DE1931801A1 - Process for cleaning metal strips or sheets - Google Patents

Description

Dipl.-Ing.

Rudolf Busselmeier Patent attorney 1931801 Augsburg 3 ■ Rehllngenstrasse β

P.O. Box 242 Pottedieddconto: MU η cht η No. 745 M ' ^T

536Ο / Ο3 Th / Em

Augsburg, June 19, 1969

Priority:

Australia, 2k. June 1968, pat. Note no. 39 589 / 6Q

Patent application

AUSTRALIAN IRON & STEEL PTY. LIMITED, 20 O'Connell Street, Sydney, New South Wales 2OQQ Australia

Process for cleaning metal strips or sheets.

The invention relates to a method for the continuous cleaning of steel or metal strips after their rolling *

The metal strip coming out of the reducing rollers is covered with rolling oil and this _%

Rolling oil must be removed before the strip can be plated or otherwise treated. Known processes for the continuous cleaning of metal strips use aqueous ¹ «solutions of detergents (alkali metal salts, soaps and / or emulsifiers), which are either immersed in flBNQ1

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5360/03 Th / Em - ^ T - June 19, I969

or low pressure spray at high temperatures -

(upset)

apply / become. Organic solvents are also used. These methods have the disadvantage that the cleaning effect produced with their help is not always sufficient for them are also expensive to operate and do not permit recovery of the rolling oil that has been removed from the metal strips.

Since large amounts of WaIz-Oil are used in the rolling of metal strips and since about 10% of the The oil used can remain on the surface of the belt coming out of the roller, that means Loss of this oil results in a very large pecuniary loss which is the cost of the steel belt produced increases.

The object of the present invention is to overcome the disadvantages of the above-described to avoid currently known methods of cleaning metal belts. The metal band should be can be completely cleaned in a single operation and it should also be possible to use the Reclaim rolling oil adhering to the metal strip.

According to the invention, a method for cleaning metal strips after they have been rolled is proposed, since the metal strip is initially continuous through at least a series of. High pressure water spray rush leads. The or each water spray point asprays water with a pressure of at least 17 kp / cm on parts of the upper and in a line lower surfaces of the belt. This serves to remove the adhering rolling oil and dirt. After that, the mixture of water and rolling oil of the tape and then the WaIz-

90-988270432 "" * - 3 -

536O / O3 Ui / em- "jr - June 19, 1969

Oil and water door a next reuse separated from each other.

According to a preferred embodiment of the invention, the belt runs through two or more Cleaning zones, the cleaning zones being delimited by rows of aligned upper and lower nip rollers spaced apart from one another Dots resting on the surfaces of the belt * A series of aligned upper and lower spray heads that span the full width of the metal belt are immediately adjacent to a " Each squeeze roller arrangement is attached and the various areas are each closed off by a spray chamber so that the water-oil mixture can be collected from the metal strip. Every PurificationSr zone can be supplied with fresh water, the water-oil mixture from the different areas summarized and to the recovery tanks for the recovery of both water and of the rolling oil. Alternatively, this can be Water-oil mixture from the last cleaning area, through which the belt runs alternately the preceding cleaning areas for use therein, the water-oil mixture in the collected in the first cleaning area and separated for reuse. In this embodiment According to the invention, the metal strip is first subjected to the action of a water-oil mixture in one or more Subject to cleaning zones and only last to the action of fresh water.

Each spray head has a number of spray nozzles arranged in the manner across the width of the belt are that the spray areas of subsequent or adjacent spray nozzles overlap each other. This takes place cleaning across the entire width of the belt. It

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is not essential that this row of spray nozzles arranged at right angles to the direction of movement of the belt, they can also be arranged that way be that the row has the shape of a flat V. Preferably the rows of spray nozzles are above of the belt, it is arranged so that its spray patterns coincide with the spray patterns from the underside of the belt and oppose the forces of the spray jets acting on the belt from below.

It is also possible that the tape is held on its sides opposite the spray cans by rollers, who work in contact with the band. This means that the metal belt is adequately and properly cleaned is made possible, are between two jurys! twenty ranks from Sprühstellai each above and below the Ribbon are arranged, required.

The level of water pressure for spraying the

Metal strip is dependent on the local conditions.

