Geometry of the Experimental Silo

The principle components of the test station consist of a steel silo for storing the material to be tested and another, experimental silo containing the instrumentation necessary for measuring the actions of the stored material. The stored material is transferred between both silos using two screw conveyors powered by electric motors.

The geometry and dimensions of the test silo are shown in Figure 2. The silo is cylindrical, with a central hopper and a roof at the top. The silo body (a vertical cylinder), the hopper and the roof are independent and can be dismantled.

The storage silo walls were constructed from sheets of stainless steel 3 mm thick, whilst the cylinder, hopper and roof reinforcement rings were 50 mm wide and 10 mm thick. Given the dimensions and the type of material used for the walls, the silo can thus be considered a rigid, smooth-walled steel silo. According to the Euro code classification, it corresponds to a slender silo, since the cylinder height/diameter ratio is equal to 2 (hc/dc =2).

To measure normal wall pressures, a vertical generatrix was located on the cylinder wall, along which 7 readings were taken at the different heights indicated in, whilst hopper pressures were measured immediately below the grain storage silo hopper transition, at the prolongation of the generatrix mentioned above for measuring cylinder pressures. Double bending beam load cells were used to measure normal wall pressures. For this, 150 x 150 mm openings were made in the wall, into which panels of the same curvature were inserted, leaving a small gap around the edges.

Muyang Silo Design

The design of bins and silos to store bulk solids involves bulk material, geometric, and structural considerations.

Bulk material considerations are important because the frictional and cohesive properties of bulk solids vary from one solid to another, and these properties affect material behavior considerably. In addition, a given bulk solid's flow properties can vary dramatically with changes in numerous parameters, including particle size, moisture, temperature, and consolidating pressure. This variability of properties makes testing at actual conditions more important for proper bin and storage silo design than at first appear.

When considering the geometric design of a steel silo, potential problems include arching across an outlet, rat holing through the material, and the flow pattern during discharge. A bulk material's propensity to arch or rat hole is primarily related to its cohesiveness, while its flow pattern during discharge depends upon internal friction as well as the friction that develops between the material and the silo's hopper walls. The goal of geometric design is to maximize the useable capacity of a silo while minimizing its capital cost, overall height, etc.

Basic Information on Muyang Silo

Steel silos are ubiquitous in manufacturing plants wherever dry granulated or powdered materials need to be stored. These silos vary in size and are usually supported by a steel frame on a reinforced concrete foundation. The steel silo loaded at the top by pumping the materials in using air pressure or using a conveyor. The silos discharge the materials to a truck or a freight car through a hop-per at the bottom.

Silo materials do not act like a fluid; dry materials have frictional or cohesive resistance and tend to form domes or "bridges" with the walls of the silo that prevent it from flowing freely downward. The lateral pressures on the grain storage silo shell from the dry materials are of a different character than the lateral pressures on a retaining wall from soil at the back of the wall. The vertical pressures on the bottom of the silo from the dry material are affected by the bridging action. In order to discharge the hoppers at the bottom, a vibratory system, called a bridge breaker that temporarily destroys the frictional resistance or cohesive bonds is required.

Features of Muyang steel silo

Large Capacity
One single-silo capacity is up to 18,000 tons with comprehensive configurations to meet customers' different requirements.

High Accuracy
Complete advanced processing equipment and technology are introduced from USA to effectively ensure working accuracy and reduce damage to galvanized layer.

Less Residues
External installable stiffeners contribute to less grain residues on storage silo walls.

Detachable and movable
With standardized and modularized production, components and parts have a high standardization and good interchangeability, thus can be partially replaced or completely transferred.

Heat Insulation Measures on Silo

At present, in order to implement related policies of energy saving, environmental protection, energy utilization efficiency, our construction industry has built external walls for insulation works. Now silos that have been built should be improved on walls in accordance with the heat insulation; meanwhile, the new grain silo must implement heat insulation measures.

The measures for heat insulation on steel silo are: Construct insulation works on the inner and outer surface. The outer surface and an inner surface of the insulation engineering collectively ensure internal and external insulation works. Wall surface insulation works created in Europe has a history of over 35 years, and the most used system is thin plaster EPS board insulation. In the mid-1980s, China external wall insulation has been a pilot project. The first project is the EPS board for thin plaster exterior insulation system. Because external wall insulation in building energy efficiency and indoor environmental has many merits, and now urban and rural housing construction has made external insulation as a key project.

Insulation system of wall surface is a system which consists of insulating layer, protective layer and fixing materials.

External wall insulation works can form building through a process of combination of external wall insulation systems, assembly and construction. Construction on storage silo now currently use EPS thin plaster external wall insulation system consisting of EPS board insulation layer, a thin layer of plaster and paint finishes layer; EPS plate fixes with adhesive on the base, thin plaster layer is covered with fiberglass mesh, light-colored plaster surfaces do all kinds of decorative paint or paste cylinder brick layers, tile surface layer, the surface layer of mosaics, marble surface layer.

Silo Calculation Principles

Silo can be divided into two categories with agriculture silo and industry silo. Agricultural silos are used to store grain, feed and other granular and powdered materials, while industrial silos are for the storage of coke, cement, salt, sugar and other bulk materials. Generally mechanization silos are 1/3 higher than the cost of mechanization Warehouse, but it can shorten the material handling processes, reduce operating and maintenance costs, eliminate heavy bag work, benifit for mechanization and automation of operations, so it has become the main barn forms.



Calculation Principles

Friction between material and the steel silo wall will reduce the pressure from material to the silo bottom and silo wall. In the calculation, the silo can be divided into deep and shallow position according to the stress conditions, when the H / D ≥ 1.5 hour (H is for the position deep, D is the diameter of circular or rectangular warehouse positions long or short side of a regular polygon inscribed circle diameter positions ), the silo can be said the deep position, less than 1.5, said low position. Deep positions should be considered the friction effect, less position can be ignored.

The bottom structure should not only withstand the weight of the material but also need to have discharge function, so we usually funnel silo. Although the flat warehouse's structure is simple, but it needs to fill slope, both feed consumption and weight gain, just for small silo. In the earthquake zone, silos should give priority to supporting structure, but for consideration of natural ventilation and lighting, we also can be support column grid structure.

Silos have characteristics of fast loading, load large and uneven, and thus we should pay more attentions to the foundation investigation and foundation design. And during the initial loading rate and load control uniformity, to avoid accidents. Canadian reserves of 27,000 tons Transco Connor granary, as of the negligence of the survey, and loading too fast first time, tilted up 26°53 ' a night, re-use after straightening.