat sensitive detection devices in contact with a moving liquid cooled backside of the lower casting belt near the casting zone; Apparatus characterized in that a second support device is provided for holding the upper casting belt in contact with the moving liquid-cooled backside in the vicinity. 6. The apparatus according to claim 4, comprising: a control device for controlling the amount of molten metal supplied to the inlet area of the continuous casting device; A device characterized in that it is provided with a circuit arrangement for interconnecting a heat-sensing detection device and a control device for automatically controlling the amount of metal supplied.