Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B02—CRUSHING, PULVERISING, OR DISINTEGRATING; PREPARATORY TREATMENT OF GRAIN FOR MILLING
  • B02C—CRUSHING, PULVERISING, OR DISINTEGRATING IN GENERAL; MILLING GRAIN
  • B02C17/00—Disintegrating by tumbling mills, i.e. mills having a container charged with the material to be disintegrated with or without special disintegrating members such as pebbles or balls
  • B02C17/18—Details
  • B02C17/22—Lining for containers

Definitions

• the present invention relates to a shielding system for a rotary mill comprising a rotary cylindrical shell intended to rotate about its longitudinal axis and to contain material to be ground and a load of grinding machines, the shielding system consisting of plates of individual shields arranged in juxtaposed rings fixed to the inner wall of the shell, each shielding plate comprising an inclined working face extending between a plate foot and a plate head and an opposite domed laying face facing the interior surface of the shell.
• Such a crusher is described in document EP0998353.
• This type of grinder is used in particular in cement works and in the mining industry.
• the material to be ground is introduced on one side of the mill and, as it progresses towards the outlet, on the opposite side, it is ground and crushed between the grinding machines.
• the cladding or armor plates of the mills have a base adapted to the radius of curvature of the ferrule and a profile varying according to the degree of lifting desired.
• the adaptation of the shielding plate to the curvature of the mill requires a similar radius of curvature for the face of the plate and the shell of the mill to avoid breakage of the plate and local hammering of the shell.
• the lifting effect desired depends on several factors related to the design of the crusher and the operating conditions of the crusher, necessitating choosing a determined value for lifting height of the plates, which can vary between 100 and 160 mm depending on the case. .
• the object of the present invention is to provide a new shielding system for a rotary grinder of the kind described in the preamble which makes it possible to equip grinders of different diameters with a plate of standard size metal shielding and with the possibility of modifying the degree of lifting.
• the shielding system proposed by the invention is characterized in that it comprises intermediate flanges intended to be inserted between the individual shielding plates and the shell of the crusher, each flange having a main face whose curvature is adapted to the curvature of the laying face of the adjacent armor plate and an opposite face whose curvature is adapted to that of the ferrule.
• the system preferably includes at least two different types of midsoles which are distinguished by the radius of curvature of their main faces.
• At least one of these types has main faces which form an angle ⁇ less than 10 ° between them.
• the shielding plates can be bolted to the ferrule using fixing bolts having semi-spherical heads retained in corresponding semi-spherical housings of the shielding plate.
• FIGS. 1a and 1b show cross sections through two different types of armor plates used until now in ball mills
• Figure 2a shows a section through a first type of a midsole according to the present invention
• Figure 2b shows a section through a second type of a midsole according to the present invention
• Figure 3 shows a section through a shield fitted with soles according to Figure 2a;
• FIGS. 4a and 4b show a section through a shield using in different ways the flanges of FIG. 2b and
• Figure 5 shows a section through a shielding plate illustrating its fixing system.
• FIGS. 1a and 1b show two well-known shielding plates 1a and 1b.
• These plates 1a and 1b comprise an inclined working surface 2 which extends between a plate foot 5 of a height h and a plate head 3 of a height H, as well as a convex laying surface 4 applied to the inner surface of the shell, not shown, and rotating, in the case of FIGS. 1a and 1b, clockwise.
• This laying surface 4 may optionally include, as shown in the figures in broken lines, recesses to reduce the weight of the plates.
• the plates 1a and 1b are fixed to the ferrule using bolts not shown.
• the plates 1a and 1b include housings to receive the head of the fixing bolts.
• the plate 1 has a working surface 2 which is smooth, while the working surface of the plate 1b has longitudinal undulations or other protuberances and hollows of various shapes to reduce the sliding of the load during the rotation of the mill.
• the laying surface 4 of the two plates must have a curvature which corresponds more or less to that of the shell, which causes the drawbacks mentioned in the introduction.
• the invention proposes the use of intermediate soles as shown in FIGS. 2a and 2b.
• FIG. 2a shows an example of a thin symmetrical flange 11 made of low-alloy steel and which therefore presents a possibility of slight deformation or also made of ductile cast iron of the spheroidal graphite cast iron type.
• This sole 11 which has the same surface as that of a plate has two main curved faces 12 and 13, the head face 12 having a radius of curvature greater than that of the face 13.
• the sole 11 has in its center a hole 16 for the passage of a fixing bolt.
• FIG. 3 shows an example of the use of flanges 11 for fixing plates 10 of the kind of those of Figure 1a on a ferrule 30 of a crusher.
• the curvature of the face 12 of the flanges 11 corresponds more or less to the curvature of the face for fitting the plate 10 while the curvature of the face 13 is adapted to the curvature of the ferrule 30.
• the sole will adapt, by deformation, to the diameter and possible irregularities of the ferrule 30 to ensure, as shown in FIG. 3, an optimal seat for each armor plate 10. Without the presence of these soles, the plates 10, which have a laying surface with a radius of greater curvature than that of the ferrule, would have no support on the ferrule in the central region and would be quickly doomed to breakage.
• the sole 11 of FIG. 2 is symmetrical and only makes it possible to tune the radii of curvature plate / ferrule without being able to modify the degree of lifting of the plate 10 which it supports. This sole will therefore be used when the lifting of the plate 10 corresponds to the desired lifting for good grinding efficiency of the mill in question.
• FIG. 2b For the case where the raising of the armor plate 10 is too low or too important for the proper functioning of the crusher, the invention proposes a second type of sole which is illustrated in FIG. 2b.
• This sole 14 also has two faces 12 and 15 with different radii of curvature to make the transition between the curvature of the plate 10 and that of the ferrule 30. However, here, the two faces 12 and 15 form an angle between them ⁇ included in 0.1 and 10 °, preferably between 1 ° and 3 °.
• FIGS. 4a and 4b illustrate two different ways of using such a sole 14. In the configuration of FIG. 4a, the sole 14 raises the height of foot 5 of plate 10 thus reducing the difference between the height h (see also Figure 1a) of foot 5 of plate 10 and the height H of head 6 of plate 10, which reduces the lifting effect of the grinding load by the grinder.
• the foot 5 of the plate remains almost at the same level, while the head 6 of the plate 10 is raised, which increases the difference between the height h of the foot of the plate 10 and the height H of the head of the plate, and thereby increases the lifting effect of the shield.
• a sole 1 1 of the type of FIG. 2 will therefore be used having a face 12 adapted to the curvature of the face for laying the plate and a face 13 with a radius of curvature between 1, 2 meters and 1, 6 meters, preferably around 1, 3 m.
• the adaptation of the curvatures between the base of the plates 10 and the shell 30 no longer has the same acuity due to the importance of the radii of curvature.
• the laying face 4 of the single armor plate 10 itself has a radius of curvature such that it allows it to be used with or without a soleplate in a whole range of large shredders according to the radius of curvature chosen for the face. fitting the plate 10.
• the use of a midsole is always recommended to avoid problems in service, ie a sole of the type 1 1 to avoid breakage and hammering of the shell 30 by the plate 10, or a sole of type 14 to vary, in addition, the lifting effect of the entire shield.
• FIG. 5 illustrates the fixing of the armor plates and of the soles to the shell 30 of a grinder. This fixing is ensured by bolts 22 which pass through the plates 10, the flanges 11 or 14 and the ferrule 30.
• the use of inclined flanges will require the use of bolts 22 with semi-spherical heads 17 which are housed in a corresponding housing also semi-spherical 18 of the plate 10. In this way, whatever the angle that the base of the plate 10 makes with the ferrule 30, the bolt 22 can be properly tightened without creating bends in the rod of the bolt 22 .
• Bolted shields can have the disadvantage of material leakage through the bolt holes.
• a washer 19 is used placed between the nut and the shell of the mill. This washer has a chamfer 20 intended to leave a space in which an O-ring 21 made of elastomer can be accommodated which compresses when the bolt is tightened and seals at the bolt hole.

