JP7245579B2 - Stirring blade for kneading device and kneading device using the same - Google Patents

Description

Application of Article 30, Paragraph 2 of the Patent Act Publisher: The Japan Mining Industry Association Publication: 65th National Meeting of Mining and Smelting Site Managers Engineering Lecture Collection Date of Issue: June 1, 2017

TECHNICAL FIELD The present invention relates to a stirring blade for a kneading device and a kneading device using the same. More specifically, the present invention relates to a stirring blade for a kneading device that has high abrasion resistance, is easy to manufacture and maintain, and is economically efficient, and a kneading device using the same.

For example, in the process of recovering zinc from electric furnace dust in a reduction roasting furnace, in order to promote the reduction reaction in the reduction roasting furnace, the electric furnace dust before being put into the reduction roasting furnace is mixed with coke. processing takes place. As a kneading device for performing this pretreatment, for example, a screw conveyor 100 as shown in FIG. 1 is widely used. As shown in FIGS. 1 and 2, this screw conveyor 100 has stirring blades 1 helically arranged on the outer periphery of a rotating shaft 2 rotated by the power of an electric drive unit 5 . The material to be kneaded is introduced from the inlet 8, conveyed while being stirred by the stirring blades 1 inside the casing 4, and discharged from the outlet 9 in a sufficiently kneaded state.

The screw conveyor 100 usually kneads materials to be kneaded, such as coke and electric furnace dust, which have an abrasive action. Therefore, the stirring blade 1 is required to have high wear resistance. For example, when the wear of the tip of the stirring blade 1 progresses with the continuation of the operation of the screw conveyor 100, the width (w) of the clearance between the tip of the stirring blade 1 and the casing 4 (see FIG. 2 ) gradually expands. When the width (w) reaches a certain value or more, various troubles will occur in the operation using the screw conveyor 100, such as a decrease in kneading and conveying capacity, or occurrence of a flushing phenomenon.

As a means for avoiding such a situation, for example, each part of the stirring blade is formed of materials with different wear resistance, and only a part with low wear resistance can be easily replaced. There has been proposed a screw conveyor that reduces the work load of replacement work when wear progresses (see Patent Document 1).

On the other hand, by attaching a plate-like member made of a high-hardness material to the tip surface of the stirring blade, the stirring blade has improved wear resistance (see Patent Document 2), or various shapes on the tip surface. Stirring blades installed by appropriately combining ceramic members have also been proposed (see Patent Document 3).

Japanese Patent Application Laid-Open No. 2003-336489 JP 2006-233695 A JP 2010-94646 A

Here, in order to determine whether or not the stirring blades need to be replaced according to the progress of wear, it is necessary to completely stop the screw conveyor and directly measure the degree of wear of the paddles through an inspection opening or the like. Regarding this point, even the screw conveyor described in Patent Document 1 is no different from the conventional screw conveyor. For this reason, in the screw conveyor described in Patent Document 1, in order to reduce the frequency of temporary suspension of operation and improve productivity, further improvement of the abrasion resistance of the stirring blade is still a solution. It remained an issue to be addressed.

On the other hand, as in the case of the stirring blades disclosed in Patent Document 2 and Patent Document 3, a high degree of wear resistance is ensured by forming a high-hardness wear-resistant layer on the tip surface of the stirrer. As for the blades, the life of the base material of the stirring blades varies depending on the hardness of the material to be kneaded and other operating conditions due to abrasion of parts other than the tip end face. Accordingly, the wear resistance required for the wear-resistant layer on the tip surface of the stirring blade also varies greatly. In other words, it is necessary to design the wear-resistant layer so that the life of the wear-resistant layer does not expire before the life of the base material expires. If the service life is longer than , the state is substantially over-specified, and the demerit due to the decrease in economic efficiency of the wear-resistant layer made of an expensive material becomes apparent. In addition, the stirring blades disclosed in Patent Documents 2 and 3 have a complicated structure, which not only requires time and effort to manufacture, but also increases manufacturing costs. Become.

Due to the circumstances described above, the agitating blades for kneading equipment that kneads the material to be kneaded that has an abrasive effect have a resistance to the tip of the agitating blade according to the type of material to be kneaded and the operating conditions that differ from one operating site to another. It is desirable to have a structure that can flexibly optimize the life (strength and durability) of the wear layer.

