JP2015164743A - Apparatus and method for manufacturing regenerated casting sand - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an apparatus and a method for manufacturing regenerated casting sand capable of stably removing deposit.SOLUTION: An apparatus 1 for manufacturing regenerated casting sand includes: a heating chute 10 provided with an introduction port 11 and a discharge port 12; a burner 20 arranged on the upper part of the side face of the heating chute 10; angle adjustment means for adjusting an inclination angle of the heating chute; and vibration means 6 for vibrating the heating chute 10. A method for manufacturing regenerated casting sand includes: a regeneration step of introducing casting sand which is used as a cast into the heating chute 10 of the manufacturing apparatus 1, and vibrating and heating the introduced casting sand; and thereby removing a resin adhering to the surface of the casting sand to produce regenerated casting sand.

Description

  The present invention relates to a production apparatus and a production method for reclaimed foundry sand obtained by reclaiming foundry sand used in a mold.

Foundry sand is sand for producing a mold used for casting, and its main component is silicon dioxide (SiO ₂ ) or mullite. The foundry sand forms a mold in a state where a few percent of a binder or additive made of a thermosetting resin is blended with natural sand made of silica sand or artificial sand made of ceramic or the like. And after using for casting, it collect | recovers and uses again as casting sand, after receiving a reproduction | regeneration process. This regeneration process is a process for removing the binder and additive adhering to the surface of the foundry sand.

  Various methods for reclaiming foundry sand have been known. For example, Patent Document 1 discloses a recycled casting by polishing recovered sand in the presence of an additive composed of a liquid having a surface tension at 25 ° C. of 35 mN / m or less and a boiling point at 1 atm of 150 ° C. or more. Techniques for producing sand are disclosed. Further, in Patent Document 2, casting sand is supplied onto the punching plate, hot air is blown upward from below the punching plate, and the casting sand on the punching plate is moved toward the discharge port while dancing with hot air. A recycling method is disclosed in which fluid roasting is performed to remove the resin from the foundry sand to obtain recycled sand.

JP 2009-214178 A JP 07-31080 A

  However, in the liquid cleaning method described in Patent Document 1, since a water tank or the like is required, the size of the equipment tends to increase, and the cost required to maintain the manufacturing process tends to increase. Moreover, when the method of fluid roasting the foundry sand with air as described in Patent Document 2, the wall surface of the equipment may be scraped off by the foundry sand, resulting in wear, and the grains of the foundry sand to be regenerated. The diameter could be reduced.

  The present invention has been made in view of the above-described problems of the prior art, and is a device for producing recycled sand that can stably remove impurities and additives and maintain the particle size distribution of the sand. Providing a method is a problem to be solved.

  The present invention relates to an apparatus for producing recycled foundry sand. The manufacturing apparatus of the present invention adjusts the inclination angle of the heating chute, the heating chute provided with the inlet at one end and the outlet at the other end, the heating means disposed above the heating chute An angle adjusting means and a vibrating means for applying vibration to the heating chute are provided.

  The present invention also provides a method for producing recycled foundry sand. The production method of the present invention includes a step of introducing casting sand used as a mold into an inclined heating chute, and a regeneration that removes additives adhering to the surface of the casting sand by heating to 300 ° C. or higher while applying vibration. And a recovery step of recovering the foundry sand from the discharge port.

  The apparatus for producing reclaimed foundry sand according to the present invention produces reclaimed foundry sand that can be reused by removing the binder and additives adhering to the foundry sand after use with a downsized apparatus. Can do.

  The manufacturing apparatus of the present invention adjusts the amount of time the casting sand stays in the heating chute and the amount of heat applied to the casting sand by controlling the inclination of the heating chute, the heating temperature of the heating means, and the amount of vibration applied by the vibration means. In addition, binders and additives having different physical properties can be suitably removed from the foundry sand.

  The production apparatus of the present invention can produce reclaimed foundry sand without changing the particle size of the foundry sand.

  The apparatus for producing reclaimed foundry sand according to the present invention reduces the possibility that the passage is scraped off by the foundry sand being processed by making the heating chute linear, and can produce reclaimed foundry sand stably for a long period of time. it can.