Landscapes

• Engineering & Computer Science (AREA)
• Food Science & Technology (AREA)
• Crushing And Grinding (AREA)
• Solid-Sorbent Or Filter-Aiding Compositions (AREA)
• Absorbent Articles And Supports Therefor (AREA)
• Adhesives Or Adhesive Processes (AREA)
• Ceramic Products (AREA)

Applications Claiming Priority (3)

Publications (2)

Family

ID=3897112

Family Applications (1)

Country Status (7)

Families Citing this family (9)

Family Cites Families (6)

• 2001
  • 2001-10-03 BE BE2001/0642A patent/BE1014412A3/fr not_active IP Right Cessation
• 2002
  • 2002-09-19 DE DE60204710T patent/DE60204710T2/de not_active Expired - Fee Related
  • 2002-09-19 AT AT02767492T patent/ATE297810T1/de not_active IP Right Cessation
  • 2002-09-19 EP EP02767492A patent/EP1432518B1/de not_active Expired - Lifetime
  • 2002-09-19 WO PCT/EP2002/010525 patent/WO2003031070A1/fr not_active Application Discontinuation
  • 2002-09-19 CN CN02819561.2A patent/CN1564712A/zh active Pending
  • 2002-09-19 ES ES02767492T patent/ES2243761T3/es not_active Expired - Lifetime

Non-Patent Citations (1)

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