Sand Stone Aggregate Line Selection Design

Sand gravel is the basic industry of national infrastructure construction and is an indispensable raw material for buildings, roads, bridges and water conservancy projects. However, in actual production, most of the production lines cannot be fully used until they are put into production, or various problems may occur during operation. This article will introduce you to six common issues and suggest improvements. We hope to help design the production line in the future.

Sand Stone Aggregate Line Selection Design

First, equipment selection problem

  1. Whether the equipment selection is reasonable is the main factor determining the success of the production line.
  2. The choice of equipment depends mainly on the physical properties of the raw materials (such as the hardness of the raw materials, the abrasion index, the soil content, etc.). Under normal circumstances, such a line designed and selected by a regular and qualified professional design unit does not suffer from such problems.
  3. However, there are also many production line investors who directly copy equipment options from other companies for construction. After the operation, there is a serious problem that the device selection is unreasonable. For example, granite, diabase, basalt and other raw materials with high hardness and high abrasive index, hammer crushers or impact crushers are selected in the production line. Although the product has excellent grain size, it hammers and impacts the board and the like. The wearing parts of sand and gravel aggregate equipment are seriously exhausted and frequently replaced, resulting in a significant increase in production costs and the inability to compete with the surrounding markets.
  4. It is often difficult to solve this problem by adjusting the process, and the manufacturer must replace the crusher equipment to ensure long-term stability and economical operation of the line.

Second, the silo or database problem

Including coarse crushing feed bins, medium and fine broken sand making buffers, product storage, and stone powder storage.

  1. 1, coarse broken feed bin. A common problem is that the side discharge opening of the bin is designed as a rectangular "door" structure. There is a dead angle between the bin and the discharge port. The material is not smoothly discharged, and large blocks are easily accumulated here, which affects the normal feeding. Improvement measures: Place an excavator beside the feeding port to clean up the accumulated material at any time; in the off-season of the market, transform the side discharge opening of the feeding bin into a trapezoidal inverted eight structure to eliminate dead spots.
  2. 2, medium and fine broken sand making buffer. A common problem is that the bottom of the warehouse is designed as a flat-bottomed steel silo structure. Because the overall material pressure at the bottom of the silo is large, during the operation of the production line, the bottom of the steel silo will be severely deformed and sunk, which will cause safety hazards. Improvement measures: Reinforce the warehouse bottom structure; the design unit should avoid using the flat bottom steel silo structure when designing. If it is unavoidable, try to select the bottom of the warehouse as a concrete structure.
  3. 3. Product repository. The product storage warehouse is generally in the form of concrete storage. The reserves are large and safe and stable. However, some enterprises choose steel silos to store sand and gravel aggregates. Then, the steel plate warehouse should be regularly inspected for wear and wear resistance.
  4. 4. Stone powder storage. A common problem is that the stone powder produced during the rainy weather is wet, and the paste bank makes it difficult to discharge the stone powder. Improvement measures: Install several air cannons under the library body, loosen the stone powder in the library with compressed air; design unit should try to control the stone powder library should not be too large in design, design the flow aid plate, air box or air in the cone part of the library.

Third, the problem of material transport gap

The large drop of material transport and transport is usually at the coarse breakout port and the shaker feed port.

1, rough breakout

The rough broken equipment has a certain concrete foundation thickness, and the discharge port is far from the downstream conveyor belt conveyor, and the material block degree after the rough break is mostly less than 300mm. These stones are directly smashed on the belt conveyor, and the buffer roller will appear. The phenomenon that the conveyor belt is torn off and the roller frame is torn off. Improvement measures: Replace the buffer roller of the downstream belt conveyor with a buffer bed to change the structure of the discharge chute to reduce the impact on downstream equipment. In addition, if the drop is particularly large and it is also possible to reduce the impact on the downstream equipment by increasing the form of the buffer feed device (such as a vibratory feeder) if the arrangement space permits.

2, vibrating screen inlet

In order to ensure that the maintenance space is left above the vibrating screen during the design of the production line, or the one-to-two material is distributed between the conveying equipment and the vibrating screen, there will be a large drop in the material entering the vibrating screen, and the material in the operation will cause a large impact on the sieve plate. The sieve plate wears quickly. Improvement measures: locally add the waste belt tape to the impact position of the vibrating screen, and adjust the slip form to reduce the impact and wear on the screen.

Fourth, environmental issues

After the formal design of the production line, the environmental protection can basically meet the requirements of the national standard, but the individual production lines are near the two broken impact crushers, and the dust near the finished product garage is larger.

Improvement measures: Firstly, according to the number of dust collection points and position, the selected dust collector specifications are calculated. For the dust near the impact crusher, if the dust collector of the selected filter is sufficient, then it is set before and after the crusher discharge point. The dust collection point can effectively reduce the dust here. For the dust near the bulk of the finished product warehouse, if the dust collector of the selected design is sufficient, and the dust collection by the bulk machine is collected by the top dust collector, it can be passed between the bulk air duct of the bulk machine and the top dust collector. Add a centrifugal fan to improve the dust collection efficiency of the top dust collector, and increase the water spray dust removal near the lower mouth of the bulk machine to effectively reduce the dust.

5. Collection and transportation of stone powder

  1. The dust particles of the production line are directly collected on the downstream conveyor belt machine, so that there are problems such as repeated dusting caused by secondary dusting and large content of stone powder in the product. In addition, there is dust overflow caused by the tight sealing of the belt guide groove and the rain cover, or rainy rain on cloudy and rainy days, which makes the stone powder wet and eventually causes the paste warehouse phenomenon.
  2. The stone powder in the production line is transported by the air conveying chute. When the rainy day stone powder is wet, the chute gas permeable layer is sealed and the material cannot be transported.
  3. Improvement measures: The dust collected by all the production lines, or at least the dust collector of the latter process, is separately transported to the stone powder storage through the zipper and the hoist equipment.

Six other issues

  1. When the vibrating screen is started, the load is large, which may cause the vibration of the exciter gear to be worn or damaged seriously. Improvement measures: Adjust the installation angle of the equipment appropriately, and increase the frequency converter to start slowly.
  2. Due to the inaccurate basic data collected during design, the selection of individual conveyor belts is too small, which affects the production capacity of the production line. Improvement measures: Increase the belt speed of the belt conveyor by replacing the drive system, thereby increasing the conveying capacity of the belt conveyor.
  3. Leakage and leakage of the connection between the inlet and outlet of the vibration equipment, the soft connection of the canvas used is not durable, and the replacement is frequent. Improvement measures: use the waste belt conveyor tape to make soft connection on site, long service life and good sealing effect.
  4. The article only lists some of the problems with existing sand gravel aggregate production lines. At present, many production lines have more or less areas for improvement, but it is believed that with the gradual maturity of the construction of sand and gravel aggregate production lines, problems that may arise in the later operation will slowly disappear in the germination design stage.

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