Nested grinding roller and preparation method thereof

Abstract

The nested grinding roller comprises an assembling layer, a connecting layer and a grinding layer which are sequentially arranged in an annular nested mode from inside to outside, the outer surfaces of the assembling layer and the connecting layer are provided with concave-convex structures in the horizontal direction and the vertical direction respectively, and the minimum inner diameter of the inner surface of the grinding layer is larger than the maximum inner diameter of the outer surface of the assembling layer. The invention further provides a preparation method of the nested grinding roller. Cheap carbon steel is used in the inner layer, high-chromium alloy with high cost is used in the outer layer, and the problems of high cost, raw material waste and the like in the abrasion replacement process due to the fact that the whole body is cast by using the high-chromium alloy are solved; after the fixing of the assembly layer and the grinding layer is removed, the assembly layer can be taken out from the axial direction and replaced with a new grinding layer, so that a new assembly layer does not need to be cast again, the processing time of a new product is saved, the replacement efficiency is improved, and meanwhile, the cost is reduced to a certain extent by repeatedly using the assembly layer.

Description

Technical Field

[0001] The present invention relates to the technical field of grinding equipment processing, and particularly relates to a nested grinding roller and a preparation method thereof. Background Art

[0002] Powder manufacturing is a very important part of modern industry. When various ores such as calcium carbonate and barium sulfate are finely processed, they all need to be pre-processed into powders and then undergo subsequent processing. At the same time, with the refined development of modern industry, the requirements for powder products are constantly increasing. Existing powder production lines use ball mills, Raymond mills, etc. as grinding hosts, and are equipped with conveyors to transport powder products and store them in storage rooms.

[0003] Among them, the Raymond mill is the most common large-scale fine powder grinding equipment, which is widely applicable to more than 280 materials in non-flammable and explosive minerals, chemicals, construction and other industries with a Mohs hardness not greater than 9.3 and a humidity below 6%, such as barite, calcite, potassium feldspar, talc, marble, limestone, dolomite, fluorite, lime, activated clay, activated carbon, bentonite, kaolin, cement, phosphate rock, gypsum, glass, thermal insulation materials, etc. The finished product particle size of the Raymond mill can be adjusted arbitrarily within the range of 80 - 325 mesh, and for some materials, it can reach up to 600 mesh at most.

[0004] The Raymond mill mainly consists of a machine shell, a main engine, an analyzer, a blower, and a discharge pipe. The main engine consists of a frame, an air inlet volute, a scraper, a grinding roller, a grinding ring, and a cover shell. During operation, the material to be crushed is added into the machine from the feed hopper on the side of the machine cover shell. Relying on the grinding roller device suspended on the plum blossom frame of the main engine, it revolves around the vertical axis and rotates itself at the same time. Due to the action of centrifugal force during rotation, the grinding roller swings outwards and presses tightly against the grinding ring, so that the scraper shovels up the material and sends it between the grinding roller and the grinding ring, and the material is crushed by the rolling and pressing of the grinding roller.

[0005] Since the grinding roller is in continuous contact with the external grinding ring during operation, it will continuously be worn. After being used for a period of time, when the surface of the grinding roller is severely worn, it cannot be in close contact with the grinding ring to achieve effective grinding. At this time, the grinding roller needs to be replaced. However, considering that the grinding roller needs to be made of high-hardness materials such as high-chromium alloy steel to maintain a long service life, its cost is relatively expensive, and only the surface of the grinding roller is worn. A large amount of raw materials inside are not directly used during replacement, resulting in a considerable degree of waste. Therefore, a more reasonable grinding roller structure is needed. Summary of the Invention

[0006] Aiming at the deficiencies in the prior art, the present invention provides a nested grinding roller and a preparation method thereof, which solve the problems of high material cost of the grinding roller and waste of raw materials during replacement in the prior art.

