CS256843B1 - Device for lubrication and cooling of metal strips in twenty-cylinder stool - Google Patents

Abstract

The purpose of the device is to thermally stabilize rolling mills, even of smaller types, and thus increase their performance. The stated purpose is achieved by creating transverse holes in the stand above and below the inlet and outlet openings, serving as pre-lubrication and cooling collectors, from which the supply lines of the individual nozzles are led out in the direction of the rolled strip.

Description

BACKGROUND OF THE INVENTION The present invention relates to an apparatus for lubricating and cooling metal strips in a twenty-cylinder mill, particularly for rolling cold-forming materials, e.g. metal strips made of stainless steel and nickel-alloyed steel, etc.

When rolling these materials, a large amount of heat is generated, which is one of the main factors limiting the performance of the rolling mill. Heat removal from the roll mill rolls and the strip is carried out using technological fluid, mainly mineral oil with pressure additives. This achieves thermal stabilization of the rolling mill. The conditions for achieving high geometric and dimensional accuracy of the rolled strip and for achieving its surface quality are created. The process liquid is transferred to the working rollers by means of guides, which at the same time feed the strip into the rolling gap and through the stripping collectors.

Increasing the rolling speed and hence the performance of the twenty-cylinder mill stand contributes to the supply of process fluid to the cooling collectors arranged on the outer sides of the guide holders in the space between the upper and lower support rollers. Spraying the strip from these collectors allows recesses made in the guide holders. However, this additional cooling of the twenty-cylinder stool has so far been performed only for larger types of stools.

For smaller types of twenty-cylinder stools, the location of the cooling collectors is very difficult for spatial reasons, as the clues as to whether they occupy a relatively larger space than for larger types of twenty-cylinder stools. 3c because the guides have to be dimensioned to virtually the same pressure of the process medium for greater mechanical stress from accidental strip breakage than would correspond to the size ratio of the smaller and larger type of twenty-roll mill.

The above-mentioned disadvantages are reduced by the device for lubrication and cooling of metal belts in a twenty-cylinder mill according to the invention.

258 843 comprising pre-erasing and cooling collectors with nozzles arranged in series in the inlet and outlet openings of the stool stand.

The principle of the device according to the invention is that transverse bores are formed as distribution lines of at least one group of pre-lubrication and cooling collectors in the mill stand, from which the supply lines of the individual t lines are led in the direction of the rolled strip.

The progress achieved by the invention can be achieved in that in the smaller types of twenty-cylinder stands, the rolling speed and thus their performance can be increased. In addition to the thermal stabilization of these rolling tables, at an increased rolling speed, the rolled strip is also cooled to a temperature such that the external environment of the rolling mills can be classified as an environment and fire hazard of flammable liquids, not an environment with a flammable gas explosion. it is possible to use electrotechnical devices with lower degree of cover on rolling stands.

An example of an embodiment of a device for lubricating and cooling metal strips in a twenty-cylinder stool according to the invention is shown in the accompanying drawing, wherein Fig. 1 is a front elevation of a stool with a partial cross-section of its left side;

The twenty-cylinder mill is formed by a stand 1 in which bores 2 are provided for the upper and lower pyramids of the cylinders 5, 6 and the support rollers 4. The inlet and outlet openings 3 are connected to this inner space of the stand 1 by means of which the rolled strip 23 enters and exits the mill. These openings 3 are interchangeable on both sides of the mill and prior to reverse rolling and their function. In the inlet and outlet apertures 5 are additional auxiliary devices which are not shown. In the bores 2 are supported the support rollers 4 supported by the intermediate rollers 5 loaded from the working rollers 6. To lubricate and cool the working rollers 6, guides 7 are provided on both sides of the stand. On the one hand, they introduce the rolled strip 23 into the rolling gap in preparation of rolling. The guides 7 are fastened to the holders 8 fixed to the vertical side walls of the lugs 2. The inner space of the stool is closed from the front side by means of the door of the back side, the lid 9 is fixed (Fig. 2),

