JP2017094381A - Core sand regeneration device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a core sand regeneration device capable of regenerating even core sand of using not only an organic binder but also an inorganic binder.SOLUTION: A rotary kiln type core sand regeneration device is a core sand regeneration device composed of a rotary cylinder, a burner, a motor, an exhaust cylinder, an input port of used core sand, a take-out port of regenerated core sand and front-rear frames for supporting these, and a core sand scraping-up plate for scraping up the core sand is added to an inner wall of the rotary cylinder, and a combustion cylinder of opening a passing hole for passing the core sand and a flame from the burner is also provided in front of the rotary cylinder, and the used core sand is inputted in the rotary cylinder from the rear used core sand input port, and while repeating rising-falling by the core sand scraping-up plate, a binder stuck to a surface of the used core sand is also burnt and melted by the combustion cylinder by passing through a preheating cylinder, and is sent to the take-out port of the regenerated core sand.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an apparatus for reclaiming used core sand.

A core is a sand mold that is inserted into a mold as a portion corresponding to a cavity, particularly when a casting having a complicated cavity is made, and sand is placed in a mold.
A complicated shape is created by placing a core in a mold called a main mold, pouring molten metal such as iron into a solidified metal, and finally collapsing the sand mold. For example, although the melting temperature of iron is about 1500 ° C., sand having a special composition is used so that it can withstand such high heat, and after semi-cooling, the core is collapsed by taking an impact to take out the sand. Therefore, each core is a consumable item.
The sand used for the core is limited to the specified type and size, etc., and the characteristics required for the core, (b) high heat resistance, (b) the amount of gas generated is small, and there is gas venting ( C) Excellent sand disintegration (d) Low cost. Core sand is currently imported mainly from Alltoria.

The core is made by mixing predetermined sand with a binder (hereinafter referred to as a binder), placing it in a mold, and molding it by heating or the like. The core is a consumable, and the core used is crushed and sandy, but the sand used for the core requires a certain type and particle size, and its unit price is somewhat expensive, Once sand has been used as a core, it must be recycled, in other words, recycled. However, since the binder is attached to the surface of the used core sand, it is necessary to remove the attached binder in order to regenerate. As will be described later, the binder can be removed by a mechanical / physical method or a combustion method. There are organic binders and inorganic binders. Currently, organic binders are often used, but inorganic binders are also starting to be used due to the influence of volatile organic compounds (VOC).
In the method of removing the binder by burning, the inorganic binder has a higher melting point than the organic one, and it is difficult to remove the inorganic binder by combustion compared to the organic one. In the child sand recycling apparatus, silicon yarns are generated between the sands, and there is a case where regeneration cannot be said.

In the area where the inventor of the present application resides, there are many transport machine manufacturers and their peripheral technologies have been cultivated. Under such circumstances, the inventor has been engaged in the manufacture and sale of so-called kneading mixers that stir and mix core sand and binder.
Therefore, the inventor of the present application made a trial production of a used core sand recycling apparatus not only for an organic binder but also for an inorganic binder based on the experience so far.
The inventor of the present application pays attention to the fact that the melting point of the inorganic binder is higher than that of the organic binder, increasing the combustion temperature, that the surface of the pulverized spent core sand is evenly burned, and the burner's direct fire Care was taken to avoid hitting.
As a result of trial and error, the inventors of the present application have invented a rotary kiln-type core sand recycling apparatus.

The following can be seen as prior art documents related to the method for regenerating core sand.
After casting, the casting mold is crushed and further pulverized to separate individual sand particles, which are then mechanically sufficient to crush the binder that covers the outer surface of the sand particles. A method for reclaiming used foundry sand that is regenerated by applying impact and further washing it with water and removing substantially all of the portion adhering to the sand particles due to electrostatic charging from the sand particles (Patent Document) 1)
A roasting process in which black sand is roasted and the inorganic material such as unburned bentonite adhering to the surface of the black sand is modified into a magnetic material, and the magnetic material layer of the black sand treated in the roasting process is a grinding stone And a separation method of separating sand from the black sand using magnetic force to the magnetic material separated in the separation step, and a magnetic sand separation step for obtaining reclaimed sand (Patent Document 2),
In a solution furnace for solutionizing an aluminum cast product cast by a die having a sand core, a first heat treatment furnace provided with an input port for introducing a cast product before sand removal after casting, and a discharge port A second heat treatment furnace provided; a shutter provided between the first heat treatment furnace and the second heat treatment furnace; a casting product conveyor for conveying a cast product from an inlet to an outlet; and a first heat treatment furnace And a sand transport conveyor provided below the cast product transport conveyor, the cast product transport conveyor has a mesh-like structure on the surface on which the cast product is placed, and the sand core is collapsed. A solution furnace (Patent Document 3) configured to allow the core sand to pass downward and drop onto the sand transport conveyor,
Prepare a drum with a rotor and striking means placed in it, load sand into the drum with each batch amount, expose the sand to high density striking, shearing and frictional forces, force the strength of quartz A method for reclaiming foundry sand used in a manufacturing process comprising adjusting a variable rotational speed of at least one of a drum and a rotor to adapt to the force required to clean the particles (Patent Document 4).