  In the method for producing reclaimed foundry sand according to the present invention, the heating conditions can be easily changed, so that the reclaimed foundry sand to which various binders and additives are attached can be stably regenerated.

FIG. 1 is a side view of a production apparatus 1 for regeneration commission sand. FIG. 2 is a rear view of the main body 2 of the recycled foundry sand manufacturing apparatus 1. FIG. 3 is a side view of the main body 2 of the recycled foundry sand manufacturing apparatus 1. FIG. 4 is a top view of the main body 2 with the upper cover 13 removed from the recycled foundry sand manufacturing apparatus 1. FIG. 5 is a rear view of the sand supply unit 4 of the recycled cast sand manufacturing apparatus 1. FIG. 6 is a side view of the recycled foundry sand manufacturing apparatus 101. FIG. 7 is a rear view of the main body 102 of the recycled foundry sand manufacturing apparatus 101. FIG. 8 is a side view of the main body 102 of the recycled foundry sand manufacturing apparatus 101. FIG. 9 is a top view of the main body 102 of the recycled foundry sand manufacturing apparatus 101. FIG. 10 is a rear view of the sand supply unit 104 of the recycled foundry sand manufacturing apparatus 101.

(Suitable manufacturing equipment for reclaimed foundry sand)
DESCRIPTION OF EMBODIMENTS Hereinafter, an embodiment of a recycled foundry sand manufacturing apparatus 1 that is a preferred embodiment of the present invention will be described with reference to the drawings. In FIG. 1, the side view of the manufacturing apparatus 1 (henceforth only the manufacturing apparatus 1) of the reproduction | regeneration molding sand of the Example of this invention is shown. The manufacturing apparatus 1 includes a main body unit 2, a pedestal unit 3, and a sand supply unit 4.

  The main body 2 includes one or a plurality of heating chutes 10. As shown in FIGS. 1 and 4, the heating chute 10 is a linear member having a flat bottom surface and both side surfaces provided substantially perpendicular to the bottom surface and having an open top. is there. The heating chute 10 is provided with an introduction port 11 at one end and a discharge port 12 at the other end. In addition, the main body 2 includes an upper cover 13 that covers the upper portion of the heating chute 10 and defines a heating chamber 19. A burner 20, which is a heating means for raising the temperature of the entire heating chamber 19 including the heating chute 10, is attached to the side surface of the upper cover 13.

  The pedestal portion 3 is disposed below the main body portion 2 and supports the main body portion 2. The pedestal portion 3 includes an angle adjusting means 31 that adjusts the inclination angle of the heating chute 10. The angle adjusting means 31 is provided on a pair of support columns that support the discharge port 12 side of the heating chute 10, and is configured to be able to change the assembly position of a plurality of members constituting the support columns in multiple stages. The angle adjusting means 31 of the present embodiment can adjust the inclination angle of the heating chute 10 stepwise from 5 ° to 25 °. The pedestal 3 supports a second chute 14 that receives and transports the reclaimed foundry sand discharged from the discharge port 12 of the heating chute 10.

  In FIG. 2, the rear view of the main-body part 2 of the manufacturing apparatus 1 is shown. A vibration means 6 (vibrator) for applying vibration is attached to the lower surface of the heating chute 10 on the inlet 11 side. As shown in FIG. 1, the vibration means 16 is also attached to the lower surface of the second heating chute 14. In the case where a plurality of heating chutes 10 are provided, the vibration means 6 is arranged for each. By providing suitable vibration independently from one vibrating means 6 to one heating chute 10, there is no occurrence of resonance or vibration interference. It can be prevented in advance.

