The foundry sand mixer machine is an indispensable equipment in the artificial sand industry, and many types of artificial sand need to use this kind of machine. This article mainly introduces what is a foundry sand mixer machine, the types of foundry sand mixer machines and some of its usage and dust removal methods.
[lwptoc]
What is a foundry sand mixer machine?
The foundry sand mixer machine is a foundry equipment used to mix molding sand or core sand. The foundry sand mixer machine generally has the following functions: the machine is to mix the old sand, new sand, molding sand binder and auxiliary materials evenly, so that the binder and auxiliary materials are evenly distributed. Effective coating on the surface of sand grains.
foundry sand mixer machines can be divided into wheel-type foundry sand mixer machines mainly based on rolling and grinding; blade-type foundry sand mixer machines mainly based on mixing; Rotor type foundry sand mixer machine and balance wheel type foundry sand mixer machine with rolling and mixing functions.
The foundry sand mixer machine can also be divided into two types: batch type and continuous type according to the working nature.
Types of foundry sand mixer machines?
Wheel type foundry sand mixer machine
The wheel-type foundry sand mixer machine first appeared in the early 20th century and is still widely used in the mixing of core sand with clay as a binder. This kind of sand mixer is equipped with a roller with a certain weight. During sand mixing, the roller can not only revolve around the main shaft of the sand mixer, but also rotate around the roller shaft.
The roller grinds the molding sand while rolling, so that the molding sand particles are covered with a film of binder. When mixing surface sand and core sand, the mixing quality is better than other sand mixers. In the early 1950s, a spring-loaded grinding wheel sand mixer was used. Due to the use of spring pressure, the self-weight of the grinding wheel was reduced, and it could be rotated by a higher spindle. Therefore, the sand mixing effect is uniform and consistent, and the sand mixing efficiency is improved.
Vane foundry sand mixer machine
The vane type foundry sand mixer machine is used to mix resin no-bake sand. This type of sand mixer uses a rotating blade. When mixing sand, the dry sand enters two sand mixing tanks, and the binder is added to one of the sand mixing tanks. The hardener is added to another sand mixing tank for premixing with the original sand, and then enters the vertical mixer from the end outlet of the sand mixing tank. Drain after quick mixing to fill sandbox or core box. After filling, the passage of hardener and binder is automatically cut off, and the sand inlet gate is closed at the same time, and the residual molding sand in the groove is discharged.
Counterflow foundry sand mixer machine
Counter-flow casting sand mixer is a new type of sand mixer for mixing clay green sand with the development of high-speed and high-pressure molding automatic production lines. Its structural feature is that a scraper and a high-speed rotor with blades are installed on the eccentric part of the sand mixer chassis, and the chassis rotates clockwise.
The rotor and the scraper rotate counterclockwise, and the speed of the rotor is higher than that of the chassis. When mixing sand, since the chassis and the rotor have opposite motions and the rotational speed is different, the molding sand on the chassis will obtain different speed differences, and corresponding friction and shear force will be generated between the sand and gravel, resulting in grinding, mixing and crushing. effect. Not only the mixing efficiency is high, but the quality of the mixed sand is also better.
The function and utility of the foundry sand mixer machine?
The foundry sand mixer machine strengthens the uniformity of molding sand preparation, and the equipment has strong power. It can meet the state of more uniform mixing of materials in production. The equipment uses stirring rotors, material troughs, and scraper tools to accelerate the more uniform mixing of materials. , The power of the equipment is durable, the mixing effect is strong, and it can meet higher production requirements in production.
The foundry sand mixer machine mainly relies on three components: stirring rotor, material tank, and fixed scraper tool. The foundry sand mixer machine is simple and quick to process materials, and the equipment adopts the strong countercurrent mixing principle to strengthen the mixing function. Promote the rapid running of materials in the cylinder, high operating efficiency, high equipment loading rate, high energy utilization rate, and more uniform processing of materials.
How to configure sand in foundry sand mixer machine?
The preparation of molding sand includes three aspects, namely the preparation of raw materials, the mixing of molding sand, and the mixing and loosening of mixed molding sand. The molding sand for foundry is composed of regenerated sand and an appropriate amount of new sand, clay and water. In order to ensure the quality of new sand, all raw materials must be inspected according to technical requirements before use. Therefore, processing preparation must be carried out before sand mixing.
New sand
In the process of purchasing and transportation, new sand is often mixed with impurities such as grass roots, coal dust, and mud lumps, and also contains a certain amount of moisture. Wet sand should not be sieved, and it is not easy to control the moisture of molding sand when mixing sand. Therefore, in addition to the low water content, the green sand can be directly prepared for artificial modeling, and the new sand must be dried and screened before use. Fresh sand can be dried by vertical or horizontal drying drums, or by air flow. Commonly used sand screening equipment includes manual screen, trommel screen and vibrating screen.