JP-A-8-243682 JP-A-6-170485 JP 2013-146741 JP-A-6-63691

Patent Document 1 and Patent Document 2 are methods for reclaiming used foundry sand by mechanical and physical action, and it may be difficult to regenerate depending on the type of core sand and binder. The surface on which the product is placed has a mesh-like structure, and is a solution furnace configured to pass the core sand downward when the sand core is collapsed, and drop it onto the sand transport conveyor, No specific method for reclaiming spent core sand is shown. Patent Document 4 is a method for reclaiming used core sand by physical action, and is not a reclaiming device for used core sand that serves as both an organic or inorganic binder.

  The problem to be solved by the present invention is to provide a facility for efficiently regenerating spent core sand using an inorganic or organic binder.

  That is, the first invention comprises a rotating cylinder, a burner for sending a flame into the rotating cylinder, a motor for rotating the rotating cylinder, a frame frame before and after supporting the rotating cylinder, a roller, and a frame on which these are mounted. From the rear, there is an inlet for used core sand, an exhaust pipe, followed by a preheating cylinder. There is an outlet for regenerated core sand in the front, and the front end of the rotary cylinder is directly connected to the burner. On the inner wall, there is a core sand lifting plate that lifts the core sand at the bottom of the rotating cylinder, drops it, disperses it, and sends it forward. Is provided with a combustion cylinder with a passage hole through which the core sand and the flame from the burner pass, and the used core sand is introduced into the rotating cylinder from the used core sand inlet, The sand sweeper moves forward while repeating ascending, falling and dispersing, Through the pre-heating cylinder in the cylinder, a further rotary kiln type core sand reproducing apparatus spent core the binder adhering to the surface of the sand is burned and melted send to outlet playback core sand in the combustion cylinder.

1 and 2 show a schematic view of a front view and a right side view of the core sand regenerator 1. The rotating cylinder 3 is supported by the front frame 2, the rear frame 6, and the rollers 51, and is mounted on the gantry 7. The rotation of the motor 5 rotates the rotating cylinder 3 via the roller 51. The front-rear direction of the rotary cylinder 3 was set so that the spent core sand inlet 21 portion was the rear, and the reclaimed core sand outlet 61 was the front, in accordance with the traveling direction of the core sand. At the used core sand inlet 21, the core sand is used core sand, being regenerated core sand in the rotary cylinder 3, and at the reclaimed core sand outlet 61, the regenerated core sand. Since it is sand, it was appropriately expressed as used core sand, core sand, and recycled core sand. 1 and 2 are schematic views, and components such as a rotating shaft that connects the motor and the roller are not described (the same applies hereinafter).

  The used core sand thrown into the rotary cylinder 3 from the used core sand inlet 21 is swept up by the core sand lifting plate 33 attached to the inner wall of the rotating rotary cylinder 3 and moved upward. While falling and being heated in the preheating cylinder 31 while being dispersed, it moves forward by an inclination slightly downward from the horizontal plane toward the front of the core sand lifting plate 33. While repeating this, the core sand proceeds to the combustion cylinder 32, and passes through the passage hole 34 or the outer wall surface of the combustion cylinder 32 a plurality of times while being repeatedly raised, dropped and dispersed by the core sand scraping plate 33. The binder adhering to the surface of the core sand is removed by burning or melting, and is carried to the outlet 61 for reclaimed core sand.