In this respect, the agitating impeller described in Patent Document 2 has a configuration in which a preformed regular wear-resistant member is installed, and it is only considered to simply form a long-life wear-resistant layer. Therefore, in optimizing the life of the abrasion-resistant layer at the tip of the stirring blade as described above, in order to improve the economic efficiency, it is necessary to start again from the production of the abrasion-resistant member, which takes a very long time and is expensive. cost.

Incidentally, the stirring blades described in Patent Document 3 are intended for materials to be kneaded that are not only wear-resistant but also corrosive. For this reason, almost the entire surface of the stirring blade is covered with a ceramic member such as an L-shaped shaped part. I can't say I like it. Moreover, as with the stirring blades described in Patent Document 2, it is also difficult to optimize the life of the wear-resistant layer at the tip of the stirring blades.

The present invention is a stirring blade for a kneading device having a wear resistance reinforced portion on the tip surface, and the wear resistance of the tip surface is reinforced to a necessary and sufficient level, and economically. The object of the present invention is to provide a stirring blade and a kneading device using the same, which facilitates optimizing the durability of the tip surface within a range that does not result in overspecification in the sense described above.

The inventors of the present invention have proposed a simple stirring blade for a kneading device, in which a formwork made of a metal plate is formed on the tip surface of the blade, and a wear-resistant alloy is cast into the formwork to form a reinforced wear-resistant portion. The inventors have found that the above problems can be solved by adopting the structure, and have completed the present invention. Specifically, the present invention provides the following.

(1) A stirring blade for a kneading device, comprising a base material, a formwork installed at the tip of the base material, and a wear-resistant reinforcement part, wherein the formwork is formed from a metal plate a stirring blade erected to surround the outer periphery of the tip end face of the base material, wherein the wear-resistant reinforcement portion is made of a wear-resistant alloy filled in the mold.

(2) The stirring blade according to (1), wherein the metal plate is an iron plate made of ordinary steel.

(3) A kneading device in which the stirring blades according to (1) or (2) are arranged.

(4) The kneading device according to (3), wherein the kneading device is a variable speed twin screw conveyor.

(5) A method of kneading a material to be kneaded using the kneading apparatus according to any one of (3) or (4), wherein the material to be kneaded is powder containing a mineral having a Vickers hardness of approximately 50 or more. kneading method.

According to the present invention, there is provided a stirring blade for a kneading device having a wear resistance reinforced portion provided on the tip surface, the wear resistance of the tip surface being reinforced to a necessary and sufficient degree, and economical efficiency. In terms of the above, it is easy to optimize the durability of the tip surface within a range that does not become overspecification in the above sense, and it is easy to manufacture and maintain, and it is economically efficient. It is possible to provide a kneading device using

It is a front view showing typically the structure of the screw conveyor which is one embodiment of the kneading device of the present invention. 1. It is sectional drawing which shows typically the internal structure of a screw conveyor in the A section of FIG. 1, and the arrangement|positioning aspect of the stirring blade of this invention. 1 is a perspective view of a stirring blade of the present invention; FIG. 1 is a plan view of a stirring blade of the present invention; FIG. 1 is a front view of a stirring blade of the present invention; FIG.

Hereinafter, an embodiment of a stirring blade 1 for a kneading device of the present invention and a screw conveyor 100 as a preferred example of a kneading device using the same will be described. However, the present invention is not limited to the following embodiments.

<Stirring blade>
A stirring blade 1 for a kneading apparatus of the present invention is a member installed on a screw conveyor 100 for the purpose of stirring a material to be kneaded, as shown in FIGS. The stirring blades 1 are arranged on the outer periphery of the rotary shaft 2 of the screw conveyor 100 in a manner capable of stirring and conveying the material to be kneaded. The kneading device in which the stirring blades 1 are arranged is not particularly limited as long as it has a function of stirring the material to be kneaded by the stirring blades 1 . However, a screw conveyor can be preferably used as a kneading device in which the stirring blades 1 are arranged. Moreover, among screw conveyors, a non-uniform twin-screw screw conveyor can be particularly preferably used. The screw conveyor 100 in this embodiment is a non-uniform twin-screw screw conveyor. Details of the kneading device will be described later.

As shown in FIGS. 3 to 5, the stirring blade 1 is a so-called paddle-type blade-like member. The stirring blade 1 includes a base material 11 , a formwork 12 , and a wear resistance reinforcing portion 121 . The base material 11 is firmly fixed onto the mounting base portion 13 by welding or the like. The formwork 12 is made of a metal plate and erected so as to surround the outer periphery of the front end surface 111 of the base material 11 . The wear-resistant reinforcing part 121 is made of a wear-resistant alloy filled in the inner space of the formwork 12 having a series of wall frames, and is installed in a manner to cover substantially the entire tip surface 111 of the base material 11 . ing. The wear-resistant reinforced portion 121 is usually formed by a method (casting method) in which a melted wear-resistant alloy is cast into the mold 12 and molded.