  The heating chute 10 has the effect of heating the foundry sand introduced from the introduction port 11 and removing unnecessary additive adhering thereto. The heating chute 10 has high heat resistance, heat shock resistance (characteristic that does not generate spalling at the operating temperature), high thermal conductivity, wear resistance, high mechanical strength, and hot load softening (load softening) The characteristic that the point is high and has volume stability in the heat) is required. For this reason, it is preferable that the heating chute 10 is formed of heat resistant steel or ceramics having characteristics similar to heat resistant steel. For example, the heating chute 10 can be formed of SUS310, nickel alloy Inconel (registered trademark), or ceramics SiSiC or SiC. In this embodiment, three heating chutes 10 made of SUS310 are arranged in parallel. In the vicinity of the heating chute 10 in the heating chamber 19, a thermocouple 7 as temperature measuring means is arranged, and the ambient temperature in the vicinity of the heating chute 10 is measured and used for management of temperature conditions.

  FIG. 3 shows a side view of the main body 2 of the manufacturing apparatus 1, and FIG. 4 shows a top view of the main body 2 of the manufacturing apparatus 1. In the present embodiment, one burner 20 is disposed on the side surface of the upper cover 13. The burner 20 can use gas, kerosene, or the like as fuel, and can raise the temperature inside the heating chamber 19 to about 1000 ° C. The burner 20 is also provided with a combustion amount control means (not shown). The burner 20 inputs data from the temperature measurement means 7 to adjust the combustion amount of the burner, specifically, adjusts the size of the flame F, and the heating chamber. Control and manage the internal temperature. By adjusting the combustion amount of the burner 20, only additives such as a binder and additives adhering to the surface of the foundry sand are burned without damaging the foundry sand introduced into the heating chute 10. Can be removed.

  The heating chute 10 is attached horizontally to the main body 2, and the inclination angle is adjusted by the angle adjusting means 31 of the pedestal 3 so that the inlet 11 of the heating chute 10 is above the outlet 12. . By controlling the inclination angle of the heating chute 10 and the vibration amount of each vibrating means 6, the residence time of the foundry sand in the heating chute 10 can be controlled. By controlling the heating temperature by the burner 20 in addition to the residence time, it is possible to reliably remove the additives on the surface of the foundry sand, while maintaining the particle size distribution without damaging the foundry sand.

  In FIG. 5, the rear view of the sand supply part 4 of the manufacturing apparatus 1 of reproduction | regeneration molding sand is shown. The sand supply unit 4 includes a hopper 40 that supplies casting sand to be processed to the inlet 11 of the heating chute 10. Moreover, the sand supply part 4 can be provided with a sorting means (sieving) (not shown), and can remove in advance casting sand that is too large to be supplied to the heating chute 10.

(Manufacturing method of recycled casting sand)
A method for producing recycled foundry sand using the production apparatus 1 will be described. The three heating chutes 10 are fixed in an inclined state by a predetermined angle by the angle adjusting means 31 of the pedestal 3. A hopper 40 of the sand supply unit 4 is connected to the introduction port 11 of the heating chute 10. The heating chamber 19 is preheated to 300 ° C. to 1000 ° C. by the burner 20 in advance. The preheating temperature is determined by the type of foundry sand used for production, particularly the thermal properties of the binder and additives added to the sand.

  Foundry sand used as a mold is introduced into the heating chute 10 from the hopper 40 via the inlet 11 at the upper end. The vibration means 6 continuously applies vibration to each heating chute 10. The introduced foundry sand is heated to 300 ° C. or higher and 1000 ° C. or lower while moving the heating chute 10 downward by inclination and vibration. This is the regeneration process. The foundry sand moves through the heating chute 10 to the lower discharge port 12, and during this time, additives such as binders and additives adhering to the surface of the foundry sand are removed by combustion or evaporation. The foundry sand that has reached the discharge port 12 becomes reclaimed foundry sand from which additives have been removed, and is discharged from the discharge port 12 to the second chute 14 and collected.

(Evaluation results of recycled casting sand)
The physical property value of the foundry sand when the reclaimed foundry sand is produced by the production apparatus 1 using the artificial foundry sand having the maximum particle size of less than 600 μm and the average particle size of 111.8 μm will be described. As an example, the characteristics of reclaimed foundry sand produced by a reclaim process in which the heating temperature was 600 ° C. and the passage time of the heating chute 10 was 1 minute were evaluated. It was verified that the particle size distribution pattern of the reclaimed foundry sand and the mode diameter, which is the maximum value of the particle size distribution, were not different from the raw foundry sand, and the sand particles were maintained. Moreover, when the reclaimed foundry sand was dried at 105 ° C. and co-heat-treated at 800 ° C. and the weight loss ratio was measured, the weight change was only 0.01% compared to before treatment, and the recycle using the production apparatus 1 was performed. The binder and additives were suitably removed by the process. Further, the mold compression strength when the reclaimed foundry sand was used again as a mold showed a strength of about 90% of that of unused foundry sand, and it became clear that it could be sufficiently used as a mold.

