RU167866U1 - PLANT FOR PREPARING FORMING MIXTURES IN A PSEUDO-FLUIDED LAYER - Google Patents

Abstract

The utility model relates to foundry. Installation for the preparation of molding mixtures includes a gas distribution grid of a sand casting core impregnated with a liquid binder. This simplifies the process of delivering a binder to the fluidized bed. Energy costs are reduced, the range of binders suitable for deposition on sand grains is expanding.

Description

The utility model relates to foundry, in particular to devices for the preparation of molding mixtures in the fluidized bed and can be used to expand the scope of this process of mixing.

It is known to use nozzles of pulsed action for feeding a binder into a fluidized bed (RF Patent No. 2356683, Method for the preparation of molding compounds, from 05.27.2009). 3 here the use of energy-intensive pumps is required, and pulsed-action nozzles are unsuitable for many modern foundry binders,

Also known is a device for fluidizing solid granular material, (RF Patent 2149682, from 05.27.2000), the gas distribution grid of which is made in the form of a dry sand casting core,

“A gas distribution device (casting core) is a capillary-porous body, the pores of which are channels of complex configuration, which leads to the absence of dominant gas agent flows at the outlet of the device. This ensures uniform distribution of the feed rate of the agent over the entire cross-sectional area of the apparatus. In order to vary the dispersion of the fluidizing agent stream, it is possible to use gas distribution devices of different thickness and structure. An increase in their thickness leads to a more uniform distribution of velocities over the cross section of the apparatus. Increased dispersion is achieved by using finer sand for the gas distribution device and by increasing the degree of compaction of the core mixture. ”

The objective of the present invention is to provide an installation for the preparation of molding mixtures in a fluidized bed allowing without the use of special energy-intensive devices and nozzles, to provide a wide range of binders in the fluidized bed.

The problem is solved due to the fact that the mixing plant is equipped with a gas distribution grid in the form of a thin-walled flat sand core impregnated with a liquid binder, regulated by the composition of the mixture being prepared. Air passing through the gas distribution grid is saturated with a binder and precipitates it on the fluidized sand.

An example of the implementation of the proposed device is the preparation of the core mixture in a laboratory apparatus for fluidizing molding sand with a gas distribution grid from a sand foundry core. The core was obtained from a mixture of sand and finely divided refractory powder, which provides optimal porosity of the gas distribution grid for uniform distribution of a small amount of binder over the surface of grains. The rod was impregnated with the required amount (0.5% of the weight of sand), an organic binder based on vegetable oil. Molded sand was poured into the fluidization tank and compressed air was fed into it. Air passing through the rod was saturated with a binder, which was deposited on suspended sand. There is no longer a need to equip the process of preparing the mixture with additional energy sources and nozzles for supplying a binder. The strength of the core mixture based on the oil binder prepared in such an installation (mixture No. 1) is presented in table 1. The strength of the mixture of the same composition prepared using nozzles for feeding the binder into the fluidized bed of sand (mixture No. 2) was 0.41-0 , 63 MPa. The strength of the mixture prepared on the proposed installation after 20 s reached 0.65 MPa, the strength of the same mixture prepared on the mixer of the company "Airich" only after a minute - strength 0.55 MPa (mixture No. 3)

Thus, the technical effect of the alleged invention is expressed in simplifying the design of the mixing apparatus, while providing increased strength of the mixture and reduced energy consumption for its preparation.

Claims (1)

Installation for preparing a molding mixture in a fluidized bed containing a container for fluidization of sand and a gas distribution grid, characterized in that the gas distribution grid is made in the form of a sand casting rod impregnated with a liquid binder, provided by the composition of the prepared molding mixture.