Why Choose a Vertical Concrete Silo to Store Soybean Meal?

Soybean Meal Storage Silo and Affiliated Facilities

Soybean meal storage in soybean processing plants generally uses three types of silos, namely the basic configuration and auxiliary facilities of flat warehouses, packaged meal warehouses, and vertical silos. Soybean meal in soybean processing plants can be stored in bulk first and then packaged quantitatively for loading and shipping; it can also be packaged quantitatively for storage and then loaded and shipped. The soybean meal processing system includes silos, packing rooms, sending sections, bagged meal storage, etc.

Flat Warehouse and Packaged Meal Warehouse
Flat Warehouse
Flat warehouses are surrounded by load-bearing walls, and the roof is pointed or vaulted. The feed distribution scraper conveyor or horizontal belt conveyor is installed close to the roof. The height of the roof is determined on the basis that the soybean meal can flow to the load-bearing wall by itself.

The advantage of the flat warehouse is that it is convenient to take materials, and it is easy to grasp the quality changes of soybean meal. The disadvantages are low visibility in the warehouse, high dust content, and poor operating environment, so pay attention to safety when using a forklift and prevent rats and birds from entering. When storing soybean meal in flat warehouses, the contact area between soybean meal and air is large, and the moisture of soybean meal will change with the change of ambient humidity.

Packaged warehouse
The packaged meal warehouse is based on the traditional large-scale room-style granary, which is divided into areas on the ground and stacked with different varieties of packaged soybean meal or soybean. Bridge-type (rotary) palletizers are used for the palletizing and direct loading of the packaged meal warehouse. The meal bags coming from the conveyor belt of the packaging line are directly loaded on the car through several kinds of conveyor belts, or they can be loaded from the ground. However, the meal bags stored on the ground for a long time will appear poisonous, and the lower part of the meal bags will agglomerate, so the packaged soybean meal should not be stored for too long.

Vertical Silo
The Structure and Configuration of Vertical Silo
The bulk meal vertical silo is generally a concrete structure, with a capacity of 2000~12000t, a bottom diameter of 15~25m, a height-to-diameter ratio of about 2:1, and a storage height of no more than 32m (the height of the material spire). The silo adopts mechanical outlet, the outlet flow rate is 30~500t/h, the roof is flat or pointed, and the feeding and conveying equipment can be directly erected on the roof.

The foundation cap of concrete silo body must be raised to avoid water accumulation. The height of the cap foundation should consider the gate valve, chute, scraper conveyor at the bottom of the silo, gear box, electronically controlled reducer and hydraulic components of the installation system under the soybean meal recovery system.

The soybean meal silo is usually composed of a silo group and a working tower, and there are conveying and dust removal equipment in the working tower. The silo group adopts determinant arrangement. The bottom of the silo is an overhead structure, which is easy to arrange the conveyor, and has good ventilation and lighting conditions. The bottom of the silo is designed to be conical or flat, and the bulk meal is transported to the conveyor belt through the lower discharge gate when it is discharged from the silo.

The soybean meal silo is equipped with corresponding supporting facilities, such as mechanical equipment, electrical equipment, automatic control system, etc. Mechanical equipment includes: belt conveyors, air-cushion belt conveyors, buried scraper conveyors, bucket elevators, pneumatic/manual gate valves at the bottom of concrete silos, sweep auger, etc.

Problems that Should be Paid Attention to During the Use of Soybean Meal Concrete Silos
1.The concrete silo has side pressure and friction, so the vertical pressure acting on a certain section is not equal to the gravity of soybean meal on the section. At the same time, the growth of vertical pressure and horizontal pressure is not proportional to the height of the silo, and the pressure of each layer of soybean meal in the silo is complicated. Therefore, the dynamic pressure in design needs to consider such loads as the internal friction angle of the silo, the width of the unloading bucket, loading and unloading, arching, cooling of the silo wall or discharge of the silo.

2.The moisture and temperature of the soybean meal in the concrete silo change gradually. Because the soybean meal is not easy to dissipate heat and moisture, and the air flow resistance is large, the temperature is sometimes 7~10°C higher than the ambient temperature. Generally, the storage time should not exceed 20 days, and the silo should be dumped once every 6-8 hours to keep the soybean meal in a loose or flowing state. The dumping period is shorter in summer and longer in winter.

3.The advantage of concrete silo storage is that the soybean meal is less affected by external environmental factors, and if the soybean meal is within the safe moisture content, the quality is stable. As the diameter of the silo increases, the classification of soybean meal will increase. In order to reduce the phenomenon of soybean meal classification, the feeding port can be added on the top of the silo, or anti-classification measures can be taken at the feeding port.

4.When the concrete silo is fed, a large amount of dust will be generated. Preventing dust explosion is the most important part of safe production.

Dust explosions are generally not expected to occur when soybean meal is stored in soybean meal silos, even at extremely high dust levels. However, since soybean meal contains a small amount of solvent and has a high dust content, precautions should be given priority to in design and use, and plug-in dust collectors should be installed on the silo roof and conveying machinery.

5.Soybean meal is mostly granular, with high protein content, and is a non-combustible substance. The roof of the silo should be used as a vent or explosion vent, and it should be divided into several small vents, which are evenly arranged on the roof. Vents can be in different structures, but pay attention to rain, water, and birds.
6.If the soybean processing plant occupies a small area, a large concrete silo is a better choice, which can maximize the economy of the plant.