(Other embodiments)
Hereinafter, with reference to FIG. 6 to FIG. 10, a recycled casting sand manufacturing apparatus 101 according to another embodiment of the present invention will be described. In FIG. 6, the side view of the manufacturing apparatus 1 (henceforth only the manufacturing apparatus 101) of the reproduction | regeneration molding sand of the Example of this invention is shown. The manufacturing apparatus 101 includes a main body unit 102, a pedestal unit 103, and a sand supply unit 104. The main body 102 includes one or more heating chutes 110. The heating chute 110 is provided with an introduction port 111 at one end and a discharge port 112 at the other end. An upper cover 113 is provided above the heating chute 110, and a plurality of burners 120 serving as heating means are disposed on the upper cover 113.

  The pedestal portion 103 can be disposed below the main body portion 102 to support the main body portion 102. The pedestal portion 103 includes angle adjusting means 131 that adjusts the inclination angle of the heating chute 110. In addition to this, the pedestal portion 103 includes vibration means 6 (vibrator) that vibrates the heating chute 110. The sand supply unit 104 includes a hopper 140 that supplies casting sand to be processed to the inlet 111 of the heating chute 110. By controlling the angle of the heating chute 110 and the vibration amount of the vibrating means 106, the time for which the foundry sand stays in the heating chute 110 can be adjusted.

  The heating chute 110 has an effect of heating the foundry sand introduced from the introduction port 111 to remove unnecessary adhering additives. Heating chute 110 has high heat resistance, heat shock resistance (characteristic that does not generate spalling at the operating temperature), high thermal conductivity, wear resistance, high mechanical strength, and hot load softening (load softening) Therefore, the heating chute 110 is preferably formed of heat-resistant steel or ceramics having characteristics similar to heat-resistant steel. For example, the heating chute 110 can be formed of Inconel (registered trademark) of nickel alloy, or SiSiC or SiC of ceramics. In the present embodiment, the plurality of heating chutes 110 are arranged in parallel. In the vicinity of the heating chute 110, a thermocouple 107, which is a temperature measuring means, is arranged, and the ambient temperature of the main body 2 is measured and used for management of temperature conditions.

  In the present embodiment, a plurality of burners 120 are arranged on the ceiling portion of the upper cover 113 of the main body 102. Combustion amount control means (not shown) is connected to each burner 120, and data from the temperature measurement means 107 is input to adjust the burner combustion amount to control the temperature inside the heating chute 110. By adjusting the amount of heating by the burner 20, additives such as a binder and additives attached to the surface of the foundry sand introduced into the heating chute 110 can be burned and removed.

  The angle adjusting means 131 of the pedestal portion 103 is a means for adjusting the height of the support column that supports the heating chute 110, and the heating chute 110 is arranged so that the introduction port 111 of the heating chute 110 is above the discharge port 112. Adjust the tilt angle. By controlling the inclination angle of the heating chute 110 and the vibration amount of the vibrating means 106, the residence time of the foundry sand in the heated chute 110 can be controlled, and the additive on the surface of the foundry sand is reliably removed. On the other hand, the particle size distribution can be maintained without damaging the foundry sand.

  Furthermore, with reference to drawings, the manufacturing apparatus 101 of the reproduction | regeneration molding sand of this embodiment and the manufacturing method of the reproduction | regeneration molding sand using this are demonstrated. In FIG. 7, the rear view of the main-body part 102 of this embodiment is shown. In FIG. 8, the side view of the main-body part 102 of the manufacturing apparatus 101 of this embodiment is shown. In FIG. 9, the top view of the main-body part 102 of this embodiment is shown. In FIG. 10, the rear view of the sand supply part 104 of this embodiment is shown.

