A foundry sand mixer is a key equipment used in the casting and building materials industries to evenly mix raw materials such as sand, binders, and water. Its main purpose is to coat the surface of sand particles with a layer of binder film, which is used to make molds or bricks.
What types are there
According to different working modes and structures, sand mixers are mainly divided into the following types. Which one to choose depends on your production needs:
1. Muller type sand mixer
Characteristics: Rolling on the grinding disc with a grinding wheel, pressing and rubbing at the same time, like a stone mill.
Advantages: The mixed sand has good quality, the adhesive is evenly wrapped, and it is suitable for making high demand surface sand.
Shortcoming: The work is slow and intermittent, mixing one pot makes one pot, suitable for small and medium-sized batches or scenes with extremely high quality requirements.
2. Continuous sand mixer (blade type)
Characteristics: Sand is put in, mixed directly, and added without stopping the machine. Stirring by high-speed rotating blades.
Advantages: Extremely high efficiency, suitable for large-scale production in large foundries, and can also automatically control the feeding amount.
Application: Mixing of self hardening sand such as resin sand and water glass sand.
3. Swing wheel sand mixer
Characteristic: The balance wheel rotates around the vertical axis, throwing sand towards the surrounding board for compaction.
Advantages: Faster speed and higher productivity than roller wheels, but the quality of sand mixing is slightly inferior to roller wheels.
Application: Mainly used for mixing back sand or single sand.
Where is it mainly used
The foundry sand mixer is not only used in foundries, but also in other industries that require the mixing of powdered or granular materials
1. Foundry industry: This is the most important application scenario, used to mix molding sand and core sand, directly determining the quality of castings.
2. Building materials manufacturing: Used to mix raw materials such as fly ash and slag when producing unburned bricks, gray sand bricks, cement bricks, and refractory bricks.
3. Other industries: Used for mixing and processing granular or powdery materials in the glass, ceramic, and chemical industries.
What are the requirements for using it
Operating a sand mixer is not just about starting it up. For safety and sand quality, there are several key points to pay attention to:
1. Raw material processing should be in place
O Screening: Both new and old sand must be screened to prevent iron blocks and debris from entering and damaging the machine.
Pre mixing of old sand: High temperature of old sand can affect its quality. It is best to cool it first and mix it with water in the pre mixing machine to fully wet the bentonite, so that the subsequent sand mixing is more stable.
2. Operation safety cannot be forgotten
O It is strictly prohibited to reach out: When the machine is rotating, it is absolutely not allowed to use hands to scrape materials or clean the grinding wheel. Sampling must be taken from a dedicated sampling hole.
Shutdown cleaning: When cleaning the sand mixing tank or conducting maintenance, the power must be cut off, and a sign reading "Maintenance personnel, no closing allowed" must be hung, and someone must supervise.
Lubrication and maintenance: Before work, it is necessary to inject oil according to regulations, keep the oil circuit unobstructed, regularly clean the filter, and check the wear of the blades.
3. Process parameters should be matched
Mixing time: The roller type mixed surface sand generally takes 6-12 minutes, and the back sand takes about 3 minutes. If the time is not enough, the sand performance will be unstable.
The order of adding materials: sand and dry materials are added first, followed by water and binder. If the order is wrong, it will affect the coating effect of the binder.
