PROCESS FOR PREPARING MOLD-SAND AND A DEVICE FOR PUTTING THE SAME INTO PRACTICE

A process for preparing mold-sand includes the steps of pouring a proportioned amount of mold-sand components into a mixer, adding the calculated amount of water, mixing the components, taking a sample and measuring the mold-sand moisture content. After taking a representative sample from the mixer, this sample is used to make a specimen by its compaction, and the moisture content is measured with the consequent adjustment of the moisture content in the considered mix batch, and the sampling is carried out by repeated pushing the mixture down into a case with the help of a periodically-operated butterfly valve until its filling with the mixture, and then the mold-sand mixture is compacted in the case with a plunger. A device prepares the mold-sand.

PREFERRED EMBODIMENT TO PUT THE INVENTION INTO PRACTICE

FIG. 1illustrates a device for preparing a mold-sand mixture, andFIG. 2illustrates an assembly for controlling its moisture.

The device for preparing a mold-sand mixture comprises a mixer under the form of a fixed pan1containing mixing elements under the form of shares2and a vortex head3, as well as an assembly (probe)4for checking the mold-send mix moisture, comprising a case5, a plunger6with a moisture detector7. The assembly (probe)4for mold-sans moisture checking is fixed on a wall of the pan1above the level of the shares2and contains a case5to form a specimen, fixed obliquely on the wall of the fixed pan1. At one end of the case5, a plunger6with a built-in moisture probe7and an air cylinder8are mounted, and the other open end of the case5located inside the pan1is provided with an additional air cylinder9and with a periodically-operated butterfly valve10serving to fill the case5with mold-sand.

Furthermore, the device of the second embodiment (seeFIG. 3) to provide cooling of the mold-sand mixture during the process of mold-sand preparing comprises an air supply channel11open in the bottom of the pan1, and the shares2present a longitudinal cavity12to enable air passage from a fan13and holes14in the rear wall of the shares2.

The process of preparing mold-sand is carried out as follows.

The process for preparing mold-sand comprises the steps of: filling a proportioned amount of mold-sand components into a mixer, adding a calculated amount of water, mixing the components, taking a sample and measuring the mold-sand moisture. A particularity of the process is that after taking a representative sample, a specimen is manufactured with this sample in the mixer by its compaction, and further its moisture is measured to be followed by the moisture adjustment in the considered mix batch.

In the operation of the devices, a proportioned amount of the mold-sand components is put into a fixed pan1, a calculated amount of water is added to prepare (or to prepare and to cool) the mold-sand, the mold-sand is mixed with the rotating shares2and with the vortex head3that convert the mixture to suspension, and, in case of combining the steps of mold-sand preparing and cooling, the mixture is blown through with a directed stream of air supplied from the fan13via the air supply channel11and the holes14in the shares2. During the process of preparing the mold-sand mixture, after reaching a relatively homogenous composition of the mixture, 30 to 40 seconds after loading all the initial materials into the mixer, the air cylinder9moves the butterfly valve10to an end position and opens the neck of the case5to enable free pouring, into it, of the mold-sand moving along the fixed pan1of the mixer. After a short pause, the butterfly valve10rotates and pushes the mixture passing between the valve and the case5into the last. This operation is repeated until the complete filling of the case5with the mixture, which is noted by the valve10end position detector (not illustrated on the drawings). After that, the air cylinder9designed for moving the valve10operates a working stroke and performs the compaction of the mold-sand mixture in the case5, the moisture detector determining the moisture of the compacted mold-sand mixture.

The operation according to the second embodiment of the device is similar to the above described, in this case, in order to provide cooling of the mold-sand mixture during its preparation, additional air passes from the fan13via the air supply channel11, the longitudinal channel12and the holes14in the shares to the mold-sand mixture to cool it.

A comparison of the technical solutions according to the present invention with the closest state of the art enables us to state they satisfy the criterion of “novelty”, and the absence of our new features in the previous art solutions means they satisfy the criterion of “inventive level”.

INDUSTRIAL APPLICABILITY

The above described advantages of the technical solutions according to the present invention provide for a possibility of a wide industrial use in the field of foundry and enable to improve the efficiency of the mold-sand preparation and to adjust the moisture content while preparing a mix batch with the moisture control.