JP2007050359A - Briquet roll, its manufacturing method and briquetting machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a briquet roll to which a granular substance is prevented from being stuck and to provide a method for manufacturing the briquet roll and a briquetting machine having the briquet roll. <P>SOLUTION: The briquetting machine is provided with a pair of briquet rolls 1 to be rotary driven synchronously. A pocket 2 is arranged on the peripheral surface of each of the briquet rolls 1. The briquet roll 1 is composed of a roll main body 3 and a cermet-thermally-sprayed layer 4 formed on the peripheral surface of the roll main body 3 and also on the inner surface of the pocket 2. A cermet contains tungsten carbide (WC) and has high hardness. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a briquette roll for compression-molding a powdery raw material into a briquette, a manufacturing method thereof, and a briquette machine having the briquette roll.

It is well known that various powders are compression-molded into a molded product (briquette) using a briquette machine having a pair of briquette rolls (for example, JP2003-201157A, JP2004-35950A). ).
JP 2003-201157 A JP 2004-35950 A

  In the conventional briquette machine, depending on the type of the granular material, the granular material may adhere to the surface of the briquette roll, and the briquette may not be manufactured stably.

  An object of this invention is to provide the briquette roll which prevents adhesion of a granular material, its manufacturing method, and a briquette machine which has this briquette roll.

  The briquette roll of the present invention has a pocket on the outer peripheral surface, and is a briquette roll for compression molding a granular raw material into a briquette. It is a feature.

As this high hardness material, cermet is preferable, and as cermet, tungsten carbide (WC) or further containing chromium carbide (Cr ₃ C ₂ ) is preferable.

  In the present invention, after spraying a high hardness material, it is preferable to polish the surface of the formed sprayed layer so that the surface roughness Ra is 3 μm or less.

  The briquette machine of the present invention has such a briquette roll of the present invention.

  The manufacturing method of the briquette roll of the present invention is a method of manufacturing a briquette roll having a pocket on the outer peripheral surface and compressing and molding a granular raw material into a briquette. It comprises a step of spraying a high hardness material on the outer peripheral surface to form a sprayed layer, and a step of polishing the surface of the sprayed layer.

  The present inventor examined the cause of the adhesion of the raw material granular material to the surface of the briquette roll. When the briquette molding was continued, wear and chipping occurred at the edge of the pocket. It was confirmed that the raw material granular material adhered to this part, and the raw material adhered to a wide range of the briquette roll surface starting from this.

  Since the briquette roll of the present invention is sprayed and polished with a high hardness material on the outer peripheral surface, wear and chipping at the pocket edge can be prevented even if molding of the raw material is continued, and the raw material does not adhere for a long time. The briquette can be stably formed.

  Hereinafter, embodiments will be described with reference to the drawings.

  1A is a schematic view of a briquette machine, FIG. 1B is a cross-sectional view of an outer peripheral surface of a briquette roll according to an embodiment, and FIG. 2 is a cross-sectional view of an outer peripheral surface of a briquette roll according to another embodiment. It is.

  This briquette machine is provided with a pair of briquette rolls (hereinafter sometimes simply referred to as rolls) 1 that are driven to rotate synchronously, and a plurality of pockets 2 are provided on the peripheral surface of each roll 1. ing. The roll 1 includes a roll main body 3 made of a steel material such as stainless steel, and a cermet sprayed layer 4 formed on the peripheral surface of the roll main body 3 including the inner surface of the pocket 2. The inner surface of the pocket 2 has a flat bottom surface in FIG. 1B, but may be a spherical surface as shown in FIG. Further, the pocket 2 may have a shape other than that illustrated.

This cermet is of high hardness containing a metal carbide such as tungsten carbide (WC) or chromium carbide (Cr ₃ C ₂ ). As a generally known material, there is a cermet sprayed coating defined in “JIS H8306”.

  In performing this thermal spraying, the adhesion between the thermal spray layer 4 and the roll body 3 can be increased by blasting the outer peripheral surface of the roll body 3 and increasing the surface roughness before spraying.

After this thermal spraying, the surface of the thermal spray layer 4 is smoothed by polishing. This polishing can be performed using, for example, diamond abrasive grains. The polishing is preferably performed so that the surface roughness _Ra is 3 μm or less, particularly 1 μm or less.