The material of the base material 11 is preferably a material such as carbon steel or stainless steel, which has an excellent balance of wear resistance, workability, and economic efficiency. The base material 11 may have any shape as long as it is capable of sufficiently stirring the material to be kneaded and has enough strength to withstand the pressure received from the material to be kneaded during operation. For example, as shown in FIGS. 3 and 4, a blade-shaped panel having a flat front surface and a flat rear surface surrounded by a tapered outer periphery in a front view can be preferably used as the base material 11 .

The material of the formwork 12 is not particularly limited as long as it is a metal plate made of a metal material having enough heat resistance to withstand the high heat generated during casting of the wear-resistant reinforcement portion 121 . In general, it is preferable to have heat resistance that can withstand heat up to about 1500° C. when the wear-resistant alloy is cast. However, as will be described later in detail, the formwork 12 is not required to have durability when the screw conveyor 100 is used. An iron plate made of steel can be used. By using an iron plate made of ordinary steel as the metal plate forming the formwork 12, the manufacturing cost and maintenance cost of the screw conveyor 100 can be suppressed, and the economic efficiency can be further improved.

It should be noted that the mold 12 is no longer an essential structure for the stirring blade 1 after the wear resistance reinforcing portion 121 is fixed to the tip surface 111 of the base material 11 by a casting method or the like. In other words, even if the mold 12 is worn away due to subsequent wear or heat damage, or even if it is detached from the stirring blade 1, after the wear resistance strengthening part 121 is completed, the tip of the stirring blade 1 This is because the wear resistance of the surface 111 is sufficiently maintained only by the wear resistance reinforced portion 121 . Therefore, in the state after forming the wear resistance enhanced portion 121, the mold 12 itself is not required to have particular wear resistance and durability. Therefore, even an iron plate made of inexpensive ordinary steel can be preferably used as the metal plate forming the form 12 .

The shape of the mold 12 may be any shape as long as it is a series of wall frame-like shapes that surround the outer periphery of the front end surface 111 of the base material 11 and are erected. It may be composed of a plurality of metal plates connected to form such a wall frame shape, or a single metal plate that is bent to form such a shape. The structure which consists of a board may be sufficient. Moreover, although the method of attaching the formwork 12 having such a shape is not particularly limited, it can be attached to the base material 11 by an attachment method such as welding, for example.

The wear-resistant reinforcing portion 121 is installed so as to cover substantially the entire tip surface 111 of the base material 11 of the stirring blade 1 . As the wear-resistant alloy forming the wear-resistant enhanced portion 121, various conventionally known metal materials having wear resistance can be appropriately used. In particular, materials such as cemented carbide, tool steel, and high-speed steel can be preferably used from a comprehensive point of view in consideration of workability and economy. A specific example of a metal material that can be particularly preferably used as a wear-resistant alloy is “STL-NEXT (manufactured by ING Trading Co., Ltd.)”.

The thickness of the wear resistance reinforced portion 121 may be appropriately optimized according to the desired wear resistance. For example, when the wear-resistant alloy "STL-NEXT" is used, the thickness of the wear-resistant enhanced portion 121 is preferably in the range of 10 mm or more and 50 mm or less. Within this thickness range, it is possible to handle various materials to be kneaded having various hardnesses, including highly abrasive carbon and the like.

Here, during the operation of the screw conveyor 100, the degree of wear resistance required of the wear resistance enhanced portion 121 of the stirring blade 1 varies in a wide range depending on the hardness of the material to be kneaded and other operating conditions. In addition, with respect to the degree of wear resistance, it is essential to have at least the minimum required strength and durability. It is preferable that the strength and durability be within a range that does not result in over-specification. The stirring blade 1 has a structure in which the type and filling amount of the wear-resistant alloy to be filled in the mold 12 (that is, the thickness of the wear-resistant reinforced portion 121) can be optimized and adjusted very easily as necessary. Therefore, it is possible to easily change the design in response to changes in the treatment target and operating conditions.