Clay
The newly mined clay often contains a lot of water, and most of it is lumpy, so it must be dried, pulverized, and ground into mud powder before use. It is mainly processed by specialized factories and packaged into bags for supply. In some factories, bentonite or clay and pulverized coal are made into clay-coal powder slurry in advance in a certain proportion, so that the clay can fully absorb water and expand, and when mixing sand, it is added to the sand mixer together with the original sand and mixed evenly.
This method can simplify sand mixing operation, facilitate transportation, improve labor conditions and improve the quality of molding sand. However, the water content of the slurry must be strictly controlled, otherwise it will affect the performance of the molding sand.
Other
Additives such as coal powder, boron, fluorine, and sulfur must be crushed and sieved before use.
Old sand
In order to save modeling materials and reduce casting costs, old sand should be recycled. The old sand occupies a large proportion in the molding sand, which has a great influence on the composition and performance of the molding sand. Used sand is often mixed with various impurities, such as nails, iron blocks and sand balls, and must be treated before reuse, including crushing the sand blocks, removing iron impurities with an electromagnetic separator, sieving, and cooling if necessary.
In a normal foundry, the demand for molding sand is very large, and the turnover rate is very fast. Often the temperature of old sand is still relatively high, and the temperature of some recycled sand is as high as 60 degrees Celsius or even higher. If you use this kind of molding sand, it is easy to stick to the mold, core box, and sand bucket.
Because the temperature of the molding sand is too high, the water will evaporate too quickly, making the performance of the molding sand unstable, and at the same time affecting the surface quality of the casting and the productivity of the molding work. Therefore, in the process of casting falling sand, old sand screening, transportation and sand mixing, ventilation and cooling must be strengthened to reduce the temperature of molding sand.
Precautions for using a foundry sand mixer machine?
The first is the equipment problem. The quality of the sand mixer itself should be tested and the design should be reasonable. For example, the sampling door, there is no sampling door, or the sampling door is damaged due to long-term use, the sampling door is rusted due to long-term non-use, and the improper installation position of the sand mixer makes the sampling door unusable. The safety factor is relatively low, and accidents are prone to occur.
There is also no protective door at the mouth of the closed sand mixer, and no protective fence on the walking platform of the open sand mixer, which creates conditions for illegal sampling, so reliable protective nets should be installed in places where illegal sampling is easy. In order not to affect the operator’s observation of the working condition of the sand mixer, a protective net with a larger mesh can be selected, but the premise is that people cannot reach into it. The role of the protective net is to prevent staff from operating illegally or switching the power supply with tools, so its height should not be lower than 1.6 meters.
There is also a sand mixer. There is no door or machine at the entrance of the sand mixer, and the electrical can not be interlocked, so safety technical transformation is required. Make it mechanical and electrical interlock, safe and reliable. That is to say, when the door at the entrance of the sand mixer is opened, the sand mixer automatically cuts off the power supply and the grinding wheel stops rotating. This is mainly to prevent accidents caused by misoperation of others when someone maintains the equipment inside the machine, or when maintenance personnel stand in the machine and operate illegally.
Dust removal process when using a foundry sand mixer machine?
The material transportation in the sand processing section and the molding sand preparation process are the biggest dust points. During the gradual cleaning process, the grinding wheel grinding, the dust overflow generated by the cleaning drum and the shot blasting drum work, and the surface grinding before the core head bonding in the core making process. The dust, sawdust, sawdust and dust in the wood type machining will cause harm to the health of the workers.
In the production process of the foundry sand mixer machine, the material conveyor in the sand processing section and the molding sand preparation process are the biggest dusting points. The addition of mud, swelling and pulverized coal in the process of stirring and rolling causes the local dust concentration to be too high.
In order to enable the operator to see the sand grinding situation clearly on the spot, an external drum is installed at the position where the operator is standing to prevent the dust from escaping to the operator’s side, which creates a larger source of dust and a large area of the workplace. The dust is flying, especially when a large amount of coal dust or graphite is flying, it is almost impossible to see the sight from a few steps away.
In this regard, the dust removal system design of the sand mixer can use a semi-closed hood, and an observation door is left on one side of the hood to observe the sand mixing condition, so the air volume of the bag filter is set to be higher. Butterfly valves can also be installed on the branch pipes of each intermittent exhaust point of the dust removal pipeline to adjust the working conditions of the equipment at different times and close the exhaust ports of the intermittent equipment, which can greatly reduce the dust.
This is the whole introduction of the foundry sand mixer machine in this article. I don’t know if everyone understands it clearly. If there are some other questions that you don’t understand clearly, you can leave a comment below the article, and we will review your comments one by one. Reply, at the same time, there are other excellent articles on our website, you are welcome to continue to browse.