US2234153A

US2234153A - Method and apparatus for manufacturing metallic strip

Info

Publication number: US2234153A
Application number: US256711A
Authority: US
Inventors: Herbert Clarence George
Original assignee: United Engineering and Foundry Co
Current assignee: United Engineering and Foundry Co
Priority date: 1939-02-16
Filing date: 1939-02-16
Publication date: 1941-03-04
Anticipated expiration: 1958-03-04

Description

Marci; 4, 1941;

'C. G. HERBERT METHOD AND APPARATUS FOR MANUFACTURING METALLIC STRI'? Filed Feb. 16, 1939 2 Sheets-Sheet 1 BY /QW ATTORNEY Mimih 1941'- c. G; HERBERT 7 2,234,153 I METHOD AND APPARATUS FOR MANUFACTURING METALLIC STRIP Filed Feb. 16, 1939 2 Sheets-Sheet '2 INVENTOR ATTORNEY Patented Mar. 4, 1941 UNITED STATES METHOD AND APPARATUS FOR MANUFAC- TURING METALLIC STRIP Clarence George Herbert, Cleveland, Ohio, assignor to United Engineering and Foundry Company, Pittsburgh, Pa.

Application February 16, 1939, Serial No. 256,711

16 Claims.

This invention relates to the cleaning of metal sheets, strips, plates and the like, and more particularly to a method and apparatus for removing lubricants and other foreign matter accumulating on the surfaces of such material during the cold rolling thereof.

In the cold rolling of sheets (used herein as a generic term for sheets, strips, plates and like material) it is the customary practice to apply cooling and lubricating liquids to the surfaces of the sheets and the mill rolls to reduce the rolling friction and the heating of the sheets and rolls, with resulting improvement in the product as well as economy in rolling. Due to this practice, however, the finished sheets emerge from the mill covered with an oily or greasy film which usually, for satisfactory results, has to be removed before the sheets are annealed, coated, galvanized or otherwise treated as such treatments all require a clean oil-free surface.

Heretofore it has been the customary procedure to remove the lubricant and dirt adhering to the sheets after completion of the rolling operation by submitting the rolled product to a cleansing operation in.which it is subjected to an acid or alkaline bath followed by rinsing, scrubbing and drying. In addition to the extra time required to carry out such an operation, cumbersome and expensive equipment is used, all of which adds considerably to the cost of production. Also, the cleaning solution sometimes damages the surface of the sheet.

It is among the objects of this invention to cleanse such sheets without the use of expensive and cumbersome equipment, without requiring any time for it in addition to the rolling time, and without injuring the finish of the sheets. More specific objects are to provide a method and apparatus for cleaning a sheet while it is passing through a cold rolling mill, which does not interfere with the rolling operation, which cleans the sheet before it passes through the last mill stand, which is economical and easy to operate, and

which materially reduces the cost of cleaning suchsheets.

The preferred embodiment of the invention is illustrated in the accompanying drawings in,

continuous cold strip mill just prior to beingwound into a coil 20. The last stand includes working rolls 8 and I0 and backing rolls l6 and 18. It is a feature of this invention that the strip is cleaned while it is being rolled so that coil 20 will be formed from clean strip ready to be annealed or otherwise treated. The cleaning occurs before the strip passes through the last stand so that it will not injure the final finish imparted to the strip by the rolls.

Accordingly, mounted in any suitable manner transversely above the strip between the last two roll stands is a header 26 from which a plurality or spray nozzles 22, independently controlled by valves 26, extend downwardly to within a short distance of the strip. This header isconnected by a pipe 28 to the bottom of a tank 30 mounted in any convenient location. The desired cleansin liquid 32 is supplied to the tank in controlled quantities through a'supply pipe 33 from a-suit able source of supply. To keep the liquid under the desired pressure so that it will spray the strip when nozzle valves 24 are opened, the top of the tank is connected by a pipe 60, shut-off valve 42 and pressure control device 44 with a tank 48 containing a pressure fluid, such as compressed air, fed in by a compressor pump 41. The liquid in tank 30 may be agitated continuously or from time to time by supplying a compressed fluid to the liquid body through a vertical perforated pipe 3% immersed therein and connected through shutoff valve 38 to a source of fluid under pressure. The liquid in this tank is maintained at a suitable temperature for best efilciency by any convenient controlled heating device,'such as themstat-controlled gas burners 38 beneath the tank.