2 hang. It has been found that a pressure of 17 kgf / cm is sufficient for sufficient cleaning of the metal belt. However, higher pressures up to 700 kp / cm can be used if so desired. The desired pressure can be generated by known means such as multi-piston pumps and multi-stage centrifugal pumps and be sustained. Preferably the pressure at the spray nozzles is within a range held by ^ 50% of the average working pressure, so that large deviations in the cleaning quality can be avoided. The increase in the number of piston pump cylinders or the provision of a pressurized water tank in the system are sufficient and satisfactory means to avoid large pressure changes.

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5360/03 Th / Em

June 19, 1969

It is not essential that all rows of spray points operate at the same pressure. For example the first spray nozzles can be used at a pressure of 50 kp /

a work, while the last spray (laen with a Working pressure of I70 kp / cm.

A preferred embodiment of the invention is described below with reference to the drawing, which schematically shows the structure for a method with represents two cleaning zones.

In the embodiment shown, this happens Steel strip 1 from an unwinding roller 2 via a deflection roller 3 and downstream nip rollers 4 in

/ (aligned ) a first spray chamber 51 which iiegenae in a line /

Has high pressure spray heads 6 and pinch rollers 7.

Then the steel strip enters a second spray chamber 8,

(Aligned) which in a line / I-hole pressure spray heads 9 and pinch rollers 10 has. Then comes that. Steel belt through hot air or other dryer 11 via deflection rollers 12 to a take-up roller 13. The spray heads 9 in the spray chamber 8 are fed with fresh water via the line lk . The mixture between rolling oil and water, which is collected in the spray chamber .8, is conveyed to a filter l6 with the aid of a high-pressure pump I5, and then, with the aid of a high-pressure pump 17, through the line l8 to the spray heads 6 in the spray chamber 5 The mixture of rolling oil and water collected in the spray chamber 5 is drawn off via a line 19 with the aid of a pump 20 and fed to a regeneration area 21, from which clean water and rolling oil can be reused via lines 22 and 23, respectively Container is guided. If the water is contaminated with iron particles after its use, then these can with the help of magnetic sieves or belts, not shown, which

let through the water to be cleaned .. *., cleaned will"

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~ 6

536O / O3 Th / Km -JT- June 19, 1969

It is possible that when using the invention Procedure the metal surface is cleaned to such an extent that it is at a subsequent annealing to a gluing or welding comes between the metal surfaces in contact with one another. This problem can can easily be avoided by passivating the metal surface after cleaning it.

As described above, the water-oil mixture from the cleaning areas into the Regeneration tank out, from which any removed dirt can be drawn off if necessary. Thereafter the water and the WaIz-Dl are separated from each other and reused. This procedure creates very large economic advantages over currently used processes in that there is recovery of the rather expensive WaIz-OlS ". More economic advantages result from the fact that only water is used in this process, whereby Avoid the cost of chemical cleaning agents. In addition, it is not necessary to use the Heat up detergent.

- patent claims -

909882/0432

Claims (1)

5360/03 lh / üra - ^ F- June 19, 1969 • A method for cleaning metal strips after their rolling, characterized in that the Metal belt continuously through at least one row . running from high pressure water spray points, with the or each row of sprays simultaneously water with a pressure of at least 17 kJ / meter in a row lying (aligned) parts of the upper and lower surfaces of the metal strip sprayed, so that adhering Rolling oil and adhering dirt are removed from the metal strip using a mixture of water and WaIz-Oil is collected from the metal belt and then the rolling-oil and the water for renewed Reuse can be disconnected. . Method according to claim 1, characterized in that the metal strip is at least two cleaning areas is guided, with each cleaning area being lined up by sets of (aligned) upper and lower squeegee rollers is limited, which points (lines the cleaning area furthermore aligned (aligned) upper and lower high pressure spray heads which extends the full width of the belt therein, each cleaning zone is closed by a spray chamber which is designed such that the mixture of water and rolling oil can be collected from the metal strip. 3. The method according to claim 2, characterized in that g e k e η η N shows that the spray heads in each of the cleaning areas are fed with fresh water. 9882/0432 5360/03 Th / Em - 4Γ -. June 19 193 June 1969 1931 801 k » Method according to claim 2, characterized in that the spray points in at least one of the cleaning areas through which the metal strip is guided is fed with fresh water, the mixture of water and WaIaS oil being collected from the last cleaning area and the One after the other 'is fed to the spray heads in the cleaning areas in front of the last cleaning area, the mixture of water and rolling oil being collected from the first of the cleaning areas and then water and rolling oil being separated for reuse. 5 · Method according to claim 4, characterized in that "the mixture of water and rolling oil filtered from the last cleaning area before going to the spray heads in the previous one Cleaning areas is performed. 909882/0432