AU2021269313A1 - Spout feeder for the discharge of materials to a ball mill - Google Patents

Abstract

SPOUT FEEDER FOR THE DISCHARGE OF MATERIALS TO A BALL MILL Abstract A spout feeder (1) that prevents the spill or loss of material to the outside when feeding a ball mill comprising: a straight spout feeder (2) externally formed by a pipe; a discharge elbow (3); and a seal to join the mill (14), wherein the straight spout feeder (2) is joined to the discharge elbow (3) by flanges and the joint seal (14) is mounted around the straight spout feeder (2), wherein: the pipe (19) of the spout feeder (2) and the discharge elbow (3) are covered with coatings on their inner surface comprising: the upper half comprises upper coatings (15, 17); and the lower half comprises lower coatings (16, 18) consisting of ceramic rubber coatings interspersed with steel coatings; the coatings of the straight spout feeder (2) are arranged in a flow shut-off arrangement; the spout feeder has an internal lubrication channel (21); the joint seal (14) comprises: a seal base (4) comprising an interior with spiral-shaped protrusions; a protective cover (7) on a circular edge (13) of the seal base (4) to fix the joint seal (14) to the inlet of the mill; an outer circular seal (9) and an inner circular seal (11) at opposite ends of the seal base (4), the outer circular seal (9) being fixed to the seal base (4) by means of a retaining ring (5) and an outer ring (10), and the inner circular seal (11) fixed to the seal base (4) by means of a retaining ring (5) and an inner ring (12). 1/6 1 14 3 FIGURE 1

Description

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SPOUT FEEDER FOR THE DISCHARGE OF MATERIALS TO A BALL MILL RELATED APPLICATIONS

[001] This application is based on and claims priority to Chilean provisional patent application No 2969-2020 filed on 16 November 2020, the content of which is incorporated by reference in its entirety.

TECHNICAL FIELD

[002] The present disclosure is developed in the field of elements for transportation of minerals and refers specifically to a spout feeder for discharge of materials to a ball mill.

DESCRIPTION OF PRIOR ART

[003] Documents of the state of the art that can be mentioned are, for example, application CL3400-2018 that discloses a spout feeder for a ball mill comprising a seal element mounted on the outer layer of the feeder in an enveloping manner with circular rubber seals located at each one of the ends of the trunnion seal, circular ceramic outer coatings on which the circular rubber seals are mounted in an enveloping manner on the outer layer of the feeder, a spacer ring forming the spout feeder in a section that is inside the mill and another section that is outside, surrounding the seal element on its surface, a protective rubber-steel seal located at one end of one of the circular rubber seals located inside the mill, and a brick seal ring located at the other end of the circular rubber seals on the outside of the mill.

[004] Another document that can be mentioned is CN209819001U which shows a utility model disclosing a curved elbow of a multi-flange impact resistant, wear-resistant ball mill, comprising a straight pipe section, a first curved pipe section and a second curved pipe section, a first flange and a second flange are respectively arranged at two ends of the straight pipe section, a third flange and a fourth flange are respectively arranged at two ends of the first curved pipe section, and a fifth flange is arranged at the upper end of the second curved pipe section; and the pipe's inner walls of the first curved pipe section and the second curved pipe section are covered with wear-resistant layers; the wear resistance of the ball mill elbow is effectively improved, the service life of the ball mill elbow is extended and maintenance costs are reduced.

[005] Another document that can be mentioned is CN106195524 (A) which describes a method for manufacturing a curved spout feeder with a replaceable abrasion-resistant coating body for a mill. Manufacturing is completed after preparing the mold, preparing the structure, preparing the abrasion-resistant polyurethane coating body, and assembling. According to the preparation method, after abrasion during use, only the abrasion-resistant polyurethane coating body should be replaced.

[006] None of the prior art solutions provides a spout feeder for discharging ball mill feed materials comprising a straight spout feeder, a discharge elbow, and a joint seal whose characteristics and arrangement make it possible to effectively prevent spill or loss to the outside when feeding a mill, and where setup of internal coatings make it possible to increase the service life of the component.

SUMMARY

[007] The present disclosure refers to a spout feeder for transportation and discharge of materials for feeding ball mills, said spout feeder comprising a straight spout feeder, a discharge elbow and a joint seal, the objective of which is to provide a spout feeder to prevent material leakage, spill, or loss to the outside when feeding mill, by creating seal against the mill.

[008] Another potential advantage of this disclosure is providing a spout feeder that increases the service life of the component.

