Method and device for cleaning a surface of a twin-roller continuous thin strip casting roller

Abstract

A method for cleaning a surface of a twin-roller continuous thin strip casting roller, each casting roller of a twin-roller continuous thin strip casting machine using two brush rollers arranged at a top and bottom for cleaning the surface, wherein a rotational direction of one brush roller is the same as the casting roller, a linear speed of the casting roller is constant and greater than a rotational speed of the casting roller, and a roller surface cleaning device controls a distance or pressure between the brush rollers and the casting roller by a position control device fixed on a casting roller bearing seat, which controls the flattening amount to be within 1-10 times of an average pit depth of a casting roller face.

Claims

1. A method for cleaning a roller surface of a twin-roller thin-belt continuous casting roller, wherein the casting roller comprises an upper brush roller and a lower brush roller in an arrangement for cleaning the roller surface thereof, wherein a rotational direction of at least one brush roller is the same as the casting roller; a linear speed of the casting roller is constant and greater than a rotational speed of the casting roller; and a roller surface cleaning device controls a distance or a pressure between the brush rollers and the casting roller by a position control device fixed on a casting roller bearing seat, the method comprising: before casting, moving the upper brush rollers and lower brush rollers adjacent to the roller surface simultaneously and rotating the upper brush rollers and lower brush rollers, wherein a rotating speed of the lower brush roller is 0.2-0.5 times of that of the upper brush roller, and a rotating speed of the upper brush roller is 1.5-3 times of that of the casting roller; and a pressure applied on the roller surface by the lower brush roller is 1-2 times of that of the upper brush roller; during a stable casting phase, moving the lower brush roller away from the casting roller surface to maintain an interval of 0.1-1 mm therebetween; wherein rotating speed of the upper brush roller is 1.5-3 times of that of the casting roller; in the end of a casting operation, moving the lower brush roller adjacent to the roller surface and rotating the lower brush roller, wherein the rotating speed of the lower brush roller is 0.2-0.5 times of that of the upper brush roller, and rotating speed of the upper brush roller is 1.5-3 times of that of the casting roller, and pressure applied on the roller surface by the lower brush roller is 1-2 times of pressure applied on the roller surface by the upper brush roller; and a unit pressure applied on the casting roller by the upper brush roller is 0.1-2.5 MPa.

2. The method according to claim 1, wherein during casting, the roller surface cleaning device conducts corresponding displacement adjustment according to an expanding amount of the casting roller to maintain constant pressure between the brush roller and the casting roller.

3. The method according to claim 1, wherein brush hair of the upper brush roller is thinner and longer than that of the lower brush roller, and a maximum brush hair diameter of the lower brush roller and upper brush roller is less than an average diameter of a half times of a roller surface pit.

4. The method according to claim 1, wherein during casting, the roller surface cleaning device conducts corresponding displacement adjustment according to an expanding amount of the casting roller and an attrition of brush hair to maintain a pressure on the casting roller to be constant; during cleaning the roller surface, the brush hair is shortened gradually, a built-in displacement sensor of an associated brush roller position control device records an abrasion amount of the brush hair and feeds it back to a casting machine control system, and the casting machine control system sends out an instruction to change angle speed of the upper brush roller or the lower brush roller to keep a constant linear speed of an outer circumference of the upper brush roller or the lower brush roller.

5. The method according to claim 1, wherein brush hair of the lower brush roller and upper brush roller are equal, and density of the brush hair distributed on the lower brush roller and upper brush roller is consistent.

6. The method according to the claim 1, wherein brush hair of the brush roller is copper wire or stainless steel wire.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) FIG. 1 is a schematic diagram of cleaning the surface of the thin-belt continuous casting roller of the present invention;

(2) FIG. 2 is a structural diagram of the roller surface cleaning device of the present invention;

(3) FIG. 3 is a top view of FIG. 2;

(4) FIG. 4 is a calculative diagram of a flattening amount of the roller brush of the present invention.