[0007] In a first aspect, the present invention provides a nested grinding roller, which includes an assembly layer, a connection layer, and a grinding layer that are sequentially nested in a ring shape from the inside to the outside. The outer surface of the assembly layer is a non-smooth surface, thus having concave-convex structures respectively along the horizontal and vertical directions. The outer surface of the connection layer is a non-smooth surface, thus having concave-convex structures respectively along the horizontal and vertical directions. The inner surface of the connection layer is closely attached to the outer surface of the assembly layer, and the outer surface of the connection layer is closely attached to the outer surface of the grinding layer. The minimum inner diameter of the inner surface of the grinding layer is greater than the maximum outer diameter of the outer surface of the assembly layer;

[0008] The assembly layer is made of carbon steel, the connection layer is made of engineering plastic, and the grinding layer is made of high-chromium alloy.

[0009] Further, annular limiting portions protruding outward are respectively provided at the top and bottom of the outer surface of the assembly layer, and the concave-convex structure of the outer surface of the assembly layer is provided between the limiting portions at the top and bottom.

[0010] Further, annular limiting portions protruding outward are respectively provided at the top and bottom of the outer surface of the connection layer, and the concave-convex structure of the outer surface of the assembly layer is provided between the limiting portions at the top and bottom.

[0011] Further, the concave-convex structure includes a plurality of convex blocks protruding from the surface of the assembly layer or the connection layer along the radial direction. The convex blocks are arranged around the central axis of the grinding roller, and there are gaps between adjacent convex blocks, and there are also gaps between the convex blocks and the limiting portions.

[0012] Further, the convex blocks are of a square structure, and accommodation grooves parallel to the circumferential direction or perpendicular to the axial direction are formed between the edges of the convex blocks and the limiting portions or adjacent convex blocks.

[0013] Further, the axial length of the grinding layer is greater than the axial lengths of the connection layer and the assembly layer, so that the bottom end of the grinding layer extends out of the connection layer and the assembly layer.

[0014] In a second aspect, the present invention also provides a preparation method for a nested grinding roller, including the following steps:

[0015] S1. Place the carbon steel raw material into an intermediate frequency induction furnace to melt it into molten steel, and then pour it into a first mold. After natural cooling, it is integrally cast into an assembly layer;

[0016] S2. Place the assembly layer into a preset second mold, heat and melt the engineering plastic particle raw material of the connection layer, and then pour it into the second mold. Wait for natural cooling to room temperature, that is, the engineering plastic solidifies to form a connection layer;

[0017] S3. Place the overall structures of the assembly layer and the connection layer into the third mold. Subsequently, put the raw materials of high-chromium alloy into an intermediate-frequency induction furnace for high-temperature melting. After the raw materials are completely melted, add a deoxidizer for deoxidation. Then, take out the molten metal at 1480°C - 1560°C and pour it into the third mold. Let it cool naturally to room temperature in the air and demold to obtain the grinding roller product.

[0018] Preferably, in the step S1, the weight percentages of the components in the carbon steel raw material are C 0.4 - 0.6%, Si 0.5 - 0.8%, Mn 0.5 - 0.6%, and the balance is Fe.

[0019] Preferably, in the step S3, the components and their weight percentages in the high-chromium alloy casting ball are C 1.6 - 2%, Cr 15 - 17%, Cu 0.7 - 0.9%, Mn 0.5 - 0.7%, Mo 0.6 - 1.0%, V 0.03 - 0.05%, Y 0.2 - 0.4%, B 0.8 - 1.2%, and the balance is Fe.

[0020] Preferably, in the step S3, add aluminum with a total mass of 0.05 - 0.08% for deoxidation during deoxidation.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] 1. The present invention has an assembly layer, a connection layer, and a grinding layer arranged in sequence. There are concave and convex structures along the horizontal and vertical directions respectively on the connection surfaces of the three layers. At the same time, the three layers are tightly connected. Therefore, through the concave and convex structures, fixation in the horizontal and vertical directions can be achieved. This not only makes the three layers tightly sleeved as a whole and prevents the situation of slipping up and down, but also limits the rotation direction of the grinding roller during rotation, avoiding relative sliding and realizing overall rotation. In this way, relatively inexpensive carbon steel can be used in the inner layer, while high-chromium alloy with a higher cost can be used in the outer layer, avoiding the problems of high cost and raw material waste caused by using high-chromium alloy for overall casting during the wear replacement process.

