Foundry crude sand screening method

Abstract

The invention provides a foundry crude sand screening method, and belongs to the technical field of sand screening. The foundry crude sand screening method solves the technical problems of low screening efficiency, poor screening effect and the like existing in the existing screening technology. The foundry crude sand screening method is characterized by comprising the following steps that a, sandcrushing treatment is performed, wherein crushing treatment of agglomerated sand is carried out by a sand crushing device; b, impurity removal treatment is carried out, wherein impurities in the sandtreated in the step a are removed by a sand filtering device; c, dust removal treatment is carried out, wherein dust contained in the sand treated in the step b is removed by a dust removing device;d, the sand treated in the step c is dried; and e, the sand treated in the step d is collected. The foundry crude sand screening method has the advantages of high screening efficiency, good screeningeffect and the like.

Description

technical field [0001] The invention belongs to the technical field of sand screening, and relates to a sand screening method, in particular to a casting raw sand screening method. Background technique [0002] Raw sand is the most basic material for molding (core) in foundry production, and the most widely used is quartz sand, commonly known as silica sand. In sand casting, raw sand is the aggregate and main component in the mixture, and the casting sand used for the first time is called raw sand. In casting, there are certain performance index requirements for raw sand, such as: (1), air permeability, in order to allow gas and liquid pyrolysis residues to escape from the casting cavity during pouring, dry sand must have sufficient air permeability sex. Excessive mud content and excessive dust content in the raw sand will reduce the air permeability of the sand. (2) Moisture content. Moisture in the sand is the root cause of many casting defects. It is necessary to elimi...

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Problems solved by technology

(3) Purity, the original sand contains other large particles of impurities, such as fine gravel mixed in the original sand, which will affect the strength of the mold and the surface quality of the casting

[0003] The traditional screening method is usually to manually screen the raw sand with a sieve, which is inefficient. In order to solve this problem, there is a machine device for screening. At present, the usual machine screening is through the set screen, using the vibration of the screen. , to screen the sand falling on the sieve. The main problems are: 1. If the sand has agglomerates, it cannot pass through the sieve if the agglomerates are not broken; 2. If the sand is relatively wet or has large particles of impurities, the sand is easy to stick Attached to the sieve hole, or the impurities are blocked on the sieve hole, causing the sieve hole to be blocked and the screening efficiency to drop; 3. The screening cannot be carried out continuously, and the impurities screened out on the sieve need to be turned over or poured out of the sieve. The impurities on the net are poured out, and then the sieve returns to its position to continue screening. During the process of the sieve being overturned, the sand cannot be screened, so that the screening cannot be carried out continuously and the screening efficiency is reduced.

Chinese patent (application number: CN201720813864.4) discloses a sand screening mechanism, which uses the vibration of the screen in the mechanism to screen the sand falling on the screen. Although the screening mechanism replaces manual screening and improves efficiency, there are also The above-mentioned sieve holes are easy to be blocked, and the screening cannot be carried out continuously.

Chinese patent (Application No.: CN201820395565.8) discloses a wet sand drying device, which pushes the wet sand from the left end of the drying cylinder to the right end of the drying cylinder under the action of the screw propeller. The sand is in contact with the wall of the drying cylinder for processing and drying. Since the wall of the drying cylinder is arc-shaped, when the wet sand advances from the left end of the drying cylinder to the right end of the drying cylinder, the wet sand accumulates together and cannot be separated from the drying cylinder. The cylinder wall is fully contacted, and the drying efficiency is not high enough

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