The liquid that is used to remove oil and grease from the metal strip is preferably an alkaline solution, such as Sunesco, a solution of soda ash, or any other solution having a suitable saponify ing or disintegratingefiect upon oil. Some of the solution sprayed on the top of the strip flows down over its edges and is caught in an open tank 52 mounted immediately below the strip and extending from behind the spray nozzles to a point close to working rolls 8 and iii of the last stand. The cleansing liquid in the tank is applied to'the lower surface of the strip by a rotatable applicator, such as a wiper 50 journaled in the sides of this tank. This roller is partially submerged in the liquid in the tank, but its top engages the bottom of the strip. The roller may be rotated by frictional engagementwith the strip, or by positive driving means. Of course, rotary brushes or even spray nozzles may be substituted for the wiper roller. The liquid in tank 52 may be kept at a uniform temperature by gas burners 54 or any other heating means.

Extending from pipe 28 are branch conduits 56 terminating in horizontal headers 51 adjacent backing rolls l6 and I8. Each of these headers is provided with a plurality ofspray nozzles 58 directed toward the adjacent backing roll for spraying the cleansing liquid -32 thereon. This liquid cuts from the surfaces of the backing rolls the oily solution picked up by the working rolls from the strip'and imparted to the backing rolls.

To'further clean the rolls'of oil and foreign matter and to minimize their tendency to remove the oil and solid or undissolved particles from the strip, the backing rolls are sprayed with a light hydrocarbon, preferably kerosene. This is done by spray nozzles 84 directed at the backing rolls and connected by headers 82 and pipes 80 to an overhead tank 6| containing the kerosene.

Another feature of this invention is that undissolved particles, as well as the removed film of oil, are prevented to a large extent from being returned by the rolls to the strip. Accordingly, bearing against the rolls are wiping members that extend longitudinally of 'the rolls. The wipers 8i for lower roll [8 are biased toward it and are also removable therefrom by means of fluid pressure motors 82. Atrough-like receptacle 83 is disposed below the bottom roll for catching the liquid and solid matter flowing from the ends of the wipers and the body of the roll itself.

Two similar wipers 66 engage the top roll at diametrically opposite points where they are supported by theupper portions of splash guards 61 that extend downwardly and part way under the top roll. Each of these guards is provided with a, drain pipe and is for the same purpose asthe bottom receptacle as well as for preventing the top rol-l from dripping onto the strip. The lower endoi' the guard on the delivery side of the rolls carries another wiper 68a close to working roll 8 to aid in preventing the foreign matter on the top roll from being carried back to the working roll. Each of these guards is pivoted at its upper end to a support 88' which carries a fluid pressure motor ii. The piston of this motor is pivotally connected to a link 14 which in turn is rigidly connected to the upper portion of the guard. These motors cause the guards to be swung toward and away from the upper roll, and also bias the wipers against the roll while the cleaning apparatusis being used. The various wipers distribute the cleansing liquid and the kerosene evenly over the surfaces of the backing rolls, and they also arrest and segregate the undissolved contaminating matter adhering to the rolls, thereby preventing it from being returned. to the strip and rolled into it.

The small amount of foreign matter. such as liquid and solid particles, that passes between the working rolls of the last stand with the strip is blown therefrom by fluid under pressure. For this purpose a pair of blow nozzles Si is mounted above the strip and another pair 82 below it with their outlets closely adjacent the working rolls where they are directed outwardly toward the edges ofthe strip in order to remove the foreign matter therefrom by the combined action of pressure and suction, as shown in Fig. 2. The inlet ends of these nozzles are disposed transversely of the strip and are telescopically' and rotatably' mounted in clamps 83 attached to suitable supports 94. Set screws 88, threaded in these clamps and bearing against the nozzles, hold them in any position to which they may be adjusted vertically or transversely of the strip, the latter adjustment being for strips of different widths. These nozzles are connected by pipes 81 to a suitable source of fluid under pressure, such as compressed air.

