GB2203371A - Apparatus for cooling of rolled stock - Google Patents

Abstract

The apparatus consists of rotatable guides 2 having throughbores 3, the guides 2 being disposed at an angle of 1 to 10 DEG in relation to the longitudinal axis of the apparatus, and the throughbores 3 are at an angle to the longitudinal axis of the guides 2. <IMAGE>

Description

APPARATUS FOR THE COOLING OF ROLLED STOCK The invention relates to an apparatus for cooling rolled stock in continuously operating wire rolling mills. The apparatus is disposed between the wire rolling bloom and the coiler.

In wire rolling mills, cooling tubes are used to cool the rolled wire while it is travelling from the wire rolling apparatus to the coiler. For this purpose, cooling tubes are used into which water is sprayed through suitable feed jets. Cooling must take place in such a way -that the required rate of cooling is achieved and the cooling is evenly spread over the circumference of the wire. The evenness of the cooling gives rise to a turbulent through-flow of cooling water through the cooling tube so that the film of vapour formed on the rolled stock is being constantly destroyed.

To achieve the intended turbulent flow, DO-PS 101 10 proposed providing the guide tube with inserts in order to arrive at a periodically changing inside diameter.

A drawback with this cooling tube is that the large cavities are created in this cooling tube which means that it is suitable only for relatively small rolling speeds and relatively large rolling stock dimensions.

Another construction of this type - DE-PS 1 602 129 like-wise provides for inserts in the cooling tube. The water is supplied by jets which are in each case staggered by 900 in the individual inserts.

The disadvantage of this construction lies in the fact that by reason of the constant impact of water jets emerging from the nozzle, pressure is exerted on the rolling stock transversely of the direction of feed, which means that this construction is suitable only for cooling relatively large cross- sections.

A further disadvantage lies in that by virtue of the constant feeding of fresh cooling water it is true that the cooling action is enhanced but entails increased consumption of cooling water.

Also known is an apparatus for cooling rolling stock - SU-PS 582 864 - including a cooling chamber and jet which is characterised in that there are provided along the cooling tube - orientated along one of the longitudinal axes and curved according to their symmetry - attachments disposed alternately on the opposite walls of the passage, the tip of each projection being offset in relation to the next opposite projection by 1/4 1/8 the length of the passage.

The disadvantage of this arrangement lies in the localised restrictions which particularly in the case of smaller rolling stock makes it possible for the tip of the rolling stock to bend over and subsequently causing jamming of the entire roll line. Furthermore, localised restrictions in the passage of the cooling chamber substantially increase its hydrodynamic resistance and impair the transport of rolling stock through the apparatus.

A further solution - SU-PS 450 836 - guarantees centring of the rod along the axis of the apparatus during the cooling process and excludes any possibility of contact with the wall of the cooling chamber.

The disadvantage with this apparatus is that the serially disposed guides are offset coaxially in relation to one another and that, in order to fulfil the function of centring the rolling stock, the throughbore in the guides must be of minimal dimensions. Movement of the flow of coolant through the guides is made more difficult and this limits the volume of coolant in which condensation of the vapour formed takes place. The conditions for even removal of the vapour jacket are impaired. Basically, the main portion of the coolant flow is screened from the surface of the rolling stock by the guides along the entire length of the apparatus. A reduction in the hydrotransport effect and irregular dissipation of heat along the periphery of the rod upsets the stability of the cooling process and reduces the production of usable rolled stock.Furthermore, a rigid fitment of the guides restricts the range of control of the cooling process which, in the case of a broadly-based range of rolling stock, like-wise reduces the production of quality material.

According to the present invention there is provided apparatus for cooling rolling stock comprising a cooling chamber formed by serially disposed rotatable guides having throughbores, the guides being disposed at an angle of 1 to 100 in relation to the longitudinal axis of the apparatus, and the throughbores being at an angle to the longitudinal axis of the guides which is equal to 0.8 to 2.2 times the angle of the guides in relation to the longitudinal axis of the apparatus.

The guides are rotatable about their own axis and are connected to one another and to the rotational transmission means, for example to a bending element, at least one of the guides being equipped with a rotary drive.

Disposing the guides at an angle of 1 to 100 in relation to the longitudinal axis of the apparatus and constructing their throughbores in each guide at an angle to the longitudinal axis of 0.8 to 2.2 of the angle of inclination of the guide in relation to the longitudinal axis through the apparatus enables, according to the technological conditions, the profile of the inner passage in the cooling chamber to be varied from straight up to the maximum admissible angle condition while having regard to the interference-free passage of the roll line through the apparatus and including the possibility of varying the kinking phase of the passage. Rotating the guides about their own axis guarantees a constant variation in profile of the passage.Equipping at least one of the guides with a rotary drive and connecting the guides to one another and to the rotational transmission means makes it possible operatively to influence the profile of the inner passage of the cooling chamber, for example forming a straight passage, for the front end of the rolled stock in order to treat the rest of the length.

The range of angles of inclination of the guides in relation to the longitudinal 0 axis of the apparatuses of 1 to 10 is necessary and adequate for the purpose underlying this invention. In the case of an angle of inclination of the guides in respect of the longitudinal axis of the apparatus of less than 10, the profile of the inner passage of the chamber varies only insubstantially and is virtually indistinguishable from a straight line. In this case, to guarantee a high intensity, considerable quantities of coolant are needed, with increased pressure on the cooling chamber inlet. This makes it difficult for the rolled stock to pass through the apparatus and reduces usable production.