[0023] 2. A connection layer made of engineering plastic is provided between the assembly layer and the grinding layer of the present invention. Then, when the grinding layer is severely worn and needs to be replaced, the engineering plastic can be melted by heating to release the fixation on the assembly layer and the grinding layer. Moreover, the minimum inner diameter of the inner surface of the grinding layer is greater than the maximum outer diameter of the outer surface of the assembly layer. At this time, the assembly layer can be taken out axially and a new grinding layer can be replaced. In this way, there is no need to re-cast a new assembly layer, saving the processing time of new products, improving the replacement efficiency, and reducing the cost to a certain extent by reusing the assembly layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a structural diagram of the assembly layer and the connection layer in the embodiment of the present invention.

[0025] Figure 2 This is a schematic axial cross-sectional view of an embodiment of the present invention.

[0026] In the above-mentioned drawings: 1. Assembly layer; 2. Connection layer; 3. Grinding layer; 4. Limiting part; 5. Protrusion; 6. Receiving groove. Detailed implementation manners

[0027] The technical solutions in the present invention will be further described below with reference to the drawings and embodiments.

[0028] As Figure 1 shown, an embodiment of the present invention provides a nested grinding roller, which includes an assembly layer 1, a connection layer 2, and a grinding layer 3 that are sequentially arranged in a ring-shaped nested manner from the inside to the outside. The assembly layer 1 is made of carbon steel, the connection layer 2 is made of engineering plastic, and the grinding layer 3 is made of high-chromium alloy.

[0029] The outer surface of the assembly layer 1 is a non-smooth surface, so it has concave and convex structures along the horizontal and vertical directions respectively. The outer surface of the connection layer 2 is a non-smooth surface, so it has concave and convex structures along the horizontal and vertical directions respectively. The inner surface of the connection layer 2 is closely attached to the outer surface of the assembly layer 1, and the outer surface of the connection layer 2 is closely attached to the outer surface of the grinding layer 3.

[0030] Preferably in this embodiment, annular limiting parts 4 protruding outward are respectively arranged at the top and bottom of the outer surface of the assembly layer 1, and the concave and convex structures on the outer surface of the assembly layer 1 are arranged between the limiting parts 4 at the top and bottom. Annular limiting parts 4 protruding outward are respectively arranged at the top and bottom of the outer surface of the connection layer 2, and the concave and convex structures on the outer surface of the assembly layer 1 are arranged between the limiting parts 4 at the top and bottom.

[0031] Preferably, the concave and convex structure includes a plurality of protrusions 5 protruding from the surface of the assembly layer 1 or the connection layer 2 along the radial direction. The protrusions 5 are arranged around the central axis of the grinding roller, and there is a gap between adjacent protrusions 5, and there is also a gap between the protrusions 5 and the limiting parts 4. Further, the protrusions 5 are of a square structure, and a receiving groove 6 parallel to the circumferential direction or perpendicular to the axial direction is formed between the edge of the protrusion 5 and the limiting part 4 or adjacent protrusions 5. Therefore, in the direction around the rotating shaft, the radial length difference is realized through the protrusions 5 and the receiving grooves 6 to maintain the fixation during the rotation process; in the axial direction, the radial length difference is realized among the protrusions 5, the receiving grooves 6 and the limiting parts 4 to maintain the axial fixation and prevent axial displacement between the assembly layer 1, the connection layer 2 and the grinding layer 3. Further explained, parts of the inner surfaces of the connection layer 2 and the assembly layer 1 protrude correspondingly and extend into the receiving groove 6, so as to achieve adjacency with the protrusions 5 and the receiving grooves 6 to complete the limiting fixation.

[0032] As Figure 2As shown in the figure, in this embodiment, the minimum inner diameter of the inner surface of the grinding layer 3 is greater than the maximum outer diameter of the outer surface of the assembly layer 1. Therefore, after the connecting layer 2 melts, the assembly layer 1 can be directly taken out axially, and a new grinding layer 3 can be replaced. In this way, there is no need to re-cast a new assembly layer 1, saving the processing time of new products. In addition, the axial length of the grinding layer 3 is greater than the axial lengths of the connecting layer 2 and the assembly layer 1, so that the bottom end of the grinding layer 3 extends out of the connecting layer 2 and the assembly layer 1. In this way, when the connecting layer 2 is placed vertically, the bottom end does not touch the ground, avoiding wear caused by the rotation of the engineering plastic and affecting the connection strength.