It will thus be seen that the apparatus contemplated by this invention is relatively simple and inexpensive and requires butlittle space. Two maior 1 advantages are that the strip is cleaned during the rolling operation, so that no additional time is required for a cleaning operation, and the cleaning is followed, instead of being preceded, by a finishing pass through the last mill stand, whereby the final finish imparted to the strip by the rolls can not be injured by the chemical in the cleaning liquid.

According to the provisions of the patent statuztes I have explained the principle and mode of operation of my invention, and have illustrated and described what I now consider to represent its best embodiment. However, I desire to have it understood that, within the scope of the apj pended'claims, the invention may be practiced otherwise than as specifically illustrated and described.

Iclaim: I

1. The method of cleaning metal sheets comprising applying a cleansing liquid to the surfaces of a sheet during cold rolling thereof and before they enter the last stand of the rolling mill, wiping the rolls of said stand to remove from their surfaces undissolved contaminating matter received by them from the sheet, and removing from the sheet as it leaves said stand substantially all of the foreign matter adhering thereto.

2. The method of cleaning metal sheets comprising applying a cleansing liquid to the surfaces of a sheet during cold rolling thereof and before they enter the last stand of the rolling mill, applying a cleaning liquid to the rolls of said stand, wiping the surfaces of said rolls to remove undissolved contaminating matter received by them from the sheet, and removing from the sheet as it leaves said stand substantially all of the foreign matter adhering thereto.

3. The method of cleaning metal sheets comprising applying a. cleansing liquid to the surfaces of a sheet during cold rolling thereof and before they enter the last stand of the rolling mill, applying a cleansing liquid to the mils of said stand, wiping the. surfaces of said rolls to remove undissolved contaminating matter received by them from the sheet, and directing fluid under pressure against the surfaces of the sheet as it leaves said stand to remove therefrom substantially all foreign matter still adhering to it.

4. The method of cleansing-metal sheets comprising applying an oil and grease solvent to the surfaces of a moving sheet between the last two stands of a cold rolling mill, applying a light hydrocarbon to the rolls of the last stand, wiping the surfaces of said rolls to remove undissolved contaminating matter received by them from the sheet, and removing from the sheet as it leaves said last stand substantially all of the foreign matter adhering thereto. 7

5. The method of cleansing metal sheets comprising applying an alkaline solution reacting mill, applying said solution and kerosene to the rolls of the last stand, wiping the surfaces of said rolls to remove undissolved contaminating matter received by them from the sheet, and directing streams of fluid under pressure against the sheet as it leaves said last stand to remove therefrom substantially all foreign matter still adhering to it.

6. Sheet cleaning apparatus comprising means for applying a cleansing liquid to the surfaces of a moving sheet on the entry side of the last stand of a cold rolling mill through which the sheet is passing, means for wiping the rolls of said stand to remove from their surfaces undissolved contaminating matter received by them from the sheet, and means for removing from the sheet as it leaves said stand substantially all of the foreign matter adhering thereto.

7. Sheet cleaning apparatus comprising means for applying a cleansing liquid to the surfaces of a moving sheet on the entry side of the last stand of a cold rolling mill through which the sheet is passing, means for applying a cleansing liquid to the rolls of said stand, means for wiping the surfaces of said rolls to remove undissolved contaminating matter received by them from thesheet, and means for removing from the sheet as it leaves said stand substantially all of the foreign matter adhering thereto.

8. Sheet cleaning apparatus comprising means for applying a cleansing liquid to the surfaces of a moving sheet on the entry side of the laststand of a cold rolling mill through which the sheet is passing, means for applying a cleansing liquid to the rolls of said stand, means'for wiping the surfaces of said rolls to remove undissolved contaminating matter received by them from the sheet, and means for directing fluid under pressure against the surfaces of the sheet-as it leaves said stand to remove therefrom substantially all foreign matter still adhering to it.

9. Sheet cleaning apparatus comprising means for applying a cleansing liquid to the surfaces of a moving sheet on the entry side of the last stand of a cold rolling mill through which the sheet is passing, means for applying saidliquid to the rolls of said stand, means for applying a light hydrocarbon to said rolls, means for wiping the surfaces of said rolls to remove undissolved contaminating matter received by them from the sheet, and means for removing from the sheet as it leaves said stand substantially all of the foreign matter adhering thereto.