  In the present embodiment, four burners 120 as heating means are arranged in a 2 × 2 rectangular array at a position on the ceiling of the upper cover 113 of the main body 102 and spaced from the heating chute 110. Has been placed. The burner 120 is adjusted so that the shape of the flame F spreads in the lateral direction (direction parallel to the ceiling of the upper cover 103).

Since the burner 120 is disposed above the heating chute 110 and is adjusted so that the shape of the flame F spreads laterally, the flame F is prevented from directly hitting the heating chute 110, and the heating chute is caused by radiant heat. 110 is heated uniformly. By the combustion of the burner 120, the temperature of the foundry sand in the heating chute 110 is controlled to 300 ° C. or higher, preferably 500 ° C. or higher and 700 ° C. or lower.

  The heating chute 110 of the present embodiment is a linear passage having a square cross section. The heating chute 10 is formed by extruding SiSiC, which is a non-oxidizing ceramic. In this embodiment, five heating chutes 10 are arranged in parallel, and casting sand is introduced into each of them.

(Manufacturing method of reclaimed foundry sand using manufacturing apparatus 101)
A method for producing reclaimed foundry sand using the production apparatus 101 will be described. The five heating chutes 110 are fixed in an inclined state by a predetermined angle by the angle adjusting means 131 of the pedestal portion 103. A hopper 140 of the sand supply unit 104 is connected to the introduction port 111 of the heating chute 110. The heating chute 110 is preheated to 300 ° C. to 800 ° C. by the burner 120 in advance.

  When the foundry sand used as a mold is introduced into the heating chute 110 from the hopper 140 via the inlet 111 at the upper end, the vibrating means 106 applies vibration to the heating chute 110. The foundry sand is heated to 300 ° C. or higher while moving the heating chute 110 downward by inclination and vibration. While moving the heating chute 110 until it reaches the lower discharge port 112, additives such as a binder and additives adhering to the surface of the foundry sand are removed by combustion or evaporation. The foundry sand that has reached the discharge port 112 becomes recycled foundry sand from which additives have been removed, and is recovered from the discharge port 112.

(Modification)
Other modifications of the reclaimed foundry sand production apparatus according to the present invention will be described below.

  In the embodiment, the heating chute 10 which is a linear member having a bottom surface and both side surfaces and the upper part is opened and the heating chute 110 which is a rectangular closed cross section have been described. It can be a letter-shaped or H-shaped groove structure, or a cylindrical shape.

  In the embodiment, a burner is used as the heating means, and the case where the burner 20 is arranged on the side surface of the upper cover 13 and the burner 120 on the ceiling of the upper cover 113 have been described. The heating means can be disposed below the heating chute 10.

  The shape and number of heating chutes and the type and arrangement of the burners are not limited to the embodiment, and the combination can be changed as appropriate. Moreover, it can replace with the other heating means which can heat foundry sand to 300 degreeC or more instead of a burner.

DESCRIPTION OF SYMBOLS 1,101 Recycled foundry sand manufacturing apparatus 2,102 Main body part 3,103 Base part 4,104 Sand supply part 6,16,106 Vibrating means 7,107 Thermocouple (temperature measuring means)
10, 110 Heating chute 11, 111 Inlet port 12, 112 Outlet port 13, 113 Upper cover 14 Second chute 19, 119 Heating chamber 20, 120 Burner (heating means)
31, 131 Angle adjustment means 40, 140 Hopper

Claims (2)

A heating chute comprising an inlet at one end and an outlet at the other end;
Heating means disposed above the heating chute;
An angle adjusting means for adjusting an inclination angle of the heating chute;
Vibration means for applying vibration to the heating chute;
An apparatus for producing reclaimed foundry sand, comprising: An introduction step of introducing the foundry sand used as a mold into an inclined heating chute;
A regeneration step of removing additives adhering to the surface of the foundry sand by heating to 300 ° C. or higher while applying vibration;
A recovery process for recovering the foundry sand from the outlet;
A method for producing reclaimed foundry sand, comprising:

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