EP0086215A1

EP0086215A1 - Cooling device for rod wire

Info

Publication number: EP0086215A1
Application number: EP82902635A
Authority: EP
Inventors: Marios Economopoulos; Nicole Lambert; Pierre Simon
Original assignee: Centre de Recherches Metallurgiques CRM ASBL
Current assignee: Centre de Recherches Metallurgiques CRM ASBL
Priority date: 1981-08-25
Filing date: 1982-08-23
Publication date: 1983-08-24
Also published as: ES8307910A1; BR8207830A; IT8268029A0; WO1983000646A1; IT1155912B; ES515214A0

Abstract

Dispositif de refroidissement en cuve (1) d'un fil étalé en spires non coaxiales sur un convoyeur horizontal comprenant en dessous du niveau des orifices d'entrée (12) et de sortie (13) du convoyeur dans la cuve (1), un compartiment équipé de moyens d'alimentation en milieu liquide de refroidissement, et des compartiments pour la récupération du dit milieu liquide; au-dessus du niveau des orifices d'entrée (12) et de sortie (13) en question, le dispositif comporte un compartiment dit de recouvrement du fil à refroidir; les compartiments d'alimentation, de recouvrement et de récupération ainsi qu'une pompe (8) constituent un circuit fermé de circulation de préférence rapide, du milieu liquide.Device for cooling in a tank (1) of a wire spread in non-coaxial turns on a horizontal conveyor comprising, below the level of the inlet (12) and outlet (13) orifices of the conveyor in the tank (1), a compartment equipped with means for supplying cooling liquid medium, and compartments for recovering said liquid medium; above the level of the inlet (12) and outlet (13) orifices in question, the device comprises a so-called compartment for covering the wire to be cooled; the supply, recovery and recovery compartments as well as a pump (8) constitute a closed circuit for circulation of the liquid medium, preferably rapid.

Description

Cooling device for wire rod.

The present invention relates to a cooling device for wire rod spread in non-coaxial turns on a conveyor, this device being able to be used indifferently in any heat treatment, particularly at the outlet of the rolling mill, comprising one or more cooling phases.

The cooling of the wire rod spread in non-coaxial turns on a conveyor is well known and can be achieved in several different ways.

For example, such cooling can be produced by blowing air, but this method is not satisfactory in all cases, because of a relatively limited cooling intensity and insufficient cooling homogeneity. Such cooling can also be produced by immersion in boiling water with the advantages of good homogeneity and a greater cooling intensity than that of air blowing. This modality has technological particularities because of the difference in level and the length necessary to immerse in the boiling water of the conveyor supporting the turns (deflection, etc.). The volume of water used in this type of cooling is therefore quite large, which can be the cause of certain difficulties in cases where temperature regulation must be ensured. It is in particular for this reason that the water temperature remains maintained at boiling point.

The applicant had the original idea of developing a device which could be suitable in all cases where a cooling of wire rod spread in non-coaxial turns on a conveyor must be practiced, whatever the type or the phase of treatment in which this operation must be inserted. Such a device is precisely the object of the present invention.

If the treatment comprises several rapid cooling operations, several devices in accordance with the invention can be used at the different stages corresponding to these operations.

This invention, based on the use of a horizontal or substantially horizontal conveyor on which the wire is spread in non-coaxial turns, in principle comprises means capable of raising the level of a liquid medium to cover the turns of this wire located on the conveyor and means capable of lowering the level of this same medium; one can thus put at will the liquid medium in contact or not with the turns of wire. This invention makes it possible to meet the requirements which a cooling operation implemented in a wire rod heat treatment should meet:

- homogeneity of cooling,

- adjustment of the cooling intensity,

- ease of installation without modification of existing trains,

- switching speed of liquid-air medium cooling.