The core sand cleaning plate 33 is one of the features of the present application. The core sand lifting plate 33 is attached to the inner wall of the rotating cylinder 3 in a straight line slightly downward from the horizontal surface of the rotating cylinder 3 toward the front. The core sand lifting plate 33 has a U-shape, and by rotating the rotary cylinder 3, the core sand at the bottom of the rotary cylinder 3 is lifted, transported upward, dropped and dispersed. Even if the used core sand is already pulverized, it can be seen that the binder adheres to the surface of each grain of fine sand and is sticky when touched. The used core sand to which the binder is attached may be a small lump of sand.
Therefore, the used core sand at the bottom of the rotating cylinder 3 is lifted up to the core sand lifting plate 33 by the rotation of the rotating cylinder 3, conveyed upward, and dropped from above the rotating cylinder 3, Is crushed into fine sand. The heat of the burner 4 is efficiently transmitted to the surface of the core sand, and the binder attached to the surface is burned and melted.
In FIG. 2, there are four core sand sweeping plates 33 as viewed from the side, and the cross section is a U-shaped cross section. However, the core sand is efficiently lifted and the rotating cylinder 3 is rotated. It is sufficient to be transported upward and fall, and the shape is not limited to the U-shape, and the number of core sand lifting plates 33 is not limited.
Further, the core sand cleaning plate 33 does not need to be a single straight line from the rear to the front in the rotary cylinder 3 as shown in FIG.
It took about 20 minutes to regenerate the spent core sand using the core sand recycling apparatus of the present application. For this reason, although the prototype of the downward slope angle of about 5 degrees with respect to the horizontal plane of the core sand scraping plate 33 was made, the angle is arbitrary.

The rotary kiln type is used to regenerate the used core sand while rotating the kiln using a kiln that directly contacts the material to be heated with fuel or heated gas. Rotary kilns are used for cement production and garbage incineration.
When the core sand recycling apparatus 1 according to the present application is used, the organic binder can be burned and removed. However, with an inorganic binder, fine silicon balls remain in the recycled core sand. However, even if this silicon ball remains, it can be sufficiently reused as core sand.

Subsequently, the second invention is the core sand recycling apparatus according to the first invention in which a core sand holding plate in which the core sand once stays is attached to the inner wall of the rotating cylinder.

FIGS. 3 and 4 show a cross-section in which the core sand holding plate 36 of the second invention is attached to the inner wall of the rotary cylinder 3 and a schematic arrangement from the front.
In order to regenerate the spent core sand, it is necessary to repeat the scraping, dropping, and dispersion by the core sand lifting plate 33, and it is necessary for a predetermined time as described above. Not all of the core sand at the bottom in the rotary cylinder 3 is swept up by the core sand lifting plate 33, and there is core sand remaining at the bottom. The core sand holding plate 36 temporarily retains the remaining core sand, and transports and drops the core sand upward by the rotation of the rotary cylinder 3 so that the core sand is swept up by the core sand lifting plate 33. It is attached to the inner wall of the building.
The core sand retaining plate 36 is not as long as the core sand cleaning plate 33, and is substantially perpendicular to the moving direction of the core sand between the core sand cleaning plates 33 on the inner wall of the rotary cylinder 3. Attached to multiple. The reason for being substantially vertical is that the core sand may be gently inclined to move forward.
The core sand holding plate 36 may be U-shaped in the opposite direction to the movement of the core sand, that is, the rear, and may have a shape in which the core sand tends to stay once, but the shape is arbitrary.

Subsequently, the third invention is the core sand regenerator of either the first invention or the second invention in which the combustion cylinders provided with the passage holes are concentrically multiplexed.

FIG. 5 is a schematic view of various combustion cylinders 32 and passage holes 34, and FIG. 6 is an arrangement schematic diagram of the burner 4 and the combustion cylinder 32.
The passage hole 34 of the combustion cylinder 32 not only has a function of urging complete combustion of the fuel from the burner 4, but also passes the core sand that is swept and dropped by the core sand lifting plate 33 to the passage hole 34 of the combustion cylinder 32. Alternatively, it also has a function of burning and melting by bringing it into contact with the surface of the combustion cylinder 32. This is because the combustion cylinder 32 is not only constituted by a single cylinder, but it is considered that the effect is further increased by concentrically doubling the triple cylinder such as double or triple.
In FIG. 6, there is one combustion cylinder 32 near the burner 4, a combustion cylinder 32 having a slightly smaller diameter is connected to the rear thereof, and a combustion cylinder 32 is provided concentrically outside the combustion cylinder 32. It is heavy.
The burner 4 can be used regardless of gaseous fuel or liquid fuel.

Then, 4th invention is the core sand reproduction | regeneration apparatus in any one from 1st invention to 3rd invention which can adjust the rotation speed of a rotary cylinder.

  Depending on the type or amount of the binder, the time required for reclaiming the used core sand varies. In the core sand regenerator 1 of the present application, the core sand lifting plate 33 is arranged so that the core sand scraping plate 33 faces the front of the rotary cylinder 3 from the rear to the front of the rotary cylinder 3 slightly downward from the horizontal plane. It is attached to the inner wall. Therefore, the reproduction time can be shortened or extended by increasing or decreasing the number of rotations of the rotating cylinder 3. The rotation speed is generally adjusted by the control panel 8 linked to the motor 5, but is not limited to this.

