JPH10202360A - Method for recovering molding sand and apparatus therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a recovering method of molding sand which improves the recovering efficiency of the molding sand so as to reduce the quantity of industrial wastes, and an apparatus therefor. SOLUTION: The molding sand for recovering, completing tentative crushing treatment is supplied into one pair of elastic rollers 9a, 9b having the setting gap S, and the insufficient crushed sand blocks 6 are crushed once more in the elastic rollers 9a, 9b. On the other hand, contained solid foreign matters 8 are passed through while burying on the surfaces of the elastic rollers 9a, 9b or passed through by push-expanding the gap S of the elastic rollers according to this size and thereafter, the reusable molding sand is separated with the other mixed material.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for recovering molding sand that can efficiently collect reusable molding sand by crushing only the sand lumps from waste containing sand lumps and solid foreign matters. A method and an apparatus therefor.

[0002]

2. Description of the Related Art Conventionally, used molding sand has been supplied to a pulverizer and pulverized, and thereafter, only molding sand having a size of about 2 mmφ or less has been sorted and recovered by a vibrating sieve. In addition, the insufficiently pulverized sand blocks of about 2 to 5 mmφ have been discarded as industrial waste along with solid foreign matters such as iron pieces and pottery waste.

[0003]

However, in such a method for recovering foundry sand, the amount of waste is enormous, and regulations on industrial waste are becoming stricter. I was Furthermore, in the conventional method, there is a waste that the reusable sand mass is discarded together with the solid foreign matter, and the depletion of sand resources has increased the cost of replenishing molding sand. Was urgently needed. The present invention has been made in view of these circumstances, and an object of the present invention is to provide a method and an apparatus for recovering molding sand that improve the collection efficiency of molding sand and reduce the amount of industrial waste. It is what it was.

[0004]

Means for Solving the Problems The present invention has been made to achieve the above object, and a method for recovering molding sand according to claim 1 includes a pair of elastic rollers having a set gap.
Supply the foundry sand for collection after the priming process, while re-crushing the insufficiently pulverized sand chunks in the elastic roller, while containing solid foreign matter, depending on its size,
It is buried in the surface of the elastic roller and allowed to pass, or a gap between the elastic rollers is pushed and passed, and then the reusable molding sand is separated from other contaminants. Further, the casting sand recovery device according to claim 2 is a supply unit that receives a supply of the recovery molding sand that has undergone the priming process, and a crushing unit that newly crushes only insufficiently crushed sand blocks.
A separating unit for collecting the crushed molding sand, wherein the crushing unit is provided with a pair of elastic rollers separated by a set gap; When a pressing force is applied from a solid foreign substance having the above-described size, the gap is held so as to expand the gap.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment according to the present invention will be described below with reference to the longitudinal sectional view of FIG. The apparatus for recovering foundry sand shown in the figure has a supply section A for recovering foundry sand and a crushing section B for crushing insufficiently crushed sand lumps and passing solid foreign matter.
And a separation section C for separating the crushed molding sand from solid foreign matter and the like. The supply unit A includes a body 1 in a horizontal direction.
A receiving port 2 having an upward opening is provided at one end of the opening, and a delivery port 3 having a smaller opening area than the receiving port 2 is provided below the other end. On the lower side of reception port 2,
A discharge port 4 for a large solid foreign matter 7 is provided, and this discharge port 4 is closed below a bottom wall of the body 1 by a partition gate 5 which can be opened and closed in a horizontal direction. The foundry sand for collection supplied from the receiving port 2 includes, in addition to the recovered sand having been subjected to the pulverization treatment, a lump of sand 6 of about 2 to 5 mmφ which is insufficiently pulverized, and a relatively large solid foreign matter 7 such as a wire. It contains relatively small solid foreign matter 8 such as iron pieces and pottery waste.

The delivery port 3 is formed at a position shifted laterally from the reception port 2 and smaller than the reception port 2. Therefore, the relatively large solid foreign matter 7 is separated by its length, weight, and the like while being held by the partition gate 5 on the supply side of the body 1 as shown in FIG.
On the other hand, the insufficiently pulverized sand mass 6 and the relatively small solid foreign matter 8 are moved toward the delivery port 3. The crushing section B includes a pair of elastic rollers 9a,
9b, and a receiving container 10 provided therebelow. The elastic rollers 9a and 9b are provided with the set gap S
The bearing 11 of the one elastic roller 9b is held by a spring or other urging member 12. Therefore, the elastic roller 9
When a pushing force of a predetermined value or more acts on a and 9b, the elastic roller 9b moves and the gap S becomes wider than the set value. The elastic rollers 9a and 9b press the sand mass 6 across the gap S and crush the sand mass 6 by making the peripheral speeds different from each other. Since the gap S is provided between the elastic rollers 9a and 9b, there is no possibility that the elastic rollers are rubbed and worn.

As the material of the elastic rollers 9a and 9b, an elastic member 13 such as urethane rubber having excellent elasticity is used. The reason is that most of the supplied solid foreign matter 8 is buried in the surface of the deformable elastic rollers 9a and 9b so that the receiving container 10 is not crushed.
In order to hand it over. Further, the friction coefficient with the sand block 6 is increased to improve the bite, and the sand block 6 is continuously and efficiently pulverized. The elastic rollers 9a, 9
It is a matter of course that the surface of the metal roller may be covered with the elastic member 13 having a predetermined thickness instead of providing the b. The receiving container 10 is large on the upper side and connected to the discharge port 14 by the inclined bottom wall on the lower side, so that the supply from the discharge port 14 is performed uniformly in the width direction of the separation part C. The separating section C includes an inclined sieving machine 15 disposed below the receiving container 10 and a collection chute 17 provided below the mesh member 16 of the inclined sieving machine 15. The mesh size of the mesh member 16 is determined in accordance with the maximum allowable size of the foundry sand to be recovered.