The device which is the subject of the present invention, a device intended for cooling the wire rod spread out in non-coaxial turns on a conveyor, is essentially characterized in that it comprises a tank provided with inlet and outlet ports for a horizontal or substantially horizontal conveyor, intended to receive the wire to be cooled, in that said tank comprises below the level of the inlet and outlet orifices of the conveyor, a preferably central compartment, called a feed compartment, with means for supplying coolant medium, and compartments called recovery of coolant medium, preferably located at the upstream and downstream ends of said feed compartment, and above said level of the inlet and outlet orifices of the conveyor a so-called cover compartment with wire to be cooled, and in that the feed, cover and recovery compartments as well as a pump e constitute a closed circuit for circulation of the liquid medium.

By liquid medium, it is necessary to understand a medium consisting either of liquid only, or for example of water, or of a liquid containing in solution and / or in suspension, surface-active elements, corrosion inhibitors, materials which reinforce the pickling power or the heat transfer capacity, mineral or organic salts, etc ...; likewise an emulsion, for example water / oil, is also considered to be a liquid medium, in the sense of the invention. According to a first embodiment of the invention, the means for supplying liquid medium allow rapid circulation of this medium and practically instantaneous switching from cooling in liquid medium to cooling in air.

According to a second embodiment of the invention, the device comprises means for regulating the temperature of the liquid medium as a function of the treatment to be carried out and / or means for controlling the emission of vapor from this liquid medium.

According to a third embodiment of the invention, the device comprises means for filtering the liquid medium used (elimination of sludge).

According to yet another embodiment of the invention, the passage of all or at least the major part of the liquid cooling medium from the supply compartment into the covering compartment is produced along the side walls of the tank.

According to a variant of this method, the passage of the cooling medium along the walls of the tank is ensured through so-called lateral outlets, formed in a wall separating the supply compartment and the covering compartment.

According to this arrangement of the invention, the cooling medium entering through said lateral vents spreads in the covering compartment on the one hand towards the central part of this compartment, located between the lateral vents and on the other hand respectively towards the areas upstream and downstream of this central part.

Still in a particular form of the device of the invention, the supply compartment includes deflectors to direct the liquid medium towards the side walls of the tank.

It is immediately understood that this way of circulating the liquid medium permanently puts in contact the coolest liquid medium - at the entrances to the covering compartment - and the largest mass of metal, that is to say that located along the side walls of the compartment, where the non-coaxial turns rest contiguously on each other; thereafter, the liquid medium spreads throughout the compartment.

According to the invention, the side vents for the passage of the liquid medium can be of any shape and size, provided that they are capable of playing their role of appropriate diffuser of the liquid medium on the wire in turn; It does not depart from the invention to use both lateral vents to ensure the passage of most of the liquid medium, and these orifices spaced from the walls of the tank to allow secondary supply through the tank.

In a particular embodiment of the improved device, object of the invention, there is available, below the level of the conveyor and above the feed compartment and partially above the recovery compartment of the liquid medium, a so-called full separation plate , in which it is optionally housed orifices preferably closable with shutters, for example with slides.

Still according to the invention, the tank can be provided, at a level located under the conveyor, with a mesh or a perforated plate above the compartments for recovering the liquid medium.

Also according to the invention, the device comprises means to modify the surface of the zone of recovery of the turns by the liquid medium, these means advantageously consisting of obturation devices, for example arranged against the grating or the perforated plate located in the zones for discharging the liquid medium.

According to yet another form of the invention, the device comprises means for retaining the liquid medium, for example constituted by valves situated above the level of the said inlet and outlet orifices of the conveyor, valves whose upper ends are fixed. has a joint and whose lower ends rest on the moving wire.

The valves mentioned above are advantageously balanced by counterweights, so as to have as little resistance as possible to the movement of the turns on which their lower ends rest.

In another embodiment, the device is equipped with hydraulic means for retaining the liquid medium, the aim of which is to increase the pressure drop in the current in circulation, without hampering the movement of the product deposited on the conveyor.