  Then, 5th invention is the core sand reproduction | regeneration apparatus in any one of 1st invention from the 1st invention which can adjust the inclination-angle of a rotary cylinder.

As in the fourth aspect of the invention, the reproduction time can be changed by increasing or decreasing the rotational speed of the rotating cylinder 3. However, it may be difficult to adjust the reproduction time by itself, and the function of adjusting the tilt angle of the rotary cylinder 3 itself is provided. In FIG. 1, a height adjusting jig 72 for changing the inclination of the rotary cylinder 3 is attached to the rear leg of the gantry.

Then, 6th invention is the core sand reproduction | regeneration apparatus in any one from 1st invention to 5th invention by which the heat insulating material was provided in the wall surface of the rotation cylinder.

In the core sand regenerator 1 of the present application, the temperature inside the combustion cylinder 32 is about 750 to 800 ° C., and the outer surface temperature of the rotary cylinder 3 containing the combustion cylinder 32 is considerably high. There is a risk of burns. In addition, it is natural to carry out heat insulation for energy efficiency. The rotary cylinder 3 has a double structure having an outer wall and an inner wall, and a heat insulating material 35 is interposed between the two.

The first invention provides a facility for efficiently regenerating used core sand using an inorganic or organic binder. In particular, the effect is exhibited by the core sand lifting plate and the combustion cylinder provided in the rotary cylinder. 2nd invention makes more efficient the effect | action of the scraping board 33 of a core sand.
The third invention is effective for complete combustion of the burner and combustion / melting of the used core sand. The fourth invention is that the regeneration work time can be appropriately set according to the type of the binder, and the fifth invention is that the regeneration work time is changed by changing the inclination angle when it is difficult to adjust the regeneration work time only by the fourth invention. Is to adjust. The sixth invention is for safety of work, improvement of work environment, and energy saving.

FIG. 1 is a schematic front view of a core sand recycling apparatus. FIG. 2 is a schematic right side view of the core sand recycling apparatus. FIG. 3 is a schematic cross-sectional arrangement of the rotating cylinder core sand holding plate. FIG. 4 is a schematic view from the front of the rotating cylinder core sand holding plate. FIG. 5 is a schematic view of various combustion cylinders and passage holes. FIG. 6 is a schematic view of the burner and the combustion cylinder. FIG. 7 is a diagram of a prototype of the core sand recycling apparatus. FIG. 8 is a diagram of a motor and a roller for rotating the rotating cylinder. FIG. 9 is a view of the rear frame and the burner. FIG. 10 is a view of the rear frame when the burner is removed. FIG. 11 is an internal view of the rotating cylinder as seen from the rear frame. 12 is a view of the inside of the rotating cylinder as seen from the same rear frame as that in FIG. FIG. 13 is a diagram of used core sand and regenerated core sand.

  Examples of the present application are shown below.

  FIG. 7 shows a prototype of the core sand recycling apparatus of the present application. FIG. 7 is a diagram seen from the back with respect to the schematic front view of FIG. The used core sand prepared in the hopper 71 is supplied to the rotary cylinder 3 in the front frame 2 from the used core sand inlet 21. The spent core sand is in the rotating cylinder 3 from the left side in FIG. 7 to the right side with the burner 4 and in the rotating cylinder 3 while being repeatedly raised, dropped and dispersed by the core sand lifting plate 33. The binder adhering to the surface of the used core sand passing through the passage hole 34 or the outer wall surface of 32 is removed by burning or melting, and is carried from the rear frame frame 6 to the outlet 61 for reclaimed core sand. . The control panel 8 controls the start and stop of the core sand regenerator, the number of rotations of the rotary cylinder 3, and the like. This apparatus is mounted on the gantry 7. Although not shown, the exhaust tube 22 is provided with a multi-stage dust removing device on its extension to take the environment into consideration.

FIG. 8 is a diagram of the motor 5 and the roller 51 for rotating the rotating cylinder. Since the motor 5 is on the left gantry facing forward, it is displayed in FIG. 1 but not in FIG. The rotational force of the motor 5 is transmitted to the roller 51 and the rotating cylinder 3 is rotated. Since a part of the motor had a trademark, the part was deleted.

FIG. 9 is a layout view of the rear frame 6 and the burner 4. Below the rear frame 6 is a reclaimed core sand outlet 61.

