JP3329683B2 - Recycling system for molding sand - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for removing a material and recovering a molding sand by a molding process, a pouring process, a cooling process, a separating process for separating the molding sand from the material, a pretreatment process for the recovered molding sand, and a recovered sand. The present invention relates to a circulating and collecting system for mold molding sand, which sequentially performs a cooling process, a storage and kneading process of cooling and collecting sand, and a supply of the kneaded sand to the mold making process.

[0002]

2. Description of the Related Art Conventionally, in a circulation system for collecting molding sand as described above, fine powder generated during a process of separating the molding sand from the material and a process of kneading the cooling and collecting sand is separated into a large dust collector and many suction ducts. And the collected fine powder is directly returned to the kneading process.

[0003]

As described above, when collecting and returning the fine powder generated in various places in the circulation system for mold molding sand to the kneading process as described above, there is no problem if the same mold always flows. In the case where molds with different sand / metal ratios flow sequentially, the amount of fine powder generated and collected in various places, the particle size distribution of fine powder, or the fine powder content of collected sand stored before kneading should be different. Therefore, even if the fine powder collected in the kneading process is supplied in a fixed amount, the content of the fine powder in the kneaded sand will be different, and accordingly, the moisture value of the kneaded sand, the compactability value, the air permeability, etc. There is a problem that the sand characteristics of the varnish vary and it is not possible to obtain kneaded sand of uniform quality. In addition, since the atmospheric temperature and humidity greatly differ depending on the place where the fine powder is generated, if air having a temperature and humidity difference is sucked and joined by many ducts, dew condensation occurs at the joining point and the duct is closed. There was a problem. The present invention has been made in view of the above-mentioned problems, and it is possible to maintain a fine powder content of a collected and cooled and kneaded mold molding sand at a predetermined value and to eliminate a duct blockage due to dew condensation of a dust collector. It is intended to provide a sand circulation recovery system.

[0004]

Means for Solving the Problems In order to achieve the above-mentioned object, a circulation and recovery system for molding sand in the present invention is provided.
Material removal and mold sand recovery by mold making process, pouring process, cooling process, mold sand and material separation process,
Pretreatment process of recovered mold sand, cooling process of pretreated recovered sand,
In the circulation and recovery system of the molding sand, which successively supplies the sand to the storage and kneading treatment process of the cooling sand and the kneading sand to the molding process of the molding sand, the sand is generated at various places in the separation and separation process of the molding sand and the material and the pretreatment process of the recovered sand. The collected fine powder is collected by the first dust collector, and the collected fine powder is returned to the original sand at a position immediately before the cooling step of the collected sand by quantitative cutout, and the cooling step of the collected sand is performed by the water collecting step. Addition and suction by a second dust collector to form the second dust collector.
The whole amount of fine powder sucked by the dust collector is returned to the recovered sand as cooled original sand, and the fine powder generated in various places in the storage and kneading process of the cooled recovered sand is collected by a third dust collector to be waste sand. It is characterized by the following.

[0005]

Embodiments of the present invention will be described below in detail with reference to the drawings. In FIG. 1, the circulation and recovery of the molding sand are performed in a molding process 1, a pouring process 2, a cooling process 3,
Separation process 4 of the mold sand of the cooling mold and the material (casting product), a magnet separator 5A for separating iron pieces of the recovered mold sand,
Pre-processing step 5 of recovered mold sand composed of a first mold sand transport conveyor 5B and a coarse sieve 5C, cooling step 6 of pre-processed recovered sand, second sand transport conveyor 7A for cooling sand, sand storage 7B, third sand transport Conveyor 7C, Cooling sand kneader 7
D, a basic line for sequentially supplying the sand to the cooling sand storage / kneading step 7 and the kneading sand to the mold forming step 1.

