Reference for horizontal molding line and sand treatment configuration
The configuration matching of the horizontal molding line and sand treatment needs to consider many aspects. The following are the specific points:
Processing capacity matching
Output correspondence: According to the production rhythm and sand box size of the horizontal molding line, the sand consumption per hour or day is calculated. The processing capacity of the sand treatment system should be able to meet the sand demand of the molding line, and there should be a certain margin to cope with possible production fluctuations. For example, if the molding line produces 80 boxes of sand molds per hour, the average sand consumption per box is 0.5 cubic meters. Considering factors such as the recycling of sand, the processing capacity of the sand treatment system per hour should be above 40 cubic meters.
Conveying speed matching: The conveying speed of the sand processing system to the molding line should match the sand adding speed of the molding line to ensure the continuity of sand supply and avoid the shutdown of the molding line due to lack of sand.
Molding sand performance matching
Particle size and mud content: The horizontal molding line generally requires uniform molding sand particle size, such as the commonly used 70/140 mesh raw sand. In terms of mud content, the horizontal line generally requires a mud content of 10%-12%.
Humidity and compaction rate: The molding line usually requires the molding sand humidity to be 2.8%-3.4% and the compaction rate to be 33%-42%. The sand mixer, loose sand machine and other equipment in the sand processing system should be reasonably added with water, bentonite and other additives and the mixing and rolling time should be controlled to make the molding sand reach the appropriate humidity and compaction rate.
Air permeability and strength: The air permeability of the molding sand of the horizontal molding line is generally 90-130, and the wet compressive strength is 0.12-0.2MPa. The sand processing system should ensure that the air permeability and strength of the molding sand meet the requirements by adjusting the original sand particle size, mud content, type and amount of additives, etc.
Equipment selection and matching
Sand mixer: For horizontal molding lines, continuous sand mixers or large-capacity intermittent sand mixers can be selected to ensure the quality and efficiency of molding sand mixing.
Screening equipment: Select appropriate screening equipment, such as vibrating screens, etc. The mesh size of the screen should be able to meet the needs of separating molding sand of particle size that meets the requirements of the molding line.
Conveying equipment: According to the distance and layout between the molding line and the sand processing system, select appropriate conveying equipment, such as belt conveyors, bucket elevators, pneumatic conveying devices, etc.
Old sand processing equipment: Horizontal molding lines use a large amount of old sand, and need to be equipped with effective old sand processing equipment, such as old sand regeneration machines, magnetic separation equipment, etc., to remove metal impurities and broken sand blocks in the old sand.
Layout and space matching
Overall layout: The sand processing system should be as close to the horizontal molding line as possible to reduce the sand transportation distance and energy loss during transportation. At the same time, the equipment maintenance space and personnel operation space should be considered.
Height and space: The equipment height and space occupied by the sand treatment system should be adapted to the height and space of the workshop where the molding line is located, so as to avoid the situation where the equipment cannot be installed or the space is too crowded.
4. Comparison of advantages and disadvantages of horizontal casting molding line
The advantages and disadvantages of horizontal casting molding line are as follows:
Advantages
Convenient process operation: The horizontal parting method makes it easier to operate the core and the lower chiller, and it is easier to perform complex core assembly work than vertical parting.
High template utilization rate: The direct pouring gate is perpendicular to the parting surface, and the effective utilization rate of the template area is high. More cavities or larger castings can be arranged on the same template area.
Easy to ensure the quality of castings: The molten iron pressure mainly depends on the height of the upper half of the mold, and the filling process is relatively stable, which is conducive to the gas, inclusions, etc. in the molten iron floating upward and discharging before solidification, thereby reducing defects such as pores and slag inclusions and improving the density of castings.
Wide range of application: It can adapt to the production of small and medium-sized castings of various types and sizes, especially small and medium-sized castings with sand cores.
High degree of automation: molding, sanding, compacting, demolding and other processes can be automated, reducing manual intervention, improving production efficiency and reducing labor intensity.
Disadvantages
Relatively low production efficiency: Compared with some vertical molding lines, its molding speed is slower and the production cycle is longer.
Complex equipment and high cost: It is necessary to equip with iron pressing equipment, box loading and unloading devices, etc. The production line is relatively complex and the equipment investment cost is high.
Difficult equipment maintenance: It contains multiple systems and components, such as sand shooting system, conveying system, etc. There are many vulnerable parts, the workload and difficulty of equipment maintenance are large, and the maintenance cost is also high.
Large floor space: The production line is long, and space for sand box storage and transportation needs to be reserved, which occupies a relatively large area in the workshop.