[0033] A preparation method of a nested grinding roller in this embodiment includes the following steps:

[0034] S1. Place the carbon steel raw material into an intermediate frequency induction furnace to melt it into molten steel, and then pour it into the first mold. After natural cooling, it is integrally cast into the assembly layer 1; the weight percentages of each component in the carbon steel raw material are C 0.4%, Si 0.5%, Mn 0.5%, and the balance is Fe.

[0035] S2. Place the assembly layer 1 into a preset second mold, heat and melt the engineering plastic PA particle raw material of the connecting layer 2, and then pour it into the second mold. Wait for natural cooling to room temperature, that is, the engineering plastic solidifies to form the connecting layer 2.

[0036] S3. Place the overall structure of the assembly layer 1 and the connecting layer 2 into the third mold. Then, put the raw material of the high-chromium alloy into the intermediate frequency induction furnace for high-temperature melting. After the raw material is completely melted, add 0.05% of the total mass of aluminum for deoxidation, and then take it out of the furnace at 1480°C and pour it into the third mold. Naturally cool to room temperature in the air and demold to obtain the grinding roller product. The components and their weight percentages in the high-chromium alloy cast balls are C 1.6%, Cr 15%, Cu 0.7%, Mn 0.5%, Mo 0.6%, V 0.03%, Y 0.2%, B 0.8%, and the balance is Fe.

[0037] Embodiment 2:

[0038] The rest of this embodiment is the same as that in Embodiment 1. The difference lies in that a preparation method of a nested grinding roller includes the following steps:

[0039] S1. Place the carbon steel raw material into an intermediate frequency induction furnace to melt it into molten steel, and then pour it into the first mold. After natural cooling, it is integrally cast into the assembly layer 1; the weight percentages of each component in the carbon steel raw material are C 0.5%, Si 0.7%, Mn 0.55%, and the balance is Fe.

[0040] S2. Place the assembly layer 1 into a preset second mold. Heat and melt the engineering plastic PA particle raw material of the connection layer 2, and then inject it into the second mold. Wait for natural cooling to room temperature, and the engineering plastic will solidify to form the connection layer 2.

[0041] S3. Place the overall structure of the assembly layer 1 and the connection layer 2 into a third mold. Then, put the raw material of high-chromium alloy into an intermediate frequency induction furnace for high-temperature melting. After the raw material is completely melted, add 0.06% of aluminum by total mass for deoxidation. Then, tap the furnace at 1520 °C and pour it into the third mold. Let it cool naturally in the air to room temperature, and demold to obtain the grinding roller product. The components and their weight percentages in the high-chromium alloy casting are C 1.8%, Cr 16%, Cu 0.8%, Mn 0.6%, Mo 0.8%, V 0.04%, Y 0.3%, B 1.0%, and the balance is Fe.

[0042] Example 3:

[0043] The rest of this example is the same as that in Example 1. The difference lies in that a preparation method of a nested grinding roller includes the following steps:

[0044] S1. Place the carbon steel raw material into an intermediate frequency induction furnace to melt it into molten steel, and then inject it into the first mold. After natural cooling, it is integrally cast into the assembly layer 1. The weight percentages of the components in the carbon steel raw material are C 0.6%, Si 0.8%, Mn 0.6%, and the balance is Fe.

[0045] S2. Place the assembly layer 1 into a preset second mold. Heat and melt the engineering plastic PA particle raw material of the connection layer 2, and then inject it into the second mold. Wait for natural cooling to room temperature, and the engineering plastic will solidify to form the connection layer 2.

[0046] S3. Place the overall structure of the assembly layer 1 and the connection layer 2 into a third mold. Then, put the raw material of high-chromium alloy into an intermediate frequency induction furnace for high-temperature melting. After the raw material is completely melted, add 0.08% of aluminum by total mass for deoxidation. Then, tap the furnace at 1560 °C and pour it into the third mold. Let it cool naturally in the air to room temperature, and demold to obtain the grinding roller product. The components and their weight percentages in the high-chromium alloy casting are C 2%, Cr 17%, Cu 0.9%, Mn 0.7%, Mo 1.0%, V 0.05%, Y 0.4%, B 1.2%, and the balance is Fe.