In this basic line, each part of a separation step 4 for separating mold sand and material, followed by a pretreatment step 5 for recovered mold sand comprising a magnet separator 5A, a first sand conveyor 5B, and a rough sieve 5C, which follows. The first dust collector 11 is communicated via a duct 12 to collect fine dust. The fine powder collected by the first dust collector 11 is stored in a cushion hopper 13, cut out by a fixed-quantity fine-powder cutting machine 14, and returned to the collected sand at a position immediately before the collected sand cooling step 6. The fine powder overflowing from the cushion hopper 13 is to be wasted. That is, the separation and dispersion step 4 and the recovered sand pretreatment step 5 in which the mold sand is in a high temperature state.
The dried fine powder generated in each place is collected and collected by the first dust collector 11 and is returned to the collected sand, which is the original sand before cooling, by a quantitative supply.

[0007] Next, after the pretreatment step 5, the recovered sand from which the dried fine powder has been returned is subjected to a second addition while receiving water.
The fine powder containing the normal sand particles sucked by the second dust collector 15 while being cooled by the suction ventilation by the dust collector 15 is returned to the recovered sand which is the original sand after cooling via the return conveyor 16. In order to add water to the collected sand and cool it effectively, it is necessary to increase the suction air volume of the second dust collector 15 and allow the air to pass through and contact the collected sand at a high speed. Some of the fine suction powder containing normal sand grains is immediately returned to the recovered sand which is the original sand after cooling. Further, the collected sand after cooling is supplied to the second sand conveyor 7A, the sand storage 7B, the third sand conveyor 7
C, each part of the cooling sand storage and kneading treatment step 7 comprising the kneading machine 7D is connected to the third dust collector 17 via the duct 18 so that the generated low-temperature and high-humidity fine powder and air are collected. The fine dust collected by the third dust collector 17 has a small recovery amount (it is difficult to generate dust due to the wet state) and is disposed of without passing through other devices in order to eliminate an obstacle due to dew condensation. .

[0008]

As is clear from the above description, the present invention collects dust at all places where fine powder is generated, and returns fine powder in a high-temperature dry state to recovered sand before cooling, which is original sand. ,
The fine powder containing a part of the normal sand of the recovered sand cooled by the addition of water and the suction of the dust collector is immediately returned to the original sand, which is the recovered sand after cooling, and the entire amount is collected. Since a small amount of fine powder is discarded without passing through other equipment, all the generated fine powder is returned to the original sand, kneaded without changing the sand properties, and its moisture value, compactability It has excellent effects such as being able to be sent to the mold making process as a kneaded sand of uniform quality without greatly changing the value and the like, and having no dew condensation in the dust collector.

[Brief description of the drawings]

FIG. 1 is a flowchart illustrating an embodiment of the present invention.

[Description of Signs] 4 Separation process of mold sand and material 5 Pretreatment process 6 Cooling process of recovered sand 7 Storage and kneading process 11 First dust collector 15 Second dust collector 17 Third dust collector

Claims (1)

(57) [Claims] 1. A mold forming process 1, a pouring process 2, a cooling process 3, a material removal and a mold sand recovery by a mold sand and material separation / balancing process 4, a pre-process 5 of a recovered mold sand, a pre-processed In the system for recovering and cooling the recovered sand, the step of storing and kneading the cooled sand, the step 7 of storing and kneading the sand, and the step of supplying the sand to the step of forming the kneaded sand 1 in the circulation and recovery system of the molding sand, The fine dust generated in each part of the pre-processing step 5 of the collected sand is collected by the first dust collector 11 and the collected fine powder is cut out by quantitative cut-out at a position immediately before the cooling step 6 of the collected sand. The cooling step 6 of the collected sand is performed by adding water and sucking and drafting by the second dust collector 15 so that the whole amount of the fine powder sucked by the second dust collector 15 is collected into the recovered sand which is cooled original sand. Put it back 3. A circulating and collecting system for mold molding sand, characterized in that fine powder generated in various places in the storage and kneading treatment step 7 of the cooling and collecting sand is collected by a third dust collector 18 into waste sand.