Spiral Let Down Chute Case Study
Spiral let down chutes, also known as spiral gravity chutes or gravity chutes, provide a simple and effective way to move bulk products vertically while controlling their descent. This type of material handling chute allows product to travel along a continuous spiral path, reducing impact velocity and helping minimize product breakage, dust, and degradation.
Because a spiral let down chute operates entirely by gravity, it has no motors, moving components, or complex mechanical systems. This makes a spiral chute system a low-maintenance solution for applications where reliable, continuous product handling is required. These gravity chutes are commonly installed inside storage bins and other vessels to support controlled, damage-free filling.
The Challenge: Expanding Existing Storage Capacity
A food processing client already had storage bins equipped with spiral let down chutes and was expanding its operation to add additional storage capacity. The expansion required three new chutes that could match the performance of the existing system while accommodating the client’s required flow rate and installation requirements.
The client approached Astro Metal Craft with hand-drawn sketches, overall dimensions, and desired product flow rates. Based on this information, Astro designed and fabricated three custom spiral chutes, each measuring 50 feet in length.
Fabricating Three 50-Foot Spiral Chutes
Each chute was constructed as a full 50-foot assembly rather than being divided into multiple shorter sections. The large 4-foot diameter provided the necessary product-handling capacity while allowing the chute to maintain a controlled product flow.
To contain material as it traveled down the spiral, the chute incorporated lips along both the inside and outside edges. These containment features help keep product on the intended path and reduce the potential for material to spill from the chute.
Continuous Welding for Structural Integrity
The chutes required continuous welding throughout their construction. Astro used MIG welding with Fronius welding equipment to produce consistent, clean welds across the assemblies.
Despite the extensive welding required, the finished chutes did not require grinding. This helped maintain fabrication efficiency while producing a clean, durable assembly suitable for the demanding material-handling application.
A Center-Pipe-Free Design
One of the notable features of this project was the chute’s structural design. Rather than using a center support pipe, the spiral was supported by a heavy-duty exterior frame.
Because the application involved handling heavy nuts, additional cross-support was incorporated into the structure to accommodate the load. The result was a rigid, self-supporting design capable of maintaining its geometry throughout the 50-foot vertical run.
Coordinating Fabrication, Delivery and Installation
The size of these chutes presented logistical challenges in addition to the fabrication requirements. Each 50-foot chute needed to be transported as a complete assembly.
Astro coordinated the fabrication and delivery of all three chutes so they could be shipped together on a single truck. The chutes arrived at the project site on schedule and in excellent condition.
The installation sequence was also important. Contractors installed the chutes after the building floor was completed, with the remaining containment structure constructed around the chutes afterward. Fabricating and delivering the assemblies in their full 50-foot length allowed the installation team to position the chutes before completing the surrounding structure.
Why Use a Spiral Gravity Chute?
For bulk material handling applications where product must be lowered vertically, a spiral gravity chute can provide several advantages:
- Controlled product descent to help minimize breakage and product damage
- Gravity-driven operation without motors or electrical power
- No moving parts, reducing maintenance requirements
- Long service life with minimal routine maintenance
- Custom configurations to accommodate different products, flow rates, heights, and installation requirements
- Continuous product containment through properly designed inside and outside lips
- Large-capacity designs for demanding industrial applications
Custom Spiral Chute Fabrication for Material Handling
Astro Metal Craft is a project-based fabricator specializing in precision stainless steel and aluminum fabrication for industrial applications. Backed by a skilled team of project managers, machinists, and certified welders, along with a wide range of in-house manufacturing capabilities, we are committed to delivering exceptional quality at every stage of the fabrication process. Reach out to us today to discuss your next spiral chute project.