[009] The present disclosure consists of a spout feeder for a mill comprising a straight spout feeder, a discharge elbow and a joint seal joined together by flanges. The straight spout feeder comprises upper coatings on the inner surface of its upper half and lower coatings on the inner surface of its lower half with coatings. The lower coatings consist of ceramic rubber coatings interspersed with steel coatings. The seal is made up of elements that prevent powder from escaping from the inside of the mill mouth to the outside. The straight spout feeder has an internal lubrication channel that lubricates the seal for rotation with the straight spout feeder. The discharge elbow is made up of three sections that add up to a 45-degree inclination between the outlet and the inlet of the elbow. The spout feeder is designed to receive material from a feed chute or funnel, through its inlet, to feed a mill by discharging said material through its outlet.

[010] Traditionally, spout feeders are manufactured from a white casting alloy cast stern tube that does not allow bending or welding due to its low ductility and is not capable of absorbing the thermal stresses generated in the base metal when welding, and, to overcome these drawbacks, preferably, the spout feeder is manufactured with a special rolled steel, made up of cold-calendered sheet, which has titanium inlays and is tempered, which is cut and rolled to be subsequently externally machined to very precise tolerances.

BRIEF DESCRIPTION OF THE DRAWINGS

[011] Figure 1 shows an isometric view of the spout feeder.

[012] Figure 2 shows a lower isometric view of the spout feeder seal.

[013] Figure 3 shows an upper isometric view of the spout feeder seal.

[014] Figure 4 shows a side view of the spout feeder seal.

[015] Figure 5 shows a sectional view of the spout feeder seal.

[016] Figure 6 shows a sectional view of the straight spout feeder.

[017] Figure 7 shows B-B section of Figure 6.

[018] Figure 8 shows a sectional view of the discharge elbow.

[019] Figure 9 shows an illustration of the concept of a flow shut-off arrangement for coatings.

[020] Figure 10 shows a segmented inner retaining ring.

DETAILED DESCRIPTION

[021] The present disclosure refers to a spout feeder (1) for transportation and discharge of materials for feeding ball mills comprising a straight spout feeder (2), a discharge elbow (3) and a joint seal (14).

[022] The straight spout feeder (2) is externally formed by a steel pipe (19) with a welded flange (20) at one of its ends, and the inner surface of said pipe (19) is covered by coatings. The upper half of the pipe's inner surface includes upper coatings (15) in the shape of a rectangular prism arranged so that their longitudinal axis is perpendicular to the radii of the straight spout feeder (2). The lower half of said pipe's inner surface (19) includes lower coatings (16) in the shape of a rectangular prism arranged radially, namely, the longitudinal axis of the lower coatings (16) is facing in a radial direction with respect to the center of the straight spout feeder (2) being perpendicular to the inner surface thereof. The lower coatings (16) consist of two types of coatings mounted in an interspersed manner, a first type made of ceramic rubber and a second type made of steel, while the upper coatings (15) are made of ceramic rubber. In a preferred embodiment, the coatings (15, 16) have a rectangular parallelepiped shape. The arrangement of the ceramics is in a flow shut-off fashion, this arrangement allows for less wear of the rubber present between the coatings, as shown in Figure 9, in which the arrangement of the coatings is in an interspersed-column fashion, wherein if the material flows over the coatings according to the direction of the F arrows parallel to the columns of coatings, the material enters the spaces that may remain between said columns and that form lines in the same direction of the F arrows, such as, for example, the H line of Figure 9, resulting in wear along the entire length of said H line. On the other hand, if the distribution is in a flow shut-off fashion, namely, the material flows over the coatings following the direction of the G arrows, perpendicular to the columns of coatings, the material enters the spaces that may remain between the coatings of the same column and that form lines in the same direction of the G arrows, such as, for example, I line of Figure 9, the wear along the length of the I line being limited by the edge of the coating. In its upper part, between the upper coatings (15) and the steel pipe (19), there is an internal lubrication channel (21) that extends parallel to the longitudinal axis (A) of said steel pipe (19), wherein the internal lubrication channel (21) lubricates the circular movement of the seal on the straight spout feeder (2) when rotating the mill. The welded flange (20) allows for joining of the straight spout feeder (2) with the discharge elbow (3).

[023] The discharge elbow (3) consists externally of three joined tube sections that create a -degree inclination between the outlet and the inlet of the elbow. One end of the discharge elbow (3) includes an inlet flange (22), and the other end of the discharge elbow includes an outlet flange (23), the inlet flange (22) is set to join a funnel or chute that delivers material to feed the mill, while the outlet flange (23) is set to join the straight spout feeder (2). The inner surface of the discharge elbow (3) is covered in its upper half by upper coatings (17) in the shape of a rectangular prism arranged so that the longitudinal axes of said coatings (17) are perpendicular to the axes (C, D, E) of the discharge elbow sections (3) where they are installed. The lower half of the inner surface of the discharge elbow (3) is covered by lower coatings (18) in the shape of a rectangular prism arranged so that the longitudinal axes of said coatings (18) are perpendicular to the axes (C, D, E) of the discharge elbow sections (3) where they are installed. The lower coatings (18) consist of two types of coatings mounted in an interspersed fashion, a first type made of ceramic rubber and a second type made of steel, the upper coatings (17) are made of ceramic rubber. In a preferred embodiment, the coatings (15, 16) have a rectangular parallelepiped shape. The ceramics are arranged in a flow shut-off fashion, equivalent to the coatings of the straight spout feeder (2).

