JPS62148053A - Molding sand cooling method - Google Patents

Abstract

PURPOSE:To cool a molding sand in short time by passing an air into a treating tank and by cooling the molding sand by the cooling means with holding the molding sand inside the treating tank in a fluid state. CONSTITUTION:When a water is distributed in a piping 3 and an air is passed into a treating tank 1 from an air passing part 5, the molding sand inside the treating tank 1 becomes in a fluid state and is effectively cooled by the water flowing in the piping 3 of a cooling means 2. Namely the still air near the cooling means 2 is moved by the fluid molding sand 8 and as the result of the film being broken the heat transfer becomes larger than the ordinary convective heat transfer and the rapid cooling of the molding sand 8 is achieved.

Description

DETAILED DESCRIPTION OF THE INVENTION (Object of the Invention: Field of Application, Prior Art, etc.) The present invention relates to a method for cooling molding sand.

Sand molds for foundries are usually made by adding resin such as a hardening agent to silica sand of uniform particle size. In this case, if the temperature of the sand is high, it hardens too quickly and a sand mold cannot be formed. Usually, it is cooled to below 30°C. Foundry sand has particles that come into contact with each other at points and are insulated by air, so the apparent thermal conductivity is extremely low, and even if it is cooled from the outside, it takes a long time to cool the inside. Conventionally used sand coolers employ a method of cooling from the outside by making the cooling layer thinner, but this method is insufficient because the cooling time cannot be shortened as desired. The present invention is a cooling method that focuses on the fact that the heat transfer coefficient between flowing sand and solid cooling means is large, and according to the present invention, foundry sand can be cooled in a short time. The present invention will be described in detail with reference to the following figures.

(Hereinafter, the structure and operation of the invention) Reference numeral 1 denotes a cooling treatment tank, and 2 denotes a cooling means provided within the treatment tank 1. In this embodiment, the cooling means 2 is provided with a pipe 3 inside the processing tank 1, and a means for circulating water is adopted in the pipe 3. An air inlet 5 is provided at the bottom of the processing tank 1 via a porous bed 4. Figure i1 shows a batch type, and in this case, the processing tank body 6 may be provided with an outlet or a door (not shown), from which it may be taken out, or as shown in Figure 2. If it is a continuous type, a partition plate 7 may be provided inside the processing tank 1. When air is fed into the processing tank 1 from the air inlet 5 while water is flowing through the pipe 3, the molding sand 8 in the processing tank 1 becomes fluid and is cooled. It is effectively cooled by the water flowing through the pipe 3, which is the means 2. That is, the still air near the solid cooling means 2 is moved by the flowing molding sand 8, and as a result of the boundary film being broken, the heat transfer is more than 10 times greater than normal convection heat transfer. rapid cooling can be achieved.

(Hereinafter, the effects of the invention) As described above, the present invention does not simply cool the foundry sand using the cooling means, but heats the sand while breaking the film formed near the solid cooling means, that is, the air insulation layer. Since the heat transfer is carried out, convective heat transfer is greatly promoted and the foundry sand can be cooled in a short time. As a result, it has the great advantage of significantly improving the sand mold making work.

[Brief explanation of drawings]

FIG. 1 is an explanatory sectional view of the patch type, and FIG. 2 is an explanatory sectional view of the continuous type. Code 1...Cooling treatment tank, 2
...Cooling means, 3. Piping, 4. Porous floor, 5.
... Air inlet part, 6... Treatment tank main body, 7... Partition plate, 8... Foundry sand.

Claims (1)

[Claims] A cooling means is provided in the cooling treatment tank, and an air inlet is provided at the bottom of the treatment tank, and air is introduced into the treatment tank from the air inlet to bring the foundry sand in the treatment tank into a fluid state. A method for cooling molding sand, characterized in that the molding sand is cooled by the cooling means while being held.