According to the invention, these means for retaining the liquid medium are constituted by devices for injecting this liquid, preferably arranged under the surface for circulation of the wire and injecting a liquid, from bottom to top, through and against the current of the liquid medium.

Also according to the invention, these means for retaining the liquid medium are constituted by protuberances formed in the upper face of the bottom plates of the overlap zone. Besides its impact on the cooling conditions of the submerged wire, this opposition to the circulation of the liquid medium also has the beneficial effect of reducing the flow rate of the supply means of the circuit; these are normally arranged to provide forced feed from below to the covering compartment and preferably consist of a single pump, for example a pump of the so-called "propeller" type.

The device according to the invention may comprise a system for conditioning the temperature of the liquid medium with the possibility of collecting, evacuating and / or condensing the vapor formed.

According to the invention, the means for controlling the temperature and the emission of vapor consist of a system for adding cold liquid medium (for example water), preferably located above the cooling device, which can comprise - nozzles (spraying, mist) and a system for evacuating the liquid medium capable of draining an amount corresponding at least to the intake (by overflow, racking, etc.).

The means for controlling the emission of vapor can also consist, according to the invention, in a system comprising fans intended for the extraction of the emitted vapor, this system being used alone or in combination with that of addition of aqueous medium cold.

According to an advantageous embodiment of the invention, the means for controlling the temperature and the emission of vapor from the liquid medium comprise a computer programmed as a function of a thermal model of the installation and of the various parameters representative of the process to be controlled.

In order to avoid the oxidation of the turns upstream of the zone of recovery of the turns by the liquified medium, the device can also include means for putting said turns under a protective atmosphere, for example under nitrogen.

With respect to already existing devices, the device which has just been recalled has in particular the following advantages:

- it is easy to apply to any conventional conveyor used in existing installations, thanks to the horizontality or the sensitive horizontality of the circulation plan of the turns;

- it makes the application of product cooling very flexible, with the consequence of using shorter lines;

- it allows the temperature of the liquid medium to be effectively and precisely regulated. This result is obtained mainly thanks to the small volume of the liquid medium used;

- It makes possible the application of new treatments and in particular so-called "short" cycles concerning mild steels, steels for welding electrodes. We can also improve the quality of prestressing steels with perlite formation, or manufacture new qualities: steels for cold stamping with ferrite-martensite formation, steels for pre-tensioned with perlite-martensite formation, steels with microstructure composite, for example resulting from a marten sitic quenching followed by a self-income.

- it is available in all cases where cooling of wire rod spread in non-coaxial turns on a horizontal or substantially horizontal conveyor must be practiced, whatever the type of the treatment phase or phases in which this operation is located.

Thanks to the invention, a compact device is available which is always easily placed below the treatment lines and which ensures the conditions of homogeneity, of intense intensity. quick switching and generally required in all wire rod heat treatments.

Figures 1 to 3 attached show, by way of non-limiting example, a method of building a device according to the invention.

According to Figure 1, the device comprises a tank 1 arranged on the path of movement of the wire 2 spread in non-coaxial turns on a conveyor circulating above perforated plates 3 and full plates 3bis; the wire moves in the direction of arrow 4.

This tank 1 comprises a central injection compartment 5 surrounded by compartments 6 and 7 for evacuating (or recovering) the aqueous medium in the direction of the pump 8; this evacuation can be braked for example using a transverse curtain of water jets, directed from bottom to top from the boxes 27 and 28.

The walls of compartments 6 and 7 located on the path of the wire have inlet 12 and outlet 13 holes for the turns in the device.

The pump 8 is located below the tank 1 which it supplies with water via the vertical duct 14. The draining circuit comprises the compartments 6 and 7, as well as the manifold 16 replenishing the pump 8.

FIG. 2 is a plan view of the area of movement of the wire turns between the inlet 12 and outlet 13 areas; this movement area includes the following sections:

- the so-called injection section, where the aqueous medium intended to cover the turns is brought in through the side vents 22 and 23; - the so-called covering section, where the aqueous medium covers the turns. This section includes the central zone 24 between the gills 22 and 23 and the zones upstream 25 and downstream 26 of the injection zone;

- the so-called evacuation section, where the aqueous medium flows into the compartments 6 and 7, through the orifices 20 made in the plates 3.