In addition, generally, when stirring the material to be kneaded which has an abrasion action in the kneading device, the agitating blade receives the abrasion action from the material to be kneaded over substantially the entire surface of the base material 11 . However, when the kneading device is a screw conveyor, among the various parts of the stirring blade 1, especially near the tip surface 111, it is subjected to a relatively strong abrasion action than other parts, and as a result, especially near the tip part Wear tends to progress quickly. This tendency becomes even more conspicuous when the kneading device is a non-uniform twin-screw screw conveyor. The agitation blade 1 is provided with a wear-resistant reinforcing portion 121 formed of a wear-resistant alloy on the tip surface 111, so that the wear resistance of the tip portion of the agitation blade 1 in particular is greatly improved. It is what I let you do. Therefore, the stirring blade 1 can be preferably used when the kneading device is a screw conveyor, and can be particularly preferably used when the kneading device is a variable speed twin screw conveyor.

<Kneading device>
1 and 2 are a front view and a sectional view schematically showing the structure of a screw conveyor 100 using the stirring blade 1 of the present invention. As shown in FIGS. 1 and 2, the screw conveyor 100 includes a casing 4 which is a hollow tubular outer shell, a conveying screw 3 arranged in the inner space of the casing 4, and a rotary drive device such as an electric drive unit 5. , support members such as the bearing 6, and the like. Support members such as the electric drive 5 and the bearings 6 are rigidly fixed to the machine base 7 .

The conveying screw 3 is a screw capable of conveying the material to be kneaded through the casing 4 while stirring the material. The conveying screw 3 is obtained by helically installing the stirring blades 1 on the rotating shaft 2 . The stirring blade 1 is firmly and detachably fixed to the rotating shaft 2 by passing a bolt through the stirring blade mounting hole 131 formed in the mounting base portion 13 .

The rotary shaft 2 is supported by a set of bearings 6 in a manner capable of axial rotation. By rotating the rotating shaft 2 by the electric drive unit 5 , the material to be kneaded in the casing 4 is conveyed in the longitudinal direction of the screw conveyor 100 while being stirred by the stirring blades 1 . Due to this transportation, the material to be kneaded introduced from the inlet 8 is pushed out in the direction of the outlet 9 .

The casing 4 may be formed from a single member, or may be formed by detachably connecting a plurality of members with bolts or the like in order to improve the maintainability of the stirring blade 1 .

In the screw conveyor 100, in order to convey the material to be kneaded smoothly and efficiently, a width is usually provided between the tip of the stirring blade 1 and the inner peripheral surface of the casing 4 as a clearance for preventing friction and the like. (w) is provided. The preferred size of this width (w) varies depending on the inner diameter of the casing and the particle size of the powder to be fed. The width (w) is preferably about 3 mm or more and 10 mm or less. If the thickness exceeds about 10 mm, the efficiency of conveying the kneaded material is lowered and the flushing phenomenon frequently occurs.

Since the screw conveyor 100 is a non-uniform twin-screw screw conveyor, the two rotating shafts 2 on which the stirring blades 1 are spirally arranged rotate at different speeds. When this rotation is constant speed, the position where the stirring blades 1 intersect is constant, so the stirring blades 1 and the rotating shaft 2 get stuck in places where the stirring blades 1 do not intersect. On the other hand, when the rotation speed is non-uniform, the crossing position of the stirring blade 1 shifts with each rotation, so the self-cleaning action of rotating while scraping off the sticking to the stirring blade 1 and the rotating shaft. It operates while generating As a result, it is possible to process even the most stubborn conveyed goods.

The screw conveyor 100 has remarkably improved abrasion resistance, particularly on the tip surface 111 of the stirring blade 1 . Therefore, especially when the tip portion of the stirring blade is subjected to a strong abrasion load, the progress of wear of the tip portion can be remarkably suppressed. Examples of materials to be kneaded that apply a strong abrasion load to the stirring blade 1 include iron and steel dust, carbon, various precipitates, RPF, and other carbon-containing powders. can.

In the kneading method using the screw conveyor 100 equipped with the stirring blade 1, as described above, steel dust, carbon, and the like can be kneaded in a preferred manner. Among them, various powders containing carbon can be kneaded in a particularly preferred manner. Further, if the material to be kneaded is a powder containing a mineral having a Vickers hardness of about 50 or more, the kneading method using a screw conveyor 100 equipped with a stirring blade 1 is preferably used, not limited to the powder containing carbon described above. can be used. Specific examples of minerals having a Vickers hardness of approximately 50 or more include barite, silica, kaseki, gypsum, and soda glass, in addition to carbon.

Further, the screw conveyor 100 equipped with the stirring blades 1 can be preferably used as a means for pre-treating the material to be kneaded before introducing it into a heating process such as a reduction roasting process. A preferred specific example is a process of kneading iron and steel dust and carbon into pellets.

