Calculating the appropriate height of a stillage cage for specific applications requires considering multiple factors related to the goods, handling equipment, and storage environment. The following methods and considerations can be used for calculation:
Based on Goods Dimensions and Quantity
- Single Layer Storage:
If the stillage cage is used for single-layer storage, the height should be slightly higher than the height of the goods. For example, if the goods are boxes with a height of 0.5 meters, considering a clearance of 0.1 – 0.2 meters for easy placement and removal, the appropriate height of the stillage cage would be 0.6 – 0.7 meters.
- Multi-layer Storage:
When storing goods in multiple layers, first determine the number of layers based on the quantity of goods and storage space requirements. Then, calculate the height of the stillage cage, which is the height of a single layer of goods, and is the clearance between layers, usually 0.05 – 0.1 meters. For instance, if there are 5 layers of goods, each layer is 0.4 meters high, and the clearance between layers is 0.08 meters, then meters.
According to Handling Equipment
- Forklift Handling:
If a forklift is used for handling, the height of the stillage cage should be within the lifting height range of the forklift. Common forklifts have a lifting height of 3 – 5 meters. Considering the height of the forklift mast and the space required for operation, the height of the stillage cage should generally not exceed 2.5 – 3.5 meters to ensure safe handling.
- Crane Handling:
For stillage cages handled by a crane, the height can be relatively higher, but it should also consider the lifting capacity and boom length of the crane. The relationship between the height of the stillage cage, the boom length of the crane, and the lifting angle is. For example, if the boom length of the crane is 8 meters and the lifting angle is 60°, then meters.
In Combination with Storage Environment and Space
- Warehouse Height Limitations:
The height of the stillage cage should not exceed the available height of the warehouse. Subtract the height of the lighting equipment, ventilation ducts, and other facilities from the total height of the warehouse to get the maximum allowable height of the stillage cage. For example, if the warehouse is 8 meters high, and the height occupied by lighting and ventilation facilities is 1.5 meters, the maximum height of the stillage cage is about 6.5 meters.
- Aisle Space:
Consider the space of the aisles in the storage area. Taller stillage cages may require wider aisles to ensure safe passage of handling equipment. If the aisle width is limited, the height of the stillage cage needs to be reduced accordingly to maintain operational efficiency and safety.
Considering Stability Requirements
1. For free-standing stillage cages, a lower height is generally more stable. According to the principle of center of gravity, the height of the stillage cage should preferably satisfy, where is the minimum side length of the bottom of the stillage cage, and is a coefficient, usually 2 – 3. For example, if the bottom of the stillage cage is a rectangle with a length of 1.2 meters and a width of 1 meter, taking, then the meters.
2. When the stillage cages are stacked, the height of a single cage should be adjusted according to the number of stacking layers and the overall stability requirements. The height of a single cage can be calculated as where is the total height limit of the stacked cages, considering stability, is the number of stacking layers, and is a reduction coefficient, usually 0.1 – 0.2, to account for the thickness of the connection parts and ensure stability. For example, if the total height limit of the stacked cages is 4 meters, there are 4 layers, and then meters.