Examples of the cermet, those containing WC or more _Cr 3 _{C 2} as hard particles. Ni, Co, Cr, Ni—Cr or the like can be used as the binder.

Suitable cermet compositions include
WC: 60 to 80 parts by weight, particularly 70 to 75 parts by weight CrC: 10 to 30 parts by weight, particularly 15 to 25 parts by weight Ni: 5 to 15 parts by weight, particularly 5 to 10 parts by weight. A cermet having a composition of 80 to 90 parts by weight of WC containing only WC as hard particles, the balance being at least one of Co, Cr, and Ni (however, Ni is preferably 2 parts by weight or less and Cr is 5 parts by weight or less). Can be used.

  The thermal spraying is preferably performed so that the thickness of the thermal spray layer 4 is about 50 to 500 μm, particularly about 100 to 300 μm on the roll peripheral surface other than the pocket.

Example 1, Comparative Examples 1-4
A roll having a diameter of 160 mm, a number of peripheral pockets of 4032, a pocket opening diameter of 4.8 mm, and a pocket depth of 1.2 mm was prototyped, and a bathing agent composition was briquetted. Details of the constituent materials of each roll are as follows.
Example 1: A cermet having a composition of 73 parts by weight of WC, 20 parts by weight of CrC, and 7 parts by weight of Ni was thermally sprayed to a thickness of 150 μm on the peripheral surface of a roll body made of SUS420 and polished to _a surface roughness _{Ra of} 1 μm.
Comparative Example 1: A roll made of SUS304. The diameter, the number of pockets, and the size are the same as in Example 1.
Comparative Example 2: A roll made of SUS329. The diameter, the number of pockets, and the size are the same as in Example 1.
Comparative Example 3: A roll in which SUS630 is welded to the peripheral surface of a roll body made of SUS329 with a thickness of about 5 mm. The diameter, the number of pockets, and the size are the same as in Example 1.
Comparative Example 4: A roll in which SUS630 was welded on the circumferential surface of a roll body made of SUS420 to a thickness of about 5 mm. The diameter, the number of pockets, and the size are the same as in Example 1.

The composition of the bath composition is as follows.
Sodium bicarbonate 35 parts by weight Sodium carbonate 20 parts by weight DL-malic acid 30 parts by weight Fumaric acid 10 parts by weight Kaolin 3 parts by weight Bentonite 2 parts by weight

  Molding was performed at a roll gap of 0.25 mm, supplying the bath composition at a rate of 540 kg / H, and a roll rotation speed of 28 rpm.

  As a result, in Comparative Examples 1 to 5, the bathing agent composition adhered to the roll within 20 hours, whereas in Example 1, it was possible to carry out the production continuously for 10 days or more without any trouble.

(A) A figure is a schematic diagram of a briquette machine, (b) A figure is sectional drawing of the outer peripheral surface of the briquette roll which concerns on embodiment. It is sectional drawing of the outer peripheral surface of the briquette roll which concerns on another embodiment.

Explanation of symbols

1 roll 2 pocket 3 roll body 4 sprayed layer

Claims (8)

In the briquette roll for having a pocket on the outer peripheral surface and compressing and molding the granular raw material into a briquette,
A briquette roll obtained by spraying a high hardness material on the outer peripheral surface and polishing it.   The briquette roll according to claim 1, wherein the high-hardness material is made of cermet.   The briquette roll according to claim 2, wherein the cermet contains tungsten carbide.   The briquette roll according to claim 2, wherein the cermet contains tungsten carbide and chrome carbide.   5. The briquette roll according to claim 1, wherein after spraying the high-hardness material, the surface of the formed sprayed layer is polished so that the surface roughness Ra is 3 μm or less. . In a briquette machine that compresses a granular raw material into a briquette by a pair of briquette rolls,
The briquette machine according to any one of claims 1 to 5, wherein the briquette roll is the briquette roll according to any one of claims 1 to 5. In the manufacturing method of the briquette roll for having a pocket on the outer peripheral surface and compression-molding the granular raw material into a briquette,
Forming a thermal spray layer by spraying a high hardness material on the outer peripheral surface of the roll body provided with pockets on the outer peripheral surface;
And a step of polishing the surface of the sprayed layer.   8. The method of manufacturing a briquette roll according to claim 7, wherein the surface of the sprayed layer is polished so that the surface roughness Ra is 3 [mu] m or less.

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