GB2238007A

GB2238007A - Cooling tube

Info

Publication number: GB2238007A
Application number: GB9020442A
Authority: GB
Inventors: Bernd Wunderlich; Walter Lilienblum; Niels Meusel; Wilfried Lampe
Original assignee: Schwermaschinenbau Kombinat Ernst Thalmann VEB; SKET Schwermaschinenbau Magdeburg GmbH
Current assignee: Schwermaschinenbau Kombinat Ernst Thalmann VEB; SKET Schwermaschinenbau Magdeburg GmbH
Priority date: 1989-11-16
Filing date: 1990-09-19
Publication date: 1991-05-22
Anticipated expiration: 2010-09-19
Also published as: GB2238007B; IT1240096B; DD288989A5; UA13219A1; RU1776212C; IT9047895A1; IT9047895A0; GB9020442D0; DE4009743A1

Abstract

A cooling tube for cooling rolled stock comprises introduction and guide tubes 1, 2 welded to respective outer cone members 3, 4. The cone members 3, 4 are threaded onto a sleeve 5 in which is mounted an inner cone member 7. Water is introduced via pipe 6. The outer cone members may be rotated to alter the pair of annular gaps between these and the inner cone member 7. The adjustability of the gap widths enables optimum cooling conditions to be provided for different stock diameters and rolling speeds. <IMAGE>

Description

COOLING TUBE The invention relates to a cooling tube for cooling rolled material. The invention is mainly employed in wire and small-sectionsteel rolling mills.

A cooling tube which has proved its worth in many situations and which operates in a co-flow process, with inserts for increasing the amount of turbulence and thus the transportation of heat, is described in DD economic patent No. 250 476. In that arrangement the levels of flow resistance in the cooling tube are such that a part of the cooling water is forced through the cooling tube, in opposite relationship to the rolling direction, in order to ensure that air is not entrained at the entrance to the cooling tube and thus the transfer of heat is not reduced. In a region of about one sixth of the length of the cooling tube downstream of the entrance thereof, the cooling tube has a plurality of nozzle bores which point in the rolling direction at an angle of about 100 relative to the axis of the cooling tube.Measurements have shown that the nozzle bores give rise to high pressure drops which have a disadvantageous effect in regard to the throughput.

Cooling tubes have been proposed which, instead of the abovementioned nozzle bores, have conical annular slot nozzles and in which moreover the slot width and therewith the speed of the water can be regulated by a screw arrangement (German published specification (DE AS) No. 16 02 356).

Such ring nozzles are also used for stripping off the cooling water (DD patent specification No. 210 621).

In regard to the first-mentioned cooling tubes, the increase in rolling speed to over 100 m-1, which is the subject of international endeavours, means that there is no longer sufficient cooling water going to the cooling tube intake to prevent air from being sucked in.

An aim of the invention is to increase the efficiency of cooling tubes for cooling rolled material and enlarging the field of use.

A more specific aim is to provide a cooling tube in which the risk of air being sucked in is eliminated or reduced and pressure drops are avoided.

It has now been found that this may be achieved by the use of a conical double annular gap nozzle in which one conical annular gap is inclined at a mean angle of about 10 in the rolling direction relative to the axis of the cooling tube while the other conical annular gap is arranged with the same angle in opposite relationship to the rolling direction.

In accordance with an aspect of the invention, the narrowest widths of the two conical annular gaps are adjustable independently of each other by a screwthread connection between an outside cone and a screwthreaded sleeve which is fixedly connected to an inside cone by way of plate metal web portions, or by means of other suitable adjusting devices.

More generally, the invention provides a cooling tube for the cooling of rolled material, the cooling tube having co-flow and counterflow portions and a cooling water supply connecting means which feeds adjustable annular gap conical nozzles, wherein one nozzle is angled to point upstream and another is angled to point downstream.

The invention has the advantage that unnecessary pressure drops are avoided by virtue of the water feed arrangement being of a more advantageous configuration from the point of view of flow conditions. That applies in particular in regard to the losses involved in changes in direction, which are greatly increased with high rolling speeds, with the amount of water which is to be passed through the arrangement in opposite relationship to the rolling direction, in the case of annular gaps which point only in the rolling direction.

The mutually independent adjustability of the two gap widths affords the possibility of providing for optimum adaptation of the cooling tube to different rolled material diameters and rolling speeds, in such a way that the desired cooling effect is achieved.

The invention will be described in greater detail hereinafter by way of example with reference to the accompanying drawing which is a view in longitudinal section through a cooling tube of a configuration according to the invention.

The introduction tube 1 and the guide tube 2 are each welded to an outside cone 3 and 4 respectively. The two are connected by way of screwthread means to the screwthreaded sleeve 5 which has a water connection member 6. The connection between the screwthreaded sleeve 5 and the double inside cone 7 is provided by plate metal web portions 8 which are welded in position. The two round rings 9 prevent cooling water from issuing through the screwthread pitches. In order to prevent the rolled material from "striking" the exit of the annular gaps formed by the outside cones 3, 4 and the inside cone 7, the passage cross-section provided for the rolled material in the inside cone 7 is larger in the region of the gap exits than in the other cross-sectional portions which serve to guide the rolled material.

The cooling tube is clamped fast by means of three eccentrics 10 and 13 on its support structure 11. By releasing one of the outer eccentrics 10 and turning one of the outside cones 3 and 4 by means of an open-ended fixed wrench, which is fitted to the wrench surfaces (flats) 12, it is possible to adjust the width of the respective annular gap formed by the outside cone 3, 4 and the inside cone 7, in a range of O ... 8 mm.

Claims

1. A cooling tube for the cooling of rolled material, the cooling tube having co-flow and counter-flow portions and a cooling water supply connecting means which feeds adjustable annular gap conical nozzles, wherein one nozzle is angled to point upstream and another is angled to point downstream.

2. A cooling tube according to claim 1, wherein the angle of the nozzles to the axis is about 10 .

3. A cooling tube for the cooling of rolled material, the cooling tube having co-flow and counter-flow portions and a cooling water supply connecting means which feeds adjustable annular gap conical nozzles, wherein an introduction tube for the counter-flow portion and a guide tube for the co-flow portion of the cooling tube are each secured to a respective outside cone member, wherein the outside cone members are screwthreadedly connected to respective ends of a sleeve which also has the cooling water supply connecting means, and wherein the sleeve is connected by one or more plate metal web members to a double inside cone member which is fixed in position thereby.

4. A cooling tube according to claim 3, wherein the passage cross-section in the double inside cone member is larger in the region of the gap exits than in the rest of the guide space of the inside cone member.

5. A cooling tube according to claim 3 or claim 4, wherein the introduction tube and the guide tube are secured with releasable eccentrics.

6. A cooling tube for the cooling of rolled material substantially as hereinbefore described with reference to the drawing.