Designing Deep-Freeze Automation that Operates at -40°F

Temperature fluctuations, physical impacts during handling, and moisture are three challenges of operating automated systems in deep-freeze conditions. While many types of automation can operate efficiently in cold conditions of -20°F, everything changes when you drop to temperatures of -40°F.

Mark Livesay, vice president of Automated Warehousing at ESI Group, says that most equipment and accompanying components used at -20°F cannot operate in deep cold environments due to the material used in their design.

Key System Design Components

Most synthetic greases and lubricants that perform at -20°F break down at -40°F. Likewise, flexible cables at -20°F may become brittle in deeper cold. Electronics designed for warmer environments will not operate reliably in extreme cold unless housed in heated enclosures. Photo eyes, in particular, are vulnerable to freezing temperatures; when enclosed, they also require airflow across the lens to prevent fogging or icing. Livesay notes that power systems for rack vehicles (RVs) vary by manufacturer—some use tethered cables, others rely on large capacitors, and some use lithium batteries that are recharged when the RV docks in the Storage Retrieval Machine (SRM). “These technologies degrade rapidly in extreme cold temperatures,” he explains. “However, advances are underway, and I expect reliability to improve in the future.”

System maintenance poses its own set of challenges. Workers must wear specialized freezer gear, as the extreme cold hinders fine motor skills and makes performing tasks more difficult. “A deep freezer — even those at -10°F — is a harsh environment,” Livesay explains. “The amount of time a person can spend inside is limited by how long they can physically endure the conditions.” These are all reasons why care must be taken to choose the most robustly designed automated storage/retrieval systems (AS/RS) possible. Livesay says “The operating temperature is critical in deciding which automation type and brand equipment should be used. For example, most AS/RS suppliers say that their equipment will perform well to -20°F, but when you get to -40°F, there is only one manufacturer that can operate in that environment.” He recalls that in 1995, Woodson Inc. offered an AS/RS capable of operating at -40°F, which is still in operation today. Though Woodson was acquired in 2003, and its machines are no longer produced, Westfalia now makes a cold-hardened deep-lane AS/RS.

Good Deep-Freeze Design Saves Space and Cost

Redundancy is key to designing an efficient, deep-freeze automated environment. For example, shared storage lanes accessible from adjacent SRM aisles provide essential redundancy if an SRM goes down. Additionally, a deep-lane storage system, whether using a cart and shuttle or aisle-running SRMs, optimizes cubic space with fewer SRM aisles. A smaller footprint equates to less cubic footage of conditioned space, resulting in realized savings on building costs.

Robust equipment feeding the SRM is also crucial. Chain Driven Live Roller (CDLR) conveyors are reliable and can handle heavier pallet loads, but care should be taken when deciding on material type and which lubricants and greases to use. At the heart of your deep-freeze storage should be a warehouse management system (WMS). A WMS facilitates the best storage of a product skew/lot over multiple SRM aisles so that one product is not stored in one storage block. Ideally, products should be simultaneously stored and retrieved with multiple SRMs. “As long as there’s no manual intervention, a WMS can maintain 99.9% accuracy,” says Livesay.

5 Tips for Choosing Automation in Deep-Freeze Environments

Livesay offers the following advice when selecting automation for cold storage applications:

1. Talk to Maintenance Teams – Visit operating facilities and ask maintenance staff about system reliability and recurring issues.

2. Evaluate SRM Construction – Assess the SRM with 1 or 2 masts. A single-masted crane at higher levels may flex, causing a pendulum effect that delays stabilization at the rack opening. A 2-masted crane is more rigid, reducing wait time and improving throughput.

3. Understand Fault Recovery Options – Ask yourself: How do you recover from a fault when shrink wrap is blocking a photo eye or you have a broken pallet? How will maintenance access this area to fix the issue?

4. Understand Pallet Storage – Is the pallet being stored on pallet support boards (PSB) or can it be stored directly in the racks where the center of the pallet is supported on a third rail? Note: PSB adds costs to the system for the insertion/extraction equipment; additional PSBs can add up to more than $1 million, depending on pallet quantity.

5. Future-Proof Your Investment – Get out your crystal ball and look at your needs 10 to 15 years from now. “We built an automated deep freezer, and the customer told me that they would never outgrow this facility,” says Livesay. “Within four years, they were having us expand their freezer. This is a very expensive addition, and they could have saved millions if they had better foresight.”

Partnering with an experienced general contractor, like ESI Group, will ensure you successfully navigate the challenges associated with designing and building an automated facility.