According to the stirring blade 1 and the kneading device (screw conveyor 100) using the same, the following effects are obtained.

(1) In the present invention, the agitating blade 1 for a kneading device consists of a base material 11, a formwork 12 installed at the tip of the base material 11, and an abrasion resistance enhancement by filling the formwork 12. 121 . By satisfying these constituent requirements, the stirring impeller 1 has improved the wear resistance in the vicinity of the tip of the base material 11 which is subjected to the wear action of the material to be kneaded. In addition, since the wear-resistant reinforced part 121 can be formed by casting a wear-resistant alloy into the mold 12, the wear-resistant reinforced part 121 can be formed according to the conditions unique to each operation site. It has also become possible to easily adjust the thickness of the film to an optimal thickness as appropriate. In other words, the stirring blade 1 can sufficiently suppress the progress of wear of the tip surface 111 of the base material 11, and the life of the wear resistance enhanced portion 121 is optimized in combination with the life of the base material 11. It is also possible to easily make adjustments to make it more flexible. As a result, the stirring blade 1 can further reduce the manufacturing and maintenance costs of the kneading device such as the screw conveyor 100, thereby significantly improving its economic efficiency. In addition, for example, as disclosed in Japanese Patent Laid-Open No. 2015-66533, compared to a stirring blade having a complicated tip structure in which a hard tip is embedded at the tip of the stirring blade, the stirring blade 1 is The manufacturing cost can be greatly reduced, and the necessary and sufficient wear resistance can be sufficiently ensured when the life of the base material 11 is taken into consideration, so that the structure is superior in economic efficiency.

(2) Furthermore, the metal plate forming the mold 12 is an iron plate made of ordinary steel, which is readily available and inexpensive. This material selection has become possible for the first time when the wear-resistant enhanced portion 121 can be formed by casting a wear-resistant alloy using the mold 12 as a mold. In the stirring blade 1, the selection of the material for the formwork 12 is bounded by wear resistance equivalent to that required for the members constituting part of the wear resistance reinforcing portion 121 and other conditions related to high durability. because there is no Thereby, the manufacturing cost and maintenance management cost of the screw conveyor 100 can be suppressed, and the economic efficiency can be further improved.

(3) Further, in the present invention, the conventional kneading device is newly provided with a stirring blade 1 . According to this, the kneading apparatus can be made superior to the conventional one in maintainability and economic efficiency while maintaining the required wear resistance.

(4) Furthermore, when the kneading device is a non-uniform twin-screw screw conveyor, the configuration is such that the stirring blades 1 are arranged on this. As a result, in the operation of a non-uniform twin-screw screw conveyor in which a particularly high load is applied to the tips of the stirring blades, the above effect (3) can be exhibited more effectively.

(5) Furthermore, the method of kneading the material to be kneaded using the kneading device of (3) or (4) is applied to the case where the material to be kneaded is a powder containing a mineral having a Vickers hardness of approximately 50 or more. It was configured. As a result, the effect of any one of the inventions (1) to (4) above is exhibited as a more pronounced effect when a material to be kneaded having a strong abrasion action represented by carbon is introduced.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments. Moreover, the effects described in the embodiments of the present invention are merely enumerations of the most suitable effects resulting from the present invention, and the effects of the present invention are limited to those described in the examples of the present invention. isn't it.

REFERENCE SIGNS LIST 1 agitating blade 11 base material 111 tip surface 12 formwork 121 wear resistance reinforcing portion 13 mounting pedestal portion 131 agitating blade mounting hole 2 rotating shaft 3 conveying screw 4 casing 5 electric drive unit 6 bearing 7 machine base 8 inlet 9 exhaust Exit 100 screw conveyor

Claims (5)

A base material, a form erected so as to surround the outer periphery of the front end surface of the base material, and a wear-resistant reinforced portion made of a wear-resistant alloy filled inside the form. death,
The formwork is made of a metal plate and fixed to the base material,
A kneading device in which stirring blades are arranged . The metal plate that constitutes the formwork is fixed to the base material by welding,
The kneading apparatus according to claim 1. 3. A kneading apparatus according to claim 1 or 2, wherein said metal plate is an iron plate made of ordinary steel. The kneading device according to any one of claims 1 to 3, which is a variable speed twin screw conveyor. A method of kneading a material to be kneaded using the kneading apparatus according to any one of claims 1 to 4 , wherein the material to be kneaded is a powder containing a mineral having a Vickers hardness of approximately 50 or more.

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