[024] The joint seal (14) of the spout feeder (1) is set to be fixedly installed at the mill inlet and is movably attached to the straight spout feeder (2) so that it can rotate on the periphery of the feeder (2). Said joint seal (14) has a polyurethane seal base (4) comprising an interior with spiral-shaped protrusions that surround the joint end of the straight spout feeder (2); an outer circular edge (13), which projects outwards preferably in the shape of a ring that surrounds the seal base (4), which allows to fix a protective cover (7) by means of a steel core ring (6) through a bolted joint (8). The protective cover (7) is made of rubber-metal and allows to fix the joint seal (14) to the mill inlet, and thus seal the inlet of the straight spout feeder (2) with the mill inlet. One end of the seal base (4) includes an inner circular seal (11), and the opposite end includes an outer circular seal (9), the inner circular seal (11) is located inside the mill when the spout feeder (1) is installed, and the outer circular seal (9) is located outside the mill during the operation thereof. The inner circular seal (11) is fixed to the seal base (4) by means of a segmented retaining ring (5) and an inner ring (12), while the outer circular seal (9) is fixed to the seal base (4) by means of another segmented retaining ring (5) and an outer ring (10). The joints of the inner circular seal (11) and the outer circular seal (9) are made by bolted joints (8). During operation, the circular seals (9, 11) prevent the entry of material into the contact area of the seal base (4) with the spout feeder (2).

[025] In a preferred embodiment, the straight spout feeder (2) and the discharge elbow (3) are manufactured with a special rolled steel, formed from a cold-calendered sheet, which has titanium inlays and is tempered, which favors machining and allows very precise tolerances.

Claims (13)

1. A spout feeder that prevents the spill or loss of material to the outside when feeding a

ball mill comprising:

- a straight spout feeder externally formed by a pipe;

- a discharge elbow; and

- a seal to join the mill,

wherein the straight spout feeder is joined to the discharge elbow by flanges and the

joint seal is mounted around the straight spout feeder, wherein:

- the pipe of the spout feeder and the discharge elbow are covered with coatings on

their inner surface comprising:

* the upper half comprises upper coatings; and

* the lower half comprises lower coatings consisting of ceramic rubber

coatings interspersed with steel coatings;

- the coatings of the straight spout feeder are arranged in a flow shut-off

arrangement;

- the spout feeder has an internal lubrication channel;

- the joint seal comprises:

• a seal base comprising an interior with spiral-shaped protrusions;

* a protective cover on a circular edge of the seal base to fix the joint seal to

the inlet of the mill;

* an outer circular seal and an inner circular seal at opposite ends of the seal

base, the outer circular seal being fixed to the seal base by means of a

retaining ring and an outer ring, and the inner circular seal fixed to the seal

base by means of a retaining ring and an inner ring.

2. The spout feeder according to claim 1, wherein the retaining rings are segmented.

3. The spout feeder according to claim 1, wherein the internal lubrication channel extends parallel to a longitudinal axis of the pipe of the straight spout feeder.

4. The spout feeder according to claim 3, wherein the internal lubrication channel lubricates the circular movement of the seal on the straight spout feeder when rotating the mill.

5. The spout feeder according to claim 1, wherein the joints of the outer circular seal (9) and the inner circular seal by means of the inner ring, the outer ring, and the retaining rings are bolted joints.

6. The spout feeder according to claim 1, wherein the joint of the protective cover with the circular edge of the seal base is made by means of a steel core ring through a bolted joint.

7. The spout feeder according to claim 1, wherein the protective cover allows to fix the joint seal to the inlet of the mill and thus seal the inlet of the straight spout feeder with the inlet of the mill.

8. The spout feeder according to claim 1, wherein the upper coatings are made of ceramic rubber.

9. The spout feeder according to claim 1, wherein the upper and lower coatings are rectangular prisms.

10. The spout feeder according to claim 9, wherein the upper coatings are arranged so that their longitudinal axis is perpendicular to the radii of the straight spout feeder.

11. The spout feeder according to claim 9, wherein the lower coatings are arranged so that their longitudinal axes are facing in a radial direction with respect to the center of the straight spout feeder being perpendicular to the inner surface thereof.

12. The spout feeder according to claim 1, wherein the discharge elbow consists of three joined tube sections that create a 45-degree inclination between the outlet and inlet of said discharge elbow.

13. The spout feeder according to claim 1, wherein the straight spout feeder and the discharge elbow are made of special rolled steel that has titanium inlays and is tempered.