Understanding VNA Racking Systems
When planning a high-density storage system to enhance warehouse storage capacity without physical expansion, a Very Narrow Aisle (VNA) system emerges as a viable option, especially for warehouses with diverse goods. It is crucial to consider the key design aspects of this particular racking system.
Components and Equipment in a VNA Racking System
A VNA racking system, also known as a Very Narrow Aisle warehouse, utilizes VNA forklifts to load and unload pallets from tall shelves within narrow aisles.
The system consists of shelves, VNA forklifts, material handling auxiliary equipment, and essential information processing systems.
The choice between high-position (Man-Up) and low-position (Man-Down) forklifts depends on specific goods retrieval requirements.
Applications of VNA Racking Systems
VNA systems are most widely used in pharmaceutical, home appliance, machinery/auto parts warehouses, and supermarket distribution centers.
These systems are suitable for storage-type warehouses that store a large quantity of goods, experience frequent movement, and have high demands for order picking.
For warehouses requiring inspection and picking of small items, manual operations combined with high-level picking and stacking machines offer a flexible solution.
Considerations for Warehouse Height and Forklift Use
The usable net height of the warehouse must be relatively high, typically greater than 8 meters, with a maximum lifting height not exceeding 16 meters, according to VNA forklift restrictions.
Ground Requirements for VNA Systems
The flatness of the floor in the VNA racking area is critical as it directly affects operational efficiency and costs.
Any changes in floor height can cause forklift mast instability, which amplifies the static tilt of the racking and forklifts.
EN25620-2008 specifies that the ground level should not exceed plus or minus 15mm from the reference point.
Collaboration and Structural Design in VNA Systems
During the warehouse design phase, it is advisable for the racking company to collaborate with the civil engineering design institute.
This ensures the layout of building columns does not interfere with the shelves and optimizes space utilization.
Additionally, reasonable average ground load and concentrated load parameters should be determined based on shelf number and cargo weight.
Seismic Design and Safety Considerations
Given that the height of VNA shelves generally ranges between 10-15 meters, specialized seismic design of the shelf structure is necessary.
If feasible, finite element analysis and calculations should be performed before selecting the shelf structure to ensure safety and stability.
Forklift Guidance Systems in Narrow Aisles
Due to limited redundancy in narrow aisles, a forklift guidance system is essential. Three main options are available:
a. Angle steel guide rails with a height of 100mm on both sides of the aisle, with guide wheels attached to the forklift’s bottom to ensure straight movement.
b. Magnetic wires installed in the middle of the aisle by the forklift company, which guide the forklift without the need for guide rails or bottom beams, allowing goods to be placed directly on the ground.
c. A secondary cement pouring process in the angle steel guide rail, which increases the impact resistance of the guide rail.
The magnetic wire method is commonly used for its efficiency and reduced impact on warehouse operations.
Safety and Fire Protection in VNA Racking
Components of VNA narrow aisle racking must be configured with appropriate safety and fire protection measures to ensure a safe operational environment.
Enhancing Storage Efficiency
A well-planned VNA racking system optimizes warehouse space and boosts efficiency. By carefully considering design factors like height, ground conditions, and safety, you can create a durable, high-capacity storage solution that meets the demands of modern warehousing.
Post time: Aug-09-2024