In the event of the guides being disposed at an angle to the longitudinal axis of the apparatus of more than 100, the flow of coolant forces the rolling stock against the walls of the cooling chamber which, with maximum amplitude, results in a loss of longitudinal rigidity of the rolling stock and thus the possibility of distortion.

The construction of continuous bores in the guide, at an angle to their longitudinal axis, of less than 0.8 of the angle of inclination to the longitudinal axis of the apparatus means that, when the guides rotate, there is no straight passage through the cooling chamber. It remains angled and only the amplitude of the bends in it will vary. As the tip of the rolled stock passes through, it can, being of negligible rigidity, lead to seizure in the apparatus.

Constructing throughbores in the guide at an angle to their longitudinal axis of more than 2.2 times the angle of inclination to the longitudinal axis of the apparatus is pointless because in this case, in order to guarantee unhindered passage of the rolled stock, the guides would have to be of very short length (less than 50mm). This will result in an unjustifiably large number of guides in the cooling chamber, there will be increased turbulence which will once again greatly increase the hydrodynamic resistance in the chamber and impair transport of the rolled stock.

In the proposed technical solution, and taken in their entirity, the features guarantee the possibility of constant and operative variation of the profile of the inner cooling chamber passage from a straight line which guarantees more favourable conditions for the transporting of rolled stock to- an interrupted line which guarantees the necessary intensity of cooling by varying the angle of incidence on the flow of rolling stock.

Furthermore, the proposed technical solution permits of differentiated cooling over the length of the rolling stock, the transport of the tip of the rolled stock which has negligible rigidity, through the apparatus without shutting down the coolant, rapid conversion to the cooling of different profile dimensions or brands of steel, a creation of more favourable conditions for stable transport for good quality cooling of the rolling stock.

An embodiment of the invention will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a cross-section through the apparatus according to the invention, and Figure 2 shows the apparatus according to the invention after the guides have been rotated about their own axis until they form a straight cooling chamber passage, i.e. until the longitudinal axes of the apparatus and the throughbores in the guides coincide.

As shown in Figures 1 and 2, the apparatus for cooling rolled stock consists of a cooling chamber 1 with serially disposed guides 2 and throughbores 3, coupled to pressure jets, not shown. The guides 2 are at an angle of 1 to 100 to the longitudinal axis of the apparatus and can be rotated about their own axis in a mounting 4. The guides 2 are connected to one another and to transmission means 5, at least one of the guides 2 being provided with a rotary drive 6.

The coolant passes under pressure into the cooling chamber 1 through which the rolled stock is being transported at the same time. Inside the passage formed by the throughbores 3 in the guides 2, the flow of coolant in the cooling chamber 1 flows and washes over the surface of the rolled stock and cools it. The degree of cooling depends upon the coolant velocity in relation to the surface of the rolled stock defined by them coolant feed, the cross-sectional areas of the cooling chamber 1 and of the rolled stock.

Another influencing factor is the disposition of the axis of the throughbore 3 in relation to the longitudinal axis through the apparatus and the reciprocal variation in the location of the angle of inclination. When it is necessary to vary the operating parameters during the cooling process of the plant (cooling intensity, hydrotranspo rt force, hydrodynam ic resistance, etc.), the rotation of the guides 2 about their own axis in the mounting 4 is carried out by the drive 6. Rotation of the drive 6 is transmitted by the transmission means 5 to the adjacent guides 2. A resilient element may be used as the transmission means 5. It is likewise possible to construct the transmission means 5 in the form of a gearwheel transmission, card an joint and so on.

Upon rotation of the guides 2 about their own axis, their angle of inclination with respect of the longitudinal axis of the apparatus is added or subtracted to the angle of rotation of the throughbore 3 to the longitudinal axis of the guides 2. In consequence, the disposition of the axis of the throughbore 3 of each guide 2 in relation to the longitudinal axis of the apparatus varies. As a function of the technical problem in hand, rotating the guides 2 makes it possible to achieve the required internal profile of the passage in the cooling chamber 1, which may vary constantly from a straight line to a bent condition, the degree of bend being of varying amplitude.

Operative variation in the profile of the cooling chamber 1 is carried out by the rotary drive 6 and a standard automatic control unit. This widens the range of control of the working parameters of the apparatus and makes it possible to influence individual parameters, for example the cooling intensity, independently of the others, e.g. hydrotransport effect.

As a result of this, the process of cooling the rolled stock becomes stablised and the useful production output is increased.

Claims (4)

1. Apparatus for cooling rolled stock comprising a cooling chamber formed by serially disposed rotatable guides having throughbores, the guides 0 being disposed at an angle of 1 to 10 in relation to the longitudinal axis of the apparatus, and the throughbores being at an angle to the longitudinal axis of the guides which is equal to 0.8 to 2.2 times the angle of the guides in relation to the longitudinal axis of the apparatus.

2. Apparatus as claimed in claim 1, in which the guides are rotationally rigidly connected about their own axis to one another by transmission means, at least one of the guides being provided with a drive means.

3. Apparatus as claimed in claim 1 or claim 2, in which the angled arrangement of the guides alternates.

4. Apparatus for cooling rolled stock, substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.

PATENTS ACT 1977 SPECIFICATION NO. 220337 it The following corrections were allowed under Section 117 on 21 March 1989 Front page Heading (71) Applicant for VEB Schwermaschinenbau-Kombinat Ernst Thalmann Magdeburg read VEB Schwermaschinenbau-Kombinat Ernst Thaelmann Magdeburg for 3611 Magdeburg read 3011 Magdeburg THE PATENT OFFICE 22 May 1989