10. Sheet cleaning apparatus comprising means for applying a cleansing liquid to the surfaces of a'moving sheet between the last two stands of a cold rolling mill, means for applying said liquid to the rolls of the last stand, means for applying a light hydrocarbon to said stand, wipers engaging the surfaces of said rolls for removing undissolved contaminating matter received by them from the sheet, nozzles directed toward the upper and lower surfaces of the sheet on the delivery side of said last stand, and means for supplying fluid under pressure to said nozzles.

11. Sheet cleaning apparatus comprising a plurality of spray nozzles disposed .transversely of the upper surface of a metal sheet between the last two stands of a cold rolling mill, means for conducting a cleansing liquid to said nozzles, a tank mounted below said sheet between said'stands, a wiping roll journaled on a horizontal axis and adapted to carry cleansing liquid out of said tank and apply it to the lower surface of the sheet, means for applying a cleansing liquid to the rolls of the last stand, wipers engaging the surfaces of said rolls for removing undissolved contaminated matter received by them from the sheet, nozzles directed toward the upper and lower surfaces of the sheet on the delivery side of said last stand, and means for supplying fluid under pressure to said nozzle.

12. A sheet cleaning apparatus comprising a plurality of spray nozzles disposed transversely of a metal sheet adjacent the delivery side of the next to the last stand of a continuous cold rolling mill, a tank, a conduit connecting the tank with the nozzles, means for supplying a cleansing liquid to said tank, means for applying pressure to the liquid in the tank, means for agitating the liquid in the tank, means for applying a cleansing liquid to the lower surface of said sheet adjacent the delivery side of said next to the last stand, means for applying a. cleansing liquid to the rolls of the last stand, means for continuously wiping the rolls of said stand, and means for removing from the sheet as it leaves said last stand substantially all of the foreign matter adhering thereto.

13. A sheet'cleaning apparatus comprising a plurality of spray nozzles disposed transversely of a metal sheet adjacent the delivery side of the next to the last stand of a continuous cold rolling mill, a tank, a conduit connecting the tank with the nozzles, means for supplying a cleansing liquid to said tank, means for applying pressure to the liquid in the tank, means for conducting a fluid under pressure into the liquid in said tank for agitating it, means for applying a cleansing liquid to the lower surface of said sheet adjacent the delivery side of said next to the last stand, means for applying a cleansing liquid to the rolls of the last stand, means for continuously wiping the rolls of said stand, and means for removing from the sheet as it leaves said last stand substantially all of the foreign matter adhering thereto. v

14. Sheet cleaning apparatus comprising a plurality of nozzles disposed transversely of the upper surface of a sheet adjacent the delivery side of the next to the last stand of a cold rolling mill, a conduit connected to said nozzles, means for supplying a cleansing liquid to said conduit, nozzles disposed longitudinally of the upper and lower rolls of the last stand of said mill, branch conduits leading from said conduit to said last-mentioned nozzles, means for applying a cleansing liquid to the lower surface of said sheet between said last two stands, adjustable wipers engaging the surfaces of said rolls, and means for directing fluid under pressure against the surfaces ,of'said sheet as it emerges from said laststand.

15. Sheet cleaning apparatus comprising means for applying a cleansing liquid to the surface of a moving sheet on the entry side of the last stand of a cold rolling mill through which thesheetis passing, wiper members extending longitudinally of the rolls of said stand and engaging their surfaces, receptacles mounted below said rolls for receiving matter removed from the rolls by said wipers, and means forremoving from the sheet as it leaves said stand substantially all of the foreign matter still adhering to it.

16. Sheet cleaning apparatus comprising means for applying a cleansing liquid to the surface of a moving sheet on the entry side of the last stand of a cold rolling mill through which the sheet is passing, wiping members extending longitudinally of the rolls of said stand and engaging their surfaces, fluid pressure actuated means connected to said wipers for biasing them against the rolls,

, means supporting the wipers engaging the upper roll for receiving foreign matter removed from said roll by the wipers, and means for .removing from the sheet as it leaves said stand substantially all of the foreign matter adhering thereto.

CLARENCE GEORGE HERBERT.