The device also includes lateral guides 21 located on either side of the wire movement area between the entry 12 and exit 13 doors.

Figure 3 gives a cross-sectional view of the injection area; the water is propelled by the pump 8 in the central duct 14 from where it reaches the injection openings 22 and 23 along the deflector 29; water thus reaches the lateral zones where the wire turns rest on each other and it spreads towards the central part of these turns, in part 24 of the overlap zone, as well as in the zones upstream and in downstream (not shown in the figure). The collecting pipe 16 brings the water back to the pump 8.

It should be understood, within the meaning of the invention, that the "compartments" may in fact be zones existing in the circulating liquid, without material separation walls.

With regard to the passage of the liquid medium from the supply compartment into the covering compartment, it should be noted that according to the invention, the direction of the flow of the liquid at the time of its entry into the covering compartment matters little; the detailed description above gives the modality, considered to be advantageous, in which this current has an ascending direction. It should also be noted that by feeding from the compartment located under the level of the inlet and outlet orifices of the conveyor, it is to be understood within the meaning of the invention, the establishment and possibly the maintenance of a bath whose upper surface is located above the level corresponding to the greatest thickness of the product deposited or to be deposited on the conveyor.

Claims

PATENT CLAIMS.

1. A device for cooling the wire spread in non-coaxial turns on a conveyor, characterized in that it comprises a tank provided with inlet and outlet openings of a horizontal or substantially horizontal conveyor intended to receive the wire to be cooled , in that said tank comprises below the level of the inlet and outlet orifices of the conveyor in the tank, a preferably central compartment, called a supply compartment equipped with means for supplying coolant medium, and compartments called recovery of the liquid medium., cooling, preferably located upstream and downstream of said feed compartment, and above the level of the inlet and outlet orifices of the conveyor in the tank, a so-called compartment cover in wire to be cooled, and in that the supply, cover and recovery compartments insi that a pump constitute a closed circuit for circulation of p quick reference, liquid medium.

2. Device according to claim 1, characterized in that the passage of all or at least the major part of the liquid cooling medium from the supply compartment into the covering compartment is produced along the side walls of the tank.

3. A wire cooling device according to claim 2, characterized in that the passage of the coolant medium along the walls of the tank is ensured through lateral openings, formed in a wall separating the supply compartment and the recovery compartment.

4. Wire cooling device according to one or other of claims 1 to 3, characterized in that one has, below the level of the conveyor and above the compartment supply and partially above the compartment for recovering the liquid medium, a separation plate in which there are optionally housings preferably closable using shutters, for example sliding shutters.

5. Device according to either of claims 1 to 4, characterized in that it comprises a system for conditioning the temperature of the liquid medium with the possibility of collecting, evacuating and / or condensing the vapor formed .

6. Device according to claim 5, characterized in that the means for controlling the temperature of the liquid medium and vapor emission consist of a system for adding cold liquid medium (for example water), preferably located above of the cooling device, which may include sprinklers (spraying, mist) and a system for discharging the liquid medium capable of draining an amount corresponding at least to the supply (by overflow, racking, etc.).

7. Device according to either of Claims 5 and 6, characterized in that the means for controlling the temperature of the liquid medium and the emission of vapor comprise a computer programmed as a function of a thermal model of the intallation and various parameters representative of the process to be checked.

8. Device according to either of claims 1 to 7, characterized in that it comprises means for placing the said turns under a protective atmosphere, for example under nitrogen.

9. wire cooling device according to either of claims 1 to 8, characterized in that it is equipped with means for retaining the liquid medium, preferably constituted by liquid injection devices arranged under the circulation surface of the wire and injecting a liquid, from bottom to top, through and against the current of the liquid medium.