256 843 through which four drive spindles (not shown) pass. In the inlet and outlet openings 3, pre-erasing collectors 11 with pre-erasing nozzles 17 are arranged on both sides of the rolled strip 23, the distribution lines of these collectors 11 being transverse pre-erasing bores 13 of the stand! On both sides of the mill stand above and below the roll 23 there are arranged three pre-erasing nozzles 17. During rolling, the technological liquid is always supplied to them only on the inlet side of the mill. Cooling collectors 12 with cooling nozzles 18 are arranged between the pre-lubrication collectors 11 and the guides 7, the distribution lines of these collectors 12 being designed as transverse cooling bores 14 of the stand 1, from which the supply lines 16 are led in the direction of the rolled strip 23. There are five cooling nozzles 18 arranged above and below the rolled strip 23 on both sides of the stand. In order to provide the process fluid flowing out of these nozzles 18 with space for producing the desired spokes and space for efficient cooling, bores 16 are provided in the holders 6. The bores 19 are provided in front of each of the cooling nozzles 16 in the foot part of the holders 8, and on the intermediate walls between the recesses 16, a run is provided for introducing the rolled strip 25 into the rolling stand. Process fluid inlets to individual collectors 11, 12 and guides 7 are provided on both sides of the mill. The connections of the right side of the stool are indicated in the right part of Fig. 1. A symmetrical arrangement is made on the left side of the stool. The guides 7 are fired by the guide line 20 of the guides 7, the cooling collectors 12 are supplied with the supply line 21 of the cooling nozzles 10 & the pre-erase collectors 11 are supplied with the supply line 22 of the pre-erase nozzles 17.

The function of the described twenty-cylinder stool is as follows.

In rolling from left to right, for example, the free end of the rolled strip 23 is first introduced through the inlet 3, the holders 8 and the guides 7 into the roll gap and continues at the insertion speed between the same elements as the left side to the right outlet side of the mill.

256 843

During this phase, the process liquid is not yet fed into the rolling mill. After the belt has been clamped in a non-drawn tensile fir reel, the inlet and outlet thrust adjustments at the desired removal rate can be started. Prior to start-up, however, process fluid is fed into the feed line 22 of the pre-lubrication nozzles 17 and the rolled strip 23 begins to be pre-lubricated on the inlet side of the stand by the pre-lubrication nozzles 17.

At this point, the process liquid also begins to feed into the supply line 20 of the guides 7 on the inlet side of the stool.

Rolling begins. In the initial stages of rolling, the process fluid is fed only to the inlet side of the stool and only to the pre-lubrication nozzles 17 and guides 7. With increasing rolling speed, heat generation between working rolls 6 increases and the cooling system efficiency increases main supply line of technological liquid. If the work rolls 6 and the strip 23 cannot be cooled in this way, the cooling elements located on the left side of the stand are connected individually. In particular, elements which are adequate to the cooling nozzles 18 shown on the stool side 3 have a great cooling effect. The cooling nozzles 13 on the left side of the stand are never rolled in this direction. During the rolling of the entire coil, a rolling stand is prepared for rolling the rolled strip 25 in the opposite direction, i. from right to left. In this reverse rolling, the entire lubrication and cooling process is repeated except that the right and left nozzles 17, 18 and guides 7 have changed functions.

Claims (2)

P Z Z D Μ £ T VY Η Λ L 2 Z U Apparatus for lubricating and cooling metal strips in a twenty-cylinder stool, comprising pre-erasing and cooling collectors with nozzles arranged one after the other in the inlet and outlet openings of the mill stand, characterized in that as distribution lines of at least one group of pre-erasing and refrigerating collectors (11, 12) transverse bores (13, 14) are formed in the mill stand (1), from which feed lines (15, 16) of the individual nozzles (17, 18) are led out towards the rolled strip (23).