SU1042872A1 - Method of controlling moulding sand composition - Google Patents

Abstract

A METHOD FOR REGULATING THE COMPOSITION OF A FORMING MIXTURE, including controlling the composition of the initial mixture and introducing additives into the working mixture, characterized in that, in order to ensure the stability of the composition, the consumption of the slurry mixture is additionally controlled and the consumption of additives is directly proportional to the consumption of the slurry mixture.

Description

The invention relates to foundry, in particular, to methods for controlling the composition of the molding mixture.

There is a method of adjusting the composition of the molding mixture in the process of its preparation in mixers, based on the control of physical and mechanical properties. In this case, the control of the dosing of components is carried out depending on the negative periodic hourly laboratory control of the properties of the prepared mixture and the adjustment of the doses of the components to the subsequent work of the mixing preparation department 1.

The method has the following disadvantages: the controlled parameter one is humidity, the control of other parameters (height of the bulk profile, moldability, bulk weight) indirectly aims to control the water content in the prepared mixture, which is not enough to get a molding mixture with the required properties for moisture content is the most important determining factor in the quality of a mixture; it is the content of the clay binder, which varies depending on a number of technological factors (mass and the temperature of the cast metal, the area of contact of the metal with the form, the cast thickness of the casting (etc.); Laboratory control of the prepared molding mixture is practically of no importance for the regulation of the composition, since it is rarely produced, while technological factors affect the mixture continuously and dynamically. All this does not provide the necessary stability of the molding mixture.

The closest to the invention to the technical essence is the method of controlling the composition of the molding mixture in the course of its circulation in the mixing system, based on controlling the ratio of the two components of the mixture - water and binder according to moldability and the introduction of additives into the circulating mixture. In this case, the regulation is carried out by changing the flow rate of the water supplied to the mixer until the specified formability value 2 is reached.

The disadvantages of this method are the low stability of the properties of the molding mixture, since only one component is subjected to regulation - water, the amount of sand, clay and used molding mixture introduced into the mixture remains unchanged, and emergencies are possible as a result of adjusting the formability, characterizing the readiness of the mixture, can be achieved with a mixture containing either an excessive amount of binder or insufficient. In both cases, marriage is inevitable.

The application of this method is possible if the content of the binder in the working mixture is guaranteed and is known in advance.

The purpose of the invention is to ensure the stability of the properties of the prepared molding sand.

The goal is achieved by the fact that according to the method of adjusting the composition of the sand, including the control

0 the composition of the initial mixture and the introduction of additives into the working mixture, additionally control the flow rate of the sludge mixture and change the consumption of additives directly proportional to the consumption of the sludge mixture.

The method of adjusting the composition of the molding mixture requires preliminary preparation, consisting in the collection of a data bank on the mass of the rods in each standard size of forms, the proportion of the quartz part in the emissions of the slurry mixture for each of the stages of the regenerator capacity.

The method includes the following operations: control of the amount of the slurry mixture discharged per unit of time into the dump from the regeneration plants; accounting Mafcc rods in cast forms; control of the number of knocked out forms per unit of time. In the process of regeneration, part of the mixture as waste is thrown into the dump, and the regenerate is sent to the mixing system to mixers. At the same time, the amount of millstone discharged into the dump per unit of time is continuously automatically controlled and recalculated for the amount of dry components introduced into the mixer maintaining a qualitative and quantitative balance of the moldable mixture in the system.

5 The method is carried out as follows.

The doses of the dry components of the slurry mixture are calculated and the components are metered into the mold mixture according to the results. The dosing of these components into the mixers is carried out in proportion to the total capacity of the mixing preparatory compartment and taking into account the technological lag time of the working mixture during its transportation from knockout to

5 mixers

Using the method of adjusting the composition of the molding mixture provides the following advantages: the ability to reduce and eliminate scrap is cast through the sand of the molding mixture by providing it

° required material composition and, consequently, properties; increasing the productivity of the mixing preparation equipment due to the possibility of introducing all the components at once into the mixer, since all the doses are known in advance; reducing the consumption of fresh molding materials by reducing the loss of the mixture from the mixing system when choosing to dump due to

control of the rate of ejection of sludge mixture from regeneration plants; and flexible automated control over the doses of fresh components introduced.

Using the proposed method of adjusting the composition of the molding mixture in combination with separate embossing of molds and regeneration of the molding mixture will save only one quartz sand of 13 thousand tons per year for a workshop with a capacity of 100 thousand tons. In monetary terms, this will amount to 26-35 thousand rubles. annual savings.

Claims (1)

METHOD FOR CONTROLING THE FORMULA MIXTURE COMPOSITION, including control of the composition of the initial mixture and the introduction of additives into the working mixture, characterized in that, in order to ensure the stability of the composition, the flow rate of the slurry mixture is additionally controlled and the flow rate of additives is directly proportional to the flow rate of the slurry mixture.