[0047] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the present invention, and they should all be covered within the scope of the claims of the present invention.

Claims

1. A nested grinding roller, characterized in that: It comprises an assembly layer, a connection layer and a grinding layer which are arranged in a circular nested manner from the inside to the outside, the outer surface of the assembly layer is a non-smooth surface, so that it has a concave-convex structure along the horizontal and vertical directions respectively, the outer surface of the connection layer is a non-smooth surface, so that it has a concave-convex structure along the horizontal and vertical directions respectively, the inner surface of the connection layer is tightly fitted with the outer surface of the assembly layer, the outer surface of the connection layer is tightly fitted with the outer surface of the grinding layer, and the minimum inner diameter of the inner surface of the grinding layer is greater than the maximum inner diameter of the outer surface of the assembly layer; The assembly layer is made of carbon steel, the connection layer is made of engineering plastic, and the grinding layer is made of high chromium alloy.

2. A nested grinding roller as claimed in claim 1, characterized in that: The top and bottom ends of the outer surface of the assembly layer are respectively provided with annular limiting parts protruding outward, and the concave-convex structure of the outer surface of the assembly layer is arranged between the limiting parts at the top and bottom ends.

3. A nested grinding roller as claimed in claim 1, characterized in that: The top and bottom ends of the outer surface of the connection layer are respectively provided with annular limiting parts protruding outward, and the concave-convex structure of the outer surface of the assembly layer is arranged between the limiting parts at the top and bottom ends.

4. A nested grinding roller as claimed in claim 2 or 3, characterized in that: The concave-convex structure comprises a plurality of protrusions radially protruding from the surface of the assembly layer or the connection layer. The protrusions are arranged around the central axis of the grinding roller, and there are gaps between adjacent protrusions, and there are also gaps between the protrusions and the limiting parts.

5. A nested grinding roller as claimed in claim 4, characterized in that: The protrusion is a square structure, and a receiving groove parallel to the circumferential direction or perpendicular to the axial direction is formed between the edge of the protrusion and the limiting portion or between adjacent protrusions.

6. A nested grinding roller as claimed in claim 1, characterized in that: The axial length of the grinding layer is greater than the axial length of the connecting layer and the assembling layer, so that the bottom end of the grinding layer extends out of the connecting layer and the assembling layer.

7. A method for preparing a nested grinding roller as claimed in claim 1, characterized in that: The steps include: S1. Place the carbon steel raw material into a medium frequency induction furnace to melt into molten steel, then inject it into a first mold, and after natural cooling, cast the whole into an assembly layer; S2, placing the assembly layer into a preset second mold, heating and melting the engineering plastic granular raw material of the connection layer, and then injecting it into the second mold, waiting for natural cooling to room temperature, that is, the engineering plastic solidifies to form a connection layer; S3. Place the overall structure of the assembly layer and the connection layer into the third mold, then place the raw material of the high chromium alloy into a medium frequency induction furnace for high-temperature smelting. After the raw material is completely melted, add a deoxidizer for deoxidation, then take it out of the furnace at 1480℃-1560℃, pour it into the third mold, naturally cool it to room temperature under air, and demold it to obtain a grinding roller product.

8. The preparation method according to claim 7, characterized in that: In step S1, the weight percentages of the components in the carbon steel raw material are C 0.4-0.6%, Si 0.5-0.8%, Mn 0.5-0.6%, and the balance is Fe.

9. The preparation method according to claim 7, characterized in that: In step S3, the components and their weight percentages in the high chromium alloy casting ball are C 1.6-2%, Cr 15-17%, Cu 0.7-0.9%, Mn 0.5-0.7%, Mo 0.6-1.0%, V0.03-0.05%, Y 0.2-0.4%, B 0.8-1.2%, and the balance is Fe.

10. The preparation method according to claim 7, characterized in that: In the step S3, 0.05-0.08% of the total mass of aluminum is added during deoxidation.

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