Next, the operation of each part of the casting sand collecting apparatus shown in FIG. 1 will be described in a confirming manner. A relatively large solid foreign matter 7 such as a wire is separated on the supply side and held by the partition gate 5, and is prevented from moving to the elastic rollers 9a and 9b. On the other hand, sand lumps 6 of about 2-5 mmφ which are insufficiently pulverized, and relatively small solid foreign matters 8 such as iron pieces and pottery swarf.
Through the delivery port 3, a pair of elastic rollers 9a, 9
b. With the elastic rollers 9a and 9b,
Is in the process of passing through the gap S between the elastic rollers 9a and 9b,
The elastic rollers 9 a and 9 b having a large coefficient of friction are crushed by the pressing action and the crushing action, and are moved to the receiving container 10. Most of the solid foreign objects 8 supplied to the elastic rollers 9a and 9b are not so large as compared with the gap S. However, when they are pressed by the elastic rollers 9a and 9b, 9a and 9b are held in a partially buried state, and are not crushed.
Moved to In this way, most solid foreign matter 8
Passes without expanding the gap S, so that the solid foreign matter 8 does not interrupt the crushing process of the sand block 6 and improves the collection efficiency of the molding sand by the continuous crushing process. be able to. In addition, solid foreign matter 8
Is not pulverized, so that no impurities are mixed in the recovered molding sand.

On the other hand, when a large iron piece or the like is supplied from the solid foreign matter 8 compared with the gap S, the urging member 12
When the elastic roller 9b moves in the direction of the arrow R against the urging force, the damage to the elastic rollers 9a and 9b is prevented, and the apparatus is protected. As a result of the above-described processing, the sand lumps 6 crushed by the elastic rollers 9a and 9b are supplied to the inclined sieving machine 15 together with solid foreign matters 8 such as pottery waste and iron pieces. Then, the casting sand that has passed through the mesh member 16 of the inclined sieving machine 15 is collected in the direction of arrow M by the collection chute 17, and the solid foreign matter 8 is converted into industrial waste by the arrow N.
Discharged in the direction. The relatively large solid foreign matter 7 separated on the supply side is taken out from the discharge port 4 in the direction of arrow E by opening the partition gate 5. In the present apparatus, when any trouble occurs, the partition gate 5 can be opened to form a bypass, so that the plant does not stop due to the trouble of the present apparatus. If the partition gate 5 is opened, the inside can be cleaned. As described above, the present invention has been described by taking the collection of molding sand as an example.According to the present invention, it is possible to efficiently collect necessary materials by pulverizing not only foundry sand but other waste. Become.

[0010]

As described above, according to the present invention, while the insufficiently crushed sand blocks are crushed again by the elastic roller, the solid foreign matter contained therein depends on the size thereof.
Since it is buried in the surface of the elastic roller and allowed to pass through, or the gap between the elastic rollers is pushed and widened, the collection efficiency of the foundry sand is improved, and the amount of industrial waste can be reduced. According to the test results, it is confirmed that the waste can be reduced to 1/12 by passing through the present apparatus. For example, 300 tons of casting sand per year (equivalent to 0.6% of the total recovered sand) can be obtained. 275 tons of foundry sand can be recovered. In addition, the structure of the apparatus is simple, the production cost is low, and the space required for installation can be reduced. In addition, since only insufficiently crushed sand blocks are crushed and solid foreign matter is removed at the separation unit without being crushed, high-quality foundry sand without crushed pieces of solid foreign matter is collected and provided. be able to.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing one embodiment of the present invention.

[Explanation of symbols]

 2 Receiving port (of supply part) 3 Discharge port (of supply part) 6 Insufficiently crushed sand 7 Relatively large solid foreign matter 8 Relatively small solid foreign matter 9 Elastic roller 15 Inclined sieving machine A (Foundry sand collecting device) ) Feeding section B Crushing section (of foundry sand recovery device) C Separation section (of foundry sand recovery device) S Gap

Claims (3)

[Claims] 1. A collection molding sand, which has been subjected to a crushing process, is supplied to a pair of elastic rollers having a set gap,
While the insufficiently pulverized sand blocks are pulverized again by the elastic roller, the contained solid foreign matter is buried in the surface of the elastic roller and allowed to pass, or the gap of the elastic roller is passed depending on the size thereof. A method for recovering molding sand, wherein the molding sand is expanded and passed, and then the reusable molding sand is separated from other contaminants. 2. A supply unit for receiving a supply of a molding sand for recovery that has undergone priming, a crushing unit for newly crushing only insufficiently crushed sand blocks, and a separating unit for collecting crushed molding sand. A molding sand collecting apparatus comprising: a crushing unit, a pair of elastic rollers are disposed with a set gap therebetween, and the elastic roller presses a solid foreign substance having a predetermined size or more. A molding sand collecting device, which is held so as to be able to widen the gap when receiving the molding sand. 3. The molding sand recovery device according to claim 2, wherein the pair of elastic rollers are set so that peripheral speeds thereof are different from each other.