10 is a view of the rear frame 6 when the burner 4 is removed, and FIG. 11 is an internal view of the rotary cylinder 3 as viewed from the rear frame 6. A combustion cylinder 3 having a passage hole 34 is provided inside the rotary cylinder 3. Further, FIG. 12 shows the arrangement of the core sand cleaning plate 33 and the core sand holding plate 36 inside the rotary cylinder 3. C-shaped steel is used for the core sand lifting plate 33, and a plurality of core sand sweeping plates 33 extend forward from the rear of the rotating cylinder 3. Further, the core sand holding plate 36 is fixed perpendicularly to the inner wall of the rotary cylinder 3 and uses a U-shaped shape.

  In FIG. 13, A is used core sand, and B is regenerated core sand that has passed through the core sand regenerator of the present application. Although the difference is not clearly understood from FIG. 13, in the finger feeling, the former is sticky, while the latter is smooth, so the difference is easily recognized.

Although the core is a field that is not generally known, it is an indispensable technology for the production of precision parts such as transportation equipment. The core sand is not only grain size and material, it is necessary that each grain of sand is rounded, and each core is a consumable item. Regeneration is necessary. The core sand reclaiming device of the present application has an advantage that used core sand using an inorganic binder can also be reclaimed, and core sand having a different binder can be reclaimed for each lot. Unlike conventional used core sand regenerators, the structure is not complicated, so it can be provided at low cost, and demand is expected.

DESCRIPTION OF SYMBOLS 1 Core sand reproduction apparatus 2 Front frame frame 21 Used core sand inlet 22 Exhaust pipe
3 Rotating cylinder 31 Preheating cylinder 32 Combustion cylinder 33 Core sand scraping plate
34 Passing hole 35 Heat insulation material 36 Core sand retaining plate 4 Burner
5 Motor 51 Roller 6 Rear frame 61 Recycling core sand outlet 7 Base 71 Hopper 72 (Base of leg) Height adjustment jig 8 Control panel

That is, the first invention comprises a rotating cylinder, a burner for sending a flame into the rotating cylinder, a motor for rotating the rotating cylinder, a frame frame before and after supporting the rotating cylinder, a roller, and a frame on which these are mounted. from the rear, the spent core Sunato inlet, exhaust stacks, followed there is pre-heating cylinder, in front has outlet playback core sand, before the tip portion of the rotary cylinder is directly connected to the burner, the rotating cylinder On the inner wall, there is a core sand lifting plate that lifts the core sand at the bottom of the rotating cylinder, drops it, disperses it, and sends it forward. Is provided with a combustion cylinder with a passage hole through which the core sand and the flame from the burner pass, and the used core sand is introduced into the rotating cylinder from the used core sand inlet, Rotating while moving forward while repeating ascending, falling and dispersing Through the pre-heating cylinder of the inner, a further rotary kiln type core sand reproducing apparatus spent core the binder adhering to the surface of the sand is burned and melted send to outlet playback core sand in the combustion cylinder.

Claims (6)

It consists of a rotating cylinder, a burner that sends a flame into the rotating cylinder, a motor that rotates the rotating cylinder, a frame frame and rollers that support the rotating cylinder, a roller, and a frame on which these are placed. There is an inlet, an exhaust tube, followed by a preheating tube, a reclaimed core sand outlet is in front, the front end of the rotating tube is directly connected to the burner, and the inner wall of the rotating tube is A core sand scraping plate that lifts, drops, and disperses the core sand at the bottom and sends it forward is attached to the front and slightly downward from the horizontal plane. A combustion cylinder with a passage hole through which the flame from is passed is provided, and the used core sand is introduced into the rotating cylinder from the used core sand inlet, and is lifted by the core sand rake plate. While moving forward while repeatedly falling and dispersing, it passes through the preheating cylinder in the rotating cylinder, Rotary kiln type core sand reproducing apparatus spent core the binder adhering to the surface of the sand is burned and melted send to outlet playback core sand in the combustion cylinder to.   The core sand recycling apparatus according to claim 1, wherein a core sand holding plate for temporarily retaining the core sand is attached to the inner wall of the rotary cylinder. 3. The core sand regenerator according to claim 1, wherein the combustion cylinders provided with the passage holes are concentrically multiplexed. The core sand recycling apparatus according to any one of claims 1 to 3, wherein the number of rotations of the rotating cylinder can be adjusted.   The core sand recycling apparatus according to any one of claims 1 to 4, wherein an inclination angle of the rotary cylinder can be adjusted. The core sand recycling apparatus according to any one of claims 1 to 5, wherein a heat insulating material is provided on a wall surface of the rotating cylinder.