EMBODIMENTS

(5) As shown in FIGS. 1-4, the method for cleaning a surface of a twin-roller thin-belt continuous casting roller of the present invention, each casting roller 10, 10′ of the twin-roller thin-belt continuous casting machine comprises two brush rollers 1, 1′, 2, 2′ arranged at the top and bottom, of which the rotational direction is opposite to that of the casting roller, for cleaning the surface thereof, a linear speed of the casting roller is constant and greater than a rotational speed of the casting roller, and a roller surface cleaning device controls a distance or a pressure between the brush rollers and the casting roller by means of a position control device fixed on a casting roller bearing seat;

(6) At the beginning of casting, the brush roller is close to the surface of the casting roller and starts cleaning, as casting is processed, the roller surface cleaning device conducts relative displacement adjustment according to a expanding amount of the casting roller to keep a constant pressure between the brush roller and the casting roller;

(7) During the roller surface cleaning process, brush hair of the brush roller is pressed to be bent on the roller surface of the casting roller under an action of the position control device, the brush roller is shown to be partly flattened in macrocosm, a minimum flattening amount of the brush roller is a difference between a brush roller diameter r and a minimum diameter r.sub.min after flattening, that is: the flattening amount Δr=r−r.sub.min, unit: mm, the flattening amount is among 1-10 times of an average pit depth of a brushed roller surface of the casting roller, that is: Δr≦(1−10).Math.R.sub.c, and the average pit depth of the roller surface is measured by an average linear height R.sub.c of a roller surface contour unit;

(8) Before casting operation starts, the upper and lower brush rollers get close to the roller surface simultaneously and rotate, a rotating speed of the lower brush roller is 0.2-0.5 time of that of the upper brush roller, a rotating speed of the upper brush roller is 1.5-3 times of that of the casting roller, and a pressure applied on the roller surface by the lower brush roller is 1-2 times larger than that of the upper brush roller; During a stable casting phase, the lower brush roller separates from the contacting with the casting roller surface and keeps an interval of 0.1-1 mm therebetween; the rotating speed of the upper brush roller is 1.5-3 times of that of the casting roller.

(9) When the casting operation is to be finished, a delivery system stops supplying molten steel, the lower brush roller gets close to the roller surface and rotates, while the rotating speed of the lower brush roller is 0.2-0.5 time of that of the upper brush roller, the rotating speed of the upper brush roller is 1.5-3 times of that of the casting roller, and the pressure applied on the roller surface by the lower brush roller is 1-2 times of the pressure applied on the roller surface by the upper brush roller; a unit pressure applied on the casting roller by the upper brush roller is 0.1-2.5 MPa.

(10) Furthermore, the upper brush roller of the brush rollers has a brush hair of which diameter thinner and longer than that of the lower brush roller, the brush hair diameter of the upper brush roller is Φ0.06-Φ0.28 mm, while the brush hair diameter of the lower brush roller is Φ0.2-Φ0.4 mm; the brush hair length of the lower brush roller is 20-50 mm, and that of the upper brush roller is 40-60 mm.

(11) The brush hair length on same brush roller is equal length or unequal length, and density of the brush hair distributed on the whole roller body of the brush roller is consistent. The brush hair of the brush roller uses copper wire or stainless steel wire.

(12) As shown in FIGS. 1-3, the apparatus for cleaning a surface of a twin-roller thin-belt continuous casting roller of the present invention, which comprising: each casting roller 10, 10′ is provided with two upper and lower brush rollers 1, 1′, 2, 2′, respectively, the brush roller has a length greater than that of the casting roller surface, two brush rollers are mounted at the outer side of the casting roller 10, 10′, both of the brush roller axes are parallel to the casting roller axis, an inner side of the casting roller faces to a molten pool 20, the upper and lower brush roller 1, 1′, 2, 2′ are symmetrically arranged at the upper and lower sides of the rotational center line of the casting roller 10, 10′; bearing seats 3, 3′, 4, 4′ supporting both ends of the brush roller 1, 1′, 2, 2′ is connected to the bearing seat 30, 30′ of the casting roller 10, 10′ though a hydraulic drive cylinder 5, 5′, 6, 6′, and one end of the brush roller 1, 1′, 2, 2′ is connected with a speed reducer 7, 7′ and a motor 8, 8′; and the hydraulic drive cylinder of the brush rollers is provided with displacement sensors 9, 9′ therein, the displacement sensor is electrically connected to the thin-belt continuous casting control system.